JP4883280B2 - Heat-sealable polyurethane elastic fiber, production method thereof, and woven / knitted fabric using the polyurethane elastic fiber - Google Patents

Description

  The present invention relates to a heat-sealable polyurethane elastic fiber that is excellent in heat resistance during heat setting and hardly breaks or deteriorates, a method for producing the same, and a woven or knitted fabric using the heat-sealable polyurethane elastic fiber.

  Products using stretch fabrics such as weft knitted fabrics, warp knitted fabrics and woven fabrics mixed with polyurethane elastic fibers are widely used because of their high elongation and good recovery and fit from the stretched state.

  However, if a product made by cutting and sewing a fabric mixed with polyurethane elastic fibers is repeatedly stretched, it will be deformed and become a non-uniform fabric, “deformation, misalignment, soft”, “fraying”, yarn coming out, and fabric Problems such as “run, densen” with ladder-like scratches and misalignment, and “curl” with curved fabric are likely to occur. In addition, the so-called “slip-in”, in which the polyurethane elastic fiber comes out of the seam at the sewing portion due to repeated elongation, tends to occur. Naturally, the portion of the fabric from which the slip-in occurs and the elastic fibers are pulled out has a problem that density shrinkage occurs on the fabric because the shrinkage force is lost, and the fabric cannot be worn.

  These phenomena occur even in a woven or knitted fabric using elastic fibers other than polyurethane elastic fibers, but are particularly remarkable in the case of polyurethane elastic fibers having strong stretchability.

  In order to cope with these problems, Japanese Patent Application Laid-Open No. 2002-339189 (Patent Document 1) discloses a method of improving the heat-fusibility of fibers by dry spinning a polyurethane urea polymer solution to which a urea compound is added. Has been proposed. However, when this knitted polyurethane fiber is used together with other fibers such as nylon to make a knitted fabric and heat-treated, the polyurethane elastic fiber is still insufficiently heat-sealed.

  In addition, a polyurethane elastic fiber obtained by melt spinning and improved in heat-fusibility having a certain tenacity retention and melting point (WO 2004/053218) has also been proposed. In the present yarn as a whole, there were some problems with the yarn breaking characteristics, and it was difficult to break the entire wound body, and polyurethane elastic fibers having uniform properties were not obtained at present.

JP 2002-339189 A WO2004 / 053218

  The present invention has been made in view of the above circumstances, has a sufficient heat-fusibility, is excellent in heat resistance at the time of heat setting, and is heat-fusible over the entire yarn of the wound body, which is less likely to break or deteriorate. An object of the present invention is to provide a polyurethane elastic fiber having excellent properties, a method for producing the same, and a woven or knitted fabric obtained using the polyurethane elastic fiber.

  As a result of intensive studies to achieve the above object, the present inventor is a polyurethane elastic fiber having a melting point of 165 to 200 ° C. measured by a flow temperature method, and does not break over the entire region of the wound body, A heat-fusible polyurethane elastic fiber having a heat-sealing force of 0.15 cN / dtex or more when heat-treated in the above temperature range in the plating knitted fabric method can solve the above-mentioned problems. When a knitted or knitted fabric woven or knitted using polyurethane elastic fibers is heat-treated near the above temperature, the polyurethane elastic fibers and / or polyurethane elastic fibers and other fibers are fused, fraying, densen, etc. Finding that it is possible to obtain a woven or knitted fabric that is unlikely to occur, and obtaining a heat-sealable polyurethane elastic fiber having the above characteristics under a predetermined condition Heading, the present invention has been accomplished.

That is, the present invention
[1] A heat-fusible polyurethane elastic having a melting point of 165 to 200 ° C. measured by a flow temperature method, and a thermal fusing force of 0.15 cN / dtex or more when heat-treated in the above temperature range in a plating knitted fabric method Fiber,
The heat-fusible polyurethane elastic fiber is obtained by melt-spinning a polymer obtained from polyol, diisocyanate and low molecular weight diol, and comprises an oil component comprising mineral oil and silicone oil, n-propylamine, n-butylamine, di-n A heat characterized by adhering or containing a base oil containing a monoamine selected from butylamine, iso-butylamine, di-iso-butylamine, 2-ethylhexylamine, monobenzylamine, distearylamine and laurylamine Fusible polyurethane elastic fiber,
[2] The heat-sealable polyurethane elastic fiber according to [1], wherein a residual strain immediately after stretching by 300% is 40% or less,
[3] The heat fusion as described in [1] or [2], comprising 1 to 10% by mass of a base oil containing 25 to 75% by mass of mineral oil and 75 to 25% by mass of silicone oil. Polyurethane elastic fiber,
[4] (I) Both end-isocyanate group prepolymer obtained by reacting polyol and diisocyanate, and (II) Both-end hydroxyl group prepolymer obtained by reacting polyol, diisocyanate and low molecular weight diol are reacted. [1], [2] characterized in that the obtained polymer is melt-spun, and a base oil containing an oil component of 25 to 75% by mass of mineral oil and 75 to 25% by mass of silicone oil is adhered or contained. ] Or the heat-fusible polyurethane elastic fiber according to [3],
[5] Any one of [1] to [4], wherein the residual isocyanate group in the polyurethane elastic fiber is reacted with the monoamine to consume 0.5 to 15 equivalent% of the residual isocyanate group. The heat-fusible polyurethane elastic fiber according to claim 1,
[6] The heat according to [4] or [5], wherein the effective cross-linking amount in the polyurethane elastic fiber is 0.05 × 10 ⁻⁵ mol / g or more and less than 10 × 10 ⁻⁵ mol / g. Fusible polyurethane elastic fiber,
[7] A heat-fusible polyurethane elastic having a melting point of 165 to 200 ° C. measured by a flow temperature method, and a thermal fusing force of 0.15 cN / dtex or more when heat-treated in the above temperature range in a plating knitted fabric method Fiber,
The heat-fusible polyurethane elastic fiber comprises a polyol, a diisocyanate, a low molecular weight diamine and / or a low molecular weight diol, a polyacrylate ester, a polyvinylpyrrolidone copolymer, a polyurethane polymer, a polyester, a polyester ether, and an epoxy resin. A heat-fusible polyurethane elastic fiber obtained by dry spinning a spinning solution containing a selected compound,
[8] The heat-sealable polyurethane elastic fiber according to [7], wherein a residual strain immediately after stretching by 300% is 40% or less,
[9] The heat fusion according to [7] or [8], comprising 1 to 10% by mass of a base oil agent containing 25 to 75% by mass of mineral oil and 75 to 25% by mass of silicone oil. Polyurethane elastic fiber,
[10] A polyurethane polymer solution obtained by reacting a heat-fusible polyurethane elastic fiber with an isocyanate-terminated intermediate polymer obtained from polyol and diisocyanate and a low molecular weight diamine and / or low molecular weight diol in an organic solvent. And a mass ratio of the polyurethane polymer and the compound is 40:60 to 80:20, and a compound selected from polyacrylic acid ester, polyvinylpyrrolidone copolymer, polyurethane polymer, polyester, polyester ether and epoxy resin. A spinning solution formed by mixing is dry-spun, and a base oil containing an oil component of 25 to 75% by mass of mineral oil and 75 to 25% by mass of silicone oil is adhered or contained. The heat-fusible polyurethane elasticity according to any one of [7] to [9] fiber,
[11] The total polyol constituting the heat-fusible polyurethane elastic fiber contains 70 mol% or more of polyether diol having a number average molecular weight of 600 to 3,500, and the urethane bond occupies the entire urethane bond and urea bond. The heat-fusible polyurethane elastic fiber according to [10], wherein the ratio is 60 to 95 mol%,
[12] (1) A step of reacting a polyol and a diisocyanate to synthesize both end isocyanate group prepolymers,
(2) a step of synthesizing a hydroxyl-terminated prepolymer at both ends by reacting a polyol, diisocyanate and a low molecular weight diol;
(3) a step of synthesizing a spinning polymer by reacting both terminal isocyanate group prepolymers and both terminal hydroxyl group prepolymers;
(4) a step of melt-spinning a spinning polymer, and (5) an oil component comprising 25 to 75% by mass of mineral oil and 75 to 25% by mass of silicone oil, and n-propylamine, n- Including a step of providing a base oil agent comprising a monoamine selected from butylamine, di-n-butylamine, iso-butylamine, di-iso-butylamine, 2-ethylhexylamine, monobenzylamine, distearylamine and laurylamine. A method for producing a heat-fusible polyurethane elastic fiber,
[13] (1) A step of reacting a polyol having a number average molecular weight of 600 to 3500 with a diisocyanate to synthesize an intermediate polymer having both terminal isocyanate groups,
(2) a step of obtaining a polyurethane polymer solution by reacting the intermediate polymer with a low molecular weight diamine and / or a low molecular weight diol in an organic solvent;
(3) The polyurethane polymer solution and a compound selected from polyacrylic acid ester, polyvinyl pyrrolidone copolymer, polyurethane polymer, polyester, polyester ether and epoxy resin having a mass ratio of the polyurethane polymer and the compound of 40: Mixing to be 60 to 80:20,
(4) a step of dry-spinning a solution containing a polyurethane polymer and the above compound, and (5) a base containing an oil component of 25 to 75% by mass of mineral oil and 75 to 25% by mass of silicone oil in the spun polyurethane elastic fiber. A method for producing a heat-fusible polyurethane elastic fiber, comprising a step of applying an oil agent;
[14] A polyurethane elastic fiber mixed woven or knitted fabric obtained by weaving and knitting the heat-fusible polyurethane elastic fiber according to any one of [1] to [11],
[15] The heat-fusible polyurethane elastic fiber according to any one of [1] to [11] and at least one non-elastic yarn, and the heat-fusible polyurethane elastic fiber mutually by dry heat or wet heat setting And / or polyurethane elastic fiber-mixed woven or knitted fabric according to [14], wherein the intersection between the elastic yarn and the inelastic yarn is heat-sealed.
[16] Briefs, panties, shorts, undershirts, camisole, girdle, bra, spats, body suits, sanitary shorts, swimwear, leotards, resort wear, homewear, underwear, sports tights, shirts, outerwear materials, Gloves, socks, arm covers, medical clothing, surgical clothing, cleanroom work clothing, dust proof clothing, supporters, eye masks, disposable diapers, incontinence pads, gauze, bandages, patch materials, packaging materials, masks, sheets, towels, A polyurethane elastic fiber-mixed woven or knitted fabric according to [14] or [15], which is a handkerchief, a clothing interlining, a microfiltration filter, an industrial wiper, or a protective cover.

  ADVANTAGE OF THE INVENTION According to this invention, the polyurethane elastic fiber which is excellent in heat-fusibility and heat resistance at the time of heat setting, and is hard to produce a thread breakage and deterioration can be provided. Further, by using the polyurethane elastic fiber of the present invention, a woven or knitted fabric that is less prone to misalignment, softness, fraying, run, densen, curl, slip-in and the like can be obtained.

Heat-sealable polyurethane elastic fiber The elastic fiber of the present invention has a melting point measured by a flow temperature method of 165 to 200 ° C., and is a polyurethane elastic fiber that does not break over the entire area of the wound yarn, This is a heat-fusible polyurethane elastic fiber having a heat-sealing force of 0.15 cN / dtex or more when heat-treated in the above temperature range.

  Here, it is preferable that melting | fusing point (flow temperature) of the heat-fusible polyurethane elastic fiber of this invention is 165-200 degreeC, More preferably, it is 170-200 degreeC. If the melting point is too low, the heat setting rate will be extremely high, but there are problems such as the stretch recovery ability of the fabric being too low and the heat resistance is practically too low, and if the melting point is too high, There is a problem that the texture of the shared fiber must be hardened or deteriorated, and production is limited due to insufficient capacity of the setting machine. Since the polyurethane elastic fiber of the present invention has a melting point in the above-mentioned range, dimensional stability and elongation recovery force of the fabric are preferable. When used in combination with other ordinary fibers, both fibers can be set at the same temperature. Therefore, it is possible to provide knitted fabrics and woven fabrics of good quality and exhibit great advantages.

  The melting point of the polyurethane elastic fiber of the present invention is measured by a flow temperature method. Specifically, a flow tester CFT-500A type (manufactured by Shimadzu Corporation) was used, and an extrusion load of 30 kg was applied with a sample amount of 1.5 g, a die (nozzle) diameter of 0.5 mm, and a thickness of 1.0 mm. When the temperature is raised at a constant rate of 3 ° C./min after a preheating time of 240 seconds at an initial set temperature of 120 ° C., a toner plunger descending amount-temperature curve is obtained. As the temperature is increased at a constant speed, the toner is gradually heated and the polymer begins to flow out. The flow temperature at this time is defined as the melting point. When the temperature is further increased, the melted toner largely flows out, and the plunger lowering stops and ends.

  Further, the thermal fluidity as an index of the heat fusibility of the polyurethane elastic fiber of the present invention can be grasped by the following test.

  Using a flow tester CFT-500A type (manufactured by Shimadzu Corporation), applying an extrusion load of 30 kg with a sample amount of 1.5 g, a die (nozzle) diameter of 0.5 mm, and a thickness of 1.0 mm, and an initial set temperature After a preheating time of 240 seconds, the movement time until the sample starts to come out from the die (nozzle) when measured at a constant temperature is measured. If this time is short, it can be evaluated that the thermal fluidity is high, and if the time is long, the thermal fluidity is low.

  For example, when the initial set temperature is 165 ° C., the preferred time is 1 to 60 minutes. More preferably, it is 5 to 50 minutes. If it is less than 1 minute, the heat fluidity is good, but the heat resistance may be lowered, and if it exceeds 60 minutes, the heat fluidity is low, so that the heat-fusibility is inferior.

  Moreover, when initial setting temperature is 180 degreeC, preferable time is 15 second-20 minutes. More preferably, it is 30 seconds to 15 minutes. If it is less than 15 seconds, the heat fluidity is good, but the heat resistance may be lowered. If it exceeds 20 minutes, the heat fluidity is low, so that the heat-fusibility is inferior.

  The polyurethane elastic fiber of the present invention preferably has a residual strain immediately after stretching by 300% of 40% or less, particularly 35% or less. A product using a polyurethane elastic fiber having a residual strain of more than 40% is not preferable because problems such as elbow slipping, knee slipping, and full stretch occur, and the correction effect of the body is not sufficiently exhibited. The lower limit of the residual strain immediately after 300% elongation is not particularly limited and may be 0%, but is usually 2% or more, particularly 5% or more.

  Residual strain immediately after 300% elongation is the residual strain (%) when the stress becomes zero immediately after stretching up to 300% at a grasping length of 4 cm and 300 mm / min, at the same speed as when stretching. ).

  Furthermore, the polyurethane elastic fiber of the present invention is characterized in that no yarn breakage occurs over the entire region of the wound body obtained by winding the spun fiber around a bobbin. Usually, the fiber spun by the spinning device is cooled, then provided with an oil agent, and wound by a winder. In the winding process, the fiber is wound around a cylindrical paper tube or the like, which is a bobbin (core), and the cylindrical winding yarn having a fiber layer thickness of 10 to 50 mm in the radial direction and a fiber winding width of 30 to 100 mm Get the body. In this case, the whole area of the wound body means the entire wound body including the inner layer and the surface layer of the wound body, and is in contact with the paper tube from the center toward the outer periphery in the radial direction of the bottom surface of the cylinder. A layer is an inner layer, and an outer layer surrounding the inner layer is a surface layer.

  Note that the wound body includes the inner layer and the surface layer as described above, but in the present invention, the melting point and the heat fusion force of the elastic fiber are within the above ranges in the entire wound body, that is, both the inner layer and the surface layer. is required.

  That is, the inner layer means a portion closest to the paper tube of the wound body, and if the paper tube width is a so-called half paper tube (outer diameter 70 to 90 mm) of about 55 to 60 mm, the paper tube contacts the wound body. If it is a so-called full paper tube (outer diameter 70-90 mm) size with a paper tube width of about 110-120 mm, the paper tube contact portion of the wound body and 60 g from there An area that returns to the subsurface. The surface layer is a portion excluding the inner layer of the wound body.

In the present invention, the fact that no breakage occurs over the entire area of the wound body means that no breakage is found in both the inner layer and the surface layer of the wound body as described above. To do so. First, using a pantyhose knitting machine with a diameter of 4 inches and 400 needles, the polyurethane elastic fibers of the inner layer and surface layer and nylon false twisted yarn 33 dtex 26 filaments were plated at a draft of 2.4 times. Open the tubular knitted fabric obtained by knitting. In addition, the polyurethane elastic fiber of the surface layer here refers to the polyurethane elastic fiber which exists in the area | region for 10 mass% of the whole surface winding amount from there.
Next, with the stretch ratio maintained at 1.0, the unfolded knitted fabric is heat-set at a predetermined temperature for 60 seconds to heat-bond the polyurethane elastic fibers in the plating knitted fabric. If there are many inclusions such as oil in the knitting machine, wash the knitted fabric before heat treatment.
Washing conditions for removing inclusions include, for example, a washing solution in which 1 mL of a soaping agent (score roll TS840 (manufactured by Asahi Denka Co.)) is dissolved in 1 L of water, and a dyeing tester MINI COLOUR (manufactured by Tecsum Giken). The knitted fabric is sufficiently washed with water at 90 ° C. for 10 minutes to remove inclusions and the soaping agent and then dried. Thereafter, heat treatment is performed.
Subsequently, after removing the nylon by immersing a knitted fabric of 17 cm in length and 30 cm in width into 200 mL of a 20% aqueous hydrochloric acid solution, the remaining polyurethane elastic fiber sample is visually observed.
The broken parts are marked with a magic or the like and observed with a stereomicroscope SZ61 [Olympus Co., Ltd.] at a magnification of 20 times to visually evaluate the presence or absence of polyurethane breakage. As a result of visual evaluation, when no yarn breakage was confirmed in the knitted fabric using the polyurethane elastic fibers of the inner layer and the surface layer, it was assumed that no yarn breakage occurred in the entire region of the wound body.

  Further, the heat sealing force of the polyurethane elastic fiber of the present invention needs to be 0.15 cN / dtex or more, particularly preferably 0.17 cN / dtex or more. When the heat-fusible force is less than 0.15 cN / dtex, it is not preferable because sufficient heat-fusibility and its effect cannot be obtained when a knitted fabric is formed. In addition, the upper limit of the heat-fusible force is around “0.25 to 0.30 cN / dtex” and is in the “unable to disassemble” state shown below.

  Here, in the present invention, heat fusion means that polyurethane elastic fibers are fused with each other and / or polyurethane elastic fibers and / or other fibers by heat or heat and pressure from outside. A state in which at least a part of the fibers are fused and in close contact with each other, or a state in which the fibers are bonded to each other even if the fusion does not occur.

The measuring method of the heat sealing force is based on the plating knitted fabric method, and the measuring method is as follows.
Using a pantyhose knitting machine with a diameter of 4 inches and 400 needles, open a tubular knitted fabric obtained by plating knitting polyurethane elastic fiber and nylon false twisted yarn 33 dtex 26 filament with draft 2.4 times Contrary.
Next, while keeping the stretch ratio at 1.0, the unfolded knitted fabric is heat-set for 60 seconds at the melting point in the flow temperature method of the polyurethane elastic fiber, and the polyurethane elastic fiber in the plating knitted fabric is Heat seal. If there are many inclusions such as oil in the knitting machine, wash the knitted fabric before heat treatment.
Washing conditions for removing inclusions include, for example, a washing solution in which 1 mL of a soaping agent (score roll TS840 (manufactured by Asahi Denka Co.)) is dissolved in 1 L of water, and a dyeing tester MINI COLOUR (manufactured by Tecsum Giken). The knitted fabric is sufficiently washed with water at 90 ° C. for 10 minutes to remove inclusions and the soaping agent and then dried. Thereafter, heat treatment is performed.

The calculation method and evaluation of the heat sealing force are as follows. Tensile tester [Precision universal testing machine manufactured by Shimadzu Corporation] The polyurethane elastic fiber knitted from the end of the knitted fabric held by the upper chuck is held by the lower chuck under a load of 0.1 cN, and the grip interval (chuck interval) is 100 mm. Then, pulling is performed at a pulling speed of 100 mm / min, and the knitting tension of the polyurethane elastic fiber from the knitted fabric is measured.
Next, with respect to the peak point of the knitting tension measured each time the thermal fusion site is dissociated, the peak points up to the third largest value between the elongation amount 100 mm to 200 mm where the knitting stress is stable are averaged, Obtain the peak average knitting tension. Subsequently, the peak average knitting tension (cN) is divided by the initial fineness (dtex) of the polyurethane elastic fiber to obtain a heat fusion force (cN / dtex).

  When the heat-sealing of the polyurethane elastic fiber becomes strong, the polyurethane elastic fiber cannot be disassembled from the end of the knitted fabric, and in that case, it is evaluated that “disassembly is impossible” and that the heat-sealing has reached the maximum. To express. Normally, when the temperature is lowered from a condition where disassembling is impossible, the heat-sealing force gradually decreases, and the heat-sealing state is achieved to such an extent that it can be knitted. The heat-bonding force in the “unbreakable” state varies depending on the type of polyurethane elastic fiber to be measured and the fineness of the fiber used, but usually when the heat-bonding force exceeds 0.2 cN / dtex, It becomes a state that is “possible” or “impossible to disassemble”. Further, when the polyurethane elastic fiber is broken in the knitted fabric during the heat treatment, the continuous polyurethane elastic fiber cannot be knitted from the knitted fabric, and thus “measurement is impossible”.

  The polyurethane elastic fiber is broken in the knitted fabric, saying that the polyurethane elastic fiber cannot be knitted from the end of the knitted fabric because the polyurethane elastic fiber is heat-sealed. The difference of “unmeasurable” in which the polyurethane elastic fiber cannot be knitted from the edge of the knitted fabric is as follows. After removing the nylon by immersing the knitted fabric of 17 cm in length and 30 cm in width into 200 mL of a 20% aqueous hydrochloric acid solution, the remaining polyurethane elastic fiber sample was visually observed, and yarn breakage of the polyurethane elastic fiber was observed on the knitted fabric. If not, it is “unassembleable” and indicates a good result of the present invention. On the other hand, if the polyurethane elastic fiber breakage is observed, it is “impossible to measure”, and the product has problems such as uneven elongation, uneven stretch recovery, expansion of the broken yarn part during repeated wear, Can be distinguished.

In addition to the plating knitted fabric method, the method for measuring the heat fusion force can also be measured and evaluated by the raw yarn crossing method and the heat fusion force measurement method described in JP-A-2002-339189.
The measuring method of the raw yarn crossing method is as follows. Two polyurethane elastic fibers 15 cm are sampled, and as shown in FIG. 11, the same polyurethane elastic fiber yarn 12 is crossed over the polyurethane elastic fiber yarn 11 loop, and a load of 0.1 cN is applied. The two polyurethane elastic fibers are gripped while the intersection is arranged near the center of 80 mm (± 5 mm from the center).
The sample is then heat treated for 45 seconds in a dryer maintained at [(melting point of 3 ° C./min flow) −20] ° C. The minimum processing temperature is 160 ° C.

  Next, the sample is gripped by the upper and lower chucks of the tensile tester with the upper part from X-X 'and the lower part from Y-Y' in FIG. At this time, the gripping interval is adjusted to 40 mm, and the intersection is adjusted to be near the center of the gripping interval (± 5 mm from the center). Tensile is performed at a pulling speed of 100 mm / min, and the maximum stress is measured when the intersection is peeled off. Subsequently, the maximum stress (cN) is divided by the initial fineness (dtex) of the urethane elastic fiber to obtain a heat fusion force (cN / dtex). When the other stretched portion of the polyurethane elastic fiber is cut off while the crossing portion is not peeled off and fused, it is evaluated as “complete fusion” and indicates that it is strongly heat-sealed. Regarding the evaluation of the heat-bonding force, the same tendency as in the plating knitted fabric method is obtained.

  The measurement of heat-bonding force (PU 100% knitted fabric test) described in JP-A-2002-339189 is as follows.

  Polyurethane elastic fibers are knitted with a draft of 2.5 times with a one-neck knitting machine having 370 needles and a diameter of 3 / 42.54 cm to obtain a cylindrical knitted fabric of elastic fibers. The obtained elastic fiber tubular knitted fabric is allowed to pass through a pin tenter at a preset temperature set under 100% elongation and a passing time of 60 seconds. Thereafter, a tensile tester (UTM-III-100 type manufactured by Orientec Co., Ltd.) Trademark))) The upper chuck and the lower chuck are adjusted so that the distance (sample length) is 10 cm, the cylindrical knitted fabric is set on the upper chuck, and the yarn is extracted from the end of the cylindrical knitted fabric to the sample length of 10 cm. And pulling at a speed of 50 cm / min to measure the extraction stress P1 (cN) when the yarn is extracted from one end of the tubular knitted fabric.

The decitex measurement method for polyurethane elastic fibers is as follows. An initial load of 1/30 g / dtex (dtex is nominal decitex) is applied to the polyurethane elastic fiber, and the polyurethane elastic fiber is cut to a length of 100.0 cm. Ten elastic fibers cut to a length of 100.0 cm, that is, a mass of 1000.0 cm length was measured with an electronic balance having four digits after the decimal point, and further, their mass was multiplied by 1000, that is, The number of grams converted to a mass of 10,000 m is defined as decitex. The heat sealing force is obtained by the following formula.
Thermal fusing power (cN / dtex) = extraction stress P1 / decitex

Production method of heat-fusible polyurethane elastic fiber The production method of the polyurethane elastic fiber of the present invention is not particularly limited as long as the polyurethane elastic fiber having the above characteristics can be obtained. Either may be adopted.

  For example, a polyol and an excess molar amount of diisocyanate are reacted to produce a polyurethane intermediate polymer having isocyanate groups at both ends, and a low molecular weight diamine having an active hydrogen that can easily react with the isocyanate group of the intermediate polymer. A polyurethane solution (polymer solution) is produced by reacting a molecular weight diol in an inert organic solvent, and then the solvent is removed to form a yarn, or a polyol, a diisocyanate, a low molecular weight diamine or a low molecular weight diol. A method in which the reacted polymer is solidified and dissolved in a solvent, and then the solvent is removed and formed into a yarn; a method in which the solidified polymer is formed into a yarn by heating without dissolving in the solvent; and the polyol and Reacting diisocyanate with low molecular weight diol to obtain a polymer and solidifying the polymer Method of forming a Ku yarn, furthermore, after mixing the polymer or polymer solution obtained in each of the above methods, the solvent was removed from the mixed polymer solution, and a method of forming the yarn.

[Melt spinning method]
First, the manufacturing method by the melt spinning method will be described. The method for obtaining the polyurethane elastic fiber of the present invention by the melt spinning method is not particularly limited. For example, the following three methods are known.
(1) A method of melt spinning a polyurethane elastic chip.
(2) A method of spinning a polyurethane elastic chip after mixing a polyisocyanate compound.
(3) A reactive spinning method in which a spinning polymer obtained by reacting a prepolymer obtained by reacting a polyol and diisocyanate with a low molecular weight diol is synthesized and then spun without solidification.

  The method (3) is simpler than the methods (1) and (2) because there is no process for handling the polyurethane elastic chip, and the injection rate of the prepolymer into the reactor is adjusted to perform spinning. This is a preferred method because the amount of residual isocyanate groups in the subsequent polyurethane elastic fiber can be adjusted, and heat resistance can be improved by a chain extension reaction with the residual isocyanate groups. Furthermore, in the method (3), as disclosed in WO99 / 39030, a low molecular weight diol is reacted in advance with a part of the prepolymer and injected into the reactor as a prepolymer having an excess of hydroxyl groups. You can also do it.

  More specifically, (I) both-end isocyanate group prepolymer (hereinafter referred to as “both-end isocyanate group prepolymer”) obtained by reacting the first polyol with diisocyanate, and (II) the second polyol, A method of melt spinning without solidifying a polymer obtained by reacting a diisocyanate and a low-molecular-weight diol obtained by reacting both terminal hydroxyl prepolymers (hereinafter referred to as “both-terminal hydroxyl prepolymers”). Can be adopted.

  In this case, the spinning polymer was synthesized by (I) synthesizing a prepolymer having both terminal isocyanate groups obtained by reacting a first polyol having a number average molecular weight of 800 to 3500 and a diisocyanate, and (II) number average molecular weight of 600 to 3; Synthesis of a hydroxyl-terminated prepolymer obtained by reacting 1,000 second polyol, diisocyanate, and low molecular weight diol, and (III) a spinning polymer in which these two prepolymers are led to a reactor and reacted continuously. It consists of three reactions of synthesis.

  When the heat-fusible polyurethane elastic fiber of the present invention is produced by the melt spinning method, the number average molecular weight of the first polyol is preferably about 800 to 3,500, and the number average molecular weight of the second polyol is preferably used. Is preferably about 600 to 3,000 polymer diol.

  If the number average molecular weight of the first polyol is smaller than this range, the elongation at break and elastic recovery of the resulting polyurethane elastic fiber may decrease, and if larger, the break strength, heat resistance, cold resistance, etc. may decrease, The extrudability at the time of spinning, for example, in the case of melt spinning, may decrease the spinnability. Therefore, more preferably, the number average molecular weight of the first polyol is about 1,000 to 3,000.

  On the other hand, if the number average molecular weight of the second polyol is smaller than this range, the yarn may become hard or lack homogeneity, and if it is large, the heat resistance and strength improvement effects may not be expected. More preferably, the number average molecular weight of the second polyol is about 800 to 2500.

When the second polyol has a lower molecular weight than the molecular weight of the first polyol, it is preferable in view of physical properties such as an increase in yarn strength.
In addition, the measuring method of the number average molecular weight of a polyol can be calculated from a hydroxyl value according to JIS K1557.

  As the polyol that can be used in the heat-fusible polyurethane elastic fiber of the present invention, polyether glycol, polyester glycol, polycarbonate glycol, or the like can be used.

  Examples of polyether glycols include polyether diols obtained by ring-opening polymerization of cyclic ethers such as ethylene oxide, propylene oxide, and tetrahydrofuran (THF); ethylene glycol, propylene glycol, 1,4-butanediol, and 1,5-pentane. Modified PTMG which is a copolymer of polyether glycol, THF and 3-methyl THF obtained by polycondensation of glycols such as diol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol Examples thereof include modified PTMG which is a copolymer of (polytetramethylene ether glycol), THF and 2,3-dimethyl THF.

  Examples of the polyester glycol include glycols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, and 3-methyl-1,5-pentanediol. Polyester glycol obtained by polycondensation of at least one selected from the group with at least one selected from dibasic acids such as adipic acid, sebacic acid, and azelaic acid; opening of lactones such as ε-caprolactone and valerolactone Examples thereof include polyester glycol obtained by ring polymerization.

  Examples of the polycarbonate glycol include dialkyl carbonates such as dimethyl carbonate and diethyl carbonate; alkylene carbonates such as ethylene carbonate and propylene carbonate; at least one organic carbonate selected from diaryl carbonates such as diphenyl carbonate and dinaphthyl carbonate; and ethylene glycol. At least one aliphatic diol selected from propylene glycol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, and the like And carbonate glycol obtained by the transesterification reaction.

  The above-exemplified polyether glycol, polyester glycol, and polycarbonate glycol can be used alone or in combination of two or more. However, in order to obtain good fusing property, the polyether diol component is 60 to 100 mass. %, Particularly 70 to 100% by mass, and the polyether diol component may be 100% by mass. In the case of the melt spinning method, the first polyol and the second polyol are preferably the same component, so that the heat fusion property is preferable, and the polyether diol is more preferable than the polyester diol.

  As the polyether diol component, in particular, modified PTMG which is a copolymer of polytetramethylene ether glycol, THF and 3-methyl THF, and modified PTMG which is a copolymer of THF and 2,3-dimethyl THF are preferably used. The Compared to ester groups, ether groups are generally considered to be excellent in heat-fusibility since they have large flexibility and flexibility and are likely to fluctuate due to heat.

  Use of polyether diol as the second polyol is effective for improving heat-fusibility and avoiding yarn breakage in the vicinity of the melting point. Although details are unknown, for example, by using polyether diol as the second polyol, the polymer skeleton becomes flexible due to free rotation of the ether bond, and molecular motion becomes active even when heated, and the polymer surface It can be presumed that the softening of the polymer is helped and the plastic deformation of the polymer is increased, which contributes to the improvement of heat-fusibility and the prevention of yarn breakage.

  Furthermore, as will be described later, in the case of a yarn with molecular cross-linking, the second polyol contributes to improving the heat resistance of the cross-linking in some form, and the yarn breaks under relatively severe conditions near the melting point. There is a possibility of preventing this.

  Next, as the diisocyanate that can be used in the production of the heat-fusible polyurethane elastic fiber by the melt spinning method of the present invention, aliphatic, alicyclic, aromatic, and aromatic fats that are usually used in the production of polyurethane are used. Arbitrary diisocyanate can be used.

  Examples of such diisocyanates include 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 1,5-naphthalene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, and 1,6-hexamethylene. Diisocyanate, p-phenylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, meta-tetramethylxylene diisocyanate, para-tetramethylxylene diisocyanate, etc. may be used, and one of these may be used alone or in combination of two or more. Among these, 4,4′-diphenylmethane diisocyanate and 4,4′-dicyclohexylmethane diisocyanate are preferably used.

  As the low molecular weight diol and low molecular weight diamine which are chain extenders, those having an appropriate reaction rate and giving appropriate heat resistance are preferable, and the molecule has at least two active hydrogen atoms capable of reacting with isocyanate. In general, a low molecular weight compound having a molecular weight of 500 or less is used.

  Examples of the low molecular weight diol that can be used in the heat-fusible polyurethane elastic fiber of the present invention include ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, and 1,6-hexanediol. Aliphatic diols such as 3-methyl-1,5-pentanediol can be used. These can be used singly or in combination of two or more, but ethylene glycol, 1,4-butanediol, 1,5-pentanediol from the viewpoint of giving workability and appropriate physical properties to the obtained fiber 1,6-hexanediol is preferably used. In view of reactivity and physical properties, it is preferable to use 1,5-pentanediol and 1,6-hexanediol in combination rather than single use.

  When 1,5-pentanediol and 1,6-hexanediol are used in combination, it is preferably used in an amount of 5 to 50% with respect to the total mass of the low molecular weight diol. More preferably, it is 10 to 30%. When the combined amount is less than 5%, the elasticity and spinnability of the polyurethane elastic fiber may not be contributed. When the combined amount exceeds 50%, the reactivity is slow, and the elastic recovery rate and compression set of the fiber deteriorate. There is.

  Moreover, as a low molecular weight diamine, ethylenediamine, butanediamine, propylenediamine, hexamethylenediamine, xylylenediamine, 4,4-diaminodiphenylmethane, hydrazine, etc. can be used, for example.

  A low molecular weight diol and a low molecular weight diamine can be used in combination, but in the method for producing a heat-fusible polyurethane elastic fiber by the melt spinning method of the present invention, a low molecular weight diol may be more preferably used as a chain length extender. it can.

  In addition, a monofunctional monool such as butanol or a monofunctional monoamine such as diethylamine or dibutylamine can be mixed and used as a reaction modifier or a polymerization degree modifier.

  Further, the active hydrogen compound having an average functional group number (number of active hydrogen atoms in the molecule) having a functional group such as a hydroxyl group and / or an amino group of 3 to 6, particularly 3 or 4, within a range not inhibiting the spinnability. Can be used. Examples of such compounds include glycerin, trimethylolethane, trimethylolpropane, hexanetriol, pentaerythritol (tetravalent), sorbose (pentavalent), sorbitol (hexavalent), 1,3,5-triaminobenzene. Etc.

  In this case, if the number of functional groups exceeds 6, it is not preferable because the elasticity (flexibility) of the finally obtained polyurethane cannot be imparted. Trifunctional compounds are preferably used, and glycerin, trimethylolethane, and trimethylolpropane are particularly preferably used.

  The amount of the active hydrogen compound used is preferably such that the trifunctional compound is within 6 equivalent% with respect to the total of the chain extender and the active hydrogen compound. If it exceeds 6 equivalent%, flexibility cannot be imparted and spinnability may not be stable. Especially preferably, it is 4 equivalent% or less.

  Optional components such as an ultraviolet absorber, an antioxidant, and a light stabilizer can be added to the heat-fusible polyurethane elastic fiber of the present invention in order to improve weather resistance, heat oxidation resistance, and yellowing resistance. When using a stabilizer, heat resistance and yellowing resistance vary greatly depending on the type and amount of the stabilizer, so select the type of stabilizer that is effective against the polyurethane polymer, and each is effective. It is preferable to use a combination of stabilizers in combination. By using suitable stability, it is possible to obtain a polyurethane elastic fiber which is hardly yellowed and has excellent heat resistance.

  Examples of the ultraviolet absorber include 2- (3,5-di-t-amyl-2-hydroxyphenyl) benzotriazole and 2- (3-t-butyl-5-methyl-2-hydroxyphenyl) -5-chloro. Examples include benzotriazole-based ultraviolet absorbers such as benzotriazole and 2- (2-hydroxy-3,5-bisphenyl) benzotriazole.

  As the antioxidant, for example, 3,9-bis (2- (3- (3-t-butyl-4-hydroxy-5-methylphenyl) -propionyloxy) -1,1-dimethylethyl) -2,4 , 8,10-tetraoxaspiro (5.5) undecane, 1,3,5-tris (4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanuric acid, pentaerythrityl-tetrakis [3 Hindered phenolic antioxidants such as-(3,5-di-t-butyl-4-hydroxyphenyl) propionate].

  Examples of the light stabilizer include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, and dimethyl succinate. Examples thereof include hindered amine light stabilizers such as 1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine condensate.

  Other stabilizers such as semicarbazide compounds, organic sulfur secondary antioxidants such as bisphenol S, phosphite secondary antioxidants, barium sulfate, magnesium oxide, magnesium silicate, calcium silicate, zinc oxide as required , Inorganic fine particles such as hydrotalcite, titanium oxide, zirconium-containing compounds, anti-adhesive agents such as magnesium stearate, calcium stearate, polytetrafluoroethylene, organosiloxane, antistatic agents such as fluorine or siloxane, colloidal Inorganic colloidal sols such as silica or colloidal alumina, silane coupling agents, thermal fusion improvers such as phosphate esters, phosphite esters, pyrophosphate esters, preservatives such as methyl paraoxybenzoate and ethyl paraoxybenzoate, etc. Colorant, fungicide, defoaming agent, plasticizer, waxes, softeners, mold release agents, foaming agents, fillers, nucleating agent, antibacterial agents, deodorants, anti-blocking agents. These additives may be blended in either or both of the prepolymers (I) and (II).

Here, when obtaining the prepolymer of (I), as for the reaction ratio of a polyol and diisocyanate, 2.0-4.0 mol of diisocyanate is preferable with respect to 1.0 mol of polyol.
When the prepolymer (II) is obtained, the reaction ratio of the polyol, the diisocyanate, and the low molecular weight diol is preferably 0.20 to 0.35 mol of the diisocyanate with respect to a total of 1.0 mol of the polyol and the low molecular weight diol. Moreover, it is preferable that the reaction ratio of a polyol and low molecular weight diol shall be 70-90 mol% of low molecular weight diol with respect to the sum total of a polyol and low molecular weight diol.
Furthermore, although low molecular weight diamine can also be made to react, in this case, it is preferable that the usage-amount of low molecular weight diamine shall be 5 mol% or less with respect to the sum total of low molecular weight diol and low molecular weight diamine.

  The composition ratio of the raw materials is preferably 0.95 to 1.25, more preferably the molar ratio of the molar amount of all diisocyanates to the total molar amount of all polyols and all low molecular weight diols. 1.005 to 1.205.

  The molar ratio of all diisocyanates and polyol (total of the first polyol and the second polyol) is preferably 2.4 to 3.8, and more preferably 2.5 to 3.5. If the molar ratio is lower than 2.4, the resulting polyurethane elastic fiber has high elongation, but the heat resistance is insufficient. If the molar ratio is higher than 3.8, the heat resistance is good, but the yarn is hard and the elongation is low. It is not preferable.

  The nitrogen content of the obtained polyurethane elastic fiber is preferably 2.5 to 4.0% by mass. If the nitrogen content is less than 2.5% by mass, the concentration of the bond related to the reaction with the isocyanate is reduced, and heat resistance and wear resistance are inferior, which is not preferable. If the nitrogen content exceeds 4.0% by mass, The cohesive force of the hard segment in the polyurethane resulting from the isocyanate compound becomes strong, and the elastic recovery rate is inferior.

  The melt spinning method will be described more specifically. The both-end isocyanate group prepolymer (I) is prepared by, for example, charging a predetermined amount of diisocyanate into a tank equipped with a hot water jacket and a stirrer and then stirring the predetermined amount of polyol. And stirred at 60 to 130 ° C. for 30 to 100 minutes, more preferably at 80 to 120 ° C. for 50 to 70 minutes under a nitrogen purge.

  When the reaction temperature is less than 60 ° C., the reaction time is significantly increased, and in some cases, the prepolymer may be precipitated. Moreover, when reaction temperature exceeds 130 degreeC, there exists a possibility that side reactions, such as a dimer of an isocyanate group, and a trimerization reaction, may become remarkable.

  Both-end isocyanate group prepolymers obtained by this reaction are injected into a polyurethane elastic fiber reactor using a jacketed gear pump (for example, KAP-1 manufactured by Kawasaki Heavy Industries, Ltd.).

  (II) The both-terminal hydroxyl group prepolymer is prepared by charging a predetermined amount of diisocyanate into a tank equipped with a warm water jacket and a stirrer, and then injecting a predetermined amount of polyol while stirring, at 30 to 100 ° C. for 30 to 100 minutes. The precursor can be obtained by stirring under a nitrogen purge, preferably at 80 to 120 ° C. for 50 to 70 minutes, and then the low molecular weight diol can be injected and stirred to react with the precursor. When the reaction temperature is 80 ° C. or lower, the reaction time is significantly increased, and in some cases, a prepolymer is precipitated. On the other hand, when the reaction temperature is 130 ° C. or higher, side reactions such as dimer and trimerization reaction of isocyanate groups may become remarkable.

  The obtained both-end hydroxyl group prepolymer is injected into a polyurethane elastic fiber reactor using a jacketed gear pump (for example, KAP-1 manufactured by Kawasaki Heavy Industries, Ltd.). In addition, the above-mentioned various chemicals for improving weather resistance, heat oxidation resistance, yellowing resistance and the like can be added during or after the synthesis of both prepolymers (I) and (II).

  Synthesis of the spinning polymer (III) can be obtained by continuously reacting the prepolymers (I) and (II) fed at a constant ratio. In this case, the reactor may be one that is used in the usual melt spinning method of polyurethane elastic fibers, and is equipped with a mechanism that heats, stirs and reacts the spinning polymer in a molten state, and further transports it to the spinning head. Is preferred.

  The reaction conditions are 160 to 220 ° C. for 1 to 90 minutes, preferably 180 to 210 ° C. for 3 to 80 minutes. When the reaction temperature is less than 160 ° C, the prepolymers (I) and (II) are in a highly viscous state, so that the uniform mixing reaction cannot be performed. When the reaction temperature is 220 ° C or more, the spinning polymer is yellowed by heat. There is a risk of deterioration.

  When the raw material is directly fed into the reactor for continuous production, a local reaction occurs in the screw, barrel, or polymer flow path, so that bis (hydroxyphenyl) s can be added to the prepolymer. Since this bis (hydroxyphenyl) does not react locally and can be polymerized under uniform kneading, as described in “Polyurethane composition” of JP-A-8-176254, it is difficult to generate scale and process stability. Highly reliable polyurethane can be supplied.

  By using these bis (hydroxyphenyl) s alone or in combination of two or more, polyurethane elastic fibers with excellent transparency and excellent physical properties such as high elongation and heat resistance. Is obtained. Preferred bis (hydroxyphenyl) s are bis (4-hydroxyphenyl) sulfone, bisphenol A, 3,3′-dimethyl-4,4′-dihydroxyphenylsulfone, 3,3 ′, 5,5′-tetramethyl- 4,4′-dihydroxyphenylsulfone and the like can be mentioned.

The heat-sealable polyurethane elastic fiber by the melt spinning method of the present invention can be obtained by transferring the synthesized spinning polymer to the spinning head without solidifying, and discharging and spinning from the nozzle. The average residence time in the reactor varies depending on the type of the reactor, and is calculated by the following equation.
Average residence time in reactor =
(Reactor volume / spinning polymer discharge rate) x specific gravity of spinning polymer

  The average residence time of the spinning polymer in the reactor is generally about 20 to 180 minutes when a cylindrical reactor is used, more preferably about 30 to 120 minutes, and 30 when a twin screw extruder is used. Second to 30 minutes, more preferably 1 to 20 minutes. The spinning temperature is preferably 160 to 230 ° C., more preferably 180 to 220 ° C., and it can be obtained by continuously extruding from a nozzle, cooling, attaching a spinning oil agent and winding.

  When the spinning temperature is less than 160 ° C., the spinning polymer causes an ejection failure from the nozzle, which is not preferable, and when the spinning temperature is 230 ° C. or higher, the spinning polymer undergoes a decomposition reaction.

  Here, the ratio of the both-end isocyanate group prepolymer and the both-end hydroxyl group prepolymer is such that the residual isocyanate group concentration (residual NCO%) in the yarn immediately after spinning is 0.2 to 1.0% by mass, more preferably It is preferable to appropriately adjust the rotation ratio of the injection gear pump so as to be 0.25 to 0.90 mass%. For example, when the residual NCO% is increased, the residual NCO% increases as the metering ratio of the both-end isocyanate group prepolymer is increased in the ratio between the both-end isocyanate group prepolymer and the both-end hydroxyl group prepolymer. When adjusting to the target residual NCO%, the residual isocyanate group concentration in the spun fiber was adjusted by adjusting the injection ratio as follows, and based on the results, both-end isocyanate group prepolymer and both-end hydroxyl group prepolymer The condition can be set by a feedback method that finely adjusts the injection ratio. When the residual isocyanate group is contained in an excess of 0.2% by mass or more, physical properties such as high elongation and heat resistance can be improved by a chain extension reaction after spinning. However, if the residual isocyanate group is less than 0.2% by mass, the heat resistance of the resulting polyurethane elastic fiber may be lowered, and if it exceeds 1.0% by mass, the viscosity of the spinning polymer is lowered, and spinning is performed. May become difficult. Moreover, there is a possibility that defects such as the melting point of the spun yarn becomes too high.

The residual isocyanate group concentration (NCO%) in the spun fiber is measured as follows.
After the spun fiber (about 1 g) was dissolved in a dibutylamine / dimethylformamide / toluene solution, excess dibutylamine was reacted with residual isocyanate groups in the sample, and the remaining dibutylamine was titrated with hydrochloric acid to remove residual isocyanate groups. Calculate the content.

  In order to perform spinning while leaving the residual isocyanate group, an oil agent must be applied during spinning. Spinning without applying an oil agent is not preferable because the residual isocyanate group reacts after spinning and the yarns adhere to each other or the unraveling property deteriorates.

Examples of the components of the base oil used in the present invention include mineral oil and silicone oil. The mineral oil includes liquid paraffinic mineral oil and naphthenic mineral oil, and liquid paraffin can be advantageously used. The mineral oil used in the present invention preferably has a viscosity at 25 ° C. of 2 × 10 ⁻⁶ to 40 × 10 ⁻⁶ m ² / s, more preferably 3 × 10 ^{−6 to} 20 × 10 ⁻⁶ m ^2. / S is preferred. If the viscosity is too small, the volatility is high, volatilizing and consuming from the surface of the yarn after spinning, lowering the smoothness of the yarn and reducing the spinnability of the yarn. On the other hand, if the viscosity is too large, it is not preferable because yarn resistance is increased or oil supply unevenness occurs during spinning oil supply, resulting in yarn unevenness. In addition, this viscosity value is a measured value with a thin tube type kinematic viscometer (Canon Fenceke SO, manufactured by Shibata Kagaku Co., Ltd.).

  Silicone oil is generally referred to as polyorganosiloxane, and examples of linear polyorganosiloxane include polydimethylsiloxane and polymethylphenylsiloxane. The silicone oil used in the present invention means a polyorganosiloxane which is not substantially modified, and polydimethylsiloxane can be preferably used.

The viscosity of the silicone oil used in the present invention can be arbitrarily selected, but considering viscosity resistance, the viscosity at 25 ° C. is preferably 2 × 10 ⁻⁶ to 40 × 10 ⁻⁶ m ² / s, more preferably Is preferably 3 × 10 ^{−6 to} 20 × 10 ⁻⁶ m ² / s. If the viscosity is too small, a large amount of low boiling point is contained, and loss due to transpiration and vaporization is large. On the other hand, if the viscosity is too large, stretched denier spots may occur due to resistance during unwinding. This viscosity value is also based on the same measurement value as that of the mineral oil.

  The base oil preferably used in the present invention contains 25 to 75% by mass of mineral oil and 75 to 25% by mass of silicone oil, and contains 100% by mass in total. In other words, conventionally, when mineral oil is used, it is convenient in terms of quick penetration of the oil into the polyurethane elastic fiber and the unwinding property of the inner layer, but it is required to melt the fiber surface and prevent fiber breakage. In particular, the polyurethane elastic fibers in the inner layer of the wound yarn are likely to swell or break easily, or additives such as ultraviolet absorbers are likely to be eluted, resulting in a decrease in physical properties. Therefore, all the yarns cannot be used over the entire area of the wound body. On the other hand, when silicone oil is used, the inner layer becomes too sticky, and problems remain, such as breakage of the yarn to unwind the yarn from the wound yarn, and occurrence of fusing spots. However, in the present invention, as described above, any part of the wound body is used by using an oil containing silicone oil together with the predetermined amount of mineral oil as the oil applied to the fiber after spinning. Therefore, it is possible to obtain a heat-sealable polyurethane elastic fiber having uniform characteristics over the entire region of the wound body without breaking the yarn. In addition, the preferable ratio of mineral oil and silicone oil is 30-70 mass% for mineral oil, and 70-30 mass% for silicone oil. Components added to base oils other than oils composed of silicone oil and mineral oil include various modified silicones such as polyester-modified silicone, polyether-modified silicone, amino-modified silicone, and modified silicone resin, and mineral fine particles (for example, silica, colloidal Alumina, talc, etc.), higher fatty acid metal salt powder (for example, magnesium stearate, calcium stearate, aluminum stearate, etc.), higher fatty acid carboxylic acid, higher fatty acid alcohol, paraffin, monoamines, polyethylene, etc. These oil agents may be used alone or in any combination as required. Among them, it is useful to add monoamines as a component that exhibits an anti-adhesion effect within a very short time, disperses and diffuses on the filament surface, and reacts rapidly with residual isocyanate groups on the surface.

  Monoamines added to the base oil used in the present invention preferably have a molecular weight of 700 or less. For example, n-propylamine, n-butylamine, di-n-butylamine, iso-butylamine, di-iso- Examples include butylamine, 2-ethylhexylamine, monobenzylamine, distearylamine, ethylene oxide adduct of laurylamine, ethylene oxide adduct of stearylamine, ethylene oxide adduct of oleylamine, laurylamine, oleylamine, stearylamine and the like. The molecular weight of monoamines having an ethylene oxide adduct is a number average molecular weight. These monoamines may be used alone or in combination of two or more in the base oil. If the molecular weight exceeds 700, the melting point becomes high and remains solid in the base oil, or even if it dissolves in the base oil, the viscosity of the oil becomes too high and the fiber being spun may break due to oil resistance. As a result, the problem that the quality of the yarn becomes unstable because it does not react quantitatively with the residual isocyanate groups in the fiber will arise.

  In addition, if the base oil contains a large amount of monoamines, the polyurethane elastic fiber may break when heat-treated, so the amount of monoamine added is the amount of residual isocyanate groups in the polyurethane elastic fiber. 0.5 to 15 eq (equivalent)%, preferably 0.7 to 14 eq%, more preferably 0.9 to 12 eq%. The amount of monoamines added is determined, for example, by determining the proportion of monoamine consumption in the residual isocyanate groups and then determining the amount of oil to be deposited, and the amount of monoamines required (equivalents of amino groups) can be obtained from the equivalent calculation. If the amount of monoamine added is less than 0.5 eq% residual isocyanate group consumption, the reactivity with residual isocyanate groups on the surface is small and the effect of preventing sticking cannot be exerted, and more than 15 eq%. In some cases, the solubility in the base oil is insufficient, the uniform adhesion to the yarn surface is deteriorated, the effective crosslinking amount consisting of residual isocyanate groups is lowered, and the heat resistance of the polyurethane elastic fiber is lowered. An appropriate amount of monoamine is contained in the oil, and the unreacted residual isocyanate group remaining in the polyurethane elastic fiber after spinning is reacted with the monoamine to improve the properties such as the unwinding property of the wound body, which will be described later. It is also possible to control the effective crosslinking amount.

As the viscosity of the oil used in the present invention, the viscosity at 25 ° C. is preferably less than 50 × 10 ⁻⁶ m ² / s, particularly preferably not more than 30 × 10 ⁻⁶ m ² / s, more preferably 20 × 10 ^{−. 6} m ² / s or less, and a more preferable range is 3 × 10 ⁻⁶ m ² / s to 15 × 10 ⁻⁶ m ² / s. When the viscosity of the oil agent is 50 × 10 ⁻⁶ m ² / s or more, the resistance increases when the spinning raw yarn is stretched, and stretch spots occur, or the raw yarn is taken by rollers and guides, resulting in stretch spots. It is not preferable because it may be scraped off by the bobbin in a state where it is caught, or it may be caught by the roller and the yarn may be broken. Further, it is not preferable because troubles such as stretch spots occur due to friction due to the viscosity of the oil agent in processes such as weaving and knitting.

Of course, it is also possible to adjust the viscosity by using a thinning agent (diluent), for example, a low-viscosity polydimethylsiloxane, if necessary.
The method for measuring the viscosity can be calculated by dividing the dynamic viscosity at each temperature by dividing the intrinsic viscosity measured by the Ubbelohde viscometer by the density.

  The oil agent is preferably applied so that the oil agent is contained in the polyurethane elastic fiber in an amount of 1 to 10% by mass, particularly 2 to 8% by mass. The above value is referred to as the ratio of the oil agent applied to the polyurethane elastic fiber, that is, the application ratio, which is a ratio of both the content ratio (the ratio included) and the adhesion ratio (the ratio applied). .

  If the oil agent is less than 1% by mass with respect to the polyurethane elastic fiber, the unwinding property is poor and wear due to metal such as a knitting needle is liable to occur, and it is not preferable, and if it exceeds 10% by mass, the paper tube A lot of oil agent adheres to the inner layer part of the yarn wound around the inner layer, the inner layer polymer is deteriorated by the oil agent, nozzle debris is generated, and oligomers of inelastic fibers are deposited when forming inelastic fibers and knitted fabrics. This is not preferable because of adverse effects.

  The application rate can be measured by gravimetric method or petroleum ether extraction method. The measurement method based on the gravimetric method measures the mass of the empty paper tube, the amount of polymer discharged from the spinning nozzle per unit time, the winding time of the yarn around the paper tube, and the mass of the wound body in advance. The remaining mass obtained by subtracting the total amount of polymer discharged and the mass of the empty paper tube from the mass of the oil is the amount of oil applied, and the ratio obtained by dividing the total amount of polymer discharged from the amount of oil obtained by calculation is the amount of oil applied. Rate.

The measuring method by petroleum ether extraction method is
(1) About 2 g of the wound yarn sample (A) is precisely weighed and then washed with 50 ml of petroleum ether for 1 minute.
(2) After this washing is repeated three times, the wound yarn sample is sandwiched between filter papers and sufficiently dried.
(3) After air drying at room temperature, the weight (B) of the wound yarn sample is measured. OPU is calculated according to the following formula.
OPU (amount of oil applied)% = {(A−B) / (B)} × 100
In simple terms, the OPU% can be obtained by the gravimetric method and by any method of the petroleum ether extraction method as a confirmation test.

  As a method for imparting an oil agent to polyurethane elastic fibers, it may be attached to polyurethane elastic fibers after spinning, or an oil agent may be preliminarily contained in a spinning dope and spinning may be performed. The step in the case of attaching the oil agent is not particularly limited as long as the spinning dope is spun and fibers are formed, but is preferably just before being wound on a winder.

  More specifically, as a method of applying an oil agent to fibers, a method in which a yarn immediately after spinning is brought into contact with an oil film formed on the surface of a rotated metal cylinder in an oil agent bath, a fixed amount discharge from a nozzle tip with a guide. A known method such as a method of adhering the oil agent to the yarn or a spraying method can be used. When the oil agent is contained in the spinning dope, the oil agent may be added to the spinning dope at any time when the spinning dope is produced, or may be dissolved or dispersed in the spinning dope.

  As described above, the yarn wound with the oil agent has 0.2 to 1% by mass of residual isocyanate groups in the yarn, and this residual isocyanate group becomes an amine when it reacts with water. It reacts with the remaining isocyanate group to form a urea bond, and the reaction between the isocyanate group and the urethane bond or urea bond generates a crosslink such as an allohanate bond or a burette bond. The greater the amount of residual isocyanate groups in the yarn, the easier the chemical reaction on the surface of the yarn proceeds and more crosslinks are generated. If the residual isocyanate group in the yarn is left as it is, sticking occurs on the surface of the yarn. Therefore, after spinning, it is necessary to carry out solid phase polymerization to complete the reaction. Further, this solid phase polymerization leads to crystallization of the hard segment and forms a higher order structure, which is considered to contribute to improvement of the elastic recovery rate and heat resistance of the fiber. In the present invention, the amount of residual isocyanate groups involved in the crosslinking reaction is referred to as an effective crosslinking amount.

  Solid-phase polymerization is 100 ° C or lower, especially 90 ° C or lower, 10 ° C or higher, especially 20 ° C or higher, when it is treated under high humidity, a quantitative cross-link is formed, and the surface layer and inner layer of the yarn wound around a paper tube are equivalent. It is preferable because it has the following physical properties. Specifically, it is preferable that the relative humidity is 20 to 90 ° C. and the relative humidity is 30 to 90% RH. If the relative humidity is less than 30% RH, the reaction is not uniform in each layer in the same wound body, and the physical properties of the finished yarn change, which is not preferable. If the relative humidity exceeds 90% RH, moisture is formed in the form of yarn. Is likely to condense, and then a different reaction proceeds at the moisture contact location and other locations, which may result in different physical properties.

  In the case of solid-state polymerization, when the heat treatment is performed at a temperature exceeding 100 ° C., the affinity between the oil agent and the polymer becomes strong, and the polymer may be deteriorated or yellowed. Is preferred. However, if the humidity is low, the filaments may stick together, or the reaction state of the surface layer and the inner layer of the yarn wound around the paper tube may be different, so that the physical properties may change greatly even if the yarn is wound around the same paper tube. There is. Moreover, although it is possible to process with warm water lower than 100 degreeC, it may become easy to be damaged when a paper tube gets wet.

  When wet winding heat treatment is applied to the wound body, solid phase polymerization and hard segment crystallization first proceed on the outermost surface of the wound body, and then the same reaction proceeds from the surface layer to the inner layer of the wound body as the temperature rises. become. Furthermore, since the temperature of the inner layer portion of the wound body is likely to be lower than that of the surface layer portion, the thickness of the fiber layer in the wound body (distance from the core surface to the outermost surface of the wound body) and fiber winding It is necessary to control the take-off width and the shape of the core.

  When winding the fiber with a winder, the shape of the wound body is preferably a cylindrical shape (tubular), particularly a hollow cylindrical shape (tubular), since the fiber can be wound uniformly. More preferably, the area is a perfect circle. From the standpoint of winding efficiency, efficiency of wet heat treatment (solid phase reaction), etc., the fiber layer thickness is preferably 10 to 50 mm in the radial direction, and the fiber winding width is preferably 30 to 110 mm. When the thickness and winding width of the fiber layer are outside the above ranges, the agglomeration progress of the hard layer of the inner layer portion and the surface layer portion of the wound body is different, and in the inner layer portion of the wound thread, the heat resistance improves as the surface layer portion. Therefore, the performance as a whole wound body is low, and the homogeneity may be insufficient.

After the solid-phase reaction described above, the effective cross-linking amount of the residual isocyanate group is preferably 0.05 × 10 ⁻⁵ mol / g or more and less than 10 × 10 ⁻⁵ mol / g. That is, if the effective crosslinking amount is less than 0.05 × 10 ⁻⁵ mol / g, improvement in heat resistance may not be obtained, and if it is 10 × 10 ⁻⁵ mol / g or more, nozzle clogging may occur. May occur, resulting in poor stability in the spinning process and a decrease in heat-fusibility of the yarn.

  The effective crosslinking amount is obtained by reacting polyurethane elastic fiber with a monoamine compound, obtaining the residual amine amount by potentiometric titration using hydrochloric acid as a titrant, and reducing the residual amine amount from the charged amine amount. The amount of amine reacted can be calculated. Details are as follows.

(1) A polyurethane elastic fiber (about 5 g) is immersed in 95 mL of a 3,000 ppm n-butylamine (nBA) / dimethylformamide solution and decomposed in a test bottle at 40 ° C. for 4 hours to obtain a test solution.
(2) Next, potentiometric titration (for example, Hiranuma automatic titration apparatus COMMITE-500) is performed with 0.1N hydrochloric acid to determine the residual amine amount.
(3) The amount of amine obtained by potentiometric titration of nBA / dimethylformamide treated in the same manner without adding fibers with hydrochloric acid is used as a reference.
(4) Then, the difference between the reference and the residual amine amount is defined as the amount of amine that has reacted with the cross-linking (consumed for the decomposition of the cross-linking), and the effective cross-linking amount (mol / g) is calculated using the following formula.
Formula for calculating effective cross-linking amount nBA amount reacted with cross-linking (ppm) = (prepared nBA amount−actual nBA amount)
Effective crosslinking amount (mol / g) =
{(Amount of nBA reacted with cross-linking [ppm] / 106)
× (Test liquid yarn amount [g] / 73)} / Yarn amount [g]

  The fineness of the heat-sealable polyurethane elastic fiber of the present invention can be appropriately selected from both the shape retention performance and production cost of the elastic fiber structure, and is preferably 11 to 800 dtex from the viewpoint of ease of production and cost. More preferably, it is 17-622 dtex. In the obtained heat-fusible polyurethane elastic fiber, it is advantageous for improving the heat setting property that the dtex per single yarn is large.

The fineness is measured by unwinding the yarn from the wound yarn, allowing it to stand for 24 hours and then shrinking it, and then placing the yarn along the straight line drawn on the fineness measurement plate in the absence of tension, to a length of 100 cm. Cut 50 pieces and measure the mass of 50 pieces in total.
Fineness (dtex) = measured mass (mg) / 50 × 10

  The reason why the heat-fusible polyurethane elastic fiber obtained by the melt spinning method is fused without causing breakage or breakage is considered as follows. The first is the effect of the components of the first polyol and the second polyol constituting the polyurethane elastic fiber, the second is the influence of the melting point (flow temperature) of the polyurethane elastic fiber, and the third is This is considered to be the heat resistance effect of the polyurethane elastic fiber. Furthermore, it is considered that these effects are exhibited over the entire region of the wound body by applying the oil agent of the present invention.

  That is, the polyol component, which is the first factor, is more affected by the ether group than the ester group, and the ether group itself has a high heat shrinkage stress due to heat and contributes to fusion because the rotational property tends to fluctuate greatly. it seems to do. The melting point (flow temperature) of the polyurethane elastic fiber, which is the second factor, has a higher fusing power as it is closer to the processing temperature of the woven or knitted fabric, so select a polyurethane elastic fiber having a melting point (flow temperature) near the processing temperature. This is considered to have an effect on fusion. The third factor is the heat resistance of the polyurethane elastic fiber. Even if the melting point (flow temperature) of the polyurethane elastic fiber is the same as the processing temperature of the woven or knitted fabric, the heat resistance at a constant temperature is Even if it is partly low, the yarn breakage of the polyurethane elastic fiber is severe even if it is fused, and there is a possibility that it is impossible to produce a woven or knitted fabric mixed with an inelastic yarn. Therefore, it is considered that heat resistance at the melting point (flow temperature) of the polyurethane elastic fiber can prevent yarn breakage and yarn breakage near the processing temperature of the woven or knitted fabric, and at the same time has an effect on fusion.

  The heat resistance of the polyurethane elastic fiber obtained by melt spinning is greatly affected by the content of residual isocyanate groups remaining in the yarn after the reaction between the both-end isocyanate group prepolymer and the both-end hydroxyl group prepolymer. It is thought that heat resistance can be controlled by forming a cross-linked bond by solid phase polymerization. As described above, it is preferable that the residual isocyanate group in the yarn immediately after spinning is 0.2 to 1.0% by mass. However, if the residual isocyanate group is less than 0.2% by mass, the amount of cross-linking generated is small. The heat resistance is low and the yarn is easily broken. On the other hand, if the residual isocyanate group exceeds 1.0% by mass, the amount of cross-linking is increased and the heat resistance increases, so that it takes time to melt and it is difficult to obtain heat-fusibility, which is not preferable.

Further, the effective cross-linking amount of the residual isocyanate group after the solid phase reaction is desirably 0.05 × 10 ⁻⁵ mol / g or more and less than 10 × 10 ⁻⁵ mol / g as described above. The heat resistance control can be adjusted by the effective crosslinking amount, and the effective crosslinking amount can be adjusted by the residual isocyanate group concentration, the monoamine concentration in the oil agent, and the conditions of solid phase polymerization.

  In the present invention, by applying the oil agent of the present invention, these controls can be satisfactorily performed over the entire region of the wound body.

[Dry spinning method]
Next, a manufacturing method by the dry spinning method will be described.
Examples of the dry spinning method for obtaining the polyurethane elastic fiber of the present invention include the following methods.
(1) A solution synthesis method in which an excess molar amount of diisocyanate is reacted with a polyol in an organic solvent to synthesize a prepolymer having isocyanate groups at both ends.
(2) A melt synthesis method in which both components of polyol and diisocyanate are reacted in a molten state in the absence of a solvent to synthesize a molten prepolymer and then dissolved in an organic solvent to obtain the prepolymer.
It can be obtained by reacting the prepolymer synthesized as in (1) and (2) with an equivalent or excess amount of chain extender.

  In the present invention, in particular, a polyol and an excess mole of diisocyanate are reacted to produce a polyurethane intermediate polymer having isocyanate groups at both ends, and low hydrogen having active hydrogen that can easily react with the isocyanate groups of this intermediate polymer. A polyurethane solution (polymer solution) is produced by reacting a molecular weight diamine and / or a low molecular weight diol in an inert organic solvent, and then a low melting point compound is mixed with this polymer solution to form a spinning stock solution. A method of obtaining a heat-sealable polyurethane elastic fiber by spinning with a dry spinning machine is preferred. Here, a low molecular weight diamine or a combination of a low molecular weight diamine and a low molecular weight diol is particularly preferable.

  In the method for producing a polyurethane elastic fiber by the dry spinning method of the present invention, a polyol and a diisocyanate are first reacted to synthesize an isocyanate-terminated intermediate polymer. As the polyol (polymer diol) and diisocyanate used in the dry spinning method, those similar to those described in the melt spinning method can be used, but the number average molecular weight of the polyol is about 600 to 3500, particularly 800. About 3,000 is preferable. If it is too small, the elongation at break and elastic recovery may be lowered. If it is too large, the breaking strength, heat resistance, cold resistance and the like may be lowered.

  As the polyol, among the above-exemplified examples, the polyether diol is used in the total polyol of the raw material in an amount of 60% by mass or more, particularly 70 to 100% by mass, because the chemical resistance is excellent when the product is post-processed. It is preferable from the point of being easy or excellent in mold resistance.

  The diisocyanate is preferably used in excess of about 1.2 to 3.0 times, more preferably about 1.4 to 2.2 times as much as the molar amount of the polyol.

  When synthesizing an isocyanate group intermediate polymer by reacting a polyol with diisocyanate, the reaction method is a batch method using a synthetic kettle or a continuous method using a static mixer or a twin-screw kneader. After charging each component at a predetermined molar ratio, the conditions are 60 to 150 ° C., particularly 65 to 130 ° C., 30 to 180 minutes, particularly 40 to 120 minutes under an inert gas atmosphere such as nitrogen and argon. It is preferable to make it react under. When the reaction temperature is less than 60 ° C., the reaction time is significantly increased, and in some cases, the prepolymer may be precipitated. Moreover, when reaction temperature exceeds 150 degreeC, there exists a possibility that side reactions, such as a dimer of an isocyanate group, and a trimerization reaction, may become remarkable.

  Next, a polyurethane polymer is synthesized by reacting the obtained intermediate polymer with a low molecular weight diamine and / or a low molecular weight diol as a chain extender and, if necessary, a monoamine as a terminal blocking agent in a polar solvent. To do.

As the low molecular weight diamine,
H ₂ NR ¹ NH ₂
R ¹ is a single bond or an alkylene group having 1 to 13 carbon atoms, preferably 1 to 8, more preferably 1 to 6 carbon atoms, or an arylene group, or a group to which these are bonded, and a methylene group. , Ethylene group, propylene group, butylene group, pentylene group, hexylene group, phenylene group, xylylene group, cyclohexylene group and the like.

  Specific examples include diamines such as ethylenediamine, propylenediamine, butanediamine, hexamethylenediamine, xylylenediamine, 4,4-diaminodiphenylmethane, and hydrazine.

  As the low molecular weight diol, those similar to those described in the melt spinning method can be used, but preferably, such as ethylene glycol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol. Diols can be mentioned.

As a monoamine as a terminal blocking agent, the following formula
NHR ² R ³
R ² and R ³ are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, preferably 1 to 6 carbon atoms, such as a methyl group, an ethyl group, a propyl group, or an isopropyl group. , N-butyl group, t-butyl group, isobutyl group, pentyl group, hexyl group, 2-ethylhexyl group and the like.

  Specifically, monoalkylamines such as isopropylamine, n-butylamine, t-butylamine, 2-ethylhexylamine; diethylamine, diisopropylamine, di-n-butylamine, di-t-butylamine, di-isobutylamine, di- Examples thereof include dialkylamines such as 2-ethylhexylamine.

  The amine is used in an equivalent ratio such that low molecular weight diamine / monoamine = 99.5 / 0.5 to 90/10, preferably 99/1 to 93/7. When the equivalent ratio of the amine compound exceeds 99.5 / 0.5, the hard segment in the polyurethane polymer increases, so that the viscosity stability of the polyurethane polymer solution is lowered, and local reactions are likely to occur during the polymerization. As a result, the gel product tends to increase in the polyurethane polymer solution, and the gel product may be broken by passing through the nozzle during spinning, or the operation stability may be reduced due to the filterability of the solution. . On the other hand, when the viscosity is lower than 90/10, the viscosity stability of the polyurethane polymer solution is good, but the degree of polymerization of the polyurethane polymer is lowered, and the heat resistance and yarn physical properties may be deteriorated.

  Further, the total addition amount of the amine is preferably equal to or greater than the residual isocyanate group contained in the intermediate polymer, more preferably 1.0 to less than 1.2 in terms of equivalent ratio. If the total amount of amine added is lower than the equivalent amount, residual isocyanate groups remaining in the system will react over time, which may lead to an increase in molecular weight or a marked increase in solution viscosity. May cause yellowing of the polyurethane polymer solution or a decrease in the viscosity of the solution over time.

  The amine is preferably a mixture of amines in an organic solvent because it is easy to react with the intermediate polymer. When the amine is reacted with the intermediate polymer, the reaction is usually carried out by dropping it into the solution of the intermediate polymer as a solution in an organic solvent. However, the residual isocyanate group concentration remaining in the intermediate polymer solution is measured in advance and the amine is reacted. Monitoring the change from the method of determining the amount of dripping or the state in which the viscosity of the intermediate polymer solution increases due to the addition of amine to the state in which the residual isocyanate group disappears, the substantial reaction is completed, and the solution viscosity does not increase. It is possible to control the dripping amount.

  In addition, as a chain extender, you may use together polyfunctional active hydrogen compounds, such as hydroxides, such as water, dihydrazide, carbodihydrazide, (beta) -aminopropionic acid hydrazide as needed. Moreover, as a terminal blocker, you may use alkyl alcohol, such as methanol, ethanol, propanol, butanol, pentanol, etc. other than a monoamine as needed.

  Further, as the organic solvent used in the dry spinning method, an inert organic solvent is used, and N, N-dimethylformamide, N, N-dimethylacetamide, N, N, N ′, N′-tetramethylurea is used. N-methylpyrrolidone, dimethyl sulfoxide, etc., which has a high solubility in polyurethane polymers and does not react with isocyanate groups or active hydrogen compounds that react with isocyanate groups, and further to additives in polyurethane polymer solutions Organic solvents that do not react are preferred. Among these, N, N-dimethylacetamide or N, N-dimethylformamide is preferably used from the viewpoint of compatibility with the polyurethane polymer, spinnability, and solvent recoverability.

  The amount of the organic solvent used is preferably adjusted so that the solid content of the polyurethane polymer is 10 to 60% by mass, particularly 20 to 40% by mass, and less than 10% by mass or 60% by mass. If it exceeds, spinnability may be adversely affected.

  In addition, a catalyst for accelerating the reaction may be used for the above polymerization reaction, if necessary, such as those having a strong tendency to activate the reaction between isocyanate and polyol, diamine, diol, isocyanate and water, etc. Those having a strong tendency to activate the reaction with the chain extender and those having both properties can be appropriately used. Representative examples of such a catalyst include tertiary amine compounds and organometallic compounds.

  As the tertiary amine compound, monoamines such as triethylamine, N, N-dimethylcyclohexylamine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetramethylpropane- Diamines such as 1,3-diamine, triamines such as N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine and tetramethylguanidine, triethylenediamine, N, N′-dimethylpiperazine, 1,8- Cyclic amines such as diazabicyclo (5,4,0) undecene-7 and N-methylmorpholine, alcohol amines such as dimethylaminoethanol and dimethylaminoethoxyethanol, bis (2-dimethylaminoethyl) ether, ethylene glycol bis (3 -Ether) such as dimethyl) -aminopropyl ether Kind, and the like.

  Examples of organometallic compounds include tin acetate, tin octylate, tin oleate, tin laurate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dichloride, lead octoate, lead naphthenate, nickel naphthenate, cobalt octoate, etc. Is mentioned.

  These catalysts may be used alone, for example, two or more kinds such as a combination of a tertiary amine compound and an organometallic compound may be used in combination. The concentration of the catalyst is usually 0.0001 to 10% by mass, preferably 0.0005 to 5% by mass with respect to the polyurethane polymer, but the addition amount may be appropriately adjusted while observing the reaction behavior.

  The reaction between the both-end isocyanate group intermediate polymer and the low molecular weight diamine and / or low molecular weight diol as the chain extender is carried out at 0 to 80 ° C., particularly 10 to 60 ° C. in an inert gas atmosphere such as nitrogen and argon. The reaction conditions are preferably 0.1 to 5 hours, particularly 0.5 to 3.5 hours, and the reaction method is a batch method using a synthetic kettle or a continuous method using a twin-screw kneader or a static mixer. It may be a method.

  The weight average molecular weight of the polyurethane polymer thus obtained was determined by using gel permeation chromatography (GPC) after dissolving the soluble component completely dissolved in an N, N-dimethylformamide solution in which lithium chloride was dissolved. Can be measured. The weight average molecular weight of the polyurethane polymer is preferably 250,000 to 450,000, more preferably 250,000 to 350,000 (polystyrene conversion).

  If the molecular weight of the polyurethane polymer is too small, the yarn physical properties such as heat resistance may decrease or the spinning spinnability may be poor and the yarn breakage may increase. It becomes necessary to increase the amount of solvent to be used, and as a result, it may not be an economical production method.

  The polyurethane polymer solution thus obtained can be dry-spun as a spinning stock solution. However, a low-melting compound can be mixed with this polymer solution to form a spinning stock solution, which can be spun by a dry spinning machine. preferable.

  As the low melting point compound, a melting point by a flow temperature method is 200 ° C. or less, particularly preferably a thermoplastic polymer having a temperature of 60 to 195 ° C., which is used as a solvent for a polyurethane polymer solution, dimethylacetamide, dimethylform Those which can be used by being mixed with the polyurethane urea polymer solution in a state dissolved in amide, dimethyl sulfoxide or the like are preferable. The weight average molecular weight of this thermoplastic polymer is preferably 20,000 to 1,000,000, particularly 50,000 to 800,000.

  Specific examples of such low melting point compounds include polyacrylonitrile homopolymers and copolymers of acrylonitrile and α, β-unsaturated monocarboxylic acid esters (as examples of α, β-unsaturated monocarboxylic acid esters). Acrylonitrile polymers such as phenyl acrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, cyclohexyl acrylate, methyl methacrylate) and acrylonitrile-acrylamide copolymers; A maleic anhydride copolymer, specifically, a copolymer comprising a styrene-maleic anhydride copolymer, and p-methylstyrene, p-methoxystyrene, p- Styrene substituted with an aromatic ring such as dimethylaminostyrene Copolymers with maleic anhydride using styrene substituted with vinyl groups such as α-methylstyrene and α, β-dimethylstyrene; N-isopropenyl-2-pyrrolidone, N-vinyl-4-methyl- 2-pyrrolidone, N-vinylpiperidone, N-vinylcaprolactam, N-vinylenantolactam, N-vinylvalerolactam, N-butenyl-2,4-di (1-butenyl) -2-pyrrolidone vinylacetate, dimethyl Polyvinylpyrrolidone copolymer, polyurethane polymer, polyacrylonitrile polymer, ABS resin synthesized from aminoethyl methacrylate, ethylene, styrene, acrylic acid, methacrylic ester, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, etc. , SAN resin, vinyl chloride resin , Vinyl chloride vinyl acetate copolymer, polypropylene, polyethylene, polystyrene, polyacetal, polyamide, polyester, polyester ether, polycarbonate, epoxy resin, amino resin, phenol resin, silicone resin, fluorine resin, hydrophilic acrylic resin, polyacrylamide, hydrophilic And cellulose resin.

  Among these, polyacrylic acid ester, polyvinylpyrrolidone copolymer, polyurethane polymer, polyester, polyester ether, epoxy resin and the like are preferable from the viewpoint of solubility in a solvent and compatibility with a polyurethane polymer. Furthermore, as described above, in order to obtain a good elastic property of the polyurethane elastic fiber, the residual strain immediately after 300% elongation is preferably 40% or less. The addition of a low melting point compound that is high and highly compatible with the polyurethane polymer is advantageous, and the addition of the polyurethane polymer is more preferred.

  The melting point of the low melting point compound can be measured by setting the initial set temperature at 30 ° C. in the same manner as the method for measuring the melting point of polyurethane elastic fiber.

  The mixing ratio of the low melting point compound to the polyurethane polymer is, by mass ratio (solid content), polyurethane polymer / low melting point compound = 80/20 to 40/60, preferably 70/30 to 50/50. If the amount of the low melting point compound is too small, the heat-sealing strength may be insufficient. If it is too large, the heat resistance will be reduced, and the polyurethane elastic fibers in the knitted fabric will be broken during processing such as dyeing and heat setting. There is a risk. In addition, the residual strain immediately after 300% elongation may increase.

  The mixing of the polyurethane polymer and the low melting point compound is not particularly limited as long as both are sufficiently mixed. Even if the low melting point compound is mixed with the polyurethane polymer, the polyurethane polymer is mixed with the low melting point compound. May be. In the former case, it is preferable to mix the low melting point compound after the reaction of the polyurethane polymer proceeds and the isocyanate group is substantially not observed. The low melting point compound is obtained by pulverizing a lump or after pulverization. Furthermore, what is remelted and pelletized may be added directly to the polyurethane polymer solution. Further, the low melting point compound may be dissolved and mixed in the same solvent as the solvent used for the synthesis of the polyurethane polymer.

  The reason why the solution containing the polyurethane polymer and the low melting point compound is superior to the conventional polyurethane fiber obtained by spinning only the polyurethane polymer is that the low melting point compound in the fiber is lower than the polyurethane polymer. It seems to start melting at temperature and adhere to the surrounding polymer while maintaining the strength of the fiber, but details are unknown.

  In the case of using a low melting point compound dissolved in a solvent, the concentration of the solution is not particularly limited, and should be about 10 to 60% by mass from the viewpoint of increasing the viscosity of the spinning solution and changing the physical properties of the spun yarn. Is more preferable, and about 20 to 40% by mass is more preferable.

  The method for adding and mixing the low melting point compound to the polyurethane polymer solution is not particularly limited. However, under a inert gas atmosphere such as nitrogen or argon, the conditions such as the mixing temperature and time are appropriately selected and mixed uniformly. It is preferable to do. The mixing temperature is preferably 10 to 120 ° C, and particularly preferably 40 to 80 ° C. If the temperature is lower than 10 ° C., there is no problem in the side reaction at the time of mixing, but it is not economical because it takes time for dissolution and the cooling cost increases. When the treatment is performed at a temperature higher than 120 ° C., the viscosity of the liquid is lowered, so that the mixing speed is increased. However, the polyurethane molecules are cleaved, which may cause a quality problem. In addition, in order to mix uniformly, it is preferable to stir at least 30 minutes or more.

  In the dry spinning method, the same active components as active hydrogen compounds and ultraviolet absorbers used in the melt spinning method can be used, and these can be added at any stage before the spinning step. Can be used.

  The spinning apparatus and spinning conditions used when dry spinning a solution containing a polyurethane polymer and a low melting point compound (spinning solution) are not particularly limited, and the composition of the polyurethane and the desired fiber thickness Depending on the properties of the yarn, etc., any known method can be selected for spinning. The spinning temperature is preferably 170 ° C. or higher, more preferably 180 ° C. or higher, further preferably 190 ° C. or higher, preferably 230 ° C. or lower, more preferably 220 ° C. or lower, and the filaments are bundled and bonded. As a result, it is possible to obtain a fiber having a fineness and a high degree of uniformity, thereby increasing the spinning speed and obtaining a high productivity.

  The polyurethane elastic fiber spun by the dry spinning method can be wound up by a winder similarly to the melt spinning method to obtain a wound body. And like the case of a melt spinning method, it is preferable to provide an oil agent so that 1-10 mass%, especially 2-8 mass% of an oil agent may be contained in a polyurethane elastic fiber. After spinning, it is desirable to store the wound body at room temperature for one day for the purpose of completely removing the solvent. In general, all isocyanate groups are reacted with active hydrogen, and in this case, it is not necessary to perform solid phase polymerization.

  The polyurethane elastic fiber of the present invention obtained by the dry spinning method has a chemical resistance of 70 mol% or more, particularly 85 mol% or more of the total polyol component constituting the polyurethane is a polyether diol having a number average molecular weight of 600 to 3500. It is preferable from the standpoints of improving heat resistance and exhibiting heat fusion properties while maintaining heat resistance. The upper limit is not particularly limited, and even if the polyether diol is 100%, it can be conveniently used. When there is too little polyether diol of the molecular weight of the said range, chemical resistance and heat resistance may fall.

  Moreover, it is preferable that the ratio of the urethane bond which occupies for the whole urethane bond and urea bond which comprises a polyurethane elastic fiber is 60-95 mol%, especially 65-90 mol%. If the ratio of the urethane bond is less than 60%, the heat resistance is high but the melting point is high, the thermal fluidity is also lowered, and the heat fusion property may be poor. If it exceeds 95 mol%, the melting point decreases and the thermal fluidity increases, but the polyurethane elastic fiber may be poor in heat resistance and elongation recovery property, which is not preferable.

  By setting it as the said range, the effect of favorable heat-fusion property can be acquired, maintaining heat resistance and chemical resistance required as a polyurethane elastic fiber.

  The heat resistance of the polyurethane elastic fiber obtained by the dry spinning of the present invention is affected by the properties and the amount of hard segments due to urea groups. By adding the low melting point compound described above, the hard segments can be aggregated. Since it can be suppressed, it can be considered that the melting point and heat resistance are controlled.

  The polyurethane elastic fiber obtained by the above production method has a melting point of 165 to 200 ° C. measured by the flow temperature method, and does not break over the entire region of the wound body, and is heat-treated in the above temperature range in the plating knitted fabric method. Therefore, by using this for a woven or knitted fabric, it is possible to obtain a woven or knitted fabric that suppresses the occurrence of fraying, densen, curl, and the like.

Polyurethane elastic fiber mixed woven / knitted fabric Next, the polyurethane elastic fiber mixed woven / knitted fabric of the present invention uses the above heat-fusible polyurethane elastic fiber and non-elastic yarn, and further has a high melting point polyurethane elastic fiber having a melting point of, for example, 200 ° C. or higher. Also, the following structure can be used.

  (1) A fabric using a composite yarn containing a heat-fusible polyurethane elastic fiber and at least one inelastic yarn as a warp and / or a weft. The texture may be any of plain weave, twill weave, satin weaving, and the like, and shuttle looms, rapier looms, air jet looms and the like can be used as the loom. Furthermore, the warp and the weft may be the composite yarn, or the composite yarn and the inelastic yarn may be mixed and used at a driving ratio of 1: 1, 1: 2, or 1: 3.

  (2) A weft knitted fabric in which a heat-fusible polyurethane elastic fiber and at least one kind of inelastic yarn are mixed in the same course of a knitting machine. The knitting structure of the weft knitted fabric knitted with the heat-fusible polyurethane elastic fiber and the non-elastic yarn may be any structure such as a flat knitting, a rubber knitting, a pearl knitting, a double-sided knitting, and a structure obtained by combining or changing these. All knitting machines such as a circular knitting machine, a flat knitting machine, a full fashion knitting machine, and a sock knitting machine can be used for the knitting machine. The heat-sealable polyurethane elastic fiber may be either inserted or knitted. Further, a plating knitting of heat-fusible polyurethane elastic fiber and inelastic yarn may be used, or a composite yarn of heat-fusible polyurethane elastic fiber and inelastic yarn may be used. Similarly to (1), the heat-sealable polyurethane elastic fiber may be knitted in all courses, or may be knitted every other course. The heat-sealable polyurethane elastic fiber and inelastic yarn may be knitted alternately or at appropriate intervals. Further, heat-sealable polyurethane elastic fibers may be mixed. Examples are shown below, but are not limited thereto.

(2) -1 Examples of all courses:
1st heat-fusible yarn and inelastic yarn, or composite yarn 2nd mouth Heat-fusible yarn and inelastic yarn, or composite yarn 3rd mouth Heat-fusible yarn and inelastic yarn, or composite yarn 4 ports Eye Heat-fusible yarn and inelastic yarn, or composite yarn (2) -2 Example of every other course:
1st neck heat-sealing yarn and inelastic yarn, or composite yarn 2nd mouth non-elastic yarn 3rd neck Heat-sealing yarn and inelastic yarn, or composite yarn 4th mouth non-elastic yarn (2) -3 Heat Example of using fusible yarn and high melting yarn every other course:
1st heat-sealing yarn and inelastic yarn, or composite yarn 2nd mouth High-melting yarn and inelastic yarn, or composite yarn 3rd mouth Heat-sealing yarn and inelastic yarn, or composite yarn 4th mouth high Melting point yarn and inelastic yarn, or composite yarn (2) -4 Alternating examples:
1st neck heat-sealing yarn 2nd neck non-elastic yarn, or heat-fusible yarn and non-elastic yarn 3rd neck heat-sealing yarn 4th port Non-elastic yarn, heat-sealing yarn and non-elastic yarn

  (3) A warp knitted fabric in which heat-fusible polyurethane elastic fibers and at least one kind of inelastic yarn are mixed. The knitting structure of warp knitted fabric knitted with heat-fusible polyurethane elastic fibers and non-elastic yarns is any structure such as combed knitting, denvi knitting, cord knitting, atlas knitting, or a combination or change of these. All the knitting machines such as a tricot knitting machine, a Raschel knitting machine, and a Milanese knitting machine can be used. As in (1), heat-sealable polyurethane elastic fibers may be knitted on the entire surface, or may be knitted at appropriate intervals. The heat-sealable polyurethane elastic fiber may be either inserted or knitted. Furthermore, a high melting point polyurethane elastic fiber may be mixed. Examples are shown below, but are not limited thereto.

(3) -1 Knitted fabric of chain structure FIGS. 1 and 2 show a chain structure frequently used for lace fabrics. This comb structure is prone to defects such as run and unravel after cutting. A run stop structure has been proposed as a countermeasure, but the trace of the run stop structure remains dirty in the fabric, and there remains a problem that impairs the sense of quality. Therefore, in FIGS. 1 and 2, a is a non-elastic yarn, and b is a heat-set polyurethane elastic fiber of the present invention, or a braided heat set as an alignment of a heat-fusible polyurethane elastic fiber and a high-melting-point polyurethane elastic fiber. Then, in the part X shown in FIG. 1, the heat-sealable polyurethane elastic fiber and the non-elastic yarn, and the heat-sealable polyurethane elastic fiber and the high-melting-point polyurethane elastic fiber are in contact with each other and heat-sealed. It is possible to obtain a knitted fabric which is good and prevents defects such as run and unraveling and which does not impair any aesthetics.

(3) -2 Knitted fabric other than comb structure Even in a structure generally used other than the comb structure, when the heat-fusible polyurethane elastic fiber of the present invention is inserted or used, it is fused with an inelastic yarn, Due to the fusion of polyurethane elastic fibers, softness (displacement, slipping out, jumping out, etc.) of the elastic fibers hardly occurs, and the durability of the fabric can be substantially improved. In addition, the fabric is more stable, curling is less likely to occur, and cost reduction during sewing can be expected.

  For example, in the organization charts shown in FIGS. 3 to 8, by using heat-sealable polyurethane elastic fibers as appropriate, it is possible to obtain a knitted fabric that is less likely to cause misalignment, softness, fraying, run, densen, curl and slip-in. Is possible.

  3, L1 and L2 are fully inserted (All-in), L1 and L2 in FIG. 4, L3 and L4 are inserted every other line (1in-1out), and L1, L2, and L3 in FIGS. Is full insertion (All-in). Further, a in FIGS. 3 to 8 is a non-elastic yarn, b is a heat-sealable polyurethane elastic fiber of the present invention used alone or in alignment with a high melting point polyurethane elastic fiber, and c in FIGS. Two heat-fusible polyurethane elastic fibers of the present invention can be used, or one heat-fusible polyurethane elastic fiber and one high-melting-point polyurethane elastic fiber of the present invention can be used.

  Furthermore, depending on the intended use, when the cut edge is used as it is without sewing, there has been a problem in the durability such as fraying due to rubbing during washing or wearing, but this can also be greatly improved.

  Here, the form of the heat-fusible polyurethane elastic fiber (filament yarn) of the present invention may be any of raw yarn (unprocessed yarn), false twisted yarn, pre-dyed yarn, etc. A composite yarn may be used. These are preferably stable yarns that are easy to twist.

  On the other hand, the inelastic yarn to be mixed with the heat-fusible polyurethane elastic fiber is not particularly limited. For example, natural fibers such as cotton, hemp, wool, and silk, regenerated fibers such as rayon, cupra, and polynosic, acetate, etc. Semi-regenerated fibers, fibers such as nylon, polyester, acrylic, polypropylene, vinyl chloride and the like can be used, but the mixture ratio of polyurethane elastic fibers is about 1-60 mass%, especially 2-50 masses. % Is preferred.

  In the woven or knitted fabric mixed with polyurethane elastic fiber of the present invention, a high melting point having a melting point of 200 ° C. or higher, preferably 210 ° C. or higher, excellent in heat resistance and elastic recovery by a dry spinning method in which chain extension reaction is performed with diamine. By mixing and using polyurethane elastic fibers, it is also possible to obtain a woven or knitted fabric having good elastic performance while maintaining the fusion property. In this case, the amount of the high-melting polyurethane elastic fiber used is preferably 10 to 90% by mass with respect to the heat-fusible polyurethane fiber.

  In addition, the measuring method of melting | fusing point of a high melting point polyurethane elastic fiber is the same as that of the flow temperature method mentioned above.

  The method for producing a woven or knitted fabric mixed with a heat-fusible polyurethane elastic fiber of the present invention can be obtained by weaving or knitting a woven fabric or knitted fabric having the above-described structure by a conventional method and then setting it with dry heat or wet heat.

  The dry heat setting method can be performed by using a setting machine such as a pin tenter and heat fixing with hot air. In this case, the set temperature is 130 to 210, particularly 160 to 200 ° C., and the set time can be 10 to 180 seconds, particularly 15 to 120 seconds.

  On the other hand, the wet heat setting method can be performed by heat setting with saturated steam at a predetermined pressure in a state where the knitted fabric is placed in a template. In this case, the set temperature is 80 to 140 ° C., particularly 90 to 135 ° C., and the set time can be 10 to 180 seconds, particularly 15 to 120 seconds.

  If the heat setting temperature is too low, the setting effect is insufficient or the dimensional stability and shrinkage characteristics of the knitted fabric are inferior, which is undesirable. If it is too high, the strength of the inelastic yarn is reduced, thermal discoloration, the texture becomes hard, etc. This is not preferable because of the negative effects.

  A heat set under high-temperature tension of about 160 to 200 ° C. in dry heat is preferably employed to finish a fabric product formed by weaving and knitting to a predetermined length of constant length and constant width. On the other hand, in the non-tension set, the size of the product after heat setting cannot be controlled due to free shrinkage at the time of heat setting, which is unsuitable for industrial implementation.

  The tension condition at that time may be arbitrarily set according to the finish target value of the width of the fabric, but may be controlled by the feeding speed to the heat treatment apparatus and the lateral tension.

  Mixed knitted and knitted fabrics using such heat-fusible polyurethane elastic fibers are mainly briefs, panties, shorts, undershirts, camisoles, girdles, bras, spats, body suits, sanitary shorts, swimwear, leotards, etc. , Resort wear, home wear, underwear, sports tights, shirts, outerwear, gloves, socks, arm covers, medical clothing, surgical clothing, clothing for cleanroom work in semiconductor factories, dustproof clothing, supporters, eye masks Clothing products such as disposable diapers, incontinence pads, gauze, bandages, patch materials, packaging materials, masks, sheets, towels, handkerchiefs and other sanitary products, clothing interlining, filters for precision filtration, industrial wipers, protective covers, etc. It is preferred to be applied to fields that require high stretchability and stretch recovery, such as industrial materials It is.

  According to the present invention, heat-sealable polyurethane elastic fibers that have excellent heat resistance during heat setting and are less likely to break or deteriorate, and misalignment, soft, fraying, run, densen, curl, slip-in and misalignment occur. It is possible to obtain a woven or knitted fabric mixed with polyurethane elastic fiber which is difficult to mix.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not restrict | limited to the following Example. In addition, in the following example, a part shows a mass part. The melting point and thermal fluidity are measured by the flow temperature method, the effective crosslinking amount is determined by potentiometric titration, the residual isocyanate group concentration (residual NCO%) is determined by titration with hydrochloric acid, and the amount of oil applied is determined by the petroleum ether extraction method. It is a measured value. The number average molecular weight is measured in accordance with JIS K1557, and the weight average molecular weight is measured in terms of polystyrene by GPC.

[Example 1] Production of polyurethane elastic fiber by melt spinning method
Synthetic diisocyanate of both terminal hydroxyl group prepolymers 4,4'-diphenylmethane diisocyanate (MDI) was charged into a reaction kettle with a warm water jacket at 80 ° C. sealed with nitrogen gas, and the number average molecular weight was used as a polymer diol. 46.5 parts of 1,000 polytetramethylene ether glycol (PTMG) was injected with stirring. After reaction for 1 hour, 25.0 parts of 1,4-butanediol as a low molecular weight diol was further injected, 4.1 parts of bis (4-hydroxyphenyl) sulfone (BHPS) was added, and the mixture was stirred for 15 minutes. A hydroxyl prepolymer was synthesized.

In parallel with this, 29.1 parts of MDI as diisocyanate was charged into an 80 ° C. reaction kettle sealed with nitrogen gas, and an ultraviolet absorber (2- [2-hydroxy-3,5- Bis (α, α-dimethylbenzyl) phenyl] -2H benzotriazole (TIN234): 20%), antioxidant (3,9-bis (2- (3- (3-t-butyl-4-hydroxy-5) -Methylphenyl) -propionyloxy) -1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro (5.5) undecane: 50%), light stabilizer (bis (2,2,6) , 6-Tetramethyl-4-piperidyl) sebacate: 30 parts), add 68 parts of PTMG having a number average molecular weight of 2,000 while stirring, and stir for 40 minutes. Continuously, a both-end isocyanate group prepolymer was obtained.

Polyurethane elastic fiber melt spinning The obtained both-end isocyanate group prepolymer and both-end hydroxyl group prepolymer are continuously connected to a cylindrical reactor for polyurethane elastic fibers having a mass ratio of 1: 0.302 and a stirring blade of 2,200 mL. Supplied. The feed rates were 32.8 g / min for both-end isocyanate group prepolymer and 9.9 g / min for both-end hydroxyl group prepolymer. The average residence time in the reactor was about 1 hour, and the reaction temperature was about 210 ° C.

  The obtained spinning polymer was introduced into two 8-nozzle spinning heads maintained at a temperature of 208 ° C. without solidifying. The spinning polymer was measured and pressurized by a gear pump installed on the head, filtered through a filter, and then discharged from a nozzle with a diameter of 0.7 mm and a hole of 1 hole into a 6 m long spinning tube at a speed of 2.67 g / min ( The total amount discharged from the nozzle: 42.67 g / min), rolled up on a paper tube having a paper tube width of 57.5 mm at a speed of 600 m / min while applying an oil containing the components shown in Table 1, and having a polyurethane elastic fiber of 44 dtex Got. The application rate of the oil agent to the polyurethane elastic fiber was 5% by mass.

  9.4 eq% of the isocyanate groups remaining in the polyurethane elastic fiber was consumed by n-butylamine contained in the oil. The total mass of the wound body wound with the polyurethane elastic fiber was 450 g, and the residual isocyanate group concentration of the polyurethane elastic fiber immediately after discharge was 0.42% by mass.

  The obtained wound body was immediately subjected to a solid phase reaction in a room at a temperature of 40 ° C. and a relative humidity of 80% for 5 days.

The finished yarn was arbitrarily taken out from the surface layer and the inner layer of the wound body, and the effective crosslinking amount was measured. As a result, the surface layer of the wound body was 1.00 × 10 ⁻⁵ mol / g, and the inner layer of the wound body was 0.00. It was 90 × 10 ⁻⁵ mol / g. Next, the completed yarn was arbitrarily taken out from the surface layer and the inner layer of the wound body, and the melting point was measured. As a result, both the surface layer and the inner layer were 191 ° C. Further, the heat fluidity of the inner layer portion of the wound yarn body at a constant temperature of 165 ° C. was determined to be 20 minutes, and the heat fluidity was good. From this result, it was confirmed that the heat fusion property was excellent.

  Moreover, the discharge speed of the nozzle of 1 hole was 2.33 g / min (the total discharge speed of the whole nozzle was 37.33 g / min), and a 156 dtex, 4-filament polyurethane elastic fiber having the same characteristics as 44 dtex fiber was obtained. It was.

[Example 2]
Except for continuously supplying the both-end isocyanate group prepolymer and both-end hydroxyl group prepolymer synthesized in Example 1 to a cylindrical reactor for polyurethane elastic fibers having a mass of 1: 0.279 and a stirring blade having a capacity of 2200 mL. Produced 44 dtex polyurethane elastic fiber in the same manner as in Example 1. The application rate of the oil agent to the polyurethane elastic fiber was 7% by mass.

  4.9 eq% of the remaining isocyanate groups were consumed by n-butylamine contained in the oil. The total mass of the wound body was 450 g, and the residual isocyanate group concentration (residual NCO%) of the polyurethane elastic fiber immediately after discharge was 0.95%.

  The obtained wound body was immediately subjected to a solid phase reaction in a room at a temperature of 50 ° C. and a relative humidity of 80% for 5 days.

When the amount of effective crosslinking of the finished yarn was measured, it was 3.3 × 10 ⁻⁵ mol / g in the surface layer of the wound yarn body and 3.2 × 10 ⁻⁵ mol / g in the inner layer. Next, the completed yarn was arbitrarily taken out from the surface layer and the inner layer of the wound yarn body, and the melting point was measured. As a result, both the surface layer and the inner layer of the wound yarn body were 195 ° C. Further, the thermal fluidity of the yarn in the inner layer portion of the wound yarn body at a constant temperature of 165 ° C. was 33 minutes, and the thermal fluidity was good. From this result, it was confirmed that the heat fusion property was excellent.

[Example 3]
The both-end isocyanate group prepolymer and the both-end hydroxyl group prepolymer synthesized in Example 1 were continuously fed to a cylindrical reactor for polyurethane elastic fibers having a capacity of 2,200 mL having a stirring blade at a mass ratio of 1: 0.3268. A 44 dtex polyurethane elastic fiber was produced in the same manner as in Example 1 except that. The application rate of the oil agent to the polyurethane elastic fiber was 3.5% by mass.

  0.9 eq% of the remaining isocyanate groups was consumed by n-butylamine contained in the oil. The total mass of the wound body was 450 g, and the residual isocyanate group concentration of the polyurethane elastic fiber immediately after discharge was 0.27%. The obtained wound body was immediately subjected to a solid phase reaction under the conditions of Example 1.

When the amount of effective crosslinking of the finished yarn was measured, it was 0.08 × 10 ⁻⁵ mol / g in the surface layer of the wound yarn and 0.07 × 10 ⁻⁵ mol / g in the inner layer. Next, the completed yarn was arbitrarily taken out from the surface layer and the inner layer of the wound yarn body, and the melting point was measured. As a result, both the surface layer and the inner layer of the wound yarn body were 177 ° C. Further, the heat fluidity of the yarn in the inner layer portion of the wound yarn body at a constant temperature of 165 ° C. was 1.2 minutes, and the heat fluidity was good. From this result, it was confirmed that the heat fusion property was excellent.

[Example 4]
A 44 dtex polyurethane elastic fiber was obtained in the same manner as in Example 1. The application rate of the oil agent to the polyurethane elastic fiber was 6.5% by mass.

  12 eq% of the remaining isocyanate groups was consumed by n-butylamine contained in the oil. The total mass of the wound body was 450 g, and the residual isocyanate group concentration of the polyurethane elastic fiber immediately after discharge was 0.42% by mass. The obtained wound body was immediately subjected to a solid phase reaction under the conditions of Example 1.

When the amount of effective crosslinking of the finished yarn was measured, it was 1.00 × 10 ⁻⁵ mol / g in the surface layer of the wound yarn body and 0.90 × 10 ⁻⁵ mol / g in the inner layer. Next, the finished yarn was arbitrarily taken out from the surface layer and the inner layer of the wound body and measured, and both were 183 ° C. at the surface layer and the inner layer of the wound body. Further, when the heat fluidity of the inner layer portion of the wound body at a constant temperature of 165 ° C. was determined, it was 15 minutes, and the heat fluidity was good. From this result, it was confirmed that the heat fusion property was excellent.

[Example 5] Production of polyurethane elastic fiber by dry spinning method
(1) Synthesis of polyurethane polymer 19.91 parts of polytetramethylene ether glycol (PTMG) having a number average molecular weight of 2,000 and 4.55 parts of 4,4′-diphenylmethane diisocyanate (MDI) at 65 ° C. in a nitrogen gas atmosphere The reaction was conducted with stirring for 100 minutes to synthesize both-end isocyanate group prepolymers. 57.07 parts of dimethylacetamide (DMAC) was added to and dissolved in the resulting both-end isocyanate group prepolymer to prepare a prepolymer solution.

  Next, an amine mixed solution in which 0.49 part of ethylenediamine (EDA) as a chain extender and 0.05 part of di-n-butylamine as a terminal blocking agent were dissolved in 17.93 parts of DMAC was added dropwise to the prepolymer solution. In addition, the mixture was stirred to obtain a solution containing a polyurethane polymer having a weight average molecular weight of 300,000 and a nitrogen content of 2.99% (spinning stock solution; concentration 25% by mass).

(2) Synthesis of Low Melting Point Compound (Polyurethane Compound) 70.81 parts of PTMG having a number average molecular weight of 2,000 and 24.11 parts of MDI were reacted with stirring at 130 ° C. for 60 minutes in a nitrogen gas atmosphere, and both end isocyanate groups A prepolymer was synthesized. Thereafter, 5.08 parts of 1,4-butanediol was added as a chain extender and stirred to obtain a polyurethane compound having a weight average molecular weight of 350,000 and a nitrogen content of 2.7%.

  The obtained polyurethane compound was heat-treated at 100 ° C. for 24 hours, then pulverized and remelted at 210 ° C., and pelletized with Tin Chemical Machine Co., Ltd. SV-65-32. The polyurethane compound pellets were dissolved in DMAC to prepare a solution having a concentration of 25% by mass. The melting point of this polyurethane compound was 165 ° C.

Preparation of spinning solution 24 kg of the polyurethane polymer solution obtained by (1) (6 kg in terms of solid content) and 16 kg of the polyurethane compound solution obtained in (2) (4 kg in terms of solid content) in a nitrogen gas atmosphere Was sufficiently mixed at 60 ° C. for 2 hours to obtain a mixed solution.
Furthermore, 1,1,1 ′, 1′-tetramethyl-4,4 ′-(methylenedi-1,4-phenylene) disemicarbazide, 1,3,5-tris (4-tert-butyl-3-hydroxy-) 2,6-dimethylbenzyl isocyanuric acid, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, 2- (2'-hydroxy-3-tert-butyl-5'-methylphenyl)- A solution for spinning by adding 5-chlorobenzotriazole so as to be 0.27% by mass, 0.13% by mass, 0.13% by mass, and 0.08% by mass, respectively, with respect to the solid content of the mixed solution. Got.

A solution for spinning and spinning polyurethane elastic fiber is measured and pressurized by a gear pump installed on a spinning head, filtered through a filter, and then discharged into an inert gas at 200 ° C. through a 4-hole or 14-hole nozzle to remove the solvent. After the coalescence, it was wound around a paper tube having a paper tube width of 55.0 mm at a speed of 500 m / min while applying an oil agent to obtain polyurethane elastic fibers of 44 dtex (4f) and 156 dtex (14f). The application rate of the oil agent to the polyurethane elastic fiber was 6% by mass. The total mass of the wound body was 450 g.

  The obtained polyurethane elastic fiber had no residual isocyanate group, but the wound body was stored at room temperature for one day for the purpose of completely removing the solvent. The effective cross-linking amount of the yarn was zero in the entire region of the wound body.

  When the melting points of the 44 dtex and 156 dtex polyurethane elastic fibers were measured, both the surface layer and the inner layer of the wound yarn body were 196 ° C. Further, the heat fluidity of the inner layer portion of the wound body at a constant temperature of 165 ° C. was 50 minutes, and the heat fluidity was good. From this result, it was confirmed that the heat fusion property was excellent.

[Example 6]
A 44-dtex polyurethane elastic fiber was obtained in the same manner as in Example 1, except that laurylamine was used as the monoamine contained in the oil, and 8.9 eq% of the remaining isocyanate groups were consumed by the laurylamine. The application rate of the oil agent to the polyurethane elastic fiber was 6.5% by mass.

The finished yarn was arbitrarily taken out from the surface layer and the inner layer of the wound body, and the effective crosslinking amount was measured. As a result, the surface layer of the wound body was 1.00 × 10 ⁻⁵ mol / g, and the inner layer of the wound body was 0.00. It was 90 × 10 ⁻⁵ mol / g. Next, the completed yarn was arbitrarily taken out from the surface layer and the inner layer of the wound body, and the melting point was measured. As a result, both the surface layer and the inner layer were 189 ° C. Further, the heat fluidity of the inner layer portion of the wound yarn body at a constant temperature of 165 ° C. was determined to be 20 minutes, and the heat fluidity was good. From this result, it was confirmed that the heat fusion property was excellent.

[Example 7]
The both-end isocyanate group prepolymer and both-end hydroxyl group prepolymer synthesized in Example 1 were continuously fed to a cylindrical reactor for polyurethane elastic fibers having a capacity of 2,200 mL having a stirring blade at a mass ratio of 1: 0.250. In addition, the monoamine contained in the oil agent is laurylamine, 12 eq% of the isocyanate groups remaining by the laurylamine is consumed, and the residual isocyanate group concentration of the polyurethane elastic fiber immediately after discharge is 1.3%. Produced polyurethane elastic fibers of 44 dtex in the same manner as in Example 1. The application rate of the oil agent to the polyurethane elastic fiber was 6.5% by mass.

The finished yarn was arbitrarily taken out from the surface layer and the inner layer of the wound body, and the effective crosslinking amount was measured. As a result, the surface layer of the wound body was 9.30 × 10 ⁻⁵ mol / g, and the inner layer of the wound body was 9. It was 20 × 10 ⁻⁵ mol / g. Next, the completed yarn was arbitrarily taken out from the surface layer and the inner layer of the wound yarn, and the melting point was measured. As a result, both the surface layer and the inner layer were 193 ° C. Further, the heat fluidity of the yarn in the inner layer portion of the wound yarn body at a constant temperature of 165 ° C. was 32 minutes, and the heat fluidity was good. From this result, it was confirmed that the heat fusion property was excellent.

  However, as a result of the nozzle pressure being increased easily during spinning and the nozzle replacement cycle being accelerated, the production efficiency was lower than in the other examples.

[Comparative Example 1]
The both-end isocyanate group prepolymer and both-end hydroxyl group prepolymer synthesized in Example 1 were continuously fed to a cylindrical reactor for polyurethane elastic fibers having a capacity of 2,200 mL having a stirring blade at a mass ratio of 1: 0.3463. A polyurethane elastic fiber of 44 dtex (1f) and 156 dtex (4f) was produced in the same manner as in Example 1 except that the oil agent containing the components shown in Table 2 was used. The application rate of the oil agent to the polyurethane elastic fiber was 6% by mass.

  17.0 eq% of the remaining isocyanate groups were consumed by n-butylamine contained in the oil. In addition, the mass of the wound body was 450 g, and the residual isocyanate group concentration of the polyurethane elastic fiber immediately after discharge was 0.10% by mass. The obtained wound body was immediately subjected to a solid phase reaction under the conditions of Example 1.

  The completed yarn was arbitrarily taken out from the surface layer and the inner layer of the wound body, and the effective crosslinking amount was measured. As a result, the surface layer and the inner layer of the wound body were both 0 mol / g. Next, the completed yarn was arbitrarily taken out from the surface layer and the inner layer of the wound yarn body, and the melting point was measured. As a result, both the surface layer and the inner layer of the wound yarn body were 160 ° C. Further, when the heat fluidity of the inner layer portion of the wound body at a constant temperature of 165 ° C. was determined, the flow started immediately after the measurement, and thus it could not be measured but was within a few seconds. Also from this result, it was confirmed that the heat resistance was low and it could not withstand the measurement temperature of the heat fusion test.

[Comparative Example 2]
As a diisocyanate, 25 parts of 4,4′-diphenylmethane diisocyanate (MDI) was charged into a 80 ° C. warm water jacketed reaction vessel sealed with nitrogen gas, and a polytetramethylene ether glycol (2,000) having a number average molecular weight of 2,000 as a polymer diol. 100 parts of PTMG) were injected with stirring. After the reaction for 1 hour, 27.6 parts of 1,4-butanediol was further injected as a low molecular weight diol and stirred for 15 minutes to synthesize a hydroxyl group prepolymer at both terminals.

  In parallel with this, 47.4 parts of MDI as a diisocyanate was charged into an 80 ° C. reaction kettle sealed with nitrogen gas, and an ultraviolet absorber (2- (3,5-di-t-amyl-2-hydroxyphenyl) benzoate was added. Triazole: 20%), antioxidant (3,9-bis (2- (3- (3-tert-butyl-4-hydroxy-5-methylphenyl) -propionyloxy) -1,1-dimethylethyl)- 2,4,8,10-tetraoxaspiro (5.5) undecane: 50%), light stabilizer (bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate: 30%) 2.2 parts were added, 100 parts of PTMG having a number average molecular weight of 2,000 was injected while stirring, and stirring was continued for 1 hour to obtain a both-end isocyanate group prepolymer.

  The obtained both-end isocyanate group prepolymer and both-end hydroxyl group prepolymer were continuously fed to a cylindrical reactor for polyurethane elastic fiber having a capacity of 2,200 mL having a stirring blade at a mass ratio of 1: 0.475. The feed rates were 28.93 g / min for both-end isocyanate group prepolymer and 13.74 g / min for both-end hydroxyl group prepolymer. The average residence time in the reactor was about 1 hour, and the reaction temperature was about 190 ° C.

  The obtained polymer was introduced into two 8-nozzle spinning heads maintained at a temperature of 192 ° C. without solidifying. The spinning polymer is weighed and pressurized by a gear pump installed on the head, filtered through a filter, and discharged from a nozzle with a diameter of 0.6 mm into a 6 m long spinning tube at a speed of 2.67 g / min ( The total amount discharged from the nozzle: 42.67 g / min) was wound around a paper tube at a speed of 600 m / min while applying an oil agent of 100% mineral oil to obtain a 44 dtex polyurethane elastic fiber. The application rate of mineral oil to the polyurethane elastic fiber was 7% by mass.

  17.0 eq% of the remaining isocyanate groups were consumed by n-butylamine contained in the oil. The total mass of the wound body was 450 g, and the residual isocyanate group concentration of the polyurethane elastic fiber immediately after discharge was 0.42% by mass.

The obtained wound body was immediately subjected to a solid phase reaction in a room at a temperature of 40 ° C. and a relative humidity of 80% for 5 days. The completed yarn was arbitrarily taken out from the surface layer and the inner layer of the wound body, and the effective crosslinking amount was measured. As a result, 1.1 × 10 ⁻⁵ mol / g was obtained for the surface layer of the wound body, and 0. It was 03 × 10 ⁻⁵ mol / g. Next, the finished yarn was arbitrarily taken out from the surface layer and the inner layer of the wound body, and the melting point was measured. As a result, the surface temperature of the wound body was 186 ° C. and the inner layer was 164 ° C. Further, when the heat fluidity of the inner layer portion of the wound body at a constant temperature of 165 ° C. was determined, the flow started immediately after the measurement, and thus it could not be measured but was within a few seconds. Also from this result, it was confirmed that the heat resistance was low and it could not withstand the measurement temperature of the heat fusion test.

[Comparative Example 3]
The both-end isocyanate group prepolymer and both-end hydroxyl group prepolymer synthesized in Example 1 were continuously fed to a cylindrical reactor for polyurethane elastic fibers having a capacity of 2,200 mL having a stirring blade at a mass ratio of 1: 0.3433. A 44 dtex polyurethane elastic fiber was produced in the same manner as in Example 1 except that. The application rate of the oil agent to the polyurethane elastic fiber was 3.5% by mass.

  0.9 eq% of the remaining isocyanate groups was consumed by n-butylamine contained in the oil. The total mass of the wound body was 450 g, and the residual isocyanate group concentration of the polyurethane elastic fiber immediately after discharge was 0.15%. The obtained wound body was immediately subjected to a solid phase reaction under the conditions of Example 1.

The finished yarn was arbitrarily taken out from the surface layer and the inner layer of the wound body, and the effective crosslinking amount was measured. As a result, the surface layer of the wound body was 0.02 × 10 ⁻⁵ mol / g, and the inner layer was 0.01 × 10 ⁻ It was ⁵ mol / g. Next, the finished yarn was arbitrarily taken out from the surface layer and the inner layer of the wound yarn body, and the melting point was measured. As a result, the surface layer of the wound yarn body was 162 ° C. and the inner layer was 160 ° C. Further, when the heat fluidity of the inner layer portion of the wound body at a constant temperature of 165 ° C. was determined, the flow started immediately after the measurement, and thus it could not be measured but was within a few seconds. Also from this result, it was confirmed that the heat resistance was low and it could not withstand the measurement temperature of the heat fusion test.

[Comparative Example 4]
A 44 dtex polyurethane elastic fiber was produced in the same manner as in Example 1. The application rate of the oil agent to the polyurethane elastic fiber was 6% by mass. Residual NCO% was consumed by 15 eq% with n-butylamine contained in the oil. The total mass of the wound body was 450 g, and the residual isocyanate group concentration of the polyurethane elastic fiber immediately after discharge was 0.42%. The obtained wound body was immediately subjected to a solid phase reaction under a normal pressure of 105 ° C. for 5 days.

The finished yarn was arbitrarily taken out from the surface layer and the inner layer of the wound body, and the amount of effective crosslinking was measured. As a result, the surface layer of the wound body was 0.80 × 10 ⁻⁵ mol / g, and the inner layer was 0.04 × 10 ⁻ It was ⁵ mol / g. Next, the finished yarn was arbitrarily taken out from the surface layer and the inner layer of the wound body, and the melting point was measured. The melting point was 181 ° C. for the surface layer and 161 ° C. for the inner layer. Further, when the heat fluidity of the inner layer portion of the wound body at a constant temperature of 165 ° C. was determined, the flow started immediately after the measurement, and thus it could not be measured but was within a few seconds. Also from this result, it was confirmed that the heat resistance was low and it could not withstand the measurement temperature of the heat fusion test.

[Comparative Example 5]
1,1,1 ′, 1′-Tetramethyl-4,4 ′-(methylenedi-1,4-phenylene) disemicarbazide, 1,3 with respect to the solid content of the polyurethane polymer synthesis solution of Example 5 , 5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzylisocyanuric acid, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, 2- (2′- Hydroxy-3-t-butyl-5′-methylphenyl) -5-chlorobenzotriazole was added so as to be 0.27% by mass, 0.13% by mass, 0.13% by mass and 0.08% by mass, respectively. The spinning solution thus obtained was spun in the same manner as in Example 5 to obtain 44 dtex (4f) and 156 dtex (14f) polyurethane elastic fibers. Grant It was 6% by mass.

  Although this polyurethane elastic fiber has no residual isocyanate group, the wound yarn was stored at room temperature for one day for the purpose of completely removing the solvent. The effective cross-linking amount of the yarn was zero in the whole area of the wound body. When the melting point of the yarn was measured, it was 215 ° C. for both the surface layer and the inner layer of the wound yarn body. Further, when the heat fluidity of the inner layer portion of the wound body at a constant temperature of 165 ° C. was determined, it was 200 minutes, and it was confirmed that the heat fluidity was poor and the heat fusion property was inferior.

  The physical properties of 44 dtex polyurethane elastic fibers obtained in Examples 1 to 7 are summarized in Tables 1 and 2, and the physical properties of 44 dtex polyurethane elastic fibers of Comparative Examples 1 to 5 are summarized in Table 3.

In Comparative Examples 1 and 3, the effective crosslinking amount was small, and the heat resistance near the melting point was poor, and the yarn was cut. Comparative Example 5 was poor in heat-fusibility as compared with others. In Comparative Examples 2 and 4, the surface layer was satisfactory with no yarn breakage, but the yarn breakage was observed in the inner layer.
The fibers of Examples 1 to 7 were excellent in heat fusion in the whole region of the wound body, and were good without breakage.

In the raw yarn crossing test, the yarns of Examples 1 to 4 were treated at 160, 165, 150, and 153 ° C., respectively, and 0.23, 0.19, 0.17, and 0.16 cN in this order. As in the plating method test, it was found that even if the temperature was lowered, excellent heat-sealing property was exhibited.
Moreover, even in the test results using a polyurethane elastic fiber (PU) 100% knitted fabric according to the method described in JP-A-2002-339189, results equivalent to the plating method test and the yarn crossing method test are obtained. Examples 1 to 7 exhibited excellent heat-fusibility.

* 1:
The mineral oil in Table 1 uses a liquid paraffinic mineral oil with a viscosity of 6.5 × 10 ⁻⁶ m ² / s (25 ° C.), and DMPS (dimethylpolysiloxane) has a viscosity of 7.5 × 10 ^−6. m ² / s (25 ° C.) was used. Moreover, the addition amount of monoamine is the ratio with respect to the oil component which consists of mineral oil and DMPS.
The plating method test, the raw yarn crossing method test, and the PU 100% knitted fabric test were all carried out by the methods described above.
As for the plating method test results, (1) and (2) are the results of measuring the inner layer, and (3) and (4) are the results of measuring two locations on the surface layer.

* 2:
The mineral oil in Table 3 uses a liquid paraffinic mineral oil having a viscosity of 6.5 × 10 ⁻⁶ m ² / s (25 ° C.), and DMPS (dimethylpolysiloxane) has a viscosity of 7.5 × 10 ^−6. m ² / s (25 ° C.) was used.

[Examples 8 to 12, Comparative Examples 6 to 10]
Fabrication of circular knitted fabric Using a circular knitting machine (bottle diameter: 38 inches, gauge: 28, yarn feeder: 100), 100% cotton spun yarn 60 and polyurethane elastic fiber are knitted with a plating knitting cylinder All needle knit knitting was performed with a needle to obtain a bare tengu knitted fabric. As the polyurethane elastic fiber, the surface layer and inner layer fibers of the wound body obtained in Examples 1 to 7 and Comparative Examples 1 to 5 were used.

The knitting yarn length of the cotton yarn was set to 25.6 cm, and the knitting yarn length of the polyurethane elastic fiber was set to 14.3 cm. Next, the obtained knitted fabric was dyed and processed under the following conditions.
1) As a presetting process, it was treated with dry heat for 50 seconds. The treatment temperature was the melting point of the polyurethane elastic fiber used (knitted fabric preset temperature shown in Table 3).
2) As a scouring step, the scouring agent was treated at 90 ° C. for 20 minutes using 2 mL / L and caustic soda 2.2 g / L.
3) As a bleaching step, treatment was performed at 90 ° C. for 30 minutes using 15% / L of 30% hydrogen peroxide, 5 mL / L of sodium silicate, and 1.1 g / L of sodium hydroxide.
4) As a dyeing process, 30 owf% of reactive dye, 90 g / L of anhydrous soot, and 16 g / L of soda ash were used and treated at 90 ° C. for 30 minutes.
5) As a fixing step, a fixing agent was treated at 50 ° C. for 20 minutes using 3.0 owf%.
6) As a soaping process, treatment was performed at 90 ° C. for 10 minutes using 1 mL / L of a soaping agent.
7) As a final setting step, the film was treated at a dry heat of 150 ° C. for 30 seconds.
In addition, the chemical | medical agent used at the said process is as follows.
Scouring agent: Brand name SSK-15A (Matsumoto Yushi Co., Ltd.)
Reactive dye: Product name KPZOL BLACK KMN (manufactured by Kiwa Chemical Co., Ltd.)
Fixing agent: Product name Dunfix RE (manufactured by Nittobo)
Soaping agent: Product name Scoreroll TS840 (Asahi Denka Co., Ltd.)

  For the finished knitted fabric, the evaluation of the polyurethane elastic fiber yarn breakage, the evaluation of the degree of thermal fusion, and the evaluation of damage to the washing test were carried out as follows, and the results are shown in Table 4.

Polyurethane elastic fiber yarn breakage A knitted fabric with a length of 17 cm and a width of 30 cm is placed on an illumination magnifier ENV-CL [manufactured by Otsuka Optical Co., Ltd.], and light is applied from below to investigate the presence or absence of yarn breakage. The broken parts are marked with a magic or the like and observed with a stereomicroscope SZ61 [Olympus Co., Ltd.] at a magnification of 20 times to visually evaluate the presence or absence of polyurethane breakage.
Evaluate the degree of thermal fusion Cut the knitted fabric in the course direction and manually check whether the polyurethane elastic fiber in the cut part can be knitted. For the knitted fabric, the knitting tension was measured by the same method as the plating knitted fabric method, and the difference in the degree of thermal fusion was quantitatively determined by the magnitude of the value.

Laundry test Damage evaluation After taking a knitted fabric sample of 5cm x 40cm in width and sewing it into a cylindrical shape, using a household 2-tank washing machine (trade name: GINGA4.5 manufactured by TOSHIBA Co., Ltd.) under the following conditions I did laundry.
Laundry (300 minutes) → Centrifugal dehydration (5 minutes) → Rinse water (10 minutes)
→ Centrifugal dehydration (5 minutes)
Liquid temperature: normal temperature (25 ° C), water flow: strong water flow Detergent: manufactured by Lion Co., Ltd., trade name: top, water volume: 30 liters 1.3 g of detergent used for 1 liter of washing water Load cloth: cotton and polyurethane elastic fiber For 1.0 kg of mixed bear tengu knitted fabric

Next, the degree of fraying at the edge of the knitted fabric in the course direction cut portion of the knitted fabric was observed and evaluated in the following four stages. In addition, (triangle | delta) and * are the bruises of the grade which hesitates to wear as clothing, and (double-circle) or (circle) is preferable at the point of washing durability.
<Evaluation criteria>
◎: No damage is observed ○: Slight damage is observed △: Damage is observed ×: Severe damage

  The polyurethane elastic fibers used in Examples 8 to 12 were heat-sealed so strongly that the knitted fabric could not be disassembled in the whole area of the wound body, and the curling suppression effect, fraying suppression effect, slip-in of the cut portion Prevention and misalignment suppression effects were observed. On the other hand, Comparative Examples 6 and 8 had a small effective cross-linking amount, poor heat resistance near the melting point, were broken, and no fraying suppression effect at the end of the knitted fabric was observed. Comparative Example 10 was hardly heat-sealed compared to the others, and the polyurethane at the cut part could be easily knitted. The cut part was severely damaged by washing, and the curl of the cut part was strong. In Comparative Examples 7 and 9, the surface layer was satisfactory without any yarn breakage, but the yarn breakage occurred in the inner layer, and the fraying suppression effect at the end of the knitted fabric was not recognized.

[Examples 13 and 14, Comparative Examples 11 and 12]
Creation of knitted fabric Using a Raschel knitting machine (Carl Meyer, 28 gauge), using 6 nylon nylon yarn 56 dtex 17 filament for L1 a and L3 c in FIG. 9 and polyurethane elastic fiber for L2 b And created a warp knitted fabric.
As the polyurethane elastic fibers, those having a fineness of 156 dtex of Example 1, Example 5, Comparative Example 1, and Comparative Example 5 were used, and those of the surface layer and the inner layer of the wound body were used. Next, the obtained knitted fabric was dyed and processed under the following conditions.

Dyeing process First, after scouring and relaxing in a bath of 2 g / L of an anionic surfactant under the treatment conditions of 60 ° C. for 5 minutes, using a pin tenter, dry heat for 50 seconds at a temperature shown in Table 5. The set was carried out.
Next, in a liquid dyeing machine (Circular NX), Kayanol Milling Red BW 2% owf (acid dye: manufactured by Nippon Kayaku Co., Ltd.), Newbon TS400 1% owf (level dye: manufactured by Nippon Kayaku Co., Ltd.), acetic acid 0 0.5 g / L, ammonium acetate 0.15 g / L was used, and the temperature was increased from 40 ° C. to 95 ° C. in 30 minutes and dyed at 95 ° C. for 40 minutes under the dyeing condition of bath ratio = 1: 30.
Then, it was washed with hot water twice at 50 ° C. × 10 minutes, Sunlife TN-8 3 g / L (synthetic fixing agent: manufactured by Nikka Chemical Co., Ltd.), oxalic acid 1 g / L, and fixed at 70 ° C. × 20 minutes, Final setting was performed at 170 ° C. for 40 to 50 seconds using a pin tenter.

  For the knitted fabric after dyeing processing, the evaluation of the polyurethane elastic fiber yarn breakage and the evaluation of the degree of thermal fusion were performed as follows, and the results are shown in Table 5. In addition, the polyurethane elastic fiber yarn breakage described below and the evaluation of the degree of thermal fusion were also applied to the evaluation of Example 15 and Comparative Example 13 and later.

Evaluation of Polyurethane Elastic Fiber Thread Breakage Similar to the plating knitted fabric method, after removing nylon by immersing a knitted fabric of 17 cm in length and 30 cm in width into 200 mL of 20% aqueous hydrochloric acid, a sample of the remaining polyurethane elastic fiber is used. By visual observation, if no yarn breakage of the polyurethane elastic fiber is observed on the knitted fabric, “No yarn breakage” is indicated. If yarn breakage is found, the situation is recorded.
Evaluation of degree of thermal fusion The resistance of the degree of thermal fusion was evaluated by measuring the pulling resistance value.
Specifically, a test piece having a weft direction (width) of 25 mm and a warp direction (length) of 100 mm was taken from the knitted fabric as shown in FIG. At this time, a total of 10 test pieces were sampled in each of 5 pieces so that the drawing direction of the polyurethane elastic fiber was the knitting start and knitting end direction.
Subsequently, the test piece was cut off at a position 40 mm (BB ′) from the lower end (DD ′) of the test piece, leaving one polyurethane elastic fiber 1 inserted in the warp direction. Next, the remaining polyurethane elastic fiber was taken out from the test piece for 5 mm (EF) toward the upper grip 2. Further, a cut 3 having a width of 3 mm was made in the weft direction on the extension line of the polyurethane elastic fiber and at a position 30 mm from the upper end of the test piece.
When measuring the pull-out resistance value with a tensile tester, adjust the gripping interval of the tensile tester to 40 mm, and then grasp the upper part of the test piece with the upper gripping margin of 25 mm (above AA ′) of the test piece. Apply an initial load of 0.1 cN to the polyurethane elastic fiber, grasp the polyurethane elastic fiber at a lower grip margin of 35 mm (below CC ′), pull it at a pulling speed of 100 mm / min, until the polyurethane elastic fiber is pulled out The maximum pull-out load was measured. This was carried out 5 times each in the knitting start and knitting end directions, a total of 10 times, and the average value was calculated to obtain the pulling resistance value.

  From the results of Example 13, when the yarn of Example 1 is used, it is difficult to draw by heat fusion. From the results of Example 14, when the yarn of Example 5 is used, the yarn of Comparative Example 5 is obtained by heat fusion. It can be seen that the pull-out resistance value is remarkably improved as compared with FIG. As shown in Comparative Example 11, the yarn of Comparative Example 1 was a knitted fabric that was substantially unusable because it was broken in the knitted fabric regardless of the heat-fusibility. Excluding Comparative Examples 11 and 12, the knitted fabric was less prone to curl, misalignment, and softness.

[Example 15]
Test A
The same knitting machine as in Example 13 is used, 6-nylon filament yarn 56 dtex 17 filament is used for L1 a in FIG. 3, and 156 dtex polyurethane elastic fiber obtained in Examples 1 and 5 is used for L2 b. Thus, a warp knitted fabric was prepared, and the same test as in Example 13 was performed. The results are shown in Table 6.
The 156 dtex polyurethane elastic fiber had the same effective cross-linking degree, melting point, heat resistance, and heat fusion strength as the 44 dtex polyurethane elastic fiber of Examples 1 and 5.

Test B
A warp knitted fabric was prepared using the same knitting machine as in Example 13, using 56 dtex 72 filament polyester yarn for L1a in FIG. 3 and 156 dtex polyurethane elastic fiber of Example 5 for L2b. . In order to increase the elongation of the knitted fabric, the amount of polyester yarn was increased to roughen the knitted fabric. Subsequently, after heat setting at 195 ° C. for 90 seconds, dyeing was carried out in the same manner as in Example 13. Table 7 shows the yarn length of the finished polyester yarn. Further, the constant load elongation and stretch fatigue properties were evaluated by the following methods. The results are also shown in Table 7.

<22N constant load elongation>
A rectangular test piece having a polyurethane elastic fiber in a direction of 16.0 cm and a perpendicular direction of 2.5 cm was collected. Next, it is attached to a tensile tester with an upper grip of 2.5 cm, a lower grip of 3.5 cm, and a grasping length of 10.0 cm, stretched at a speed of 300 mm / min, and measured for elongations of loads 9.8N, 14.7N, and 22N. To do. The average value of two samples is adopted as data.
<Elastic fatigue test>
A rectangular test piece having a polyurethane elastic fiber in the direction of 17.0 cm and a perpendicular direction of 9.0 cm was collected. The test elongation was determined based on the results in the 22N constant load elongation test. When the elongation of 14.7N was less than 100%, the elongation was 14.7N. When the 14.7N elongation was 100% or more, a value obtained by dividing the value obtained by adding the 9.8N elongation and the 14.7N elongation by 2 was defined as the test elongation. However, 150% is the upper limit.
As the stretch fatigue property, the test piece was set on the gripper with a tensile interval (holding length) of 7.0 cm of a stretch fatigue tester. With the set elongation, horizontal movement was reciprocated 7500 times at a rotation speed of 200 times / min, and the expansion and contraction was repeated.
The determination was made based on whether or not the polyurethane elastic fiber was broken.

[Comparative Example 13]
Test A
The same test as in Example 15 was performed except that the 156 dtex polyurethane elastic fiber obtained in Comparative Examples 1 and 5 was used. The results are shown in Table 6.
The 156 dtex polyurethane elastic fiber had an effective cross-linking degree, a melting point, heat resistance, and heat fusion strength equivalent to the 44 dtex polyurethane elastic fiber of Comparative Examples 1 and 5.

Test B
A test similar to that of Example 15 was performed except that the normal dry polyurethane elastic fiber obtained in Comparative Example 5 was used instead of the polyurethane elastic fiber of Example 5. The results are shown in Table 7.
A processed warp knitted fabric similar to Comparative Example 5 was obtained except that the finished polyester yarn had a yarn length of 25.6 cm / 50 course. The results are shown in Table 7.

[Example 16]
Using a knitting machine similar to that of Example 13, using 6-nylon filament yarn 56 dtex 17 filaments for L1 and L2 in FIG. 4 and polyurethane elastic fiber of Example 15 for b of L3 and L4 A knitted fabric was prepared, and the same test as in Example 15 Test A was performed. The results are shown in Table 8.

[Comparative Example 14]
A warp knitted fabric was prepared in the same manner as in Example 16 except that the elastic fiber of Comparative Example 13 was used for L3 and L4 in FIG. The results are shown in Table 8.

  As shown in the results of Example 16, when the yarn of Example 1 is used, it is difficult to pull out by thermal fusion, and when the yarn of Example 5 is used, it is more resistant to drawing than the yarn of Comparative Example 5 by thermal fusion. The value has improved dramatically. The knitted fabrics using the yarns of Examples 1 and 5 were knitted fabrics that hardly cause curling, misalignment, and softness due to heat fusion.

[Example 17]
Create the knitted fabric by the following method, and after heat setting and dyeing process, measure the knitting tension of the knitted fabric, confirm the fusion of polyurethane elastic fibers, and check the knitted fabric by washing test (washing durability) ) Was visually evaluated. The results are shown in Table 9.

Creation of knitted fabric A raschel knitting machine (28 gauge, manufactured by Karl Mayer) was used to create a knitted fabric having the organization chart shown in FIG. In FIG. 5, 6-nylon filament yarn 56 dtex 17 filament is used for L1a, elastic fiber of Example 1 or 5 is used for c of L2, and polyurethane elastic fiber of Example 1 or 5 is used for C of L3. A warp knitted fabric was knitted to make the main knitted fabric. Further, a warp knitted fabric was prepared using nylon filament yarn 110 dtex 24 filaments as a cut yarn between the main knitted fabrics.

As the processing temperature of the heat setting and dyeing processing heat setting, the processing was performed for 50 seconds at the same temperature as the melting point of the polyurethane elastic fiber of Example 1. Others were processed in the same manner as in Example 13.
Measurement of knitting tension The knitting tension of the nylon thread was measured. The knitting speed was 100 mm / min, the knitting tension for 1 minute was measured, and the average value at five peak points was calculated.
Confirmation of Fusion Situation The nylon yarn of the main knitted fabric was dissolved in 20% dilute hydrochloric acid, and the fusion situation of the contact portion between the polyurethane elastic fibers was observed.
Preparation of a sample for evaluation of damage to a knitted fabric A strip-shaped sample having a length of 3.3 cm and a width of 24.0 cm is cut out with respect to the knitting direction of the heat-set knitted fabric, and 40 degrees in the knitting direction is cut from the cut surface in the horizontal direction. A cut was made at an angle, divided into a “knitting start side” and a “knitting end side”, and the cut portions in the vertical direction were combined and sewn with an overlock sewing machine to create an annular sample.

[Comparative Example 15]
The elastic fiber of Comparative Example 1 or 5 was used for c of L2 and L3 in FIG. 5, and the treatment temperature of the heat set was treated for 50 seconds at the same temperature as the melting point of the polyurethane elastic fiber. The other tests were the same as in Example 17. The results are shown in Table 9.

  In the structure of FIG. 5, it is not possible to measure the heat-bonding force of the polyurethane elastic fiber by deknitting, but in Example 17, in the knitted fabric using the polyurethane elastic fiber of Examples 1 and 5, the polyurethane elastic fiber mutual Was heat-sealed so strongly that it could not be peeled off, and the degree of damage to the knitted fabric by washing was also good. On the other hand, as shown in the results of Comparative Example 15, when the polyurethane elastic fiber of Comparative Example 1 was used, yarn breakage occurred everywhere in the knitted fabric. When the yarn of Comparative Example 5 was used, there was no yarn breakage, but the contact portions between the polyurethane elastic fibers could be easily peeled off, and the knitted fabric was severely damaged by washing.

[Example 18]
The same knitting machine as in Example 17 was used, and 6-nylon filament yarn 56 dtex 17 filament was applied to L1a in FIG. 6, polyurethane elastic fiber of Example 1 or 5 was applied to L2c, and L3c was applied to L3c. A warp knitted fabric was prepared using the polyurethane elastic fiber of Example 1 or 5, and the same test as in Example 17 was performed. The results are shown in Table 10.

[Comparative Example 16]
A warp knitted fabric was prepared in the same manner as in Example 18 except that the elastic fiber of Comparative Example 1 or 5 was used for c of L2 and L3 in FIG. 6, and the same test as in Comparative Example 15 was performed. The results are shown in Table 10.

  In the structure of FIG. 6, the polyurethane elastic fiber cannot measure the heat-bonding force due to the deknitting, but in the knitted fabric using the polyurethane elastic fiber of Examples 1 and 5 (Example 18), Was heat-sealed so strongly that it could not be peeled off, and the degree of damage to the knitted fabric by washing was also good. On the other hand, when the polyurethane elastic fiber of Comparative Example 1 was used, yarn breakage occurred throughout the polyurethane elastic fiber in the knitted fabric. The yarn of Comparative Example 5 was not broken, but the contact portions between the polyurethane elastic fibers could be easily peeled off, and the knitted fabric was severely damaged by washing (Comparative Example 16).

[Example 19]
The same knitting machine as in Example 17 was used, and 6-nylon filament yarn 56 dtex 17 filament was used for L1a in FIG. 7, and polyurethane elastic fiber of Example 2 was used for L2b. A warp knitted fabric was prepared by using the above method without using a thread, and the same test as in Example 17 was performed. The results are shown in Table 11.

[Comparative Example 17]
A warp knitted fabric was prepared in the same manner as in Example 19 except that the elastic fiber of Comparative Example 2 was used for b of L2 in FIG. 7, and the same test as in Comparative Example 15 was performed. The results are shown in Table 11.

  In the structure of FIG. 7, the polyurethane elastic fiber forms a closing line, and the heat-bonding force due to the knitting cannot be measured. However, in the knitted fabric using the polyurethane elastic fiber of Example 2, polyurethane elastic fibers Was heat-sealed so strongly that it could not be peeled off, and the knitted fabric was damaged well by washing (Example 19). On the other hand, in the knitted fabric using the polyurethane elastic fiber of Comparative Example 2, the result using the surface layer of the wound body was equivalent to the result of the polyurethane elastic fiber of Example 2, but in the inner layer part, Among them, yarn breakage occurred everywhere in the polyurethane elastic fiber (Comparative Example 17).

[Example 20]
The same knitting machine as in Example 17 was used, 6-nylon filament yarn 56 dtex 17 filament was used for L1a in FIG. 8, and polyurethane elastic fiber of Example 3 was used for L2b. A warp knitted fabric was prepared by using the above method without using a thread, and the same test as in Example 17 was performed. The results are shown in Table 12.

[Comparative Example 18]
A warp knitted fabric was prepared in the same manner as in Example 20 except that the elastic fiber of Comparative Example 3 was used for L2b in FIG. 8, and the same test as in Comparative Example 15 was performed. The results are shown in Table 12.

  In the structure of FIG. 8, the polyurethane elastic fiber forms a closed line, and it is not possible to measure the heat-sealing force by deknitting, but in the knitted fabric using the polyurethane elastic fiber of Example 3 (Example 20) The polyurethane elastic fibers were strongly heat-sealed to such an extent that they could not be peeled from each other, and the knitted fabric was damaged well by washing. On the other hand, in the knitted fabric using the polyurethane elastic fiber of Comparative Example 3 (Comparative Example 18), the portion where the polyurethane elastic fibers were in contact with each other was easily peeled off, and the damage caused by washing was severe.

It is an example of the organization chart of a knitted fabric. It is another example of the organization chart of a knitted fabric. It is an example of the organization chart of a warp knitted fabric. It is another example of the organization chart of a warp knitted fabric. It is another example of the organization chart of a warp knitted fabric. It is another example of the organization chart of a warp knitted fabric. It is another example of the organization chart of a warp knitted fabric. It is another example of the organization chart of a warp knitted fabric. It is another example of the organization chart of a warp knitted fabric. It is a test piece for a tensile test of a warp knitted fabric. It is an example of a raw yarn crossing method test method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Polyurethane elastic fiber 2 Upper part grip 3 Notch 4 Lower part grip 11 Polyurethane yarn 12 Polyurethane yarn

Claims (16)

This is a heat-fusible polyurethane elastic fiber having a melting point of 165 to 200 ° C. measured by the flow temperature method and a thermal fusing force of 0.15 cN / dtex or more when heat-treated in the above temperature range in the plating knitted fabric method. And
The heat-fusible polyurethane elastic fiber is obtained by melt-spinning a polymer obtained from polyol, diisocyanate and low molecular weight diol, and comprises an oil component comprising mineral oil and silicone oil, n-propylamine, n-butylamine, di-n A heat characterized by adhering or containing a base oil containing a monoamine selected from butylamine, iso-butylamine, di-iso-butylamine, 2-ethylhexylamine, monobenzylamine, distearylamine and laurylamine Fusing polyurethane elastic fiber.   2. The heat-fusible polyurethane elastic fiber according to claim 1, wherein a residual strain immediately after stretching by 300% is 40% or less.   The heat-fusible polyurethane elastic fiber according to claim 1 or 2, comprising 1 to 10% by mass of a base oil containing 25 to 75% by mass of mineral oil and 75 to 25% by mass of silicone oil.   (I) A polymer obtained by reacting a both-terminal isocyanate prepolymer obtained by reacting a polyol and a diisocyanate; and (II) A polymer obtained by reacting a hydroxyl-terminated prepolymer obtained by reacting a polyol, a diisocyanate and a low molecular weight diol. 4. A base oil agent comprising 25 to 75% by mass of a mineral oil and 75 to 25% by mass of a silicone oil is attached or contained by melt spinning. Heat-sealable polyurethane elastic fiber.   The residual isocyanate group in the polyurethane elastic fiber is reacted with the monoamine to consume 0.5 to 15 equivalent% of the residual isocyanate group. Heat-sealable polyurethane elastic fiber. 6. The heat-fusible polyurethane elasticity according to claim 4, wherein an effective crosslinking amount in the polyurethane elastic fiber is 0.05 × 10 ⁻⁵ mol / g or more and less than 10 × 10 ⁻⁵ mol / g. fiber. This is a heat-fusible polyurethane elastic fiber having a melting point of 165 to 200 ° C. measured by the flow temperature method and a thermal fusing force of 0.15 cN / dtex or more when heat-treated in the above temperature range in the plating knitted fabric method. And
The heat-fusible polyurethane elastic fiber comprises a polyol, a diisocyanate, a low molecular weight diamine and / or a low molecular weight diol, a polyacrylate ester, a polyvinylpyrrolidone copolymer, a polyurethane polymer, a polyester, a polyester ether, and an epoxy resin. A heat-sealable polyurethane elastic fiber obtained by dry spinning a spinning solution containing a selected compound.   8. The heat-fusible polyurethane elastic fiber according to claim 7, wherein the residual strain immediately after stretching by 300% is 40% or less.   The heat-fusible polyurethane elastic fiber according to claim 7 or 8, comprising 1 to 10% by mass of a base oil containing 25 to 75% by mass of mineral oil and 75 to 25% by mass of silicone oil.   A heat-fusible polyurethane elastic fiber comprises a polyurethane polymer solution obtained by reacting an isocyanate-terminated intermediate polymer obtained from polyol and diisocyanate with a low molecular weight diamine and / or low molecular weight diol in an organic solvent, The mass ratio of the polyurethane polymer to the compound is 40:60 to 80:20 with respect to the compound selected from acrylic acid ester, polyvinylpyrrolidone copolymer, polyurethane polymer, polyester, polyester ether and epoxy resin. 8. A spinning solution prepared by mixing with a base oil is dry-spun, and a base oil containing an oil component consisting of 25 to 75% by mass of mineral oil and 75 to 25% by mass of silicone oil is adhered or contained. The heat-fusible polyurethane elastic fiber of any one of thru | or 9.   The total polyol constituting the heat-fusible polyurethane elastic fiber contains 70 mol% or more of polyether diol having a number average molecular weight of 600 to 3500, and the proportion of urethane bonds in the total of urethane bonds and urea bonds. It is 60-95 mol%, The heat-fusible polyurethane elastic fiber of Claim 10 characterized by the above-mentioned. (1) A step of reacting a polyol and a diisocyanate to synthesize both terminal isocyanate group prepolymers,
(2) a step of synthesizing a hydroxyl-terminated prepolymer at both ends by reacting a polyol, diisocyanate and a low molecular weight diol;
(3) a step of synthesizing a spinning polymer by reacting both terminal isocyanate group prepolymers and both terminal hydroxyl group prepolymers;
(4) a step of melt-spinning a spinning polymer, and (5) an oil component comprising 25 to 75% by mass of mineral oil and 75 to 25% by mass of silicone oil, and n-propylamine, n- Including a step of providing a base oil agent comprising a monoamine selected from butylamine, di-n-butylamine, iso-butylamine, di-iso-butylamine, 2-ethylhexylamine, monobenzylamine, distearylamine and laurylamine. A method for producing a heat-fusible polyurethane elastic fiber. (1) a step of reacting a polyol having a number average molecular weight of 600 to 3500 with a diisocyanate to synthesize an isocyanate-terminated intermediate polymer at both ends,
(2) a step of obtaining a polyurethane polymer solution by reacting the intermediate polymer with a low molecular weight diamine and / or a low molecular weight diol in an organic solvent;
(3) The polyurethane polymer solution and a compound selected from polyacrylic acid ester, polyvinyl pyrrolidone copolymer, polyurethane polymer, polyester, polyester ether and epoxy resin having a mass ratio of the polyurethane polymer and the compound of 40: Mixing to be 60 to 80:20,
(4) a step of dry-spinning a solution containing a polyurethane polymer and the above compound, and (5) a base containing an oil component of 25 to 75% by mass of mineral oil and 75 to 25% by mass of silicone oil in the spun polyurethane elastic fiber. The manufacturing method of the heat-fusible polyurethane elastic fiber characterized by including the process of providing an oil agent.   A polyurethane elastic fiber mixed woven or knitted fabric obtained by weaving and knitting the heat-fusible polyurethane elastic fiber according to any one of claims 1 to 11.   A heat-sealable polyurethane elastic fiber according to any one of claims 1 to 11 and at least one non-elastic yarn, and heat-sealable polyurethane elastic fiber and / or this by heat or wet heat setting. The polyurethane elastic fiber-mixed woven or knitted fabric according to claim 14, wherein a crossing portion between the elastic yarn and the inelastic yarn is heat-sealed.   Briefs, panties, shorts, undershirt, camisole, girdle, bra, spats, bodysuit, sanitary shorts, swimwear, leotard, resort wear, homewear, underwear, sports tights, shirt, outerwear, gloves, socks , Arm cover, medical clothing, surgical clothing, cleanroom work clothing, dustproof clothing, supporters, eye masks, disposable diapers, incontinence pads, gauze, bandages, packaging materials, packaging materials, masks, sheets, towels, handkerchiefs, clothing The polyurethane elastic fiber mixed woven or knitted fabric according to claim 14 or 15, which is an interlining, a filter for microfiltration, an industrial wiper, or a protective cover.