JP3752250B2 - High specific gravity / high strength composite fiber - Google Patents

Description

  The present invention relates to a composite fiber suitable for industrial material applications having both high specific gravity and high strength, and more particularly, to a composite fiber suitable for fish nets having excellent durability and no problem of marine environment contamination.

  Traditionally, fishery materials used in fishnets have been focused on the high sedimentation rate of fishnets in seawater and the shape retention of tidal currents. It is known that a fish net with a small complementary angle and good shape retention can be obtained. In particular, in the stationary net, the shape of the fish net in the sea with respect to the school of fish greatly influences the catch, so that a fiber having a large specific gravity, good drainage, and good wear resistance has been required. Moreover, the hue of the fiber required a black color tone that does not give a sense of vigilance to the fish and does not give a sense of incongruity.

  From this point of view, vinylidene chloride fibers having a relatively large specific gravity have been widely used in the past. However, high-strength fibers that can be stably used for high-speed netting with the development of netting technology have been used. There has been a problem of insufficient strength in vinylidene chloride fibers. In addition, when a pigment is added to color the fiber, there is a problem that the strength of the fiber further decreases.

  In order to solve such problems, development of fishery material fibers having both high specific gravity and high strength has been carried out, and various types have been proposed. As one of the means, fibers of a combination of a resin that develops high strength by a stretching treatment and a high specific gravity powder are considered. Specifically, (1) a fiber in which a high specific gravity powder is uniformly dispersed in a resin. (For example, Japanese Patent Publication No. 51-37378, Japanese Unexamined Patent Publication No. 56-61936, Japanese Unexamined Patent Publication No. 61-613), (2) A high specific gravity powder is mixed and dispersed in a low softening point resin. Further, a fiber mixed with a resin for imparting strength (Japanese Patent Publication No. 57-20407) and (3) a mixture of a low softening point resin and a high specific gravity powder is used as a core layer, and a resin imparting strength is used as a sheath layer. Core-type fibers (Japanese Patent Laid-Open Nos. 58-4819 and 62-15327) have been proposed.

However, even with the above, the present situation is that the high sedimentation speed and high speed netting required for fishnet fibers have not been sufficiently satisfied. In addition, depending on the type of high specific gravity powder used, the weather resistance is insufficient, and the resin constituting the fiber is deteriorated by being irradiated with sunlight for a long time, resulting in a significant decrease in strength, and as a fish net There was a problem that it became impossible to use. In addition, when metallic lead or its compound is used as high specific gravity powder, lead compound or the like may fall out of the fiber due to friction with the guide in the fiber manufacturing process or processing process, or it may elute into seawater during use as a fish net and lead Pollution problems could occur. Further, when discarding used fishnets, there is a possibility that similar pollution problems may occur, such as lead-containing harmful components remaining after disposal and incineration, which makes it difficult to dispose of them. In addition, fishing nets made of vinylidene chloride fibers that do not contain lead also have a problem that incineration is difficult because hydrogen chloride gas is generated during incineration.
JP 58-4819 A Japanese Patent Laid-Open No. 62-15327

  An object of the present invention is to provide a fiber having excellent weather resistance that has high sedimentation speed and sufficient fiber strength that does not cause a problem in net making, and does not cause a decrease in strength even when used as a fish net for a long period of time. is there. Furthermore, it is providing the fiber which has the color tone which does not feel uncomfortable with respect to a fish, satisfy | filling this characteristic.

  That is, the present invention comprises a core polymer component containing 50 to 85% by weight of fine particles of iron oxide and titanium dioxide, and a protective polymer component that covers the core polymer component and to which a colorant is added. A composite fiber having a specific gravity of 1.5 or more and a strength of 3.5 g / d or more.

  The fiber of the present invention has a specific gravity of 1.5 or more and a strength of 3.5 g / d. When the specific gravity is less than 1.5, high sedimentation in seawater and shape retention of fishing nets are achieved. If it is difficult to achieve and the strength is less than 3.5 g / d, the fiber is damaged during high-speed netting, which is not preferable. From such a viewpoint, it is desirable that the fiber has a specific gravity of 1.55 or more and a strength of 4.0 g / d or more. In the present invention, it is essential to contain the fine particles having a specific gravity of 3 or more in order to increase the specific gravity of the fiber. Examples of the fine particles include iron oxide and titanium dioxide.

  If fine particles with a specific gravity of less than 3 are used, the content of fine particles in the fiber must be increased and the composite ratio of the core polymer component must be increased in order to achieve the desired fiber specific gravity. Even if a fiber having a specific gravity is obtained, the processability such as spinnability and stretchability is poor, and only low fiber strength is obtained, so that it is unsuitable for use as a fishing net.

  The content of fine particles in the core polymer component must be 50 to 85% by weight. If it is less than 50% by weight, in order to obtain the desired fiber specific gravity, the composite ratio of the core polymer component (B) must be increased, and only a fiber having a low fiber strength can be obtained. On the other hand, when it exceeds 85% by weight, the polymer melt fluidity at the time of spinning is deteriorated, and yarn breakage frequently occurs.

  Next, it is desirable that the average particle size of the primary particles is 5 μm or less. If it is 5 μm or more, yarn breakage and fluff are likely to occur during spinning and drawing, which is not preferable. Moreover, it is preferable that the average particle diameter of a primary particle is 0.05 micrometer or more. If the particle size is too small, on the contrary, when adding fine particles into the polymer, heat agglomeration occurs due to heat during the molding process, resulting in coarse particles, or when a high addition polymer is melt-extruded during spinning, the polymer melt line This is not preferable because thermal aggregation of fine particles is likely to occur in the pipes and troubles such as clogging of the line frequently occur.

  About the kind of microparticles | fine-particles to be used, in this invention, it is especially meaningful to use iron oxide or titanium dioxide.

First, the case where iron oxide is used will be described. Iron oxide includes black magnetite, ie magnetite (Fe ₃ O ₄ ), brown γ-form hematite, red-brown α-form hematite, etc. In fishing net fibers such as stationary nets, the hue is black. Then, since it does not give a sense of vigilance to the fish, it is possible to give a good result to the catch, and it is preferable to use magnetite that exhibits black color. At this time, it is desirable that 20% by weight or more of the total fine particles used is magnetite. By using magnetite, the dyeing process and the like can be simplified or omitted, but even in such a case, it is possible to use an original polymer as the protective polymer component.

  The magnetite particle shape includes spherical, octahedral, hexahedral, and polyhedral shapes, and any shape can be used. However, the use of spherical magnetite fine particles provides the best dispersibility in the core polymer component. preferable. In particular, the use of the spherical particles has a remarkable effect when the fine particles are added to the polymer at a high addition rate of several tens% as in the present invention. When such particles are used, The occurrence of filter clogging is small, and the occurrence of yarn breakage during spinning and drawing is also small.

  Furthermore, it is preferable to use fine particles subjected to surface coating treatment with an organic or inorganic compound as the magnetite fine particles because the heat resistance and fine particle dispersibility can be further improved. In particular, it is preferable to use magnetite coated with silica or ferrite coated magnetite on the surface of fine particles.

  When the content of the magnetite fine particles in the core polymer component is 50% by weight or more, the fine particles to be blended in the core polymer component can be used at the time of melt extrusion as described above even if the appropriate particle shape and particle size are used. Contamination due to thermal agglomeration in the line, and troubles such as clogging of piping may occur in severe cases. To make the content of fine particles in the core polymer component 50% by weight or more, magnetite and other Use in combination with fine particles.

  In particular, when a fine denier yarn is produced, the residence time of the molten polymer in the line becomes long, and troubles of line clogging occur remarkably. As other fine particles used in combination with magnetite, it is necessary to select a fine particle having a specific gravity of 3 or more, an average particle diameter of 5 μm or less, less thermal aggregation and less expensive. A preferred example is titanium dioxide.

  Heavy metal-based inorganic substances such as lead compounds such as red lead and tin compounds such as tin oxide are suitable for the specific gravity of the particles, but are not preferable in terms of toxicity. In particular, when it is used up, it is difficult to dispose of fishing nets. In some cases, secondary pollution such as environmental pollution may occur. In addition, tungsten-based inorganic particles and bismuth-based inorganic particles are high specific gravity particles, and are desirable inorganic particles to express target performance, but are very expensive and should be used for fishing net applications. Is difficult.

  In the present invention, titanium dioxide is most preferable among inorganic particles that can be used in combination with magnetite fine particles. The total content of the fine particles with respect to the core polymer component is in the range of 50% to 85% by weight. Even if the mixing ratio of titanium dioxide with magnetite is arbitrarily changed, the spinnability and stretchability are good and no major trouble occurs. The target fiber can be obtained. Examples of suitable mixing ratios include, for example, when the total fine particle content in the core polymer component is 70% by weight, magnetite is 30% by weight, titanium dioxide is If the total fine particle content in the core polymer component is 60% by weight, the mixture ratio of magnetite is 30% by weight, titanium dioxide is 30% by weight, etc. Is also preferable. A preferable range of the mixing ratio of magnetite and titanium dioxide is magnetite / titanium dioxide = 2/8 to 7/3.

  When the content of fine particles in the polymer is as high as 50% by weight or more, and when magnetite is added at a high level, troubles such as line clogging at the time of melt extrusion can be caused by mixing and adding titanium dioxide particles. In addition, the present inventors have found for the first time among various studies that the desired fiber can be obtained in a state where the dispersibility in the polymer is good, the yarn breakage during the process is small, and the A rating is high. It has been issued.

  Next, the case where titanium dioxide is used will be described. The object of the present invention is to provide a net for a net having both excellent mechanical properties and high specific gravity, and at the same time to provide a net for a fishing net that can cope with various hues. When the colored particles are blended at a high addition rate, the hue cannot be freely changed, but titanium dioxide is white, and such white particles are added to the core polymer component, and the protective polymer component By blending a pigment or the like of a desired color, the target color can be expressed without being disturbed by the color of the core component.

  Titanium dioxide has three forms of anatase, rutile, and brookite depending on the crystal form. Anatase and rutile are generally used as pigments. In particular, anatase type is mainly used for chemical fibers because of the relationship between hardness on the wear resistance of titanium dioxide in the process and the problem of dispersibility in solvents or dispersion media, but the specific gravity of anatase type is 3.9. On the other hand, since the specific gravity of rutile type is as large as 4.2, rutile type titanium dioxide is preferably used for the purpose of the present invention.

  In this case, the Mohs hardness is larger in the rutile type than in the anatase type, and there is a concern that troubles such as wear in the process may occur. However, in the composite fiber of the present invention, the core polymer component containing fine particles is substantially a protective polymer component. Therefore, there are no problems such as wear of the nozzle cap during spinning and wear damage of the guides and rollers during the machining process.

  Furthermore, when compared with other fine particles, titanium dioxide is added to the polymer at a high rate, and when the polymer is melt extruded, thermal aggregation is less likely to occur and clogging due to contamination in the molten polymer line is less likely to occur. Therefore, it is preferable to use titanium dioxide rather than using other white fine particles.

  Titanium dioxide may be used alone or may be partially replaced with other white fine particles having a specific gravity of 3 or more and an average particle size of 5 μm or less. However, since there is a problem of thermal aggregation as described above, it is desired to use titanium dioxide at least 15% by weight, particularly preferably 40% by weight. As other white fine particles, for example, zinc oxide, alumina, barium sulfate, lithopone, magnesium oxide and the like which are less toxic than tin oxide (tin stone) can be used.

  Next, a base polymer of a core polymer component to which fine particles are added, a thermoplastic polymer exhibiting heat resistance at the spinning temperature of the protective polymer component is used. For example, nylon 6, nylon 66, nylon 610, nylon 12, nylon 11 , Polyamides such as nylon 4, nylon 46, polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate, polyolefins such as polyethylene and polypropylene, hydrogen of SBS (polystyrene-polybutadiene-polystyrene block copolymer) Additive, hydrogenated product of SIS (polystyrene-polyisoprene-polystyrene block copolymer), hydrogenated product of SI (polystyrene-polyisoprene block copolymer), poly α-methyl Styrene - polyisoprene - can be appropriately selected from poly α- methyl styrene block copolymer aromatic vinyl block and a conjugated diene block copolymers and hydrogenated products of such.

  In particular, when a high amount of fine particles is added as in the present invention, use is made of a base polymer having the best spinnability and stretchability with good wettability between the fine particles and the polymer and dispersibility of the particles in the polymer. From this point of view, it is desirable to use polyamides, particularly polyamides based on nylon 6 in the present invention.

  The degree of polymerization of the nylon 6 base polymer used as a suitable example is about 22,000 or less, more preferably 20,000 or less, 6,000 or more in terms of number average molecular weight. If the degree of polymerization is too high, the melt viscosity at the time of preparation of the kneaded polymer when the fine particles are added at a high level becomes too high, and troubles and poor dispersion are likely to occur. In addition, when melt-extruding and fiberizing a polymer to which a high amount of inorganic particles are actually added, if the melt viscosity is too high, troubles on equipment are likely to occur frequently, and at the same time, many yarn breaks occur, which is not preferable. On the other hand, if the degree of polymerization is too low, the melt viscosity becomes too low with respect to the protective polymer component, making it difficult to form the core-sheath cross section. In addition, when polyamide is used as the core polymer component, it is necessary that the water content is 500 ppm or less, preferably 300 ppm or less, as the core component containing inorganic fine particles. This is because when a large amount of fine particles are contained in a water-absorbing polymer such as polyamide, if the moisture content is high, the fluidity is extremely lowered at the time of melting, and the process condition is seriously impaired. In general, a polyamide that does not contain a large amount of fine particles is used at about 500 to 1000 ppm, whereas in the present invention that a large amount is contained, it is a point that must be particularly considered. Further, the polyamides as the core polymer component may be copolymerized with a small amount of the third component, or may contain a small amount of additives, stabilizers and the like.

  The main purpose of use of the fiber of the present invention is for fishing nets, but since the fishing nets are used outdoors, the weather resistance over time is important. Things that cause problems cannot be used. When using a polyamide with a large amount of fine particles as described above, fiber strength may decrease when used for a long time as a fishing net, but in the present invention, the polyamide as a base polymer, Addition of 0.01 wt% or more, especially 0.1 wt% or more and 2 wt% or less of copper salt such as copper iodide as a heat stabilizer improves fiber strength over time to a level where it does not become a practical problem. Is done. Furthermore, when titanium dioxide is used as the fine particles, it is preferable to add an antioxidant or the like because deterioration of the polymer is easily promoted by excitation of titanium atoms by ultraviolet rays.

  Various methods can be used as a method for causing the base polymer, which is the core polymer component, to contain fine particles. For example, a twin-screw extruder is suitable. When the base polymer and the fine particles are kneaded, it is preferable to add various dispersants such as a stearic acid metal salt, a silane coupling agent, and a titanium coupling agent because dispersibility is improved.

  The composite fiber of the present invention can be obtained by composite spinning using the core polymer component containing fine particles as described above as one component and the protective polymer component that is a fiber-forming thermoplastic polymer as another component. As the composite cross-sectional shape, it is desirable that the protective polymer component occupies 60% or more, preferably 80% or more, particularly preferably 100% of the fiber surface circumference. Specific examples of the composite form of the core polymer component and the protective polymer component include various types, and typical examples include those shown in FIGS. 1 (1) to (8).

  In FIG. 1, (1) is a single core, (2) is a three-core, (3) is a four-core core-sheath fiber, (4) is a three-layer concentric circle, (5) and (6) are partially exposed types (7) and (8) are split type composite structures. Depending on the combination of the core polymer component and the protective polymer component, the structure of (7) and (8) may be peeled off at the interface between the two components, and the structure of (5) and (6) is a guide or roller. It is not possible to sufficiently eliminate such friction. The core polymer as in (1) to (4) seems to be completely covered with the protective polymer from the point that it can further prevent friction and thread breakage of guides, rollers, etc. and prevent peeling between polymers. A core-sheath structure is preferred. In these figures, the hatched portion is the core polymer component, and the portion without the hatched portion is the protective polymer component.

  The composite weight ratio of the protective polymer component and the core polymer component is 30:70 to 80:20, more preferably 50:50 to 80:20. If the ratio of the protective polymer component is too small, the fiber strength decreases, which is not preferable. Moreover, when there are too many ratios of a protective polymer component, since the effect of making fiber specific gravity high cannot fully be exhibited, it is unpreferable.

  The protective polymer component of the present invention is not particularly limited as long as it is a thermoplastic polymer having fiber forming ability, but is not particularly limited, but in terms of practical performance as a fiber, polyethylene terephthalate and polybutylene terephthalate are the main components. A polyester-based polymer is preferred. Moreover, what copolymerized a small amount of 3rd components in these polymers can also be used. For example, as polyester, terephthalic acid, isophthalic acid, naphthalene-2,5-dicarboxylic acid, α, β- (4-carboxyphenoxy) ethane, 4,4′-dicarboxydiphenyl, alkylene oxide adduct of bisphenol A, adipic acid , Azelaic acid, sebacic acid, trimellitic acid, ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, pentaerythritol, cyclohexane-1,4-dimethanol, polyethylene Fiber-forming properties synthesized from aromatic, aliphatic, and alicyclic dicarboxylic acids such as glycol, polytetramethylene glycol, and sodium salt of 5-sulfoisophthalic acid, and oxycarboxylic acids such as diol and hydroxybenzoic acid A polyester-based polymer is preferred, in which 80 mol% or more, particularly 90 mol% or more of the structural units are ethylene terephthalate units or butylene terephthalate units. Further, these polymers may contain additives such as a fluorescent brightening agent and a stabilizer.

  In particular, carbon black may be contained in order to maintain the weather resistance of the whole fiber, that is, the strength retention over time, at a better level. An important requirement when using a polyester-based polymer as the protective polymer component is that the intrinsic viscosity [η] of the polymer is 0.7 or more. Here, intrinsic viscosity [η] is a value measured at a temperature of 30 ° C. using a 50:50 mixed solution of phenol and tetrachloroethane.

  In ordinary clothing fibers, polyethylene terephthalate [η] of about 0.60 to 0.65 is used, whereas in the present invention, in order to express the desired fiber strength, ordinary polymerization is performed. Polyester having a degree of polymerization greater than the degree is used. If [η] is less than 0.7, it is difficult to achieve both a fiber specific gravity of 1.5 or more and a fiber strength of 3.5 g / dr or more, and the composite ratio of the protection polymer component and the core polymer component is changed, and the protection polymer component rich As a result, the fiber specific gravity could not reach the target level. Conversely, if the core polymer component was made rich, the fiber strength did not reach the target level. That is, by using a polyester [η] of 0.7 or more, which is a protective polymer component, a polyester satisfying both fiber strength and fiber specific gravity was obtained for the first time.

  [Η] in the present invention is [η] of the polyester component in which the fiber after spinning is formed. That is, it goes without saying that when a degree of polymerization is lowered due to thermal decomposition or hydrolysis at the time of spinning, it is necessary to fiberize a polymer having a slightly higher degree of polymerization.

  By the way, in the present invention, a colorant is added to the protective polymer component to obtain a hue suitable for the fishing net use as described above, and an organic pigment having heat resistance capable of withstanding the melt spinning temperature of the polymer component. And inorganic pigments can be used as appropriate. Specifically, for example, normal original colorants such as carbon black, anthraquinone brown colorant, anthraquinone purple colorant, and benzoquinone red colorant can be used. These pigments can be used alone or in combination of two kinds. What is necessary is just to mix | blend with a protective polymer component in the range about 0.1-5 weight% of addition rates using above.

  When the added amount of the colorant is less than 0.1% by weight, it is difficult to obtain an original yarn for fishing nets exhibiting sufficient “color” and “shininess”. This is not preferable.

  In particular, most of the hue of the fishing net original yarn that is currently required is black. In such a case, it is preferable to add 1 to 3% by weight of carbon black to the protective polymer component. This is because carbon black has an effect of absorbing ultraviolet rays and preventing polymer deterioration, and can prevent a decrease in light resistance of the fiber, that is, strength with time, and exhibits a synergistic effect.

  The method for obtaining the conjugate fiber of the present invention is not particularly limited, but the protective polymer component and the core polymer component are heated and melted in separate melting systems, and each is spun up to the spinneret by a normal extrusion spinning device. It is obtained by feeding the two components together in the composite shape as described above immediately before feeding and spinning, winding up the yarn obtained by extrusion, further drawing and heat treatment. Moreover, after extruding from the spinneret, a method of drawing immediately without winding, or a method of extruding from the spinneret and winding up at a high speed to obtain a product as it is can be used.

  Specifically, it is taken up at a speed of about 4000 m / min or less, and once wound, the so-called FOY or POY stretching method, or the spin draw method of stretching without winding, or more than 4000 m / min. In the DSY method or the DSY method of taking at a high speed, a method in which a heater is provided between the nozzle and the take-up roller and the take-up is performed while stretching can be applied. Among these, a method of drawing at 300 to 4000 m / min, more preferably 600 to 2000 m / min, stretching (which may be FOY or spin draw) and subsequently heat-treating is preferable. If the speed is less than 300 m / min, the degree of orientation of the undrawn yarn is low, and it is necessary to increase the draw ratio in order to obtain the desired fiber strength. As a result, a large number of voids are generated in the fiber, resulting in high specific gravity. It may not be able to be fully achieved. On the other hand, in the case of taking over in the so-called DSY region exceeding 4000 m / min, the target physical property may be obtained without carrying out the drawing heat treatment operation, but it is compared with the method of drawing and heat-treating at 600 to 2000 m / min. However, it is inevitable that the strength decreases.

  Stretching may be one-stage stretching or two-stage stretching. In addition, the draw ratio varies depending on the spinning speed and cannot be uniquely specified, but it is preferable to employ a ratio of about 75 to 85% of the ratio leading to breakage. In particular, a characteristic point in the production of the fiber of the present invention is the heat treatment after stretching. That is, heat treatment is performed at a temperature not lower than (melting point or softening point −80) ° C. of the thermoplastic polymer of the core component and not higher than (melting point or softening point −5) ° C. of the thermoplastic polymer of the protective component. For example, a fiber having a high fiber specific gravity and a high toughness can be obtained by setting it to a high level within a range where fluff does not occur. This is because the voids in the polymer around the fine particles in the fiber generated during stretching are repaired to some extent while the fiber shrinks when heated at a temperature close to or higher than the melting point or softening point of the core polymer component. This is presumed to be due to the fact that the crystallization of the protective component that expresses the mechanical properties of the fiber is promoted by increasing the treatment temperature. If the temperature of the heat treatment exceeds (melting point or softening point −5) ° C. of the protective component polymer, yarn breakage occurs frequently. If the temperature of the core component polymer is lower than (melting point or softening point −80) ° C., the void is sufficiently repaired. Is difficult. The lower limit of the preferable heat treatment temperature is (melting point or softening point −60) ° C. of the thermoplastic polymer of the core component, and the upper and lower values are (melting point or softening point −10) ° C. of the thermoplastic polymer of the protective component. . For example, when the core polymer component is nylon 6 and the protective polymer component is polyester, the temperature of the heat treatment is desirably 160 ° C. or higher and 255 ° C. or lower.

  In addition, in order to stabilize the stretching and suppress the generation of voids, in addition to the contact heating method such as a heat roll, heating during stretching is used in combination with a non-contact heating method such as steam jet or air heating. It is preferable. This is intended to stretch in a state where the fluidity of the core polymer is enhanced at a temperature sufficiently higher than that of the core polymer component. For example, when the core polymer component is nylon 6, it is 350 ° C. or higher, preferably 400 ° C. As described above, it is particularly preferable to perform heat stretching using a steam jet of 430 ° C. or higher. The temperature of the steam jet does not indicate the heat treatment temperature itself in the present invention, and the heat treatment temperature in the present invention means a contact heating temperature. From these findings, it is preferable that the base polymer of the core polymer component has a melting point or softening point that is 20 ° C. or more, preferably 30 ° C. or less lower than that of the protective polymer component. As this polymer, a crystalline fiber-forming polymer is preferable from the viewpoint of fiber forming processability, but an amorphous polymer can also be used for the purpose of the present invention.

  Moreover, the composite fiber of the present invention can be used for a wide variety of uses, either alone or in combination with other fibers. When mixed with other fibers, any means such as mixed fiber, mixed yarn, twisted yarn, union weaving, union knitting, etc. can be used, and the obtained fabric is subjected to various post-processing treatments as necessary. Can be used for various purposes. Preferable uses of the composite fiber of the present invention include unconventional high specific gravity, polyester fiber having a fiber strength that can withstand practical use, and stab nets, seine nets, lathe nets, and building nets that make the most of the characteristics. It is most suitable for various types of fishing nets such as bed nets. Especially, it is most suitable for stationary nets such as salmon, yellowtail, tuna, horse mackerel, mackerel, sardine, perch, squid and others.

  Other than fishing net use, it can be applied to various industrial material uses as a polyester fiber having high specific gravity performance, which is unprecedented, such as for silt protectors used in civil engineering work. In addition to industrial materials, applications in non-clothing fields such as curtains and blackouts are also suitable.

  The present invention obtains a composite fiber composed of a core polymer component and a protective polymer component to which specific inorganic particles are highly added, thereby providing unprecedented high fiber strength and high specific gravity, and as a fiber for stationary nets. There can be provided a composite fiber having no pollution problem and having a suitable hue.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples at all. [Η], average particle diameter of fine particles, fiber specific gravity, strength, elongation, and number average molecular weight of nylon in the present invention can be determined by the following methods.
Polyester [η]: Measured at a temperature of 30 ° C. using a mixed solvent of phenol and tetrachloroethane 1: 1 as a solvent.
-Number average molecular weight of nylon: measured by GPC chromatogram by HLC-510 manufactured by Waters.
-Average particle diameter of fine particles: Measured with a centrifugal automatic particle size distribution measuring apparatus CAPA-500 manufactured by HORIBA, Ltd.
Fiber specific gravity: Using carbon tetrachloride and normal hexane as a solvent, a density gradient was created and measured at 20 ° C.
Fiber strength and elongation: Measured using a tensile tester (Autograph IM-100) manufactured by Shimadzu Corporation at 20 ° C. and 65 RH%.

Example 1
Nylon 6 powder having a number average molecular weight of 11,000 (trade name P1011F) manufactured by Ube Industries, Ltd. is used as the base polymer of the core polymer component, and a spherical magnetite powder having an average particle diameter of 0.2 μm with respect to such polymer powder 30% by weight (manufactured by Toda Kogyo Co., Ltd .: surface ferrite coated product, specific gravity 5.0) and 40% by weight of titanium dioxide having an average particle size of 0.35 μ (specific gravity 4.2 manufactured by Titanium Industry Co., Ltd.) The mixture was melt-kneaded with a twin-screw kneader and extruded into a strand shape, the strand was cut and pelletized, and vacuum dried at 90 ° C. to a moisture content of 180 ppm. On the other hand, as the protective polymer component, a polyethylene terephthalate having an intrinsic viscosity [η] 0.80 containing 0.08% by weight of titanium dioxide was melt-polymerized by a conventional method and pelletized.

  The obtained protective polymer component and core polymer component are melt-extruded with separate extruders, and merged at the nozzle portion so that the protective polymer component becomes a sheath at a spinning temperature of 295 ° C., and a composite weight ratio (protective polymer component): ( The core polymer component was set to 2: 1, the cross-section was made into a core-sheath shape as shown in FIG. 1 (1), the nozzle diameter was 0.4 mmφ, and it was discharged by an 8-hole nozzle, and wound at a spinning speed of 1000 m / min. At this time, the polyethylene terephthalate forming the protective polymer component after fiber formation was [η] 0.75.

  The obtained spinning yarn was drawn at a hot roller of 80 ° C. and a hot plate of 140 ° C. at a draw ratio of 4.0, followed by heat treatment at a hot roller of 180 ° C. with 3% overfeed, and then 75 denier 8 filaments. The multifilament was scraped off. When the cross-sectional shape of the multifilament yarn was observed with a microscope, the core-sheath ratio was almost constant in any fiber and in the length direction, and the core component was completely covered with the sheath component. Excellent homogeneity and no fuzz. Moreover, no troubles were observed in the spinning process and the drawing process. The resulting fiber specific gravity was 1.58, the strength was 4.5 g / dr, and the elongation was 15%.

  A net is made by combining the obtained drawn yarns and subjected to an injection test in the sea. Sedimentation is good, there is little net shaking in the sea, it is excellent in durability, and is a suitable fiber as a fishing net. Was confirmed.

  It turned out that the specific gravity of the fiber obtained by changing the heat processing temperature at the time of extending | stretching differs. As a result of drawing the spinning conditions collected under the same conditions described above under the following conditions, fibers having the following physical properties were obtained.

Elongation temperature condition Textile property
HR ₁ HP HR ₂ p DT DE Fluff [1] 80 ° C 140 ° C 180 ° C 1.58 4.5g / d 15 ○
[2] 〃 〃 160 1.53 4.3 13 ○
[3] 〃 ２３０ 230 1.60 4.7 10 ×
Note: HR ₁ = hot roller (first roller), HP = hot plate, HR ₂ = hot roller (second roller), p = specific gravity, DT = strength, DE = elongation

  It was found that the fiber properties were better when the heat treatment temperature during the shrinkage treatment was higher. However, an extremely high heat treatment temperature is not preferable because stretched fluff frequently occurs.

  Further, the magnetite fine particles were changed to the above-described ones, and fiberization was performed in the same manner using a Toda Kogyo Co., Ltd. non-surface coated specific gravity: 5.0. As a result, a fiber having a specific gravity of 1.53, which is slightly lower than that when using a surface coat product, was obtained.

Example 2
A composite fiber was produced in the same manner as in Example 1 except that 0.2% by weight of copper iodide was added to the core polymer component, and the strength retention of the obtained fiber was examined. As an evaluation means, the strength retention after irradiation with carbon fading at 83 ° C. for 400 hours and the strength retention after irradiation with xenon weathering at 83 ° C. for 400 hours were examined. As a result, after 400 hours of carbon fade, the average strength retention of n = 5 was about 86%, and after 400 hours of xenon weather, the average strength retention of n = 5 was about 84%. In contrast, the fiber obtained in Example 1 had a strength retention of about 42% after 400 hours of carbon fade and a strength retention of about 36% after 400 hours of xenon weather.

Examples 3-8
In Example 3, the core polymer component fine particles are 50% by weight of magnetite and 20% by weight of titanium dioxide, Example 4 is 70% by weight in total of 20% by weight of magnetite and 50% by weight of titanium dioxide, and Example 5 is a magnetite. A composite fiber was obtained in the same manner as in Example 2 except that 10% by weight and 60% by weight of titanium dioxide totaled 70% by weight. In either case, there was no trouble in processability, and a fiber having good fiber properties was obtained. In Example 4, the hue of the obtained fiber was gray and slightly different from black. In Example 5, the hue of the fiber was whitish gray. In Example 6, the content of fine particles in the core polymer component was 30% by weight of magnetite and 20% by weight of titanium dioxide to make a total of 50% by weight. In Example 7, [η] of the protective polymer component was set to 0.85. 8 was carried out in the same manner as in Example 2 except that the composite ratio of the protective polymer component and the core polymer component was 1: 1. All of them had good processability, and high specific gravity and high strength fibers were obtained. Table 1 summarizes the [η] of the protective polymer component in these examples, the type and mixing ratio of fine particles in the core polymer component, the composite ratio of the protective polymer component and the core polymer component, and the cross-sectional shape of the fiber, Table 2 shows the evaluation of process properties and physical properties of these fibers.

Examples 9-10
Example 9 was subjected to composite spinning in the same manner as in Example 2 except that the cross-sectional shape was changed to FIG. 1 (2) and Example 10 was changed to FIG. 1 (3). In both cases, good processability and good fibers were obtained (see Tables 1 and 2).

Example 11
A composite fiber was produced in the same manner as in Example 3 except that nylon 12 (3014U manufactured by Ube Industries, Ltd.) was used as the base polymer of the core polymer component. Was obtained (see Tables 1 and 2).

Example 12
A composite fiber was obtained in the same manner as in Example 2 except that nylon 6 having a number average molecular weight of 22,000 (trade name P1022 manufactured by Ube Industries, Ltd.) was used as the core polymer component ( Table 1 and Table 2).

Comparative Example 1
A polyethylene terephthalate chip having a [η] before spinning of 0.65 as a protective polymer component was used in the same manner as in Example 2 except that spinning was performed so that the [η] after spinning was 0.60. A composite fiber was obtained. As a result, some fluff was generated during spinning and stretching, and the fiber strength was as low as 2.5 g / d due to the low viscosity of the protective polymer component, which was inferior to Example 2.

Comparative Example 2
A composite fiber was obtained in the same manner as in Example 2 except that 15% by weight of magnetite and 15% by weight of titanium dioxide were added as fine particles to give a total of 30% by weight. The processability was good and fiberization was possible, but the fiber specific gravity was 1.45, which was inferior to Example 2.

Comparative Examples 3-4
Comparative Example 3 uses silicon dioxide particles having an average particle diameter of 0.1 μ and specific gravity of 2.2 instead of titanium dioxide, and Comparative Example 4 uses kaolin particles having an average particle diameter of 1.0 μ and specific gravity of 2.5. Was carried out in the same manner as in Example 2. In all cases, fluff was generated and spinnability and stretchability were not so good. The specific gravity of the obtained fiber was also inferior to that of Example 2.

Comparative Examples 5-6
The same polymer as in Example 2 was used, Comparative Example 5 was a protective polymer component: core polymer component composite ratio of 85:15, and Comparative Example 6 was a protective polymer component: core polymer component composite ratio of 15:85. Composite spinning was carried out in the same manner as in No. 2. In Comparative Example 5, fiberization was possible, but the fiber specific gravity performance was inferior. In Comparative Example 6, spinnability and stretchability were poor, fluff and yarn breakage occurred frequently, and a fiber that could be evaluated for performance could not be obtained. Table 1 summarizes the [η] of the protective polymer component in Comparative Examples 1 to 6, the type of fine particles in the core polymer component and their blending ratio, the composite ratio of the protective polymer component and the core polymer component, and the cross-sectional shape of the fiber. In addition, the evaluation of the process properties and physical properties of these fibers is as shown in Table 2.

Example 13
Titanium dioxide with an average particle size of 0.35μ (rutile type; specific gravity 4.2 manufactured by Titanium Industry Co., Ltd.) 25% by weight and α-type hematite powder with an average particle size of 0.2μ (made by Toda Kogyo Co., Ltd., specific gravity 5.2) Nylon 6 having a number average molecular weight of 12,000 containing 50% by weight as the core polymer component (water content 200 ppm) and 1.0% by weight of carbon black (manufactured by Degussa) has an intrinsic viscosity [η] of 1. Polyethylene terephthalate which is 0 as a protective polymer component is melt-extruded by a separate extruder, and merged at the nozzle portion so that the protective polymer component becomes a sheath at a spinning temperature of 300 ° C., and a composite weight ratio (protective polymer component): ( The core polymer component was set to 2: 1, the cross-section was made into a core-sheath shape as shown in FIG. 1 (1), and the nozzle diameter was 0.6 mm.phi. The discharged yarn is passed through a heating zone of 20 cm length and 380 ° C. provided immediately under the nozzle, and then cooled with a cooling air of 25 ° C. and 7 Nm ^{3 /} min. It took over at / min.

Subsequently, without taking up the yarn once, stretching and heat treatment were carried out in the following manner and wound up.
Elongation: After heating with a hot roll at 110 ° C., one-stage drawing is performed 4.8 times while spraying heated steam at 450 ° C.
Heat treatment: 4% shrinkage treatment between hot roll and relaxation roll at 210 ° C.
As a result, the process stability was good, and a highly practical fiber was obtained as a fiber for a fishing net having a density of 1002 denier, a strength of 5.5 g / d, an elongation of 19%, and a specific gravity of 1.62.

1 (1) to 1 (8) are schematic views showing typical composite forms of a core polymer component and a protective polymer component in the fiber cross section of the present invention.

Explanation of symbols

1: Core polymer component 2: Protective polymer component

Claims (1)

Consists of a core polymer component containing 50 to 85% by weight of fine particles of iron oxide and titanium dioxide , and a protective polymer component that covers the core polymer component and to which a colorant is added, and has a fiber specific gravity of 1.5 or more A composite fiber having a strength of 3.5 g / d or more.

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