JPH0474457B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to elastic fibers, and its purpose is to provide polyurethane elastic fibers with excellent elastic properties, chemical resistance, strength, etc. In general, polyurethane elastomers are produced by reacting a polyhydroxy compound such as polyester or polyether having hydroxyl groups at the ends with an excess molar amount of organic diisocyanate to produce a linear polyurethane intermediate polymer having essentially isocyanate groups at both ends. After producing a substantially linear segmented polyurethane by reacting the intermediate polymer with a diamino compound having an active hydrogen that can easily react with isocyanate groups in an inert organic solvent, molding is performed, and then the solvent is removed. By removing the polyurethane elastomer, polyurethane elastomer molded products such as films and threads having elastic properties are formed. In addition to elastic properties, other important properties of polyurethane elastomers include physical properties such as chemical resistance, strength, and abrasion resistance, as well as light resistance. In particular, in order to obtain elastic fibers with excellent elastic properties, chemical resistance, physical properties, etc., it is necessary to spin segmented polyurethane having a high logarithmic viscosity. However, manufacturing elastic fibers by spinning polymers with high logarithmic viscosity has operational drawbacks such as the need to lower the solution concentration or slow the spinning speed because the polymer solution has a high viscosity. Or you won't get the desired effect. According to Japanese Patent Publication No. 40-3717, when a polymerization reaction is carried out using an intermediate polymer having an isocyanate end and an excess amount of a difunctional or monofunctional compound having an active hydrogen, an excellent polymer (with an intrinsic viscosity of approx.
0.6-1.2) and a solution is obtained. However, it is still difficult to obtain elastic fibers with satisfactory physical properties using this method alone. The present inventors have achieved the present invention as a result of intensive research in order to solve the above-mentioned drawbacks and obtain an elastic fiber with excellent elastic properties and strength. That is, in the present invention, a polymer diol having a molecular weight of 500 to 6000 is reacted with an excess molar amount of an organic diisocyanate to obtain an intermediate polymer having a terminal isocyanate group, and the intermediate polymer is reacted with an amount of an amino compound satisfying the following formula. After spinning and winding the polymer obtained by
An elastic fiber characterized by being made to have a high molecular weight by heat treatment at 100°C for 2 hours or more. 1.5≦(B+C-A)/C≦5.0 (wherein A: equivalent weight of the isocyanate group in the intermediate polymer, B: equivalent weight of the polyfunctional amino compound,
C: Equivalent weight of monofunctional amino compound) The polyurethane elastomer in the present invention is produced by reacting a polymer diol with a polyfunctional isocyanate and, if desired, a small amount of water, a low molecular weight glycol, etc. to form an intermediate whose both ends are substantially isocyanate groups. It is a polyurethane urea polymer obtained by producing a polymer and reacting the obtained intermediate polymer with a polyfunctional amino compound and a monofunctional amino compound in a normally inert organic solvent. The polymer diol used is a substantially linear polymer diol having a number average molecular weight of 500 to 6000, such as polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol, polyoxypentamethylene glycol, Polyether diol such as oxypropylenetetramethylene glycol, one or more dibasic acids such as adipic acid, sebacic acid, maleic acid, itaconic acid, azelaic acid, malonic acid, and ethylene glycol;
1,2-propylene glycol, 1,3-propylene glycol, 2,2-dimethyl-1,3-propanediol, 1,4-butanediol, 2,
3-butanediol, hexamethylene glycol, diethylene glycol, 1,10-decanediol, 1,3-cyclohexanedimethanol,
Polyester diols obtained from one or more glycols such as 1,4-cyclohexanedimethanol, polylactone diols such as poly-ε-caprolactone and polyvalerolactone, polyesteramide diols, and polyether diols.
Examples include ester diol and polycarbonate diol. The molecular weight of the polyhydroxy compound is usually about 500 to 6000, preferably
1000-5000. In addition to polymer diols, low molecular weight glycols that can be used as desired include ethylene glycol, propylene glycol,
Examples include 1,4-butanediol, but the amount used is preferably within a range of usually 10 mol% or less of water and low molecular weight glycol based on the total of the polymer diol, water and low molecular weight glycol. As the organic diisocyanate used in the present invention, any of aliphatic, alicyclic and aromatic diisocyanates which dissolve or are liquid under the reaction conditions can be used. For example, p-phenylene diisocyanate, bis(4-isocyanatophenyl)methane, bis(3-methyl-4-isocyanatophenyl)methane, bis(4-isocyanatocyclohexyl)methane, 2,4-tolylenedi Isocyanate, 2,6-tolylene diisocyanate, hexamethylene diisocyanate, etc. are exemplified, and the ratio of the molar amount of the organic diisocyanate to the molar amount of the polymer diol used in the present invention is determined by considering the desired elastic properties and physical properties. The ratio is 1:1.5 to 1:2.5, but is not particularly limited. In addition, polyfunctional amino compounds include ethylenediamine, propylenediamine, trimethylenediamine, hexamethylenediamine, hydrazine,
carbodihydrazide, adipic acid dihydrazide,
Examples include difunctional aliphatic diamines such as sebacic acid dihydrazide and N,N'bis(γ-aminopropyl)-N,N'-dimethylethylenediamine. As a monofunctional amino compound used at the same time,
For example, monofunctional secondary amines include dimethylamine, methylethylamine, diethylamine, methyl-n-propylamine, methyl-isopropylamine, diisopropylamine, methyl-n-butylamine, methyl-isobutylamine, methyl-isoamylamine, etc. can be mentioned. The inert organic solvent used in the present invention is a solvent capable of dissolving the above-mentioned raw materials and dissolving or dispersing the produced polyurethaneurea polymer, such as known solvents such as dimethylformamide, dimethylacetamide, and dimethylsulfoxide. can be mentioned. The reaction between an intermediate polymer and an amino compound is usually carried out by introducing a solution of the intermediate polymer dissolved in an inert organic solvent into an inert organic solvent containing a polyfunctional amino compound and a monofunctional amino compound. , a polyurethaneurea polymer is produced. Here, a polyfunctional amino compound containing a molar excess of amino groups over the equivalent of isocyanate groups in the intermediate polymer is reacted with a mixture of monofunctional amino compounds, and the end groups of the resulting polymer are It becomes an amino group or an alkyl group introduced by a monoamine. The concentration of the polymer solution at this time is 30~
40% by weight is preferred and the logarithmic viscosity of the polymer is 0.6
The amount of polyfunctional amino compound and monofunctional amino compound added is adjusted so that the amount is ~0.9 dl/g.
The amount of amino compound used is within the range shown by the following formula. 1.5≦(B+C-A)/C≦5.0 (wherein A: equivalent weight of the isocyanate group in the intermediate polymer, B: equivalent weight of the polyfunctional amino compound,
C: Equivalent of monofunctional amino compound) When the amount of the amino compound added is outside the above range, that is, less than 1.5, the viscosity of the polymer before spinning is too low, resulting in poor physical properties of the elastic yarn.
On the other hand, if it exceeds 5.0, it becomes difficult to obtain the effect of heat treatment after spinning. The obtained polymer solution is usually dry-spun using a conventional method, wound onto a bobbin, and then heated to a temperature of 50 to 100 ℃.
C., preferably 60 to 90.degree. C. for 2 hours or more, preferably 3 to 24 hours. Thus, the logarithmic viscosity of the polymer constituting the yarn increases to 1.1 dl/g or more, preferably 1.4 to 2.5 dl/g, resulting in improved physical properties such as cutting strength, elastic recovery rate, setting rate, etc. It also has the advantage of improving chemical properties such as chemical resistance. In particular, since a relatively low viscosity is required during spinning, it is possible to form yarn at a high spinning speed, and it is also a great advantage in industrialization that it is possible to obtain high molecular weight and improve physical properties by simple means after spinning. The increase in viscosity due to heat treatment is at least 0.2 or more, preferably 0.5 or more. The solution of the polyurethane elastomer of the present invention may optionally further contain gas yellowing inhibitors, stabilizers such as ultraviolet absorbers, inorganic fine particles such as barium sulfate, magnesium silicate, calcium silicate, and zinc oxide, calcium stearate, and stearic acid. Anti-tack agents such as magnesium, polytetrafluoroethylene, organopolysiloxane, anti-mold agents, and other compounding agents may be appropriately blended. In addition, along with the post-spinning oil agent, a fungicide having affinity for fibers, such as 2
-(4-4azolylbenzimidazole, N-dimethyl-N'-phenyl-(N'-fluorodichloromethylthio)sulfamide, etc.) can also be added to the fibers and fixed by heat treatment. To explain the invention, the characteristic values of the yarn in the examples were determined by the following method.
In addition, parts in the examples are based on weight. Strength and elongation, elastic recovery and set ratio were measured using a tensile tester. (1) Strength (g/d) is the cutting strength when stretched at a rate of 1000%/min. (2) Elongation (%) is the cutting elongation when elongated at a speed of 1000%/min. (3) Elastic recovery rate (%) is 300 at a rate of 1000%/min.
% elongation, remove tension and leave for 1 minute {1-
(Unrecovered rate)}×100% value. (4) Set rate (%) is 0 and 0 at a speed of 1000%/min.
This value is the residual elongation rate of the yarn length after repeating 5 times between 300% elongation and is expressed by the following formula. Set rate (%) = (L - Lo) / Lo × 100 (However, L ₀ is the original sample length, L is the sample length after repeated elongation) (5) Logarithmic viscosity is ln (n / no) / C It is expressed as
n is the viscosity of the dilute solution of the segmented polyurethane and no is the viscosity of the solvent at the same temperature. C is the concentration in grams of polyurethane per dl of solution. The logarithmic viscosity in the examples is 30
Values measured in dimethylacetamide at °C (C = 0.3 g/dl). Example 1 250 parts of 4,4'-diphenylmethane diisocyanate was added to 1000 parts of polytetramethylene glycol having a number average molecular weight of 1980, and the mixture was heated to 70°C and reacted for 60 minutes. Next, 1250 parts of dimethylacetamide was added to prepare an intermediate polymer solution, and the mixture was cooled to 15°C. This intermediate polymer solution was gradually added to a mixed solution consisting of 39.6 parts of 1,2-propylene diamine, 2.7 parts of diethylamine, and 1150 parts of dimethylacetamide to obtain a polymer solution. The viscosity of the solution is 30℃
is 1620 poise, and the logarithmic viscosity of the polymer is 0.81
It was dl/g. This polymer solution was dry spun using a conventional method to obtain a 40 denier multifilament elastic yarn. This filament was heated at 80° C. for 24 hours while wound on a bobbin. The logarithmic viscosity of the polymer after heating was 1.72 dl/g, and the physical properties of the elastic yarn before and after heating are shown in Table 1. Incidentally, the amount of added amino compound B+C-A/C as used in the present invention was 2.88.

[Table] By the method of the present invention, the cutting strength and elastic recovery rate were greatly improved, and the setting rate was also improved. Note that when the heating temperature was 40°C, almost no change was observed in the physical property values before heating. Examples 2-3 Polytetramethylene glycol shown in Table 2,
A polymer solution was obtained in the same manner as in Example 1 using the 4,4'-diphenylmethane diisocyanate/diol molar ratio, diamine and monoamine, and dry spun to obtain a 40 denier multifilament elastic yarn. Table 3 shows the physical properties obtained by heating the obtained elastic yarn at 70° C. for 12 hours.

【table】

[Table] Elastic threads with excellent physical properties were obtained according to the present invention.

Claims (1)

[Claims] 1. A polymer diol having a molecular weight of 500 to 6000 is reacted with an excess mole of organic diisocyanate to obtain an intermediate polymer having a terminal isocyanate group, and the intermediate polymer is reacted with an amount of an amino compound satisfying the following formula. After the polymer obtained by the reaction is spun and wound, the temperature is
An elastic fiber characterized by being made to have a high molecular weight by heat treatment at 50 to 100°C for 2 hours or more. 1.5≦(B+C-A)/C≦5.0 (wherein A: equivalent weight of the isocyanate group in the intermediate polymer, B: equivalent weight of the polyfunctional amino compound,
C: equivalent weight of monofunctional amino compound).