JP2939974B2 - Elastic fiber - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elastic fiber, and an object of the present invention is to provide a polyurethane elastic fiber excellent in elastic properties, chemical resistance, strength and the like. It is in. 2. Description of the Related Art In general, a polyurethane elastomer is obtained by reacting a polyhydroxy compound such as polyester or polyester having a hydroxyl group at an end thereof with an excess molar amount of an organic diisocyanate to form a linear elastomer having isocyanate groups at both ends. Producing a polyurethane intermediate polymer and reacting the intermediate polymer with a diamino compound having an active hydrogen capable of easily reacting with an isocyanate group in an inert organic solvent to produce a substantially linear segmented polyurethane. After doing
By molding and then removing the solvent, it is molded into a polyurethane elastic molded article such as a film or a thread having elastic properties. [0003] In addition to the elastic properties, physical properties such as chemical resistance, strength and abrasion resistance, as well as light resistance, etc. are important properties of the polyurethane elastic body. . In particular, in order to obtain elastic fibers excellent in elastic properties, chemical resistance, physical properties, and the like, it is necessary to spin a segmented polyurethane having a high logarithmic viscosity. However, the production of elastic fibers by spinning a polymer having a high logarithmic viscosity has a disadvantage in operation that the polymer solution has a high viscosity, so that it is necessary to lower the solution concentration or reduce the spinning speed. Not only that, the expected effect cannot be obtained. According to Japanese Patent Publication No. 40-3717, when a polymerization reaction is carried out using an excess amount of an intermediate polymer having an isocyanate terminal and a difunctional or monofunctional compound having active hydrogen, an excellent polymer (having an intrinsic viscosity of about 0.6 ~
1.2) and a solution is obtained. However, it is difficult to obtain elastic fibers having satisfactory physical properties by this method alone. [0004] The present inventors have solved the above-mentioned drawbacks, and as a result of intensive studies to obtain an elastic fiber having excellent elastic properties and strength, have reached the present invention. That is, in the present invention, an intermediate polymer having a terminal isocyanate group is obtained by reacting tetramethylene glycol having a molecular weight of 500 to 6000 with an excess mole of an organic diisocyanate, and the intermediate polymer is converted into a polyfunctional amino compound having an amount satisfying the following formula. After spinning a polyurethane elastic fiber obtained by spinning a polymer obtained by reacting with ethylenediamine and / or propylenediamine, and a monofunctional amino compound, a heat treatment is performed at a temperature of 50 to 100 ° C for 2 hours or more. An elastic fiber characterized by having a high molecular weight having a logarithmic viscosity of 1.1 to 2.5 dl / g. 1.5 ≦ (B + CA) /C≦5.0 (where A: equivalent of an isocyanate group in the intermediate polymer, B: equivalent of a polyfunctional amino compound, C: equivalent of a functional amino compound) The polyurethane elastomer in the present invention is prepared by reacting a polymer diol with a polyfunctional isocyanate and, if desired, a small amount of water, a low molecular weight glycol or the like to produce an intermediate polymer having both ends substantially having isocyanate groups. ,
A polyurethane urea polymer obtained by reacting the obtained intermediate polymer with a polyfunctional amino compound and / or a monofunctional amino compound in an inert organic solvent. The polymer diol used has a number average molecular weight of 5
No. 00-6000 polytetramenthylene glycol. The molecular weight of the polyhydroxy compound is usually from 500 to: 6.
000, preferably 1,000 to 5,000. Examples of the low molecular glycol optionally used in addition to the polymer diol include ethylene glycol, propylene / glycol, 1,4-butanediol, and the like. On the other hand, the content of water and low-molecular-weight glycol is usually preferably 10 mol% or less. As the organic diisocyanate used in the present invention, all of the aliphatic, alicyclic and aromatic diisocyanates which are soluble or liquid under the reaction conditions can be applied. For example, p-phenylenediisocyanate, bis (4-isocyanatophenyl) methane, bis (3-methyl-4-isocyanatophenyl) methane, bis (4-isocyanatocyclohexyl) methane, 2,4-tolylenediisocyanate, , 6-tolylene diisocyanate, hexamethylene diisocyanate and the like. The ratio of the molar amount of the organic diol 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 1.5 to 1: 2.5, but is not particularly limited. The polyfunctional amino compounds include ethylene diamine and propylene diamine. As a monofunctional amino compound used simultaneously, for example, a monofunctional secondary compound
Secondary amines include dimethylamine, methylethylamine,
Examples thereof include diethylamine, methyl-n-propylamine, methyl-isopropylamine, diisopropylamine, methyl-n-butylamine, methyl-isobutylamine, and methyl-isoamylamine. As the inert organic solvent used in the present invention, a solvent capable of dissolving the above-mentioned raw materials and dissolving or dispersing the resulting polyurethaneurea polymer, for example, a known solvent such as dimethylformamide, dimethylacetamide, and dimethylsulfoxide. Is mentioned. The reaction between the polymer and the amino compound is usually carried out by introducing an intermediate polymer solution dissolved in an inert organic solvent into an inert organic solvent containing a polyfunctional amino compound and a monofunctional amino compound. And a polyurethane urea polymer is produced. Here, a mixture of a polyfunctional amino compound containing an amino group in excess of an equivalent of isocyanate groups in the intermediate polymer and a monofunctional amino compound is reacted, and the resulting polymer has an end group having an amino group. Or an alkyl group introduced by a monoamine. At this time, the concentration of the polymer solution is preferably 30 to 40% by weight, and the logarithmic viscosity of the polymer is 0.6 to 0.9.
The addition amount of the polyfunctional amino compound and the monofunctional amino compound is adjusted so as to be dl / g. The amount of the amino compound used is in the range shown by the following formula. 1.5 ≦ (B + CA) /C≦5.0 (where A is an equivalent of a dissocyanate group in the intermediate polymer, B is an equivalent of a polyfunctional amino compound, and C is a functional amino compound. When the amount of the amino compound is out of the above range, that is, when it is less than 1.5, the viscosity of the polymer before spinning is too low, and the physical properties of the obtained elastic yarn are inferior. If it exceeds, it becomes difficult to obtain a heat treatment effect after spinning. The obtained polymer solution is usually dry-spun by a conventional method, wound up on a bobbin, and usually at a temperature of 50 to 100.
C., preferably at 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 is increased to 1.1 dl / g or more, preferably 1.4 to 2.5 dl / g, and improved physical properties such as cutting strength, elastic recovery, and set rate And the like, and at the same time, have the feature of improving chemical properties such as chemical resistance. In particular, since a relatively low viscosity is required during spinning, it is possible to spin at a high spinning speed, and it is also a great advantage in industrialization that high molecular weight and improved physical properties can be obtained by simple means after spinning. The increase in viscosity due to heat treatment is at least 0.2 or more, preferably 0.5
That is all. The solution of the polyurethane elastomer of the present invention may further contain a stabilizer such as a gas yellowing inhibitor and an ultraviolet absorber, inorganic fine particles such as barium sulfate, magnesium silicate, calcium silicate and zinc oxide, and calcium stearate. , Magnesium stearate, polytetrafluoroethylene, organopolysiloxane, etc., an anti-tackiness agent, a fungicide, and other compounding agents. Further, a fungicide having fiber affinity, for example, 2- (4-4 azolylbenzimidazole, N-dimethyl-N'-phenyl- (N'-fluorodichloromethylthio) sulfamide, etc. is provided together with the oil after spinning, In the following, the present invention will be described with reference to examples.
The characteristic values of the yarns in the examples were determined by the following methods. Parts in the examples are on a weight basis. The elongation, elastic recovery and set ratio were measured by a tensile tester. (L) Strength (g / d) is the breaking strength when stretched at a rate of 1000% / min. (2) Elongation (%) is the elongation at break when elongated at a rate of 1000% / min. (3) The elastic recovery (%) is 30 at a speed of 1000% / min.
The strain is removed after 0% elongation, and 1- (recovery rate) × 100% value after standing for 1 minute. (4) Set rate (%) is 0 and 3 at a speed of 1000% / min.
It is a value represented by the following formula, which is the residual elongation of the length of the yarn after repeating the process between 00% elongation and 5 times. Set ratio (%) = (L−L ₀ ) / L ₀ × 100 (where L ₀ is the original sample length, L is the sample length after repeated elongation) (5) Logarithmic viscosity is 1n (n / no) / C.
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 solution 1
It is the concentration expressed in g of polyurethane per dl.
The logarithmic viscosity in the examples is a value measured in dimethylacetamide at 30 ° C. (C = 0.39 / dl). Example 1 To 1000 parts of polytetramethylene glycol having a number average molecular weight of 1980, 250 parts of 4,4'-diphenylmethane diisocyanate was added, heated to 70 ° C., and reacted for 60 minutes. Next, 1250 parts of dimethylacetamide was added to obtain an intermediate polymer solution, and the mixture was cooled to 15 ° C. This intermediate polymer solution was mixed with 39.6 parts of 1,2-propylenediamine, 2.7 parts of diethylamine and 115 parts of dimethylacetamide.
The mixture was gradually added to a mixed solution consisting of 0 parts to obtain a polymer solution. The solution viscosity was 1620 poise at 30 ° C. and the logarithmic viscosity of the polymer was 0.81 dl / g. This polymer solution was dry-spun in a conventional manner to obtain a 40-denier multifilament elastic yarn. The filament was heated at 80 ° C. for 24 hours while being 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. In addition, the addition amount B + CA / C of the amino compound in the present invention was 2.88. According to the method of the present invention, the cutting strength and the elastic recovery rate were greatly improved, and the setting rate was improved. When the heating temperature was 40 ° C., the physical property values before heating hardly changed. [Table 1] Examples 2-3 Polytetramethylene glycol, 4,4 'shown in Table 2
A polymer solution was obtained in the same manner as in Example 1 using a diphenylmethane diisocyanate / diol molar ratio, a diamine and a monoamine, and dry-spun to obtain a 40-denier multifilament elastic yarn. 7
Table 3 shows the physical properties obtained by heating at 0 ° C. for 12 hours. [Table 2] [Table 3] According to the present invention, it is possible to provide an elastic yarn having excellent physical properties, that is, significantly improved cutting strength and elastic recovery.

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Claims (1)

(57) [Claims] A polytetramethylene glycol having a molecular weight of 500 to 6000 is reacted with an excess mole of an organic diisocyanate to obtain an intermediate polymer having a terminal isocyanate group. And / or a high molecular weight polyurethane elastic fiber obtained from a polymer obtained by reacting with propylene diamine and a monofunctional amino compound, wherein the fiber has a logarithmic viscosity of 1.1 to 2.5 dl / g. Elastic fiber. 1.5 ≦ (B + CA) /C≦5.0 (where A: equivalent of an isocyanate group in the intermediate polymer, B: equivalent of a polyfunctional amino compound, C: equivalent of a functional amino compound) Equivalent)