JPH0376811A - Polyurethane elastomer fiber - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to polyurethane elastic fibers.

[Prior Art] Polyurethane elastic fibers are generally produced by wet spinning, dry spinning, or melt spinning.

Conventionally, polyurethane used as elastic fiber has been manufactured using polyether diol, but it has poor chlorine resistance.

In addition, elastic fibers made from polyurethane produced using polyester diol have poor water resistance and mold resistance.

2-methyl-1,8 in JP-A No. 62-22817
Polyurethanes using octanediol have been described, and it has been suggested that they can be made into elastic fibers either dry or wet.

[Problems to be Solved by the Invention] The purpose of the present invention is to provide a polyurethane elastic fiber that is excellent in all of the properties of chlorine resistance, water resistance, mold resistance, elastic recovery, and heat resistance, and has high elongation. .

[Means for Solving the Problems] The present invention provides a polyurethane elastic w&fiber made of polyurethane obtained by polymerizing a polymeric diol (A), an organic diisocyanate (B) and a chain extender (C), The polymer diol has a number average molecular ffi of 1000 to 35
00, where 11i1 is the following structural unit (T), (II) and/or (III), and R2 is a divalent organic group, polyester diol, or - Consists of a structural unit represented by the general formula %, in which R1 is a polycarbonate that is the following structural unit (I), (I[) and/or (III), and the following structural unit ( [), (“), (III) are [(II) + (II
I) co/[(1)+(II)+(III)] is 0.1 or more in molar ratio, and [(1)+(If)]
/ [(I)+(II)+(III)] using a polymeric diol with a molar ratio of more than 0.5 as the main component, -(CHt,)e'-... (1)-CH, −
CH, -CH-CHt-CHt-... ([[
)(B)/(A) molar ratio is 1.5 to 4.5,
A polyurethane elastic fiber characterized by satisfying the following formula (1'Y), CV>.

Hot water resistance strength retention rate (%) ≧60 (I
V) Elastic recovery rate (%) ≧80...
(V) The polymeric diol used in the present invention has the structural units (I) and (I) as diol residues.
It is a polyester diol or polycarbonate diol containing groups represented by I) and/or (II[). As a compound giving the group shown in (1), 1
．． 9-nonanediol is mentioned, a compound giving a group represented by (■) is 2-methyl-1,8-octanediol, and a compound giving a group represented by ([I) is 3-methyl. -1,5-bentanediol is mentioned. In the present invention, [(I
The molar ratio of I)+(I[I)]/[([)+(n)+(■)] is 0.1 or more, and [(1)+(II)]
The molar ratio of /[(I)+(II)+(I[I)] is required to be greater than 0.5. [(II)+
(III)]/[([)+ (II)+ (I[[)
] When the molar ratio is less than 0.1, the elastic recovery property decreases,
Elongation becomes smaller.

[(1)+(II)] / [(1)+([[)+(I
)] when the molar ratio is 0.5 or less, water resistance, mold resistance,
Cold resistance decreases.

Further, among the polymer diols, as the dicarboxylic acid component that provides the dicarboxylic acid residue R'' constituting the polyester diol, an aliphatic or aromatic dicarboxylic acid having 5 to 12 carbon atoms is preferable.Among them, aliphatic dicarboxylic acids is preferred. Examples of aliphatic dicarboxylic acids include glutaric acid, adipic acid, pimelic acid, superric acid, azelaic acid, and sebanic acid. Examples of aromatic dicarboxylic acids include phthalic acid, terephthalic acid, and isophthalic acid. In particular, adipic acid, azelaic acid, and sebacic acid are preferably used.

The number average molecular chain of the polymer diol used in the present invention is 1
000-3500, more preferably 1500-3000
It is. If it is less than 1,000, heat resistance and elastic recovery properties will decrease, and if it is greater than 3,500, spinnability will decrease.

Polymer diols other than those mentioned above may be used as the polymer diol used in the present invention, if necessary.

The polyester diol used in the present invention may be produced by any method. For example, using a method similar to the known method used in the production of polyethylene terephthalate or polybutylene terephthalate, that is, using a diol corresponding to the diol residue and a dicarboxylic acid or a ester-forming derivative thereof corresponding to the dicarboxylic acid residue. It can be produced by transesterification or direct esterification followed by melt polycondensation reaction.

The method for producing the polycarbonate diol used in the present invention is not particularly limited. For example, it can be produced by a method similar to the known method used in the production of polycarbonate from diphenyl carbonate and bisphenol A, that is, by transesterification.

The carbonate compound used in producing the polycarbonate diol used in the present invention is preferably diaryl carbonate such as dialkyl carbonate or diphenyl carbonate, or alkylene carbonate.

Suitable organic diisocyanates used in the present invention include aliphatic, ring ring or aromatic organic diisocyanates known in the art, specifically 4,
4°-diphenylmethane diisocyanate, p-phenylene diisocyanate, toluylene diisocyanate,
Examples include diisocyanates having a molecular weight of 500 or less, such as 1,5-naphthylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisonanate, and 4,4°-dicyclohexylmethane diisocyanate. Preferred organic diisocyanates are those having a molecular weight of 200 to 500, especially 4,4'-diphenylmethane diisocyanate. Note that as the organic diisocyanate, a compound having a blocked isocyanate group that is converted into a free isocyanate group may be used.

The chain extender used in the present invention is a chain extender commonly used in the polyurethane industry, that is, a low-molecular compound with a molecular weight of 400 or less containing at least 2 hydrogen atoms capable of reacting with isocyanate, such as ethylene glycol, 1, 4-butanediol, propylene glycol, 1,6-hexanediol, 3-methyl-1,5
-bentanediol, I, 4-bis(2-hydroxyethoxy)benzene, 1,4-cyclohexanediol,
Examples include falls such as bis(β-hydroxyethyl) terephthalate and xylene glycol. These compounds may be used alone or in combination of two or more. The most preferred chain extender is 1,4-butanediol (
BD) and/or 1,4-bis(2-hydroxyethoxy)benzene (BHEB).

By mixing BD and BHEB in a molar ratio of 9515 to 5/95, preferably 20/80 to 80/20, elastic recovery and flexibility can be greatly improved.

The quantitative relationship of the polymer diol, organic diisocyanate, and chain extender used to produce the polyurethane used in the present invention is such that the resulting polyurethane has particularly good heat resistance and elastic recovery properties. The amount of organic diisocyanate used is preferably 0.9 to 1.2 times the total number of moles of the polymer diol and chain extender used, and is preferably 0.95 to 1□15 times. More preferably, the amount is 02 to 1.15 times the number of moles of t, since the obtained polyurethane not only has the above-mentioned features but also can form elastic fibers with large elongation. is particularly preferred.

As for the method of producing a thermoplastic polyurethane by polymerizing a polymeric diol, an organic diisocyanate, and a chain extender, a known urethanization reaction technique can be employed. According to research conducted by the present inventors, it has been found that melt polymerization in the substantially absence of an inert solvent is preferable, and continuous melt polymerization using a multi-screw extruder is particularly preferable.

The temperature for melt polymerization is not particularly limited, but is 200°C or higher2.
The temperature is preferably 40°C or lower. By keeping the temperature below 240°C, heat resistance increases, and by keeping the temperature above 200°C, it becomes possible to produce a thermoplastic polyurethane with excellent spinnability.

Organic diisocyanate (
The ratio of B) (B)/(A) is the molar ratio t, S ~ 4.5
is required from the viewpoint of elastic recovery, texture, heat resistance, and cold resistance, and is preferably 1.8 to 4.0.

Matting agents such as titanium oxide, additives such as ultraviolet absorbers and antioxidants, and colorants such as dyes and pigments can be added to the polyurethane elastomer used in the present invention.

The polyurethane thus obtained can be made into fibers by conventionally known dry spinning methods, wet spinning methods, melt spinning methods, and the like.

Melt spinning is preferable because it allows for finer denier, and specifically, polyurethane is pelletized and then melt spun, or thermoplastic polyurethane obtained by melt polymerization is directly spun through a spinneret. can be adopted. From the viewpoint of spinning stability, direct polymerization spinning is preferred.

The polyurethane elastic fiber of the present invention has a logarithmic viscosity (η1nh) of 0.2 to 1.6 di.
2/g, particularly preferably 0.3 to 1.4 d12/g.

By setting it within this range, the fiber will have excellent elastic recovery properties. The logarithmic viscosity of the sample was n-
It can be determined from the following formula by dissolving it in N,N-dimethylformamide containing 1% by weight of butylamine and measuring it with an Utsperohde viscometer in a thermostat kept at 30°C for 24 hours.

77re(2=t/t.

(n(ηref) ηinh = t: solution flow time (seconds) and o: solvent flow time (seconds) C: polymer concentration (g/dI2) The polyurethane constituting the polyurethane elastic fiber of the present invention is substantially Generally speaking, (a) a divalent structural unit in which two hydrogen atoms in the hydroxyl groups at both ends of the molecule are removed from a polymeric diol, (b) a general formula derived from an organic diisocyanate (in the formula, R3 is a divalent organic group, and X and y each represent an integer 2 of 0 or 1. It consists of a structural unit represented by a divalent structural unit with two reactive hydrogen atoms removed, where the structural unit (a) forms a urethane bond with the structural unit (b). It is considered that some of the structural units (b) may be bonded to other structural units (b) by forming an allophanate bond.

Furthermore, polymeric diol (A), organic diisonanate (
B), chain extender (C) in a composition ratio of (B)/[(
A) + (C) A thermoplastic polyurethane polymerized with an excess isocyanate system having a molar ratio of 1.02 to 1.15, or a polyisocyanate compound or a blocked polyisocyanate compound added and mixed during spinning B)/ [(
By spinning a polyurethane containing an excess of isocyanate with a molar ratio of A) + (C) of 1.02 to 1.15,
The molar ratio of (b)/[(a) + (c)] is 1
．． 02 to 1.15, polyurethane elastic fibers with excellent heat resistance, elastic recovery properties, and high elongation can be obtained.

A polyisocyanate compound is a compound having at least two isocyanate groups in the molecule, for example, 4,4゛-, which is commonly used in polyurethane production.
Diphenylmethane diisocyanate, tolylene diisocyanate, naphthalene diisocyanate, and isocyanate-terminated prepolymers synthesized by reacting polyols with a molecular weight of 300 to 3,000 with more than twice the equivalent of organic diisocyanates with a molecular weight of 500 or less. Dimers of diisocyanate or carbodiimide-modified polyisocyanates are included. The number of isocyanate groups contained in one molecule of the polyisocyanate compound is preferably 2 to 3, and a diisocyanate compound having 2 is particularly preferred.

In addition, the term "blocked polyisocyanate compound" refers to the isocyanate group of the polyisocyanate compound that is substituted with phenol, ε
- Compounds that are reacted with caprolactam, oxime ethyl acetoacetate, acetamide, etc., and include all compounds that cause thermal dissociation at high temperatures to produce free isocyanate groups.

The molecular weight of a suitable polyisocyanate compound is 200-3
It is 000. If the amount of the polyisocyanate compound added to the polyurethane is too small, the effect of the present invention will be small, and if it is too large, the spinnability will become unstable. For polyurethane to which a polyisocyanate compound is added during spinning, (B)/
The molar ratio of [(A) + (C)] is 0.95 to 1.08
Those polymerized with are preferred.

The polyurethane elasticity of the present invention is obtained by spinning the above-mentioned polyurethane containing an excess of isocyanate, and then spinning the fiber with an excess of n-butylamine. ON f) The amount of allophanate bond dissolved in N,N-dimethylformamide solution and determined by back titration is o, oos ~ 0.05 mmof2
/g, the fiber can have excellent elastic recovery properties.

In order to obtain the polyurethane elastic fiber of the present invention that satisfies the above conditions (I) and (II) by the melt spinning method, for example, the method described below is used.

First, the spinning speed is important; 900 m/min or less;
In particular, it is preferable to set it to below Boom/min.

Apparent draft rate (nozzle single hole area/single fiber cross-sectional area) is 5
0 or more, preferably 100 or more, more preferably 150 or more.

Further, the spinning tension when winding the spun yarn onto a bobbin with a winding machine is 0.1 g/d or less, more preferably 0.
．． It is preferable that the yarn feeding speed difference from the godet roller to the winding machine does not exceed 5% underfeed, and it is particularly preferable that the yarn feeding speed be close to a constant speed.

In addition, the wound yarn was heated from +20'C to 15°C with respect to the glass transition point (Tg) of the hard segment under low humidity.
7) It is preferable to carry out the heat treatment in the range of 0°C to sufficiently perform phase separation from the -do and knot segments.

Furthermore, as mentioned above, polyurethane spun with an excess of isocyanate changes its yarn quality and thermal properties over time. This is polyurethane polymerized with an excess of isocyanate. This is due to the formation of allophanate bonds through reactions such as urethane bonds and urethane bonds.

As this reaction progresses, improved effects such as improved elastic recovery, improved heat resistance, and increased elongation can be achieved, which is particularly noticeable when the polymeric diol used in the present invention is used.

In addition, when carrying out the present invention, Z is 70 to 12 mm after spinning.
Preferably, the heat treatment is carried out at 0°C for 1 to 48 hours.

Although the causes of these are not clear, it is presumed that the above-mentioned effects become more pronounced because microphase separation is progressing in the polyurethane made from the long-chain glycol-based polymer diol of the present invention.

The polyurethane elastic fiber of the present invention has good hot water resistance, and the hot water resistant strength retention rate is 60% or more, preferably 70%.
% or more (fibers that are 60% or more when measured at 120°C but less than 60% when measured at 135°C are also included within the scope of the present invention).

Further, the polyurethane elastic fiber of the present invention has good elastic recovery properties, and a practical elastic recovery rate is 80% or more, preferably 90% or more.

It is practical for the polyurethane elastic fiber of the present invention to have an elongation of 350% or more, preferably 450% or more.

Furthermore, the polyurethane elastic fibers referred to in the present invention are substantially continuous 'a fibers or Ia fibers, and have a length of loom.
It is preferable that the unevenness of fineness when removed is within ±15%, more preferably within ±IO%.

As described above, the elastic fiber made from polyurethane using the polymeric diol of the present invention has excellent heat resistance, water resistance, and elastic recovery, and has high elongation and good chlorine resistance.

This will be explained below using examples.

In addition, hot water resistance (strength retention) and elastic recovery rate in Examples were measured by the following methods.

・Hot water resistance (strength retention) The sample was stretched and fixed by 10%, and the tensile strength retention was measured after heat treatment with hot air at 160°C for 1 minute and hot water treatment at 130°C for 90 minutes.

・Measurement of strength and elongation , strength and elongation were determined according to MSL-1013.

・Elastic recovery The sample was stretched by 200% and held for 1 minute, then the tension was removed and the elastic recovery rate was measured after being left for 3 minutes.

Elastic recovery rate = (1-(Q-Qo)/12o) x
100 (%) Q; Length of the sample after being left for 3 minutes after tension removal Qo; Length of the sample before elongation The compounds used are indicated using abbreviations, but the relationship between the abbreviations and compounds is as follows. be. (Table 1) Reference Example I (Manufacture of polyester diol) Mixture of 2-methyl-1,8-octanediol and 1,9-nonanediol (molar ratio 235/65) 1600
1,460 g of adipic acid (molar ratio of diol/adipic acid: IJ/l) were esterified at a temperature of about 220° C. under normal pressure while passing nitrogen gas while distilling off condensed water. When the acid value of the polyester became 0.3 or less, the degree of vacuum was gradually increased using a vacuum pump to complete the reaction. In this way, a polyester diol (hereinafter referred to as polyester a) having a hydroxyl value of 56 and an acid value of 0.12 was obtained. The molecular weight of this polyester a was 2,000.

Reference Examples 2 to 9 Polyesters (polyesters b to I) shown in Table 2 were obtained in the same manner as in Reference Example except that the acid components and diol components shown in Table 2 were used.

Reference Example 11 (Manufacture of polycarbonate and diol) Under nitrogen stream, 2
-Methyl-1,8-octanediol (MOD) and 1.
A mixture of 1730 g of 9-nonanediol (ND) (MOD/ND molar ratio: 35/65) and 2140 g of diphenyl carbonate was heated, and 2
Phenol was distilled off from the reaction system at 00°C. The temperature was gradually raised to 210 to 220°C, and after most of the phenol had been distilled off, vacuum was applied, and 6 to 10 mm and 1 g of 210
The remaining phenol was completely distilled off at ~220°C. As a result, a polycarbonate diol (polycarbonate k) having 56 hydroxyl groups and a molecular weight of 2000 was obtained.

Reference Example 12 As a diol component, 9-nonanediol 1730
The molecule It 2 was prepared in the same manner as in Reference Example 11 except that g was used.
000 polycarbonate diol (polycarbonate I2) was obtained.

Margin examples below! A food stall made of polyester a and BD heated to 30°C and MDI heated and melted to 50°C are combined into polyester a.
/MDI/BD usage molar ratio is 1/3/
2 was continuously charged into a twin-screw extruder rotating in the same direction using a metering pump, and continuous melt polymerization was performed. At this time, the temperature of the middle part (polymerization temperature) is 2.
The temperature was 30°C. The polyurethane produced was continuously extruded into water in the form of a strand, and then formed into pellets using a pelletizer.

The pellets were vacuum-dried for 80' CIO hours, and then spun at a spinning temperature of 235°C and a spinning speed of 65°C using a spinning machine equipped with a single-screw extruder.
Spinning was carried out at a spinning speed of 0 Ill/min, an apparent draft rate of 816, a spinning tension of 0.05 g/d, and a yarn feeding speed difference of 20 m/min to obtain a polyurethane fiber of 70 denier/2 filaments. When this wt specimen was heat treated at 80° C. for 20 hours and its physical properties were measured, favorable results were obtained as shown in Table 3.

Examples 2 to 5 Polyurethanes having the compositions shown in Table 3 were synthesized in the same manner as in Example 1, and fed to the spinning head as they were without being pelletized, at a spinning temperature of 235° C. and a spinning speed of 800 m/min. Spinning tension at apparent draft rate: 0.06 g/d,
70 denier/2 by spinning with a yarn feeding speed difference of 30 m/min
A filament polyurethane fiber was obtained.

When this fiber was heat treated at 100° C. for 48 hours and its physical properties were evaluated, favorable results were obtained as shown in Table 3.

Example 6 Polycarbonate polyurethane having the composition shown in Table 3 was
Synthesis and spinning heat treatment were performed in the same manner as in Example 1, and the physical properties were measured. As shown in Table 3, favorable results were obtained, particularly excellent in hot water resistance.

Comparative Example 1 Polyurethane fibers having the composition shown in Table 3 were obtained in the same manner as in Example 1, and the physical properties were evaluated.As shown in Table 3, the elongation, hot water resistance, and elastic recovery were extremely poor. became.

Comparative Example 2 Polyurethane obtained in the same manner as in Example 4 except that the composition of the polyurethane was changed to the composition shown in Table 3 Comparative Example 3 Physical properties of polyurethane mi obtained in the same manner as in Example 1 and having the composition shown in Table 3 When evaluated, elongation, elastic recovery,
It had poor hot water resistance.

Comparative Examples 4 to 6 When the physical properties of polyurethane fibers having the compositions shown in Table 3 obtained in the same manner as in Example 1 were evaluated, they were found to be poor in terms of elastic recovery and elongation.

Comparative Example 7 In the same manner as in Example 1, the apparent draft rate was set to 30, and the spinning tensicon was 0.1 g/dr1, and the yarn feeding speed difference was 20.
Spinning was performed at m/min to obtain polyurethane elastic m-fibers of 70 denier/2 filaments. This fiber is 80"C20
When the material was heat treated for a period of time and its physical properties were measured, as shown in Table 3, the elongation and elastic recovery were low, which were unfavorable results.

Example 7 A mixture of polyester a and BD heated to 30°C and MDI heated and melted to 50°C were mixed into polyester a.
/MDI/BD used molar ratio is l/3.
Example 1 except that the amount of 24/2 was continuously charged into a twin screw extruder rotating in the same direction using a metering pump.
In the same manner as above, a 70 denier/2 filament polyurethane fiber was obtained. This fiber was heat treated at 80°C for 20 hours,
When the physical properties were measured, favorable results were obtained as shown in Table 4.

Example 8 Polyurethane having the composition shown in Table 4 was combined in the same manner as in Example 1, and fed to the spinning head as it was without being made into pellets. Polyurethane fibers of 70 denier/2 filaments were obtained by spinning at a draft rate, a spinning tension of 0.07 g/d, and a yarn feeding speed difference of -10 m/l lin. When this fiber was heat treated at 100° C. for 48 hours and its physical properties were evaluated, favorable results were obtained as shown in Table 4.

Examples 9 to 11 Polyurethane 3 having the composition shown in Table 4 in the same manner as Example 1
The seeds were synthesized and made into a beret. These pellets at 80℃
After vacuum drying for 12 hours, it was extruded using a twin-screw extruder equipped with a loss-in weight type feeder, and from the vent part, polyisocyanate was obtained with a molecular weight of 5.
00 P T G 1. : Two times the mole of MDI reacted, in Example 11, MDI blocked with ε-caprolactam, was mixed with a metering pump so that the molar ratio of (B)/[(A)+(C) was 1, 12.1
．． 12.1.15 was added to cause crosstalk. This molten polyurethane was supplied as it was to the spinning head, and the spinning temperature was 235°C, the spinning speed was 800 m/aIin, the apparent draft rate was as shown in Table 4, and the spinning tension was 0.06 g/d.
Spun at a yarn feeding speed difference of 20 m/win, 70 denier/2
Three types of filament polyurethane fibers were obtained. These fibers were heat treated at 100° C. for 24 hours and their physical properties were evaluated, and as shown in Table 4, they were favorable.

Example 12 Polycarbonate polyurethane having the composition shown in Table 4 was
Synthesis and spinning heat treatment were carried out in the same manner as in Example 1, and physical properties were measured. As shown in Table 4, favorable results were obtained, particularly excellent in hot water resistance.

Comparative Example 8 Polyurethane fibers having the compositions shown in Table 4 were obtained in the same manner as in Example 1, and their physical properties were evaluated. As shown in Table 4, the hot water resistance and elastic recovery properties were extremely poor.

Comparative Example 9 The composition of polyurethane was as shown in Table 4, and Example IO
(B) after adding polyisocyanate in the same manner as [
(A)+(C)] of 1.08 was obtained. When the physical properties of the fiber were evaluated, it was found that the elongation was good, but the hot water resistance and elastic recovery were poor.

Comparative Example 1O When the physical properties of the polyurethane fiber having the composition shown in Table 4 obtained in the same manner as in Example 1 were evaluated, it was found to have poor hot water resistance.

Comparative Examples If-13 When the physical properties of polyurethane fibers having the compositions shown in Table 4 obtained in the same manner as in Example 1 were evaluated, they were found to be poor in terms of elastic recovery and elongation.

The following margin Example 13 Polyester a, BD and BHEB (molar ratio 7/
3) and a mixture heated to 30°C consisting of 5
MDI heated and melted at 0°C and polyester/MD
The molar ratio of I/(BD/BHEB) used is 1/3.
An amount of 3/(1,4+0.6) was continuously fed into a twin screw extruder rotating in the same direction using a metering pump, and continuous melt polymerization was performed. At this time, the extruder was divided into three zones: front, middle, and rear, and the temperature (polymerization temperature) in the middle was 230°C. The polyurethane produced was continuously extruded into water in the form of a strand, and then formed into pellets using a pelletizer.

The pellets were dried in a vacuum at 80°C for 16 hours, and then spun using an ordinary single-screw extruder spinning machine at a spinning temperature of 240°C, a winding speed of 800 m/win, an apparent draft rate shown in Table 5, and a spinning tension of 0.02 g/win. d, Yarn feeding speed difference -10m/m
A polyurethane fiber of 70 denier/2 filaments was obtained. 80% of the obtained polyurethane fiber
After heat treatment at ℃ for 24 hours, good results were obtained when strength, elongation, elastic recovery rate, and hot water resistance were measured.

Examples 14-15 Polyurethane pellets having the composition shown in Table 5 were obtained in the same manner as in Example 13, and the results of spinning in the same manner as in Example 13 are shown in Table 5.
Shown below.

Example 16 Polyurethane pellets having the composition shown in Table 5 were obtained in the same manner as in Example 13. The pellets were vacuum-dried at 80°C for 24 hours, extruded using a twin-screw extruder with a loss-in-weight meter, and the isocyanate-terminated prepolymer made by reacting PTG with a molecular weight of 500 with twice the equivalent of MDI was melted from the vent part. Then, the composition was supplied using a metering pump to obtain the composition shown in Table 5, thoroughly kneaded, and extruded from the spinning head at 240°C.
A polyurethane fiber of 70 denier/2 filaments was obtained by winding at a speed of 0 m/min. This fiber was heated at 90℃30
As a result of heat treatment for a period of time and measurement of physical properties, good results were obtained.

This is shown in Table 5.

Example 17 Example! Polyurethane pellets having the composition shown in Table 5 were obtained in the same manner as in Example 3. The pellets were vacuum dried at 80°C for 24 hours and extruded using a single-screw extruder with a kneading function at the tip. Caprolactam was reacted with MDI as a blocked isocyanate compound in the middle of the cylinder of the extruder, just before the kneading function. A mixture obtained by heating and melting the isocyanate groups blocked was injected using a metering pump to obtain the composition shown in Table 5, kneaded, and extruded. It was further kneaded using a 56-element static mixer, and spun at a spinning temperature of 235°C and a winding speed of 700 m/ff1in.
A polyurethane fiber of 0 denier/2 filaments was obtained.

When this fiber was heat treated at 110° C. for 48 hours and its physical properties were measured, the good results shown in Table 5 were obtained.

Comparative Examples 14 to 19 Polyurethane fibers were obtained in the same manner as in Example 13, and the results shown in Table 5 were obtained. Although the strength was good, the elongation was low and the hot water resistance was poor (Comparative Examples 17 and 18 were good)
Also, the elastic recovery rate was poor, and a satisfactory result could not be obtained.

Example 18 The same procedure as Example 13 was carried out except that polycarbonate k was used as the polymeric diol and the molar ratio of polycarbonate/MD I/(HD+BHEB) was 1/3.15/(1,4+0.8). Polyurethane pellets were obtained. Using this pellet, the amount of isocyanate-terminated prepolymer (polyisocyanate compound) added is (B)
/ [(A) + (C)] Polyurethane fibers were obtained in the same manner as in Example 16, except that the molar ratio was 110. This fiber was heat treated at 90'C for 20 hours and its properties were measured. As shown in Table 5, good results were obtained, particularly in hot water resistance.

Comparative Example 20 The physical properties of the polyurethane fiber obtained in the same manner as in Example 13 except that the composition was as shown in Table 5 were measured, and as shown in Table 5, it had unsatisfactory low elastic recovery and elongation. It was the result.

Example 19 Polyurethane and urethane having the same composition as in Example 13 were synthesized in the same manner, fed directly to the spinning head without being made into pellets, and spun at a spinning temperature of 240° C. and a spinning speed of HOm/min to obtain 70 denier/ A two-filament polyurethane fiber was obtained. This fiber was heat treated at 100°C for 30 hours and its physical properties were measured, and as shown in Table 5, the properties were favorable.

Below is a margin [Effects of the Invention] As is clear from the above examples, the polyurethane elastic fiber of the present invention has high elongation, good elastic recovery, and excellent hot water resistance and heat resistance, making it highly useful. Moreover, it has become possible to respond to a wide range of applications.

Claims (1)

[Scope of Claims] A polyurethane elastic fiber made of polyurethane obtained by polymerizing a polymeric diol (A), an organic diisocyanate (B), and a chain extender (C), which has a number average as the polymeric diol. It consists of a structural unit represented by (1) General formula ▲ Numerical formula, chemical formula, table, etc.▼ with a molecular weight of 1000 to 3500, where R^1 is the following structural unit (I), (II) and/or (III). ) and R^
2 is a polyester diol, which is a divalent organic group, or (2) a structural unit represented by the general formula ▲ Numerical formula, chemical formula, table, etc. ▼, where R^1 is the following structural unit (I), ( II) and/or (III), and the following structural units (I), (II), and (III) occupying R^1 are [(II)+(
III)]/[(I)+(II)+(III)] is 0 in molar ratio
．． 1 or more, and [(I)+(II)]/[(I)+(
II) + (III)] with a molar ratio of more than 0.5 is used as the main component, −(CH_2)＿■−・・・(I) ▲Mathematical formulas, chemical formulas, tables, etc. are included▼・......(II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼......(III) The molar ratio of (B)/(A) is 1.5 to 4.5, and the following formula ( A polyurethane elastic fiber characterized by satisfying the conditions IV) and (V). Hot water resistance strength retention rate (%)≧60...(IV) Elastic recovery rate (%)≧80...(V)