JPH0782608A - Prodution of high-tenacity eleasic yarn - Google Patents

Abstract

PURPOSE:To obtain elastic yarn of polyurethane-urea having excellent stability of polymer solution, developing high strength at break, not causing knitting unevenness in processing, by specifying a fraction of 2,4'-diphenylmethane diisocyanate. CONSTITUTION:A substantially linear polymer diol having 600-5,000 molecular weight and diphenylmethane diisocyanate having 1.80-13.0wt.%, preferably 3.00-10.0wt.% fraction of 2,4'-diphenylmethane diisocyanate. The isocyanate group of the prepared intermediate polymer containing end isocyanate group is reacted with an amino compound to give a polymer. The polymer is spun.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polyurethane urea elastic yarn, and more specifically, 2,4'-diphenylmethane diisocyanate (hereinafter 2,4'-MDI).
And a diphenylmethane diisocyanate (hereinafter referred to as MDI) containing an essential component, which is excellent in stability of a polymer solution, exhibits high breaking strength, and does not cause uneven knitting when processed. The present invention relates to a manufacturing method capable of manufacturing.

[0002]

2. Description of the Related Art Generally, a polyurethaneurea elastic material is obtained by reacting a polymer diol such as polyester or polyether having a hydroxyl group at a terminal group with an excess molar amount of an organic diisocyanate to obtain a polyurethane intermediate polymer having an isocyanate group at both terminals. A segmented polyurethane urea is produced by reacting a diamino compound having an active hydrogen capable of easily reacting with an isocyanate group of the intermediate polymer with an inert organic solvent, followed by molding and removing the solvent. It is obtained by

Due to its elastic properties, polyurethane urea elastic yarn is used in a swimsuit, foundation, innerwear, support type pantyhose, etc., mixed with nylon, polyester, etc. 1.75 g to obtain an elastic yarn with excellent processing performance that does not cause thread breakage during product processing
It is necessary to spin a segmented polyurethane urea which exhibits a high breaking strength of / D or more. As a method of improving the breaking strength, for example, there is a method of increasing the spinning speed to increase the tension in the spinning cylinder, but there is a drawback that the breaking elongation decreases due to the orientation of the molecular chains. As a method of solving this, there is a method of increasing the polymerization degree of the polymer, but if the polymerization degree of the polymer is excessively increased, an elastic yarn with high breaking strength can be obtained, but the viscosity of the stock solution increases and the elongation at break decreases. To do. It is also considered that the aggregation of the polymer proceeds, but the viscosity of the polymer solution increases with time and becomes unstable, making it difficult to spin a yarn of constant quality. It tends to cause spots. Therefore, there is a limit to increase the polymerization degree of the polymer, and the expected effect cannot be obtained.

According to Japanese Examined Patent Publication (Kokoku) No. 4-74457, an isocyanate-terminated intermediate polymer and an active hydrogen-containing polyfunctional and monofunctional amino compound are used in a quantitative ratio of 1.5 ≦. (B + C−A) / C ≦ 5.
0 (however, in the formula A: equivalent amount of isocyanate group in intermediate polymer, B: equivalent amount of polyfunctional amino compound, C: equivalent amount of functional amino compound), the polymer obtained by the reaction is spun. After taking, it is heat treated to obtain a high molecular weight elastic yarn that exhibits excellent elastic properties. However, in this method, the number of post-processes such as heat treatment after the winding of the spinning yarn is increased, which not only has a disadvantage in operation, but also does not satisfy the physical properties listed in the present invention.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyurethane urea elastic yarn which is excellent in stability of a polymer solution, exhibits high breaking strength and does not cause uneven knitting during processing.

[0006]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made intensive studies to solve the above-mentioned drawbacks and obtain an excellent elastic yarn having a high breaking strength. As a result, the fluidity of a polymer solution, particularly a hard segment, is The inventors arrived at the present invention by discovering that it affects yarn uniformity. That is, the present invention has a molecular weight of 6
A substantially linear polymer diol having a content of 00 to 5000 and MDI having a 2,4′-MDI fraction of 1.80 to 13.0 wt% are subjected to an excess molar reaction with respect to the diol,
After obtaining an intermediate polymer having a terminal isocyanate group, a polymer obtained by reacting the isocyanate group of the intermediate polymer with an equivalent or excess amount of an amino compound is spun,
It is a manufacturing method capable of providing an elastic yarn having a high breaking strength.

The polyurethane urea elastic material in the present invention is obtained by reacting a polymer diol and MDI containing a predetermined amount of 2,4'-MDI in an inert organic solvent,
It is a polyurethane urea polymer obtained by producing an intermediate polymer having substantially isocyanate groups at both ends and reacting the intermediate polymer with a polyfunctional amino compound and a monofunctional amino compound.

The polymer diol used has a number average molecular weight of 600 to 5000, preferably 1000 to 30.
00 substantially linear polymer diols such as polyether diols such as polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol, polyoxypentamethylene glycol, polyoxypropylene tetramethylene glycol, and adipic acid. , Sebacic acid, maleic acid, itaconic acid, azelaic acid, malonic acid and the like, one or more dibasic acids and ethylene glycol, propylene glycol, 1,3-propanediol, 2,2-dimethyl-
1,3-propanediol, 1,4-butanediol,
2,3-butanediol, hexamethylene glycol,
Diethylene glycol, 1,10-decanediol,
Polyester diols obtained from one or more glycols such as 1,3-cyclohexanedimethanol and the like, polylactone diols such as poly-ε-caprolactone and polyvalerolactone, polyester amide diols, polythioether diols and polycarbonates Mention may be made of diols, or mixtures thereof.

The organic diisocyanate used in the present invention is 1.80 to 13.0% by weight of 2,4'-MDI. Considering the stability of the polymer solution, the lower limit is preferably 3.
Considering the heat resistance when molded into an elastic yarn, the upper limit is preferably 10.0% by weight, that is, 3.00 to 10.0% by weight, preferably MDI, and the rest is 4,4 '. -MDI. The control of the 2,4'-MDI fraction is 2,4'-in addition to the commercially available 4,4'-MDI.
This can be easily done by adding a predetermined amount of liquid MDI containing a large amount of MDI. The 2,4′-MDI fraction in MDI can be measured by gas chromatography with MDI dissolved in 1,2-dichloroethane. The 2,4'-MDI fraction described in the present invention means a value represented by the following equation. That is, 2,4′-MDI fraction (%) = 2
4'-MDI weight / (2,4'-MDI weight + 4,4 '
-MDI weight) x 100. Further, the ratio of the molar amount of the polymer diol used in the present invention to the molar amount of the organic diisocyanate is 1: 1.3 to 1: 2.0, but is not particularly limited.

As the polyfunctional amino compound, ethylenediamine, propylenediamine, hexamethylenediamine, trimethylenediamine, hexamethylenediamine, hydrazine, carbodihydrazide, adipic acid dihydrazide, N, N-bis (γ-aminopropyl)- N,
Examples thereof include bifunctional aliphatic diamines such as N-dimethylethylenediamine, aromatic diaminourea compounds, and mixtures thereof.

Examples of monofunctional amino compounds used at the same time include dimethylamine, ethylmethylamine, diethylamine, methylpropylamine, isopropylmethylamine, diisopropylamine, butylmethylamine, isobutylmethylamine and isopentylmethylamine. You can Examples of the inert organic solvent used in the present invention include solvents capable of dissolving the above-mentioned various raw materials and dissolving or dispersing the resulting polyurethaneurea polymer, for example, solvents such as dimethylformamide, dimethylacetamide and dimethylsulfoxide. .

The reaction between the intermediate polymer and the amino compound is usually carried out by introducing an inert solvent solution containing a polyfunctional amino compound and a monofunctional amino compound into an inert organic solvent solution of the intermediate polymer. A polymer is produced. Here, the monofunctional amino compound is reacted with the polyfunctional amino compound having an isocyanate group in the intermediate polymer and an amino group of 1.0 to 1.5 times the isocyanate group. At this time, the concentration of the polymer solution is 20 to 45% by weight.
Is preferred, and the viscosity of the polymer solution is 200 at 30 ° C.
0-7000 poise (B type viscometer),
The degree of polymerization of the polymer is determined by adjusting the addition ratio of the polyfunctional amino compound and the monofunctional amino compound. When the concentration of the polymer solution exceeds 45% by weight, the hard segments in the polymer solution are aggregated, which makes it difficult to maintain a constant viscosity and the stability of the stock solution is reduced.
If the amount is less than 20% by weight, the amount of solvent evaporated during spinning is large, so under a certain amount of heat, the amount of heat used for latent heat of evaporation of the solvent is large, and the amount of heat used to express the physical properties of the yarn is small, resulting in a decrease in breaking strength To do. Viscosity of polymer solution is 7000
If it exceeds poise, the pressure during spinning becomes too high, making spinning in a spinning cylinder difficult, and if it is less than 2000 poise, the yarn in the spinning cylinder will sway greatly during spinning, resulting in large yarn unevenness, which is not preferable. Therefore, the concentration of the polymer solution is 20 to 45% by weight and the viscosity is 2000 to 7000.
It is preferable to adjust the poise range to obtain a uniform yarn.

The stability of the polymer solution can be evaluated by measuring the viscosity of the polymer solution immediately after the polymerization of polyurethaneurea and the viscosity of the polymer solution after one week. If the polymer solution viscosity after one week when left at room temperature is almost the same as the viscosity immediately after polymerization (the difference is less than 200 poise (B type viscometer)), it is stable. The obtained polymer solution is usually dry-spun and wound on a bobbin by a conventional method.

In the solution of the polyurethaneurea polymer of the present invention, if desired, a gas yellowing inhibitor which is usually used,
Stabilizers such as UV absorbers, barium sulfate, magnesium silicate, calcium silicate, inorganic fine particles such as zinc oxide, magnesium stearate, polytetrafluoroethylene,
An anti-tacking agent such as organopolysiloxane and other aligning agents may be appropriately blended. Further, after spinning, known oil agents, lubricants and the like can be added.

2,4 'in MDI used as a raw material
-The reason why the breaking strength is high when the MDI fraction is 1.80 to 13.0% by weight is probably because the isocyanate group is 2,
Due to its steric hindrance due to its 4'position,
As a result of intermolecular hydrogen bonds in the hard segment or intramolecular hydrogen bonds being disturbed and intermolecular cohesion less likely to occur, the polymer solution becomes a uniform dispersed phase of the hard segment, and therefore the hard segment becomes in the yarn during spinning. It is thought that this is because the particles can be dispersed uniformly, the agglomerates of huge hard segments do not exist in the yarn, and the defect structure of the yarn is extremely reduced. The 2,4'-MDI fraction in MDI is 1.8.
If it is less than 0% by weight, the higher order structure of the hard segment in the polymer solution is non-uniform, so non-uniform spots remain on the spun yarn as it is, causing knitting during processing, and only a yarn with normal breaking strength is obtained. However, it is difficult to increase the concentration of the polymer solution in consideration of the stability of the polymer solution. If the 2,4'-MDI fraction exceeds 13.0% by weight, 2,4'-MDI disturbs the hard segment portion, and the heat resistance is lowered, which is not preferable. Therefore, the 2,4′-MDI fraction in MDI is preferably 1.80 to 13.0% by weight, preferably 3.00 to 10.0% by weight, and the stability of the polymer solution is high and the heat resistance is maintained. An elastic yarn having high breaking strength and free from knitting can be obtained.

The heat resistance of the yarn can be evaluated by the time until the yarn is cut by pressing the yarn against the wall surface of the metal cylinder controlled at 180 ° C. under 50% elongation (hereinafter referred to as heat-resistant cutting seconds). Considering the heat resistance of the yarn at the time of heat setting, the heat-resistant cutting time is preferably 130 seconds or more. The knitting unevenness during processing can be evaluated by the stress fluctuation when the stress (hereinafter referred to as running stress) when the elastic yarn is run at the draft rate of 3.0 is recorded in the chart. There is a correlation between running stress fluctuations and knitting unevenness. When running stress fluctuations are small, there are few knitting spots, and when running stress fluctuations are large, there are many knitting spots.

[0017]

EXAMPLES Specific examples of the present invention will be described with reference to the following examples. In addition, 2,4'-M in the raw material MDI in the examples
The DI fraction, the characteristic value of the yarn, the running stress variation, and the heat-resistant cutting seconds were measured by the following methods. (1) Fraction of 2,4'-MDI in raw MDI (a) Sample preparation MDI containing a predetermined amount of 2,4'-MDI was melted and stirred in a warm water bath at 80 ° C for 1 hour, and then put in a 20 ml sample bottle. 0.
Weigh 50 g, 10.00 g of 1,2-dichloroethane
Addition, stirring and dissolution were used as an analytical sample.

(B) 2, by gas chromatography
4'-MDI fraction quantitative measuring instrument: HEWLETT PACKARD HP58
90 column: Ultra-1 (Crosslinked M
Ethyl Silicone Gum) INJ: 300 ° C. FID: 300 ° C. Column: 200 ° C. (0 min) −5 ° C./min-275
C (0 min) Carrier: He Sample amount: 1 μl Quantitative method: The 2,4′-MDI fraction was determined by the relative area ratio of isomers. (2) Characteristic value of yarn (a) Measuring condition Measuring instrument: Tensile tester Toyo Baldwin UT
M-III-100 Conditions: Initial length 50 mm, elongation speed 500 mm / min Evaluated by breaking strength (g / D) and elongation at break (%) when elongated under the above conditions. (3) Fluctuation of running stress: A roller for feeding and a roller for winding are installed at intervals of 1.5 m, and a stress measuring device (EIKO S) is installed at the center between the rollers.
OKKI type 3000) is placed and the feed speed is 43m /
The elastic yarn was run at min and a winding speed of 98 m / min, and the stress fluctuation at that time was recorded on a chart. It evaluated by the following judgments.

Judgment: Almost no variation ◎ Some variation was observed ○ Large variation × (4) Heat-resistant cutting seconds: 50% on the wall surface of the metal cylinder controlled to 180 ° C
The time until the thread was pressed under the extension and cut was determined.

[0020]

Example 1 Solid MDI of Nippon Polyurethane Co., Ltd.
(Brand name Millionate MT, 2,4'-MDI fraction 1.
2% by weight) liquid MDI of Takeda Badish Industry Co., Ltd.
(Product name Luplanate MI, 2,4'-MDI fraction 50
(% By weight) is added in a predetermined amount to give a 2,4'-MDI fraction of 1.8.
217.47 parts by weight of MDI adjusted to 0% by weight and 1000 parts by weight of polyoxytetramethylene glycol having a number average molecular weight of 1800 were reacted at 80 ° C. for 3 hours. After completion of the reaction, N, N-dimethylacetamide 1826.2
1 part by weight was added to obtain an intermediate polymer solution.

Ethylenediamine 1 was added to the intermediate polymer solution.
A mixed solution consisting of 7.22 parts by weight, diethylamine 2.87 parts by weight and N, N-dimethylacetamide 1007.15 parts by weight was introduced, mixed and reacted to obtain a 30% by weight polymer solution. The viscosity of the polymer solution is 30 ° C.
The measurement resulted in 3500 poise (B-type viscometer). The viscosity of the obtained polymer solution after one week when left at room temperature was as stable as the viscosity immediately after polymerization.

The polymer solution is dry-spun by a conventional method,
An elastic yarn of 20D / 2 filament was obtained. The characteristic values of the elastic yarn are as follows: breaking strength 1.90 g / D, breaking elongation 630%,
The running stress fluctuation was judged as good and the heat-resistant cutting time was 300 seconds.

[0023]

[Example 2] The 2,4'-MDI fraction in the raw material MDI was adjusted to 3.00% by weight and the same procedure as in Example 1 was repeated.
A 30 wt% polymer solution of 00 poise was prepared. The viscosity of the obtained polymer solution after one week when left at room temperature is as stable as the viscosity immediately after polymerization,
An elastic yarn of 20D / 2 filament was obtained using this polymer solution. The characteristic value of the elastic yarn is a breaking strength of 2.02 g.
/ D, elongation at break 629%, running stress variation judgment ⊚, heat resistant cutting time 282 seconds.

[0024]

[Example 3] The 2,4'-MDI fraction in the raw material MDI was adjusted to 5.00% by weight, and the same method as in Example 1 was used.
A 30 wt% polymer solution of 00 poise was prepared. The viscosity of the obtained polymer solution after one week when left at room temperature is as stable as the viscosity immediately after polymerization,
An elastic yarn of 20D / 2 filament was obtained using this polymer solution. The characteristic value of the elastic yarn is a breaking strength of 2.10 g.
/ D, elongation at break 625%, running stress variation judgment ⊚, heat-resistant cutting seconds 260 seconds.

[0025]

[Example 4] The 2,4'-MDI fraction in the raw material MDI was adjusted to 7.00% by weight, and the same method as in Example 1 was used.
A 30 wt% polymer solution of 00 poise was prepared. The viscosity of the obtained polymer solution after one week when left at room temperature is as stable as the viscosity immediately after polymerization,
An elastic yarn of 20D / 2 filament was obtained using this polymer solution. The characteristic value of the elastic yarn is a breaking strength of 2.31 g.
/ D, elongation at break 620%, running stress variation judgment ⊚, heat resistant cutting time 223 seconds.

[0026]

[Example 5] The 2,4'-MDI fraction in the raw material MDI was set to 1
Adjust to 0.0% by weight and 300 in the same manner as in Example 1.
0 poise of a 30% by weight polymer solution was prepared.
The viscosity of the obtained polymer solution after one week when left at room temperature was as stable as the viscosity immediately after polymerization, and an elastic yarn of 20D / 2 filament was obtained using this polymer solution. The characteristic value of the elastic yarn is a breaking strength of 2.40 g /
D, elongation at break 622%, running stress variation judgment ⊚, heat-resistant cutting seconds 179 seconds.

[0027]

[Example 6] The 2,4'-MDI fraction in the raw material MDI was set to 1
Adjust to 3.0% by weight and 300 in the same manner as in Example 1.
0 poise of a 30% by weight polymer solution was prepared.
The viscosity of the obtained polymer solution after one week when left at room temperature was as stable as the viscosity immediately after polymerization, and an elastic yarn of 20D / 2 filament was obtained using this polymer solution. The characteristic value of the elastic yarn is a breaking strength of 2.50 g /
D, elongation at break 623%, running stress variation judgment ⊚, heat resistant cutting time was 135 seconds.

[0028]

Example 7 The 2,4′-MDI fraction in the raw material MDI was adjusted to 5.00% by weight, an intermediate polymer solution was synthesized in the same manner as in Example 1, and the intermediate polymer solution was added to A mixed solution of 17.22 parts by weight of ethylenediamine, 2.87 parts by weight of diethylamine and 472.12 parts by weight of N, N-dimethylacetamide was introduced, mixed and reacted to obtain a 35% by weight polymer solution. The viscosity of the polymer solution is 30
It was 5500 poise (B-type viscometer) measured at ℃, and the viscosity after one week when left at room temperature was as stable as the viscosity immediately after polymerization.
An elastic yarn of D / 2 filament was obtained. The characteristic values of the elastic yarn were a breaking strength of 2.00 g / D, a breaking elongation of 660%, a running stress variation judgment ⊚, and a heat-resistant cutting time of 250 seconds.

[0029]

Comparative Example 1 The same procedure as in Example 1 was repeated with the 2,4′-MDI fraction in the raw material MDI being 1.20% by weight.
A 30 wt% polymer solution of 00 poise was prepared.
The viscosity of the obtained polymer solution after one week when left at room temperature was as stable as the viscosity immediately after polymerization, and an elastic yarn of 20D / 2 filament was obtained using this polymer solution. The characteristic value of the elastic yarn is a breaking strength of 1.70 g /
D, elongation at break 630%, running stress variation judgment x, heat-resistant cutting seconds 320 seconds.

[0030]

[Comparative Example 2] The 2,4'-MDI fraction in the raw material MDI was set to 1
Adjusted to 5.0% by weight and 285 in the same manner as in Example 1.
A 0 poise 30 wt% polymer solution was prepared. The viscosity of the obtained polymer solution after one week when left at room temperature was as stable as the viscosity immediately after polymerization, and an elastic yarn of 20D / 2 filament was obtained using this polymer solution. The characteristic value of the elastic yarn is a breaking strength of 2.55 g / D,
The breaking elongation was 620%, the running stress variation was ⊚, and the heat-resistant cutting time was 121 seconds.

[0031]

Comparative Example 3 A polymer solution was produced in the same manner as in Example 7 while keeping the 2,4′-MDI fraction in the raw material MDI at 1.20% by weight to obtain a 35% by weight polymer solution. .
The viscosity of the polymer solution is 6600 poi measured at 30 ° C.
It became se (B type viscometer), and gelled when left at room temperature for 1 week, and spinning was not possible.

Examples 1 to 7, Comparative Example 1, Comparative Example 2
The physical properties of the elastic yarn obtained in 1. are shown in Tables 1 and 2 and FIGS.

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

INDUSTRIAL APPLICABILITY In the present invention, 2,4'-in the raw material MDI is used.
The stability of the polymer solution is improved by controlling the MDI fraction to be 1.80 to 13.0% by weight, and the breaking elongation and heat resistance are well balanced, high breaking strength, and knitting unevenness do not occur. It is possible to obtain an elastic yarn having excellent physical properties.

[Brief description of drawings]

FIG. 1 is a breaking strength with respect to a 2,4′-MDI fraction in a raw material MDI.

FIG. 2 is the heat-resistant cutting seconds with respect to the 2,4′-MDI fraction in the raw material MDI.

Claims (2)

[Claims] 1. A method for producing a polyurethane urea elastic yarn, which comprises using diphenylmethane diisocyanate having a fraction of 2,4′-diphenylmethane diisocyanate of 1.80 to 13.0% by weight. 2. The method for producing a polyurethane urea elastic yarn according to claim 1, wherein the fraction of 2,4′-diphenylmethane diisocyanate is 3.00 to 10.0% by weight.