JPH0423009B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to stabilized elastane yarns, processes for their production and intermediate products preferably used as stabilizers. The term "elastane yarn" (spandex yarn) is used herein to refer to a yarn consisting of at least 85% by weight segmented polyurethane. Elastic and mechanical properties are
It is obtained by using polyurea polyurethanes prepared from aromatic diisocyanates.
The elastane is produced by spinning a solution by wet spinning or preferably dry spinning. Polar solvents such as dimethyl sulfoxide, N-methylpyrrolidone and preferably dimethylformamide or dimethylacetamide are suitable for this purpose. Elastane must be essentially stabilized against light and toxic gases, and for this purpose contains stabilizers that are introduced as additives into the spinning solution or incorporated into the segmented polyurethane. If a stabilizer is used, it must not be volatile under the spinning conditions. When elastane is produced by a spinning process in which air is used as the spinning gas, the oxidation effect of the spinning gas, which occurs at relatively high spinning temperatures, must be taken into account when selecting the stabilizer component. .
Spinning gas temperatures of 200-400°C are employed in normal spinning processes. The use of polymeric amines as stabilizers for segmented polyurethanes was published in German Publication No.
It is known from specification No. 1669511 or German publication No. 1126603. The stability of these polyurea polyurethanes does not meet current technological requirements. That is, on the one hand, the stabilizing compound must not have a negative effect on the mechanical and elastic properties;
On the other hand, the effectiveness of the stabilizer system used must not be compromised at any stage of the process, from the manufacture of the yarn to the final product, such as a corset or swimsuit. DE 1918066 discloses the use of unsegmented polyurethanes containing tertiary butylamino groups in the polymer chain as stabilizers. This stabilization also did not give the desired result and testorakis-[3-(3,5-
Combinations with phenolic stabilizers such as di-t-butyl-4-hydroxyphenyl)-propionyl-oxymethyl]-methane do not provide sufficient stabilization. When at least one component of the system to be spun contains tertiary amino groups and phenols, which do not produce colored nitro compounds, are used as antioxidants, highly stabilized elastane yarns are prepared from polyurea polyurethanes. I have now discovered that I can obtain it. The question whether colored nitro compounds are formed is determined by a toxic gas test according to ISO 105/G02. The combination according to the invention of compounds having a stabilizing effect can be added to the polyurea polyurethane solution either during the synthesis or after the synthesis has ended. One particular method of synthesizing and stabilizing the fiber polymers according to the invention is to use tertiary simines containing hydroxyl groups, such as bis-2-hydroxypropyl, as an additional diol component for the preparation of the prepolymer. It consists of using methylamine. Another preferred method consists in adding to the spinning solution a polyurethane obtained from aliphatic diisocyanates, especially dicyclohexylmethane diisocyanate and tertiary amino diols. Suitable aminodiols are described in section 11. The phenols to be used according to the invention are those that do not produce nitrogen oxides and nitro compounds in the atmosphere. That is, the above phenol is represented by the following general formula. (However, R ₁ and R ₂ represent a C ₁ -C ₆ alkyl group, and X represents an isocyanurate residue.) The polyurea polyurethane can be prepared by a known method. One method that has been found to be particularly satisfactory is the synthesis of fiber raw materials by the propolymer method, in which long-chain diols are reacted with diisocyanates in the first step of the process, either in solution or without solvent. A prepolymer is formed such that the product contains isocyanate end groups. The diols used are preferably polyester diols or polyether diols.
Mixtures of polyester and polyether diols can also be used. Diol is generally 1000
It has a molecular weight of ~6000. Suitable polyester diols include, for example, dicarboxylic acid polyesters which can be derived from several alcohols and several carboxylic acids. Particularly suitable are copolyesters of adipic acid, hexanediol and neopentyl glycol in a molar ratio of 1:0.7:0.43. The polyester preferably has a molecular weight of 1000-4000. Examples of suitable polyether diols include polytetramethylene oxide diols, preferably having a molecular weight of 1000 to 2000. Particular preference is given to copolyethers obtained by reaction of polytetramethylene oxide diol and ethylene oxide. Mixtures of polyether and/or polyester diols with diols containing tertiary amino groups can of course also be used. Here, as the diol containing a tertiary amino group, N-C ₁ to _{C 8}
-Alkyl- or _-C5 - _C7 -cycloalkyl-N,N bis(hydroxyalkyl)amines are used. Examples include the following. 4-t-butyl-4-azaheptane-2,6-
Diol; 4-methyl-4-azaheptane-2,
6-diol; 3-ethyl-3-azapentane 1,5-diol; 2-ethyl-2-dimethylaminomethyl-propane-1,3-diol: 4-
t-Pentyl-4-azaheptane-2,6-diol; 3-cyclohexyl-3-azapentane-
1,5-diol, 3-t-butylmethyl-3-
Azapentanediol-1,5; 3-t-pentyl-3-azapentanediol-1,5. Conventional aromatic diisocyanates can be used to synthesize elastane feedstocks, optionally mixed with small proportions of aliphatic diisocyanates. Examples of aromatic diisocyanates include 2,4
Examples include -tolylene diisocyanate and its isomer mixture, and 4,4'-diphenylmethane diisocyanate and its isomer mixture. Mixtures of different aromatic diisocyanates may also be used. The following aliphatic diisocyanates are also suitable components for the mixture: hexamethylene diisocyanate, isophorone diisocyanate or dicyclohexylmethane diisocyanate. Another particularly advantageous synthesis method of the elastane raw material according to the invention consists in mixing polyester- and polyether-polyurethane prepolymers and then reacting them according to known methods to form the polyurea polyurethane.
The ratio of polyester diols and polyether diols to be used for any given purpose can be easily determined by preliminary tests. In the synthesis of polyurea polyurethane, the necessary urea groups are introduced into macromolecules by a chain extension reaction. The macrodiisocyanates synthesized in the prepolymer stage are usually reacted in solution with diamines such as ethylene diamine, tetramethylene diamine, 1,3-cyclohexane diamine, isophorone diamine or mixtures of these diamines. Small amounts of monoamines such as diethylamine or dibutylamine can be used to adjust the molecular weight of the final polyurethaneurea during chain extension. _CO2 can be used as a retarder in chain extension reactions. The mixing of the polyester and polyether polyurethane urea may take place after the elastane synthesis has been completed. Phenol is based on polyurethane polyurea
It is used in an amount of 0.1-2% by weight. On the other hand, the tertiary amine is used in an amount to provide 0.02-0.3% by weight of tertiary nitrogen in the elastane. Amines for additives and for incorporation into polymers are N-C ₁ -
_C8 -alkyl- or _-C5 - _C7 -cycloalkyl-di- _C2 - _C3 -alkanol-amines are used. Example 1 10kg of polytetramethylene ether glycol with a molecular weight of 2000 and an OH number of 56 is converted into dimethylacetamide.
Diluted with 3.07Kg. Add 2.27Kg of diphenylmethane diisocyanate to the mixture adjusted to 25℃,
The reaction was allowed to proceed at 50-55° C. for 60-90 minutes until the isocyanate content of the prepolymer was 2.65%. 220 g of ethylenediamine and 23 g of diethylamine as a chain terminator were added to dimethylacetamide.
37.2 Kg and placed in a reaction vessel, then 250 g of solid CO ₂ were added such that the carbamate suspension was added to this suspension with vigorous stirring. A homogeneous, transparent and colorless elastomer solution was obtained with a solids content of 22% by weight and a solution viscosity of 70 Pas. The inherent viscosity of the polymer is 1.2 dl/g
(5g/dimethylacetamide, 30°C). The viscous polymer solution is then added with 4% titanium dioxide and 1% 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-tris) by weight based on the PU solids. -dimethyl-benzyl)-isocyanurate and dicyclohexylmethane diisocyanate and 4-tert-pentyl-4-azaheptanediol-2,6 according to Example 2A, with an inherent viscosity of 0.21 dl/g (25°C,
5 g/dimethylacetamide) was added to give a tertiary nitrogen content of 100 milliequivalents (mVal)/Kg solids content. Example 2 A 4-methyl-4-azeheptanediol-
3.67Kg of 2,6, 6.42Kg of dicyclohexylmethane diisocyanate, and dimethylacetamide.
6.73Kg, 20g of dibutyl-tin-dilaurate,
Heated at 70°C for 3.5 hours with stirring. All of the isocyanate input to the process had reacted by the end of that time. The solution was cooled and diluted to 22% by weight by adding 29Kg of dimethylacetamide. Inherent viscosity (see example 1) 0.26
A clear, highly fluid solution of basic polyurethane was obtained. B Contains terminal hydroxyl group, molecular weight 2000 and OH
A polyester having the number 56 was prepared by reaction of 10Kg of adipic acid with 8.1Kg of hexanediol and 7.1Kg of neopentyl glycol. 10 Kg of the polyester of C B was heated with 3.1 Kg of dimethylacetosimide and 2.3 Kg of diphenylmethane diisocyanate to 50-54°C for 60 minutes to give an isocyanate content of the prepolymer to 2.66%. 240 g of ethylenediamine was dissolved in 41.4 Kg of dimethylacetamide and introduced into a reaction vessel, and 260 g of solid CO ₂ was added to form a carbamate suspension. To this suspension, 15.35 kg of polyester-isocyanate prepolymer solution was added at 10° C. with vigorous stirring. A homogeneous, transparent elastomer solution with a solids content of 22% by weight and a solution viscosity of 98 Pas was obtained. 4% by weight of titanium dioxide and 1% by weight of 1, respectively, based on the PU solids content.
3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethyl-benzyl)-isocyanurate and 2.5 kg of solution A were added to the viscous polymer solution to determine the tertiary nitrogen content. 100m
Val/solid content Kg. Example 3 4-methyl-4 instead of additives from 4-tert-pentyl-4-azeheptanediol-2,6- and dicyclohexylmethane diisocyanate
The scan of Example 1 was repeated using -azaheptane-2,6-diol and isophorone diisocyanate and using 0.5% by weight of a compound of the following formula: [Molecular weight Mn 3000 or more, melting point 55-70℃, density 1.18
g/cm ³ of pale yellow powder] Example 4 The scan of Example 2 was repeated with the following additives: 4a: 3-Methyl-3-schizapentane-1,5-
4b from diol and dicyclohexylmethane diisocyanate: 3-cyclohexyl-3-azapentane-
4c:4-tert-butyl-4-azaheptane-2,6 from 1,5-diol and dicyclohexylmethane diisocyanate
- diol and dicyclohexylmethane diisocyanate 4d: 3-t-butylmethyl-3-azaheptane-1,5-diol and dicyclohexylmethane diisocyanate 4e: 3-t-pentyl-3-azaheptane-1,
4f from 5-diol and dicyclohexylmethane diisocyanate: 4-methyl-4-azaheptane-2,6-diol and hexamethylene diisocyanate and additionally from 0.5% by weight of the compound of the formula of Example 3 from Example 5 10 Kg of the polyester of Example 2 , 190g of 4-methyl-4-azaheptanediol-2,6, 2.6Kg
of diphenylmethane diisocyanate and 3.2
199 at 50-54℃ with Kg dimethylacetamide
The mixture was heated with stirring for a minute to bring the isocyanate content of the prepolymer to 2.66% by weight. 245 g of ethylene diamine was dissolved in 43.35 Kg of dimethylacetamide and introduced into the reaction vessel and 270 g of solid CO ₂ was added to form a carbamate suspension. 16 kg of the prepolymer solution was added to this suspension while stirring vigorously. Solids content 22% by weight and solution viscosity
A homogeneous and transparent elastomer solution of 92.6 Pas was obtained. 2 of 4% by weight each based on PU solids content
Titanium oxide and 1% by weight of 1,3,5-tris(4
-t-Butyl-3-hydroxy-2,6-dimethyl-benzyl)-isocyanurate and 0.5% by weight of a compound of the formula of Example 3 were added to the viscous polymer solution. Example 6 (Comparative) A solution of segmented linear polyester polyurea polyurethane was prepared as described in Example 5. Instead of the described additives of example 3, PU
4% by weight of titanium dioxide and 1% by weight of pentaerythyl-tetrakis-[3-(3-tert-butyl-4,5-dimethyl-4) each, based on solids content.
-hydroxyphenyl)-propionate] was added to the resulting polymer solution. Example 7 Example 3 was repeated using the polyester of Example 2 instead of the polyether. Example 8 (comparative example) Pentaerythrityl-tetrakis-[3-(3-
pentaerythrityltetrakis-[3-3,5-di-t-
Example 6 was repeated using butyl-4-hydroxyphenyl)-propionate. Manufacture of test samples The solutions prepared in each example were dry-spun by a conventional method to form multifilament yarns with a total fineness of 160 dtex. Cirula knitted samples of these yarns were either (a) bleached in an acidic medium or (b) bleached in a basic medium by the method described below and then oxidized by ISO 105/G02. It was subjected to a fastness test against nitrogen and a fastness test against light using a fading test device. The results shown in the table below were obtained, where 5 represents the best result and 1 represents the worst result. How to conduct a combustion gas test ISO 105/G02 specifies exposure to nitrogen oxides using butane gas, a commercially available camp gas (Ca-
This was done by burning gas (mping gas).
Through the exchange cycle, the temperature is at the same level as the sample.
Recorded by compnsograph, measured using a Ni-Cr-Ni thermocouple. The relative humidity in the device was also recorded. During the test operation the following conditions were adopted: Air circulation stirrer rotation: 2.5/min Number of cycles per series: 1 Duration of cycles, temperature and relative humidity:

Table: A cycle was completed when the particular comparison sample introduced into the device along with the test specimen showed a distinct change in color. Camp gas is distinguished from pure butagas by small amounts of added propane or odorants added in amounts in the ppm range. The color change of each exposed sample was compared to the starting material and evaluated using the outer gray scale. The number 5 corresponds to no practical color change, and the number 1 corresponds to an obvious color change. Series A was performed on original filaments, B on filaments bleached under acidic conditions, and C on filaments bleached under basic conditions. Series B and C are necessary because the elastane filaments are processed either with polyamide filaments that are whitened under acidic conditions or with cotton that is bleached under basic conditions. Acidic whitening was carried out in a conventional manner using a solution containing 1.8% by weight of an anionic brightener and 3g/ml of sodium hydrosulfite and having a pH of 5. The material was introduced into the liquid at 40°C and the liquid was heated to 90°C and held at this temperature for 60 minutes. The material was removed, washed with hot and cold washing solutions, and dried at 70°C. Basic bleaching is performed using 35% strength (by weight) H ₂ O ₂ /
was carried out using a solution containing 6 ml and 1% by weight of a substsntive brightener and having a pH of 11. The operation was carried out in the same manner as for acid whitening.

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Claims (1)

[Claims] 1. A method for producing elastane yarn by solution spinning a polyurea polyurethane using conventional spinning methods and adding a phenolic stabilizer and a tertiary amine component, comprising: producing colored nitro groups; No, and the following general formula Phenol equivalent to (where R ₁ and R ₂ are
C ₁ -C ₆ alkyl group, X is an isocyanurate residue) is used in an amount of 0.1 to 2% by weight based on the polyurethane, and at least one component of the system to be spun is a third
It is characterized by containing a tertiary amino group, and the amount of the tertiary amino group is N-C ₁ to N-C 1 as a hydroxyl group-containing tertiary amine in elastane.
tertiary nitrogen selected from _C8 -alkyl- or N- _C5 - _C7 -cycloalkyl-N,N-bis(hydroxyalkyl)amines in an amount such that it contains 0.02 to 0.3% by weight; and , The above hydroxyl group-containing tertiary amine is
- as an additional diol component for the preparation of prepolymers; or (b) an NCO-free polyurethane obtained from the above-described N-alkyl-N,N-bis(hydroxyalkyl)amine and an equivalent amount of aliphatic diisocyanate. The above method, which is added as a. 2 Phenol is 1,3,5-tris(4-t-
butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, N- _C1 to _C8-
Alkyl-N,N-bis(hydroxyalkyl)
The amine is 4-t-butyl-4-azaheptanediol-2,6,4-t-pentyl-4-azaheptanediol-2,6,4-methyl-4-azaheptanediol-2,6,3- Ethyl-3-azapentane-1,5-diol, 3-t-butyl-
3-Azapentane-1,5-diol, 3-t-
The method according to claim 1, wherein the diol is pentyl-3-azapentane-1,5-diol or 3-cyclohexyl-3-azapentane-1,5-diol. 3 Phenol is 1,3,5-tris(4-t-
4-methyl-4-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate in which the tertiary amino group component is reacted as an additional diol component for the preparation of the NCO-prebolimer.
- azaheptanediol. 4 Phenol is 1,3,5-tris(4-t-
butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, an NCO-free polyurethane containing 4-methyl-4-azaheptanediol-2,6 and dicyclohexylmethane diisocyanate; Heptanediol-2,6- and isophorone diisocyanate; 3-methyl-3-azapentane-1,5-diol and dicyclohexylmethane diisocyanate; 3-cyclohexyl-3-azapentane-
The method according to claim 1, which is obtained from 1,5-diol and dicyclohexylmethane diisocyanate; or 4-tert-butyl-4-azaheptane-2,6-diol and dicyclohexylmethane diisocyanate. 5 The following compound, 5. The method according to claim 3 or 4, wherein the method is additionally used as a stabilizer.