KR970010727B1 - Method for the preparation of polyurethane filaments with heat resistant and anti-chlorine property - Google Patents

Abstract

A diol compound 1 mole consisting of 90-95 mole % of a high molecula weight diol and of 5-10 mole % of a low molecular weight diol is preliminary polymerized with a diisocyanate compound in the ratio of 1.25-2.5 mol, and is mixed with a solvent for producing the solution of the preliminary polymer. Then using the preliminary polymer in the ratio of 60-98 mole %, subjecting an isocyanate of its tip to the chain growth, a diamine compound is obtained in a viscosity of 500-4,000 poise suitable for spinning, having a monoamine compound chain stopped using a diamine compound in the ratio of 1-30 mole % from among the total amount.

Description

Method for producing a polyurethane-based elastic fiber excellent in heat resistance and chlorine resistance.

The present invention relates to a method for producing a polyurethane-based elastic fiber having excellent physical properties while maintaining the inherent physical properties of the elastic fiber.

Polyurethane-based elastic fibers are excellent in elasticity and elastic recovery power is widely used in stretch fabrics, such as stockings, women's underwear and swimwear. However, polyurethane-based elastic fibers have a disadvantage in that they are discolored when exposed to sunlight due to poor light resistance, and the elasticity, which is inherent in elastic fibers, is reduced due to oxidation reaction caused by NO _x gas and oxygen in the atmosphere. there was. In particular, the phenomenon of discoloration and decrease in elasticity in the air occurs rapidly when used as an external exposure part, as in the case of stockings containing a large amount of elastic yarn.

In addition, the heat resistance is poor, when blended with other materials such as polyester fiber, when used at high temperature of about 130 ℃ is impossible due to restrictions on use. In addition, when applied as a polyurethane-based elastic fiber swimsuit, various problems are caused, such as damage to the chlorine contained in the pool water to reduce the strength of the fiber and discoloration phenomenon.

Among the above-mentioned problems, for the antioxidant roll, hydrogenated m-phenylenediamine (HmPD), hydrogenated p-phenylenediamine (HpPD) and tetrachloro-p-xylenediamine as described in Japanese Patent Application Laid-Open No. 1-204920 are used. 1,1bis (2-methyl-4-hydroxy-5-t) as an antioxidant to a prepolymer obtained by reacting polyalkeneetherglycol prepared at a ratio of 40/20 with t-alkyl diisocyanate (TMXDI). -Butylphenol) butanol A method of adding about 1% of the weight of the polymer, a method of adding an antioxidant of phenols as described in Japanese Patent Application Laid-Open No. 63-126915, as described in Japanese Patent Application Laid-Open No. 60-21187 A method for improving the anti-myxing performance by adding 0.3 to 10% by weight of an amine compound and 2,4,6-tri (2,6-dimethyl-4-t-butyl- as described in U.S. Pat. 3-hydroxybenzyl) isocinurate (tradename Anox 1790) or p-cresol, Methods of using dicyclopentadiene and isobutane condensate (wingstay-L) and the like are known.

In addition, the method using the stabilizer mentioned in Japanese Patent Laid-Open No. 61-47749, that is, a molecular weight having a hydroxyl group of 1 × 10 ^-4 mol or more in 1 gram of a polyurethane-based compound synthesized from a trifunctional phenol compound and an organic diisocyanate It is known to add stabilizers in the range of 1,000 to 50,000. However, the above-mentioned methods are somewhat improved but not satisfactory oxidation resistance, and has the drawback of lowering the elastic modulus and elastic recovery rate, which is the inherent properties of polyurethane fibers.

In addition, in order to improve light resistance, a method of improving daylight fastness by containing 0.1 to 10% by weight of a phenolic compound as described in Japanese Patent Laid-Open No. 61-47819, and a chlorine bleach as described in Japanese Patent Laid-Open No. 57-176260 Method for improving the discoloration resistance by using a method of improving photostability using a bisbenzotriazole urea-based compound as described in US Pat. No. 5,258,582 and polyurethane as described in Japanese Patent Application Laid-Open No. 56-11948. It is known to add 0.1 to 10% by weight of a phenolic compound into the polymer to improve daylight fastness.

Japanese Patent Laid-Open No. 5-5217 discloses a method of composite spinning a polyether-based polyurethane having an allophanate bond and a polyether-based or polycarbonate-based polyurethane having no allophanate bond. There are various manufacturing problems, such as the need to perform a process.

In addition, in order to improve the heat resistance, a method of adding a heat resistance enhancer or replacing a portion of the polymer diol compound with a low molecular weight diol compound such as ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, and the like is known. Japanese Unexamined Patent Publication No. 4-74457 discloses an elastic yarn prepared by reacting polytetramethylene glycol with an excess of 4,4'-diphenylmethane diisocyanate and spinning a polymer chain-grown with 1,2-propylenediamine and diethyleneamine. The method of improving the elastic recovery by heating at a constant temperature is described, but the manufacturing process by this method is not only difficult to work due to the addition of the heat treatment process of the elastic yarn, the degree of improvement of heat resistance was insignificant.

As a method for improving chlorine resistance, polytetramethylene glycol and excess 4,4'-diphenylmethane diisocyanate are prepolymerized as described in Japanese Patent Application Laid-Open No. 60-36560, followed by chain extension and chain stop with amine. Method for improving chlorine resistance by adding a tertiary nitrogen-containing urethane polymer to the polymer, after prepolymerization of polyester glycol and 4,4'-diphenylmethane diisocyanate as mentioned in Japanese Patent Laid-Open No. 56-107010 A method of increasing the chlorine resistance by adding a fatty acid metal compound before spinning after producing a polymer having a constant viscosity by chain extension using an amine, as described in US Pat. No. 4,837,292. Polyurethane polymer containing a special polycarbonate soft segment synthesized as a mixture of diol and poly (hexane-l, 6-carbonate) diol. Method for improving chlorine resistance by synthesizing, as mentioned in Japanese Patent Laid-Open No. 57-29609, after reacting polytetramethylene ether glycol with p, p'-methylenediphenyl diisocyanate, diethylamine and ethylenediamine and 1, A method of imparting chlorine resistance to a polymer obtained by chain extension using 3-cyclohexylenediamine using 1 to 3% by weight of zinc oxide having an average particle diameter of 0.01 to 1 micro, as mentioned in Japanese Patent Laid-Open No. 62-574. Likewise, when polytetramethylene glycol is reacted with 4,4'-diphenylmethane diisocyanate to obtain a prepolymer, 1,2-propylenediamine is added for chain extension, and monoethanolamine is added to complete the polymerization. There is a method of adding chlorine resistance and light resistance by adding a polymer type oxidation inhibitor obtained by addition polymerization of phenol having a benzene and a methyl group or an ethyl group as a substituent.

However, in the case of the polyurethane elastomer produced by the above methods, there is a problem that the chlorine resistance is somewhat improved or not satisfactory, and the elastic recovery rate, which is inherent in the polyurethane elastomer, is reduced or the strength is decreased.

Accordingly, an object of the present invention is to provide a method for producing a polyurethane elastic fiber excellent in heat resistance and chlorine resistance while maintaining the inherent physical properties of the polyurethane elastic fiber by eliminating the above-mentioned drawbacks.

In order to achieve the above object as well as another easily expressed object, in the present invention, a high molecular weight diol having a number average molecular weight of 1,000 to 3,000 and a low molecular weight diol having a number average molecular weight of 50 to 500 is prepolymerized with a diisocyanate of a charge and a solvent. After mixing in a constant ratio to prepare a solution of the prepolymer, the terminal isocyanate is chain-grown using an appropriate amount of diamine compound to obtain a suitable viscosity for spinning, and then the terminal is blocked using a monoamine compound to improve heat resistance. By adding a compound having a function and a chlorine resistant compound, it was possible to obtain a polyurethane-based elastic fiber that significantly improved heat resistance and chlorine resistance while maintaining the inherent physical properties of the elastic yarn.

The present invention is described in more detail as follows.

Diisocyanate compound 1.25-2.5 molar ratio with respect to 1 mol of diol compounds which consist of 90-95 mol% of high molecular weight diol compounds of the number average molecular weight 1,000-3,000, and 5-10 mol% of the low molecular weight diol compounds of the number average molecular weight 50-500. After prepolymerization, a suitable amount of the solvent was mixed to prepare a solution of the prepolymer, and then a terminal isocyanate was chain-grown using 60 to 98 mol% of the diamine compound to produce a 500 to 4,000 poise having a viscosity suitable for spinning. Then, the monoamine compound was used for 1-30 mol% of the diamine compound used as the chain growth agent and the chain was stopped. Then, the heat resistance improving additive was added with respect to the polymer solids while maintaining the viscosity suitable for spinning using the anti-corrosive stabilizer. It is added to -1% by weight, and the chlorine resistance enhancer is added to the polymer solids to add 0.01 to 3% by weight to obtain a polymer, which is spun in elasticity. While maintaining the inherent physical properties of the material it was produced elastic fibers which significantly improves the heat-resistance and chlorine resistance.

Examples of high molecular weight diol compounds that act as soft segments in elastomers include polyester compounds such as polyoxypropylene glycol, polyoxyethylene glycol, polyoxytetramethylene glycol, polyoxypentamethylene glycol, polyethylene adipate, Although polyester-based compounds, such as polybutylene adipate, poly neopentyl adipate, polyhexamethylene adipate, and polycaprolacton, polycarbonate compounds, such as polybutylene carbonate and polyhexamenylene carbonate, can all be used, The polyether compound is most preferably the polytetramethylene ether glycol compound in consideration of the physical properties of the elastomer.

In addition, the high molecular weight diol compound used in the present invention is preferably a compound having a number average molecular weight of 1,000 to 3,000, and particularly preferably a compound having a horizontal group molecular weight of 1,500 to 2,500.

On the other hand, low molecular weight diol compounds used to improve heat resistance include compounds such as ethylene glycol, diethylene clecle, propylene glycol, dipropylene glycol, 1,4-butanediol, and heat resistance by increasing the degree of crosslinking of the polyurethane polymer. In order to impart the most, a glycle compound having a molecular weight of 50 to 500 is the best.

The total amount of the high molecular weight diol compound and the low molecular weight diol compound is 40 to 80 mole% with respect to the diisocyanate compound, and below 40 mole%, the strength of the polymer is improved, but the elongation and elastic recovery rate are lowered, thereby inherent as an elastomer. When it is used in excess of 80 mol%, the elongation and elastic recovery rate are improved, but the strength is lowered and the use of elastic fibers is restricted.

In addition, the molar ratio A / B of the high molecular weight diol compound (A) and the low molecular weight diol compound (B) is suitably in the range of 1 to 20. If the molar ratio is less than 1, the intrinsic physical properties of the elastic fiber are lowered. The degree of improvement is minimal.

Examples of dimisocyanate compounds which combine with an amine compound which is a chain growth agent and act as a hard segment include p-phenyl diisocyanate, m-phenylene diisocyanate, 2,4 trienedi isocyanate and 2,6-torylene diisocyanate. , 1 chloro 1,2 phenylene diisocyanate, 1,5 naphthalene diisocyanate, 1,4 phenylene diisocyanate, chlorophenylene, 2,4 'diisocyanate, methylene bis 4. phenyl diisocyanate, hexamethylene diisocyanate, polymethylene Polyphenyl diisocyanate, methylcyclohexylene diisocyanate, paraphenyl diisocyanate, paraphenylene diisocyanate, 4,4 'diphenyl isopropylidine diisocyanate, 3,3' dimethyl 4,4 'diphenyl diisocyanate, 3 , 3 'dimethoxy 4,4' diphenyl diisocyanate, and 4,4 'diphenylmethane diisocyanate. The 4,4 'diphenylmethane diisocyanate compound is most preferred in consideration of the reactivity with the diol compound and the physical properties of the elastomer.

Suitable amount of diisocyanate compound is 1.25 to 2.5 moles per 1 mole of diol compound, and less than 1.25 moles of polymer is excellent in elongation, but its strength is low and its elastic recovery ability is insufficient. The recovery is good but the elongation is poor resulting in the inherent degradation of physical properties as an elastomer.

The prepolymer obtained by combining the diol compound and the diisocyanate compound is chain-grown by the diamine compound, and chain-grown at a constant molecular weight, followed by chain stopping with monoamine, thereby obtaining a polymer having an appropriate molecular weight. Examples of the diamine compound for chain-growing the prepolymer include 1,2 propylenediamine, 2,3 butylenediamine, methylimino bispropylamine, metaxylenediamine, 2,5 dimethylpiperazine, 2 methylperazine, ethylenediamine, Compounds such as ethanoldiamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1 methyl 2,4 diaminebenzene, 1,2 cyclohexadiamine, octamethylenediamine, paraphenylenediamine and the like are used.

However, in order to improve the viscosity stability of the polymer in the chain growth compound and the properties of the elastic yarn after spinning, a mixture of linear diamines and cyclic diamines is used in an appropriate ratio. The molar ratio C / D of the linear diamine (C) and the cyclic diamine (D) is in the range of 2 to 20, and when the C / D is less than 2, the reactivity is poor and a low molecular weight polymer is produced, resulting in high strength and elongation. When mechanical properties are lowered, and the C / D exceeds 20, the reaction rate is excessively applied to generate a large amount of side reactions, thereby degrading the stability of the polymer and lowering the heat resistance.

In order to maintain the reaction speed moderately, maintain the viscosity stability of the polymer and prevent mechanical degradation of the spun elastic yarn, it is best to use an appropriate amount of ethylenediamine and 1,2-propylenediamine as the linear diamine, and meta amine as the cyclic diamine. It is best to use a mixture of xylenediamine and 1,4-cyclohexanediamine.

The molar ratio of ethylenediamine and 1,2-propylenediamine is in the range of 1: 10 to 10: 1, and the reactivity is poor when the molar ratio is less than 1: 10, and when it exceeds 10: 1, chain growth Insufficient molecular weight that can have adequate physical properties

In addition, when the use molar ratio of the metal xylene diamine and 1,4-cyclohexanediamine is in the range of 1:10 to 10: 1, and the use molar ratio is less than 1:10, the reactivity is fast and the side reactions are easily formed. When it exceeds 10: 1, it is low in reactivity and a polymer having excellent physical properties cannot be obtained.

Examples of all-amine compounds, which are chain stoppers for blocking the ends of the chain-grown prepolymer, are monoethanolamine, diethanolamine, propylamine, isopropylamine, dipropylpropyl, 2-ethylhexylamine, di (2-ethylhexyl) There are compounds such as amine and bunylamine, and isopropylamine has an excellent chain stop effect, maintains the molecular weight of the polymer moderately and suppresses the secondary non-reaction to impart stability of the polymer. The amount of monoamine-based compound used is 1 to 30 mol% of the mole used as a chain growth agent, and when it is less than 1 mol%, the chain stopping effect is poor. In the case of larger than 30 mol%, the chain growth of the polymer may be impeded to prevent the proper molecular weight of the polymer from being obtained. Therefore, it is not possible to obtain a viscosity suitable for spinning, and the strength, elongation and elastic recovery rate of the physical properties of the polymer. This is bad.

Solvents for improving radioactivity by controlling the solid content of the polymer include dimethylacetamide, dimethylformamide, hexamethylphosphoramide, dimethylnitrosoamine, dimethylpropionamide, methoxydimethylacetamide, N-methylpyrrolidine, dimethyl There are compounds such as sulfoxide, tetramethylene sulfone and the like, and dimethylacetamide or dimethylformamide is advantageous in terms of compatibility with the polymer, radioactivity and solvent recovery. The amount of the solvent to be used is preferably adjusted to 15 to 45% of the solid content of the polymer, if less than 15% or more than 45% adversely affects the radioactivity.

In the present invention, a phosphorus compound having an amine bond represented by the following general formula (I) is used for improving heat resistance.

(Wherein R ¹ , R ² , R ³ and R ⁴ are hydrogen atoms or alkyl groups or aryl groups having 1 to 10 carbon atoms, and R ⁵ is an alkylene group or benzene ring having 1 to 10 carbon atoms.)

Examples of the compound having an amine bond include phosphoryldimethylethanolamine, 2-dimethylaminophenoldiphenylphosphate, 2-diethylaminoethanoldimethylphosphate, 2-ethylpropylaminophenoldihydrogenphosphate, and 2-dibutylaminophenoldi. Hydrogenphosphate can be used.

The amount of the phosphorus compound having an amine bond is preferably 0.01 to 1.0% by weight, preferably 0.05 to 0.5% by weight, based on the solid content of the final polymer, and when it is less than 0.01% by weight, the improvement of heat resistance cannot be guaranteed and exceeds 10% by weight. Lower surface additives may cause deterioration of polymer properties during spinning due to the addition of excess stabilizer.

Polyurethane polymer prepared by the above-mentioned method is excellent in mechanical properties and anti-oxidation, but poor in chlorine resistance, and is damaged by chlorine in swimming pool when worn as a bathing suit, which lowers the strength and elastic recovery rate of fibers and causes discoloration. do. Therefore, in this invention, the diester metal salt compound represented by following formula (II) was added as a chlorine resistance improving agent.

(Wherein R ₁ : ethyl or phenyl group, R ₂ : alkyl group having 1 to 10 carbon atoms, aryl group or alkylaryl group, M ₁ , M ₂ : same or different metal ion among Na, Ca, Al, Zn, Ba, Pb)

Metal-based compounds are used as compounds to prevent damage by chlorine, and as such compounds, aliphatic metal salts such as zinc deslate, zinc laurate, zinc licinolate, zinc oxate and zinc benzoate, zinc oxide, aluminum oxide, Metal oxide compounds such as nitrous oxide, magnesium oxide, ditin tin oxide, cerium oxide, and anhydride compounds are reacted with alcohols to form diester compounds, and then metal salt compounds are used in which the terminal hydrogen is replaced with a metal. Examples of the anhydride-based compound are benzoic anhydride, acetic benzoic anhydride, acetic anhydride, phthalic anhydride, succinic anhydride, maleic anhydride, aceticptanoic anhydride compound And chlorine without compromising the inherent properties of the elastomer. The most effective compound for improving the fastness 185 is the most effective metal salt compound of the terminal hydrogen of the diester compound prepared from the anhydride compound substituted with a metal.

The proper amount of the metal salt-based compound is 0.01 to 3% by weight based on the solid content of the polymer, and at less than 0.01% by weight, the chlorine resistance effect is insufficient, and when it exceeds 3% by weight, the chlorine resistance synergistic effect is insignificant. It inhibits the elastomer and its inherent physical properties and adversely affects radioactivity.

Various physical properties of the polymer solution prepared by the above method were prepared by using a conventional dry spinning method to prepare a polyurethane elastic yarn of 70 days. Tensile strength, elongation and elastic recovery rate described in the Examples were measured according to KSK 0219, and heat resistance was evaluated by strength retention rate and color change (Gray scale: ISO international standard) after 60 minutes treatment of the elastic yarn in a hot air dryer at 130 ° C. Chlorine resistance was 200 P.PM effective chlorine concentration, pH 7 was prepared after the solution temperature was maintained at 25 ℃ and the elastic yarn in the solution after a certain time to evaluate the tensile strength and elongation change.

In addition, the viscosity of the polymer was measured by Brookfield (Brook Field) model number DV-III.

The following examples and comparative examples further illustrate the present invention, but do not limit the scope of the present invention.

(Example 1)

1.7 mol of 4,4 'dimethyl diisocyanate was added to a solution containing 0.92 mol of polytetramethylene ether glycol having a molecular weight of 1980 and 0.08 mol of 1,4-butanediol, and then polymerized in a nitrogen gas atmosphere at 75 캜 for 60 minutes to prepare a prepolymer. Prepared. The prepolymer was dissolved in dimethylacetamide, the solution was cooled to 5 ° C., and then linear diamine, ethylene diamine, 1,2-propylenediman, and cyclic diamine 1,4-cyclohexanediamine and metazyme as chain growth agents. Rendiamine is mixed at a molar ratio of 7.0 / 1.5 / 1.2 / 0.3 based on the total diamine moles and then dissolved in dimethylacetamide with a concentration of 20%. The number of moles of total diamine in this solution is 0.95 compared to the terminal diisocyanate of the prepolymer, and is slowly added to the polymerization solution. The viscosity of the prepared polymer was 3,700 poise. A solution obtained by dissolving isopropylamine in dimethylacetamide at a concentration of 20% was gradually added to a chain-grown polymer with a molar number of isopropylamine of 0.05 mole compared to the terminal isocyanate of the first prepolymer, resulting in a viscosity of 3,000 poises. To the polymer solution, 250 g of a solution in which acetic anhydride was dissolved in dimethylacetamide at a concentration of 2% was added to stabilize the viscosity of the polymer.

After the completion of the polymerization, a solution of phosphoryldimethylethanolamine dissolved in dimethylacetamide at a concentration of 10% was added so that phosphoryldimethylethanolamine became 0.2% by weight of the final polymer solids, and at the same time, as a chlorine resistance enhancer. A solution obtained by dissolving a compound substituted with terminal hydrogen in zinc of a diester metal salt compound prepared from a lide compound at a concentration of 2% in dimedylacetamide was added so that the chlorine resistance enhancer was 0.5% by weight of the final polymer solids. Solid content of the polymer was adjusted to 32% with a viscosity of 3,300 poise.

This polymer was used in a conventional dry spinning method to prepare a polyurethane elastic yarn of 70 denier after spinning, the results of the evaluation of physical properties are shown in Table 1.

Comparative Example 1

Polymerization was carried out in the same manner as in Example 1 except that no phosphoryldimethylethanol amine compound was used, and the results of the evaluation of the physical properties are shown in Table 1.

Comparative Example 2

The polymerization was carried out in the same manner as in Example 1 except that the chlorine resistance enhancer was not used, and the results of evaluating the physical properties are shown in Table 1.

[Table 1] Property evaluation results

Claims (3)

The ratio of 1 mol of a diol compound and 1.25 to 2.5 mol of a diisocyanate compound consisting of 90 to 95 mol% of a high molecular weight diol compound having a number average molecular weight of 1,000 to 3,000 and 5 to 10 mol% of a low molecular weight diol compound having a number average molecular weight of 50 to 500 After prepolymerization, solvents were mixed to prepare a solution of the prepolymer, and chain growth was performed using 0.60-0.98 mol% of a pre-polymerized chain growth agent mixed with four diamine compounds at a constant ratio to make a viscosity favorable for spinning. After the chain stops with 1 to 30 mol% of a monoamine compound with respect to the diamine compound, a heat resistance improving additive represented by the general formula (I) and a diester metal salt compound which is a chlorine resistance enhancer represented by the general formula (II) are added. Method for producing an elastic fiber, characterized in that to obtain a polymer by spinning (Wherein R ¹ , R ² , R ³ and R ⁴ are hydrogen atoms or alkyl groups or aryl groups having 1 to 10 carbon atoms, and R ⁵ is an alkylene group or benzene ring having 1 to 10 carbon atoms.) (Wherein R ₁ : ethyl or phenyl group, R ₂ : alkyl group having 1 to 10 carbon atoms, aryl group or alkylaryl group, M1, M2: same or different metal ion among Na, Ca, Al, Zn, Ba, Pb) The method for producing an elastic fiber according to claim 1, wherein the amount of the heat resistance improving additive is 0.01 to 1.0% by weight based on the polymer solids. The method of manufacturing an elastic fiber according to claim 1, wherein the amount of the chlorine resistance enhancer is 0.01 to 3% by weight, based on the polymer solid content.