KR19980016619A - Polyurethane Elastic Fiber Manufacturing Method - Google Patents

Abstract

The present invention relates to a method for producing a polyurethane-based elastic fiber is widely used in stretch fabrics such as stockings, women's underwear, swimwear with excellent elasticity and elastic recovery power, in particular the heat resistance and elastic recovery power that is a drawback of the conventional polyurethane fiber It was devised to improve.

The present invention is a method for achieving the above object by prepolymerizing a long chain diol mixed with a polyether diol and an aliphatic polyester diol and a long chain polyol having a tertiary amino group with an excess of an organic diisocyanate compound and mixed in a fixed ratio with a solvent. After the chain growth using a diamine compound as a chain growth agent and chain stop by adding a heat resistance additive and a property deterioration inhibitor, and then a polymer obtained by adding a viscosity stabilizer and a heat resistance additive is used to prepare a polyurethane elastic fiber It provides a method, and the elastic fiber produced in this way has the characteristics of improved heat resistance and elastic recovery while maintaining the inherent properties of the existing.

Description

Polyurethane Elastic Fiber Manufacturing Method

The present invention relates to a method for producing a polyurethane-based elastic fiber improved heat resistance and elastic recovery while maintaining the inherent properties of the polyurethane-based elastic fiber.

Polyurethane-based elastic fibers have been widely used in stockings and women's underwear and stretch fabrics because of their excellent elasticity and elastic recovery ability, and their use is also expanding.

However, since the heat resistance is poor and mixed with other materials, such as polyester fibers, it is impossible to dye at a high temperature of about 130 ° C.

In order to improve the heat resistance, additional heat resistance additives such as triazoles, hindered phenols, and semicarbazide end groups may be introduced, or a part of the polymer diol compound may be replaced with a low molecular weight diol compound. In this case, as the low molecular weight diol compound, ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol and the like are used.

In addition, as described in Japanese Patent Application Laid-Open No. 4-74457, a polymer in which polytetramethylene glycol is reacted with an excess of 4,4'-diphenylmethane diisocyanate and chain-grown with 1,2-propylene diamine and diethylene amine There is a method of improving the elastic recovery rate by heating the elastic yarn prepared by spinning at a constant temperature, as described in European Patent 343572 (A2), European Patent 358555 (A2), European Patent 409735 (A1) or A method of securing heat resistance and moisture resistance by spinning with a polymer obtained by chain growth using a polycaprolactone diol compound in a general manner has been proposed.

In addition, a method of improving heat resistance using a modified amine has been proposed, but in most cases, the degree of improvement in heat resistance is insignificant.

In addition, as a method for improving the elastic recovery rate, the heat treatment method after the spinning process mentioned above, the method of chain growth using a tertiary nitrogen amine compound, the step of prepolymer forming a diol and / or diamine compound having a divalent or higher end group Or there is a method such as introduced into the polymer forming step of the chain growth process, but these methods had a disadvantage such that the elastic properties are rather deteriorated by the formation of excessive cross-linking rather than improving the elastic recovery rate.

The present invention is to provide a method for producing a polyurethane polymer for elastic fibers that significantly increased the heat resistance and elastic recovery of the elastic fibers while maintaining the inherent properties of the polyurethane elastic fibers, polyether diol (A -1) and the long chain diol (A) which mixed polyester-based diol (A-2), and 2-7 amino groups and 3-12 carbon atoms which have at least 1 tertiary amino group in excess After prepolymerization with diisocyanate (C), a solvent and a certain ratio are mixed, chain growth is carried out using an appropriate amount of a diamine compound (D) in the terminal isocyanate to obtain a viscosity suitable for spinning, and then a monoamine compound (E) is used. It relates to a method for producing a polyurethane-based elastic fiber, characterized in that the polymer is obtained by blocking the end and adding a heat resistance improving additive (F).

Hereinafter, the present invention will be described in detail.

Polyurethane elastic fiber according to the present invention is a long-chain diol (A) component that acts as a soft segment, and a molar ratio (A-) of polyether diol (A-1) and polyester-based diol (A-2) having excellent elastic recovery and heat resistance. 2) is mixed to a molar ratio (A-2 / A-1) of 0.2 to 5 (more preferably 0.5 to 3), and a polyol (B) having a tertiary amino group is combined with a long chain diol (A). After mixing so that the molar ratio (A / B) is 5 to 50 (more preferably, 12 to 35), prepolymerization with excess diisocyanate compound (C) and a suitable amount of a solvent such as dimethyl acetamide are mixed to prepare a prepolymer solution. Thereafter, 0.5 to 0.98 moles of the diamine compound was used to chain-grow the terminal isocyanate to obtain a moderate viscosity (approximately 500 to 4,000 poise) for spinning, and the chain stop monoamine compound was 1 to 30% of the total amine usage. Addition of viscosity stabilizer and heat resistance improvement after chain stop by adding mol% To obtain an elastic fiber using a polymer prepared by adding 0.01 to 1% by weight to not only significantly improve heat resistance by synergistic effect with the polyester diol introduced in the prepolymer forming step, but also by tertiary nitrogen amine compound The effect of greatly improving the elastic recovery force is obtained.

As the polyether diol (A-1), polyethylene glycol, polypropylene glycol, polytetramethylene glycol, or the like may be used, and the molecular weight is suitably in the range of 1000 to 3000 (more preferably 1500 to 2500).

As the polyester diol (A-2), polyester diols having a molecular weight of 500 to 5,000 (more preferably 700 to 3,000) prepared by aliphatic dibasic acid and low molecular weight glycol are used. If the molecular weight is less than 500, rather than improving the heat resistance will cause a decrease in the elastic recovery of the final spun yarn.

As the aliphatic dibasic acid in the composition of the polyester diol, an aliphatic dibasic acid having 3 to 14 carbon atoms alone or a mixture thereof including succinic acid, adipic acid, glutaric acid, maleic acid, pimeric acid, azeaic acid, sebacic acid, etc. may be used. Low molecular glycols may include glycols having 2 to 10 carbon atoms, such as ethylene glycol, diethylene glycol, triethylene glycol, 1, 2-propylene glycol, 1, 3-propylene glycol, 1, 4-butanediol , 2, 3-butane diol, 1, 5-pentane diol, 1, 6-hexane diol, 1, 4-cyclohexane diol, 1, 4-cyclohexane dimethanol, 2, 2-dimethyl-1, 3-propane Glycols such as diols, 1,8-octane diols, or mixtures thereof can be used.

In the present invention, the molar ratio of the polyester diol (A-2) and the polyether diol (A-1) used as the long-chain diol (A) component of the polyurethane resin is (A-2 / A-1) 0.2 to 5 (more Preferably 0.5 to 3) is suitable, and if the molar ratio exceeds 5, the durability of the final polymer is lowered, and if it is less than 0.2, synergistic effects on the intended heat resistance improvement cannot be expected.

In addition, the polyurethane elastic fibers of the third class by side chain at positions other than both ends using polyols (B) having 2 to 7 amino groups and 3 to 12 carbon atoms having at least one or more tertiary amino groups. By introducing the amino group has a network structure by the urea bond with the isocyanate to form a strong bond, thereby improving the heat resistance and elastic recovery ability and improve the viscosity stability of the polymer to maintain a suitable viscosity for spinning.

Examples of the polyol (B) component having a tertiary amino group include ethylene oxide, propylene oxide, butylene oxide, and the like in primary amines represented by R-NH ₂ (R: C _{2n + 1} , n-1 to 30). Diols and derivatives thereof made by addition of 2 to 55 moles may be used.

For example, N-methyl diethanolamine and N-ethyl diethanolamine obtained by adding 2 moles of ethylene oxide to primary amines such as methylamine, ethylamine, isopropylamine, n-butyl amine and isobutanamine. Ethylene to alkylamines such as polyoxyethylene oleylamine in which 20 to 55 moles of ethylene oxide is added to N-alkyl diethanolamine such as N-isopropyl diethanolamine and laurylamine, stearyl amine, and oleylamine. Diols to which an oxide, propylene oxide, and the like are added may be used.

The molar ratio between the long-chain diol (A) and the polyol (B) having a tertiary amino group is preferably A / B = 5 to 50 (more preferably 12 to 35), and less than 5 does not dissolve well in the solvent. If there is a problem with the spinning and is larger than 50, the improvement of elastic recovery force is minimal.

Examples of the diisocyanate compound (C) which combines with the amine compound which is a chain growth agent and acts as a hard segment include paraphenyl diisocyanate, metaphenylene diisocyanate, 2,4-torylene diisocyanate, 2 and 6-tori Ethylene diisocyanate, 1-chlor-2, 1-phenylene diisocyanate, 1, 5-naphthalene diisocyanate, 1, 4-phenylene diisocyanate, chlorphenylene-2, 4′-diisocyanate, methylenebis-4 -Phenyl diisocyanate, hexamethylene diisocyanate, polymethylene polyphenyl diisocyanate, methylcyclo hexylene diisocyanate, paraphenyl diisocyanate, paraphenylene diisocyanate, 4, 4'-diphenyl isopropylidine diisocyanate, 3, 3′-dimethyl-4, 4′-diphenyl diisocyanate, 3, 3′-dimethoxy-4, 4′-diphenylene diisocyanate, 4, 4′-dipe There are compounds such as diisocyanate, are considered when the physical properties of the elastomer and the reactive 4, 4'-diphenylmethane-diisocyanate compound with a diol compound is more preferable.

The amount of the diisocyanate compound (C) is suitably C / (A + B) = 1.23 to 2.7 for the compound (A + B) mixed with the long-chain diol (A) and the polyol (B) having a tertiary amino group. In the case of less than 1.23, the polymer is excellent in elongation but the strength is low and the elastic recovery is insufficient. In the case of over 2.7, the strength and elastic recovery are excellent, but the elongation is poor, resulting in inherent deterioration of physical properties as an elastomer.

The prepolymers in which the long-chain diol (A), the polyol (B), and the diisocyanate compound (C) are bonded are chain-grown by the diamine compound, and chain-grown at a constant molecular weight and then chain-stopped with monoamine to form a polymer having a suitable molecular weight. You can get it.

As diamine compound (D) which chain-grows a prepolymer, methyliminobispropylamine, 2, 5- dimethyl piperazine, 1, 2- propylene diamine, 2, 3- butylene diamine, para styrene diamine, 2-methyl pipe Razine, ethylene diamine, ethanol diamine, tetramethylene diamine, pentamethylene diamine, hexamethylene diamine, 1-methyl-2, 4-diamine benzene, 1, 2-cyclohexane diamine, 1, 3-cyclohexane diamine, 1, 4 -Cyclohexane diamine, octamethylene diamine, paraphenylene diamine and the like, and the use range is 0.5 ~ 0.98 moles with respect to the eppolymer, outside the range is not obtained the properties required in the present invention.

In order to improve the viscosity stability of the polymer and the properties of the elastic yarn after spinning in the chain growth compound, a linear amine and a cyclic amine should be mixed in an appropriate ratio.

The molar ratio (D-1) / (D-2) of the linear diamine (D-1) and the cyclic diamine (D-2) is in the range of 2 to 18, and (D-1) / (D- When the molar ratio of 2) is less than 2, a low molecular weight polymer is produced, resulting in deterioration of mechanical properties such as strength, elongation and elastic recovery rate, and the molar ratio of (D-1) / (D-2) is greater than 18. If it is increased, the reaction rate is too fast, so that a large amount of side reactants are generated, which lowers the stability of the polymer and lowers the heat resistance.

Examples of the monoamine-based compound (E) which is a chain stopper for blocking the ends of the chain-grown prepolymer are monoethanol amine, diethanol amine, propyl amine, isopropyl amine, diisopropyl amine, 2-ethylhexine amine, and di (2 -Ethylhexyl) amine, butyl amine, etc., considering the reactivity with the chain growth diamine compound, isopropyl amine has a particularly excellent chain stop effect to maintain the molecular weight of the polymer moderately and to suppress secondary side reactions To impart stability of the polymer.

The amount of isopropyl amine used is 1 ~ 30% (mol%) of the total amine use, and below 1%, the chain stopping effect is poor, so that the viscosity of the polymer rapidly rises and the viscosity changes with time, so that the viscosity keeps rising. Inappropriate, and when used in excess of 30%, the chain growth of the polymer is prevented, so that it is not grown into a polymer having an appropriate molecular weight, so that a suitable viscosity for spinning cannot be obtained, and the physical properties, strength, elongation and elastic recovery rate of the polymer are poor.

Solvents for controlling the solid content of the polymer to improve radioactivity are dimethylacetamide, dimethylformamide, hexamethylphosphoramide, dimethylnitrosoamine, dimethyl propionamide, methoxydimethylacetamide, N-methylpyrrolidine, dimethyl sulfoxide Seeds, tetramethylene sulfone, and the like, in particular dimethylacetamide or dimethylformamide are advantageous in terms of compatibility with the polymer, radioactivity, solvent recovery. The amount of the solvent to be used is preferably adjusted so that the solid content of the polymer is 15 to 43% by weight, but less than 15% or more than 43% adversely affects the radioactivity.

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

(Wherein R ¹ , R ² , R ³ , R ⁴ are hydrogen atoms or alkyl groups or aryl groups having 1 to 20 carbon atoms, and R ⁵ is an alkylene group or benzene ring having 1 to 10 carbon atoms)

Phosphoryl compounds having an amine bond include phosphoryldimethylethanolamine, 2-dimethylaminophenoldiphenyl phosphate, 2-diethylaminoethanoldimethyl phosphate, 2-ethylpropylaminophenoldihydrogen phosphate, and 2-dibutylaminophenol dihydro Gen phosphate and the like can be used.

The amount of the phosphorus compound having an amine bond is preferably 0.01 to 1.0% by weight (more preferably 0.05 to 0.5% by weight) based on the solids of the final polymer.

If less than 0.01% by weight can not guarantee the improvement of the heat resistance, if the use of more than 1.0% by weight may cause deterioration of the polymer properties during spinning due to the addition of excess stabilizer.

The polymer solution prepared by the above method produces a polyurethane-based elastic fiber using a conventional dry spinning method.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. Tensile strength, elongation and elastic recovery rate shown in the Examples were measured by KSK 0219, and heat resistance was evaluated by strength retention and color change (Gray Scale: ISO international standard) after 60 minutes treatment of the elastic yarn in a hot air dryer at 130 ° C.

Example 1

1 mol of 1,500 aliphatic polyester diols synthesized from 1,12-dodecanedioic acid and 2, 2-dimethyl-1, 3-propane diol, 1 mol of polytetramethylene glycol having a molecular weight of 1,800, N-isopropyl diethanol 0.1 mole of amine was stirred at 82 ° C. under reduced pressure to remove water, and then 4.2 moles of 4,4-diphenylmethane diisocyanate, pre-heated at 50 ° C., were added, followed by polymerization at 80 ° C. × 60 min in a nitrogen gas atmosphere to prepare a prepolymer. It was.

The prepolymer was dissolved in dimethyl acetamide and the solution was cooled to 5 ° C., followed by 1 mole of ethylene diamine as linear amine, 0.8 mole of 1,2-propylene diamine as a chain growth agent, and 0.2 mole of metastyrene diamine as cyclic amine. A chain growth agent solution in which 0.1 mol of 1,4-cyclohexane diamine was dissolved in dimethyl acetamide at a concentration of 15% was slowly added to the eppolymer to obtain a polymer having a viscosity of 2,950 poise.

A solution of 0.2 mol of isopropyl amine dissolved in dimethyl acetamide at a concentration of 15% was slowly added to this polymer to obtain a polymer having 3,000 poises.

After the completion of the polymerization, the solution of dissolving the phosphorus dimethyl ethanol amine, a heat resistance improving additive, in dimethylacetamide at a concentration of 10% was added so that the heat-resistant additive was 0.2% by weight of the final polymer solid to adjust the solid content of the final polymer to 30%. It was. The viscosity at this time is 2,600 poise (@ 45 degreeC).

40 denier polyurethane elastic yarn was prepared using the conventional dry spinning method, and the results of the evaluation of the physical properties are shown in Table 1.

Comparative Example 1

N-isopropyl diethanolamine having a tertiary amino group and phosphoryldimethylethanol amine as a heat resistance improving additive were carried out in the same manner as in Example 1, and the results of the evaluation of the physical properties are shown in Table 1. .

Comparative Example 2

Except for not using phosphoryl dimethyl ethanol amine as a heat resistance improving additive was carried out in the same manner as in Example 1, the results of the evaluation of the physical properties are shown in Table 1.

Comparative Example 3

2 moles of polytetramethylene glycol having a molecular weight of 1,800 and 0.1 moles of N-isopropyl diethanolamine were removed at 82 DEG C under reduced pressure without using an aliphatic polyester diol to remove moisture, and then preheated 4, 4 'at 50 DEG C. After adding prepolymer to 80 ° C. × 60 minutes in a nitrogen gas atmosphere by adding 4.2 moles of diphenylmethane diisocyanate, the polymerization was carried out in the same manner as in Example 1. The viscosity of the polymer after chain growth was 3,200 poise and the additive was The viscosity of the final polymer with 30% solids charged was 2,900 poise (@ 45 ° C). The results of evaluating the physical properties are shown in Table 1.

Comparative Example 4

4.1 moles of polytetramethylene glycol having a molecular weight of 1,800 under reduced pressure were removed at 82 ° C. under reduced pressure without using aliphatic polyester diols, N-isopropyl diethanolamines and heat resistance enhancing additives, and then preheated at 4 ° C. 4, 4 After the polymerization was performed at 80 ° C. for 60 minutes in a nitrogen gas atmosphere by adding 4.2 mol of ′ -diphenylmethane diisocyanate to prepare a prepolymer, the polymerization reaction was carried out in the same manner as in Example 1. The viscosity of the polymer after chain growth was 3,000 poises and a solid content. The viscosity of the final polymer at 30% was 2,700 poises (@ 45 ° C). The results of evaluating the physical properties are shown in Table 1.

TABLE 1

* Grade of heat resistance indicates that grade 5 is the best and grade 1 is the worst.

Claims (7)

One or two long-chain diols (A) and tertiary amino groups obtained by mixing a polyether diol (A-1) having a number average molecular weight of 1,000 to 3,000 and an aliphatic polyester diol (A-2) having a horizontal molecular weight of 500 to 5,000 After pre-polymerizing the polyol (B) having 2 to 7 amino groups and 3 to 12 carbon atoms (B) with an excess of the organic diisocyanate compound (C), the solid content is mixed to 15 to 43% by weight, and the diamine compound as a chain growth agent ( D) was chain-grown using 0.5 ~ 0.98 moles of the prepolymer, followed by addition of monoamine (E) as a chain stopper to 1-30 mole% of the total amine, followed by chain stoppage, followed by viscosity stabilizer and general formula (1) A method for producing a polyurethane-based elastic fiber, characterized by using a polymer obtained by adding 0.01 to 0.1% by weight of the heat resistance improvement additive represented by. (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) The method of claim 1, wherein the long-chain diol (A) is a mixture of polyetherdiol (A-1) and aliphatic polyester diol (A) in a molar ratio of (A-2) / (A-1) = 0.2-5. Method for producing a polyurethane-based elastic fiber characterized in that. The method for producing a polyurethane-based elastic fiber according to claim 1, wherein the molar ratio of the long-chain diol (A) and the polyol (B) is used in the range of A / B = 5 to 50. The method for producing a polyurethane-based elastic fiber according to claim 1, wherein the organic diisocyanate compound (C) is used such that its molar ratio is in the range of C / A + B = 1.23 to 2.7. The diamine compound (D) as a chain growth agent according to claim 1, wherein the molar ratio of linear diamine (D-1) and cyclic diamine (D-2) is used as (D-1) / (D-2) = 2 ~. Method for producing a polyurethane-based elastic fiber, characterized in that used in the range of 18 mixed. The method for producing a polyurethane-based elastic fiber according to claim 1, wherein the solvent is selected from dimethylacetamide or dimethylformamide. The method of claim 1, wherein the heat resistance improving additive is phosphoryldimethylethanol amine, 2-dimethylaminophenoldiphenyl phosphate, 2-diethylaminoethanoldimethyl phosphate, 2-ethylpropylaminophenoldihydrogen phosphate, 2-dibutylamino Method for producing a polyurethane-based elastic fiber, characterized in that selected from phenol dihydrogen phosphate.