JP2006193867A - Polyurethane elastic fiber and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyurethane elastic fiber, excellent in hot melt-bonding property, capable of melt-bonding the fibers to each other by heat-treating at approximately 190°C, hardly forming a fray, thread casting off, etc., capable of making the thread intertwining softly since the thread casting off is less and capable of obtaining a very flexible woven or knitted fabric equipped also with practical strength, elastic characteristic, etc., jointly. <P>SOLUTION: This polyurethane elastic fiber is obtained by spinning a spinning solution obtained by mixing (A) a solution containing a polyurethane polymer obtained by reacting a prepolymer (a) having isocyanate groups at both terminals and obtained by reacting a polyol with an organic diisocyanate, with an amine compound in an organic solvent with (B) a polyurethane compound obtained by reacting a prepolymer (b) having isocyanate groups at both terminals and obtained by reacting a polyol with an organic diisocyanate, with a low molecular weight diol, by a mass ratio of (A):(B)=(80:20)-(40:60). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a polyurethane elastic fiber and a method for producing the same.

Products using stretch fabrics such as circular knitted fabrics, warp knitted fabrics, and woven fabrics mixed with polyurethane elastic fibers are widely used because of their high elongation and good recovery and fit from the stretched state. However, if a product made by cutting and sewing a fabric mixed with polyurethane elastic fibers is repeatedly stretched, it will be deformed and become a non-uniform fabric, “deformation, misalignment, soft”, “fraying”, yarn coming out, and fabric Problems such as “run, densen” with ladder-like scratches and misalignment, and “curl” with curved fabric are likely to occur. In addition, the so-called “slip-in”, in which the polyurethane elastic fiber comes out of the seam at the sewing portion due to repeated elongation, tends to occur. The portion of the fabric where the slip-in occurs and the elastic fiber comes out is of course, but there is a problem that density shrinkage occurs on the fabric because the shrinkage force is lost, and the fabric cannot be worn.
These phenomena occur even in a woven or knitted fabric using elastic fibers other than polyurethane elastic fibers, but are particularly remarkable in the case of polyurethane elastic fibers having strong stretchability.

  For this reason, various studies have been made on spinning methods in order to improve the physical properties of polyurethane elastic fibers. Known methods for spinning polyurethane elastic fibers include dry spinning, wet spinning, chemical reaction spinning, melt spinning, and the like (see Patent Document 1: Japanese Patent Laid-Open No. 39-16667). JP-A-2002-339189 (Patent Document 2) reports that a polyurethane elastic fiber having heat-fusibility can be obtained by dry spinning a spinning solution to which a low molecular weight urea compound is added.

  However, normally, the dry polyurethane elastic fiber does not exhibit a sufficient fusing force by a heat treatment of about 200 ° C. When the knitted fabric using such a polyurethane elastic fiber is heat-treated, the end of the knitted fabric is curled. There is a drawback that the edges are frayed when the fabric is cut or cut.

Japanese Unexamined Patent Publication No. 39-16667 JP 2002-339189 A WO2004 / 053218 A1

  The present invention has been made in view of the above circumstances, it is difficult to cause problems such as softness, curling, and thread loss, and can maintain a practical strength even after heat treatment, and can obtain a woven or knitted fabric excellent in flexibility. An object of the present invention is to provide a polyurethane elastic fiber excellent in heat-fusibility and a method for producing the same.

  As a result of intensive investigations to achieve the above object, the present inventor obtained by reacting a polyol compound and an organic diisocyanate with both terminal isocyanate group prepolymers a and an amine compound in an organic solvent. A polyurethane compound (B) obtained by reacting a solution of the polyurethane polymer (A) obtained, and a both-end isocyanate group prepolymer b obtained by reacting a polyol and an organic diisocyanate with a low molecular weight diol, has a specific mass. It has been found that polyurethane elastic fibers obtained by spinning a spinning solution mixed at a ratio are excellent in inter-filament bonding, and troubles such as yarn cracking in a covering process and the like are reduced. Furthermore, by heat-treating the woven fabric using the polyurethane elastic fibers, the polyurethane elastic fibers and the polyurethane elastic fibers and other fibers are heat-sealed, so that there is little thread loss and the tissue yarn is softened. It has been found that a woven or knitted fabric that is very flexible and retains practical strength and elasticity even after heat treatment can be obtained, and has led to the present invention.

That is, the present invention
[1] A solution containing a polyurethane polymer (A) obtained by reacting a both-end isocyanate group prepolymer a obtained by reacting polyol and organic diisocyanate with an amine compound in an organic solvent, and polyol and organic diisocyanate A polyurethane compound (B) obtained by reacting a both-end isocyanate group prepolymer b obtained by reacting with a low molecular weight diol,
(A): (B) = polyurethane elastic fiber obtained by spinning a spinning solution mixed at a mass ratio of 80:20 to 40:60,
[2] The polyurethane according to [1], wherein the polyurethane polymer (A) has a weight average molecular weight of 250,000 to 450,000, and the polyurethane compound (B) has a weight average molecular weight of 200,000 to 500,000. Elastic fiber,
[3] [I] a step of reacting a polyol and an organic diisocyanate to synthesize both-end isocyanate group prepolymer a, and [II] a reaction of the both-end isocyanate group prepolymer a and an amine compound in an organic solvent. A step of obtaining a solution of the polyurethane polymer (A),
[III] a step of reacting a polyol and an organic diisocyanate to synthesize both-end isocyanate group prepolymer b, and [IV] a reaction between the both-end isocyanate group prepolymer b and a low molecular weight diol to react with a polyurethane compound (B). And a step of obtaining
[V] a step of mixing the solution containing the polyurethane polymer (A) and the polyurethane compound (B) in a mass ratio of (A) :( B) = 80: 20 to 40:60; and [VI] polyurethane weight A process for producing a polyurethane elastic fiber, comprising a step of spinning a solution containing the coalescence (A) and the polyurethane compound (B);
[4] Further, after step [IV], the polyurethane compound (B) is heat-treated, and the resulting polyurethane compound (B) is pulverized, remelted and pelletized. I will provide a.

  ADVANTAGE OF THE INVENTION According to this invention, the polyurethane elastic fiber which the cohesion property between filaments improved and the yarn cracking trouble in a covering process etc. reduced can be provided. Since the polyurethane elastic fiber of the present invention is excellent in heat-fusibility, when used in a woven or knitted fabric or the like, it can be heat-treated at about 190 ° C. to fuse the fibers together, and fraying, cracking, curling, yarn removal, etc. Since the yarn is less likely to be formed and is less likely to come off by fusing, it is possible to soften the yarn of the structure, and to obtain a woven / knitted fabric that is very flexible and also has practical strength, elastic characteristics and the like.

The polyurethane elastic fiber according to the present invention is
A solution containing a polyurethane polymer (A) obtained by reacting a polyol and an organic diisocyanate with both end-isocyanate group prepolymers a and an amine compound in an organic solvent, and reacting a polyol and an organic diisocyanate. A polyurethane compound (B) obtained by reacting the both-end isocyanate group prepolymer b obtained by the above and a low molecular weight diol,
(A): (B) = Spinning solution formed by spinning at a mass ratio of 80:20 to 40:60.

  In the present invention, the polyurethane polymer (A) can be synthesized by a conventionally known method. The polyol as a raw material is not particularly limited, but is preferably a polyol having a hydroxyl group at the terminal and a number average molecular weight of 400 to 5,000, more preferably a polyol having a number average molecular weight of 800 to 3,500. Is used. The number average molecular weight can be calculated from the hydroxyl value according to JIS K1557. When the hydroxyl value is 280.5 mgKOH / g, the number average molecular weight is 400, and when the hydroxyl value is 22.44 mgKOH / g, the number average molecular weight is 5,000.

  As such a polyol, polyether diol, polyester diol, polyether ester diol, polylactone diol, polycarbonate diol, silicone diol and the like can be used.

  Examples of the polyether diol include polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol, polyoxypentamethylene glycol, neopentyl glycol, polytetramethylene ether glycol (PTMG), tetrahydrofuran (THF), and 3- Modified PTMG, which is a copolymer of methyltetrahydrofuran (3-MeTHF), modified PTMG, which is a copolymer of THF and 2,3-dimethyltetrahydrofuran; By ring-opening polymerization of polyether diols such as polyalkylene diols and cyclic ethers (polyethylene oxide, polypropylene oxide, trimethylene oxide, tetrahydrofuran, etc.) Polyether diols and the like to be.

  Examples of the polyester diol include one or more selected from dibasic acids such as succinic acid, malonic acid, glutaric acid, adipic acid, sebacic acid, maleic acid, itaconic acid, azelaic acid, ethylene glycol, propylene Glycol, hexamethylene glycol, diethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentylene glycol, 1,3-dimethylolcyclohexane, 1,4-dimethylolcyclohexane Examples thereof include polyester diols obtained by polycondensation with one or more selected from glycols such as xane, 1,5-pentanediol, and 3-methyl-1,5-pentanediol.

  Examples of the polyether ester diol include those produced by reacting the above-described polyester diol with the above-mentioned cyclic ether, and those obtained by reacting the above-described polyester diol and polyether diol.

  Examples of the silicone diol include polydimethylsiloxane diol and polydimethylsiloxane terminal alkylene oxide adducts.

  Examples of the polylactone diol include poly ε-caprolactone diol and polyvalerolactone diol.

  Examples of the polycarbonate diol include at least one organic carbonate selected from dialkyl carbonates such as dimethyl carbonate and diethyl carbonate; alkylene carbonates such as ethylene carbonate and propylene carbonate; diaryl carbonates such as diphenyl carbonate and dinaphthyl carbonate; and ethylene. At least one aliphatic selected from glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, and the like Examples thereof include polycarbonate glycol obtained by transesterification with diol.

  The above exemplified polyether diol, polyester diol, polyether ester diol, silicone diol, polylactone diol, and polycarbonate diol can be used singly or in combination of two or more. It is preferable to use ether diol and / or polycarbonate diol in an amount of 30% by mass or more of the total polyol from the viewpoints of easy chemical processing and excellent mold resistance when the product is post-processed. More preferably, 60-100 mass% is used.

  The organic diisocyanate used in the present invention can be applied without particular limitation as long as it is dissolved or shows liquid under reaction conditions among aliphatic, alicyclic and aromatic diisocyanates. For example, 2,4-tolylene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate (HDI), 1,4-phenylene diisocyanate, 1,4-cyclohexane diisocyanate, 4,4′- Dicyclohexylmethane diisocyanate (HMDI), naphthalene diisocyanate, xylylene diisocyanate (XDI), meta-tetramethylxylylene diisocyanate, para-tetramethylxylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, and the like. Can be used alone or in combination of two or more thereof, but among these, MDI and HMDI are preferred.

  The organic diisocyanate is preferably used in excess of about 1.2 to 3.0 times, more preferably about 1.4 to 2.2 times in excess of the polyol.

  When synthesizing a prepolymer a having both terminal isocyanate groups by reacting a polyol with an organic diisocyanate, the reaction method may be a continuous method using a static mixer, a twin-screw kneader, or the like, even in a batch method using a synthetic kettle. After each component is charged in a predetermined molar ratio, it is 60 to 150 ° C., particularly 65 to 130 ° C., 30 to 180 minutes, particularly 40 to 120 minutes in an inert gas atmosphere such as nitrogen or argon. It is preferable to react under conditions.

  Next, a predetermined amount of amine compounds 1 and 2 represented by the following formulas (1) and (2) are added to the obtained both-end isocyanate group prepolymer a, and these are added in the prepolymer a and the organic solvent. To produce a polyurethane polymer (A).

The amine compound 1 used by reacting with the both-end isocyanate group prepolymer a is an amine compound having at least two active hydrogen atoms capable of reacting with the isocyanate represented by the following formula (1) in the molecule, Used as an agent. Moreover, the amine compound 2 is shown by following formula (2), and is used as a terminal blocker which seals the terminal of a polyurethane polymer.
H ₂ NR ¹ NH ₂ (1)
NHR ² R ³ (2)

Here, R ¹ is a single bond or an alkylene group having 1 to 13 carbon atoms, preferably 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms, or an arylene group or a group to which these are bonded. Group, butylene group, pentylene group, hexylene group, phenylene group, xylylene group, cyclohexylene group and the like. R ² and R ³ are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, preferably 1 to 6 carbon atoms, such as methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, t- A butyl group, an isobutyl group, a pentyl group, a hexyl group, a 2-ethylhexyl group, etc. can be mentioned.

  Specific examples of the amine compound 1 include diamines such as ethylenediamine, propylenediamine, butanediamine, hexamethylenediamine, xylylenediamine, 4,4-diaminodiphenylmethane, and hydrazine.

  Examples of the amine compound 2 include monoalkylamines such as isopropylamine, n-butylamine, t-butylamine, 2-ethylhexylamine; diethylamine, diisopropylamine, di-n-butylamine, di-t-butylamine, di-isobutylamine, di- Examples thereof include dialkylamines such as -2-ethylhexylamine.

  The amine compound is used in an equivalent ratio such that amine compound 1 / amine compound 2 = 99.5 / 0.5 to 90/10, preferably 99/1 to 93/7. When the equivalent ratio of the amine compound exceeds 99.5 / 0.5, the hard segment in the polyurethane polymer increases, so that the viscosity stability of the polyurethane polymer solution is lowered, and local reactions are likely to occur during the polymerization. As a result, the gel product tends to increase in the polyurethane polymer solution, and the gel product may be broken by passing through the nozzle during spinning, or the operation stability may be reduced due to the filterability of the solution. . On the other hand, when it is lower than 90/10, the viscosity stability of the polyurethane polymer solution is good, but the degree of polymerization of the polyurethane polymer may be lowered, and the yarn physical properties may be deteriorated.

  Further, the total addition amount of the amine compounds 1 and 2 is preferably equal to or greater than the isocyanate group contained in the prepolymer a, and more preferably 1.0 to less than 1.1 in terms of equivalent ratio. If the total amount of amine compound added is lower than the equivalent amount, the isocyanate groups remaining in the system will react over time, which may lead to an increase in molecular weight and a significant increase in solution viscosity. May cause yellowing of the polyurethane polymer solution or a decrease in the viscosity of the solution over time.

  It is preferable that the amine compounds 1 and 2 be a mixture of amine compounds in an organic solvent because they can easily react with the prepolymer a. When the amine compound is reacted with the prepolymer a, the reaction is usually carried out by dropping it into the solution of the prepolymer a as a solution dissolved in an organic solvent, but the amine group concentration remaining in the prepolymer a solution is measured in advance. From the method of determining the amount of the compound dropped or the state in which the viscosity of the prepolymer a solution is increased by adding an amine compound, the isocyanate group is eliminated, the substantial reaction is completed, and the solution viscosity is not increased. It is possible to control the amount of dripping by monitoring.

  As the chain extender, if necessary, in addition to the amine compound 1, diols such as ethylene glycol, 1,4-butanediol, 1,6-hexanediol, water, dihydrazide, carbodihydrazide, β- Polyfunctional active hydrogen compounds such as hydroxides such as aminopropionic hydrazide may be used in combination. Moreover, as terminal blocker, you may use alkyl alcohol, such as methanol, ethanol, propanol, butanol, pentanol, etc. other than the amine compound 2 as needed.

  An inert organic solvent is used in the polyurethane polymerization reaction. Examples of the organic solvent include N, N-dimethylformamide, N, N-dimethylacetamide, N, N, N ′, N′-tetramethylurea, N-methylpyrrolidone, and dimethyl sulfoxide. Needless to say, an organic solvent that has high solubility and does not react with an isocyanate group or an active hydrogen compound that reacts with the isocyanate group and does not react with an additive in the polyurethane polymer solution is preferable. Of these, N, N-dimethylacetamide or N, N-dimethylformamide is preferably used from the viewpoint of compatibility with the polyurethane polymer, spinnability and solvent recoverability.

  The amount of the organic solvent used is preferably adjusted so that the solid content of the polyurethane polymer (A) is 10 to 60% by mass, particularly 20 to 40% by mass, less than 10% by mass or 60%. If it exceeds mass%, the spinnability may be adversely affected.

  In addition, a catalyst for accelerating the reaction may be used for the above polymerization reaction, if necessary, such as those having a strong tendency to activate the reaction between isocyanate and polyol, diamine, diol, isocyanate and water, etc. Those having a strong tendency to activate the reaction with the chain extender and those having both properties can be appropriately used. Representative examples of such a catalyst include tertiary amine compounds and organometallic compounds.

  As the tertiary amine compound, monoamines such as triethylamine, N, N-dimethylcyclohexylamine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetramethylpropane- Diamines such as 1,3-diamine, triamines such as N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine and tetramethylguanidine, triethylenediamine, N, N′-dimethylpiperazine, 1,8- Cyclic amines such as diazabicyclo (5,4,0) undecene-7 and N-methylmorpholine, alcohol amines such as dimethylaminoethanol and dimethylaminoethoxyethanol, bis (2-dimethylaminoethyl) ether, ethylene glycol bis (3 -Ether) such as dimethyl) -aminopropyl ether Kind, and the like.

  Organic metal compounds include tin acetate, tin octylate, tin oleate, tin laurate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dichloride, lead octoate, lead naphthenate, nickel naphthenate, cobalt octoate, etc. Is mentioned.

  These catalysts may be used alone, for example, two or more kinds such as a combination of a tertiary amine compound and an organometallic compound may be used in combination. The concentration of the catalyst is usually 0.0001 to 10% by mass, preferably 0.0005 to 5% by mass, based on the polyurethane polymer (A), but the addition amount may be adjusted appropriately while observing the reaction behavior. .

  The reaction between the both-end isocyanate group prepolymer a and the amine compounds 1 and 2 is carried out under an inert gas atmosphere such as nitrogen and argon at 0 to 80 ° C., particularly 10 to 60 ° C., and 0.1 to 5 hours, particularly The reaction conditions are preferably 0.5 to 3.5 hours, and the reaction method may be a batch method using a synthetic kettle or a continuous method using a twin-screw kneader or a static mixer.

  The weight average molecular weight of the polyurethane polymer (A) thus obtained is determined by gel permeation chromatography (GPC) using a soluble component completely dissolved in an N, N-dimethylformamide (DMF) solution in which lithium chloride is dissolved. Gel permeation chromatography) can be used. The weight average molecular weight of the polyurethane polymer (A) is preferably 250,000 to 450,000, more preferably 250,000 to 350,000 (polystyrene conversion). If the molecular weight of the polyurethane polymer is too small, the yarn physical properties such as heat resistance may decrease or the spinning spinnability may be poor and the yarn breakage may increase. It becomes necessary to increase the amount of solvent to be used, and as a result, it may not be an economical production method.

  Next, the polyurethane compound (B) to be mixed with the polyurethane polymer (A) can also be obtained by a known method, and the polyol and organic diisocyanate used as raw materials have been described as raw materials for the polyurethane polymer (A). Similar ones can be used.

  The organic diisocyanate is preferably used in excess of about 1.5 to 6.0 times, more preferably about 1.8 to 3.0 times in excess of the polyol.

  The reaction method for synthesizing the both-end isocyanate group prepolymer b by reacting a polyol and an organic diisocyanate may be a batch method using a synthetic kettle or a continuous method using a static mixer or a twin-screw kneader. Well, after preparing each component at a predetermined molar ratio, under an inert gas atmosphere such as nitrogen, argon, etc. under conditions of 60 to 150 ° C., particularly 65 to 130 ° C., 30 to 180 minutes, particularly 40 to 120 minutes It is preferable to make it react with.

  Next, the polyurethane compound (B) is synthesized by reacting the obtained both-end isocyanate group prepolymer b and a low molecular weight diol.

  The low molecular weight diol used as the chain extender is not particularly limited as long as it is a compound having in the molecule two active hydrogen atoms capable of reacting with isocyanate, but a low molecular weight diol having a molecular weight of 500 or less is preferable, for example, ethylene Examples include glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, and 3-methyl-1,5-pentanediol. These may be used singly or in combination of two or more, but 1,4-butanediol is preferable from the viewpoint of workability and imparting appropriate physical properties to the resulting fiber.

  The amount of the low molecular weight diol used is preferably 0.88 to 1.0, more preferably 0.9 to 0.97 in terms of an equivalent ratio with respect to the both-end isocyanate group prepolymer b. If the amount used is too large, the stretchability of the resulting polyurethane elastic fiber may decrease, and the texture of the knitted fabric may deteriorate, or the yarn may break during processing due to a decrease in strength or heat resistance. There is a tendency that the gel-like material increases, and the gel material is broken by passing through the nozzle during spinning, or the operation stability is lowered due to the filterability of the solution.

  The reaction between the both-end isocyanate group prepolymer b and the low molecular weight diol is carried out under an inert gas atmosphere such as nitrogen or argon at 60 to 220 ° C., particularly 65 to 200 ° C., for 5 to 180 minutes, particularly 10 to 120 minutes. It is preferable that the reaction conditions are as follows. The reaction method may be a batch method using a synthetic kettle or a continuous method using a twin-screw kneader or a static mixer.

  The weight average molecular weight of the polyurethane compound (B) thus obtained is preferably 200,000 to 500,000, more preferably 300,000 to 400,000. If the weight average molecular weight is too small, the heat resistance will decrease, and the polyurethane elastic fiber in the knitted fabric may break during processing such as dyeing and heat setting. In some cases, a problem may occur in the process such as making it difficult. In addition, the measuring method of a weight average molecular weight measured the soluble part melt | dissolved completely in the N, N- dimethylformamide (DMF) solution which melt | dissolved lithium chloride using a gel permeation chromatography (GPC: Gel permeation chromatography). can do

  The polyurethane elastic fiber of the present invention can be obtained by spinning a spinning solution obtained by mixing the polyurethane polymer (A) solution (stock solution for spinning) and the polyurethane compound (B) at a predetermined ratio. it can.

  In this case, the mixing ratio of the polyurethane compound (B) to the polyurethane polymer (A) is (A) :( B) = 80: 20 to 40:60, preferably 70: 30-50: 50. If the blending amount of the polyurethane compound (B) is too small, the heat-sealing strength may be insufficient. If it is too large, the heat resistance is lowered, and the polyurethane elastic fiber in the knitted fabric is broken during processing such as dyeing and heat setting. There is a risk of doing so.

  The mixing of the polyurethane polymer (A) and the polyurethane compound (B) is not particularly limited as long as both are sufficiently mixed. Even if the polyurethane compound (B) is mixed with the polyurethane polymer (A), The polyurethane polymer (A) may be mixed with the polyurethane compound (B). In the former case, it is preferable that the polyurethane compound (B) is mixed after the reaction of the polyurethane polymer (A) has progressed and the isocyanate group is substantially not recognized. After completion of the polymerization of B), it may be mixed with the solution of the polyurethane polymer (A) as it is, and once crushed and pulverized, or pulverized and then remelted into pellets, the polyurethane polymer ( You may add directly to the solution of A). Further, the polyurethane compound (B) may be dissolved and mixed in the same solvent as the solvent used for the synthesis of the polyurethane polymer (A). In this case, the pelletized material is preferable in that the polyurethane compound is re-melted, so that thermal decomposition occurs and the cross-linking of the molecule is broken and the polymer is easily dissolved in the solvent (or the solution of the polyurethane polymer (A)). Can be used.

  The reason why the solution containing the polyurethane polymer (A) and the polyurethane compound (B) is superior to the conventional polyurethane fiber obtained by spinning only the polyurethane polymer (A) is that the polyurethane compound in the fiber This is because (B) melts at a lower temperature than the polyurethane polymer (A), so that it adheres to the surrounding polymer while maintaining the fiber strength.

  When the polyurethane compound (B) is used by dissolving in a solvent, the concentration of the solution is not particularly limited, and is about 10 to 60% by mass from the viewpoint of increasing the viscosity of the spinning solution and changing the physical properties of the spun yarn. Preferably, it is 20 to 40% by mass.

  The method of adding and mixing the polyurethane compound (B) to the polyurethane polymer (A) solution is not particularly limited, but the conditions such as the mixing temperature and time are appropriately set under an inert gas atmosphere such as nitrogen and argon. It is preferable to select and mix uniformly. The mixing temperature is preferably 10 to 120 ° C, and particularly preferably 40 to 80 ° C. When the temperature is lower than 10 ° C., there is no problem in the side reaction at the time of mixing, but it is not economical because it takes time for dissolution and the cooling cost increases. When the treatment is performed at a temperature higher than 120 ° C., the viscosity of the liquid is lowered, so that the mixing speed is increased. In addition, in order to mix uniformly, it is preferable to stir at least 30 minutes or more.

  In the present invention, various stabilizers, inorganic metal salts, inorganic oxides, natural radioactive rare earth earth ceramics, and other inorganic additives can be added. The addition amount of these additives can be used without particular limitation as long as the object of the present invention is not impaired, but in order not to reduce the heat-fusibility, it is used at 10% by mass or less with respect to the polyurethane polymer. Is more preferable, and more preferably 7% by mass or less. If the amount added is too large, the yarn physical properties may be lowered.

  Examples of inorganic metal salts and inorganic oxides include salts or oxides of metal elements selected from the group consisting of titanium, magnesium, aluminum, zinc, silica, iron, calcium, zirconium, and silver.・ As mineral ceramics, mineral ceramics that emit far-infrared rays, negative ions, etc., such as Iomix manufactured by Mino Pigment Chemical Co., Ltd., far-infrared radiation ceramics manufactured by Nippon Serum Co., Ltd. (Resonium FC-0045), etc. Is exemplified.

  As a method of blending the stabilizer and additive into polyurethane, it can be blended at any stage of the step of synthesizing the polyurethane polymer (A) or the step of adding the polyurethane compound (B). Further, at the time of addition, it may be added directly to the polyurethane polymer or may be added to the raw material, or it may be added after being dispersed or dissolved in a small amount of solvent.

  Moreover, in this invention, the well-known organic or inorganic compound used for the synthesis | combination of a polyurethane polymer can be mix | blended. For example, UV absorbers such as benzophenone compounds and benzotriazole compounds, hindered phenol compounds, phosphite compounds, antioxidants such as thioether compounds, hindered amine compound light stabilizers, semicarbazide compounds, amine compounds Stabilizers such as compounds, inorganic fine particles such as barium sulfate, magnesium oxide, magnesium silicate, calcium silicate, zinc oxide, hydrotalcite, anti-adhesive agents such as magnesium stearate, calcium stearate, polytetrafluoroethylene, organosiloxane , Other pigments, brighteners, dyeing enhancers, gas discoloration inhibitors, fillers, stabilizers, flame retardants, antistatic agents, surface treatment agents, matting agents, colorants, antifungal agents, softeners, release agents, Foaming agents, extenders, nucleating agents, etc. can be added as appropriate That.

  Specific examples of the ultraviolet absorber include 2- (3-t-butyl-2-hydroxy-5-methylphenyl) -5-chlorobenzotriazole, 2- (3,5-di-t-butyl-2-hydroxy Phenyl) benzotriazole, 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-5-t-octylphenyl) benzotriazole, 2- (3,5-di-t-amyl- 2-hydroxyphenyl) benzotriazole, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] benzotriazole, 2- (2-hydroxy-octoxyphenyl) benzotriazole, 2 -[2-Hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2- (3,5-di t-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy-3 '-(3 ", 4", 5 ", 6" -tetrahydrophthalimido-methyl) -5'-methylphenyl ) Benzotriazole compounds such as benzotriazole, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, etc. Benzoates such as benzophenone compounds, 2,4-di-t-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate, n-hexadecyl-3,5-di-t-butyl-4-hydroxybenzoate A compound can be mentioned. Among these, a benzotriazole type ultraviolet absorber is preferable.

  Specific examples of the antioxidant include 6-di-t-butyl-4-methylphenol, 2,6-di-t-butyl-4-methylphenol, and 2,6-di-t-butyl-4-ethyl. Phenol, 2,4,6-tri-t-butylphenol, 2,6-di-t-butyl-4-hydroxymethylphenol, 2,2'-methylenebis (4-ethyl-6-t-butylphenol), 2, 2'-methylenebis (6-cyclohexyl-4-methylphenol), 2,2'-methylenebis (4,6-di-t-butylphenol), 4,4'-methylenebis (2,6-di-t-butylphenol) 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) pro Onate], triethylene glycol bis-3 (3-t-butyl-4-hydroxy-5-methylphenyl) propionate, 3,9-bis (2- (3- (3-t-butyl-4-hydroxy-5 -Methylphenyl) -propionyloxy) -1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5.5] undecane, 1,3,5-tris (4-t-butyl-3 -Hydroxy-2,6-dimethylbenzyl) isocyanate, 1,3,5-tris (3,5-di-t-butyl-4'-hydroxy-benzyl) isocyanate, 1,3,5-trimethyl-2,4 , 6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, isobutylene adduct of polyaddition product of p-cresol and dicyclopentadiene, p-ethylphenol Lumpur dicyclopentadiene polycondensate styrene compound, polycondensation products of p- cresol and p- divinylbenzene are exemplified.

  Specific examples of the light stabilizer include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 2-methyl-2- (2,2,6,6-tetramethyl-4-piperidyl) amino-N- (2,2,6,6-tetramethyl-4-piperidyl) propionamide, bis (1,2 , 2,6,6-pentamethyl-4-piperidyl) 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate, tetrakis (2,2,6,6- Tetramethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, dimethyl succinate and 1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine Polycondensate, N, N- (3-aminopropyl) ethylenediamine and 2,4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5 Polycondensates with triazine, 1,2,2,6,6-pentamethyl-4-piperidinol and 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,4,8,10- Examples thereof include a polycondensate of tetraoxaspiro [5.5] undecane and 1,2,3,4-butanetetracarboxylic acid.

  Specific examples of the semicarbazide compound and the amine compound include 1,1,1 ′, 1′-tetramethyl-4,4 ′-(hexamethylene) disemicarbazide, 1,1,1 ′, 1′-tetramethyl. -4,4 '-(methylenedi-p-phenylene) disemicarbazide, 1,1,1', 1'-tetraisopropyl-4,4 '-(methylenedi-p-phenylene) disemicarbazide, 1,1,1' , 1′-tetramethyl-α, α- (β-xylylene) disemicarbazide, 1,1,1 ′, 1′-tetramethyl-1,4- (cyclohexylene) disemicarbazide, 1,1,1 ′, 1′-tetramethyl-1,6- (hexamethylene) disemicarbazide, 1,1,1 ′, 1′-ditetramethylene-4,4 ′-(2,5 (2,6) -bicyclo [2. 2.1] heptylene-2, (2,6) -Dimethylene) disemicarbazide, 1,1,1 ′, 1′-ditetramethylene-4,4 ′-(3-methylene-3,5,5-trimethyl-1,3-cyclohexylene ) Disemicarbazide, N, N-bis (2-hydroxyethyl) -t-butylamine and the like.

  The above various additives can be added and used at any stage before the spinning process.

  The polyurethane elastic fiber of the present invention can spin a solution (spinning solution) containing the polyurethane polymer (A) and the polyurethane compound (B) by either a dry method or a wet method. The spinning device and spinning conditions used for spinning are not particularly limited, and any known method may be selected and spun according to the polyurethane composition, target fiber thickness, yarn physical properties, etc. Can do. For example, in the case of dry spinning, it is preferably 200 ° C. or higher, more preferably 220 ° C. or higher, still more preferably 240 ° C. or higher, preferably 320 ° C. or lower, more preferably 270 ° C. or lower, and the filaments are converged. Fibers can be obtained by bonding. In the present invention, a dry spinning method can be suitably employed, whereby a fine yarn or a highly balanced yarn can be obtained, the spinning speed can be increased, and high productivity can be obtained. The benefits of

  The fineness of the polyurethane elastic fiber obtained by the production method of the present invention is preferably 10 to 320 dtex, more preferably 15 to 280 dtex. If the fineness is too small, the strength becomes low, so that there is a risk of increased yarn breakage in the spinning process and the processing process. In addition, the stretchability of the obtained product may be inferior, and if it is too large, the spinnability may be lowered, the yarn uniformity may be lowered, and the productivity may be lowered.

  The polyurethane-based elastic fibers of the present invention include natural fibers such as cotton, hemp, wool, and silk, regenerated fibers such as rayon, cupra, polynosic, high-strength regenerated cellulose fibers (for example, trade name Tencel), and semi-regenerated fibers such as acetate. , Nylon, polyester, acrylic, polypropylene, polyurethane, polylactic acid, etc. can be used in combination with one or more kinds of fibers, such as plain weave, twill weave, satin weave, tengu knitting, It can be used in combination with one or a combination of two or more warp knitted fabrics such as circular knitted fabrics such as rubber knitting and pearl knitting, other weft knitted fabrics, combed knitted fabrics, denvi knitted fabrics, cord knitted fabrics and atlas knitted fabrics Can be woven.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited to the following Example. The weight average molecular weight is measured by LC-VP (GPC) manufactured by Shimadzu Corporation, and the nitrogen content is a value measured by CHN coder MT-6 manufactured by Yanaco. Moreover, in the following example, a part shows a mass part and% shows the mass%.

[Example 1]
(1) Synthesis of polyurethane polymer 19.91 parts of polytetramethylene ether glycol (PTMG) having a number average molecular weight of 2,000 and 4.55 parts of 4,4′-diphenylmethane diisocyanate (MDI) were added at 65 ° C. in a nitrogen gas atmosphere. The mixture was reacted for 100 minutes with stirring to synthesize a prepolymer having isocyanate groups at both ends. 57.07 parts of dimethylacetamide (DMAC) was added to and dissolved in the resulting both-end isocyanate group prepolymer to prepare a prepolymer solution. Next, an amine mixed solution in which 0.49 part of ethylenediamine (EDA) as a chain extender and 0.05 part of di-n-butylamine as a terminal blocker were dissolved in 17.93 parts of DMAC was dropped into the prepolymer solution. In addition, stirring was performed to obtain a solution (spinning stock solution; concentration 25%) containing a polyurethane polymer having a weight average molecular weight of 300,000 and a nitrogen content of 2.99%.

(2) Synthesis of polyurethane compound 70.81 parts of PTMG having a number average molecular weight of 2,000 and 24.11 parts of MDI were reacted with stirring at 130 ° C. for 60 minutes under a nitrogen gas atmosphere to synthesize an isocyanate group prepolymer at both ends. . Thereafter, 5.08 parts of 1,4-butanediol was added as a chain extender and stirred to obtain a polyurethane compound having a weight average molecular weight of 350,000 and a nitrogen content of 2.7%. The obtained polyurethane compound was heat treated at 100 ° C. for 24 hours, then pulverized, remelted at 210 ° C., and pelletized by Isuzu Chemical Industries, Ltd. SV-65-32. The polyurethane compound pellets were dissolved in DMAC to prepare a 25% concentration solution.

  24 kg of the polyurethane polymer solution obtained in (1) (6 kg in terms of solid content) and 16 kg (4 kg in terms of solid content) of the polyurethane compound obtained in (2) at 60 ° C. in a nitrogen gas atmosphere The mixture was mixed for 2 hours and sufficiently stirred to obtain a spinning solution.

Spinning method The spinning solution is weighed and pressurized by a gear pump installed in the spinning head, filtered through a filter, and discharged from a nozzle with a diameter of 0.2 mm and 14 holes into a 10 m long spinning cylinder at a speed of 27.34 g / min. The polyurethane elastic fiber of 156 dtex / 14f was obtained by winding at a speed of 500 m / min while applying the oil agent.

Preparation of knitted fabric Using a polyurethane elastic fiber and nylon yarn (trade name: Promiran 33T26, manufactured by Toray Industries, Inc.) obtained as described above, a circular knitted fabric was prepared using L416 / R manufactured by LONATI. Soap was removed by a conventional method.

The knitted fabric obtained by heat treatment was fixed to 1.0 times in length and 1.1 times in width, and was subjected to dry heat treatment under the conditions of temperature and time shown in Table 1 using a heat setting machine.

Evaluation method of heat- fusibility The heat-treated knitted fabric is treated with a 20% aqueous hydrochloric acid solution to dissolve and remove nylon, and then the stress when pulling out the polyurethane elastic fiber is measured with an autograph (AG-I manufactured by Shimadzu Corporation). Measured at a pulling speed of 100 mm / min. The results are shown in Table 1.

[Comparative Example 1]
A knitted fabric was prepared using a polyurethane elastic fiber of 156 dtex obtained in the same manner as in Example 1 except that the polyurethane compound synthesized in (2) of Example 1 was not used, and the thermal fusing force measurement (strength measurement) was performed. went. The results are shown in Table 1.

[Comparative Example 2]
The polyurethane compound synthesized in (2) of Example 1 was heat-treated at 100 ° C. for 24 hours, then pulverized and dried, then remelted at 210 ° C., weighed and pressurized with a gear pump installed on the spinning head, and filtered through a filter The nozzle is discharged from a nozzle with a diameter of 0.6 mm and a 4-hole nozzle at a speed of 9.35 g / min into a 6 m-long spinning cylinder (total discharge amount from the nozzle: 37.38 g / min), and 600 m / min while applying an oil agent. Winding up at a speed of minutes, polyurethane elastic fiber of 156 dtex was obtained. The NCO group content of the polyurethane elastic fiber immediately after discharge was 0.16%.
A knitted fabric was prepared in the same manner as in Example 1 using the obtained 156 dtex polyurethane elastic fiber, and the thermal fusing force measurement (strength measurement) was performed. The results are shown in Table 1.

Unit: cN
Full fusion: The yarns are integrated with each other and the yarn cannot be pulled out.

FIG. 1 shows a partially enlarged photograph of the knitted fabric (after 190 ° C. × 60 seconds treatment) obtained in Example 1. From this picture, it can be seen that heat fusion has occurred.
FIG. 2 is a partially enlarged photograph of the knitted fabric (after processing at 190 ° C. × 60 seconds) obtained in Comparative Example 1. It can be seen from the photograph that heat fusion is not performed.

[Examples 2 to 5]
44 dtex polyurethane elastic fibers were obtained in the same manner as in Example 1 except that the mixing ratio of the polyurethane polymer solution and the polyurethane compound solution was changed as follows, and knitted fabrics were respectively prepared. The heat treatment conditions shown in Table 2 were obtained. Was subjected to heat treatment, and the thermal fusing force was measured (strength measurement). Further, the tenacity retention rate of the yarn (raw yarn) was calculated by the following method. The results are also shown in Table 2.
Example 2: 80% polyurethane polymer solution, 20% polyurethane compound solution
Example 3: 70% polyurethane polymer solution, 30% polyurethane compound solution
Example 4: 60% polyurethane polymer solution, 40% polyurethane compound solution
Example 5: 40% polyurethane polymer solution, 60% polyurethane compound solution

<1> (Dry) Heat Treatment Conditions The yarn is allowed to stand in a dryer at 40 ° C. for 20 minutes.
2. The yarn is fixed to the frame with a length of 8 cm in an unstretched state.
3. The yarn is stretched 100% (16 cm in this case) and set to a heat treatment temperature (190 ° C.).
Dry heat treatment for 45 seconds in a heat setting machine.
4. Leave at room temperature for 30 seconds.
5. Thereafter, the yarn is stretched 50% (in this case, 12 cm) and left for 5 minutes 30 seconds, and then the yarn is taken out.

<2> Thermal fusion power (strength measurement)
1. The heat-treated yarn is set on an autograph (AG-I manufactured by Shimadzu Corporation) with a grip length of 4 cm.
2. The strength is measured at a drawing speed of 100 mm / min (the force applied when the yarn breaks is measured: the unit is cN).

<3> Tensile retention rate Tensile retention rate = (strength of heat-treated yarn) / (strength of unheat-treated yarn) × 100 (%)

[Comparative Example 3]
Compared except that the nozzle is 0.6mm in diameter and discharged from a nozzle of 1 hole into a 6m-long spinning cylinder at a rate of 2.67g per minute (total discharge from the nozzle: 42.74g / min), and the fineness is 44dtex. A polyurethane elastic fiber was obtained in the same manner as in Example 2. Next, a knitted fabric was prepared in the same manner as in Example 1, and then heat-treated under the heat treatment conditions shown in Table 2 to measure the thermal fusing force (strength measurement).

  For the yarns (raw yarns) obtained in Comparative Examples 1 and 3, the strength retention was calculated in the same manner as in Examples 2-5. The results are also shown in Table 2.

[Examples 6 to 8]
Polyurethane elastic fibers were obtained in the same manner as in Example 1 except that the heat treatment time of the knitted fabric was changed to the following conditions, and then each knitted fabric was prepared and heat-treated, and the thermal fusing force measurement (strength measurement) was performed. The results are shown in Table 2.
Example 6: Fineness 156 dtex, heat treatment time 80 seconds Example 7: Fineness 156 dtex, heat treatment time 100 seconds Example 8: Fineness 156 dtex, heat treatment time 60 seconds × 2 times

As for the heat sealing force of Comparative Example 3, the yarn in the knitted fabric was broken during the heat treatment. The heat resistance (strong retention) of the yarn alone could not be measured because the yarn was broken during the heat treatment.
FIG. 3 is a partially enlarged photograph of the knitted fabric (190 ° C. × 60 seconds (twice)) obtained in Example 8. From this picture, it can be seen that the heat fusion is sufficient.

It is a photograph which shows the heat sealing | fusion state of the knitted fabric (after nylon removal) obtained in Example 1 (190 degreeC * 60 second). It is a photograph which shows the heat sealing | fusion state of the knitted fabric (after nylon removal) obtained in the comparative example 1 (190 degreeC x 60 second). It is a photograph which shows the heat sealing | fusion state of the knitted fabric (after nylon removal) obtained in Example 8 (190 degreeC x 60 second (2 times)).

Claims (4)

A solution containing a polyurethane polymer (A) obtained by reacting a polyol and an organic diisocyanate with both end-isocyanate group prepolymers a and an amine compound in an organic solvent, and reacting a polyol and an organic diisocyanate. A polyurethane compound (B) obtained by reacting the both-end isocyanate group prepolymer b obtained by the above and a low molecular weight diol,
(A) :( B) = polyurethane elastic fiber obtained by spinning a spinning solution mixed at a mass ratio of 80:20 to 40:60.   The polyurethane elastic fiber according to claim 1, wherein the polyurethane polymer (A) has a weight average molecular weight of 250,000 to 450,000, and the polyurethane compound (B) has a weight average molecular weight of 200,000 to 500,000. [I] a process in which a polyol and an organic diisocyanate are reacted to synthesize both-end isocyanate group prepolymer a, and [II] the above-mentioned both-end isocyanate group prepolymer a and an amine compound are reacted in an organic solvent to form a polyurethane polymer. Obtaining a solution of the combined (A);
[III] a step of reacting a polyol and an organic diisocyanate to synthesize both-end isocyanate group prepolymer b, and [IV] a reaction between the both-end isocyanate group prepolymer b and a low molecular weight diol to react with a polyurethane compound (B). And a step of obtaining
[V] a step of mixing the solution containing the polyurethane polymer (A) and the polyurethane compound (B) in a mass ratio of (A) :( B) = 80: 20 to 40:60; and [VI] polyurethane weight A method for producing a polyurethane elastic fiber, comprising a step of spinning a solution containing the coalescence (A) and the polyurethane compound (B). Furthermore, the manufacturing method of Claim 3 which heat-processed the polyurethane compound (B) after process [IV], grind | pulverized and remelted the obtained polyurethane compound (B), and pelletized.