Polyurethane elastic fiber and its manufacturing method

Abstract

To provide: a polyurethane urea elastic fiber and a method of manufacturing the same by modifying structure and a terminal of a molecular chain of polyurethane, where temporal stability of yarn physical properties and spinning stability are both excellent with existing stretchability not impaired; and also the polyurethane urea elastic fiber and the method of manufacturing the same by using a polyurethane urea elastic fiber obtained thereby, where stock management and processing condition management of the fiber are made easy and a cloth having stable fabric physical properties or fabric quality can be obtained.SOLUTION: A polyurethane urea elastic fiber includes: a polyurethane urea copolymer A including a molecular chain in which polymer diol, diisocyanate, and organic amin are starting materials and at least one of terminals is a primary or a secondary amino group; and a polyurethane urea copolymer B including a molecular chain in which polymer diol, diisocyanate, organic amin, and organic carboxylic acid are starting materials, the molecular chain including an amino bond. The primary or secondary amino group at the terminal is contained in a range of 0.1 meq or more and 20 meq or less per 1 kg of the polyurethane urea elastic fiber.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyurethane elastic fiber and a method for producing the same. [Background technology]

[0002] Polyurethane elastic fibers are roughly classified into polyurethane urethane elastic fibers, which mainly use diol as a chain extender, and polyurethane urea elastic fibers, which mainly use diamine as a chain extender.

[0003] The former is characterized by high strength and high elongation. For example, Patent Document 1 shows an example of a polyurethane urethane elastic fiber whose yarn properties are unlikely to change over time.

[0004] On the other hand, the latter has high elongation but is inferior in strength to the former, and furthermore, since the yarn properties are prone to change over time, there are problems with inventory management and management of processing conditions for the fiber, making it difficult to obtain fabrics with stable fabric properties and quality. In other words, there has not been a polyurethane elastic fiber made of polyurethane urea elastic fiber that has high strength and yarn properties that are resistant to change over time while maintaining conventional properties.

[0005] In order to compensate for the instability of yarn properties that occurs with time, attempts have been made to obtain polyurethane elastic fibers that have excellent functions such as ease of putting on and taking off, fit, and moisture absorption and release properties (Patent Document 2). However, in order to maximize the effectiveness of the method described in Patent Document 2, it is necessary to increase the amount of polyacrylic acid and / or polyacrylamide added to the spinning dope.

[0006] Patent Document 3 describes an example of a polyurethane urea elastic fiber in which a specific compound is used as a terminator in the production of polyurethane urea, and describes that an increase in the viscosity of the polyurethane urea solution is suppressed. Patent Document 4 discloses that adding a benzophenone-based ultraviolet absorber containing one or more sulfonic acid groups in the molecule to polyurethane elastic fiber results in a polyurethane elastic fiber with high strength and elongation, high recovery, and excellent light resistance. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent Publication No. 11-81045 [Patent Document 2] Patent Publication No. 2002-249930 [Patent Document 3] Patent Publication No. 2003-155624 [Patent Document 4] Patent Publication No. 2011-144491 Summary of the Invention [Problem to be solved by the invention]

[0008] A polyurethane urea elastic fiber that retains the initial mechanical properties of conventional polyurethane urea elastic fibers and is less susceptible to changes in yarn properties over time, and a method for obtaining such a fiber, have not been known.

[0009] The present invention aims to provide a polyurethane urea elastic fiber and a method for producing the same, which are obtained by modifying the molecular chains and ends of a polyurethane urea polymer, thereby maintaining the initial mechanical properties of the polyurethane urea elastic fiber and exhibiting excellent stability over time in the physical properties of the yarn. Another object of the present invention is to provide a polyurethane urea elastic fiber and a method for producing the same, which can be used to obtain fabrics with stable physical properties and quality by facilitating inventory management and management of processing conditions for the fiber. [Means for solving the problem]

[0010] In order to solve the above problems, the present invention employs any of the following means. (1) a polyurethane urea polymer A having a molecular chain derived from a polymer diol, a diisocyanate, and an organic amine as starting materials, at least one of whose terminals is a primary or secondary amino group; A polyurethane urea elastic fiber comprising a polyurethane urea polymer B having a molecular chain containing an amide bond, the polyurethane urea polymer B being produced using a polymer diol, a diisocyanate, an organic amine, and an organic carboxylic acid as starting materials, Contains terminal primary or secondary amino groups in the range of 0.1 meq to 20 meq per kg of polyurethane urea elastic fiber Polyurethane urea elastic fiber. (2) The polyurethane urea elastic fiber according to (1) above, wherein the total content of the amide bonds per 1 kg of the polyurethane urea elastic fiber is in the range of 0.1 meq to 10 meq. (3) The polyurethane urea elastic fiber according to either (1) or (2), wherein the structural portion derived from the organic carboxylic acid has a molecular weight of 100 or more and 300 or less. (4) a polyurethane urea polymer A having a molecular chain derived from a polymer diol, a diisocyanate, and an organic amine as starting materials, at least one of whose terminals is an amino group; A method for producing a polyurethane urea elastic fiber, comprising dry-spinning a spinning dope containing a polyurethane urea polymer B having a molecular chain containing an amide bond, using a polymer diol, a diisocyanate, an organic amine, and an organic carboxylic acid as starting materials, the method comprising: The sum of polyurethane urea polymer A and polyurethane urea polymer B contained in the spinning solution A method for producing polyurethane urea elastic fibers, in which the terminal primary or secondary amino groups contained therein are in the range of 0.1 meq to 25 meq per kg. (5) preparing a solution a containing a polyurethane urea polymer A having a molecular chain formed from a polymer diol, a diisocyanate, and an organic amine as a starting material, and at least one end of which has a primary or secondary amino group; The method for producing a polyurethane urea elastic fiber described in (4) above comprises adding an organic carboxylic acid compound to the solution a and reacting it with a part of the polyurethane urea polymer A to produce a polyurethane urea polymer B having a molecular chain containing an amide bond, thereby forming a spinning solution containing the polyurethane urea polymer A and the polyurethane urea polymer B, and dry-spinning the spinning solution. (6) preparing a solution a containing a polyurethane urea polymer A having a molecular chain formed from a polymer diol, a diisocyanate, and an organic amine as a starting material, and at least one end of which has a primary or secondary amino group; A part of the solution a is divided, and an organic carboxylic acid compound is added to one of the divided portions and reacted with the polyurethane urea polymer A to produce a polyurethane urea polymer B having a molecular chain containing an amide bond, thereby preparing a solution b; Next, the solution a and the solution b are mixed to obtain a spinning solution containing polyurethane urea polymer A and polyurethane urea polymer B, and the spinning solution is dry-spun. (4) The method for producing polyurethane urea elastic fiber. (7) The method for producing polyurethane urea elastic fibers according to any one of (4) to (6), wherein a cyclic acid anhydride having a molecular weight of 100 to 300 is used as the organic carboxylic acid compound. [Effects of the Invention]

[0011] The polyurethane urea elastic fiber of the present invention has high elongation and low residual strain, and therefore clothing and the like made using this elastic fiber have excellent ease of putting on and taking off, fit, wearing comfort, etc. Furthermore, since this elastic fiber has excellent stability over time in its mechanical properties, when this fiber is subjected to advanced processing alone or in combination with other fibers, it has excellent processability in covering, knitting, looms, etc. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described in further detail below.

[0013] First, the polyurethane urea used in the present invention will be described.

[0014] In the following, a polyurethane urea polymer having a molecular chain made from polymer diol, diisocyanate, and organic amine as starting materials, and at least one end of the molecular chain being a primary or secondary amino group, will be referred to as "polyurethane urea polymer A," and a polymer having a molecular chain containing an amide bond made from polymer diol, diisocyanate, organic amine, and organic carboxylic acid as starting materials will be referred to as "polyurethane urea polymer B."

[0015] The polyurethane urea polymer B can be obtained, for example, by reacting an organic carboxylic acid with at least one end of the polyurethane urea polymer A to form an amide bond in the molecular chain, but the production method is not limited thereto. The polyurethane urea polymer B preferably has an alkyl group or a carboxyl group having a structure derived from the organic carboxylic acid at at least one end, and more preferably has carboxyl groups having a structure derived from the organic carboxylic acid at both ends.

[0016] Furthermore, when polyurethane urea polymer A and polyurethane urea polymer B are collectively referred to, they will be simply referred to as "polyurethane urea polymer," and when referring to a mixture of polyurethane urea polymers containing polyurethane urea polymer A and polyurethane urea polymer B, they will be referred to as "polyurethane urea polymer mixture."

[0017] The method for obtaining a polyurethane urea polymer mixture containing polyurethane urea polymer A and polyurethane urea polymer B may be any method, as will be described in detail below, and is not particularly limited. For example, polyurethane urea polymer A and polyurethane urea polymer B can be prepared separately and then mixed to obtain a polyurethane urea polymer mixture. As another method, an excess amount of polyurethane urea polymer A can be reacted with an organic carboxylic acid to adjust the amount of polyurethane urea polymer B produced, thereby leaving polyurethane urea polymer A and obtaining a polyurethane urea polymer mixture.

[0018] The polyurethane urea polymer A used in the present invention is not particularly limited, and may be any polymer as long as it has a molecular chain derived from a polymer diol, a diisocyanate, and an organic amine as starting materials, and at least one end is a primary or secondary amino group.Similarly, the polyurethane urea polymer B is not particularly limited, and may be any polymer as long as it has a molecular chain derived from a polymer diol, a diisocyanate, an organic amine, and an organic carboxylic acid as starting materials, and has an amide bond.

[0019] Here, "using a polymer diol, a diisocyanate, and an organic amine as starting materials," or "using a polymer diol, a diisocyanate, an organic amine, and an organic carboxylic acid as starting materials," means that the resulting polyurethane polymer has a structure derived from each of these components. In other words, this specification specifies the structure of a polyurethane urea polymer obtained from a polymer diol, a diisocyanate, and an organic amine as starting materials, or a polyurethane urea polymer obtained from a polymer diol, a diisocyanate, an organic amine, and an organic carboxylic acid as starting materials; it does not specify the raw materials themselves; an equivalent structure may be formed from different raw materials. Similarly, even when synthesized using the same raw materials, the synthesis method is not particularly limited. For example, it may be a polyurethane urea polymer composed of a polymer diol, a diisocyanate, and a low-molecular-weight diamine, or it may be a polyurethane urea polymer using a polymer diol, a diisocyanate, and a compound having a hydroxyl group and an amino group in the molecule as a chain extender. Two or more polyurethane urea polymers using different starting materials may be mixed in any ratio. It is also preferable to use tri- or higher functional glycols, isocyanates, and the like, as long as the effects of the present invention are not impaired.

[0020] Here, typical structural units constituting the polyurethane urea polymer of the present invention will be described.

[0021] The polymer diol that provides the structural units constituting the polyurethane urea polymer is preferably a polyether diol, a polyester diol, a polycarbonate diol, etc. In particular, from the viewpoint of imparting flexibility and elongation to the polyurethane urea elastic fiber, it is preferable to use a polyether diol.

[0022] Preferred examples of polyether diols include polyethylene oxide, polyethylene glycol, polyethylene glycol derivatives, polypropylene glycol, polytetramethylene ether glycol (hereinafter abbreviated as PTMG), modified PTMG (hereinafter abbreviated as 3M-PTMG) which is a copolymer of tetrahydrofuran (THF) and 3-methyltetrahydrofuran, modified PTMG (hereinafter abbreviated as THF and 2,3-dimethylTHF) which is a copolymer, polyols having side chains on both sides as disclosed in Japanese Patent No. 2615131, and random copolymers in which THF and ethylene oxide and / or propylene oxide are irregularly arranged. These polyether diols may be used alone or in combination or copolymerized with two or more.

[0023] Furthermore, from the viewpoint of obtaining abrasion resistance and light resistance, polyester-based diols such as butylene adipate, polycaprolactone diol, and polyester polyols having side chains as disclosed in JP-A-61-26612, and polycarbonate diols as disclosed in JP-B-2-289516 are preferably used.

[0024] These polymer diols may be used alone or in combination or copolymerized with two or more kinds.

[0025] The molecular weight of the polymer diol is preferably a number average molecular weight of 1,000 to 8,000, more preferably 1,800 to 6,000, from the viewpoint of obtaining elongation, strength, heat resistance, etc. when made into a polyurethane urea elastic fiber. By using a polyol with a molecular weight in this range, an elastic fiber excellent in elongation, strength, elastic recovery, and heat resistance can be easily obtained. The molecular weight is measured by GPC and converted into polystyrene.

[0026] Next, as diisocyanates, aromatic diisocyanates such as diphenylmethane diisocyanate (hereinafter abbreviated as MDI), tolylene diisocyanate, 1,4-diisocyanatobenzene, xylylene diisocyanate, and 2,6-naphthalene diisocyanate are particularly suitable for synthesizing polyurethanes with high heat resistance and strength. Furthermore, as alicyclic diisocyanates, for example, methylenebis(cyclohexyl isocyanate) (hereinafter abbreviated as H12MDI), isophorone diisocyanate, methylcyclohexane 2,4-diisocyanate, methylcyclohexane 2,6-diisocyanate, cyclohexane 1,4-diisocyanate, hexahydroxylylene diisocyanate, hexahydrotolylene diisocyanate, and octahydro-1,5-naphthalene diisocyanate are preferred. Aliphatic diisocyanates are particularly effective in suppressing yellowing of polyurethaneurea elastic fibers. These diisocyanates may be used alone or in combination of two or more.

[0027] Next, when synthesizing a polyurethane urea polymer from the above-mentioned polymer diol and diisocyanate, an organic amine is used as a chain extender. It is preferable to use at least one low-molecular-weight amine having two or more amino groups as the organic amine. When such a chain extender becomes a terminal, a primary amino group terminal is formed. A low-molecular-weight diamine having two amino groups is particularly preferable. Incidentally, an organic amine having a hydroxyl group and an amino group in the molecule, such as ethanolamine, may also be used.

[0028] Preferred low-molecular-weight diamines include, for example, ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, hexamethylenediamine, p-phenylenediamine, p-xylylenediamine, m-xylylenediamine, p,p'-methylenedianiline, 1,3-cyclohexyldiamine, hexahydrometaphenylenediamine, 2-methylpentamethylenediamine, and bis(4-aminophenyl)phosphine oxide. It is preferable to use one or more of these. Ethylenediamine is particularly preferred. The use of ethylenediamine facilitates the production of polyurethane urea elastic fibers with excellent elongation, elastic recovery, and heat resistance. A triamine compound capable of forming a crosslinked structure, such as diethylenetriamine, may be added to these chain extenders to an extent that the effect is not lost.

[0029] Furthermore, the polyurethane urea polymer may have a terminal structure introduced by using one or more of the following compounds as a terminal blocking agent. In such cases, the compound used as the terminal blocking agent to introduce the terminal structure is preferably a monoamine such as dimethylamine, diisopropylamine, ethylmethylamine, diethylamine, methylpropylamine, isopropylmethylamine, diisopropylamine, butylmethylamine, isobutylmethylamine, isopentylmethylamine, dibutylamine, diamylamine, or cyclohexylamine. The terminal structure introduced by such a terminal blocking agent is a secondary or tertiary amino group.

[0030] The polyurethane urea polymer A used in the present invention is a polyurethane urea polymer having a molecular chain made from polymer diol, diisocyanate, and organic amine as starting materials, and at least one end of which is a primary or secondary amino group.

[0031] As described above, a structure having a primary amino group at the end is formed when a chain extender serves as the terminal, and a structure having a secondary amino group at the end can be formed by an end-capping agent, as described above. By adjusting these, a polyurethane urea polymer having at least one terminal being a primary or secondary amino group can be obtained.

[0032] From the viewpoint of obtaining fibers with high durability and strength, the molecular weight of the polyurethane urea polymer used in the present invention is preferably in the range of 30,000 to 150,000 in terms of number average molecular weight. The molecular weight is measured by GPC and converted into polystyrene.

[0033] The polyurethaneurea elastic fiber of the present invention is a polyurethaneurea elastic fiber that contains the above-mentioned polyurethaneurea polymer A and polyurethaneurea polymer B having an amide bond in the molecular chain, and that contains primary or secondary amino groups at the terminals of the polyurethaneurea polymer in a range of 0.1 meq to 20 meq per kg of polyurethaneurea. By using a polyurethaneurea elastic fiber that contains polyurethaneurea polymer B having an amide bond in the molecular chain and in which the polyurethaneurea polymer (polyurethane polymer A and a part of polyurethane polymer B) contains primary or secondary amino groups at the terminals in a range of 0.1 meq to 20 meq per kg of polyurethaneurea elastic fiber, it is possible to obtain a polyurethaneurea elastic fiber that has excellent stability of yarn properties over time and excellent spinning stability without impairing the stretch performance inherent to polyurethaneurea elastic fiber.

[0034] The polyurethane urea polymer B is preferably obtained by reacting at least one of the primary and secondary amino groups present at the molecular chain terminals of the polyurethane urea polymer A with an organic carboxylic acid.

[0035] The organic carboxylic acid as a starting material in the present invention is a concept that virtually represents an organic compound having a carboxyl group in the molecule that can react with an isocyanate compound to form a urethane bond. Therefore, in the method for producing polyurethane urea elastic fiber of the present invention, the specific raw material used may be not only the organic carboxylic acid itself but also an anhydride of the organic carboxylic acid, as long as it is a compound that gives a structure derived from such organic carboxylic acid. Such compounds that give a structure derived from organic carboxylic acid in the method for producing polyurethane urea elastic fiber of the present invention are collectively referred to as organic carboxylic acid compounds.

[0036] The molecular weight of the organic carboxylic acid used as the starting material is preferably 100 to 300, from the viewpoints of stereoselectivity in the reaction with the terminals of a polyurethane urea polymer having primary or secondary amino groups at both ends of the molecular chain and optimizing steric hindrance with the molecular chain of the resulting polyurethane urea polymer. The molecular weight of the organic carboxylic acid compound used in the method for producing polyurethane urea elastic fiber of the present invention is also determined by substituting it for the structure of the corresponding organic carboxylic acid. For example, when the organic carboxylic acid used as the starting material is maleic acid (molecular weight 116), even if maleic anhydride (molecular weight 98) is used as the organic carboxylic acid compound in the method for producing polyurethane urea elastic fiber of the present invention, the molecular weight of the organic carboxylic acid used as the starting material is maleic acid, and therefore the molecular weight is treated as 116.

[0037] Examples of the organic carboxylic acid as a starting material include methanoic acid, acetic acid, propiolic acid, acrylic acid, glyoxylic acid, propanoic acid, glycolic acid, methacrylic acid, pyruvic acid, isobutyric acid, butyric acid, oxalic acid, lactic acid, maleic acid, succinic acid, acetoacetic acid, acetic acid, pentanoic acid, malonic acid, glyceric acid, 2-furancarboxylic acid, 3-furancarboxylic acid, sorbic acid, fumaric acid, maleic acid, hexanoic acid, succinic acid, benzoic acid, isonicotinic acid, nicotinic acid, heptanoic acid, oxaloacetic acid, glutaric acid, malic acid, anthranilic acid, salicylic acid, octanoic acid, adipic acid, phthalic acid, cinnamic acid, tartaric acid, tetrahydrophthalic acid, hexahydrophthalic acid, nonanoic acid, himic acid, isophthalic acid, terephthalic acid, phthalic acid, methyltetrahydrophthalic acid, methylhexahydrophthalic acid, gallic acid, and 2-naphthoic acid. , decanoic acid, aconitic acid, citric acid, trimellitic acid, dodecanoic acid, pyromellitic acid, benzilic acid, tetradecanoic acid, palmitic acid, dodecenylsuccinic acid, heptadecanoic acid, linolenic acid, linoleic acid, oleic acid, stearic acid, tetrachlorophthalic acid, ethylenediaminetetraacetic acid, eicosapentaenoic acid, arachidonic acid, docosahexaenoic acid, mellitic acid, chlorendic acid, tetrabromophthalic acid, etc. Furthermore, as the organic carboxylic acid compound used in the method for producing polyurethane urea elastic fiber of the present invention, in addition to these acids themselves, it is also preferable to use the corresponding acid anhydrides, etc.

[0038] Among these, organic carboxylic acids having a molecular weight of 100 or more and 300 or less as starting materials include succinic acid, acetoacetic acid, pentanoic acid, malonic acid, glyceric acid, 2-furancarboxylic acid, 3-furancarboxylic acid, sorbic acid, fumaric acid, maleic acid, hexanoic acid, succinic acid, benzoic acid, isonicotinic acid, nicotinic acid, heptanoic acid, oxaloacetic acid, glutaric acid, malic acid, anthranilic acid, salicylic acid, octanoic acid, adipic acid, phthalic acid, cinnamic acid, tartaric acid, tetrahydrophthalic acid, hexahydrophthalic acid, nonanoic acid, himic acid, isophthalic acid, terephthalic acid, phthalic acid, methyltetrahydrophthalic acid, methylhexahydrophthalic acid, gallic acid, and 2-naphthoic acid. , decanoic acid, aconitic acid, citric acid, trimellitic acid, dodecanoic acid, pyromellitic acid, benzilic acid, tetradecanoic acid, palmitic acid, dodecenylsuccinic acid, heptadecanoic acid, linolenic acid, linoleic acid, oleic acid, stearic acid, tetrachlorophthalic acid, and ethylenediaminetetraacetic acid. These organic carboxylic acids may have any substituent within the range that does not reduce the yarn properties of the polyurethane urea elastic fiber below conventional levels, and these may be used alone or in combination of two or more. Particularly preferred organic carboxylic acid compounds used in the production method of the polyurethane urea elastic fiber of the present invention are succinic anhydride and phthalic anhydride.

[0039] In addition, in the present invention, from the viewpoint of improving the yield of polyurethane urea polymer B, it is preferable that the polyurethane urea polymer before the formation of the amide bond has a primary or secondary amino group terminal as the molecular chain terminal, and a primary amino group terminal is more preferable.

[0040] The polyurethaneurea elastic fiber having an amide bond in its molecular structure contains terminal amino groups used as the chain extender and / or end-capping agent in an amount ranging from 0.1 meq to 20 meq per kg of polyurethaneurea. By limiting the content of terminal amino groups to 20 meq or less per kg of polyurethaneurea, the yarn properties of the polyurethaneurea elastic fiber can be stabilized. While the mechanism behind this stabilization of yarn properties is not yet clear, it is believed that when a certain amount of terminal amino groups is present in the polyurethaneurea elastic fiber, polyurethaneurea molecular chains are linked together in the fiber via solid-state reactions or the like, increasing the molecular weight of the polyurethaneurea and leading to changes in yarn properties. To achieve better stabilization of yarn properties, the content of terminal amino groups is preferably in the range of 0.1 to 10 meq per kg of polyurethaneurea. The content of terminal amino groups can be identified and quantified for polyurethaneurea elastic fiber using various analytical methods, such as 1H-NMR and acid-base neutralization titration.

[0041] Furthermore, in the present invention, the amide bond contained in the molecular chain of the polyurethane urea polymer B is derived from the terminal amino group derived from the organic amine and the organic carboxylic acid. From the viewpoint of stabilizing spinnability without impairing the inherent stretchability of the polyurethane urea elastic fiber, the content of the amide bond is preferably in the range of 0.01 meq to 10 meq per kg of polyurethane urea. More preferably, it is in the range of 0.03 meq to 5 meq per kg of polyurethane urea, and even more preferably, it is in the range of 0.05 meq to 2 meq per kg of polyurethane urea. The content of such amide bonds can be identified and quantified for polyurethane urea elastic fiber by various analytical methods such as 1H-NMR and elemental analysis.

[0042] Furthermore, in the present invention, when obtaining a polyurethane urea elastic fiber from a spinning dope, it is preferable that the polyurethane urea elastic fiber contains a polyurethane polymer having a tertiary amine in its molecular structure, from the viewpoint of achieving both good spinnability and stability over time of the stretch characteristics and yarn properties of the polyurethane urea elastic fiber finally obtained.

[0043] Examples of polyurethanes having a tertiary amine in their molecular structure include those containing polyurethane and / or polyurethane urea polymers having a structure containing a tertiary nitrogen-containing diol and / or a tertiary nitrogen-containing diamine and a diisocyanate as starting materials. Further examples include adding a polymer having an N,N-dialkylsemicarbazide terminal group to these polymers. By including a compound having tertiary nitrogen in the main chain and an N,N-dialkylsemicarbazide at the end, high heat resistance is exhibited during dyeing even at low concentrations of N,N-dialkylsemicarbazide, and polyurethane urea elastic fibers with higher strength and elongation than those not containing N,N-dialkylsemicarbazide can be obtained.

[0044] Specific preferred examples of the tertiary nitrogen-containing diol include N-methyl-N,N-diethanolamine, N-methyl-N,N-dipropanolamine, N-methyl-N,N-diisopropanolamine, N-butyl-N,N-diethanolamine, Nt-butyl-N,N-diethanolamine, N-octadecane-N,N-diethanolamine, N-benzyl-N,N-diethanolamine, Nt-butyl-N,N-diisopropanolamine, and piperazine derivatives such as bishydroxyethylpiperazine and bishydroxyisopropylpiperazine. Of these, Nt-butyl-N,N-diethanolamine and N-benzyl-N,N-diethanolamine are particularly preferred.

[0045] Specific preferred examples of the tertiary nitrogen-containing diamine include N-methyl-3,3'-iminobis(propylamine), N-butyl-aminobis-propylamine, N-methyl-aminobis-ethylamine, Nt-butyl-aminobis-propylamine, piperazine-N,N'-bis(3-aminopropyl), and piperazine-N,N'-bis(2-aminoethyl), etc. Among these, N-methyl-3,3'-iminobis(propylamine) and piperazine-N,N'-bis(3-aminopropyl) are particularly preferred.

[0046] Specific preferred examples of the diisocyanate used as the starting material in the polyurethane and / or polyurethane urea polymer having a structure containing the above-mentioned tertiary nitrogen-containing diol and / or tertiary nitrogen-containing diamine and diisocyanate as starting materials include aliphatic diisocyanates such as methylene-bis(4-cyclohexylisocyanate), isophorone diisocyanate, lysine diisocyanate, and DDI derived from dimer acid. Among these, methylene-bis(4-cyclohexylisocyanate) or isophorone diisocyanate are particularly preferred.

[0047] Furthermore, the terminal group of the polyurethane or polyurethane urea polymer is preferably a semicarbazide group. When reacting with a diisocyanate to form a terminal semicarbazide group, a substituted hydrazine or the like is preferably used. Specific examples of preferred substituted hydrazines include N,N-dimethylhydrazine, N,N-diethylhydrazine, N,N-dipropylhydrazine, N,N-diisopropylhydrazine, N,N-dibutylhydrazine, N,N-diisobutylhydrazine, N,N-dihydroxyethylhydrazine, and N,N-dihydroxyisopropylhydrazine. Of these, N,N-dimethylhydrazine and N,N-dihydroxyethylhydrazine are particularly preferred.

[0048] Particularly preferred examples of polyurethane and / or polyurethane urea polymers having a structure containing the aforementioned tertiary nitrogen-containing diol and / or tertiary nitrogen-containing diamine and diisocyanate as starting materials include polyurethanes produced by reacting Nt-butyl-N,N-diethanolamine with methylene-bis(4-cyclohexyl isocyanate), polyurethanes produced by reacting Nt-butyl-N,N-diethanolamine with methylene-bis(4-cyclohexyl isocyanate) and reacting N,N-dimethylhydrazine at the terminals of the polyurethanes, and polyureas produced by reacting N-methyl-3,3'-iminobis(propylamine) with methylene-bis(4-cyclohexyl isocyanate). The reaction ratio of Nt-butyl-N,N-diethanolamine to methylene-bis(4-cyclohexyl isocyanate) is not particularly limited as long as it does not interfere with the effects of the present invention. For example, a reaction ratio of about 1:1.05 is preferred, and in this case, the total concentration of urethane groups and urea groups in the alternating copolymer is about 5.1 mol / kg.

[0049] The polyurethane urea elastic fiber of the present invention may contain various stabilizers, pigments, etc. For example, it is preferable to include light stabilizers, antioxidants, etc., such as hindered phenol-based agents such as BHT and Sumitomo Chemical Co., Ltd.'s "Sumilizer" (registered trademark) GA-80, various benzotriazole-based and benzophenone-based agents such as Ciba-Geigy's "Tinuvin" (registered trademark), phosphorus-based agents such as Sumitomo Chemical Co., Ltd.'s "Sumilizer" (registered trademark P-16), various hindered amine-based agents, various pigments such as iron oxide and titanium oxide, minerals such as hydrotalcite compounds, huntite, hydromagnesite, and tourmaline, inorganic substances such as zinc oxide, cerium oxide, magnesium oxide, calcium carbonate, and carbon black, fluorine-based or silicone-based resin powder, metal soaps such as magnesium stearate, disinfectants and deodorizers containing silver, zinc, or their compounds, lubricants such as silicone and mineral oil, and various antistatic agents such as cerium oxide, betaine, and phosphate-based agents, and it is also preferable to react these with the polymer. In order to further enhance durability, particularly to light and various nitrogen oxides, it is also preferable to use a nitrogen oxide scavenger such as HN-150 manufactured by Nippon Hydrazine Co., Ltd., a thermal oxidation stabilizer such as Sumilizer (registered trademark) GA-80 manufactured by Sumitomo Chemical Co., Ltd., or a light stabilizer such as Sumisorb (registered trademark) 300#622 manufactured by Sumitomo Chemical Co., Ltd. When these various stabilizers and pigments are blended, it is also preferable to use an inorganic chemical that has been surface-treated with, for example, an organic substance such as a fatty acid, a fatty acid ester, or a polyol-based organic substance, a silane-based coupling agent, a titanate-based coupling agent, or a mixture thereof, for the purposes of improving dispersibility in the polyurethane urea elastic fiber and stabilizing spinnability.

[0050] Next, the method for producing the polyurethane urea elastic fiber of the present invention will be described in detail.

[0051] The method for producing polyurethane urea elastic fiber of the present invention involves dry spinning a spinning dope containing a polyurethane urea polymer A, which has a molecular chain made from a polymer diol, a diisocyanate, and an organic amine as starting materials and has an amino group at at least one end, and a polyurethane urea polymer B, which has a molecular chain containing an amide bond and has a polymer diol, a diisocyanate, an organic amine, and an organic carboxylic acid as starting materials, wherein the total amount of terminal primary or secondary amino groups contained in the spinning dope for polyurethane urea polymer A and polyurethane urea polymer B is in the range of 0.1 meq to 25 meq per kg. By dry spinning the spinning dope in which the total amount of terminal primary or secondary amino groups contained in the polyurethane urea polymer A and polyurethane urea polymer B is in the range of 0.1 meq to 25 meq per kg, polyurethane urea elastic fiber having terminal primary or secondary amino groups in the range of 0.1 meq to 20 meq per kg of polyurethane urea elastic fiber can be obtained.

[0052] The method for preparing the spinning dope containing the polyurethane urea polymer A and the polyurethane urea polymer B may be any method.

[0053] For example, a method may be used in which a solution a containing a polyurethane urea polymer A having molecular chains formed from a polymer diol, a diisocyanate, and an organic amine as starting materials and at least one end of which is a primary or secondary amino group, and a solution b containing a polyurethane urea polymer B having molecular chains containing an amide bond and formed from a polymer diol, a diisocyanate, an organic amine, and an organic carboxylic acid as starting materials are separately prepared, and the two are mixed to obtain a spinning dope. When obtaining a spinning dope using this method, a portion of the solution a containing the polyurethane urea polymer A may be divided, and an organic carboxylic acid may be added to one of the divided portions to react with the polyurethane urea polymer A, thereby preparing a solution b in which a polyurethane urea polymer B having molecular chains containing an amide bond is produced.

[0054] Another method is to prepare a solution a containing a polyurethane urea polymer A having a molecular chain formed from a polymer diol, a diisocyanate, and an organic amine as starting materials, and at least one end of which is a primary or secondary amino group, and then add an organic carboxylic acid to the solution a to react with a portion of the polyurethane urea polymer A, thereby converting a portion of the polyurethane urea polymer A contained in the solution a into a polyurethane urea polymer B having a molecular chain containing an amide bond, thereby obtaining a spinning dope containing the polyurethane urea polymer A and the polyurethane urea polymer B.

[0055] As another method for obtaining a spinning dope containing polyurethane urea polymer A and polyurethane urea polymer B, an organic carboxylic acid may be added without completing the reaction, thereby obtaining a spinning dope containing a mixture of polyurethane urea polymer A and polyurethane urea polymer B. In this case, it is not a problem if some unreacted organic carboxylic acid remains in the spinning dope.

[0056] As the organic carboxylic acid compound used in this production method, it is preferable to use a cyclic acid anhydride having a molecular weight of 100 or more and 300 or less.

[0057] Furthermore, the method for producing the polyurethane urea polymer, which is the solute of the solution, may be either melt polymerization or solution polymerization, or other methods. However, solution polymerization is more preferred. In the case of solution polymerization, the polyurethane urea polymer generates less foreign matter such as gel, is easy to spin, and polyurethane urea elastic fibers with low fineness can be easily obtained. In addition, solution polymerization has the advantage of eliminating the operation of preparing a solution.

[0058] Examples of polyurethane urea polymers that are particularly suitable for the present invention include those synthesized using PTMG having a number average molecular weight of 1,800 or more and 6,000 or less as the polymer diol, MDI as the diisocyanate, and at least one of ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, and hexamethylenediamine as the chain extender.

[0059] The polyurethane urea polymer can be obtained by synthesizing the above-mentioned raw materials in a solvent such as DMAc, DMF, DMSO, NMP, or a solvent containing these as the main component. Particularly suitable methods include the so-called one-shot method in which the raw materials are charged into such a solvent, dissolved, and heated to an appropriate temperature to react to form a polyurethane urea polymer, and a method in which a polymer diol and a diisocyanate are first melt-reacted, and then the reactant is dissolved in a solvent and reacted with the chain extender to form a polyurethane urea polymer.

[0060] When the molecular weight of the polymer diol is 1800 or more, in order to make the melting point on the higher temperature side 200° C. or higher, it is preferable to carry out the polymerization at a ratio of (moles of MDI) / (moles of polymer diol)=1.5 or more.

[0061] In addition, in synthesizing such polyurethane, it is also preferable to use one or a mixture of two or more catalysts such as amine catalysts and organometallic catalysts.

[0062] Examples of amine catalysts include N,N-dimethylcyclohexylamine, N,N-dimethylbenzylamine, triethylamine, N-methylmorpholine, N-ethylmorpholine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethyl-1,3-propanediamine, N,N,N',N'-tetramethylhexanediamine, bis-2-dimethylaminoethyl ether, N,N,N',N',N'-pentamethyldiethylenetriamine, tetramethylguanidine, and triethylene Examples of suitable amines include diamine, N,N'-dimethylpiperazine, N-methyl-N'-dimethylaminoethyl-piperazine, N-(2-dimethylaminoethyl)morpholine, 1-methylimidazole, 1,2-dimethylimidazole, N,N-dimethylaminoethanol, N,N,N'-trimethylaminoethylethanolamine, N-methyl-N'-(2-hydroxyethyl)piperazine, 2,4,6-tris(dimethylaminomethyl)phenol, N,N-dimethylaminohexanol, and triethanolamine.

[0063] Examples of the organometallic catalyst include tin octoate, dibutyltin dilaurate, and dibutyl lead octoate.

[0064] The concentration of the polyurethane urea polymer in the polyurethane urea polymer solution thus obtained is usually preferably in the range of 30% by mass or more and 80% by mass or less.

[0065] In the present invention, an organic carboxylic acid is added to the polyurethane urea polymer A solution to obtain a polyurethane urea polymer solution containing polyurethane urea polymer B. Any method can be used to add the organic carboxylic acid to the polyurethane urea polymer A solution. Typical methods include a method using a static mixer, a method using stirring, a method using a homomixer, and a method using a twin-screw extruder.

[0066] Next, any reaction conditions can be used for the polyurethane urea polymer solution to which the organic carboxylic acid has been added. Reaction conditions include, for example, temperature, time, and the presence or absence of a catalyst. However, these are not particularly limited, as they depend on the reactivity between the organic carboxylic acid and the terminal amino groups of the polyurethane urea polymer A. That is, before spinning, polyurethane urea polymer A and the organic carboxylic acid may be stirred at 10 to 40°C for 0.5 to 2 hours to obtain polyurethane urea polymer B, which may then be spun to obtain a polyurethane urea elastic fiber. Before spinning, polyurethane urea polymer A and the organic carboxylic acid may be mixed, and then, while the polyurethane urea polymer A and the organic carboxylic acid are still unreacted, reactive spinning may be performed at 100 to 300°C for 10 seconds to produce polyurethane urea polymer B, thereby obtaining a polyurethane urea elastic fiber.

[0067] In addition, from the viewpoint of controlling the viscosity of the polyurethane urea polymer solution to a level suitable for spinning depending on the spinning conditions, it is also preferred to mix one or more of monoamines such as dimethylamine, diisopropylamine, ethylmethylamine, diethylamine, methylpropylamine, isopropylmethylamine, diisopropylamine, butylmethylamine, isobutylmethylamine, isopentylmethylamine, dibutylamine, and diamylamine, and monools such as ethanol, propanol, butanol, isopropanol, allyl alcohol, and cyclopentanol.

[0068] The spinning dope thus prepared can be subjected to dry spinning, wet spinning, or melt spinning, followed by winding, to obtain the basic fiber of the present invention. Among these, dry spinning is preferred from the viewpoint of enabling stable spinning of fibers of any fineness, from fine to thick.

[0069] The polyurethane urea elastic fiber of the present invention is not particularly limited in fineness, cross-sectional shape, etc. For example, the cross-sectional shape of the polyurethane urea elastic fiber may be circular or flat.

[0070] The dry spinning method is not particularly limited, and spinning conditions may be appropriately selected to suit the desired properties and spinning equipment.

[0071] For example, the permanent set and stress relaxation of the polyurethane urea elastic fiber of the present invention are particularly susceptible to the influence of the speed ratio between the godet roller and the winder, and therefore it is preferable to determine these appropriately depending on the intended use of the polyurethane urea elastic fiber. That is, from the viewpoint of obtaining a polyurethane urea elastic fiber having the desired permanent set and stress relaxation, it is preferable to wind the fiber at a speed ratio between the godet roller and the winder in the range of 1.10 to 1.65. Furthermore, from the viewpoint of improving the strength of the resulting polyurethane urea elastic fiber, it is preferable that the spinning speed be 250 m / min or more. [Example]

[0072] The present invention will be described in more detail using examples, but the present invention is not limited to these examples.

[0073] <Method for preparing polyurethane urea polymer A> Solution A1 Starting materials were PTMG having a molecular weight of 1800 as the polymer diol, MDI as the diisocyanate, ethylenediamine as the organic amine, and diethylamine as the end-blocking agent, and polymerization was carried out by a conventional method to prepare solution a, which was a DMAc solution (concentration 35% by mass) of polyurethane urea polymer A having a molecular chain with polymer diol, diisocyanate, and organic amine as starting materials, at least one end of which being a primary or secondary amino group; this solution was designated solution a1. ·Solution a2 Starting materials were 3M-PTMG with a molecular weight of 3,500 as the polymer diol, MDI as the diisocyanate, ethylenediamine as the organic amine, and diethylamine as the end-blocking agent, and polymerization was carried out in a conventional manner to prepare solution a, which was a DMAc solution (concentration 35% by mass) of polyurethane urea polymer A having a molecular chain with polymer diol, diisocyanate, and organic amine as starting materials, at least one end of which being a primary or secondary amino group; this solution was designated solution a2. ·Solution a3 Starting materials were PTMG having a molecular weight of 1800 as the polymer diol, MDI as the diisocyanate, 1,2-propanediamine as the organic amine, and diethylamine as the end-blocking agent, and polymerization was carried out in a conventional manner to prepare solution a, which was a DMAc solution (concentration 35% by mass) of polyurethane urea polymer A having a molecular chain with polymer diol, diisocyanate, and organic amine as starting materials, at least one end of which being a primary or secondary amino group; this solution was designated solution a3. ·Solution a4 Starting materials were PTMG having a molecular weight of 2900 as the polymer diol, MDI as the diisocyanate, ethylenediamine as the organic amine, and cyclohexyl as the end-capping agent, and polymerization was carried out in a conventional manner to prepare solution a (35% by mass concentration) in DMAc of polyurethane urea polymer A having a molecular chain with polymer diol, diisocyanate, and organic amine as starting materials, at least one end of which being a primary or secondary amino group; this solution was designated solution a4.

[0074] <Method for preparing polyurethane urea polymer B> To 90-99% by mass of a DMAc solution of polyurethane urea polymer A (solution ax (x is 1-4, as described above): concentration 35% by mass), 1-10% by mass of a DMAc solution of an organic carboxylic acid (solution cy (y is 1-6, as described below): concentration 35% by mass) was added and mixed uniformly. Mixing was continued for 0.5-2 hours at 20-40°C under a nitrogen atmosphere to prepare a DMAc solution (concentration 35% by mass) of polyurethane urea polymer B having an amide bond in the molecular chain of polyurethane urea polymer A, which was obtained as solution b. Solution b will be referred to as "solution xby" due to the raw materials of polymer B contained therein (solution ax and solution cy as described above).

[0075] <Content of primary or secondary amino groups at the terminals of polyurethane urea molecules per 1 kg of polyurethane urea elastic fiber> The content of amino groups at the molecular ends of polyurethane urea per 1 kg of polyurethane urea elastic fiber was measured by acid-base neutralization titration.

[0076] <Evaluation method> [1] Properties of elastic fibers To measure the basic properties and stability over time of the elastic fiber, a tensile test was carried out using an Instron 4502 tensile tester under the following conditions.

[0077] Specifically, a 5 cm (L1) sample was stretched 300% at a tensile speed of 50 cm / min five times, and the stress at the fifth 300% stretch was defined as (G1). The sample was then held at 300% stretch for 30 seconds. The stress after the 30-second stretch was defined as (G2). The sample was then allowed to recover, and the length of the sample when the stress returned to zero was defined as (L2). The sample was then stretched a sixth time until it broke. The stress at break was defined as (G3), and the sample length at break was defined as (L3). The strain and stress at the recovery time after the fifth 30-second stretch were plotted to draw a curve, and the stress at 200% strain was defined as (P-200). The strength in the practical use range for the stretch characteristics of a given fineness (22 dtex) was calculated as (G4).

[0078] The number of measurements was n=3, and the arithmetic mean values thereof were used to calculate the above-mentioned properties.

[0079] (1) Basic properties of elastic fibers The basic properties of the elastic fiber were measured, including breaking strength, breaking elongation, and permanent set. Hereinafter, the above properties are calculated using the following formulas. Breaking strength (cN) = (G3) Breaking elongation (%) = 100 × ((L3) - (L1)) / (L1) ·Permanent distortion rate (%)=100×((L2)-(L1)) / (L1).

[0080] (2) Stability of elastic fibers over time The stability of the elastic fiber over time was measured by measuring the change in strength over time in the actual use range and the change in permanent set over time. The day on which a polyurethane urea elastic fiber sample (hereinafter referred to as test yarn) was collected immediately after spinning was set as day 0. After storing the test yarn at a temperature of 21°C and a humidity of 60%, the physical properties of the test yarn were measured after 1 day and 3 months, and the above properties were calculated using the following formula. Ratio of change in strength over time in actual use area (%) = [(strength in actual use area of polyurethane urea elastic fiber 3 months after spinning) / (strength in actual use area of polyurethane urea elastic fiber 1 day after spinning)] × 100 Permanent set rate change over time (%) = [(permanent set rate of polyurethane urea elastic fiber after 3 months of spinning) / (permanent set rate of polyurethane urea elastic fiber after 1 day of spinning)] x 100 In this case, the actual use area intensity is calculated by the following formula. ·Actual usage area strength (cN)=(G4) Furthermore, the smaller the difference in the following property values of the polyurethane urea elastic fiber between one day after spinning and three months after spinning, the better the stability over time was judged to be. That is, for the ratio of change in strength over time in the actual use region and the ratio of change in permanent set over time, a value of 90% or more but less than 120% was judged to have particularly excellent stability over time, as indicated by a double circle; a value of 85% or more but less than 90% or a value of 120% or more but less than 125% was judged to have excellent stability over time, as indicated by a circle; and a value of less than 85% or 125% or more was judged to have problems with stability over time, as indicated by an x.

[0081] [2] Spinnability of elastic fibers Spinning was carried out continuously for 48 hours, and the number of thread breakages during that time was used as an index for evaluating spinnability. That is, when the number of thread breakages during 48 hours of continuous spinning was less than two, it was judged as ⊚. When the number of thread breakages during 48 hours was two or more and less than two during 24 hours, it was judged as ◯. When the number of thread breakages during 24 hours was two or more, it was judged as x.

[0082] [Example 1] Solution a1 was prepared as solution a, which was a DMAc solution of polyurethane urea polymer A, by the method described in <Preparation method of polyurethane urea polymer A>.

[0083] According to the method described in <Preparation Method of Polyurethane Urea Polymer B>, solution 1b1 was prepared as solution b, which is a DMAc solution of polyurethane urea polymer B, in the following procedure. Succinic anhydride was used as the organic carboxylic acid, and solution c1 was prepared as a DMAc solution of the organic carboxylic acid. Note that the molecular weight of succinic acid, the carboxylic acid corresponding to succinic anhydride, is 118.09. Solution 1b1 was prepared from solution a1 and solution c1. Solution 1b1 was prepared by adding 2% by mass of solution c1 to 98% by mass of solution a1, mixing them uniformly, and then mixing at 25°C for 1 hour.

[0084] A DMAc solution (concentration 35% by mass) of polyurethane (Methachlor (registered trademark) 2462 manufactured by DuPont) produced by the reaction of t-butyldiethanolamine and methylene-bis-(4-cyclohexylisocyanate) was prepared, and this was designated solution t1 containing other additives.

[0085] Solutions a1, 1b1, and t1 were uniformly mixed at 98.9 mass%, 0.1 mass%, and 1.0 mass%, respectively, to prepare a spinning dope. This was then dry-spun at a spinning speed of 600 m / min with a godet roller to winder speed ratio of 1.2 and wound up to obtain a 22 dtex, 2fil multifilament polyurethane elastic fiber. The composition of the polyurethane urea elastic fiber is shown in Table 1, and its various properties are shown in Table 2.

[0086] [Example 2] Solutions a1, 1b1, and t1 were uniformly mixed at 98.0 mass%, 1.0 mass%, and 1.0 mass%, respectively, to prepare a spinning dope, and a multifilament polyurethane elastic fiber of 22 dtex and 2fil was obtained according to the method of Example 1. The composition of the polyurethane urea elastic fiber is shown in Table 1, and various properties are shown in Table 2.

[0087] [Example 3] Solutions a1, 1b1, and t1 were uniformly mixed at 97.0 mass%, 2.0 mass%, and 1.0 mass%, respectively, to prepare a spinning dope, and a multifilament polyurethane elastic fiber of 22 dtex and 2fil was obtained according to the method of Example 1. The composition of the polyurethane urea elastic fiber is shown in Table 1, and various properties are shown in Table 2.

[0088] [Example 4] Solutions a1, 1b1, and t1 were uniformly mixed at 91.0 mass%, 8.0 mass%, and 1.0 mass%, respectively, to prepare a spinning dope, and a multifilament polyurethane elastic fiber of 22 dtex and 2fil was obtained according to the method of Example 1. The composition of the polyurethane urea elastic fiber is shown in Table 1, and various properties are shown in Table 2.

[0089] [Example 5] Solutions a1, 1b1, and t1 were uniformly mixed at 84.0 mass%, 15.0 mass%, and 1.0 mass%, respectively, to prepare a spinning dope, and a multifilament polyurethane elastic fiber of 22 dtex and 2fil was obtained according to the method of Example 1. The composition of the polyurethane urea elastic fiber is shown in Table 1, and various properties are shown in Table 2.

[0090] [Example 6] Solution c2 was prepared as a DMAc solution of an organic carboxylic acid using terephthalic acid instead of solution c1 according to the method of Example 1. Solution 1b2 obtained from a1 and c2 was prepared as solution b, which is a DMAc solution of polyurethane urea polymer B.

[0091] Solutions a1, 1b2, and t1 were uniformly mixed at 98.9 mass%, 0.1 mass%, and 1.0 mass%, respectively, to prepare a spinning dope, and a multifilament polyurethane elastic fiber of 22 dtex and 2fil was obtained according to the method of Example 1. The composition of the polyurethane urea elastic fiber is shown in Table 1, and various properties are shown in Table 2.

[0092] [Example 7] Solutions a1, 1b2, and t1 were uniformly mixed at 97.0 mass%, 2.0 mass%, and 1.0 mass%, respectively, to prepare a spinning dope, and a multifilament polyurethane elastic fiber of 22 dtex and 2fil was obtained according to the method of Example 1. The composition of the polyurethane urea elastic fiber is shown in Table 1, and various properties are shown in Table 2.

[0093] [Example 8] Solution c3 was prepared as a DMAc solution of an organic carboxylic acid using acetic acid instead of solution c1 according to the method of Example 1. Solution 1b3 obtained from solution a1 and solution c3 was prepared as solution b, which is a DMAc solution of polyurethane urea polymer B.

[0094] Solutions a1, 1b3, and t1 were uniformly mixed at 98.9 mass%, 0.1 mass%, and 1.0 mass%, respectively, to prepare a spinning dope, and a 22 dtex, 2fil multifilament polyurethane elastic fiber was obtained according to the method of Example 1. The composition of the polyurethane urea elastic fiber is shown in Table 1, and various properties are shown in Table 2.

[0095] [Example 9] Solutions a1, 1b3, and t1 were uniformly mixed at 87.0 mass%, 12.0 mass%, and 1.0 mass%, respectively, to prepare a spinning dope, and a multifilament polyurethane elastic fiber of 22 dtex and 2fil was obtained according to the method of Example 1. The composition of the polyurethane urea elastic fiber is shown in Table 1, and various properties are shown in Table 2.

[0096] [Example 10] Solution c4 was prepared as a DMAc solution of an organic carboxylic acid using ethylenediaminetetraacetic acid instead of solution c1 according to the method of Example 1. Solution 1b4 was prepared from solution a1 and solution c4 as solution b, which is a DMAc solution of polyurethane urea polymer B.

[0097] Solutions a1, 1b4, and t1 were uniformly mixed at 98.0 mass%, 1.0 mass%, and 1.0 mass%, respectively, to prepare a spinning dope, and a multifilament polyurethane elastic fiber of 22 dtex and 2fil was obtained according to the method of Example 1. The composition of the polyurethane urea elastic fiber is shown in Table 1, and various properties are shown in Table 2.

[0098] [Example 11] Solutions a1, 1b4, and t1 were uniformly mixed at 86.0 mass%, 13.0 mass%, and 1.0 mass%, respectively, to prepare a spinning dope, and a multifilament polyurethane elastic fiber of 22 dtex and 2fil was obtained according to the method of Example 1. The composition of the polyurethane urea elastic fiber is shown in Table 1, and various properties are shown in Table 2.

[0099] [Example 12] Solution c5 was prepared as a DMAc solution of an organic carboxylic acid using succinic acid instead of solution c1 according to the method of Example 1. Solution 1b5 obtained from solution a1 and solution c5 was prepared as solution b, which is a DMAc solution of polyurethane urea polymer B.

[0100] Solutions a1, 1b5, and t1 were uniformly mixed at 98.0 mass%, 1.0 mass%, and 1.0 mass%, respectively, to prepare a spinning dope, and a multifilament polyurethane elastic fiber of 22 dtex and 2fil was obtained according to the method of Example 1. The composition of the polyurethane urea elastic fiber is shown in Table 1, and various properties are shown in Table 2.

[0101] [Example 13] Solution c6 was prepared as a DMAc solution of an organic carboxylic acid using acetic anhydride instead of solution c1 according to the method of Example 1. Solution 1b6 obtained from solution a1 and solution c6 was prepared as solution b, which is a DMAc solution of polyurethane urea polymer B.

[0102] Solutions a1, 1b6, and t1 were uniformly mixed at 98.0 mass%, 1.0 mass%, and 1.0 mass%, respectively, to prepare a spinning dope, and a multifilament polyurethane elastic fiber of 22 dtex and 2fil was obtained according to the method of Example 1. The composition of the polyurethane urea elastic fiber is shown in Table 1, and various properties are shown in Table 2.

[0103] [Example 14] Solution a2 was prepared as solution a, which was a DMAc solution of polyurethane urea polymer A. Solution 2b1 obtained from solution a2 and solution c1 was prepared as solution b, which was a DMAc solution of polyurethane urea polymer B.

[0104] Solutions a2, 2b1, and t1 were uniformly mixed at 98.9 mass%, 0.1 mass%, and 1.0 mass%, respectively, to prepare a spinning dope, and a multifilament polyurethane elastic fiber of 22 dtex and 2fil was obtained according to the method of Example 1. The composition of the polyurethane urea elastic fiber is shown in Table 1, and various properties are shown in Table 2.

[0105] [Example 15] Solutions a2, 2b1, and t1 were uniformly mixed at 84.0 mass%, 15.0 mass%, and 1.0 mass%, respectively, to prepare a spinning dope, and a multifilament polyurethane elastic fiber of 22 dtex and 2fil was obtained according to the method of Example 1. The composition of the polyurethane urea elastic fiber is shown in Table 1, and various properties are shown in Table 2.

[0106] [Example 16] Solutions a1, 2b1, and t1 were uniformly mixed at 98.0 mass%, 1.0 mass%, and 1.0 mass%, respectively, to prepare a spinning dope, and a multifilament polyurethane elastic fiber of 22 dtex and 2fil was obtained according to the method of Example 1. The composition of the polyurethane urea elastic fiber is shown in Table 1, and various properties are shown in Table 2.

[0107] [Example 17] Solutions a2, 1b1, and t1 were uniformly mixed at 91.0 mass%, 8.0 mass%, and 1.0 mass%, respectively, to prepare a spinning dope, and a multifilament polyurethane elastic fiber of 22 dtex and 2fil was obtained according to the method of Example 1. The composition of the polyurethane urea elastic fiber is shown in Table 1, and various properties are shown in Table 2.

[0108] [Example 18] Solutions a1 and 1b1 were uniformly mixed at 99.9% by mass and 0.1% by mass, respectively, to prepare a spinning dope, and a multifilament polyurethane elastic fiber of 22 dtex and 2fil was obtained according to the method of Example 1. The composition of the polyurethane urea elastic fiber is shown in Table 1, and various properties are shown in Table 2.

[0109] [Example 19] Solutions a1 and 1b1 were uniformly mixed at 98.0% by mass and 2.0% by mass, respectively, to prepare a spinning dope, and a multifilament polyurethane elastic fiber of 22 dtex and 2fil was obtained according to the method of Example 1. The composition of the polyurethane urea elastic fiber is shown in Table 1, and various properties are shown in Table 2.

[0110] [Comparative Example 1] Solutions a1 and t1 were uniformly mixed at 99.0% by mass and 1.0% by mass, respectively, to prepare a spinning dope, and a multifilament polyurethane elastic fiber of 22 dtex and 2fil was obtained according to the method of Example 1. The composition of the polyurethane urea elastic fiber is shown in Table 1, and various properties are shown in Table 2.

[0111] Comparative Example 2 Solutions a2 and t1 were uniformly mixed at 99.0% by mass and 1.0% by mass, respectively, to prepare a spinning dope, and a multifilament polyurethane elastic fiber of 22 dtex and 2fil was obtained according to the method of Example 1. The composition of the polyurethane urea elastic fiber is shown in Table 1, and various properties are shown in Table 2.

[0112] Comparative Example 3 Solutions a3 and t1 were uniformly mixed at 99.0% by mass and 1.0% by mass, respectively, to prepare a spinning dope, and a multifilament polyurethane elastic fiber of 22 dtex and 2fil was obtained according to the method of Example 1. The composition of the polyurethane urea elastic fiber is shown in Table 1, and various properties are shown in Table 2.

[0113] Comparative Example 4 Solutions a4 and t1 were uniformly mixed at 99.0% by mass and 1.0% by mass, respectively, to prepare a spinning dope, and a multifilament polyurethane elastic fiber of 22 dtex and 2fil was obtained according to the method of Example 1. The composition of the polyurethane urea elastic fiber is shown in Table 1, and various properties are shown in Table 2.

[0114] [Table 1]

[0115] [Table 2] [Industrial Applicability]

[0116] The polyurethane urea elastic fiber of the present invention has high elongation and low residual strain, and therefore clothing and the like made using this elastic fiber have excellent ease of putting on and taking off, fit, wearing comfort, etc. Furthermore, since this elastic fiber has excellent stability over time in its mechanical properties, when this fiber is subjected to advanced processing alone or in combination with other fibers, it has excellent processability in covering, knitting, looms, etc.

[0117] Furthermore, according to the present invention, the polyurethane urea elastic fiber has these excellent properties, and therefore, it can be used alone or in combination with various fibers to obtain excellent stretch fabrics, which are suitable for knitting, weaving, and string processing. Specific applications of the polyurethane urea elastic fiber include tightening materials for various textile products, such as socks, stockings, circular knitting, tricot, swimwear, ski trousers, work clothes, fireworks wear, Western clothing, golf trousers, wetsuits, brassieres, girdles, gloves, and socks, tightening materials for leak prevention in sanitary products such as disposable diapers, tightening materials for waterproofing materials, artificial bait, artificial flowers, electrical insulating materials, wiping cloths, copy cleaners, and gaskets, and the fiber can be expanded into various applications.

Claims

1. a polyurethane urea polymer A having a molecular chain derived from a polymer diol, a diisocyanate, and an organic amine as starting materials, and at least one end of which has a primary or secondary amino group; A polyurethane urea elastic fiber comprising a polyurethane urea polymer B having a molecular chain containing an amide bond, the polyurethane urea polymer B being produced using a polymer diol, a diisocyanate, an organic amine, and an organic carboxylic acid as starting materials, Contains terminal primary or secondary amino groups in the range of 0.1 meq to 20 meq per kg of polyurethane urea elastic fiber Polyurethane urea elastic fiber.

2. 2. The polyurethane urea elastic fiber according to claim 1, wherein the total content of the amide bonds per 1 kg of the polyurethane urea elastic fiber is in the range of 0.1 meq to 10 meq.

3. 3. The polyurethane urea elastic fiber according to claim 1, wherein the molecular weight of the structural portion derived from the organic carboxylic acid is 100 or more and 300 or less.

4. a polyurethane urea polymer A having a molecular chain derived from a polymer diol, a diisocyanate, and an organic amine as starting materials, and having an amino group at at least one end; A method for producing a polyurethane urea elastic fiber, comprising dry-spinning a spinning dope containing a polyurethane urea polymer B having a molecular chain containing an amide bond, using a polymer diol, a diisocyanate, an organic amine, and an organic carboxylic acid as starting materials, The sum of polyurethane urea polymer A and polyurethane urea polymer B contained in the spinning solution A method for producing polyurethane urea elastic fibers, wherein the amount of terminal primary or secondary amino groups contained in the polyurethane urea elastic fibers is in the range of 0.1 meq to 25 meq per kg.

5. A solution a is prepared containing a polyurethane urea polymer A having a molecular chain formed from a polymer diol, a diisocyanate, and an organic amine as a starting material, the molecular chain having a primary or secondary amino group at at least one end; The method for producing a polyurethane urea elastic fiber according to claim 4, wherein an organic carboxylic acid compound is added to the solution a and reacted with a part of the polyurethane urea polymer A to produce a polyurethane urea polymer B having a molecular chain containing an amide bond, thereby forming a spinning solution containing the polyurethane urea polymer A and the polyurethane urea polymer B, and then dry-spinning the spinning solution.

6. A solution a is prepared containing a polyurethane urea polymer A having a molecular chain formed from a polymer diol, a diisocyanate, and an organic amine as a starting material, the molecular chain having a primary or secondary amino group at at least one end; A part of the solution a is divided, and an organic carboxylic acid compound is added to one of the divided portions and reacted with the polyurethane urea polymer A to prepare a solution b in which a polyurethane urea polymer B having a molecular chain containing an amide bond is produced; The method for producing a polyurethane urea elastic fiber according to claim 4, wherein the solution a and the solution b are then mixed to obtain a spinning dope containing the polyurethane urea polymer A and the polyurethane urea polymer B, and the spinning dope is dry-spun.

7. 7. The method for producing polyurethane urea elastic fiber according to claim 4, wherein a cyclic acid anhydride having a molecular weight of 100 or more and 300 or less is used as the organic carboxylic acid or the organic carboxylic acid compound.

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