JPWO2000056958A1 - Polyurethane urea elastic fiber and its manufacturing method - Google Patents

Abstract

(57) [Abstract] A polyurethane urea elastic fiber characterized by containing a urea compound obtained by reacting (a) a nitrogen-containing compound having a bifunctional amino group selected from at least one of a primary amine and a secondary amine and a nitrogen-containing group selected from at least one of a tertiary nitrogen and a heterocyclic nitrogen, (b) an organic diisocyanate, and (c) at least one selected from the group consisting of a mono- or dialkyl monoamine, an alkyl monoalcohol, and an organic monoisocyanate. The addition of a specific urea compound highly improves elasticity and heat setting properties, enabling the stable production of polyurethane urea elastic fibers capable of fast dyeing through spinning. The polyurethane urea elastic fiber of the present invention is an improved elastic fiber material that has excellent shape retention and is resistant to weave peeling, making it possible to produce elastic secondary products such as swimsuits and pantyhose.

Description

TECHNICAL FIELD The present invention relates to a polyurethane urea elastic fiber that has excellent heat setting properties and can be dyed to a high degree, and further to a method for producing a polyurethane urea elastic fiber that also provides excellent elasticity and spinning stability.

BACKGROUND ART Polyurethane urea elastic fibers are known, which are obtained by chain-extending an isocyanate-terminated prepolymer synthesized from a polyalkylene ether glycol and an excess of an organic diisocyanate with a diamine. Polyurethane urea elastic fibers are interwoven with polyamide fibers or polyester fibers and used as stretch functional materials in a wide range of clothing, including foundations, socks, pantyhose, swimwear, sportswear, and leotards.

Polyurethane urea elastic fibers exhibit excellent elastic properties because hard segments consisting of urea groups form strong physical crosslinks through hydrogen bonds. However, in fields where shape retention is particularly required for finished fabrics, such as circular knitting for leg parts such as pantyhose and tights, warp knitting for innerwear and sportswear such as brassieres, girdles, and swimsuits, and woven fabrics for outerwear such as bottoms, polyurethane urea elastic fibers have poor heat setting properties during processing of intermediate products, resulting in problems such as failure to achieve a large finished shape, making them difficult to wear, and curling of the edges of the fabric (a phenomenon in which the edges curl up in a rounded shape), making sewing difficult.

Furthermore, when a desired tenter length is desired for a product, the product must be set multiple times or at a higher temperature, which causes problems such as a decrease in production efficiency and thermal efficiency.

On the other hand, elastic fibers that do not have urea groups, such as polyurethane elastic fibers (elastic fibers consisting only of urethane bonds) and polyether ester elastic fibers (polyesters copolymerized with a polyalkylene ether glycol component), are also known, similar to polyurethane urea elastic fibers. These elastic fibers have excellent heat setting properties and good shape retention of finished fabrics, but because they do not have hard segments consisting of urea groups, they have the disadvantage of being prone to losing their elastic function, such as being inferior in elastic recovery and greater in stretch fatigue compared to polyurethane urea elastic fibers. In other words, in practical clothing, there are problems with the durability of providing a moderate wearing comfort and maintaining that comfort. In particular,
Polyether ester elastic fibers not only lack the elongation required of elastic fibers, but also undergo large stress changes with elongation, making them prone to feeling restrictive when moving around the body.
Furthermore, these elastic fibers have poor thermal durability, so in areas such as stretch outerwear, which is processed at high temperatures, or in areas such as foundations, where color matching is difficult and re-dyeing is required, the elastic fibers in the fabric tend to wear out or break, damaging the appearance of the product.

Therefore, if it were possible to impart heat setting properties to polyurethane urea elastic fibers without sacrificing their heat resistance and elasticity, they would be useful in these fields.

For the purpose of improving the heat setting property of polyurethane urea elastic fiber having excellent elasticity, JP-A-3-97915 proposes a polyurethane urea elastic fiber based on polyether in which isocyanate-terminated prepolymer is chain-extended with a specific mixed diamine, and JP-A-8-13824 proposes a polyurethane urea elastic fiber in which diamine, monoamine and prepolymer are polymerized in a specific ratio.Furthermore, JP-A-7-150147 discloses a polyurethane urea elastic fiber to which a specific alkali metal salt is added at a low concentration.The present applicant also proposed a polyurethane urea elastic fiber in JP-A-7-316 for the purpose of improving the heat setting property without impairing the elasticity property of polyurethane urea elastic fiber.
In the publication of 19922, polyurethane urea elastic fibers and their manufacturing methods were disclosed, which contain 1 to 14% by weight of a thermoplastic polymer selected from a specific polyacrylonitrile polymer, a specific polyurethane polymer, and a specific styrene-maleic anhydride copolymer. However, in all cases, although the heat setting property of conventional polyurethane urea elastic fibers was improved, the results were not entirely satisfactory, and the elastic properties of the polyurethane urea elastic fibers were sometimes sacrificed, or spinning was difficult due to the occurrence of yarn breakage.

Polyurethane urea elastic fibers are always blended with polyamide or polyester fibers and dyed. When blended with polyamide fibers, acid dyes are primarily used. Because polyurethane urea polymers lack the dye-binding sites for acid dyes, the dye primarily distributes to the polyamide fibers, leaving the elastic fibers largely undyed. Disperse dyes are primarily used to dye blends with polyester fibers. While these dyes readily penetrate the elastic fibers, they are often removed during reduction washing after dyeing, resulting in virtually no dye. Alternatively, if reduction washing is insufficient, the resulting fabric may appear dyed, but the dye may be removed from the elastic fibers during washing or dry cleaning, resulting in a deterioration in overall fastness. In particular, when dyeing deeply, if the polyamide or polyester fibers are dyed but the elastic fibers are not, problems such as a loss of color depth and the elastic fibers glare or appear white under stretch (called "grain blemishes") can occur.

To address the above-mentioned problems, there have been almost no proposals that can satisfactorily improve the polyurethane urea elastic fiber itself, and at present, no polyurethane urea elastic fiber that also has improved heat setting properties, or a method for producing a polyurethane urea elastic fiber that combines excellent elastic function and stable spinnability have been found.

The object of the present invention is to solve the problems of the prior art described above and to provide a polyurethane urea elastic fiber that has excellent elastic function and heat resistance, and also has high setting ability and is capable of being dyed with improved dyeability and fast dyeing. Another object of the present invention is to provide a polyurethane urea elastic fiber that can be used to produce fabrics that have good shape retention, excellent elastic function, and excellent dyeability with little occurrence of grain peeling. Another important object of the present invention is to provide a method for producing a polyurethane urea elastic fiber that has excellent elastic function and is capable of producing the polyurethane urea elastic fiber modified as described above under stable spinning.

DISCLOSURE OF THE INVENTION The present inventors have discovered that polyurethane urea elastic fibers containing a specific urea compound described below can be modified to polyurethane urea elastic fibers that are uniquely excellent in elastic function and heat resistance, as well as in heat setting and dyeability, and that the modified fibers can be produced under stable spinning, thereby completing the present invention.

The present invention provides a method for producing a polymerizable composition comprising: (a) a nitrogen-containing compound containing a bifunctional amino group selected from at least one of a primary amine and a secondary amine and a nitrogen-containing group selected from at least one of a tertiary nitrogen and a heterocyclic nitrogen; and (b) an organic diisocyanate.
and (c) at least one selected from the group consisting of mono- or di-alkyl monoamines, alkyl monoalcohols, and organic monoisocyanates, in an amount of 1 to 15% by weight based on the polyurethane urea polymer.

The polyurethane urea elastic fiber of the present invention and its production method will be described below.
Detail description.

The urea compound used in the present invention comprises: (a) a nitrogen-containing compound containing a bifunctional amino group selected from at least one of a primary amine and a secondary amine and a nitrogen-containing group selected from at least one of a tertiary nitrogen and a heterocyclic nitrogen; (b) an organic diisocyanate; (c) at least one selected from the group consisting of mono- or dialkyl monoamines, alkyl monoalcohols, and organic monoisocyanates;
The molar equivalent ratio of (a), (b), and (c) must be adjusted before the reaction so that no active terminal remains in the resulting urea compound.

The resulting urea compound has a tertiary nitrogen skeleton represented by the following formula (3) and the following formula (4):
) and (5). However, when an alkyl monoalcohol is reacted, a urethane bond shown in the following formula (6) is also included.

The urea compound of the present invention can be prepared by selecting the compound (c) and by combining the compounds (3) to (6) above.
The structures satisfying the formula are classified into the following two types of structures (7) and (8).

i) When (c) is a mono- or di-alkyl monoamine or alkyl monoalcohol, it is (c)-[(b)-(a)]n-(b)-(c) (7) ii) When (c) is an organic monoisocyanate, it is (c)-[(a)-(b)]n-(a)-(c) (8) (n in the structure represents the number of polymerization repeats of 1 or more). A more preferred structure is the one represented by formula (8) where (c) is an organic monoisocyanate.

The urea compounds having these two types of structures are preferably used alone, but may also be used in combination.

The nitrogen-containing compound containing a bifunctional amino group selected from at least one of primary amines and secondary amines and a nitrogen-containing group selected from at least one of tertiary nitrogen and heterocyclic nitrogen, which is the compound (a) used to obtain the urea compound of the present invention, includes N-butyl-bis(2-aminoethyl)amine, N-butyl-bis(2-aminopropyl)amine, N-butyl-bis(2-aminobutyl ...propyl)amine,
Amines, N,N-bis(2-aminoethyl)-isobutylamine, N,N-bis(2-aminopropyl)-isobutylamine, N,N-bis(2-aminoethyl)-t-butylamine, N,N-bis(2-aminoethyl)-1,1-dimethylpropylamine, N,N-bis(2-aminopropyl)-1,1-dimethylpropylamine, N,N-bis(2-aminobutyl)-1,1-dimethylpropylamine, N-(N,N-diethyl-3-aminopropyl)-bis(2-aminoethyl)amine, N-(N,N-dibutyl-3-aminopropyl)-bis(2-aminopropyl)amine, piperazine, piperazine derivatives such as 2-methylpiperazine, 1-(2-aminoethyl)-4-(3-aminopropyl)piperazine, 2-aminoethyl ...
, 5- and 2,6-dimethylpiperazine, N,N'-bis(2-aminoethyl)piperazine, N,N'-bis(3-aminopropyl)piperazine, N-(2-
piperidine derivatives such as 4-aminoethylpiperidine, N-amino-4-(2-aminoethyl)piperidine, N-bis(2-aminoethyl)amine-piperidine, etc.; pyrrolidone derivatives such as 4-aminoethylpiperidine, N-amino-4-(2-aminoethyl)piperidine, N-bis(2-aminoethyl)amine-piperidine, etc.;
For example, N-amino-4-(2-aminoethyl)-2-pyrrolidone, N-(3-aminopropyl)-4-(3-aminopropyl)-2-pyrrolidone, N-bis(2
Examples of the nitrogen-containing compound include piperazine and piperazine derivatives. In particular, N-(2-aminoethyl)piperazine and N-(2-aminopropyl)piperazine are preferred, as the resulting urea compounds have extremely good solubility in amide solvents. These compounds can be used alone.
Alternatively, they can be used in combination.

The organic diisocyanate (b) used to obtain the urea compound of the present invention includes trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, 3-methylhexane-1,6-diisocyanate, 3,3'-dimethylpentane-1,5-
Examples of diisocyanates include 1,3- and 1,4-cyclohexylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, m- and p-xylylene diisocyanate, α,α,α',α'-tetramethyl-p-xylylene diisocyanate, 4,4'-diphenylmethane diisocyanate, isophorone diisocyanate, and 2,4-tolylene diisocyanate. Alicyclic diisocyanates such as isophorone diisocyanate and 4,4'-dicyclohexylmethane diisocyanate are preferred. These can be used alone or in combination.

The mono- or dialkylmonoamine of compound (c) used to obtain the urea compound of the present invention is a monoamine having an alkyl group having 1 to 10 carbon atoms, such as isopropylamine, n-butylamine, t-butylamine, diethylamine, 2-ethylhexylamine, diisopropylamine, di-n-butylamine, di-t-butylamine, di-isobutylamine, di-2-ethylhexylamine, etc. Furthermore, the alkyl chain may contain a tertiary nitrogen atom or an oxygen atom, such as 3-dibutylamino-propylamine, 3-diethylamine-propylamine, 3-ethoxypropylamine, and 3-(2-ethylhexyloxy)propylamine. These may be used alone or in combination.

Furthermore, the alkyl monoalcohol of compound (c) used to obtain the urea compound of the present invention is a monoalcohol having an alkyl group having 1 to 10 carbon atoms, such as methanol, ethanol, 2-propanol, 2-methyl- ...
1-propanol, 1-butanol, 2-ethyl-1-hexanol, 3-methyl-1-butanol, etc. These may be used alone or in combination.

The mono- or di-alkylamines and alkyl alcohols may be used alone or in combination, but are preferably used alone.

Furthermore, examples of the organic monoisocyanate of compound (c) used to obtain the urea compound of the present invention include n-butyl isocyanate, phenyl isocyanate, 1-naphthyl isocyanate, p-chlorophenyl isocyanate, cyclohexyl isocyanate, m-tolyl isocyanate, benzyl isocyanate,
Examples of suitable organic monoisocyanates include m-nitrophenyl isocyanate. These can be used alone or in combination. However, they cannot be used in combination with the above-mentioned mono- or di-alkylamines and alkyl alcohols. The active hydrogen of the mono- or di-alkylamines and alkyl alcohols is blocked by the organic monoisocyanate to produce compounds, and the reaction (7)
Not only does this reduce the effective amount of the urea compound having the structure of formula (8), but the compound also bleeds out during the processing of polyurethaneurea elastic fibers, causing scum that stains knitting machines and dye baths.

The compound (c) used to obtain the urea compound of the present invention is selected from three types as described above, and blocks the active terminal (amino group or isocyanate group) of the urea compound obtained from the compound (a) and the compound (b). This active terminal deteriorates the spinning stability of the polyurethane urea elastic fiber and reduces the fastness. When the reaction molar equivalent is (a) > (b), the terminal of the urea compound is an amino group, so the compound (
For c), an organic monoisocyanate is selected, and when (a)<(b), since the urea compound has an isocyanate group at its terminal, it is necessary to select at least one of a mono- or di-alkylamine and an alkyl monoalcohol for (c). Preferably, an organic monoisocyanate is selected as described above.

The urea compound of the present invention is characterized by containing an average of 4 to 40 urea bond units represented by the following formulas (9) and (10) per molecule, where "average" refers to a number average.

When compound (c) is a mono- or di-alkyl monoamine or alkyl monoalcohol, the structure of the urea compound is represented by formula (11): (n in the structure represents the number of polymerization repeats of 1 or more). A urea compound having a desired average number of urea bond units can be obtained by adjusting the molar ratio of the compounds (a), (b) and (c) used in the reaction.
):(c)=n:n+1:2, the average number of urea bond units present in one molecule is 2n+2 for mono- or dialkylmonoamines and 2n for alkylmonoalcohols.

When (c) is an organic monoisocyanate, the structure of the urea compound is represented by formula (12) (n in the structure represents the number of polymerization repetitions of 1 or more).

In this case, if the ratios are adjusted so that (a):(b):(c)=n+1:n:2,
The average number of urea bond units present in one molecule is 2n+2.

The urea compound of the present invention has an average number of urea bond units in one molecule of 4 to 4
0. Converted into the number of polymerization repeats n in the structure, it is 1 to 19 for mono- or dialkyl monoamines and organic monoisocyanates, and 2 to 20 for alkyl monoalcohols. If the average number of urea bond units is less than 4 or exceeds 40, sufficient heat setting properties cannot be obtained. Furthermore, if the average number of urea bond units is less than 4, it will bleed out during the processing of the polyurethane urea elastic fiber, causing scum that stains the knitting machine and dye bath. Furthermore, if the average number of urea bond units exceeds 40, the urea compound will precipitate in the polyurethane urea spinning dope, causing spun yarn breakage or a decrease in the elongation of the polyurethane urea elastic fiber, impairing its elastic function.
The average number of urea bond units is preferably 4 to 15 in one molecule of the urea compound.

The number of urea bond units present in one molecule of the urea compound of the present invention is (a), (b),
The reaction temperature can be adjusted by the molar ratio of reaction charges (b) and (c). The reaction temperature is preferably 20 to 60°C. The reaction is preferably carried out in an amide-based polar solvent in which the polyurethane urea polymer dissolves, such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc. When a solvent in which the polyurethane urea polymer does not dissolve is used, the solid content can be removed after the reaction and dissolved in a solvent in which the polyurethane urea polymer dissolves, and then added to the polyurethane urea polymer.

In one example of the reaction method, 2 moles of N-(2-aminomethyl)piperazine as (a), 1 mole of isophorone diisocyanate as (b), and 2 moles of phenyl isocyanate as (c) are reacted at 50°C for 2 hours to form a 50% by weight dimethylacetamide solution. The reaction is carried out by adding isophorone diisocyanate and phenyl isocyanate dropwise to N-(2-aminomethyl)piperazine dissolved in dimethylacetamide, but the reaction method is not limited to this and other known methods can be used. The polymerization repeat number n of the resulting urea compound is 1, and the number of urea bond units present per molecule is 4.

The polyurethaneurea elastic fiber of the present invention can be obtained by dry spinning a spinning dope prepared by adding a urea compound dissolved in an amide-based polar solvent to a polyurethaneurea polymer solution. The addition can be carried out at any stage from the end of polymerization of the polyurethaneurea polymer to spinning.

The amount of the urea compound contained in the polyurethane urea elastic fiber of the present invention is
The amount may be any amount as long as it satisfies the setting property and dyeability required for the finished fabric and does not impair the excellent elasticity and spinning stability.
Preferably, the amount of the urea compound added is 1% by weight or less, the heat setting effect and dyeability are small, and if the amount of the urea compound added is more than 15% by weight, not only the heat setting effect is saturated and the dye fastness is deteriorated, but also spinning stability is reduced due to thread breakage during spinning, and elastic functions such as strength, elongation, and elastic recovery are impaired.
A more preferred amount is 2 to 10% by weight.

In the polyurethane-urea elastic fiber of the present invention, the heat-setting effect is also exhibited when a urea compound is added to a polyurethane elastic fiber (elastic fiber having only urethane bonds), but not only is the effect smaller than when the urea compound is added to a polyurethane-urea elastic fiber, but in the case of a polyurethane elastic fiber, the elastic function and spinning stability are impaired.

In addition, in modifying the polyurethane urea elastic fiber of the present invention, known techniques for improving heat setting properties can also be used in combination.For example, at least one thermoplastic polymer selected from polyacrylonitrile polymers, polyurethane polymers, and styrene-maleic anhydride copolymers, as described in JP-A-7-316922, may be simultaneously added.In this case, it is preferable that the total amount of the thermoplastic polymer and the urea compound of the present invention added is 15% by weight or less, and the amount of the thermoplastic polymer added does not exceed the amount of the urea compound of the present invention added.

The reason why the polyurethane urea elastic fiber containing the urea compound of the present invention exhibits excellent heat setting and dyeability without at least sacrificing heat resistance, elastic function, and spinning stability is not clear, but is thought to be due to the following reasons. The excellent dyeability and fastness are due to the effect of the specific nitrogen-containing compound, that is, the effect of the urea compound containing a specific number of urea bond units. That is, the excellent dyeability and fastness are presumed to be due to the fact that the nitrogen-containing compound containing a bifunctional amine consisting of at least one of a primary amine and a secondary amine, and at least one of a tertiary nitrogen and a heterocyclic nitrogen, strongly adsorbs and holds acid dyes and disperse dyes.

On the other hand, the excellent heat setting property is presumably due to the urea compound having an average of 4 to 40 urea bond units per molecule. Polyurethane urea elastic fiber is a segmented polymer having urethane bonds and urea bonds, and among them, the urea bonds form extremely strong physical crosslinks due to hydrogen bonds, forming crystalline domains. Therefore, while it exhibits excellent elastic function at room temperature, it is difficult to heat set even at high temperatures because these hydrogen bonds are not easily broken. The urea compound of the present invention having a specific number of urea bond units forms strong hydrogen bonds with the urea bonds in the polyurethane urea elastic fiber and assimilates with the crystalline domains in the polyurethane urea elastic fiber, resulting in a polyurethane urea elastic fiber that exhibits excellent elastic function at room temperature. However, the urea compound of the present invention has the effect of lowering the glass transition temperature of the crystalline domains, and at high temperatures, the hydrogen bonds are broken, making the crystalline domains more susceptible to heat flow, resulting in a polyurethane urea elastic fiber with excellent heat setting property. If the amount of the urea compound of the present invention added to the polyurethane urea elastic fiber is too small,
On the other hand, if the amount added is too large, the heat setting effect will be satisfactory, but the glass transition temperature of the crystalline domain will be too low, causing heat flow at high temperatures during spinning, making it impossible to ensure spinning stability, and it is thought that even the elastic function will be impaired.

The polyurethane urea polymer of the present invention is a polymer glycol having hydroxyl groups at both ends and a number average molecular weight of 600 to 5,000, an organic diisocyanate,
It is produced from a chain extender of a diamine compound and an end-capping agent of a monoamine compound.
Examples of polymer glycols include various diols consisting of substantially linear homo- or copolymers, such as polyester diols, polyether diols, polyesteramide diols, polyacrylic diols, polythioester diols, polythioether diols, polycarbonate diols, mixtures thereof, or copolymers thereof. Preferred are polyalkylene ether glycols, such as polyoxyethylene glycol, polyoxypropylene glycol,
Examples of such copolymers include polytetramethylene ether glycol, polyoxypentamethylene glycol, copolymerized polyether glycols consisting of tetramethylene groups and 2,2-dimethylpropylene groups, copolymerized polyether glycols consisting of tetramethylene groups and 3-methyltetramethylene groups, and mixtures thereof. Among these, polytetramethylene ether glycol, copolymerized polyether glycols consisting of tetramethylene groups and 2,2-dimethylpropylene groups, and mixtures thereof, which exhibit excellent elasticity, are preferred.
Copolymerized polyether glycols comprising dimethylpropylene groups are preferred. The organic diisocyanate used in the polyurethane urea polymer of the present invention can be, for example, any aliphatic, alicyclic, or aromatic diisocyanate that dissolves or is liquid in an amide-based polar solvent under reaction conditions. For example, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,4- and 2,6-tolylene diisocyanate, m- and p-xylylene diisocyanate, α,α,α',α'-tetramethyl-xylylene diisocyanate, 4,4'-diphenylether diisocyanate, 4,4'-dicyclohexyl diisocyanate, 1,3- and 1,4-cyclohexylene diisocyanate, 3-(α-isocyanatoethyl)phenyl isocyanate, 1,6-
Examples include hexamethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, mixtures thereof, and copolymers thereof, etc. Preferred is 4,4'-diphenylmethane diisocyanate.

Examples of diamine compounds used as chain extenders in the polyurethane urea polymer of the present invention include ethylenediamine, 1,2-propylenediamine, 1,3-diaminocyclohexane, 2-methyl-1,5-pentadiamine, hexamethylenediamine, triethylenediamine, m-xylylenediamine, piperazine, o-
Examples of the diamine include m- and p-phenylenediamine, diamines having a urea group as described in JP-A-5-155841, and mixtures thereof. Preferably, ethylenediamine alone or at least one selected from the group consisting of 1,2-propylenediamine, 1,3-diaminocyclohexane, and 2-methyl-1,5-pentadiamine is used.
The species is an ethylenediamine mixture containing 5 to 40 mole percent of the species.

Examples of the monoamine compound used as the terminal terminator in the polyurethane urea polymer of the present invention include monoalkylamines such as isopropylamine, n-butylamine, t-butylamine, and 2-ethylhexylamine; diethylamine, diisopropylamine, di-n-butylamine, di-t-butylamine, and di-
Examples of the monoamine compound include dialkylamines such as isobutylamine and di-2-ethylhexylamine, which can be used alone or in combination. 1,1-dimethylhydrazine can also be mixed with the monoamine compound.

The polyurethane urea polymer can be prepared by a known polyurethane urea reaction technique. For example, an intermediate polymer having an isocyanate group at its terminal is prepared by reacting a polyalkylene ether glycol having a number average molecular weight of 600 to 5000 with an excess molar amount of an organic diisocyanate in an amide-based polar solvent. The intermediate polymer is then dissolved in an amide-based polar solvent and reacted with a chain extender and a terminal terminator to obtain the polyurethane urea polymer.

The polyurethane urea elastic fiber of the present invention can be obtained by dry spinning a spinning dope containing 1 to 15% by weight of the urea compound of the present invention relative to the polyurethane urea polymer.

In addition to the urea compound of the present invention, known organic or inorganic compounding agents useful for polyurethane urea elastic fibers, polyurethane elastic fibers, and polyurethane compositions, such as ultraviolet absorbers, antioxidants, light stabilizers, gas-resistant coloring inhibitors, colorants, matting agents, and lubricants, can be added to the spinning dope simultaneously or successively.

The polyurethane urea polymer spinning dope thus obtained can be formed into a fiber by known dry spinning, wet spinning, etc., to produce a polyurethane urea elastic fiber. Dry spinning is preferred, as it exhibits excellent elasticity and is highly productive.

Furthermore, the larger the single yarn fineness of the resulting polyurethane urea elastic fiber, the more advantageous it is for improving heat setting properties. A single yarn fineness of 6 to 33 decitex is preferred. This is thought to be due to the large relaxation of orientation of the crystalline portion of the fiber. At 6 decitex, the orientation is large, and above 33 decitex, although the relaxation of orientation is small, the crystal size becomes large, making it difficult for crystal flow to occur during heat setting. This is not limited to polyurethane urea elastic fibers, but can be applied to all types of elastic fibers.

The heat setting rate of the present invention is a combination of a 120°C wet heat treatment and a 120°C dry heat treatment. In actual processing, elastic fibers are often dried after wet heat treatment (steam setting, dyeing, etc.), so this evaluation method is more suitable for practical situations than evaluation methods using only dry heat treatment or only wet heat treatment. The polyurethane urea elastic fiber of the present invention preferably has a heat setting rate of 50% or more. If it is less than 50%, problems such as insufficient shape retention of the product and curling of the edges of the fabric are likely to occur, which is not preferred. More preferably, the heat setting rate is 60% or more.
% or more.

The polyurethane urea fiber of the present invention has a strength retention rate of 40% after dry heat treatment at 180°C.
If it is less than 50%, the heat resistance is low, and the elastic fibers in the fabric may become worn or break due to high-temperature treatment, high-temperature setting, or re-dyeing of the fabric, which is not preferable. More preferably, the strength retention rate is 60% or more.

The obtained polyurethane urea elastic fiber was mixed with polydimethylsiloxane, polyester modified silicone, polyether modified silicone, amino modified silicone, mineral oil,
Oils such as mineral fine particles, for example, silica, colloidal alumina, talc, etc., higher fatty acid metal salt powders, for example, magnesium stearate, calcium stearate, etc., higher aliphatic carboxylic acids, higher aliphatic alcohols, paraffin, polyethylene, and other waxes that are solid at room temperature, may be applied alone or in any combination as required.

The polyurethane urea elastic fiber of the present invention is rarely knitted or woven alone, but can be mixed and woven with natural fibers such as cotton, silk, wool, etc., polyamide fibers such as N6 and N66, polyester fibers such as polyethylene terephthalate, polytrimethylene terephthalate, polytetramethylene terephthalate, cationic dyeable polyester fibers, cuprammonium rayon, viscose rayon, acetate rayon, etc., or with textured yarns that have been coated, entangled, plied, or twisted with these fibers to form fabrics.

Fabrics using the polyurethane urea elastic fiber of the present invention can be used for swimwear, girdles, brassieres, intimate goods, various stretch foundations such as underwear, elastic cuffs for socks, tights, pantyhose, waistbands, body suits,
It can be used for applications such as spats, stretch sportswear, stretch outerwear, bandages, supports, medical wear, stretch linings, and disposable diapers.
BEST MODE FOR CARRYING OUT THE INVENTION Before describing examples of the present invention, various evaluation methods for performance evaluation and a method for producing pantyhose will be described.

[1] Measurement of breaking strength, breaking elongation, and elastic recovery:
A test yarn having a sample length of 5 cm is pulled at a rate of 50 cm/min in an atmosphere of °C and 65% RH to measure the breaking strength (g) and breaking elongation (%).

The elastic recovery is evaluated by measuring the reciprocating modulus at 200% after the third repeated stretch from 0 to 300%, and calculating the 200% stress retention rate (%) using the following formula (13).

(In the formula, fR is the 200% return modulus at the third repeated stretching of 0 to 300%, and fS is the 200% forward modulus at the third repeated stretching of 0 to 300%). A higher 200% stress retention indicates better recovery.

[2] Evaluation method of heat resistance A 14 cm test yarn is stretched by 50% to 21 cm, and pressed against a stainless steel heat column with a surface temperature of 185 ° C (approximately 1 cm of the test yarn contacting the heat column), and the number of seconds until the test yarn breaks is measured. The longer the number of seconds, the higher the heat resistance, and the better the fabric's high-temperature dyeing, high-temperature setting,
There is less settling when re-dyeing, and fewer thread breakages occur.

[3] Evaluation method for heat setting property A test yarn having an initial length of 5 cm was placed in a pressurized steam atmosphere at 120°C under 100% elongation for 15 minutes.
After leaving it for 10 seconds, it is dried in a dryer at 120°C for 30 seconds. Then, it is left to shrink in an atmosphere at 50°C for 1 hour. After leaving it for 16 hours in an atmosphere at 20°C and 65% RH, the thread length (L cm) is read. Note that leaving it at 50°C is a treatment to accelerate changes over time. The heat setting rate (%) is calculated using the following formula (14).

The higher the heat setting rate, the better the shape retention of the fabric.

[4] Evaluation of strength retention after 180°C dry heat treatment Test yarn E with an initial length of 5 cm is heat-treated in a dryer at 180°C for 1 minute under 100% elongation. After leaving it for 16 hours in an atmosphere of 25°C and 60% RH, the breaking strength of the test yarn is measured according to the measurement method in [1]. Although the test yarn has changed from its initial length at this time, measurements are made for 5 cm of the initial length. The ratio (%) of the yarn strength of the test yarn after treatment to the strength of the untreated yarn is taken as the strength retention. The higher the retention rate, the higher the heat resistance, the smaller the settling of the fabric due to high-temperature dyeing, high-temperature setting, and re-dyeing, and the less yarn breakage occurs.

[5] Evaluation of dyeability and fastness Using a circular knitting machine (Koike Machinery Manufacturing Co., Ltd., CR-C type), a bare knitted fabric of the test yarn is prepared. 1.2 g of the bare knitted fabric is weighed, and 4.8 g of bare knitted fabric made of polyamide fiber is weighed.
Combine the above ingredients and place them in a stainless steel container. Add 4g of acid milling dye (black).
The dyeing process is carried out at 90°C for 60 minutes in a bath ratio of 1:50 and pH 4.0. After the fixation and softening agent treatment, the knitted fabric is washed with water and air-dried, and the dyed state is evaluated on a 5-point scale from dark dyeing grade 5 to light dyeing grade 1. The higher the grade, the more darkly dyed the fabric is.

1 g of the dyed bare knit fabric and 1 g of bare knit fabric made of polyamide fiber were mixed together to obtain 0.8 g
The test yarn is washed with 300cc of detergent solution containing 1/L of water. The knitted fabric is removed, rinsed, and air-dried. The dyeing condition of the bare knitted fabric made from the test yarn is evaluated on a 5-point scale from dark dyeing grade 5 to light dyeing grade 1. The higher the grade, the more darkly dyed the fabric is, and the more preferable it is. The color staining condition of the bare knitted fabric made from polyamide fiber is evaluated on a 5-point scale from light dyeing grade 5 to dark dyeing grade 1. The higher the grade, the more preferable it is in a state where the color staining is minimal.

[6] Preparation of pantyhose Polyamide elastic fiber (Leona 11 dtex/5f, manufactured by Asahi Chemical Industry Co., Ltd.) and test yarn were covered (draft ratio 2.7, twist number 1600 T/m, single cover S twist, Z twist 2 strands each) and knitted on a knitting machine (Nagata Simplex KT-6 type, 400
The yarn is fed into all four yarn feed holes (gauge) to knit so-called Zokki pantyhose (pantyhose in which all courses are knitted with covering yarn) with a total of 2500 courses. The knitted fabric is preset at 50°C and then dyed at 95°C for 45 minutes. After fixing and softening treatment, the knitted fabric is set in pressurized steam at 120°C for 15 seconds while still covered with a stainless steel foot last, and then dried at 120°C for 30 seconds. The knitted fabric is removed from the foot last and left to stand in an atmosphere of 20°C and 65% RH for 3 days.

[7] Evaluation of heat setting property of pantyhose The length (cm) of the leg part of the pantyhose prepared above was measured. A longer length indicates that the test yarn used has better heat setting property.

[8] Evaluation of spinning stability Polyurethane urea spinning dope was filtered through a 40 μm Naslon filter (Nippon Seisen Co., Ltd.).
The mixture was passed through a spinneret (manufactured by the manufacturer) and discharged through two 0.15 mm diameter spinnerets at a spinning temperature of 230°C.
Dry spinning was carried out at ℃ to obtain polyurethane urea elastic fibers of 17 dtex/2 filaments. The winding speed was initially set to 300 m/min and fixed for 5 minutes,
The winding speed is gradually increased, and when the winding speed is X m/min at which yarn breakage occurs in the spinning tube, the spinnability is evaluated by the limiting single yarn fineness per filament calculated according to the following formula (15).

The smaller the limiting single yarn fineness, the better the spinning stability.

EXAMPLES The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples.

Example 1: Polytetramethylene ether glycol 1,500 having a number average molecular weight of 1,800
g (parts by weight, the same applies hereinafter) and 4,4'-diphenylmethane diisocyanate 3
12 g of the mixture was reacted with stirring in a nitrogen gas stream at 60°C for 90 minutes to obtain a polyurethane prepolymer having isocyanate groups. After cooling to room temperature, 2,600 g of dry dimethylformamide was added and dissolved to obtain a polyurethane prepolymer solution. Meanwhile, 23.4 g of ethylenediamine and 3.7 g of diethylamine were dissolved in 1,400 g of dry dimethylformamide, and the prepolymer solution was added to the solution at room temperature to obtain a polyurethane urea polymer solution with a viscosity of 320 Pascal-seconds (30°C).

The polymer solution thus obtained was mixed with 1.5% by weight of an isobutylene adduct of a polyadduct of p-cresol and dicyclopentadiene, 2.5% of N,N-bis(2-hydroxyethyl)-t-butylamine, 0.3% of 2-(2'-hydroxy-3',5-dibenzyl-phenyl)-benzotriazole, 0.1% of magnesium stearate, and 0.1% of a hydroxybenzoate.
0.05% by weight of urea compound having an average number of urea bond units of 4 and consisting of N-(2-aminoethyl)piperazine, 4,4-diphenylmethane diisocyanate, and phenyl isocyanate (molar ratio 2:1:2) was added to prepare a spinning dope.

This spinning dope was dry spun at a spinning speed of 600 m/min and a hot air temperature of 230° C.
A 7 dtex/2 filament polyurethane urea elastic fiber was produced.

[Examples 2 to 5] Instead of the urea compound of Example 1, N-(2-aminoethyl)piperazine,
6% by weight of a urea compound having an average number of urea bond units of 4, which is composed of isophorone diisocyanate and phenyl isocyanate (molar ratio 2:1:2), N,N-bis(2
8% by weight of a urea compound having an average number of 6 urea bond units, which is composed of N-(2-aminoethyl)piperazine, hexamethylene diisocyanate, and t-butylamine (molar ratio 2:3:2), 8% by weight of a urea compound having an average number of 6 urea bond units, which is composed of N-(2-aminoethyl)piperazine, isophorone diisocyanate, and 1-butanol (molar ratio 3:2:2).
8% by weight of a urea compound having an average number of urea bond units of 6 (composed of methyl urea, ...

Example 6 Polyurethane urea elastic fibers were spun in the same manner as in Example 1, except that 8% by weight of the urea compound of Example 2, which had an average number of urea bond units of 17 (respective molar ratios of 17:15:4), was added.

Instead of the urea compound in Example 1, 4% by weight of a polyurethane polymer described in Example 4 of JP-A-7-316922 (a polyurethane polymer having a number average molecular weight of 30,000, composed of 1,4-butanediol, polytetramethylene ether glycol having a number average molecular weight of 650 (molar ratio 9:1), and 4,4'-diphenylmethane diisocyanate (molar ratio 0.99:0.11:1)) and N,N'-bis(3
Polyurethane urea elastic fibers were spun in the same manner as in Example 1, except that 4% by weight of a urea compound having an average number of urea bond units of 4 and consisting of (-aminopropyl)piperazine, isophorone diisocyanate, and phenyl isocyanate (molar ratio 2:1:2) was added.

Comparative Examples 1 to 3 In Example 1, the amount of the urea compound added was changed to 0 wt %, 0.4 wt %, and 18 wt %, to produce polyurethane urea elastic fibers.

Comparative Example 4: The urea compound of Example 2, which had been adjusted to have an average number of urea bond units of 45 (molar ratio 45:43:4), was added in an amount of 8% by weight, and polyurethane urea elastic fibers were spun in the same manner as in Example 1. However, frequent breakage of the spun yarn occurred, making it impossible to produce the fibers.

Comparative Example 5 Polyurethane urea elastic fibers were produced using the same urethane compound as in Example 6 at 8% by weight and the urea compound at 0% by weight.

Comparative Example 6 Instead of the urea compound in Example 1, 0.12% by weight of potassium benzoate described in Example 1 of JP-A-7-150417 was added to produce polyurethaneurea elastic fibers.

The polyurethane urea elastic fibers obtained in Examples 1 to 7 and Comparative Examples 1 to 6 were evaluated for breaking strength, breaking elongation, elastic recovery, heat resistance, strength retention after dry heat treatment at 180°C, heat setting property, dyeability and color fastness, and spinning stability, and the results are shown in Tables 1 and 2.

[Examples 8 to 10, Comparative Examples 7 to 9] Using the polyurethane urea elastic fibers obtained in Examples 1, 2, and 7 and Comparative Examples 1, 5, and 6, zokki pantyhose were produced.

The evaluation results of the heat setting properties of the Zokki pantyhose obtained in Examples 8 to 10 and Comparative Examples 7 to 9 are shown in Table 3.

From Tables 1 to 3, it can be seen that the polyurethane urea elastic fiber of the present invention has high heat setting property, excellent dyeability, maintains good fastness, and has excellent elastic function and heat resistance, and the fiber can be produced under stable spinning.

Industrial Applicability The polyurethane urea elastic fiber of the present invention has excellent shape retention during heat setting, dyeability during dyeing, fastness to washing and other processes, heat resistance, and elasticity, making it an improved elastic fiber material suitable for the production of elastic fabrics that have excellent elasticity, are capable of fast dyeing, do not lose their shape during heat treatment, have good shape retention, and are less likely to develop loose weaves. Thus, the present invention makes it possible to provide an elastic fiber material with excellent elasticity and processability that can be used in a wide range of fields, including circular knit fabrics such as pantyhose, socks, and tights, warp knit fabrics such as foundations and swimsuits, and woven fabrics for outerwear. In particular, the polyurethane urea elastic fiber of the present invention is suitable for zokki pantyhose and weft- or warp-stretch woven fabrics.

───────────────────────────────────────────────────── (Note) This publication is based on the publication published internationally by the International Bureau of Patents (WIPO). The effect of the international publication of the Japanese patent application (Japanese utility model registration application) related to this publication arises pursuant to Article 184-10, Paragraph 1 of the Patent Act (Article 48-13, Paragraph 2 of the Utility Model Act) and is unrelated to this publication.

Claims (7)

[Claims] [Claim 1] A polyurethane urea elastic fiber characterized by containing 1 to 15 weight % of a urea compound obtained by reacting (a) a nitrogen-containing compound containing a bifunctional amino group selected from at least one of a primary amine and a secondary amine and a nitrogen-containing group selected from at least one of a tertiary nitrogen and a heterocyclic nitrogen, with (b) an organic diisocyanate, and (c) at least one compound selected from the group consisting of mono- or dialkyl monoamines, alkyl monoalcohols, and organic monoisocyanates, relative to the polyurethane urea polymer. [Claim 2] A polyurethane urea elastic fiber according to claim 1, characterized in that the urea compound contains an average of 4 to 40 urea bond units represented by the following formulas (1) and (2) per molecule: 3. The polyurethane urea elastic fiber according to claim 1, wherein the nitrogen-containing compound is at least one selected from the group consisting of piperazine and bifunctional piperazine derivatives. 4. The polyurethane urea fiber according to claim 1, wherein the compound (C) is an organic monoisocyanate. 5. The polyurethane urea fiber according to claim 1, wherein the fineness per single yarn is 6 to 33 decitex. 6. The polyurethane urea elastic fiber according to claim 1, which has a heat setting rate of 50% or more and a strength retention rate of 50% or more after dry heat treatment at 180°C. 7. A polyurethane urea polymer obtained by reacting a polyalkylene ether glycol having a number average molecular weight of 600 to 5,000 with an excess molar amount of organic diisocyanate to form an intermediate polymer having an isocyanate group at its terminal, and a diamine compound and a monoamine compound, and 1 to 15% by weight of a urea compound produced from a bifunctional piperazine derivative, an organic diisocyanate, and an organic monoisocyanate is added to the intermediate polymer.
1. A method for producing polyurethane urea elastic fibers, comprising dry spinning a polyurethane urea solution containing the polyurethane urea dissolved in an amide polar solvent.