JP2008266800A - Acrylonitrile-based flat fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an acrylonitrile-based flat fiber that is dyed at a low temperature, hardly develops fine crimps during dyeing, provides a pile product having a natural pelage-like appearance and feeling and excellent crimp removal. <P>SOLUTION: The acrylic fiber is composed of 20-60 mass% of a polymer (A) and 40-80 mass% of a polymer (B) and has a fiber gloss difference between before and after warm water treatment at 80°C of ≤10%. The polymer (A) is composed of 80-94 mass% of an acrylonitrile unit and 6-20 mass% of a monomer units copolymerizable with acrylonitrile. The polymer (B) is composed of 50-70 mass% of an acrylonitrile unit, 3-5 mass% of a sulfonic acid group-containing monomers and 25-47 mass% of a vinyl chloride and/or vinylidene chloride monomer units. The total of the polymer (A) and the polymer (B) is 100 mass%. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an acrylonitrile-based flat fiber having a good crimp removability capable of obtaining a pile product having a natural fur-like appearance and texture.

  Acrylic synthetic fibers are widely used in the high pile field assuming natural fibers as fibers having animal-like texture and luster. Originally, the structure of animal hair consists of a double-layered structure of guard hair (upper hair) and down hair (lower hair), and the guard hair has a straight shape without crimps, and has a soft and soft texture. And has a characteristic of giving a clean and glossy appearance. On the other hand, the down hair is originally provided with a crimp in order to improve heat insulation and to give a sense of volume.

  A pile product (hereinafter referred to as a raised fabric) made of synthetic fibers is imitating such animal hair as it is and is usually composed of guard hair and down hair. The crimp at the tip of the guard hair is After being made into a raised fabric, it is removed by a polisher process to give an animal hair-like appearance and texture. In addition, it is important to leave the majority of the down hair crimp without removing it, in order to give a sense of volume.

  However, as conventional acrylic synthetic fibers, it is common to perform dyeing after crimping, and it is difficult to remove crimps in the polishing process when subjected to high-temperature thermal history during the dyeing process. Met. In addition, a method of increasing the number of polishings or increasing the polishing temperature in the polishing step has been generally used to solve these crimps because fine crimps are easily expressed during dyeing. Increasing the number of polishing more than necessary or raising the temperature led to removal of the down hair crimp that does not require removal of the crimp, and tended to be a product without a sense of volume or luxury.

In order to solve these problems, Patent Document 1 discloses an approach of a method in which a raw solution colored fiber is used as a raw material for piles, but has a serious problem such as a limited hue of the fiber. However, the current situation is that it has not yet been fully resolved. Since the pile fabric is required to have an appearance characteristic, various hues are also required for the raw cotton for piles. In this method, only the hue produced by coloring in the spinning process can be obtained.
JP-A-8-260289

  The object of the present invention is to improve the above-mentioned conventional drawbacks, and the crimp imparted to the fiber can be easily removed with a smaller number of polisher treatments than usual, and a napped fabric having an excellent texture and appearance can be obtained. The object is to provide acrylic fibers for piles.

  An object of the present invention is to solve the above-mentioned problems of the prior art, and to obtain an acrylic flat fiber that can be dyed at a low temperature, is difficult to express a fine crimp at the time of dyeing, and can be easily removed after dyeing. . As a result of studying to solve the above-mentioned problems, the inventors have found an acrylic fiber that can solve the problems by spinning a stock solution obtained by mixing two kinds of acrylic polymers having a specific monomer composition.

  That is, the present invention is an acrylic fiber composed of 20 to 60% by mass of the polymer (A) and 40 to 80% by mass of the polymer (B), and the difference in fiber gloss before and after the 80 ° C. hot water treatment is 10% or less. The polymer (A) is composed of 80 to 94% by mass of acrylonitrile units and 6 to 20% by mass of monomer units copolymerizable with acrylonitrile. The polymer (B) is composed of 50 units of acrylonitrile units. The total amount of the polymer (A) and the polymer (B) consisting of ˜70% by mass, 3 to 5% by mass of sulfonic acid group-containing monomer units, and 25 to 47% by mass of vinyl chloride and / or vinylidene chloride monomer units. Is an acrylonitrile-based flat fiber having a mass of 100% by mass.

  The acrylonitrile-based flat fiber of the present invention can be dyed at a low temperature, has good crimp removability after dyeing, is useful as a high pile material component, and is extremely significant in industry.

  This invention is an acrylic fiber which consists of a polymer (A) 20-60 mass% and a polymer (B) 40-80 mass%, Comprising: The fiber glossiness difference before and behind a 80 degreeC warm water process is 10% or less. It is an acrylonitrile-based flat fiber, the polymer (A) is composed of 80 to 94% by mass of acrylonitrile units and 6 to 20% by mass of monomer units copolymerizable with acrylonitrile, and the polymer (B) is composed of 50 to 50 units of acrylonitrile units. 70% by mass, 3 to 5% by mass of sulfonic acid group-containing monomer units, and 25 to 47% by mass of vinyl chloride and / or vinylidene chloride monomer units, and the total amount of polymer (A) and polymer (B) is The acrylic fiber is 100% by mass.

  In a polymer (A), an acrylonitrile unit is 80-94 mass%, and 85-90 mass% is more preferable. If the acrylonitrile unit is less than 80% by mass, the heat resistance of the portion of the polymer (A) contained in the resulting fiber will be low, and if it exceeds 94% by mass, the heat resistance will be too high, and sufficient dyeability and shrinkage will be achieved. Cannot be obtained.

  Other copolymerizable monomers in the polymer (A) include acrylic acid and methacrylic acid and their lower alkyl esters, N- or N, N-alkyl substituted aminoalkyl esters and glycidyl esters, acrylamide and methacrylamide, and the like. Their N- or N, N-alkyl-substituted products, carboxyl group-containing vinyl monomers represented by acrylic acid, methacrylic acid, itaconic acid and the like, and anionic vinyl monomers such as sodium, potassium or ammonium salts thereof Cationic vinyl monomers such as quaternized aminoalkyl esters of acrylic acid and methacrylic acid, vinyl group-containing lower alkyl ethers, vinyl group-containing lower carboxylic acid esters typified by vinyl acetate, vinyl chloride, chloride Vinylidene, vinyl bromide, vinyl bromide Vinyl halides and / or vinylidene halides such as represented in den or the like, styrene and the like are preferable, and can be used singly or two or more of these monomers. Content of the other copolymerizable monomer in a polymer (A) is 6-20 mass%, and 8-12 mass% is more preferable. If it exceeds 20% by mass, the heat resistance of the resulting fiber will be low, and if it is less than 6% by mass, low-temperature dyeability will not be obtained.

  Examples of the sulfonic acid group-containing monomer (SAM) that can be used in the polymer (A) include allyl sulfonic acid, methallyl sulfonic acid, styrene sulfonic acid, vinyl sulfonic acid, isoprene sulfonic acid, and 2-acrylamido-2-methylpropane. Sulfonic acids or their metal salts and amine salts are preferred, and these can be used alone or in combination of two or more. The content of the sulfonic acid-containing monomer in the polymer (A) is preferably 0.1 to 2% by mass and more preferably 0.5 to 1.5% by mass from the viewpoint that voids are easily generated in the obtained fiber. .

  The content of the acrylonitrile unit in the polymer (B) is required to be 50 to 70% by mass, and more preferably 55 to 60% by mass. When it exceeds 70 mass%, heat resistance will become high and sufficient dyeability and shrinkage will not be obtained. As the sulfonic acid group-containing monomer in the polymer (B), the compounds described above as the sulfonic acid group-containing monomer in the polymer (A) are used. The content of the sulfonic acid-containing monomer in the polymer (B) is 3 to 5% by mass, and more preferably 3 to 4% by mass. If it exceeds 5% by mass, voids and sticking occur in the fiber, which causes a decrease in strength and elution during dyeing. Further, if it is less than 3% by mass, sufficient dyeing performance cannot be obtained.

  The content of vinyl chloride and / or vinylidene chloride monomer in the polymer (B) is 25 to 47% by mass, and more preferably 35 to 45% by mass. If it is less than 25% by mass, the crimp removability during the production of the pile fabric is lowered.

  The acrylonitrile-based flat fiber of the present invention comprises 20 to 60 parts by mass of the polymer (A) and 40 to 80 parts by mass of the polymer (B), and 20 to 40 parts by mass of the polymer (A) and the polymer (B) 60. More preferably, it is -80 mass parts. However, a polymer (A) and a polymer (B) are mix | blended so that it may become a total of 100 mass parts. If the polymer (B) is less than 40 parts by mass, sufficient dyeability and crimp removal properties cannot be obtained. If the polymer (B) exceeds 80 parts by mass, the fiber texture changes during dyeing, and the resulting pile product feels. Gets worse.

  In the acrylonitrile-based flat fiber of the present invention, the total content of sulfonic acid group-containing monomers in the polymer (A) and the polymer (B) is 1 of the total amount of monomers in the polymer (A) and the polymer (B). 0.5 to 5% by mass is preferable, and 2 to 4% by mass is more preferable. If the amount is less than 1.5% by mass, sufficient dyeability cannot be obtained, and if it exceeds 5% by mass, voids and sticking occur in the fiber and the strength decreases, which is not preferable.

  The polymer (A) and polymer (B) in the present invention are known compounds as polymerization initiators, such as peroxide compounds, azo compounds, or various redox compounds, emulsion polymerization, suspension polymerization, solution. It can be obtained by a general vinyl polymerization method such as polymerization.

  The polymer (A) and the polymer (B) are dissolved in an organic solvent such as acetonitrile, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, or an inorganic solvent such as zinc chloride, nitric acid, rhodan salt, etc. to obtain a spinning dope. be able to. It is also possible to use an inorganic and / or organic pigment such as titanium oxide or a pigment for coloring, a stabilizer effective in preventing coloring, weather resistance, etc. in this spinning dope as long as it does not interfere with spinning. .

  Examples of the solvent for wet-spinning the copolymer include organic solvents such as acetone, acetonitrile, dimethylformamide, dimethylacetamide, and dimethylsulfoxide. The stock solution for spinning may be dissolved in an organic solvent having the highest solubility of the above copolymer in consideration of spinnability and process stability, and a known general dissolution method can be used. The spinning solution is preferably wet-spun with a copolymer concentration of 20% by weight or more. As the spinning bath, water or an aqueous solution obtained by mixing water and the same solvent used for the spinning dope can be used.

  In the present invention, stretching in a bath is performed on fibers in a gel-swelled state (a state in which a solvent and moisture are contained inside the fibers) before drying. The stretching method is not particularly limited, and a known stretching device can be used, but the stretching ratio is preferably 4.0 to 6.0 times. When the draw ratio is less than 4 times, the relaxation heat treatment is not sufficiently performed, and when the draw ratio exceeds 6 times, yarn breakage occurs frequently, and the spinning operability is deteriorated. Usually, after this stretching, drying and densification are performed after applying a spinning oil as necessary. Although there is no restriction | limiting in particular as drying temperature, It is preferable to carry out at 100 to 140 degreeC, More preferably, it is 125 to 135 degreeC. The densified acrylonitrile fiber can then be subjected to relaxation heat treatment at a high temperature to give desired thermal properties, but the relaxation rate is 0.80 times (20%) to 0.90 times (10%). ) Is preferred. The relaxation heat treatment temperature is preferably 110 ° C to 170 ° C, more preferably 130 ° C to 160 ° C. If the temperature is less than 110 ° C., relaxation of 0.9 times or less (10% or more) cannot be obtained. If the temperature exceeds 170 ° C., problems such as yellowing and sticking of fibers tend to occur.

  When the relaxation heat treatment exceeds 0.9 times (less than 10%), sufficient crimp removal property cannot be obtained, shrinkage occurs in the raw cotton dyeing process, and glossiness after dyeing is greatly reduced. In the case of less than 0.80 times (greater than 20%), it is necessary to set the temperature to 170 ° C., which causes the problem of yellowing and sticking of fibers. In this way, those that have been stretched in a bath, dried and then subjected to a high relaxation treatment can be crimped at a low temperature, which is considered to be the reason why crimp removal is facilitated. The relaxation heat treatment may be any of dry heat, saturated steam, pressurized steam, superheated steam, and the like. The fibers after the relaxation heat treatment can be appropriately subjected to necessary treatments and operations such as oiling, mechanical crimping and cutting by known methods.

  The fineness of the acrylonitrile-based flat fiber of the present invention is preferably 2 to 40 denier, and particularly preferably in the range of 5 to 30 denier because the characteristics are easily exhibited. If it is less than 2 denier, the fibers are too thin to produce a standing upright fabric with no waist, and if it exceeds 40 deniers, the fibers are too thick and a textured hard fabric is not preferred. The acrylic fiber produced by the method of the present invention has a flat shape that faithfully reproduces the shape of the die, and the major axis / minor axis ratio (B) is usually about 4.5 to 15. If this ratio is 4.5 or more, preferably 6 to 15, a good animal hair texture can be obtained when a textile product such as woven or knitted fabric or yarn is used. If necessary, stabilizers that are effective in preventing rust, preventing coloring, weather resistance, and the like may be added to these fibers.

The acrylonitrile-based flat fibers of the present invention thus obtained can be dyed at a low temperature. The dyeing temperature is preferably 60 to 80 ° C. If the dyeing temperature is less than 60 ° C., sufficient dyeing cannot be performed. If the dyeing temperature exceeds 90 ° C., the texture change (sagging) of the fibers occurs at the time of dyeing, and fine crimps are easily developed. . As a result, the glossiness of the raw cotton decreases before and after dyeing, and the crimp removability during processing of the pile fabric decreases. When the fiber glossiness of the raw cotton and the raw cotton treated with 80 ° C. warm water is measured according to JIS-Z8741 (mirror gloss measurement method), particularly good crimp removability is obtained when the gloss difference is 10% or less.
The acrylic contractile flat fibers of the present invention can be dyed at a low temperature and have good crimp removal properties even after dyeing. Therefore, it is possible to plan new products rich in variations in hues for clothing, toys (stuffed animals, etc.) and interiors.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to these at all. Prior to the description of the examples, a method for evaluating a napped fabric will be described. In the examples, “parts” and “%” mean “parts by mass” and “% by mass” unless otherwise specified.

[Evaluation of standing fabric]
The raw cotton obtained by wet spinning in the examples was prepared, and then the temperature was changed at a cationic dye concentration of 2% by mass with respect to the raw cotton weight using an Overmeier dyeing machine, dyeing was performed for 60 minutes, and then the sliver knitting machine A raised fabric was knitted. The case where the adsorption rate of the cationic dye on the raw cotton was 60% or more was judged as dyeability: ○, and the case where it was less than 60% was judged as dyeability: x. Next, after pre-polishing at 120 ° C. (preliminary polishing to remove pile directionality distortion) and pre-shearing (preliminary tip cutting of the pile), the pile length was adjusted to 17 mm, Back coating was performed on the back of the pile with an acrylic ester adhesive. After that, polishing at 160 ° C., followed by brushing, further combining polishing and shearing at 140 ° C., 125 ° C., and 95 ° C., and removing the crimp on the raised surface layer portion, a raised fabric having a pile length of 20 mm was created. .

[Evaluation criteria for crimp removal]
The above-mentioned raised fabric was subjected to sensory evaluation by five judges from the visual and sensory viewpoints when the number of polisher finishes was changed, and was evaluated according to the following criteria.
○: The crimp is completely removed and has a texture very similar to animal hair.
(Triangle | delta): The removal property of a crimp is a little inferior.
X: The removability of a crimp is inferior.

[Glossiness measurement]
The raw yarn before being cut into staples was treated in warm water at 80 ° C. for 30 minutes and then dried at room temperature to obtain a warm water treated yarn. Similarly, a raw yarn not treated with warm water was prepared, and the gloss was measured according to JIS-Z8741 (mirror gloss measurement method). The result was the gloss of the raw cotton. The measurement was made by winding a card winding with 5 reciprocating sample yarns wound at a tension of 0.3 g / dtex while traversing the acrylic plate to a density of 2.8 pieces / mm, and the variable angle gloss meter VGS-300A. (Nippon Denshoku Industries Co., Ltd.) was used to measure the 45 degree specular gloss with respect to the fiber axis direction. Measurement was carried out at five points, and the average value was obtained.

(Examples 1 to 3, Comparative Example 1)
According to an aqueous suspension polymerization method, the reduced viscosity (measured at 25 ° C. using a 0.5% solution of dimethylformamide (hereinafter abbreviated as DMF)) of 1.9, 88% by mass of acrylonitrile units, methyl acrylate Polymer (A) comprising 10% by mass of unit, 2% by mass of sodium 2-acrylamido-2-methylpropanesulfonate unit, 57% by mass of acrylonitrile unit, 40% by mass of vinylidene chloride unit, 2-acrylamido-2-methylpropanesulfone A polymer (B) comprising 3% by mass of sodium acid unit was obtained. Each polymer is dissolved in dimethylacetamide (hereinafter abbreviated as DMAC) to prepare a polymer solution having a polymer concentration of 23%, and the polymer solutions are mixed so that the polymer ratio becomes the ratio shown in Table 1. A stock solution for spinning was prepared. The spinning dope is spun into a coagulation bath of 40% DMAC / 60% water and 40 ° C. using a nozzle with a flat hole shape and a number of holes of 5000, and is subjected to 5 times spinning drawing through a three-stage washing / drawing bath in which the solvent concentration decreases sequentially. After applying an oil agent to the obtained fiber, secondary stretching was performed 1.1 times in a dry heat atmosphere at 125 ° C., followed by 0.85 times (15%) in a dry heat atmosphere at 160 ° C. Heat treatment was performed at a relaxation rate. The obtained fibers (total fineness 55000 dtex, single fiber fineness 11 dtex, flat cross section, major axis / minor axis ratio 11) were evaluated for dyeability and napped fabric. Sticking occurred (Table 1). Similarly, a fiber bundle having a total fineness of 330 dtex was prepared, and the glossiness of the untreated warm water yarn and the 80 ° C. warm water treated yarn was measured. As a result, the glossiness of the undyed yarn was 35%, and the glossiness of the warm water treated yarn was 27%.

(Examples 4 and 5, Comparative Examples 2 and 3)
Flat fibers were obtained in the same manner as in Example 1 except that the relaxation heat treatment conditions were changed. The fiber was evaluated for dyeability at 80 ° C. and napped fabric evaluation (Table 2). Similarly, fiber bundles having a total fineness of 330 dtex were prepared, and the glossiness of warm water untreated yarn and 80 ° C. hot water treated yarn was measured (Table 3).

(Examples 6 and 7, Comparative Examples 4 and 5)
By an aqueous suspension polymerization method, the reduced viscosity (measured at 25 ° C. using a 0.5% solution of DMF) is 1.9, the acrylonitrile unit is 92% by mass, the methyl acrylate unit is 7% by mass, 2-acrylamide-2. -Polymer (A) comprising 1% by mass of sodium methylpropanesulfonate unit, 57% by mass of acrylonitrile unit, 40% by mass of vinylidene chloride unit, polymer comprising 3% by mass of sodium 2-acrylamido-2-methylpropanesulfonate unit (B) was obtained. Each polymer was dissolved in DMAC to prepare a polymer solution having a polymer concentration of 23%, and each polymer solution was mixed so that the polymer ratio became the ratio shown in Table 4 to obtain a stock solution for spinning. The spinning dope is spun into a coagulation bath of 40% DMAC / 60% water and 40 ° C. using a nozzle with a flat hole shape and a number of holes of 5000, and is subjected to 5 times spinning drawing through a three-stage washing / drawing bath in which the solvent concentration decreases sequentially. After applying an oil agent to the obtained fiber, secondary stretching was performed 1.1 times in a dry heat atmosphere at 125 ° C., followed by 0.85 times (15%) in a dry heat atmosphere at 160 ° C. Heat treatment was performed at a relaxation rate. The obtained fibers (total fineness 55000 dtex, single fiber fineness 11 dtex, flat cross section, major axis / minor axis ratio 11) were evaluated for napped fabric. Comparative Example 4 had a hard texture. (Table 4). Similarly, a fiber bundle having a total fineness of 330 dtex was prepared, and the change in glossiness before and after the hot water treatment was measured (Table 5).

(Comparative Examples 6-8)
By an aqueous suspension polymerization method, the reduced viscosity (measured at 25 ° C. using a 0.5% solution of DMF) is 1.9, 95% by mass of acrylonitrile units, 4% by mass of methyl acrylate units, 2-acrylamido-2 -Polymer (A) comprising 1% by mass of sodium methylpropanesulfonate unit, 75% by mass of acrylonitrile unit, 23% by mass of vinylidene chloride unit, polymer comprising 2% by mass of sodium 2-acrylamido-2-methylpropanesulfonate unit (B) was obtained. Each polymer was dissolved in DMAC to prepare a polymer solution having a polymer concentration of 23%, and each polymer solution was mixed so that the polymer ratio A / B was 60/40 to obtain a spinning stock solution. The spinning dope is spun into a coagulation bath of 40% DMAC / 60% water and 40 ° C. using a nozzle with a flat hole shape and a number of holes of 5000, and is subjected to 5 times spinning drawing through a three-stage washing / drawing bath in which the solvent concentration decreases sequentially. After applying an oil agent to the obtained fiber, secondary stretching was performed 1.1 times in a dry heat atmosphere at 125 ° C., followed by 0.93 times (7%) in a dry heat atmosphere at 160 ° C. A relaxation heat treatment was performed. The obtained fibers (total fineness 55000 dtex, single fiber fineness 11 dtex, flat cross section, major axis / minor axis ratio 11) were evaluated for dyeability and napped fabric (Table 6). Similarly, a fiber bundle having a total fineness of 330 dtex was prepared, and the glossiness of the untreated warm water yarn and the 80 ° C. warm water treated yarn was measured. As a result, the glossiness of the undyed yarn was 35%, and the glossiness of the warm water treated yarn was 22%.

Claims (3)

An acrylonitrile-based flat fiber having 20 to 60% by mass of the polymer (A) and 40 to 80% by mass of the polymer (B), wherein the difference in fiber gloss before and after the 80 ° C. hot water treatment is 10% or less .
The polymer (A) comprises 80 to 94% by mass of acrylonitrile units and 6 to 20% by mass of monomer units copolymerizable with acrylonitrile.
The polymer (B) comprises 50 to 70% by mass of acrylonitrile units, 3 to 5% by mass of sulfonic acid group-containing monomer units, and 25 to 47% by mass of vinyl chloride and / or vinylidene chloride monomer units.
The total amount of the polymer (A) and the polymer (B) is 100% by mass.   The acrylonitrile-based flat fiber according to claim 1, wherein up to 2% by mass of the monomer unit copolymerizable with the acrylonitrile unit of the polymer (A) is a sulfonic acid group-containing monomer.   The acrylonitrile-based flat fiber according to claim 1 or 2, wherein the total content of the sulfonic acid group-containing monomer in the fiber is 1.5 to 3% by mass.