JPS6160167B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to hygroscopic acrylonitrile fibers. Although the hygroscopicity of fibers is essential for basic functions such as comfort and sweat absorption, the biggest drawback of conventional acrylonitrile fibers is that this hygroscopicity is lower than that of natural fibers. It was found to be extremely inferior. Copolymerization with hydrophilic monomers, such as copolymerization with acrylamide, methacrylamide, acrylic acid, acrylic esters, methacrylic esters, etc., has been attempted in the past as a measure to improve this point. However, these series of monomers reduce the thermal stability of the fiber, and those containing groups such as amide groups and glycol esters cause coloration, and in general, large amounts of such monomers are copolymerized. This may lead to a decrease in hot stretchability and dimensional stability. The present invention has succeeded in improving the hygroscopicity as well as improving the drawbacks that occur when the above-mentioned monomers are introduced. That is, the present invention has (1) the general formula R ₁ −CH ₂ −COOH −() and (However, R ₁ is an alkyl group with 8 to 20 carbon atoms, R ₂ is an alkyl group with 4 to 19 carbon atoms, and R ₃ is an alkyl group with 1 to 10 carbon atoms), of which 50 Alkylene of mixed fatty acids containing % weight or more〓〓〓〓
(2) Acrylonitrile, (3) Can be copolymerized with acrylonitrile other than (1) In the monomer having a vinyl group, (1) is 2 to 20% by weight, (2)
It is a hygroscopic acrylonitrile fiber obtained by copolymerizing 60 to 98% by weight of (3) and 0 to 20% by weight of (3). To describe the present invention in more detail, the mixed fatty acid used for the ester (1) has a total number of carbon atoms of 10 to 22, preferably 12 to 19.
Alternatively, it can be mixed with fatty acids obtained by decomposing natural fats and oils, and the mixed fatty acids contain α-position side chain fatty acids represented by the general formula ().
% weight or more. If the content of α-position side chain fatty acids is less than 50%, not only the thermal stability and hot stretchability of the obtained copolymer are impaired, but also the desired hygroscopicity cannot be obtained sufficiently. Further, examples of the unsaturated carboxylic acid or its lower ester include acrylic acid, methacrylic acid, and methyl ester thereof. In addition, (2) is acrylonitrile, and (3) is a monomer having a vinyl group that can be copolymerized with acrylonitrile, such as methyl acrylate,
Examples include methyl methacrylate, acrylamide, vinyl acetate, vinyl chloride, vinylidene chloride, styrene sulfonic acid, diallylsulfonic acid, and vinylpyridine. The monomers (1), (2), and (3) used in the present invention are preferably 2 to 20%, 60 to 98%, 0 to 20%, preferably 5 to 10%, 80 to 90% by weight, respectively. It has been found that by copolymerizing at a ratio of 0 to 10%, acrylonitrile fibers with improved hygroscopicity can be obtained without deteriorating thermal stability, hot drawability, dimensional stability, etc. The monomer (1) used here has the general formula (), ()
It can be obtained by reacting an addition product obtained by adding an alkylene oxide to a mixed fatty acid with the above-mentioned unsaturated carboxylic acid or a lower ester thereof. Examples of alkylene oxides include ethylene oxide and propylene oxide, and these addition reactions are performed by adding alkylene oxide to fatty acids in the presence of an alkaline catalyst such as caustic potash, caustic soda, or sodium methoxide at a temperature of 100 to 180°C.
It is obtained by blowing under normal or elevated pressure at .degree. This addition product and an unsaturated carboxylic acid or a lower ester thereof are mixed in a molar ratio of 1:1.2 to 10, respectively, using an acidic catalyst such as hydrochloric acid, sulfuric acid, para-toluenesulfonic acid or an alkaline catalyst such as caustic soda, caustic potash, sodium chloride, etc. The reaction is carried out under reflux or in the presence of an organic solvent or an unsaturated carboxylic acid lower ester in the presence of methoxide and heated to 50 to 120°C to obtain monomer (1). Monomers in copolymers
The amount of (1) is 2 to 20% by weight; if it is less than 2%, hygroscopicity cannot be obtained, and if it exceeds 20%, it will not be possible to form a filament or draw it, and the physical properties as a single fiber will deteriorate. cause a decline. The copolymerization reaction of monomers (1), (2), and (3) includes solution polymerization,
Either suspension polymerization or emulsion polymerization can be carried out, but in the case of suspension polymerization, water is placed in a polymerization tank, and a catalyst such as ammonium persulfate or azobisisobutylnitrile is added and dissolved. The above monomers are added to this, stirred, and polymerized at 40 to 80°C.
Filter, wash with water, and dry to obtain a copolymer. The copolymer can be spun by either wet spinning or dry spinning, but in the case of dry spinning, it is dissolved in an organic solvent such as dimethylformamide (DMF), spun, dried, and then stretched. Monomer (1) is a copolymer with acrylonitrile,
Alternatively, by using acrylonitrile, a copolymer obtained by copolymerization of the above-mentioned acrylonitrile and a monomer (3) having a copolymerizable vinyl group, the hygroscopicity of acrylonitrile fibers can be improved. improve. Conventionally, there is a method of copolymerizing acrylonitrile with a glycol ester of acrylic acid or a glycol ester of methacrylic acid for the purpose of improving hygroscopicity, but the hydrophobic group bonded to the glycol group is a linear alkyl group, and Since the number of moles of ethylene oxide added as a hydrophilic group bonded thereto is large, thermal stability is poor, transparency is low, coloring is likely to occur, and hot stretchability is easily impaired. On the other hand, the copolymer obtained using the monomer (1) of the present invention can improve hygroscopicity without impairing thermal stability and hot stretchability. By containing a fatty acid having a side chain in the mixed fatty acid used in the present application, it has little effect on thermal stability and hot drawability, and provides fibers with stable properties. The present invention will be explained below with reference to Examples. Example 1 〓〓〓〓
R ₁ −CH ₂ −COOH (i) (However, R ₁ is an alkyl group having 10 to 13 carbon atoms, R ₂ is
Alkyl group with 5 to 12 carbon atoms, R ₃ is 1 to 6 carbon atoms
Synthetic fatty acids obtained from olefins by the oxo method as a mixture of general formulas (i) and (ii), with a weight ratio of (i) and (ii) of 10:90, as shown in Table 1. 210g of mixed fatty acids with the following composition, 0.4% of caustic soda
g and ethylene oxide at 140-180℃.
Addition product 1500 obtained by adding 1320 g (30 mol)
g (1.0 mol), 108 g (1.5 mol) of acrylic acid and para-toluenesulfonic acid (PTSA) as a catalyst.
16.5 g was added and stirred in benzene at 70-82°C for 10 hours. Thereafter, excess acrylic acid was distilled off to obtain 1520 g of unsaturated ester. Unsaturated ester 1000g, acrylonitrile 8000g
g, 1000 g of styrene sulfonic acid and 100 g of water were placed in a 20 polymerization reactor equipped with a stirring device, and 70 g of ammonium persulfate and 7 g of sodium metabisulfite were added as polymerization catalysts, and then PH was added with sulfuric acid.
4.0 and polymerization was carried out at 50°C for 8 hours. After filtering, washing with water, and dehydrating the obtained polymerization product.
It was dried at 80°C to obtain 7890 g of copolymer. copolymer
Dissolve 2000g in 8000g DMA, filter, and defoam under reduced pressure. This solution is pumped through a spinneret by a gear pump into a coagulation bath at 80-90°C. The coagulation bath was DMF:water = 2:1 (W/W) at 90°C, then passed through a drawing bath at 130°C with the same composition as the coagulation bath, and then dried with hot air at 90 to 100°C to form the filament. I got it. The physical properties of the filament are shown in Table-2.

【table】

[Table] The following products were used as comparative products A and B. Comparative product A: Commercially available polyacrylonitrile fiber. Comparative product B: A filament obtained by polymerizing and spinning the reaction in exactly the same manner except that coconut fatty acid (neutralization value 267.2, increased melting point 42.1°C) was used instead of the mixed fatty acid used in the example. Moisture absorption rates were also measured for the examples and comparative products. The results are shown in Table-3.

[Table] The moisture absorption rate was measured as follows. The increase in weight after absorbing moisture was measured at 20°C and 65% relative humidity (RH), and the weight was calculated as before absorbing moisture (absolutely dry).
It is expressed as a percentage of Example 2 R ₁ −CH ₂ −COOH ………(iii) (However, R ₁ is an alkyl group having 14 to 17 carbon atoms, R ₂ is an alkyl group having 8 to 16 carbon atoms, and R ₃ is an alkyl group having 1 to 6 carbon atoms.) (iii):(iv) is the weight ratio Add 0.5 g of caustic soda to 270 g of mixed fatty acids (neutralization value 207.8) with the composition shown in Table 4 obtained by the oxo method from olefin with a ratio of 40:60, and add 660 g of ethylene oxide (15 930 g (1.0 mol) of the addition product obtained by adding methyl methacrylate
400.4 g (4 moles) and 13.3 g of sodium methoxide as a catalyst were added, and the reaction was heated, and the methanol produced as the transesterification reaction progressed was converted into a methanol-methyl methacrylate azeotrope at a tower top temperature of 64 to 66°C. It was distilled off for 8 hours. Then, excess methyl methacrylate was distilled off under reduced pressure.
1030 g of methacrylic acid ester of mixed fatty acid ethylene oxide adduct was obtained. In place of 1000 g of the unsaturated ester in Example 1, 1000 g of the ester obtained above was used, other raw materials and catalysts were used in the same amounts as in Example 1, the polymerization reaction conditions were the same as in Example 1, and the polymerization product was processing, spinning,
Got filament. The physical properties and hygroscopicity of this filament were measured in the same manner as in Example 1. The results are shown in Table-5.

【table】

[Table] 〓〓〓〓

Claims (1)

[Claims] 1 (1) General formula R ₁ −CH ₂ −COOH −() and (However, R ₁ is an alkyl group having 8 to 20 carbon atoms, R ₂ is an alkyl group having 4 to 19 carbon atoms, and R ₃ is an alkyl group having 1 to 20 carbon atoms.
10 alkyl groups), of which 50
% weight or more of mixed fatty acid alkylene oxide adducts (1 to 50 mol) and unsaturated carboxylic acids or their lower esters (2) Acrylic nitrile (3) Acrylics other than (1) Among monomers having a vinyl group that can be copolymerized with nitrile, (1) is copolymerized in a ratio of 2 to 20% by weight, (2) in 60 to 98% by weight, and (3) in a ratio of 0 to 20% by weight. Hygroscopic acrylonitrile fiber obtained by