Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
  • D01F6/28—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from copolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D01F6/38—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from copolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds comprising unsaturated nitriles as the major constituent

Definitions

• the present invention relates to a modified acrylonitrile fiber, a method for producing the fiber, and a fiber structure containing the fiber.
• Patent Document 1 a crosslinked acrylate fiber obtained by chemically modifying an acrylic fiber is known.
• the fiber contains a crosslinked structure and a carboxyl group, and has excellent moisture absorption performance.
• acrylic fibers having a carboxyl group acrylic fibers made of an acrylonitrile-based polymer having a monomer having a carboxyl group such as acrylic acid as a copolymerization component are known.
• acrylic acid as a copolymerization component
• spinning becomes difficult, and it is difficult to achieve high hygroscopicity.
• it becomes a problem when it is used for clothing such as elution under alkaline conditions such as alkaline soaping in dyeing.
• the present invention has been made in view of the current state of the prior art, and an object thereof is to provide a hygroscopic acrylonitrile-based fiber that can be produced by a simpler process than before.
• the present inventor obtained a spinning stock solution in which an acrylonitrile-based polymer was dissolved from a nozzle, and was obtained through the steps of coagulation, water washing and stretching. It has been found that by hydrolyzing the dried fiber, a modified acrylonitrile fiber can be obtained while maintaining practical fiber properties without being subjected to a crosslinking treatment.
• the present invention is achieved by the following means. (1) Having a carboxyl group of 0.2 to 4.0 mmol / g, solubility in 58% aqueous sodium thiocyanate is 95% or more, and solubility in dimethylformamide is 50% or less.
• a modified acrylonitrile-based fiber characterized by being.
• the notable effect of the present invention is that a spinning solution in which an acrylonitrile polymer is dissolved is spun from a nozzle, and then hydrolyzed on undried fibers obtained through the respective steps of coagulation, washing with water, and stretching, thereby performing a crosslinking treatment.
• an acrylonitrile-based fiber having hygroscopicity can be obtained while maintaining practical fiber properties without being subjected to.
• the fiber can be continuously produced by a normal fiber production facility by the above production method, and has high productivity.
• the fibers can also exhibit properties such as deodorant properties, flame retardancy, antibacterial properties, antiviral properties, and antiallergenic properties, as described later. It can be used for products and applications.
• the modified acrylonitrile fiber of the present invention is obtained by hydrolyzing the undried fiber obtained through the steps of coagulation, water washing and stretching after spinning a spinning stock solution in which an acrylonitrile polymer is dissolved from a nozzle. It is something that can be done.
• the method for obtaining the modified acrylonitrile fiber of the present invention is described in detail below.
• the acrylonitrile-based polymer as a raw material contains acrylonitrile as a polymerization composition, preferably 40% by weight or more, more preferably 50% by weight or more, and still more preferably 85% by weight or more. Therefore, as the acrylonitrile-based polymer, a copolymer of acrylonitrile and another monomer can be employed in addition to the acrylonitrile homopolymer.
• Other monomers in the copolymer are not particularly limited, but vinyl halides and vinylidene halides; (meth) acrylic acid esters (note that (meth) is indicated with or without the word “meta”.
• sulfonic acid group-containing monomers such as methallylsulfonic acid and p-styrenesulfonic acid and salts thereof, acrylamide, styrene, vinyl acetate and the like.
• the above acrylonitrile polymer is dissolved in a solvent to prepare a spinning dope.
• the spinning solution is spun from a nozzle, and then subjected to coagulation, water washing, and stretching steps, and the moisture content of the undried fiber after stretching (hereinafter also referred to as gel acrylic fiber) is 20 to 250% by weight, preferably 25%. To 130% by weight, more preferably 30 to 100% by weight.
• the moisture content of the gel-like acrylic fiber when the moisture content of the gel-like acrylic fiber is less than 20% by weight, the drug may not penetrate into the fiber in the hydrolysis treatment described later, and the carboxyl group may not be generated throughout the fiber. . If it exceeds 250% by weight, the fiber contains a large amount of moisture, and the fiber strength becomes too low. In the case where the height of fiber strength is more important, it is desirable to set it within the range of 25 to 130% by weight.
• the coagulation bath temperature is ⁇ 3 ° C. to 15 ° C., preferably ⁇ 3 ° C. to 10 ° C.
• the draw ratio is 5 It is desired to be about 20 times, preferably about 7 to 15 times.
• Such gel acrylic fiber is then subjected to a hydrolysis treatment.
• the nitrile group in the gel acrylic fiber is hydrolyzed to generate a carboxyl group.
• hydrolysis treatment there is a means for heat treatment in a state of impregnation or immersion in a basic aqueous solution such as alkali metal hydroxide, alkali metal carbonate or ammonia, or an aqueous solution such as nitric acid, sulfuric acid or hydrochloric acid.
• a basic aqueous solution such as alkali metal hydroxide, alkali metal carbonate or ammonia
• an aqueous solution such as nitric acid, sulfuric acid or hydrochloric acid.
• various conditions such as the concentration of the treatment agent, reaction temperature, reaction time and the like may be appropriately set in consideration of the above-described range of the amount of carboxyl groups.
• the wet heat atmosphere refers to an atmosphere filled with saturated steam or superheated steam.
• a cation such as alkali metal or ammonium corresponding to the type of alkali metal hydroxide, alkali metal carbonate, ammonia or the like used in the hydrolysis treatment is contained.
• the salt-type carboxyl group used as a counter ion has been generated, a treatment for converting the counter ion of the carboxyl group may be performed as necessary.
• ion exchange treatment is performed with an aqueous metal salt solution such as nitrate, sulfate, or hydrochloride, a salt-type carboxyl group having a desired metal ion as a counter ion can be obtained.
• an aqueous metal salt solution such as nitrate, sulfate, or hydrochloride
• the modified acrylonitrile fiber according to the present invention can be obtained as described above, but may be washed with water and dried as necessary.
• an inorganic salt such as sodium rhodanate is used as a solvent
• the above conditions are the same even when an organic solvent is used.
• the coagulation bath temperature is controlled by selecting a temperature suitable for the solvent and controlling the moisture content of the gel acrylic fiber within the above range.
• the modified acrylonitrile fiber of the present invention obtained as described above has an unprecedented combination of properties. That is, it has a carboxyl group of 0.2 to 4.0 mmol / g and has a solubility in a 58% aqueous sodium thiocyanate solution of 95% or more, and a solubility in dimethylformamide of 50% or less, or 1 g / L Solubility in sodium carbonate aqueous solution is 5% or less.
• the structure of the fiber is as follows. That is, since the solubility of acrylonitrile-based polymer in 58% aqueous sodium thiocyanate, which is a good solvent, is 95% or more, the acrylonitrile-based polymer constituting the fiber has an intermolecular cross-linked structure. It is thought not to.
• the property that the solubility of acrylonitrile-based polymer in dimethylformamide, which is a good solvent, is 50% or less can be considered to be influenced by the increase in hydrophilicity due to the carboxyl group introduced by hydrolysis.
• a monomer containing a carboxyl group such as methacrylic acid is copolymerized in an acrylonitrile polymer, it can be dissolved in dimethylformamide, so the above characteristics are unlikely to be simply due to the presence of the carboxyl group. .
• the gel-like acrylic fiber is hydrolyzed, so that it is not sequentially hydrolyzed from the fiber surface, but the drug penetrates into the inner part of the fiber and is hydrolyzed throughout the fiber. It is done.
• an acrylic fiber is mixed with a crystalline portion where an acrylonitrile-based polymer is oriented and an amorphous portion where the structure is disordered. For this reason, the crystal part is hydrolyzed from the outside, but the amorphous part is considered to be hydrolyzed as a whole.
• the property that the solubility in a 1 g / L sodium carbonate aqueous solution is 5% or less indicates that the polymer constituting the fiber of the present invention has a carboxyl group but is hardly eluted into an alkaline aqueous solution.
• the fiber of the present invention it is considered that a portion having a high nitrile group concentration is present throughout the fiber as described above, and the portion having a high nitrile group concentration is alkali resistant, so that it can be dissolved in a 1 g / L sodium carbonate aqueous solution. It is presumed to decrease the performance.
• the structure of the modified acrylonitrile fiber of the present invention does not have an intermolecular cross-linking structure due to a covalent bond, and has a structure in which a portion having a high carboxyl group concentration and a portion having a high nitrile group concentration exist throughout the fiber. Presumed to be.
• fibers having the above-described characteristics are obtained by hydrolyzing gel-like acrylic fibers.
• the acrylic acrylic fiber after drying is not used without gel-like acrylic fiber, that is, undried fiber after stretching, the drug does not penetrate into the inner part of the fiber and hydrolyzes sequentially from the fiber surface.
• a structure in which there are many carboxyl groups in the fiber surface layer and few carboxyl groups in the inner part of the fiber is induced.
• the fiber having such a structure is not practically usable because elution of the fiber surface layer into water occurs.
• the property that the solubility in a 58% sodium thiocyanate aqueous solution is 95% or more is reusable by dissolution, which was impossible with the conventional crosslinked acrylate-based hygroscopic fiber. It shows that it has sex.
• the property that the solubility in dimethylformamide is 50% or less indicates that it has organic solvent resistance.
• Solubility in 1 g / L sodium carbonate aqueous solution is 5% or less. Soaping in washing and dyeing processes while having no intermolecular cross-linking structure due to covalent bond and having many highly hydrophilic carboxyl groups It shows that it can withstand processing.
• the amount of carboxyl groups in the modified acrylonitrile fiber of the present invention is 0.2 to 4.0 mmol / g, preferably 0.5 to 3.5 mmol / g, more preferably 1.0 to 3.5 mmol / g.
• the amount of the carboxyl group is less than the lower limit, sufficient moisture absorption performance may not be obtained.
• the amount exceeds the upper limit the water swellability of the fiber becomes too high, which may not be practically preferable.
• the counter ion is a cation other than H when emphasizing moisture absorption performance.
• the cation include alkali metals such as Li, Na, and K, alkaline earth metals such as Be, Ca, and Ba, metals such as Cu, Zn, Al, Mn, Ag, Fe, Co, and Ni, NH 4 , cations such as amines, and the like can be mentioned, and a plurality of types of cations may be mixed.
• Li, Na, K, Mg, Ca, Zn and the like are preferable.
• the counter ion is H, that is, in the form of COOH as the state of the carboxyl group, it is particularly excellent in terms of deodorizing performance, antiviral performance, and antiallergen performance of amine gases such as ammonia, triethylamine, and pyridine. Is expressed.
• the saturated moisture absorption rate at 20 ° C. and a relative humidity of 65% is preferably 3% by weight, more preferably 5% by weight, and still more preferably. It is desirable that it is 10 weight% or more.
• the modified acrylonitrile fiber of the present invention it is desirable that carboxyl groups exist throughout the fiber.
• being present throughout the fiber means that the coefficient of variation CV of the content ratio of the magnesium element in the fiber cross section measured by the measurement method described later is 50% or less.
• a portion having a high carboxyl group concentration and a portion having a high nitrile group concentration exist throughout the fiber, so that the fiber becomes brittle due to moisture absorption and water absorption of the carboxyl group. It is considered that the fiber properties can be used practically without having a crosslinked structure.
• the modified acrylonitrile fiber of the present invention described above can be used as a fiber structure useful in many applications, either alone or in combination with other materials.
• Appearance forms of the fiber structure include yarns, non-woven fabrics, paper-like materials, sheet-like materials, laminates, and cotton-like materials (including spherical and massive materials).
• any layer in the case of a structure having a plurality of layers distributed substantially uniformly by mixing with other materials, any layer (single or even A plurality of them may be present in a concentrated manner, and others may be distributed at a specific ratio in each layer.
• the appearance form and content of the fiber structure exemplified above, other materials constituting the fiber structure, and other members combined with the fiber structure are determined depending on the type of the final product (for example, Functions, characteristics, and shapes required for clothing, filters, curtains and carpets, bedding, cushions, insoles, etc.) and how the modified acrylonitrile fiber of the present invention contributes to such functions. Is determined as appropriate.
• ⁇ Measurement of solubility in dimethylformamide> The solubility is calculated in the same manner as in ⁇ Measurement of solubility in aqueous sodium thiocyanate> except that the solution is changed to DMF and the immersion condition is changed to 30 ° C. for 1 hour.
• ⁇ Measurement of solubility in aqueous sodium carbonate solution> The solubility is calculated in the same manner as in ⁇ Measurement of solubility in aqueous sodium thiocyanate> except that the solution is changed to a 1 g / L aqueous sodium carbonate solution and the immersion condition is changed to 95 ° C. for 30 minutes.
• a fiber sample is subjected to an ion exchange treatment by immersing it in an aqueous solution in which magnesium nitrate corresponding to twice the amount of carboxyl groups contained in the fiber is dissolved, and washed with water and dried to obtain carboxyl groups.
• the counter ion of is magnesium.
• a magnesium salt type fiber sample is selected from 10 points at roughly equal intervals from the outer edge to the center of the fiber cross section using an energy dispersive X-ray spectrometer (EDS), and the magnesium element content at each measurement point is measured. To do.
• Example 1 A spinning stock solution prepared by dissolving 10 parts of an acrylonitrile-based polymer composed of 90% acrylonitrile and 10% methyl acrylate in 90 parts of a 48% aqueous sodium thiocyanate solution was spun into a -2.5 ° C. coagulation bath, coagulated, washed with water, The raw material gel acrylic fiber having a moisture content of 35% was obtained by stretching 12 times. The fiber is immersed in a 1.0% aqueous sodium hydroxide solution, squeezed, hydrolyzed in a humid heat atmosphere at 123 ° C. for 25 minutes, washed with water, dried, and the modified acrylonitrile system of the present invention. Fiber was obtained. The evaluation results of the obtained fiber are shown in Table 1.
• Example 2 ⁇ Examples 2 to 6>
• the concentration of the aqueous sodium hydroxide was 2.5% in Example 2, 7.5% in Example 3, 10% in Example 4, 15% in Example 5, and Example 6
• the evaluation results of the obtained fiber are shown in Table 1.
• Example 7 In the formulation of Example 3, instead of 7.5% aqueous sodium hydroxide, 7.5% aqueous potassium hydroxide was used in Example 7, 7.5% aqueous lithium hydroxide was used in Example 8, and In No. 9, the modified acrylonitrile fiber of the present invention was obtained in the same manner except that a 7.5% aqueous sodium carbonate solution was used. The evaluation results of the obtained fiber are shown in Table 1.
• Example 10 In the formulation of Example 1, except that the coagulation bath temperature is 10 ° C., the moisture content of the gel acrylic fiber is adjusted to 67%, and the concentration of the sodium hydroxide aqueous solution is changed to 3.8%. Similarly, the modified acrylonitrile fiber of the present invention was obtained. The evaluation results of the obtained fiber are shown in Table 1.
• Example 11 and 12 In the formulation of Example 3, the modified acrylonitrile fiber of the present invention was obtained in the same manner except that the temperature condition of the hydrolysis treatment was 113 ° C. in Example 11 and 135 ° C. in Example 12. The evaluation results of the obtained fiber are shown in Table 1.
• Comparative example 4 The fiber having no carboxyl group obtained in Comparative Example 1 is impregnated with an aqueous solution containing 0.5% hydrazine and 2% sodium hydroxide, and heat-treated at 115 ° C. for 2 hours to have a crosslinked structure and a carboxyl group. Fiber was obtained. The evaluation results of the obtained fiber are shown in Table 1.
• the modified acrylonitrile fibers of Examples 1 to 12 obtained by the production method of the present invention have a carboxyl group of 0.2 to 4.0 mmol / g, into a 58% aqueous sodium thiocyanate solution.
• the solubility in dimethylformamide is 50% or less, or the solubility in 1 g / L sodium carbonate aqueous solution is 5% or less.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Artificial Filaments (AREA)
• Chemical Or Physical Treatment Of Fibers (AREA)

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• 2016
  • 2016-09-12 CN CN201680089157.3A patent/CN109689951B/zh active Active
  • 2016-09-12 JP JP2018537988A patent/JP6819686B2/ja active Active
  • 2016-09-12 WO PCT/JP2016/076815 patent/WO2018047344A1/ja active Application Filing
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