JP4968597B2 - Manufacturing method of composite fiber - Google Patents

Description

  The present invention relates to a method for producing a composite fiber in which a raw material fiber, a hydrogen peroxide, and a monomer are mixed with each other to polymerize the monomer in the mixed liquid to polymerize the raw material fiber.

  Several methods have been proposed so far for newly combining a polymer with a raw fiber. For example, a method of imparting a function to a fiber by graft polymerization of a monomer having a hydrophilic group on the fiber (see JP 2002-371470 A), after a monomer and / or oligomer of a thermoplastic resin is imparted to the fiber surface , A method of compounding a polymer and a fiber by polymerization (see JP 2003-277530 A), a non-aqueous solvent, a lithium inorganic salt, and a pregel solution containing a monomer that is polymerized by an electron beam, an acrylic fiber A method for producing a non-woven fabric composite gel electrolyte for a polymer battery, comprising impregnating a non-woven fabric base material as a main component and polymerizing a monomer by irradiation with an electron beam to form a matrix polymer (Japanese Patent Application Laid-Open No. 2002-246065) (See the publication).

  In the method of JP-A-2002-371470, the polymerization reaction is advanced by irradiation with steam of 100 ° C. or higher and ultraviolet rays, and it is necessary to prepare an apparatus for generating ultraviolet rays and vapors. is there. In the method of Japanese Patent Application Laid-Open No. 2003-277530, the polymer to be combined with the raw fiber is combined only on the fiber surface, and the polymer is not combined in the fiber. The polymer to be combined is limited to a polymer obtained by polymerizing a monomer of a thermoplastic resin. In the method disclosed in Japanese Patent Application Laid-Open No. 2002-246065, a polymer is produced by polymerizing a monomer using an electron beam in a nonwoven fabric substrate, and is combined with the nonwoven fabric. Due to the electron beam polymerization, a relatively expensive apparatus must be used, which is industrially disadvantageous.

  The object of the present invention is to solve the problems of the conventional technology that the composite polymer is localized on the fiber surface or an electron beam irradiation device or an ultraviolet irradiation device is required at the start of polymerization, and the polymer is applied to the raw fiber. An object of the present invention is to provide a method for producing a composite fiber that can be easily combined.

The above object of the present invention is achieved by the following means. That is,
[1] In a mixed solution containing a raw material fiber having a degree of swelling with respect to water of 0.5 or more and having a crosslinked structure and a carboxyl group, hydrogen peroxide, and a monomer, by polymerizing the monomer in the mixed solution, A method for producing a composite fiber, wherein a polymer is combined with a raw fiber.
[2] The composite fiber according to [1], wherein the raw fiber is a polyacrylic acid-based crosslinked fiber, a maleic anhydride-based crosslinked fiber, an alginate-based crosslinked fiber, or an acrylate-based crosslinked fiber. Manufacturing method.
[3] The material fiber is an acrylate-based crosslinked fiber, and the crosslinked structure of the material fiber is introduced by a nitrogen-containing compound having two or more nitrogen atoms in one molecule. 2] The method for producing a composite fiber according to [2].
[4] A composite fiber obtained by the production method according to any one of [1] to [3].

  According to the production method of the present invention, the polymer in the fiber is obtained by polymerizing the monomer in the mixed solution including the raw fiber having a degree of swelling of 0.5 or more and having a crosslinked structure, hydrogen peroxide, and the monomer. A composite conjugate fiber can be easily obtained, and composite fibers having various functions can be easily obtained by arbitrarily changing the composite polymer.

The present invention is described in detail below.
The raw fiber used in the present invention is required to have a degree of swelling with respect to water of 0.5 or more. When the degree of swelling is less than 0.5, polymerization inside the fiber hardly occurs, and a composite fiber having a sufficient function cannot be obtained. When the degree of swelling is 0.5 or more, many polymers can be combined, and a high function can be imparted to the raw fiber. Therefore, a higher degree of swelling is preferable, but if the degree of swelling is too high, the fiber strength of the raw fiber itself is weakened, and therefore the degree of swelling is preferably 0.5 to 4.5 industrially. Examples of the method for controlling the degree of swelling include a method of changing the content of the crosslinked structure in the raw fiber. Specifically, when ester crosslinking is formed from a carboxyl group and a hydroxyl group, the degree of swelling can be increased by changing the content ratio of the carboxyl group or hydroxyl group contained in the raw fiber or the crosslinking agent, or by changing the treatment temperature or time. Can be controlled. In addition, when cross-linking is introduced into the acrylonitrile fiber by a cross-linking agent, the degree of swelling can be controlled by changing the bath ratio and concentration of the cross-linking agent or the processing temperature and time. In addition, when crosslinking is introduced by heat or electron beam, the degree of swelling can be controlled by changing temperature, electron beam intensity, treatment time, and the like. The degree of swelling can also be controlled by changing the hydrophilicity of the polymer constituting the raw fiber. Specifically, a method of adjusting the ratio between the hydrophilic monomer and the hydrophobic monomer can be mentioned. Alternatively, when a hydrophilic group is introduced by hydrolysis or the like, a method of adjusting the degree of hydrolysis and changing the amount of the hydrophilic group to control the degree of swelling can be mentioned.

  The raw fiber used in the present invention needs to have a crosslinked structure. By having a crosslinked structure, even if the degree of swelling is high, a raw fiber having high fiber strength can be obtained. As the fiber having such a crosslinked structure, a hydrophilic group-containing monomer such as a carboxyl group or an alkali metal base thereof is copolymerized with a hydroxyl group-containing monomer that can react with the carboxyl group to form an ester crosslinked structure, and an ester. After introducing a crosslinked structure into the polyacrylic acid-based crosslinked fiber, maleic anhydride-based crosslinked fiber, alginic acid-based crosslinked fiber, and acrylonitrile-based fiber into which a crosslinking bond has been introduced by a crosslinking agent, the carboxyl group is obtained by hydrolysis. An acrylate-based cross-linked fiber into which is introduced. In particular, acrylate-based crosslinked fibers can be obtained by controlling the crosslinking conditions and hydrolysis conditions with a crosslinking agent, so that fibers having a high degree of swelling and excellent fiber strength can be obtained. Is preferable. As a cross-linking agent for introducing a cross-linked structure into acrylonitrile fiber, any conventionally known cross-linking agent can be used, but the use of a nitrogen-containing compound is effective in the cross-linking reaction and ease of handling. To preferred. This nitrogen-containing compound needs to have two or more nitrogen atoms in one molecule. This is because a crosslinking reaction does not occur when the number of nitrogen atoms in one molecule is less than two. Specific examples of such nitrogen-containing compounds are not particularly limited as long as they can form a crosslinked structure, but amino compounds and hydrazine compounds having two or more primary amino groups are preferred. Examples of amino compounds having two or more primary amino groups include diamine compounds such as ethylenediamine and hexamethylenediamine, diethylenetriamine, 3,3′-iminobis (propylamine), N-methyl-3,3′-iminobis ( Triamine compounds such as propylamine), triethylenetetramine, N, N′-bis (3-aminopropyl) -1,3-propylenediamine, N, N′-bis (3-aminopropyl) -1,4 Examples include tetramine compounds such as butylenediamine, polyamine compounds having two or more primary amino groups such as polyvinylamine and polyallylamine. Examples of the hydrazine-based compound include hydrazine hydrate, hydrazine sulfate, hydrazine hydrochloride, hydrazine bromate, and hydrazine carbonate. The upper limit of the number of nitrogen atoms in one molecule is not particularly limited, but is preferably 12 or less, more preferably 6 or less, and particularly preferably 4 or less. When the number of nitrogen atoms in one molecule exceeds the above upper limit, the cross-linking agent molecule becomes large and it may be difficult to introduce cross-linking into the fiber.

In the method for producing a composite fiber of the present invention, a mixed solution of raw fiber, hydrogen peroxide, and monomer is used. Hydrogen peroxide functions as a polymerization catalyst that forms radicals for activating and polymerizing monomers. In particular, when an acrylate-based crosslinked fiber is used as a raw material fiber, it is thought that a radical is formed by an oxidation-reduction reaction with an amino group present in the raw material fiber, but by using hydrogen peroxide as a polymerization catalyst. Many polymers can be combined with hydrogen peroxide alone. The monomer mixed with the raw fiber may be a monomer that dissolves in water, or a monomer that dissolves in an organic solvent such as alcohols or ethers in which hydrogen peroxide can be dissolved. It is selected accordingly. Examples of monomers include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, hydroxyethyl methacrylic acid and their salts; methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate , (Meth) acrylic acid esters; vinyl halides such as vinyl chloride and vinyl fluoride; vinyl esters such as vinyl acetate, vinyl propionate and vinyl benzoate; vinyl sulfonic acid, p-styrene sulfonic acid, acrylamide t- Unsaturated hydrocarbon sulfonic acids such as butyl sulfonic acid and methallyl sulfonic acid and salts thereof; (meth) acrylamide derivatives such as acrylamide and N-isopropylacrylamide, methacrylamide, N-isopropylmethacrylamide and N, N-dimethylacrylamide ; Unsaturated monomers having a nitrile group such as acrylonitrile and methacrylonitrile; unsaturated ketones such as methyl vinyl ketone and methyl isopropenyl ketone; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; acrylic acid amides and alkyl-substituted products thereof; Examples include styrene such as styrene, α-methylstyrene, and chlorostyrene and alkyl or halogen substituted products thereof; allyl alcohol and esters or ethers thereof; vinyl pyridine; basic compounds such as vinyl imidazole and dimethylaminoethyl methacrylate. it can.

  Moreover, a crosslinkable monomer can also be used as needed. Examples of such crosslinkable monomers include N, N′-methylenebisacrylamide, N, N′-propylenebisacrylamide, di (acrylamidomethyl) ether, 1,2-diacrylamide ethylene glycol, 1,3-diacryloylethylene urea, Bifunctional compounds such as ethylene diacrylate, ethylene glycol dimethacrylate, N, N′-diallyl tartardiamide, N, N′-bisacrylylcystamine, and trifunctionals such as triallyl cyanurate and triallyl isocyanurate Examples are sex compounds.

  The method for preparing the mixed solution is not particularly limited. For example, a method in which a monomer is dissolved in water or an organic solvent or a mixed solution thereof, mixed with raw material fibers, and then hydrogen peroxide is included in the monomer solution. Alternatively, after adding hydrogen peroxide to the monomer solution, a method of mixing the raw material fibers, a method of dispersing the raw material fibers in water or an organic solvent or a mixed solution thereof, and adding hydrogen peroxide and the monomer can be mentioned. . In addition, when using an organic solvent, it is necessary to be an organic solvent in which hydrogen peroxide can be dissolved.

  The amount of the monomer in the mixed solution should be appropriately set according to the amount of the polymer to be combined with the raw material fiber, in other words, the function ability to be imparted to the raw material fiber, and is not particularly limited. If the amount of the polymer to be combined with the fiber is too small, the function that can be imparted is also small. The amount of hydrogen peroxide added varies depending on the type of solvent, the type and concentration of the monomer, and the temperature. Therefore, it cannot be generally stated, but about 0.01 to 50% by weight with respect to the raw fiber is preferably used. . When the amount of hydrogen peroxide added is less than 0.01% by weight, polymerization hardly occurs and it is difficult to combine the polymer with the raw fiber. On the other hand, when it exceeds 50% by weight, polymerization in a solvent is likely to occur, and the composite amount to the raw fiber is reduced.

  In the method for producing a conjugate fiber of the present invention, it is preferable to set the pH to 6.0 or less when the monomer in the mixed solution is polymerized. By setting the pH to 6.0 or lower, polymerization occurs and the polymer is combined in the fiber. In particular, when the pH is 1.0 to 4.0, many polymers are complexed in the fiber, which is industrially preferable. On the other hand, if the pH exceeds 6.0, polymerization inside the fiber hardly occurs, and a composite fiber having a sufficient function may not be obtained. The method for adjusting the pH to 6.0 or lower is not particularly limited as long as the system is pH 6.0 or lower during polymerization by adding an acid or the like. In addition, when reducing acrylate type crosslinked body fiber is used as raw material fiber, it is not necessary to adjust pH. The reduced acrylate-based crosslinked fiber is prepared by reducing the acrylate-based crosslinked fiber with a reducing agent. The reducing agent used in the reduction treatment at this time is not particularly limited, but is selected from the group consisting of hydrosulfite salt, thiosulfate, sulfite, nitrite, thiourea dioxide, ascorbate, and hydrazine compounds. One kind or a combination of two or more kinds can be suitably used. The conditions for the reduction treatment are not particularly limited, and examples include immersing the treated fiber in an aqueous solution having a drug concentration of 0.1 to 5% by weight at a temperature of 50 ° C. to 120 ° C. for 30 minutes to 5 hours. .

  The polymerization temperature is not particularly limited, but by polymerizing at a low temperature and slowing the polymerization rate, more polymer is combined, but if the polymerization rate is too slow, the polymer is not combined efficiently. Therefore, 40-80 degreeC is preferable. Further, the polymerization time varies depending on the polymerization temperature and the monomer concentration, and may be appropriately determined, and is not limited, but is generally industrially preferable from 2 hours to 20 hours.

  Even if the composite fiber obtained by the production method of the present invention is immersed in an acidic solution or an alkaline solution, the composite polymer has a very small dropout amount and is excellent in dropout durability.

  In the production method of the present invention, a composite that is useful in various fields such as daily necessities, medicine, agriculture, civil engineering, industry, etc., by arbitrarily changing the polymer to be combined and combining the polymer having various functions in the fiber. Fiber can be obtained.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited at all by the description of these Examples. Parts and percentages in the examples are on a weight basis unless otherwise indicated. The weight increase rate, the degree of swelling, and the durability of the polymer in the composite fiber falling off were determined by the following methods.

(1) Weight increase rate (%)
The raw material fibers are immersed in water, and an aqueous hydrochloric acid solution is added to adjust the pH of the aqueous solution to 2.0. Thereafter, the raw fiber is taken out from the aqueous hydrochloric acid solution and dried completely, and the weight is measured (X (g)). A composite fiber is produced using the raw fiber and then dried completely, and the weight is set to Y (g). The weight increase rate is expressed by the following formula.
Weight increase rate (%) = {(Y−X) / X} × 100
(2) Degree of swelling The raw fiber is immersed in water, and an aqueous hydrochloric acid solution is added to adjust the pH of the aqueous solution to 2.0. Thereafter, the raw fiber is taken out from the aqueous hydrochloric acid solution, washed with water, put into a centrifuge having a distance from the center to the sample of 11.5 cm, and dehydrated at 1200 rpm for 5 minutes. The weight of the raw fiber after dehydration is measured (Y (g)). Thereafter, the raw fiber is absolutely dried and the weight is measured (X (g)). The degree of swelling is expressed by the following formula.
Swelling degree = (Y−X) / X
(3) Dropout durability of the polymer in the composite fiber The composite fiber is immersed in hydrochloric acid (pH 0.5) at 60 ° C. for 2 hours, then washed with water and dried completely, and the weight is measured (X (g)). The fibers are immersed in an aqueous caustic soda solution (pH 12.5) at 60 ° C. for 1 hour. Then, after dipping in hydrochloric acid (pH 0.5) at 60 ° C. for 2 hours, it is completely dried and the weight is measured (Y (g)). The drop-off durability of the polymer in the composite fiber is represented by the weight retention rate of the following formula. When the weight retention is high, the drop-out durability is high, and when it is low, the drop-out durability is low.
Weight retention (%) = (Y / X) × 100

Example 1
A spinning stock solution obtained by dissolving 10 parts of an acrylonitrile-based polymer composed of 90% acrylonitrile and 10% methyl acrylate in 90 parts of a 48% rhodium soda aqueous solution is spun, drawn and dried according to a conventional method to obtain a 1.7 dTex acrylic fiber. It was.
The acrylic fiber was added to a 15% hydrazine aqueous solution and subjected to a hydrazine crosslinking reaction at 100 ° C. for 4 hours. The obtained crosslinked fiber was washed with water, dehydrated, added to a 5% aqueous sodium hydroxide solution, and subjected to a hydrolysis reaction at 90 ° C. for 2 hours. After washing with water and dehydrating, it was treated in an aqueous solution adjusted to pH 2.0 with hydrochloric acid, washed with water, dehydrated, and dried to produce a raw fiber. The degree of swelling of the raw fiber was 0.8.
0.8 g of the raw fiber was immersed in 50 g of an aqueous solution of sodium p-styrenesulfonate (SPSS) adjusted to pH 2.0 using 1 mol / l hydrochloric acid. The SPSS concentration in the aqueous solution was adjusted to be 417% by weight with respect to the raw fiber. Thereafter, 2.7% by weight of hydrogen peroxide was added to the raw fiber, heated at 60 ° C. for 5 hours, washed with water, dehydrated and dried to obtain the composite fiber of the present invention.
The weight increase rate of the composite fiber was measured and found to be 74%. With regard to the drop-off durability, the weight retention rate was 99.7%, and the composite fiber with high drop-off durability with which the polymer in the fiber hardly dropped off. there were.

(Example 2)
Raw material fibers were produced in the same manner as in Example 1 except that the hydrazine crosslinking reaction time in the hydrazine aqueous solution was 5 hours. The swelling degree of the raw fiber was 0.6. A composite fiber was produced in the same manner as in Example 1 except that the raw material fiber was used. As a result, the weight increase rate was 48.4% and the weight retention rate was 99.7% with respect to the drop-off durability.

(Example 3)
The acrylic fiber obtained in Example 1 was added to a 30% aqueous hydrazine solution and treated at 98 ° C. for 2 hours, then 50% dimethylaminopropylamine was treated at 98 ° C. for 120 hours, and finally 10% caustic soda was added. Treated at 98 ° C. for 24 hours. The fiber was washed with water, dehydrated, and dried to produce a raw fiber. The swelling degree of the raw fiber was 1.0. A composite fiber was produced in the same manner as in Example 1 except that the raw material fiber was used. As a result, the weight increase rate was 40.9%, and the drop-off durability was 99.7%.

Example 4
A composite fiber was produced in the same manner as in Example 1 except that N-isopropylacrylamide was used instead of SPSS. As a result, the weight increase rate was 75.4%, and the drop-off durability was 99.7%.

(Example 5)
1.0 g of the raw material fiber obtained in Example 1 was immersed in 50 g of a 0.5% aqueous thiourea dioxide solution having a pH of 7, subjected to reduction treatment at 80 ° C. for 1 hour, washed with water and dehydrated to obtain a reduced acrylate-based crosslinked fiber. Produced. The degree of swelling of this reduced acrylate-based crosslinked fiber was 0.8. Thereafter, a composite fiber of the present invention was obtained in the same manner as in Example 1 except that it was immersed in an aqueous solution of sodium p-styrenesulfonate without adjusting the pH. The pH at the time of polymerization was 7.5. When the weight increase rate of the obtained composite fiber was measured, it was 73%, and regarding the drop-off durability, the weight retention rate was 99.5%.

(Example 6)
The acrylic fiber obtained in Example 1 was added to a 15% N-methyl-3,3′-iminobis (propylamine) aqueous solution, and a crosslinking reaction was performed at 115 ° C. for 8 hours. The obtained crosslinked fiber was washed with water, dehydrated, added to a 3% aqueous sodium hydroxide solution, and subjected to a hydrolysis reaction at 95 ° C. for 2 hours. After washing with water and dehydrating, it was treated in an aqueous solution adjusted to pH 2.0 with hydrochloric acid, washed with water, dehydrated, and dried to produce a raw fiber. The degree of swelling of the raw fiber was 1.0.
1.0 g of the raw fiber was immersed in 50 g of an SPSS aqueous solution adjusted to pH 2.0 using 1 mol / l hydrochloric acid. The SPSS concentration in the aqueous solution was adjusted to 325% by weight with respect to the raw fiber. Thereafter, 2.7% by weight of hydrogen peroxide was added to the raw fiber, heated at 60 ° C. for 24 hours, washed with water, dehydrated and dried to obtain the composite fiber of the present invention.
The weight increase rate of the composite fiber was measured and found to be 65%. With respect to the drop-off durability, the weight retention rate was 99.9%, and the composite fiber with high drop-off durability in which almost no polymer in the fiber dropped off. there were.

(Example 7)
Raw material fibers were prepared in the same manner as in Example 6 except that 3,3′-iminobis (propylamine) was used instead of N-methyl-3,3′-iminobis (propylamine). . The swelling degree of the raw fiber was 1.3.
A composite fiber was obtained in the same manner as in Example 6 except that the raw material fiber was used. The weight increase rate of the composite fiber was measured and found to be 82%. With respect to the drop-off durability, the weight retention rate was 99.9%, and the composite fiber having high drop-off durability in which most of the polymer in the fiber does not drop off. Met.

(Example 8)
Raw material fibers were produced in the same manner as in Example 6 except that ethylenediamine was used for the crosslinking reaction instead of using N-methyl-3,3′-iminobis (propylamine). The degree of swelling of the raw fiber was 0.8.
A composite fiber was obtained in the same manner as in Example 6 except that the raw material fiber was used. The weight increase rate of the composite fiber was measured and found to be 50%. With regard to the dropout durability, the weight retention rate was 99.9%, and the composite fiber having high dropout durability in which most of the polymer in the fiber does not drop off Met.

(Comparative Example 1)
The swelling degree of the acrylic fiber obtained in Example 1 was 0.3. A composite fiber was produced in the same manner as in Example 1 except that the acrylic fiber was used as a raw material fiber as it was without performing a crosslinking reaction and a hydrolysis reaction. As a result, there was no weight increase and composite fibers could not be produced.

(Comparative Example 2)
The acrylic fiber obtained in Example 1 was added to a 15% hydrazine aqueous solution and subjected to a hydrazine crosslinking reaction at 98 ° C. for 3 hours, but no hydrolysis reaction was performed. The degree of swelling of this fiber was 0.4. A composite fiber was produced in the same manner as in Example 1 except that the fiber was used as a raw material fiber. As a result, there was no weight increase and composite fibers could not be produced.

Claims (4)

  In a mixed solution containing a raw material fiber having a degree of swelling with respect to water of 0.5 or more and having a crosslinked structure and a carboxyl group, hydrogen peroxide, and a monomer, the monomer in the mixed solution is polymerized to form a raw material fiber. A method for producing a composite fiber, comprising combining a polymer.   2. The method for producing a composite fiber according to claim 1, wherein the raw fiber is a polyacrylic acid-based crosslinked fiber, a maleic anhydride-based crosslinked fiber, an alginic acid-based crosslinked fiber, or an acrylate-based crosslinked fiber.   The raw material fiber is an acrylate-based crosslinked fiber, and the crosslinked structure of the raw material fiber is introduced by a nitrogen-containing compound having two or more nitrogen atoms in one molecule. Manufacturing method of composite fiber.   The composite fiber obtained by the manufacturing method as described in any one of Claims 1-3.