JPH06192963A - Method for modifying cellulosic fiber - Google Patents

Abstract

PURPOSE:To obtain modified cellulosic fiber by efficiently and economically subjecting cellulosic fiber to the graft copolymerization in an aqueous solution system. CONSTITUTION:This method for modifying cellulosic fiber is characterized by subjecting cellulosic fiber in which mercapto group is previously introduced thereinto to the graft copolymerization with a vinyl compound.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for modifying cellulose fibers.

[0002]

2. Description of the Related Art Conventionally, carboxymethylation, cyanoethylation, carbamoylethylation, etc. for improving the dyeing properties of cellulose fibers, physical properties such as heat resistance and microbial resistance, and imparting cation exchangeability. It is known to carry out the reaction treatment of. However, these reaction methods are
There are still problems in terms of reaction treatment efficiency and reactor efficiency. Further, in order to modify the cellulose fiber, it has been attempted to graft-copolymerize a vinyl compound with the cellulose fiber. For example, in order to improve the wrinkle resistance of the cellulose fibers, it has been proposed to graft-copolymerize acrylonitrile onto the cellulose fibers in a gas phase system. However, since this method is a gas phase system,
There is a drawback that the reaction device becomes large and the device efficiency is low. On the other hand, even if an attempt is made to graft-copolymerize a vinyl compound to cellulose fibers in an aqueous solution system, in this case, it is difficult to smoothly proceed the reaction, and the use of a usual oxidizer system or redox system polymerization initiator. Then, the graft copolymerization does not proceed sufficiently, and a practical graft copolymer cannot be obtained. As a method of graft-copolymerizing a vinyl compound with a high reaction rate on a cellulose fiber in an aqueous solution system, a method of using a cerium (IV) compound as a polymerization initiator and a method of performing a reaction under radiation are known. However, none of these methods are industrially practical because of high product cost.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for obtaining a modified cellulose fiber by efficiently and economically graft-copolymerizing a vinyl compound with cellulose fiber in an aqueous solution system.

[0004]

The present inventors have completed the present invention as a result of intensive studies to solve the above problems. That is, according to the present invention, there is provided a method for modifying a cellulose fiber, which comprises graft-copolymerizing a vinyl compound onto a cellulose fiber having a mercapto group introduced in advance.

The cellulose fiber used in the present invention can be various cellulose-containing fibers such as cotton and hemp, and the shape thereof can be thread-like, cotton-like, cloth-like, tow-like or non-woven-like. Further, other fibers may be mixed with the cellulose fiber.

In the present invention, a mercapto group is introduced into the cellulose fiber in advance before carrying out the graft copolymerization reaction step. As a method for this, a conventionally known method, for example, a silane coupling agent containing a mercapto group, a titanate coupling agent, an aluminum coupling agent or the like is used as a mercapto group-introducing agent, which is used in a cellulose fiber. Can be used. These coupling agents are
It is composed of a metal portion having a mercapto group in its molecule and a reactive active group such as an alkoxy group or an ester group as a coupling reactive group, and the metal portion has a property of reacting with active hydrogen such as a hydroxyl group. . Such coupling agents are conventionally known. In the present invention, the general formula HS-R ¹ -Si (In the formula, R ¹ represents an alkylene group, an R ² is an alkyl group) (OR ²⁾ ₃
A silane coupling agent represented by is preferably used. Examples of such a silane coupling agent include γ-mercaptopropyltrimethoxysilane.

In order to react the mercapto group-containing coupling agent with the cellulose fiber, the cellulose fiber may be soaked in a reaction solvent containing the coupling agent and reacted. An aqueous medium or an organic solvent is used as the reaction solvent, and water or a mixture of water and an organic solvent is used as the aqueous medium. As the organic solvent, alcohol such as isopropyl alcohol or aromatic solvent such as xylene or benzene is used. The reaction is usually carried out under heating at 50 ° C. or higher, and the upper limit of the reaction temperature is determined according to the boiling point of the reaction solvent used. When water is used as the reaction solvent, a temperature of 50 to 100 ° C., preferably 80 to 100 ° C. is adopted. The concentration of the coupling agent in the reaction solvent is 0.015 to 0.08 mol / l, preferably 0.0
It is 3 to 0.05 mol / l. In addition, in the reaction solvent,
An appropriate amount of acid such as sulfuric acid, hydrochloric acid, phosphoric acid, or formic acid can be added, whereby the reaction between the coupling agent and the hydroxyl group contained in the cellulose fiber can be promoted. The proportion of the coupling agent used is 0.01 to 0.06 mol, preferably 0.02, per 100 g of the cellulose fiber.
˜0.04 mol. By introducing the mercapto group into the cellulose fiber at such a ratio, the ratio of the mercapto group capable of smoothly grafting the vinyl compound in the subsequent graft copolymerization reaction step is 0.005 to 0.015 mol per 100 g of the fiber. It is possible to obtain the cellulose fiber containing.

In the present invention, the vinyl compound is graft-copolymerized with the mercapto group-introduced cellulose fiber as described above in an aqueous solution containing a catalyst.
As the catalyst, a conventionally known graft copolymerization catalyst, for example, an oxidizing agent such as persulfate or hydrogen peroxide can be used. The mercapto group introduced into the fiber acts as a reducing agent,
The combination of these oxidizers and mercapto groups constitutes a redox catalyst and accelerates the graft copolymerization reaction of the vinyl compound with the cellulose fibers. The redox-based catalyst is composed of a combination of an oxidizing agent and a regenerating agent,
In the present invention, since the mercapto group introduced into the fiber acts as a reducing agent, it is not particularly necessary to add a reducing agent from the outside, but of course, if necessary, a conventionally known reducing agent, for example, Iron (II) salt and the like can also be added.

If necessary, an acid can be added to the aqueous solution. By adding this acid, the reaction rate (grafting rate) of the vinyl compound can be improved. Examples of the acid include sulfuric acid and hydrochloric acid.
The acid concentration in the aqueous solution is 0.01 to 0.04 mol / l, preferably 0.01 to 0.02 mol / l. further,
A conventionally known sequestering agent, for example, a phosphoric acid-based or phosphonic-acid-based one, EDTA, NTA, or the like can be added to this aqueous solution. The weight ratio (bath ratio) of the aqueous solution to the cellulose fiber (absolute dry weight) is 3 to 30, preferably 5 to 15. The reaction temperature is 50 to 100 ° C., preferably 60 to 80 ° C., and the reaction time is 60 to 180.
Minutes, preferably 60 to 120 minutes. The use ratio of the vinyl compound used in the present invention is 10 to 100 parts by weight with respect to 100 parts by weight of cellulose fiber (excess dry weight),
It is preferably 10 to 30 parts by weight. If the proportion of the vinyl compound used is less than this, a sufficient fiber-modifying effect due to the vinyl compound cannot be obtained, while if it exceeds the above range, there is no particular improvement in the modifying effect, which is economically disadvantageous. Become.

In the modified cellulose fiber obtained in the present invention, the grafting ratio of vinyl compound (reaction weight ratio of vinyl compound to cellulose fiber) is 5 to 30% by weight, preferably 5 to 15% by weight. Even if the grafting ratio exceeds the above range, a remarkable improvement of the fiber modifying effect cannot be obtained. On the other hand, if the grafting ratio is less than the above range, a practically sufficient fiber modifying effect cannot be obtained. The grafting ratio can be adjusted by the ratio of the vinyl compound used to the fibers and the reaction conditions. Various vinyl compounds can be used in the present invention. As such, acrylonitrile, acrylamide, acrylic acid and its ester, methacrylic acid and its ester,
Examples include styrene and the like.

[0011]

According to the present invention, it is possible to smoothly and economically carry out the graft copolymerization reaction of a vinyl compound on cellulose fibers, which has been difficult in the past. The cellulose fiber thus modified with a vinyl compound generally has improved physical properties such as wrinkle resistance, heat resistance, and abrasion resistance. Further, the fiber modified with a vinyl compound having an acidic group such as a carboxyl group has excellent adsorptivity to basic malodorous substances such as ammonia and amine, and exhibits an action as a deodorizing fiber.

[0012]

EXAMPLES Next, the present invention will be described in more detail by way of examples.
In addition,% shown below shows weight%.

Example 1 Aqueous solution 1 containing 0.7% of 3-mercaptopropyltrimethoxysilane as a silane coupling agent and 0.3% of a surfactant (Tripon A, manufactured by Yatsusha Yushi Kogyo Co., Ltd.).
Immerse 10 g of scoured cotton in 50 ml and
It was treated at ° C for 1 hour. The cotton treated in this manner was washed with hot water and water to remove unreacted materials, and then dried. Next, this cotton was immersed in 150 ml of an aqueous solution containing 1.3% methacrylic acid, 0.3% ammonium persulfate and 0.3% sulfuric acid (50 ° Be ′), and treated at 80 ° C. for 2 hours. Monomers and homopolymers were removed by washing with hot water and dried. The grafting rate of the treated cotton thus obtained was 9.5%.

Example 2 0.7% 3-mercaptopropyltrimethoxysilane,
Trypon A 0.3% and sulfuric acid (50 ° Be ') 0.3%
10 g of the scoured cotton yarn was dipped in 150 ml of an aqueous solution containing and treated at 80 ° C. for 1 hour to obtain a cotton yarn treated with a coupling agent. After washing with hot water and without drying, methacrylic acid 1.3%, ammonium persulfate 0.3%, sulfuric acid (50%
° Be ') immersed in 150 ml of an aqueous solution containing 0.3%,
It was treated at 80 ° C. for 2 hours. It is washed with hot water and water to remove the monomer and homopolymer, and dried. The grafting ratio of the obtained cotton yarn was 10.2%.

Example 3 0.7% of 3-mercaptopropyltrimethoxysilane,
Trypon A 0.3% and sulfuric acid (50 ° Be ') 0.3%
The cotton yarn is dipped in 150 ml of an aqueous solution containing the above and treated at 80 ° C. for 1 hour. After washing with hot water and water to remove unreacted substances, acrylonitrile 1.5%, surfactant (Neugen HC, manufactured by Dai-ichi Kogyo Seiyaku) 0.3%, and ammonium persulfate 0.3% without drying. It was immersed in 150 ml of an aqueous solution containing it and treated at 80 ° C. for 2 hours in a nitrogen atmosphere.
Wash with methanol, then with a nonionic activator, wash with hot water, wash with water and dry. The grafting rate of the obtained cotton yarn is 8.8%.
Met.

Example 4 3-mercaptopropyltrimethoxysilane 0.7%,
Aqueous solution containing Trypon A 0.3% and sulfuric acid 0.3% 15
Immerse the purified rayon yarn in 0 ml and stir at 80 ° C for 1
After the time treatment, it was washed with hot water, washed with water and dipped in 150 ml of an aqueous solution containing 1.3% methacrylic acid, 0.3% ammonium persulfate and 0.3% sulfuric acid (50 ° Be ') without drying. It was treated at 80 ° C. for 2 hours. It is washed with hot water and water to remove the monomer and homopolymer, and dried. The grafting rate of the obtained rayon yarn was 8.5%.

Example 5 A grafted hemp was obtained in the same manner as in Example 4, except that the rayon yarn was changed to hemp (ramie sliver). The graft ratio of this product was 7.3%.

Example 6 A cotton thread was made of 5-mercaptopropyltrimethoxysilane 5
% Xylene solution at room temperature for 30 minutes, then squeezed to a solution content of 100% and cured at 100 ° C. for 1 hour. It was washed with ethanol and then with water to obtain a raw material for graft copolymerization. Then, an aqueous solution containing 5% methacrylic acid and 0.3% ammonium persulfate was taken in an amount 10 times the weight of the cotton yarn, and the cotton yarn obtained above was dipped in this aqueous solution and graft-copolymerized at 70 ° C. for 1 hour. I went. It was washed with hot water, washed with water and dried. The grafting ratio of this cotton yarn was 6.1%.

Example 7 In a mixed solvent of isopropyl alcohol (IPA) and water, 1% of 3-mercaptopropyltrimethoxysilane,
After immersing 10 g of each scoured cotton thread in 200 ml of a solution containing 1% of hydrochloric acid (35%) and treating at 50 ° C. for 1 hour,
It was washed with hot water and water. 10 g of this mercapto group-containing cotton yarn
It was immersed in 150 ml of an aqueous solution containing 5% methacrylic acid and 0.27% potassium persulfate, treated at 70 ° C. for 1 hour, washed with hot water, washed with water and dried. The grafting rate of the cotton yarn thus obtained is shown in Table 1.

[0020]

[Table 1]

Comparative Example 1 In Example 1, cotton cotton was directly subjected to graft copolymerization treatment without being treated with a silane coupling agent. The grafting rate of the cotton obtained in this case was 0.77%.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location D06M 13/513

Claims (1)

[Claims] 1. A method for modifying a cellulose fiber, which comprises graft-copolymerizing a vinyl compound onto a cellulose fiber having a mercapto group introduced in advance.