JPH09143875A - Modified polyester-based fabric and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyester-based fabric of hydrophilic nature without deterioration of physical properties as fiber, such as mechanical strength, by weaving polyester-based multi-filament yarns which contain several kinds of single fibers differing in rates of graft polymerization of a hydrophilic vinyl monomer from one another. SOLUTION: This method for producing the subject hydrophilic polyester fabric comprises graft-polymerizing a hydrophilic vinyl monomer such as methacrylic acid to polyester-based fibers, forming polyester-based multi-filament yarns composed of two kinds of single fibers different in graft ratios by 5% to 50% from each other by arranging polyester-based single fiber of higher rate of graft polymerization of 10-50% in core portion and polyester-based single fibers of lower rate of graft polymerization of 0-10% in sheath portion, weaving the multi-filament yarns thus prepared as warps and wefts to obtain a hydrophilic polyester fabric, applying the hydrophilic vinyl monomer to this fabric, and heat-treating the fabric to effect graft polymerization of the monomer to the fabric.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester cloth composed of polyester fibers modified by a graft polymerization process while suppressing deterioration of physical properties inherent in a fiber material, and a method for producing the same.

[0002]

2. Description of the Related Art A method for modifying a synthetic fiber by graft-polymerizing a hydrophilic vinyl monomer is disclosed in JP-B-59-5126.
JP, JP-A-51-87592, JP-A-62-
It is disclosed in Japanese Patent Publication No. 199875.

JP-B-59-5126, JP-A-51
The method described in Japanese Patent No. 87592 relates to graft polymerization by heating in a bath. In this graft polymerization method in the bath, a large amount of unreacted monomer remains, the graft efficiency is low, and in addition, there is a problem of contamination of the processing machine by homopolymer generated in a large amount in the bath and wastewater contamination. Further, the immersion heating method in the bath usually requires a processing time of about 2 hours in the coexistence of the fiber swelling agent at a processing temperature of 100 ° C. or higher, including a heating process. In the modified polyester fiber thus obtained, the hydrophilic vinyl monomer almost completely penetrates into the fiber, similar to the diffusion of the dye into the fiber during dyeing, and the whole is uniformly modified. As a result, the modified polyester fiber cannot maintain the original physical properties of the polyester fiber even if it is modified by graft polymerization, resulting in reduced strength, poor dimensional stability, and process shrinkage. There is also a problem of increase.

On the other hand, Japanese Patent Laid-Open No. 62-199875 proposes a method in which only the surface layer of polyester fiber is modified by graft polymerization and the inside of the fiber is not modified in order to solve the above-mentioned problems. ing.

However, in order to modify only the surface layer of the fiber, it is necessary to manage advanced processing conditions for controlling the modification depth from the surface layer of the fiber, and to process the monofilament of polyester fiber. Depending on the fineness, it was impossible to do such processing.

[0006]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art and suppresses the deterioration of the physical properties originally possessed by the polyester fiber material in the polyester fabric modified by graft polymerization. An object of the present invention is to provide a modified polyester-based fabric that exhibits a modification effect such as hydrophilicity by a graft polymerization process, and a method for producing the same.

[0007]

To achieve the above object, the modified polyester fabric of the present invention has the following constitution.

[0008] That is, a modified polyester-based cloth characterized by comprising two or more kinds of polyester-based fibers having different graft polymerization rates in a cloth made of polyester-based fibers graft-polymerized with a hydrophilic vinyl monomer. Is.

A modified polyester fabric, characterized in that, as the polyester fiber, a polyester multifilament yarn composed of two or more kinds of single fibers having different graft polymerization rates is used, preferably a grafted polyester fabric. A modified polyester fabric characterized by comprising a polyester multifilament yarn in which polyester single fibers having a high polymerization rate are arranged in a core portion, and polyester fibers having a low graft polymerization rate are arranged in a sheath portion. is there.

Further, preferably, as the polyester fiber, a polyester fiber having a graft polymerization rate of 10 to 50% and a polyester fiber having a graft polymerization rate of 0 to 10% are used. Quality polyester cloth.

Still more preferably, the polyester fibers have a graft polymerization rate difference of 5% or more and 50% or more.
A modified polyester-based fabric comprising the following two types of polyester-based fibers having different graft polymerization rates.

The method for producing a modified polyester fabric of the present invention has the following constitution.

That is, it is a method for producing a modified polyester cloth, which comprises applying a hydrophilic vinyl monomer to a cloth made of two or more kinds of polyester fibers having different grafting efficiencies and then heat-treating the cloth.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The polyester fiber as used in the present invention is not particularly limited as long as it is a fiber made of polyester, and examples thereof include polyalkylene terephthalate fibers such as polyethylene terephthalate fiber and polybutylene terephthalate fiber, or these. It includes a fiber made of a modified polymer or a fiber obtained by mixing these fibers, and includes fibers having various shapes and cross-sectional shapes.
Further, in the modified polyester fabric of the present invention, natural fibers may be used in combination with the above polyester fibers.

The hydrophilic vinyl monomer referred to in the present invention is
A compound containing at least one polymerizable unsaturated group, the polymer being more hydrophilic than the polymer constituting the fiber to be treated. The molecular weight is not particularly limited. Specific examples thereof include unsaturated carboxylic acids such as acrylic acid, methacrylic acid and maleic acid, unsaturated amides such as acrylamide and N-vinylpyrrolidone, unsaturated sulfonic acid compounds such as vinylsulfonic acid and styrenesulfonic acid. Examples include various unsaturated compounds. Further, derivatives of these monomers, for example, polyethylene glycol monoacrylate obtained by adding ethylene oxide to the above-mentioned monomer, acrylamide ethylene oxide adduct, and the like can also be used. Among these, particularly preferred compounds are acrylic acid, methacrylic acid and their derivatives. These may be used alone or in combination of two or more.

The modified polyester fabric of the present invention is required to use two or more types of polyester fibers having different graft polymerization rates. The graft polymerization rate as used herein is represented by the rate of increase in weight with respect to the weight of the fiber before graft processing.

In the modified polyester fabric of the present invention, when the polyester fiber having a graft polymerization rate of 10 to 50% and the polyester fiber having a graft polymerization rate of 0 to 10% are used, the effect of the present invention is remarkable. It is preferable because it can be obtained.

The higher the graft polymerization rate, the lower the strength of the polyester fiber. On the other hand, the lower the graft polymerization rate, the lower the modifying effect. In the modified polyester cloth of the present invention, the graft polymerization rate Since two or more different polyester fibers are used, the lower graft polymerization rate of the polyester fibers is mainly used to prevent the strength of the fabric from being lowered, and the higher graft polymerization rate of the polyester fibers is mainly used for the fabric. A reforming effect can be exhibited. From such a viewpoint, in the modified polyester cloth of the present invention, the difference in graft polymerization rate is 5
% Or more and 50% or less, it is preferable to include two types of polyester fibers having different graft polymerization rates.

The following are examples of the effect of modifying the hydrophilic vinyl polymer by graft polymerization. When methacrylic acid is graft-polymerized on the polyester fiber, it has an effect of deodorizing bad odors such as ammonia odor and trimethylamine odor. Further, when the graft polymer is treated with soda ash and hydrogen of the carboxylic acid of the methacrylic acid graft copolymer is replaced with sodium, hygroscopicity can be imparted. When a sodium-substituted product is treated with zinc sulfate, sodium is replaced with zinc, and a deodorizing effect on ammonia, hydrogen sulfide, trimethylamine and methyl mercaptan odor can be imparted.

The mixed fiber ratio of the lower graft polymerization rate polyester fiber and the higher graft polymerization rate polyester fiber can be set according to the target performance, but from the viewpoint of preventing a decrease in strength. The mixing ratio of the polyester fiber having the higher graft polymerization rate in the fabric is preferably 50% by weight or less.

The modified polyester fabric of the present invention may be in any form such as knit, woven fabric or nonwoven fabric as long as it uses polyester fibers having different graft polymerization rates.
In the modified polyester fabric of the present invention, other fibers such as natural fibers may be used in combination with the above polyester fibers.

Next, the method for producing the modified polyester fabric of the present invention will be described.

A fabric is prepared by using two or more kinds of polyester fibers having different grafting efficiency, that is, at least one kind of polyester fiber and a polyester fiber having a relatively higher grafting efficiency than that kind of polyester fiber. By doing so, the modified polyester fabric of the present invention can be obtained. Any combination of polyester fibers can be used as long as they have different grafting efficiencies. The term "graft efficiency" as used herein means the degree to which graft polymerization of hydrophilic vinyl monomers onto fibers occurs under predetermined conditions, and the higher the graft efficiency, the easier the graft polymerization.

As the polyester fiber having a higher grafting efficiency, for example, a fiber made of a cationic dye-dyeable polyester obtained by copolymerizing a sulfonated aromatic dicarboxylic acid, or a fiber having a lower draw ratio than usual and a lower degree of orientation. A fiber made of polyethylene terephthalate may, for example, be mentioned.

On the other hand, as the polyester fiber having a grafting efficiency lower than that of the above fiber, a fiber made of polyethylene terephthalate, especially a polyethylene terephthalate fiber having a slightly higher draw ratio than usual and a higher degree of orientation is preferably used.

As the polyester fibers having different grafting efficiency, two or more kinds of polyester filaments having different grafting efficiency are air-processed, mixed or twisted into a single multifilament to obtain a polyester multifilament yarn. A thread can be used to make a fabric. In this case, when yarns with high grafting efficiency are arranged in the core part and fibers with low graft polymerization rate are arranged in the sheath part at the stage of making multifilaments, the texture and touch surface of the fabric, and further the strength decrease after grafting Is preferable because it can be suppressed.

The modified polyester fabric of the present invention can also be obtained by alternately arranging polyester fibers having different grafting efficiencies at the stage of forming the fabric by weaving, knitting or the like.

[0028] A modified polyester-based cloth is obtained by directly applying a solution containing a high concentration of a hydrophilic vinyl monomer to a cloth formed of two or more kinds of polyester-based fibers having different grafting efficiencies and heat-treating it to carry out a graft polymerization process. Can be obtained. The heat treatment is preferably performed in a short time to complete the graft polymerization reaction. As a preferred method of applying the solution, for example, padding, spraying,
A centrifugal dehydration method after immersion may be used, and the method is appropriately selected depending on conditions such as the form of the object to be treated and the degree of modification. Also,
As the heating method, steam heating, dry heating heating, hot air heating, infrared heating, high frequency dielectric heating, heating by microwaves or high frequencies, etc. can be adopted, but a heating method using both microwaves or high frequencies and steam is preferable.

[0029]

EXAMPLES The present invention will be described in more detail below with reference to examples.

The evaluation items in the examples were measured as follows.

(1) Moisture absorption rate A sample was placed in a weighing bottle and dried at 110 ° C for 2 hours, and then a dry weight W _{0 of the} sample was obtained. Then, the sample was placed in a desiccator containing a saturated aqueous solution of sodium nitrite at 20 ° C for 24 hours. After standing, the weight W ₁ is measured. Weight increase rate (%) at that time
That is, 100 × (W ₁ −W ₀ ) / W ₀ is the moisture absorption rate (%).

(2) Graft Polymerization Rate The rate of increase in the weight W ₁₁ after grafting (after washing with hot water and drying) relative to the weight W ₁₀ of the fabric before processing, that is,
Graft polymerization rate (%) of 100 × (W ₁₁ −W ₁₀ ) / W ₁₀
And

(3) Tear tenacity retention rate The tear tenacity retention rate was calculated according to JIS-L-1096 "General woven fabric test method" (Pendulum method), and the tear tenacity retention rate was calculated based on the relaxed and refined raw cloth. .

Example 1 1 g of organic peroxide (NIPPER BMT.K40 manufactured by NOF CORPORATION) as a graft polymerization initiator, 30 g of methacrylic acid as a hydrophilic vinyl monomer, a quaternary ammonium salt type surfactant (Daiichi Kogyo Co., Ltd. ) CATIOGEN AN Super)
5 g was diluted with water to prepare 100 g of an aqueous mixed solution.

Next, polyethylene terephthalate fibers (75 denier 36 filaments), cation dyeable polyester fibers (50 denier 36 filaments, 1.7 mol% dimethyl 5-sodium sulfoisophthalate, 1.7 mol% and polyethylene glycol) of relaxed scouring and drying were used. A satin woven fabric made of vertical and weft yarns made of a mixed fiber made of polyester (copolymerized with polyethylene terephthalate of 1% by weight (molecular weight 1000)) is dipped in the above water-based mixture, squeezed with a mangle, and rolled. It was wound up on a glass and then sealed with a vinylidene chloride film. The pickup rate at this time was 6 with respect to the weight of the dried knitted fabric.
2%.

Next, the sealed knitted fabric was put into a microwave treatment device (Apollopet made by Ichikin), heated and irradiated with steam at 100 ° C. for 10 minutes in a microwave, washed with hot water and dried, and the initial dry knitted fabric weight was obtained. The weight increase rate was calculated.

This is taken as the graft polymerization rate of the entire fabric, and the woven yarn is decomposed to similarly give the graft polymerization rate of the regular polyester (low graft fiber) and the graft polymerization rate of the cationic dyeable polyester (high graft fiber). I asked.

Then, a dry heat treatment was carried out at 180 ° C. for 30 seconds using a dry heat treatment machine (hot air type pin tenter manufactured by Saikai Dyeing Industry Co., Ltd.).

Next, an aqueous solution of 10 g / l of soda ash was adjusted to a bath ratio of 1:30, and immersion heat treatment was performed at 60 ° C. for 30 minutes. Then washed with water, dried, with a vertical density of 125 lines / in and a horizontal density of 75 lines / in, with different graft polymerization rates 2
A woven fabric composed of various kinds of fibers was obtained, and the moisture absorption rate and the tear strength retention rate were measured. Table 1 shows the results.

Comparative Example 1 A satin fabric woven in the same manner as in Example 1 was used, using a mixed yarn in which polyethylene terephthalate fiber having 75 denier 36 filaments and polyethylene terephthalate fiber having 50 denier 24 filaments were mixed and woven. It processed similarly and evaluated. Table 1 shows the results.

COMPARATIVE EXAMPLE 2 75 denier 36 filaments of cationic dyeable polyester fiber having the same composition as used in Example 1 and 5
A satin fabric woven in the same manner as in Example 1 was used by using a mixed yarn in which two types of cationic dyeable polyester having 0 denier 36 filaments were mixed and woven, and processed and evaluated in the same manner as in Example 1. Table 1 shows the results.

[0042]

[Table 1] As shown in Table 1, the modified polyester fabric according to the present invention (Example 1) had a high tenacity retention rate and a high moisture absorption rate, and was excellent in practicality. On the other hand, the fabric according to Comparative Example 1 had a high tear strength retention rate but a low moisture absorption rate, and the fabric according to Comparative Example 2 had a high moisture absorption rate but a low tear strength retention rate.

[0043]

By comparing the conventional modified fiber having the same hydrophilic performance with the modified fiber of the present invention, the present invention shows that the fiber having a low graft polymerization rate has a high graft polymerization rate while suppressing the deterioration of the fiber physical properties. The modified polyester fiber can suppress the deterioration of fiber properties such as tenacity as a fabric structure because of its modified property.

Claims (6)

[Claims] 1. A modified polyester fabric comprising a polyester fiber in which a hydrophilic vinyl monomer is graft-polymerized, wherein two or more types of polyester fibers having different graft polymerization rates are used. . 2. The modified polyester fabric according to claim 1, wherein a polyester multifilament yarn composed of two or more kinds of single fibers having different graft polymerization rates is used as the polyester fiber. 3. A polyester multifilament yarn in which polyester single fibers having a high graft polymerization rate are arranged in a core portion and polyester fibers having a low graft polymerization rate are arranged in a sheath portion are used as the polyester fibers. The modified polyester fabric according to claim 2, wherein 4. A polyester fiber having a graft polymerization rate of 10 to 50% and a polyester fiber having a graft polymerization rate of 0 to 10% are used as the polyester fiber. Modified polyester fabric. 5. The modified fiber according to claim 1, wherein the polyester fiber includes two types of polyester fibers having different graft polymerization rates of 5% or more and 50% or less. Polyester cloth. 6. A method for producing a modified polyester cloth, which comprises applying a hydrophilic vinyl monomer to a cloth made of two or more kinds of polyester fibers having different grafting efficiencies and then heat-treating the cloth.