JPH0770818A - Flame-retardant acrylic fiber and flame-retardant fiber composite produced therefrom - Google Patents

Abstract

PURPOSE:To obtain a flame-retardant acrylic fiber having high flame retardancy and mechanical properties such as excellent spinnability and excellent workability and a flame-retardant fiber composite produced therefrom. CONSTITUTION:A fiber composed of (A) 40 to 90 pts.wt. acrylonitrile-based polymer copolymerized by using 30 to 50wt.% vinyl chloride and/or vinylidene chloride, (B) 30 to 5 pts.wt. antimony compound and (C) 30 to 5 pts.wt. polymer having :50wt.% halogen content and a composite composed of another fiber and this.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a flame-retardant acrylic fiber and a flame-retardant fiber composite containing the flame-retardant acrylic fiber.

[0002]

2. Description of the Related Art As a method for imparting flame retardancy to acrylic fibers, a flame retardant monomer such as vinyl chloride, vinylidene chloride, vinyl bromide or vinylidene bromide is copolymerized with acrylonitrile to form a base polymer itself of acrylic fibers. Various methods for making flame retardant are known and commercialized. Further, when high flame retardancy is required, a method of adding a flame retardant such as antimony trioxide or antimony pentoxide to the base polymer is also known.

For example, a method of copolymerizing a flame retardant monomer and adding a flame retardant is disclosed in JP-A-63-126913, JP-A-61-89339 and JP-A-5-78.
As disclosed in Japanese Patent Publication No. 936, it is difficult to add a large amount of antimony pentoxide to obtain high flame retardancy. Addition of a large amount of antimony trioxide satisfies both high flame retardancy and mechanical properties. There is a problem that acrylic fiber cannot be obtained.

[0004]

DISCLOSURE OF THE INVENTION In order to impart a high degree of flame retardancy to acrylic fibers, the present invention provides copolymerization of a flame retardant monomer with a base polymer, the use of a flame retardant which can be added in a large amount, and a flame retardant. The combined use of a flammable polymer solves the problems in the prior art. That is, an object of the present invention is to provide a flame-retardant acrylic fiber and a flame-retardant fiber composite thereof having a high degree of flame retardancy and having mechanical properties with good spinnability and processability.

[0005]

According to the present invention, the content of halogen atoms in an acrylonitrile polymer (A), an antimony compound (B) and a polymer which are copolymerized with vinyl chloride and / or vinylidene chloride in an amount of 30 to 50% by weight is used. From 50% by weight or more of the composition of the composition, the polymer (C) is 40 to 90 parts by weight of (A), 30 to 5 parts by weight of (B) and 30 to 5 parts by weight of (C) in total 100 parts by weight. And a flame-retardant acrylic fiber, and a flame-retardant fiber composite comprising 40 to 80% by weight of the flame retardant acrylic fiber and 60 to 20% by weight of other fibers.

In the present invention, the acrylonitrile-based polymer (A) used as a component of the composition of the acrylic fiber substrate
Is a polymer obtained by copolymerizing acrylonitrile with vinyl chloride and / or vinylidene chloride in an amount of 30 to 50% by weight. When the copolymerization amount of vinyl chloride and / or vinylidene chloride is less than 30% by weight, satisfactory flame retardancy can be obtained. On the contrary, if it exceeds 50% by weight, the heat resistance and dyeing sharpness of the obtained fiber are lowered, and further, the stiffness of the fiber is also lowered.

Further, in the present invention, the acrylonitrile-based polymer (A) may contain, in addition to vinyl chloride and / or vinylidene chloride, other copolymerization components for improving dyeability, fiber characteristics and the like. Often, examples of the copolymerization component include a sulfo group-containing vinyl monomer such as methallyl sulfonic acid, acryl sulfonic acid, styrene sulfonic acid, and vinylbenzene sulfonic acid, unsaturated carboxylic acid such as (meth) acrylic acid, and (meth) Acrylic ester,
Vinyl monomers such as (meth) acrylic acid amide and vinyl ester such as vinyl acetate can be mentioned, and they can be copolymerized within a range not exceeding 5% by weight.

Examples of the antimony compound (B) as a component of the composition in the present invention include antimony trioxide, antimony pentoxide and the like, and antimony pentoxide is particularly preferably used. The antimony compound (B) used is
The particle size in the fiber is important and the particle size as an additive component is not particularly limited, but the average particle size is 8
It is preferably 0 nm or less.

Further, the polymer (C) having a halogen atom content of 50% by weight or more in the polymer which is a component of the composition includes polyvinyl chloride, polyvinylidene chloride, polyvinyl bromide and polyvinylidene bromide. And the like. Particularly, polyvinyl chloride and polyvinylidene chloride are preferably used, and the molecular weight is not particularly limited.

The ratio of each component in the composition of the present invention is 40 to 90 parts by weight of the acrylonitrile polymer (A), 30 to 5 parts by weight of the antimony compound (B) and 100 parts by weight of the composition, and a halogen atom. When the polymer (C) is 30 to 5 parts by weight and the antimony compound (B) is less than 5 parts by weight, sufficient flame retardancy cannot be obtained, and when it exceeds 30 parts by weight, spinning nozzle clogging, yarn breakage and the like And the mechanical properties of the fiber are also reduced. Further, if the halogen atom-containing polymer (C) is less than 5 parts by weight, sufficient flame retardancy cannot be obtained, and if it exceeds 30 parts by weight, the mechanical properties of the fiber,
Dyeing sharpness is reduced.

The flame-retardant acrylic fiber of the present invention can be obtained by shaping the composition into a fiber by a known spinning method. The antimony compound (B) maintains the mechanical properties of the fiber and is flame-retardant. From the standpoint of exhibiting the performance, it is necessary that the fibers are uniformly present in a finely dispersed state, and the average particle size of the antimony compound (B) in the fibers is preferably 200 nm or less. The fine dispersion of the antimony compound (B) uniformly in the fiber can be achieved by preparing a spinning dope by the following method during fiber shaping.

The flame-retardant acrylic fiber of the present invention is prepared by dissolving the above composition in a solvent to prepare a spinning dope, and spinning the solution using any spinning method such as a wet spinning method, a dry-wet spinning method and a dry spinning method.
It can be obtained by spinning by a known method. The solvent used in the preparation of the spinning dope may be any solvent that can dissolve the acrylonitrile-based polymer (A) and the halogen atom-containing polymer (C) in the composition, for example, dimethylformamide, dimethylacetamide, dimethylsulfoxide. Etc.

In obtaining the flame-retardant acrylic fiber of the present invention,
Preferred methods for preparing the spinning dope include the following methods (1) and (2) from the viewpoint of preventing the particle size from increasing due to the aggregation of the antimony compound in the spinning dope or the fibers. (1) Prepare a colloidal dispersion of antimony pentoxide having an average particle size of 80 nm or less as the antimony compound (B) using the same solvent as that used for the spinning stock solution, dilute the colloidal dispersion with the required amount of solvent, and Adjust the pH of the solution to 5-6. Then, a predetermined amount of acrylonitrile-based polymer (A) and polyhalogen atom-containing polymer (C) are added together with a solvent to the adjusted liquid, and the mixture is heated and dissolved to prepare a spinning dope. Solvents are (A), (B) and (C)
An amount of 250 to 500 parts by weight per 100 parts by weight of the above is appropriately divided and used at the time of preparing each liquid.

(2) The same solvent as that used for the spinning dope is used, and the antimony compound (B) has an average particle size of 80 n.
Prepare a colloidal dispersion of antimony pentoxide of m or less,
The halogen atom-containing polymer (C) and a solvent are added to the colloidal dispersion liquid whose pH is adjusted to 5 to 6 and dissolved by heating to prepare an antimony pentoxide dispersion polymer (C) liquid. Separately, a mixture of acrylonitrile-based polymer (A) and a solvent is heated and dissolved to prepare an acrylonitrile-based polymer (A) solution. Then, the antimony pentoxide-dispersed polymer (C) solution and the acrylonitrile-based polymer (A) solution are mixed with a static mixer or the like to prepare a spinning dope. The solvent is 100 in total of (A), (B) and (C).
An amount of 250 to 500 parts by weight is appropriately divided and used at the time of preparing each liquid.

In the preparation of the spinning dope, including the above methods (1) and (2), the pH of the antimony compound dispersion liquid is 5 to 5.
When the pH is less than 5, the antimony compound easily aggregates, and when the pH exceeds 6, the acrylonitrile-based polymer is likely to be colored when the acrylonitrile-based polymer is added, and the whiteness of the fiber is lowered. pH
The adjustment solution is not particularly limited in the adjustment solution, and an ordinary buffer solution or the like is used. The acrylonitrile-based polymer is preferably melted by heating at 60 ° C. or lower, and if it exceeds 60 ° C., the polymer is likely to be thermally deteriorated and the whiteness of the fiber is lowered.

The flame-retardant acrylic fiber of the present invention has a high degree of flame-retardant property by containing a large amount of antimony compound which is a flame retardant. Strength 2.5g / d or more, single fiber elongation 25
%, Which retains excellent mechanical properties of not less than%.

The flame-retardant acrylic fiber of the present invention can exert its flame-retardant effect remarkably even when it is compounded with another fiber, and the flame-retardant acrylic fiber 40 to 80 of the present invention.
A flame-retardant fiber composite can be obtained by compounding the weight% and the other fiber 60 to 20% by weight. When the composite rate of the flame-retardant acrylic fiber is less than 40% by weight, the composite does not have a sufficient flame retardant effect.

Other fibers that can be composited include, for example,
Examples thereof include natural fibers such as cotton, hemp, wool and silk, acetate fibers, chemical fibers such as rayon, synthetic fibers such as polyester fibers, nylon and acrylic fibers. Examples of the compounding means include any method such as blending, combusting, mixing and weaving, and knitting, and the form of the composite may be any of yarn, woven fabric, knitted fabric, felt, nonwoven fabric, paper and the like.

In the flame-retardant fiber composite, when cotton is compounded as the other fiber, it is possible to obtain a flame-retardant fiber composite having a high flame-retardant property. Particularly, the flame-retardant acrylic fiber 60 to 75% by weight and cotton When a composite of 40 to 25% by weight is used,
Surprisingly, it is possible to obtain a flame-retardant fiber composite in which the flame-retardant property is remarkably improved as compared with the case of using the flame-retardant acrylic fiber alone, and the cotton has excellent texture, moisture absorption and water absorption.

The reason why the composite of the flame-retardant acrylic fiber of the present invention and the cotton exhibits high flame retardancy is considered as follows.

Generally, in the process of burning a polymer, OH radicals generated by the reaction between oxygen in the air and the polymer cause a chain reaction to continue the burning of the polymer. But,
When chlorine atoms are present in the polymer, the polymer itself generates hydrochloric acid due to thermal decomposition, and this hydrochloric acid traps OH radicals to exert a flame retardant effect. When antimony pentoxide is present here, antimony pentoxide forms a cycle composed of antimony oxychloride and antimony trioxide at high temperature, and contributes to the improvement of flame retardancy. In addition, the presence of cotton reacts with antimony trichloride and the cotton becomes the driving force for this cycle. Therefore, the effects of the products in the combustion process are as follows.

The effect of diluting oxygen by the produced water and carbon dioxide. Oxygen blocking effect of antimony trichloride staying around combustibles. Oxygen blocking effect of carbon film produced by carbonization of organic matter. Suppressing effect of combustion chain reaction by trapping OH radicals of hydrochloric acid and antimony trichloride. Flame retardant effect of cotton by chlorination of cotton with antimony trichloride.

In this flame retardant mechanism, it is necessary to efficiently convert an antimony compound into antimony oxychloride and antimony trichloride in order to improve flame retardancy. Therefore, in the present invention, antimony oxychloride is used. In order to speed up the conversion of the antimony trichloride and antimony trichloride, the use of the chlorine atom-containing monomer and the halogen-containing polymer and the fine dispersion of the antimony compound in the polymer have achieved the development of the flame retardant mechanism.

[0024]

EXAMPLES The present invention will be specifically described below with reference to examples. In the examples, parts and% mean parts by weight and% by weight, respectively. For evaluation of flame retardancy, a spun yarn of the fiber to be evaluated was used to make a knitted fabric having a basis weight of 400 g / m ² , and the LOI value was measured according to JIS K7201A-1. The reduced viscosity of the polymer was measured with a 0.5% dimethylformamide solution at 25 ° C. using a Canon Fenske viscometer manufactured by Canon Inc., and the average particle size of antimony pentoxide in the fiber was determined by measuring the transmission electron of the fiber. It was observed and measured with a microscope.

(Examples 1 to 3) pH 40 containing 40% of antimony pentoxide (Sb ₂ O ₅ ) having an average particle diameter of 60 nm.
To 50 parts of the antimony pentoxide colloid-dispersed dimethylacetamide (DMAc) solution of 2, was added 30 parts of DMAc,
The mixture was stirred for 1 hour to obtain a diluted colloidal dispersion having a pH of 5.6. Add polyvinyl chloride (P
VC) (20 parts) was added, mixed with stirring, and heated and dissolved at 60 ° C. to obtain a PVC solution having antimony pentoxide dispersed therein. next,
25 parts of an AN polymer having a reduced viscosity of 1.98 and comprising 57.5% of acrylonitrile (AN), 40% of vinylidene chloride and 2.5% of sodium methallylsulfonate is DMAc7.
Add to 5 parts, mix with stirring, heat to dissolve at 60 ° C and AN
A polymer solution was obtained. This AN-based polymer solution 280
Parts and 75 parts of the antimony pentoxide-dispersed PVC solution were mixed using a static mixer, and DMA was prepared by a wet spinning method using a nozzle having a hole diameter of 0.06 mm and a hole number of 3000.
c40% / 60% water, spun into a coagulation bath at 30 ° C., desolvated in hot water, stretched 6 times in boiling water, applied with an oil agent, dried, and subjected to heat and moisture relaxation to obtain a single fiber fineness of 2 A denier acrylic fiber was obtained.

In the same manner, as shown in Table 1, AN
An acrylic fiber was obtained in which the amounts of the base polymer, antimony pentoxide, and PVC were changed. Next, a knitted fabric was prepared using the obtained spun yarn of each acrylic fiber, flame retardancy was evaluated, and the results are shown in Table 1. Also, each acrylic fiber 70% and cotton 30
% Was mixed and spun into a spun yarn to prepare a knitted fabric, and the flame retardancy of the composite was evaluated. The results are shown in Table 1.

[0027]

[Table 1]

(Examples 4 to 5 and Comparative Examples 1 and 2) DM containing antimony pentoxide (Sb ₂ O ₅ ) having an average particle diameter of 60 nm at 40% and having a pH of 5.2 and containing antimony pentoxide colloid.
DMAc (385 parts) was added to Ac solution (25 parts), and the mixture was stirred and mixed for 1 hour to obtain a diluted colloidal dispersion having a pH of 5.6. To this diluted colloidal dispersion, 60 parts of an AN-based polymer having a reduced viscosity of 1.98 consisting of 57.5% AN, 40% vinylidene chloride and 2.5% sodium methallyl sulfonate and PV
C30 parts was added and mixed by stirring, and each polymer was heated and dissolved at 60 ° C. This solution was subjected to a wet spinning method using a nozzle having a pore size of 0.06 mm and a number of holes of 3000 to prepare DMAc.
Spin on a coagulation bath of 40% / 60% of water, 30 ° C., desolvate in hot water, stretch 6 times in boiling water, apply oil agent,
Drying and moist heat relaxation treatment were performed to obtain an acrylic fiber having a single fiber fineness of 2 denier.

Similarly, as shown in Table 2, AN
An acrylic fiber was obtained in which the amounts of the base polymer, antimony pentoxide, and PVC were changed. Next, a knitted fabric was prepared using the obtained spun yarn of each acrylic fiber, and the flame retardancy was evaluated. The results are shown in Table 2. Also, each acrylic fiber 70% and cotton 30
% Was mixed to form a spun yarn, a knitted fabric was prepared, and the flame retardancy of the composite was evaluated. The results are shown in Table 2.

[0030]

[Table 2]

Comparative Example 3 An acrylic fiber was obtained in the same manner as in Example 1 except that antimony trioxide (Sb ₂ O ₃ ) having an average particle diameter of 300 nm was used instead of antimony pentoxide in Example 1. A knitted fabric was prepared using the obtained spun yarn of acrylic fiber, flame retardancy was evaluated, and the results are shown in Table 3.

[0032]

[Table 3]

Example 6 An acrylic fiber was obtained in the same manner as in Example 1 except that polyvinylidene chloride was used instead of polyvinyl chloride in Example 1. A knitted fabric was prepared using the obtained spun yarn of acrylic fiber, and the flame retardancy was evaluated. The results are shown in Table 4.

[0034]

[Table 4]

(Examples 7 to 9) 70% of the acrylic fiber obtained in Example 2 and wool, diacetate fiber, AN93
%, Vinyl acetate 7%, a knitted fabric is prepared by using a spun yarn obtained by mixing 30% of each of ordinary acrylic fibers from a copolymer,
The flame retardancy was evaluated, and the results are shown in Table 5.

[0036]

[Table 5]

(Examples 10 to 12 and Comparative Examples 4 to 5) A knitted fabric was prepared by using a spun yarn obtained by mixing the acrylic fiber obtained in Example 2 and cotton in the ratio shown in Table 6 to make it difficult. The flammability was evaluated and the results are shown in Table 6.

[0038]

[Table 6]

[0039]

EFFECTS OF THE INVENTION The flame-retardant acrylic fiber of the present invention has a high degree of flame-retardant property and has good mechanical properties such as spinnability and processability. Since a fiber composite in which a flexible acrylic fiber is composited with other fibers also has a high degree of flame retardancy, the acrylic fiber and the fiber composite according to the present invention can be used in a wide range of applications such as interiors, bedding and clothing. It can be preferably used.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadao Kobayashi 20-1 Miyukicho, Otake City, Hiroshima Prefecture Mitsubishi Rayon Co., Ltd. Otake Office

Claims (4)

[Claims] 1. Vinyl chloride and / or vinylidene chloride 3
Acrylonitrile-based polymer (A) copolymerized with 0 to 50% by weight, antimony compound (B), and polymer (C) having a halogen atom content of 50% by weight or more, (A) 40 to 90 parts by weight , (B) 30 to 5 parts by weight and (C) 30 to 5 parts by weight, the flame-retardant acrylic fiber comprising the composition in a ratio of 100 parts by weight in total. 2. The content of halogen atoms in the polymer is 5
The flame-retardant acrylic fiber according to claim 1, wherein 0% by weight or more of the polymer (C) is polyvinyl chloride or polyvinylidene chloride. 3. The flame-retardant acrylic fiber according to claim 1, wherein the average particle size of the antimony compound (B) in the fiber is 200 nm or less. 4. The flame-retardant acrylic fiber 40 according to claim 1.
A flame-retardant fiber composite comprising -80% by weight and other fibers 60-20% by weight.