JPH0770817A - Flame-retardant acrylic fiber and flame-retardant fiber composite obtained by using the same - Google Patents

Abstract

(57) [Summary] [Purpose] Flame-retardant acrylic fiber having a high degree of flame-retardant property and good mechanical properties with good spinnability and processability, and a flame-retardant fiber composite obtained using the same. Provide the body. [Structure] 3 to 65 parts by weight of an antimony compound having an average particle diameter of 200 nm or less is dispersed in 100 parts by weight of an acrylonitrile polymer obtained by copolymerizing vinylidene chloride in a proportion of 30 to 42% by weight, and Flame-retardant acrylic fiber having a single fiber strength of 1.5 g / d or more.

Description

Detailed Description of the Invention

[0001]

The present invention has a high degree of flame retardancy,
In addition, the present invention relates to a flame-retardant acrylic fiber having good mechanical properties with good spinnability and processability, and a flame-retardant fiber composite obtained using the same.

[0002]

2. Description of the Related Art As a method for making acrylic fibers flame-retardant,
Conventionally, vinyl chloride, vinylidene chloride, vinyl bromide,
There is known a method of flame-retarding the polymer itself by copolymerizing a flame-retardant monomer such as vinylidene bromide with acrylonitrile, and various flame-retardant acrylic fibers and modacrylic fibers have already been put on the market.

Further, in the case where a high degree of flame retardancy such as kathene is required, antimony trioxide is added to the fiber made of a copolymer of acrylonitrile and vinylidene chloride to further impart flame retardancy. JP-A-63-126913 proposes a method of adding a metal oxide such as antimony pentaoxide as a flame retardant to a polymer of acrylic fiber.

However, in the method disclosed in the above publication, the flame retardancy is saturated when the added amount of antimony pentaoxide reaches 4.0% by weight, and when the antimony pentaoxide is added in a larger amount than that. However, no further effect can be obtained.

Further, JP-A-61-89339 discloses that acrylonitrile, vinyl chloride, vinylidene chloride,
A fiber made of a copolymer of soda methallyl sulfonate,
Add 8 wt% to 70 wt% of antimony trioxide, and manufacture a fiber composite with various fibers, and compare the flame resistance of the fiber composite with the flame resistance of the acrylic flame-retardant fiber alone. It is disclosed that the flame retardancy is less reduced when the content of antimony trioxide is set in a specific range and when it is compounded with cotton.

Further, Japanese Patent Laid-Open No. 5-78936 discloses that
6 to 5 relative to a polymer containing 17 to 86% by weight of halogen
A flame-retardant composite is proposed in which a fiber containing 0% by weight of an antimony compound is combined with a natural fiber or a chemical fiber. However, if a large amount of antimony trioxide is added to the fiber by this method to improve the flame retardancy, there is a problem that the spinnability and the mechanical properties of the fiber deteriorate.
That is, according to this method, when the amount of the antimony compound added is in the range of 6 to 12%, the spinnability and the mechanical properties of the fiber are good, but the flame retardant performance is low. On the other hand, when the addition amount of the antimony compound is in the range of 12 to 40%, although a high degree of flame retardancy is obtained, the mechanical characteristics (fiber formability) of the fiber deteriorate. Therefore, it is the current situation that flame-retardant acrylic fibers satisfying both high flame retardancy, spinnability and mechanical properties with good processability have not yet been obtained.

[0007]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a flame-retardant acrylic fiber having a high degree of flame-retardant property and mechanical properties with good spinnability and processability, and the same. Another object of the present invention is to provide a flame-retardant fiber composite obtained by using.

[0008]

The first gist of the present invention is that the average particle diameter is 200 nm in 100 parts by weight of an acrylonitrile polymer obtained by copolymerizing vinylidene chloride in a proportion of 30 to 42% by weight. The flame-retardant acrylic fiber is characterized in that 3 to 65 parts by weight of the following antimony-based compound is dispersed and the single fiber strength is 1.5 g / d or more.

A second aspect of the present invention is a flame-retardant fiber composite obtained by compounding the flame-retardant acrylic fiber obtained in the first aspect with other fibers.

The acrylonitrile polymer used in the present invention is a copolymer with acrylonitrile containing 30 to 42% by weight of a vinylidene chloride component. When the copolymerization amount of vinylidene chloride is less than 30% by weight, the flame retardancy is lowered, which is not preferable. On the other hand, when it exceeds 42% by weight, the heat resistance and dyeing sharpness of the obtained fiber are lowered, and further, the stiffness of the fiber is lowered, which is not preferable.

Further, in the present invention, the acrylonitrile polymer may contain other copolymerization components within a range not departing from the object of the present invention. The other copolymerization component is not particularly limited, and any one can be selected according to the purpose. For example, a sulfonic acid group-containing monomer is preferable.

This copolymer component has the effect of suppressing the trouble of uneven dyeing in the dyeing process, and it is preferably contained in the copolymer in an amount of 0.5 to 5% by weight.

Examples of the sulfonic acid group-containing vinyl monomer include methallyl sulfonic acid, acrylic sulfonic acid, styrene sulfonic acid, vinyl benzene sulfonic acid,
Or the salt thereof is mentioned.

Further, in order to improve the characteristics of the fiber, (meth)
It is possible to use unsaturated monomers copolymerizable with acrylonitrile, such as unsaturated carboxylic acids such as acrylic acid, (meth) acrylic acid esters, (meth) acrylic acid amides, vinyl esters such as vinyl acetate. is there.

In the present invention, the spinning solvent for the acrylonitrile polymer is not particularly limited as long as it dissolves the polymer, and it can be arbitrarily selected according to the spinning technique, for example, dimethyl. Formamide, dimethylacetamide, dimethylsulfoxide and the like can be mentioned.

In the flame-retardant acrylic fiber of the present invention, 3 to 65 parts by weight of the antimony compound having an average particle diameter of 200 nm or less must be dispersed in 100 parts by weight of the acrylonitrile polymer.

If the average particle size of the antimony-based compound in the fiber of the present invention exceeds 200 nm, the mechanical properties of the fiber deteriorate, probably because the antimony particle becomes a defect point.
In addition, the flame retardant performance is significantly reduced due to the increase in particle size.

Therefore, the fiber of the present invention has a single fiber strength of 1.5 from the viewpoint of processability in the subsequent spinning process and the like.
The average particle size of the antimony-based compound is essential to be 200 nm or less in order to obtain good single fiber strength, although it is necessary that the g / d be at least 2.5 g / d, preferably at least 2.5 g / d. is there.

Further, when the amount of the antimony compound added is less than 3 parts by weight, sufficient flame retardancy cannot be obtained, and conversely 65
If the amount is more than the weight part, nozzle clogging during spinning may occur, yarn breakage may occur, and the mechanical properties of the obtained fiber may deteriorate.

Examples of the antimony compound used in the present invention include antimony oxides such as antimony pentaoxide, antimony tetraoxide, antimony trioxide and antimony trioxide, antimonic acid and antimony oxychloride. These compounds may be used alone or in combination of two or more. In the present invention, particularly high flame retardancy can be obtained by using antimony pentoxide.

As described above, in the present invention, it is very important to disperse the ultrafine antimony compound particles having an average particle diameter of 200 nm or less in the fiber. It can be obtained by the method shown in.

First, in the present invention, the average particle size is 8
It is necessary to use an antimony compound colloidal dispersion of 0 nm or less. The solvent used in this dispersion is preferably the same organic solvent as the spinning solvent for the acrylonitrile polymer used in the present invention.

Even when an antimony compound colloidal dispersion having an average particle size of 80 nm or less is used,
Depending on the method of addition to the polymer, if the antimony compound partially aggregates without being uniformly dispersed and the average particle size of the antimony compound exceeds 200 nm, the mechanical properties of the fiber are significantly deteriorated. Therefore, the antimony compound used is preferably in the organic solvent colloid state.

To give an example of preparing the spinning solution for use in the present invention, first, 100 parts by weight of an acrylonitrile polymer, 3 to 65 parts by weight of an antimony compound, and a spinning solvent 2 are used.
After mixing and diluting the colloidal dispersion with the spinning solvent so as to be 75 to 725 parts by weight, the pH of the solution is adjusted to 5 to 5.
6 and then add 3% vinylidene chloride to the adjustment solution.
An acrylonitrile-based polymer copolymerized in a proportion of 0 to 42% by weight is added and dissolved by heating to prepare a spinning dope.

In the above method, the pH of the antimony compound dispersion before adding the acrylonitrile polymer is adjusted to 5-6. The pH adjusting solution is not particularly limited, and can be appropriately selected from known ones such as a commercially available ordinary buffer solution according to the purpose.

If the pH of the solution is lower than 5, the antimony compound is likely to aggregate in the step of adjusting the stock solution for spinning. On the contrary, if the pH exceeds 6, the acrylonitrile polymer is likely to be colored, which is obtained. This causes a decrease in the whiteness of the fiber.

The heat dissolution of the polymer is preferably carried out at 60 ° C. or lower. When the temperature is higher than 60 ° C., the polymer is likely to be deteriorated by heat and the whiteness of the fiber is apt to be lowered.

Using the spinning dope prepared as described above, an acrylic fiber is obtained by spinning the acrylic fiber by a known spinning method. The spinning method is not particularly limited, and depending on the purpose, a dry spinning method, a wet spinning method,
Any one of the dry and wet spinning methods may be selected.

The acrylic fiber of the present invention thus obtained has a single fiber strength of 1.5 g / d or more and a single fiber elongation of 25, even though it contains a large amount of a flame retardant antimony compound. It is possible to obtain a fiber composite having excellent mechanical properties of not less than 100% and having a high degree of flame retardancy even when it is composited with other synthetic fibers or natural fibers.

In the present invention, a flame-retardant fiber composite can be obtained by compounding 35 to 85 parts by weight of the highly flame-retardant acrylic fiber and 65 to 15 parts by weight of the other fiber.

When the mixing ratio of the flame-retardant acrylic fiber exceeds 85 parts by weight, the hygroscopicity and texture of the obtained flame-retardant fiber composite may be deteriorated. On the other hand, if it is less than 35 parts by weight, the flame retardancy of the flame-retardant fiber composite decreases.

The other fibers in the present invention are not particularly limited, and any known fiber can be used.
For example, it is possible to use natural fibers such as cotton, wool, hemp and silk, regenerated fibers such as rayon, semi-synthetic fibers such as acetate fibers, and synthetic fibers such as polyester, nylon and acrylic.

The method of compounding is not particularly limited, and methods such as mixed spinning, mixed twisting, mixed cotton, mixed woven, and mixed knitting can be used. Further, examples of the form of the obtained fiber composite include spun yarn, woven and knitted fabric, felt, non-woven fabric, paper and the like.

In this flame-retardant fiber composite, particularly when cotton is used as the other fiber, high flame retardancy can be obtained. Furthermore, when the cotton mixing ratio of 35 to 85 parts by weight of the flame-retardant acrylic fiber, preferably 45 to 80 parts by weight and 65 to 15 parts by weight of cotton, preferably 55 to 20 parts by weight, is surprisingly difficult. It is possible to obtain a fiber composite having a significantly improved flame retardancy as compared with the case of using only the flammable acrylic fiber, and having the excellent texture, hygroscopicity, and water absorption of cotton.

In the present invention, particularly when antimony pentaoxide is used as the antimony compound and cotton is used as the other fiber, the highest flame retardancy is exhibited.

The reason for this is not clear, but it is considered as follows. 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. However, when a chlorine atom is present in the polymer, thermal decomposition of the polymer itself produces hydrochloric acid, and this hydrochloric acid traps OH radicals to exhibit a flame-retardant effect, and the generated water enhances the flame-retardant effect. . Further, when antimony pentoxide is present here, antimony pentoxide forms a cycle composed of antimony oxychloride and antimony trioxide to enhance the flame retardant effect and carbon dioxide formed by the reaction between antimony pentoxide and the polymer. Improves the flame retardancy. Furthermore, when cotton coexists, antimony trichloride reacts with cotton to form a driving force in the above-described cycle, which enhances flame retardancy, water generation and chlorination of cotton, which contributes to flame retardancy.

Therefore, it can be presumed that the compound produced in this process has the following flame retardant effects, which act in a complicated manner and greatly enhance the flame retardant effect. (1) Effect of diluting oxygen due to generation of water and carbon dioxide (2) Effect of blocking oxygen due to retention of high specific gravity antimony trioxide gas around combustible substances (3) Hydrochloric acid and antimony trichloride are OH radicals (4) Flame-retardant effect of cotton due to chlorination of cotton due to reaction of cotton with antimony trichloride. Therefore, antimony pentoxide can be efficiently treated with antimony oxychloride and antimony trichloride. High flame retardancy can be obtained by converting to. That is, when the particle size of the antimony-based compound, particularly antimony pentaoxide, is set to 200 nm or less, the conversion efficiency can be increased and high flame retardancy can be obtained.

[0038]

EXAMPLES The present invention will be specifically described below with reference to examples.

The flame retardancy (LOI) is evaluated by using a spun yarn obtained from flame-retardant acrylic fiber or a spun yarn of flame-retardant fiber composite obtained by mixing the acrylic fiber and other fibers. A knitted fabric with a basis weight of 400 g / m ² was created and JIS K
It was measured according to No. 7201 A-1.

The reduced viscosity (η _red ) of the polymer is 0.
It was measured using a Canon Fenske viscometer at 25 ° C. with a 5% dimethylformamide solution.

The average particle size of the antimony-based compound in the fiber was determined by observing with a transmission electron microscope and averaging the diameters of 100 particles of the arbitrarily selected antimony compound. Furthermore, "parts" and "%" in the examples mean parts by weight and% by weight, respectively.

<Examples 1 to 3 and Comparative Examples 1 and 2> pH containing 40% of antimony pentaoxide having an average particle diameter of 60 nm.
To 20 parts of the dimethylacetamide (abbreviated as DMAc) colloidal dispersion of 5.2, 318 parts of DMAc was added and mixed with stirring for 1 hour to obtain a diluted colloidal dispersion having a pH of 5.6.
To this colloidal dispersion, 57.5% acrylonitrile,
Vinylidene chloride 40%, methallyl sulfonic acid soda 2.
Acrylonitrile polymer comprising _{5% (η re d = 1} .
98) 100 parts were added and mixed with stirring. Next, this mixed solution was heated to 50 ° C. to dissolve the above-mentioned polymer to obtain a spinning dope. This spinning dope has a nozzle hole diameter of 0.06 m.
m, nozzle number of 3000, DMAc / water = 4
After spinning in a coagulation bath of 0/60% and 30 ° C., desolvation treatment in hot water, stretching 6 times in boiling water, application of oil agent,
Drying and heat-moisture relaxation treatment were performed to obtain a 2-denier acrylic fiber. Hereinafter, in the same manner, as shown in Table 1, the content of antimony pentoxide was changed to the acrylonitrile-based polymer 10
Five kinds of acrylic fibers were obtained, in which 0 parts were changed to 2, 4, 18, 42 and 70 parts. Next, a knitted fabric was prepared from the spun yarn obtained by using each of the above acrylic fibers, and the flame retardancy was evaluated. The obtained results are shown in Table 1. Further, a knitted fabric was prepared from a spun yarn obtained by mixing 70 parts of each acrylic fiber and 30 parts of cotton, and the flame retardancy was evaluated. The obtained results are shown in Table 1.

[0043]

[Table 1]

As is clear from Table 1, even if the amount of antimony pentoxide added is increased to a considerable level, the mechanical properties of the obtained fiber are excellent. Moreover, it is found that the flame retardancy is remarkably improved when the acrylic fiber and the cotton are mixed-spun.

Comparative Example 3 The procedure of Example 1 was repeated except that an antimony pentaoxide colloidal dispersion having an average particle size of 200 nm was used, and the amount of antimony pentaoxide added to the fiber was relative to that of the acrylonitrile polymer. 8 parts of acrylic fiber was produced to evaluate flame retardancy. The obtained results are shown in Table 2.

[0046]

[Table 2]

<Comparative Example 4> An antimony pentoxide colloidal dispersion having an average particle size of 60 nm, the pH of which was adjusted to 4.5, was used, and the pH of the resulting diluted colloidal dispersion was adjusted to 4.9. As in Example 1, 5 in the fiber
An acrylic fiber was produced in which the amount of antimony oxide added was 8 parts based on the acrylonitrile polymer, and flame retardancy was evaluated. The results obtained are shown in Table 3.

[0048]

[Table 3]

Comparative Example 5 In the same manner as in Example 1 except that an antimony trioxide dispersion liquid having an average particle diameter of 300 nm was used, the amount of antimony trioxide added to the fiber was changed to an acrylonitrile polymer. On the other hand, 8 parts of acrylic fiber was produced and flame retardancy was evaluated. Table 4 shows the obtained results.
It was shown to.

[0050]

[Table 4]

<Examples 4, 5, and 6> 70 parts by weight of the flame-retardant acrylic fiber obtained in Example 2 and wool, diacetate fiber, acrylonitrile and vinyl acetate were used in a weight ratio of 93/7.
A flame-retardant composite spun yarn was prepared by blending with a regular acrylic fiber obtained by copolymerization in 1. to evaluate the flame-retardant performance.
The results obtained are shown in Table 5.

[0052]

[Table 5]

<Examples 7, 8, 9, 10, 11> The acrylic fiber obtained in Example 2 and cotton were mixed-spun in the ratios shown in Table 6, and the flame-retardant performance of each spun yarn obtained was evaluated. evaluated. The obtained results are shown in Table 6.

[0054]

[Table 6]

[0055]

INDUSTRIAL APPLICABILITY The acrylic fiber of the present invention has a high degree of flame retardancy and also has good mechanical properties such as spinnability and processability, and it is used as a blend with other fibers. Since the flame-retardant fiber composite obtained as described above has a very high flame-retardant performance, it can be used in a wide range of applications from interiors to clothing, and its effect is extremely large.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location D03D 15/12 Z 7199-3B // D01F 6/48 A 7199-3B (72) Inventor Tadao Kobayashi 20-1 Miyukicho, Otake City, Hiroshima Prefecture Mitsubishi Rayon Co., Ltd. Otake Office

Claims (4)

[Claims] 1. 3 to 65 parts by weight of an antimony compound having an average particle diameter of 200 nm or less is dispersed in 100 parts by weight of an acrylonitrile polymer obtained by copolymerizing vinylidene chloride in a proportion of 30 to 42% by weight, A flame-retardant acrylic fiber having a single fiber strength of 1.5 g / d or more. 2. The flame-retardant acrylic fiber 35 according to claim 1.
-85 parts by weight and 65 to 15 parts by weight of other fibers are combined into a total of 100 parts by weight to obtain a flame-retardant fiber composite. 3. The flame-retardant fiber composite according to claim 2, wherein the other fiber is cotton. 4. The flame-retardant acrylic fiber 60 according to claim 1.
The flame-retardant fiber composite according to claim 3, which is obtained by compounding ˜75 parts by weight and 40 to 25 parts by weight of cotton so that the total amount is 100 parts by weight.