JPH0873684A - Flame-retardant resin composition - Google Patents

Abstract

PURPOSE: To obtain a composition suitable for a household appliance and an OA(office automation) device material, having excellent heat resistance and impact resistance, comprising a styrenic resin, a specific bromine-based flame- retardant, antimony trioxide and a styrene-butadiene copolymer. CONSTITUTION: This composition comprises (A) 100 pts.wt. of a styrenic resin, (B) 10-30 pts.wt. (preferably 15-25 pts.wt.) of a bromine-based flame-retardant of the formula (R is O or a 1-6C alkylene; (i) and (j) are 0-5) having >=30wt.% bromine content, (C) 2-10 pts.wt. (preferably 4-7 pts.wt.) of antimony trioxide powder having 1-150μm average particle diameter and (D) 5-20 pts.wt. (preferably 10-15 pts.wt.) of a styrene-butadiene block copolymer. A (high-impact) polystyrene, AS resin, ABS resin, AAS resin and AES resin may be cited as the component A.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a resin used as a molding material for various molded products which are excellent in light resistance, heat resistance and impact resistance and require flame retardancy, such as home electric appliances and OA equipment. It relates to a composition.

[0002]

2. Description of the Related Art Styrenic resins are used in various applications because of their excellent workability and physical properties.

[0003] Further, in recent years, the demand for flame retardancy of molded products mainly for electrical insulation applications has become increasingly strict, and by adding a large amount of flame retardant, the demand of the market is met. There is an increasing demand for improvement of light resistance and impact resistance in addition to flame retardancy for equipment parts, particularly housings.

Conventionally, there has been proposed a technique for imparting flame retardancy by adding an organic halogen compound and antimony trioxide as a flame retardant aid to a styrene resin. However, in general, this composition easily causes dripping during combustion, and it is difficult to obtain UL94-5V, which requires high flame retardancy.

[0005]

When a bromine-based flame retardant represented by the formula (I) is added to a styrene resin, UL94V is obtained.
A flame retardancy of −0 or less can be imparted. However, it is difficult to obtain a thickness of 2.5 mm in the UL94-5V standard. However, the present invention is capable of obtaining a thickness of 2.5 mm in the UL94-5V standard, is not only excellent in mechanical strength such as impact resistance and light resistance, but also has good heat resistance and heat resistance. It is intended to obtain a composition having excellent stability.

[0006]

The present invention comprises: (a) 100 parts by weight of a styrene resin (b) a brominated flame retardant represented by the following general formula (I) 10
~ 30 parts by weight

Embedded image (In the formula, R represents oxygen or an alkylene group having 1 to 6 carbon atoms, i and j represent an integer of 0 to 5.) (c) Antimony trioxide 2 to 10 parts by weight (d) Block of styrene and butadiene Copolymer 5
It relates to a flame-retardant resin composition containing 20 parts by weight.

The styrene resin which is the component (a) of the present invention is a homopolymer or copolymer of styrene or a styrene derivative such as α-methylstyrene and vinyltoluene, and these monomers and acrylonitrile and methylmethacrylate. A copolymer obtained by graft-polymerizing a copolymer with a vinyl monomer such as a rate, a diene rubber such as polybutadiene, an ethylene / propylene rubber, an acrylic rubber or the like with styrene or a styrene derivative and another vinyl monomer. , Polystyrene, high-impact polystyrene, AS resin, ABS resin, AAS resin, AES resin and the like.

The brominated flame retardant which is the component (b) of the present invention is represented by the following general formula (I).

[0009]

[Chemical 3] In the above formula, R represents oxygen or an alkylene group having 1 to 6 carbon atoms, and i and j represent integers of 0 to 5. A methylene or ethylene group is preferably used as the alkylene group. Also, the bromine content is 30% by weight or more,
If it is less than 30% by weight, the flame retardant effect is not sufficient, which is not preferable.

The component (c) of the present invention, antimony trioxide, generally acts as a flame retardant aid,
The powder has an average particle size of 1 to 150 μm.

Styrene (S) which is the component (d) of the present invention
And a block copolymer of butadiene (B) are usually produced by block copolymerization by a method of anionic living polymerization, and have a total styrene content of 20 to 60% by weight and a total butadiene content of 80 to 40% by weight. It is a thing. The block structure composed of the block copolymer styrene and butadiene is arbitrarily obtained by adding styrene or butadiene alone or a mixture thereof in a predetermined ratio to a polymerization system in a predetermined order. The structure of the block copolymer is S (B-
S) n (however, n = 1 to 3) type is desirable.

In the resin composition of the present invention, the amount of the brominated flame retardant as the component (b) is 10 to 30 parts by weight, preferably 100 parts by weight of the styrene resin as the component (a). 15 to 25 parts by weight. If the amount is less than 10 parts by weight, the flame retardant effect is not sufficient, and if it exceeds 30 parts by weight, the mechanical properties of the composition are impaired, the impact strength is lowered, and the electrical properties are also lowered, which is not preferable. The compounding amount of the antimony trioxide as the component (c) is 2 to 100 parts by weight of the styrene resin as the component (a).
10 parts by weight, preferably 4 to 7 parts by weight are used. If the blending amount of antimony trioxide is less than 2 parts by weight, sufficient flame retardancy cannot be exhibited. On the other hand, if it exceeds 10 parts by weight, there is a problem in impact resistance. The compounding amount of the block copolymer of styrene and butadiene which is the component (d) is 5 to 20 parts by weight, preferably 10 to 15 parts by weight with respect to 100 parts by weight of the styrene resin as the component (a). If the blending amount of the block copolymer of styrene and butadiene is less than 5 parts by weight, the effect of preventing dripping cannot be sufficiently exhibited and there is a problem in flame retardancy. On the other hand, if it exceeds 20 parts by weight, a problem occurs in flame retardancy unless the amount of the flame retardant added is increased. The resin composition of the present invention can be obtained by blending these components in predetermined amounts, and the production method may be according to a conventional method. For example, the components (a) to (d) are premixed with a mixer such as a Henschel mixer, a tumbler blender, or a kneader, and then kneaded with an extruder, or by melt kneading with a heating roll or a Banbury mixer. To manufacture. At this time, various additives which are generally blended with the styrene resin as required, for example, fillers, lubricants, reinforcing agents, stabilizers, light stabilizers, ultraviolet absorbers, plasticizers, antistatic agents, A hue improver or the like may be added.

[0013]

EXAMPLES The present invention will be described in more detail below by showing Examples and Comparative Examples, but the scope of the present invention is not limited to these Examples.

The flame-retardant styrene resin compositions of the following examples and comparative examples were evaluated in the following manner.

(1) Impact strength The impact strength was measured using a notched Izod impact strength as a scale and in accordance with ASTM D256 using a 1/4 inch thick test piece.

(2) Fluidity As a fluidity evaluation scale, the melt flow rate was evaluated according to JIS K7210.

(3) Light discoloration resistance As an evaluation scale of light discoloration resistance, an Atlas kissenon weatherometer (Ci35A manufactured by Atlas Co., no rain) was used, and a test piece (natural color) was used for 100 hours at a black panel temperature of 63 ° C. After UV irradiation, the color difference (ΔE) from the unirradiated test piece was measured by a color difference meter (Nippon Denshoku Industries Co., Ltd.
The color was measured in 80). The smaller the color difference (ΔE) is, the more excellent the light discoloration resistance is. The light discoloration resistance is determined according to the following criteria.

◯: ΔE ≦ 8 ×: ΔE> 8 xx: ΔE> 15 (4) Flame retardancy As a rating scale of flame retardancy, vertical flammability test (94- A test piece (bar sample) having a thickness of 2.5 mm was evaluated according to 5 VA).

Examples 1 and 2 Daicel Styrol S85 (manufactured by Daicel Chemical Co., Ltd., high impact polystyrene) was used as a styrene resin.
As a block copolymer of styrene and butadiene, JS
RTR2400 (styrene-butadiene thermoplastic elastomer manufactured by Nippon Synthetic Rubber Co., Ltd.) was used. Formula (I)
As a brominated flame retardant represented by, SAYTEX 801
0 (Ethyl) is AN as antimony trioxide
TIMONY BLOOM 500A (Dowa Mining Co., Ltd.)
(Manufactured by Mitsui Chemical Co., Ltd.) and mixed in a tumbler blender in the combinations and ratios shown in Table 1, and then melt-kneaded by an extruder to obtain a pelletized resin composition. Next, a test piece for general physical properties was prepared with an injection molding machine (cylinder temperature 220 ° C., mold temperature 50 ° C.), and physical properties were measured according to standard methods. The results are shown in Table 1.

Comparative Examples 1 to 6 As the styrene resin, the block copolymer of styrene and butadiene, the bromine flame retardant represented by the formula (I), and antimony trioxide, the same as in Examples 1 and 2, DBDP
DE-83 (a flame retardant decabromodiphenyl ether manufactured by Great Lakes) is used as E, and Pratherm EC14 (a flame retardant manufactured by Dainippon Ink and Chemicals, Inc.) is used as a brominated bisphenol A type epoxy polymer. After mixing with a tumbler blender in such combinations and ratios, they were melt-kneaded with an extruder to obtain a pellet-shaped resin composition. Next, injection molding machine (cylinder temperature 220 ℃, mold temperature 5
A test piece for general physical properties was prepared at 0 ° C., and the physical properties were measured according to standard methods. The results are also shown in Table 1.

[0021]

[Table 1]

[0022]

The combination of the brominated flame retardant represented by the formula (I) and the block copolymer of styrene and butadiene makes it difficult to obtain UL94-5.
A resin composition capable of obtaining V (2.5 mm thickness) can be obtained.

The resin composition obtained by the present invention is a composition excellent in flame retardancy, impact resistance, light resistance and thermal stability.

Claims (1)

[Claims] (A) 100 parts by weight of styrene resin (b) Brominated flame retardant represented by the following general formula (I) 10
~ 30 parts by weight (In the formula, R represents oxygen or an alkylene group having 1 to 6 carbon atoms, i and j represent an integer of 0 to 5.) (c) Antimony trioxide 2 to 10 parts by weight (d) Block of styrene and butadiene Copolymer 5
A flame-retardant resin composition containing 20 parts by weight.