JP2664418B2 - Flame-retardant styrenic resin composition with excellent light resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a styrene resin composition excellent in light resistance, heat resistance and flame retardancy. More specifically, the present invention relates to a styrene-based resin composition containing a styrene-based resin, a chlorine-based flame retardant, a halogenated bisphenol A-type epoxy resin, and antimony trioxide and having excellent light resistance, heat resistance, and flame retardancy.

<Prior Art> In recent years, the fields of use of plastics materials have become increasingly diverse. Among them, styrene-based thermoplastic resins such as high-impact polystyrene and ABS resin are used in very many fields as automobile parts, electric equipment, office equipment, and various other molded products due to their excellent impact resistance and moldability. I have.

On the other hand, with the expansion of such uses, various legal regulations have arisen, and a high level of flame retardancy is required for flame retardant materials. In addition, most office equipment is generally used indoors. However, there is also a case where light enters through a window and is directly or indirectly exposed to light even in a room. Therefore, these materials for OA equipment are required to be self-extinguishing and have good light resistance. Numerous documents have been published so far on flame retardancy of polystyrene resins for such uses. For example, as a method for making a flammable thermoplastic resin flame-retardant, tetrabromobisphenol A is used.
(TBBA) and triphenyl phosphate (TPP) (JP-B-51-37106) or a combination of decabromodiphenyl oxide and antimony trioxide (JP-A-58-187450). There is a method of blending the flame retardant contained in the powder.

However, the inventions disclosed in these documents all provide flame retardancy or heat resistance, and have very poor light resistance.

<Problems to be Solved by the Invention> When a bromine-based flame retardant is used, it is inferior to a chlorine-based flame retardant in light resistance but has good thermal stability. Thermoplastics dominate the market.

However, the thermoplastic resin using the above-mentioned flame retardant undergoes remarkable discoloration when irradiated with sunlight or ultraviolet rays such as fluorescent lamps. Therefore, in the past, as a measure for imparting light resistance, in general, ultraviolet absorbers, light stabilizers are added alone or in combination, or in actuality, such as by painting a molded article. A flame-retardant resin composition having excellent light resistance has not yet been obtained.

An object of the present invention is to provide a styrenic resin composition having good light fastness and excellent heat resistance and flame retardancy.

<Means for Solving the Problems> The present inventor has studied to obtain a styrene-based resin composition having flame retardancy and excellent light resistance. As a result, the halogenated bisphenol A-type epoxy resin has light resistance in addition to the flame retardant effect. It has also been found that the use of chlorine-based flame retardants significantly improves heat resistance and light resistance. The present inventors have found a composition having excellent light resistance that does not cause harmful coloring in practical use due to the influence of ultraviolet rays as compared with the flame-retardant styrene-based resin composition, and reached the present invention.

That is, the present invention relates to (A) 3 to 25 parts by weight of a compound represented by the chemical formula (I) based on 100 parts by weight of a styrene resin. (B) 3 to 25 parts by weight of a halogenated bisphenol A type epoxy resin represented by the following general formula (II) and having a halogen content of 10% by weight or more Wherein X is a hydrogen atom or a halogen atom, n is a number from 0 to 5, l and m are integers from 1 to 4. (C) 0.5 to 15 parts by weight of antimony trioxide; The ratio with the component (B) is (A) /
(B) = 15/85 to 85/15 (weight ratio), which is a styrene resin composition excellent in flame retardancy.

The styrene resin used in the present invention uses at least one monomer selected from the group consisting of a styrene monomer and another vinyl monomer copolymerizable with the styrene monomer. According to the above, a product obtained by polymerizing in the presence of a rubber-like substance is also referred. Among them, first, styrene-based monomers are styrene and α-
Are those hydrogen atoms of methyl styrene, and benzene nucleus collectively and styrene derivatives substituted by a halogen atom or a C ₁ -C ₄ becomes an alkyl group, To exemplify typical as such styrene monomer Styrene, o-chlorostyrene, p-chlorostyrene, p-methylstyrene, 2,4-dimethylstyrene or t-butylstyrene.

Typical examples of the other copolymerizable vinyl monomers include acrylonitrile monomers such as (meth) acrylonitrile, α-chloroacrylonitrile, and vinylidene cyanide; (meth) acrylic acid, ) Methyl acrylate, ethyl (meth) acrylate,
(Meth) acrylic acid such as butyl (meth) acrylate, glycidyl (meth) acrylate, 2-ethylhexyl (meth) acrylate or β-hydroxyethyl (meth) acrylate, and various esters thereof; or acetic acid Examples include vinyl, vinyl chloride, vinylidene chloride, vinylpyrrolidone, (meth) acrylamide, dimethyl (meth) acrylamide, maleic anhydride, itaconic anhydride, and maleimide, as well as vinyl ketones and vinyl ethers.

Further, typical examples of the rubbery substance include polybutadiene rubber, styrene / butadiene copolymer rubber, styrene / butadiene / styrene block copolymer rubber, ethylene / propylene terpolymer rubber, butadiene / acrylonitrile copolymer rubber, Rubber obtained using a conjugated 1,3-diene monomer such as isoprene or chloroprene, such as butyl rubber, acrylic rubber, styrene / isobutylene / butadiene copolymer rubber, or isoprene / acrylate copolymer rubber. These are used alone or in combination of two or more.

One or two of the styrenic resins obtained above
Combinations of more than one kind and combinations with other resins such as polycarbonate, polybutylene terephthalate, and polyphenylene ether resins can be used.

The flame retardant (A) represented by the chemical formula (I) used in the present invention is of a chlorine type and sold under the trade name of Dechlorane Plus 25 by Occidental Chemical Company.

In order to increase the flame retardancy of the styrene resin of the present invention, the amount of the chlorine type flame retardant (A) is 3 to 25 parts by weight based on 100 parts by weight of the styrene resin, and the addition amount is 25 parts by weight. When exceeding, the fluidity of the resin composition is significantly reduced,
In addition, the impact resistance is greatly reduced. On the other hand, if the weight is less than 3 weight, the flame retardancy is not sufficient, which is not preferable.

The halogenated bisphenol A type epoxy resin (B) used in the present invention is represented by the following general formula (II).

In the above formula, X is a hydrogen atom or a halogen atom, and n is 0 to
The number 5, 1 and m represent an integer of 1 to 4. As the halogen atom, bromo is preferable, and 1 and m are each preferably 2 compounds.

Specifically, it is obtained by reacting halogen-containing bisphenol A with epichlorohydrin according to a conventional method. The polymerization degree n in the general formula (II) is 5 or less. Is undesirably reduced. Further, the halogen content is 10% by weight or more, and if it is less than 10% by weight, the flame-retardant effect is not sufficient, which is not preferable.

The amount of the flame retardant (B) to be added can be changed in the range of 3 to 25 parts by weight based on 100 parts by weight of the styrene resin, but the preferred compounding ratio is 5 to 21 parts by weight. If the amount is less than 3 parts by weight, the flame-retardant effect is not sufficient, and if it exceeds 25 parts by weight, the heat resistance of the composition is undesirably reduced.

The addition ratio of the flame retardant (A) and the flame retardant (B) is (A)
/ (B) is mixed at a ratio of 15/85 to 85/15 (weight ratio), whereby the flame retardant effect is synergistically increased. As shown in FIG. 1, the combustion time shows the lowest value at the mixing ratio of 50/50 (weight ratio).

Antimony trioxide (C) used in the present invention is an essential component for efficiently obtaining a resin composition having high flame retardancy. The amount of antimony trioxide added is in the range of 0.5 to 15 parts by weight, preferably 5 to 13 parts by weight, based on 100 parts by weight of the styrene resin.
Antimony trioxide has the effect of acting as a flame retardant aid on halogen-containing flame retardants, and is 1/1 of halogen-containing flame retardants.
Must be present in 6-1 / 2 amount. Preferably, 1 /
It is 5 to 1 / 2.5.

In addition, in addition to the above three additives, if necessary, commonly used additives such as a heat stabilizer, an antioxidant, a light stabilizer, an ultraviolet absorber, a lubricant, and a coloring agent may be added. it can.

The method for producing the composition of the present invention can be easily produced by a conventional mixing device, for example, a hot roll, a Banbury mixer or an extruder, without requiring any special means or order.

<Operation> The reason why the composition of the present invention exerts an unexpected effect in terms of imparting flame retardancy is not clear at present, but the synergism between the two due to the chemical structural compatibility with the styrene resin and the like. The effect can be considered. Regarding the excellent light fastness, it is thought that the epoxy rings at both ends of the halogenated bisphenol A type epoxy resin catch the halogen generated during the resin kneading and act as a stabilizer. Can be

<Effects> The present invention combines the chlorine-based flame retardant (A), the halogenated bisphenol A type epoxy resin (B) and the antimony trioxide (C) to obtain a light-resistant flame-retardant styrene resin. It is the one that improved the character. In addition, excellent heat resistance was obtained by the combined use of the flame retardant. Furthermore, by using these flame retardants together,
It has the feature that the same flame retardant effect can be obtained with a small amount of addition as compared with the case of using each alone.

<Examples> Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but all the addition ratios in the examples indicate parts by weight. In the present invention, the flame retardancy is a subject standardized by Underwriters Laboratories (UL) in the United States.
Based on No. 94 (abbreviation UL-94), the test was performed using a test piece of 5 inches long x 1/2 inch wide x 1/16 inch thick. The flame resistance class was 94V-0, 94V-1, 94V-2 and BN (Bur
ning). The burning time indicates the sum of the burning times of five samples.

The heat deformation temperature is ASTM D-648 (load 18.56 kg / cm ² ), and the Izod impact strength is ASTM D-256 (width 1/4 "notch, 2
3 ° C.).

The light fastness is a test method based on JIS K7102. A xenon long life fade meter (manufactured by Suga Test Instruments Co., Ltd.) is used as a light fastness tester at a black panel temperature of 63 ° C. The color was measured with a color difference meter manufactured by Color Corporation, and the color difference (ΔE) was determined by the Lab method. ΔE
The larger the value of, the greater the discoloration. In relation to the visual sense, when the numerical value of ΔE becomes 12 or more, the color tone change becomes conspicuous.

 Further, the compound represented by the chemical formula (I) used here
Is a flame retardant (A) manufactured by Oxydental Chemical Company
Dechlorane plus 25 was used. And the halogenated bis
Phenol A type epoxy resin (II)
Epicoat made by Kishi Corporation Resin was used.

Examples 1 to 3, Comparative Examples 1 to 6 ABS resin (DP-10, manufactured by Nippon Synthetic Rubber Co., Ltd.), Dechlorane Plus 25, brominated bisphenol A type epoxy resin (degree of polymerization n = 1.5, l, m = 2, Bromine content (51%) and antimony trioxide were blended in the proportions shown in Table 1 and pelletized with an extruder at a cylinder temperature of 240 ° C to obtain a flame-retardant styrene resin composition. In addition, cylinder temperature 240 ° C
A test piece was prepared using an injection molding machine.

The flame-retardant styrenic composition of the present invention has excellent light resistance,
Further, it can be seen that they are excellent in impact resistance, heat resistance and the like.

When only one of the flame retardants is used as in Comparative Examples 1 and 2, the burning time is longer than that of the combined system, and the light resistance,
It can be seen that various properties such as impact resistance and heat resistance are inferior.

It can be seen that when other flame retardants such as tetrabromobisphenol A or decabromodiphenyl ether are used as in Comparative Examples 3 and 4, various properties such as light resistance, impact resistance and heat resistance are inferior.

Examples 4 to 8 and Comparative Examples 7, 8 An ABS resin (DP-10, manufactured by Nippon Synthetic Rubber Co., Ltd.) was mixed with dechlorane plus 25 and a brominated bisphenol A type epoxy resin represented by the general formula (I) (polymerization degree n = 1.5, l, m = 2, bromine content 51%) and antimony trioxide in the ratio shown in Table 2 and pelletized by an extruder at a cylinder temperature of 240 ° C.
A test piece was prepared by injection molding at a cylinder temperature of 240 ° C. using an injection molding machine, and the physical properties were measured. The results are shown in Table 2. FIG. 1 is a graph showing the relationship between the burning time and the compounding ratio of the flame retardant.

It can be seen that the composition of the present invention is a flame retardant composition having excellent light resistance, impact resistance, heat resistance and the like.

Examples 9 and 10, Comparative Examples 9 and 10 The styrene resin in Example 3 was replaced with A instead of ABS resin.
ES resin (Clarastic MH manufactured by Sumitomo Nogatack) and
Using a HIPS resin (Esbrite 8-62A manufactured by Sumitomo Chemical Co., Ltd.), a composition was prepared at the compounding ratio shown in Table 3, and the physical properties were measured. The results are shown in Table 3.

[Brief description of the drawings]

Fig. 1 shows dechlorane plus 25 and brominated bisphenol A
It is a graph which shows the relationship between the ratio of a type epoxy resin and a burning time.

Claims (1)

(57) [Claims] (1) 100 parts by weight of a styrene resin, (A)
3 to 25 parts by weight of a compound represented by the formula (I) (B) 3 to 25 parts by weight of a halogenated bisphenol A type epoxy resin represented by the following general formula (II) and having a halogen content of 10% by weight or more (Where X is a hydrogen atom or a halogen atom, and n is 0 to 5)
And 1 and m represent an integer of 1 to 4. (C) 0.5 to 15 parts by weight of antimony trioxide,
The ratio of the component (A) to the component (B) is (A) / (B) = 15
A flame-retardant styrenic resin composition excellent in light resistance, characterized by having a weight ratio of / 85 to 85/15.