JP2000143930A - Flame-retarded thermoplastic resin composition and molded product comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a flame-retarded thermoplastic resin composition excellent in light resistance, rigidity, molding resistance, the flame retardance of a thin molded product and the drop impact resistance of the thin molded product and suitable for the thin molded products by adding a specific organic phosphorous compound and a specific cresol novolak resin in a specified ratio. SOLUTION: This flame-retarded thermoplastic resin composition comprises (A) 100 pts.wt. of a rubber-reinforced styrenic resin, (B) 1-20 pts.wt. of an organic phosphorous compound of formula I [X is a group of formula II or III (R1 to R8 are each H or a 1-5C alkyl) or the like; Ar1 to Ar4 are each (substituted) phenyl; (n) is 0 or larger; (k) and (m) are each 0-2, respectively, provided that (k)+(m)=0 to 2], and (C) 0.1-10 pts.wt. of a non-thermally reactive cresol novolak resin containing p-cresol residues in an amount of >=40 mol.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has excellent flame retardancy, light resistance, impact resistance, rigidity, moldability and, in particular, light resistance,
Also excellent in flame retardancy and falling weight impact with thin wall,
The present invention relates to a thermoplastic resin composition suitable for a thin molded article.

[0002]

2. Description of the Related Art Plastics have excellent mechanical properties,
Due to its moldability and electrical insulation, it is used in a wide range of fields including home electric appliances, OA appliances, automobiles and other parts. However, in recent years, most of plastics used in such fields are flammable, and there is an increasing demand for flame retardancy due to safety issues, and various flame retardant technologies have been devised.

[0003] Generally, a method is employed in which a halogen-based flame retardant such as a bromine compound having a high flame-retardant efficiency and antimony oxide are blended with a resin to make the resin flame-retardant. However, the use of flame retardants that do not contain chlorine and bromine has become highly desirable due to environmental impact.

Heretofore, as a method of making a thermoplastic resin flame-retardant without using a chlorine or bromine-based flame retardant, a method of blending red phosphorus and a metal oxide with a styrene resin (Japanese Patent Laid-Open No.
No. 106140), a method of blending red phosphorus and an organic phosphorus compound (JP-A-4-106142), a method of blending a phosphate ester with a rubber-reinforced styrene resin (JP-A-8-337703), thermoplastics A method of blending a phosphorus compound and a phenolic resin with the resin
No. -2088884) has been proposed.

[0005]

However, the method using a halogen-based flame retardant has a problem of environmental pollution because a gas is generated by decomposition of a halogen compound at the time of molding or burning. Further, the composition disclosed in JP-A-4-106140 has poor impact resistance and molding processability.
The composition described in JP-B-142 is poor in impact resistance, and the coloring of the resin composition is limited, which is not satisfactory. The composition described in JP-A-8-337703 has poor flame retardancy, and the composition described in JP-A-8-208884 has poor light resistance. Thus, these did not satisfy various properties.

The present invention is excellent in flame retardancy, light resistance, impact resistance, rigidity, and moldability, and is particularly excellent in light resistance, flame retardancy in thin wall and impact of falling weight. An object is to provide a resin composition suitable for a product.

[0007]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present invention has found that by adding a specific amount of an organic phosphorus compound and a modified phenolic resin to a rubber-reinforced styrene-based resin, a specific amount of a drip-out flame can be obtained. It has been found that flame retardancy and light resistance, molding processability, and thin wall falling weight impact are excellent.

That is, the present invention relates to (A) 100 parts by weight of a rubber-reinforced styrene resin, (B) 1 to 20 parts by weight of an organic phosphorus compound represented by the general formula (1), and (C) p-cresol. A flame-retardant thermoplastic resin composition comprising 0.1 to 10 parts by weight of a non-heat-reactive cresol novolak resin containing at least 40 mol% of a residue.

Embedded image (In the above formula, R ^{1 to} R ⁸ represent the same or different hydrogen atoms or alkyl groups having 1 to 5 carbon atoms.
r ¹ , Ar ² , Ar ³ and Ar ⁴ represent the same or different phenyl groups or phenyl groups substituted with halogen-free organic residues. Y is a direct bond, O, S, S
O ₂ , C (CH ₃ ) ₂ , CH ₂ , and CHPh, and Ph represents a phenyl group. N is an integer of 0 or more. K and m are each an integer of 0 or more and 2 or less, and k +
m is an integer of 0 or more and 2 or less. ) "And molded articles comprising the same.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. The weight in the present invention means mass.

The rubber-reinforced styrenic resin (A) in the present invention has a structure in which a (co) polymer containing a styrene monomer is grafted to a rubbery polymer, and a resin containing a styrene monomer. It also includes those having a structure in which the (co) polymer is not grafted to the rubbery polymer.

Specifically, 95 to 20 parts by weight of a monomer or monomer mixture containing 20% by weight or more of an aromatic vinyl monomer is graft-polymerized to 5 to 80 parts by weight of a rubbery polymer. (A1) Graft (co) polymer 5-10
0% by weight and 0 to 95% by weight of a (A2) vinyl (co) polymer obtained by polymerizing a monomer or monomer mixture containing at least 20% by weight of an aromatic vinyl monomer. Are preferred.

As the rubbery polymer, those having a glass transition temperature of 0 ° C. or less are preferred, and diene rubbers are preferably used. Specifically, polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, styrene-butadiene block copolymer,
Examples include diene rubbers such as butyl acrylate-butadiene copolymer, acrylic rubbers such as polybutyl acrylate, polyisoprene, and ethylene-propylene-diene terpolymer. Among them, polybutadiene or butadiene copolymer is preferred.

The gel content of the rubbery polymer is preferably at least 50%, more preferably at least 60%, from the viewpoint of impact resistance and gloss of the resin composition. If necessary, no gel as measured with a toluene solvent, or loose gel such as “JSR0561” manufactured by JSR Corporation, “Nipol 4850A” manufactured by Zeon Corporation, etc. may be used for all rubbery polymers. , 40% by weight or less.

Although the rubber particle diameter of the rubbery polymer is not particularly limited, the weight average particle diameter of the rubber particles is 0.15 to 2.0.
μm, particularly 0.20 to 1.0 μm, is preferable because of excellent impact resistance. The average weight particle diameter of the rubber particles is “Ru
bber Age Vol. 88 p. 484-490
(1960) by E.I. Schmidt, P .; H. B
sodium salt alginate method described in “Idison” (particles having a cumulative weight fraction of 50% from the cumulative weight fraction of the creamed weight ratio and the sodium alginate concentration utilizing the fact that the particle size of polybutadiene to be creamed varies depending on the concentration of sodium alginate) (Determining the diameter).

As the aromatic vinyl monomer, styrene,
Examples include α-methylstyrene, vinyltoluene, o-ethylstyrene, pt-butylstyrene, etc., with styrene being particularly preferred.

As a monomer other than the aromatic vinyl monomer, a vinyl cyanide monomer is used for the purpose of further improving impact resistance, and a (meth) acrylic monomer is used for the purpose of improving toughness and color tone. Acid ester monomers are preferably used. Examples of the vinyl cyanide-based monomer include acrylonitrile, methacrylonitrile, ethacrylonitrile, and the like, and acrylonitrile is particularly preferable. Examples of the (meth) acrylate-based monomer include methyl and ethyl esters of acrylic acid and methacrylic acid with ethyl, propyl, n-butyl and i-butyl. Particularly, methyl methacrylate is preferred.

If necessary, other vinyl monomers,
For example, maleimide monomers such as maleimide, N-methylmaleimide, and N-phenylmaleimide can be used.

(A1) The monomer or monomer mixture used in the graft (co) polymer is preferably at least 20% by weight of an aromatic vinyl monomer from the viewpoint of the impact resistance of the resin composition. It is preferably at least 50% by weight. When a vinyl cyanide monomer is mixed, the amount is preferably 60% by weight or less, and more preferably 50% by weight or less, from the viewpoint of moldability of the resin composition. When a (meth) acrylate monomer is mixed, toughness,
From the viewpoint of impact resistance, the content is preferably 80% by weight or less, and more preferably 75% by weight or less. The total amount of the aromatic vinyl-based monomer, vinyl cyanide-based monomer and (meth) acrylate-based monomer in the monomer or monomer mixture is preferably 95 to 20% by weight, and Preferably it is 90 to 30% by weight.

(A1) The ratio of the rubbery polymer to the monomer mixture in obtaining the graft (co) polymer is preferably at least 5 parts by weight of the rubbery polymer based on 100 parts by weight of the total graft copolymer. , More preferably at least 10 parts by weight,
The amount is preferably 0 parts by weight or less, more preferably 70 parts by weight or less. From the viewpoint of the impact resistance of the resin composition, the proportion of the rubbery polymer is preferably at least 5 parts by weight, and the impact resistance and the appearance of the molded article are not impaired.
0 parts by weight or less is preferred.

The (A1) graft (co) polymer can be obtained by a known polymerization method. For example, it can be obtained by a method in which a mixture of a monomer and a chain transfer agent and a solution of a radical generator dissolved in an emulsifier are continuously supplied to a polymerization vessel in the presence of a rubbery polymer latex to carry out emulsion polymerization.

(A1) The graft (co) polymer contains a non-grafted copolymer in addition to a material having a structure in which a monomer or a monomer mixture is grafted on a rubbery polymer. It is. The graft ratio of the (A) graft (co) polymer is not particularly limited, but is preferably from 20 to 200%, particularly preferably from 25 to 150%, in order to obtain a resin composition having excellent impact resistance and gloss. Here, the graft ratio is calculated by the following equation.

Graft ratio (%) = <amount of vinyl copolymer graft-polymerized on rubbery polymer> / <rubber content of graft copolymer> × 100

The properties of the non-grafted (co) polymer are not particularly limited, but the intrinsic viscosity [η] (measured at 30 ° C.) of the methyl ethyl ketone-soluble component is 0.25-0.
6 dl / g, especially in the range of 0.25 to 0.5 dl / g,
Since a resin composition having excellent impact resistance can be obtained, it is preferably used.

(A1) The graft (co) polymer has a structure in which a (co) polymer containing 20% by weight or more of an aromatic vinyl monomer is individually contained in the rubbery polymer particles (occluded structure). It is preferable to use a rubbery polymer having the following in order to improve the flame retardancy, falling weight impact strength and heat resistance in a well-balanced manner. Here, the occluded structure means that an aromatic vinyl monomer having a particle size of 0.01 μm or more is contained in the rubbery polymer.
The structure is such that one or more (co) polymer particles containing at least one weight% are included.

In order to efficiently exhibit the effects of the present invention, the rubbery polymer having an occluded structure containing 5 or more, preferably 10 or more, of the above (co) polymer particles with respect to all the rubbery polymers is used. It is preferable to contain 10% or more on average. The occluded structure can be observed by an electron microscope, for example, by forming an ultrathin section of the resin composition stained with osmic acid.

(A2) The vinyl (co) polymer is a copolymer essentially containing an aromatic vinyl monomer. Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, p-methylstyrene, t-butylstyrene, vinyltoluene, o-ethylstyrene, and the like, with styrene being particularly preferred. One or more of these can be used.

As a monomer other than the aromatic vinyl monomer, a vinyl cyanide monomer is preferably used for the purpose of further improving impact resistance. For the purpose of improving toughness and color tone, (meth) acrylate monomers are preferably used. Examples of the vinyl cyanide-based monomer include acrylonitrile, methacrylonitrile, ethacrylonitrile, and the like, and acrylonitrile is particularly preferable.
(Meth) acrylic ester monomers include acrylic acid and methacrylic acid methyl, ethyl, propyl, n
Examples thereof include an esterified product with -butyl and i-butyl, and methyl methacrylate is particularly preferable.

As other vinyl monomers copolymerizable therewith, maleimide monomers such as maleimide, N-methylmaleimide and N-phenylmaleimide can be used as required.

(A2) From the viewpoint of the impact resistance of the resin composition, the proportion of the aromatic vinyl monomer as a component of the vinyl (co) polymer is preferably at least 20% by weight based on all monomers. Preferably, it is more preferably at least 50% by weight. When a vinyl cyanide monomer is mixed, the content is preferably 60% by weight or less, more preferably 50% by weight or less, from the viewpoint of impact resistance and fluidity. When a (meth) acrylate monomer is mixed, the amount is preferably 80% by weight or less, more preferably 75% by weight or less from the viewpoint of toughness and impact resistance. When other vinyl monomers copolymerizable therewith are mixed, the content is preferably 60% by weight or less, more preferably 50% by weight or less.

The properties of the vinyl (co) polymer are not limited, but the intrinsic viscosity [η] (methyl ethyl ketone solvent, 30 ° C.
Measurement) is 0.40 to 0.65 dl / g, especially 0.40
０．５0.55 dl / g, N, N-dimethylformamide solvent, and 0.30 when measured at 30 ° C.
5 to 0.85 dl / g, especially 0.45 to 0.70 dl / g
Those having a range of g are preferable because a resin composition having excellent impact resistance and moldability can be obtained.

The method for producing the vinyl (co) polymer is not particularly limited, and includes a bulk polymerization method, a suspension polymerization method, an emulsion polymerization method, and a bulk polymerization method.
Conventional methods such as a suspension polymerization method and a solution-bulk polymerization method can be used.

The rubber-reinforced styrene resin obtained by the above method has an intrinsic viscosity [η] (30
° C) is from 0.35 to 0.55 dl / g, preferably from 0.40 to 0.50 dl / g, particularly preferably 0.43
Those having a range of -0.48 dl / g are preferable because of excellent balance between flame retardancy and impact resistance.

The (B) organophosphorus compound used in the present invention is a phosphoric ester represented by the following general formula (1).

[0034]

Embedded image

In the above formula (1), n is an integer of 0 or more. K and m are each an integer of 0 or more and 2 or less, and k + m is an integer of 0 or more and 2 or less. Preferably, k and m are each an integer of 0 or more and 1 or less, particularly preferably k or m. Is 1.

In the formula (1), R ^{1 to} R ⁸ represent the same or different hydrogen or an alkyl group having 1 to 5 carbon atoms. Here, specific examples of the alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group and a tert-
Butyl group, n-isopropyl, neopentyl, tert
A pentyl group, 2-isopropyl, neopentyl, te
rt-pentyl group, 3-isopropyl, neopentyl,
a tert-pentyl group, neoisopropyl, neopentyl, tert-pentyl group and the like.
A methyl group and an ethyl group are preferable, and hydrogen is particularly preferable.

Ar ¹ , Ar ² , Ar ³ and Ar ⁴ represent the same or different phenyl groups or phenyl groups substituted by halogen-free organic residues. Specific examples include a phenyl group, a tolyl group, a xylyl group, a cumenyl group,
Examples include a mesityl group, a naphthyl group, an indenyl group, an anthryl group, and the like. A phenyl group, a tolyl group, a xylyl group, a cumenyl group, and a naphthyl group are preferable, and a phenyl group, a tolyl group, and a xylyl group are particularly preferable.

Y is a direct bond, O, S, SO ₂ , C
(CH ₃ ) ₂ , CH ₂ , and CHPh, and Ph represents a phenyl group.

One or more of the above organic phosphorus compounds can be used arbitrarily by changing the ratio.

(B) The method for producing the organic phosphorus compound is not particularly limited. For example, after reacting phosphorus oxychloride and hydroquinone in a solvent at a substantially 2: 1 molar ratio,
Hydroquinone-bis (2,6-dimethylphenyl) phosphate can be obtained by adding an appropriate amount of dimethylphenol and reacting.

In the present invention, when (B) an organic phosphorus compound is blended, (A) 100 parts by weight of the resin composition,
0.1 to 20 parts by weight, preferably 1 to 20 parts by weight, more preferably 5 to 15 parts by weight. When the amount of the organic phosphorus compound (B) is within the above range, flame retardancy and moldability are improved.

Non-thermally reactive cresol novolak resin containing at least 40 mol% of (C) p-cresol residue used in the present invention (hereinafter abbreviated as modified phenolic resin)
Is a polymer having a substituted phenol residue represented by the general formula (2).

[0043]

Embedded image (In the above formula, R represents an alkyl group having 1 to 10 carbon atoms.)

Here, specific examples of the alkyl group having 1 to 10 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, te
rt-butyl group, n-isopropyl, neopentyl, t
tert-pentyl, 2-isopropyl, neopentyl, tert-pentyl, 3-isopropyl, neopentyl, tert-pentyl, neoisopropyl, neopentyl, tert-pentyl, hexyl, heptyl, octyl and the like. Among them, a methyl group, an ethyl group, and an octyl group are preferable, and a methyl group is particularly preferable because of excellent flame retardancy and light resistance.

The shape is not particularly limited, and any of pulverized products, granules, flakes, powders, needles, and liquids can be used.

The modified phenolic resin (C) can be used alone or in combination of two or more, if necessary.

In order to effectively exert the object of the present invention, the modified phenolic resin (C) needs to have at least 40 mol% of p-cresol residues in the substituted phenolic residues, preferably It is 60 mol% or more. When the p-cresol residue is present in the substituted phenol residue in an amount of 40 mol% or more, a composition excellent in light resistance due to remarkable suppression of oxidative discoloration due to light can be obtained. When the content of the p-cresol residue is 40 mol% or less, the discoloration proceeds with time,
The appearance of a molded article of the composition is impaired, which is not preferable.

The molecular weight of the modified phenolic resin is not particularly limited, but is preferably in the range of 200 to 2,000 in number average, and particularly preferably in the range of 400 to 1,500 in terms of mechanical properties, moldability and economical efficiency. Excellent and preferred. The phenolic resin can be measured by gel permeation chromatography using a tetrahydrafuran solution and a phenol resin standard sample.

The modified phenolic resin (C) used in the present invention preferably has a softening temperature of 70 to 200 ° C. 70 ° C. or higher is preferred from the viewpoint of heat resistance of the resin composition, and 200 ° C. or lower is preferred from the viewpoint of flame retardancy of the resin composition. The softening temperature of the modified phenolic resin (C) used in the present invention can be measured according to JIS K2207-1980.

When the modified phenolic resin (C) is blended in the present invention, 0.1 to 10 parts by weight, preferably 0.2 to 5 parts by weight, more preferably 100 to 100 parts by weight of the resin composition (a). Preferably it is 0.5 to 3 parts by weight. (C)
When the compounding amount of the modified phenolic resin is within the above range, flame retardancy, impact resistance, and moldability are improved without impairing light resistance.

In the present invention, by further adding (D) a specific hindered phenolic antioxidant, a resin composition having more excellent flame retardancy and light resistance can be obtained.

(D) The hindered phenolic antioxidant preferably has a molecular weight of 500 or more, especially octadecyl 3- (3,5-ditert-butyl-4).
-Hydroxyphenyl) propionate and pentaerythrityl-tetrakis [3- (3,5-ditert-butyl-4-hydroxyphenyl) propionate] are preferably used because they have excellent light resistance without impairing the flame retardancy.

In the present invention, when (D) a hindered phenolic antioxidant is blended, (A) the resin composition 100
0.01 to 2 parts by weight, preferably 0.1 to 2 parts by weight, per part by weight.
It is 0.5 to 1 part by weight, more preferably 0.1 to 0.5 part by weight. When the amount of the (D) hindered phenolic antioxidant is within the above range, the light resistance becomes good.

In the present invention, a higher fatty acid amide can be added for the purpose of further enhancing the drip-extinguishing property and the falling weight impact of a thin molded article. As higher fatty acid amides,
For example, stearic acid monoamide, stearic acid bisamide, lauric acid bisamide, lauric acid ethylene bisamide, stearic acid ethylene bisamide, hydroxystearic acid bisamide, hydroxystearic acid ethylene bisamide, and the like, in particular, stearic acid ethylene bisamide, hydroxystearic acid ethylene bisamide, Ethylene bisamide laurate is excellent in flame retardancy and impact resistance and can be suitably used.

The method for producing the flame-retardant resin plastic composition of the present invention is not particularly limited. For example, (A) a rubber-reinforced styrene resin, (B) an organic phosphorus compound, (C) a modified phenolic resin, and (D) is supplied to an extruder or the like with or without premixing of a hindered phenolic antioxidant, and sufficiently melt-kneaded in a temperature range of 150 to 300 ° C. In this case, the product is produced by melt-kneading using, for example, a single-screw having a “Dalmage” type screw, a twin-screw having a changed screw shape, a multi-screw extruder, a roll, a kneader, or the like.

The flame-retardant thermoplastic resin composition of the present invention may contain this and another thermoplastic resin. For example, polyphenylene ether, polycarbonate, polyglutarimide, polycyclohexane dimethylene terephthalate, etc. are mixed to improve impact resistance and heat resistance.Polyolefin, polybutylene terephthalate, polyethylene terephthalate, etc. are mixed to improve chemical resistance. be able to. If necessary, fillers such as glass fibers, antioxidants such as phenylisodecyl phosphate, various stabilizers such as ultraviolet absorbers, lubricants and plasticizers can be added in necessary amounts.

The flame-retardant thermoplastic resin composition of the present invention is melt molded and used as a resin molded product. This resin molded product is excellent in drip-extinguishing property at a molded product thickness of 0.5 to 3 mm, especially 2 mm or less, shows flame resistance of V-2 or more according to UL94 standard, and has light resistance and falling weight impact of a thin molded product. Due to its excellent characteristics, printers, PCs, displays, CRT displays, faxes, copiers, word processors, notebook computers, DVD drives, PD drives, floppy disk drives, etc., and DVDs with molded products having a thickness of 3 mm or less, DVD drive,
Related components of storage devices such as PD drives and floppy disk drives, liquid crystal display components, FDD carriages, FDD chassis HDD components, electrical and electronic components represented by computer related components, etc .; VTR components, TV components, irons, hair dryers , Rice cooker parts, microwave oven parts, audio parts, audio equipment parts such as audio / laser disk / compact disk, lighting parts,
Useful for refrigerator parts and air conditioner parts.

[0058]

EXAMPLES The present invention will be described more specifically with reference to examples and comparative examples. In the examples, the number of parts and% indicate parts by weight and% by weight, respectively, and the unit "" means inches (1 inch = 2.54 cm).

Reference Example 1 (A1) Preparation of Rubber Reinforced Styrenic Resin A method for preparing a rubber reinforced styrene resin is described below. The graft ratio was determined by the following method. Acetone was added to a predetermined amount (m) of the graft copolymer and refluxed for 4 hours. This solution is cooled to 8000 rpm (480 × 10 ³ s ⁻¹ ).
(Acceleration 10,000G (about 100 × 10 ³ m / s ² ))
After centrifugation for 30 minutes, insoluble matter was filtered. This insoluble content is 7
It dried under reduced pressure at 0 degreeC for 5 hours, and measured the weight (n).

Graft ratio = [(n)-(m) × L] /
[(M) × L] × 100 Here, L means the rubber content of the graft copolymer.

<A1-1> A monomer mixture 40 composed of 72% styrene and 28% acrylonitrile in the presence of 60 parts (in terms of solid content) of 60 parts of polybutadiene latex (average rubber particle diameter 0.3 μm, gel content 85%) And then emulsion polymerization was carried out. The obtained graft copolymer is coagulated with sulfuric acid,
The mixture was neutralized with caustic soda, washed, filtered and dried to prepare a powdery graft copolymer <A1-1>. The obtained graft copolymer had a graft ratio of 36%. This graft copolymer contained 17.9% of a non-graft copolymer composed of 72% of styrene structural units and 28% of acrylonitrile. The intrinsic viscosity of the soluble portion of methyl ethyl ketone was 0.33 dl / g.

<A1-2> 35 parts (in terms of solids) of polybutadiene (average rubber particle diameter 0.23 μm, gel content 80%), styrene-butadiene copolymer rubber copolymerized with 25% styrene (average rubber particles) Styrene 7 in the presence of 10 parts (solid content) with a diameter of 0.61 μm and a gel content of about 0%.
Monomer mixture 5 consisting of 4% and 26% acrylonitrile
Emulsion polymerization was conducted by adding 5 parts. The obtained graft copolymer was coagulated with sulfuric acid, neutralized with caustic soda, washed, filtered and dried to prepare a powdery graft copolymer <A1-2>. The obtained graft copolymer has a graft ratio of 39%.
Met. This graft copolymer contained 37% of a non-graft copolymer composed of 74% of styrene structural units and 26% of acrylonitrile. In addition, the intrinsic viscosity in a methyl ethyl ketone solvent is 0.421 dl /
g.

Reference Example 2 (A2) Preparation of Vinyl Copolymer A vinyl copolymer was prepared by subjecting a monomer mixture composed of 70% of styrene and 30% of acrylonitrile to suspension polymerization.
The intrinsic viscosity of the obtained vinyl copolymer in a methyl ethyl ketone solvent was 0.51.

Reference Example 3 (B) Organophosphorus Compound <B-1>"PX200" (manufactured by Daihachi Chemical Co., Ltd.) which is resorcinol bis (di-2,6-dimethylphenyl) phosphate was used.

<B-2> Triphenyl phosphate “TPP” (manufactured by Daihachi Chemical Co., Ltd.) was used.

Reference Example 4 (C) Modified phenolic resin <C-1> Non-thermo-reactive, and p-cresol residue is 1
“PR53053” (manufactured by Sumitomo Durez Co., Ltd.), which is a cresol novolak resin having a softening temperature of 86 ° C. and a mole ratio of 00 mol%, was used.

<C-2> A cresol novolak resin which is non-reactive and has a softening temperature of 146 ° C. and m / p = 4/6 (molar ratio) was used.

<C-3> Phenol novolak resin "PR53195" (manufactured by Sumitomo Durez Co., Ltd.), which is non-thermal reactive and does not contain a p-cresol residue and has a softening temperature of 110 ° C., was used.

Reference Example 5 (D) Hindered phenolic antioxidant Pentaerythrityl-tetrakis [3- (3,5-ditert-butyl-4-hydroxyphenyl) propionate] having a molecular weight of 1178 ("IRGANOX 1
010 "(manufactured by Nippon Ciba Kaigie Co., Ltd.).

Examples 1 to 14 (A) Rubber-modified styrenic resin prepared in Reference Example,
(B) an organic phosphorus compound, (C) a modified phenolic resin,
(D) A hindered phenolic antioxidant was mixed at the compounding ratio shown in Table 1, melt-kneaded and extruded at a resin temperature of 220 ° C. using a vented 30 mm φ twin screw extruder to produce a pellet-shaped polymer. . Next, a test piece was molded by an injection molding machine at a cylinder temperature of 230 ° C. and a mold temperature of 60 ° C., and the physical properties were measured under the following conditions. Table 3 shows the results
Shown in

(1) 1/2 "Izod impact strength: AS
TM D256-56A.

(2) Drop weight impact strength: Disc molded product (40φ
× 2 mmt), a weight having a 5R tip is dropped, and the height at which the test piece breaks by 50% and the weight of the weight at that time are determined.

(3) MFR: JIS K7210 (23
0 ° C., load: 2.16 kgf (21.18 N)) A larger value means better fluidity during molding.

(4) Light fastness: 60 mm × 90 mm × 3 m
Using an mt square plate, exposure treatment was performed under the following conditions, and the hue difference (ΔE ^* ) before and after the treatment was determined using a color difference meter. Measurement is based on JIS
According to K7103, Sand M manufactured by Suga Test Instruments Co., Ltd.
The test was performed using a color computer (SM-3 type). Treatment conditions: 55 ° C, xenon weather meter, no rain, 3
Irradiated for 00 hours.

(5) Flame retardancy: A vertical combustion test was performed according to the UL94 standard. The test piece had a thickness of 1.5 mm.

Comparative Examples 1 to 5 (A) Rubber-modified styrenic resin prepared in Reference Example,
(B) The organic phosphorus compound and (C) the modified phenolic resin were mixed at the compounding ratio shown in Table 2, and each physical property was measured in the same manner as in the examples. Table 4 shows the measurement results.

[0077]

[Table 1]

[0078]

[Table 2]

[0079]

[Table 3]

[0080]

[Table 4]

The following is clear from the results in Tables 3 and 4. The resin compositions (Examples 1 to 10) of the present invention are all excellent in impact resistance, fluidity, flame retardancy, and light resistance.

On the other hand, when the amount of the organic phosphorus compound (B) is less than 1 part by weight (Comparative Example 1), the flame retardancy is poor, and when it exceeds 20 parts by weight (Comparative Example 2), the falling weight impact strength is Becomes worse, which is not preferable. When the amount of the modified phenolic resin (C) is less than 0.1 part by weight (Comparative Example 3), the flame retardancy is poor, and when the amount exceeds 10 parts by weight (Comparative Example 4), impact resistance and light resistance are obtained. It is not preferable because the property deteriorates. . (C) When a phenolic resin other than the modified phenolic resin of the present invention is used (Comparative Example 5), light resistance deteriorates, which is not preferable.

[0083]

The flame-retardant thermoplastic resin composition of the present invention comprises:
It does not necessarily require bromine or chlorine compounds, and exhibits excellent flame retardancy, impact resistance, light resistance, moldability, especially the falling weight impact strength, flame retardancy and light resistance of thin-walled molded products.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // (C08L 51/04 61:06) F term (Reference) 4F071 AA10 AA22 AA41 AA68 AA77 AA85 AC11 AC15 AE05 AE07 AG28 AH12 AH16 BA01 BB05 BC12 4J002 BC041 BC061 BC071 BC081 BC091 BN031 BN061 BN121 BN141 BN151 BN161 CC052 EJ067 EW046 FD077 FD130 FD132 FD136 FD200 GQ00

Claims (8)

[Claims] (A) 100 parts by weight of a rubber-reinforced styrene resin, (B) 1 to 20 parts by weight of an organic phosphorus compound represented by the general formula (1), and (C) 40 parts by weight of a p-cresol residue. A flame-retardant thermoplastic resin composition comprising 0.1 to 10 parts by weight of a non-thermally reactive cresol novolak resin containing at least mol%. Embedded image (In the above formula, R ^{1 to} R ⁸ represent the same or different hydrogen atoms or alkyl groups having 1 to 5 carbon atoms.
r ¹ , Ar ² , Ar ³ and Ar ⁴ represent the same or different phenyl groups or phenyl groups substituted with halogen-free organic residues. Y is a direct bond, O, S, S
O ₂ , C (CH ₃ ) ₂ , CH ₂ , and CHPh, and Ph represents a phenyl group. N is an integer of 0 or more. K and m are each an integer of 0 or more and 2 or less, and k +
m is an integer of 0 or more and 2 or less. ) 2. The flame-retardant thermoplastic resin composition according to claim 1, wherein the softening temperature of the non-thermally-reactive cresol novolak resin (C) containing at least 40 mol% of a p-cresol residue is 70 to 200 ° C. object. 3. A hindered phenolic antioxidant (D) per 100 parts by weight of (A) a rubber-reinforced styrene resin.
3. The composition according to claim 1, further comprising 01 to 2 parts by weight.
The flame-retardant thermoplastic resin composition according to the above. 4. The flame-retardant resin composition according to claim 3, wherein (D) the hindered phenolic antioxidant has a molecular weight of 500 or more. 5. The method of claim 1, wherein (D) the hindered phenolic antioxidant is octadecyl 3- (3,5-ditert-butyl-4-).
The flame-retardant thermoplastic resin composition according to claim 3, which is (hydroxyphenyl) propionate. 6. The flame retardant according to claim 3, wherein (D) the hindered phenolic antioxidant is pentaerythrityl-tetrakis [3- (3,5-ditert-butyl-4-hydroxyphenyl) propionate]. Thermoplastic resin composition. 7. The flame-retardant thermoplastic resin composition according to claim 1, wherein the flame retardancy based on UL94 standard is V-2 or more at a test piece thickness of 1.5 mm. 8. A molded article comprising the flame-retardant thermoplastic resin composition according to claim 1 and having a minimum thickness of 2 mm or less.