JP2000109636A - Flame-retardant thermoplastic resin composition and injection molding made therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition excellent in moldability and desirable for a thin-wall molding having well-balanced and excellent flame retardancy, impact resistance, rigidity, heat resistance, and moldability by mixing a modified rubber-reinforced styrene resin with an organic phosphorus compound, a phenolic resin, and a colorant in a specified ratio. SOLUTION: This composition comprises 100 pts.wt. (A) modified rubber- reinforced styrene resin containing 1-20 wt.% α-methylstyrene residues and/or maleimido residues represented by formula I, 1-20 pts.wt. (B) organic phosphorus compound represented by formula II, 0.1-10 pts.wt. (C) phenolic resin, and 0.1-5 pts.wt. (D) colorant in a C/D ratio of 90/10 to 10/90 by weight. In formula I, R is hydrogen, a 1-5C alkyl, or the like. In formula II, X is formula III, IV, or V; R1 to R8 are each H or a 1-5C alkyl; Ar1, Ar2, Ar3, and Ar4 are each a (substituted)phenyl; Y is a direct bond, S, or the like; n is an integer of 0 or greater; and k and m are each an integer of 0-2, provided that k+m is an integer of 0-2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has excellent flame retardancy, impact resistance, rigidity, heat resistance, moldability, and thermal stability, and is particularly excellent in flame retardancy at thin wall and falling weight impact. The present invention relates to a thermoplastic resin composition which is suitable for a thin-walled molded product, has excellent thermal stability, and can stably provide a product having excellent mechanical properties and appearance of the molded product.

[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.
106140), a method of blending red phosphorus and an organic phosphorus compound (JP-A-4-106142), a method of blending an aromatic phosphate ester with a rubber-reinforced styrene resin (JP-A-8-337703), A method of blending a phosphorus compound and a phenol resin with a thermoplastic resin (JP-A-8-208884) 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 not satisfactory because of its poor heat resistance. The composition described in JP-A-8-337703 has insufficient heat resistance and poor flame retardancy.
The composition described in JP-A-8884 has poor impact resistance. Thus, these did not satisfy various properties.

The present invention is excellent in flame retardancy, impact resistance, rigidity, heat resistance, moldability and thermal stability, and is particularly excellent in flame retardancy in thin-wall and falling impact, and is a thin-walled molded product. It is an object of the present invention to provide a resin composition suitable for a resin.

[0008]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present invention is directed to a modified rubber-reinforced styrene resin containing a specific amount of α-methylstyrene residue and / or a specific maleimide residue. By combining a specific amount of an organic phosphorus compound, a phenolic resin and an inorganic colorant in a specific amount, flame retardancy and heat resistance excellent in dripping flame-extinguishing properties,
The present inventors have found that the moldability, thermal stability and falling weight impact are remarkably excellent, and have reached the present invention.

That is, the present invention relates to "(A) 100 parts by weight of a modified rubber-reinforced styrene resin containing 1 to 20% by weight of an α-methylstyrene residue and / or a maleimide residue represented by the general formula (1). (B) 1 to 20 parts by weight of an organic phosphorus compound represented by the general formula (2), (C) 0.1 to 10 parts by weight of a phenolic resin, and (D) 0.1 to 5 parts of a colorant.
Parts by weight, and the weight ratio of (C) and (D) is 9
A flame-retardant thermoplastic resin composition having a ratio of 0:10 to 10:90.

Embedded image (In the above formula, R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, a cyclo group, an aralkyl group, or an aryl group.)

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. ) ".

[0010]

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

In the present invention, (A) a modified rubber-reinforced styrene resin containing α-methylstyrene residue and / or a maleimide residue represented by the general formula (1) (hereinafter referred to as a modified rubber-reinforced styrene resin) Abbreviations) include those having a structure in which a (co) polymer containing a styrene monomer is grafted on a rubbery polymer, and those having a structure in which a (co) polymer containing a styrene monomer is a rubbery polymer. (A1) containing a grafted structure and a vinyl polymer (A2) containing an α-methylstyrene residue and / or a maleimide residue represented by the general formula (1). It is.

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 was measured when measured with a toluene solvent, or loose gel, for example, JSR0561 manufactured by Nippon Synthetic Rubber Co., Ltd., Nipol 4850A manufactured by Nippon Zeon Co., Ltd. % By weight or less can be used.

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 size of the rubber particles is "Ru
bber Age Vol. 88p. 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, α-methylstyrene is excluded, and examples thereof include styrene, vinyltoluene, o-ethylstyrene, and pt-butylstyrene. Styrene is particularly preferred.

As monomers other than the aromatic vinyl monomers, vinyl cyanide monomers are used for the purpose of further improving impact resistance, and (meth) acrylic monomers are 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.

(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. (A) The graft ratio of the graft (co) polymer is not particularly limited, but is preferably from 20 to 200% by weight, particularly preferably from 25 to 150% by weight 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.

The above-mentioned occlude structure is a structure in which one or more (co) polymer particles containing 20% by weight or more of an aromatic vinyl monomer having a particle size of 0.01 μm or more are contained in a rubbery polymer.

In order to efficiently exhibit the effects of the present invention, a 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 with an electron microscope by making an ultrathin section of the resin composition dyed with osmic acid.

(A2) α-methylstyrene residue and / or
Alternatively, as a vinyl copolymer containing a maleimide residue represented by the following general formula (1) (hereinafter abbreviated as a vinyl copolymer), α-methylstyrene and / or a compound represented by the following general formula (1) A maleimide compound represented by copolymerization with an aromatic vinyl monomer (excluding α-methylstyrene) and a vinyl cyanide monomer.

[0029]

Embedded image (In the above formula, R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, a cyclo group, an aralkyl group, or an aryl group.)

Examples of the aromatic vinyl monomer are those excluding α-methylstyrene, and include styrene, p-methylstyrene, t-butylstyrene, vinyltoluene, o-ethylstyrene, etc., with styrene being particularly preferred. . One or more of these can be used.

Examples of the vinyl cyanide-based monomer include acrylonitrile, methacrylonitrile, ethacrylonitrile and the like, and acrylonitrile is particularly preferred.

Further, if necessary, methyl, ethyl, propyl, n-butyl, i-
A (meth) acrylate monomer such as an esterified product with butyl can also be used.

In order to effectively exert the object of the present invention, it is preferable that the thermal decomposition temperature of the vinyl copolymer (A2) is 300 ° C. or higher. (A2) When the thermal decomposition temperature of the vinyl copolymer is 300 ° C. or higher, a resin composition having excellent heat resistance and flame retardancy can be obtained. The pyrolysis temperature is measured by TG-DTA in a nitrogen atmosphere, and means the temperature at which the heat loss reaches 1%.

In order to achieve the object of the present invention more effectively, it is preferable that the vinyl copolymer (A2) satisfies the general formula (3). (50−N) × 0.54 ≦ M ≦ (100−N) × 0.46 (3) (In the above formula, N is an integer of 10 to 40, and the amount of vinyl cyanide monomer residue (weight M represents the amount (% by weight) of α-methylstyrene residue and / or maleimide group residue.) When M is within the above range, heat resistance, heat stability, and difficulty are improved. Both of the flammability characteristics are more excellent. When the M value is less than 5.4% by weight, the heat resistance may not be improved in some cases.
If it exceeds 1.4% by weight, at least impact resistance,
Any of the flame retardancy may worsen.

(A2) The properties of the vinyl copolymer are not limited, but the intrinsic viscosity [η] (methyl ethyl ketone solvent, 3
0.degree. C.), 0.40 to 0.65 dl / g, especially 0.1.
In the range of 45 to 0.55 dl / g, N, N-
Dimethylformamide solvent, 0.40 to 0.90 dl / g when measured at 30 ° C, particularly 0.45 to 0.70
A resin composition in the range of dl / g is preferred because a resin composition having excellent impact resistance and moldability can be obtained.

The method for producing the vinyl copolymer is not particularly limited, and ordinary methods such as bulk polymerization, suspension polymerization, emulsion polymerization, bulk-suspension polymerization, and solution-bulk polymerization can be used. it can.

The modified rubber-reinforced styrenic resin may be, if necessary, a monomer or monomer mixture containing at least 20% by weight of an aromatic vinyl monomer (excluding α-methylstyrene). A (co) polymer obtained by polymerization can be blended. Examples of the aromatic vinyl monomer include styrene, p-methylstyrene, t-butylstyrene, vinyltoluene, o-ethylstyrene, and the like, with styrene being particularly preferred. One or more of these can be used. Compounding ratio is (A1) graft (co)
A polymer comprising (A3) (co) polymer of 0 to 95% by weight with respect to 5 to 100% by weight of the polymer is preferred.

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.

(A3) From the viewpoint of the impact resistance of the resin composition, the proportion of the aromatic vinyl monomer as a component of the (co) polymer is preferably 20% by weight or more based on all monomers. 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-based monomer is mixed, from the viewpoint of toughness and impact resistance, 8
It is preferably 0% by weight or less, more preferably 75% by weight or less. When other vinyl monomers copolymerizable therewith are mixed, the content is preferably 60% by weight or less, more preferably 50% by weight or less.

(A3) The properties of the (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 0.45
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.

(A3) The method for producing the (co) polymer is not particularly limited, and includes bulk polymerization, suspension polymerization, emulsion polymerization, and bulk polymerization.
Conventional methods such as a suspension polymerization method and a solution-bulk polymerization method can be used.

(A1) Graft (co) thus obtained
The modified rubber-reinforced styrene resin composed of the polymer, the (A2) vinyl copolymer and, if necessary, the (A3) (co) polymer is represented by an α-methylstyrene residue and / or a general formula (1). The components (A1), (A2) and (A3) can be arbitrarily blended so that the amount of the maleimide residue to be obtained is 1 to 20% by weight.

[0043]

Embedded image (In the above formula, R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, a cyclo group, an aralkyl group, or an aryl group.)

The (B) organic phosphorus compound used in the present invention is a phosphoric ester represented by the following general formula (2).

[0045]

Embedded image

In the formula (2), 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 (2), R ^{1 to} R ⁸ are the same or different and represent 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 in different ratios.

(B) The method for producing the organophosphorus 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.

When the organic phosphorus compound (B) is blended in the present invention, 0.1 to 20 parts by weight, preferably 1 to 20 parts by weight, more preferably 5 to 20 parts by weight, based on 100 parts by weight of the modified rubber-reinforced styrene resin. １５15 parts by weight. (B) when the compounding amount of the organic phosphorus compound is within the above range, flame retardancy,
Good moldability.

The phenolic resin (C) used in the present invention is not particularly limited as long as it is a polymer having a plurality of phenolic hydroxyl groups. For example, novolak-type, resol-type and heat-reactive resins, or modified resins thereof Resins. These may be an uncured resin, a semi-cured resin, or a cured resin without a curing agent added. Above all, a phenol novolak resin which does not contain a curing agent and is non-thermally reactive is preferred in terms of flame retardancy, falling weight impact strength, and economy.

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

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

(C) The phenolic resin is not particularly limited, and commercially available phenolic resins can be used. For example, in the case of a novolak type phenol resin, phenols and aldehydes are charged into a reaction tank at a molar ratio of 1: 0.7 to 1: 0.9, and oxalic acid, hydrochloric acid,
After adding a catalyst such as sulfuric acid or toluenesulfonic acid, the mixture is heated and refluxed for a predetermined time. Vacuum dehydration or static dehydration to remove generated water, and further, a method of removing remaining water and unreacted phenols can be obtained. The co-condensed phenol resin obtained by using these resins or a plurality of raw material components can be used alone or in combination of two or more.

In the case of a resole type phenol resin,
The molar ratio of phenols to aldehydes is 1: 1 to 1: 2
After charging into a reaction tank in such a ratio as follows, adding a catalyst such as sodium hydroxide, aqueous ammonia, and other basic substances, the same reaction and treatment as for the novolak-type phenol resin can be performed.

Here, phenols are phenol, o
-Cresol, m-cresol, p-cresol, thymol, p-tert-butylphenol, tert-butylcatechol, catechol, isoeugenol, o-
Methoxyphenol, 4,4'-dihydroxyphenyl-2,2-propane, isoamyl salicylate, benzyl salicylate, methyl salicylate, 2,6-di-tert
-Butyl-p-cresol and the like. One or more of these phenols can be used.
On the other hand, aldehydes include formaldehyde, paraformaldehyde, polyoxymethylene, trioxane and the like. One or more of these aldehydes can be used as needed.

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

The colorant (D) used in the present invention is not particularly limited, and any known colorant can be used as needed. Examples thereof include organic pigments such as carbon black, titanium oxide, red iron oxide, and ultramarine blue. And organic dyes. These colorants are used to improve compatibility with resins, silane coupling agents, surfactants,
Those which have been surface-treated with a lubricant, silicon oxide or the like are also included.

As the coloring agent, a mixture of titanium oxide such as titanium white and an optional pigment and, if necessary, a fluorescent whitening agent is used.

In the present invention, the blending amount of the phenolic resin (C) is based on 100 parts by weight of the resin composition (a).
0.1 to 10 parts by weight, preferably 0.2 to 8 parts by weight, more preferably 0.5 to 5 parts by weight. When the blending amount of the (C) phenolic resin is within the above range, the flame retardancy becomes good.

In the present invention, (D) the colorant is added in an amount of 0.1 parts by weight based on 100 parts by weight of the resin composition.
-5 parts by weight, preferably 0.5-5 parts by weight, more preferably 1-4 parts by weight. (D) When the amount of the coloring agent is within the above range, the Izod impact strength becomes good.

Further, in order to exert the effect of the present invention, it is necessary that the weight ratio of (C) the phenolic resin to (D) the colorant is 90:10 to 10:90, preferably 80:20 to 20:80, more preferably 7
5:25 to 40:60, more preferably 70:30 to 4
0:60. When the weight ratio of (C) and (D) is within the above range, the compatibility between (A) the modified rubber-reinforced styrene resin and (C) the phenolic resin and (D) the colorant is improved, and the flame retardancy is improved. Properties, thin wall falling weight impact strength and heat resistance are extremely good.

Further, a radical generator (E) can be used if necessary. As the radical generator (E),
There is no particular limitation as long as it is a compound that generates a radical by light or heat, but a compound such as —O—O— bond, —C—C
Compounds having any one type of chemical bond can be used. Among such radical generators, those that do not generate radicals during melting compound but generate radicals during combustion are preferable in order to obtain a high effect as a flame retardant. For this purpose, the radical generator used in the present invention has a one-minute half-life of 200 ° C.
Or more, more preferably 250 ° C.
That is all.

Here, the one-minute half-life can be measured by a known method. 0.1 mol of radical generator
% Benzene solution, sealed in a glass ampoule purged with nitrogen, attached to a thermostat set at a predetermined temperature (T), and thermally decomposed. Assuming that the thermal decomposition time at this time is t, the concentration of the decomposed radical generator is X, the initial concentration of the radical generator is a, and the decomposition rate constant is k, lna / (ax) = kt (6) Holds.

Here, since the half-life is the time until the concentration of the radical generator is reduced to half of the initial value due to radical generation, the half-life is represented by t _1/2 and the relation of X = a / 2 is satisfied. By substituting into the above equation, kt _1/2 = ln2 (7) is obtained.

Accordingly, thermal decomposition is performed at a certain temperature, the relationship between time t and lna / (ax) is plotted, k is determined from the slope of the obtained straight line, and t _{1 / 2} can be measured. The above measurement was measured at several temperatures (T), the relationship between t _1/2 and 1 / T obtained from each was plotted, and the decomposition temperature at 1 minute half life was measured from the obtained straight line. be able to.

Preferred (E) radical generators include
Specific examples include a compound represented by the following general formula (4).

[0070]

Embedded image (In the above formula, R ^{9 to} R ¹⁴ represent the same or different hydrogen atoms or monovalent organic residues having 1 to 10 carbon atoms.)

Here, specific examples of the monovalent organic residue having 1 to 10 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. Groups, n-pentyl group, 2-pentyl group, 3-pentyl group, neopentyl group, allyl group, phenyl group, xylyl group, cumenyl group, naphthyl group, etc., and methyl group, ethyl group, and phenyl group are preferable. Particularly, a methyl group and a phenyl group are preferable.

Among the radical generators represented by the general formula (4), those represented by the following general formula (5) can be more preferably used in terms of flame retardancy.

[0073]

Embedded image (In the above formula, R ^{10 to} R ¹³ represent the same or different hydrogen atoms or monovalent organic residues having 1 to 10 carbon atoms.)

Here, specific examples of the monovalent organic residue having 1 to 10 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. Groups, n-pentyl group, 2-pentyl group, 3-pentyl group, neopentyl group, allyl group, phenyl group, xylyl group, cumenyl group, naphthyl group, etc., and methyl group, ethyl group, and phenyl group are preferable. Particularly, a methyl group and a phenyl group are preferable.

In the present invention, when (E) a radical generator is blended, (A) the modified rubber-reinforced styrene resin 100
5 parts by weight or less, preferably 0.01 to
It is at most 3 parts by weight, more preferably at most 0.05 to 1 part by weight. When the amount of the radical generator (E) is within the above range, flame retardancy and Izod impact strength can be further improved.

In the present invention, a higher fatty acid amide may be added for the purpose of further enhancing the drip-extinguishing property and the falling weight impact of a thin molded article.

The higher fatty acid amide includes, 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 particularly stearic acid. Ethylene bisamide, hydroxystearic acid ethylene bisamide, and lauric acid ethylene bisamide have excellent 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 modified rubber-reinforced styrene resin, (B) an organic phosphorus compound, (C) a phenolic resin and (D) ) It is prepared by supplying a colorant to an extruder or the like with or without pre-mixing, and sufficiently kneading the mixture in a temperature range of 150 to 300 ° C. In this case, for example, a single screw with a “Dalmage” type screw, a twin screw with a different screw shape, a multi-screw extruder,
It is commercialized by melt-kneading with a roll or kneader.

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. Also, 9,10-dihydro-9-oxa-
By adding an antioxidant such as 10-phosphaphenanthrene-10-oxide and phenylisodecyl phosphate, thermal stability and flame retardancy can be further improved. If necessary, UV absorbers, lubricants and plasticizers,
A necessary amount of a filler such as glass fiber can be added.

The flame-retardant thermoplastic resin composition of the present invention is melt molded and used as a resin molded product. This resin molded article has excellent drip-extinguishing property at a molded article thickness of 0.5 to 3 mm, especially 2 mm or less, exhibits flame resistance of V-2 or more according to UL94 standard, and has excellent falling weight impact of a thin molded article. From the characteristics, printer, PC, display, CRT display, fax, copy, word processor, notebook PC, DVD drive, PD drive, floppy disk drive, etc., DVD drive, PD drive , Related parts of storage devices such as floppy disk drives, liquid crystal display parts, FDD carriages, FDD
Chassis HDD parts, electrical and electronic parts such as computer-related parts; VTR parts, TV parts, irons, hair dryers, rice cooker parts, microwave parts, audio parts, audio equipment parts such as audio, laser disks, and compact disks Useful for lighting parts, refrigerator parts, air conditioner parts.

[0081]

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 graft (co) polymer A method for preparing a graft (co) polymer which is a component of the 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. Add this solution to 8
000 rpm (480 × 10 ³ s ⁻¹ ) (acceleration 10,000
After centrifugation at 00G (about 100 × 10 ³ m / s ² )) for 30 minutes, insoluble matter was filtered. This insoluble matter was dried under reduced pressure at 70 ° C. for 5 hours, and the weight (n) was measured.

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

Polybutadiene latex (average rubber particle diameter 0.3 μm, gel content 85%) 60 parts (solid content conversion)
Was added and 40 parts of a monomer mixture composed of 72% of styrene and 28% of acrylonitrile was added to carry out emulsion polymerization. The obtained graft copolymer was coagulated with sulfuric acid, neutralized with caustic soda, washed, filtered and dried to prepare a powdery graft copolymer (A1). The obtained graft copolymer had a graft ratio of 36%. This graft copolymer is
Styrene structural unit 72% and acrylonitrile 28%
Contained 17.9% of a non-grafting copolymer consisting of The intrinsic viscosity of the soluble portion of methyl ethyl ketone was 0.31 dl / g.

Reference Example 2 (A2) Preparation of vinyl copolymer <A2-1> Styrene 39%, α-methylstyrene 28
% And acrylonitrile 33% were subjected to suspension polymerization to prepare a vinyl copolymer. The intrinsic viscosity of the obtained vinyl copolymer in a methyl ethyl ketone solvent was 0.52.

The thermal decomposition temperature was TG-DT under a nitrogen atmosphere.
A, the 1% weight loss temperature measured at a heating rate of 20 ° C./min is 3
It was 50 ° C.

<A2-2> A vinyl copolymer was prepared by emulsion polymerization of a monomer mixture comprising 50% of styrene, 20% of acrylonitrile and 30% of N-phenylmaleimide. The intrinsic viscosity of the obtained vinyl copolymer in an N, N-dimethylformamide solvent was 0.57.

The pyrolysis temperature measured in the same manner as in <A2-1> was 340 ° C.

<A2-3> α-methylstyrene 75%,
A monomer mixture comprising 25% of acrylonitrile was emulsion-polymerized to prepare a vinyl copolymer. The intrinsic viscosity of the obtained vinyl copolymer in an N, N-dimethylformamide solvent was 0.53.

The thermal decomposition temperature measured in the same manner as in <A2-1> was 275 ° C.

Reference Example 3 (A3) Preparation of (co) polymer A (co) polymer was prepared by subjecting a monomer mixture composed of 72% of styrene and 28% of acrylonitrile to suspension polymerization. The intrinsic viscosity of the obtained vinyl copolymer in a methyl ethyl ketone solvent was 0.51.

Reference Example 4 (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 was used.

Reference Example 5 (C) Phenolic Resin A phenol novolak resin which is non-thermally reactive and has a polystyrene equivalent weight average molecular weight of 3,000 was used.

Reference Example 6 (D) Colorant Gray colorant CN46 containing titanium white as a main component.
4 (manufactured by Nippon Pigment Co., Ltd.) was used.

Reference Example 7 (E) Radical generator An example using 2,3-diphenyl-2,3-dimethylbutane (Nofuma BC, manufactured by NOF Corporation) having a half-life temperature of 330 ° C. for 1 minute. 1 to 14 (A1) graft copolymer prepared in Reference Example, (A2)
The mixing ratios of the vinyl copolymer, (A3) (co) polymer, (B) organic phosphorus compound, (C) phenolic resin, (D) colorant, and (E) radical generator as shown in Table 1. And a resin temperature of 220 with a vented 30 mmφ twin screw extruder.
A pellet-shaped polymer was produced by performing melt-kneading and extrusion at a temperature of ° C. 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.
Physical properties were measured under the following conditions. Table 3 shows the results.

(1) 1/2 "Izod impact strength: AS
TM D256-56A (2) Deflection temperature under load: ASTM D648 (Load:
(1.82MPa) (3) Drop weight impact strength: Disc molded product (40φ × 2mmt)
A weight with a 5R tip is dropped on the
The height at which 0% fracture occurs and the weight of the weight at that time are determined.

(4) Thermal stability: The resin composition was allowed to stay in a cylinder of an injection molding machine for 20 minutes at 260 ° C.
A 1/2 "Izod impact test piece was molded and evaluated for impact resistance.

(5) Flame retardancy: A vertical combustion test was performed in accordance with UL94 standard. The test piece had a thickness of 1.5 mm.

Comparative Examples 1 to 12 (A1) Graft copolymer prepared in Reference Example, (A2)
A vinyl copolymer, (A3) (co) polymer, (B) an organic phosphorus compound, (C) a phenolic resin, and (D) a colorant were mixed at the compounding ratio shown in Table 2, and the same as in the example. Each physical property was measured by the method described above. Table 4 shows the measurement results.

[0101]

[Table 1]

[0102]

[Table 2]

[0103]

[Table 3]

[0104]

[Table 4]

The following is clear from the results in Tables 3 and 4. The resin compositions (Examples 1 to 14) of the present invention are all excellent in impact resistance, flame retardancy, heat resistance, particularly thermal stability, flame retardancy at thin wall, and falling weight impact resistance. .

On the other hand, when the content of α-methylstyrene residue and / or maleimide group residue in the rubber-reinforced styrene resin is less than 1% by weight (Comparative Example 1), heat resistance is inferior, and 20% by weight When it exceeds (Comparative Example 2), the flame retardancy and the thermal stability deteriorate, which is not preferable.

When the amount of the organic phosphorus compound (B) is less than 1 part by weight (Comparative Example 11), the flame retardancy is inferior, and when it exceeds 20 parts by weight (Comparative Example 12), the heat resistance becomes poor, which is not preferable. .

When the weight ratio of the phenolic resin (C) to the colorant (D) is out of the range of 90:10 to 10:90 (Comparative Examples 3, 4, 9, and 10), Or, the impact resistance is deteriorated, which is not preferable.

(C) The compounding amount of the phenolic resin is 0.1
When the amount is less than 10 parts by weight (Comparative Example 7), the impact resistance is deteriorated.

(D) When the amount of the coloring agent is less than 0.1 part by weight (Comparative Example 6), the impact resistance and flame retardancy are poor, and when it exceeds 5 parts by weight (Comparative Example 8), the impact resistance is It is not preferable because the property deteriorates.

[0111]

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 and impact resistance, especially flame retardancy of thin-walled molded articles, falling weight impact strength, heat resistance and thermal stability.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 25/16 C08L 25/16 55/02 55/02 // (C08L 51/04 25:16 61:06 ) B29K 25:00 55:00 F term (reference) 4F206 AA13G AA13K JA07 JF01 JF02 4J002 BC04W BH02W BN14X BN15X BN16X CC033 DE137 EA018 EA048 EW046 FD097 FD13W FD13X FD13Y FD136 PA08A46P08

Claims (14)

[Claims] 1. A method according to claim 1, wherein (A) an α-methylstyrene residue and / or a maleimide residue represented by the general formula (1) is from 1 to 20.
(B) 1 to 20 parts by weight of an organic phosphorus compound represented by the general formula (2), and (C) 0.1 to 10 parts by weight of a phenolic resin based on 100 parts by weight of a modified rubber-reinforced styrene resin containing 100% by weight.
Parts by weight, (D) 0.1 to 5 parts by weight of a coloring agent, and the weight ratio of (C) and (D) is 90:10 to 10:90.
Flame-retardant thermoplastic resin composition. Embedded image (In the above formula, R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, a cyclo group, an aralkyl group, or an aryl group.) (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 modified rubber-reinforced styrenic resin (A)
(A1) A graft obtained by graft-polymerizing 95 to 20 parts by weight of a monomer or a monomer mixture containing 20% by weight or more of an aromatic vinyl monomer to 5 to 80 parts by weight of a rubbery polymer ( 5 to 99% by weight of a (co) polymer and (A2) a vinyl copolymer 95 or more containing an α-methylstyrene residue and / or a maleimide group residue represented by the general formula (1).
The flame-retardant thermoplastic resin composition according to claim 1, which is a resin composition comprising 1% by weight. (A2) α-methylstyrene residue and / or
3. The flame-retardant thermoplastic resin composition according to claim 2, wherein the vinyl copolymer having a maleimide group residue represented by the general formula (1) has a thermal decomposition temperature of 300 ° C. or higher. 4. (A2) α-methylstyrene residue and / or
4. The flame-retardant thermoplastic resin composition according to claim 2, wherein the vinyl copolymer having a maleimide group residue represented by the general formula (1) satisfies the general formula (3). (50−N) × 0.54 ≦ M ≦ (100−N) × 0.46 (3) (In the above formula, N is an integer of 10 to 40, and the amount of vinyl cyanide monomer residue (weight M represents the amount (% by weight) of α-methylstyrene residue and / or maleimide group residue.) 5. The method according to claim 1, wherein the phenolic resin (C) is a non-thermally reactive phenol novolak resin, and has a polystyrene equivalent weight average molecular weight of 500 to 20,000. Flammable thermoplastic resin composition. 6. The phenolic resin (C) has a softening temperature of 70.
The flame-retardant thermoplastic resin composition according to any one of claims 1 to 5, wherein the temperature is from 200 to 200 ° C. 7. The colorant is titanium oxide or a mixture of titanium oxide and a pigment or dye.
The flame-retardant thermoplastic resin composition according to any one of the above. 8. A method according to claim 1, wherein the modified rubber-reinforced styrene resin contains 20% by weight of an aromatic vinyl monomer in the rubber polymer particles.
The flame-retardant thermoplastic resin according to any one of claims 1 to 7, which is a resin composition containing 1 to 30 parts by weight of a rubbery polymer having a structure in which the above-mentioned (co) polymers are individually occluded. Composition. 9. A modified rubber-reinforced styrenic resin 100
The flame-retardant thermoplastic resin composition according to any one of claims 1 to 8, further comprising 0.01 to 5 parts by weight of (E) a radical generator with respect to parts by weight. 10. The one-minute half-life of (E) the radical generator is 2
The flame-retardant resin composition according to claim 9, which is at least 00 ° C. 11. The flame-retardant thermoplastic resin composition according to claim 9, wherein (E) the radical generator is represented by the general formula (4). Embedded image (In the above formula, R ^{9 to} R ¹⁴ represent the same or different hydrogen atoms or monovalent organic residues having 1 to 10 carbon atoms.) 12. The flame-retardant thermoplastic resin composition according to claim 9, wherein (E) the radical generator is represented by the general formula (5). Embedded image (In the above formula, R ^{10 to} R ¹³ represent the same or different hydrogen atoms or monovalent organic residues having 1 to 10 carbon atoms.) 13. A test piece having a flame retardancy based on UL94 standard of V-2 at a thickness of 0.5 to 3.0 mm.
The flame-retardant thermoplastic resin composition according to claim 1, wherein: 14. An injection-molded article comprising the flame-retardant thermoplastic resin composition according to claim 1, having a minimum thickness of 2 mm or less.