JPH08151513A - Flame-retardant polycarbonate resin composition - Google Patents

Abstract

PURPOSE: To obtain a flame-retardant polycarbonate resin composition widely useful as parts of automobile, electrical/electronic products and building materials, having excellent workability, thermal stability, impact resistance and surface state. CONSTITUTION: This flame-retardant polycarbonate resin composition comprises (A) 98.994-76wt.% of a polycarbonate resin, (B) 0.001-2.0 wt.% of shell-modified fine particles of tetrafluoroethylene polymer, (C) 0.005-2.0wt.% of an aromatic sulfur-containing compound and (D) 1-20wt.% of a chlorine and/or bromine- containing compound, has excellent heat resistance, mechanical properties, workability, heat stability and external appearance and does not cause dripping.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant polycarbonate resin composition which has excellent heat resistance and mechanical properties and has a good appearance.

[0002]

2. Description of the Related Art Polycarbonate resins are:
It has excellent heat resistance, transparency, and mechanical properties and is used in various fields such as vehicle parts, electrical products, and building materials. However, in electric / electronic devices and building materials, they are flame retardant, especially self-extinguishing properties that do not cause dripping during ignition (for example, Underwriters Laboratories
L) Self-extinguishing property based on standard 94 "VO", "V-"
1 "class) is required, and there are various restrictions on its use in such fields.

In order to impart flame retardancy, halogen compounds such as tetrabromobisphenol A (TBA) and decabromodiphenyl ether (DBDE), or a combination thereof with an antimony compound is used. Although flame retardancy can be achieved by blending these compounds, there is a problem in that the heat resistance and impact resistance, which are characteristics of polycarbonate resin, are significantly reduced. further,
It has been proposed to add polytetrafluoroethylene to prevent dripping (JP-A-60-23442, JP-A-60-260647, JP-A-61-57645), but polytetrafluoroethylene is processed. Since they sometimes aggregate easily, there are problems such as poor feedability, poor appearance of the product surface due to poor dispersion, and reduced impact strength.

In order to solve this problem, Japanese Patent Laid-Open No. 63-
In 154744, it is proposed to improve the appearance defect of a molded product due to aggregation of polytetrafluoroethylene by mixing a polycarbonate-organic solvent and a polytetrafluoroethylene aqueous dispersion. Although such a method has been successful in terms of improving the appearance defect, it has a new problem that the thermal stability is lowered. Further, polytetrafluoroethylene easily aggregates in an atmosphere at room temperature or higher, and once aggregated, it is difficult to redisperse, so that it is necessary to pay close attention during storage and use, and there is a problem that handling is difficult.

[0005]

[Means for Solving the Problems] The inventors of the present invention have conducted extensive studies in view of the above problems, and as a result, by using a tetrafluoroethylene polymer having a specific structure, excellent heat resistance, which is a feature of polycarbonate, is obtained. Also, the present invention has been accomplished by finding a flame-retardant polycarbonate resin composition which has good workability, thermal stability, and good appearance of molded articles without sacrificing impact resistance and does not cause dripping. is there.

That is, the present invention provides a polycarbonate resin (A), shell-modified polytetrafluoroethylene polymer fine particles (B), an aromatic sulfur-containing compound (C) and a chlorine-containing and / or bromine-containing compound (D), or A flame-retardant polycarbonate resin composition which is excellent in heat resistance and mechanical properties, has a good appearance, and does not cause dripping, characterized by comprising them and acidic sulfuric acid and / or its metal salt (E). It is provided.

[0007]

The flame-retardant polycarbonate resin composition of the present invention will be described in detail below.

The polycarbonate resin (A) used in the present invention is obtained by a phosgene method in which various dihydroxydiaryl compounds are reacted with phosgene, or a transesterification method in which a dihydroxydiaryl compound is reacted with a carbonic acid ester such as diphenyl carbonate. A typical example of the polymer is a polycarbonate resin produced from 2,2-bis (4-hydroxyphenyl) propane (bisphenol A).

Examples of the dihydroxydiaryl compound include bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, and 2,2-bis (4-hydroxyphenyl), in addition to bisphenol A.
Butane, 2,2-bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, 2,2-bis (4-hydroxyphenyl-3-methylphenyl) propane, 1,1-bis (4 -Hydroxy-3-tert-butylphenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) propane,
2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4-hydroxy-3,
Bis (hydroxyaryl) alkanes such as 5-dichlorophenyl) propane, bis (hydroxyaryl) such as 1,1-bis (4-hydroxyphenyl) cyclopentane and 1,1-bis (4-hydroxyphenyl) cyclohexane Cycloalkanes, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-
Dihydroxy diaryl ethers such as 3,3′-dimethyldiphenyl ether, 4,4′-dihydroxydiphenyl sulfide, 4,4′-dihydroxy-3,
Dihydroxydiaryl sulfides such as 3'-dimethyldiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-
Examples thereof include dihydroxydiaryl sulfoxides such as 3,3′-dimethyldiphenyl sulfoxide, 4,4′-dihydroxydiphenyl sulfone, and dihydroxydiaryl sulfones such as 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfone. To be

These may be used alone or in admixture of two or more, but in addition to these, piperazine, dipiperidyl hydroquinone, resorcin, 4,4'-dihydroxydiphenyl and the like may be mixed and used.

Further, the above-mentioned dihydroxyaryl compound may be mixed with a phenol compound having a valence of 3 or more as shown below.

Examples of trihydric or higher phenols include phloroglucin, 4,6-dimethyl-2,4,6-tri- (4-hydroxyphenyl) -heptene-2,4,6-dimethyl-2,4,6-tri. -(4-Hydroxyphenyl) -heptane, 1,3,5-tri- (4-hydroxyphenyl) -benzol, 1,1,1-tri- (4-hydroxyphenyl) -ethane and 2,2-bis- [4,4-
(4,4′-dihydroxydiphenyl) -cyclohexyl] -propane and the like.

The viscosity average molecular weight of the polycarbonate resin is usually 10,000 to 100,000, preferably 150.
It is 00-35000. In producing such a polycarbonate resin, a molecular weight modifier, a catalyst and the like can be used if necessary.

The shell-modified polytetrafluoroethylene fine particles (B) used in the present invention have a specific structure, that is, a core / shell structure, and are polytetrafluoroethylene in which at least the shell is modified. It is a fine particle. "Modification" means that a small amount of another fluorine-based monomer is copolymerized when tetrafluoroethylene is polymerized. The modification amount is such that the content of the copolymerization monomer in the entire polymer fine particles produced is 0.001 to 2% by weight, preferably 0.04 to 1% by weight, and particularly preferably 0.1 to 0.5% by weight. Is.

Generally, polytetrafluoroethylene fine particles are obtained by emulsion polymerization and have a property of easily fibrillating due to shearing force. However, when modified, its properties tend to be suppressed. The fine particles used in the present invention are basically fine particles having a small shell modification amount.
Due to the modification of the shell, when such fine particles are mixed with a resin or other additives, fibrils do not occur as easily as ordinary polytetrafluoroethylene fine particles, so that they are easier to mix, but in the state where they are melt-kneaded at a high temperature, the fine particles are Becomes soft and deforms, and the core mainly becomes fibrils. Therefore, although it is considered that the shell-modified polytetrafluoroethylene fine particles (B) used in the present invention have a smaller fibril generation amount than ordinary polytetrafluoroethylene fine particles, they are necessary and sufficient for preventing dripping, and the fibrils are also sufficient. Since the fibril formation is appropriate, the fibrils are less likely to aggregate during melt-kneading, and the appearance of the molded product is improved. Depending on the method of shell modification, rectangular shaped small pieces may be formed in the molded product instead of the fibril-like shape, but the same effect is recognized. The shell-modified polytetrafluoroethylene fine particles (B) are also produced by a known emulsion polymerization method, have a number average particle diameter of 0.1 to 0.5 μm, and are obtained in the form of an aqueous dispersion. The form used in the present invention is a powder obtained by coagulating and drying an aqueous dispersion. The powder may be in the form of an aggregate of fine particles.

As the copolymerization monomer used for modification, fluorinated monomers such as chlorotrifluoroethylene, hexafluoropropane and perfluoro (alkyl vinyl ether) are generally used. As an example of the shell-modified polytetrafluoroethylene fine particles (B) suitable for the present invention, as described in JP-B-56-26242, the fine particles are formed in the central portion of the particles corresponding to 70% by weight of the whole fine particles. Concentration of at least 0.01 mol% in the outer shell portion (shell) which is present in less than 50% of the total chlorotrifluoroethylene content and which is the surface portion of the fine particles and corresponds to 10% by weight of the whole fine particles. And fine particles modified so that chlorotrifluoroethylene is present therein, or fine particles modified with a core / shell copolymer described in JP-A-1-247408, 1-278506, and 4-15247.

The compounding amount of the shell-modified polytetrafluoroethylene polymer (B) is 0.001 to 2.0% by weight. If it is less than 0.001% by weight, the effect of preventing dripping is poor, and if it exceeds 2.0% by weight, the mechanical strength is lowered. Preferably, it is 0.001 to 1.0% by weight.

Examples of the aromatic sulfur-containing compound (C) include aromatic sulfonamides, aromatic sulfonimides, aromatic sulfonic acids, aromatic sulfuric acids and their metal salts, and one or more of them may be used. it can. Generally, an aromatic sulfonamide metal salt and an aromatic sulfonimide metal salt represented by the following formula 1 or 2 are preferable.

[0019]

Embedded image (Ar—SO ₂ —N ⁻ ) _n M ⁺ (Formula 1)

However, Ar is an aromatic group or a substituted aromatic group, and M ⁺ is a metal cation. _n is a number corresponding to the valence of M. Suitable metals include Group I and Group II metals, copper, aluminum, antimony and the like. Particularly, sodium and potassium are preferable.

[0021]

[Chemical-2]

However, Ar is an aromatic group or a substituted aromatic group, and M ⁺ is a metal cation. R is a monovalent organic and _n is a number corresponding to the valence of M. Suitable metals include Group I and Group II metals, copper, aluminum,
Such as antimony. Particularly, sodium and potassium are preferable.

Aromatic sulfonamides and metal salts thereof include saccharin, N- (p-tolylsulfonyl)-
p-toluene-sulfoamide, N- (N'-benzylaminocarbonyl) sulfanilamide, N- (phenylcarboxyl) sulfanilamide, N- (2-pyrimidinyl) sulfanilamide, N- (2-thiazolyl)
And sulfanilamide and its sodium or potassium salts.

Aromatic sulfonimides and metal salts thereof include N- (p-tolylsulfonyl) -p-toluene-sulfonimide, N- (N'-benzylaminocarbonyl) sulfanylimide and N- (phenylcarboxyl) sulfanyl. Imido, N- (2-pyrimidinyl) sulfanylimide, N- (2-thiazolyl) sulfanylimide and its sodium or potassium salt and the like.

The compounding amount of the aromatic sulfur-containing compound (C) is
It is 0.005 to 2.0% by weight. If it is less than 0.005% by weight, the flame retardance is poor, and if it exceeds 2.0% by weight, the mechanical strength is lowered. Preferably, it is 0.001 to 1.0% by weight.

Chlorine-containing and / or bromine-containing compound (D)
Are a monomer, an oligomer or a polymer of a chlorine-substituted organic compound or a bromine-substituted organic compound, or an oligomer or a polymer of a chlorinated bisphenol carbonate derivative or a brominated bisphenol carbonate derivative. For example, tetrabromobisphenol A, tetrabromobisphenol S, polybromodiphenyl ether, brominated polycarbonate oligomer, brominated epoxy resin, brominated phenoxy resin,
Examples thereof include brominated polystyrene, brominated phenylene ether, tribromophenoxyethane and the like.

Chlorine-containing and / or bromine-containing compound (D)
The compounding amount of is 1 to 20% by weight. If it is less than 1% by weight, flame retardance is poor, and if it exceeds 20% by weight, mechanical properties are poor. It is preferably 1 to 10% by weight.

By blending the above components (C) and (D) with the polycarbonate resin (A), flame retardancy is exhibited, but this is not sufficient. In the present invention, by blending not only the components (C) and (D) but also the component (B), that is, shell-modified polytetrafluoroethylene, with the polycarbonate resin (A), a synergistic effect can be obtained, and dripping It is possible to provide a composition which is self-extinguishing and does not cause the appearance and has an excellent appearance.

The component (A) specified in the present invention,
In mixing (B), (C), (D) or further (E), there is no restriction on the form and order. For example, organic solvent solution, powder, polycarbonate resin (A) in pellet state, (B), (C) in powder state
And (D), or a method of adding the component (E), and the polycarbonate resin (A) in the molten state, the components (B), (C) and (D) in the powder state, or the component (E) is further added. Method. In addition, there is a method of mixing all the components at once or a method of mixing the optional components and then blending the remaining components. A "masterbatch" in which the component (A) is mixed with the component (A) and then the component (A) is mixed to prepare the composition of the present invention.
A method can also be adopted.

The flame-retardant thermoplastic resin composition of the present invention comprises
Known additives such as antioxidants [2,6-di-t-butyl-4-methylphenol, 2- (1-methylcyclohexyl) -4,6-dimethylphenol, 2,2-methylenebis- (4- Ethyl-6-t-methylphenol), 4,4'-thiobis- (6-t-butyl-3-methylphenol), dilaurylthiodipropionate,
Examples thereof include tris (di-nonylphenyl) phosphite. ], An ultraviolet absorber [pt-butylphenyl salicylate, 2,2'-dihydroxy-4-methoxybenzophenone, 2- (2'-hydroxy-4'-n-octoxyphenyl) benzotriazole and the like are exemplified. . ], Lubricants [paraffin wax, stearic acid, hydrogenated oil, stearamide, methylenebis stearamide,
Examples thereof include ethylene bis stearamide, n-butyl stearate, ketone wax, octyl alcohol, lauryl alcohol, hydroxystearic acid triglyceride and the like. ], A colorant [for example, titanium oxide, carbon black], and a filler [calcium carbonate, clay, silica, glass fiber, glass sphere, carbon fiber and the like. ], A fluidity improver [triphenyl phosphate and the like. ], A decomposition inhibitor for a polycarbonate resin [an aromatic sulfur-containing compound such as KHSO4 is exemplified. ] Etc. can be added as needed.

Further, in the present invention, a rubber reinforced material obtained by graft-polymerizing an impact modifier (rubber such as polybutadiene, polyacrylic acid ester, ethylene-propylene rubber, etc., with a compound such as methacrylic acid ester, styrene, acrylonitrile, etc.). Other thermoplastic resins such as resin), polyamide, polybutylene terephthalate, polyphenylene oxide, polyoxymethylene, and chlorinated polyethylene can be mixed if necessary.

In order to describe the present invention more specifically, examples and comparative examples will be described below. However, the present invention is not limited to these.

Example Component (A) A: Polycarbonate resin (PC) having a viscosity average molecular weight of 19000

Component (B) B-1: The reaction was carried out according to Example 4 described in JP-B-56-26242, and an aqueous dispersion (solid content) of shell-modified polytetrafluoroethylene fine particles having a number average particle size of 0.24 μm. A concentration of 34%) was obtained. The modifier (chlorotrifluoroethylene) content was 0.35% by weight.
The powder obtained by coagulating, washing and drying the aqueous dispersion by a conventional method was used for blending. B-2: In the reaction of B-1, chlorotrifluoroethylene was not added in the early stage of the reaction, and the amount of the polymer produced was 8 with respect to the final amount.
40 g of perfluoro (propyl vinyl ether) instead of chlorotrifluoroethylene at 5% by weight
Basically, the same operation was performed except that it was added. An aqueous dispersion (solid content concentration 30%) of shell-modified polytetrafluoroethylene fine particles having a number average particle diameter of 0.29 μm was obtained. The content of the modifier perfluoro (propyl vinyl ether) was 0.05% by weight when measured according to the method described in JP-A-64-1711 Example 1. The powder obtained by coagulating, washing and drying the aqueous dispersion by a conventional method was used for blending. b-1: Aggregated powder of commercially available unmodified polytetrafluoroethylene fine particles, manufactured by Daikin Industries, Ltd., trade name: Polyflon T
FE Fine Powder F-104 (Japanese Patent Publication Sho-56-540)
According to the molecular weight measurement method described in 16 publication, it is about 4.5 million). b-2: b-1 was used without particular temperature control.

Component (C) C: potassium para-tolyl sulfimide (KTPS)
M)

Component (D) D: Phenoxy-terminated tetrabromobisphenol A
Carbonate oligomer (TBBA oligomer)

Component (E) E: potassium acid sulfate (KHSO ₄ ).

Other components (F) F-1: Impact modifier --- Methylmethacrylate-diene rubber-styrene resin (MBS) F-2: Impact modifier-Methylmethacrylate-acrylic acid ester-based Rubber-Styrene resin (MAS) F-3: Fluidity improver ··· Triphenyl phosphate (TPP)

After blending the components shown in Table 1, granulation was performed using a twin-screw extruder, and the obtained pellets were subjected to each test using a 3.5 ounce injection molding machine at a cylinder set temperature of 220 ° C. A piece was prepared and the following evaluations were performed. Table 1 shows the evaluation results.

(1) Impact resistance The notched Izod impact strength was measured according to ASTM D-256. Unit: kg ・ cm / cm2

(2) Flame-retardant property A flame-retardant property (self-extinguishing property) was measured with a test piece having a thickness of 1.6 mm in accordance with UL94, and V-0 (do No ripping),
Classified as V-1 (no dripping) or V-2 (with dripping).

(3) Surface condition The appearance (absence of abnormality) of the injection-molded product was evaluated with the naked eye,
Good (◯) and bad (×) were judged.

(4) Workability Melt flow rate. ASTM D-1238 (300
C, 1.2 kg load). g / 10 minutes.

[0044]

[Table 1]

[0045]

INDUSTRIAL APPLICABILITY In the flame-retardant thermoplastic resin composition of the present invention, due to the synergistic effect of the combination of the tetrafluoroethylene polymer having a specific structure and two specific compounds, workability, impact resistance, and appearance are obtained. And is highly useful as various flame-retardant industrial parts materials that require non-dripping properties.

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Claims (2)

[Claims] 1. A polycarbonate resin (A) 98.994.
To 76 wt%, shell-modified polytetrafluoroethylene polymer fine particles (B) 0.001 to 2.0 wt%, aromatic sulfur-containing compound (C) 0.005 to 2.0 wt% and chlorine-containing and / or A flame-retardant polycarbonate resin composition comprising 1 to 20% by weight of a bromine-containing compound (D). 2. A polycarbonate resin (A) 98.989.
-74 wt%, shell-modified polytetrafluoroethylene polymer fine particles (B) 0.001-2.0 wt%, aromatic sulfur-containing compound (C) 0.005-2.0 wt%, chlorine-containing and / or Bromine-containing compound (D) 1-20% by weight and acidic sulfuric acid and / or its metal salt (E) 0.005-
A flame-retardant polycarbonate resin composition comprising 2.0% by weight.