JPH11286599A - Aromatic polycarbonate-based resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an aromatic polycarbonate-based resin composition having an excellent mechanical strength and preventing the generation of white streaks and giving greatly excellent appearance when molded. SOLUTION: This aromatic polycarbonate-based resin composition is obtained by adding (d) 10-30 pts.wt. of wollastonite whose surface is treated with (d1) a mixture of a polyalkoxysiloxane with an epoxy silane-based coupling agent and/or (d2) a reaction product of a polyalkoxysiloxane with an epoxy silane- based coupling agent, to 100 pts.wt. of a resin composition comprising (a) 80-50 wt.% of an aromatic polycarbonate resin, (b) 19-49 wt.% of a thermoplastic aromatic polyester and (c) 1-10 wt.% of an elastomer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a polycarbonate resin composition.

[0002]

2. Description of the Related Art A resin composition comprising an aromatic polycarbonate resin and a thermoplastic aromatic polyester resin has excellent mechanical properties, heat resistance, chemical resistance, etc., and is therefore used in automobiles, copiers, printers, cameras, agricultural equipment and the like. Widely used as exterior parts. However, its mechanical properties, especially mechanical strength such as tensile strength and flexural strength, are insufficient with resin alone, so various inorganic reinforcing materials such as glass fiber, mica, talc, carbon fiber, wollastonite And reinforcement with potassium titanate fiber and the like have been attempted. In particular, it has been reported that a molded article having excellent surface properties can be obtained when wollastonite is used (Japanese Patent Application Laid-Open No. 9-286904).

[0003]

However, particularly with respect to a resin composition comprising an aromatic polycarbonate resin and a thermoplastic aromatic polyester resin, there is a problem that the mechanical strength is not sufficiently improved by wollastonite. Was. Furthermore, when wollastonite is used, during molding,
Silver-white streaks, so-called silver, occur in the direction of flow of the resin and impair the appearance. Even if painted, the defects are conspicuous, reducing the commercial value of parts requiring sharpness,
In the case of molding for a long time or after molding, the disadvantage is remarkable. An object of the present invention is to provide an aromatic polycarbonate resin composition having excellent mechanical strength and preventing generation of silver during molding. Another object of the present invention is to provide an aromatic polycarbonate-based resin composition which can provide a very excellent appearance without performing a coating treatment and is suitable as an exterior part of an automobile.

[0004]

The present invention comprises (a) 80 to 50% by weight of an aromatic polycarbonate resin, (b) 19 to 49% by weight of a thermoplastic aromatic polyester, and (c) 1 to 10% by weight of an elastomer. (D) (d1) a mixture of a polyalkoxysiloxane and an epoxysilane-based coupling agent and / or (d2)
Wollastonite 10 surface-treated with a reaction product of a polyalkoxysiloxane and an epoxysilane-based coupling agent
The present invention relates to an aromatic polycarbonate resin composition containing up to 30 parts by weight.

[0005] Preferred embodiments of the present invention are as follows. (1) Wollastonite has an average fiber length of 20 to 50 μm, an average fiber diameter of 0.05 to 5 μm, and an average aspect ratio of 8 to 100.
The aromatic polycarbonate resin composition according to claim 1, which is:

The present inventor has found that by treating wollastonite with a specific surface treating agent, the mechanical strength can be remarkably improved and the generation of silver can be prevented, and the present invention has been completed.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The aromatic polycarbonate resin which can be used in the present invention is not particularly limited, and a conventionally known polycarbonate resin such as a resin produced by reacting an aromatic phenol compound with phosgene or a carbonic acid diester. Can be widely used. In the present invention, a branched polycarbonate resin can also be used.
As a specific example of the polycarbonate resin, a polycarbonate resin synthesized from bisphenol A as a main raw material by a solvent method or a melting method can be exemplified. The molecular weight of the polycarbonate resin that can be used in the present invention is not particularly limited. For example, those having a viscosity average molecular weight in a range of 19000 to 30000 measured in a methylene chloride solvent are preferably used.

The thermoplastic aromatic polyester resin which can be used in the present invention is a resin obtained by a polycondensation reaction between an aromatic or aliphatic diol compound and an aromatic or aliphatic dibasic acid. Can be widely used. Specific examples include polybutylene terephthalate, polyethylene terephthalate, polyhexamethylene terephthalate, polycaprolactone, and the like.
Among these, the intrinsic viscosity measured with a mixed solvent of phenol / tetrachloroethane (volume 6/4) is 0.7 to 1.2.
Are preferred.

The elastomers usable in the present invention include polyester elastomers, MBS resins (methyl methacrylate-butadiene-styrene resin),
MAS resin (methyl methacrylate-acrylonitrile-
(Styrene resin), acrylate core-shell graft copolymer, polyolefin and polyolefin-based elastomer, styrene core-shell graft copolymer, SBR (styrene butadiene rubber), SIS (styrene isoprene styrene block copolymer), SEBS
(Styrene-ethylene-butadiene-styrene copolymer), polyurethane-based elastomer and the like, and these may be used alone or in combination of two or more. In the present invention,
Among the above, aromatic polycarbonate resin, and compatibility with thermoplastic aromatic polyester, from the viewpoint of heat resistance,
In particular, polyester-based elastomers, MAS resins, acrylate core-shell graft copolymers, styrene-based core-shell graft copolymers and the like are preferably used.

The wollastonite used in the present invention is Ca
It is a fibrous or acicular natural mineral containing SiO ₃ as a main component, and generally contains impurity elements such as Fe, Mn, Al, C, K, and Na. In the present invention, the average fiber length is 20 to
Wollastonite having a particle size of 50 μm, an average fiber diameter of 0.05 to 5 μm, and an average aspect ratio of 8 to 100 is preferably used because it has a high effect on improving the strength of the target resin composition. Many wollastonites contain Na, K, etc. on the surface or inside, and are often accompanied by elution of alkali when added to the resin. The amount of such alkali elution can be estimated from the amount of alkali elution in water. In this specification,
What is the elution alkali of wollastonite?
1 g was dispersed in 100 ml of water, stirred at room temperature for 1 hour, filtered through a No ₅ C filter paper, and the amount of alkali determined by measuring the filtrate by atomic absorption spectrometry. As the wollastonite used in the present invention, a wollastonite having an alkali elution amount of 30 ppm or less of Na and a K of 40 ppm or less is particularly preferably used from the viewpoint of improving the strength of a molded article and preventing silver from being generated. Such wollastonite can be obtained by sufficiently washing naturally occurring wollastonite with water. The washing condition depends on the amount of alkali contained in wollastonite, but it can be obtained by dispersing wollastonite in water, stirring for about 15 minutes to 3 hours, centrifuging, further washing with water, and drying.

In the present invention, wollastonite is (d1)
A mixture of a polyalkoxysiloxane and an epoxysilane coupling agent and / or (d2) a surface treatment with a reaction product of a polyalkoxysiloxane and an epoxysilane coupling agent is used. The polyalkoxysiloxane is a compound represented by the following formula (1), wherein n is 2 to 20, preferably 2 to 7, and examples of the alkoxy group for R include methoxy, ethoxy, and propoxy groups. And particularly preferably a methoxy group.

[0012]

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As the epoxysilane coupling agent, γ- (methacryloyloxypropyl) trimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, β
-(3,4-epoxycyclohexyl) ethyltrimethoxysilane and the like can be exemplified. (D1) As a mixture of a polyalkoxysiloxane and an epoxysilane-based coupling agent, a mixture having a former: latter ratio of about 100: 1 to 1:10, preferably about 10: 1 to 1: 1 (weight ratio) is used. Can be (D2) The reaction product of the polyalkoxysiloxane and the epoxysilane-based coupling agent is a polyalkoxy having a side chain having an epoxy group, which is obtained by reacting the polyalkoxysiloxane with the epoxysilane-based coupling agent. A siloxane compound having a viscosity average molecular weight of about 500 to 50,000 can be exemplified. Specific examples of such a reactant include, for example, a reactant represented by the following formula (2). l is 2 to 20, m is 1 to 1
0, l / m = 10/1 to 1/1, preferably 5/1 to 3
/ 1, especially preferably about 4/1, R is the same as above.

[0014]

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The treatment of wollastonite with the component (d1) or (d2) is performed at a rate of 0.1 to 30 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of wollastonite. Is good. Such a treatment is carried out while stirring wollastonite using a super mixer, a Henschel mixer, a ribocorn mixer, or the like, while (d1) or (d)
2) It can be carried out by dropping or spraying the components.

In the present invention, (a) 80 to 50% by weight, preferably 75 to 60% by weight of an aromatic polycarbonate resin, (b) 19 to 49% by weight, preferably 20 to 35% by weight of a thermoplastic aromatic polyester, (C) 100 parts by weight of a resin composition containing 1 to 10% by weight, preferably 3 to 6% by weight of an elastomer, and (d) a mixture of (d1) a polyalkoxysiloxane and an epoxysilane-based coupling agent and / or ( d2) 10-30 parts by weight, preferably 12 parts by weight, of wollastonite surface-treated with a reaction product of a polyalkoxysiloxane and an epoxysilane-based coupling agent
-25 parts by weight are blended.

The resin composition of the present invention contains a polystyrene resin, a styrene-acrylonitrile resin, a polyethylene resin, a polyolefin resin, a polypropylene resin, a polyamide resin, a polyether resin, a polysulfone resin, and a polyether resin as long as the object of the present invention is not impaired. A resin such as a sulfone resin may be further compounded. Further, the resin composition of the present invention, a heat stabilizer, as long as the object of the present invention is not impaired,
Lubricants, release agents, pigments, dyes, ultraviolet absorbers, flame retardants, lubricants, fillers, reinforcing agents, and the like can be added as appropriate.
As the heat stabilizer, phosphorous acid, hindered phenol, phosphite and the like are particularly preferable.

In producing the resin composition of the present invention, it can be produced by a widely known production method. As a specific example of the production method, while the respective resin components (a), (b) and (c) are melt-kneaded by a twin-screw kneader or the like, the wollastonite of the component (d) and, if necessary, added. A method in which other components are charged from a side hopper and kneaded can be exemplified. The obtained resin composition may be formed into a desired shape as it is, or may be once distributed and stored as pellets.

[0019]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples. W-1: average fiber diameter 2.0 μm, average fiber length 25 μ obtained by subjecting US-made wollastonite to a water washing step and drying.
m, elution alkali analysis result: Na: 11 ppm, K: 6 ppm
2% by weight of wollastonite surface treated with poly-3- (2,3-epoxypropoxy) propylmethoxysiloxane [manufactured by Mitsubishi Chemical Corporation, trade name: MSEP-2].

W-2: The wollastonite used in Example 1 was treated with γ-methacryloxypropyltrimethoxysilane [manufactured by Nippon Yunika Co., Ltd., trade name A187] and polymethoxysiloxane [manufactured by Mitsubishi Chemical Corp. Name MS-5
1] A mixture of 1: 2 treated with 2% by weight surface. W-3: The same wollastonite as in Example 1 but without surface treatment. W-4: US-made wollastonite (average fiber diameter 2.0 μm,
Average fiber length 25 μm, elution alkali analysis result Na: 50
ppm, K: 52 ppm) subjected to the same surface treatment as W-1.

W-5: Average fiber diameter 6.0 μm, average fiber length 132 μm, elution alkali analysis result Na: 36 ppm, K:
36 ppm wollastonite subjected to the same surface treatment as W-1. GF: ECSO3T-511: glass fiber manufactured by NEC Corporation. T: Talc P-3, Talc from Nippon Talc Co., Ltd. PC (polycarbonate): Iupilon S2000 [Mitsubishi Engineering Plastics Co., Ltd.]

PBT: Duranex 2002 [Polyplastics Co., Ltd., polybutylene terephthalate] Elastomer: Staphyloid MG1011 [Takeda Pharmaceutical Co., Ltd., styrene-based core-shell graft copolymer] Stabilizer: ADK STAB AX-71 [ Asahi Denka Co., Ltd.]

Examples 1 to 3 and Comparative Examples 1 to 5 The components shown in Table 1 were used in the proportions shown in Table 1 first, PC,
PBT, elastomer, and stabilizer are mixed by a tumbler, supplied to the main hopper of a twin-screw kneader set at 260 ° C, supplied with an inorganic filler from a side feeder, melt-kneaded, and then granulated by strand cutting. It has become. After drying the obtained pellet, a test piece was molded by injection molding (cylinder temperature: 280 ° C.), and the characteristics were evaluated by the following methods. Table 2 shows the results.

Tensile test: ASTM D 638 Bend test: ASTM D 790 Izod (IZOD) test: ASTM D 256 HDT: ASTM D 648 (18.5 kg / cm ² )

Appearance: The appearance of the surface of the 90503 mm plate was visually judged. ：: good appearance ×: poor appearance Silver generation: After a residence time of 30 minutes in the cylinder, 5 shot molding was performed, and the presence or absence of silver generation near the gate was visually judged. ○: No silver generation ×: Large silver generation

[0026]

[Table 1]

[0027]

[Table 2]

[0028]

According to the present invention, an aromatic polycarbonate resin composition having excellent mechanical strength and preventing generation of silver during molding can be obtained. Further, according to the present invention, an extremely excellent appearance can be obtained without applying a coating treatment, and an aromatic polycarbonate resin composition suitable as an exterior part of an automobile can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 21:00)

Claims (2)

[Claims] (A) Aromatic polycarbonate resin 80
To 50% by weight, (b) thermoplastic aromatic polyester 19
(D) a mixture of (d1) a polyalkoxysiloxane and an epoxysilane-based coupling agent and / or (d2) a poly (d) in 100 parts by weight of a resin composition containing 1 to 10% by weight of an elastomer (c). An aromatic polycarbonate resin composition comprising 10 to 30 parts by weight of wollastonite surface-treated with a reaction product of an alkoxysiloxane and an epoxysilane coupling agent. 2. The amount of alkali dissolved in wollastonite is N
The aromatic polycarbonate resin composition according to claim 1, wherein a is 30 ppm or less and K is 40 ppm or less.