JPH05117515A - Polycarbonate resin composition - Google Patents

Abstract

PURPOSE:To provide a polycarbonate resin composition excellent in adhesiveness to plated films and excellent in the appearance, heat resistance and impact resistance of its molded products after plated. CONSTITUTION:The resin composition comprises (A) 80-98 pts.wt. of a thermoplastic aromatic polycarbonate resin and (B) 2-20 pts.wt. of a MBS resin produced by (co)polymerizing a methacrylic ester component, if necessary, with a vinyl cyanide component in the presence of a dienic rubber and having an average particle diameter of 0.2-0.5mum, a thio ether thermal stabilizer, a phosphite thermal stabilizer and a phenolic thermal stabilizer having a mol.wt. of >=500.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a resin composition suitable for a molding material containing a thermoplastic aromatic polycarbonate resin as a main component. The present invention relates to a polycarbonate resin composition having excellent impact resistance and heat resistance.

[0002]

2. Description of the Related Art Aromatic polycarbonate resins are used in various applications as resins having excellent impact resistance, and plated molded products are also used, for example, as automobile parts. When plating a polycarbonate molded product, pretreatment with a specific solvent is performed to improve the adhesion of the plated film, and then the surface of the molded product is roughened with a chemical etching solution. Have been proposed (for example, Japanese Examined Patent Publication (Kokoku) No. Sho 45-12996 and Japanese Patent Laid-Open No. Sho 49-1).
No. 24168, etc.). However, it is also known that these methods impair the high impact strength, which is an inherent feature of polycarbonate. It has been attempted to add a fine particle filler to polycarbonate in order to make up for such drawbacks (Japanese Patent Publication No. 50-29515), but with this method, the effect of suppressing the reduction in impact strength is not always satisfactory. Also, the adhesion strength of the plating film is low. It is also possible to blend butadiene-styrene rubber in polycarbonate (Japanese Patent Publication No.
No. 39102), there is also proposed a method of improving adhesion strength by mixing MBS resin and AS resin or MBS resin and saturated polyester resin (JP-A-55-84330). The original toughness of engineering plastics of polycarbonate is not utilized.

[0003]

In view of the deficiencies of the known techniques as described above, the present inventors have found that the polycarbonate has excellent physical properties, that is, heat resistance, impact resistance, surface gloss, etc. As a result of various studies to obtain a plated molded product, the present invention has been achieved. It is an object of the present invention to provide a molding material having an aromatic polycarbonate as a main component and having a molded article that retains excellent impact resistance even when plated. A further object of the present invention is to provide a plastic plated product that replaces the die cast plated product. That is, the present invention, (a) 80-98 parts by weight of a thermoplastic aromatic polycarbonate resin,
(b) A diene rubber component is obtained by copolymerizing an aromatic vinyl component and a methacrylic acid ester component, and optionally a vinyl cyanide component, and has an average particle size of 0.2 to 0.5 μm. A polycarbonate resin composition for plating containing 2 to 20 parts by weight of an MBS resin containing at least one of a phyto-based heat stabilizer and a phenol-based heat stabilizer having a molecular weight of 500 or more.

The thermoplastic aromatic polycarbonate resin in the present invention is an optionally branched thermoplastic polycarbonate polymer prepared by reacting an aromatic dihydroxy compound or a small amount of this polyhydroxy compound with phosgene or a diester of carbonic acid. Is. Examples of aromatic dihydroxy compounds include 2,2-bis (4-hydroxyphenyl) propane (= bisphenol A), tetramethylbisphenol A, tetrabromobisphenol A,
Examples thereof include bis (4-hydroxyphenyl) -p-diisopropylbenzene, hydroquinone, resorcinol and 4,4-dihydroxydiphenyl, and bisphenol A is particularly preferable. Further, in order to obtain a branched aromatic polycarbonate resin, phloroglucin, 4,6-dimethyl-2,4,6-tri (4-hydroxyphenyl) heptene-2,4,6-dimethyl-2,4,6- Tri (4-hydroxyphenyl) heptane, 2,6
-Dimethyl-2,4,6-tri (4-hydroxyphenyl) heptene-3,1,3,5-tri (4-hydroxyphenyl) benzene, 1,1,1-tri (4-hydroxyphenyl) ethane, etc. Examples of polyhydroxy compounds and 3,3-bis (4-
(Hydroxyaryl) oxindole (= isatin bisphenol), 5-chlorisatin bisphenol, 5,7-
Dichloroisatin bisphenol, 5-bromoisatin bisphenol, etc. are partially replaced with the polyhydroxy compound, for example, 0.1 to 2 mol%. Further suitable monovalent aromatic hydroxy compounds for controlling the molecular weight are m- and p-methylphenol, m- and p-propylphenol, p-bromophenol, p-tert-butylphenol and p-long-chain alkyl-substituted phenols. Are preferred. The aromatic polycarbonate resin is typically a bis (4-hydroxyphenyl) alkane-based dihydroxy compound, particularly a polycarbonate containing bisphenol A as a main raw material, and is obtained by using two or more aromatic dihydroxy compounds in combination. The polycarbonate copolymer may also be a branched polycarbonate obtained by using a small amount of a trivalent phenol compound. The aromatic polycarbonate resin may be a mixture of two or more kinds.

In the present invention, the MBS resin is a diene rubber component, for example, a butadiene rubber polymer such as polybutadiene or butadiene-styrene copolymer, a methacrylic ester component, and an aromatic vinyl component such as an aromatic monovinyl compound. And, if desired, one or more vinyl cyanide components in bulk polymerization, suspension polymerization, bulk / suspension polymerization,
It is obtained by graft polymerization by a method such as solution polymerization or emulsion polymerization, particularly emulsion polymerization. The amount of the butadiene-based polymer used is usually 10 to 85% by weight, preferably 30% by weight.
The content of the butadiene component in the butadiene-based polymer is preferably 50% by weight or more. The amount of butadiene-based polymer used is 10
If it is less than 5% by weight, the impact resistance of the molded product obtained from the obtained polycarbonate composition is low, and if it exceeds 85% by weight, the moldability of the obtained composition is deteriorated, which is not preferable. As the methacrylic acid ester, an alkyl ester having 1 to 4 carbon atoms, particularly methyl methacrylate is preferable. Examples of the aromatic monovinyl compound include styrene, halogenated styrene, vinyltoluene, α-methylstyrene and vinylnaphthalene, and styrene is particularly preferable. Examples of the vinyl cyanide compound include acrylonitrile, methacrylonitrile, α-halogenated acrylonitrile, and the like, and acrylonitrile is particularly preferable. The average grain size of the MBS resin is 0.2 to 0.5 μ. If it is less than 0.2μ, the low-temperature impact strength of the molded product after plating will be reduced to 0.5
If it exceeds μ, the appearance of the molded product after plating will deteriorate.

In the present invention, the MBS resin has a thioether heat stabilizer, a phosphite heat stabilizer and a molecular weight of 5%.
By blending a phenolic heat stabilizer of 00 or more, the heat-resistant coloring property and heat deterioration resistance can be improved. Examples of the thioether-based heat stabilizer include dialkyl-3,3'-thiodipropionate, tetrakis [methylene-3- (alkylthio) propionate] methane, bis [2-methyl-4-
(3-Alkyl-thiopropionyloxy) -5-tert-butylphenyl] sulfide is preferred. The phosphite-based heat stabilizer is preferably one having a pentaerythritol skeleton in the molecule, particularly di (2,4-ditertiarybutylphenyl) pentaerythritol diphosphite, bis (2,6-ditertiarybutyl-4). -Methylphenyl) pentaerythritol diphosphite is preferred. As a phenolic heat stabilizer, a hindered phenolic compound having a molecular weight of 500 or more, which hides the -OH group property of the phenolic compound, is preferable, and n-octadecyl is particularly preferable.
-3- (3 ', 5'-ditertiarybutyl-4'-hydroxyphenyl) propionate, triethylene glycol-bis [3- (3-tertiarybutyl-5-methyl-4-hydroxyphenyl) propionate] are preferred .. A compound containing a stabilizer for the MBS resin, for example, a compound commercially available from Mitsubishi Rayon Co., Ltd. under the trade name of "METABLEN MBS E-901" is preferably used.

The present invention is a resin composition containing (a) 80 to 98 parts by weight of a thermoplastic aromatic polycarbonate resin and (b) 2 to 20 parts by weight of an MBS resin. When the blending amount of the polycarbonate is less than the weight part, the physical properties inherent to the polycarbonate are deteriorated, and it becomes difficult to control the plating process. Also,
If the blending amount of the MBS resin is less than 2 parts by weight, it is not possible to suppress the decrease in impact strength of the molded product after plating.

In the thermoplastic resin composition of the present invention, various additives such as stabilizers, pigments, dyes, lubricants, etc. may be added, if necessary.
Reinforcing agents exemplified by inorganic or organic fibrous materials, various fillers exemplified by glass beads, etc. can be blended, and further other resin components may be added within a range not impairing the characteristics of the composition of the present invention. You may mix.

In preparing the thermoplastic resin composition of the present invention, conventionally known methods can be adopted, and for example, a method of kneading with an extruder, Banbury mixer, roll or the like is appropriately selected.

The method for plating a molded product molded from the resin composition of the present invention is not particularly limited, and known plating techniques can be used. For example, the surface of the molded article is treated with a pretreatment liquid prepared by diluting an aprotic polar solvent exemplified by dialkylformamide, dialkylacetamide, etc. with one or more diluents such as ethylene glycol, lower alcohol and water, and then chemical etching. The surface is roughened with a liquid, and plating is performed according to a conventional method. Details of the procedure of the method exemplified here are described in, for example, JP-B-51-24549 and JP-A-49-124168.

In the plated product of the molded product obtained by using the resin composition of the present invention, the adhesion between the polycarbonate substrate and the plated film is good, the appearance is good, the heat resistance is high, and the impact resistance is particularly high. Is kept at an extremely high level.

[0012]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples. Unless otherwise specified,% is% by weight. Examples 1 to 3, Comparative Example 1 Bisphenol A as an aromatic polycarbonate resin (Mitsubishi Gas Chemical Co., Ltd., trade name Iupilon S-2000; molecular weight 24,000, hereinafter referred to as PC) and MBS resin (Mitsubishi Rayon, E -901; average particle size 0.3μm, thioether heat stabilizer, phosphite heat stabilizer and phenol heat stabilizer with molecular weight of 500 or more) are mixed in a tumbler in the ratios shown in Table 1, and each is uniaxial. The pellets were extruded with a vent type extruder. The pellets are heated in a hot air dryer at 120 ° C.
After drying at 270 ° C. for 5 hours, an Izod impact test piece with a disc having a thickness of 3.2 mm and a diameter of 101 mm and a notch of 1.0 R was molded at a resin temperature of 270 ° C. The molded product obtained was treated with 70% by volume of dimethylformamide, 20% by volume of ethylene glycol and 10% by volume of water.
And a mixed acid, followed by chemical plating and electroplating according to a standard method to obtain a chrome-plated product. Table 1 shows the properties of the obtained plated product. Adhesion strength reaches the base material on the metal film of the plated product
The stress when peeling the metal film in the vertical direction with two cuts at 1 cm intervals was shown. Izod impact strength is ASTM D
Measured based on -256.

Comparative Example 2 PC and MBS resin (manufactured by Mitsubishi Rayon, C-223; without heat stabilizer) were mixed in a tumbler at a ratio shown in Table 1 and extruded into pellets by a uniaxial vented extruder. .. After drying the pellets at 120 ° C. for 5 hours in a hot air drier, a test piece similar to that of Example 1 was molded. The obtained molded product was plated in the same manner as in Example 1 and the properties of the plated product were measured. The results are also shown in Table 1.

Comparative Example 3 PC and MBS resin (manufactured by Japan Synthetic Rubber Co., Ltd., 67E; average particle size 0.17 μm, no heat stabilizer) were mixed in a tumbler at the ratios shown in Table 1, and each was uniaxially bent. Pellets were extruded with a rotary extruder. 1 in a hot air dryer
After drying at 20 ° C. for 5 hours, a test piece similar to that in Example 1 was molded. The obtained molded product was plated in the same manner as in Example 1 and the properties of the plated product were measured. The results are also shown in Table 1.

Comparative Example 4 Example 1 except that the average particle size of the MBS resin was 0.17 μm.
Same as. The results are also shown in Table 1.

[0016]Table 1 Ratio 1 Fruit 1 Fruit 2 Fruit 3 Ratio 2 Ratio 3 Ratio 4 Resin composition (wt%)  PC 70 80 90 97 90 90 90 MBS Resin 30 20 10 3 10 10 10 Average particle size μm 0.30 0.30 0.30 0.30 0.30 0.17 0.17 With / without stabilizer Yes Yes Yes Yes Yes No No Yes Yes Change of molded product Change Change Change Yellowing Change Yellowing Change Heat resistance test ^* None None None None None Plating Appearance Plating Good Good Good Good Pit Pit Good Not arrived Occurred Occurred Plating film 0.6 1.1 1.6 1.5 0.8 1.3 1.3 Adhesion strength (kg / cm) 〜 1.2 〜 1.5 〜 2.2 〜 2.3 〜 1.4 〜 1.8 〜 1.5 Izod impact strength (kg / cm) 23 ℃ 82 82 90 80 70 85 80−40 ° C 35 40 60 25 24 8 7 Thermal aging test Blisters change change change change change change Occurrence at 130 ℃, 5 hours None None None None None None None ^*In the table, heat resistance test is in an oven maintained at 120 ° C.
The result of observing the change of state after left for 5 hours is shown below.

[0017]

The plated product of the molded product obtained by using the resin composition of the present invention has good adhesion between the polycarbonate substrate and the plated film, good appearance, and high heat resistance.
In particular, the impact resistance is kept at an extremely high level.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takami Enoki 5-6-2 Higashi-Hachiman, Hiratsuka-shi, Kanagawa Sanryo Gas Chemical Co., Ltd. Plastics Center

Claims (1)

[Claims] 1. A copolymer of (a) 80 to 98 parts by weight of a thermoplastic aromatic polycarbonate resin, (b) a diene rubber component, an aromatic vinyl component and a methacrylic acid ester component, and optionally a vinyl cyanide component. MB having an average particle size of 0.2 to 0.5 μm and a thioether heat stabilizer, a phosphite heat stabilizer and a phenol heat stabilizer having a molecular weight of 500 or more.
Polycarbonate resin composition for plating containing 2 to 20 parts by weight of S resin