JPS6212818B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel thermoplastic resin composition, and more specifically, it is a thermoplastic resin composition that has excellent solvent resistance and paintability, and has improved moldability. Traditionally, ABS resin, a typical diene-based rubber graft copolymer, has been added to polycarbonate resin.
Attempts to improve the moldability of polycarbonate resin by adding MBS resin or ABSM resin and further reduce the thickness dependence of impact strength were made by Tokko Sho.
No. 38-15225, Special Publication No. 39-71 or Special Publication No. 52
- Proposed in No. 11496. A method of improving impact resistance using ABS resin produced by bulk-suspension polymerization has also been proposed. (Tokuko Showa 51-
(No. 11142) However, all of these compositions are insufficient in solvent resistance or paintability, which are important practical characteristics of molding materials, and are particularly difficult to use in injection molding, which is the most common molding method for thermoplastic resin compositions. Defects related to solvent resistance are likely to occur, such as stress cracks caused by solvents due to residual strain in molded products or stress cracks caused by thinner during painting. The present inventor has arrived at the present invention as a result of extensive research into the solvent resistance and paintability of such compositions comprising polycarbonate resins and polymers. That is, the present invention relates to a thermoplastic resin composition having excellent solvent resistance, paintability, and processability, which is obtained by blending a small amount of polyamide resin into a composition consisting of a polycarbonate resin and a polymer. The thermoplastic resin composition of the present invention will be explained in detail below. Various types of polycarbonate resins can be used in the present invention. 2. by transesterification method or phosgene method
2-(4.4'-dihydroxydiphenyl)-propane, a so-called aromatic polycarbonate, is preferred. Conjugated diene rubber - aromatic vinyl - carboxylic acid alkyl ester polymer or conjugated diene rubber - aromatic vinyl - carboxylic acid alkyl ester -
Conjugated diene rubbers constituting other polymerizable monomers include polybutadiene and styrene-based rubbers.
Examples include butadiene copolymers. Examples of the aromatic vinyl include styrene, α-methylstyrene, dimethylstyrene, vinyltoluene, and the like. In addition, as carboxylic acid alkyl esters, methacrylic acid esters such as methyl methacrylate and ethyl methacrylate, acrylic acid esters such as methyl acrylate and ethyl acrylate, and carboxylic acid hydroxyalkyl esters such as hydroxyethyl acrylate and hydroxymethyl methacrylate. can be mentioned. Further, examples of other polymerizable monomers include vinyl cyanides such as acrylonitrile and methacrylonitrile. Furthermore, as polyamide resin, nylon 4,
Examples include nylon 6, nylon 7, nylon 8, nylon 9, nylon 11, nylon 12, nylon 66, nylon 610, etc., and one or more types can be used. The amounts of polycarbonate resin and polymer are respectively
20-80% by weight and 80-20% by weight. If the polycarbonate resin exceeds 80% by weight, the melt viscosity during molding will increase, the moldability will deteriorate, and the residual strain of the injection molded product will increase, and even if polyamide resin is added, paintability or solvent resistance will not be improved. . On the other hand, if the polycarbonate resin is less than 20% by weight, the heat resistance will decrease and the compatibility with the polyamide resin will also deteriorate, resulting in a decrease in impact strength. Preferably polycarbonate resin 50-80% by weight
It is. The polyamide resin is used in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the composition of polycarbonate resin and polymer. If it is less than 0.1 part by weight, there will be no effect of improving solvent resistance or paintability, and if it exceeds 20 parts by weight, compatibility will deteriorate and impact strength will drop significantly. Addition of 0.1 to 20 parts by weight of polyamide resin also improves the moldability of the composition. The thermoplastic resin composition of the present invention can be mixed by a known mixing method using a conventional roll, Banbury mixer, extruder, or the like. The thermoplastic resin composition of the present invention may be used with the addition of colorants, dispersants, lubricants, fillers, etc., if necessary. The present invention will be specifically explained below using Examples, but the present invention is not limited thereto. Examples: Panlite L-1250W (manufactured by Teijin Kasei) commercially available as a polycarbonate resin and Unitika Nylon A- commercially available as a polyamide resin.
1030BRL ("Nylon 6" manufactured by Unitika) and Diamid L-1940 ("Nylon 12" manufactured by Daicel-Hyuls) were used. In addition, a polymer obtained by the following production method was used as the polymer. Polycarbonate resin, polymer, and polyamide resin were mixed in a Henschel mixer based on the formulation shown in Table 1, and then granulated in a 65φ vented extruder. The obtained pellets were used to mold test pieces for physical property tests and flat plates for painting (90 x 130 x 2 mm) using a 5-ounce injection molding machine. In addition, in order to determine the critical strain, a flat plate (20 x 120 x 3 mm) was formed using a press molding machine. Table 2 shows the results of basic physical properties, solvent resistance (critical strain), and paintability (stress cracks in and around the gate). Solvent Resistance After applying various solvents to a press-formed plate, the critical strain was determined using the jig shown in FIG. The larger the critical strain, the better the solvent resistance. Critical strain = 3h・Xc・δ/2l ³ ×100(%
) h: Thickness of the sample (3 mm) Xc: Distance from the maximum deflection point to the crack occurrence point l: Distance from the fixed end to the maximum deflection point δ: Maximum amount of deflection

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【table】 [Brief explanation of the drawing]

Figure 1 shows a jig used to determine the critical strain during solvent application, which is one of the solvent resistance tests. A: Holder, B: Sample.

Claims (1)

[Scope of Claims] 1 20 to 80% by weight of polycarbonate resin and conjugated diene rubber-aromatic vinyl-carboxylic acid alkyl ester polymer or conjugated diene-based rubber-aromatic vinyl-carboxylic acid alkyl ester polymer and other polymerizable monomers Composition 100 consisting of 80-20% by weight of combined
1. A thermoplastic resin composition comprising 0.1 to 20 parts by weight of polyamide resin and 0.1 to 20 parts by weight of polyamide resin. 2. The thermoplastic resin composition according to claim 1, wherein the other polymerizable monomer is vinyl cyanide. 3. The thermoplastic resin composition according to claim 1, which contains 50 to 80% by weight of polycarbonate resin and 50 to 20% by weight of polymer.