JPH032387B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a thermoplastic resin having excellent surface smoothness and excellent weather resistance. Polycarbonate resin (hereinafter abbreviated as PC) is an excellent resin with high heat resistance and is widely used in various fields. However, PC has high notch sensitivity when it comes to impact resistance, and becomes extremely brittle when scratched at a sharp angle. It has poor fluidity and requires high temperature molding. Poor chemical resistance. There are other difficulties. As a way to compensate for these drawbacks, ANS resin (Special Publication No. 38-15225) was used for PC.
Many modifications have been proposed by mixing rubber-reinforced styrene resins with MBS resin (Japanese Patent Publication No. 39-71), olefin rubber-modified thermoplastic resin (Japanese Patent Publication No. 51-24540), etc. However, because the rubber-like polymer used in rubber-reinforced thermoplastic resins such as ABS resin and MBS resin is diene rubber, these compositions have significantly poor weather resistance when used outdoors, and are not satisfactory materials. It can't be. Olefin rubber-modified thermoplastic resin
If blended with PC, the composition will have improved weather resistance, but the surface smoothness of the injection molded product will be poor, and weld marks will occur at the weld area where the resin joins in the mold cavity during injection molding. However, there were disadvantages in that the product value of the molded product was significantly lowered due to poor appearance and deterioration of physical properties. Therefore, the present inventors have developed a resin composition that is a blend composition of an olefin rubber-modified thermoplastic resin and PC that has excellent processability, heat resistance, and weather resistance without causing surface smoothness and weld mark defects in injection molded products. As a result of intensive study, the present invention was arrived at. That is, the present invention adds a monomer mixture (b) consisting of an aromatic compound, a vinyl cyanide compound, and, if necessary, a vinyl compound copolymerizable with these, to an ethylene/α-olefin rubber-like polymer (a). Thermoplastic resin obtained by graft copolymerization ()45~
A monomer mixture consisting of a rubbery polymer (c) mainly consisting of 95% by weight and a diene rubbery polymer, an unsaturated carboxylic acid alkyl ester compound, an aromatic vinyl compound, and optionally a cyanide vinyl compound. A rubber modified thermoplastic resin (A) consisting of 5 to 55% by weight of a thermoplastic resin obtained by graft copolymerizing (d) (A) 10 to 80% by weight, and a polycarbonate resin (B)
It is a thermoplastic resin composition consisting of 90 to 20% by weight. The present invention provides a blend composition of an olefinic rubber-modified thermoplastic resin () and PC as a third component.
Obtained by graft copolymerizing a monomer mixture consisting of an unsaturated carboxylic acid alkyl ester compound, an aromatic vinyl compound, and optionally a vinyl cyanide compound to a rubbery polymer mainly consisting of a diene rubbery polymer. By mixing a rubber-reinforced thermoplastic resin (2), the surface smoothness of the composition and the ease with which weld marks occur are improved. Moreover, the resin composition of the present invention has excellent weather resistance even though it contains a rubber-modified resin based on diene rubber. Almost no characteristics are lost. The thermoplastic resin () used in the present invention is an ethylene-α olefin copolymer or an ethylene-α olefin copolymer.
A monomer mixture containing an aromatic vinyl compound and a vinyl cyanide compound as main components in the presence of a rubbery polymer (a) such as an olefin-nonconjugated diene copolymer rubber.
It is a resin mixture consisting of a graft copolymer obtained by copolymerizing (b) or a copolymer of the above-mentioned monomer mixture. As a manufacturing method, various methods including radical polymerization of vinyl monomers in the presence of rubber, such as emulsion polymerization, bulk polymerization, suspension polymerization, and solution polymerization, can be used. Aromatic vinyl compounds used as monomers include styrene, α-methylstyrene, and P-methylstyrene. The vinyl cyanide compound is selected from acrylonitrile, methacrylonitrile, and the like. Furthermore, it is possible to use a small amount of vinyl compounds copolymerizable with these, such as alkyl acrylates and alkyl methacrylates. The rubber content in the thermoplastic resin ( ) used in the present invention is preferably 10 to 60% by weight, more preferably
It is 15-40% by weight. On the other hand, the composition amount of aromatic vinyl compound (a), vinyl cyanide compound (b), and other copolymerizable vinyl compound (c) in the monomer component is (a)/(b)
The weight ratio of is 90:10 to 60:40, and (a) + (b) is 100
50% by weight, and (c) preferably 0 to 50% by weight. The thermoplastic resin () used in combination with the thermoplastic resin () is produced by copolymerizing a monomer mixture (d) mainly composed of an unsaturated carboxylic acid alkyl ester compound in the presence of a diene rubber (c). It is a resin mixture consisting of a graft copolymer obtained by the above method or a copolymer of a mixture of the graft copolymer and a mixture whose main component is an unsaturated carboxylic acid alkyl ester compound. Production methods include various methods of radical polymerization of vinyl monomers in the presence of rubber, such as emulsion polymerization method, bulk polymerization method,
It can be manufactured by suspension polymerization method, solution polymerization method, etc. The diene rubber used in the present invention includes butadiene rubber, styrene-butadiene copolymer rubber, isoprene rubber, and the like. Unsaturated carboxylic acid alkyl ester compounds used as monomers include methyl acrylate, ethyl acrylate,
Methyl methacrylate, ethyl methacrylate,
The polymer is a methacrylic acid ester compound such as n-propyl methacrylate or isopropyl methacrylate whose glass transition temperature is higher than room temperature, and methyl methacrylate, which has a high glass transition temperature, is particularly preferred. The same aromatic vinyl compounds and vinyl cyanide compounds used in the thermoplastic resin (A) can be used, and one or more vinyl monomers selected from these compounds can be used. The composition ratio of () is 5 to 70% diene rubber component, 95 to 30% monomer component, and the content of unsaturated carboxylic acid alkyl ester component in monomer component (d) is 45 to 95%. It is preferable. More preferably, the diene rubber component is 10 to 50% and the monomer component is 90 to 50%, and the content of the unsaturated carboxylic acid alkyl ester component in the monomer component is 50 to 85%. If the diene rubber component is less than 5%, the desired tensile strength and surface gloss of the weld portion can be obtained, but if it exceeds 70%, the weather resistance decreases, which is not preferable. If the content of the unsaturated carboxylic acid alkyl ester component in the monomer component is low, the desired surface gloss and weld mark cannot be sufficiently improved. on the other hand
If it exceeds 95%, thermal stability will decrease and the molded product may become discolored or flash (silver streaks).
This is not desirable because it causes The blending ratio of thermoplastic resin () and thermoplastic resin (2) is preferably 95:5 to 45:55 in weight% ratio.
The range is 90:10 to 50:50. If the amount of thermoplastic resin () exceeds this range, it will not be effective in improving surface smoothness and weld marks, which are the characteristics of the present invention, and conversely, if the amount of AES resin is less than this range, weather resistance will decrease. Undesirable. The polycarbonate resin (B) is a commonly used aromatic polycarbonate, which is produced using bisphenol as a main raw material by a phosgene method, a transesterification method, or the like.
As the raw material bisphenol, 2,2-(4,
A typical example is a 4,4'-dihydroxyphenylalkane polycarbonate obtained using 4'-hydroxydiphenyl)-propane, so-called bisphenol A. The thermoplastic resin of the present invention is a thermoplastic resin ()
The composition ratio of the total amount of the thermoplastic resin (A) and the polycarbonate resin (B) is 10:90 to 80:20.
If the proportion of the polycarbonate resin (B) exceeds 90% by weight, there will be no characteristic in molding processability, and if it is less than 20% by weight, the impact resistance will be poor, which is not preferable. To obtain the thermoplastic composition of the present invention, powders or pellets of the thermoplastic resin () and rubber-reinforced thermoplastic resin () and powders or pellets of the polycarbonate resin may be mixed, respectively;
Pre-mixed pellets of () and ()
(A) may be mixed with polycarbonate (B). As the mixing method, a known mixing method using a Banbury mixer, an extruder, etc. is used. Although the examples of the present invention are shown using products to which no dyes or pigments are added, similar effects can be obtained with color products to which dyes or pigments are added. It is also possible to use known stabilizers, lubricants, antistatic agents, ultraviolet absorbers, and fillers during mixing. The present invention will be specifically explained below using examples. Parts and % in Examples and Comparative Examples indicate parts by weight and % by weight, respectively. Thermoplastic resin () <Polymer No.-1> Iodine value 15, Mooney viscosity 42, 5-ethylidene-2- as the diene component, which was made into a homogeneous solution in advance in a stainless steel autoclave with an internal volume of 50 and equipped with a ribbon-type stirring blade. 20 parts by weight of EPDM containing norbornene (JSR EP22 manufactured by Japan Synthetic Rubber Co., Ltd.), 56 parts by weight of styrene
parts by weight, 120 parts by weight of toluene, and 0.1 parts by weight of tertiary decyl mercaptan were charged, the temperature was raised while stirring, and at 50°C, 24 parts by weight of acrylonitrile, 0.5 parts by weight of benzoyl peroxide, and 0.1 parts by weight of dicumyl peroxide were added. The temperature further increases to 80
After reaching the temperature, the polymerization reaction is carried out at a stirring speed of 100 rpm while controlling the temperature to be constant at 80°C. 120℃ for 1 hour from 6 hours after the start of the reaction
The temperature was raised to 100.degree. C., and the reaction was continued for an additional 2 hours to complete the reaction.
The polymerization rate was 97%. After cooling to 100℃,
2,2'-methylene-bis(4-methyl-6-t-
After adding and mixing 0.7 parts by weight (butylphenol), the reaction mixture was extracted from the autoclave,
Most of the unreacted monomers and solvent are distilled off by steam distillation, and after finely pulverized, the volatile matter is substantially distilled off using a 40 mmφ vented extruder (220°C > 700 mmHg vacuum), and the polymer is made into pellets. Recovered. <Polymer No.-2> A polymer was obtained in the same manner as <Polymer No.-1> above, except that 40 parts by weight of EPDM, 42 parts by weight of styrene, 18 parts by weight of acrylonitrile, and 150 parts by weight of toluene were used. Manufacturing method of thermoplastic resin (Polymer No.-1) After sufficiently purging the inside of a stainless steel reactor with a stirrer with nitrogen, 20 parts of polybutadiene latex (JSR0700 manufactured by Japan Synthetic Rubber Co., Ltd.) (solid content) was added in a nitrogen stream. ), 200 parts of ion-exchanged water, and 3 parts of potassium stearate, and while stirring, add 24 parts of styrene.
48 parts of methyl methacrylate, 8 parts of acrylonitrile
part, 0.2 parts of tertiary lead decyl mercaptan,
Sodium formaldehyde sulfonate dihydrate
0.4 parts sodium ethylenediaminetetraacetate
Add 0.2 parts, 0.01 parts of ferrous sulfate, and 0.3 parts of cumene hydroperoxide. 60℃ with continuous stirring
The polymerization reaction was carried out for 4 hours. The polymerization conversion rate at that time was 95%. After coagulating using an aqueous sulfuric acid solution, washing with water, dehydration, and drying were performed to obtain a polymer. <Polymer No.-2> 20 parts of polybutadiene latex (as solid content), 32 parts of methyl methacrylate, 36 parts of styrene,
Except for using 12 parts of acrylonitrile, <Polymer No.
A polymer was obtained in the same manner as in -1>. <Polymer No.-3> 20 parts of polybutadiene latex (as solid content), 64 parts of methyl methacrylate, 8 parts of styrene,
<Polymer No. except that 8 parts of acrylonitrile was used.
A polymer was obtained in the same manner as in -1>. <Polymer No.-4> Except that 20 parts of polybutadiene latex (as solid content) and 80 parts of methyl methacrylate were used.
A polymer was obtained in the same manner as in Polymer No.-1>. Polycarbonate resin (B) A commercially available polycarbonate resin, Idemitsu Petrochemical Polycarbonate A2200, was used. Examples and Comparative Examples The thermoplastic resin () obtained by the above method, the rubber-modified thermoplastic resin (), and the polycarbonate resin (B) were mixed into pellets using an extruder (set at 230°C).
It was obtained by melt-kneading. Table 1 shows the resin composition.
Shown below. Test pieces were molded using a Toshiba Machine IS70A injection molding machine (set at 250°C) and their physical properties were measured. Regarding weld marks and strength, test pieces were similarly obtained using a mold into which resin flows from both ends of a JIS No. 1 dumbbell, and weld marks were visually observed and strength was determined by tensile strength. The strength is shown in comparison to the strength of a test piece without weld marks. Regarding weather resistance, the gloss after 1000 hours on the Sunshine Weather Ometer (both incident angle and reflection angle is 45
℃). As an index expressing the surface smoothness of a molded test piece,
The surface gloss was measured and shown.

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Claims (1)

[Claims] 1 Ethylene/α-olefin rubber-like polymer (a)
45 to 95% by weight of a thermoplastic resin () obtained by graft copolymerizing a monomer mixture (b) consisting of an aromatic compound, a vinyl cyanide compound, and, if necessary, a vinyl compound copolymerizable with these. and rubber-like polymers (c) mainly composed of diene-based rubber-like polymers
, an unsaturated carboxylic acid alkyl ester compound,
Thermoplastic resins () 5 to 55 obtained by graft copolymerizing a monomer mixture (d) consisting of an aromatic vinyl compound and, if necessary, a vinyl cyanide compound
Rubber-modified thermoplastic resin (A) consisting of 10 to 80% by weight
% by weight and 90 to 20% by weight of polycarbonate resin (B).