JPS6129977B2 - - Google Patents

Description

[Detailed description of the invention]

Polypropylene is an inexpensive resin and is widely used in various molded products and films. However, when used as molded products, it has many defects such as low rigidity, low low-temperature impact strength, high mold shrinkage, and poor paintability, adhesion, dyeability, and plating properties. Inorganic fillers such as glass fiber, calcium carbonate, talc, and asbestos are added to improve rigidity and mold shrinkage. Although these additions serve the purpose of improving rigidity and molding shrinkage, they also cause other problems such as deterioration of moldability and wear of the molding machine. On the other hand, styrene resins do not have the disadvantages of polypropylene, but they are expensive and their excellent characteristics cannot be said to be fully utilized over a wide range of areas. Therefore, it is possible to improve the defects of polypropylene by mixing polypropylene and styrene resin, while lowering the price of styrene resin and expanding the uses of each. Polypropylene is a crystalline polymer, and styrenic resin is an amorphous polymer, and the two have considerably different chemical structures. Therefore, even if they are kneaded by ordinary mechanical melt-kneading, the resulting molded product will exhibit peeling and layer peeling, and will have very poor physical properties. The present inventors have worked hard to improve the physical properties of a mixture of polypropylene and styrene resin, which have poor compatibility and miscibility, and have found that ethylene acetic acid has been graft copolymerized with a monomer mainly composed of vinyl chloride. The present invention has been reached in which the addition of vinyl copolymers has a surprising effect. In other words, the composition ratio (weight) of polypropylene and ABS resin is 50/
The tensile strength of the molded product is 50 in a mixture consisting of 50
What is only Kg/cm ² can be improved to 240 to 260 Kg/cm ² by adding ethylene-vinyl acetate copolymer obtained by graft copolymerizing vinyl chloride. The composition of the resin to be mixed is 2 parts by weight to 98 parts by weight of polypropylene, preferably 10 parts by weight to 98 parts by weight.
90 parts by weight and styrene resin in 98 parts by weight to 2 parts by weight, preferably 90 parts to 10 parts by weight. If the mixed composition is outside this range, one component will be in a small amount and the properties of both will be affected in the mixed resin composition. I can't get anything that will allow me to fully utilize my abilities. Ethylene-vinyl acetate copolymer, which is obtained by graft copolymerizing a monomer whose main component is vinyl chloride, is a resin composition consisting of polypropylene and styrene resin.
It is added in an amount of 0.10 to 30 parts by weight, preferably 0.25 to 25 parts by weight, per 100 parts by weight.
If the amount is too small, no effect will be observed, and if the amount is too large, it will not only reduce mechanical strength but also cause "scorching" and become difficult to handle. Ethylene-vinyl acetate copolymer is a graft copolymer of a monomer whose main component is vinyl chloride.It is a monomer whose main component is vinyl chloride and an ethylene-vinyl acetate copolymer containing 20 to 60% by weight of vinyl acetate. The content of ethylene vinyl acetate in the graft copolymer is 5 to 70% by weight. Into the graft copolymer, an ethylene vinyl acetate copolymer is dissolved in a monomer mainly composed of vinyl chloride alone or in the coexistence of an acetate-based solvent, and an oil-soluble radical polymerization initiator such as azobisisobutyro is added to the graft copolymer. It can be obtained by suspension polymerization or solution polymerization using nitrile. The vinyl chloride-based monomer to be graft copolymerized to the ethylene-vinyl acetate copolymer is a mixture of vinyl chloride as the main component and monomers copolymerizable with it, such as styrene and α-methylstyrene. These are aromatic vinyl monomers such as, unsaturated nitriles such as acrylonitrile and methacrylonitrile, and α/β monoolefinic unsaturated carboxylic acid esters such as methyl methacrylate, each alone or in a mixture of two or more. . The polypropylene used in the present invention is not only a highly crystalline propylene homopolymer but also α- such as ethylene, butene-1, pentene-1, 3-methylpentene-1, and 4-methylpentene-1, which contain 90 mol% or more of propylene units. It includes a random or block copolymer composed of one or more olefins, or a resin composition in which two or more of these homopolymers and copolymers are mixed. Styrenic resins include styrene homopolymers, copolymers of styrene with α-methylstyrene, chlorostyrene, etc., high-impact polystyrenes obtained by graft polymerizing styrene monomers onto diene rubber elastomers, and mixtures thereof. These monomers are copolymerized with vinyl monomers such as unsaturated nitriles and α/β mono-olefinic unsaturated carboxylic acid esters. rubber, chlorinated polyethylene,
These include impact-resistant resins graft-polymerized with ethylene vinyl acetate copolymers, etc., or mixtures of copolymers and impact-resistant resins. In addition to ethylene-vinyl acetate copolymers obtained by graft copolymerization of vinyl monomers, polymers such as ethylene-vinyl acetate copolymers, butadiene-styrene block copolymers, ethylene-propylene elastomers, chlorinated polyolefins, etc. Adding molecular substances, stabilizers such as heat stabilizers for halogen-containing polymers, heat stabilizers and antioxidants for polyolefins, heat stabilizers used for styrene resins, and other ultraviolet absorbers or dyes and pigments. I can do it. Furthermore, flame retardants such as halogen compounds, phosphorus compounds, or inorganic compounds, inorganic or organic fillers, antistatic agents, nucleating agents, plasticizers, etc. can also be used in combination. Various methods can be used for kneading. Either the mixed resin is coprecipitated by dissolving and mixing in a solvent and pouring into a non-solvent, or the solvent is rapidly dried after casting. For melt kneading, rolls, kneaders,
There is a method of sufficiently kneading the composition in an extruder or the like while keeping it at a temperature at which it can be melted and processed. Alternatively, there is a method of emulsifying or suspending, mixing, and coagulating.
In extreme cases, during in-line screw type injection molding, a method may be used in which predetermined amounts of both resin compositions are charged into a hopper and kneaded during molding. The mixed resin composition can be molded by a commonly used molding method, such as press molding or injection molding. The mixed composition has good moldability, low molding shrinkage, and rigidity, and is also excellent in adhesion, paintability, dyeability, and plating performance. It has a wide range of uses, including light electrical equipment parts, automobile parts, general equipment parts, miscellaneous goods, pipes, and building materials. Examples are shown below to specifically explain the present invention, but the present invention is not limited thereto. Example 1-6 Composition ABS resin as shown below; "Sevian" V200 manufactured by Daicel KK (1) Polypropylene; Sumitomo "Noblen" H501 manufactured by Sumitomo Chemical Industries (2) PVC graft copolymerized ethylene vinyl acetate copolymer; Japan “Graftomer” GR-R- manufactured by Zeon KK
5 (ethylene vinyl acetate copolymer content 50% by weight) (3) Stabilizer; Nitto Kasei KK TVS 8831 (4) TVS 8813 (5) (50/50 ratio of (1) and (2)) A predetermined amount of (3) was charged into a Bravader Plastograph manufactured by Brabender Corporation equipped with a roller mixer type rotor at a temperature of 230°C and a rotor rotation speed of 40 rpm. Kneading was carried out for 5 minutes after the preparation. The obtained kneaded part was press-molded to a thickness of 1 mm. For press molding, preheat at 230℃ for 7 minutes,
Pressure was applied for 3 minutes. A dumbbell-shaped test piece with a parallel part length of 20 mm and width of 10 mm was punched out from the molded product and a tensile test was conducted at a tensile speed of 50 mm/min. The results are shown in Table 1.

[Table] Comparative Example 1 The same procedure as in Example 1 was carried out except that the vinyl chloride graft copolymerized ethylene vinyl acetate copolymer and the stabilizer were not used. The results are shown in Table 1. Example 7 In Example 3, “graftomer” GR-R5
The same procedure was carried out except that GR-R3 (ethylene-vinyl acetate copolymer content: 30% by weight) was used instead. The results are shown in Table 1. Examples 8 to 15 The same procedure as in Example 1 was carried out except that component (3) was kept constant and the ratio with component (2) was varied. The results are shown in Table 2. Comparative Examples 2-9 In Examples 8-15 and Example 2, component (3),
The same procedure was carried out except that (4) and (5) were not used. The results are shown in Table 3.

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[Table] Example 16 Composition ABS resin as below; "JSR" 010 (1) manufactured by Japan Synthetic Rubber KK
18 grams polypropylene; manufactured by Sumitomo Chemical KK Sumitomo "Noblen" S501(2) 42 grams PVC graft copolymerized ethylene vinyl acetate copolymer; manufactured by Nippon Zeon KK "Graftomer" GR-R5
(3) 2.1 gram stabilizer; Nippon Kasei KK TVS 8831(4) 0.5 gram TVS 8813(5) 0.5 gram was used to carry out the same operation as in Example 1. The results are shown in Table 4. Comparative Example 10 The same procedure as in Example 16 was carried out except that components (3), (4) and (5) were not used. The results are shown in Table 4. Example 17 Composition AS resin as below; “Sevian N” manufactured by Daicel KK (1)
30 grams polypropylene; manufactured by Sumitomo Chemical KK Sumitomo "Noblen" H501(2) 30 grams PVC graft copolymerized ethylene vinyl acetate copolymer and stabilizer were the same as in Example 16, and the same procedure as in Example 1 was used. I did this. The results are shown in Table 4. Comparative Example 11 The same operation as in Example 17 was carried out using only components (1) and (2). The results are shown in Table 4. Example 18 Composition as below AAS resin; "Vitax" 6101A manufactured by Hitachi Chemical KK (1) Polypropylene; Sumitomo "Noblen" H501 manufactured by Sumitomo Chemical KK (2) PVC graft copolymerized ethylene vinyl acetate copolymer and The same stabilizer as in Example 16 was used and the same operation was carried out. The results are shown in Table 4. Comparative Example 12 The same operation as in Example 18 was carried out using only components (1) and (2). The results are shown in Table 4.

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[Table] Comparative Example 13 The same procedure as in Example was carried out except that the vinyl chloride graft copolymerized ethylene vinyl acetate copolymer was not used. The results are shown in Table 5. Comparative Examples 14 to 15 The same procedure as in Example 3 was carried out except that an ethylene vinyl acetate copolymer (Evaflex 460 manufactured by Mitsui Polychemicals) was used instead of the vinyl chloride graft copolymerized ethylene vinyl acetate copolymer. The same procedure was carried out in the case where no stabilizer was used. The results are shown in Table 5.

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Claims (1)

[Scope of Claims] 1. A monomer containing vinyl chloride as a main component per 100 parts by weight of a resin composition consisting of 2 to 98 parts by weight of polypropylene and 98 parts to 2 parts by weight of styrene resin. 0.1 part by weight or more of ethylene vinyl acetate copolymer obtained by graft copolymerization of
A new synthetic resin composition containing 30 parts by weight. 2. A claim in which an ethylene vinyl acetate copolymer obtained by graft copolymerizing a monomer containing vinyl chloride as a main component contains 5 to 70% by weight of an ethylene vinyl acetate copolymer containing 20 to 60% by weight of vinyl acetate. The novel synthetic resin composition according to item 1.