JP4553359B2 - Thermoplastic resin composition and resin molded product - Google Patents

Description

  The present invention relates to a thermoplastic resin composition capable of stably obtaining a molded article having excellent impact resistance and weather resistance and having an extremely matte appearance under a wide range of molding conditions (molding temperature, etc.) and the resin thereof It relates to molded products.

  In general, thermoplastic resins such as ABS resin have a good surface gloss and are used for various applications, but some automobile interior parts and OA equipment require a non-glossy molding surface. As a conventional matting method for molded products, (1) a method of applying a texture to the mold surface, (2) a method of adding an inorganic filler such as talc or calcium carbonate, and (3) polymerized particles of crosslinked particles Examples thereof include a method of adding (Cited document 1) and (4) a method of three-dimensionalization using a functional group-containing monomer (Cited document 2).

  However, the method (1) of applying the embossing to the mold surface is difficult to produce and maintain the embossed surface, and has problems such as occurrence of uneven gloss. Regarding (2), there are problems such as the roughness of the product surface and the reduction of impact strength. Regarding (3), there are problems such as a decrease in mechanical strength, a decrease in heat resistance, and a decrease in weather resistance. With respect to (4), there is a problem that stable moldability cannot be obtained, and the mechanical strength is remarkably lowered and gloss unevenness occurs on the surface of the molded product.

In particular, molded products by melt processing methods such as extrusion molding and blow molding, unlike injection molded products, have no mold transfer due to pressure, so the gloss changes due to the influence of the polishing roll, mold temperature, resin temperature, etc. However, it is difficult to control the molding conditions, and gloss unevenness occurs in the conventional method.
JP-A-8-199027 JP 2002-167492 A

  An object of the present invention is to solve the above-mentioned problems, and it is possible to stably obtain a molded article having a very good matte appearance under a wide range of molding conditions (molding temperature, etc.) without particularly impairing mechanical properties. And providing a thermoplastic resin composition and a resin molded product thereof.

In accordance with the present invention, an aromatic vinyl monomer (b) in the presence of an acrylic rubber polymer (a) having a mass average particle size of 0.6 μm or more and a mass average particle size of 0.4 μm or less of 10% by mass or less. ), 5 to 95 parts by mass of a graft rubber copolymer (A) obtained by copolymerizing a vinyl cyanide monomer (c) and another monomer (d) which can be copolymerized if necessary, and an aromatic A vinyl copolymer (B) obtained by copolymerizing an aromatic vinyl monomer (b ′), a vinyl cyanide monomer (c ′) and, if necessary, another monomer (d ′) copolymerizable ) 95-5 parts by mass,
Content (GA) of vinyl cyanide monomer (c) in the whole monomer grafted to acrylic rubbery polymer (a) in the graft rubber copolymer (A) and the vinyl copolymer Provided is a thermoplastic resin composition characterized in that the difference (SA = RA-GA) from the content (RA) of the vinyl cyanide monomer (c ′) in (B) is 10% by mass or more. Is done.

  Moreover, according to this invention, the resin molded product characterized by consisting of the said thermoplastic resin composition is provided.

  As described above, according to the present invention, the surface of the sheet after extrusion molding is extremely matte and has a high level of impact resistance and fluidity, and this resin composition is used. It became possible to provide the molded products that had been.

  In particular, the balance between matteness and appearance after extrusion molding is at a very high level that cannot be obtained with a conventionally known thermoplastic resin composition, and the utility value as various industrial materials is extremely high.

  The graft rubber copolymer (A) used in the present invention comprises an aromatic vinyl monomer (b), a vinyl cyanide monomer (c) and necessary in the presence of the acrylic rubbery polymer (a). Is a graft polymer obtained by graft polymerization with another monomer (d) that can be copolymerized according to the above.

  Examples of the rubber component of the acrylic rubbery polymer (a) used in the present invention include acrylic acid esters such as ethyl acrylate, butyl acrylate and octyl acrylate.

  It is essential that the mass average particle diameter of the acrylic rubbery polymer (a) is 0.6 μm or more, and the mass average particle diameter of 0.4 μm or less is 10% by mass or less, and the mass average particle diameter is 0.6 μm. And / or if the mass average particle size of 0.4 μm or less exceeds 10% by mass, the gloss will change depending on the molding conditions, resulting in poor practical use.

  Examples of the component of the aromatic vinyl monomer (b) include styrene, α-methylstyrene, o-, m- or p-methylstyrene, vinylxylene, monochlorostyrene, dichlorostyrene, monobromostyrene, dibromostyrene, Fluorostyrene, p-tert-butyl styrene, ethyl styrene, vinyl naphthalene, and the like can be mentioned. Styrene and α-methyl styrene are preferable, and one or more of these can be used.

  Examples of the component of the vinyl cyanide monomer (c) include acrylonitrile and methacrylonitrile, and one or more of these can be used.

  In the production of the graft rubber copolymer (A) used in the present invention, in addition to the above-mentioned aromatic vinyl monomer (b) component and vinyl cyanide monomer (c) component, a monomer copolymerizable with these components. The monomer (d) can be used as long as the object of the present invention is not impaired. Examples of such a copolymerizable monomer (d) include α, β-unsaturated carboxylic acids such as acrylic acid and methacrylic acid; methyl (meth) acrylate (“(meth) acrylate” is “acrylate and Methacrylates), α, β-unsaturated carboxylic acid esters such as ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethyl (meth) acrylate, 2-ethylhexyl methacrylate; anhydrous Α, β-unsaturated dicarboxylic anhydrides such as maleic acid and itaconic anhydride; α, β-unsaturated such as maleimide, N-methylmaleimide, N-ethylmaleimide, N-phenylmaleimide, and N-o-chlorophenylmaleimide Examples thereof include imide compounds of saturated dicarboxylic acids, and one or more of these monomers The top can be used.

  Moreover, there is no restriction | limiting in particular as a manufacturing method of graft rubber copolymer (A), For example, it carries out emulsion polymerization using redox-type polymerization initiators, such as a persulfate or cumene hydroperoxide-sodium formaldehyde sulfoxylate. be able to.

  In addition, the aromatic vinyl monomer (b) and cyanide are preferably adjusted so that the content of the acrylic rubber-like polymer (a) in the graft rubber copolymer (A) is preferably 30 to 80% by mass. It is a graft polymer obtained by graft polymerization of a vinyl monomer (c) and, if necessary, another monomer (d) copolymerizable.

  The vinyl copolymer (B) used in the present invention comprises an aromatic vinyl monomer (b ′), a vinyl cyanide monomer (c ′), and other monomers copolymerizable as necessary. (D ') is copolymerized.

  Aromatic vinyl monomer (b ′), vinyl cyanide monomer (c ′) used in vinyl copolymer (B), and other monomer (d ′) copolymerizable as necessary The same monomers as those used for the production of the graft rubber copolymer (A) can be used.

  The mass% of the vinyl cyanide monomer (c ′) in the vinyl copolymer (B) is preferably 30 to 50 mass% in order to improve chemical resistance. If it is less than 30% by mass, the chemical resistance effect is not sufficiently exhibited, and if it exceeds 50% by mass, the thermal stability is likely to be deteriorated.

  The mixing ratio of the graft rubber copolymer (A) and the vinyl copolymer (B) is 5 to 95 parts by weight of the graft rubber copolymer (A), preferably 40 to 70 parts by weight, and more preferably. Is 40-60 parts by mass. If the amount is less than 5 parts by mass, the matting effect is reduced and the impact property is also lowered. Moreover, when it exceeds 95 mass parts, a moldability will worsen.

  The thermoplastic resin composition giving a good matte surface of the present invention and the resin molded product thereof occupy the whole monomer grafted to the acrylic rubber polymer (a) in the graft rubber copolymer (A). Difference between content (GA) of vinyl cyanide monomer (c) and content (RA) of vinyl cyanide monomer (c ′) in vinyl copolymer (B) (SA = RA−GA ) Is 10% by mass or more. When the SA is less than 10% by mass, the gloss easily changes depending on the molding conditions, and the matte effect cannot be sufficiently exhibited.

  In the present invention, the acrylic rubbery polymer (a) has a mass average particle size of 0.6 μm or more, and a mass average particle size of 0.4 μm or less is 10% by mass or less. Difference between content (GA) of vinyl halide monomer (c) and content (RA) of vinyl cyanide monomer (c ′) in vinyl copolymer (B) (SA = RA−GA) Can be imparted with a very good matting property in a small range of 10% by mass or more, and a wide range of thermoplastic resin compositions and resin molded products thereof can be obtained.

  In addition, the thermoplastic resin composition of the present invention and the resin molded product thereof are blended with an inorganic filler such as calcium carbonate and talc within a range that does not impair this effect, and the molded product is modified and the moldability is improved. be able to.

  The method for mixing the resin composition of the present invention is not particularly limited, but melt kneading is preferable. For example, an extruder, a Banbury mixer, etc. are mentioned. In the resin composition of the present invention, a pigment, a dye, a lubricant, an ultraviolet absorber, an antioxidant, an antistatic agent, a reinforcing agent, a flame retardant, and the like are blended in the resin composition of the present invention as long as the physical properties are not impaired. Can do.

  In addition, as a method of molding a resin molded product from the thermoplastic resin composition of the present invention, molding that processes various molten resins such as profile extrusion molding, blow molding, sheet molding, vacuum molding after sheet molding, and pressure molding. The method can be adopted.

  The present invention will be described more specifically with reference to the following examples. However, the scope of the present invention is not limited to these examples. In the following, “parts” represents parts by mass.

  The mass average particle diameter of the acrylic rubbery polymer (a) was determined by a dynamic light scattering method using Microtrac Model: 9230UPA manufactured by Nikkiso Co., Ltd. Further, the vinyl cyanide monomer (c) content (GA) in the total amount of monomers grafted to the acrylic rubbery polymer (a) in the obtained graft rubber copolymer (A) It was determined by decomposition gas chromatography. Furthermore, the content (RA) of the vinyl cyanide monomer (c ′) in the vinyl copolymer (B) is C.I. H. N. It calculated from the elemental analysis value using the coder.

(Synthesis Example 1) ... Production of Graft Rubber Copolymer (A) The following materials were charged in a pressure vessel,
Semi-cured beef tallow soap 1.5 parts Sodium pyrophosphate 0.3 parts Deionized water 200 parts Heated to 80 ° C under a nitrogen stream,
Butyl acrylate 100 parts Potassium persulfate 0.3 part Triallyl cyanurate 0.3 part was dropped over 4 hours and polymerized. After completion of the dropwise addition, the reaction was terminated after cooling for 1 hour and then cooling. The obtained polybutyl acrylate latex had a mass average particle size of 0.1 μm and a solid content of 33.4%.

  Next, 0.15 part of sodium dodecylbenzenesulfonate was added to 100 parts of this polybutyl acrylate latex (in terms of solid content), and 100 parts by weight of solid content of the polybutyl acrylate latex (solid content) Conversion), an acetic acid aqueous solution having a concentration, addition amount, and addition time as shown in Table 1 was added. After the addition was completed, the mixture was stirred for 5 minutes, and 10% by mass sodium hydroxide was added dropwise to terminate the enlargement, thereby obtaining six types of enlarged polybutylacrylate latex (a1) to (a6). Further, Table 1 shows the mass average particle diameter (μm) and the ratio (mass%) of the mass average particle diameter of 0.4 μm or less of the obtained enlarged latex.

  Next, using polybutyl acrylate latex of six kinds of enlarged particles (a1) to (a6), 28 parts of styrene and 12 parts of acrylonitrile are blended with 60 parts of latex (in terms of solid content), and 60 to 70 ° C. The emulsion was subjected to emulsion polymerization for 3 hours, sulfuric acid coagulation, water washing, dehydration and drying to obtain graft rubber copolymers (A) (A1 to A4 and A6) shown in Table 1.

  Moreover, the graft rubber copolymer (A5) was obtained by changing a mixing ratio with 31 parts of styrene and 9 parts of acrylonitrile, and polymerizing similarly.

  Table 2 shows the content (GA) of vinyl cyanide monomer in the total monomer grafted to the acrylic rubbery polymer in the obtained graft rubber copolymer (A).

Synthesis Example 2 Production of Vinyl Copolymer (B) 120 parts of water, 0.02 part of sodium dodecylbenzenesulfonate, 0.5 part of polyvinyl alcohol, 0.3 part of azoisobutylnitrile in a nitrogen-substituted reactor Part, 48 parts of acrylonitrile and 15 parts of styrene, and after 1 hour when the reaction start temperature reached 60 ° C., the remaining 37 parts of styrene were added dropwise over 6 hours, and further 5 hours after the start of the reaction, the temperature was raised to 120 ° C. The reaction was continued for 4 hours. The vinyl cyanide monomer (c ′) content (RA) of the finally obtained vinyl copolymer (B) was 43% by mass (B1).

  Moreover, RA was obtained 39 mass% (B2), 35 mass% (B3), and 25 mass% (B4) by changing the mixing ratio of acrylonitrile and styrene and polymerizing similarly. These are summarized in Table 3.

  The graft rubber copolymers (A) (A1 to A6) and vinyl copolymers (B) (B1 to B4) obtained in Synthesis Examples 1 and 2 were mixed together with the lubricant in the ratios shown in Tables 4 and 5. The mixture was shaped by a degassing twin-screw extruder ("PCM-30" manufactured by Ikekai Tekko Co., Ltd.) heated to a barrel temperature of 230 ° C to produce pellets.

  Using the 40 mmφ single screw extruder manufactured by Chuo Kikai Co., Ltd., the pellets obtained were discharged at a barrel temperature of 190 ° C. and 250 ° C., a cooling roll temperature of 50 ° C. in a sheet form from a 60 mm wide die, and the winding speed A sheet with a width of 200 mm, whose thickness was adjusted to 0.9 mm to 1.1 mm, was extruded.

  The thermoplastic resin compositions obtained in Examples and Comparative Examples were evaluated by the following evaluation tests. The evaluation results are shown in Tables 4 and 5.

(I) Molding Glossiness and Temperature Dependence The glossiness was measured as a reflectance of incident light of 60 °. The temperature dependence of the molded sheet under barrel temperature conditions of 190 ° C. and 250 ° C. was determined by the following formula (1);
Gloss difference (%) = (Glossiness at 250 ° C. molding) − (Glossiness at 190 ° C. molding) Formula (1)

(Ii) Molding appearance Judging from the visual judgment, the matteness, the appearance of fish eyes and die lines, and the fineness of the surface are judged. Those which could not be tolerated were evaluated as x, and the middle was evaluated as Δ.

(Iii) Chemical resistance After the strip-shaped test piece shape 150 × 10 × 2 mm produced by injection molding is fixed along the bending home method test jig, a chemical solution is applied to the test piece and the environment is 23 ° C. After leaving for 48 hours, the occurrence of craze and cracks was confirmed, and the critical strain (%) was determined from the curvature of the test jig (the measured value is 1.6% for the convenience of the test jig). As a chemical, Powers manufactured by Este Chemical Co., Ltd. was used.

(Iv) Charpy impact strength The Charpy impact strength was measured by a method according to ISO 179, and a test piece with a notch was used, and the test piece was allowed to stand for 12 hours or more in an atmosphere at 23 ° C., and then measured.

(V) Melt volume rate (fluidity)
Measurement was performed under the conditions of a barrel temperature of 220 ° C. and a load of 98 N by a method based on ISO 1133.

  From the examples and comparative examples, the following became clear.

  1) The thermoplastic resin compositions containing the graft rubber copolymers (A2) to (A5) of Examples 1 to 9 had a low surface gloss after extrusion and extremely excellent matte properties. . Furthermore, it showed high performance with a good balance in impact resistance and extrudability.

  2) On the other hand, in Comparative Example 1, the vinyl cyanide monomer (c) of the vinyl monomer mixture constituting the graft rubber copolymer (A) and the vinyl copolymer constituting the vinyl copolymer (B) are used. The difference (SA) of the vinyl cyanide monomer (c ′) in the monomer mixture is as high as 13% by mass, but the mass average particle diameter of the acrylic rubbery polymer (a) is as small as 0.4 μm. In addition, the extrusion temperature dependency was large.

  3) In Comparative Examples 2 to 4, the difference (SA) in the vinyl cyanide monomer of the vinyl monomer mixture constituting the graft rubber copolymer (A) and the vinyl copolymer (B) was 9 mass. %, Which is below the range defined in the present invention, the gloss depends greatly on the molding conditions, and the appearance of the extruded sheet is inferior.

  4) Comparative Example 5 is an example using the graft rubber copolymer (A6), and the mass average particle diameter is 0.6 μm or more, but the ratio of 0.4 μm or less exceeds 10% by mass. Therefore, the extrusion molding temperature dependency is large.

  Since the matte thermoplastic resin composition of the present invention does not depend on molding conditions, a desired molded product can be easily obtained without waste, and further, since it has excellent chemical resistance and weather resistance, It can be suitably used in the fields of automobile interior parts such as instrument panels and residential building materials.

Claims (2)

Aromatic vinyl monomer (b), cyanide in the presence of acrylic rubbery polymer (a) having a mass average particle size of 0.6 μm or more and a mass average particle size of 0.4 μm or less of 10% by mass or less. 5 to 95 parts by mass of a graft rubber copolymer (A) obtained by copolymerizing a vinyl monomer (c) and another monomer (d) that can be copolymerized if necessary, and an aromatic vinyl monomer Vinyl copolymer (B) 95 to 5 obtained by copolymerization of body (b ′), vinyl cyanide monomer (c ′) and other monomer (d ′) copolymerizable as necessary Containing parts by mass,
Content (GA) of vinyl cyanide monomer (c) in the whole monomer grafted to acrylic rubbery polymer (a) in the graft rubber copolymer (A) and the vinyl copolymer The thermoplastic resin composition, wherein the difference (SA = RA-GA) from the content (RA) of the vinyl cyanide monomer (c ′) in (B) is 10% by mass or more.   A resin molded product comprising the thermoplastic resin composition according to claim 1.