JP5651489B2 - Thermoplastic resin composition - Google Patents

Description

  The present invention relates to a thermoplastic resin composition that is excellent not only in color developability but also in scratch resistance and that does not cause molding defects due to mold contamination, and a molded product thereof.

  Conventionally, styrenic resins have a good balance of molding processability and mechanical properties, and are excellent in electrical insulation, so they have been used in a wide range of fields such as the electrical / electronic equipment field and OA equipment field. Yes. However, at the stage of commercialization, when the molded product obtained by molding the resin is transported to the assembly line, for example, when the molded product is packed one by one with a soft nonwoven fabric or the like for the purpose of preventing fine scratches Therefore, a great deal of labor and cost are required.

  In addition, in order to give various designs to the resin product and to prevent the product from being damaged during use, the product may be fully or partially coated. However, the coating process has a problem that the production yield is likely to decrease due to poor coating. In addition, from the recent trend of suppressing VOC emissions, the design can be colored with a vivid color or deep color, or have a metallic or pearly appearance, etc., with as little coating as possible. Resins that are easy to impart properties and are not easily damaged are desired.

  A method for improving scratch resistance by adding an appropriate amount of polyethylene wax or silicone oil to a styrene resin having a specific structure is known (Patent Document 1). However, in recent years, the color developability is not suitable for applications requiring a high-quality appearance. Furthermore, there is a problem that silicone oil bleeds out and is inferior in mold contamination. In addition, a method is disclosed that can improve scratch resistance without bleeding out by using a compatibilizer with silicone oil (Patent Document 2). However, the color developability is still insufficient.

JP 2000-119477 A

Japanese Patent Laid-Open No. 2001-40160

  An object of the present invention is to provide a thermoplastic resin composition that is excellent not only in scratch resistance but also in color developability and that does not cause molding defects due to mold contamination, and a molded product thereof.

  As a result of intensive studies to solve the problems of the prior art, the present inventors have found that a graft copolymer in which a specific monomer is grafted and a copolymer in which a specific monomer is polymerized The present inventors have found that the above object can be achieved by adding a silicone compound having a specific structure to a resin composition containing the present invention.

That is, the present invention, an aromatic vinyl monomer in the presence of a rubbery polymer, a vinyl cyanide monomer, (meth) acrylic acid ester monomers and other copolymerizable monomers at least one monomer to graft polymerization was graft copolymer (a) 15 to 50 parts by weight of an aromatic vinyl monomer, vinyl cyanide monomer selected from the group consisting of the body, ( 50 to 85 parts by weight of (co) polymer (B) obtained by copolymerizing at least one monomer selected from the group consisting of (meth) acrylic acid ester monomers and other copolymerizable monomers A thermoplastic resin composition comprising 0.1 to 10 parts by weight of a silicone compound (C) obtained by graft-polymerizing a reactive polyorganosiloxane to an olefin copolymer with respect to 100 parts by weight of the resin composition. (However, trees According to the molded article obtained by using the composition into 100 parts by weight does not include copolymers of polymethacrylic acid alkyl esters or methacrylic acid alkyl ester and acrylic acid alkyl ester and 20 parts by weight or more) and the resin composition.

  According to the present invention, it is possible to obtain a thermoplastic resin composition and its molded product, which are excellent not only in scratch resistance but also in color developability, and further free from molding defects due to mold contamination.

The present invention will be described in detail below.
The thermoplastic resin composition used in the present invention comprises an aromatic vinyl monomer, a vinyl cyanide monomer, a (meth) acrylic acid ester monomer, and other monomers in the presence of a rubber-like polymer. Graft copolymer (A) obtained by graft copolymerization with at least one monomer selected from the group consisting of copolymerizable monomers (A) 15-50 parts by weight, aromatic vinyl monomer, vinyl cyanide (Co) polymer (B) 50 obtained by copolymerizing at least one monomer selected from the group consisting of monomers, (meth) acrylic acid ester monomers and other copolymerizable monomers It is characterized by containing 0.1 to 10 parts by weight of a silicone compound (C) obtained by graft polymerization of a reactive polyorganosiloxane to an olefin copolymer with respect to 100 parts by weight of a resin composition containing ~ 85 parts by weight. .

  The rubbery polymer used in the graft copolymer (A) used in the present invention is not particularly limited, but polybutadiene rubber, styrene-butadiene rubber (SBR), styrene-butadiene-styrene (SBS) block copolymer. Styrene- (ethylene-butadiene) -styrene (SEBS) block copolymer, acrylonitrile-butadiene rubber (NBR), diene rubber such as butyl acrylate-butadiene, butyl acrylate rubber, butadiene-butyl acrylate rubber, 2-ethylhexyl acrylate- Acrylic rubbers such as butyl acrylate rubber, 2-ethylhexyl methacrylate-butyl acrylate rubber, stearyl acrylate-butyl acrylate rubber, polyorganosiloxane-butyl acrylate composite rubber, ethylene-propyl Ngomu, ethylene - propylene - polyolefin rubber polymer such as diene rubber, silicone rubber polymers such as polyorganosiloxane rubber and the like, which may be used alone or in combination. In particular, polybutadiene rubber, styrene-butadiene rubber, butyl acrylate rubber, and ethylene-propylene-diene rubber are preferable.

  The rubbery polymer used in the graft copolymer (A) is preferably contained in an amount of 30 to 85 parts by weight in 100 parts by weight of the graft copolymer (A) from the viewpoint of balance of physical properties, and 40 to 75 weights. More preferably, it is contained.

  The weight average particle diameter of the rubbery polymer used in the graft copolymer (A) is preferably 0.05 to 2.0 μm, more preferably 0.1 to 1.0 μm, from the viewpoint of physical property balance and color development. It is.

  Examples of the aromatic vinyl monomer used in the graft copolymer (A) include styrene, α-methyl styrene, p-methyl styrene, t-butyl styrene, and dimethyl styrene, and one or more of them are used. be able to. Styrene is particularly preferable as the aromatic vinyl monomer.

  Examples of the vinyl cyanide monomer used in the graft copolymer (A) include acrylonitrile, methacrylonitrile, ethacrylonitrile, and fumaronitrile, and one or more of them can be used. As the vinyl cyanide monomer, acrylonitrile is particularly preferable.

  Examples of the (meth) acrylic acid ester monomer used in the graft copolymer (A) include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl. Acrylate, phenyl (meth) acrylate, 4-t-butylphenyl (meth) acrylate, bromophenyl (meth) acrylate, dibromophenyl (meth) acrylate, 2,4,6-tribromophenyl (meth) acrylate, monochlorophenyl ( A meth) acrylate, a dichlorophenyl (meth) acrylate, a trichlorophenyl (meth) acrylate etc. can be illustrated, and can be used 1 type or more. As the (meth) acrylic acid ester monomer, methyl methacrylate is particularly preferable.

  From the viewpoint of scratch resistance and color developability, when the total amount of monomers used for graft copolymerization of the graft copolymer (A) is 100 parts by weight, the (meth) acrylate monomer is The content is preferably 50 parts by weight or more, and more preferably 70 parts by weight or more.

  Examples of other copolymerizable monomers used in the graft copolymer (A) include maleimide monomers (for example, N-phenylmaleimide, N-cyclohexylmaleimide, etc.), unsaturated carboxylic acids, and the like. Alternatively, anhydrides thereof (for example, acrylic acid, methacrylic acid, maleic anhydride, etc.), amide monomers (for example, acrylamide, methacrylamide, etc.) and the like can be used, one or more of each. Can be used in combination.

  The graft copolymer (A) used in the present invention is required to be contained in 15 to 50 parts by weight in 100 parts by weight of the resin composition. When the amount is less than 15 parts by weight, the impact resistance is lowered. When the amount is more than 50 parts by weight, the scratch resistance and the fluidity are lowered. Preferably it is 20-45 weight part.

  There is no restriction | limiting in particular about the polymerization method of a graft copolymer (A), It can manufacture by emulsion polymerization, suspension polymerization, block polymerization, solution polymerization, or these combination.

  The (co) polymer (B) used in the present invention is an aromatic vinyl monomer, vinyl cyanide monomer, (meth) acrylic acid ester monomer and other copolymerizable monomers. This is a (co) polymer obtained by polymerizing one or more monomers selected from the group containing the body, but the monomer used is described as an example used in the graft copolymer (A) The same thing as each monomer currently used can be used.

  From the viewpoint of scratch resistance and color development, the (meth) acrylic acid ester monomer is preferably contained in 50 parts by weight or more in 100 parts by weight of the (co) polymer (B), and 70 parts by weight or more. More preferably it is included.

  The (co) polymer (B) used in the present invention must contain 50 to 85 parts by weight in 100 parts by weight of the resin composition. When the amount is less than 50 parts by weight, the scratch resistance decreases, and when the amount exceeds 85 parts by weight, the impact resistance decreases. The amount is preferably 10 to 45 parts by weight.

  There is no restriction | limiting in particular about the polymerization method of (co) polymer (B), It can manufacture by well-known emulsion polymerization, suspension polymerization, block polymerization, solution polymerization, or these combination.

  The silicone compound (C) used in the present invention is a compound obtained by graft polymerization of a reactive polyorganosiloxane to an olefin copolymer.

  The reactive polyorganosiloxane used in the silicone compound (C) is a polyorganosiloxane having a reactive group at the molecular side chain or molecular end. Examples of reactive groups include hydroxy groups, amino groups, aminoalkyl groups, carboxyl groups, epoxy groups, glycidyloxyalkyl groups, (meth) acryloyl groups, mercapto groups, and the like.

  Typical polyorganosiloxanes include, for example, polydialkylsiloxanes such as polydimethylsiloxane, polyalkylalkenylsiloxanes such as polymethylvinylsiloxane, polyalkylarylsiloxanes such as polymethylphenylsiloxane, and polydiarylsiloxanes such as polydiphenylsiloxane. And polyalkyl hydrogen siloxane such as polymethyl hydrogen siloxane.

  Among these, preferable polyorganosiloxanes include polydialkylsiloxanes (particularly polydimethylsiloxane) and polyalkylarylsiloxanes (polymethylphenylsiloxane).

  Examples of the olefin copolymer used in the silicone compound (C) include polyethylene, polypropylene, ethylene ethyl acrylate copolymer, ethylene vinyl acetate copolymer, ethylene methyl methacrylate copolymer, and ethylene vinyl alcohol copolymer. Etc. are exemplified.

The silicone compound (C) used in the present invention is a compound obtained by graft polymerization of a reactive polyorganosiloxane to an olefin copolymer. When grafting the reactive polyorganosiloxane to the olefin copolymer, a crosslinking agent or a reaction terminator can be used. The ratio of the reactive polyorganosiloxane and the olefin copolymer is not particularly limited, but the reactive polyorganosiloxane is preferably contained in 20 to 80 parts by weight in 100 parts by weight of the silicone compound (C). It is particularly preferable that it is contained in 70 parts by weight.

  The usage-amount of the silicone compound (C) used for this invention is 0.1-10 weight part with respect to 100 weight part of resin compositions. If it is less than 0.1 part by weight, the scratch resistance is insufficient, and if it exceeds 10 parts by weight, the color developability is poor. Preferably it is 0.1-3 weight part.

  The thermoplastic resin composition in the present invention may contain various additives as necessary, for example, known antioxidants, light stabilizers, lubricants, plasticizers, antistatic agents, colorants, flame retardants, matting agents, fillers. Glass fiber or the like can be added as appropriate.

  Although the thermoplastic resin composition in the present invention can be used alone, it can also be used by mixing with other thermoplastic resins as necessary. Examples of such other thermoplastic resins that can be used include acrylic resins such as polymethyl methacrylate, polycarbonate resins, polybutylene terephthalate resins, polyethylene terephthalate resins, polyamide resins, and polylactic acid resins.

  The thermoplastic resin composition in the present invention can be obtained by mixing the above-described components. In order to mix, well-known kneading apparatuses, such as an extruder, a roll, a Banbury mixer, a kneader, can be used, for example.

  Furthermore, the thermoplastic resin composition in the present invention can be molded by a known molding method such as extrusion molding, injection molding, blow molding, press molding and the like, and various molded products can be produced.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In the examples, “parts” and “%” are based on weight.

<Examples 1-8 and Comparative Examples 1-7>
For the graft copolymer (A), copolymer (B) and silicone compound (C) having the composition ratios shown in Tables 1 and 2, Sumiplast Black HB (manufactured by Sumitomo Chemical Co., Ltd.) was used as a colorant. 0 parts were mixed. Using a vented 50 mm single-screw extruder (manufactured by ON Machinery), the mixture was melt-mixed at a cylinder temperature of 210 ° C. and pelletized to obtain black colored pellets. In addition, each component shown in Table 1 and Table 2 is as follows.

Graft copolymer (A)
Graft copolymer (A-1): 50 parts (solid content) of styrene-butadiene rubber latex (styrene 5% by weight, weight average particle diameter 0.25 μm), 150 parts of water, ethylenediaminetetraacetic acid diacetate in a nitrogen-substituted reactor. Add sodium salt 0.1 part, ferrous sulfate 0.001 part, sodium formaldehyde sulfoxylate 0.3 part and after heating to 60 ° C, styrene 35 parts, acrylonitrile 15 parts and cumene hydroperoxide 0.2 parts The mixture consisting of was continuously added over 3 hours and further polymerized at 60 ° C. for 2 hours. Thereafter, after salting out, dehydration and drying, a graft copolymer (A-1) was obtained. The graft ratio of the obtained graft copolymer and the intrinsic viscosity of the acetone-soluble component were 50% and 0.53 dl / g, respectively.

  Graft copolymer (A-2): 50 parts (solid content) of styrene-butadiene rubber latex (styrene 5% by weight, weight average particle size 0.25 μm), 150 parts of water, ethylenediaminetetraacetic acid diacetate in a nitrogen-substituted reactor. Sodium salt (0.1 part), ferrous sulfate (0.001 part), sodium formaldehyde sulfoxylate (0.3 part) were added, heated to 60 ° C., styrene (15 parts), methyl methacrylate (35 parts) and cumene hydroperoxide (0.15 parts). A 2 part mixture was continuously added over 3 hours and further polymerized at 60 ° C. for 2 hours. Thereafter, after salting out, dehydration and drying, a graft copolymer (A-2) was obtained. The graft ratio of the obtained graft copolymer and the intrinsic viscosity of the acetone-soluble component were 50% and 0.50 dl / g, respectively.

  Graft copolymer (A-3): 50 parts (solid content) of styrene-butadiene rubber latex (styrene 5% by weight, weight average particle size 0.25 μm), 150 parts of water, ethylenediaminetetraacetic acid diacetylate in a nitrogen-substituted reactor. Add sodium salt 0.1 part, ferrous sulfate 0.001 part, sodium formaldehyde sulfoxylate 0.3 part and after heating to 60 ° C., 12 parts styrene, 5 parts acrylonitrile, 33 parts methyl methacrylate and cumene hydro A mixture consisting of 0.2 parts of peroxide was continuously added over 3 hours and further polymerized at 60 ° C. for 2 hours. Thereafter, after salting out, dehydration and drying, a graft copolymer (A-3) was obtained. The graft ratio of the obtained graft copolymer and the intrinsic viscosity of the acetone-soluble component were 50% and 0.49 dl / g, respectively.

Copolymer (B)
Copolymer (B-1): A copolymer (B-1) comprising 75 parts by weight of styrene and 25 parts by weight of acrylonitrile was obtained by a known bulk polymerization method.
Copolymer (B-2): A copolymer (B-2) comprising 30 parts by weight of styrene and 70 parts by weight of methyl methacrylate was obtained by a known bulk polymerization method.

Silicone compound (C)
Silicone compound (C-1): BY27-219 (manufactured by Toray Dow Corning Co., Ltd.)
A silicone compound obtained by graft-polymerizing a reactive polyorganosiloxane to an ethylene methyl methacrylate copolymer.
Silicone compound (C-2): BY27-202H (manufactured by Dow Corning Toray)
A silicone compound obtained by graft polymerization of reactive polyorganosiloxane to low density polyethylene.
Silicone compound (C-3): BY27-220 (manufactured by Toray Dow Corning Co., Ltd.)
A silicone compound obtained by graft-polymerizing a reactive polyorganosiloxane to an ethylene vinyl acetate copolymer.
Silicone compound (C-4): SH200-100CS (manufactured by Toray Dow Corning Co., Ltd.)
Dimethyl silicone oil. Viscosity: 100 mm ² / s
Silicone compound (C-5): BY27-007 (manufactured by Dow Corning Toray)
Pellets (silicone content 50%) made by melt-kneading (ungrafted) ultrahigh molecular weight dimethyl silicone polymer and ABS resin.

<Test example>
The colored pellets obtained in each of the examples and comparative examples were used for the following evaluation. The results are shown in Table 1 and Table 2, respectively.

(1) Color developability The lightness (L *) of the molded product was measured by hue measurement based on JIS-Z8729 and used as a measure of color developability. (Since the lightness (L *) of the molded product is smaller, the jetness of the molded product is better, and as a result, the color develops when the same colorant is added in the same amount.) And using the colored pellets obtained in the comparative example, a molded product (150 mm × 120 mm × 3 mm) molded by an injection molding machine (J-150EP manufactured by Nippon Steel Works, cylinder temperature: 200 ° C., mold temperature: 80 ° C.) Using. The spectrophotometer used was CMS-35SP manufactured by Murakami Color Research Co., Ltd.

(2) Scratch resistance reciprocating wear tester (product name: Tribogear TYPE: 30S, manufactured by Shinto Kagaku Co., Ltd.), set a cotton cloth No. 3 on an indenter with a tip of 27 mm in diameter, and a constant load of 500 g Below, the surface of the molded product was rubbed 20 times (speed: 600 mm / min). As the molded product, the same molded product as used in (1) was used. After the test, scratches on the surface of the molded product were visually confirmed, and scratch resistance was evaluated by the following judgment.
No scratches are seen: ◎
Scratches are hardly seen: ○
Scratches are slightly visible:
Scratches are clearly seen: ×

(3) Mold fouling property Using colored pellets obtained in each Example and Comparative Example, using J-150EP manufactured by Nippon Steel Works, cylinder set temperature 240 ° C, mold temperature 50 ° C, molding cycle 30 seconds, A flat plate test piece (length: 150 mm, width: 150 mm, thickness: 3 mm) was subjected to 1000 shot injection molding, and the mold contamination was evaluated by the following judgment.
No change on mold surface: ○
The mold surface is cloudy: △
The mold surface is extremely dirty and the appearance of the molded product is poor: ×

(4) Impact resistance Various test pieces were molded in accordance with ISO test method 294 using the colored pellets obtained in each of the examples and comparative examples, and the impact resistance was measured.
The impact resistance was in conformity with ISO 179, and a Charpy impact value with a notch was measured at a thickness of 4 mm. Unit: kJ / m ²

(5) Fluidity Using the colored pellets obtained in each Example and Comparative Example, melt volume flow rate was measured under the conditions of 220 ° C. and 10 kg load according to ISO1133. Unit; ^cm 3/10 minutes

  As shown in Table 1, it can be seen that the thermoplastic resin composition of the present invention is excellent not only in scratch resistance but also in color development and mold contamination. In particular, when an acrylic acid ester monomer was used for the graft copolymer (A) and (co) polymer (B), the color development and scratch resistance were particularly excellent.

  As shown in Table 2, Comparative Examples 1 to 3 that do not use a silicone compound having a specific structure are inferior in scratch resistance. In Comparative Example 6 using silicone oil, the scratch resistance was good, but the silicone oil bleeded out and caused mold contamination during molding. In Comparative Example 7 using pellets obtained by blending a silicone polymer and ABS, the scratch resistance and physical property balance were good, but the color development and mold contamination were poor. Comparative Example 4 in which the amount of the graft copolymer (A) used is small is inferior in the balance between physical properties of impact resistance and fluidity, and Comparative Example 5 in which the amount of use is large is that of scratch resistance and balance between physical properties of impact resistance and fluidity. Inferior to

  The thermoplastic resin composition of the present invention can be used in a wide range of fields including the electric / electronic equipment field, the OA equipment field, and the like by taking advantage of the above-described excellent characteristics. It is particularly suitable for applications in which both excellent physical property balance, color developability and scratch resistance are achieved.

Claims (2)

Selected an aromatic vinyl monomer in the presence of a rubbery polymer, vinyl cyanide monomers, from the group consisting of (meth) acrylic ester monomer and other copolymerizable monomers at least one monomer to graft polymerization was graft copolymer (a) 15 to 50 parts by weight of an aromatic vinyl monomer, vinyl cyanide monomer to be, (meth) acrylic acid ester 100 weight of resin composition containing 50 to 85 parts by weight of (co) polymer (B) obtained by copolymerizing at least one monomer selected from the group consisting of monomers and other copolymerizable monomers A thermoplastic resin composition (however, a resin composition ) containing 0.1 to 10 parts by weight of a silicone compound (C) obtained by graft-polymerizing a reactive polyorganosiloxane to an olefin copolymer 100 parts by weight A copolymer of polymethacrylic acid alkyl esters or methacrylic acid alkyl ester and acrylic acid alkyl ester contains no more than 20 parts by weight) to.
A resin molded product obtained from the thermoplastic resin composition according to claim 1.