JP2000186182A - Thermoplastic resin composition and formed article thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an excellent thermoplastic resin composition having a number of properties of weather resistance, shock resistance, pigment coloring property, chemical resistance and transparency. SOLUTION: This composition is a thermoplastic resin composition comprising 15 pts.wt. or more and less than 50 pts.wt. of a graft copolymer (I) obtained by graft-polymerizing a monomer mixture (B) consisting of an aromatic alkenyl compound and a vinyl cyanide compound in the presence of a composite rubber (A) having a weight average particle size of 0.08-0.16 μm consisting of a polyorganosiloxane (a-1) and a polyalkyl acrylate (a-2) and exceeding 50 pts.wt. and 85 pts.wt. or less of a polymethyl methacrylate resin (II) [(I)+(II)=100]. The content of the composite rubber (A) in the thermoplastic resin composition is 10-25 pts.wt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition having excellent weather resistance, impact resistance, pigment coloring property and chemical resistance and having transparency, and a molded product thereof.

[0002]

2. Description of the Related Art Generally, resin parts used outdoors are required to have weather resistance and impact resistance. In particular, for buttons and display components such as vending machines, ticket vending machines, and public telephones, and for applications such as advertising lights and guide lights, light irradiation and display colors from the back of the components are used to facilitate identification of display contents. Techniques such as highlighting differences are adopted,
For the thermoplastic resin used for these applications, transparency (light transmission) and pigment coloring are also required. In addition, components for these applications are regularly cleaned with commercial or household detergents, but recent detergents have increased their detergency, resulting in a stronger influence on the resin, and the resin molded product has been washed by the detergent. There is a problem of cracking. This is thought to be caused by a phenomenon called "crack under environmental stress" or "chemical cracking under stress", and the thermoplastic resin used is required to have chemical resistance to detergents etc. It has become. That is, thermoplastic resins used for buttons and display parts of vending machines, vending machines, public telephones, etc. have many performances such as weather resistance, impact resistance, pigment coloring, chemical resistance and transparency. Will be required. On the other hand, as thermoplastic resins for outdoor use, ASA resin (acrylonitrile-styrene-acryl rubber copolymer resin) and AES resin (acrylonitrile-ethylene-propylene rubber-styrene copolymer resin) are used.
Although these resins are excellent in weather resistance and impact resistance, they have a disadvantage that they are inferior in pigment coloring property. A styrene-based resin (hereinafter referred to as a SAS resin) modified with a composite rubber composed of polyorganosiloxane and polyalkyl acrylate is an example of a weather-resistant and impact-resistant thermoplastic resin having improved pigment coloring properties. Kaiping 01
-190746 and JP-A-03-231907. Like the ASA resin, this SAS resin is also excellent in chemical resistance (it does not easily crack under environmental stress), and is used not only for outdoor applications but also for chemical applications such as bath, sanitary, kitchen and the like. As a thermoplastic resin having further improved pigment coloring property of this SAS resin, S
A thermoplastic resin composition comprising an AS resin and a PMMA resin (polymethyl methacrylate resin) is disclosed in
No. 83524.

[0003]

However, the thermoplastic resin composition described in Japanese Patent Application Laid-Open No. 08-283524 is a resin material intended for exterior parts for vehicles such as automobiles, and has weather resistance and impact resistance. Although it is excellent in pigment coloring property and chemical resistance, it does not have practical transparency (light transmission) at present. The present invention has been made in order to solve the above problems, and provides an excellent thermoplastic resin composition having many performances such as weather resistance, impact resistance, pigment coloring, chemical resistance and transparency. Aim.

[0004]

According to the present invention, there is provided a resin composition comprising a SAS resin and a PMMA resin, wherein the particle diameter of the composite rubber comprising polyorganosiloxane and polyalkyl acrylate is occupied in the resin composition of the composite rubber. It was made by finding that a thermoplastic resin composition exhibiting desired properties can be obtained by limiting the ratio and the ratio between the SAS resin and the PMMA resin to specific amounts. That is, the present invention relates to a polyorganosiloxane (a-1) and a polyalkyl acrylate (a
-2) having a weight average particle diameter of 0.08 to 0.16 μm
Graft copolymer (I) obtained by graft-polymerizing a monomer mixture (B) comprising an aromatic alkenyl compound and a vinyl cyanide compound in the presence of the composite rubber (A)
A thermoplastic resin composition comprising 15 parts by weight or more and less than 50 parts by weight and polymethyl methacrylate resin (II) more than 50 parts by weight and 85 parts by weight or less (provided that (I) + (II) = 1
00 parts by weight), wherein the composite rubber (A) accounts for 10 to 25 parts by weight in the thermoplastic resin composition, and a resin molded product thereof.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The polyorganosiloxane (a-1) constituting the composite rubber according to the present invention is not particularly limited, but is preferably a polyorganosiloxane containing a vinyl polymerizable functional group. . More preferably, the vinyl polymerizable functional group-containing siloxane unit is 0.3 to 3
It is a polyorganosiloxane comprising mol% and dimethylsiloxane units of 97 to 99.7 mol%, and further containing 1 mol% or less of silicon atoms having three or more siloxane bonds based on all silicon atoms in polydimethylsiloxane. When the amount of the siloxane unit having a vinyl polymerizable functional group in the polyorganosiloxane (a-1) is less than 0.3% by mole, the complexation with the polyalkyl acrylate (a-2) becomes insufficient, and the resin composition molded article becomes poor. Surface appearance deteriorates.
Further, the amount of the siloxane unit having a vinyl polymerizable functional group in the polyorganosiloxane (a-1) exceeds 3 mol%, or one or more silicon atoms having three or more siloxane bonds are included in the total amount of silicon atoms in the polyorganosiloxane. If it exceeds mol%, the impact resistance of the resin composition tends to be low. Further, considering both the impact resistance and the molded appearance of the resin composition, preferably the polyorganosiloxane (a-1)
The vinyl polymerizable functional group-containing siloxane unit in the
It is preferably 2 mol%, more preferably 0.5 to 1 mol%.

The method for producing the polyorganosiloxane (a-1) is not particularly limited, but is preferably an emulsion polymerization. For example, a mixture comprising dimethylsiloxane and a vinyl-polymerizable functional group-containing siloxane, or a mixture comprising Using a homomixer that atomizes a latex obtained by emulsifying a mixture containing a siloxane-based cross-linking agent with an emulsifier and water according to the shear force generated by high-speed rotation, or a homogenizer that atomizes by jetting power from a high-pressure generator. After micronization, polymerization at high temperature using an acid catalyst,
Next, a method of neutralizing the acid with an alkaline substance may be mentioned. Examples of a method for adding an acid catalyst used for polymerization include a method of mixing with a siloxane mixture, an emulsifier, and water, and a method of dropping a latex in which a siloxane mixture is finely divided into a high-temperature aqueous acid solution at a constant rate. Considering the ease of controlling the particle size of the siloxane, a method of dropping a latex in which the siloxane mixture is finely divided into a high-temperature acid aqueous solution at a constant rate is preferable. As the dimethylsiloxane used for the production of the polyorganosiloxane (a-1), a dimethylsiloxane-based cyclic body having three or more membered rings can be mentioned, and a three- to seven-membered ring is preferable. Specific examples include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, and the like. These may be used alone or as a mixture of two or more.

The siloxane containing a vinyl polymerizable functional group is a siloxane containing a vinyl polymerizable functional group and capable of bonding to dimethylsiloxane through a siloxane bond. Various alkoxysilane compounds containing a functional group are preferred. Specifically, β-methacryloyloxyethyldimethoxymethylsilane, γ-methacryloyloxypropyldimethoxymethylsilane, γ-methacryloyloxypropylmethoxydimethylsilane, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropylethoxydiethylsilane, γ-
Methacryloyloxysiloxanes such as methacryloyloxypropyldiethoxymethylsilane and δ-methacryloyloxybutyldiethoxymethylsilane; vinylsiloxanes such as tetramethyltetravinylcyclotetrasiloxane; p-vinylphenyldimethoxymethylsilane; and γ-mercaptopropyldimethoxymethylsilane And mercaptosiloxanes such as γ-mercaptopropyltrimethoxysilane. In addition, these vinyl polymerizable functional group-containing siloxanes can be used alone or as a mixture of two or more. As the siloxane-based crosslinking agent, a trifunctional or tetrafunctional silane-based crosslinking agent such as trimethoxymethylsilane, triethoxyphenylsilane, tetramethoxysilane, tetraethoxysilane, or tetrabutoxysilane is used.

The emulsifier used in the production of the polyorganosiloxane (a-1) according to the present invention is preferably an anionic emulsifier, and is selected from sodium alkylbenzene sulfonate, sodium polyoxyethylene nonylphenyl ether sulfate and the like. Used emulsifiers are used. Especially sodium alkylbenzenesulfonate,
Sulfonic acid-based emulsifiers such as sodium lauryl sulfonate are preferred. These emulsifiers are used in an amount of about 0.05 to 5 parts by weight based on 100 parts by weight of the siloxane mixture. If the amount used is small, the dispersion state becomes unstable and the emulsified state with a fine particle diameter cannot be maintained. In addition, when the amount used is large, coloring of the resin composition molded article caused by the emulsifier becomes severe. The method of mixing a siloxane mixture, an emulsifier, water and / or an acid catalyst includes mixing by high-speed stirring and mixing by a high-pressure emulsifying device such as a homogenizer. This is a preferable method because the distribution becomes small. Polyorganosiloxane (a
Examples of the acid catalyst used for the polymerization of -1) include sulfonic acids such as aliphatic sulfonic acid, aliphatic substituted benzenesulfonic acid, and aliphatic substituted naphthalenesulfonic acid, and sulfuric acid, hydrochloric acid,
Mineral acids such as nitric acid; These acid catalysts are used alone or in combination of two or more. Among these, aliphatic substituted benzenesulfonic acid is preferred in that it is also excellent in stabilizing action of the polyorganosiloxane latex, and n-dodecylbenzenesulfonic acid is particularly preferred. When n-dodecylbenzenesulfonic acid and a mineral acid such as sulfuric acid are used in combination, coloring of the resin composition caused by the emulsifier component of the polyorganosiloxane latex can be reduced.

The polymerization temperature of the polyorganosiloxane is 5
The temperature is preferably 0 ° C or more, more preferably 80 ° C or more. The polymerization time of the polyorganosiloxane (a-1) was determined by mixing the acid catalyst with the siloxane mixture, emulsifier and water,
When the polymerization is carried out by micronization, the polymerization time is 2 hours or more, more preferably 5 hours or more. In the method of lowering the latex in which the siloxane mixture has been micronized in an aqueous solution of an acid catalyst, after the dropping of the latex is completed, it is maintained for about 1 hour. Is preferred. Termination of the polymerization can be carried out by cooling the reaction solution and further neutralizing the latex with an alkaline substance such as caustic soda, caustic potash, and sodium carbonate.

A composite rubber can be obtained by impregnating the polyorganosiloxane latex thus produced with a component comprising an alkyl acrylate and a polyfunctional alkyl (meth) acrylate and then polymerizing it. The amount of the polyorganosiloxane (a-1) in the composite rubber (A) according to the present invention is not particularly limited, but is preferably 1 to 20% by weight. If the amount is less than 1% by weight, the impact resistance of the resin composition is low due to the small amount of the polyorganosiloxane, and if it exceeds 20% by weight, the transparency and pigment coloring of the resin composition are reduced. In consideration of both impact resistance and transparency of the resin composition, the amount of the polyorganosiloxane (a-1) in the composite rubber (A) is preferably 6 to 20% by weight, more preferably 10 to 20% by weight. % By weight. The polyalkyl acrylate (a-2) according to the present invention comprises an alkyl acrylate and a polyfunctional alkyl (meth) acrylate. Examples of the alkyl acrylate include methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, and the like. These can be used alone or in combination of two or more. Of these, it is preferable to use n-butyl acrylate. As a polyfunctional alkyl (meth) acrylate,
For example, allyl methacrylate, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,
Examples thereof include 4-butylene glycol dimethacrylate, triallyl cyanurate, triallyl isocyanurate and the like, and these can be used alone or in combination of two or more. An example of a preferable polyfunctional alkyl (meth) acrylate is a method in which allyl methacrylate and 1,3-butylene glycol dimethacrylate are used in combination.

The amount of the polyfunctional alkyl (meth) acrylate used is 0.1 to 20 in the component consisting of the alkyl acrylate and the polyfunctional alkyl (meth) acrylate.
%, Preferably 0.2 to 5% by weight, more preferably 0.2 to 1% by weight. The polyorganosiloxane (a-1) and the polyalkyl acrylate (a-
The composite rubber (A) comprising 2) is obtained by adding a mixture comprising the above-mentioned alkyl acrylate component and a polyfunctional alkyl (meth) acrylate to a latex of a polyorganosiloxane (a-1), and adding a usual radical polymerization initiator to the latex. It can be prepared by acting and polymerizing. As a method for adding the acrylate component, polyorganosiloxane
There are a method of mixing with the latex of (a-1) at once, and a method of dropping at a constant rate into the latex of polyorganosiloxane (a-1). In consideration of the impact resistance of the resin composition, a method in which the resin composition and the latex of the polyorganosiloxane (a-1) are mixed at once is preferable. Further, as the radical polymerization initiator used for the polymerization, peroxide, azo-based initiator,
Alternatively, a redox initiator combining an oxidizing agent and a reducing agent is used. Among these, a redox initiator is preferable, and a sulfoxylate initiator obtained by combining ferrous sulfate, disodium ethylenediaminetetraacetate, Rongalit, and hydroperoxide is particularly preferable. The weight average particle diameter of the composite rubber (A) is 0.08 to 0.16 μm.
m. When the weight average particle diameter is less than 0.08 μm, the impact resistance of the resin composition becomes low, and
If it exceeds 6 μm, the transparency of the resin composition will be low. A more preferred weight average particle size is 0.1 to 0.15 μm.
m.

[0012] The graft copolymer (I) of the present invention is added to the composite rubber (A) produced by emulsion polymerization as described above,
It can be produced by graft copolymerizing a monomer mixture (B) composed of an aromatic alkenyl compound and a vinyl cyanide compound. Examples of the aromatic alkenyl compound used for graft copolymerization include styrene and α-methylstyrene, and examples of the vinyl cyanide compound include acrylonitrile. Of these, styrene and acrylonitrile are preferably used in consideration of the impact resistance and thermal stability of the resin composition. The amount of the monomer used for the graft copolymerization is from 65 to 65.
85% by weight, 15 to 35% by weight of a vinyl cyanide compound,
It is preferably 0 to 15% by weight (total 100% by weight) of other monomers copolymerizable therewith. If the amount is outside these ranges, the impact resistance and transparency of the resin composition may be impaired. In addition, various chain transfer agents for adjusting the molecular weight and graft ratio of the graft polymer can be added to the monomer mixture used in the graft copolymerization. The graft copolymerization can be carried out in one step or in multiple steps by a radical polymerization technique by adding a monomer mixture (B) comprising an aromatic alkenyl compound and a vinyl cyanide compound to the latex of the composite rubber (A). In consideration of the impact resistance and pigment coloring property of the resulting resin composition containing the graft copolymer, the polymerization is preferably carried out in two or more stages. The amount of the monomer mixture (B) used for graft copolymerization is 80 to 140 parts by weight, preferably 100 to 1 part by weight, per 100 parts by weight of the composite rubber (A).
20 parts by weight. In the graft copolymerization, not all of the monomer mixture becomes a graft component, and a part of the mixture may be present as a single copolymer.

Further, an emulsifier can be added to the graft copolymer to stabilize the polymer latex. The emulsifier to be used is not particularly limited, but preferable examples are a cationic emulsifier, an anionic emulsifier and a nonionic emulsifier, and more preferable examples are a sulfonate emulsifier or a sulfate emulsifier and a carboxylate emulsifier. It is a method used in combination. After the completion of the graft polymerization, the latex is poured into hot water in which a metal salt such as calcium acetate or aluminum sulfate is dissolved, salted out and coagulated to separate and collect the graft copolymer.

The polymethyl methacrylate resin (II) used in the present invention is not particularly limited, but preferably contains at least 80% by weight of a methyl methacrylate unit. 20% by weight or less may contain a vinyl monomer unit other than methyl methacrylate. Examples of the vinyl monomer include an alkyl (meth) acrylate other than methyl methacrylate and styrene. The graft copolymer (I) and the polymethyl methacrylate resin (II) can be extruded by a generally known kneading machine. If necessary, a dye, a pigment, a stabilizer, a reinforcing agent, a filler, a flame retardant, and the like can be added. The resin composition of the present invention includes injection molding, vacuum molding, pressure molding, blow molding, gas injection profile extrusion, sheet extrusion, multilayer extrusion, co-extrusion with a different resin,
A molded product can be formed by a molding method such as injection compression molding, press molding, inflation molding, calendar molding, or the like. The obtained molded product is cold-worked, cut, self-tapped, bit insert, heat staking, metallizing (plating, vapor deposition, sputtering), painting, hot stamping, silk printing, laser marking, bonding (solvent bonding, bonding) Processing such as bonding with an agent, ultrasonic welding, vibration welding, and hot plate welding. In addition, a molded product having a structure such as a snap fit, a hinge, and a boss can be used. The proportion of the polymethyl methacrylate resin (II) in the resin composition in the present invention needs to be 50 to 85 parts by weight. When the amount is less than 50 parts by weight, the transparency becomes low, and when it exceeds 85 parts by weight, the impact resistance becomes low. Further, the proportion of the composite rubber (A) in the resin composition in the present invention needs to be 10 to 25 parts by weight. If the amount is less than 10 parts by weight, the impact resistance is low, and if it is more than 25 parts by weight, the transparency is low. A more desirable ratio is 15 to 25 parts by weight.

[0015]

The present invention will be described in detail with reference to the following examples. In Reference Examples, Examples and Comparative Examples, “parts” and “%” mean “parts by weight” and “% by weight” unless otherwise specified. The weight average particle diameter of the polyorganosiloxane (a-1) and the composite rubber (A) in the latex was determined by a dynamic light scattering method using DLS-700 manufactured by Otsuka Electronics Co., Ltd.

Reference Example 1 Production of Polyorganosiloxane Latex (L-1) 98 parts of octamethylcyclotetrasiloxane and 2 parts of γ-methacryloyloxypropyldimethoxymethylsilane were mixed to obtain 100 parts of a siloxane-based mixture. To this, 300 parts of distilled water in which 0.65 part of sodium dodecylbenzenesulfonate is dissolved is added, and 90 parts thereof are mixed with a homomixer.
After stirring at 00 rpm for 2 minutes, the mixture was added to a homogenizer for 3 minutes.
It was passed once at a pressure of 0 MPa to obtain a stable premixed organosiloxane latex. On the other hand, 10 parts of dodecylbenzenesulfonic acid and 90 parts of distilled water were injected into a reactor equipped with a reagent injection container, a cooling pipe, a jacket heater and a stirrer to prepare a 10% aqueous solution of dodecylbenzenesulfonic acid. . With this aqueous solution heated to 85 ° C,
The above premixed organosiloxane latex was added dropwise over 4 hours, and after completion of the addition, the temperature was maintained for 1 hour and cooled. Then, the reaction product was neutralized with an aqueous solution of sodium hydroxide to obtain a latex. The latex thus obtained was dried at 170 ° C. for 30 minutes to determine the solid content.
It was 8.0%. The weight average particle diameter of the polyorganosiloxane in the latex was 0.07 μm.

Reference Example 2 Production of Polyorganosiloxane Latex (L-2) In Reference Example 1, after stirring with a homomixer at 10,000 rpm for 2 minutes, a homogenizer was used for 30MP.
a), and 25 parts of dodecylbenzenesulfonic acid and 75 parts of distilled water were placed in a reactor equipped with a reagent injection vessel, a cooling pipe, a jacket heater and a stirrer.
And a latex was prepared in the same manner as in Reference Example 1 except that a 25% aqueous solution of dodecylbenzenesulfonic acid was prepared. The solid content of the obtained latex is 19.5.
%, The weight average particle size of the polyorganosiloxane in the latex was 0.02 μm. (Reference Example 3) Polyorganosiloxane latex (L-
Production of 3) In Reference Example 1, the aqueous solution of the emulsifier to be added to 100 parts of the siloxane-based mixture was prepared by dissolving 1 part of sodium dodecylbenzenesulfonate in 200 parts of distilled water. The procedure of Reference Example 1 was repeated except that 2 parts of dodecylbenzenesulfonic acid and 98 parts of distilled water were injected into a reactor equipped with a jacket heater and a stirrer to prepare a 2% aqueous solution of dodecylbenzenesulfonic acid. To prepare latex. The solid content of the obtained latex was 17.8%, and the weight average particle diameter of the polyorganosiloxane in the latex was 0.21 μm.

[Preparation of Composite Rubber (A-1-3) Latex] The polyorganosiloxane latex (prepared in Reference Example 1) was prepared in a reactor equipped with a reagent injection container, a cooling pipe, a jacket heater and a stirrer. L-1) 45.2
Part, polyoxyethylene alkyl phenyl ether sulfate ("Emal NC-35" manufactured by Kao Corporation)
After 0.18 parts were collected and 148.5 parts of distilled water were added and mixed, 42 parts of butyl acrylate, 0.3 part of allyl methacrylate, 0.1 part of 1,3-butylene glycol dimethacrylate and t-part were used. A mixture of 0.11 parts of butyl hydroperoxide was added. By passing a nitrogen stream through this reactor, the atmosphere is replaced with nitrogen,
The temperature was raised to 60 ° C. When the internal temperature of the solution reached 60 ° C., an aqueous solution obtained by dissolving 0.000075 parts of ferrous sulfate, 0.00000225 parts of disodium ethylenediaminetetraacetate and 0.2 parts of Rongalite in 10 parts of distilled water was added. Then, radical polymerization was started. The liquid temperature rose to 78 ° C. due to the polymerization of the acrylate component. This state was maintained for 1 hour to complete the polymerization of the acrylate component to obtain a composite rubber (A-1) latex of polyorganosiloxane and butyl acrylate rubber. A part of the latex was sampled, and the weight average particle diameter of the obtained composite rubber (A-1) was measured to be 0.13 μm.

A composite rubber (A-2) was obtained by performing the same operation using the polyorganosiloxane latex (L-2) produced in Reference Example 2. The weight average particle diameter of the obtained composite rubber (A-2) was 0.06 μm. Further, a composite rubber (A-3) was obtained by performing the same operation using the polyorganosiloxane latex (L-3) produced in Reference Example 3. The weight average particle diameter of the obtained composite rubber (A-3) was 0.28 μm.

[Preparation of Graft Copolymer (I-1-3)] After the liquid temperature of the composite rubber (A-1) latex was lowered to 70 ° C. inside the reactor, 0.25 parts of Rongalite was distilled water. An aqueous solution dissolved in 10 parts is added, then 2.5 parts of acrylonitrile, 7.5 parts of styrene and t-
A mixed solution containing 0.05 parts of butyl hydroperoxide was added dropwise over 2 hours to carry out polymerization. After the completion of dropping, temperature
After maintaining at 0 ° C. for 1 hour, ferrous sulfate 0.001
Parts, disodium ethylenediaminetetraacetate 0.003
Parts, Rongalit 0.2 parts and "Emal NC-3"
5 "(manufactured by Kao Corporation) in an aqueous solution obtained by dissolving 0.18 parts in 10 parts of distilled water, and then adding acrylonitrile 10
, 30 parts of styrene and 0.2 part of t-butyl hydroperoxide were added dropwise over 2 hours to carry out polymerization. After completion of the dropwise addition, the temperature was maintained at a temperature of 60 ° C. for 0.5 hour, 0.05 parts of cumene hydroperoxide was added, and the temperature was maintained at a temperature of 60 ° C. for 0.5 hour, followed by cooling. The obtained graft copolymer latex,
By coagulation, dehydration and drying with an aqueous solution of calcium acetate, a graft copolymer (I-1) was obtained. In the same manner, the graft copolymer (I-2) is used by using the composite rubber (A-2) latex, and the graft copolymer (I-3) is used by using the composite rubber (A-3) latex. ) Got.

[Preparation of Graft Copolymer (I-4)] After the liquid temperature of the composite rubber (A-1) latex was lowered to 70 ° C. inside the reactor, 0.25 parts of Rongalite was added to 10 parts of distilled water. 9.5 parts of methyl methacrylate, 0.5 part of methyl acrylate,
A mixed solution of 0.05 part of t-butyl hydroperoxide and 0.1 part of sodium polyoxyethylene nonylphenyl ether phosphate (“LO-529” manufactured by Toho Chemical) was dropped and polymerized over 2 hours. After dropping,
After maintaining the state at a temperature of 60 ° C. for 1 hour, ferrous sulfate was added at a temperature of 0.1 °
001 parts, disodium ethylenediaminetetraacetate 0.1
003 parts, 0.2 parts of Rongalite in 10 parts of distilled water were added, and then 38 parts of methyl methacrylate, 2 parts of methyl acrylate, 0.15 parts of t-butyl hydroperoxide, n- A mixed solution consisting of 0.1 part and 0.2 parts of octyl mercaptan “LO-529” was dropped and polymerized over 2 hours. After completion of the dropwise addition, the temperature was maintained at 60 ° C. for 0.5 hour, 0.05 parts of cumene hydroperoxide was added, and the temperature was maintained at 60 ° C. for 0.5 hour, followed by cooling. The obtained graft copolymer latex was coagulated, dehydrated, and dried with an aqueous solution of calcium acetate to obtain a graft copolymer (I-4).

[Examples 1 to 3 and Comparative Examples 1 to 6, Test Example 1] Each of the above-obtained graft copolymers (I-1 to 4)
And polymethyl methacrylate resin (PMMA resin) or acrylonitrile-styrene copolymer resin (PA
S resin) were mixed in the composition shown in Table 1, and 0.3 parts of ADK STAB C, 0.2 parts of ADK STAB LA-36 manufactured by Asahi Denka Co., Ltd. were added as stabilizing agents and lubricants. A resin composition was prepared by mixing 0.3 part of barium and 0.4 part of ethylenebisstearylamide (0.8 part of carbon black for evaluating pigment coloring property) using a Henschel mixer. The polymethyl methacrylate resin is "Acrypet V" manufactured by Mitsubishi Rayon Co., Ltd.
H "and PAS (acrylonitrile-styrene copolymer) resin," Stylac AS7 "manufactured by Asahi Kasei Corporation.
89 "was used. Further, the obtained resin composition as a mixture was supplied to a devolatilizing extruder heated to 230 ° C., and was melt-kneaded to obtain pellets. The obtained pellet was formed into a predetermined test piece, and the Izod impact strength, transparency, and pigment coloring property were evaluated.

The measurement of the Izod impact strength is performed according to ASTM.
Performed by a method according to D258. Transparency is obtained by using a natural color resin composition on an injection molding machine (“IS-10”).
0EN "manufactured by Toshiba Machine Co., Ltd.)
ASTM using a 100 mm x 100 mm x 1.5 mm plate
The evaluation was made based on the total light transmittance measured in accordance with D1003. If the total light transmittance is 40% or more, it is determined that there is practical light transmission. The pigment coloring property was as follows. Carbon black ("CB-960" manufactured by Mitsubishi Chemical Corporation)
Based on JIS Z8729, using a 100 mm x 100 mm x 3 mm plate molded with a resin composition colored in black by adding 8 parts by weight using an injection molding machine ("IS-100EN" manufactured by Toshiba Machine Co., Ltd.) The evaluation was made by obtaining the L ^* value of the molded plate by the hue measurement. In general, the L ^* value indicates that the smaller the value, the more the blackness increases, and the value is 1
If it is 1 or less, it is determined that the black coloring property is excellent.
Table 1 shows the evaluation results.

[0024]

[Table 1]

As shown in Examples 1 to 3, it can be seen that the resin composition according to the present invention has practically sufficient levels of impact resistance, transparency and pigment coloring. Comparative Examples 1 and 2
Is that the weight average particle size of the composite rubber (A) deviates from the present invention, but the impact resistance is insufficient in Comparative Example 1 in which the composite rubber (A) is smaller, and the transparency is in Comparative Example 2 in which the weight average particle size is larger. Is found to be insufficient. In Comparative Examples 3 and 4, the ratio of the composite rubber (A) in the resin was out of the range of the present invention, but in Comparative Example 3 in which the ratio was smaller, the impact resistance was insufficient, and the ratio was larger. In Comparative Example 4, the transparency was found to be insufficient. In Comparative Example 5, a methyl methacrylate-based component was introduced into the graft component. It can be seen that although excellent in transparency and pigment coloring, impact resistance is low. Comparative Example 6 uses an acrylonitrile-styrene copolymer resin as a matrix component. Although it has high impact resistance and practically sufficient pigment coloring properties, it can be seen that the molded product becomes opaque.

[Test Example 2] Using the resin composition of Example 1 and a molded plate used for evaluation of pigment coloring property, using a sunshine weather meter (manufactured by Suga Test Instruments Co., Ltd.), JIS D0
An accelerated exposure test was performed in accordance with No. 205 (black panel temperature: 63 ° C., with rain), and the weather resistance was evaluated based on the change in gloss of the surface of the molded plate. The gloss is measured using a digital gloss meter (“GM-26
D "(manufactured by Murakami Color Research Laboratory) and evaluated under the conditions of an incident angle of 60 ° and a light receiving angle of 60 °.

[0027]

[Table 2]

As is clear from Table 2, it can be seen that the molded article of this example has a small decrease in the surface gloss of the molded plate and is excellent in weather resistance even after long-time exposure.

Test Example 3 Using a compression molded plate molded from the resin composition of Example 1, using a chemical such as a household detergent, the chemical resistance was determined by the critical strain value measured by the 1/4 elliptic test method. Was evaluated. That is, first, a 35 mm × 120 mm × 2 mm test piece was prepared by compression molding of the resin composition. The 1/4 elliptical jig has a major axis of 1
After using a 20mm short diameter 40mm, attach the test piece along the elliptical arc, apply various detergents on the test piece surface, and after 5 hours at room temperature no cracks are observed but the maximum distortion (Critical strain value;%) was measured. Generally, when the critical strain value is 0.8% or more, it is judged that there is no fear of chemical cracking under practical stress (crack under environmental stress).

[0030]

[Table 3]

As is clear from Table 3, the resin composition of this example hardly causes chemical cracking even when it comes into contact with various chemicals such as detergents, and has excellent chemical resistance.

[0032]

Industrial Applicability The resin composition of the present invention or a resin molded product thereof is excellent in weather resistance, impact resistance, transparency, pigment coloring property and chemical resistance, so that its industrial utility value is extremely large. Utilizing the weather resistance, impact resistance, and transparency of transparency, parts for display parts such as vending machines, ticket vending machines, and public telephones installed outdoors, and outdoor advertising lights that can be displayed by lighting at night It can be used for parts such as emergency lights and emergency guidance lights. In addition, since it has excellent weather resistance, impact resistance, and chemical resistance, it can be used for applications such as outdoor equipment parts, automobile exterior parts, and exterior that are regularly cleaned. Its value as a material for use is extremely high.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F071 AA33 AA77 AF02 AF23 AF30 AF57 AH12 BA01 BB05 BC07 4J002 BG062 BN111 BN121 BN221 BN231

Claims (2)

[Claims] 1. An aromatic alkenyl group comprising a polyorganosiloxane (a-1) and a polyalkyl acrylate (a-2) having a weight average particle diameter of 0.08 to 0.16 μm in the presence of a composite rubber (A). A graft copolymer (I) obtained by graft polymerization of a monomer mixture (B) composed of a compound and a vinyl cyanide compound, in an amount of 15 to 50 parts by weight, and more than 50 parts by weight of a polymethyl methacrylate resin (II) 85 parts by weight or less of the thermoplastic resin composition (provided that (I) + (II) = 100 parts by weight), wherein the composite rubber (A) accounts for 10 to 25 in the thermoplastic resin composition.
A thermoplastic resin composition in parts by weight. 2. A resin molded article comprising the thermoplastic resin composition according to claim 1.