JP6760829B2 - Thermoplastic resin composition and molded products using it - Google Patents

Description

The present invention relates to a thermoplastic resin composition and a molded product using the same.

Styrene-based resins and ABS resins have been expanding their application fields in recent years, such as vehicle parts, home appliance parts, and various industrial materials, with the development of technology. Secondary processing technology related to resin bonding is also one of the technologies that contributes to its expansion.
Resin joining methods include, for example, mechanical joining with screws and bolts, joining with adhesives such as hot melt, hot plate welding by applying heat typified by hot plate welding, and vibrating the joint. Examples thereof include vibration welding using the frictional heat generated by the above, laser welding by irradiating the joint portion with laser light and utilizing the absorption heat generated at the portion. Recently, laser welding has been increasing its usefulness from the viewpoints of reduction of processing process, weight reduction, reduction of environmental load, and appearance of welding.

In laser welding, usually, two materials, a "transmissive material" that transmits laser light and an "absorbent material" that absorbs laser light, are joined. For example, when the absorbent material and the transmissive material are placed in contact with each other and the laser light is irradiated from the transmissive material side to the material contact interface without contact, the irradiated laser light passes through the transmissive material as it is. It reaches the surface of the absorbent material and is absorbed. The light energy absorbed on the surface of the absorbent material is converted into heat and melts the bonding site. Further, the heat of fusion is transferred to the transmission material to melt the bonding portion of the transmission material. After that, the melted adhesive parts of the absorbent material and the transparent material are solidified and fused with cooling. The resin bonded body obtained through such a process is excellent in strength, airtightness, and appearance (no burrs, etc.). In addition, laser welding has features such as a good working environment and less damage to the built-in parts when some parts are built in the resin member to be joined.
However, in laser welding, if the laser light to be irradiated is too strong, the amount of heat generated by the resin increases, which causes poor appearance such as foaming, charring, and discoloration. On the other hand, if the laser beam to be irradiated is too weak, the bonding strength is lowered, and in some cases, problems such as insufficient welding may occur. Therefore, when performing laser welding, it is very important to control the calorific value of the resin within an appropriate range.

By the way, a molded product obtained from a thermoplastic resin is often used in a state of being colored with a pigment (colored molded product). From the viewpoint of product design, the color tone of colored molded products is very important. Color tones are also very important for vehicle parts, but the demand for black color tends to increase year by year because the design is especially popular in the market.
Since carbon black, which is a typical black colorant, has high absorption of laser light, it is efficient in increasing the amount of heat generated and melting the resin.
However, if the amount of carbon black added is too large, the amount of heat generated becomes excessive, and as described above, poor appearance such as foaming, charring, and discoloration is likely to occur during irradiation with laser light. That is, if the amount of carbon black added is increased in order to obtain a deep blackness, the appearance after laser welding is deteriorated. Therefore, it is very difficult to achieve both the color tone (particularly blackness) and the appearance after laser welding.

Patent Document 1 contains a styrene resin and a colorant as a colored styrene resin molded product having excellent laser marking properties and the appearance (surface gloss) of the molded product, and contains a secondary of 0.1 to 10 μm in the molded product. Those in which the number of colorants present in the particles is 100 to 20000 / m ² are disclosed.
However, in this document, there is no description about achieving both the color tone (particularly blackness) of the molded product and the appearance after laser welding. The colored styrene resin molded product disclosed in Patent Document 1 has technical problems as a laser welding material from the viewpoint of the balance between blackness and absorption of laser light and impact resistance.

Patent Document 2 describes a rubber-reinforced copolymer resin (a rubbery polymer having a gel content of 70% or more) in order to improve a defective phenomenon that occurs during laser welding in joining a lamp housing to another member. A composition obtained by polymerizing a vinyl-based monomer containing an aromatic vinyl compound and a vinyl cyanide compound in the presence of the resin) or a composition of the rubber-reinforced copolymer resin and a (co) polymer of the vinyl-based monomer. A thermoplastic resin composition for a lamp housing in which a rubber-reinforced resin made of a product and a copolymer containing a maleimide-based monomer unit and / or a (co) polymer of α-methylstyrene are combined in a specific ratio It is disclosed.
However, in this document, there is no description about achieving both the color tone (particularly blackness) of the molded product and the appearance after laser welding. The composition disclosed in Patent Document 2 has not been able to sufficiently satisfy the required level for blackness.

Japanese Unexamined Patent Publication No. 2000-309639 Japanese Unexamined Patent Publication No. 2004-182835

An object of the present invention is to provide a thermoplastic resin composition capable of obtaining a molded product having excellent color tone, impact resistance, molded appearance, weather resistance and laser welding appearance.
Another object of the present invention is to provide a molded product having excellent color tone, impact resistance, molded appearance, weather resistance and laser welding appearance.

As a result of diligent studies, the present inventors have made a thermoplastic resin composition containing a graft copolymer in which a vinyl-based polymer is grafted on a composite rubber-like polymer in which a polyorganosiloxane and an alkyl (meth) acrylate-based polymer are composited. We have found that the above problems can be solved by blending carbon black and a composite oxide with a product, and have arrived at the present invention.
That is, the gist of the present invention is as follows.

[1] To 100 parts by weight of the thermoplastic resin (A), 0.1 to 3.0 parts by weight of carbon black (B) and 0.1 to 0.1 parts of a composite oxide (C) containing titanium, antimony and manganese. A thermoplastic resin composition containing 3.0 parts by weight.
When the blending amount of the carbon book (B) is x parts by weight and the blending amount of the composite oxide (C) is y parts by weight, 0.2 ≦ y / x ≦ 5 is satisfied.
Moreover, the thermoplastic resin (A) is a graft copolymer (D) having a structure in which a vinyl-based polymer is grafted onto a composite rubber-like polymer in which a polyorganosiloxane and an alkyl (meth) acrylate-based polymer are composited. A thermoplastic resin composition containing.

[2] The thermoplastic resin composition according to [1], wherein the composite oxide (C) has an average particle size of 1 μm or less.

[3] A molded product using the thermoplastic resin composition according to [1] or [2].

According to the thermoplastic resin composition of the present invention, a molded product having excellent color tone, impact resistance, molded appearance, weather resistance and laser welding appearance can be obtained.
The molded product of the present invention is excellent in color tone, impact resistance, molded appearance, weather resistance and laser welding appearance.

Hereinafter, the present invention will be described in detail.
In the following description, the "molded article" is a product obtained by molding the thermoplastic resin composition of the present invention. Further, in the following description, unless otherwise specified, "excellent in color tone" means that the molded product has a deep blackness (darkness). Further, "excellent welded appearance" means that there is no defective appearance in the welded portion after laser welding the molded product. Poor appearance means charring, discoloration, or insufficient welding in the laser-welded welded portion.

"Thermoplastic resin composition"
The thermoplastic resin composition of the present invention contains a thermoplastic resin (A), carbon black (B), and a composite oxide (C) containing titanium, antimony, and manganese.
The thermoplastic resin (A) contains the graft copolymer (D). The graft copolymer (D) is a composite rubber-like polymer grafted with a vinyl-based polymer, and the composite rubber-like polymer is a composite of a polyorganosiloxane and an alkyl (meth) acrylate-based polymer. It was done.
The thermoplastic resin (A) can further contain a thermoplastic resin (E) other than the graft copolymer (D).
The thermoplastic resin composition of the present invention is, if necessary, a composite containing the thermoplastic resin (A), carbon black (B), and titanium, antimony, and manganese, as long as the effects of the present invention are not significantly impaired. In addition to the oxide (C), other additives may be contained.

<Polyorganosiloxane>
The polyorganosiloxane constituting the composite rubber-like polymer is not particularly limited, but a polyorganosiloxane containing a vinyl polymerizable functional group (polyorganosiloxane containing a vinyl polymerizable functional group) is preferable, and a vinyl polymerizable functional group is contained. A polyorganosiloxane having a siloxane unit and a dimethylsiloxane unit is more preferable.

Examples of the vinyl polymerizable functional group include a methacryloyl group, an acryloyl group, a vinyl group and the like.
The vinyl polymerizable functional group-containing siloxane is not particularly limited as long as it contains a vinyl polymerizable functional group and can be bonded to dimethylsiloxane via a siloxane bond. However, considering the reactivity with dimethylsiloxane, An alkoxysilane compound containing a vinyl polymerizable functional group is preferable. Specifically, β-methacryloyloxyethyl dimethoxymethylsilane, γ-methacryloyloxypropyldimethoxymethylsilane, γ-methacryloyloxypropylmethoxydimethylsilane, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropylethoxydiethylsilane, Examples thereof include methacryloyloxysiloxane such as γ-methacryloyloxypropyldiethoxymethylsilane and δ-methacryloyloxybutyldiethoxymethylsilane; vinylsiloxane such as tetramethyltetravinylcyclotetrasiloxane and p-vinylphenyldimethoxymethylsilane; and the like.

The vinyl polymerizable functional group-containing siloxane unit contained in the polyorganosiloxane may be one type or two or more types.
The content of the vinyl polymerizable functional group-containing siloxane unit is preferably 0.3 to 3 mol% with respect to the total number of moles (100 mol%) of all the units constituting the polyorganosiloxane. When the content of the vinyl polymerizable functional group-containing siloxane unit is within the above range, the polyorganosiloxane and the alkyl (meth) acrylate-based polymer are sufficiently composited, and the polyorganosiloxane bleeds out on the surface of the molded product. It becomes difficult. Therefore, the surface appearance of the molded product is improved, and the impact resistance of the molded product is further improved.

The content of silicon atoms having three or more siloxane bonds in the polyorganosiloxane is preferably 0 to 1 mol% with respect to the total number of moles of all silicon atoms in the polyorganosiloxane. When the content of silicon atoms having 3 or more siloxane bonds is 1 mol% or less, the surface appearance of the molded product is further improved.

Preferred embodiments of the polyorganosiloxane include a vinyl polymerizable functional group-containing siloxane unit of 0.3 to 3 mol% and a dimethylsiloxane unit of 99.7 to 97 mol% (provided that the vinyl polymerizable functional group-containing siloxane unit and dimethylsiloxane). The total unit is 100 mol%), and a polyorganosiloxane having a silicon atom content of 3 or more siloxane bonds of 1 mol% or less with respect to the total silicon atom can be mentioned.

Polyorganosiloxane is typically granular.
The average particle size of the polyorganosiloxane is not particularly limited, but is preferably 400 nm or less, more preferably 300 nm or less, because the surface appearance of the molded product is further improved.
Here, the average particle size of the polyorganosiloxane is a value (mass average particle size) calculated from the mass-based particle size distribution measured by using a capillary type particle size distribution measuring device. is there.

(Manufacturing method of polyorganosiloxane)
The polyorganosiloxane can be obtained, for example, by polymerizing a siloxane mixture containing a vinyl polymerizable functional group-containing siloxane and a dimethylsiloxane oligomer.

As the dimethylsiloxane oligomer, a dimethylsiloxane-based cyclic body having a 3-membered ring or more is preferable, and a dimethylsiloxane-based cyclic body having a 3- to 7-membered ring is more preferable. Specific examples thereof include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane. These dimethylsiloxane oligomers may be used alone or in combination of two or more.

The method for polymerizing the siloxane mixture is not particularly limited, but emulsion polymerization is preferable.
Emulsion polymerization is usually carried out using an emulsifier, water and an acid catalyst.
As the emulsifier, an anionic emulsifier is preferable. Specific examples thereof include sodium alkylbenzene sulfonate, sodium lauryl sulfonate, sodium polyoxyethylene nonylphenyl ether sulfate and the like. Among these, sulfonic acid-based emulsifiers such as sodium alkylbenzene sulfonate and sodium lauryl sulfonate are preferable. These emulsifiers may be used alone or in combination of two or more.
The amount of the emulsifier used is preferably 0.05 to 5 parts by mass, more preferably 0.5 to 3 parts by mass with respect to 100 parts by mass of the siloxane mixture. When the amount of the emulsifier used is 0.05 parts by mass or more, the dispersed state is likely to be stable, and the emulsified state with a fine particle size is easily maintained. On the other hand, when the amount of the emulsifier used is 5 parts by mass or less, coloring of the molded product due to the emulsifier can be suppressed.

Examples of the acid catalyst include organic acid catalysts such as sulfonic acids (for example, aliphatic sulfonic acids, aliphatic substituted benzenesulfonic acids, aliphatic substituted naphthalene sulfonic acids, etc.); and inorganic acids such as mineral acids (for example, sulfuric acid, hydrochloric acid, nitric acid, etc.). Examples include catalysts. These acid catalysts may be used alone or in combination of two or more.
Among these, aliphatic-substituted benzenesulfonic acid is preferable, and n-dodecylbenzenesulfonic acid is particularly preferable, because it is also excellent in stabilizing the latex of the siloxane latex described later. Further, when n-dodecylbenzenesulfonic acid and a mineral acid such as sulfuric acid are used in combination, the influence of the color of the emulsifier used for producing the polyorganosiloxane on the color of the molded product can be suppressed to a small extent.
The amount of the acid catalyst added may be appropriately determined, but is usually about 0.1 to 20 parts by mass with respect to 100 parts by mass of the siloxane mixture.

The acid catalyst may be mixed with the siloxane mixture at the timing of mixing the emulsifier and water, or the siloxane mixture, the emulsifier and water are mixed and emulsified to form a latex (siloxane latex), and the siloxane latex is made into fine particles. After the conversion, it may be mixed with the siloxane latex. Since it is easy to control the particle size of the obtained polyorganosiloxane, it is preferable to make the siloxane latex into fine particles and then mix the siloxane latex with an acid catalyst. In particular, it is preferable to drop the finely divided siloxane latex into the acid catalyst aqueous solution at a constant rate.
When the acid catalyst is mixed with the siloxane mixture at the timing of mixing the emulsifier and water, it is preferable to mix them and then atomize them into fine particles.

The siloxane latex can be made into fine particles by using, for example, a homomixer or a homogenizer. The homomixer uses the shearing force of high-speed rotation to make fine particles. The homogenizer is atomized by the jet output of the high-pressure generator.
Examples of the method of mixing the siloxane mixture, the emulsifier, the water and the acid catalyst, and the method of mixing the finely divided siloxane latex and the acid catalyst include mixing by high-speed stirring and mixing by a high-pressure emulsifying device such as a homogenizer. .. Above all, the method using a homogenizer is preferable because the distribution of the particle size of the polyorganosiloxane can be reduced.

The polymerization temperature is preferably 50 ° C. or higher, more preferably 80 ° C. or higher.
When the finely divided siloxane latex is dropped into the acid catalyst aqueous solution, the temperature of the acid catalyst aqueous solution is preferably 50 ° C. or higher, more preferably 80 ° C. or higher.

When the acid catalyst is mixed at the timing of mixing the siloxane mixture, the emulsifier and water, the polymerization time is preferably 2 hours or more, more preferably 5 hours or more. On the other hand, when the finely divided siloxane latex and the acid catalyst are mixed, it is preferable that the entire amount of the finely divided siloxane latex is added dropwise to the acid catalyst aqueous solution and then held for about 1 to 10 hours.

To stop the polymerization, after cooling the reaction solution, neutralize the reaction solution with an alkaline substance such as sodium hydroxide, potassium hydroxide, or sodium carbonate so that the pH of the reaction solution at 25 ° C. becomes about 6 to 8. Can be done by.

The average particle size of the polyorganosiloxane can be controlled by adjusting the composition of the siloxane mixture, the amount of the acid catalyst used (the content of the acid catalyst in the acid catalyst aqueous solution), the polymerization temperature, and the like. For example, the average particle size tends to increase as the amount of the acid catalyst used decreases, and the average particle size tends to decrease as the polymerization temperature increases.

<Alkyl (meth) acrylate-based polymer>
The alkyl (meth) acrylate-based polymer constituting the composite rubber-like polymer is a polymer having an alkyl (meth) acrylate monomer unit. The alkyl (meth) acrylate-based polymer may further have a monomer unit other than the alkyl (meth) acrylate monomer unit.

Examples of the alkyl (meth) acrylate monomer include acrylic acid alkyl esters such as methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate; hexyl methacrylate and methacrylic acid. Examples thereof include methacrylic acid alkyl esters such as 2-ethylhexyl and n-lauryl methacrylate. These alkyl (meth) acrylates may be used alone or in combination of two or more. The alkyl group of the alkyl (meth) acrylate monomer preferably has 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms. As the alkyl (meth) acrylate monomer, n-butyl acrylate is particularly preferable in that the impact resistance of the molded product is further improved.

The content of the alkyl (meth) acrylate monomer unit in the alkyl (meth) acrylate-based polymer is preferably 80 to 100% by mass with respect to the total mass of all the units constituting the alkyl (meth) acrylate-based polymer. , 90-100% by mass is more preferable.

The other monomer is not particularly limited as long as it can be copolymerized with an alkyl (meth) acrylate monomer, and is, for example, an aromatic vinyl compound (for example, styrene, α-methylstyrene, p-methylstyrene, etc.). , Vinyl cyanide compounds (for example, acrylonitrile, methacrylonitrile, etc.), acid group-containing monomers (for example, unsaturated compounds having a carboxy group such as (meth) acrylic acid, itaconic acid, crotonic acid, etc.) and the like. These other monomers may be used alone or in combination of two or more.

The alkyl (meth) acrylate-based polymer is obtained by polymerizing a monomer component containing at least one alkyl (meth) acrylate monomer.
The method for polymerizing the monomer component is not particularly limited, and it can be carried out according to a known method.

<Composite rubber-like polymer>
The composite rubber-like polymer constituting the graft copolymer (D) is a composite of a polyorganosiloxane and an alkyl (meth) acrylate-based polymer.

The ratio of the polyorganosiloxane to the alkyl (meth) acrylate-based polymer in the composite rubber-like polymer is not particularly limited, but the polyorganosiloxane is used because the impact resistance and surface appearance of the molded product are improved. When the total with the alkyl (meth) acrylate-based polymer is 100% by mass, the proportion of polyorganosiloxane is preferably 2 to 14% by mass.

The gel content of the composite rubber-like polymer is preferably 50 to 99% by mass, more preferably 60 to 95% by mass, and particularly preferably 70 to 85% by mass. When the gel content is within this range, the impact resistance of the molded product becomes better.

Specifically, the gel content of the composite rubber-like polymer is measured by the following method.
The weighed composite rubbery polymer is dissolved in a suitable solvent at room temperature (23 ° C.) for 20 hours, then centrifuged, and the supernatant is removed by decantation to remove the remaining insoluble matter at 60 ° C. 24. Weigh after drying for hours. The ratio (mass%) of the insoluble content to the composite rubber-like polymer weighed first is determined, and the ratio is defined as the gel content of the composite rubber-like polymer. As the solvent used for dissolving the composite rubber-like polymer, for example, toluene or acetone can be used.

The composite rubbery polymer is typically granular.
The average particle size of the composite rubber-like polymer is not particularly limited, but is preferably 100 to 1000 nm, more preferably 150 to 500 nm. When the average particle size of the composite rubber-like polymer is 100 nm or more, the impact resistance is good, and when it is 1000 nm or less, the vapor deposition appearance is good.
The average particle size of the composite rubber-like polymer can be calculated from the obtained particle size distribution by measuring the volume-based particle size distribution using a laser diffraction or scattering type particle size distribution measuring device.

(Method for producing composite rubber-like polymer)
The method for producing the composite rubber-like polymer is not particularly limited, and for example, a method for heteroaggregating or co-enlargement of a plurality of latex containing polyorganosiloxane and an alkyl (meth) acrylate-based polymer; polyorganosiloxane and alkyl. Examples thereof include a method of polymerizing and complexing a monomer component forming the other polymer in the presence of a latex containing any one of the (meth) acrylate-based polymers.

As a method for producing the composite rubber-like polymer, since the volume average particle size of the composite rubber-like polymer can be easily adjusted to be within the above range, alkyl (meth) is present in the presence of latex-like polyorganosiloxane. ) A step of radically polymerizing a monomer component containing one or more acrylate monomers to obtain a polymer latex (radical polymerization step) and a step of mixing the polymer latex and an acid group-containing copolymer latex to obtain the polymer latex. A method having a step of enlarging the polymer latex (enlargement step) is preferable. This method preferably further includes a step of adding a condensate to the polymer latex (condensate addition step) after the radical polymerization step and before the bloating step.

"Radical polymerization process"
The radical polymerization step is a step of radical polymerization of a monomer component containing one or more alkyl (meth) acrylate monomers in the presence of latex-like polyorganosiloxane.
The monomer component containing one or more alkyl (meth) acrylate monomers may be added collectively to the latex-like polyorganosiloxane, or may be added continuously or intermittently.

When radical polymerization of a monomer component containing one or more alkyl (meth) acrylate monomers, either one or both of a graft cross-linking agent and a cross-linking agent may be used, if necessary.
Examples of the graft cross-linking agent or cross-linking agent include allyl methacrylate, triallyl cyanurate, triallyl isocyanurate, divinylbenzene, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, and 1,3-butylene glycol diester. , Dimethacrylic acid 1,4-butylene glycol diester and the like. These may be used alone or in combination of two or more.

Radical polymerization initiators and emulsifiers are usually used for radical polymerization. For example, at room temperature, an emulsifier, a monomer component, and if necessary, one or both of a graft cross-linking agent and a cross-linking agent are added to the latex of polyorganosiloxane to raise the temperature to 50 to 100 ° C. A radical polymerization initiator is added to the mixture, and polymerization is carried out until polymerization heat generation is no longer confirmed, and the state is maintained for about 1 to 5 hours. As a result, a polymer latex containing a composite rubber in which a polyorganosiloxane and an alkyl (meth) acrylate-based polymer are composited can be obtained.

Examples of the radical polymerization initiator include peroxides, azo-based initiators, and redox-based initiators in which an oxidizing agent and a reducing agent are combined. Among these, a redox-based initiator is preferable, and a sulfoxylate-based initiator in which ferrous sulfate, ethylenediaminetetraacetic acid disodium salt, sodium formaldehyde sulfoxylate, and hydroperoxide are combined is particularly preferable.

The emulsifier is not particularly limited, but various carboxylic acids such as sodium sarcosate, potassium fatty acid, sodium fatty acid, dipotassium alkenyl succinate, and soap loginate are excellent in stability of the latex during radical polymerization and can increase the polymerization rate. Salt is preferred. Among these, dipotassium alkenyl succinate is preferable because gas generation can be suppressed when the obtained graft copolymer (D) and the thermoplastic resin composition containing the same are molded at a high temperature.

"Condensate addition step"
The condensate addition step is a step of adding a condensate to the polymer latex obtained in the radical polymerization step prior to the enlargement step. By adding a condensate to the polymer latex before mixing with the acid group-containing copolymer latex in the bloating step, bloating is facilitated. Therefore, the amount of the acid group-containing copolymer latex added can be reduced, and the volume average particle size of the composite rubber-like polymer can be easily adjusted within the above-mentioned range.

Examples of the condensing acid salt include salts of a condensing acid and an alkali metal and / or an alkaline earth metal. Examples of the condensing acid include phosphoric acid and silicic acid. Among these, a salt of pyrophosphate, which is a condensing acid of phosphoric acid, and an alkali metal is preferable, and sodium pyrophosphate or potassium pyrophosphate is particularly preferable.

The amount of the condensing salt added may be adjusted so that the volume average particle size and the particle size distribution of the composite rubber-like polymer are within the above-mentioned ranges, but usually, the polymer latex obtained in the radical polymerization step is used. The solid content of the above is preferably 0.1 to 5 parts by mass, more preferably 0.3 to 3 parts by mass with respect to 100 parts by mass. When the amount of the condensate added is 0.1 parts by mass or more, the enlargement is likely to proceed sufficiently. When the amount of the condensate added is 5 parts by mass or less, the enlargement proceeds sufficiently, or the rubber latex is easily stabilized, and it is possible to suppress the generation of a large amount of agglomerates.
The condensate is preferably added collectively to the polymer latex.

The pH of the polymer latex to which the condensate is added (a mixture of the polymer latex and the condensate) at 25 ° C. is preferably 7 or more. If the pH is 7 or more, hypertrophy is likely to proceed sufficiently.
In order to make this pH 7 or more, general alkaline compounds such as sodium hydroxide and potassium hydroxide can be added.

"Enlargement process"
The bloating step is obtained by mixing a polymer latex obtained in a radical polymerization step and to which a condensate is added in a condensate addition step, if necessary, and an acid group-containing copolymer latex. This is a step of enlarging this polymer latex.

(Acid group-containing copolymer latex)
The acid group-containing copolymer has an acid group-containing monomer unit and an alkyl (meth) acrylate monomer unit. If necessary, it may further have other monomer units copolymerizable with these.
As the acid group-containing monomer, an unsaturated compound having a carboxy group is preferable, and examples of the compound include (meth) acrylic acid, itaconic acid, crotonic acid and the like, and (meth) acrylic acid is particularly preferable. The acid group-containing monomer may be used alone or in combination of two or more.

The alkyl (meth) acrylate monomer is preferably an alkyl (meth) acrylate having an alkyl group having 1 to 8 carbon atoms, for example, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, acrylate. Examples include isobutyl, t-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate and the like. Be done. Among these, alkyl (meth) acrylates having an alkyl group having 1 to 8 carbon atoms are preferable. The alkyl (meth) acrylate monomer may be used alone or in combination of two or more.

The other monomer is a monomer copolymerizable with the acid group-containing monomer and the alkyl (meth) acrylate monomer, and other than the acid group-containing monomer and the alkyl (meth) acrylate monomer. It is a monomer of. Other monomers include aromatic vinyl compounds (eg, styrene, α-methylstyrene, p-methylstyrene, etc.), vinyl cyanide compounds (eg, acrylonitrile, methacrylonitrile, etc.), and two or more polymerizable compounds. Examples thereof include compounds having a functional group (for example, allyl methacrylate, polyethylene glycol dimethacrylate, triallyl cyanurate, triallyl isocyanurate, triallyl trimellit, etc.). The other monomers may be used alone or in combination of two or more.

As the acid group-containing copolymer, the ratio of the acid group-containing monomer unit to the total mass of all the units constituting the acid group-containing copolymer is 5 to 40% by mass, and the alkyl (meth) acrylate monomer is used. The unit ratio is preferably 60 to 95% by mass, the ratio of other monomer units is 0 to 35% by mass, the ratio of the acid group-containing monomer unit is 8 to 30% by mass, and the alkyl (meth) is used. More preferably, the proportion of the acrylate monomer unit is 70 to 92% by mass, and the proportion of the other monomer unit is 0 to 22% by mass.
When the ratio of the acid group-containing monomer unit is 5% by mass or more and the ratio of the alkyl (meth) acrylate monomer unit is 95% by mass or less, sufficient bloating ability can be obtained.
When the ratio of the acid group-containing monomer unit is 40% by mass or less and the ratio of the alkyl (meth) acrylate monomer unit is 60% by mass or more, a large amount of agglomerates are produced during the production of the acid group-containing copolymer latex. It is possible to suppress the formation of things.
When the ratio of the other monomer units is 35% by mass or less, the obtained acid group-containing copolymer latex can have sufficient bloating ability.

The acid group-containing copolymer latex used for bloating contains an acid group-containing monomer, an alkyl (meth) acrylate monomer, and, if necessary, another monomer copolymerizable with these in water. It is obtained by polymerizing the containing monomer components.
The polymerization of the monomer component can be carried out by a general emulsion polymerization method.
Emulsion polymerization is usually carried out using an emulsifier and a polymerization initiator.

As the emulsifier used in the emulsification polymerization, a known emulsifier can be used, and for example, a carboxylic acid-based emulsifier such as an alkali metal salt of oleic acid, palmitic acid, stearic acid, logonic acid, and an alkali metal salt of alkenyl succinic acid. Anionic emulsifiers such as alkyl sulfate ester, sodium alkylbenzene sulfonate, sodium alkyl sulfosuccinate, sodium polyoxyethylene nonylphenyl ether sulfate; and the like. These emulsifiers may be used alone or in combination of two or more.

As a method of using the emulsifier, the whole amount may be added all at once at the initial stage of polymerization, or may be added continuously or intermittently. Depending on the amount of emulsifier and the method of use thereof, the particle size of the acid group-containing copolymer latex may affect the particle size of the composite rubber-like polymer latex having an enlarged particle size. It is preferable to select the method of use.

Examples of the polymerization initiator used in emulsion polymerization include a thermal decomposition type initiator and a redox type initiator. Examples of the pyrolysis initiator include potassium persulfate, sodium persulfate, ammonium persulfate and the like. Examples of the redox-type initiator include combinations of organic peroxides such as cumene hydroperoxide, sodium formaldehyde sulfoxylate, and iron salts. These polymerization initiators may be used alone or in combination of two or more.

During emulsion polymerization, chain transfer agents such as mercaptans (eg t-dodecyl mercaptan, n-octyl mercaptan, etc.), terpinolene, α-methylstyrene dimer, etc. are used to adjust the molecular weight, and the pH is adjusted. Therefore, an alkali, an acid, or an electrolyte as a thickener can be added.

(Enlarged polymer latex)
In the bloating step, the amount of the acid group-containing copolymer latex added to the polymer latex (solid content equivalent amount) should be adjusted so that the volume average particle size of the obtained composite rubber-like polymer is within the above range. However, usually, 0.1 to 5 parts by mass is preferable, and 0.3 to 3 parts by mass is more preferable with respect to 100 parts by mass of the solid content of the polymer latex. When the amount of the acid group-containing copolymer latex added is 0.1 parts by mass or more, bloating proceeds sufficiently. In addition, it is possible to suppress the generation of a large amount of agglomerates. On the other hand, when the amount of the acid group-containing copolymer latex added is 5 parts by mass or less, it is possible to suppress a decrease in the pH of the bloated latex, and the latex is less likely to become unstable.

The acid group-containing copolymer latex may be added collectively to the polymer latex, or may be added continuously or intermittently by dropping.
It is preferable to control the stirring at the time of bloating appropriately. If the stirring is insufficient, the unenlarged rubber-like polymer may remain due to the local progress of hypertrophy. On the other hand, excessive stirring may cause the bloated latex to become unstable and generate a large amount of agglomerates.
The temperature at the time of bloating is not particularly limited, but is preferably 20 to 90 ° C, more preferably 30 to 80 ° C. If the temperature is outside this range, bloat may not progress sufficiently.

The composite rubber-like polymer is obtained by a radical polymerization step, and the copolymer latex to which a condensing acid salt is added as needed is enlarged by using the acid group-containing copolymer latex as described above. After that, it may be produced by further adding a monomer component containing one or more alkyl (meth) acrylate monomers and polymerizing.

<Vinyl polymer>
The vinyl-based polymer constituting the graft copolymer (D) has a vinyl-based monomer unit.
The vinyl-based monomer is a monomer having a polymerizable unsaturated double bond. The vinyl-based monomer is not particularly limited, but aromatic vinyl compounds, (meth) acrylic acid alkyl esters, vinyl cyanide compounds and the like are preferable. "(Meta) acrylic acid alkyl ester" is a general term for acrylic acid alkyl ester and methacrylic acid alkyl ester.
Examples of the aromatic vinyl compound include styrene, α-methylstyrene, p-methylstyrene and the like. Examples of the (meth) acrylic acid alkyl ester include methyl methacrylate, ethyl methacrylate, 2-ethylhexyl methacrylate, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate and the like. Can be mentioned. Examples of the vinyl cyanide compound include acrylonitrile and methacrylonitrile. These vinyl-based monomers may be used alone or in admixture of two or more.
Among the above, as the vinyl-based monomer, it is preferable to use styrene and acrylonitrile in combination because the impact resistance of the molded product is further improved. That is, the vinyl polymer preferably has a styrene unit and an acrylonitrile unit.

<Graft copolymer (D)>
The graft copolymer (D) is obtained by grafting the vinyl-based polymer onto the composite rubber-like polymer.
In the graft copolymer (D), the mass ratio of the composite rubber-like polymer to the vinyl-based polymer is not particularly limited, but is based on the total mass (100% by mass) of the composite rubber-like polymer and the vinyl-based polymer. , The composite rubber-like polymer is preferably 10 to 80% by mass, the vinyl-based polymer is preferably 20 to 90% by mass, the composite rubber-like polymer is 30 to 70% by mass, and the vinyl-based polymer is 30 to 70% by mass. It is particularly preferable that it is%. When the mass ratio of the composite rubber-like polymer to the vinyl-based polymer is within the above range, the impact resistance of the molded product becomes more excellent.
In the graft copolymer (D), it is difficult to specify how the composite rubber-like polymer and the vinyl-based polymer are polymerized. That is, there are circumstances (impossible / impractical circumstances) in which it is impossible or approximately impractical to directly identify the graft copolymer (D) by its structure or properties.

(Method for Producing Graft Copolymer (D))
The graft copolymer (D) is obtained by grafting a vinyl-based polymer onto a composite rubber-like polymer.
Examples of the method of grafting the vinyl-based polymer onto the composite rubber-like polymer include a method of polymerizing (graft-polymerizing) the vinyl-based monomer in the presence of the composite rubber-like polymer. The graft copolymer (D) thus obtained has a form in which the vinyl-based polymer obtained by polymerizing the vinyl-based monomer is grafted onto the composite rubber-like polymer.

The method for performing graft polymerization is not particularly limited, but emulsion polymerization is preferable because the reaction can be controlled so as to proceed stably. Specifically, a method in which vinyl-based monomers are collectively charged into the latex of a composite rubber-like polymer and then polymerized; a part of the vinyl-based monomers is first charged into the latex of the composite rubber-like polymer. A method of dropping the rest onto the polymerization system while polymerizing at any time; a method of dropping the entire amount of the vinyl-based monomer onto the latex of the composite rubber-like polymer and polymerizing at any time can be mentioned. The polymerization of the vinyl-based monomer may be carried out in one stage or may be carried out in two or more stages. When it is divided into two or more stages, it is also possible to change the type and composition ratio of the vinyl-based monomer in each stage.

The mass ratio of the rubber-like polymer to the vinyl-based monomer is not particularly limited, but the composite rubber-like polymer is 10 to 80% by mass based on the total mass of the composite rubber-like polymer and the vinyl-based monomer. The vinyl-based monomer is preferably 20 to 90% by mass, the composite rubber-like polymer is preferably 30 to 70% by mass, and the vinyl-based monomer is particularly preferably 30 to 70% by mass. When the mass ratio of the composite rubber-like polymer to the vinyl-based monomer is within the above range, the mass ratio of the composite rubber-like polymer to the vinyl-based polymer in the graft copolymer (D) is in the above-mentioned preferable range. It is easy to be inside.

Emulsion polymerization is usually carried out using a radical polymerization initiator and an emulsifier. For example, a vinyl-based monomer is added to the latex of a rubber-like polymer containing a rubber-like polymer, water, and an emulsifier, and the vinyl-based monomer is radically polymerized in the presence of a radical polymerization initiator.
When performing radical polymerization, various known chain transfer agents may be added in order to control the molecular weight and graft ratio of the obtained graft copolymer (D).
The polymerization conditions for radical polymerization are not particularly limited, and examples thereof include polymerization conditions at 50 to 100 ° C. for 1 to 10 hours.

Examples of the radical polymerization initiator include peroxides, azo-based initiators, and redox-based initiators in which an oxidizing agent and a reducing agent are combined. Among these, a redox-based initiator is preferable, and a sulfoxylate-based initiator in which ferrous sulfate, ethylenediaminetetraacetic acid disodium salt, sodium formaldehyde sulfoxylate, and hydroperoxide are combined is particularly preferable.

The emulsifier is not particularly limited, but is excellent in the stability of the latex during radical polymerization and can increase the polymerization rate. Acid salts are preferred. Among these, dipotassium alkenyl succinate is preferable because gas generation can be suppressed when the obtained graft copolymer (D) and the thermoplastic resin composition containing the same are molded at a high temperature.

The graft copolymer (D) obtained by performing graft polymerization as described above is usually in the state of latex.
As a method of recovering the graft copolymer (D) from the latex of the graft copolymer (D), for example, the latex of the graft copolymer (D) is put into hot water in which a coagulant is dissolved. A wet method of coagulating into a slurry; a spray-drying method of semi-directly recovering the graft copolymer (D) by spraying the latex of the graft copolymer (D) in a heated atmosphere can be mentioned.

Examples of the coagulant used in the wet method include inorganic acids such as sulfuric acid, hydrochloric acid, phosphoric acid and nitric acid; and metal salts such as calcium chloride, calcium acetate and aluminum sulfate, which are selected according to the emulsifier used in the polymerization. .. For example, when only a carboxylic acid soap such as a fatty acid soap or a rosin acid soap is used as an emulsifier, one or more of the above-mentioned coagulants can be used. When an emulsifier that exhibits stable emulsifying power even in an acidic region such as sodium alkylbenzene sulfonate is used as the emulsifier, a metal salt is suitable as the coagulant.

When the wet method is used, a slurry-like graft copolymer (D) can be obtained. As a method for obtaining the dried graft copolymer (D) from the slurry-like graft copolymer (D), first, the remaining emulsifier residue is eluted with water and washed, and then the slurry is centrifuged or A method of dehydrating with a press dehydrator or the like and then drying with an air flow dryer or the like; a method of simultaneously performing dehydration and drying with a squeezing dehydrator or an extruder can be mentioned. By such a method, a powder or particulate dry graft copolymer (D) is obtained.

The cleaning conditions are not particularly limited, but it is preferable to perform cleaning under conditions in which the amount of emulsifier residue contained in 100% by mass of the graft copolymer (D) after drying is in the range of 0.5 to 2% by mass. When the emulsifier residue in the graft copolymer (D) is 0.5% by mass or more, the fluidity of the obtained graft copolymer (D) and the thermoplastic resin composition containing the same tends to be further improved. .. On the other hand, when the emulsifier residue in the graft copolymer (D) is 2% by mass or less, gas generation when the thermoplastic resin composition is molded at a high temperature can be suppressed.
It is also possible to directly send the graft copolymer (D) discharged from the squeezing dehydrator or the extruder to the extruder or the molding machine for producing the resin composition to obtain a molded product.

<Thermoplastic resin (A)>
The thermoplastic resin (A) may be composed of only the graft copolymer (D), or may further contain a thermoplastic resin (E) other than the graft copolymer (D). From the viewpoint of the balance between impact resistance and fluidity, the thermoplastic resin (A) preferably contains another thermoplastic resin (E).

The thermoplastic resin (A) is preferably composed of 20 to 100% by mass of the graft copolymer (D) and 0 to 80% by mass of the other thermoplastic resin ( E ), and the graft copolymer (D). ) Is more preferably composed of 20 to 60% by mass and 40 to 80% by mass of the other thermoplastic resin (E) (however, of the graft copolymer (D) and the other thermoplastic resin (E). The total is 100% by mass.). When the content of the graft copolymer (D) in the thermoplastic resin (A) is at least the lower limit of the above range, the impact resistance and the welded appearance of the molded product are more excellent.

<Other thermoplastic resin (E)>
The other thermoplastic resin (E) is not particularly limited, but for example, an acrylonitrile-styrene copolymer (AS resin), an acrylonitrile-α-methylstyrene copolymer (αSAN resin), and a styrene-maleic anhydride copolymer. , Acrylonitrile-styrene-N-substituted maleimide ternary copolymer, styrene-maleic anhydride-N-substituted maleimide ternary copolymer, acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-styrene-alkyl ( Meta) acrylate copolymer (ASA resin), acrylonitrile-ethylene-propylene-diene-styrene copolymer (AES resin), polymethyl methacrylate, polycarbonate resin, polybutylene terephthalate (PBT resin), polyethylene terephthalate (PET resin) , Polyvinyl chloride, polyethylene, polyolefins such as polypropylene, styrene-butadiene-styrene (SBS), styrene-butadiene (SBR), hydrogenated SBS, styrene elastomers such as styrene-isoprene-styrene (SIS), various olefins Elastomer, various polyester-based elastomers, polystyrene, methyl methacrylate-styrene copolymer (MS resin), acrylonitrile-styrene-methyl methacrylate copolymer, polyacetal resin, modified polyphenylene ether (modified PPE resin), ethylene-vinyl acetate Examples thereof include copolymers, polyphenylene sulfide (PPS resin), polyether sulfone (PES resin), polyether ether ketone (PEEK resin), polyarylate, liquid crystal polyester resin, polyamide resin (for example, nylon) and the like. These other thermoplastic resins ( E ) may be used alone or in combination of two or more.

<Carbon black (B)>
Examples of the carbon black (B) include channel black, furnace black, lamp black, thermal black, Ketjen black, naphthalene black and the like. Any one of these can be used alone or in combination of two or more.

The carbon black (B) may have a particle surface that has been secondarily treated.
Examples of the secondary treatment include the addition of surface functional groups by oxidation treatment, graphitization by crystal structure by heat treatment in an inert atmosphere, and pirate activity treatment with steam or carbon dioxide gas. Examples of the oxidation treatment include treatment with ozone, nitric acid, nitrite, sodium hypochlorite, and hydrogen peroxide. By the oxidation treatment, acidic functional groups such as carboxyl groups and phenolic hydroxyl groups are generated on the surface of carbon black, and the wettability and dispersibility of the surface of carbon black are improved.

The content of carbon black (B) in the thermoplastic resin composition is 0.1 to 3.0 parts by mass with respect to 100 parts by mass of the thermoplastic resin (A), and is 0.3 to 2.0 parts by mass. Is preferable, and 0.4 to 1.0 parts by mass is more preferable.
When the content of carbon black (B) is 0.1 part by mass or more, the color tone of the molded product obtained from the thermoplastic resin composition is excellent. In addition, sufficient bonding strength can be obtained by laser welding.
When the content of carbon black (B) is 3.0 parts by mass or less, charring and discoloration are less likely to occur during laser welding, and the welded appearance is excellent.

<Composite oxide (C)>
The composite oxide (C) is a composite oxide containing titanium, antimony, and manganese, and may contain other oxides. The particle size is preferably 1 μm or less, and preferably 0.8 μm or less. The content of the composite oxide (C) is preferably 0.1 to 3.0 parts by weight, more preferably 0.2 to 1.5 parts by weight, based on 100 parts by weight of the thermoplastic resin composition (A). More preferably, 0.5 to 1.0 parts by weight. When the content of the composite oxide (C) is less than 0.1 parts by weight, the laser-welded appearance of the laser-welded thermoplastic resin composition of the present invention tends to deteriorate, and sufficient bonding strength is obtained after laser welding. It may not be obtained. On the other hand, if it exceeds 3.0 parts by weight, the color tone and the molded appearance tend to deteriorate.
Further, when the blending amount of the carbon book (B) is x parts by weight and the blending amount of the composite oxide (C) is y parts by weight, it is preferably 0.2 ≦ y / x ≦ 5, more preferably. 0.5 ≦ y / x ≦ 3. If 0.2> y / x, sufficient bonding strength may not be obtained after laser welding. Further, when y / x> 5, the color tone is inferior.

<Other additives>
Other additives include, for example, various stabilizers such as antioxidants and light stabilizers, lubricants, plasticizers, mold release agents, dyes, pigments, antistatic agents, flame retardants, inorganic fillers, metal powders and the like. Can be mentioned.
The content of the other additives is appropriately set according to the type of the additive and is not particularly limited, but is preferably 10 parts by mass or less with respect to 100 parts by mass of the thermoplastic resin (A), and is preferably 0 parts by mass. It may be.

<Manufacturing method of thermoplastic resin composition>
The thermoplastic resin composition of the present invention contains, for example, a thermoplastic resin (A), carbon black (B), a composite oxide (C) containing titanium, antimony, and manganese, and if necessary, other additives. Is mixed and dispersed by a V-type blender, a Henschel mixer, etc., and the mixture obtained by this is melt-kneaded by a melt-kneader such as a screw extruder, a Banbury mixer, a pressure kneader, or a mixing roll. Will be done. Further, if necessary, the melt-kneaded product may be pelletized using a pelletizer or the like.

<Action effect>
In the thermoplastic resin composition of the present invention described above, a graft polymer obtained by grafting a vinyl-based polymer onto a composite rubber-like polymer in which a polyorganosiloxane and an alkyl (meth) acrylate-based polymer are composited ( Since it contains a thermoplastic resin (A) containing D), carbon black (B), and a composite oxide (C), it has sufficient impact resistance as a resin member and excellent color tone when made into a molded product. It develops (especially blackish), weather resistance and molded appearance. In addition, this molded product has an excellent laser welding appearance and can exhibit sufficient bonding strength.

"Molding"
The molded article of the present invention uses the thermoplastic resin composition of the present invention.
The molded article of the present invention can be produced by molding the thermoplastic resin composition of the present invention.
As the molding method, a known molding method can be used, and examples thereof include an injection molding method, a press molding method, an extrusion molding method, a vacuum forming method, and a blow molding method.

The molded product of the present invention can be welded by laser welding. For example, a resin bonded body can be obtained by welding the molded products of the present invention to each other, or the molded product of the present invention and another resin molded product by laser welding. This resin bonded body is excellent in appearance and bonding strength of the welded portion.

Examples of applications of the molded product of the present invention and the resin joint using the same include vehicle parts such as lamps, interiors and exteriors, OA equipment, home appliance parts, medical appliances, various industrial materials and the like. , Vehicle lighting fixtures are suitable.

Hereinafter, examples will be specifically shown. However, the present invention is not limited to the following examples. In addition, "%" and "part" in the following examples are based on mass unless otherwise specified.
Various measurement and evaluation methods in the following examples and comparative examples are as follows.

<Evaluation of Charpy impact>
A test piece (molded product 1) was prepared from a pellet-shaped thermoplastic resin composition by an injection molding machine (manufactured by Toshiba Machine Co., Ltd., "IS55FP-1.5A") in accordance with ISO 3167. The Charpy impact strength of this test piece was measured in a notched, 23 ° C. atmosphere in accordance with ISO 179-1: 2000.

<Evaluation of laser welding appearance>
From the pelletized thermoplastic resin composition produced in each example, a 4 ounce injection molding machine (manufactured by Japan Steel Works, Ltd.) was used, the cylinder set temperature was 260 ° C, the mold temperature was 60 ° C, and the injection rate was 20 g / sec. Under the above conditions, a plate-shaped test piece (molded product 2) having a length of 100 mm, a width of 100 mm, and a thickness of 2 mm was prepared, and this was used as an absorbent material.
A transmission material was prepared in the same procedure as the absorbent material, except that the resin used was changed from the pellet-shaped thermoplastic resin composition produced in each example to the pellet-shaped acrylic resin.
Laser light with the conditions of output: 3W, focal diameter: 2mm, scanning speed: 20mm / sec, welding length: 30mm, using the "laser welding machine NOVOLAS-C type" manufactured by Leister Technologies by superimposing the absorbent material and the transmitting material. Was irradiated from the transmission material side and welded to the absorbent material to obtain a bonded body. Then, the welded appearance of the joint surface of the joint was visually observed and evaluated according to the following criteria.
◯: There is no foaming.
Δ: There is some foaming.
X: There is foaming or charring on the whole.

<Measurement of vapor deposition appearance (diffuse reflectance (%))>
An aluminum film having a thickness of 50 nm is formed on the surface of the molded product 2 by a vacuum vapor deposition method (VPC-1100 manufactured by ULVAC) under the conditions of a vacuum degree of 6.0 × 10-3 Pa and a film formation rate of 10 angstroms / sec (direct vapor deposition). )did. The diffuse reflectance (%) of the film-forming surface of the obtained molded product 2 was measured with a reflectance meter (TR-1100AD manufactured by Tokyo Denshoku Co., Ltd.). The lower the diffuse reflectance, the more brilliant the surface of the molded product is.

<Measurement of color tone>
The color tone (L *) was measured with a colorimeter (CM-3500d manufactured by KONICA MINOLTA) using the same test piece used for evaluating the appearance of laser welding. The smaller the value of L *, the deeper (darker) the blackness of the molded product.

<Measurement of volume average particle size of polymer in latex>
The volume average particle size was determined by a dynamic light scattering method using a Nanotrac UPA-EX150 manufactured by Nikkiso Co., Ltd.

<Measurement of gel content of rubber-like polymer>
The weighed rubber-like polymer is dissolved in toluene at room temperature (23 ° C.) for 20 hours, centrifuged, the supernatant is removed by decantation, and the remaining insoluble matter is dried at 60 ° C. for 24 hours. Weighed. The ratio (%) of the insoluble content to the rubber-like polymer weighed first was determined, and the ratio was taken as the gel content of the rubber-like polymer.

<Evaluation of weather resistance>
Molded product 2 was produced in the same manner as described above. Using "Sunshine Super Long Life Weather Meter WEL-SUN-DCH Type" manufactured by Suga Test Instruments Co., Ltd., the molded product 2 was exposed for 1000 hours in an environment of 63 ° C. and cycle conditions: 60 minutes (rainfall: 12 minutes). .. The degree of discoloration (ΔE) of the molded product before and after exposure for 1000 hours was measured using a color difference meter.

"Manufacturing of acid group-containing copolymer latex"
<Production Example 1: Production of acid group-containing copolymer latex (K)>
200 parts of ion-exchanged water, 2 parts of potassium oleate, 4 parts of sodium dioctyl sulfosuccinate, 0.003 ferrous sulfate heptahydrate in a reactor equipped with a reagent injection container, a cooling tube, a jacket heater and a stirrer. Parts, 0.009 part of ethylenediaminetetraacetic acid disodium salt and 0.3 part of sodium formaldehyde sulfoxylate were charged under a nitrogen stream, and the temperature was raised to 60 ° C. From the time when the temperature reached 60 ° C., a mixture consisting of 85 parts of n-butyl acrylate, 15 parts of methacrylic acid and 0.5 part of cumene hydroperoxide was continuously added dropwise over 120 minutes. After completion of the dropping, aging was carried out for another 2 hours at 60 ° C., and the solid content was 33%, the polymerization conversion rate was 96%, and the volume average particle size of the acid group-containing copolymer was 120 nm. Copolymer latex (K) was obtained.

"Manufacturing of polyorganosiloxane"
<Production Example 2: Production of Polyorganosiloxane (F)>
98 parts of octamethylcyclotetrasiloxane and 2 parts of γ-methacryloyloxypropyldimethoxymethylsilane were mixed to obtain 100 parts of a siloxane mixture. An aqueous solution consisting of 0.67 parts of sodium dodecylbenzenesulfonate and 300 parts of ion-exchanged water was added thereto, and the mixture was stirred with a homomixer at 10000 rpm for 2 minutes, and then passed through a homogenizer twice at a pressure of 30 MPa. A stable premixed organosiloxane latex was obtained.
Separately, 10 parts of dodecylbenzenesulfonic acid and 90 parts of ion-exchanged water are put into a reactor equipped with a reagent injection container, a cooling tube, a jacket heater and a stirrer, and a 10% dodecylbenzenesulfonic acid aqueous solution (acid) is added. Aqueous catalyst solution) was prepared.
While the acid catalyst aqueous solution was heated to 85 ° C., the premixed organosiloxane latex was added dropwise over 2 hours, and the temperature was maintained for 3 hours after the completion of the addition, and then cooled to 40 ° C. or lower. The reaction was then neutralized to pH 7.0 with a 10% aqueous sodium hydroxide solution to give a latex of polyorganosiloxane (F).
When 2 g of the obtained latex of polyorganosiloxane (F) was dried at 180 ° C. for 30 minutes to determine the solid content, it was 18.2%. The mass-based average particle size of the polyorganosiloxane (F) in the latex was 50 nm.

"Manufacturing of graft copolymer"
<Production Example 3: Production of Graft Copolymer (D-1)>
In a reactor equipped with a reagent injection container, a cooling tube, a jacket heater and a stirrer, 2.0 parts of polyorganosiloxane (F) latex in terms of solid content, 0.8 parts of dipotassium alkenyl succinate, and 190 parts of ion-exchanged water was charged and mixed. Then, a mixture consisting of 48.0 parts of n-butyl acrylate, 0.6 parts of allyl methacrylate, 0.1 part of 1,3-butylene glycol dimethacrylate and 0.1 part of t-butyl hydroperoxide was added. Nitrogen was replaced in the atmosphere by passing a nitrogen stream through this reactor, and the internal temperature was raised to 60 ° C. When the internal temperature reaches 60 ° C, from 0.000075 parts of ferrous sulfate heptahydrate, 0.00023 parts of ethylenediaminetetraacetic acid disodium salt, 0.2 parts of sodium formaldehyde sulfoxylate and 10 parts of ion-exchanged water. An aqueous solution was added to initiate radical polymerization. After the polymerization heat generation was confirmed, the jacket temperature was set to 75 ° C., the polymerization was continued until the polymerization heat generation was no longer confirmed, and this state was maintained for another hour, and the composite rubber was a composite of polyorganosiloxane and polybutylacrylate rubber. Was obtained (radical polymerization step). The volume average particle size of the obtained composite rubber was 90 nm.
After the liquid temperature inside the reactor was lowered to 70 ° C., 0.60 part of a 5% aqueous sodium pyrophosphate solution was added as a solid content. After controlling the internal temperature at 70 ° C., 0.60 part of acid group-containing copolymer latex (K) was added as a solid content, and the mixture was stirred for 30 minutes and enlarged to obtain a latex of a composite rubber-like polymer (latex of a composite rubber-like polymer). Enlargement process).
The volume average particle size of the composite rubber-like polymer in the obtained latex was 180 nm. The gel content was 88%.

An aqueous solution consisting of 0.001 part of ferrous sulfate heptahydrate, 0.003 part of ethylenediaminetetraacetic acid disodium salt, 0.3 part of longalit and 10 parts of ion-exchanged water was added to the latex of this composite rubber-like polymer. .. Then, a mixed solution consisting of 10 parts of acrylonitrile, 30 parts of styrene and 0.18 parts of t-butyl hydroperoxide was added dropwise over 80 minutes for polymerization. After completion of the dropping, the temperature was maintained at 75 ° C. for 30 minutes, and then a mixture consisting of 2.5 parts of acrylonitrile, 7.5 parts of styrene, 0.05 parts of t-butyl hydroperoxide and 0.02 parts of n-octyl mercaptan. Was added dropwise over 20 minutes to polymerize. After completion of the dropping, the temperature of 75 ° C. was maintained for 30 minutes, 0.05 part of cumenehydroperoxide was added, and the temperature of 75 ° C. was maintained for 30 minutes, then cooled to form a composite rubber-like polymer. A silicone / acrylic composite rubber-based graft copolymer (D-1) latex was obtained by graft-polymerizing acrylonitrile and styrene.
Next, 150 parts of a 1% aqueous calcium acetate solution was heated to 60 ° C., and 100 parts of the latex of the graft copolymer (D-1) was gradually added dropwise into the mixture to solidify. Then, the precipitate was separated, dehydrated, washed, and then dried to obtain a graft copolymer (D-1) of a composite rubber-like polymer.

<Production Example 4: Production of Graft Copolymer (D-2)>
In a reactor equipped with a reagent injection container, a cooling tube, a jacket heater and a stirrer, 150 parts of ion-exchanged water and polybutadiene latex (volume average particle size 0.2 μm, gel content 84%) are placed in a solid content equivalent of 50. , 1 part of disproportionated potassium rosinate, 0.03 part of potassium hydroxide, and after heating to 60 ° C, 0.007 part of ferrous sulfate heptahydrate, 0.1 part of sodium pyrophosphate, 0 crystalline glucose . 3 parts were added. Next, a mixed solution consisting of 15 parts of acrylonitrile, 35 parts of styrene, 0.4 parts of cumene hydroperoxide, and 0.5 parts of t-dodecyl mercaptan was added dropwise over 120 minutes for polymerization. After completion of the dropping, the temperature of 70 ° C. was maintained for 60 minutes, 0.05 part of cumene hydroperoxide was added, the temperature of 70 ° C. was maintained for 30 minutes, and then the mixture was cooled to add acrylonitrile and styrene to polybutadiene. Was graft-polymerized to obtain a latex of a polybutadiene-based graft copolymer (D-2).
Next, an antioxidant was added to the latex, 150 parts of a 1% aqueous sulfuric acid solution was heated to 60 ° C., and 100 parts of the latex of the graft copolymer (D-2) was gradually added dropwise into the latex to solidify. Then, the precipitate was separated, dehydrated, washed, and then dried to obtain a graft copolymer (D-2).

<Production Example 5: Production of Graft Copolymer (D-3)>
In a reactor equipped with a reagent injection container, a cooling tube, a jacket heater and a stirrer, 2.0 parts of polybutadiene latex (volume average particle size 200 nm) in terms of solid content and 0.8 parts of dipotassium alkenyl succinate were added. , 190 parts of ion-exchanged water was charged and mixed. Then, a mixture consisting of 48.0 parts of n-butyl acrylate, 0.6 parts of allyl methacrylate, 0.1 part of 1,3-butylene glycol dimethacrylate, and 0.1 part of t-butyl hydroperoxide was added. Nitrogen was replaced in the atmosphere by passing a nitrogen stream through this reactor, and the internal temperature was raised to 60 ° C. When the internal temperature reaches 60 ° C, from 0.000075 parts of ferrous sulfate heptahydrate, 0.00023 parts of ethylenediaminetetraacetic acid disodium salt, 0.2 parts of sodium formaldehyde sulfoxylate, and 10 parts of ion-exchanged water. An aqueous solution of formaldehyde was added to initiate radical polymerization. After the polymerization heat generation was confirmed, the jacket temperature was set to 75 ° C., the polymerization was continued until the polymerization heat generation was not confirmed, and this state was maintained for another 1 hour to obtain a composite rubber in which polybutadiene and polybutyl acrylate rubber were composited. (Radical polymerization step). The volume average particle size of the obtained composite rubber was 280 nm.
After the liquid temperature inside the reactor was lowered to 70 ° C., 0.60 part of a 5% aqueous sodium pyrophosphate solution was added as a solid content. After controlling the internal temperature at 70 ° C., 0.60 part of acid group-containing copolymer latex (K) was added as a solid content, and the mixture was stirred for 30 minutes and enlarged to obtain a latex of a composite rubber-like polymer (latex). Enlargement process). The volume-equal particle size of the composite rubber-like polymer in the obtained latex was 300 nm, and the gel content was 83%.

An aqueous solution consisting of 0.001 part of ferrous sulfate heptahydrate, 0.003 part of ethylenediaminetetraacetic acid disodium salt, 0.3 part of longalit, and 10 parts of ion-exchanged water was added to the latex of this composite rubber-like polymer. .. Next, a mixed solution consisting of 10 parts of acrylonitrile, 30 parts of styrene, and 0.18 parts of t-butyl hydroperoxide was added dropwise over 80 minutes for polymerization. After completion of the dropping, the temperature was maintained at 75 ° C. for 30 minutes, and then a mixture consisting of 2.5 parts of acrylonitrile, 7.5 parts of styrene, 0.05 part of t-butyl hydroperoxide, and 0.02 part of n-octyl mercaptan. Was added dropwise over 20 minutes to polymerize. After completion of the dropping, the state of the temperature of 75 ° C. was maintained for 30 minutes, 0.05 part of cumenehydroperoxide was added, and the state of the temperature of 75 ° C. was further maintained for 30 minutes and then cooled to form a composite rubber-like polymer. , A latex of a butadiene / acrylic composite rubber-based graft copolymer (D-3) obtained by graft-polymerizing acrylonitrile and styrene was obtained.
Next, 150 parts of a 1% calcium acetate aqueous solution was heated to 60 ° C., and 100 parts of the latex of the graft copolymer (D-3) was gradually added dropwise into the mixture to solidify. Then, the precipitate was separated, dehydrated, washed, and then dried to obtain a graft copolymer (D-3).

<Production Example 6: Production of Graft Copolymer (D-4)>
190 parts of ion-exchanged water, 0.6 parts of dipotassium alkenyl succinate, 50 parts of n-butyl acrylate, 0.6 parts of allyl methacrylate in a reactor equipped with a reagent injection container, a cooling tube, a jacket heater and a stirrer. , A mixture consisting of 0.1 parts of t-butyl hydroperoxide was added. Nitrogen was replaced in the atmosphere by passing a nitrogen stream through this reactor, and the internal temperature was raised to 55 ° C. When the internal temperature reaches 55 ° C, from 0.0001 parts of ferrous sulfate heptahydrate, 0.0003 parts of ethylenediaminetetraacetic acid disodium salt, 0.2 parts of sodium formaldehyde sulfoxylate, and 10 parts of ion-exchanged water. An aqueous solution of formaldehyde was added to initiate radical polymerization. After the heat generation of polymerization was confirmed, the jacket temperature was set to 75 ° C., and the polymerization was continued until the heat generation of polymerization was no longer confirmed, and this state was maintained for another 1 hour. The volume average particle size of the obtained rubber-like polymer was 100 nm.
After the liquid temperature inside the reactor was lowered to 70 ° C., 0.6 part of a 5% aqueous sodium pyrophosphate solution was added as a solid content. After controlling the internal temperature at 70 ° C., 1.2 parts of the acid group-containing copolymer latex (K) was added as a solid content, and the mixture was stirred for 30 minutes and enlarged to obtain a latex of a rubber-like polymer. The volume average particle size of the obtained latex-like rubber-like polymer was 290 nm, and the gel content was 85%.

The obtained rubbery polymer latex was added to 0.001 part of ferrous sulfate heptahydrate, 0.003 part of ethylenediaminetetraacetic acid disodium salt, 0.3 part of sodium formaldehyde sulfoxylate, and 10 parts of ion-exchanged water. An aqueous solution was added. Then, a mixed solution consisting of 15 parts of acrylonitrile, 35 parts of styrene, and 0.225 parts of t-butyl hydroperoxide was added dropwise over 100 minutes for polymerization. After completion of the dropping, the temperature of 80 ° C. was maintained for 30 minutes, 0.05 part of cumene hydroperoxide was added, the temperature of 75 ° C. was maintained for 30 minutes, and then the mixture was cooled to obtain a graft copolymer (D). -4) Latex was obtained.
Next, 100 parts of a 1.5% sulfuric acid aqueous solution was heated to 80 ° C., and 100 parts of the latex of the graft copolymer (D-4) was gradually added dropwise into the mixture to solidify. Then, the precipitate was separated, dehydrated, washed, and then dried to obtain a graft copolymer (D-4).

"Other thermoplastic resin (E)"
<Manufacturing Example 7: Production of Other Thermoplastic Resin (E-1)>
27 parts of acrylonitrile and 73 parts of styrene were polymerized by a known suspension polymerization to obtain an acrylonitrile-styrene copolymer having a reduced viscosity of 0.61 dl / g measured at 25 ° C. from an N, N-dimethylformamide solution. This was used as another thermoplastic resin (E-1).

<Manufacturing Example 8: Production of Another Thermoplastic Resin (E-2)>
Acrylonitrile-styrene having a reduced viscosity of 0.65 dl / g measured at 25 ° C. from an N, N-dimethylformamide solution obtained by polymerizing 19 parts of acrylonitrile, 53 parts of styrene and 28 parts of N-phenylmaleimide by a known continuous solution polymerization. A −N-phenylmaleimide ternary copolymer was obtained. This was used as another thermoplastic resin (E-2).

"Examples 1 to 6, Comparative Examples 1 to 10"
Graft copolymer (D), other thermoplastic resin (E) and carbon black (B) of the type and amount (parts) shown in Tables 1 and 2, composite oxide (C), ethylene bisstearylamide 1 part , 0.2 parts of silicone oil SH200 (manufactured by Toray Dow Corning Co., Ltd.), 0.2 parts of Adecastab AO-60 (manufactured by ADEKA Co., Ltd.), and 0.4 parts of Adecastab LA-57 (manufactured by ADEKA Co., Ltd.) And were mixed using a Henschel mixer. The obtained mixture is melt-kneaded at 250 ° C. using a screw extruder (manufactured by Japan Steel Works, Ltd., TEX-30α twin-screw extruder), and then pelletized with a pelletizer to form pellets of thermoplastic. A resin composition was obtained.
The obtained thermoplastic resin composition was evaluated for color tone, impact resistance, molded appearance, weather resistance and laser welding appearance by the above procedure. These results are shown in Tables 1-2.

"Carbon black (B)"
(B-1) "RB-92995S" manufactured by Koshiya Kasei Kogyo Co., Ltd.

"Composite oxide (C)"
(C-1) "Brown10P850" manufactured by Shepherd Color Japan Inc.
Mn / Sb / Ti oxide (average particle size 0.7 μm)
(C-2) "Yellow10P225" manufactured by Shepherd Color Japan Inc.
Cr / Sb / Ti oxide (average particle size 0.9 μm)
(C-3) "Black10P922" manufactured by Shepherd Color Japan Inc.
Fe / Cr oxide (average particle size 1.7 μm)

As shown in Tables 1 and 2, molded products having excellent color tone, impact resistance, molded appearance, weather resistance, and laser welding appearance were obtained from the thermoplastic resin compositions obtained in each example.
On the other hand, in the case of each comparative example, the result was inferior to any one or more of the color tone, impact resistance, molded appearance, weather resistance and laser welding appearance of the molded product.
Specifically, in the case of Comparative Example 1, since the content of carbon black (B) was large, the laser welding appearance was inferior.
In the case of Comparative Example 2, since the content of carbon black (B) was small, the laser welded appearance was inferior.
In the case of Comparative Example 3, since the content of the composite oxide (C) was large, the laser welded appearance, the molded appearance, and the color tone were inferior.
In the case of Comparative Example 4, the appearance of laser welding was inferior because the content of the composite oxide (C) was small.
In the case of Comparative Example 5, the color tone was inferior because the composite oxide (C) did not contain antimony and manganese.
In the case of Comparative Example 6, since the composite oxide (C) did not contain antimony, manganese, and titanium, the molded appearance was inferior.
In the case of Comparative Example 7, the impact resistance was inferior because the graft copolymer (D) was not contained.
In the cases of Comparative Examples 8 and 9, the weather resistance was inferior because the composite rubber-like polymer in which the polyorganosiloxane and the alkyl (meth) acrylate-based polymer were composited was not contained.
In the case of Comparative Example 10, since the composite rubber-like polymer in which the polyorganosiloxane and the alkyl (meth) acrylate-based polymer were composited was not contained, the impact resistance was inferior.

According to the present invention, it is possible to provide a thermoplastic resin composition which is excellent in color tone, molded appearance, weather resistance and laser welding appearance, and can obtain a molded product having sufficient impact resistance as a resin member. .. In particular, the balance between the color tone of the molded product, the molded appearance, and the appearance after laser welding is at a very high level that cannot be obtained with conventionally known thermoplastic resin compositions, and vehicle parts such as lamps, interiors, and exteriors. , OA equipment, home appliance parts, medical equipment, and various industrial materials have extremely high utility value.

Claims (3)

Carbon black (B) is 0.1 to 3.0 parts by weight, and composite oxide (C) containing titanium, antimony, and manganese is 0.1 to 3.0 parts by weight with respect to 100 parts by weight of the thermoplastic resin (A). A thermoplastic resin composition blended in parts by weight.
When the blending amount of the carbon book (B) is x parts by weight and the blending amount of the composite oxide (C) is y parts by weight, 0.2 ≦ y / x ≦ 5 is satisfied.
Moreover, the thermoplastic resin (A) is a graft copolymer (D) having a structure in which a vinyl-based polymer is grafted on a composite rubber-like polymer in which a polyorganosiloxane and an alkyl (meth) acrylate-based polymer are composited. 20 to 60% by mass of the above and 40 to 80% by mass of the other thermoplastic resin (E) (however, the total of the graft copolymer (D) and the other thermoplastic resin (E) is 100% by mass. %) , Thermoplastic resin composition. The thermoplastic resin composition according to claim 1, wherein the composite oxide (C) has an average particle size of 1 μm or less. A molded product using the thermoplastic resin composition according to claim 1 or 2.