JP2017141406A - Thermoplastic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition capable of obtaining a molded product which is excellent in color tone and appearance after laser welding and has sufficient impact resistance and weather resistance as a resin member, and to provide a molded product formed from a thermoplastic resin composition which is excellent in color tone and appearance after laser welding and has sufficient impact resistance and weather resistance as a resin member.SOLUTION: Reflectivity in a visible light region and absorptivity in a near-infrared region of a thermoplastic resin composition containing a graft copolymer using a composite rubbery polymer obtained by combining polyorganosiloxane and an alkyl(meth)acrylate polymer are suitably controlled.SELECTED DRAWING: None

Description

  The present invention relates to a thermoplastic resin composition.

In recent years, with the development of technology, resin has expanded its application fields such as automotive parts, home appliance parts, and various industrial materials. Secondary processing technology related to resin bonding is one of the technologies that contribute to the expansion.
Examples of resin bonding include mechanical bonding with screws and bolts, bonding with an adhesive such as hot melt, thermal bonding by heating and melting, represented by hot plate welding, and vibrating the bonding portion. Examples include vibration welding using the generated frictional heat, and laser welding using the heat generated by irradiating the joint with laser light. Recently, hot plate welding, vibration welding, and laser welding have increased their usefulness from the viewpoint of reduction of processing steps, weight reduction, and reduction of environmental load.

  In laser welding, normally, two materials, a “transmitting material” that transmits laser light and an “absorbing material” that absorbs laser light, are joined. The laser light irradiated from the transmissive material side to the material contact interface in a non-contact manner passes through the transmissive material as it is and reaches the absorber surface. The light energy absorbed on the surface of the absorber is converted into heat and melts the irradiated part. The heat of fusion is also transferred to the permeable material, and the permeable material is also melted. Thereafter, the melted portion is solidified and fused together with cooling. The resin bonded body laser-welded through these processes is not only excellent in strength, airtightness, and appearance (no burr generation, etc.), but also very good from the viewpoint of work environment and damage to built-in parts. It has the feature.

  However, if the laser beam irradiation is too strong, the amount of heat generated by the resin increases, which causes appearance defects such as foaming, scorching, and discoloration. On the other hand, if the laser beam irradiation is too weak, the bonding strength may be reduced, and in some cases, the welding may not be sufficiently performed. For this reason, it is very important to control the heat generation amount of the resin within an appropriate range when performing laser welding.

From the viewpoint of controlling the amount of heat generation, a method of adjusting the optical characteristics of the material with respect to the laser beam can be considered. As such a technique, for example, Patent Documents 1 to 3 disclose resin compositions that exhibit a predetermined transmittance with respect to a specific wavelength or a specific range of wavelengths.
However, all of the resin compositions described in Patent Documents 1 to 3 are used as a “transmitting material” by allowing a laser beam having a sufficient energy amount to reach the welded portion by defining the transmittance to a certain value or more. However, this technology is not suitable for use as an “absorbent”.

  Light incident on the material is divided into transmitted light, reflected light, and absorbed light. That is, when the ratio of incident light is 100%, the ratio of each light component is established as follows: transmittance + reflectance + absorption rate = 100%. In the case of the “transmitting material”, attention is paid to the transmittance from the viewpoint of causing the laser beam to reach the welded portion. On the other hand, in the case of the “absorbing material”, from the viewpoint of controlling the calorific value within an appropriate range, the optical characteristic to be noted is the transmittance, not the transmittance. The reason is that when the absorbing material is thermally melted by the energy of the laser beam, if the absorbed amount is excessive, appearance defects such as foaming, scorching, and discoloration will be insufficient, and if it is insufficient, welding will be insufficient. This is to cause a malfunction. Thus, in order to obtain a molded article excellent in laser weldability, it is very important to control the absorption rate of the “absorbing material”.

  By the way, a molded product obtained from a thermoplastic resin is usually used in a state colored with a dye / pigment (colored molded product), and its color tone is very important from the viewpoint of product design. . Such a color tone is a result of observing light of various wavelengths in the visible light region reflected by the material with the human eye in principle. Although the color tone changes variously depending on the wavelength of light reflected by the material, a dark color tone such as black or dark gray indicates that the reflectance of light in the visible light region is generally low. In other words, from the viewpoint of color tone control, the optical characteristic to be focused on is the reflectance in the visible light region, and particularly in the dark color tone, it is important to control the reflectance in the visible light region within a specific low range. .

  As the wavelength of light in laser welding, light having a wavelength in the near-infrared region is preferably used in terms of excellent oscillation efficiency. On the other hand, the wavelength of light in the color tone corresponds to light having a wavelength in the visible light region as described above. That is, it is possible to provide a material excellent in laser weldability and color tone by suitably controlling the absorptance in the near infrared region and the reflectance in the visible light region. Furthermore, as a feature of the present invention, by suitably controlling the ratio of the absorptance in the near infrared region and the reflectance in the visible light region, it is possible to provide a material that is extremely excellent in the balance between laser weldability and color tone. Is possible.

Japanese Patent No. 4017994 JP 2007-8974 A JP 2007-269890 A

  An object of this invention is to provide the thermoplastic resin composition which can obtain the molded article which is excellent in the color tone and the external appearance after laser welding, and has sufficient impact resistance and weather resistance as a resin member. Another object of the present invention is to provide a molded article made of a thermoplastic resin composition having excellent color tone and appearance after laser welding and having sufficient impact resistance and weather resistance as a resin member.

  As a result of intensive studies, the present inventors have found that a thermoplastic resin composition containing a graft copolymer using a composite rubber-like polymer in which a polyorganosiloxane and an alkyl (meth) acrylate-based polymer are combined has a visible light region. The present inventors have found that the above-mentioned problems can be solved by suitably controlling the reflectance and the absorptance in the near-infrared region, and have completed the present invention.

That is, the present invention includes the following aspects.
[1] Graft copolymer obtained by grafting vinyl polymer (D) onto composite rubber-like polymer (C) in which polyorganosiloxane (A) and alkyl (meth) acrylate polymer (B) are combined. E) a thermoplastic resin composition comprising
When the light reflectance (% R) and the light absorptance (% A) represented by the following formula (1) were measured from the visible light region to the near infrared light region at a wavelength interval of 1 nm,
The average value (visible% R) of the light reflectance of 380 nm to 780 nm is 5% to 10%,
A thermoplastic resin composition satisfying an average value (near infrared% A) of a light absorption rate of 780 nm to 1180 nm of 25% to 93%.
Light Absorption Rate (% A) = 100−Light Transmittance (% T) −Light Reflectance (% R) (1)
[2] The ratio (near infrared% A / visible% R) of the average value of the light absorptance in the near infrared region and the average value of the light reflectance in the visible light region is 16.5 to 4.5. The thermoplastic resin composition according to [1], wherein
[3] A molded product obtained by molding 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 and appearance after laser welding and having sufficient impact resistance and weather resistance as a resin member can be obtained.
The molded product of the present invention is excellent in color tone and appearance after laser welding, and has sufficient impact resistance and weather resistance as a resin member.

Hereinafter, the present invention will be described in detail.
In the following description, the “molded product” is formed by molding the thermoplastic resin composition of the present invention. Further, unless otherwise specified in the following description, “excellent color tone” means that the molded product exhibits a dark color tone (dark gray, black, etc.). Also, “excellent weld appearance” means that scorching and discoloration are suppressed at the joint after laser welding.

"Thermoplastic resin composition"
The thermoplastic resin composition of the present invention contains a graft copolymer (E).

<Graft copolymer (E)>
The graft copolymer (E) is obtained by grafting a vinyl polymer (D) onto a composite rubber-like polymer (C) in which a polyorganosiloxane (A) and an alkyl (meth) acrylate polymer (B) are combined. It is a polymerized copolymer.

<Polyorganosiloxane (A)>
The polyorganosiloxane (A) constituting the composite rubber-like polymer (C) is not particularly limited, but a polyorganosiloxane containing a vinyl polymerizable functional group (vinyl polymerizable functional group-containing polyorganosiloxane) is preferable, and vinyl A polyorganosiloxane having a polymerizable functional group-containing siloxane unit and a dimethylsiloxane unit is more preferred.
The ratio of the vinyl polymerizable functional group-containing siloxane unit is preferably 0.3 to 3 mol%. If the ratio of the vinyl polymerizable functional group-containing siloxane unit is within the above range, the polyorganosiloxane (A) and the alkyl (meth) acrylate polymer (B) are sufficiently complexed to form a polyorgano on the surface of the molded product. Siloxane (A) is difficult to bleed out. Therefore, the surface appearance of the molded product becomes better, and the impact resistance of the molded product is further improved.

As polyorganosiloxane (A), since the surface appearance of the molded article is further improved, the silicon atom having three or more siloxane bonds is 0 to 1 mol% with respect to all silicon atoms in the polyorganosiloxane. It is preferable.
As a preferable aspect of polyorganosiloxane (A), 0.3-3 mol% of vinyl polymerizable functional group containing siloxane units and 99.7-97 mol% of dimethylsiloxane units (however, vinyl polymerizable functional group containing siloxane units) And a total of 100 mol% of dimethylsiloxane units), and a polyorganosiloxane having 3 or more siloxane bonds and not more than 1 mol% of all silicon atoms in the polyorganosiloxane. It is done.

The average particle diameter of the polyorganosiloxane (A) is not particularly limited, but is preferably 400 nm or less, more preferably 150 nm or less, because the surface appearance of the molded product becomes even better. About a lower limit, 20 nm or more is preferable.
Here, the average particle size of the polyorganosiloxane (A) is a value (mass average particle size) calculated from the particle size distribution obtained by measuring the mass size particle size distribution using a particle size distribution analyzer. is there.

(Production method of polyorganosiloxane (A))
The polyorganosiloxane (A) can be obtained, for example, by polymerizing a siloxane mixture containing dimethylsiloxane and vinyl polymerizable functional group-containing siloxane. The polymerization method is not particularly limited, but emulsion polymerization is preferred.

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

  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, but considering the reactivity with dimethylsiloxane. Various alkoxysilane compounds containing a vinyl polymerizable functional group are suitable. Specifically, β-methacryloyloxyethyldimethoxymethylsilane, γ-methacryloyloxypropyldimethoxymethylsilane, γ-methacryloyloxypropylmethoxydimethylsilane, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropylethoxydiethylsilane, methacryloyloxysiloxane such as γ-methacryloyloxypropyldiethoxymethylsilane, δ-methacryloyloxybutyldiethoxymethylsilane; vinylsiloxane such as tetramethyltetravinylcyclotetrasiloxane; p-vinylphenyldimethoxymethylsilane, γ-mercaptopropyldimethoxy And mercaptosiloxanes such as methylsilane and γ-mercaptopropyltrimethoxysilane. These vinyl polymerizable functional group-containing siloxanes may be used alone or in combination of two or more.

The polymerization of the siloxane mixture is usually performed using an emulsifier, water, and an acid catalyst.
As the emulsifier, an anionic emulsifier is preferable. Specific examples 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 with respect to 100 parts by mass of the siloxane mixture. If the usage-amount of an emulsifier is 0.05 mass part or more, a dispersion state will be easy to be stabilized and it will become easy to hold | maintain the emulsification state of a fine particle diameter. On the other hand, if the usage-amount of an emulsifier is 5 mass parts or less, coloring of the molded article resulting from an emulsifier can be suppressed.

Examples of the acid catalyst include organic acid catalysts such as sulfonic acids (eg, aliphatic sulfonic acid, aliphatic substituted benzene sulfonic acid, aliphatic substituted naphthalene sulfonic acid, etc.); inorganic acids such as mineral acids (eg, sulfuric acid, hydrochloric acid, nitric acid, etc.) A catalyst etc. are mentioned. 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 in that it is excellent in the stabilizing action of the latex of the siloxane latex (a) described later. In addition, 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 in the production of the polyorganosiloxane (A) on the color of the molded product can be reduced.
Although the addition amount of an acid catalyst should just be determined suitably, it is about 0.1-20 mass parts normally with respect to 100 mass parts of siloxane mixtures.

The acid catalyst may be mixed at the timing when the siloxane mixture, the emulsifier and water are mixed, or the emulsifier and water are added to the siloxane mixture and emulsified to form a latex (siloxane latex (a)), which is finely divided. It may be after Since it is easy to control the particle diameter of the resulting polyorganosiloxane (A), it is preferable to mix the siloxane latex (a) and the acid catalyst after making the siloxane latex (a) fine. In particular, it is preferable that the finely divided siloxane latex (a) is dropped into the acid catalyst aqueous solution at a constant rate.
In addition, when mixing an acid catalyst at the timing which mixes a siloxane mixture, an emulsifier, and water, it is preferable to atomize after mixing these.

The siloxane latex (a) can be formed into fine particles by using, for example, a homomixer that makes fine particles by a shearing force generated by high-speed rotation or a homogenizer that makes fine particles by jetting power from a high-pressure generator.
Examples of the method of mixing the siloxane mixture, the emulsifier, water, and the acid catalyst, and the method of mixing the finely divided siloxane latex (a) and the acid catalyst include mixing by high-speed stirring, mixing by a high-pressure emulsifier such as a homogenizer, etc. Is mentioned. Among them, the method using a homogenizer is preferable because the particle size distribution of the polyorganosiloxane (A) can be reduced.

The polymerization temperature is preferably 50 ° C. or higher, and preferably 80 ° C. or higher.
In addition, when dripping the micronized siloxane latex (a) into the acid catalyst aqueous solution, the temperature of the acid catalyst aqueous solution is preferably 50 ° C. or higher, and preferably 80 ° C. or higher.

  The polymerization time is preferably 2 hours or longer, and more preferably 5 hours or longer when the acid catalyst is mixed at the timing of mixing the siloxane mixture, the emulsifier and water. On the other hand, when the finely divided siloxane latex (a) and the acid catalyst are mixed, it is preferable that the finely divided siloxane latex (a) is dropped into the acid catalyst aqueous solution and held for about 1 hour.

  The polymerization is stopped by cooling the reaction solution and neutralizing the reaction solution with an alkaline substance such as sodium hydroxide, potassium hydroxide, sodium carbonate or the like so that the pH of the reaction solution at 25 ° C. is about 6-8. Can be done by.

  The average particle diameter of the polyorganosiloxane (A) 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 aqueous acid catalyst 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 polymer (B)>
The alkyl (meth) acrylate polymer (B) constituting the composite rubber-like polymer (C) is obtained by polymerizing a monomer component containing at least one alkyl (meth) acrylate monomer. . This monomer component may contain a monomer (another monomer) other than the alkyl (meth) acrylate monomer.

Examples of the alkyl (meth) acrylate monomer include alkyl acrylates such as methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate and 2-ethylhexyl acrylate; hexyl methacrylate and methacrylic acid. Examples include methacrylic acid alkyl esters such as 2-ethylhexyl and n-lauryl methacrylate. These alkyl (meth) acrylate monomers may be used individually by 1 type, and may use 2 or more types together. Among these, n-butyl acrylate is preferable because the impact resistance of the molded product is further improved.
80-100 mass% is preferable and, as for the ratio of the alkyl (meth) acrylate monomer in 100 mass% of monomer components, 90-100 mass% is more preferable. When the ratio of the alkyl (meth) acrylate monomer in 100% by mass of the monomer component is within the above range, the impact resistance of the molded product is further improved.

  Other monomers are not particularly limited as long as they can be copolymerized with alkyl (meth) acrylate monomers, but are aromatic vinyl compounds (for example, styrene, α-methylstyrene, p-methylstyrene, etc.), cyanide. And vinyl chloride compounds (for example, acrylonitrile, methacrylonitrile, etc.). These other monomers may be used individually by 1 type, and may use 2 or more types together.

  The production method of the alkyl (meth) acrylate polymer (B) is not particularly limited, and can be performed according to a known method.

<Composite rubbery polymer (C)>
The composite rubber-like polymer (C) is a composite rubber in which a polyorganosiloxane (A) and an alkyl (meth) acrylate polymer (B) are combined.

The average particle size of the composite rubber-like polymer (C) is not particularly limited, but is preferably 0.1 to 1 μm, and more preferably 0.2 to 0.5 μm. When the average particle diameter is within the above range, the impact resistance of the molded product is further improved.
The average particle size of the composite rubbery polymer (C) can be calculated from the particle size distribution obtained by measuring the volume-based particle size distribution using a particle size distribution analyzer.

(Method for producing composite rubber-like polymer (C))
The method for producing the composite rubbery polymer (C) is not particularly limited, but a method for heteroaggregating or co-hypertrophying a plurality of latexes each containing a polyorganosiloxane (A) and an alkyl (meth) acrylate polymer (B) In the presence of a latex containing one of the polyorganosiloxane (A) and the alkyl (meth) acrylate polymer (B), the monomer component that forms the other polymer is polymerized and combined. The method etc. are mentioned.
In particular, since the volume average particle diameter of the composite rubber-like polymer (C) can be easily adjusted so as to be within the above-mentioned range, the alkyl (meth) acrylate monomer in the presence of the latex-like polyorganosiloxane (A) After radical polymerization of a monomer component containing one or more compounds to obtain a copolymer latex (radical polymerization step), the copolymer latex and the acid group-containing copolymer latex are mixed to obtain a copolymer latex. A method of enlarging the polymer latex (the enlargement process) is preferred. Furthermore, it is preferable to add a condensed acid salt to the copolymer latex before mixing the copolymer latex and the acid group-containing copolymer latex.

Radical polymerization process:
The radical polymerization step is a step of radical polymerization of a monomer component containing at least one alkyl (meth) acrylate monomer in the presence of latex polyorganosiloxane (A).
The monomer component containing at least one alkyl (meth) acrylate monomer may be added to the latex polyorganosiloxane (A) all at once, or continuously or intermittently. Also good.

When radically polymerizing a monomer component containing one or more alkyl (meth) acrylate monomers, a graft crossing agent or a crosslinking agent may be used as necessary.
Examples of the graft crossing agent and the crosslinking agent include allyl methacrylate, triallyl cyanurate, triallyl isocyanurate, divinylbenzene, dimethacrylic acid ethylene glycol diester, dimethacrylic acid propylene glycol diester, dimethacrylic acid 1,3-butylene glycol diester. And 1,4-butylene glycol diester of dimethacrylic acid. These may be used individually by 1 type and may use 2 or more types together.

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

  Although it does not restrict | limit especially as an emulsifier, since it is excellent in the stability of the latex at the time of radical polymerization and a polymerization rate can be raised, various carboxylic acids, such as sodium sarcosinate, fatty acid potassium, fatty acid sodium, alkenyl succinate dipotassium, rosin acid soap, etc. Salts are preferred. Of these, dipotassium alkenyl succinate is preferable because gas generation can be suppressed when the obtained graft copolymer (E) and the thermoplastic resin composition containing the graft copolymer (E) are molded at high temperature.

  The ratio between the polyorganosiloxane (A) and the alkyl (meth) acrylate polymer (B) in the composite rubber-like polymer (C) is not particularly limited, but the molded article has better impact resistance and surface appearance. Therefore, when the total of the polyorganosiloxane (A) and the alkyl (meth) acrylate polymer (B) is 100% by mass, the ratio of the polyorganosiloxane (A) is 2 to 14% by mass. Preferably there is.

Enlargement process:
The enlargement step is a step of enlarging the copolymer latex by mixing the copolymer latex obtained in the radical polymerization step and the acid group-containing copolymer latex.
The acid group-containing copolymer latex used for enlargement is composed of an acid group-containing monomer, an alkyl (meth) acrylate monomer, and, if necessary, other monomers copolymerizable with these in water. It is the latex of the acid group containing copolymer obtained by superposing | polymerizing the monomer component to contain.

  As the acid group-containing monomer, an unsaturated compound having a carboxy group is preferable. Examples of the compound include (meth) acrylic acid, itaconic acid, crotonic acid and the like, and (meth) acrylic acid is particularly preferable. An acid group containing monomer may be used individually by 1 type, and may use 2 or more types together.

  Examples of the alkyl (meth) acrylate monomer include esters of acrylic acid and / or methacrylic acid and an alcohol having a linear or branched alkyl group having 1 to 12 carbon atoms. For example, methyl acrylate, acrylic Ethyl acetate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, 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, and alkyl (meth) acrylates having an alkyl group having 1 to 8 carbon atoms are particularly preferable. An alkyl (meth) acrylate monomer may be used individually by 1 type, and may use 2 or more types together.

  Other monomers are monomers copolymerizable with acid group-containing monomers and alkyl (meth) acrylate monomers, and other than acid group-containing monomers and alkyl (meth) acrylate monomers Is a monomer. Other monomers include aromatic vinyl compounds (eg, styrene, α-methylstyrene, p-methylstyrene, etc.), vinyl cyanide compounds (eg, acrylonitrile, methacrylonitrile, etc.), two or more polymerizable Examples include compounds having a functional group (for example, allyl methacrylate, polyethylene glycol ester dimethacrylate, triallyl cyanurate, triallyl isocyanurate, triallyl trimellitic acid, etc.). Another monomer may be used individually by 1 type and may use 2 or more types together.

  The amount of these monomers used is such that the proportion of the acid group-containing monomer unit is 5 to 40% by mass as the proportion in the solid content of 100% by mass of the acid group-containing copolymer latex, alkyl (meth) acrylate. The amount that the monomer unit is 60 to 95% by mass, the amount that the other monomer unit is 0 to 48% by mass, the amount that the acid group-containing monomer unit is 8 to 30% by mass, the alkyl The amount that the (meth) acrylate monomer unit is 70 to 92% by mass and the amount that the other monomer unit is 0 to 30% by mass are more preferable. 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 enlargement ability is obtained. Further, 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 acid group-containing copolymer latex is produced. The formation of agglomerates can be suppressed. Moreover, if other monomer units are 48 mass% or less, the obtained acid group containing copolymer latex can have sufficient enlargement capability.

The acid group-containing copolymer latex can be produced by a general emulsion polymerization method.
Examples of emulsifiers used in emulsion polymerization include carboxylic acid-based emulsifiers exemplified by oleic acid, palmitic acid, stearic acid, alkali metal salts of rosin acid, alkali metal salts of alkenyl succinic acid, etc .; alkyl sulfate esters, alkylbenzene sulfones Known emulsifiers such as anionic emulsifiers selected from sodium acid, sodium alkylsulfosuccinate, sodium polyoxyethylene nonylphenyl ether sulfate and the like can be mentioned. 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 in the initial stage of polymerization, or may be added continuously or intermittently. Depending on the amount of emulsifier and how it is used, the particle size of the acid group-containing copolymer latex, and thus the particle size of the composite rubber-like polymer (C) latex with an enlarged particle size may be affected. It is preferred to select the correct amount and method of use.

  As a polymerization initiator used for emulsion polymerization, a thermal decomposition initiator, a redox initiator, or the like can be used. Examples of the thermal decomposition type initiator include potassium persulfate, sodium persulfate, and ammonium persulfate. Examples of the redox type initiator include organic peroxides represented by cumene hydroperoxide-sodium formaldehyde sulfoxylate-iron. Combinations of salts and the like are exemplified. These polymerization initiators may be used alone or in combination of two or more.

  In the case of emulsion polymerization, a chain transfer agent such as mercaptans (for example, t-dodecyl mercaptan, n-octyl mercaptan, etc.), terpinolene, α-methylstyrene dimer or the like is used to adjust the molecular weight or the pH is adjusted. Therefore, an electrolyte can be added as an alkali, an acid, or a thickener.

The addition amount of the acid group-containing copolymer latex in the enlargement process (solid content conversion amount) may be adjusted so that the volume average particle diameter of the composite rubber-like polymer (C) is within the above-described range. Usually, 0.1-5 mass parts is preferable with respect to 100 mass parts of solid content of the copolymer latex obtained at a radical polymerization process, and 0.3-3 mass parts is more preferable. If the addition amount of the acid group-containing copolymer latex is 0.1 parts by mass or more, the enlargement proceeds sufficiently. Moreover, it can suppress that agglomerates generate | occur | produce in large quantities. On the other hand, if the addition amount of the acid group-containing copolymer latex is 5 parts by mass or less, the pH of the enlarged latex can be suppressed from being lowered, and the latex is less likely to become unstable.
The acid group-containing copolymer latex may be added all at once to the copolymer latex, or may be added continuously or intermittently by dropping.

  In addition, it is more preferable to add a condensed acid salt to the copolymer latex prior to the enlargement process. If a condensation salt is added to the copolymer latex before the acid group-containing copolymer latex is added, the addition of the acid group-containing copolymer latex can be reduced because the enlargement tends to proceed. This makes it easy to adjust the volume average particle size and particle size distribution of the composite rubber-like polymer (C) within the above-described ranges.

  As the condensed acid salt, for example, a salt of a condensed acid such as phosphoric acid or silicic acid and an alkali metal and / or alkaline earth metal is used. Among these, pyrophosphoric acid and alkali metal salts which are condensed acids of phosphoric acid are preferable, and sodium pyrophosphate or potassium pyrophosphate is particularly preferable.

The addition amount of the condensed acid salt may be adjusted so that the volume average particle size and the particle size distribution of the composite rubber-like polymer (C) are within the above-mentioned ranges, but usually it is obtained in the radical polymerization step. It is preferable to set it as 0.1-5 mass parts with respect to 100 mass parts of solid content of copolymer latex, and 0.3-3 mass parts is more preferable. When the addition amount of the condensed acid salt is 0.1 parts by mass or more, the enlargement is sufficiently advanced, and when it is 5 parts by mass or less, the enlargement is sufficiently advanced, or the rubber latex is easily stabilized, and a large amount of aggregation is caused. The generation of lumps can be suppressed.
The condensed acid salt is preferably added to the copolymer latex all at once.

  The pH of the mixture of copolymer latex and condensed acid salt at 25 ° C. is preferably 7 or more and 10 or less. If the pH is 7 or more and 10 or less, enlargement is likely to proceed sufficiently. In order to make pH 7 or more, general alkali compounds, such as sodium hydroxide and potassium hydroxide, can be used.

It is preferable to appropriately control stirring during enlargement. If the stirring is insufficient, the unexpanded rubbery polymer may remain due to local enlargement. On the other hand, if the stirring is performed excessively, the enlarged latex becomes unstable and a large amount of agglomerates may be generated.
Although the temperature in particular when performing enlargement is not restrict | limited, 20-90 degreeC is preferable and 30-80 degreeC is more preferable. If the temperature is outside this range, the enlargement may not proceed sufficiently.

  The composite rubber-like polymer (C) is further enlarged using the acid group-containing copolymer latex as described above, and then further includes a monomer component containing one or more alkyl (meth) acrylate monomers. You may manufacture by adding and polymerizing.

The graft copolymer (E) has a form in which a vinyl polymer (D) obtained by polymerizing various vinyl monomers is grafted to the composite rubber-like polymer (C). Yes.
Although it does not restrict | limit especially as a vinyl-type monomer, For example, an aromatic vinyl compound, (meth) acrylic-acid alkylester, a cyanidation vinyl compound etc. are mentioned.

Examples of the aromatic vinyl compound include styrene, α-methylstyrene, p-methylstyrene, and the like.
Examples of (meth) acrylic acid alkyl esters include methyl methacrylate, ethyl methacrylate, 2-ethylhexyl methacrylate, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, and t-butyl acrylate. Can be mentioned.
Examples of the vinyl cyanide compound include acrylonitrile and methacrylonitrile.
These vinyl monomers may be used alone or in combination of two or more.
Among the vinyl monomers described above, it is preferable to use styrene and acrylonitrile in combination since the impact resistance of the molded product is further improved.

The graft copolymer (E) is obtained by graft polymerization of the vinyl polymer (D) to the composite rubber-like polymer (C).
The method for carrying out the graft polymerization is not particularly limited, but emulsion polymerization is preferred because it can be controlled so that the reaction proceeds stably. Specifically, a method in which a vinyl monomer is collectively charged into the composite rubber polymer (C) and then polymerized; a part of the vinyl monomer is first added to the composite rubber polymer (C). A method in which the remainder is dropped into the polymerization system while being charged and polymerized at any time; a method in which the total amount of the vinyl monomer is dropped into the composite rubber-like polymer (C) at any time, and the like. It can be divided into stages or more. It is also possible to change the type and composition ratio of the vinyl monomer at each stage.

  The mass ratio of the composite rubbery polymer (C) and the vinyl polymer (D) is not particularly limited, but the composite rubbery polymer (C) is 10 to 80% by mass, and the vinyl polymer (D) is 20 to 20%. It is preferably 90% by mass, more preferably 30 to 70% by mass of the composite rubbery polymer (C) and 30 to 70% by mass of the vinyl polymer (D) (however, the composite rubbery heavy (The total of the union (C) and the vinyl polymer (D) is 100 mass%) When graft polymerization is performed at such a mass ratio, the impact resistance of the molded product tends to be more excellent.

In the graft polymerization, a radical polymerization initiator and an emulsifier are usually used.
Examples of the radical polymerization initiator include peroxides, azo initiators, redox initiators in which an oxidizing agent and a reducing agent are combined. Among these, a redox initiator is preferable, and a sulfoxylate initiator in which ferrous sulfate, disodium ethylenediaminetetraacetate, sodium formaldehyde sulfoxylate, and hydroperoxide are combined is particularly preferable.
Moreover, when performing radical polymerization, in order to control the molecular weight and graft ratio of the graft copolymer (E) obtained, you may add various well-known chain transfer agents.

  Although it does not restrict | limit especially as an emulsifier, since it is excellent in the stability of the latex at the time of radical polymerization and a polymerization rate can be raised, various carboxylic acids, such as sodium sarcosinate, fatty acid potassium, fatty acid sodium, alkenyl succinate dipotassium, rosin acid soap, etc. Salt. In these, since the generation | occurrence | production of gas can be suppressed when the obtained graft copolymer (E) and the thermoplastic resin composition containing the same are molded at high temperature, dipotassium alkenyl succinate is preferable.

  The graft copolymer (E) is usually obtained in a latex state. As a method for recovering the graft copolymer (E) from the latex of the graft copolymer (E), for example, the latex of the graft copolymer (E) is poured into hot water in which a coagulant is dissolved. Examples thereof include a wet method of coagulating in a slurry state; a spray drying method of recovering the graft copolymer (E) semi-directly by spraying the latex of the graft copolymer (E) in a heated atmosphere.

  Examples of the coagulant used in the wet method include inorganic acids such as sulfuric acid, hydrochloric acid, phosphoric acid, and nitric acid; metal salts such as calcium chloride, calcium acetate, and aluminum sulfate, and are selected according to the emulsifier used in the polymerization. . For example, when only a carboxylic acid soap such as fatty acid soap or rosin acid soap is used as an emulsifier, one or more of the above-mentioned coagulants can be used. Further, when an emulsifier exhibiting a 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 a wet method is used, a slurry-like graft copolymer (E) is obtained. As a method of obtaining a dry graft copolymer (E) from the slurry graft copolymer (E), first, the remaining emulsifier residue is eluted and washed in water, and then the slurry is centrifuged or pressed. Examples include a method of dehydrating with a dehydrator or the like and then drying with an airflow dryer or the like; a method of simultaneously performing dehydration and drying with a press dehydrator or an extruder. By this method, a powder or particulate dry graft copolymer (E) is obtained.

Although it does not restrict | limit especially as washing | cleaning conditions, It is preferable to wash | clean on the conditions from which the amount of emulsifier residue contained in 100 mass% of graft copolymers (E) after drying becomes the range of 0.5-2 mass%. If the emulsifier residue in the graft copolymer (E) is 0.5% by mass or more, the fluidity of the resulting graft copolymer (E) and the thermoplastic resin composition containing the graft copolymer (E) tends to be further improved. . On the other hand, if the emulsifier residue in the graft copolymer (E) is 2% by mass or less, gas generation can be suppressed when the thermoplastic resin composition is molded at high temperature.
Note that the graft copolymer (E) discharged from the press dehydrator or the extruder may not be collected, but may be directly sent to an extruder or a molding machine for producing the thermoplastic resin composition to obtain a molded product.

(Other resins)
The thermoplastic resin composition may contain only the above-mentioned graft copolymer (E). However, from the viewpoint of moldability of the resulting thermoplastic resin composition and molded product appearance, the graft copolymer ( It is preferable to further contain a thermoplastic resin other than E) (other thermoplastic resin (F)).

Although it does not restrict | limit especially as another thermoplastic resin (F), For example, an acrylonitrile-styrene copolymer (AS resin), an acrylonitrile-alpha-methylstyrene copolymer (alpha SAN resin), a styrene-maleic anhydride copolymer, Acrylonitrile-styrene-N-substituted maleimide terpolymer, styrene-maleic anhydride-N-substituted maleimide terpolymer, 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) , Polyolefins such as polyvinyl chloride, polyethylene and polypropylene, styrene elastomers such as styrene-butadiene-styrene (SBS), styrene-butadiene (SBR), hydrogenated SBS, styrene-isoprene-styrene (SIS), and various olefin elastomers , Various polyester elastomers, polystyrene, methyl methacrylate-styrene copolymer (MS resin), acrylonitrile-styrene-methyl methacrylate copolymer, polyacetal resin, modified polyphenylene ether (modified PPE resin), ethylene-vinyl acetate copolymer , PPS resin, PES resin, PEEK resin, polyarylate, liquid crystal polyester resin, polyamide resin (nylon) and the like.
One of these other thermoplastic resins (F) may be used alone, or two or more thereof may be used in combination.

  The content of the graft copolymer (E) in the thermoplastic resin composition is preferably 20 to 60% by mass, and the content of the other thermoplastic resin (F) is 40 to 80% by mass (however, the graft The total of the copolymer (E) and the other thermoplastic resin (F) is preferably 100% by mass). When the content of the graft copolymer (E) is 20% by mass or more (the content of the other thermoplastic resin (F) is 80% by mass or less), the impact resistance of the molded product is further increased. On the other hand, if the content of the graft copolymer (E) is 60% by mass or less (the content of the other thermoplastic resin (F) is 40% by mass or more), the thermoplastic resin composition has sufficient moldability. Have.

<Optional component>
The thermoplastic resin composition of the present invention, if necessary, in addition to the above-mentioned graft copolymer (E) and other thermoplastic resins (F), as long as the light absorption and reflectivity are not impaired. An optional component may be contained.
Examples of optional components include various stabilizers such as antioxidants and light stabilizers, additives such as lubricants, plasticizers, mold release agents, dyes, pigments, antistatic agents, flame retardants, metal powders, and inorganic fillers. It is done.

<Manufacturing method>
The thermoplastic resin composition is obtained by mixing and dispersing the graft copolymer (E), other thermoplastic resin (F), if necessary, and optional components using a V-type blender or Henschel mixer. The mixture is melt-kneaded using a melt-kneader such as a screw extruder, Banbury mixer, pressure kneader, or mixing roll. Moreover, you may pelletize a melt-kneaded material using a pelletizer etc. as needed.

<Average value of light reflectance of 380 nm to 780 nm (visible% R)>
In the thermoplastic resin composition of the present invention, it is necessary that the average value (visible% R) of the light reflectance in the wavelength range of 380 nm to 780 nm is 5% to 10%. Here, the light reflectance is a measured value of a test piece obtained by molding a thermoplastic resin composition to a thickness of 2 mm. When the light reflectance is 10% or less, the amount of reflected light in the visible light region is small, and the color tone of the molded product is preferable.

<Average value of light absorptance of 780 nm to 1180 nm (near infrared% A)>
In the thermoplastic resin composition of the present invention, it is necessary that the average value (near infrared% A) of the light absorptance in the wavelength range of 780 nm to 1180 nm is 25% to 93%. Here, the light absorptance (% A) is calculated by the following equation (1) using measured values of the light reflectance (% R) and the light transmittance (% T). The light reflectance is a measured value for a test piece obtained by molding a thermoplastic resin composition to a thickness of 2 mm. The light transmittance is a measured value for a test piece obtained by molding a thermoplastic resin composition to a thickness of 0.1 mm. If the light absorptance is 93% or less, the amount of light absorption in the near infrared region does not become excessive, and when the molded product is used as an absorber, the absorber and the transmissive material are laser-welded and burned or discolored. It is possible to prevent the appearance of welding from deteriorating. When the light absorptance is 25% or more, the amount of light absorbed in the near infrared region increases, so that sufficient bonding strength can be obtained after laser welding.

Light Absorption Rate (% A) = 100−Light Transmittance (% T) −Light Reflectance (% R) (1)

<Ratio of optical characteristics>
In the thermoplastic resin composition of the present invention, the ratio (near infrared% A / visible% R) of the average value of the light absorptance in the near infrared region and the average value of the light reflectance in the visible light region is 16. It is preferably 5 to 4.5, and more preferably 10.0 to 5.0. If it is 16.5 or less, the absorption of light in the near-infrared region is controlled, and there is a tendency that the appearance after the laser welding is burned and discolored. On the other hand, if it is 4.5 or more, it becomes easy to obtain sufficient bonding strength after laser welding, and the color tone of the molded product tends to be more excellent.

<Effect>
The thermoplastic resin composition of the present invention described above contains the graft copolymer (E), and the light reflectance of the visible light region and the light absorption rate of the near infrared light region of the test piece have specific numerical values. Therefore, it is possible to obtain a molded article having excellent color tone and appearance after laser welding and having sufficient impact resistance and weather resistance as a resin member.

  The thermoplastic resin composition of the present invention is excellent in color tone when formed into a molded article, can be prevented from being burnt or discolored in appearance after laser welding, and can exhibit sufficient bonding strength, and can be a resin member. It has sufficient impact resistance and weather resistance. Therefore, the thermoplastic resin composition of the present invention can provide molded products suitable as vehicle parts such as lamps, interiors and exteriors, OA equipment, home appliance parts, medical instruments, and various industrial materials.

"Molding"
The molded product of the present invention is formed by molding the above-described thermoplastic resin composition of the present invention by a known molding method.
Examples of the molding method include an injection molding method, a press molding method, an extrusion molding method, a vacuum molding method, and a blow molding method.

The molded product of the present invention is excellent in color tone, can be prevented from being burnt and discolored in appearance after laser welding, can exhibit sufficient bonding strength, and has sufficient impact resistance and weather resistance as a resin member. Have
Applications of the molded article include vehicle parts such as lamps / interior / exterior, OA equipment, home appliance parts, medical instruments, various industrial materials, etc., and vehicle lamps are preferred.

The molded product of the present invention can be welded to other molded products by laser welding to form a resin joined body. When laser welding, the molded product of the present invention is used as an “absorbing material” that absorbs laser light, and the other molded product is used as a “transmitting material” that transmits laser light.
The material of the transmitting material is not particularly limited as long as it can transmit laser light, and examples thereof include acrylic resins and polycarbonate resins.
The resin joined body obtained according to the present invention is excellent in appearance because it is suppressed from burning and discoloration at the joint. In addition, sufficient bonding strength can be expressed.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited to a following example. In the following examples, “%” and “part” are based on mass unless otherwise specified.
Various measurements and evaluation methods in the following examples and comparative examples are as follows.

"Measurement / Evaluation"
<Measurement of light reflectance (% R)>
Using a 4-ounce injection molding machine (manufactured by Nippon Steel Co., Ltd.), a cylinder-shaped temperature of 260 ° C., a mold temperature of 60 ° C., and an injection rate of 20 g / sec. A plate-shaped test piece (molded product) having a width of 100 mm and a thickness of 2 mm was produced. Next, assuming that the total reflectance of the standard white plate (BaSO4) is 100%, the total reflectance of light having a wavelength of 380 nm to 1180 nm is measured using a spectrophotometer (manufactured by JASCO Corporation, “V-770”) at a wavelength interval of 1 nm. Measured with

<Measurement of light transmittance (% T)>
A film-shaped test piece having a thickness of 0.1 mm was produced from the pellet-shaped thermoplastic resin composition at a set temperature of 250 ° C. Next, the transmittance of light having a wavelength of 380 nm to 1180 nm was measured at a wavelength interval of 1 nm using a spectrophotometer (manufactured by JASCO Corporation, “V-770”).

<Calculation of light absorption rate (% A)>
Using the measured light reflectance (% R) and light transmittance (% T), the absorbance of light having a wavelength of 380 nm to 1180 nm was calculated at a wavelength interval of 1 nm according to the formula (1).

<Evaluation of impact resistance>
In accordance with ISO 3167, a test piece (molded product) was produced from the pellet-shaped thermoplastic resin composition using an injection molding machine (Toshiba Machine Co., Ltd., “IS55FP-1.5A”). The Charpy impact strength of the obtained test piece was measured in an atmosphere of 23 ° C. according to ISO 179.

<Evaluation of laser welding appearance>
Using a 4-ounce injection molding machine (manufactured by Nippon Steel Co., Ltd.), a cylinder set temperature of 260 ° C., a mold temperature of 60 ° C., and an injection rate of 20 g / sec. A plate-like test piece (molded product) having a thickness of 2 mm was prepared and used as a permeable material.
On the other hand, as the absorbent material, a test piece prepared using the thermoplastic resin composition of the present invention in the form of pellets under the same conditions as the acrylic resin was used.
The absorbent material and the transparent material were overlapped, and a laser resin welding apparatus (manufactured by Fine Devices Co., Ltd.) was used to irradiate laser light from the transparent material side under the following conditions to weld the absorbent material to obtain a resin joined body. The appearance of welding at the joint of the obtained resin joined body was visually evaluated.
(Welding conditions)
・ Output: 6W
・ Focus diameter: 3mm
・ Scanning speed: 5 mm / second ・ Welding length: 20 mm
・ Pressure: 0.5 MPa

<Evaluation of color tone>
The lightness (L value) was measured with a colorimeter using the same test piece used for the measurement of light reflectance. The lower the L value, the darker the color and the better the color tone.

<Evaluation of weather resistance>
Using the same test piece as that used for the measurement of the light reflectivity, “Sunshine Super Long Life Weather Meter WEL-SUN-DCH type” manufactured by Suga Test Instruments Co., Ltd., 63 ° C., cycle condition: 60 minutes (rainfall : Exposure for 12 hours under an environment of 12 minutes). The degree of color change (ΔE) of the molded product before and after 1000 hours of exposure was measured using a colorimeter.

"Manufacture of polyorganosiloxane"
<Production Example 1: Production of polyorganosiloxane (A)>
98 parts of octamethylcyclotetrasiloxane and 2 parts of γ-methacryloyloxypropyldimethoxymethylsilane were mixed to obtain 100 parts of a siloxane mixture. To this was added an aqueous solution consisting of 0.67 parts of sodium dodecylbenzenesulfonate and 300 parts of ion-exchanged water, and the mixture was stirred at 10000 rpm for 2 minutes with a homomixer. Then, the homogenizer was charged with ^{2 at} a pressure of 300 kg / cm 2. Through circulation, a stable premixed organosiloxane latex was obtained.
Separately, 10 parts of dodecylbenzenesulfonic acid and 90 parts of ion-exchanged water were put into a reactor equipped with a reagent injection container, a cooling tube, a jacket heater, and a stirrer, and a 10% aqueous solution of dodecylbenzenesulfonic acid ( Acid catalyst aqueous solution) was prepared.
While this acid catalyst aqueous solution was heated to 85 ° C., the premixed organosiloxane latex was added dropwise over 2 hours. After the completion of the addition, the temperature was maintained for 3 hours and then cooled to 40 ° C. or lower. Next, this reaction product was neutralized to pH 7.0 with a 10% aqueous sodium hydroxide solution to obtain a latex of polyorganosiloxane (A).
The obtained polyorganosiloxane (A) latex was dried at 180 ° C. for 30 minutes and the solid content was determined to be 18.2%. Further, the mass basis average particle size was 30 nm.

"Production of acid group-containing copolymer latex"
<Production Example 2: Production of acid group-containing copolymer latex (K)>
In a reactor equipped with a reagent injection container, a condenser, a jacket heater and a stirrer, 200 parts of ion exchange water, 2 parts of potassium oleate, 4 parts of sodium dioctylsulfosuccinate, ferrous sulfate heptahydrate 0.003 Part, 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. When the temperature reached 60 ° C., a mixture composed 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 dropwise addition, ripening was further performed for 2 hours while maintaining the temperature at 60 ° C., the solid content was 33%, the polymerization conversion was 96%, and the acid group-containing copolymer had an acid group content of 120 nm. A copolymer latex (K) was obtained.

"Production of graft copolymer (E)"
<Production Example 3: Production of Graft Copolymer (E-1)>
In a reactor equipped with a reagent injection container, a condenser, a jacket heater and a stirrer, 2.0 parts of latex of polyorganosiloxane (A) in terms of solid content, 0.8 part of dipotassium alkenyl succinate, 190 parts of ion exchange water was charged and mixed. Subsequently, a mixture comprising 48.0 parts of n-butyl acrylate, 0.6 parts of allyl methacrylate, 0.1 part of 1,3-butylene glycol diester dimethacrylate, and 0.1 part of t-butyl hydroperoxide was added. did. The atmosphere was purged with nitrogen by passing a nitrogen stream through the reactor, and the internal temperature was raised to 60 ° C. When the internal temperature reached 60 ° C., from 0.000075 part of ferrous sulfate heptahydrate, 0.00023 part of ethylenediaminetetraacetic acid disodium salt, 0.2 part of sodium formaldehyde sulfoxylate, 10 parts of ion-exchanged water The resulting aqueous solution was added to initiate radical polymerization. After the polymerization exotherm is confirmed, the jacket temperature is set to 75 ° C., the polymerization is continued until the polymerization exotherm is not confirmed, and this state is maintained for another hour, and a composite rubber in which polyorganosiloxane and polybutyl acrylate rubber are combined. (Radical polymerization step). The obtained composite rubber had a volume average particle diameter of 90 nm.
After the liquid temperature inside the reactor dropped to 70 ° C., 0.60 part of 5% sodium pyrophosphate aqueous solution was added as a solid content. After controlling at an internal temperature of 70 ° C., 0.60 parts of acid group-containing copolymer latex (K) is added as a solid content, stirred for 30 minutes and enlarged, and a composite rubber-like polymer (C) latex is prepared. Obtained (blowing process).
The obtained latex-like composite rubber-like polymer (C) had a volume average particle size of 0.2 μm.

An aqueous solution comprising 0.001 part of ferrous sulfate heptahydrate, 0.003 part of disodium ethylenediaminetetraacetate, 0.3 part of Rongalite, and 10 parts of ion-exchanged water was added to the latex of the obtained composite rubber-like polymer. Added. Subsequently, a mixed liquid composed of 10 parts of acrylonitrile, 30 parts of styrene, and 0.18 part of t-butyl hydroperoxide was dropped over 80 minutes for polymerization. After completion of dropping, the mixture is kept at a temperature of 75 ° C. for 30 minutes, and then a mixture comprising 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 dropping, after maintaining the temperature at 75 ° C. for 30 minutes, 0.05 part of cumene hydroperoxide was added, and after maintaining the temperature at 75 ° C. for 30 minutes, the mixture was cooled, and a composite rubber polymer ( A latex of a silicone / acrylic composite rubber graft copolymer (E-1) obtained by graft polymerization of acrylonitrile and styrene on C) was obtained.
Subsequently, 150 parts of a 1% calcium acetate aqueous solution was heated to 60 ° C., and 100 parts of the latex of the graft copolymer (E-1) was gradually dropped into the solution to be solidified. Then, the precipitate was separated, dehydrated, washed and then dried to obtain a graft copolymer (E-1).

<Production Example 4: Production of Graft Copolymer (E-2)>
In a reactor equipped with a reagent injection vessel, a cooling tube, a jacket heater and a stirrer, 150 parts of ion exchange water, 50 parts of polybutadiene latex (volume average particle diameter 0.2 μm) in terms of solid content, disproportionated rosin 1 part of potassium acid and 0.03 part of potassium hydroxide were added and heated to 60 ° C., followed by addition of 0.007 part of ferrous sulfate heptahydrate, 0.1 part of sodium pyrophosphate and 0.3 part of crystalline glucose . Subsequently, a mixed liquid composed of 15 parts of acrylonitrile, 35 parts of styrene, 0.4 part of cumene hydroperoxide, and 0.5 part of t-dodecyl mercaptan was dropped over 120 minutes for polymerization. After completion of dropping, after maintaining the state at a temperature of 70 ° C. for 60 minutes, 0.05 part of cumene hydroperoxide was added, and after maintaining the state at a temperature of 70 ° C. for 30 minutes, cooling was performed, and polybutadiene was added with acrylonitrile and styrene. A latex of a polybutadiene-based graft copolymer (E-2) obtained by graft polymerization was obtained.
Next, an antioxidant was added to the latex, 150 parts of a 1% sulfuric acid aqueous solution was heated to 60 ° C., and 100 parts of the latex of the graft copolymer (E-2) was gradually dropped therein to solidify. Then, the precipitate was separated, dehydrated, washed, and dried to obtain a graft copolymer (E-2).

"Manufacture of other thermoplastic resins (F)"
<Production Example 5: Production of other thermoplastic resin (F-1)>
27 parts of acrylonitrile and 73 parts of styrene were polymerized by known suspension polymerization to obtain an acrylonitrile-styrene copolymer having a reduced viscosity of 0.61 dl / g measured from an N, N-dimethylformamide solution at 25 ° C. This was used as another thermoplastic resin (F-1).

<Production Example 6: Production of other thermoplastic resin (F-2)>
19 parts of acrylonitrile, 53 parts of styrene and 28 parts of N-phenylmaleimide are polymerized by known continuous solution polymerization, and acrylonitrile-styrene having a reduced viscosity of 0.65 dl / g measured from an N, N-dimethylformamide solution at 25 ° C. An —N-phenylmaleimide terpolymer was obtained. This was used as another thermoplastic resin (F-2).

<Optional component>
The following were used as pigments.
Carbon black: “# 960” manufactured by Mitsubishi Chemical Corporation
・ Iron oxide: “KN-320” manufactured by Toda Kogyo Co., Ltd.
・ Titanium oxide: “JR-407” manufactured by Teika Co., Ltd.
The following were used as dyes.
Perinone dyes: LANXESS Corporation “MACROLEX Orange 3G”
Anthraquinone dyes: LANXESS Corporation “MACROLEX Red Violet R”
Anthraquinone dyes: LANXESS Corporation “MACROLEX Green 5B”

"Examples 1-4, Comparative Examples 1-6"
Graft copolymers (E) in amounts shown in Tables 1-2, other thermoplastic resins (F), carbon black, titanium oxide, iron oxide, and dyes, 1 part of ethylenebisstearylamide, silicone oil SH200 ( Using a Henschel mixer, 0.2 part of Toray Dow Corning Co., Ltd.), 0.2 part of Adeka Stub AO-60 (manufactured by ADEKA Co., Ltd.) and 0.4 part of Adeka Stub LA-57 (manufactured by ADEKA Co., Ltd.) And mixed. Thermoplastic resin obtained by melt-kneading the obtained mixture at 250 ° C. using a screw type extruder (manufactured by Nippon Steel, Ltd., “TEX-30α type twin screw extruder”) and then pelletizing with a pelletizer A composition was obtained.
A test piece (molded article) is prepared using the obtained pellet-shaped thermoplastic resin composition, light reflectance and light transmittance are measured, light absorptance is calculated, impact resistance, laser welding appearance, The color tone and weather resistance were evaluated. These results are shown in Tables 1-2.

  The near infrared% A / visible% R in Tables 1 and 2 indicate that the average value of the light absorptance in the near infrared region is near infrared% A, and the average value of the light reflectance in the visible light region is visible% R. The ratio of near-infrared% A to visible% R in this case.

As shown in Tables 1-2, from the thermoplastic resin compositions obtained in each Example, molded articles having excellent impact resistance and weather resistance, excellent laser weld appearance, and excellent color tone are obtained. It was. Further, in the resin joined body obtained in each example, the permeable material and the absorbent material were sufficiently joined.
On the other hand, in the case of each comparative example, the result was inferior to any of the items of impact resistance, weather resistance, laser weld appearance, and color tone of the molded product.
Specifically, in the case of Comparative Example 1, since the visible% R was 10% or more, the color tone was inferior.
In the case of Comparative Example 2, since the near infrared% A was 93% or more, the laser welding appearance was inferior.
In the case of Comparative Example 3, since the near infrared% A was less than 25%, the transmitting material and the absorbing material were not sufficiently bonded.
In Comparative Examples 4 and 5, the rubbery polymer contained in the graft copolymer was not a composite rubbery polymer in which polyorganosiloxane and an alkyl (meth) acrylate polymer were combined. It was inferior.
In the case of Comparative Example 6, since the graft copolymer was not contained, the impact resistance was poor.

  ADVANTAGE OF THE INVENTION According to this invention, the thermoplastic resin composition which can obtain the molded article which was excellent in the color tone and the external appearance after laser welding, and had sufficient impact resistance and a weather resistance as a resin member can be provided. In particular, the balance between the color tone of the molded product and the appearance after laser welding is at a very high level that cannot be obtained with the conventionally known thermoplastic resin compositions, such as parts for vehicles such as lamps, interiors and exteriors, and OA equipment. And its utility value as home appliance parts, medical equipment, and various industrial materials is extremely high.

Claims (3)

A graft copolymer (E) obtained by grafting a vinyl polymer (D) onto a composite rubber-like polymer (C) in which a polyorganosiloxane (A) and an alkyl (meth) acrylate polymer (B) are combined. A thermoplastic resin composition comprising:
When the light reflectance (% R) and the light absorptance (% A) represented by the following formula (1) were measured from the visible light region to the near infrared light region at a wavelength interval of 1 nm,
The average value (visible% R) of the light reflectance of 380 nm to 780 nm is 5% to 10%,
A thermoplastic resin composition satisfying an average value (near infrared% A) of a light absorption rate of 780 nm to 1180 nm of 25% to 93%.
Light Absorption Rate (% A) = 100−Light Transmittance (% T) −Light Reflectance (% R) (1)   The ratio (near infrared% A / visible% R) of the average value of the light absorptance in the near infrared region and the average value of the light reflectance in the visible light region is 16.5 to 4.5. The thermoplastic resin composition according to claim 1.   The molded article which shape | molded the thermoplastic resin composition as described in any one of Claim 1 or 2.