JP2018184560A - Thermoplastic resin composition and molded article thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition capable of giving a molded article excellent in impact resistance, color development, weather resistance and scratch resistance, and to provide a molded article excellent in impact resistance, color development, weather resistance and scratch resistance.SOLUTION: The thermoplastic resin composition contains: a graft copolymer (A) comprising a crosslinked ethylene/α-olefin copolymer (a) moiety having a volume average particle diameter of 0.18-0.55 μm and a vinyl polymer moiety being a polymer of a vinyl monomer mixture (m1) having a (meth)acrylate ester content of 88-100 mass%; and a methacrylate ester resin (B) being a polymer of a vinyl monomer mixture (m2) containing a methacrylate ester. The content of the crosslinked ethylene/α-olefin copolymer (a) moiety is 7-30 mass% based on the total mass of the thermoplastic resin composition.SELECTED DRAWING: None

Description

  The present invention relates to a thermoplastic resin composition and a molded article thereof.

  Improving the impact resistance of the molded product not only expands the applications of the molded product, but also makes it extremely useful for industrial applications, such as making it possible to reduce the thickness and size of the molded product. . Therefore, various techniques have been proposed so far for improving the impact resistance of the molded product. Among these methods, a method for increasing the impact resistance of a molded product by using a resin material in which a rubbery polymer and a hard resin are combined has already been industrialized. Examples of such resin materials include acrylonitrile-butadiene-styrene (ABS) resin, acrylonitrile-styrene-acrylic acid ester (ASA) resin, acrylonitrile-ethylene / propylene / non-conjugated diene copolymer-styrene (AES) resin, and the like. Can be mentioned.

When high designability is required for a molded product, a coating process is performed on the molded product obtained from the resin material as described above to obtain high appearance quality. However, the coating process has problems such as a large environmental load, complicated processes, and high manufacturing costs. Therefore, the coating treatment of the molded product may be omitted. In this case, the molded product is required to have, for example, the following characteristics in addition to mechanical properties such as impact resistance.
-Hard to discolor even when exposed to direct sunlight (weather resistance).
・ No scratches or scratches are noticeable (scratch resistance).
Resin materials that can provide molded products with good weather resistance include ethylene-propylene-non-conjugated diene copolymers, acrylic ester rubbers, hydrogenated rubbers (hydrogenated butadiene rubbers, etc.) as rubbery polymers. ), And those using silicone rubber or the like are known.
Resin materials that can be used to obtain molded products with good scratch resistance include those in which the ratio of the rubbery polymer is lowered to harden the surface of the molded products, and lubricants (silicone oil, olefin wax, etc.) are added. For example, a product with improved surface slipperiness is known.

For example, the following materials have been proposed as resin materials from which molded articles having excellent impact characteristics and transparency can be obtained.
(1) A graft copolymer obtained by polymerizing a monomer component containing a (meth) acrylate ester in the presence of a rubbery polymer, or the graft copolymer and a (meth) acrylate ester A thermoplastic resin composition comprising a rubber-reinforced thermoplastic resin comprising a mixture of a monomer component containing a copolymer and a copolymer of (meth) acrylic acid ester and maleimide compound (Patent Document 1) ).
(2) A graft copolymer obtained by polymerizing a vinyl monomer mixture containing an aromatic vinyl compound and a vinyl cyanide compound in the presence of a rubbery polymer which is a styrene elastomer, and an aromatic vinyl compound And a styrene resin obtained by polymerizing a vinyl cyanide compound (Patent Document 2).

For example, the following materials have been proposed as resin materials capable of obtaining molded articles with good scratch resistance and weather resistance.
(3) A rubbery material comprising a graft copolymer obtained by polymerizing a vinyl monomer mixture containing an aromatic vinyl compound and a vinyl cyanide compound in the presence of a rubbery polymer, and a hard resin. A thermoplastic resin composition having a low polymer ratio (Patent Document 3).

International Publication No. 2003/080724 JP 2001-131369 A JP-A-11-001600

However, when the thermoplastic resin compositions (1) and (2) are used, the impact properties and transparency of the molded product are improved, but the weather resistance and scratch resistance of the molded product are low, and the use of the molded product is low. Limited.
When the thermoplastic resin composition of (3) is used, the hardness of the surface of the molded product is increased, so that the scratch resistance against scratches is improved, but the ratio of the rubbery polymer is reduced, so Impact resistance is reduced.
Thus, it has been difficult to achieve both impact resistance, weather resistance, and scratch resistance of the molded product.
Further, when the thermoplastic resin compositions (2) and (3) are used, there is a problem that the color developability of the molded product is inferior.

  The present invention provides a thermoplastic resin composition from which a molded article excellent in impact resistance, color developability, weather resistance and scratch resistance is obtained, and a molded article excellent in impact resistance, color developability, weather resistance and scratch resistance. To do.

The present invention includes the following aspects.
[1] Vinyl whose cross-linked ethylene / α-olefin copolymer (a) portion has a volume average particle size of 0.18 to 0.55 μm and the content of (meth) acrylic acid ester is 88 to 100% by mass. A graft copolymer (A) comprising a vinyl polymer portion which is a polymer of the monomer mixture (m1),
A methacrylate ester resin (B) that is a polymer of a vinyl monomer mixture (m2) containing a methacrylate ester,
A thermoplastic resin composition, wherein the content of the crosslinked ethylene / α-olefin copolymer (a) is 7 to 30% by mass relative to the total mass of the thermoplastic resin composition.
[2] The content of the methacrylic ester resin (B) is 60 to 90% by mass with respect to the total mass of the graft copolymer (A) and the methacrylic ester resin (B). ] The thermoplastic resin composition as described in.
[3] A molded article using the thermoplastic resin composition according to [1] or [2].

According to the thermoplastic resin composition of the present invention, a molded article having excellent impact resistance, color development, weather resistance and scratch resistance can be obtained.
The molded article of the present invention is excellent in impact resistance, color development, weather resistance and scratch resistance.

It is the schematic explaining the abrasion-resistance test by car wash towel abrasion.

The following definitions of terms apply throughout this specification and the claims.
“Molded product” means a product formed by molding a thermoplastic resin composition.
“Lightness (L ^* )” means a lightness value (L ^* ) among color values in the L ^* a ^* b ^* color system adopted in JIS Z 8729.
The “SCE method” means a method of measuring a color by using a spectrocolorimeter in accordance with JIS Z 8722 and removing specularly reflected light with an optical trap.

"Thermoplastic resin composition"
The thermoplastic resin composition of the present invention includes a graft copolymer (A) and a methacrylate ester resin (B).
The thermoplastic resin composition of the present invention may contain other thermoplastic resins and various additives as required within the range not impairing the effects of the present invention.

The graft copolymer (A) comprises a crosslinked ethylene / α-olefin copolymer (a) portion and a vinyl polymer portion which is a polymer of the vinyl monomer mixture (m1). In other words, the graft copolymer (A) is a graft copolymer obtained by polymerizing the vinyl monomer mixture (m1) in the presence of the crosslinked ethylene / α-olefin copolymer (a). is there.
The graft copolymer (A) was typically obtained by polymerizing the vinyl monomer mixture (m1) in an aqueous dispersion containing the crosslinked ethylene / α-olefin copolymer (a). Is. The aqueous dispersion is typically obtained by crosslinking the aqueous olefin resin dispersion (c) containing the ethylene / α-olefin copolymer (b).
The methacrylic ester resin (B) is a polymer of a vinyl monomer mixture (m2) containing a methacrylic ester. In other words, it is a polymer obtained by polymerizing a vinyl monomer mixture (m2) containing a methacrylic acid ester.
Hereinafter, each component ((A), (B), (a), (b), (c), (m1), (m2), etc.) will be described.

<Ethylene / α-olefin copolymer (b)>
The ethylene / α-olefin copolymer (b) includes an ethylene unit and an α-olefin unit obtained by copolymerizing ethylene and an α-olefin having 3 or more carbon atoms by a known polymerization method. It is a copolymer.
The ethylene / α-olefin copolymer (b) may further contain a non-conjugated diene unit.

  Examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-icosene and 1-docosene. Of these, α-olefins having 3 to 20 carbon atoms are preferable, and propylene is particularly preferable from the viewpoint of impact resistance of the obtained molded product.

  Non-conjugated dienes include dicyclopentadiene, 5-ethylidene-2-norbornene, 1,4-hexadiene, 1,5-hexadiene, 2-methyl-1,5-hexadiene, 1,4-cycloheptadiene, 1, 5-cyclooctadiene etc. are mentioned. Of these, dicyclopentadiene and / or 5-ethylidene-2-norbornene are preferred because the resulting molded article has excellent impact resistance and scratch resistance.

  The ethylene unit content of the ethylene / α-olefin copolymer (b) is 45 to 45% when the total of all the structural units constituting the ethylene / α-olefin copolymer (b) is 100% by mass. 80 mass% is preferable and 50-75 mass% is more preferable. When the ethylene unit content is within the above range, the balance of scratch resistance and impact resistance of the molded product is further improved.

  The total content of ethylene units and α-olefin units is preferably 90 to 100% by mass when the total of all the structural units constituting the ethylene / α-olefin copolymer (b) is 100% by mass. 95-99 mass% is more preferable. When the total content of the ethylene unit and the α-olefin unit is within the above range, the balance of scratch resistance and impact resistance of the molded product is further improved.

The mass average molecular weight (Mw) of the ethylene / α-olefin copolymer (b) is preferably 4 × 10 ^{4 to} 35 × 10 ^{4, and} more preferably 17 × 10 ^{4 to} 32 × 10 ⁴ . When the mass average molecular weight (Mw) is within the above range, the molded article has excellent scratch resistance, color developability and impact resistance.

  The molecular weight distribution (Mw / number average molecular weight (Mn)) of the ethylene / α-olefin copolymer (b) is preferably from 1.0 to 5.0, more preferably from 1.9 to 4.0. When the molecular weight distribution (Mw / Mn) is within the above range, the molded article has excellent scratch resistance and impact resistance.

  The mass average molecular weight (Mw) and the number average molecular weight (Mn) of the ethylene / α-olefin copolymer (A) are values measured by gel permeation chromatography (GPC) and converted to standard polystyrene.

  The method for producing the ethylene / α-olefin copolymer (b) is not limited. The ethylene / α-olefin copolymer (b) is usually obtained by copolymerizing ethylene and α-olefin or ethylene, α-olefin and non-conjugated diene using a metallocene catalyst or Ziegler-Natta catalyst. Manufactured.

As a metallocene catalyst, a catalyst obtained by combining an organic compound having a cyclopentadienyl skeleton with a transition metal (zirconium, titanium, hafnium, etc.), a metallocene complex in which a halogen atom or the like is coordinated, an organoaluminum compound, an organoboron compound, etc. Is mentioned.
Examples of the Ziegler-Natta catalyst include a catalyst in which a halide of a transition metal (titanium, vanadium, zirconium, hafnium, etc.) is combined with an organic aluminum compound, an organic boron compound, or the like.

  Examples of the polymerization method include a method of copolymerizing ethylene and α-olefin or ethylene, α-olefin and non-conjugated diene in a solvent in the presence of a catalyst (metallocene catalyst or Ziegler-Natta catalyst). . Examples of the solvent include hydrocarbon solvents (benzene, toluene, xylene, pentane, hexane, heptane, octane, etc.). A hydrocarbon solvent may be used individually by 1 type, and 2 or more types may be mixed and used for it. Moreover, you may use the raw material alpha olefin as a solvent. In the polymerization, a molecular weight regulator such as hydrogen may be used.

  By changing the reaction conditions such as supply amount of ethylene, α-olefin and non-conjugated diene, type and amount of molecular weight regulator, type and amount of catalyst, reaction temperature, pressure, etc., ethylene / α-olefin copolymer The ethylene unit content, mass average molecular weight (Mw), and molecular weight distribution (Mw / Mn) of (b) can be adjusted.

<Olefin resin aqueous dispersion (c)>
The aqueous olefin resin dispersion (c) is obtained by dispersing the ethylene / α-olefin copolymer (b) in an aqueous medium.
The olefin resin aqueous dispersion (b) may contain an emulsifier, an acid-modified olefin polymer and the like as other components.

  Examples of the aqueous medium include water, an organic solvent miscible with water (hereinafter, also referred to as “water-miscible organic solvent”), and a mixture thereof. Examples of water-miscible organic solvents include alcohols such as methanol, ethanol, n-propanol, and isopropanol; ketones such as acetone and methyl ethyl ketone; polyalkylene glycols such as ethylene glycol, diethylene glycol, and propylene glycol; Alkyl ethers; and lactams such as N-methyl-2-pyrrolidone. As the aqueous medium, it is preferable to use only water or a mixture of water and a water-miscible organic solvent.

Examples of the emulsifier include known ones, and examples thereof include long-chain alkyl carboxylates, sulfosuccinic acid alkyl ester salts, and alkylbenzene sulfonates.
The content of the emulsifier in the aqueous olefin resin dispersion (c) can suppress thermal coloring of the resulting thermoplastic resin composition, and the ethylene / α-olefin copolymer dispersed in the aqueous olefin resin dispersion (c). In view of easy control of the particle diameter of the combined body (b), 1 to 8 parts by weight is preferable with respect to 100 parts by weight of the ethylene / α-olefin copolymer (b).

Examples of the acid-modified olefin polymer include those obtained by modifying an olefin polymer having a mass average molecular weight of 1,000 to 5,000 (polyethylene, polypropylene, etc.) with a compound having a functional group (such as an unsaturated carboxylic acid compound). It is done. Examples of the unsaturated carboxylic acid compound include acrylic acid, maleic acid, itaconic acid, maleic anhydride, itaconic anhydride, maleic acid monoamide, and the like.
The acid value of the acid-modified olefin polymer is preferably 20 to 40 mgKOH / g.
The content of the acid-modified olefin polymer in the aqueous olefin resin dispersion (c) is preferably 1 to 40 parts by mass with respect to 100 parts by mass of the ethylene / α-olefin copolymer (b). When the addition amount of the acid-modified olefin polymer is within the above range, the balance between scratch resistance and impact resistance of the molded product is further improved.

The method for preparing the aqueous olefin resin dispersion (c) is not limited. As the preparation method, for example, (M1) the ethylene / α-olefin copolymer (b) is melt-kneaded by a known melt-kneading means (kneader, Banbury mixer, multi-screw extruder, etc.), and mechanical shear force is increased. (M2) The ethylene / α-olefin copolymer (b) is dissolved in a hydrocarbon solvent (pentane, hexane, heptane, benzene, toluene, xylene, etc.), and then added to an aqueous medium. And then emulsifying and emulsifying the mixture, followed by sufficient stirring to distill off the hydrocarbon solvent. In preparing the aqueous olefin resin dispersion (c), an acid-modified olefin polymer, an emulsifier, and the like may be added as other components.
In the method (M1), the temperature condition for melt kneading is preferably 150 to 250 ° C.

The method for adding the acid-modified olefin polymer is not limited. For example, in the method (M1), the ethylene / α-olefin copolymer (b) and the acid-modified olefin polymer are mixed and melt-kneaded, and in the method (M2), the ethylene / α-olefin is mixed. Examples thereof include a method of dissolving the copolymer (b) and the acid-modified olefin polymer in a hydrocarbon solvent.
The mixing method of the ethylene / α-olefin copolymer (b) and the acid-modified olefin polymer is not particularly limited. Examples of the mixing method include a melt kneading method using a kneader, a Banbury mixer, a multi-screw extruder and the like. In this case, the step of mixing the ethylene / α-olefin copolymer (b) and the acid-modified olefin polymer may also serve as a step of melt-kneading the mixture.
The method for adding the emulsifier is not particularly limited. For example, the method similar to the addition method of an acid-modified olefin polymer is mentioned. Examples of the method (M1) or (M2) include a method of adding an emulsifier to an aqueous medium, and a method of dissolving the emulsifier in a hydrocarbon solvent in the method (M2).

The volume average particle diameter of the ethylene / α-olefin copolymer (b) constituting the olefin resin aqueous dispersion (c) is 0.18 to 0.55 μm from the viewpoint of excellent impact resistance and color developability of the molded product. 0.19 to 0.50 μm is preferable, and 0.20 to 0.45 μm is more preferable.
The volume average particle diameter is measured by the method described in Examples described later.
The volume average particle diameter of the ethylene / α-olefin copolymer (b) constituting the aqueous olefin resin dispersion (c) is the same as that of the crosslinked ethylene / α-olefin copolymer (a ) Is confirmed by image analysis using an electron microscope.

  The method for controlling the volume average particle size of the ethylene / α-olefin copolymer (b) dispersed in the aqueous olefin resin dispersion (c) includes the type or amount of emulsifier, the type of acid-modified olefin polymer. Or the method of adjusting content, the shear force added at the time of kneading | mixing, temperature conditions, etc. is mentioned.

<Crosslinked ethylene / α-olefin copolymer (a)>
The crosslinked ethylene / α-olefin copolymer (a) is an ethylene / α-olefin copolymer having a crosslinked structure. Specifically, a crosslinked structure is formed in the ethylene / α-olefin copolymer (b). Typically, it is obtained by crosslinking the ethylene / α-olefin copolymer (b) or the ethylene / α-olefin copolymer (b) dispersed in the aqueous olefin resin dispersion (c). It is what was done. By having a crosslinked structure, the impact resistance of the molded product is further improved.

The gel content of the crosslinked ethylene / α-olefin copolymer (a) is preferably from 35 to 75 mass%, more preferably from 40 to 70 mass%, from the viewpoint of impact resistance of the molded product.
The gel content in the present invention means that the crosslinked ethylene / α-olefin copolymer (a) is swollen with toluene, and the crosslinked ethylene / α-olefin copolymer (a) before swelling is dried. This is the proportion of toluene insoluble matter. In detail, it calculates | requires by the method as described in an Example.

The crosslinked ethylene / α-olefin copolymer (a) portion is granular.
The volume average particle diameter of the crosslinked ethylene / α-olefin copolymer (a) portion in the thermoplastic resin composition is 0.18 to 0.55 μm, preferably 0.19 to 0.50 μm, and 0.20. -0.45 micrometer is more preferable. When the volume average particle diameter is within the above range, the impact resistance and color developability of the molded product are excellent.

The crosslinked ethylene / α-olefin copolymer (a) can be obtained by crosslinking the ethylene / α-olefin copolymer (b) or the aqueous olefin resin dispersion (c).
The crosslinking treatment of the ethylene / α-olefin copolymer (b) or the aqueous olefin resin dispersion (c) can be performed by a known method. Examples of the crosslinking treatment method include (M3) a method in which an organic peroxide and, if necessary, a polyfunctional compound are added to carry out a crosslinking treatment, and (M4) a method in which a crosslinking treatment is performed with ionizing radiation. The method (M3) is preferable from the viewpoint of impact resistance and color development of the molded product.

Specifically, as the method of (M3), an ethylene / α-olefin copolymer (b) or an aqueous olefin resin dispersion (c) is mixed with an organic peroxide and, if necessary, a polyfunctional compound. The method of adding and heating is mentioned.
For example, an organic peroxide and, if necessary, a polyfunctional compound are added to the ethylene / α-olefin copolymer (b), melt-kneaded, and pulverized to form a crosslinked ethylene / α-olefin copolymer. The powder (a) is obtained. When an organic peroxide and, if necessary, a polyfunctional compound are added to the olefin resin aqueous dispersion (c) and subjected to crosslinking treatment, an aqueous dispersion of the crosslinked ethylene / α-olefin copolymer (a) is obtained. can get.
The gel content of the crosslinked ethylene / α-olefin copolymer (a) can be adjusted by adjusting the addition amount of organic peroxide and polyfunctional compound, heating temperature, heating time and the like.
The heating temperature varies depending on the type of organic peroxide. The heating temperature is preferably −5 ° C. to + 30 ° C., which is the 10-hour half-life temperature of the organic peroxide.
The heating time is preferably 3 to 15 hours.

  The organic peroxide is for forming a crosslinked structure in the ethylene / α-olefin copolymer (b). Examples of the organic peroxide include a peroxy ester compound, a peroxy ketal compound, a dialkyl peroxide compound, and the like. An organic peroxide may be used individually by 1 type, and may be used in combination of 2 or more type.

As the organic peroxide, a dialkyl peroxide compound is particularly preferable because the gel content of the crosslinked ethylene / α-olefin copolymer (a) can be easily adjusted.
Specific examples of the dialkyl peroxide compound include α, α′-bis (t-butylperoxy) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, and t-butyl. Examples include cumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3 and the like.

  The amount of the organic peroxide added is that the gel content of the crosslinked ethylene / α-olefin copolymer (a) can be easily adjusted to a range of 35 to 75% by mass, so that the ethylene / α-olefin copolymer (b ) 0.1 to 5 parts by mass is preferable with respect to 100 parts by mass.

The polyfunctional compound is used in combination with an organic peroxide as necessary in order to adjust the gel content of the crosslinked ethylene / α-olefin copolymer (a).
Examples of the multifunctional compound include divinylbenzene, allyl methacrylate, ethylene glycol dimethacrylate, 1,3-butylene dimethacrylate, tetraethylene glycol diacrylate, triallyl cyanurate, triallyl isocyanurate, pentaerythritol tetraacrylate, and the like. From the viewpoint of easily adjusting the gel content, divinylbenzene is preferable. A polyfunctional compound may be used individually by 1 type, and may be used in combination of 2 or more type.

  The amount of the polyfunctional compound added is that the gel content of the crosslinked ethylene / α-olefin copolymer (a) can be easily adjusted to 35 to 75% by mass, so that the ethylene / α-olefin copolymer (b) 100 is added. 0.1-5 mass parts is preferable with respect to mass parts.

When the ethylene / α-olefin copolymer (b) is crosslinked to obtain a crosslinked ethylene / α-olefin copolymer (a), an acid-modified olefin polymer is added to the ethylene / α-olefin copolymer (b). It may be added.
The acid-modified olefin polymer is the same as that mentioned in the description of the aqueous olefin resin dispersion (c). The amount of the acid-modified olefin polymer added is the same as the content of the acid-modified olefin polymer in the olefin resin aqueous dispersion (c), with respect to 100 parts by mass of the ethylene / α-olefin copolymer (b). 1-40 mass parts is preferable.
The method for adding the acid-modified olefin polymer is not limited. The ethylene / α-olefin copolymer (b) and the acid-modified olefin polymer may be mixed and then crosslinked, or the ethylene / α-olefin copolymer (b) and the acid-modified olefin polymer may be combined. You may mix, after each crosslinking process.
The mixing method of the ethylene / α-olefin copolymer (b) and the acid-modified olefin polymer is not particularly limited. Examples of the mixing method include a melt kneading method using a kneader, a Banbury mixer, a multi-screw extruder and the like.

  The volume average particle diameter of the crosslinked ethylene / α-olefin copolymer (a) in the aqueous dispersion is 0.18 to 0.55 μm, preferably 0.19 to 0.50 μm, preferably 0.20 to 0. .45 μm is more preferable. When the volume average particle diameter is within the above range, the impact resistance and color developability of the molded product are excellent.

The crosslinked ethylene / α-olefin copolymer (a) in the aqueous dispersion of the crosslinked ethylene / α-olefin copolymer (a) obtained by crosslinking the aqueous dispersion of olefin resin (c) with an organic peroxide. The volume average particle diameter does not change with respect to the volume average particle diameter of the ethylene / α-olefin copolymer (b) in the aqueous olefin resin dispersion (c).
When the graft copolymer (A) is obtained using an aqueous dispersion of a crosslinked ethylene / α-olefin copolymer (a), the crosslinked ethylene / α-olefin copolymer in the aqueous dispersion is used. Confirming that the volume average particle diameter of the polymer (a) indicates the volume average particle diameter of the crosslinked ethylene / α-olefin copolymer (a) in the thermoplastic resin composition by image analysis of an electron microscope. Yes.

<Vinyl single monomer mixture (m1)>
The vinyl monomer mixture (m1) contains at least a (meth) acrylic acid ester as a monomer. “(Meth) acrylic acid ester” means acrylic acid ester or methacrylic acid ester.
The vinyl monomer mixture (m1) may further contain other vinyl monomers other than the (meth) acrylic acid ester, if necessary.

  As (meth) acrylic acid ester, acrylic acid ester (methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, etc.), methacrylic acid ester (methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate) Etc.), and methyl methacrylate is preferred from the viewpoint of color developability and impact resistance of the molded product. A (meth) acrylic acid ester compound may be used individually by 1 type, and may be used in combination of 2 or more type.

  Other vinyl monomers include aromatic vinyl compounds (styrene, α-methylstyrene, o-, m- or p-methylstyrene, vinylxylene, pt-butylstyrene, ethylstyrene, etc.), cyanide Examples include vinyl compounds (acrylonitrile, methacrylonitrile, etc.), maleimide compounds (N-cyclohexylmaleimide, N-phenylmaleimide, etc.) and the like. Another vinyl-type monomer may be used individually by 1 type, and may be used in combination of 2 or more type.

  In the vinyl monomer mixture (m1), the content of (meth) acrylic acid ester is 88 to 100% by mass, preferably 90 to 100% by mass, and more preferably 95 to 99% by mass. If the content rate of (meth) acrylic acid ester is in the said range, the weather resistance of a molded article will be excellent. The content rate of (meth) acrylic acid ester is the ratio of the mass of (meth) acrylic acid ester with respect to the total mass (100 mass%) of a vinyl-type monomer mixture (m1).

<Graft copolymer (A)>
The graft copolymer (A) comprises a crosslinked ethylene / α-olefin copolymer (a) portion and a vinyl polymer portion which is a polymer of the vinyl monomer mixture (m1).

In the graft copolymer (A), the content of the crosslinked ethylene / α-olefin copolymer (a) portion is 40 to 80% by mass, and the content of the vinyl polymer portion is 20 to 60% by mass. Preferably, the content of the crosslinked ethylene / α-olefin copolymer (a) part is 50 to 75% by mass, and the content of the vinyl polymer part is more preferably 50 to 25% by mass. . Each content rate is a rate with respect to the total mass (100 mass%) of a graft copolymer (A).
In other words, the graft copolymer (A) is a vinyl-based monomer mixture (m1) 20 to 60% by mass in the presence of 40 to 80% by mass of the crosslinked ethylene / α-olefin copolymer (a) ( However, the total of the crosslinked ethylene / α-olefin copolymer (a) and the vinyl monomer mixture (m1) is preferably 100% by mass). -It is more preferable that it is a thing obtained by superposing | polymerizing 50-25 mass% of vinyl-type monomer mixtures (m1) in presence of 50-75 mass% of alpha olefin copolymer (a).
When the content ratio of the crosslinked ethylene / α-olefin copolymer (a) portion is within the above range, the impact resistance of the molded article and the physical property balance of color development properties are further improved.

The graft ratio of the graft copolymer (A) is preferably 20 to 100% by mass from the viewpoint of the balance between impact resistance and color development of the molded product.
The graft ratio is measured by the method described in Examples described later.

Examples of the method for producing the graft copolymer (A) include a method of polymerizing the vinyl monomer mixture (m1) in the presence of the crosslinked ethylene / α-olefin copolymer (a).
Examples of the polymerization method of the vinyl monomer mixture (m1) include known polymerization methods (emulsion polymerization method, solution polymerization method, suspension polymerization method, bulk polymerization method, etc.).

Examples of the method for producing the graft copolymer (A) by the emulsion polymerization method include, for example, a mixture obtained by mixing an organic peroxide with a vinyl monomer mixture (m1), an aqueous olefin resin dispersion (c), or crosslinked ethylene. -The method of adding continuously with respect to the aqueous dispersion of (alpha) -olefin copolymer (a), and carrying out emulsion polymerization is mentioned.
The polymerization conditions for emulsion polymerization are not particularly limited, and examples include polymerization conditions at 50 to 90 ° C. for 1.5 to 3.5 hours.
The organic peroxide is preferably used as a redox initiator that combines an organic peroxide, a transition metal, and a reducing agent.
In the polymerization, a chain transfer agent, an emulsifier or the like may be used depending on the situation.

As a redox initiator, it is not necessary to set the polymerization reaction conditions at a high temperature, and it is possible to avoid deterioration of the crosslinked ethylene / α-olefin copolymer (a) and avoid a decrease in impact resistance of the molded product. A combination of an organic peroxide, ferrous sulfate, a chelating agent and a reducing agent is preferable.
Examples of the organic peroxide include cumene hydroperoxide, diisopropylbenzene hydroperoxide, and t-butyl hydroperoxide.
The redox initiator is more preferably composed of t-butyl hydroperoxide, ferrous sulfate, sodium pyrophosphate, and dextrose.

Examples of chain transfer agents include mercaptans (octyl mercaptan, n- or t-dodecyl mercaptan, n-hexadecyl mercaptan, n- or t-tetradecyl mercaptan, etc.), allyl compounds (allylsulfonic acid, methallylsulfonic acid, these Sodium salts, etc.), α-methylstyrene dimers, and the like, and mercaptans are preferred from the viewpoint of easy adjustment of the molecular weight. A chain transfer agent may be used individually by 1 type, and may be used in combination of 2 or more type.
The method for adding the chain transfer agent may be any of batch, split, and continuous.
The addition amount of the chain transfer agent is preferably 2.0 parts by mass or less with respect to 100 parts by mass of the vinyl monomer mixture (m1).

Examples of the emulsifier include anionic surfactants, nonionic surfactants, and amphoteric surfactants.
Examples of the anionic surfactants include higher alcohol sulfates, alkylbenzene sulfonates, fatty acid sulfonates, phosphate salts, fatty acid salts, and amino acid derivative salts.
Examples of nonionic surfactants include ordinary polyethylene glycol alkyl ester types, alkyl ether types, and alkyl phenyl ether types.
Examples of the amphoteric surfactant include those having a carboxylate salt, sulfate ester salt, sulfonate salt, phosphate ester salt and the like in the anion portion and amine salts and quaternary ammonium salts in the cation portion.
The amount of the emulsifier added is preferably 10 parts by mass or less with respect to 100 parts by mass of the vinyl monomer mixture (m1).

The graft copolymer (A) obtained by the emulsion polymerization method is in a state of being dispersed in an aqueous medium.
As a method for recovering the graft copolymer (A) from the aqueous dispersion containing the graft copolymer (A), for example, a precipitation agent is added to the aqueous dispersion, heated and stirred, and then the precipitation agent is separated. And a precipitation method in which the precipitated graft copolymer (A) is washed with water, dehydrated and dried.
Examples of the precipitating agent include aqueous solutions of sulfuric acid, acetic acid, calcium chloride, magnesium sulfate, and the like. A precipitation agent may be used individually by 1 type, and may be used in combination of 2 or more type.
You may add antioxidant to the aqueous dispersion containing a graft copolymer (A) as needed.

  A graft copolymer (A) may be used individually by 1 type, and may be used in combination of 2 or more type.

<Vinyl monomer mixture (m2)>
The vinyl monomer mixture (m2) contains at least a methacrylic acid ester as a monomer.
The vinyl monomer mixture (m2) may further contain other vinyl monomers other than the methacrylic acid ester, if necessary.

  Examples of the methacrylic acid ester include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate, amyl methacrylate, Examples include isoamyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, decyl methacrylate, lauryl methacrylate, cyclohexyl methacrylate, penzyl methacrylate, and phenyl methacrylate. From the viewpoint of further improving the heat resistance and impact resistance of the molded article, it is preferable to contain at least one of methyl methacrylate and ethyl methacrylate. A methacrylic acid ester may be used individually by 1 type, and may be used in combination of 2 or more type.

  Examples of other vinyl monomers include acrylic acid esters, maleimide compounds, vinyl cyanide compounds, and aromatic vinyl compounds. Specific examples of these vinyl monomers include the same as those mentioned for the vinyl monomer mixture (m1). Acrylic acid esters are preferred because the weather resistance of the molded product is further improved. Another vinyl-type monomer may be used individually by 1 type, and may be used in combination of 2 or more type.

  In the vinyl monomer mixture (m2), the content of the methacrylic acid ester is preferably 50 to 100% by mass and more preferably 80 to 100% by mass from the viewpoint that the scratch resistance and color developability of the molded product are further improved. . The content rate of the methacrylic acid ester is a ratio of the mass of the methacrylic acid ester to the total mass (100% by mass) of the vinyl monomer mixture (m2).

<Methacrylate resin (B)>
The methacrylic ester resin (B) is a polymer of a vinyl monomer mixture (m2), and can be obtained by polymerizing the vinyl monomer mixture (m2).
Since the vinyl monomer mixture (m2) includes a methacrylic ester, the methacrylic ester resin (B) includes a unit derived from the methacrylic ester.
In the case where the vinyl monomer mixture (m2) contains two or more types of monomers, the methacrylate ester resin (B) typically has random units derived from the two or more types of monomers. It is a random copolymer arranged in.

  The content rate of the unit derived from the methacrylic acid ester is 50 with respect to the total mass (100% by mass) of all the units constituting the methacrylic acid ester resin (B) from the point that the scratch resistance and color developability of the molded product are further improved. -100 mass% is preferable, and 80-100 mass% is more preferable.

The weight average molecular weight of the methacrylic ester resin (B) is preferably 50,000 to 200,000, more preferably 60,000 to 120,000.
The weight average molecular weight (Mw) of the methacrylic ester resin (B) is a value measured using gel permeation chromatography (GPC) and converted to standard polystyrene.

The methacrylic ester resin (B) can be obtained by polymerizing the vinyl monomer mixture (m2).
The polymerization method of the vinyl monomer mixture (m2) is not particularly limited. Examples of the polymerization method include known polymerization methods (emulsion polymerization method, suspension polymerization method, solution polymerization method, etc.).

As a method for producing a methacrylic ester resin (B) by emulsion polymerization, for example, a vinyl monomer mixture (m2), an emulsifier, a polymerization initiator, and a chain transfer agent are charged in a reactor and polymerized by heating. Then, an aqueous dispersion containing the methacrylate ester resin (B) is obtained, and the methacrylate ester resin (B) is recovered from the aqueous dispersion by a precipitation method.
The polymerization conditions for emulsion polymerization are not particularly limited, and examples include polymerization conditions at 40 to 120 ° C. for 1 to 15 hours.
Examples of the emulsifier include usual emulsion polymerization emulsifiers (potassium rosinate, sodium alkylbenzenesulfonate, etc.).
Examples of the polymerization initiator include organic and inorganic peroxide initiators.
Examples of chain transfer agents include mercaptans, α-methylstyrene dimers, terpenes and the like.
As the precipitation method, a method similar to that used for recovering the graft copolymer (A) from the aqueous dispersion can be employed.

Examples of the method for producing the methacrylate ester resin (B) by suspension polymerization include, for example, a vinyl monomer mixture (m2), a suspending agent, a suspending aid, a polymerization initiator, and a chain transfer agent in a reactor. And heating to polymerize to obtain a slurry containing a methacrylate ester resin (B), and dehydrating and drying the slurry to recover the methacrylate ester resin (B).
The polymerization conditions for suspension polymerization are not particularly limited, and examples include polymerization conditions at 40 to 120 ° C. for 1 to 15 hours.
Examples of the suspending agent include tricalcium phosphite and polyvinyl alcohol.
Examples of the suspension aid include sodium alkylbenzene sulfonate.
Examples of the polymerization initiator include organic peroxides.
Examples of chain transfer agents include mercaptans, α-methylstyrene dimers, terpenes and the like.

  A methacrylic ester resin (B) may be used individually by 1 type, and may be used in combination of 2 or more type.

<Other thermoplastic resins>
Other thermoplastic resins include, for example, polycarbonate, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyvinyl chloride, polystyrene, polyacetal, modified polyphenylene ether (modified PPE), ethylene-vinyl acetate copolymer, poly Examples include arylate, liquid crystal polyester, polyethylene, polypropylene, fluororesin, and polyamide (for example, nylon).

<Various additives>
Examples of various additives include antioxidants, lubricants, processing aids, pigments, dyes, fillers, silicone oils, paraffin oils, and the like.

<Content of each component>
In the thermoplastic resin composition, the content (rubber content) of the crosslinked ethylene / α-olefin copolymer (a) portion is 7 to 30 mass relative to the total mass (100 mass%) of the thermoplastic resin composition. %, Preferably 10 to 25% by mass, more preferably 11 to 20% by mass. When the rubber content is not less than the lower limit of the above range, the impact resistance and scratch resistance of the molded product are excellent. When the rubber content is not more than the upper limit of the above range, the color developability and weather resistance of the molded product are excellent.

The content of the methacrylic ester resin (B) is preferably 60 to 90% by mass, more preferably 65 to 85% by mass with respect to the total mass of the graft copolymer (A) and the methacrylic ester resin (B). 68 to 80% by mass is more preferable.
Therefore, the content of the graft copolymer (A) is preferably 10 to 40% by mass, and 15 to 35% by mass with respect to the total mass of the graft copolymer (A) and the methacrylic ester resin (B). More preferred is 20 to 32% by mass.
When the content of the methacrylic ester resin (B) is within the above range, the balance of impact resistance, color developability, and scratch resistance of the molded product is more excellent.

<Method for producing thermoplastic resin composition>
The thermoplastic resin composition of the present invention is obtained by mixing the graft copolymer (A), the methacrylate ester resin (B), and other components (other thermoplastic resins and additives) as necessary. can get.

<Effect>
In the thermoplastic resin composition of the present invention described above, a vinyl monomer containing a crosslinked ethylene / α-olefin copolymer (a) portion and a (meth) acrylate compound at a specific content. A graft copolymer (A) comprising a vinyl polymer portion which is a polymer of the mixture (m1); and a methacrylate ester resin (a polymer of a vinyl monomer mixture (m2) containing a methacrylate ester) ( B) and the content of the crosslinked ethylene / α-olefin copolymer (a) part is within a specific range, so that a molded article having excellent impact resistance, color development, weather resistance and scratch resistance is obtained. be able to.
Since the thermoplastic resin composition of the present invention can provide a molded article having excellent scratch resistance and weather resistance, it can also be used in vehicle interior and exterior parts.

"Molding"
The molded article of the present invention can be obtained by molding the thermoplastic resin composition of the present invention by a known molding method.
Examples of the molding method include injection molding, press molding, extrusion molding, vacuum molding, and blow molding.
The use of the molded product includes vehicle interior / exterior parts, office equipment, home appliances, building materials, etc., and vehicle interior / exterior parts are suitable.

Hereinafter, an example is shown concretely. However, the present invention is not limited to these examples. In the following, “%” means “% by mass” and “parts” means “parts by mass” unless otherwise specified.
Various measurements and evaluation methods in Examples and Comparative Examples described below are as follows.

<Method for Measuring Mass Average Molecular Weight (Mw) and Molecular Weight Distribution (Mw / Mn) of Ethylene / α-Olefin Copolymer (A)>
Using a GPC device (GPC: “GPC / V2000” manufactured by Waters, column: “Shodex AT-G + AT-806MS” manufactured by Showa Denko KK), using o-dichlorobenzene (145 ° C.) as a solvent, a mass average in terms of polystyrene Molecular weight (Mw) and number average molecular weight (Mn) were measured, and molecular weight distribution (Mw / Mn) was calculated.

<Measuring method of mass average molecular weight (Mw) of methacrylic ester resin (B)>
Using GPC (GPC: “HLC8220” manufactured by Tosoh Corporation, column: “TSK GEL SuperHZM-H” manufactured by Tosoh Corporation), the mass average molecular weight (Mw) in terms of polystyrene was measured as a solvent of tetrahydrofuran (THF: 40 ° C.). .

<Method for measuring acid value>
The acid value was measured according to JIS K 2501.

<Measurement method of volume average particle diameter>
The volume average particle diameter (MV) was measured using a microtrack (“Nanotrack 150” manufactured by Nikkiso Co., Ltd.) using pure water as a measurement solvent.
The volume of the ethylene / α-olefin copolymer (b) dispersed in the aqueous olefin resin dispersion (c) and the volume of the crosslinked ethylene / α-olefin copolymer (a) dispersed in the aqueous dispersion. It has been confirmed by image analysis of an electron microscope that the average particle diameter indicates the volume average particle diameter of the crosslinked ethylene / α-olefin copolymer (a) in the thermoplastic resin composition as it is.

<Measurement method of gel content>
An aqueous or solvent dispersion of the crosslinked ethylene / α-olefin copolymer (a) is coagulated with dilute sulfuric acid, washed with water and dried, and 0.5 g of a coagulated powder sample [D1] is added to 200 mL of 110 ° C. toluene. 5 hours, and then filtered through a 200 mesh wire mesh, the residue is dried, the mass of the dried product [D2] is measured, and from the following formula (1), a crosslinked ethylene / α-olefin copolymer The gel content of (a) was determined.
Gel content rate (%) = dry substance amount [D2] (g) / coagulated powder sample mass [D1] (g) × 100 (1)

<Measurement method of graft ratio>
1 g of the graft copolymer (A) is added to 80 mL of acetone, heated and refluxed at 65 to 70 ° C. for 3 hours, and the resulting suspension acetone solution is added to a centrifuge (“CR21E” manufactured by Hitachi Koki Co., Ltd.). The mixture was centrifuged at 14,000 rpm for 30 minutes to separate a precipitation component (acetone insoluble component) and an acetone solution (acetone soluble component). And the precipitation component (acetone insoluble component) was dried, the mass (Y (g)) was measured, and the graft ratio was computed from following formula (2). In Formula (2), Y is the mass (g) of the acetone-insoluble component of the graft copolymer (A), and X is the total mass (g) of the graft copolymer (A) used to determine Y. The rubber fraction is the solid content of the crosslinked ethylene / α-olefin copolymer (a) of the graft copolymer (A).
Graft rate (%) = {(Y-X × rubber fraction) / X × rubber fraction} × 100 (2)

<Preparation of molded product for physical property evaluation 1>
The pellets of the thermoplastic resin composition are injection-molded by an injection molding machine (“TOSHIKI MACHINE Co., Ltd.,“ IS55FP-1.5A ”) under the conditions of a cylinder temperature of 200 to 270 ° C. and a mold temperature of 60 ° C., 100 × 100 mm A black colored plate (thickness 3 mm) was obtained. This was designated as a molded product (Ma1).

<Preparation of molded product for physical property evaluation 2>
The pellets of the thermoplastic resin composition were injection-molded under the conditions of a cylinder temperature of 200 to 270 ° C. and a mold temperature of 60 ° C. using an injection molding machine (Toshiba Machine Co., Ltd., “IS55FP-1.5A”). A molded article for measuring a deflection temperature under load having a width of 10 mm and a thickness of 4 mm was obtained. This was designated as a molded product (Ma2).

<Evaluation of color development>
The brightness L ^* of the molded product (Ma1) was measured by the SCE method using a spectrocolorimeter (“CM-3500d” manufactured by Konica Minolta Optips, Inc.). The L ^* thus measured was designated as “L ^* (ma)”. The lower L ^* , the more black and the better the color developability.

<Evaluation of weather resistance>
For the molded product (Ma1), using an i-super UV tester (SUV-W151 type manufactured by Iwasaki Electric Co., Ltd.), black panel temperature of 63 ° C., cycle condition 360 minutes (irradiation 240 minutes, dark 120 minutes, water shower at switching) ) For 144 hours. The lightness L ^* of the surface of the molded article (Mb) after the treatment was measured by the SCE method using a spectrocolorimeter. L ^* measured in this way was defined as L ^* (mb), and a weather resistance determination index ΔL ^* was calculated from the following formula (3). The larger the absolute value of ΔL ^* (mb−ma), the worse the weather resistance.
ΔL ^* (mb−ma) = L ^* (mb) −L ^* (ma) (3)

<Evaluation of scratch resistance>
As shown in FIG. 1, a rod-like jig 10 having a tip 11 formed in a hemispherical shape was prepared, and a car wash towel (Joiful Car Wash Towel 3p) 12 was placed on the tip 11. The tip part 11 covered with the car wash towel 12 is brought into contact with the surface of the molded product (Ma1) 13 so that the rod-shaped jig 10 is at a right angle, and the tip part 11 is brought into contact with the surface of the molded product (Ma1) 13. Were slid in the horizontal direction (in the direction of the double arrow in the figure) and reciprocated 100 times. At that time, the applied load was 1 kg (9.8 N). After reciprocating 100 times, the lightness L ^* of the surface of the scratched molded article (Mc) was measured by the SCE method using a spectrocolorimeter. L ^* measured in this way was defined as L ^* (mc), and the scratch resistance determination index ΔL ^* was calculated from the following formula (4). As the absolute value of ΔL ^* (mc−ma) is larger, the scratches are more conspicuous and the scratch resistance is inferior.
ΔL ^* (mc−ma) = L ^* (mc) −L ^* (ma) (4)

<Impact resistance>
The molded product (Ma2) was subjected to a Charpy impact test (notched) at 23 ° C. according to ISO 179 standard, and the Charpy impact strength was measured.

  In the examples and comparative examples described later, the following ethylene / α-olefin copolymer (b), olefin resin aqueous dispersion component (c), crosslinked ethylene / α-olefin copolymer (a), and graft copolymer (A) Methacrylate resin (B) was used.

<Ethylene / α-olefin copolymer (b)>
(Preparation of ethylene / propylene copolymer (b-1))
A 20 L stainless polymerization tank equipped with a stirrer was sufficiently purged with nitrogen. Thereafter, 10 L of dehydrated and purified hexane was added, and a hexane solution of ethylaluminum sesquichloride (Al (C ₂ H ₅ ) _1.5 · Cl _1.5 ) prepared to 8.0 mmol / L was added in an amount of 5 L / h. For 1 hour continuously. Thereafter, a hexane solution of VO (OC ₂ H ₅ ) Cl ₂ adjusted to 0.8 mmol / L as a catalyst was continuously supplied in an amount of 5 L / h and hexane in an amount of 5 L / h. On the other hand, from the upper part of the polymerization tank, the polymerization liquid was continuously extracted so that the polymerization liquid in the polymerization tank was always 10 L. Using a bubbling tube, ethylene was supplied in an amount of 2000 L / h, propylene was supplied in an amount of 1000 L / h, hydrogen was supplied in an amount of 8 L / h, and a polymerization reaction was performed at 35 ° C.
A polymerization reaction was performed under the above conditions to obtain a polymerization solution containing an ethylene / propylene copolymer (b-1). The obtained polymerization solution was deashed with hydrochloric acid, and then poured into methanol to precipitate the ethylene / propylene copolymer (b-1). The precipitate was collected and dried, and the ethylene / propylene copolymer ( b-1) was obtained. Table 1 shows the polymer properties of the ethylene / propylene copolymer (b-1).

<Olefin resin aqueous dispersion component (c)>
(Preparation of aqueous dispersion of olefin resin (c-1))
100 parts of an ethylene / propylene copolymer (b-1) and maleic anhydride-modified polyethylene (Mitsui Chemicals, "Mitsui High Wax 2203A", acid average molecular weight: 2,700, acid value: 30 mg / g) 20 parts and 5 parts of potassium oleate as an anionic emulsifier were mixed to obtain a mixture.
This mixture is supplied at 4 kg / h from a hopper of a twin screw extruder (Ikegai, “PCM30”, L / D = 40), and is supplied from a supply port provided in a vent portion of the twin screw extruder. While continuously supplying an aqueous solution obtained by mixing 0.5 part of potassium hydroxide and 2.4 parts of ion-exchanged water, it was heated to 220 ° C., melt-kneaded and extruded. The extruded melt-kneaded product was continuously supplied to a cooling device attached to the tip of the twin screw extruder and cooled to 90 ° C. Then, the solid discharged from the tip of the twin screw extruder is poured into warm water at 80 ° C., continuously dispersed, diluted to a solid content concentration of around 40%, and an aqueous olefin resin dispersion (c -1) was obtained. Table 2 shows the volume average particle diameter of the ethylene / α-olefin copolymer (b) dispersed in the aqueous olefin resin dispersion (c-1).

(Preparation of aqueous olefin resin dispersions (c-2) to (c-5))
As shown in Table 2, the aqueous olefin resin dispersion was the same as the aqueous olefin resin dispersion (c-1) except that the number of added parts of potassium hydroxide and the number of added parts of ion-exchanged water during emulsification were changed. (C-2) to (c-5) were obtained.
Table 2 shows the volume average particle diameter of the ethylene / α-olefin copolymer (b) dispersed in each of the olefin resin aqueous dispersions (c-2) to (c-5).

<Crosslinked ethylene / α-olefin copolymer (a)>
(Preparation of crosslinked ethylene / α-olefin copolymer (a-1))
Ion exchange water was added to the olefin resin aqueous dispersion (c-1) (100 parts as a solid content) so that the solid content concentration was 35%, and 1 part of t-butylcumyl peroxide as an organic peroxide was multifunctional. An aqueous dispersion of a crosslinked ethylene / α-olefin copolymer (a-1) was prepared by adding 1 part of divinylbenzene as a functional compound and reacting at 130 ° C. for 5 hours. Table 3 shows the volume average particle diameter and gel content of the crosslinked ethylene / α-olefin copolymer (a-1).

(Preparation of crosslinked ethylene / α-olefin copolymers (a-2) to (a-5))
The crosslinked ethylene / α-olefin copolymer is the same as the crosslinked ethylene / α-olefin copolymer (a-1) except that the type of the olefin resin aqueous dispersion (c) is changed as shown in Table 3. Aqueous dispersions (a-2) to (a-5) were obtained. Table 3 shows the volume average particle diameter and gel content of the crosslinked ethylene / α-olefin copolymers (a-2) to (a-5).

<Graft copolymer (A)>
(Preparation of graft copolymer (A-1))
An aqueous dispersion of a crosslinked ethylene / α-olefin copolymer (a-1) (70 parts as a solid content of the crosslinked ethylene / propylene copolymer (a-1)) is placed in a stainless polymerization tank equipped with a stirrer. In addition, ion-exchanged water was added so that the solid content concentration of the crosslinked ethylene / α-olefin copolymer (a-1) was 30%, and further, 0.006 part of ferrous sulfate and 0.3 part of sodium pyrophosphate And 0.6 part of dextrose was charged, and the temperature was 73 ° C. Subsequently, 29 parts of methyl methacrylate, 1 part of methyl acrylate, and 0.34 part of t-butyl hydroperoxide were continuously added for 150 minutes, and the polymerization temperature was kept at 73 ° C. to carry out emulsion polymerization. An aqueous dispersion containing 40 μm of graft copolymer (A-1) was obtained. An antioxidant is added to the aqueous dispersion containing the graft copolymer (A-1), solids are precipitated with sulfuric acid, and after washing, dehydration, and drying, a powdered graft copolymer ( A-1) was obtained. When the graft ratio of the graft copolymer (A-1) was measured, it was 30%. Further, the volume average particle diameter of the crosslinked ethylene / α-olefin copolymer (a-1) in the thermoplastic resin composition obtained using the graft copolymer (A-1) in Example 1 and the like described later is used. It was 0.40 micrometer when confirmed with the electron microscope.

(Preparation of graft copolymers (A-2) to (A-9))
As shown in Tables 4 to 5, except that the type and amount of the monomer constituting the crosslinked ethylene / α-olefin copolymer (a) or the vinyl monomer mixture (m1) were changed, In the same manner as the graft copolymer (A-1), graft copolymers (A-2) to (A-9) were obtained. The graft ratios of the graft copolymers (A-2) to (A-9) are shown in Tables 4 to 5.

(Preparation of graft copolymer (A-10))
An aqueous dispersion of a crosslinked ethylene / α-olefin copolymer (a-1) (70 parts as a solid content of the crosslinked ethylene / propylene copolymer (a-1)) is placed in a stainless polymerization tank equipped with a stirrer. In addition, ion-exchanged water was added so that the solid content concentration of the crosslinked ethylene / α-olefin copolymer (A-1) was 30%, and further, 0.006 part of ferrous sulfate and 0.3 part of sodium pyrophosphate And 0.35 part of fructose was charged, and the temperature was set to 80 ° C. Subsequently, 19.8 parts by mass of styrene, 10.2 parts by mass of acrylonitrile and 0.6 parts by mass of cumene hydroperoxide were continuously added for 150 minutes, and the polymerization temperature was kept at 80 ° C. to carry out emulsion polymerization, and the average particle size was 0. An aqueous dispersion containing a 40 μm graft copolymer (A-10) was obtained. An antioxidant is added to the aqueous dispersion containing the graft copolymer (A-10), solids are precipitated with sulfuric acid, and after washing, dehydration, and drying steps, the powdered graft copolymer ( A-10) was obtained. When the graft ratio of the graft copolymer (A-10) was measured, it was 30%. Moreover, the average particle diameter of the crosslinked ethylene / α-olefin copolymer (a) in the thermoplastic resin composition obtained by using the graft copolymer (A-10) in Comparative Example 6 described later was confirmed by an electron microscope. As a result, it was 0.40 μm.

<Methacrylate resin (B)>
(Preparation of methacrylate resin (B-1))
In a stainless polymerization tank equipped with a stirrer, 150 parts of ion exchange water, 98 parts of methyl methacrylate, 2 parts of methyl acrylate, 0.2 part of 2,2′-azobis (isobutyronitrile), 0.24 part of n-octyl mercaptan , 0.47 part of calcium hydroxyapatite and 0.003 part of potassium alkenyl succinate were charged. The internal temperature of the polymerization tank was set to 75 ° C. for 3 hours, and the temperature was raised to 90 ° C. for 1 hour. The contents were extracted, washed with a centrifugal dehydrator, and dried to obtain a powdered methacrylate resin (B-1). The composition of the resulting methacrylic ester resin (B-1) was methyl methacrylate / methyl acrylate = 98/2 (mass ratio), and the mass average molecular weight was 98,200.

[Examples 1 to 10, Comparative Examples 1 to 6]
The graft copolymer (A) and the methacrylic ester resin (B) are mixed in the formulation shown in Tables 6 to 7, and the total amount of the graft copolymer (A) and the methacrylic ester resin (B) is 100 parts. 0.8 parts of carbon black is mixed and colored, and melt-kneaded at a cylinder temperature of 240 ° C. and 93.325 kPa vacuum using a twin screw extruder with a 30 mmφ vacuum vent (“PCM30” manufactured by Ikegai Co., Ltd.), and thermoplasticity A resin composition was obtained.
After melt-kneading, the thermoplastic resin composition is pelletized using a pelletizer (“SH type pelletizer” manufactured by Souken Co., Ltd.), and various molded products (Ma1, Ma2) are molded to provide impact resistance, color development, and scratch resistance. The weather resistance was evaluated. The results are shown in Tables 6-7.
In Tables 6 to 7, the rubber content is the content of the crosslinked ethylene / α-olefin copolymer (a) portion relative to the total mass of each thermoplastic resin composition.

Molded articles obtained from the thermoplastic resin compositions of Examples 1 to 10 were excellent in impact resistance, color developability, scratch resistance, and weather resistance.
Therefore, when the thermoplastic resin composition of the present invention is used, a molded product excellent in impact resistance, color development, scratch resistance, and weather resistance can be obtained, and used for vehicle interior / exterior parts, office equipment, home appliances, building materials, etc. It can be seen that it can be applied.
On the other hand, the molded articles obtained from the thermoplastic resin compositions of Comparative Examples 1 to 6 were inferior in any one or more of impact resistance, color developability, scratch resistance, and weather resistance.

  A molded article using the thermoplastic resin composition of the present invention is useful as a vehicle interior / exterior part, office equipment, home appliance, building material and the like.

10 Jig 11 Tip 12 Car Wash Towel 13 Molded Product (Ma1)

Claims (3)

Crosslinked ethylene / α-olefin copolymer (a) portion having a volume average particle diameter of 0.18 to 0.55 μm, and a vinyl monomer having a content of (meth) acrylate of 88 to 100% by mass A graft copolymer (A) comprising a vinyl polymer part which is a polymer of the body mixture (m1);
A methacrylate ester resin (B) that is a polymer of a vinyl monomer mixture (m2) containing a methacrylate ester,
A thermoplastic resin composition, wherein the content of the crosslinked ethylene / α-olefin copolymer (a) is 7 to 30% by mass relative to the total mass of the thermoplastic resin composition.   The content of the methacrylic ester resin (B) is 60 to 90% by mass with respect to the total mass of the graft copolymer (A) and the methacrylic ester resin (B). Thermoplastic resin composition.   A molded article using the thermoplastic resin composition according to claim 1.

Images