JP2014080525A - Thermoplastic resin composition having scratch resistance and molded article thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition having scratch resistance, excellent in weather resistance, scratch resistance, color development, and shock resistance and heat resistance, and to provide its molded article.SOLUTION: There are provided a composition containing 10 pts.mass or more and less than 30 pts.mass of a graft polymer (B) obtained by graft polymerization of a specific monomer mixture (m1) to a crosslinked ethylene and α-olefin copolymer (A) crosslinking treated so that the gel content is 50 to 85 mass%, 10 to 80 pts.mass of a methacrylic ester resin (C) having specific glass transition temperature obtained by polymerization of monomer mixture (m2) containing N-substituted maleimide or maleic acid anhydride, aromatic vinyl and methacrylic acid ester to the crosslinked ethylene and α-olefin copolymer (A), and 10 to 80 pts.mass of a methacrylate ester resin (D) obtained by polymerization of monomer components (m3) containing methyl methacrylate of 95 mass% or more to the crosslinked ethylene and α-olefin copolymer (A) (excluding the methacrylic acid ester resin (C)) (where, (B)+(C)+(D)=100 pts.mass), and a molded article.

Description

  The present invention relates to a scratch-resistant thermoplastic resin composition having excellent weather resistance, scratch resistance, color development, impact resistance, and heat resistance, and a molded product thereof.

  In recent years, exterior resin parts in the automobile field or the like are required to be usable without painting from the viewpoint of reducing manufacturing costs. Therefore, characteristics (required characteristics) required in addition to mechanical properties such as impact resistance have been widened.

Of the required properties, for example, regarding heat resistance, although the required heat resistant temperature differs for each member, a heat resistant temperature of 80 ° C. or higher is required even for mirrors and pillars having relatively low required temperatures.
In addition, it is required to exhibit a molded appearance having good colorability, which has been conventionally applied to painting, even without painting, and weather resistance is also required that the molded appearance is not easily discolored even when exposed to direct sunlight. The
Further, in the case of exterior resin parts for automobiles, scratch resistance is required such that they are not scratched and are not conspicuous during running, car washing, wiping off dirt and wax, and the like.

  There are roughly two types of scratches on exterior resin parts: scratches caused by hard and sharp objects such as stepping stones and dust during travel, and scratches when wiped with work gloves or gauze. The scratch resistance with respect to these is often evaluated by pencil hardness or the like because the surface hardness mainly affects the former, and generally a hardness of F or higher is required. On the other hand, in the latter case, since the composite physical properties such as elongation and slidability are affected, the appearance of rubbing with gauze or a work gloves is often visually evaluated.

As described above, the resin used for the coating-less exterior resin part has many required characteristics, and it has been difficult to satisfy all of them.
For example, as a material having good color developability, there are a polycarbonate resin and a methacrylic ester resin. However, the polycarbonate resin has a low surface hardness and is very easily damaged by a hard pointed object. Further, it cannot be said that the weather resistance is good, and there is a problem of yellow discoloration over time. On the other hand, methacrylic ester resins have high surface hardness and are not easily scratched by hard and sharp objects, but are easily scratched by work gloves or gauze. Moreover, since heat resistance and impact resistance are low, there was a problem in wide use in the automobile field.

  Against this background, for example, Patent Document 1 uses an acrylic resin-based core-shell type impact modifier, which is added to a specific low molecular weight methacrylic resin and a specific high molecular weight methacrylic resin. A method is described. For example, Patent Document 2 discloses a method of adding an AES graft to a heat-resistant methacrylic ester resin containing an N-substituted maleimide.

Special table 2008-528712 JP 2004-352842 A

However, the method described in Patent Document 1 is insufficient in improving the abrasion caused by work gloves or gauze.
On the other hand, in the method described in Patent Document 2, the heat resistance is good, but the color developability and the impact resistance are not sufficient.

The present invention has been made in view of the above circumstances, and provides a scratch-resistant thermoplastic resin composition having excellent weather resistance, scratch resistance, color development, impact resistance, and heat resistance, and a molded article thereof. With the goal.
In the present specification, the term “scratch resistance” simply means the difficulty of being scratched by both hard and pointed scratches and abrasions caused by work gloves and gauze.

The present invention has the following configuration.
[1] Monomer mixture (m1) containing aromatic vinyl and vinyl cyanide in the crosslinked ethylene / α-olefin copolymer (A) crosslinked so that the gel content is 50 to 85% by mass 10 parts by mass or more and less than 30 parts by mass of graft polymer (B) obtained by graft polymerization of
Methacrylate resin (C) 10 to 80 having a glass transition temperature of 135 ° C. or lower obtained by polymerizing a monomer mixture (m2) containing N-substituted maleimide or maleic anhydride, aromatic vinyl and methacrylic acid ester Part by mass;
10 to 80 parts by mass of a methacrylic ester resin (D) obtained by polymerizing a monomer component (m3) containing 95% by mass or more of methyl methacrylate (however, it does not correspond to the methacrylic ester resin (C)); And a scratch-resistant thermoplastic resin composition (however, (B) + (C) + (D) = 100 parts by mass).
[2] A molded article, wherein the scratch-resistant thermoplastic resin composition according to [1] is molded.

  According to the present invention, a scratch-resistant thermoplastic resin composition excellent in weather resistance, scratch resistance, and color developability, and excellent in impact resistance and heat resistance, and a molded product thereof can be obtained.

It is a schematic explanatory drawing explaining the evaluation method of "gauze wear" in an Example.

Hereinafter, the present invention will be described in detail.
<Scratch-resistant thermoplastic resin composition>
The scratch-resistant thermoplastic resin composition of the present invention (hereinafter sometimes simply referred to as a resin composition) includes the following graft polymer (B), methacrylic ester resin (C), and methacrylic ester resin (D). 3 components at least.
(1) Monomer mixture (m1) containing aromatic vinyl and vinyl cyanide in the crosslinked ethylene / α-olefin copolymer (A) crosslinked so that the gel content is 50 to 85% by mass A graft polymer (B) obtained by graft polymerization.
(2) Methacrylate resin (C) having a glass transition temperature of 135 ° C. or less obtained by polymerizing a monomer mixture (m2) containing N-substituted maleimide or maleic anhydride, aromatic vinyl, and methacrylate. .
(3) A methacrylic ester resin (D) obtained by polymerizing a monomer component (m3) containing 95% by mass or more of methyl methacrylate. However, the methacrylic ester resin (D) does not correspond to the methacrylic ester resin (C).

[Graft polymer (B)]
The graft polymer (B) contained in the resin composition of the present invention is obtained by adding an aromatic vinyl to a crosslinked ethylene / α-olefin copolymer (A) that has been crosslinked so that the gel content is 50 to 85% by mass. And a monomer mixture (m1) containing vinyl cyanide and vinyl cyanide.

(Crosslinked ethylene / α-olefin copolymer (A))
The crosslinked ethylene / α-olefin copolymer (A) is obtained by subjecting an ethylene / α-olefin copolymer to a crosslinking treatment and adjusting the gel content thereof. The graft polymer (B) obtained by grafting the monomer mixture (m1) to the ethylene / α-olefin copolymer (A) can sufficiently secure a molecular chain contributing to elastic deformation, and can be used under shear stress. Deformation of the graft polymer (B) particles is suppressed. Therefore, by blending the graft polymer (B), excellent impact resistance, scratch resistance, and color developability can be exhibited in the resin composition and the molded product thereof.
The gel content of the crosslinked ethylene / α-olefin copolymer (A) is 50 to 85% by mass, preferably 60 to 75% by mass. When the gel content of the cross-linked ethylene / α-olefin copolymer (A) is less than the above range, the resin composition and its molded article have impact resistance, color developability, and scratch resistance to scratches caused by work gloves and gauze. If the above range is exceeded, the impact resistance is poor.

In addition, the gel content of the crosslinked ethylene / α-olefin copolymer (A) in the present specification is determined as follows.
(1) While stirring a solution composed of 300 ml of methanol and 120 ml of 5% sulfuric acid, 20 ml of an emulsified latex of the crosslinked ethylene / α-olefin copolymer (A) was dropped into the solution over 10 minutes, and further 20 Continue stirring for a minute.
(2) The obtained solution is filtered through a 200-mesh wire mesh to obtain a solid 1 as a filtration residue.
(3) The obtained solid 1 is put into 300 ml of distilled water and washed, and then filtered through a 200 mesh wire net to obtain a solid content 2 as a filtration residue.
(4) The obtained solid content 2 is washed in 300 ml of methanol and then filtered through a 200 mesh wire net to obtain a solid 3 as a filtration residue.
(5) The solid 3 is vacuum-dried to obtain a solidified crosslinked ethylene / α-olefin copolymer (A). The mass of the solidified crosslinked ethylene / α-olefin copolymer (A) is defined as W1. The solidified crosslinked ethylene / α-olefin copolymer (A) is swelled with toluene at 105 ° C. for 6 hours, and then cooled to room temperature. The swollen crosslinked ethylene / α-olefin copolymer is filtered off from toluene using a 200-mesh wire mesh, and then dried in vacuo to obtain a dry gel. Let the mass of this dry gel be W2.
Gel content is calculated | required by the following formula | equation (1).
Gel content = W2 × 100 / W1 (1)

The ethylene / α-olefin copolymer is a copolymer of ethylene and α-olefin. As the α-olefin, one or more of ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, and copolymers thereof can be used.
The ethylene / α-olefin copolymer may contain one or more units composed of non-conjugated diene components such as 1,4-hexadiene, 5-ethylidene-2-norbornene, 5-vinylnorbornene, and dicyclopentadiene. From the viewpoint of imparting excellent impact resistance and scratch resistance to the resin composition and its molded product, it is preferable not to include a unit comprising a non-conjugated diene component.
As the ethylene / α-olefin copolymer, it is preferable to use an ethylene / propylene copolymer that does not contain a unit composed of a non-conjugated diene component from the viewpoint of impact resistance and color developability of the resin composition and its molded product. .

The production method of the ethylene / α-olefin copolymer is not limited, but those produced using a Ziegler-Natta catalyst or a metallocene catalyst are usually used.
As the Ziegler-Natta catalyst, a highly active catalyst is preferable, and a highly active catalyst in which a solid catalyst component containing magnesium, titanium, halogen, and an electron donor as an essential component and an organoaluminum compound is particularly preferable.

  Examples of metallocene catalysts include organic compounds having a cyclopentadienyl skeleton on transition metals such as zirconium, hafnium, titanium, metallocene complexes coordinated with halogen atoms, alumoxane compounds, ion-exchange silicates, organoaluminum compounds, etc. A combination of these can be used.

  Examples of the polymerization method for polymerizing the ethylene / α-olefin copolymer include a slurry polymerization method, a gas phase polymerization method, a bulk polymerization method, a solution polymerization method, and a multistage polymerization method combining these.

The cross-linking treatment of ethylene / α-olefin can be carried out by a known method, and among them, an organic peroxide and, if necessary, a polyfunctional compound are added to the ethylene / α-olefin copolymer for cross-linking. The method of performing the treatment is preferred from the viewpoint of impact resistance and color developability of the resin composition and its molded product.
Specifically, a method of heating an ethylene / α-olefin copolymer or an emulsion latex of an ethylene / α-olefin copolymer, an organic peroxide, and a polyfunctional compound used as necessary, etc. Is mentioned. Here, the gel content of the resulting crosslinked ethylene / α-olefin copolymer (A) can be easily adjusted by adjusting the addition amount of organic peroxide and polyfunctional compound, heating temperature, heating time, etc. it can. The heating temperature varies depending on the type of organic peroxide used, and is preferably −5 ° C. to + 30 ° C., which is the 10-hour half-life temperature of the organic peroxide used. A preferred heating time is 3 to 15 hours.

Further, when an emulsion latex of an ethylene / α-olefin copolymer is crosslinked, a latex of a crosslinked ethylene / α-olefin copolymer (A) is obtained. The volume average particle diameter in the latex A) is preferably 100 to 400 nm, more preferably 100 to 300 nm, from the viewpoint of color developability and impact resistance of the resin composition and the molded product thereof.
Examples of other crosslinking treatment methods include known crosslinking treatment methods such as a crosslinking treatment method with ionizing radiation.

  The emulsion latex of ethylene / α-olefin copolymer is a dispersion of resin solids containing ethylene / α-olefin copolymer dispersed in water or in a solvent as finely dispersed particles. It can be produced by a method, a solution method or the like. Among them, after an ethylene / α-olefin copolymer and a surfactant are melt-kneaded to obtain a kneaded product, a basic substance and water are added to the kneaded product and melt-kneaded. The method of diluting is preferable from the viewpoint of impact resistance and color developability of the resin composition and its molded product. At the time of melt kneading, a wax component such as maleic anhydride-modified polyethylene may be used together with a surfactant from the viewpoint of kneading properties.

  The organic peroxide is for forming a crosslinked structure in the ethylene / α-olefin copolymer, and examples thereof include a peroxyester compound, a peroxyketal compound, and a dialkyl peroxide compound. The above can be used.

  Specific examples of the peroxyester compound include α, α′-bis (neodecanoylperoxy) diisopropylbenzene, cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecano Eight, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylper Oxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexane, 1- Cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy-2-hexyl Hexanoate, t-butyl peroxy 2-hexyl hexanoate, t-butyl peroxyisobutyrate, t-hexyl peroxyisopropyl monocarbonate, t-butyl peroxymaleic acid, t-butyl peroxy 3,5 5-trimethylhexanoate, t-butylperoxylaurate, 2,5-dimethyl-2,5-bis (m-toluoylperoxy) hexane, t-butylperoxyisopropyl monocarbonate, t-butylperoxy 2-ethylhexyl monocarbonate, t-hexylperoxybenzoate, 2,5-dimethyl-2,5-bis (benzoylperoxy) hexane, t-butylperoxyacetate, t-butylperoxy-m-toluoyl Benzoate, t-butylperoxybenzoe , Bis (t-butylperoxy) Isofutareito the like.

  Specific examples of the peroxyketal compound include 1,1-bis (t-hexylperoxy) 3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis. (T-butylperoxy) 3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) cyclododecane, 2,2-bis (T-butylperoxy) butane, n-butyl 4,4-bis (t-butylperoxy) valerate, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane and the like. .

  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. , T-butylcumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3, and the like.

  Among these organic peroxides, dicumyl peroxide, t-butylcumyl peroxide, di-t-butylperoxide are preferable because the gel content of the crosslinked ethylene / α-olefin copolymer (A) can be easily adjusted. It is particularly preferable to use a dialkyl peroxide compound such as oxide.

  The amount of the organic peroxide added during the crosslinking treatment is such that the gel content of the crosslinked ethylene / α-olefin copolymer (A) is adjusted in the range of 50 to 85% by mass, and the resin composition and its molded product are excellent. In view of exhibiting high impact resistance, scratch resistance, and color developability, it is preferably 0.3 to 5 parts by mass with respect to 100 parts by mass of the ethylene / α-olefin copolymer, and 0.8 to 2. 5 parts by mass is more preferable.

  The polyfunctional compound is used in combination with an organic peroxide as necessary in order to adjust the gel content of the ethylene / α-olefin copolymer. For example, divinylbenzene, allyl methacrylate, Examples thereof include ethylene glycol dimethacrylate, 1,3-butylene dimethacrylate, tetraethylene glycol diacrylate, triallyl cyanurate, triallyl isocyanurate, pentaerythritol tetraacrylate and the like, and one or more thereof can be used. Of these, divinylbenzene is preferred from the viewpoint of easily adjusting the gel content.

  The addition amount of the polyfunctional compound is easy to adjust the gel content of the crosslinked ethylene / α-olefin copolymer (A) in the range of 50 to 85% by mass, and has excellent impact resistance to the resin composition and its molded product. It is preferable to use it in the range of 10 parts by mass or less with respect to 100 parts by mass of the ethylene / α-olefin copolymer from the viewpoint of easily exhibiting the property, scratch resistance and color developability.

(Monomer mixture (m1))
The graft polymer (B) is obtained by graft polymerization of the monomer mixture (m1) to the crosslinked ethylene / α-olefin copolymer (A) crosslinked so that the gel content is 50 to 85% by mass. Is obtained. The monomer mixture (m1) is a monomer mixture containing at least aromatic vinyl and vinyl cyanide as monomers.

  Examples of the aromatic vinyl include styrene, α-methyl styrene, o-, m- or p-methyl styrene, vinyl xylene, pt-butyl styrene, ethyl styrene, and one or more of these. Can be used. Among these, it is preferable to use at least one of styrene and α-methylstyrene.

  65-82 mass% is preferable, as for content of the aromatic vinyl in 100 mass% of monomer mixtures (m1), 73-80 mass% is more preferable, and 75-80 mass% is still more preferable. When the content of aromatic vinyl in the monomer mixture (m1) is within the above range, the color developability and impact resistance of the resin composition and the molded product thereof are further improved.

Examples of vinyl cyanide include acrylonitrile and methacrylonitrile, and one or more of these can be used.
18-35 mass% is preferable, as for content of vinyl cyanide in 100 mass% of monomer mixtures (m1), 20-27 mass% is more preferable, and 20-25 mass% is still more preferable. When the content of vinyl cyanide in the monomer mixture (m1) is within the above range, the color developability and impact resistance of the resin composition and the molded product thereof are improved.

The monomer mixture (m1) may contain, in addition to the above aromatic vinyl and vinyl cyanide, other monomers copolymerizable therewith within a range not impairing the effects of the present invention.
Other monomers include α, β- such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethyl (meth) acrylate, 2-ethylhexyl methacrylate and the like. Examples thereof include unsaturated carboxylic acid esters, maleimides such as N-cyclohexylmaleimide, N-phenylmaleimide, and the like, and one or more can be used as necessary.
In the present specification, “(meth) acrylate” means acrylate and methacrylate.

The graft polymer (B) can be obtained by graft polymerization of the monomer mixture (m1) in the presence of the above-described crosslinked ethylene / α-olefin copolymer (A).
The ratio of the crosslinked ethylene / α-olefin copolymer (A) during graft polymerization is preferably 50 to 80% by mass, and the ratio of the monomer mixture (m1) is preferably 20 to 50% by mass. More preferably, the ratio of the crosslinked ethylene / α-olefin copolymer (A) is 60 to 80% by mass, and the ratio of the monomer mixture (m1) is 20 to 40% by mass (provided that the crosslinked ethylene / α -The sum total of an olefin copolymer (A) and a monomer mixture (m1) shall be 100 mass%. If the ratio of the cross-linked ethylene / α-olefin copolymer (A) is within the above range, the productivity of the graft polymer (B) is good and the color developability and impact resistance of the resin composition and its molded product are good. Improves.

  The graft polymer (B) preferably has a graft ratio of 23 to 100% and more preferably 25 to 100% because the color developability and impact resistance of the resin composition and the molded product thereof are good.

The graft ratio (G) in this specification is calculated | required from following formula (2).
G = 100 (PE) / E (2)
P: Mass of acetone-insoluble matter (Graft polymer (B) or scratch-resistant thermoplastic resin composition was washed with methanol, extracted with acetone, and separated into acetone-soluble and acetone-insoluble components with a centrifuge. , Mass (g) after vacuum-drying the obtained acetone insoluble matter)
E: Mass (g) of the crosslinked ethylene / α-olefin copolymer (A) used for the production of the graft polymer (B)

  The graft polymer (B) is produced by a known method such as a bulk polymerization method, a solution polymerization method, a bulk suspension polymerization method, a suspension polymerization method, and an emulsion polymerization method, and emulsion polymerization is preferable in that it can be easily polymerized. . Below, an example of the method of manufacturing a graft copolymer (B) by emulsion polymerization is shown concretely.

By the method described above, an emulsion latex of an ethylene / α-olefin copolymer is obtained, and as described above, an organic peroxide and, if necessary, a multifunctional compound A cross-linking treatment is carried out by a method of adding an emulsion to obtain an emulsified latex of the cross-linked ethylene / α-olefin copolymer (A).
Next, after the latex of the crosslinked ethylene / α-olefin copolymer (A) was charged into a reaction vessel equipped with a stirring blade jacket, the monomer mixture (m1) was added with stirring, and the mixture was added at 40 to 90 ° C. for 5 to 60 ° C. Leave for a minute. Thereafter, the initiator is added. Here, the monomer mixture (m1) may be added all at once, or the whole amount may be added dropwise continuously. Alternatively, the monomer mixture (m1) may be added in several portions. At that time, the monomer mixture (m1) may be added all at once, or may be added dropwise continuously.
As a result, the added monomer mixture (m1) is impregnated into the crosslinked ethylene / α-olefin copolymer (A), polymerized in and on the crosslinked ethylene / α-olefin copolymer (A), and grafted. A polymer (B) is formed.

  The blending amount of the graft polymer (B) in the resin composition of the present invention is excellent in the color developability, impact resistance, and scratch resistance of the resin composition. When the total of the resin (C) and the methacrylic ester resin (D) described later is 100 parts by mass, it is 10 parts by mass or more and less than 30 parts by mass.

[Methacrylate resin (C)]
The methacrylate ester resin (C) is a resin obtained by polymerizing the monomer mixture (m2), and has a glass transition temperature of 135 ° C. or lower. The monomer mixture (m2) is a mixture of monomers including at least N-substituted maleimide or maleic anhydride, aromatic vinyl, and methacrylic acid ester as monomers.

  In this specification, the glass transition temperature is a value obtained by differential scanning calorimetry (DSC), and specifically, after raising the temperature from 35 ° C. to 250 ° C. at 10 ° C./min in a nitrogen atmosphere. , The glass transition temperature observed when cooled to 35 ° C. and heated again to 250 ° C. Hereinafter, the glass transition temperature may be referred to as Tg.

  The Tg of the methacrylic ester resin (C) is 135 ° C. or lower, preferably 110 to 134 ° C. When the Tg of the methacrylic ester resin (C) exceeds 135 ° C., the impact resistance of the resin composition and the molded product thereof is inferior, and the heat resistance tends to be inferior despite the high Tg. When the Tg of the methacrylic ester resin (C) is less than 110 ° C., the heat resistance of the resin composition or its molded product may be inferior.

  The N-substituted maleimide contained in the monomer mixture (m2) is not particularly limited. For example, N-methylmaleimide, N-ethylmaleimide, Nn-propylmaleimide, Ni-propylmaleimide, Nn N-cycloalkylmaleimide such as N-cyclohexylmaleimide; N-phenylmaleimide, N-alkyl-substituted phenylmaleimide, N-chlorophenylmaleimide and the like N- An aryl maleimide; N-aralkyl maleimide; etc. are mentioned, One or more types can be used. Among these, N-arylmaleimide is preferable and N-phenylmaleimide is particularly preferable because a resin composition and a molded article excellent in heat resistance and impact resistance can be easily obtained.

  The content of N-substituted maleimide or maleic anhydride in the monomer mixture (m2) is preferably 5 to 18% by mass. When the content of N-substituted maleimide or maleic anhydride is less than the above range, the heat resistance of the resin composition or molded product may be inferior. When the above range is exceeded, the Tg of the methacrylic ester resin (C) tends to exceed 135 ° C., and therefore the impact resistance of the resin composition or molded product tends to be inferior.

  The aromatic vinyl contained in the monomer mixture (m2) is not particularly limited, and one or more kinds of aromatic vinyls already exemplified in the description of the monomer mixture (m1) can be used.

  The content of the aromatic vinyl in the monomer mixture (m2) is 1 to 20% by mass, preferably 3 to 19% by mass. If the aromatic vinyl content is less than the above range, the reactivity between N-substituted maleimide or maleic anhydride and methacrylic acid ester tends to be poor. In that case, there is a possibility that industrial production concerns may arise due to a decrease in the yield of the methacrylic ester resin (C). When the content of the aromatic vinyl exceeds the above range, the scratch resistance and color developability of the resulting resin composition may not be sufficiently improved.

  Examples of the methacrylic acid ester contained in the monomer mixture (m2) include, for example, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, Examples include t-butyl methacrylate, amyl methacrylate, isoamyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, decyl methacrylate, lauryl methacrylate, cyclohexyl methacrylate, penzyl methacrylate, and phenyl methacrylate. More than seeds can be used. Among these, it is preferable to use at least one of methyl methacrylate and ethyl methacrylate since the heat resistance and impact resistance of the resin composition and molded product are more excellent.

  The content of the methacrylic acid ester in the monomer mixture (m2) is 62 to 94% by mass, preferably 63 to 92% by mass. When the content of the methacrylic acid ester is within the above range, the weather resistance, scratch resistance, and color developability of the resulting resin composition or molded product are more excellent.

  The monomer mixture (m2) may contain other monomers as necessary. Examples of the other monomer include vinyl cyanide such as acrylonitrile, and one or more kinds can be used.

  It does not restrict | limit especially as a manufacturing method of methacrylic ester resin (C), Well-known methods, such as emulsion polymerization, suspension polymerization, block polymerization, and solution polymerization, are mentioned. From the viewpoint of the heat resistance of the resin composition or molded product, suspension polymerization and bulk polymerization are preferred.

  The molecular weight of the methacrylic acid ester resin (C) is not particularly limited. However, since the moldability of the resin composition and the impact resistance of the resin composition and the molded article are increased, the mass average molecular weight is 50,000 to 300,000. It is preferable that

  The blending amount of the methacrylic ester resin (C) in the resin composition of the present invention is the sum of the graft polymer (B), the methacrylic ester resin (C), and the methacrylic ester resin (D) described later. When it is 100 parts by mass, it is 10 to 80 parts by mass, and preferably 20 to 70 parts by mass. When the blending amount of the methacrylic ester resin (C) is less than the above range, the heat resistance of the resin composition or the molded product is inferior, and when it exceeds the above range, the impact resistance of the resin composition or the molded product is inferior.

[Methacrylate resin (D)]
The methacrylic ester resin (D) is a resin obtained by polymerizing the monomer component (m3). A monomer component (m3) contains 95 mass% or more of methyl methacrylate, and contains another monomer in 5 mass% or less as needed. The methacrylic ester resin (D) does not correspond to the methacrylic ester resin (C).
When the content of methyl methacrylate in the monomer component (m3) is less than 95% by mass, the impact resistance and color developability of the resin composition or molded product are poor. In addition, the resistance to scratches caused by hard and sharp objects tends to decrease. The preferable content of methyl methacrylate in the monomer component (m3) is 97% by mass or more.

  Examples of the monomer included in the monomer mixture (m3) as necessary include aromatic vinyl and vinyl cyanide already exemplified in the description of the monomer mixture (m1), and description of the monomer mixture (m2). Examples include N-substituted maleimides and maleic anhydrides already exemplified in 1), and one or more of them can be used.

  The Tg of the methacrylic ester resin (D) is preferably 95 to 125 ° C, more preferably 105 to 120 ° C. When the Tg of the methacrylic ester resin (D) is in the above range, the impact resistance and heat resistance of the resin composition and the molded product are more excellent.

  It does not restrict | limit especially as a manufacturing method of methacrylic ester resin (D), Well-known methods, such as emulsion polymerization, suspension polymerization, block polymerization, and solution polymerization, are mentioned. From the viewpoint of the heat resistance of the resin composition or molded product, suspension polymerization and bulk polymerization are preferred.

  The molecular weight of the methacrylic ester resin (D) is not particularly limited, but the mass-average molecular weight is 50,000 to 300,000 because the moldability of the resin composition and the impact resistance of the resin composition and the molded product are increased. It is preferable that

  The blending amount of the methacrylic ester resin (D) in the resin composition of the present invention is the total of the above graft polymer (B), the above methacrylic ester resin (C) and the methacrylic ester resin (D) being 100. When it is set as a mass part, it is 10-80 mass parts, and it is preferable that it is 20-70 mass parts. When the amount of the methacrylic ester resin (D) is less than the above range, the impact resistance is inferior, and when it exceeds the above range, the heat resistance is inferior.

[Additive]
In addition to the graft polymer (B), the methacrylic ester resin (C), and the methacrylic ester resin (D), the resin composition of the present invention includes a resin as long as the physical properties of the resin composition and the molded product are not impaired. Other conventional additives such as lubricants, pigments, dyes, fillers (carbon black, silica, titanium oxide, etc.), heat-resistant agents, oxidative degradation inhibitors, weather resistance during production (mixing) and molding An agent, a release agent, a plasticizer, an antistatic agent and the like can be blended.

<Method for producing scratch-resistant thermoplastic resin composition>
The resin composition of the present invention can be produced by a known method using a known apparatus. For example, there is a melt mixing method as a general method, and examples of an apparatus used in this method include an extruder, a Banbury mixer, a roller, and a kneader. Either a batch type or a continuous type may be employed for mixing. Moreover, there is no restriction | limiting in particular in the mixing order of each component, etc., All the components should just be mixed uniformly.

<Molded product>
The molded product of the present invention is obtained by molding the above resin composition. Examples of the molding method include an injection molding method, an injection compression molding machine method, an extrusion method, a blow molding method, a vacuum molding method, a compressed air molding method, a calendar molding method, and an inflation molding method. Among these, the injection molding method and the injection compression molding method are preferable because they are excellent in mass productivity and a molded product with high dimensional accuracy can be obtained.
The molded product of the present invention is excellent in weather resistance, scratch resistance, color developability, impact resistance, and heat resistance, so it is suitable for products used in the field for a long period of time, especially automobile exterior parts. Can be used.

  EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated concretely, this invention is not limited to the following Example.

Measurement of each value in the following examples was performed as follows.
(1) Gel content and graft ratio were determined by the methods described above.
In the following examples, P in the above formula (2) is obtained by washing each of the graft copolymers (B1) to (B12) with methanol, then extracting with acetone, and separating the acetone-soluble matter with a centrifuge. It is a mass (g) after separating into acetone insolubles and vacuum drying the obtained acetone insolubles.
(2) Volume average particle diameter The volume average particle diameter was measured using "Nanotrack 150" manufactured by Nikkiso Co., Ltd.
(3) Glass transition temperature It was determined by differential scanning calorimetry (DSC). Specifically, the glass transition temperature observed when the sample was heated from 35 ° C. to 250 ° C. at a rate of 10 ° C./min in a nitrogen atmosphere, then cooled to 35 ° C., and again raised to 250 ° C. Asked.

[Production Example 1: Emulsified latex of crosslinked ethylene / α-olefin copolymer (A1)]
100 parts by mass of an ethylene / α-olefin copolymer (Mitsui Chemical Co., Ltd. “P-0275”: ethylene / propylene copolymer) and maleic anhydride modified polyethylene (Mitsui Chemicals Co., Ltd. “Mitsui High Wax 2203A” “) 20 parts by mass and 5 parts by mass of a surfactant (“ KS Soap ”manufactured by Kao Corporation) were added to a twin-screw extruder (screw diameter: 30 mm, L / D; 40, barrel temperature: 200 ° C.). It was supplied from the inlet and melt-kneaded. In addition, 0.7 parts by mass of a potassium hydroxide aqueous solution in which potassium hydroxide, which is a basic substance, is dissolved in water, is continuously press-fitted at 1.8 MPa from a supply port provided in the vent part of the twin-screw extruder. Then, it was melt kneaded in a twin screw extruder. The solid dispersion discharged from the tip of the twin-screw extruder is dispersed in 150 parts by mass of warm water and diluted to obtain an emulsion latex of an ethylene / α-olefin copolymer having a volume average particle size of 220 nm. Obtained.
0.7 parts by mass of t-butyl-cumyl peroxide and 1 part by mass of divinylbenzene are added at 135 ° C. with respect to 100 parts by mass in terms of solid content of the emulsion latex of the obtained ethylene / α-olefin copolymer. The mixture was reacted for 5 hours to obtain a crosslinked ethylene / α-olefin copolymer (A1) having a gel content of 48% by mass. The volume average particle diameter of the crosslinked ethylene / α-olefin copolymer (A1) was 220 nm.

[Production Example 2: Emulsion latex of crosslinked ethylene / α-olefin copolymer (A2)]
A cross-linked ethylene / α-olefin copolymer (A2) having a gel content of 55% by mass was obtained by reacting under the same conditions as in Production Example 1 except that 1.0 part by mass of t-butyl-cumyl peroxide was used. The volume average particle diameter of the crosslinked ethylene / α-olefin copolymer (A2) was 220 nm.

[Production Example 3: Emulsified Latex of Crosslinked Ethylene / α-Olefin Copolymer (A3)]
A cross-linked ethylene / α-olefin copolymer (A3) having a gel content of 68% by mass was obtained by reacting under the same conditions as in Production Example 1 except that 1.8 parts by mass of t-butyl-cumyl peroxide was used. The volume average particle diameter of the crosslinked ethylene / α-olefin copolymer (A3) was 220 nm.

[Production Example 4: Emulsified Latex of Crosslinked Ethylene / α-Olefin Copolymer (A4)]
A cross-linked ethylene / α-olefin copolymer (A4) having a gel content of 77 mass% was obtained by reacting under the same conditions as in Production Example 1 except that t-butyl-cumyl peroxide was 2.2 parts by mass. The volume average particle diameter of the crosslinked ethylene / α-olefin copolymer (A4) was 220 nm.

[Production Example 5: Emulsified latex of crosslinked ethylene / α-olefin copolymer (A5)]
A crosslinked ethylene / α-olefin copolymer (A5) having a gel content of 88% by mass was obtained by reacting under the same conditions as in Production Example 1 except that 2.7 parts by mass of t-butyl-cumyl peroxide was used. The volume average particle diameter of the crosslinked ethylene / α-olefin copolymer (A5) was 220 nm.

[Production Example 6: Emulsified latex of crosslinked ethylene / α-olefin copolymer (A6)]
The gel was reacted under the same conditions as in Production Example 1 except that 17 parts by weight of maleic anhydride-modified polyethylene, 4.3 parts by weight of surfactant, and 1.8 parts by weight of t-butyl-cumyl peroxide were used. A crosslinked ethylene / α-olefin copolymer (A6) having a content of 67% by mass was obtained. The volume average particle diameter of the crosslinked ethylene / α-olefin copolymer (A6) was 290 nm.

[Production Example 7: Emulsified latex of crosslinked ethylene / α-olefin copolymer (A7)]
The gel content ratio was reacted under the same conditions as in Production Example 1 except that 15 parts by mass of maleic anhydride-modified polyethylene, 4 parts by mass of surfactant, and 1.8 parts by mass of t-butyl-cumyl peroxide were used. A 67% by mass of a crosslinked ethylene / α-olefin copolymer (A7) was obtained. The volume average particle diameter of the crosslinked ethylene / α-olefin copolymer (A7) was 320 nm.

[Production Example 8: Graft polymer (B1)]
To 70 parts by mass (in terms of solid content) of an emulsified latex of a crosslinked ethylene / α-olefin copolymer (A1), 0.15 parts by mass of sodium pyrophosphate, 0.006 parts by mass of ferrous sulfate heptahydrate, and fructose 0 .35 parts by mass were charged, and the internal temperature was kept at 80 ° C. A monomer mixture (m1) consisting of 23 parts by mass of styrene and 7 parts by mass of acrylonitrile and 0.6 parts by mass of cumene hydroperoxide were simultaneously added dropwise to each of them over 140 minutes to polymerize. Went. During this time, the internal temperature was controlled to be constant at 80 ° C. After completion of dropping, the mixture was kept at 80 ° C. for 100 minutes and then cooled to complete graft polymerization. The reaction product latex was coagulated with an aqueous sulfuric acid solution, washed with water, and dried to obtain a graft polymer (B1). The graft ratio of the graft polymer (B1) was 29%.

[Production Example 9: Graft polymer (B2)]
The graft polymer (B2) was reacted under the same conditions as in Production Example 8 except that the crosslinked ethylene / α-olefin copolymer (A2) was used instead of the crosslinked ethylene / α-olefin copolymer (A1). ) The graft ratio of the graft polymer (B2) was 31%.

[Production Example 10: Graft polymer (B3)]
The graft polymer (B3) was reacted under the same conditions as in Production Example 8 except that the crosslinked ethylene / α-olefin copolymer (A3) was used instead of the crosslinked ethylene / α-olefin copolymer (A1). ) The graft ratio of the graft polymer (B3) was 32%.

[Production Example 11: Graft polymer (B4)]
The graft polymer (B4) was reacted under the same conditions as in Production Example 8 except that the crosslinked ethylene / α-olefin copolymer (A4) was used instead of the crosslinked ethylene / α-olefin copolymer (A1). ) The graft ratio of the graft polymer (B4) was 30%.

[Production Example 12: Graft polymer (B5)]
The graft polymer (B5) was reacted under the same conditions as in Production Example 8 except that the crosslinked ethylene / α-olefin copolymer (A5) was used instead of the crosslinked ethylene / α-olefin copolymer (A1). ) The graft ratio of the graft polymer (B5) was 29%.

[Production Example 13: Graft polymer (B6)]
Manufactured except that the cross-linked ethylene / α-olefin copolymer (A3) was used in place of the cross-linked ethylene / α-olefin copolymer (A1), and 24.3 parts by mass of styrene and 5.7 parts by mass of acrylonitrile were used. The reaction was conducted under the same conditions as in Example 8 to obtain a graft polymer (B6). The graft ratio of the graft polymer (B6) was 29%.

[Production Example 14: Graft polymer (B7)]
Manufactured except that the cross-linked ethylene / α-olefin copolymer (A3) was used in place of the cross-linked ethylene / α-olefin copolymer (A1), and 21.6 parts by mass of styrene and 8.4 parts by mass of acrylonitrile were used. The reaction was conducted under the same conditions as in Example 8 to obtain a graft polymer (B7). The graft ratio of the graft polymer (B7) was 29%.

[Production Example 15: Graft polymer (B8)]
Manufactured except that the cross-linked ethylene / α-olefin copolymer (A3) was used in place of the cross-linked ethylene / α-olefin copolymer (A1), and 20.4 parts by mass of styrene and 9.6 parts by mass of acrylonitrile were used. The reaction was carried out under the same conditions as in Example 8 to obtain a graft polymer (B8). The graft ratio of the graft polymer (B8) was 30%.

[Production Example 16: Graft polymer (B9)]
1 part by weight of disproportionated potassium rosinate and 0.03 part by weight of potassium hydroxide are added to 70 parts by weight (in terms of solid content) of an emulsified latex of polybutyl acrylate having a gel content of 84% and heated to 60 ° C. Then, 0.1 parts by mass of sodium pyrophosphate, 0.007 parts by mass of ferrous sulfate heptahydrate, and 0.3 parts by mass of fructose were charged, and the internal temperature was kept at 60 ° C. To this, a monomer mixture consisting of 23 parts by mass of styrene and 7 parts by mass of acrylonitrile and 0.5 parts by mass of cumene hydroperoxide were simultaneously added dropwise from another supply port over 120 minutes for polymerization. After completion of dropping, the mixture was kept at 70 ° C. for 100 minutes and then cooled to complete the graft polymerization. The latex of the reactive organism was coagulated with an aqueous sulfuric acid solution, washed with water, and dried to obtain a graft polymer (B9). The graft ratio of the graft polymer (B9) was 32%.

[Production Example 17: Graft polymer (B10)]
The graft polymer (B10) was reacted under the same conditions as in Production Example 8 except that the crosslinked ethylene / α-olefin copolymer (A6) was used instead of the crosslinked ethylene / α-olefin copolymer (A1). ) The graft ratio of the graft polymer (B10) was 29%.

[Production Example 18: Graft polymer (B11)]
The graft polymer (B11) was reacted under the same conditions as in Production Example 8 except that the crosslinked ethylene / α-olefin copolymer (A7) was used instead of the crosslinked ethylene / α-olefin copolymer (A1). ) The graft ratio of the graft polymer (B11) was 27%.

[Production Example 19: Graft polymer (B12)]
Similar to Production Example 8, except that the crosslinked ethylene / α-olefin copolymer (A3) was used instead of the crosslinked ethylene / α-olefin copolymer (A1) and the cumene hydroperoxide was changed to 0.4 parts by mass. The graft polymer (B12) was obtained by reacting under the following conditions. The graft ratio of the graft polymer (B12) was 24%.

[Production Example 20: Methacrylate resin (C1)]
In a pressure-resistant reaction vessel, a mixture of 150 parts by weight of distilled water, 8 parts by weight of N-phenylmaleimide, 3 parts by weight of styrene, 2 parts by weight of α-methylstyrene, and 87 parts by weight of methyl methacrylate as a monomer mixture (m2); 2,2′-Azobis (isobutyronitrile) 0.2 part by mass, n-octyl mercaptan 0.25 part by mass, polyvinyl alcohol 0.7 part by mass were charged, and the internal temperature was raised to 75 ° C. for 3 hours. Reaction was performed. Then, it heated up to 90 degreeC and reaction was completed by hold | maintaining for 60 minutes. The contents were washed with a centrifugal dehydrator, dehydrated repeatedly, and dried to obtain a methacrylic ester resin (C1). The methacrylate ester resin (C1) had a Tg of 121 ° C. and a mass average molecular weight of 91,000.

[Production Example 21: Methacrylate resin (C2)]
A methacrylic ester resin (C2) is reacted under the same conditions as in Production Example 20 except that 15 parts by mass of N-phenylmaleimide, 5 parts by mass of styrene, 5 parts by mass of α-methylstyrene, and 75 parts by mass of methyl methacrylate are used. Got. The methacrylate ester resin (C2) had a Tg of 133 ° C. and a weight average molecular weight of 89000.

[Production Example 22: Methacrylate resin (C3)]
A methacrylic ester resin (C3) is reacted under the same conditions as in Production Example 20 except that 20 parts by mass of N-phenylmaleimide, 7 parts by mass of styrene, 7 parts by mass of α-methylstyrene, and 66 parts by mass of methyl methacrylate are used. Got. The methacrylate ester resin (C3) had a Tg of 140 ° C. and a mass average molecular weight of 92,000.

[Methacrylate resin (C4)]
As the methacrylic ester resin (C4), “Polyimilex PML203” manufactured by Nippon Shokubai Co., Ltd., which is an N-phenylmaleimide / N-cyclohexylmaleimide / styrene / methyl methacrylate copolymer was used. The methacrylate ester resin (C4) had a Tg of 128 ° C. and a mass average molecular weight of 161,000.

[Methacrylate resin (C5)]
As the methacrylic ester resin (C5), “Delpet 980N” manufactured by Asahi Kasei Co., Ltd. which is a maleic anhydride / styrene / methyl methacrylate copolymer was used. The methacrylate ester resin (C5) had a Tg of 127 ° C. and a mass average molecular weight of 128,000.

[Production Example 23: Methacrylate resin (D1)]
In a pressure-resistant reaction vessel, 150 parts by mass of distilled water, a mixture of 99 parts by mass of methyl methacrylate and 1 part by mass of methyl acrylate as a monomer component (m3), and 2,2′-azobis (isobutyronitrile) 0. 2 parts by mass, 0.25 parts by mass of n-octyl mercaptan, 0.47 parts by mass of calcium hydroxyapatite, 0.003 parts by mass of potassium alkenyl succinate were added, the internal temperature was raised to 75 ° C., and the reaction was performed for 3 hours. went. Then, it heated up to 90 degreeC and reaction was completed by hold | maintaining for 60 minutes. The contents were washed with a centrifugal dehydrator, dehydrated repeatedly, and dried to obtain a methacrylic ester resin (D1). The methacrylate ester resin (D1) had a Tg of 98 ° C. and a mass average molecular weight of 75,000.

[Production Example 24: Methacrylate resin (D2)]
Instead of 99 parts by weight of methyl methacrylate and 1 part by weight of methyl acrylate, the reaction was conducted under the same conditions as in Production Example 23 except that 2 parts by weight of acrylonitrile, 7 parts by weight of styrene, and 91 parts by weight of methyl methacrylate were used. An acid ester resin (D2) was obtained. The methacrylate ester resin (D2) had a Tg of 103 ° C. and a weight average molecular weight of 79000.

[Production Example 25: Methacrylate resin (D3)]
Instead of 99 parts by weight of methyl methacrylate and 1 part by weight of methyl acrylate, the reaction was conducted under the same conditions as in Production Example 23 except that 7 parts by weight of acrylonitrile, 23 parts by weight of styrene, and 70 parts by weight of methyl methacrylate were used. An acid ester resin (D3) was obtained. The methacrylate ester resin (D3) had a Tg of 108 ° C. and a mass average molecular weight of 81,000.

<Examples 1-16, Comparative Examples 1-14>
Each component is mixed with the composition (parts by mass) shown in Tables 1 to 4, and melt-kneaded at 260 ° C. using a 28 mm twin screw extruder (“TEX-28V” manufactured by Nippon Steel Works), with pellet-like scratch resistance. A thermoplastic resin composition was obtained.
The molded article obtained by injection-molding the obtained scratch-resistant thermoplastic resin composition was evaluated for weather resistance, scratch resistance (pencil hardness, gauze wear), color development, impact resistance, and heat resistance by the following methods.
The evaluation results are shown in Tables 1 to 4.

[Weatherability]
100 parts by mass of the scratch-resistant thermoplastic resin composition was mixed with 0.8 parts by mass of carbon black and colored, and a 100 × 100 mm (thickness 2 mm) black colored plate (test piece) was injection molded. The black colored plate was treated with a sunshine weather meter (manufactured by Suga Test Instruments Co., Ltd.) for 1000 hours at a black panel temperature of 63 ° C. and a cycle condition of 60 minutes (rainfall 12 minutes). Then, the degree of discoloration (ΔE) before and after the treatment was measured with a color difference meter and evaluated.

[Pencil hardness]
Based on JIS K5600, the pencil hardness of the molded product (test piece) was measured at a load of 750 g. The higher the pencil hardness, the better the scratch resistance when scratched with a hard object. F or higher was accepted.

[Gauze wear]
As shown in FIG. 1, a rod-shaped jig 10 having a tip portion 11 formed in a substantially hemispherical shape was prepared, and the tip portion 11 was covered with a laminated sheet S in which eight sheets of gauze were stacked. And the front-end | tip part 11 with which the lamination sheet S was covered is made to contact with the surface of the molded article (test piece) M so that the rod-shaped jig | tool 10 may become a right angle, and this front-end | tip part 11 of the molded article M is contacted. The surface was slid in the horizontal direction (arrow direction in the figure) and reciprocated 100 times. At that time, the applied load was 1 kg. After reciprocating 100 times, scratches on the surface of the molded product M were visually observed and evaluated according to the following four stages.
The better the gauze wear, the better the scratch resistance when the surface of the molded product is wiped with work gloves, gauze or cloth, or when clothing is rubbed. “O” or higher was accepted.
◎: Scratches are scarce ○: Scratches are inconspicuous △: Scratches are prominent ×: Scratched scratches are noticeable when touched by hand

[Color development]
About the same black colored board (test piece) as what was used by evaluation of a weather resistance, L * was measured with the color difference meter. The lower L *, the more black and the better the color developability.

[Shock resistance]
In accordance with ISO test method 179, Charpy impact strength (KJ / m ² ) of 4 mm and V notch was measured at 23 ° C. and −30 ° C.

[Heat-resistant]
In accordance with ISO test method 75, the deflection temperature under load (° C.) was measured by the flat-wise method at 1.83 MPa, 4 mm.

As shown in Examples 1 to 16 in Tables 1 and 2, according to each example, the weather resistance, scratch resistance, color developability, impact resistance, heat resistance were excellent, and these characteristics were combined. A scratch-resistant thermoplastic resin composition and a molded article were obtained.
On the other hand, as shown in Tables 3 to 4, the resin composition and molded product obtained in each Comparative Example are insufficient in at least one of weather resistance, scratch resistance, color development, impact resistance, and heat resistance. Met.
That is, Comparative Example 1 is inferior in gauze wear (scratch resistance), color developability, and impact resistance because the gel content of the graft polymer (B1) is low. Comparative Example 2 is a graft polymer (B5). Due to the high gel content, the impact resistance was poor. In Comparative Example 3, the rubber component of the graft polymer (B9) is not cross-linked ethylene / α-olefin copolymer but polybutyl acrylate, so that gauze wear (scratch resistance), color development, and impact resistance are improved. inferior.
As shown in Comparative Examples 4 to 7, when one of the methacrylic ester resin (C) and the methacrylic ester resin (D) was not included, the impact resistance or heat resistance was poor.
In Comparative Example 8, since the Tg of the methacrylic ester resin (C3) was high, the impact resistance was inferior and the heat resistance was also inferior.
Comparative Example 9 is insufficient in heat resistance because the addition amount of the methacrylic ester resin (C2) is small, and Comparative Example 10 is impact resistant because the addition amount of the methacrylic ester resin (D1) is small. Was insufficient.
In Comparative Example 11, since the amount of the graft polymer (B3) added was small, the impact resistance was insufficient and the gauze wear (scratch resistance) was inferior. Since the comparative example 12 had much addition amount of the graft polymer (B3), pencil hardness (scratch resistance) was inferior.
Comparative Examples 13 and 14 were inferior in color developability and impact resistance due to the use of methacrylate ester resins (D2) and (D3) obtained from monomer components having a low methyl methacrylate content. .

Claims (2)

A monomer mixture (m1) containing aromatic vinyl and vinyl cyanide is graft-polymerized to a crosslinked ethylene / α-olefin copolymer (A) crosslinked so that the gel content is 50 to 85% by mass. Grafted polymer (B) 10 parts by weight or more and less than 30 parts by weight;
Methacrylate resin (C) 10 to 80 having a glass transition temperature of 135 ° C. or lower obtained by polymerizing a monomer mixture (m2) containing N-substituted maleimide or maleic anhydride, aromatic vinyl and methacrylic acid ester Part by mass;
10 to 80 parts by mass of a methacrylic ester resin (D) obtained by polymerizing a monomer component (m3) containing 95% by mass or more of methyl methacrylate (however, it does not correspond to the methacrylic ester resin (C));
Is a scratch-resistant thermoplastic resin composition (however, (B) + (C) + (D) = 100 parts by mass).   A molded article, wherein the scratch-resistant thermoplastic resin composition according to claim 1 is molded.

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