JP2000302936A - Thermoplastic resin composition excellent in scuff resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermoplastic resin composition and its molded product excellent in scuff resistance of the surface of the molded product, having low head injurity criteria(HIC) and further high heat distortion resistance and excellent in molding processability and appearance properties. SOLUTION: This resin composition comprises (A) 100 pts.wt. of a resin composition comprising (i) 5-65 pts.wt. of an acrylic ester-based copolymer having <=20 deg.C Tg and <=10 wt.% gel content, (ii) 15-80 pts.wt. of a styrene-based copolymer and (iii) 15-80 pts.wt. of a graft copolymer prepared by polymerizing (b) 90-10 pts.wt. of a monomer mixture in the presence of (a) 10-90 pts.wt. of a rubber polymer having 100-1,000 volume average particle diameter and having 10-70 wt.% graft ratio and (B) 0.01-50 pts.wt. of a methyl methacrylate-based copolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a thermoplastic resin having excellent resistance to scratches on the surface of a molded article, a low head impact index (HIC), high heat deformation resistance, and excellent moldability and appearance. It relates to a composition.

[0002]

2. Description of the Related Art Styrene resins, especially ABS resins, have excellent rigidity, impact resistance, heat deformation resistance, moldability, etc., and are therefore used for various miscellaneous goods, interior and exterior materials of automobiles, jar rice cookers, microwave ovens. , Housing for home appliances such as vacuum cleaners,
Housing for OA equipment such as parts, telephone, facsimile,
Widely used for parts.

In recent years, particularly in interior and exterior materials of automobiles, in addition to characteristics such as dimensional stability and surface appearance at high temperatures, characteristics relating to collision safety have been improved as seen in side collision regulations in the United States and other countries. Is desired. That is, as the interior / exterior resin material in the side collision control, a molded article has a low head impact index (HIC), a high impact resistance, a high heat deformation resistance, and an appearance (surface property). There is a demand for a resin having excellent moldability. Incidentally, the head impact index in FMVSS is defined as the maximum value of the integrated value of the acceleration change for a certain period of time.

[0004] Various studies have been made to satisfy these characteristics, but none of them has yet been obtained having sufficient characteristics.

For example, Japanese Patent Application Laid-Open No. 59-20346 discloses a method of adding a specific plasticizer to a rubber-reinforced styrenic resin. is not. The use of a polypropylene-based resin having a specific composition is also being studied, but has the drawback of poor surface appearance of the molded product due to sink, poor dimensional stability due to warping, and poor adhesion to other materials.

A composition of an ABS resin and an acrylate copolymer is disclosed in Japanese Patent Application Laid-Open No. Sho 58-17925.
No. 7 discloses a composition comprising a rubber-containing styrenic resin and an acrylic ester copolymer having a high gel content, and JP-A-63-17954 discloses a rubber-containing maleimide-styrene copolymer, an ABS resin and an acrylate ester. Although it is described that a composition comprising a base copolymer improves chemical resistance, these compositions have high HIC values, low impact resistance, poor surface appearance, and A desired resin having high low-temperature impact resistance, low HIC value, high heat deformation resistance, and excellent appearance (surface properties) and moldability has not been obtained.

Further, in the composition comprising a rubber-containing maleimide-styrene copolymer and an acrylate copolymer described in JP-A-10-204237, the HIC value, impact resistance, and appearance ( Although a resin having satisfactory surface properties is obtained, it has a drawback that the molded article surface has poor scratch resistance and surface hardness to be used as an interior / exterior material for automobiles.

[0008] Japanese Patent Application Laid-Open No. 10-306183 discloses ABS.
The improvement in chemical resistance by a composition comprising a resin and a methyl methacrylate copolymer is described, but the matrix is a styrene-acrylonitrile copolymer or a maleimide-styrene-acrylonitrile copolymer and an acrylic ester. No proposal has been found for a resin comprising a system copolymer.

[0009]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, has excellent molded article surface scratch resistance, has a low head impact index (HIC), has a high heat deformation resistance, and has a molding process. An object of the present invention is to provide a thermoplastic resin composition having excellent properties and appearance and a molded article thereof.

[0010]

[Means for Solving the Problems] Improving scratch resistance,
Low HIC value, high heat deformation resistance, moldability,
In order to improve the appearance (surface properties), it is necessary to add a methyl methacrylate-based copolymer to a composition comprising a rubber-containing maleimide and a styrene-based copolymer and an acrylate-based copolymer.

The present inventors have conducted intensive studies and found that low T
g, a styrene-based copolymer (b) and a graft copolymer (c) containing an acrylic ester copolymer (a) having a low gel content and an aromatic vinyl compound in an amount of 49 mol% or more.
By adding a methyl methacrylate-based copolymer (B) to the resin composition (A) consisting of
Low HIC value, high heat deformation resistance, moldability,
It has been found that the appearance (surface properties) is excellent, and the present invention has been achieved.

That is, the present invention relates to an acrylic ester of 40 to 95% by weight, a vinyl cyanide compound of 5 to 40% by weight, an aromatic vinyl compound of 55% by weight or less and a monomer copolymerizable therewith with 0 to 30% by weight. % (Total 100% by weight)
Has a Tg of 20 ° C. or less and a gel content of 1
0% by weight or less of acrylate copolymer (a) 5
To 65 parts by weight, 10 to 40% by weight of a vinyl cyanide compound, 60 to 90% by weight of a total of an aromatic vinyl compound or a maleimide monomer and an aromatic vinyl compound, and a monomer 0 to be copolymerizable therewith. Styrene-based copolymer (b) 15 to 80 obtained by polymerizing 30% by weight (total 100% by weight) and containing an aromatic vinyl compound in an amount of 49 mol% or more.
Diene rubber polymer, olefin rubber polymer, acrylic rubber polymer, or silicone rubber polymer (a) 1 having a weight part and a volume average particle diameter of 100 to 1000 nm
In the presence of 0 to 90 parts by weight, the aromatic vinyl compound 10
90% by weight, 10 to 90% by weight of a (meth) acrylate or vinyl cyanide compound, and 0 to 30% by weight of a monomer copolymerizable therewith (total 100% by weight) (b) A) a graft copolymer obtained by polymerizing 90 to 10 parts by weight and having a graft ratio of 10 to 70% by weight (c) 15 to 80 parts by weight ((a), (b) and (c) in total 100 parts by weight) ), And the reduced viscosity (30 ° C., N, N) of the methyl ethyl ketone soluble portion of the acrylate-based copolymer (a) and the styrene-based copolymer (b)
0.3 to 1.2 dl in a dimethylformamide solution)
/ G of the resin composition (A) in the range of 0.01 to 5 / g, and a methyl methacrylate (co) polymer (B) of 0.01 to 5 parts by weight.
A thermoplastic resin composition (Claim 1) comprising 0 parts by weight and having excellent scratch resistance, wherein a methyl methacrylate (co) polymer (B) is a monomer containing homopolymerized methyl methacrylate or containing methyl methacrylate as a main component. The thermoplastic resin composition having excellent scratch resistance according to claim 1, which is a homopolymer or a copolymer obtained by copolymerizing body components (claim 2), wherein the rubber polymer (a) is acrylic acid, 5 to 50% by weight of at least one unsaturated acid (c) among methacrylic acid, itaconic acid and crotonic acid, and at least one (meth) alkyl acrylate (d) 50 having 1 to 12 carbon atoms in the alkyl group. Rubber weight produced by a coagulation enlargement method using an acid group-containing latex (S) prepared by polymerizing 0 to 95% by weight and 0 to 40% of a monomer copolymerizable with (c) and (d). Coalescence The thermoplastic resin composition having excellent scratch resistance according to claim 1 or 2, wherein the rubber polymer content is 5 to 50% by weight in the resin (claim 3), and the acid group-containing latex (S) is At least one unsaturated acid of acrylic acid, methacrylic acid, itaconic acid and crotonic acid (c) 5 to 25% by weight, and at least one alkyl acrylate having an alkyl group having 1 to 12 carbon atoms (d) 5 to 30% by weight, alkyl group having 1 to 12 carbon atoms
At least one alkyl methacrylate (e) 80
To 20% by weight, an aromatic vinyl monomer copolymerizable with (c), (d), and (e), and / or a monomer having two or more polymerizable functional groups in a molecule, and Or a thermoplastic resin composition having excellent scratch resistance according to claim 3, wherein the latex is an acid group-containing latex prepared by polymerizing 0 to 40% of a vinyl cyanide compound. Polymer (a) and styrene copolymer (b)
However, after polymerizing 0 to 80% by weight of the styrene-based copolymer (b), the acrylate-based copolymer (a) is polymerized, and then 20 to 20% of the remaining styrene-based copolymer (b) is polymerized.
The thermoplastic resin composition having excellent scratch resistance according to claim 1, 2, or 3, which is a mixed polymer (d) for polymerizing 100 wt%.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The methyl methacrylate copolymer (B) of the present invention is a particularly important portion used for improving scratch resistance, and is a monomer component containing methyl methacrylate as a main component. Is a homopolymer or copolymer obtained by homopolymerization or copolymerization of

Preferably, Rockwell hardness (JIS
K7202) M50 or more, melt flow rate (JIS
K7210, 230 ° C, 3.8 kg / cm ² ) 0.1
-100 g / 10 min, more preferably Rockwell hardness M60 or more, melt flow rate 0.2-50 g / 1
0 minutes. If the Rockwell hardness is less than M50, the scratch resistance decreases, and if the melt flow rate is less than 0.1 g / 10 minutes, the workability decreases. If the melt flow rate exceeds 100 g / 10 minutes, the impact resistance decreases.

The monomer component contained in the methyl methacrylate copolymer (B) comprises methyl methacrylate and other copolymerizable monomers. As other copolymerizable monomers, (meth) acrylic acid esters, (meth) acrylic acid, aromatic vinyl compounds, vinyl cyanide compounds, maleimide compounds and the like are used as necessary. Of these, (meth) acrylates are preferred. These may be used alone or in combination of two or more.

Further, a rubber polymer may be contained. As the (meth) acrylate, methyl acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-
Ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate,
2-hydroxylethyl (meth) acrylate, glycidyl (meth) acrylate, cyclohexyl (meth) acrylate, butylcyclohexyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth)
Acrylate and the like. Among these, methyl acrylate, ethyl (meth) acrylate, butyl acrylate, 2-hydroxylethyl acrylate,
Butylcyclohexyl methacrylate is preferred from an industrial point of view. These may be used alone or in combination of two or more.

Examples of the vinyl cyanide compound include acrylonitrile and methacrylonitrile.

As the aromatic vinyl compound, styrene,
α-methylstyrene, p-methylstyrene, vinylnaphthalene, chlorostyrene, bromostyrene and the like. Examples of the maleimide compound include maleimide, N-cyclohexylmaleimide, and N-phenylmaleimide.

The acrylate copolymer (a) of the present invention is a portion used for lowering the HIC value and increasing the impact resistance.
95% by weight, preferably 5 in terms of HIC value and impact resistance.
0 to 90% by weight, more preferably 55 to 80% by weight, 5 to 40% by weight of the vinyl cyanide compound, preferably 5 to 30% by weight, more preferably 10 to 3% from the viewpoint of impact resistance.
0% by weight, 0 to 55% by weight of an aromatic vinyl compound, preferably 0 to 40% by weight, more preferably 2 to 35% by weight, and 0 to 35% by weight of a monomer copolymerizable therewith.
It is obtained by copolymerizing 30% by weight, preferably 0 to 20 parts by weight, more preferably 0 to 10 parts by weight (total 100% by weight).

When the content of the acrylate is less than 40% by weight, the HIC value is high, the impact resistance is low, and 95% by weight.
When it exceeds, the heat-resistant deformation property is low, and it is easy to peel off. If the content of the vinyl cyanide compound is less than 5% by weight, it is easy to peel off and the HIC value is high. If it exceeds 40% by weight, it is easy to peel off, the HIC value is high and the impact resistance is low. On the other hand, if the content of the aromatic vinyl compound exceeds 55% by weight, the impact resistance is low and the HIC value is high.

The T of the acrylate copolymer (a)
g (glass transition temperature) is at most 20 ° C, preferably at most 0 ° C, more preferably at most -10 ° C from the viewpoint of the HIC value. If it exceeds 20 ° C., the HIC value increases.

The gel content of the acrylate copolymer (a) [gel content is defined as methyl ethyl ketone, 2%
The solution was left at 23 ° C. for 24 hours, filtered through a 100-mesh wire gauze, and the filtration residue was dried. The value was expressed by (weight of filtration residue / original weight) × 100. ] Is 10% by weight or less, preferably 5% by weight or less, more preferably 3% by weight or less from the viewpoint of processability. If it exceeds 10% by weight, the moldability will be reduced.

Also, the reduced viscosity (30%) of the methyl ethyl ketone soluble portion of the acrylate copolymer (a)
C, in N, N-dimethylformamide solution)
-1.2 dl / g, preferably 0.4-1.0 dl / g
g, particularly preferably 0.45 to 0.9 dl / g. If it is less than 0.3 dl / g, the impact resistance becomes 1.2 dl / g.
If it exceeds g, the workability will decrease.

As the acrylate, methyl acrylate, ethyl acrylate, butyl acrylate,
Examples thereof include 2-ethylhexyl acrylate, lauryl acrylate, stearyl acrylate, 2-hydroxylethyl acrylate, and glycidyl acrylate. Of these, butyl acrylate is preferred from an industrial point of view. These may be used alone or in combination of two or more.

Examples of the vinyl cyanide compound include acrylonitrile and methacrylonitrile. Among them, acrylonitrile is preferable from an industrial viewpoint. These may be used alone or in combination of two or more.

As the aromatic vinyl compound, styrene,
Examples thereof include α-methylstyrene, p-methylstyrene, vinylnaphthalene, chlorostyrene, and bromostyrene, and among these, styrene is preferable from an industrial viewpoint. However, these are used alone or in combination of two or more.

Examples of the monomer copolymerizable with the compound include acrylic acid, methacrylic acid, maleimide,
N-phenylmaleimide and the like can be mentioned.

The styrenic copolymer (b) of the present invention contains 10 to 40% by weight, preferably 15% by weight of a vinyl cyanide compound.
35 to 35% by weight, and a total of 60 to 90% by weight of the aromatic vinyl compound or the maleimide monomer and the aromatic vinyl compound,
It preferably comprises 65 to 85% by weight and 0 to 30% by weight, preferably 0 to 20% by weight (total 100% by weight) of monomers copolymerizable therewith, and contains at least 49% by mole of an aromatic vinyl compound. Is a copolymer obtained by polymerizing a monomer mixture.

In the styrenic copolymer (b), if the vinyl cyanide compound is less than 10% by weight, the impact resistance becomes poor.
If the amount exceeds 40% by weight, the processability becomes insufficient. If the total amount of the aromatic vinyl compound or the maleimide monomer and the aromatic vinyl compound is less than 60% by weight, the heat resistance becomes high. Each falls.

The proportion of the aromatic vinyl compound in the monomer mixture is particularly important, and the content in the monomer mixture is at least 49 mol%, preferably at least 50 mol%. If the ratio of the aromatic vinyl compound is less than 49 mol%, the thermal stability, impact resistance, and mold stain resistance are significantly reduced.

The reduced viscosity of the styrene copolymer (b) is as follows:
From the viewpoint of impact resistance, moldability, and especially appearance, the reduced viscosity of the methyl ethyl ketone-soluble component (30 ° C., in N, N-dimethylformamide solution) is 0.3 to 1.2 dl / g, and more preferably 0. 0.35 to 1.0 dl / g, particularly preferably 0.40 to 0.9 dl / g. If the reduced viscosity of the styrenic copolymer (b) is less than 0.3 dl / g, the impact resistance will be reduced, and if it exceeds 1.2 dl / g, the moldability will be reduced.

Acrylonitrile, methacrylonitrile and the like are used as the vinyl cyanide compound of the styrene copolymer (b) used in the present invention, and styrene, α-methylstyrene and p-methylstyrene are used as the aromatic vinyl compounds. , P-isopropylstyrene, chlorostyrene,
Bromostyrene, vinyl naphthalene, and the like, as maleimide monomers, maleimide, N-methylmaleimide,
N-ethylmaleimide, N-propylmaleimide, N-
Butylmaleimide, N-phenylmaleimide, N- (p
-Methylphenyl) maleimide and the like. From an industrial standpoint, acrylonitrile is particularly preferred as the vinyl cyanide compound, styrene as the aromatic vinyl compound, and N-phenylmaleimide as the maleimide monomer. These are used alone or in combination of two or more. Examples of the copolymerizable monomer include (meth) acrylic acid and its methyl, ethyl, propyl, butyl,
(Meth) acrylate monomers such as hydroxylethyl, 2-ethylhexyl and glycidyl. These may be used alone or in combination of two or more.

The graft copolymer (C) of the present invention must be compatible with the styrene copolymer and the acrylate copolymer, and is used for improving the HIC value and the impact resistance. .

The rubber polymer (a) in the graft copolymer (c) has a volume average particle size of 100 to 1000 nm, preferably 100 to 900 nm, more preferably 150 to 8 nm.
One or more rubber polymers of a 00 nm diene rubber polymer, olefin rubber polymer, acrylic rubber polymer, and silicone rubber polymer.

When the volume average particle size of the rubber polymer (a) of the graft copolymer (c) is less than 100 nm, the impact resistance tends to decrease, and when it exceeds 1000 nm, the impact resistance decreases. descend.

The rubber polymer (a) may be a mixture of two or more kinds having different volume average particle diameters.

Specific examples of the rubber polymer (a) include diene rubber polymers such as polybutadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, butadiene-acrylate rubber, hydrogenated styrene-butadiene rubber, and ethylene. -Propylene rubber, olefin polymers such as ethylene-propylene-diene rubber, polyacrylate rubber, acrylic rubber polymers such as ethylene-acrylate rubber, silicone rubber,
Examples thereof include silicone rubber polymers such as silicone-acrylate rubber, which are used alone or in combination of two or more. In particular, when weather resistance is required, acrylic rubber polymers and silicone rubber polymers are preferred.

The rubber polymer (a) is preferably produced by an enlargement method using an acid group-containing latex (S).

The rubber polymer (a) contains at least one of acrylic acid, methacrylic acid, itaconic acid and crotonic acid.
5 to 50% by weight of at least one unsaturated acid (c), 50 to 95% by weight of at least one (meth) alkyl acrylate having 1 to 12 carbon atoms in the alkyl group, and (c), (d)
A rubber polymer produced by a coagulation enlargement method using an acid group-containing latex (S) prepared by polymerizing 0 to 40% of a monomer copolymerizable with acrylic acid, methacrylic acid, itacone Acid, at least one unsaturated acid (c) of crotonic acid in an amount of 5 to 25% by weight,
5 to 30% by weight of at least one alkyl acrylate (d) having 1 to 12 carbon atoms in the alkyl group, 80 to 20% by weight of at least one alkyl methacrylate (e) having 1 to 12 carbon atoms in the alkyl group, (C), (d),
An aromatic vinyl monomer copolymerizable with (e), and / or
Manufactured by a coagulation enlargement method using a monomer having two or more polymerizable functional groups in a molecule and / or an acid group-containing latex (S) prepared by polymerizing 0 to 40% of a vinyl cyanide compound. Preferred are rubber polymers. When an acid group-containing latex is to be used, the amount of the latex is 0.1 to 100 parts by weight (solid content) of the rubber latex.
5 to 10 parts (based on solid content).

The graft copolymer (c) of the present invention can be prepared by adding an aromatic vinyl compound 10 to 90 in the presence of a rubber polymer (a).
%, Preferably 15 to 85% by weight, more preferably 20 to 80% by weight, at least one of (meth) acrylic acid ester and vinyl cyanide compound, 10 to 90% by weight, preferably 15 to 85% by weight, furthermore Preferably 20 to 80% by weight, and 0 to 30% by weight of a monomer copolymerizable therewith;
The monomer mixture (b) preferably comprises 0 to 20% by weight, more preferably 0 to 15% by weight (total 100% by weight).
Is a graft copolymer having a graft ratio of 10 to 70% by weight, preferably 20 to 70% by weight, and more preferably 25 to 65% by weight. If the amount and the graft ratio of the (meth) acrylate, vinyl cyanide compound or aromatic vinyl compound are out of the above ranges, HIC
Values, surface cracks at impact, and appearance (surface properties) tend to decrease.

Examples of the (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, and glycidyl (meth) acrylate. A) acrylate and the like. Of these, methyl methacrylate is preferred from an industrial point of view. These can be used alone or 2
Used in combination of more than one species.

Examples of the vinyl cyanide compound include acrylonitrile and methacrylonitrile, and examples of the aromatic vinyl compound include styrene, α-methylstyrene, p-methylstyrene, p-isopropylstyrene, chlorostyrene, bromostyrene, and vinylnaphthalene. Etc. are given,
From an industrial viewpoint, acrylonitrile is particularly preferred as the vinyl cyanide compound, and styrene is particularly preferred as the aromatic vinyl compound. These may be used alone or in combination of two or more. Examples of the copolymerizable monomer include (meth) acrylic acid, maleimide, N-phenylmaleimide, and the like. These may be one kind or two or more kinds.

The graft copolymer (c) has a rubber polymer (a) content of 10 to 90 parts by weight, preferably 20 to 85 parts by weight, in view of the HIC value, surface cracking upon impact, and appearance (surface properties). More preferably, 30 to 80 parts by weight, 10 to 90 parts by weight, preferably 15 to 80 parts by weight, more preferably 20 to 70 parts by weight of the monomer mixture (b) are polymerized.

The thermoplastic resin composition of the present invention contains 5 to 65 parts by weight, preferably 10 to 60 parts by weight, more preferably 15 to 60 parts by weight of an acrylate copolymer (a), 15-80 parts by weight, preferably 15-75 parts by weight, more preferably 20-70 parts by weight, graft copolymer (c) 15-80 parts by weight, preferably 15-75 parts by weight, more preferably Is a resin composition (A) 1 comprising 20 to 70 parts by weight (100 parts by weight in total)
0.01 to 50 parts by weight, preferably 0.05 to 2 parts by weight, of the methyl methacrylate copolymer (B) with respect to 00 parts by weight.
5 parts by weight, more preferably 0.1 to 10 parts by weight.

The acrylate-based copolymer (a) is 5
When the amount is less than 65 parts by weight, the HIC value increases, and when the amount exceeds 65 parts by weight, heat resistance and appearance deteriorate. If the styrene-based copolymer (b) exceeds 80 parts by weight, the HIC value increases,
If the amount is less than 5 parts by weight, heat resistance will be reduced. When the amount of the graft copolymer (c) is less than 15 parts by weight, the HIC value increases, and the surface cracking property upon impact decreases. When the amount exceeds 80 parts by weight, heat resistance and appearance are deteriorated.

Methyl methacrylate copolymer (B)
If the amount is less than 0.01 part by weight, the scratch resistance is reduced, and if it exceeds 50 parts by weight, the HIC value is undesirably high.

If a composition falling within the range of the present invention is obtained, an acrylic ester-based copolymer (a), a styrene-based copolymer (b), a graft copolymer (c), and a methyl methacrylate-based copolymer (c) B) may be produced using any polymerization method, initiator, chain transfer agent, or surfactant. For example, known bulk polymerization, solution polymerization,
Any one produced by any polymerization method such as a suspension polymerization method, an emulsion polymerization method, an emulsion-suspension polymerization method, and an emulsion-bulk polymerization method may be used as long as the composition can be controlled within the range of the present invention.

The acrylate-based copolymer (a) and the styrene-based copolymer (b) can be used for styrene-based copolymers because of their production stability (generation of scale and control of adhesion to a polymerization machine) and microphase separation. After polymerizing 0 to 80% by weight of the polymer (b), the acrylate copolymer (a) is polymerized, and then 20 to 100% of the remaining styrene copolymer (b).
The mixed polymer to be polymerized by weight% is referred to as (d). By this production method, generation of scale derived from the acrylate-based copolymer (a) and adhesion to the polymerization machine can be controlled.
The initial styrenic copolymer (b) is 0 to 80% by weight, preferably 1 to 50% by weight, more preferably 2 to 30% by weight, and the late styrenic copolymer (b) is 20 to 100% by weight.
%, Preferably 50 to 99% by weight, more preferably 70 to 98% by weight. Furthermore, from an industrial point of view,
Emulsion polymerization is preferred.

The graft copolymer (c) is preferably an emulsion polymerization method because the graft ratio can be easily controlled.

Further, as long as it is within the scope of the present invention, any one produced using any initiator, chain transfer agent or emulsifier may be used. Known initiators such as a thermal decomposition initiator such as potassium persulfate and a redox initiator such as Fe-reducing agent-organic peroxide can be used as the initiator. Known chain transfer agents such as t-dodecyl mercaptan, n-dodecyl mercaptan, α-methylstyrene dimer and terpinolene can be used. Examples of the emulsifier include fatty acid metal salt-based emulsifiers such as sodium oleate, sodium palmitate, and sodium rosinate, sodium dodecylbenzenesulfonate, and having 12 to 12 carbon atoms.
Known emulsifiers such as a sulfonic acid metal salt-based emulsifier such as sodium alkyl sulfonate 20 and sodium dioctyl sulfosuccinate can be used. In the thermoplastic resin composition used in the present invention, well-known antioxidants, heat stabilizers, UV absorbers, pigments, antistatic agents, and lubricants can be appropriately used as needed. In particular, phenol-based, sulfur-based, phosphorus-based, hindered amine-based stabilizers, antioxidants, benzophenone-based, benzotriazole-based ultraviolet absorbers and organopolysiloxanes, aliphatic hydrocarbons, and higher fatty acids used in styrene resins. Internal lubricants and external lubricants such as esters of higher alcohols, amides or bisamides of higher fatty acids and modified products thereof, oligoamides, metal salts of higher fatty acids, etc. can be used as molding resins for higher performance. .

These stabilizers and the like can be used alone or in combination of two or more.

The thermoplastic resin composition of the present invention may further comprise another styrene resin, for example, acrylonitrile-styrene copolymer, acrylonitrile-styrene-α-methylstyrene copolymer, acrylonitrile-α-methylstyrene copolymer Styrene-maleimide copolymer, styrene-maleic anhydride copolymer and the like can be mixed at 50% by weight or less, preferably at 40% by weight or less, to adjust the desired performance.

Further, it is also possible to mix polycarbonate resin, polyvinyl chloride resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyamide resin and the like.

The resin or resin mixture of the acrylate-based copolymer (a), the styrene-based copolymer (b), the graft copolymer (c), and the methyl methacrylate-based copolymer (B) is prepared by a method for producing the same. For example, they can be manufactured by mixing these in the form of latex, slurry, solution, powder, pellets, or the like, or a combination thereof. For example, when polymer powder is recovered from the latex of the acrylate-based copolymer (a), the latex of the styrene-based copolymer (b) and / or the latex of the graft copolymer (c) after polymerization, a usual method is used. For example, alkaline earth metal salts such as calcium chloride, magnesium chloride, magnesium sulfate, alkali metal salts such as sodium chloride, sodium sulfate, inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, and organic latex After coagulating the latex by adding an acid, the latex can be dehydrated and dried. Also, a spray drying method can be used.

A part of the amount of the stabilizer used may be added in the form of a dispersion to a latex or slurry of these resins.

The method of kneading the thermoplastic resin composition used in the present invention is not particularly limited, and may be a known technique, for example, an acrylate copolymer (a), a styrene copolymer ( B) a graft copolymer (c), a powder or pellet comprising a methyl methacrylate copolymer (B) alone or a mixture of two or more of these;
Mix the above stabilizer, if necessary, lubricant, pigment, etc., and mix with Henschel mixer, tumbler, blender, etc.,
Kneading can be carried out using a known melt kneader such as a Banbury mixer, a roll mill, a kneader, a single screw extruder, a twin screw extruder, or the like. There is no particular limitation on the kneading order.

The thermoplastic resin composition of the present invention can be molded by a known molding method such as injection molding, extrusion molding, blow molding, compression molding, calender molding, and vacuum molding.

Hereinafter, the present invention will be described with reference to specific examples.
These examples do not limit the invention. In the examples, "parts" indicates parts by weight, and "%" indicates% by weight.

[0059]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Production of mixed copolymer (d), acrylate-based copolymer (a) and styrene-based copolymer (b) a) Production of mixed copolymer (d-1) Stirrer, reflux condenser, nitrogen introduction 250 parts of pure water, 1.0 part of sodium dioctylsulfosuccinate, 0.5 part of sodium formaldehyde sulfoxylate, EDTA in a reactor equipped with an inlet, a monomer inlet, and a thermometer.
0.01 parts and 0.0025 parts of ferrous sulfate were charged.

The reactor was stirred at 65 ° C. under a nitrogen stream.
Temperature. After reaching 65 ° C., the first-stage monomer mixture <PMI 1.5 parts, AN 2.4 parts, St 3.1
Parts, αMSt 3.0 parts (the amount of aromatic vinyl in the monomer mixture is 50 mol%), tDM 0.035 parts, CHP
0.03 parts> was continuously dropped in one hour, and after the dropping,
Stirring was continued at 65 ° C. for 1 hour. Thereafter, 0.5 parts of sodium dioctyl sulfosuccinate was added, and the second-stage monomer mixture <30.4 parts of BA, 4.8 parts of AN, St
4.8 parts, tDM 0.14 parts, CHP 0.12 parts>
Was continuously added dropwise over 4 hours. After dropping, add 1
Stirring was continued for hours. Further, 0.5 part of sodium dioctyl sulfosuccinate was added, and the third-stage monomer mixture <P
MI 7.5 parts, AN 12.0 parts, St 15.5
Parts, αMSt 15.0 parts (the amount of aromatic vinyl in the monomer mixture is 50 mol%), tDM 0.175 parts, CHP
0.15 parts> was continuously dropped in 5 hours. After completion of the dropwise addition, stirring was continued at 65 ° C. for 1 hour to terminate the polymerization, thereby producing a composite copolymer (d-1). Table 1 shows the results. b) Production of mixed copolymer (d-2-4) In the same manner as mixed copolymer (d-1), mixed copolymer (d-2-4) was obtained as a monomer mixture shown in Table 1. ) Manufactured. c) Production of acrylic ester-based copolymer (a-1 to 2) In the same manner as for mixed copolymer (d-1), an acrylic ester-based copolymer was obtained as a monomer mixture shown in Table 2. (A-1 and 2) were produced. d) Production of styrenic copolymer (b-1) In the same manner as mixed copolymer (d-1), styrene-based copolymer (b-1) was obtained as a monomer mixture shown in Table 3. ~ 2)
Was manufactured.

[0061]

[Table 1]

[0062]

[Table 2]

[0063]

[Table 3] (2) Production of Rubber Polymer (a) a) Production of Rubber Polymer (a-1) As a first step, an acrylate rubber polymer (a
An unexpanded rubber polymer (R-1) required for enlarging to -1) was produced. A reactor equipped with a stirrer, a reflux condenser, a nitrogen inlet, a monomer inlet, and a thermometer was charged with 200 parts of pure water and 0.55 part of sodium palmitate. The reactor was heated to 60 ° C. under a nitrogen stream while stirring. After the temperature was raised, 0.3 part of sodium formaldehyde sulfoxylate, 0.0025 part of ferrous sulfate, and 0.01 part of disodium ethylenediaminetetraacetate were charged. Further, 98.5 parts of BA, 1.5 parts of TAC, CHP
0.3 parts of the monomer mixture was added dropwise over 6 hours, and after completion of the addition, stirring was continued at 60 ° C. for 1 hour to complete the polymerization. At 1.5 hours after dropping the monomer mixture, 0.3 parts of sodium palmitate was added, and at 4 hours after dropping, 0.35 parts of sodium palmitate was added. The polymerization conversion was 98%, and the particle size of the unexpanded rubber polymer (R-1) was 92 nm.

In the second step, the unexpanded rubber polymer (R-
An acid group-containing latex (S) necessary for enlarging the rubber polymer (a-1) from 1) was produced as follows.

A reactor equipped with a stirrer, a reflux condenser, a nitrogen inlet, a monomer inlet, and a thermometer was charged with 200 pure water.
Part, sodium dioctyl sulfosuccinate 0.6 part,
Sodium formaldehyde sulfoxylate 0.5
Parts, 0.01 parts of sodium ethylenediaminetetraacetate,
0.0025 part of ferrous sulfate was charged.

The reactor was stirred at 70 ° C. under a nitrogen stream.
Temperature. After reaching 70 ° C, 25 parts of BMA, B
A 5 parts, a monomer mixture of 0.1 parts of tDM and 0.15 parts of CHP were added dropwise over 2 hours, and then BMA 50
Part, BA 4 part, MAA 16 part, tDM 0.5 part,
0.15 parts of CHP was added dropwise over 4 hours. After completion of the addition, stirring was continued at 70 ° C. for 1 hour to terminate the polymerization, thereby obtaining an acid group-containing latex (S-1). The polymerization conversion was 98%.

In the third step, an acrylic ester-based rubber polymer (a-1) was produced by using the previously produced unexpanded rubber polymer (R-1) and the acid group-containing latex (S-1). did. Latex 1 of unexpanded rubber polymer (R-1)
2. An acid group-containing latex (S-1) is added to 00 parts (solid content).
After adding 5 parts (solid content) at 60 ° C., stirring was continued for 1 hour to enlarge the product, thereby producing a rubber polymer (a-1). The particle size of the rubber polymer (a-1) was 350 nm. b) Production of Rubber Polymer (a-2) As a first step, an unexpanded rubber polymer (R-2) necessary for enlarging the rubber polymer (a-2) was produced.

A 100 L polymerization machine was charged with 230 parts of pure water, 0.2 parts of potassium persulfate and 0.2 parts of tDM.

After removing the air in the polymerization machine with a vacuum pump,
0.6 part of sodium oleate, 2 parts of sodium rosinate and 100 parts of butadiene were charged.

The temperature of the system was raised to 60 ° C. to initiate polymerization. The polymerization was completed in 25 hours. 96% polymerization conversion,
The particle size of the unexpanded rubber polymer (R-2) was 85 nm.

In the second step, the unpolymerized rubber polymers (R-1) and (R-2) prepared above and the acid group-containing latex (S-1) were used to prepare the rubber polymer (a-2) Was manufactured. 2. 75 parts (solid content) of latex of the unexpanded rubber polymer (R-1) and 25 parts (solid content) of the latex of the unexpanded rubber polymer (R-2);
After adding 5 parts (solid content) at 60 ° C., stirring was continued for 1 hour to enlarge the rubber, thereby producing a rubber polymer (a-2). The particle size of the rubber polymer (a-2) was 450 nm. (3) Production of Graft Copolymer (C) a) Production of Graft Copolymer (C-1) Pure water was placed in a reactor equipped with a stirrer, reflux condenser, nitrogen inlet, monomer inlet, and thermometer. Water 280 parts, rubber polymer (a-1) (solid content) 65 parts, sodium formaldehyde sulfoxylate 0.3 part, EDTA 0.
01 parts and 0.0025 parts of ferrous sulfate were charged.

The reactor was stirred at 60 ° C. under a nitrogen stream.
Temperature. After reaching 60 ° C, 10 parts of AN, St
A mixture of 10 parts, 15 parts of MMA and 0.2 parts of CHP was dropped continuously over 5 hours. After completion of the dropwise addition, stirring was continued at 60 ° C. for 2 hours to terminate the polymerization, and the graft polymer (C
1) was obtained. Table 4 shows the results. b) Production of graft copolymer (c-2) In the same manner as for graft copolymer (c-1), rubber polymer (a-2) was used instead of rubber polymer (a-1). To produce a graft copolymer (C-2). c) Production of Graft Copolymer (C-3) In the same manner as in the graft copolymer (C-1), the above unexpanded rubber polymer (R-1) (particle size: 92 nm) was used.
A graft copolymer (C-3) was produced.

[0073]

[Table 4] (4) Production of thermoplastic resin composition Latex of acrylic ester copolymer (a), styrene copolymer (b) and / or mixed copolymer (d) produced in (1) and (3) The latex of the graft copolymer (c) produced in (1) was mixed at a predetermined ratio shown in Table 5, a phenolic antioxidant was added, and calcium chloride was added to coagulate. The solidified slurry was heat-treated, dehydrated and dried to obtain a powder of the mixed resin composition (A) of (A), (B), (C) and (D). A predetermined amount of the methyl methacrylate copolymer (B) shown below was mixed with 1 part of ethylenebisstearylamide as shown in Table 5, and 20 parts of Tabata Co., Ltd.
Blended uniformly in an L blender. Further, the mixture was melt-kneaded at 240 ° C. with a 40 m / m single screw extruder manufactured by Tabata Co., Ltd. to produce pellets of a thermoplastic resin composition. (Examples -1 to 10 and Comparative Examples 1 to 6) [Methyl methacrylate-based copolymer (B)] (B-1) Commercially available polymethacrylic resin (PMMA): Sumipex EX (Sumitomo Chemical) Rockwell hardness M10
0, melt flow rate (230 ° C, 3.8 kg / cm
² ) 1.5 g / 10 min (catalog value).

(B-2) Commercially available polymethacrylic resin (P
MMA): Sumipex LG6 (Sumitomo Chemical) Rockwell hardness M88, melt flow rate (230 ° C, 3.
8 kg / cm ² ) 20 g / 10 min (catalog value). [Calculation of Tg (Glass Transition Temperature)] The Tg of the acrylate copolymer (a) is the Tg of the homopolymer of each component.
g (described in Polymer Handbook) using the Fox equation. [Measurement of Gel Content] Calcium chloride was added to the latex of the acrylate copolymer (a) to coagulate it. The resin powder obtained by heat treatment, dehydration and drying of the coagulated slurry was converted into a 2% methyl ethyl ketone solution,
The mixture was left for a while, filtered through a 100-mesh wire gauze, and the residue was dried and measured. (Filtration residue weight / original weight) x 1
Represented by 00. [Measurement of Reduced Viscosity] Calcium chloride was added to the latex of the acrylate-based copolymer (a), the styrene-based copolymer (b), and the mixed copolymer (d) to coagulate. The reduced viscosity was measured at 30 ° C. as a 0.3 g / dl N, N-dimethylformamide solution of a resin powder obtained by subjecting the coagulated slurry to heat treatment and dehydration drying. [Graft Ratio of Graft Copolymer] The powder of the graft copolymer (C) was dissolved in methyl ethyl ketone,
The mixture was centrifuged to obtain a soluble portion and an insoluble portion of methyl ethyl ketone. The graft ratio was specified from the ratio of the insoluble component to the soluble component. [Particle Size of Rubber Polymer] The rubber polymer (a) latex was measured using a Nicomp particle size analyzer manufactured by Pacific Science Co., Ltd. [Conversion rate during polymerization] The conversion rate during polymerization was calculated from the solid content concentration. [Scale Amount at the Time of Polymerization] A latex of an acrylate copolymer (a), a styrene copolymer (b), and a mixed copolymer (d) was filtered through a 100-mesh sieve,
The scale amount was specified from the ratio between the remaining scale amount (dried) and the charged amount. [Scale attached state at the time of polymerization] It was confirmed that the scale attached to the reactor was easily peeled off with a finger. Those that were easy to peel were evaluated as ○ (good), those that hardly peeled were evaluated as Δ, and those that hardly peeled were evaluated as x (bad). [Characteristics of thermoplastic resin composition] The scratch resistance was evaluated by pencil hardness. Pencil hardness is JISK on No. 1 dumbbell surface
Using a method of a pencil scratch value of -5400, evaluation was made on the presence or absence of scratches on the molded product surface (unit: concentration symbol of pencil).

The hardness was evaluated on a Rockwell hardness R scale. Rockwell hardness R is JIS K-7202
It was measured at 23 ° C. according to the standard (1/4 inch thickness) method (unit: none).

The HIC value (index) is determined by measuring the vertical ribs 2 and the horizontal ribs 3 inside the main body 1 having a substantially C-shaped cross section as shown in FIGS.
Pillar cover for automobiles, the unit of numbers in the figure is m
m) at a speed of 24 km / Hr at 4.2 kg (heart R = 8
(2.5 mm) was applied and a change in acceleration-time was measured and calculated.

Further, the presence or absence of cracks on the top surface of the molded body after the test was evaluated by ○ (absent) and × (existent).

The impact resistance was evaluated by IZOD impact strength. The IZOD impact strength is based on the ASTM D-256 standard (1
/ 4 inch thickness) at 23 ° C. (unit: kgcm / cm).

The tensile strength (unit: kg / cm ² ) and tensile elongation (unit:%) were evaluated using a No. 1 dumbbell according to ASTM D638 standard, at 23 ° C. and a tensile speed of 2 m / sec.

Heat resistance (HDT) is as per ASTM D648
Of 18.6 kg / cm ² load.
(Unit: ° C) The test pieces used for the pencil hardness, hardness, IZOD impact strength, tensile strength, tensile elongation, and heat resistance described above were molded at a cylinder temperature of 250 ° C using a FAS100B injection molding machine manufactured by FANUC Corporation. And subjected to evaluation. (Comparative Examples 2 and 6 were molded at 210 ° C.) The fluidity was measured using a FAS100B injection molding machine manufactured by Fanuc Co., Ltd., at a cylinder temperature of 250 ° C. and an injection pressure of 135.
The flow length (unit: mm) of the resin in a spiral mold having a thickness of 3 mm at 0 kg / cm ² was evaluated.

The appearance of the molded article is shown in FIG. 1 and FIG. 2 (an automobile pillar cover in which a vertical rib 2 and a horizontal rib 3 are provided inside a main body 1 having a substantially C-shaped cross section; Is m
m) Color unevenness, flow mark visually, ○ (good), △
(Slightly poor) and x (bad) were evaluated.

[0082]

From the results in Table 6, the thermoplastic resin compositions of the present invention represented by Examples 1 to 10 are particularly excellent in pencil hardness and hardness, low in HIC value, high in impact resistance, Further, there is no crack at the time of impact, high heat deformation resistance, and excellent moldability.

[0083]

[Table 5]

[0084]

[Table 6]

[Brief description of the drawings]

 FIG. 1 is a rear view of an example of a molded body. FIG. 2 is a cross-sectional view of an example of a molded body.

FIG.

FIG. 2

[Explanation of symbols]

BA: butyl acrylate 2EHA: 2-ethylhexyl acrylate AN: acrylonitrile St: styrene tDM: t-dodecyl mercaptan CHP: cumene hydroperoxide PMI: N-phenylmaleimide αMSt: α-methylstyrene MMA: methyl methacrylate MAA: methacrylic acid

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) C08L 33:12)

Claims (5)

[Claims] 1. An acrylic acid ester of 40 to 95% by weight,
5 to 40% by weight of a vinyl cyanide compound, 55% by weight or less of an aromatic vinyl compound, and a monomer 0 copolymerizable therewith
Tg obtained by polymerizing ３０30% by weight (total 100% by weight)
Is not more than 20 ° C. and the gel content is not more than 10% by weight. (A) 5 to 65 parts by weight, vinyl cyanide compound 10 to 40% by weight, aromatic vinyl compound or maleimide type monomer A total of 60 to 90% by weight of the body and the aromatic vinyl compound and 0 to 30% by weight of a monomer copolymerizable therewith (total 100% by weight) are polymerized,
A styrene-based copolymer (b) containing at least 49 mol% of an aromatic vinyl compound and (b) 15 to 80 parts by weight, and a diene-based rubber polymer having a volume average particle diameter of 100 to 1000 nm;
10 to 90% by weight of an aromatic vinyl compound in the presence of 10 to 90 parts by weight of an olefin rubber polymer, acrylic rubber polymer or silicone rubber polymer (a), (meth)
Acrylic acid ester or vinyl cyanide compound 10
90% by weight, and monomers 0 to 30 copolymerizable therewith
% (Total 100% by weight) of the monomer mixture (b) 90
From 15 to 80 parts by weight (a total of (a), (b) and (c) 100 parts by weight) of a graft copolymer (c) having a graft ratio of 10 to 70% by weight obtained by polymerizing 10 to 10 parts by weight. And the reduced viscosity (30 ° C., in N, N-dimethylformamide solution) of the methyl ethyl ketone soluble portion of the acrylate copolymer (a) and the styrene copolymer (b) is 0.3 to 1 A thermoplastic resin composition having excellent scratch resistance, comprising 100 parts by weight of a resin composition (A) in a range of 0.2 dl / g and 0.01 to 50 parts by weight of a methyl methacrylate (co) polymer (B). . 2. The methyl methacrylate (co) polymer (B) is a homopolymer or a copolymer obtained by homopolymerizing methyl methacrylate or copolymerizing a monomer component containing methyl methacrylate as a main component. The thermoplastic resin composition according to claim 1, which is excellent in scratch resistance. 3. The rubber polymer (a) comprises 5 to 50% by weight of an unsaturated acid (c) of at least one of acrylic acid, methacrylic acid, itaconic acid and crotonic acid, wherein the alkyl group has 1 carbon atom. (C) 50 to 95% by weight of at least one (meth) alkyl acrylate of (c),
(D) a rubber polymer produced by a coagulation enlargement method using an acid group-containing latex (S) prepared by polymerizing 0 to 40% of a monomer copolymerizable with the polymer, and a rubber polymer content The thermoplastic resin composition having excellent scratch resistance according to claim 1 or 2, which is 5 to 50% by weight of the resin. 4. An acid group-containing latex (S) comprising 5 to 25% by weight of at least one unsaturated acid (c) selected from acrylic acid, methacrylic acid, itaconic acid and crotonic acid, wherein the carbon number of the alkyl group is 5 to 30% by weight of at least one kind of alkyl acrylate (d) of 1 to 12, 80 to 20% by weight of at least one kind of alkyl methacrylate (e) having 1 to 12 carbon atoms of the alkyl group, (c), (d) ), An aromatic vinyl monomer copolymerizable with (e) and / or 2 in the molecule.
The thermoplastic resin having excellent scratch resistance according to claim 3, which is an acid group-containing latex prepared by polymerizing a monomer having one or more polymerizable functional groups and / or 0 to 40% of a vinyl cyanide compound. Resin composition. 5. The acrylate copolymer (b) and the styrene copolymer (b) polymerize 0 to 80% by weight of the styrene copolymer (b), and then polymerize the acrylate copolymer. The scratch resistance according to claim 1, 2 or 3, wherein the polymer (a) is polymerized, and thereafter, a mixed polymer (d) in which 20 to 100% by weight of the remaining styrene-based copolymer (b) is polymerized. Excellent thermoplastic resin composition.