JPH0616896A - Thermoplastic resin composition excellent in coatability - Google Patents

Abstract

PURPOSE:To obtain a resin compsn. excellent in brightness, adhesion to a coating film, and resistances to water, humidity, chemicals, and impact. CONSTITUTION:The compsn. comprises 40-90 pts.wt. graft copolymer obtd. from 10-40 pts.wt. rubberlike polymer, 30-60 pts.wt. arom. vinyl compd., 15-40 pts.wt. vinyl cyanide compd., and, if necessary, 0-20 pts.wt. alkyl alpha,beta-unsatd. carboxylate in a proportion of the vinyl cyanide compd. of 36-50wt.% based on the sum of the monomers and 10-60 pts.wt. copolymer obtd. from 30-70 pts.wt. arom. vinyl compd., 30-50 pts.wt. vinyl cyanide compd., and, if necessary, 0-20 pts.wt. alkyl alpha,beta-unsatd. carboxylate or/and unsatd. monomer copolymerizable with those monomers in a proportion of the vinyl cyanide compd. of 25-40wt.% based on the sum of monomers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition having excellent paintability and impact resistance.

[0002]

2. Description of the Related Art Acrylonitrile-butadiene-styrene (ABS) resin, which is one type of resin reinforced with a rubber component, is excellent in impact resistance and molding processability and is therefore used in various fields such as automobiles and household appliances. Widely used.
Generally, an ABS resin has a vinyl cyanide ratio of 15 to 4 as disclosed in JP-B-39-336.
The graft copolymer and the copolymer in the range of 0% by weight are blended and used. Further, since ABS resin is excellent in chemical resistance and paintability, its application to be used after coating is expanding.

It is known that the ratio of vinyl cyanide compound has a great effect when it is used after coating, and the chemical resistance and paintability are improved by the method of increasing the ratio of vinyl cyanide compound. It is possible to do it.
However, simply increasing the proportion of the vinyl cyanide compound is effective in preventing stress cracks due to thinner at the time of painting and improving leveling defects in the coating performance, but the adhesion of the coating film Was much inferior. In addition, the water resistance and moisture resistance of the coating film and the drawbacks such as peeling of the coating film against chemicals and solvents become more serious.

Further, depending on the type of paint, it cannot be practically used because the coating film is easily peeled off after the coating is dried, resulting in poor adhesion and reduced impact resistance. Thus, the coating properties include not only stress crack prevention and adhesion of the coating film, but also the clearness of the coating film, water resistance and moisture resistance of the coating film, and the phenomenon of poor film peeling due to chemicals and solvents. It is required to have a wide range of properties such as improvement of and the impact resistance after painting.

On the other hand, as a method of defining the proportion of vinyl cyanide in order to improve the coating property, for example,
Japanese Patent Publication No. 60-28311 and Japanese Patent Publication No. 60-28
In Japanese Patent Laid-Open No. 312-320, the proportion of vinyl cyanide in the graft copolymer is 32 to 37% by weight and the proportion of vinyl cyanide in the copolymer is 20 to 37% by weight, or 20 to 32% by weight and 32 to 37% by weight. A method of incorporating graft copolymers having different percentages of vinyl cyanide is disclosed.

However, in these methods, since the ratio of vinyl cyanide in the graft copolymer is low, the sufficient effect cannot be obtained, and the impact resistance of the graft copolymer and that of the copolymer are not sufficient. When the proportions of vinyl cyanide were significantly different, a significant decrease could be seen, which did not represent an improvement in maintaining excellent coating performance and impact resistance. Moreover, in Japanese Patent Publication No. 63-30953, 2
Disclosed is a method of blending a graft copolymer containing 0 to 35% by weight of vinyl cyanide with a copolymer having a vinyl cyanide content of 38 to 65% by weight and higher, thereby improving coatability. is doing.

However, although this method is effective for stress cracking, it is insufficient to satisfy all practical properties of coating performance because the proportion of vinyl cyanide compound in the graft copolymer is low. The water resistance and moisture resistance of the coating film and the effect of improving the defective phenomena such as peeling of the coating film against chemicals and solvents were poor. In addition, JP-A-59-
In JP-A-226050, coating properties are improved by adding polystyrene and high-impact-resistant polystyrene to styrene resin. However, in this method, a component having poor chemical resistance is added, so that the improvement of the image clarity of the coating film, the water resistance and moisture resistance of the coating film, and the chemical resistance of the coating film have not been sufficiently improved.

[0008]

DISCLOSURE OF THE INVENTION The present invention provides an aromatic vinyl-based graft copolymer and a composition containing the copolymer, wherein the proportion of the graft copolymer and the vinyl cyanide compound lower than that of the graft copolymer. By blending a copolymer with a specific ratio in a specific ratio, it is excellent in the coating performance of molded products such as sharpness, adhesion of coating film, water resistance, moisture resistance and chemical resistance, and excellent impact resistance. The present invention also provides a resin composition.

[0009]

Means for Solving the Problems As a result of extensive studies on the above problems, the present inventors have found that in a composition containing an aromatic vinyl-based graft copolymer and a copolymer, the graft copolymer and the graft copolymer are combined. By blending a copolymer with a ratio of vinyl cyanide compound lower than that of the polymer in a specific ratio, the coating performance of molded products such as sharpness, adhesion of coating film, water resistance, moisture resistance and chemical resistance. The inventors have found that a resin composition having excellent properties and excellent impact resistance can be obtained, and completed the present invention.

That is, in the present invention, the aromatic vinyl compound 30 is added in the presence of 10 to 40 parts by weight of the rubber-like polymer (A).
To 60 parts by weight, vinyl cyanide compound 15 to 40 parts by weight, α, β-unsaturated carboxylic acid alkyl ester 0 to 2
A graft copolymer in which 0 to 20 parts by weight and 0 to 20 parts by weight of one or more kinds of monomers selected from unsaturated monomers copolymerizable therewith are graft-copolymerized,
Ratio of vinyl cyanide compound to the total amount of monomers (G
40 to 90 parts by weight of the graft copolymer in which N) is in the range of 36 to 50% by weight, and (B) the aromatic vinyl compound 30 to 7
0 parts by weight, vinyl cyanide compound 30 to 50 parts by weight,
0 to 20 parts by weight of an α, β-unsaturated carboxylic acid alkyl ester and 0 to 20 parts by weight of one or more kinds of monomers selected from unsaturated monomers copolymerizable therewith as necessary. In the copolymerized copolymer, the ratio (FN) of the vinyl cyanide compound to the total amount of the monomers is 25 to 40% by weight, and the composition (A) is composed of 10 to 60 parts by weight of the copolymer. (GN-FN), which is the difference between the GN of No. 1 and the FN of the component (B), is +4 or more, and the component (A).
(Bw) is the ratio of the weight (Gw) of the ungrafted copolymer to the weight (Bw) of the copolymer of component (B).
/ (Gw) is in the range of 0.1 to 2.0, and relates to a resin composition having excellent coatability and impact resistance.

The present invention will be described in more detail below. The rubbery polymer in the component (A) used in the present invention is a polymer having elastomeric properties in order to improve the impact resistance of the composition of the present invention. Examples of such a polymer include diene-based polymers such as polybutadiene, styrene-butadiene rubber, butadiene-acrylonitrile rubber, butadiene-isoprene rubber, polyisobutylene, and polyalkyl acrylates having alkyl having 1 to 13 carbon atoms, Examples thereof include ethyl acrylate, propyl acrylate, butyl acrylate and 2-ethylhexyl acrylate.

Further, there may be mentioned polyalkylmethacrylates having alkyl having 4 to 13 carbon atoms, such as butylmethacrylate, amylmethacrylate, hexylmethacrylate, octylmethacrylate, 2-ethylhexylmethacrylate and the like. Furthermore, in the range that does not impair the flexibility of the rubber-like polymer, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, propylene glycol dimethacrylate, dicyclopentadiene acrylate, divinylbenzene, diallyl phthalate, triallyl isocyanurate, It may be a copolymer crosslinked using a polyfunctional compound such as triallyl cyanurate.

Further, other graft copolymerizable ethylene-propylene rubber, ethylene-propylene-diene rubber, styrene-butadiene block copolymer, hydrogenated polymer of styrene-butadiene block copolymer, styrene-isoprene. Block copolymers, hydrogenated polymers of styrene-isoprene block copolymers,
Silicone rubber or the like can also be used.

These rubbery polymers can be obtained by emulsion polymerization, suspension polymerization, or a method of emulsifying the polymer with an emulsifier or the like. The average particle size of the rubber-like polymer is preferably in the range of 0.03 to 1.0 μm in order to improve the surface gloss, impact resistance and chemical resistance of the composition. More preferably, it is 0.08 to 0.5 μm, and the most preferable range is 0.1 to 0.35 μm. 0.03 μm
If it is less than 100, impact resistance and chemical resistance are poor. If it exceeds 1.0 μm, the surface gloss and impact resistance are poor.

As the monomer to be graft-copolymerized with the rubber-like polymer of the present invention, an aromatic vinyl compound, a vinyl cyanide compound, an α, β-unsaturated carboxylic acid alkyl ester and, if necessary, a copolymer with these compounds can be used. At least one monomer selected from the polymerizable unsaturated monomers is used.

As the aromatic vinyl compound, for example, halogenated styrene such as styrene, α-methylstyrene, chlorinated styrene and brominated styrene, alkylated styrene such as vinyltoluene and dimethylstyrene, vinylnaphthalene and the like are used. These may be mixed and used. Of these, styrene is preferred. Further, as the vinyl cyanide compound, for example, acrylonitrile,
Methacrylonitrile or the like is used. Among these,
Acrylonitrile is preferred.

As the α, β-unsaturated carboxylic acid alkyl ester, an alkyl acrylate having an alkyl group having 1 to 10 carbon atoms, for example, methyl acrylate,
Ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, hydroxyethyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate and the like, and alkyl methacrylate having an alkyl group having 1 to 10 carbon atoms, for example, methyl methacrylate, ethyl methacrylate, propyl. Methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, hydroxyethyl methacrylate, glycidyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate and the like can be mentioned.

As the unsaturated monomer copolymerizable with these monomers, N-substituted maleimides, α, β-unsaturated carboxylic acid, maleic anhydride and the like may be used.
Examples of the N-substituted maleimides include maleimide, N-methylmaleimide, N-cyclohexylmaleimide and N-phenylmaleimide. Examples of the α, β-unsaturated carboxylic acid include acrylic acid and methacrylic acid.

The graft copolymer (A) is added to 10 to 40 parts by weight, preferably 20 to 40 parts by weight of the above rubber-like polymer, and 90 to 60 parts by weight of a monomer used in the graft copolymerization.
Preferably, 80 to 60 parts by weight are used. The proportion of each monomer is 50 to 64% by weight of aromatic vinyl, preferably 40 to 55% by weight, 36 to 50% by weight of vinyl cyanide, preferably 37 to 45% by weight, α, β-unsaturated. Carboxylic acid alkyl ester 0 to 20% by weight, preferably 0
~ 15 wt% and other copolymerizable unsaturated monomers 0-2
It is 0% by weight, and the total monomer amount is 100% by weight.

That is, it is a graft copolymer in which the ratio (GN) of vinyl cyanide compound to the total amount of monomers is in the range of 36 to 50% by weight. The graft copolymer is
It can be obtained by mixing monomers or by stepwise graft-copolymerizing in a proportion of 60 to 90 parts by weight.

If the proportion of the rubber-like polymer is less than 10 parts by weight, the impact resistance of the obtained composition is not sufficient, and 40
If it exceeds the weight part, the sharpness of the coating film, the molding processability and the thermal stability deteriorate. The ratio of each monomer is 50% by weight when the aromatic vinyl exceeds 64% by weight, the sharpness and chemical resistance are deteriorated.
If it is less than the above range, the thermal stability at the time of molding is impaired and the adhesion of the coating film is reduced. In addition, vinyl cyanide is 36
If it is less than 5% by weight, stress cracking at the time of coating and leveling are poor and the image clarity is deteriorated. If it exceeds 50% by weight,
The thermal stability at the time of molding is impaired and the adhesion of the coating film is reduced. The α, β-unsaturated carboxylic acid alkyl ester is 0 to 20% by weight in a range that does not deteriorate the coating property,
It is preferably used in a proportion of 0 to 15% by weight.

Further, in the graft polymerization, the graft ratio showing the ratio of the monomer grafted to the rubber-like polymer is
It is preferably in the range of 30 to 70%. If it is less than 30%, the sharpness and impact resistance of the coating film are poor, and if it exceeds 70%, the impact resistance is poor. Further, the ratio (Fw) of the copolymer not grafted to the rubber-like polymer was measured by the following method and determined by the following formula.

A certain amount of the graft copolymer (this value is represented by a) is immersed in a solvent, for example, acetone, methyl ethyl ketone, tetrahydrofuran or the like, dissolved and then centrifuged, and the dissolved components are separated by decantation. ,
The copolymer was obtained by reprecipitation in a poor solvent such as methanol or ethanol, and the weight (this value is represented by b) was measured. And Fw was calculated | required by the following formula.

[0024]

[Equation 1]

These rubber-like polymer graft copolymers are produced by known polymerization methods such as emulsion polymerization, suspension polymerization, bulk polymerization and solution polymerization. The copolymer which is the component (B) used in the present invention includes an aromatic vinyl compound, a vinyl cyanide compound, an α, β-unsaturated carboxylic acid alkyl ester, and an unsaturated monomer which can be copolymerized therewith as necessary. It is a copolymer obtained by copolymerizing one or more kinds of monomers selected from the body.

As such an aromatic vinyl compound,
For example, styrene, α-methylstyrene, chlorinated styrene, halogenated styrene such as brominated styrene, vinyltoluene, alkylated styrene such as dimethylstyrene, vinylnaphthalene, and the like are used, and these may be used in combination. Of these, styrene is preferred. As the vinyl cyanide compound, for example, acrylonitrile, methacrylonitrile, etc. are used. Of these, acrylonitrile is preferred.

The α, β-unsaturated alkyl ester may be an alkyl acrylate having an alkyl group having 1 to 10 carbon atoms, such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, hydroxyethyl. Acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, etc. and carbon number 1
An alkyl methacrylate having an alkyl group of 10 to, for example, methyl methacrylate, ethyl methacrylate,
Propyl methacrylate, butyl methacrylate, 2-
Examples thereof include ethylhexyl methacrylate, hydroxyethyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate and benzyl methacrylate. Of these, methyl methacrylate, methyl acrylate, phenyl methacrylate, phenyl acrylate and cyclohexyl methacrylate are preferable.

As the unsaturated monomer copolymerizable with these monomers, N-substituted maleimides, α, β-unsaturated carboxylic acid, maleic anhydride and the like may be used.
Examples of the N-substituted maleimides include maleimide, N-methylmaleimide, N-cyclohexylmaleimide and N-phenylmaleimide. Among these,
N-phenylmaleimide is preferred. Examples of the α, β-unsaturated carboxylic acid include acrylic acid and methacrylic acid.

The proportion of each monomer is the aromatic vinyl 6
0 to 75% by weight, preferably 60 to 70% by weight, vinyl cyanide 25 to 40% by weight, preferably 30 to 40% by weight, α, β-unsaturated carboxylic acid alkyl ester 0 to 2
It is 0% by weight, preferably 0 to 15% by weight, and 0 to 20% by weight of another copolymerizable unsaturated monomer, and the total amount of the monomers is 100% by weight. That is, the ratio (FN) of vinyl cyanide compound to the total amount of monomers is 2
The copolymer is 5 to 40% by weight. The copolymer can be obtained by mixing monomers or copolymerizing them stepwise.

With respect to the proportion of each monomer, when the proportion of aromatic vinyl exceeds 75% by weight, sharpness and chemical resistance are deteriorated, and 60
If it is less than wt%, the thermal stability at the time of molding is impaired and the adhesion of the coating film is reduced. If the proportion of vinyl cyanide is less than 25% by weight, stress cracking and leveling at the time of coating are poor and the image clarity is lowered, and if it exceeds 40% by weight, the thermal stability during molding is impaired, The adhesion of the film is reduced. The α, β-unsaturated carboxylic acid alkyl ester is 0 to 2 as long as the coating property is not deteriorated.
It is used in an amount of 0% by weight, preferably 0 to 15% by weight.
These copolymers are produced by known polymerization methods such as emulsion polymerization, suspension polymerization, bulk polymerization and solution polymerization.

The ratio of the components constituting the composition of the present invention is
The composition comprises 40 to 90 parts by weight of the graft copolymer (A) and 60 to 10 parts by weight of the copolymer (B), so that the total composition is 100 parts by weight. Further, in the above blending ratio, the ratio (GN) of vinyl cyanide of the component (A) and the component (B)
Of the vinyl cyanide (FN) of (GN-
FN) is a combination of +4 or more, and is the ratio of the weight (Gw) of the ungrafted copolymer of component (A) to the weight (Bw) of the copolymer of component (B) ( B
It is necessary that w) / (Gw) be in the range of 0.1 to 2.0.

When the amount of the component (A) is less than 40 parts by weight, impact resistance and chemical resistance are deteriorated, and when it exceeds 90 parts by weight, coating properties are poor and heat distortion temperature and mechanical strength are deteriorated. . In this sense, it is more preferably 50-
80 parts by weight. The component (B) is preferably 40 to 40 in order to have excellent coatability and moldability.
Used in the range of 10 parts by weight.

The proportion of vinyl cyanide as component (A) (GN) and the proportion of vinyl cyanide as component (B) (FN)
The more preferable range of (GN-FN), which is the difference between
It is 5 to +10. If it is less than +5, the adhesiveness of the coating film on the molded product, the water resistance, the moisture resistance and the like are poor. If it exceeds +10, the impact resistance is poor. The ratio (Bw) / (Gw) of the weight (Gw) of the non-grafted copolymer of the component (A) to the weight (Bw) of the copolymer of the component (B) is more preferably It is 0.3 to 1.5. If it is less than 0.3, the adhesion, water resistance and moisture resistance of the coating film are poor, and 1.5
If it exceeds the range, the solvent crack prevention property and the image clarity are poor.

In the copolymer of component (B), one or more copolymers having different vinyl cyanide ratios (FN) may be used in combination. In that case, one or more of the copolymers of the component (B) used are the difference between the GN of the component (A) and the ratio (FN) of the vinyl cyanide compound of the component (B) (GN- FN) is +4 or more and the ratio (Bw) / (Gw) of the weight (Gw) of the ungrafted copolymer of the component (A) to the weight (Bw) of the copolymer is , 0.1 to 2.0 is required.

The method of blending the composition of the present invention is not particularly limited, and powders and granules are mixed by a known technique, for example, a Henschel mixer, a tumbler, a blender, etc., and this is mixed with an extruder or a kneader. It can be produced by various methods such as a method of melt-mixing with a mixer or the like, a method of sequentially mixing another resin with a resin which has been melted in advance. The resin composition of the present invention contains various additives, dyes, pigments, light stabilizers, antioxidants, plasticizers, antistatic agents, flame retardants, and flame retardants, if desired, within a range that does not impair the physical properties. Auxiliary agents, organic fillers, inorganic fillers and the like may be mixed in advance.

[0036]

EXAMPLES The present invention will be specifically described by the following examples, which do not limit the scope of the present invention.

Reference Example 1 Graft Copolymer (A-1) 1000 parts by weight of butadiene rubber latex having a weight average particle size of 0.25 μm (swelling degree 25, solid content 30% by weight), emulsifier [potassium alkenyl succinate (alkenyl) group C ₁₃ is -C _15)] were charged into a polymerization vessel of 2 parts by weight, with stirring, the temperature was raised to 70 ° C. in a nitrogen stream, to, styrene 420 parts by weight of a vinyl cyanide 280 parts by weight, cumene Hydroperoxide (2 parts by weight), t-dodecyl mercaptan (0.7 parts by weight), distilled water (500 parts by weight), sodium formaldehyde sulfoxylate (1.0 parts by weight), ferrous sulfate (FeSO ₄ .7H ₂ O) Polymerization was carried out by adding an aqueous solution in which 0.01 parts by weight and 0.4 parts by weight of ethylenediaminetetraacetic acid / 2Na salt were dissolved for 6 hours.

After the addition was completed, stirring was continued for another hour,
The polymerization was completed. The polymerization rate was 96%. The obtained copolymer latex is coagulated and salted out, washed and dried,
A white solid was obtained. The ratio of vinyl cyanide (GN) in this graft copolymer was 39.5% by weight from the reaction rate. In addition, the ratio of the ungrafted copolymer (Fw)
Was 55% by weight.

Reference Example 2 Graft Copolymer (A-2) 1000 parts by weight of a butadiene rubber latex having a weight average particle diameter of 0.30 μm (swelling degree 20, solid content 30% by weight), emulsifier (disproportionated potassium rosinate) ) 2 parts by weight were charged into a polymerization tank and the temperature was raised to 70 ° C. in a nitrogen stream while stirring, to which 380 parts by weight of styrene, 220 parts by weight of acrylonitrile, 2 parts by weight of cumene hydroperoxide, t-dodecyl mercaptan were added. A mixture of 0.5 parts by weight and 500 parts by weight of distilled water was added to 1.0 part by weight of sodium formaldehyde sulfoxylate and ferrous sulfate (FeSO ₄ .7).
H ₂ O) 0.01 parts by weight, ethylenediaminetetraacetic acid ・ 2
Polymerization was carried out by adding an aqueous solution in which 0.3 part by weight of Na salt was dissolved for 6 hours. The obtained copolymer latex was coagulated and salted out, washed and dried to obtain a white solid. The ratio of vinyl cyanide (GN) in this graft copolymer was 36.1% by weight from the reaction rate.
The proportion (Fw) of the ungrafted copolymer is 5
It was 6% by weight.

Reference Example 3 Graft Copolymer (A-3) 1000 parts by weight of butadiene rubber latex having a weight average particle diameter of 0.3 μm (swelling degree 15, 40% by weight in terms of solid content), 280 parts by weight of styrene, 220 parts by weight of acrylonitrile. Polymerization was performed in the same manner as in Reference Example 1 except that parts were used. The polymerization rate was 95%. The vinyl cyanide ratio (GN) of this graft copolymer is 43.2 from the reaction rate.
% By weight. The proportion (Fw) of the ungrafted copolymer was 41% by weight.

Reference Example 4 Graft Copolymer (A-4) 750 parts by weight of deionized water and 3 parts by weight of an emulsifier (sodium dodecylbenzene sulfonate) were placed in a polymerization tank and stirred at 70 ° C. in a nitrogen stream. The temperature was raised, and as the first stage polymerization, 300 parts by weight of butyl acrylate, 1.5 parts by weight of triallyl isocyanurate, 0.07 parts by weight of ammonium persulfate, 0.5 of an emulsifier (sodium dodecylbenzene sulfonate) were added. 2 parts by weight of mixture
Polymerization was carried out by adding over time.

After the completion of the addition, as a second stage polymerization, 300 parts by weight of styrene, 220 parts by weight of acrylonitrile, 80 parts by weight of methyl methacrylate, 0.1 part by weight of ammonium persulfate, 0.1 part of t-dodecyl mercaptan.
Polymerization was carried out by adding 6 parts by weight of the mixed solution over 6 hours. The stirring was continued for 1 hour to complete the polymerization. The polymerization rate was 96%. The obtained copolymer latex was coagulated and salted out, washed and dried to obtain a white solid.
Ratio of vinyl cyanide in this graft copolymer (GN)
Was 36.0% by weight from the reaction rate. The proportion (Fw) of the ungrafted copolymer was 51% by weight.

Reference Example 5 Graft Copolymer (A-5) Polymerization was carried out in the same manner as in Reference Example 4 except that 360 parts by weight of styrene and 240 parts by weight of acrylonitrile were used as the second-stage polymerization. The polymerization rate was 98%. The ratio of vinyl cyanide (GN) in this graft copolymer was 39.0% by weight from the reaction rate. The proportion (Fw) of the ungrafted copolymer was 49% by weight.

Reference Example 6 Graft Copolymer (A-6) 1000 parts by weight of butadiene rubber latex having a weight average particle diameter of 0.3 μm (swelling degree 25, solid content 30% by weight), styrene 350 parts by weight, acrylonitrile 150 parts by weight. Polymerization was performed in the same manner as in Reference Example 2 except that parts were used. The polymerization rate was 98%. The ratio of vinyl cyanide (GN) of this graft copolymer is 29.8 from the reaction rate.
% By weight. The proportion (Fw) of the ungrafted copolymer was 43% by weight.

Reference Example 7 Graft Copolymer (A-7) 1000 parts by weight of butadiene rubber latex having a weight average particle diameter of 0.15 μm (swelling degree 25, solid content 40% by weight), styrene 330 parts by weight, acrylonitrile 170 parts by weight. Polymerization was performed in the same manner as in Reference Example 2 except that parts were used. The polymerization rate was 95%. The ratio of vinyl cyanide (GN) of this graft copolymer is 33.
It was 2% by weight. The proportion (Fw) of the ungrafted copolymer was 45% by weight.

Reference Example 8 Copolymer (B-1) To 180 parts by weight of water, 0.4 parts by weight of potassium persulfate and 2.0 parts by weight of potassium rosinate were added and dissolved to give 30 parts by weight of acrylonitrile and 70 parts by weight of styrene. And 0.5 parts by weight of t-dodecyl mercaptan and distilled water 500
Polymerization was carried out by adding 0.2 parts by weight of sodium formaldehyde sulfoxylate to parts by weight and adding the aqueous solution over 6 hours. After the addition was completed, stirring was continued for another hour to complete the polymerization. The polymerization rate was 95%. The obtained copolymer latex is coagulated and salted out,
It was washed and dried to obtain a white solid.

Reference Example 9 Copolymer (B-2) A copolymer was obtained by the same procedure as in Reference Example 8 except that 35 parts by weight of acrylonitrile and 65 parts by weight of styrene were used.

Reference Example 10 Copolymer (B-3) A copolymer was obtained in the same manner as in Reference Example 8 except that 37 parts by weight of acrylonitrile and 63 parts by weight of styrene were used.

Reference Example 11 Copolymer (B-4) A copolymer was obtained by the same procedure as in Reference Example 8 except that 40 parts by weight of acrylonitrile and 60 parts by weight of styrene were used.

Reference Example 12 Copolymer (B-5) A copolymer was obtained in the same manner as in Reference Example 8 except that 37 parts by weight of acrylonitrile, 53 parts by weight of styrene and 10 parts by weight of butyl acrylate were used.

Reference Example 13 Copolymer (B-6) A copolymer was obtained in the same manner as in Reference Example 8 except that 40 parts by weight of acrylonitrile, 50 parts by weight of styrene and 10 parts by weight of butyl acrylate were used.

Example 1 60 parts by weight of (A-1) obtained in Reference Example 1 and 40 parts by weight of the copolymer (B-2) obtained in Reference Example 9 were mixed and premixed with a Henschel mixer. Next, the mixture was melt-mixed and pelletized using an extruder. Next, a test piece was prepared by forming this pellet with an injection molding machine, and the physical properties were evaluated. The results are shown in Tables 1 and 2. The characteristics shown in the following examples and comparative examples were measured by the following methods.

(1) Tensile strength and elongation: ASTM
It measured according to D-638. (2) Izod impact strength: ASTM D-256
The measurement was performed according to the method of. (Notched, thickness 1/4 inch) (3) Coating test: Flat plate test piece (100 x 100 mm
3mm thick, urethane-based paint (High Urethane No.
5000: made by NOF Corporation) with a film thickness of about 40 μm (after drying)
After spray coating and drying so as to obtain the following, the appearance of the coated surface was observed, the image clarity was measured, the adhesion test, the water resistance test and the moisture resistance test were performed.

(3-A) Observation of appearance O: No stress crack. Good leveling. B: Some stress cracks are observed. ×: Stress cracks are remarkable. (3-B) Image clarity measurement In order to measure the state of the image on the surface, image clarity was measured using an image measurement device (manufactured by Suga Test Instruments Co., Ltd.). (Measured values are expressed in percentage, 100 being the best value).

(3-C) Adhesion test: JIS K54
It measured according to 00. After painting, leave at 23 ° C x 60% RH for 1 hour and then 1x with a multi-cross cutter
100 pieces of 1 mm bases were prepared, and a peeling test was performed using JIS cellophane tape. The test results are expressed as the number of base stitches / the number of base stitches that do not peel. (3-D) Water resistance test: The test piece was immersed in warm water at 50 ° C. for 100 hours, and then at 23 ° C. × 60% RH for 24 hours.
After leaving for a while, by the same basic method as (3-C),
A peel test was performed. The test result is the number of base stitches that do not peel /
It is displayed by the number of bases.

(4) Chemical resistance: Painted test pieces (10
0 × 12.7 × 3 mm) at 23 ° C. with a nonionic sea surface active agent Emulgen 109P (manufactured by Kao),
The presence or absence of cracks was examined when left for 24 hours. (5) Drop weight impact test: Placed on the center of the sample support with the coating surface of the molded piece facing upward, and a radius of 6.35 ± 0.03.
A weight having a hemispherical tip of mm was dropped, and impact energy (load × height: kg · cm) was measured.

Examples 2 to 8 Pellets having the composition ratios shown in Tables 1 and 2 were used as pellets, and the following operations were performed in the same manner as in Example 1 to evaluate the respective physical properties, and the results are shown in Tables 1 and 2. It was

Comparative Examples 1 to 5 Pellets having the composition ratio of each component shown in Table 3 were used as pellets, and the following operations were carried out in the same manner as in Example 1 to evaluate the respective physical properties and shown in Table 3. Examples 1 to 8 and Comparative Example 1 described above
The overall evaluation of 5 is shown in Table 4. From the comprehensive evaluation of Table 4, it is clearly seen that the composition of the present invention is excellent in paintability and impact resistance and exhibits a good balance of physical properties.

[0059]

[Table 1]

[0060]

[Table 2]

[0061]

[Table 3]

[0062]

[Table 4]

[0063]

According to the present invention, in a composition in which an aromatic vinyl-based graft copolymer and a copolymer are blended, the graft copolymer and the copolymer having a lower vinyl cyanide ratio than the graft copolymer. By blending in a specific ratio, the sharpness, which is the coating performance of the molded product, the adhesion of the coating film,
There is an effect that a resin composition having excellent water resistance, moisture resistance, chemical resistance, and impact resistance can be obtained.

Claims (2)

[Claims] 1. (A) In the presence of 10 to 40 parts by weight of a rubbery polymer, 30 to 60 parts by weight of an aromatic vinyl compound, 15 to 40 parts by weight of a vinyl cyanide compound, an α, β-unsaturated carboxylic acid. Graft copolymerization in which 0 to 20 parts by weight of alkyl ester and 0 to 20 parts by weight of one or more kinds of monomers selected from unsaturated monomers copolymerizable with these are graft-copolymerized. In the combined product, 40 to 90 parts by weight of a graft copolymer having a ratio (GN) of vinyl cyanide compound to the total amount of monomers of 36 to 50% by weight and 30 to 70 parts by weight of (B) an aromatic vinyl compound. 1 to 30 parts by weight of a vinyl cyanide compound, 0 to 20 parts by weight of an α, β-unsaturated carboxylic acid alkyl ester, and an unsaturated monomer copolymerizable with them, if necessary.
In a copolymer obtained by copolymerizing 0 to 20 parts by weight of one or more kinds of monomers, the ratio (FN) of vinyl cyanide compound to the total amount of the monomers is 25 to 40% by weight.
In the composition consisting of 60 parts by weight, the difference between the GN of the component (A) and the FN of the component (B) (G
N-FN) is +4 or more and is the ratio of the weight (Gw) of the ungrafted copolymer of component (A) to the weight (Bw) of copolymer of component (B) (Bw). / (Gw)
Is in the range of 0.1 to 2.0. A resin composition having excellent coatability and impact resistance. 2. The copolymer of component (B), which is a copolymer of one or more copolymers having different vinyl cyanide ratios (FN) of the copolymer. One or more of the copolymers of (B) are GN of the component (A).
And the ratio (FN) of the vinyl cyanide compound of component (B) (GN-FN) is +4 or more, and the weight (Gw) of the ungrafted copolymer of component (A).
And (Bw) / weight of the copolymer (Bw) /
The thermoplastic resin composition according to claim 1, wherein (Gw) is in the range of 0.1 to 2.0.