JPH0711099A - Resin composition excellent in coating property and plating property - Google Patents

Abstract

PURPOSE:To obtain a thermoplastic resin composition capable of forming a coating film excellent in all the properties of visual appearance, clearness, adhesion, multi-coat adhesion, water resistance, chemical resistance, plating properties and heat cycle properties. CONSTITUTION:This thermoplastic resin composition is composed of (A) a graft copolymer synthesized by grafting an aromatic vinyl compound, a vinyl cyanide compound and, as necessary, a monomer copolymerizable therewith on a rubbery polymer and (B) a copolymer synthesized by copolymerizing an aromatic vinyl compound, a vinyl cyanide compound and, as necessary, a monomer copolymerizable therewith, and the VCN content of the graft chain is 25 to 45wt.%. In this resin composition, the amount of a free copolymer component having 20 to 28wt.% VCN content and that of another free copolymer component having 32 to 45wt.% VCN content are respectively within a specified range.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition having excellent coating properties and plating properties.

[0002]

2. Description of the Related Art A resin composition obtained by graft-copolymerizing a vinyl cyanide compound and an aromatic vinyl compound with a rubber-like polymer is known as acrylonitrile / butadiene / styrene resin (hereinafter referred to as ABS resin). It is used in a wide range of fields due to its excellent physical properties and good moldability. In particular, in the field of automobiles, it is used not only as an interior part but also as an exterior part due to its merit of weight reduction. In this case, it is often coated or plated for weather resistance or for design reasons.

It is generally known that the chemical resistance is improved by increasing the content of the vinyl cyanide compound in the ABS resin, and until now, the ratio thereof in the ABS resin has been examined. Several methods have been reported for improving paintability. For example, Japanese Patent Publication No. 60-283
In JP-A-11, a graft copolymer having a vinyl cyanide compound content of the side chain of 32 to 37 parts by weight and a copolymer having a vinyl cyanide compound content of 20 to 37 parts by weight are disclosed. A method is disclosed in which the content of the vinyl cyanide compound in the total free copolymer is 22 to -35% by mixing. However, in this method, the adhesion to the coating film after coating, particularly the adhesion after immersion in water (hereinafter referred to as water resistance) was insufficient.

In addition, when a coating failure occurs, the defective portion is sanded or the like to pass through the coating line again to apply multiple coatings. At this time, under the same drying conditions as the single coating, the coating film is applied. There is a problem that the adhesiveness (hereinafter referred to as the multilayer coating adhesiveness) is significantly lowered.
In addition, during plating, there was a problem in that adhesion was poor with the plating film due to insufficient etching, and swelling and cracking occurred in the heat cycle test.

On the other hand, in Japanese Patent Publication No. 60-28312, the content of the vinyl cyanide compound constituting the side chain portion is 20 to 32 parts by weight, and the content of the vinyl cyanide compound is 20 to 32 parts by weight. Disclosed is a method of mixing 20 to 37 parts by weight of the copolymer and setting the content of the vinyl cyanide compound in the total free copolymer to 28 to 33 parts by weight. However, this method also has a problem that the image clarity after coating is insufficient, and there are problems such as poor adhesion with the plating film due to overetching during plating, and swelling and cracking in the heat cycle test. There was a point.

[0006]

As described above, according to the above-mentioned conventional techniques, the appearance, sharpness, adhesion, and
It was not possible to satisfy all the properties of multi-layer coating adhesion, water resistance, chemical resistance, plating property and heat cycle property. The present invention determines the content and distribution state of vinyl cyanide compounds in free copolymers in a graft copolymer composition, and the content of vinyl cyanide compounds in graft chains copolymerized with a rubbery polymer. By prescribing, all of the adhesiveness with the coating film, water resistance, chemical resistance, multi-layer coating adhesion, plating property, and heat cycle property can be achieved without reducing the appearance and sharpness of the coated film. It is intended to provide an excellent resin composition.

[0007]

Means for Solving the Problems As a result of intensive studies on the above problems, the present inventors have found that the content ratio of vinyl cyanide compound in the free copolymer and the ratio of the components thereof, and the copolymerization with the rubbery polymer. By defining the content of the vinyl cyanide compound in the graft chain, the clearness of the coating film after coating, adhesion, multilayer coating adhesion, water resistance, chemical resistance, plating property, and heat The inventors have found that a resin composition having excellent cycle characteristics can be obtained, and have completed the present invention.

That is, a graft copolymer composition obtained by copolymerizing a rubbery polymer with an aromatic vinyl compound, a vinyl cyanide compound, and 0 to 50% by weight of a monomer copolymerizable with the above compounds ( A) and a copolymer composition obtained by copolymerizing an aromatic vinyl compound and a vinyl cyanide compound, and 0 to 50% by weight of a monomer copolymerizable with the aromatic vinyl compound or the vinyl cyanide compound ( In the resin composition comprising B), the average content of vinyl cyanide compounds in the graft chain copolymerized with the rubbery polymer is 2
In the free copolymer which is 5 to 45% by weight and is not grafted to the rubbery polymer, the proportion of the component (F1) having a vinyl cyanide compound content of 20 to 28% by weight is the point in FIG. The proportion of the component (F2) within the range of the shaded area surrounded by ABCDEF and having the vinyl cyanide compound content of 32 to 45% by weight is indicated by the point GHIJKL in FIG.
The present invention relates to a thermoplastic resin composition characterized by being in the range of the shaded area surrounded by.

The rubbery polymer used in the present invention includes, as a diene rubber, a polybutadiene, a butadiene-styrene copolymer, a butadiene-acrylonitrile copolymer, a diene rubber such as polyisobrene, butyl acrylate, methyl methacrylate, (meth). Acrylic rubbers such as acrylic acid ester polymers, saturated rubbers such as hydrogenated polybutadiene, ethylene-propylene copolymer rubbers, fluororubbers and silicone rubbers can be used.

As the aromatic vinyl compound, styrene,
α-Methylstyrene, chlorinated styrene, halogenated styrene such as brominated styrene, vinyltoluene, alkylated styrene such as dimethylstyrene, vinylnaphthalene and the like. Among them, preferred monomers are styrene, It is α-methylstyrene. Examples of the vinyl cyanide compound include acrylonitrile and methacrylonitrile.

The copolymerizable monomers include phenylmaleimide, maleic anhydride, methacrylic acid, and α, β.
-Unsaturated carboxylic acid alkyl ester, for example, alkyl (meth) acrylate having an alkyl group having 1 to 10 carbon atoms, such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl ( Examples thereof include (meth) acrylate, 2-ethylhexyl (meth) acrylate, hydroxyethyl (meth) acrylate, cyclohexyl (meth) acrylate, phenyl (meth) acrylate, and benzyl (meth) acrylate. Among these, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, phenyl acrylate, phenyl methacrylate, cyclohexyl acrylate, and glycidyl methacrylate are preferable.

The free copolymer means a copolymer component which is not grafted to the rubbery polymer in the resin composition,
The graft chain represents a copolymer component grafted on a rubbery polymer. Further, VCN representing the ratio of the free copolymer and the vinyl cyanide compound in the graft chain means a value defined by the following formula. VCN = (weight occupied by vinyl cyanide compound) /
[(Weight occupied by vinyl cyanide compound + aromatic vinyl compound + other monomer)] × 100

In the graft copolymer (A), the proportion of the rubbery polymer is 5 to 60% by weight, preferably 1
0 to 50% by weight, and the proportion of the aromatic vinyl compound is
10 to 75% by weight, preferably 11 to 71% by weight, and the proportion of the vinyl cyanide compound is 4 to 47% by weight, preferably 9 to 44% by weight.

The proportion of the aromatic vinyl compound in the copolymer (B) is 27 to 80% by weight, preferably 3%.
8-78% by weight, more preferably 44-78% by weight,
The proportion of the vinyl cyanide compound is 10 to 45% by weight, preferably 14 to 45% by weight, more preferably 1
6 to 45% by weight.

During the polymerization, a method of polymerizing at a constant monomer mixing ratio so that the VCN of the graft chain falls within a predetermined range, a method of blending a graft copolymer having two or more different VCNs, a single amount There is a method of gradually changing the proportion of the body or a method of sequentially changing the proportion, or a method of combining these.

The VCN of the graft chain is 25 to 45, preferably 26 to 43, more preferably 27 to 40.
When the VCN of the graft chain is less than 25, sufficient image clarity cannot be obtained, and at the time of plating, the peel strength and heat cycle property are deteriorated due to over-etching. The adhesiveness, especially the multilayer coating adhesiveness, is inferior, and since sufficient etching is not performed during plating, sufficient peel strength and heat cycle properties cannot be obtained.

When blending two or more kinds of graft copolymers having different VCNs, the VCN of each graft copolymer is 20 to 50, preferably 23 to 47, and more preferably 24 to 46.

In the free copolymer, VCN 20-28
And the free copolymer (F2) of VCN32 to 45 are used in combination.
In the component (F1), when VCN is less than 20, sharpness after coating cannot be obtained, and over-etching occurs during plating, resulting in a decrease in peel strength.
If it exceeds, sufficient coating adhesion cannot be obtained. With respect to the component (F2), if the VCN is less than 32, sufficient image clarity cannot be obtained, and if it exceeds 45, the adhesion is deteriorated, and sufficient etching is not performed during plating. The sex is lost.

In FIG. 1, when the proportion (%) of the F1 component is taken as the Y axis and the content (wt%) of the vinyl cyanide compound in the graft chain is taken as the X axis, the coordinates of the vertices in the shaded area ( X, Y) are A (31, 100), B (25, 4)
0), C (25,0), D (45,100), E (4
5, 60) and F (36, 100).

In FIG. 2, the ratio (%) of the F2 component is Y
When the content (wt%) of the vinyl cyanide compound in the axis and the graft axis is taken as the X axis, the coordinates (X, Y) of each vertex in the range of the diagonal line are G (25, 100), H (25, 6
0), I (31,0), J (36,0), K (45,4)
0) and L (45, 90).

In the regions (1) and (2) shown in FIGS. 1 and 2, the composition with a high VCN is small and the composition with a low VCN is too large. Therefore, sufficient sharpness is obtained after coating. In addition, the plating strength is overetched at the time of plating, and the peel strength and the heat cycle property are deteriorated.

Further, in the region (3), the component having a low VCN is small and the component having a high VCN is too large, so that the adhesiveness to the coating film is low and it is not sufficiently etched during plating. However, the heat cycle property is inferior.

For example, when the graft chain VCN is 29, the proportion of the component (F1) is 2 to 80%, preferably 10 to 70%, more preferably 15 to 50%.
At this time, the proportion of the component (F2) is 20 to 98%, preferably 30 to 90%, more preferably 50 to 85%. If the (F1) component exceeds 80%, or (F1)
If the content of the component 2) is less than 20%, the coating film will not have sufficient clarity, and plating will result in overetching, resulting in deterioration of peel strength and heat cycle properties.

When the VCN of the graft chain is 33,
The proportion of the component (F1) is 5 to 100%, preferably 10
˜90%, more preferably 15 to 85%. At this time, the proportion of the component (F2) is 0 to 95%, preferably 1
It is 0 to 90%, more preferably 15 to 85%.
If the content of the component (F1) is less than 5% or the content of the component (F2) exceeds 95%, sufficient adhesion to the coating film cannot be obtained, and etching is insufficient, resulting in peel strength, The heat cycle property is inferior.

When the graft chain VCN is 40,
The proportion of the component (F1) is 7-82%, preferably 10-.
75%, more preferably 20 to 70%. At this time, the proportion of the component (F2) is 18 to 93%, preferably 25 to 90%, more preferably 30 to 80%.
If the content of the component (F1) is less than 7% or the content of the component (F2) exceeds 93%, sufficient adhesion to the coating film, particularly multilayer coating adhesion, cannot be obtained, and etching during plating does not occur. Since it is insufficient, the peel strength and heat cycle property are inferior. When the content of the (F1) component exceeds 82% or when the content of the (F2) component is less than 18%, the image clarity after coating is deteriorated, and during plating,
Over-etching occurs, and sufficient peel strength and heat cycle properties cannot be obtained.

The VCN and the ratio thereof in the free copolymer are determined by the method of polymerization of the graft copolymer, the method of polymerization of the copolymer, the method of blending the graft copolymer and the copolymer, or a combination thereof. And the like. For example, in the graft copolymer polymerization, a method in which the ratio of the monomers is changed stepwise so that the free copolymer has a predetermined VCN ratio, or is changed sequentially, At
A method in which the ratio of monomers to be reacted is changed stepwise or sequentially, a method in which copolymers having two or more different VCNs are combined and blended, and two or more different VCNs are blended. There is a method of blending the above graft copolymers in combination, or a method of blending the graft copolymer and the copolymer in different combinations of VCN.

Further, in the VCN distribution state of the free copolymer, one having a plurality of peak tops, one having a broad distribution state, or a combination thereof, a copolymer having the above range is obtained. be able to. These polymers are obtained by emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization and a combination of these methods.

In the resin composition of the present invention, various additives such as pigments, dyes, lubricants, antioxidants, ultraviolet absorbers, antistatic agents, reinforcing agents, and fillers are added to the resin composition to the extent that their physical properties are not impaired. Can be blended into.

[0029]

The present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited to these examples.

Reference Example 1 Production of Graft Copolymer (A-1) Polybutadiene rubber latex (weight average particle size 0.2
5 μm, rubber solid content 45% by weight) 1000 parts by weight, potassium alkenyl succinate (alkenyl group is C _{13 to} C ₁₅ )
2 parts by weight were placed in a polymerization tank equipped with a ring cooler, and the gas phase was heated to 70 ° C. while substituting with nitrogen. Acrylonitrile 280
Parts by weight, 420 parts by weight of styrene, 2 parts of cumene hydroperoxide, 0.7 parts by weight of t-dodecyl mercaptan, and 500 parts of deionized water, 1.0 part of sodium formaldehyde sulfoxylate, and ferrous sulfate. 0.0
A solution in which 1 part and 0.4 part of sodium ethylenediaminetetraacetate were dissolved was continuously added and reacted for 6 hours. During this period, control the temperature of the polymerization system to 70 ° C,
After the additional addition was completed, the state was maintained for another hour to complete the polymerization. The obtained copolymer latex was coagulated and salted out, washed, dehydrated and dried to obtain a solid powder of the graft copolymer. The VCN of the graft chain was 39.9.

Reference Examples 2 to 6 Graft copolymer (A-2
~ 6) Production Except that the ratio of the vinyl cyanide compound and the aromatic vinyl compound was changed, it was produced in the same manner as the graft copolymer A-1,
The following graph and copolymer were obtained. Graft copolymer A-2: VCN of graft chain was 32.
It was 9. Graft copolymer A-3: VCN of the graft chain was 28.
It was 0. Graft copolymer A-4: VCN of graft chain was 25.
It was 6. Graft copolymer A-5: VCN of graft chain was 20.
It was 3. Graft copolymer A-6: VCN of graft chain was 47.
It was 5.

Reference Example 7 Production of Copolymer (B-1) Using 40 parts by weight of acrylonitrile, 60 parts by weight of styrene and ethylbenzene as a solvent, the above mixed solution was continuously fed to a completely mixed type polymerization reactor, The temperature of the polymerization system was controlled at 120 to 130 ° C to carry out the polymerization reaction. Then, the mixed liquid containing the polymer was taken out from the polymerization reactor, and the unreacted monomer and the solvent were removed under vacuum to obtain a copolymer. The VCN was 37.8 as a result of nitrogen analysis.

Reference Examples 8 to 10 Copolymers (B-2 to 4)
Manufacture of, except that the proportion of acrylonitrile and styrene was changed,
It was produced in the same manner as the copolymer B-1 to obtain the following copolymer. The copolymer B-2: VCN had a nitrogen analysis result of 33.5. The copolymer B-3: VCN had a nitrogen analysis result of 27.8. The result of nitrogen analysis of the copolymer B-4: VCN was 22.2.

Reference Example 11 Production of Copolymer (B-5) Production was carried out in the same manner as in Reference Example 7 except that 40 parts by weight of acrylonitrile, 50 parts by weight of styrene and 10 parts by weight of methyl acrylate were continuously added. VCN is the result of nitrogen analysis 3
It was 8.9. Further, the content of methyl acrylate was 9.6 wt% by IR analysis.

Example 1 35 parts by weight of the graft copolymer (A-1), the copolymer (B
-1) 5 parts by weight and 60 parts by weight of the copolymer (B-3) were blended and then melt-kneaded with an extruder to obtain pellets. Then, a test piece for measuring physical properties was produced using the pellets at a cylinder temperature of 240 ° C. and a mold temperature of 45 ° C. by an injection molding machine.

This test piece was evaluated by the method described for each of the following items. 50 × with injection molding machine
A 90 × 3 mm flat plate was molded and plated under the following conditions.

(1) Etching (sulfuric acid (98%) / chromic anhydride = 20 vol% / liter / 400 g / liter) was adjusted to 68 ° C., the test piece was immersed for 10 to 20 minutes, and then deionized water was used. It wash | cleaned and performed the following process. (2) Acid treatment A 10% hydrochloric acid aqueous solution was brought to 23 ° C., immersed for 1 minute, washed with pure water, and subjected to the next step treatment.

(3) Catalyst An aqueous solution of palladium chloride, stannous chloride and hydrochloric acid was kept at 20 ° C., immersed for 2 minutes, washed with pure water and subjected to the next step treatment. (4) Accelerator A sulfuric acid (10%) aqueous solution was brought to 40 ° C., immersed for 3 minutes, washed with pure water, and subjected to the next step treatment.

(5) Chemical Nickel Plating An aqueous solution of nickel sulfate, sodium citrate, sodium hypophosphite, ammonium chloride and ammonium water was brought to 40 ° C., immersed for 8 minutes and washed with pure water.
The following process treatment was performed.

(6) Copper electroplating An aqueous solution containing copper sulfate, sulfuric acid and a brightener is heated to 20 ° C.,
After dipping for 60 minutes at a current density of 4 A / dm ^2, it was washed with pure water, dried at 80 ° C. for 2 hours, and then sufficiently cooled. The thickness of the plated coating was about 40 μm.

Plating property evaluation item (1) Peel strength: Plating coating has a constant width (10 mm)
After cutting into pieces, the strength at the time of peeling from the test piece at an angle of 90 ° was measured. (2) Heat cycle test: -30 ° C for plated molded products
1 hour → room temperature × 15 minutes → 80 ° C × 1 hour → room temperature × 15
The test was conducted for 8 cycles with one minute as one cycle, and the presence or absence of swelling or cracking of the plating film was observed. ○ ……… No swelling or cracking. × ……… Blisters and cracks.

Coating test A flat plate of 50 × 90 × 3 mm was molded with an injection molding machine and coated under the following conditions. Paint: Acrylic-epoxy two-component paint (Kawakami Paint, Acton 500 NH 237P) Undercoat (black) + topcoat (clear) (1) Surface cleaning: Wipe the surface with gauze containing isopropanol. (2) Spray coating: Undercoat (film thickness 20-25
(3) Setting: Room temperature x 5 minutes (4) Spray coating: Top coat (film thickness 20-25μ
m) (5) Setting: Room temperature x 10 minutes (6) Baking: 75 ° C x 30 minutes (7) Cooling: Room temperature x 30 minutes In the case of a few coats, (8) Air baking: 75 ° C x 30 minutes ( 9) → (2) to (8) steps were repeated twice or three times to carry out coating to obtain a test sample.

Evaluation items for coating property (1) Image clarity: Image clarity measuring device ICM-ID (manufactured by Suga Test Instruments Co., Ltd.) Comb width 1 mm, reflection angle 45 ° went. The measured value was expressed in percentage, and the maximum value was set to 100, and the judgment was made according to the following judgment criteria. ○: A sharpness of 50% or more. ×: The sharpness is less than 50%.

(2) Adhesion: A test piece that had been applied once was subjected to a cross-cut (100 squares of 1 × 1 mm) on the gate side and the non-gate side with a multi-cross cutter.
A cellophane tape peeling test was performed. The evaluation was performed by obtaining an average of (the number of squares that do not peel) / (the number of crosses) on the gate side and the non-gate side.

(3) Adhesion of multi-layer coating: A cross-cut (1 × 1 mm square 100 on a gate side and a non-gate side) on a test piece with a few coats using a multi-cross cutter.
Cellophane tape peeling test. The evaluation was performed by obtaining an average of (the number of squares that do not peel) / (the number of crosses) on the gate side and the non-gate side.

(4) Water resistance: A test piece once coated is at 40 ° C.
After immersing in warm water for 240 hours, a cross-cut (1 x 1 mm) on the gate side and non-gate side with a multi-cross cutter
Then, a cellophane tape peeling test was performed. The evaluation was carried out by obtaining the average of (the number of squares without peeling) / (the number of crosses) on the gate side and the non-gate side.

(5) Chemical resistance: A non-ionic surfactant Ermagen was brought into contact with a test piece which had been applied once, and the test piece was subjected to 24 at 23 ° C.
The presence or absence of cracks and the presence or absence of peeling of the coating film after standing for a period of time were observed and evaluated according to the following criteria. ○ ……… No cracks and peelings × ………… Cracks and peelings are shown in Table 3 below. The ratio of VCN in the resin composition, VCN of the graft chain grafted on the rubbery polymer and VCN of the free copolymer and its components was determined by the following measuring method, and the results are shown in Table 2. .

Total VCN Measurement Method ABS resin pellets are compression molded at 180 ° C. to form a film having a thickness of about 3 μm. The film was measured by the IR transmission method, and each component was quantified by the calibration curve method. At that time, (the weight occupied by the vinyl cyanide compound) / (the weight occupied by the vinyl cyanide compound + the aromatic vinyl compound + the other monomers excluding the rubbery polymer)
The value of × 100 was taken as Total VCN.

Method for measuring VCN of graft chain ABS resin is dissolved in acetone and the insoluble matter is dried. This is compression-molded at 180 ° C. to form a film having a thickness of about 3 μm. IR the film
It was measured by a transmission method, and each component was quantified by a calibration curve method. At that time, (weight occupied by vinyl cyanide compound)
The value of / (vinyl cyanide compound + aromatic vinyl compound + weight occupied by other monomer excluding rubber-like weight body) × 100 was taken as VCN of the graft chain.

VCN of the free copolymer and the amount of its components ABS resin was dissolved in acetone, and the soluble component was dried to obtain a free copolymer. This was dissolved in tetrahydrofuran and used as a sample. Using a standard sample whose VCN is already known by nitrogen analysis, the relationship between VCN and retention time (Tr) is represented by a calibration curve. The samples were separated by high performance liquid chromatography, and VCN was determined from the calibration curve and retention time (Tr).

The measurement conditions are as follows. Equipment: High Performance Liquid Chromatography (manufactured by Shimadzu Corporation) Column: Silica-based cyanopropyl treated product Developing solvent: Tetrahydrofuran / n-hexane Detector: Ultraviolet ray (254 nm) Incidentally, the amount of (F1) component and the proportion (%) of (F2) (%) Was calculated from the peak area ratio by high performance liquid chromatography as shown in FIG. Δ _{254 in} FIG. 3 represents the absorbance at 254 nm.

Examples 2 to 12 Samples were prepared and evaluated in the same manner as in Example 1 except that the graft copolymer (A) and the copolymer (B) were blended in the proportions shown in Table 1.

Comparative Examples 1 to 9 Samples were prepared and evaluated in the same manner as in Example 1 except that the graft copolymer (A) and the copolymer (B) were blended in the proportions shown in Table 1.

The above results are shown as a fourth evaluation. From the comprehensive evaluation in Table 4, the resin composition of the present invention shows that the plating property, the heat cycle property, the image clarity after coating, the adhesion property,
It can be seen that the multi-layer coating adhesion, water resistance, and chemical resistance are all excellent.

[0055]

[Table 1]

[0056]

[Table 2]

[0057]

[Table 3]

(Note) In the above table, coating appearance: ○: Flow mark, no suction ×: Flow mark, suction included Heat cycle property: ○: No swelling or cracking ×: Swelling or cracking Chemical resistance Properties: ○ …… No cracking or peeling of coating film × …… Cracking or peeling of coating film

[0059]

[Table 4]

(Note) In the above table: Peel strength: ○ …… 1.0 or more × less than 1.0 ・ Heat cycle property: ○ …… No swelling or cracking × …… Swelling or cracking Appearance: ○ …… No flow mark, no suction × …… Flow mark, no suction ・ Vividness: ○ …… 50% or more × …… Less than 50% ・ Adhesion: ○ …… 100/100 (no peeling) × …… Peeling ・ Multilayer coating adhesion: ○ …… No peeling in both second and third coating × …… Peeling ・ Water resistance: ○ …… 100/100 (no peeling) × …… Peeling ・ Chemical resistance: ○ …… No cracks or peeling of coating film × …… Cracks or peeling of coating film

[0061]

EFFECTS OF THE INVENTION According to the present invention, the adhesion and water resistance of a coating film after coating are not deteriorated without deteriorating the appearance and sharpness of the coating film.
The effect of being able to provide a resin composition excellent in all of chemical resistance, multilayer coating adhesion, plating property, and heat cycle property is great.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between a range of a ratio of an F1 component and a range of a content ratio of a vinyl cyanide compound in a graft chain.

FIG. 2 is a diagram showing a relationship between a range of a ratio of an F2 component and a range of a content ratio of a vinyl cyanide compound in a graft chain.

FIG. 3 is an explanatory diagram of high performance liquid chromatography used for calculating the component amounts of F1 and F2.

Claims (2)

[Claims] 1. A graft copolymer obtained by copolymerizing a rubbery polymer with an aromatic vinyl compound and a vinyl cyanide compound, and optionally with a monomer copolymerizable with them in an amount of up to 50% by weight. A graft copolymer composition (A) consisting of a polymer and a free copolymer, and an aromatic vinyl compound and a vinyl cyanide compound, and optionally an aromatic vinyl compound or a vinyl cyanide compound in an amount of up to 50% by weight. Copolymer (B) obtained by copolymerizing a copolymerizable monomer
In the thermoplastic resin composition, the content of the vinyl cyanide compound (VCN) in the graft chain copolymerized with the rubber-like polymer is 25 to 45% by weight, and the grafting is performed on the rubber-like polymer. Not in free copolymer,
The ratio of the component (F1) having a vinyl cyanide compound content (VCN) of 20 to 28% by weight is the point ABCDE in FIG.
The ratio of the component (F2) within the range of the shaded area surrounded by F and having the vinyl cyanide compound content (VCN) of 32 to 45% by weight is the range of the shaded area surrounded by the point GHIJKL in FIG. A thermoplastic resin composition characterized by being in. 2. The content (VCN) of the vinyl cyanide compound in the graft chain copolymerized with the rubbery polymer is 25.
% To 45% by weight of the graft copolymer is a graft copolymer obtained by blending two or more kinds of graft copolymers in which the VCN in each graft chain is 20 to 50% by weight. The thermoplastic composition described.