JPH06329977A - Primer composition - Google Patents

Abstract

PURPOSE:To improve the adhesion of a primer compsn. to the surface of an object to be coated without the pretreatment of the surface with a chlorinous solvent by compounding a specific modified copolymer with an org. solvent. CONSTITUTION:A modified copolymer is obtd. by grafting 0.1-20wt.% hydroxylated ethylenically unsatd. monomer at 50 deg.C or higher for 2-10hr in the presence of a radical polymn. initiator onto a triblock copolymer comprising three blocks: a PS block having a number average mol.wt. (in tetrahydrofuran at 40 deg.C) by gel permeation chromatography) of 1X10<4>-18X10<4>, an elastomer block having a carbon backbone of the formula (wherein n is 0-6; and m is a positive integer), and another PS block or onto a hydrogenation product of the triblock copolymer with a degree of hydrogenation of at least 80%. A primer compsn. is obtd. by compounding 100 pts.wt. the modified copolymer with 50-10,000 pts.wt. org. solvent.

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a primer composition, and more particularly to a primer composition capable of exhibiting good adhesion to a material such as polyolefin without subjecting the coated surface of the material to pretreatment with a chlorine-based solvent.

[0002]

2. Description of the Related Art Conventionally, the added value has been increased by coating the surface of a molded product of polyolefin such as polypropylene or forming another resin layer. However, polyolefins are generally poor in polarity and have poor adhesion to general paints and other resins. Therefore, conventionally, the surface of a molded article made of polyolefin has been treated with a primer to improve the adhesion and adhesion to the surface. Therefore, the present inventors, as a composition that can be used for the application of these primers,
I made some suggestions earlier. For example, a primer composition containing, as a main component, a modified copolymer obtained by graft copolymerizing a styrene / butadiene block copolymer or a hydrogenated product thereof with an α, β-unsaturated vinyl monomer having a hydroxyl group (Japanese Patent Laid-Open No. 02- No. 110168), a primer composition containing a modified copolymer obtained by graft copolymerizing a styrene / isoprene block copolymer or a hydrogenated product thereof with an α, β-unsaturated vinyl monomer having a hydroxyl group as a main component (special (Kaihei 03-109471), a styrene-isoprene block copolymer or a hydrogenated product thereof is mainly a modified copolymer obtained by graft-copolymerizing a monoolefin dicarboxylic acid and its anhydride, and a monoalkyl ester of the monoolefin dicarboxylic acid. A primer composition (Japanese Patent Laid-Open No. 04-264174) as a component has been proposed. The primer composition containing these modified copolymers as a main component exhibited excellent adhesion to a material that has been conventionally pretreated by steam cleaning with 1,1,1-trichloroethane.

By the way, in recent years, from the viewpoint of protecting the global environment, the use of these chlorine-based solvents such as 1,1,1-trichloroethane has been restricted. Therefore, instead of pretreatment with a chlorine-based solvent, pretreatment with water-based cleaning, alcohol cleaning or the like is being considered, and the primer composition is also required to be compatible with these pretreatments. However, the previously proposed primer composition has not always been able to exhibit sufficient adhesiveness and adhesiveness to these pretreated materials. Therefore, the inventors of the present invention conducted further studies and added α to the modified copolymer described above.
-A priming composition having a chlorinated product of an olefin polymer and capable of exhibiting excellent adhesion and adhesion even to a material not subjected to pretreatment with a chlorine solvent was previously proposed. (Japanese Patent Laid-Open No. 04-248845)

[0004]

However, the above-mentioned Japanese Patent Laid-Open No.
The primer composition described in JP-A-4-248845 is
Since chlorinated polyolefin is used, it cannot be said that it is preferable from the standpoint of global environment protection in terms of production and recycling of the material itself.

Therefore, an object of the present invention is to form a primer layer having good adhesion on polyolefins such as polypropylene and other resin molded articles without pretreatment with a chlorine-based solvent, and It is an object of the present invention to provide a non-chlorine-based primer composition which can be coated with a coating material on the top to obtain a coated article having excellent adhesion.

[0006]

In order to solve the above-mentioned problems, the present invention provides a triblock copolymer composed of polystyrene block / elastomer block having a carbon skeleton represented by the following general formula (A) / polystyrene block. Alternatively, 100 parts by weight of a modified copolymer obtained by graft-copolymerizing the hydrogenated product with 0.1 to 20% by weight of an ethylenically unsaturated monomer having a hydroxyl group, and 50 to 10000 parts by weight of an organic solvent. The present invention provides a primer composition containing

[0007]

[Chemical 2] [In the formula, n is an integer of 0 to 6 and m is a positive integer]

The elastomer block having a carbon skeleton represented by the general formula (A) is preferably a block structural unit derived from vinylisoprene.

The ethylenically unsaturated monomer having a hydroxyl group is preferably a (meth) acrylic acid ester having a hydroxyl group in the ester portion.

The primer composition of the present invention will be described in detail below.

The modified copolymer which is an essential component of the primer composition of the present invention is a polystyrene block / elastomer block having a carbon skeleton represented by the following general formula (A) / a triblock copolymer having a polystyrene block or An unsaturated monomer having a hydroxyl group is graft-copolymerized with the hydrogenated product.

This polystyrene block / general formula (A)
A triblock copolymer composed of an elastomer block / polystyrene block having a carbon skeleton represented by
It is a copolymer in which a polystyrene block, which is a polymer block derived from one or more styrenes, and an elastomer block represented by the general formula (A) are shared therebetween.

The styrene content in the triblock copolymer or hydrogenated product thereof is 10 to 60% by weight from the viewpoints of adhesion of the coating film of the primer composition obtained, low temperature characteristics, coating strength, stickiness and the like. %, Particularly preferably 12 to 45% by weight.

The elastomer block is composed of the block structural unit represented by the general formula (A). In the general formula (A), n is an integer of 0 to 6,
m is a positive integer, and usually m is a positive integer of 100 to 3000. Examples of the monomer for forming the elastomer block include isoprene, piperylene, 4-methyl-1-pentene and the like.

The hydrogenated product of the triblock copolymer is one in which hydrogen is added to a part or all of the unsaturated bonds in the molecule, and when a modified copolymer is produced by a graft copolymerization reaction. Moreover, it is preferable in that gelation during the reaction can be suppressed. The hydrogenation rate of the hydrogenated product of this triblock copolymer is usually 80% or more, preferably 85% or more.

Specific examples of the triblock copolymer or hydrogenated product thereof include those marketed under the trade name: HYBRAR (Kuraray Co., Ltd.).

This triblock copolymer or its hydrogenated product (hereinafter simply referred to as "triblock copolymer")
In terms of strength and solid content concentration of the obtained primer composition, the number average molecular weight measured by gel permeation chromatography at 40 ° C. in a tetrahydrofuran solvent is 1 × 10 ⁴ to 18 × 10 ^4. From the standpoint of production, those of 1.5 × 10 ^{4 to} 12 × 10 ⁴ are particularly preferable.

In order to obtain the modified copolymer used in the present invention, the ethylenically unsaturated monomer having a hydroxyl group, which is graft-copolymerized with the triblock copolymer, has at least one hydroxyl group in the molecule. And a compound having at least one ethylenic double bond. This ethylenically unsaturated monomer has, for example, a hydroxyl group in the ester part (meth)
Examples thereof include acrylic acid ester, unsaturated alcohol, hydroxyl group-containing styrene derivative, and hydroxy vinyl ether. In the present invention, the modified copolymer may be formed by graft copolymerizing one kind of the ethylenically unsaturated monomer or two or more kinds thereof simultaneously.

Examples of the (meth) acrylic acid ester having a hydroxyl group in the ester part include hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate and 2-hydroxy-3. -Phenoxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, glycerin mono (meth)
Examples thereof include acrylate, pentaerythritol mono (meth) acrylate, trimethylolpropane mono (meth) acrylate, tetraethylolethane mono (meth) acrylate, butanediol mono (meth) acrylate, and polyethylene glycol mono (meth) acrylate.

As the unsaturated alcohol, for example, 10
-Undecen-1-ol, 1-octen-3-ol, 2-methanol norbornene, allyl alcohol and the like can be mentioned.

Examples of the hydroxyl group-containing styrene derivative include hydroxystyrene and the like.

Examples of the hydroxy vinyl ether include the following formula (I): CH ₂ ═CH (CH ₂ ) _n O (CH ₂ ) _m OH (I) [wherein n is an integer of 0 to 2 and m Is an integer of 1 to 4]. Specific examples of the hydroxy vinyl ether include hydroxymethyl vinyl ether, hydroxyethyl vinyl ether, hydroxymethyl propenyl ether, hydroxymethyl isopropenyl ether and the like.

Further, as the ethylenically unsaturated monomer having a hydroxyl group, N-methylol acrylamide, 2-
(Meth) acryloyloxyethyl acid phosphate, glycerin monoallyl ether, allyl alcohol, allyloxyethanol, 2-butene-1,4-diol and the like can be mentioned.

In the present invention, among these ethylenically unsaturated monomers, the ester portion has a hydroxyl group because it has high reactivity as a monomer, is easily available, and is advantageous in cost. ) Acrylic acid esters are preferable, and 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and 2-hydroxyethyl methacrylate are particularly preferable.

Further, the grafting amount of the ethylenically unsaturated monomer having a hydroxyl group in the modified copolymer, that is, the content in the modified copolymer, is a coating amount which is applied as a primer to a molded article so that the coating material has high adhesiveness. 0.1 to 20% by weight, preferably 0.2 to 15% by weight, from the viewpoint that a film is obtained, and that the adhesion between the coating film and the molded article is good and a primer composition having a good appearance is obtained. % By weight.

As a method for graft-copolymerizing an unsaturated monomer having a hydroxyl group with the triblock copolymer, various methods can be mentioned. For example, a method in which the triblock copolymer is dissolved in an organic solvent, the ethylenically unsaturated monomer and the radical polymerization initiator are added, and the mixture is heated and stirred to perform a graft copolymerization reaction, the triblock copolymer Is heated and melted, an ethylenically unsaturated monomer and a radical polymerization initiator are added to the obtained melt, and the mixture is stirred to carry out a graft copolymerization reaction, the triblock copolymer, and an ethylenically unsaturated monomer. Body and a radical initiator are mixed in advance, the resulting mixture is fed to an extruder and a graft copolymerization reaction is performed while heating and kneading, the powdery triblock copolymer, an ethylenically unsaturated monomer and After impregnating a solution prepared by dissolving a radical polymerization initiator in an organic solvent, it is heated to the maximum temperature at which the powdery triblock copolymer is not dissolved, and the graft copolymerization reaction is performed. It can be mentioned, such as how to. When the unsaturated bond of the triblock copolymer and the hydrogenated product thereof remains, the radical polymerization initiator is not always necessary, and the graft copolymerization described above is performed in the absence of the radical polymerization initiator. The reaction can be carried out.

The reaction temperature is 50 ° C. or higher, particularly 80 to 20.
The range of 0 ° C. is suitable, and the reaction time is about 2 to 10 hours. The reaction system may be either a batch system or a continuous system, but the batch system is preferred in order to uniformly carry out the graft copolymerization.

When the graft reaction is carried out using a radical polymerization initiator, any radical polymerization initiator may be used so long as it promotes the reaction between the triblock copolymer and the ethylenically unsaturated monomer. However, organic peroxides and organic peresters are particularly preferable. Specifically, benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di (peroxybenzoate) hexyne-3,1,4-bis (tert. -Butylperoxyisopropyl) benzene, lauroyl peroxide, tert-butyl peracetate, 2,5-dimethyl-2,5-di (tert-
Butylperoxy) hexyne-3,2,5-dimethyl-
2,5-di (tert-butyl peroxide) hexane, tert-butyl benzoate, tert-butyl perphenyl acetate, tert-butyl perisobutyrate, tert-butyl per-c-octoate,
There are tert-butyl perpiperate, cumyl perpiperate and tert-butyl perdiethyl acetate, as well as other azo compounds such as azobis-isobutyl nitrile and dimethylazoisobute. Among these, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di (tert.
Dialkyl peroxides such as -butylperoxy) hexyne-3,2,5-dimethyl-2,5-di (tert-butylperoxy) hexane and 1,4-bis (tert-butylperoxyisopropyl) benzene are preferred.

The primer composition of the present invention further contains an organic solvent in addition to the modified copolymer. As the organic solvent used, for example, benzene, toluene, aromatic hydrocarbons such as xylene, hexane, heptane, octane, aliphatic hydrocarbons such as decane, cyclohexane, cyclohexene, alicyclic hydrocarbons such as methylcyclohexane, Examples thereof include aliphatic alcohols such as ethanol and isopropyl alcohol, ketone-based solvents such as acetone, methyl isobutyl ketone, and methyl ethyl ketone. You may use these individually by 1 type or in mixture of 2 or more types. Among these, aromatic hydrocarbons are preferable, and alkyl group-substituted aromatic hydrocarbons are particularly preferable.

The mixing ratio of the modified copolymer and the organic solvent in the primer composition of the present invention is 50 to 10,000 parts by weight of the organic solvent based on 100 parts by weight of the modified copolymer,
The ratio of the organic solvent is preferably 200 to 2000 parts by weight with respect to 100 parts by weight of the modified copolymer.

Further, the primer composition of the present invention contains various stabilizers such as antioxidants, weather resistance stabilizers, and heat resistance inhibitors, colorants such as inorganic pigments and organic pigments, and conductive materials such as carbon black and ferrite, if necessary. It may contain components such as a sex-providing agent.

Examples of the pigment used include cadmium pigments such as titanium oxide, zinc oxide, lead white, red lead, cuprous oxide, red iron oxide, wet synthetic iron oxide, iron black, cadmium yellow, molybdenum red, silver vermilion, and the like. Examples include yellow lead, zinc chromate, chromium oxide, navy blue, carbon black, precipitated barium sulfate, barite powder, ordinary light calcium carbonate, ultrafine calcium carbonate, alumina white, and white carbon. You may use these individually by 1 type or in mixture of 2 or more types.

The primer composition of the present invention is effective for improving the adhesion of the coating material to the surface of a molded article made of an olefin polymer or copolymer or other polymer. For example, high-pressure polyethylene, medium-low-pressure polyethylene, polypropylene, poly-4-methyl-1-pentene,
It can be preferably used for a molded article made of a polyolefin such as polystyrene or a polyolefin copolymer such as an ethylene / propylene copolymer, an ethylene / butene copolymer, or a propylene / butene copolymer.

Further, in addition to the above-mentioned polyolefin and its polymer, the primer composition of the present invention is a molded product made of polypropylene and synthetic rubber, polyamide resin, unsaturated polyester resin, polybutylene terephthalate resin, polycarbonate. It can also be used for molded articles such as bumpers for automobiles made of resin or the like, and further for surface treatment of steel sheets, electrodeposited steel sheets and the like. In addition, polyurethane resin, fatty acid-modified polyester resin, oil-free polyester resin, melamine resin, epoxy resin, etc. as a main component, primer, adhesive, etc. While improving the adhesion,
It is also used to form coatings with excellent image clarity and low-temperature impact resistance.

In particular, the primer composition of the present invention comprises a molded article made of polyolefin such as polypropylene, a molded article made of polypropylene and synthetic rubber such as an automobile bumper, an SMC molded article using an unsaturated polyester resin, an epoxy resin, etc. R-RIM molded product of polyurethane resin,
It is suitable for undercoating a glass fiber reinforced polyamide resin molded product, a polyurethane resin molded product, a cationic electrodeposition coated steel plate or the like to improve the adhesion of the coating material to the surface of these molded products.

The molded article to which the coating method of the present invention is applied can be produced by injection molding, compression molding, hollow molding, extrusion molding, rotational molding, or any other known molding method in which the above-mentioned various polymers or resins are used. It may be molded by a method.

The primer composition of the present invention is particularly applied when the molded article to which the primer composition is applied is blended with an inorganic filler such as talc, zinc white, glass fiber, titanium white, magnesium sulfate and the like, a pigment and the like. A primer coating film having good film adhesion can be formed.

In addition to the above, the molded product may also contain various stabilizers, ultraviolet absorbers, hydrochloric acid absorbers and the like. Stabilizers preferably used include, for example, 2,
6-di-t-butyl-4-methylphenol, tetrakis [methylene (3,5-di-t-butyl-4-hydroxyhydrocinnato)] methane, metaoctadecyl-3
-(4'-hydroxy-3,5-di-t-butylphenyl) propionate, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 4,4'-butylidenebis (3-methyl) -6-t-butylphenol),
4,4'-thiobis (3-methyl-6-t-butylphenol), 2,2-thiobis (4-methyl-6-t-butylphenol), 1,3,5-trimethyl-2,4
Phenolic stabilizers such as 6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene and 1,3,5-tris (2-methyl-4-hydroxy-5-t-butylphenol) butane Examples thereof include sulfur stabilizers such as dilauryl thiodipropionate and distearyl thiodipropionate, and phosphorus stabilizers such as tridecyl phosphite and trinonylphenylyl phosphite.

The ultraviolet absorbers preferably used include, for example, 2-hydroxy-4-octoxybenzophenone, 2-ethylhexyl-2-cyano-3,3-diphenyl acrylate, paraoctylphenyl salicylate and the like. Further, as the hydrochloric acid absorbent, for example, calcium stearate or the like is preferably used.

As a method for applying the primer composition of the present invention to the surface of a molded product, spray coating is suitable, and for example, a method of spraying the surface of the molded product with a spray gun is adopted. The coating on the molded product may be carried out at room temperature, and after coating, it can be dried by an appropriate method such as natural drying or forced drying by heating to form a primer coating film.

As described above, the primer composition of the present invention is applied to the surface of a molded article and dried to form a primer coating film on the surface of the molded article, and then a coating material is applied to obtain a good coating. Can be painted. At this time, the coating can be applied by any method such as electrostatic coating, spray coating, and brush coating. Further, the coating material may be applied by a method of overcoating after undercoating. After applying the paint, nichrome wire, infrared,
The coating film can be cured according to a usual method of heating with high frequency to obtain a molded article having the desired coating film on the surface. The method for curing the coating film can be appropriately selected depending on the material and shape of the molded product, the properties of the coating material used, and the like.

The paint applied to the primer coating film formed by the primer composition of the present invention is not particularly limited, and any paint may be used. In particular, the primer composition of the present invention is a solvent-type thermoplastic acrylic resin coating material, a solvent-type thermosetting acrylic resin coating material, an acrylic modified alkyd resin coating material, an epoxy resin coating material, a polyurethane resin coating material, a melamine resin coating material, etc. In addition, it is preferable because the primer coating film having high paint adhesion can be formed by previously undercoating the coated surface of the molded product.

Further, the primer composition of the present invention can be applied to a wide range of applications in addition to the above-mentioned use as a primer for molded articles, by taking advantage of its characteristics.
For example, it can be applied to applications such as adhesives and paint additives.

[0044]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In the following, the physical property test of the coating film,
The procedure was as follows.

Cross-cut test According to the method of the cross-cut test described in JIS K 5400, a cross-cut test piece is prepared, and a cellophane adhesive tape (Nichiban Co., Ltd. product) is attached onto the cross-cut test. After that, this was rapidly pulled in the 90 ° direction to be peeled off, and the number of crosses not peeled out of the 100 crosses was evaluated.

Peeling strength A coating film was prepared on a substrate, a 1 cm width was cut by a cutter blade until the blade reached the substrate, the end portion was peeled off, and the end portion of the peeled coating film was removed. The peel strength was determined by pulling in the direction of 180 ° at a speed of 50 mm / min.

(Example 1) Volume 1.0 l equipped with a stirring blade
Was added to a glass autoclave of polystyrene / polyvinylisoprene / polystyrene triblock copolymer (HYBRAR HVS-3 Kuraray Co., Ltd.).
105 g of styrene, number average molecular weight 10 × 10 ⁴ , styrene content: 20% by weight, and 340 ml of dehydrated toluene were added, and heated at 165 ° C. to dissolve. Subsequently, a solution of 12.84 g of 2-hydroxypropyl acrylate dissolved in 40 ml of dehydrated toluene and a solution of 1.23 g of di-t-butylperoxide dissolved in 40 ml of dehydrated toluene were prepared, and both solutions were prepared for 4 hours. It dripped sequentially. After completion of the dropping, the reaction was carried out at 165 ° C. for 2 hours. After completion of the reaction, a large amount of methanol was added to the reaction mixture to precipitate the modified copolymer. The resulting modified copolymer was repeatedly washed with methanol and then placed in a vacuum drier to obtain 60
It was dried at 40 ° C. and 40 cmHg overnight.

The graft amount of 2-hydroxypropyl acrylate of the obtained modified copolymer was measured by oxygen analysis and found to be 6.8% by weight.

Next, the modified copolymer thus obtained was dissolved in toluene to prepare a toluene solution having a modified copolymer concentration of 15% by weight.

The obtained toluene solution was spray-applied to a square plate of polypropylene (X440: manufactured by Mitsui Petrochemical Industry Co., Ltd.) the surface of which was wiped with isopropyl alcohol so as to have a rate of 200 g / m ^2, and then a topcoat paint ( R-271 manufactured by Nippon Bee Chemical Co., Ltd. was applied to a dry film thickness of 40 μm to form a coating film. After leaving it for 10 minutes at room temperature, it was placed in an air oven at 85 ° C. and baked for 30 minutes. This was used as a sample for a cross-cut test and a peel strength test. The results are shown in Table 1.

(Example 2) Using the toluene solution obtained in Example 1, the topcoat paint was changed to Soflex 1200 (Kansai Paint Co., Ltd.) and the baking conditions were set to 120 ° C.
A sample was obtained in the same manner as in Example 1 except that the time was changed to 30 minutes. This sample was subjected to a cross-cut test and a peel strength test. The results are shown in Table 1.

(Example 3) In Example 1, the solution of 2-hydroxypropyl acrylate added dropwise was replaced with a solution of 4.28 g of 2-hydroxypropyl acrylate dissolved in 40 ml of dehydrated toluene, and di-t-butylperoxide was added. -A reaction was carried out in the same manner as in Example 1 except that no oxide was used to obtain a modified copolymer. The graft amount of 2-hydroxypropyl acrylate of the obtained modified copolymer was 2.1% by weight. Next, a toluene solution of this modified copolymer was prepared in the same manner as in Example 1, and coating was performed in the same manner as in Example 1 using this toluene solution as a sample.
It was subjected to a cross-cut test and a peel strength test. The results are shown in Table 1.

(Comparative Example 1) A hydrogenated product of polystyrene / polyisoprene / polystyrene triblock copolymer (Kuraray Co., Septon 200) was used as the starting material resin to be modified.
2, number average molecular weight: 4.5 × 10 ⁴ , styrene content: 3
A modified copolymer was obtained in the same manner as in Example 1 except that 0% by weight) was used. The graft amount of 2-hydroxypropyl acrylate of the obtained modified copolymer was 5.8% by weight.
Met. Next, a toluene solution of the modified copolymer was prepared in the same manner as in Example 1, and the toluene solution was used as a sample for coating in the same manner as in Example 1 and subjected to a cross-cut test and a peel strength test. The results are shown in Table 1.

Comparative Example 2 A raw material resin to be modified is a hydrogenated product of polystyrene / polybutadiene / polystyrene triblock copolymer (Kreton G manufactured by Shell Chemical Co., Ltd.).
1652, number average molecular weight: 8.5 × 10 ⁴ , styrene content: 30% by weight) were used to obtain a modified copolymer in the same manner as in Example 1. 2- of the obtained modified copolymer
The graft amount of hydroxypropyl acrylate is 5.2
% By weight. Next, a toluene solution of the modified copolymer was prepared in the same manner as in Example 1, and the toluene solution was used as a sample for coating in the same manner as in Example 1 and subjected to a cross-cut test and a peel strength test. The results are shown in Table 1.

[0055]

[0056]

INDUSTRIAL APPLICABILITY The primer composition of the present invention can form a primer layer having good adhesion on polyolefins such as polypropylene and other resin molded products without pretreatment with a chlorine-based solvent. Further, it is a chlorine-free composition which can be coated with a coating material to obtain a coated article having excellent adhesion.

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Hajime Inagaki Mt. 6-1, 1-2 Waki, Waki-cho, Kuga-gun, Yamaguchi Prefecture Mitsui Petrochemical Industry Co., Ltd.

Claims (3)

[Claims] 1. A polystyrene block / the following general formula (A)
The graft block of the triblock copolymer consisting of an elastomer block / polystyrene block consisting of a carbon skeleton represented by or a hydrogenated product thereof containing 0.1 to 20% by weight of an ethylenically unsaturated monomer having a hydroxyl group. 100 parts by weight of a modified copolymer obtained by polymerization, and an organic solvent 50
A primer composition containing 1 to 10,000 parts by weight. [Chemical 1] [In the formula, n is an integer of 0 to 6 and m is a positive integer] 2. The primer composition according to claim 1, wherein the elastomer block having a carbon skeleton represented by the general formula (A) is a block structural unit derived from vinylisoprene. 3. The primer composition according to claim 1, wherein the ethylenically unsaturated monomer having a hydroxyl group is a (meth) acrylic acid ester having a hydroxyl group in the ester portion.