JPH0489829A - Aqueous dispersion - Google Patents

Abstract

PURPOSE:To obtain an aqueous dispersion excellent in adhesion to a resin molding and desirable as a primer by dispersing a specified amount of a chlorinated polyolefin prepared by chlorinating a specified modified styrene/isoprene block copolymer in water. CONSTITUTION:A chlorinated polyolefin of a chlorine content of 10-50wt.% prepared by chlorinating a modified polymer which is prepared by grafting 0.05-25wt.% hydroxylated alpha,beta-unsaturated vinyl monomer [e.g. hydroxyethyl (meth)acrylate or glycerol mono(meth)acrylate] onto a styrene/isoprene block copolymer or its hydrogenated product, is dispersed in water to obtain an aqueous dispersion comprising 5-70 pts.wt. above chlorinated polyolefin and 95-30 pts.wt. water. This dispersion excels in adhesion to a resin molding especially a molding of a polyolefin such as PP, can give a coating film having sufficient peeling strength and adhesion, does not contain any organic solvent, can keep the working environment good, and is desirable as a primer.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an aqueous dispersion, and particularly to an aqueous dispersion that can be used as an undercoat for a molded article to improve the adhesion of a paint to the surface of the molded article.

<Prior Art> Conventionally, the surface of a molded product made of polyolefin such as polypropylene is coated to increase its added value. However, polyolefins generally have poor polarity and poor paint adhesion. Therefore, conventionally, the surface of the molded article is treated with a brimer in advance to improve the adhesion and adhesion of the paint.

Therefore, as a binder for a paint that can be applied in one coat directly to molded products without using a primer, (meth)acrylic acid ester is added to a hydrogenated product of styrene/butadiene/styrene block copolymer in an inert organic solvent. ,
In particular, resin compositions for coatings obtained by polymerizing vinyl monomers having hydroxyl groups have been proposed. (Unexamined Japanese Patent Publication No. 63-51
477 Publication) <Problem to be Solved by the Invention> However, even if the resin composition for paint described in the above-mentioned JP-A-63-51477 is used, the resulting coating film does not have sufficient peel strength. isn't it. Additionally, all conventional brimers, including this composition, contain organic solvents or are used after being dissolved in organic solvents, which poses the problem of deteriorating the working environment during manufacture and use. .

Therefore, the object of the present invention is to have excellent adhesion to resin molded products, especially polyolefin molded products such as VOPP propylene, so that a coating film with sufficient peel strength can be obtained, and since it is water-based, it can be used in a working environment. can be kept in good condition,
The object of the present invention is to provide an aqueous dispersion suitable as a brimer.

<Means for Solving the Problems> In order to solve the above problems, the present invention provides a styrene/isoprene block copolymer or a hydrogenated product thereof with zero α,β-unsaturated vinyl monomers having hydroxyl groups. .05~2
An aqueous dispersion obtained by dispersing in water a chlorinated polyolefin having a chlorine content of 10 to 50% by weight, which is obtained by further chlorinating a modified polymer obtained by graft copolymerizing to contain 5% by weight of the chlorine. The present invention provides an aqueous dispersion containing 95 to 30 parts by weight of water to 5 to 70 parts by weight of polyolefin.

Further, it is preferable that the α,β-unsaturated vinyl monomer having a hydroxyl group is a (meth)acrylic ester of a monohydric alcohol or a mono(meth)acrylic ester of a polyhydric alcohol.

Hereinafter, the aqueous dispersion of the present invention will be explained in detail.

The styrene-isoprene block copolymer, which is the main component of the modified polymer that is a constituent component of the aqueous dispersion of the present invention, contains a styrene polymer block that is a repeating structural unit derived from one or more styrenes, and a styrene polymer block that is a repeating structural unit derived from one or more styrenes. It is a copolymer containing an isoprene polymer block which is a repeating structural unit derived from isoprene, for example, - formula: % formula % (wherein, S represents a styrene polymer block, ■ represents an isoprene polymer block, n is an integer of 1 or more).

This styrene-isoprene block copolymer is disclosed in, for example, US Patent No. 3,265. ．． Specification No. 765, JP-A-6
Examples include those manufactured by the method described in JP 1-192743 and the like. This styrene
Specific examples of isoprene block copolymers include those commercially available as Kaliflex R1107 and TR1117 (both manufactured by Shell Chemical Co., Ltd.).

Further, the hydrogenated product of this styrene/isoprene block copolymer is, for example, one having an iodine value of 20% or less,
Examples include those manufactured by the methods described in Japanese Patent Publication No. 48-3555, Japanese Patent Publication No. 48-3555, and the like.

These styrene-isoprene block copolymers or their hydrogenated products are suitable for gel permeation at 40°C using tetrahydrofuran as a solvent, from the viewpoint of the peel strength and solid content concentration of the coating film of the aqueous dispersion of the present invention. The number average molecular weight measured by chromatography is I
0' to 18X10' is preferred, especially 1.5
Preferably, the range is from X10' to 12X10'. In addition, the styrene content is determined to be 10% from the viewpoint of adhesion, peel strength, low temperature properties, stickiness, etc. of the coating film of the aqueous dispersion of the present invention.
It is preferably from 12 to 55% by weight, particularly preferably from 12 to 55% by weight.

The aqueous dispersion of the present invention consists of a styrene/isoprene block copolymer or a hydrogenated product thereof (hereinafter simply referred to as a "block copolymer") containing α,β-unsaturated vinyl having a hydroxyl group. It is made by dispersing in water a chlorinated modified polyolefin obtained by chlorinating a modified polymer obtained by graft copolymerizing monomers (hereinafter simply referred to as "vinyl monomers"). Examples of the vinyl monomer include hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxybrobyl (meth)acrylate, and 2-hydroxypropyl (meth)acrylate.
(meth)acrylic acid esters of monohydric alcohols such as hydroxy-3-phenoxypropyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate; glycerin mono (meth)acrylate, pentaerythritol mono (meth)acrylate; ) acrylate, mono(meth)acrylate esters of polyhydric alcohols such as trimethylolpropane mono(meth)acrylate, tetraethyloethane mono(meth)acrylate, butanediol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate, etc. :l○-Undecene 1
-ol, 1-octen-3-ol, 2-methanol norbornene, hydroxystyrene, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, N
-methylol acrylamide, 2-(meth)acryloyloxyethyl acid phosphate, glycerin monoallyl ether, allyl alcohol, allyloxyethanol, and the like. Among these, (meth)acrylic esters of monohydric alcohols or mono(meth)acrylic esters of polyhydric alcohols are preferably used.

This vinyl monomer is graft copolymerized to the above-mentioned block copolymer to constitute a modified polymer so that the vinyl monomer is contained in an amount of 0.05 to 25% by weight, preferably 1 to 10% by weight. By using such a modified polymer, it is possible to obtain an aqueous dispersion that forms a coating film with excellent adhesion and water resistance.

The production of the modified polymer which is a constituent component of the aqueous dispersion of the present invention can be carried out, for example, by adding the vinyl monomer to the block copolymer in the presence of a radical polymerization initiator, in the presence or absence of an inert solvent. This can be done by graft copolymerizing the body.

As a method of graft copolymerization in the presence of an inert solvent, for example, 10 to 3000 kg of a block copolymer, preferably 20 to 100 kg, of a block copolymer is added to 1 m'' of an inert solvent such as toluene.
After preparing a solution by dissolving 0 kg, add 0.5 to 10 vinyl monomers per 1 kg of block copolymer in the solution.
The radical polymerization initiator is added sequentially at a rate of 0 mmol/min, preferably 1 to 20 mmol/min, and the radical polymerization initiator is added at a rate of 5X10-' to 50 mmol/min, preferably lXl0-2 to 5 mmol/kg of block copolymer. There is a method of sequentially adding and reacting at a ratio of At this time,
The ratio of radical polymerization initiator/vinyl monomer used is usually 1/100 to 315, preferably 1720 in molar ratio.
It is in the range of ~1/2. Further, the reaction is preferably carried out under heating and stirring. The reaction temperature is 50°C or higher, especially 80°C.
The temperature range is preferably 200° C. to 200° C., and the reaction time is about 2 to 10 hours. The reaction method may be either batch or continuous, but in order to carry out the graft copolymerization uniformly,
A batch method is preferred.

In addition, as a method for performing graft copolymerization in the absence of an inert solvent, for example, the block copolymer is A method may be mentioned in which the copolymer is heated and melted and stirred vigorously to cause the reaction to occur. Furthermore, the block copolymer, the vinyl monomer, and the radical polymerization initiator can be mixed in advance, and the mixture can be heated and melted in an extruder and graft copolymerized while being extruded. In the methods carried out in the absence of these inert solvents, the amounts of vinyl monomer and radical polymerization initiator used, as well as the proportions of both, are the same as in the methods carried out in the presence of the above-mentioned inert solvents. .

Examples of the radical polymerization initiator used in the graft copolymerization include benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-t
-Butylperoxide, 25-dimethyl-di(peroxybenzoate)hexyne-3,1,4-bis(1-butylperoxyisopropyl)benzene, lauroylperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy) -hexyne-3,2,5-dimethyl-2
, 5-di(1-butylperoxy)-hexane and other organic peroxides, t-butyl peracetate, t-butyl perbenzoate, t-butyl perphenylacetate, t-butyl perisobutyrate, t-butyl peruvooct ate, t-butyl bivalate, cumyl perpivalate, t-butyl perdiethyl acetate and other organic peresters; azo compounds such as azobisisobutyronitrile and dimethylazoisobutyronitrile;
Preferred are organic peroxides and organic bersesters.

The aqueous dispersion of the present invention is obtained by further chlorinating the modified polymer obtained as described above to prepare a chlorinated modified polyolefin, and dispersing this chlorinated modified polyolefin in water. This chlorinated modified polyolefin is easily dissolved in a solvent (it is easy to produce an aqueous dispersion using the solvent substitution method described later), and can be applied to molded products to obtain a coating film with high paint adhesion. In that an aqueous dispersion is obtained, the chlorine content is 10 to 40% by weight, preferably 1
5 to 35% by weight. In addition, this chlorinated modified polyolefin usually has a solution viscosity of 100 to 100.
00 cps, preferably about 200 to 5000 cps.

This chlorinated modified polyolefin can be produced by dissolving or dispersing the modified polymer in a suitable organic solvent and then reacting it with chlorine gas. This reaction is usually carried out at a temperature of about 50 to 120°C and about 0.5 to 5
It is common to do this by time. In addition, in order to make the reaction proceed efficiently, we may irradiate it with ultraviolet rays or visible light.
Alternatively, a radical polymerization initiator may be used.

Examples of organic solvents used include aliphatic hydrocarbons such as hexane, heptane, octane, decane, dodecane, and tetradodecane; alicyclic hydrocarbons such as methylcyclobencune, cyclohexane, methylcyclohexane, cyclooctane, and cyclododecane. ; Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene, ethyltoluene, trimethylbenzene, diisopropylbenzene, etc.; , halogenated hydrocarbons such as trichloroethane, trichloroethylene, and tetrachloroethylene. These may be used alone or in combination of two or more.

Further, when a radical polymerization initiator is used, examples of the radical polymerization initiator include those used in the graft copolymerization described above.

The aqueous dispersion of the present invention is obtained by dispersing the chlorinated modified polyolefin obtained as described above in water. Examples of the method for producing the aqueous dispersion of the present invention by dispersing the chlorinated modified polyolefin in water include a drum emulsification method in which the chlorinated modified polyolefin, water, and a surfactant are mixed all at once and emulsified; A pulverization method in which a pre-pulverized chlorinated modified polyolefin is poured into water with a surfactant and dispersed, and a chlorinated modified polyolefin dissolved in an organic solvent is mixed with a surfactant and water.
Solvent substitution method for removing the organic solvent: homomixer method for performing dispersion using a homomixer; phase inversion method, etc., which are appropriately selected depending on the physical properties of the chlorinated modified polyolefin used.

As the surfactants used, mention may be made of nonionic and anionic surfactants. Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, boxoxyethylene sorbitan ester, polyoxyethylene alkylamine ether, and the like.

Examples of anionic surfactants include fatty acid salts,
Higher alcohol sulfate ester, sodium alkylbenzene sulfonate, naphthalene sulfonate formalin condensate,
Examples include polyoxyethylene alkyl ether sulfate, and sodium alkylbenzene sulfonate is particularly preferred.

The amount of this surfactant used is usually 0.05% based on the amount of the modified polymer, in order to ensure a good dispersion state of the modified polymer and good adhesion of the resulting aqueous dispersion to the molded product. ~1
It is preferably about 0% by weight, particularly preferably 0.1 to 7% by weight.

The blending ratio of the modified polymer and water in the aqueous dispersion of the present invention is 95 to 3 parts by weight of water to 5 to 70 parts by weight of the modified polymer.
The proportion is appropriately selected within the range of 0 parts by weight. In particular, when spray-coating the aqueous dispersion of the present invention, it is less likely that spots will form on the coated surface, and that variations in the adhesion of the coating film will not occur (and that the formed coating layer will be The amount is preferably 3 to 45% by weight since the coating film does not become thick (for example, when used as a brimer, the smoothness of the coated film after painting is improved).

Further, a thickener, a basic substance, an antifoaming agent, etc. can be added to the aqueous dispersion of the present invention, if necessary.

Further, in order to improve wettability with the material, a small amount of an organic solvent may be added as necessary.

Examples of thickeners include mineral thickeners such as ammonium alginate, sodium alginate, and bentonite clay; acrylic thickeners such as sodium polyacrylate, ammonium polyacrylate, and crosslinked acrylic emulsion copolymers; Examples include cellulose derivatives such as carboxymethylcellulose, methylcellulose, hydroxypropylmethylcellulose, and hydroxyethylcellulose, with carboxymethylcellulose being particularly preferred.

Examples of antifoaming agents include vegetable oils such as castor oil, soybean oil, and linseed oil; mineral oils such as spindle oil and liquid paraffin; fatty acids such as nistearic acid and oleic acid; oleyl alcohol, polyoxyalkylene glycol, octyl alcohol, etc. Alcohols: Fatty acid esters such as ethylene glycol distearate and polyoxyethylene sorbitan monolaurate; Phosphate esters such as tributyl phosphate and sodium octyl phosphate; Amides such as polyoxyalkylene amide; Aluminum stearate, oleic acid Examples include metal soaps such as potassium and calcium stearate, silicones such as dimethyl silicone, polyether-modified silicone, and amines such as cyamylamine and polyoxypropylene alkylamine.

The aqueous dispersion of the present invention may be blended with chlorinated polypropylene, chlorinated maleated polypropylene, hydroxyl group-containing chlorinated polypropylene, styrene-butadiene block copolymer or its hydrogenated product, styrene-ethylene - It may contain a propylene block copolymer, etc., or a modified copolymer obtained by introducing a single or multiple types of chlorine atoms, hydroxyl groups, carboxyl groups, or anhydride groups thereof into these copolymers. In addition, styrene, other than the modified polymer which is the main component of the aqueous dispersion of the present invention,
A modified copolymer obtained by introducing one or more types of chlorine atom, hydroxyl group, carboxyl group, or anhydride group thereof into the isoprene/styrene block copolymer or its hydrogenated product may be contained.

Furthermore, in addition to the above, the aqueous dispersion of the present invention may optionally contain various stabilizers such as antioxidants, weather-resistant stabilizers, and heat-resistant inhibitors, titanium oxide, coloring agents such as organic pigments: carbon black, ferrite, etc. The conductivity imparting agent may be contained.

The aqueous dispersion of the present invention is applied to the surface of a molded article made of polyolefin or other polymer, and used as a brimer or the like to improve the adhesion of paint to the surface. In particular, the aqueous dispersion of the present invention may include polyolefins such as high-pressure polyethylene, medium-low pressure polyethylene, polypropylene, poly-4-methyl-1-pentene, poly-1-butene, and polystyrene; ethylene-propylene copolymers. It can be suitably used for molded products made of olefin copolymers such as , ethylene/butene copolymers, propylene/butene copolymers, etc.

Furthermore, in addition to the above-mentioned polyolefins and their copolymers, the aqueous dispersion of the present invention can also be made of molded products made of polypropylene and synthetic rubber, polyamide resins, unsaturated polyester resins, polybutylene terephthalate resins, polycarbonate resins, etc. It can also be used for surface treatment of molded products such as automobile bumpers, and furthermore, steel plates and steel plates for electrodeposition treatment. In addition, undercoat the surface coated with paints, primers, adhesives, etc. whose main components are polyurethane resin, fatty acid-modified polyester resin, oil-free polyester resin, melamine resin, epoxy resin, etc. to improve the adhesion of the paint, etc. to the surface. It is also used to improve the image quality and form coating films with excellent image clarity and low-temperature impact resistance.

The aqueous dispersion of the present invention can be applied to molded products containing inorganic fillers such as talc, zinc white, glass fiber, titanium white, magnesium sulfate, pigments, etc. A brimer coating film with good adhesion can be formed. Furthermore, the molded article coated with the aqueous dispersion of the present invention may contain various stabilizers, ultraviolet absorbers, hydrochloric acid absorbers, etc. in addition to the above.

Preferably used stabilizers include, for example, 26-di-7-butyl-4-methylphenol, tetrakis[methylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate)]methane, metaoctadecyl-3 −(
4'-Hydoxy-3,5-di-t-butylphenyl)propionate, 2,2'-methylenebis(4-methyl-
6-tert-butylphenol)44'-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-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)
Phenol stabilizers such as benzene, 1.3.5-tris(2-methyl-4-hydroxy-5-t-butylphenol)butane; Sulfur stabilizers such as dilaurylthiodipropionate and distearylthiodipropionate Agents; Examples include phosphorus stabilizers such as tridecyl phosphite and trinonylphenyl phosphite.

Further, as the ultraviolet absorber used, for example, 2-
Examples thereof include hydroxy-4-octoxybenzophenone, 2-ethylhexyl-2-cyano-33-diphenylacrylate, and roseoctylphenyl salicylate.

Examples of the hydrochloric acid absorbent include calcium stearate.

The aqueous dispersion of the present invention is suitable for spray application to a molded article, for example, by spraying onto the surface of the molded article with a spray gun. The coating on the molded article may be carried out at room temperature, and after the coating is applied, it is dried by an appropriate method such as natural drying or forced drying under heat to form a coating film.

As described above, after the aqueous dispersion of the present invention is applied to the surface of a molded article and dried, the surface of the molded article is coated with electrostatic coating,
Spraying may be performed by painting, brushing, or the like, and the coating may be applied by applying an undercoat and then topcoating. After the paint is applied, the paint film is cured according to a conventional method of heating with nichrome wire, infrared rays, high frequency waves, etc., and a molded article having the desired paint film on the surface can be obtained. The method for curing the coating film is appropriately selected depending on the material and shape of the molded article, the properties of the paint used, etc.

<Examples> Hereinafter, the present invention will be specifically explained with reference to Examples and Comparative Examples of the present invention, but the present invention is not limited to these Examples in any way.

Further, in the following, the physical properties of the coating film were evaluated according to the following method.

11 Dan 51 A test piece with a base grain was prepared according to the method for the base grain test described in JIS K5400, and adhesive tape made by Chiban (trade name) was pasted on the base grain of the test piece. Thereafter, this was quickly pulled in a direction of 90'' to peel it off, and the number of base grains that were not peeled out of 100 base grains was counted, and the number was determined as adhesive seeding.

L1 Emperor 1 Prepare a coating film on the base material, make a cut with a cutter blade to a width of 1 Crr1 until the blade reaches the base material, peel off the edge, and then cut the edge of the peeled coating film into a 50 mm7 The peel strength was measured by pulling the coating film in a direction of 180° at a speed of 10 minutes until it peeled off.

After the test piece was immersed in water at 40° C. for 240 hours, it was subjected to a substrate test to evaluate adhesion.

(Example 1) (Production of modified styrene/isoprene block copolymer) A hydrogenated styrene/isoprene block copolymer (Califlex 1117 manufactured by Shell Chemical Co., Ltd.) was placed in an autoclave with a capacity of 1.5ρ equipped with a stirring device. ) 250 parts by weight and 500 parts by weight of toluene were added, and 160 parts by weight were added under stirring.
The temperature was raised to ℃. Next, 25 parts by weight of 2-hydroxypropyl acrylate and 6.5 parts by weight of di-t-butyl peroxide were each added dropwise over 5 hours, and the mixture was further reacted with stirring at 160°C for 2 hours. After the reaction was completed, a large excess of acetone was added to the reaction mixture, and the resulting modified styrene/isoprene block copolymer was precipitated, separated, washed repeatedly with acetone, and then dried under reduced pressure.

The content of 2-hydroxypropyl acrylate in the obtained modified styrene/isoprene block copolymer was measured and found to be 4.1% by weight.

(Production of chlorinated modified styrene/isoprene block copolymer) The modified styrene/isoprene block copolymer obtained in the above reaction was heated to 110°C in chlorobenzene to completely dissolve it, and then the temperature was maintained. Meanwhile, light was completely blocked, chlorine gas was supplied, and the reaction was allowed to proceed for about 2 hours and 30 minutes. After the reaction was completed, a large excess of methanol was added to the reaction mixture, and the resulting chlorinated modified styrene/isoprene block copolymer was precipitated, separated, washed repeatedly with methanol, and then dried under reduced pressure.

The chlorine content of the obtained chlorinated modified styrene/isoprene block copolymer was measured and found to be 30% by weight.

(Preparation of aqueous dispersion) The obtained chlorinated modified styrene/isoprene block copolymer was dissolved in toluene, and the polymer concentration was 125 g/ρ.
A solution was prepared. 500 g of this polymer solution, 500 g of distilled water, and 1.44 g of sodium dodecylbenzenesulfonate (Neoperex F-25, manufactured by Kao@) were mixed with stirring at a rotation speed of 10,000 rpm for 15 minutes. Next, 0.72 g of polyacrylic acid (manufactured by Wako Tsumugi Pharmaceutical Co., Ltd., Hibiswako-304) was added and stirred and mixed to obtain an emulsion.

Toluene in the obtained emulsion was distilled off under reduced pressure using an evaporator to obtain an aqueous dispersion with a polymer concentration of 20% by weight.

(Coating) This aqueous dispersion was spray-coated to a polypropylene square plate (X440, manufactured by Mitsui Petrochemical Industries, Ltd.) that had been washed with 1,1,1-trichloroethane vapor at a coating weight of 200 g/m''.

After drying this square plate by heating at 100° C. for 30 minutes in an air oven, it was subjected to a base grain test, peel strength measurement, and water resistance evaluation. The results are shown in Table 1.

(Example 2) In the same manner as in Example 1, after applying the aqueous dispersion to a polypropylene square plate, a top coat (manufactured by Nippon B Chemical Co., Ltd., R-271) was further applied to a dry film thickness of 60 μm. . After cooling in the open for 10 minutes at room temperature, baking was performed in an air oven at 100° C. for 30 minutes. A sample of the obtained coating film was subjected to a base grain test, peel strength measurement, and water resistance evaluation. The results are shown in Table 1.

(Example 3) 3 kg of the same styrene-isoprene block copolymer used in Example 1, 120 g of 2-hydroxypropyl acrylate, J and 2,5-dimethyl-di(t-
4.8 g of butylperoxy)hexane was mixed in advance with a Henschel mixer, and the resulting mixture was fed to a twin-screw press (manufactured by Ikegai Iron Works, PCM-45) at a resin temperature of 230°C.
The mixture was heat-kneaded and reacted at a rotation speed of 26 ORPM to obtain a modified styrene/isoprene block copolymer.

The content of 2-hydroxypropyl acrylate in the obtained modified styrene/isoprene block copolymer was 3.
It was 5% by weight.

Using this modified styrene/isoprene block copolymer, it was chlorinated in the same manner as in Example 1 to prepare an aqueous dispersion. Example 2 using the obtained aqueous dispersion
Coating was carried out in the same manner as above, and the obtained coating film samples were subjected to a substrate grain test, measurement of peel strength, and evaluation of water resistance.
The results are shown in Table 1.

(Example 4) Instead of 2-hydroxypropyl acrylate, 2-
A modified styrene/isoprene block copolymer was obtained in the same manner as in Example 1 except that hydroxyethyl methacrylate was used. The content of 2-hydroxyethyl methacrylate in this modified styrene/isoprene block copolymer was 2.2% by weight. Next, using this modified styrene/isoprene block copolymer, Example 1
A chlorinated modified styrene/isoprene block copolymer was obtained in the same manner as above, and an aqueous dispersion was further prepared.

Using the obtained aqueous dispersion, coating was carried out in the same manner as in Example 2, and the obtained coating film samples were subjected to a substrate surface test, measurement of peel strength, and evaluation of water resistance. The results are shown in Table 1.

(Example 5) A molded product made by injection molding glass fiber reinforced nylon,
A coating film sample was prepared in the same manner as in Example 2, except that a polypropylene square plate was used, and the obtained coating sample was subjected to a base grain test, peel strength measurement, and water resistance evaluation. The results are shown in Table 1.

(Comparative Example 1) Synthesis was carried out in the same manner as in Example 1 except that 2-hydroxypropyl acrylate was not graft copolymerized to obtain an aqueous dispersion of a chlorinated copolymer. This was applied to a polypropylene square plate in the same manner as in Example 1, and then top coated in the same manner as in Example 2. The physical properties of the resulting coating film are listed in Table 1.

Able to maintain a good working environment during surface and coating work.
It is suitable as a brimer.

same

Claims (2)

[Claims] (1) A modified polymer obtained by graft copolymerizing a styrene/isoprene block copolymer or its hydrogenated product so that it contains 0.05 to 25% by weight of an α,β-unsaturated vinyl monomer having a hydroxyl group. An aqueous dispersion in which a chlorinated polyolefin having a chlorine content of 10 to 50% by weight, obtained by further chlorinating the above, is dispersed in water, wherein 95 to 30 parts by weight of water per 5 to 70 parts by weight of the chlorinated polyolefin. an aqueous dispersion containing parts. (2) The α,β-unsaturated vinyl monomer having a hydroxyl group is a (meth)acrylic ester of a monohydric alcohol or a mono(meth)acrylic ester of a polyhydric alcohol. Aqueous dispersion.