JP3470331B2 - Aqueous dispersion - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for paints obtained for the purpose of protection or cosmetics of polyolefin resins such as polypropylene, polyethylene and ethylene-vinyl acetate copolymer, or an aqueous dispersion of an adhesive. It is about.

[0002]

2. Description of the Related Art Conventionally, olefin resins such as polypropylene have high chemical stability, are inexpensive, have an excellent balance of physical properties, and are recyclable, so that the amount of olefin resin used is limited to automobile parts. , Household electrical appliances and household miscellaneous goods are increasing year by year. However, since the olefin resin does not contain a polar group in the molecular chain, it has a drawback that it is difficult to be coated and it is difficult to bond it. Therefore, in the case of polypropylene-based coating or adhesion, it is general to use a resin containing chlorinated polypropylene as a main component as a primer or one coat. However, chlorinated polypropylene generally uses an aromatic organic solvent such as toluene or xylene, which is problematic in terms of health and safety and environmental pollution.

Therefore, attempts have been made to produce an aqueous dispersion of chlorinated polypropylene. Aqueous dispersion of chlorinated polyolefin containing carboxyl group (Japanese Patent Publication No. 8-600
9), a method for producing a resin composition emulsion (Patent 272703)
2), use of reactive surfactant (Patent 2603173), etc. have been proposed.

In recent years, due to these environmental problems, in particular for automobile interior applications, aqueous solution has been intensively studied. In this case, not only adhesion but also flexibility is required as required performance. However, in order to satisfy the demand for improving the flexibility of coating films in recent automobile interior coatings, a flexibility imparting component is necessary. However, the above-mentioned aqueous resin dispersion of chlorinated polypropylene alone has good adhesion to polypropylene, but cannot improve flexibility. Furthermore, the above-mentioned aqueous resin dispersion of chlorinated polypropylene alone has poor adhesion to materials other than polypropylene, particularly ethylene-vinyl acetate copolymer (hereinafter referred to as EVA) used in shoes.

On the other hand, regarding EVA copolymer emulsions, there are inventions such as water-based adhesives for paper, OPP film, and wood (JP-A-62-135583, JP-A-6-65550), but they are not used for olefins. As an aqueous adhesive for polyolefin substrates, an aqueous adhesive (patent No. 2561495) in which a chlorinated resin is mixed with an acrylic ester copolymer has been proposed, but an aromatic solvent such as toluene and xylene is chlorine-containing. It is hard to say that it is a complete water system because it is added in an amount of 2 to 20 times the weight of the resin. In addition, since the chlorinated resin used is not acid-modified, it can be used only for adhesives, and when used as a primer, the adhesion to the topcoat paint is poor and there is a practical problem.

Further, regarding a system in which an aqueous dispersion of chlorinated polyolefin and an aqueous dispersion of EVA copolymer are mixed, a water-soluble polyethylene primer composition (JP-A-4-35)
1681) and a water-based adhesive composition for polyolefin and a primer (JP-A-6-25628). But,
The former is to provide a solvent-type polyethylene primer which is water-solubilized with a large amount of an aromatic solvent in order to increase the solubility of a raw material resin during the production of an aqueous dispersion, and cannot be called an aqueous dispersion.

On the other hand, in the latter case, 2 to 50 parts by weight of a surfactant solution (component 1) having a chlorinated polyolefin concentration of 5 to 25% is prepared, and an EVA copolymer emulsion is added to 50 to 98 parts by weight (component 2). Mixed. Therefore, when the amount of component 1 is small, the adhesiveness to polyolefin is poor, while when the amount of component 1 is large, the amount of surfactant is relatively large, and therefore when used as a primer, water resistance is low. It is easy to infer that it is inferior to. Further, when it is used as a primer, a preliminary washing treatment with a chlorinated solvent such as 1,1,1-trichloroethylene is required, which is complicated in the process.

[0008]

DISCLOSURE OF THE INVENTION The present invention has excellent adhesion to a molding or film of a polyolefin resin as a primer for paints, inks or adhesives, coating film appearance, solvent resistance, and The present invention relates to an aqueous dispersion which gives a coating film having good flexibility.

[0009]

Means for Solving the Problems As a result of intensive studies by the present inventors in order to solve the above-mentioned problems, the chlorine content is 15 to
It has been found that 35% by weight of chlorinated polyolefin and ethylene-vinyl acetate copolymer can be achieved with an aqueous dispersion having a mixing ratio of 90/10 to 10/90.

That is, the chlorinated polyolefin component is a chlorinated polyolefin having a chlorine content of 15 to 35% by weight, preferably a carboxylic acid-modified one.
The acid value is 10 to 100 and the number average molecular weight is 2000 to 40,000. On the other hand, the ethylene-vinyl acetate copolymer component is preferably modified with a carboxylic acid. A mixture of the above (A) carboxylic acid modified chlorinated polyolefin and (B) carboxylic acid modified ethylene-vinyl acetate copolymer is neutralized with a basic substance,
Aqueous dispersions that have been dispersed in water using a nonionic surfactant are used for the molding or film of polyolefin-based resin for adhesion, flexibility, and appearance of the coating film as a primer for paints, inks, or adhesives. It has been found to give good coatings.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The aqueous dispersion used in the present invention contains a mixture of (A) a carboxylic acid-modified chlorinated polyolefin and (B) a carboxylic acid-modified ethylene-vinyl acetate copolymer as a main component. The details will be described below.

The (A) carboxylic acid-modified chlorinated polyolefin is obtained by dissolving polyolefin in a chlorine-inert solvent such as chloroform and blowing chlorine gas to chlorinate it, and it is unsaturated before or after chlorination. A carboxyl group can be introduced by graft-copolymerizing a carboxylic acid or an anhydride thereof.

A polyolefin is a homocopolymer of ethylene or polypropylene, or a comonomer of ethylene or propylene, such as butene-1, pentene-.
1, a random copolymer of hexene-1, butene-1, heptene-1, octene-1, etc. having 2 or more carbon atoms, preferably 2 to 6 α-olefin comonomers, and a random copolymer rather than a block copolymer. Polymers are preferred. Further, two or more kinds of comonomers may be copolymerized.

If the chlorine content of the (A) carboxylic acid-modified chlorinated polyolefin is less than 15% by weight, the melting point and melt viscosity are too high to disperse well in water. If it exceeds 35% by weight, the adhesion to the substrate becomes poor. Preferably 18-28
% By weight.

The carboxylic acid-modified polyolefin is a polyolefin obtained by modifying the above-mentioned polyolefin by a graft reaction with an α, β-unsaturated carboxylic acid or an anhydride thereof.

The acid value of the carboxylic acid-modified chlorinated polyolefin (A) is preferably 10 to 100. When the acid value is less than 10, the adhesiveness to polar materials is poor, and when the acid value exceeds 100, the adhesiveness to polypropylene is poor. Get inferior.

Α, β used for modification of polyolefin
Examples of the unsaturated carboxylic acid or its anhydride include maleic acid, fumaric acid, itaconic acid, citraconic acid, allyl succinic acid, mesaconic acid, aconitic acid and their acid anhydrides. In addition to these, esters of these carboxylic acids are also included. Of these, acid anhydrides are preferred. The method of graft-copolymerizing the α, β-unsaturated carboxylic acid or its anhydride onto the polyolefin may be a known method (for example, Japanese Patent No. 2019232). For example, it is preferable to carry out by a method of heating and melting the polyolefin above the melting point and graft-copolymerizing in the presence of a radical generator.

The number average molecular weight of the chlorinated polyolefin graft-copolymerized with α, β-unsaturated carboxylic acid or its anhydride is preferably 2000 to 40,000, and when it is less than 2000, the cohesive force is insufficient and the adhesion force to the polyolefin resin is low. If it exceeds 40,000, the operability at the time of dispersing it in water becomes poor, which is not preferable. In order to suppress the molecular weight within this range, it is possible to select the molecular weight of the raw material or the conditions for carrying out the graft reaction, or it is also possible to use the method of once lowering the molecular weight of the raw material and then carrying out the graft reaction. . The number average molecular weight can be measured by GPC (gel permeation chromatography).

The carboxylic acid-modified ethylene-vinyl acetate copolymer (B) can be produced by a known method. For example, as in JP-A-3-12836, EVA is dissolved in an aromatic hydrocarbon such as toluene or xylene, a lower alcohol such as methyl alcohol or ethyl alcohol is added, and an alkali alcoholate catalyst is added in the presence of a specific amount of water. Is used to carry out a saponification reaction. The obtained saponified product is an unsaturated carboxylic acid or an acid anhydride thereof, such as maleic acid, fumaric acid, itaconic acid, citraconic acid, allyl succinic acid, mesaconic acid, aconitic acid and their acid anhydrides, and their carboxylic acids. Esters are also included and can be obtained by reacting these with a radical initiator.

The vinyl acetate content of the (B) carboxylic acid-modified ethylene-vinyl acetate copolymer is preferably 5 to 60% by weight.
However, if the vinyl acetate content is less than 5% by weight, it is difficult to melt since it is difficult to melt, and if it exceeds 60% by weight, the adhesion to the olefin resin molded product and the film is insufficient. The acid value is preferably from 1 to 60, and when it is less than 1, it is difficult to disperse in water, and when it exceeds 60, the water resistance is deteriorated.

In the present invention, the aqueous dispersion is described in Patent 2700.
It can be obtained by a known method as described in 526. That is, (A) carboxylic acid-modified chlorinated polyolefin or (B) carboxylic acid-modified ethylene-vinyl acetate copolymer is mixed at a ratio of (A) / (B) = 90/10 to 10/90 to obtain about 10
Melt at 0 ° C., add 0.4 to 1.5 chemical equivalents of basic substance to the nonionic surfactant and carboxyl group, melt and knead, and in the molten state, add water at 80 to 98 ° C.
A water-based dispersion of the present invention is formed by forming a / O-type dispersion and subsequently inversion of the phase into an O / W-type dispersion while adding water, and adding an additional amount of water as necessary. Can be obtained.

Further, using a twin-screw extruder, (A) / (B) = 90
By mixing in a ratio of 10/10 to 90/10, melt-kneading, and then melt-kneading by adding a nonionic surfactant and a basic substance, and then adding water to invert the phase from W / O to O / W. The aqueous dispersion of the present invention can be obtained.

The components (A) and (B) are melted alone to obtain an aqueous dispersion by the above method, and then (A) /
(B) = 90/10 to 10/90 may be mixed.

Examples of the nonionic surfactant include polyoxyethylene alkyl ester, polyoxyethylene alkyl ether, polyoxyethylene alkylphenol ether, sorbitan alkyl ester, polyoxyalkylene alkyl ether and the like. As the nonionic surfactant, two kinds having different HLB may be mixed and used. Further, a nonionic surfactant as a main component and a small amount of anionic surfactant may be used together.

The amount of the surfactant used is preferably 1 to 25% by weight, and particularly 3 to 15% by weight, based on the resin constituents of the (A) carboxylic acid-modified chlorinated polyolefin and (B) carboxylic acid-modified EVA. Is desirable. If the amount of the surfactant is less than 1% by weight, the stability of the aqueous dispersion will be poor, and if it exceeds 25% by weight, the adhesion and water resistance of the coating film will be poor.

The basic substance is added in order to neutralize the carboxyl group and ionize it to improve the dispersion in water. If the basic substance is not added, a stable dispersion liquid cannot be obtained. . As the basic substance, sodium hydroxide, potassium hydroxide, ammonia, methylamine, ethylamine, propylamine, butylamine, hexylamine,
Examples include octylamine, ethanolamine, propanolamine, diethanolamine, N-methyldiethanolamine, dimethylamine, triethylamine, morpholine and the like.

The amount of the basic substance to be used is 0.4 to 1.5 chemical equivalents with respect to the carboxyl groups of the resin constituents of the (A) carboxylic acid-modified chlorinated polyolefin and (B) carboxylic acid-modified EVA used. Something is preferable. 0.
When the amount used is less than 4 chemical equivalents or more than 1.5 chemical equivalents, the stability of the resulting aqueous dispersion is poor.

When the content of the (A) carboxylic acid-modified chlorinated polyolefin exceeds 90%, the effect of the (B) carboxylic acid-modified EVA is not sufficient, the flexibility is insufficient, and the adhesion to the EVA base material is particularly high. bad. On the other hand, if the amount of the carboxylic acid-modified chlorinated polyolefin (A) is less than 10%, the adhesion to the polypropylene base material is particularly lowered.

The aqueous dispersion thus obtained has excellent adhesion to polyolefin resins, especially polypropylene and EVA substrates, and has excellent flexibility of the coating film, small particle size and good stability. is there. The aqueous dispersion of the present invention may be used as it is, mixed with a pigment, or may be blended with another aqueous resin.

The aqueous dispersion of the present invention should be used as a component of a topcoat paint, a coating agent for polyolefin film, an ink resin component or a primer for resin molding, especially as a primer for polyolefin resin molded articles which are interior and exterior materials for automobiles. You can It can also be used as a primer for an adhesive of shoes whose material is EVA.

[0031]

EXAMPLES The present invention will now be described in detail with reference to examples, but the present invention is not limited thereto.

[Production Example 1] 500 g of isotactic polypropylene having a number average molecular weight of 30,000 was placed in a three-necked flask equipped with a stirrer, a dropping funnel and a cooling tube for refluxing a monomer, and kept constant at 180 ° C. It completely dissolved in a dripped oil bath. After replacing the nitrogen in the flask for about 10 minutes, 20 g of maleic anhydride was added with stirring for about 5 minutes, and then 2 g of di-t-butyl peroxide was added.
It was dissolved in 10 ml of heptane and charged with a dropping funnel over about 30 minutes. At this time, the inside of the system was kept at 180 ° C., and after continuing the reaction for an additional 1 hour, unreacted maleic anhydride was removed over about 30 minutes while depressurizing the inside of the flask with an aspirator. Next, about 300 g of this product was put into a reaction kettle, 5 liters of chloroform was added, and it was sufficiently dissolved under a pressure of ² kg / cm ² , and then while being irradiated with ultraviolet rays, the chlorine content became 24% by weight. So that gaseous chlorine was blown in from the bottom of the reaction kettle. After completion of the reaction, the solvent chloroform was distilled off under reduced pressure using a twin-screw extruder to obtain solid pellets of carboxyl group-containing chlorinated polypropylene. This product had an acid value of 26, a melting point of 90 ° C. and a number average molecular weight of 28,000.

[Production Example 2] 500 g of an ethylene-propylene copolymer having an ethylene content of 6.1 mol% with a number average molecular weight of 30,000, a stirrer, a dropping funnel, and a three-necked cooling pipe for refluxing the monomer. Put in a flask, 180
It completely dissolved in an oil bath kept constant at 0 ° C. After replacing the nitrogen in the flask for about 10 minutes, 33 g of maleic anhydride was graft-copolymerized in the same manner as in Production Example 1 while stirring. Next, about 300 g of this product was charged into a reaction kettle, and gaseous chlorine was blown from the bottom of the reaction kettle in the same manner as in Production Example 1 so that the chlorine content was 18% by weight. After completion of the reaction, the solvent chloroform was distilled off under reduced pressure using a twin-screw extruder to obtain solid pellets of carboxyl group-containing chlorinated polypropylene. This product has an acid value of 62 and a melting point of 72.
C., the number average molecular weight was 22,000.

[Production Example 3] E having a vinyl acetate content of 28% by weight
VA was saponified to obtain saponified EVA having a saponification degree of 20. To 100 parts by weight of this saponified EVA, 1 part by weight of maleic anhydride and 0.2 part by weight of benzoyl peroxide were mixed well and kneaded and extruded by an extruder set at 150 ° C to obtain a melt flow rate of 7.0 g / 10. A carboxyl-modified EVA having an acid value of 5 grafted with maleic anhydride in minutes was obtained.

[Production Example 4] E having a vinyl acetate content of 28% by weight
VA was saponified to obtain saponified EVA having a saponification degree of 20. To 100 parts by weight of this saponified EVA, 2 parts by weight of maleic anhydride and 0.2 parts by weight of benzoyl peroxide were mixed well and kneaded and extruded by an extruder set at 150 ° C to obtain a melt flow rate of 5.0 g / 10. A carboxyl-modified EVA having an acid value of 10 grafted with maleic anhydride was obtained.

[Production Example 5] E having a vinyl acetate content of 42% by weight
VA was saponified to obtain saponified EVA having a saponification degree of 40. To 100 parts by weight of this saponified EVA, 3 parts by weight of maleic anhydride and 0.2 parts by weight of benzoyl peroxide were well mixed and kneaded and extruded by an extruder set at 150 ° C to obtain a melt flow rate of 10.0 g / 10 A carboxyl-modified EVA having an acid value of 15 grafted with maleic anhydride in minutes was obtained.

Example 1 85 g of the carboxylic acid-modified chlorinated polyolefin (A) obtained in Production Example 1 and 15 g of the carboxylic acid-modified EVA obtained in Production Example 3 were placed in a flask equipped with a stirrer and heated to 100 ° C. to melt. It was Thereafter, 10 g of a nonionic surfactant was added and well stirred, and 1.5 g (0.7 chemical equivalent) of morpholine was added. While maintaining the temperature at 100 ° C, water at 90 ° C was added little by little while stirring vigorously. Viscosity increased,
The viscosity decreased when water was continuously added as it was. When 150 g of water was added, the contents were taken out to obtain a milky white emulsion.

Example 2 The same as Example 1 except that 70 g of the carboxylic acid-modified chlorinated polyolefin (A) obtained in Production Example 1 and 30 g of the carboxylic acid-modified EVA (B) obtained in Production Example 3 were used. The operation was performed to obtain a milky white emulsion.

Example 3 The same as Example 1 except that 50 g of the carboxylic acid-modified chlorinated polyolefin (A) obtained in Production Example 1 and 50 g of the carboxylic acid-modified EVA (B) obtained in Production Example 3 were used. The operation was performed to obtain a milky white emulsion.

Example 4 The same as Example 1 except that 30 g of the carboxylic acid-modified chlorinated polyolefin (A) obtained in Production Example 1 and 70 g of the carboxylic acid-modified EVA (B) obtained in Production Example 3 were used. The operation was performed to obtain a milky white emulsion.

Example 5 The same as Example 1 except that 85 g of the carboxylic acid-modified chlorinated polyolefin (A) obtained in Production Example 2 and 15 g of the carboxylic acid-modified EVA (B) obtained in Production Example 3 were used. The operation was performed to obtain a milky white emulsion.

[Example 6] The same as Example 1 except that 15 g of the carboxylic acid-modified chlorinated polyolefin (A) obtained in Production Example 2 and 85 g of the carboxylic acid-modified EVA (B) obtained in Production Example 3 were used. The operation was performed to obtain a milky white emulsion.

[Example 7] The same as Example 1 except that 70 g of the carboxylic acid-modified chlorinated polyolefin (A) obtained in Production Example 2 and 30 g of the carboxylic acid-modified EVA (B) obtained in Production Example 4 were used. The operation was performed to obtain a milky white emulsion.

[Example 8] The same as Example 1 except that 70 g of the carboxylic acid-modified chlorinated polyolefin (A) obtained in Production Example 2 and 30 g of the carboxylic acid-modified EVA (B) obtained in Production Example 5 were used. The operation was performed to obtain a milky white emulsion.

Comparative Example 1 100 g of the carboxylic acid-containing chlorinated polyolefin (A) obtained in Production Example 1 was processed in the same manner as in Example 1 to obtain a milky white aqueous dispersion.

Comparative Example 2 100 g of the carboxylic acid-modified EVA (B) obtained in Production Example 3 was treated in the same manner as in Example 1 to obtain a milky white aqueous dispersion.

Example 9 The aqueous dispersions obtained in Comparative Examples 1 and 2 were mixed at (A) / (B) = 70/30 to obtain a milky white aqueous dispersion.

[Example 10] The same operation as in Example 1 was carried out except that the carboxylic acid-modified chlorinated polyolefin (A) obtained in Production Example 1 and the carboxylic acid-modified EVA (B) obtained in Production Example 5 were used. Then, a milky white emulsion was obtained.

Comparative Example 3 70 g of the carboxylic acid-modified chlorinated polyolefin (A) obtained in Production Example 1 and commercially available unmodified E
30 g of VA (V5772ET, acid value 0, Mitsui DuPont Chemical Co., Ltd.) was treated in the same manner as in Example 1.

[Test Example 1] Table 1 shows the storage stability results of each aqueous dispersion at 50 ° C. for one month. Only in Comparative Example 3, the aqueous dispersion was obtained by separating two layers. Measurement method / appearance: visually determined. -PH: Measured with a pH meter after immersing in a constant temperature bath at 25 ° C for about 1 hour.・ Average particle size: Zetasizer (measuring range 1 μm or less, M
Measured by ARVARON).

[Test Example 2] A polypropylene resin plate was spray-coated with a liquid obtained by filtering the aqueous dispersions of Examples 1 to 10 and the aqueous dispersion of Comparative Example 1.2, and dried at 80 ° C for 30 minutes.
Next, a two-pack urethane topcoat paint was applied, allowed to stand at room temperature for 10 minutes, and dried at 80 ° C. for 30 minutes using a hot air dryer. After leaving the obtained coated plate at room temperature for 1 day, the coating film was tested. The results are shown in Table 2.

The test method is as follows.・ 2mm by making a cut on the surface of the adhesive coating to reach the substrate with a cutter
100 grids were made at intervals, cellophane adhesive tape was adhered on them and peeled off in the direction of 180 degrees, and the number of remaining grids was counted. If the number of crosses that did not come off was 100, it was ○, and if 99 or less, it was ×. -The gasoline-resistant coating film surface was cut with a cutter to reach the base material, and then the state of the coating film after being immersed in regular gasoline for 2 hours was visually observed. When no change was observed on the surface of the coating film, it was evaluated as ○, and when there was a change in appearance such as blistering or peeling, it was evaluated as ×.・ After leaving the flexible coated polypropylene plate in a freezer at -20 ° C for 1 hour, quickly set it in the DuPont impact tester and set the height of the coated polypropylene plate to 50c.
When 500 g of hard spheres were dropped from the position of m, the film having no crack in the coating film was marked with ◯, and the film having cracks in the coating film was marked with x.

[Test Example 3] A liquid obtained by filtering the aqueous dispersions of Examples 1 to 10 and Comparative Examples 1 and 2 was spray-coated on an EVA substrate and dried at 80 ° C for 30 minutes. Next, apply a two-component urethane topcoat paint, leave it for 10 minutes at room temperature,
It dried at 80 degreeC for 30 minutes using the hot air dryer. After leaving the obtained coated plate at room temperature for 1 day, the coating film was tested. The paint test results are shown in Table 2.

The test method is as follows.・ 2mm by making a cut on the surface of the adhesive coating to reach the substrate with a cutter
100 grids were made at intervals, cellophane adhesive tape was adhered on them, and peeled off in the direction of 180 degrees, and the number of remaining grids was counted. If the number of crosses that did not come off was 100, it was ◯, and if 99 or less, it was x.

[Test Example 4] The aqueous dispersions of Examples 1 to 10 and the aqueous dispersions of Comparative Examples 1 and 2 were applied to an EVA foamed shoe substrate so as to have a dry film thickness of 10 µm, and the temperature was 60 ° C. It was dried for 10 minutes. For comparison, a commonly used solvent-based primer (epoxy resin-based) was applied. afterwards,
100 parts of water-based urethane adhesive mixed with 5 parts of curing agent (aliphatic polyisocyanate) on EVA base material 100
It was applied so as to be g / m ² . On the other hand, a water-based adhesive and a curing agent were applied to a vinyl chloride leather to be attached to an EVA base material so as to be 100 g / m ² as in the EVA base material. Then each 6
After drying at 0 ° C. for 10 minutes, both coated surfaces (EVA base material / PVC leather) were laminated.

After that, the test piece was cut to have a width of 1 cm, and EVA was used with a tensilon under the conditions of 5 kg weight and 100 mm / min.
The base material and the PVC leather were peeled off, and the peeling strength was measured. The test was performed 3 times, and the average value was used as the result. The results are shown in Table 3.

[0057]

[Table 1] Table 1 Storage stability results

Measurement method / appearance: visually determined. No change in appearance: ○ ・ pH: Measured with a pH meter after immersing in a constant temperature bath at 25 ℃ for about 1 hour.・ Average particle size: Zetasizer (measuring range 1 μm or less, M
Measured by ARVARON).

[0059]

[Table 2] Table 2 Paint test results

[0060]

[Table 3] Table 3 Results of tensile test

From Table 2, the (A) carboxylic acid-modified chlorinated polyolefin alone does not provide flexibility and has no adhesiveness to an EVA substrate. Further, (B) carboxylic acid modified E
VA alone has no adhesion to polypropylene substrates. On the other hand, it can be seen that the aqueous dispersion of the present invention in which the (A) carboxylic acid-modified chlorinated polyolefin and the (B) carboxylic acid-modified EVA are used together is useful for both.
Furthermore, from the results in Table 3, the aqueous dispersion of the present invention has a tensile strength equivalent to that of the solvent-based primer.

[0062]

EFFECTS OF THE INVENTION According to the present invention, it has excellent adhesion to a polyolefin resin molding or film as a primer for paints, inks or adhesives, coating film appearance, solvent resistance, and good flexibility. The present invention relates to an aqueous dispersion that gives a smooth coating film. That is, it is possible to obtain an aqueous dispersion liquid which has not only the adhesion of the coating film but also the effect of imparting flexibility to the polypropylene resin and has excellent adhesive force to the EVA resin used for shoes and the like.

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hironori Muramoto 2-8-1 Iida-cho, Iwakuni-shi, Yamaguchi Nippon Paper Industries Co., Ltd., Chemicals Research Laboratory (56) References JP 2001-220474 (JP, A) ) JP-A-7-102134 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08J 3/03-3/075 C08L 23/26 C08L 31/04 C09D 123/26 C09D 131 / 04 C09J 123/26 C09J 131/04

Claims (9)

(57) [Claims] 1. An aqueous resin dispersion, wherein the resin component (A) has a chlorine content of 15 to 35% by weight and an acid value of 10.
Of 100 to 100 carboxylic acid-modified chlorinated polyolefin and (B) carboxylic acid-modified ethylene-vinyl acetate copolymer, which is dispersed in water using a basic substance and a nonionic surfactant. Aqueous dispersion. 2. A mixing ratio (A) / (B) of the resin components
Is 90/10 to 10/90, The aqueous dispersion according to claim 1. Wherein (A) an aqueous dispersion of claim 1 or 2 any one of claims number average molecular weight of the carboxylic acid-modified chlorinated polyolefin is from 2,000 to 40,000. Wherein (B) carboxylic acid-modified ethylene - acid value of vinyl acetate copolymer is 1 to 60 claims 1-3 aqueous dispersion according to any one. 5. In the (B) carboxylic acid-modified ethylene-vinyl acetate copolymer, vinyl acetate is 5% of the copolymer.
60 by weight% claim 1-4 aqueous dispersion according to any one. 6. A primer for a coating material for a polyolefin substrate, which uses the aqueous dispersion according to any one of claims 1 to 5 . 7. The adhesive primer for claims 1 to 5 any one polyolefin substrate using an aqueous dispersion as claimed. 8. The coating primer according to claim 6, wherein the polyolefin base material is an ethylene-vinyl acetate copolymer. 9. The primer for an adhesive according to claim 7, wherein the polyolefin base material is an ethylene-vinyl acetate copolymer.