JPH0446904A - Aqueous dispersion - Google Patents

Abstract

PURPOSE:To obtain an aqueous dispersion excellent in adhesion and tight bonding with a molding of a polyolefin resin and useful as a primer by selecting an aqueous dispersion containing a specified chlorinated olefin polymer in a specified concentration. CONSTITUTION:An aqueous dispersion containing 5-80wt.% (in terms of solid matter) chlorinated olefin polymer which is a product of chlorination of an olefin polymer having a molar ratio of propylene units to 4-6C alpha-olefin units of 15/85 to 90/10 and an intrinsic viscosity in decalin (at 135 deg.C) of 0.5-5.0dl/g and has a Cl content of 5-40wt.% is selected.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an aqueous dispersion, particularly for undercoating molded products made of polyolefin resins such as polyethylene and polypropylene, and molded products such as automobile bumpers made of polypropylene and synthetic rubber. The present invention relates to an aqueous dispersion that can be used as a brimer to improve the adhesion of paint to the surface of molded articles.

<Prior Art> Conventionally, the surface of a molded article 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. Regarding the composition used in this brimer, the applicant has:
Previously, various compositions were proposed (Japanese Patent Publication No. 59-4269).
No. 3, No. 62-21027 and No. 61-11250
No. 64-74235).

<Problems to be Solved by the Invention> However, conventional brides, including the above-mentioned composition,
Since all of them contain organic solvents or are used after being dissolved in organic solvents, there is a problem in that they deteriorate the working environment during production and use, and are particularly difficult to use in open areas. Furthermore, in recent years, water-based paints have been increasingly used, and as a result, the need for water-based brushers has increased.

Therefore, in order to solve the above-mentioned problems, the present invention provides an aqueous dispersion that has excellent adhesion and adhesion to resin molded products, particularly polyolefin molded products such as polypropylene, and is suitable as a water-based brimer. It is in.

Means for Solving the Problems> In order to solve the above problems, the present invention provides a composition in which the content ratio of propylene units (a)/α-olefin units having 4 to 6 carbon atoms (b) is 15/85 to 90/ 10 (molar ratio), and the intrinsic viscosity [η] measured at 135°C in decalin is 0.
5 to 5, a chlorinated product of an olefin polymer having a chlorine content in the range of 5 to 40% by weight, Odβ/g, at a solid concentration of 5 to 5.
It provides an aqueous dispersion containing 80% by weight.

Further, the α-olefin unit (b) is 1-butene,
Preferably, it is at least one selected from 1-pentene, 4-methyl-1-pentene, 3-methyl-1-pentene, and 1-hexene.

Hereinafter, the present invention will be explained in detail.

The chlorinated olefin polymer, which is the main component of the aqueous dispersion of the present invention, is a chlorinated olefin polymer composed of propylene units (a) and α-olefin units (b).

The α-olefin unit (b) which is a constituent component of the olefin polymer is, for example, l-butene.

At least one a-olefin having 4 to 6 carbon atoms selected from 1-hen, 4-methyl-1-pentene, 3-methyl-1-pentene, and 1-hexene.

In addition, this olefin polymer may contain, as structural units other than the propylene unit (a) and a-olefin unit (b), within a range that does not impede the effects of the present invention, for example,
Conjugated dienes such as butadiene and isoprene; 174-hexadiene, 1,7-octadiene, dicyclopentadiene, 5-ethylidene-2-norbornene, 5-vinyl-
2-norbornene, 5-methylene 2-norbornene, 2
, 5-turbonasien, etc.; (meth)acrylic acid, (meth)acrylate, (meth)acrylic acid ester, vinyl acetate, vinyl alcohol, l-undecylenic acid, l-undecenol, maleic anhydride component unit and aromatic vinyl monomers such as styrene, vinyltoluene, α-methylstyrene, and indene.

When the olefin polymer contains the above-mentioned conjugated or non-conjugated diene, the content thereof is preferably 3 mol% or less, more preferably 0.3 mol% or less. Moreover, 30 mol% or less of all the constituent components of the olefin polymer may be ethylene.

Furthermore, the olefin polymer may be one obtained by graft copolymerizing a polymerizable unsaturated compound such as acrylic acid, methacrylic acid, or maleic anhydride to this olefin polymer.

In this olefin polymer, a propylene unit (a)/α-olefin unit can be obtained in that a chlorinated olefin polymer having sufficient heat-resistant adhesiveness and excellent heat resistance and adhesiveness with polyolefin can be obtained. The content ratio of (b) is 15/85 to 90/10, preferably 20/80 to 85/15 in molar ratio.

Specific examples of such olefin polymers include propylene/l-butene copolymer, propylene/4-methyl-
Pentene copolymer, propylene/3-methyl-1-pentene copolymer, propylene/l-butene/ethylene copolymer, propylene/1-butene/1-undecylenic acid copolymer, propylene/4-methyl-1 -Pentene/1-
Undecylenic acid copolymer, propylene/l-butene/1
-Undecenol copolymer, propylene/4-methyl-
1-pentene/l-undecenol copolymer, propylene/1-butene/(anhydrous) maleic acid copolymer, propylene/l-butene/(anhydrous) itaconic acid copolymer, propylene/1-butene/ethylene/( anhydrous) maleic acid copolymer, propylene/1-butene/styrene copolymer,
Examples include propylene/3-methyl-1-butene/styrene copolymer, propylene/4-methyl-1-pentene/styrene copolymer, and propylene 73-methyl-1-pentene/styrene copolymer. Among these, propylene/1-butene copolymers and propylene/l-butene/ethylene copolymers are particularly preferred.

In the present invention, among these olefin polymers, the intrinsic viscosity measured at 135°C in decalin [ η] is 0.5 to 5. Odi! ,/g, preferably in the range of 0.8 to 4.0 dβ/g. Further, this olefin polymer is desirably a crystalline polyolefin having a degree of crystallinity preferably in the range of 10 to 50%, more preferably in the range of 10 to 40%.

These olefin polymers are produced by copolymerizing propylene and the α-olefin using a conventional method, for example, using a vanadium catalyst, a titanium catalyst containing magnesium, titanium, halogen, etc. can be manufactured.

The aqueous dispersion of the present invention has a chlorinated olefin polymer, which is a chlorinated product of the above-mentioned olefin polymer, as a main component.

The chlorine content in this chlorinated olefin polymer has good heat-resistant adhesion with chlorine-containing polymers and/or aromatic polymers in high-temperature atmospheres, and good adhesion with general polyolefins. The content is 5 to 40% by weight, preferably 8 to 35% by weight, since it has good heat-resistant adhesion with the adhesive.

This chlorinated olefin polymer can be produced, for example, by the following method.

First, the first method is to grind the olefin polymer into fine particles, bring the resulting fine particles into an aqueous sap state, and contact them with molecular chlorine at a temperature of about 70 to 90°C;
The second method is to dissolve the olefinic polymer in a chlorine-stable solvent such as carbon tetrachloride, tetrachloroethylene, or chlorobenzene, and bring it into contact with molecular chlorine in a uniform solution state; The third method is N-chloroacetamide, N-chlorsucci(n)amide, 1.
Examples include a method in which a chlorine compound such as 3-dichloro-5,5-dimethylhydantoin is uniformly kneaded into an olefin polymer using a roll or Banbury mixer, and then heated to a temperature at which chlorine is liberated. . Among these methods, the first and second methods, which carry out chlorination in an aqueous solution state or in a solution state, do not generate free chlorine and are
It is particularly preferred because it is easy to maintain a good working environment and uniform chlorination is easy. Furthermore, in the method of chlorinating in a solution state, it is more preferable to carry out the reaction in the presence of a radical (polymerization) initiator or under irradiation with ultraviolet rays or visible light because the reaction proceeds efficiently. In these methods, the chlorine content of the resulting chlorinated olefin polymer can be adjusted by appropriately selecting the amount of molecular chlorine or other chlorinating agent used, reaction time, reaction temperature, etc. .

This chlorinated olefin polymer usually has a degree of blackness of 4.
It is desirable that the content be 5% or less, preferably 30 to 10%. Further, the intrinsic viscosity [η] is usually in almost the same range as the olefin polymer that is the raw material, but is preferably 0.8 to 4.0 dj2/g.

The aqueous dispersion of the present invention contains the chlorinated olefin polymer in a solid content of 5 to 80% by weight, preferably 15 to 70% by weight.
It is made by dispersing it in weight%. The dispersed particle size of the dispersed chlorinated olefin polymer can be arbitrarily selected within a range that allows it to be stably dispersed in water.
It is about 1 to 30 μm+, preferably about 0.05 to 15 μm.

The water dispersion of the present invention may be one in which only the chlorinated olefin polymer is dispersed in water, but other polymer components and antioxidants may be added as necessary to the extent that the effects of the present invention are not impaired. , ultraviolet absorber, hydrochloric acid absorber, dehydrochloric acid inhibitor,
It may contain additives such as pigments, dyes, fillers, nucleating agents, antiblocking agents, snop agents, antistatic agents, and flame retardants.

Other polymers used include olefin polymers before chlorination, ethylene/α-olefin copolymer rubber, ethylene/α-olefin/diene copolymer rubber, polyisobutylene, butyl rubber, and styrene/butadiene copolymer. Examples include rubber components such as composite rubber, nitrile rubber, and silicone rubber.

Examples of antioxidants include 2,6-tert-
Butyl-p-cresol, o-tert-butyl-p
-cresol, tetrakis-[methylene-3-(3,5
-di-tert-butyl-4-hydroxyphenyl)propionate comethane, β-naphthylamine, p-phenylenediamine, and the like.

Examples of ultraviolet absorbers include 2,4-dihydroxybenzophenone, 2-(2'-dihydroxy-3'
5'-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2-hydroxy-3-t
Examples include ert-butyl-5-methylphenyl)-5-chlorobenzotriazole and bis(2,2',6.6')-tetramethyl-4-piperidine) sebacate.

Examples of hydrochloric acid absorbers and dehydrochlorination inhibitors include epoxy soybean oil, metal salts of saturated or unsaturated higher fatty acids such as stearic acid, dibutyltin maleate, tribromophosphate, and tetrasodium birophosphate. , 4'-tert-butylphenyl salicyle-1.
, zincium-0-phosphate, alkali metal pyrophosphate, 0-phosphate, phosphite, and the like.

In order to disperse the chlorinated olefin polymer and optionally various polymers or additives in water, it is preferable to use an emulsifier.

In addition, a thickener to increase the viscosity of the resulting aqueous dispersion,
Alternatively, an antifoaming agent or the like may be added to suppress foaming during dispersion.

Surfactants are used as emulsifiers, such as alkylnaphthalene sulfonates, Na salts of naphthalene sulfonic acid formaldehyde condensates, Na salts of cresol-Schaefer acid formaldehyde condensates, Na alkyldiphenyl ether disulfonates, and Ca lignin sulfonates.
salt, melamine resin sulfonic acid Na salt, special polyacrylate, gluconate, olefin maleate copolymer, carboxymethylcellulose Na salt, -metallic stone f
i (Zn, Aff, Na, K salt), sulfonic acid or carboxylic acid type anionic surfactants such as stearic acid triethanolamine salt, fatty acid monoglyceride, sorbitan fatty acid partial ester, sugar fatty acid partial ester, polyglycerin fatty acid Partial ester, polyoxyethylene alkyl ether, bonooxyethylene alkyl phenyl ether, polyoxyethylene sorbitan fatty acid partial ester, polyoxyethylene sorbitol fatty acid partial ester, polyoxyethylene glycerin fatty acid partial ester, polyoxyethylene fatty amide, polyoxyethylene Fatty amine, polyoxyethylene (hardened)
Nonionic surfactants such as castor oil, polyethylene glycol fatty acid ester, polyoxyethylene polyoxybrobylene block copolymer, hydroxyethyl cellulose, polyvinyl alcohol, polyvinylpyrrolidone, methylcellulose; alkylammonium chloride, trimethylalkylammonium bromide, alkylpyridinium chloride, etc. Cationic surfactants; examples include amphoteric surfactants such as dimethylalkylbetaine and alkylglycine.

The amount of the emulsifier used is usually about 1 to 50 parts by weight, preferably about 0.2 to 45 parts by weight, based on 100 parts by weight of the resin solid content.

Examples of thickeners include water-soluble polymers such as carboxymethyl cellulose, methyl cellulose, sodium polyphosphate, polyvinyl alcohol, sodium polyacrylate, ammonia milk casein, vinyl alcohol/methacrylic acid copolymer, starch, and protein. Can be mentioned.

When adding this thickener, the amount added can normally be up to 200 parts by weight per 100 parts by weight of the resin solid content, but it is preferably 100 parts by weight or less.

Dispersion methods include, for example, directly dispersing the chlorinated olefin polymer, other polymers, various additives, etc. in powder form in water; dispersing the resin (
A method in which the chlorinated olefin polymer is melted by increasing the concentration of the olefin polymer (chlorinated olefin polymer) and dispersed under high stirring;
Examples include a method of directly forming an aqueous dispersion.
In addition, as a preferred dispersion method, the chlorinated olefin polymer and other polymers and various additives as necessary are dissolved in an organic solvent such as benzene or toluene to a concentration of 10 to 50% by weight. The solution was added to water together with a hydrophilic solvent such as methyl alcohol, ethyl alcohol, or isopropyl alcohol, and an emulsifier, and stirred using a homomixer or the like to obtain an emulsion.Then, the organic solvent and hydrophilic solvent were removed using an evaporator or the like. One example is a method of removing it.

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 can be used, for example, in high-pressure polyethylene, medium-low pressure polyethylene, polypropylene, polyethylene, etc.
Polyolefins such as 4-methyl-1-pentene, poly-1-butene, and polystyrene: Molded products made of olefin copolymers such as ethylene/propylene copolymers, ethylene/butene copolymers, propylene/butene copolymers, etc. It can be suitably used for.

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.

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

As described above, after applying the aqueous dispersion of the present invention to the surface of a molded product and drying it, a paint can be applied by an appropriate method such as electrostatic painting, spraying, brushing, etc. I can do it. Further, these paints may be applied by applying a primer coat and then a top coat.

The paint used for painting is not particularly limited, but in particular,
If a coating film with high paint adhesion is required, solvent-based thermoplastic acrylic resin paint, solvent-based thermosetting acrylic resin paint, acrylic modified alkyd resin paint, epoxy resin paint, polyurethane resin paint, melamine resin paint, etc. is preferably used. After applying such paint, the paint is
The coating film can be cured by a conventional method of heating with nichrome wire, infrared rays, high frequency waves, etc., to obtain a molded article whose surface is coated. The method for curing the coating film may be 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.

5a A test piece with a base grain is prepared according to the method of base grain test described in JIS K5400, and after pasting a cellophane (manufactured by Chiban ■, trade name) on the base grain of the test piece, This was quickly pulled in a 90° direction to peel it off, and the number of base lines that were not peeled out of 100 base lines was counted, which was used as an index of adhesion.

L1 Wataru 1 Prepare a coating film on the base material, make a 1 cm wide cut with a cutter blade until the blade reaches the base material, peel off the edge, and then
1 at a speed of 501IIIZ.
The peel strength was measured by pulling the coating in an 80° direction until it peeled off.

(Example 1) Propylene/1 having an intrinsic viscosity [η] of 2.0627 g
-Butene (70/30 molar ratio) copolymer was chlorinated according to a conventional method. The chlorine content in the obtained chlorinated product was analyzed by oxygen combustion method and was found to be 21% by weight.

400 g of a solution prepared by dissolving this chlorinated compound in toluene to a concentration of 20% by weight, and 300 g of ion-exchanged water.
, isopropyl alcohol 180g, oleic acid 2.2
g and potassium hydroxide 0.5g, internal volume 1.5f
The mixture was charged into the reactor (i) and stirred for 5 minutes using a homomixer to obtain an emulsion. Next, while heating under reduced pressure with an evaporator, isopropyl alcohol and toluene were mixed together to obtain an aqueous dispersion with a solid content of 21% by weight.

Propylene/ethylene block copolymer resin (ethylene content, 24 mol%, MFR: 10 g/10 min (AST
A base material was prepared, the surface of which was washed with white gasoline. The above water dispersion was applied to this test piece at a dry film thickness of 1 u.
After coating with a spray gun to give a coating film of +11, it was baked in an air oven at 100°C for 30 minutes, and then a top coat (manufactured by Nippon B Chemical ■, R-271) was applied to a dry film thickness of 601 tm. It was applied to. After drying at room temperature for 10 minutes, in an air oven at 100 °C for 3
Baked for 0 minutes. The coating film formed on the surface of the base material was subjected to a base grain test and peel strength measurement. Table 1 shows the results.
Shown below.

(Example 2) Coating was carried out in the same manner as in Example 1, except that an olefinic thermoplastic elastomer (a mixture of polypropylene and a partially crosslinked ethylene-propylene copolymer, 80:20 (weight ratio)) was used as the base material. A membrane was obtained. The obtained coating film was subjected to a substrate grain test and peel strength measurement. The results are shown in Table 1.

(Example 3) Cleaning of the base material in 1.1. A coating film was obtained in the same manner as in Example 1, except that steam cleaning with l-h dichloroethane was performed.

The obtained coating film was subjected to a substrate grain test and peel strength measurement. The results are shown in Table 1.

(Comparative Example 1) A base material coated with a top coat was prepared in the same manner as in Example 1 except that the water dispersion was not coated, and was subjected to a base grain test and peel strength measurement. The results are shown in Table 1.

Table 1 Note 0: Shown as number of base lines that were not peeled/100 base lines.

<Effects of the Invention> The aqueous dispersion of the present invention can be applied to the surface of a molded article, particularly a molded article made of polyolefin resin such as polyethylene or polypropylene, or a molded article made of polypropylene and synthetic rubber. It can improve the adhesion of paint to the surface and is suitable as a brimer. Furthermore, since the aqueous dispersion of the present invention does not use an organic solvent, it is possible to maintain a good working environment during manufacturing and coating operations.

Claims (2)

[Claims] (1) The content ratio of propylene units (a)/α-olefin units having 4 to 6 carbon atoms (b) is 15/85 to 90/10
(molar ratio), and the intrinsic viscosity [η] measured in decalin at 135°C is in the range of 0.5 to 5.0 dl/g, and the chlorine content is 5. An aqueous dispersion containing a chlorinated olefin polymer in a solid content of 5 to 80% by weight in a range of 40% by weight. (2) The α-olefin unit (b) is 1-butene,
The aqueous dispersion according to claim 1, which is at least one selected from 1-pentene, 4-methyl-1-pentene, 3-methyl-1-pentene, and 1-hexene.