JPH0435497B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for applying a light- or radiation-curable resin composition to a molded article of a polyolefin resin composition. More specifically, polyolefins and general formula -OCOR,

【formula】

[Formula] Ma Taha

[Formula] (where R and R' are H or a hydrocarbon group having 1 to 8 carbon atoms) A resin composition consisting of a polyolefin polymer compound having a polar group represented by After obtaining various plastic molded products (hereinafter referred to as plastic molded products refers to pressure molded, extrusion molded, and injection molded products), they are pretreated with an alkaline aqueous solution with a pH of 9 to 14, washed with water, and dried. , if necessary, wash with a neutral cleaning solution, dry, and if necessary use the general formula -X,- as a vehicle in advance.
OCOR, −COOR, −OR,

【formula】

[expression] or

[Formula] (where X is halogen, R and R' are H or carbon number 1-8
A primer solution containing 1 to 90% by weight of at least one type of polyolefin polymer compound having at least one type of polar group (hydrocarbon group) is applied as an undercoat, dried, and then the surface is cured with light or radiation. The present invention relates to a method of applying a resin composition. Polyolefins are used in a wide range of applications because they have excellent mechanical properties such as rigidity and tensile strength, as well as excellent chemical resistance and processability.
However, polyolefins have the disadvantage of poor scratch resistance. Possible methods to overcome these drawbacks include a method of blending a modifier and a method of applying it to the surface. However, the former method deteriorates other physical properties of the polyolefin, and the latter method has a problem in that good adhesion between the coating agent and the polyolefin cannot be obtained because the polyolefin is a nonpolar polymer. As a result of intensive studies to solve these problems, the inventors of the present invention have found a method that provides good adhesion and improves hardness and scratch resistance, leading to the present invention. That is, the present invention provides polyolefins and general formulas -OCOR,

【formula】

[Formula] Also teeth

[Formula] (where R and R' are H or a hydrocarbon group having 1 to 8 carbon atoms) A polyolefin resin composition molded article consisting of a composition of an olefin polymer compound having a polar group represented by The present invention relates to a method in which a primer solution consisting of an olefinic polymer compound having a polar group is applied as necessary, and then a light- or radiation-curable resin composition is applied to the surface. Typical polyolefins used in the present invention include polyethylene, polypropylene,
Ethylene-propylene copolymer, propylene-ethylene-butene terpolymer, ethylene-4-methyl-pentene-1 copolymer, polybutene, etc.
and combinations thereof. Further, the olefin-based polymer compound having a polar group that can be mixed with the polyolefin improves the paintability of the polyolefin, and preferably has a structure that has affinity with the paint to be applied. Such polar groups include the general formula −OCOR,

【formula】

【formula】

It is represented by the formula: (where R and R' are H or a hydrocarbon group having 1 to 8 carbon atoms). Examples of such compounds include ethylene-vinyl acetate copolymer or partially saponified product thereof, ethylene-acrylic (methacrylic) acid ester copolymer or partially hydrolyzed product thereof, ethylene-maleic anhydride copolymer or partially hydrolyzed product thereof, etc. Decomposed products, partially esterified products, ethylene-glycidyl methacrylate copolymer or its partially ring-opened products with organic acids, primary amines, secondary amines, acrylic acid modified polypropylene, maleic anhydride modified polypropylene, Examples include ethylene-methacrylic acid dialkylaminoethyl ester. Such an olefin-based polymer compound having a polar group has the effect of increasing the adhesion strength of the paint by changing the surface tension of the polyolefin, but if it is added in an amount of 50 parts by weight or more, the desired physical properties of the polyolefin cannot be maintained. Further, if necessary, a styrene elastomer such as a styrene-butadiene random copolymer or a styrene-butadiene block copolymer may be added to improve the adhesion of the paint. Further, 0 to 40 parts by weight of various fillers such as glass fiber, talc, wood flour, and calcium carbonate may be added as necessary.
Regarding the use of a primer as a means of improving the adhesion between the polyolefin resin composition molded article and adhesive according to the present invention, the use of an olefin polymer compound having a polar group, and the surface treatment of the polyolefin resin composition molded article, etc. After conducting various studies, our researchers were surprised to find that the polyolefin of the present invention and the general formula -OCOR,

【formula】

[expression] or

[Formula] (where R and R' are H or a hydrocarbon group having 1 to 8 carbon atoms) The surface of a polyolefin resin composition molded article made of a polyolefin polymer compound having a polar group represented by
14, preferably with an alkaline aqueous solution having a pH of 11 to 14, it has been found that it can firmly adhere to a light or radiation resin composition, leading to the present invention. In the present invention, the alkaline aqueous solution includes metal silicates, metal phosphates, metal carbonates,
Examples include aqueous solutions of caustic soda, caustic potash, etc., and silicate metal salts, caustic soda, caustic potash, etc. are preferred. If the pH of the alkaline aqueous solution is 9 or less, the degreasing power will be weak and sufficient adhesive strength with the light- or radiation-curable resin composition will not be obtained. Although adhesion with the photo- or radiation-curable resin composition can be achieved by the above-mentioned pretreatment with an alkaline aqueous solution, in order to further enhance the effect, it may be pretreated with an alkaline aqueous solution, washed with water, and then washed with a neutral detergent. Neutral detergents are conventional anionic or nonionic surfactants. The pretreatment method with an alkaline aqueous solution is as simple as applying it to the surface of a polyolefin resin molded product using a sprayer and washing with water, or immersing the plastic molded product. After pretreatment with the alkaline aqueous solution, washing with water,
After drying, apply the next primer solution as an undercoat, dry, and then apply a light- or radiation-curable resin composition to further improve adhesion. Such primers may have general formulas -X, -OCOR, -COOR, -OR,

【formula】

[expression] or

At least one polyolefin polymer compound having at least one polar group represented by the formula (X is a halogen, R and R' are H or a hydrocarbon group having 1 to 8 carbon atoms) 0.01 to
A primer solution containing 90% by weight can be used. Such polar groups include the general formula -X, -
OCOR, −COOR, −OR,

【formula】

【formula】

[Formula] (where X is a halogen, R and R' are H or a hydrocarbon group having 1 to 8 carbon atoms); It is preferably 1 to 60% by weight based on the solid content. If it is less than 1% by weight, the effect of the polar groups will be poor and it will be difficult to adhere to the cured resin composition of the top coat.On the other hand, if it is more than 60% by weight, there will be too many polar groups and it will not adhere closely to the molded article made of the polyolefin composition. Hateful.
Further, two or more types of these polar groups may be combined for the purpose of complementing the adhesion. Examples of such compounds include chlorinated polyethylene, brominated polyethylene, chlorinated polypropylene, chlorinated products of ethylene-propylene copolymers, ethylene-vinyl acetate copolymers or partially silicified products thereof, and ethylene-vinyl acetate copolymers. Modified maleic anhydride, ethylene-acrylic (methacrylic) acid copolymer, ethylene-acrylic (methacrylic) acid ester copolymer or partially hydrolyzed product thereof, ethylene-maleic anhydride copolymer or partially hydrolyzed product thereof , partially esterified products, ethylene-glycidyl methacrylate copolymers or partially ring-opened products thereof with organic acids, primary amines, secondary amines, alkali acid modified products of polypropylene,
Examples include polypropylene modified with maleic anhydride, ethylene-methacrylic acid dialkylaminoethyl ester, and the like. The solvent used in the primer is preferably one that is industrially easily available, has appropriate volatility, and can completely dissolve or uniformly disperse the primer vehicle. For this purpose, for example, halogenated aliphatic hydrocarbons such as carbon tetrachloride, trichlorethylene, 1.1.1-trichloroethane, and aromatic hydrocarbons such as toluene, xylene, benzene, decalin, tetralin, as mentioned above, Examples include halogenated aromatic hydrocarbons such as chlorobenzene, ketones such as acetone and methyl ethyl ketone, and tetrahydrofuran, which can be used alone or as a mixed solvent of two or more. The method for applying this undercoat is simple, such as applying it to the surface of the polyolefin resin molded product using a brush, brush, spray, etc., or immersing the plastic molded product in the undercoat solution, which requires equipment costs. I don't. After pretreatment with an alkaline aqueous solution, the surface is washed with water, dried, and if necessary, an undercoat is applied and dried, and the surface is further coated with a light- or radiation-curable resin composition. The light- or radiation-curable resin used in the present invention includes conventionally known unsaturated polyester resins,
There are urethane/alkali resins, melamine/acrylic resins, acrylated polyester resins, epoxy/acrylic resins, etc., and one or two of these resins are used.
Used in combination of types. In addition to the above-mentioned light- or radiation-curable resins, commonly used ethylenically unsaturated monomers such as styrene, vinyl,
Acetate, 2-vinylpyridine, N-vinylpyrrolidone, N-vinylcarbazole, methyl acrylate, ethyl acrylate, butyl acrylate, lauryl acrylate, stearyl acrylate, benzyl acrylate, hydroxyethyl acrylate, cyclohexyl acrylate,
Ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, methacrylic acid, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate , triethylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate,
Trimethylolpropane trimethacrylate, pentaerythritol tetramethacrylate, etc. can be used. Of course, these may be used alone or in combination of two or more. Further, for the purpose of imparting properties such as flexibility, the present invention is characterized by the use of polymers such as saturated polyester resins, alkali resins, alkyd resins, ethylene-vinyl acetate copolymers, pigments, colorants, plasticizers, etc. It's okay as long as it doesn't damage it. In order to cure the light- or radiation-curable resin composition of the present invention with ultraviolet rays or electron beams, benzoins such as benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether, ketones such as benzophenone and micellar ketone, and azobisiso This can be carried out using known photoinitiators such as azos such as butyronitrile or quinones such as anthraquinone, or various combinations thereof. Further, the light- or radiation-curable resin of the present invention may be diluted with a solvent such as ethyl acetate or n-butyl acetate as necessary. Methods for applying the light- or radiation-curable resin composition to the molded article include commonly used methods such as brush coating, spray coating, and dipping. The present invention will be explained below with reference to Examples. Synthesis Example 1 222.3 g of isophorone diisocyanate and 114 g of n-butyl acetate were placed in a flask equipped with a stirrer, a thermometer and a cooling condenser, 139.3 g of 2-hydroxyethyl acrylate and 0.114 g of phenothiazine were added, and the mixture was heated at 90°C for 3 hours. The reaction resulted in a pale yellow viscous resin liquid. 209 g of Desmofene #1150 manufactured by Sumitomo Bayer Urethane Co., Ltd. and 0.209 g of dibutyltin diacetate were added dropwise to the above resin liquid and reacted at 90°C for 4 hours to obtain a pale yellow viscous resin liquid (A). Example 1 90 parts by weight of an inorganic material-filled polyolefin consisting of 80% by weight of homopolypropylene with a melt index of 8 and 20% by weight of talc and ethylene with a melt index of 50 consisting of 82% by weight of ethylene and 18% by weight of glycidyl methacrylate. and 10 parts by weight of a copolymer of glycidyl methacrylate were mixed and passed through an extruder to obtain a molding resin. This was molded using an injection molding machine at a molding temperature of 230°C to a thickness of 2 mm.
An injection molded plate with a width of 90 mm and a length of 150 mm was molded and used for testing. The molded plate was immersed in an aqueous solution of sodium ortho silicate (Na ₄ SiO ₄ ) having a pH of 13.5 at 60° C. for 3 minutes while stirring the solution, and then washed with water. Then, photocurable resin liquid (A) 80 parts trimethylolpropane triacrylate
A photocurable resin composition prepared using a formulation of 20 parts n-butyl acetate, 20 parts benzophenone, and 3 parts was applied to the above-mentioned treated plate using a bark quarter #26 (film thickness 26μ), and then heated using a mercury lamp of 80 W/cm at a belt conveyor speed.
Irradiation was performed 15 times (irradiation time 30 seconds) at 10 m/min. As a result, the pencil hardness of the coated plate was 2H, and the retention rate in the cellophane tape peel test was 100/100. Comparative Example 1 The homo-polypropylene molded plate used in Example 1 had a pencil hardness of B. Comparative Example 2 Coating and irradiation were carried out in the same manner as in Example 1, except that the pretreatment with an alkaline aqueous solution was omitted. As a result, the residual ratio of the coated plate in the peel test using Sellotape was 60/100. Example 2 In Example 1, before applying the photocurable resin composition to the molded plate, a chlorine content of 27% by weight obtained by chlorinating alkali acid-modified polypropylene with an alkali acid content of 2% by weight was used as a primer. Example 1 was carried out in the same manner as in Example 1, except that a 5% by weight toluene solution was spray applied. As a result, the pencil hardness of the coated plate was 2H, and the retention rate in the cellophane tape peel test was 100/100.

Claims (1)

[Claims] 1 A polyolefin and a polar group represented by the general formula -OCOR, [Formula] [Formula] or [Formula] (wherein R and R' are H or a hydrocarbon group having 1 to 8 carbon atoms) A molded article made of a composition of a polyolefin-based polymer compound having a polyolefin-based polymer compound is pretreated with an alkaline aqueous solution having a pH (hydrogen ion concentration) of 9 to 14, washed with water, dried, and then a photo- or radiation-curable resin composition is applied to the surface of the molded article. 1. A method for applying a light- or radiation-curable resin composition to a polyolefin resin molded article having excellent scratch resistance, hardness, and adhesion (peel strength) on the coated surface. 2 Polyolefin and an olefin-based polymer compound having a polar group represented by the general formula -OCOR, [Formula] [Formula] or [Formula] (where R and R' are H or a hydrocarbon group having 1 to 8 carbon atoms) A molded article consisting of a composition of formula -X-, -OCOR, -COOR, -OR, [Formula] [ At least one type of olefinic polymer compound having at least one type of polar group represented by the following formula: ~
Damage resistance, hardness, and adhesion (peel strength) of the coated surface characterized by applying a primer solution containing 90% by weight as an undercoat, drying it, and then applying a light- or radiation-curable resin composition to the surface. A method for applying a light- or radiation-curable resin composition to a polyolefin resin molded product.