KR950011505B1 - Paint composition to be harden by uv - Google Patents

Abstract

The UV curable coating compsn is composed of 30-89 wt.pts(parts) of a reactive oligomer of formula (I) [R1=H or methyl; R2=C3-8 unsatd. (meth)acrylyloxy; R3=HOOC [(CH2m) CO; m=0-4 , 10-60 wt.pts(parts) of a reactive monomer i.e. trimethylolpropane triacrylate, 1,6-hexanediol diacrylate, tripropyleneglycol triacrylate, neopentylglycol diacrylate, pentaerithritol tetra acrylate, etc, 0.5-10 wt.pts(parts) of a photo-initiator i.e. hydroxycyclohexyl phenylketone, 2,2-dimethoxy-2-phenyl acetopheone or benzophenone, 0.1-0.5 wt.pts(parts) of a levelling agent i.e. diacrylate or silicone polyacrylate cpd., and a residual thixotropic agent and antifoaming agent. The plastic molded article is obtained by coating the coating compsn. on the polycarbonate, polystyrene, polyester or ABS in the 0.1-10 micrometer thickness. The coating compsn. has an improved hardness, abrasion resistance, scratch resistance and weather resistance.

Description

UV curable coating composition and plastic molded article coated with the same.

The present invention is coated with a UV-curable coating composition and the coating composition on a plastic molded article such as polycarbonate, polystyrene, styrene-acrylnotryl, polyester, acrylonitrile-butadiene-styrene to improve the aesthetics and durability of the molded article. It's about improving.

Most of the molded products have been used as a substitute for glass, and besides showing excellent performance on its gloss and impact resistance, it is easy to process, and it shows metal by aluminum vacuum deposition, thereby causing pollution by plating and reducing costs. The usage continues to increase, for example, to solve problems.

However, the molded articles have a weaker point than glass in terms of surface wear resistance, scratch resistance, solvent resistance, and the like.

Thus, attempts to remedy the defect have been made for a long time. Silicone resins and melamine resins have been mainly used for this purpose, and these are thermosetting paints, which need to be exposed to heat for a long time. There are a number of bad effects on moles. In addition, there is a problem in the adhesion between the paint and aluminum during aluminum vacuum deposition. In order to solve this problem, U.S. Patent Nos. 427380, 4397723, 4576775 and 4617194 disclose UV-curable coating compositions containing two acryloyloxy groups. In particular, US Pat. No. 4717194, which is more recent, uses acrylic or methacrylic ester resins of polyglycidyl ethers of bisphenol a-formaldehyde condensates containing at least three acryloyloxy or methacryloyloxy. Although UV curable varnishes are manufactured, the properties of these UV curable varnish cured products are somewhat inferior in physical properties such as hardness, detergent resistance, abrasion resistance, scratch resistance, and weather resistance.Adhesion between aluminum film and paint, coating of paints and plastics with aluminum vacuum deposition There was a disadvantage of poor adhesion.

The present invention is a UV-curable coating composition for plastic coatings that has excellent wear resistance, scratch resistance, weather resistance, solvent resistance, hardness, detergent resistance, aluminum adhesion, etc., which is a reactive oligomer, reactive monomer, photoinitiator, leveling agent, and the like. It is composed of additives.

Accordingly, an object of the present invention is to provide an ultraviolet curable paint composition having improved hardness, detergent resistance, abrasion resistance, scratch resistance and weather resistance.

Another object of the present invention is to provide a plastic molded article having improved adhesion between aluminum film and paint and adhesion between paint and plastic during aluminum vacuum deposition.

Hereinafter, the present invention will be described in more detail.

The present invention relates to an ultraviolet curable coating composition, which is coated with a plastic molded article such as polycarbonate, polystyrene, styrene-rylonitrile, polyester, and acrylonitrile-butadiene-styrene, to increase the appearance and durability of the molded article. It relates to a coating composition.

The reactive oligomer used in the present invention is a modified epoxylate of the following formula (1) to form a dense network structure during the curing reaction by ultraviolet light, so that the coating film wear resistance, scratch resistance, solvent resistance, detergent resistance, Hardness, Weatherability and Aluminum Attachment The reactive oligomer may be obtained by addition of acrylic acid to a bisphenol A type epoxy resin, followed by non-catalytic reaction between hydroxyl groups and acid anhydrides formed in the molecule.

R ₃ is an aliphatic carboxylic acid residue of formula HOOC (CH ₂ ) _m CO where _m is an integer of 0 to 4, and R ₄ Of aromatic carbyl groups or R ₄ Aliphatic carbonyl groups wherein R ₄ is carboxyl

Unsaturated acryloyloxy or methacryloyl oxy groups having 3 to 8 carbon atoms of R ₂

R ₁ is a hydrogen atom or methyl group n is an integer of 0 to 20.

Acid anhydrides from which the reactive oligomers can be prepared include phthalic anhydride, hexoxide lophdalic anhydride hydroxalian hydride, maleic hydride, succinic anhydride or glutaric anhydride.

The reactive ligation polymer may be used in the preparation of varnish 5 to 90% by weight of the whole composition, but it is preferable to use 10 to 60% in consideration of workability such as viscosity of the varnish. At this time, when it is 5% or less, adhesiveness with a plastics and an aluminum film is bad, and when it is 90% or more, workability worsens.

Reactive oligomers used in the present invention, in addition to the compound of formula (1), by mixing one or more reactive oligomers of one or more types of polyurethane acrylate, polyester acrylate, polyepoxy acrylate, polyether acrylate Although it can be used, it is mainly used as polyester acrylate because the adhesion to the plastic to be coated is good and the coating after the curing is strong, the adhesion and hardness to the plastic is good.

In addition, the reactive monomer of the present invention may be polymerized with the oligomer to affect the physical properties of the coating film, and one or more monomers may be used. The main monomers are acrylic ester monomers prepared by reacting an alcohol with an unsaturated carboxylic acid ester. 1, 3-butanol diacrylate, 1, 4-butanediol acrylate, 1, 6-hexanediolidiacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, neopentyl glycol diacrylate , Ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, tripropylene glycol diacrylate, pentaerythritol tetraacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate Trimethylolpropane triacrylate , Trimethylolpropanetrimethacrylate, dipentaerythritol pentaacrylate, pentaerythritol triacrylate, and the like, in consideration of physical properties and economical properties of the coating film, 1,6-hexanediolidiacrylate, tripropylene glycoldia Clate, trimethylolpropanetriacrylate, or pentaerythritol terraacrylate is usefully used.

The amount of the varnish composition may be used in an amount of 10 to 80 parts by weight based on the total weight of the varnish composition.

The photoinitiator uses a conventional polymerization initiator exhibiting activity by ultraviolet rays, and 0.5 to 10 parts by weight of compounds such as benzophenone series, benzyldimethyl ketal series, acetophenone series, anthraquinone series, and thioxoxanthone series use. In particular, as the photoinitiator, hydroxy-cyclohexyl phenyl ketone, 2,2-dimethoxy-2phenylacetophenone, benzophenone or phenyl-2-hydroxy-2-propyl ketone are mainly used.

It is preferable to use about 0.1 to 0.5 weight% of the whole varnish composition using a compound of a diacrylate type or a silicone polyacrylate as a leveling agent.

Coating work on plastic molded parts consists of spraying, dipping or polar coating, which can be chosen to favor the plastic depending on the material, shape and thickness of the molded part.

Different viscosity is required depending on the coating method, which can be used by adjusting the viscosity by adding an appropriate amount of volatile solvent. Also. Volatile solvents give chemical impact to plastic molded parts before hardening during painting to increase the adhesion of the coating. Solvents that can be used are ketones, alcohols, acetates, aromatic compounds, and the like, and one or more thereof are mixed and used.

The usage-amount can be used as varnish / solvent weight ratio 4/1-3/1.

Other additives can be used by varying the addition amount of known compounds such as thixotropic agents, antifoaming agents and the like as required.

As shown in Table 1, in which the physical properties of the UV-curable coating composition of the present invention were compared and evaluated according to the following examples, the general formula (1) used a reactive oligomer, such as hardness, abrasion resistance, solvent resistance, scratch resistance, and afterlife. Excellent physical properties in preparation, chemical resistance and adhesion to the aluminum film.

Example 1

Epoxy arc obtained by adding 4 parts by weight of triethylamine to 630 parts by weight of bisphenol atime epoxy resin (Corox R8828 manufactured by Korea Chemical Co., Ltd .: 184-194) and adding 236 parts by weight of acrylic acid for 2 hours to react for 10 hours. 20 parts by weight of a reactive oligomer obtained by mixing 338 parts by weight of an acrylate compound and 173 parts by weight of a phthalic hydride for 15 hours at 90 ° C., 30 parts by weight of a bifunctional urethane acrylate (EB284, manufactured by UCB), and trimethylolpropane UV curable varnish by stirring 24 parts of triacrylate, 22.5 parts of 1,6 hexanediol diacrylate, 3 parts of 2,2 dimethoxy-2phenylacetophenone, and 0.5 parts of silicone polyacrylate (EB360 from UCB) Make

Example 2

338 parts by weight of an epoxy acrylate compound obtained in the same manner as in Example 1 using bisphenol atime epoxy resin (Corox R8828 manufactured by Korea Chemical Co., Ltd., epoxy equivalent: 184 to 194) and acrylic acid and hexahydrophthalic hydride 180.4 20 parts by weight of an acid anhydride-modified epoxy acrylate compound obtained by the same method as in Example 1 by mixing parts by weight, 30 parts by weight of a bifunctional urethane acrylate (EB284, manufactured by UCB), 24 parts of trimethylolpropane triacrylate, 1, 6 22.5 parts of hexanediol diacrylate, 3 parts of 2,2 dimethoxy-2phenylacetophenone, and 0.5 parts of silicone polyacrylate (EB360, a diameter UCB company) were stirred at 50 ° C. to prepare an ultraviolet curable varnish.

Example 3

340 parts by weight of an epoxy acrylate compound obtained in the same manner as in Example 1 using 754 parts by weight of a hydrogenated bisphenol atime epoxy resin (manufactured by New Nippon Chemical Co., Ltd., HBE-100, epoxy equivalent: 220-250) and hexahydro 20 parts by weight of acid anhydride-modified epoxy acrylate obtained by mixing 180.4 parts by weight of talian hydride under the same conditions as in Example 1, 30 parts by weight of a bifunctional urethane acrylate (EB284, manufactured by UCB), and 24 parts of trimethylolpropane triacrylate 22.5 parts of 1, 6-hexanediol diacrylate, 3 parts of 2,2-dimethoxy-2phenylacetophenone, and 0.5 parts of silicone polyacrylate (EB360 from UCB, Calif.) Were stirred at 50 ° C to prepare an ultraviolet curable varnish.

Comparative Example 1

50 parts of bifunctional polyurethane acrylates (EB284 of U.S. diameter UCB), 24 parts of trimethylolpropane triacrylates, 22.5 parts of 1,6 hexanediol diacrylate, 3 parts of 2,2-dimethoxy-2phenylacetophenone, silly 0.5 parts of ton polyacrylates (EB360 from UCB) was stirred at 50 ° C to produce an ultraviolet curable varnish.

Comparative Example 2

Except for using 50 parts of epoxy acrylate prepared by adding 1 mole of acrylic acid to 1 mole of Korepox R8828 (Epoxy equivalent: 184 to 194), which is a bisphenol epoxy resin of Koryo Chemical, instead of the bifunctional urethane acrylate of Comparative Example 1 An ultraviolet curable niche was prepared with the same composition and content as in Comparative Example 2.

TABLE 1

◎: most effective, ○: good, △: bad

＊ Curing condition: 80 watts / ㎝, 2 lamps, irradiation distance 10㎝

＊ Dry film thickness: 7.-15㎛

＊ Diluted by varnish / methyl ethyl ketone = 1/1 weight ratio and reinforced by spray coating on plastic molding.

＊ ABS: Acrylonitrile-butadiene-styrene

＊ ¹⁾ Measured by JIS DO202 (CROSS-CUT)

* ²⁾ Measured according to JIS DO202 (UNI-PENCI1 used)

＊ ³⁾ Observation of color change after 7 days of sunlight X

＊ ⁴⁾ BYK's dual-0 measuring instrument (DUR-0-TESTER)

＊ ⁵⁾ Coating state after immersion at room temperature X 24 hours

＊ ^{6) Use of} dual abrasion measuring instrument (Model 505)

＊ ⁷⁾ Detergent resistance: Observe the coating state after standing for 1 week after immersion in 3% high tie solution (45 ℃)

Claims (4)

(Correction) 30-89 weight% of reactive oligomers represented by the following formula (I), trimethylolpropane triacrylate, 1,6-hexadiol diacrylate, tripropylene glycol triacrylate, pentaerythritol tetraacrylate, di 10 to 60 wt% of reactive monomers such as pentaerythritol pentaacrylate, tripropylene glycol diacrylate, neopentyl glycol diacrylate or 1,6-hexanediol diacrylate, 0.5 to 10 wt% leveling agent 0.1 to photoinitiator An ultraviolet curable coating composition comprising 0.5 parts by weight and additives such as a thixotropic agent and an antifoaming agent. R ₁ is a hydrogen atom or a methyl group: R ₂ is an unsaturated acrylyloxy or methacrylyloxy having 3 to 8 carbon atoms: R ₃ is an aliphatic carboxylic acid residue of the formula HOOC (CH _2m ) CO, wherein _m is 0 Integer of 4 to 4) Formula R ₄ CO aromatic carbonyl group, or R ₄ Cyclic aliphatic carbonyl group of CO (wherein R ₄ is carboxy): and n is an integer of 0 to 20. The ultraviolet curable coating composition according to claim 1, wherein the photoinitiator is benzophenone benzyl dimethyl ketal, acetophenone series, anthraquinone series or thioxoxanthone series. The UV curable coating composition according to claim 1, wherein the leveling agent is a compound of silicone diacrylate or silicone polyacrylate. (Correction) Polycarbonate, polystyrene, styrene-acrylonitrile, polyester, characterized in that the cured UV curable varnish containing the reactive oligomer represented by the following formula (I) by coating 0.1 ~ 10ml thickness on the plastic surface. And plastic molded products such as acrylonitrile-butadiene-styrene. R ₁ is a hydrogen atom or a methyl group: R ₂ is an unsaturated acrylyloxy or methacryloyloxy having 3 to 8 carbon atoms: R ₃ is an aliphatic carboxylic acid residue of the formula HOOC (CH ₂ ) _m CO (where _m Is an integer from 0 to 4), Formula R ₄ CO aromatic carbonyl group, or R ₄ Cyclic aliphatic carbonyl group of CO (wherein R ₄ is a carboxyl group): and n is an integer of 0 to 20.