KR0132260B1 - Uv-curable coating compositions - Google Patents

Abstract

The invention relates to a UV-hardened coating composition which comprises 5-90% of silane modified epoxyacrylate oligomer (Formula I), 5-80% of a reactive monomer, 0.1-20% of photoinitiator, 0-10% of labeling agent and small amount of additives. In the formula I, R1 is hydrogen atom or methyl group, R2 is unsaturated acryloyloxy or methacryloyloxy with carbon number of 3-8; R3 is a siloxane compound; n is a integer of 0-20; R4 is methyl or phenyl; m is a integer of 1-40. The coating composition is useful for coating plastic articles, and has abrasion resistance and scratch resistance.

Description

UV Curable Coating Composition

The present invention relates to a UV curable paint composition, and more particularly, to a paint composition comprising a reactive oligomer, a reactive monomer, a photoinitiator, a leveling agent, and an additive, such as polycarbonate, polystyrene, styrene-acrylonitrile, polyester, and acryl. The present invention relates to an ultraviolet curable coating composition which is coated on plastic molded articles such as ronitrile-butadiene-styrene, polyethylene, and polypropylene to improve aesthetics, durability, and workability of molded articles.

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 abrasion resistance, scratch resistance, chemical resistance, and the like. Therefore, attempts to remedy such defects have been made for a long time, and silicone resins and melamine resins have been mainly used for this purpose.

However, these synthetic resins must be exposed to heat for a long time in order to form a coating film as a thermosetting paint. As a result, the yield decreases due to prolonged heating, and the high temperature causes various adverse effects on the properties of the molded plastic. Problems of workability were raised.

In order to solve the above problems, an ultraviolet curable paint composition containing two acryloyloxy groups has been proposed (Japanese Patent Laid-Open No. 63-150,355, No. 63-221119, No. 59-1117561, Pyeongseong 1-2-267609, Pyeongsung 1-65631, Patent No. 132260, Article 2/6) Particularly, Japanese Laid-Open Patent Publication No. Hei 165531 uses ultraviolet curing type resins using non-reactive resins such as polymethyl methacrylate and polyvinylacetate and acrylic or methacrylate resins of four or more polyglycidyl ethers. Although a sheath was manufactured, physical properties such as hardness, detergent resistance, abrasion resistance, scratch resistance, and weather resistance of the UV curable varnish cured product were somewhat inferior and poor workability during coating.

The present invention is a UV-curable coating composition for flaksteel coating having excellent wear resistance, scratch resistance, weather resistance, chemical resistance, workability, etc., which is made up of reactive oligomers, reactive monomers, photoinitiators, leveling agents, and additives.

Accordingly, it is an object of the present invention to provide an ultraviolet curable coating composition having improved abrasion resistance, scratch resistance and chemical resistance.

It is another object of the present invention to improve workability when painting such molded articles.

Reactive oligomer used in the present invention is a siloxane-modified epoxy acrylate oligomer of the general formula (1) to form a high-density network structure during the curing reaction by UV light, wear resistance, scratch resistance, chemical resistance and workability during coating There is an advantage to improve.

The siloxane-modified epoxy acrylate oligomer can be obtained by the addition of acrylic acid to a bisphenol-type epoxy resin, followed by reaction of a hydroxyl group formed in the molecule with an epoxy-modified siloxane compound on one end with an acid catalyst.

Wherein R ¹ is a hydrogen atom or a methyl group, R ² is an unsaturated acryloyloxy or methacryloyloxy group having 3 to 8 carbon atoms, R ³ is a siloxane compound, and n is an integer of 0 to 20.

The single-ended epoxy modified polysiloxane used for manufacture of the siloxane modified epoxy acrylate oligomer of the said General formula (1) is a substance which has the molecular weight 250-3000 represented by following General formula (2).

Here, R <^4> is a methyl group or a phenyl group, m is an integer between 1-40.

Representative polysiloxanes containing single-ended epoxy groups include the following.

Single-Ended Epoxy Modified Dimethyl Siloxane Polymer

Single-Ended Epoxy Modified Phenylmethyl Siloxane Polymer

Single-Ended Epoxy Modified Diphenylsiloxane Polymer

L: integer between 3 and 25

In the above formula, the reaction equivalent ratio of epoxy acrylate and single-ended epoxy-modified polysiloxane is 1: 0.1 to 1: 0.95, but when the molar ratio of polysiloxane is 0.10 or less, the hardened material property is poor and there is a risk of gel formation when it is 0.95 or more. .

Therefore, in consideration of the hardenability and workability, the appropriate equivalent ratio is preferably 1: 0.1 to 1:06.

The siloxane modified epoxy acrylate oligomer of the present invention has a low surface energy due to the Si-O bond of polysiloxane, and it has a wear resistance, scratch resistance, solvent resistance, etc. This is improved.

The siloxane-modified epoxy acrylate oligomer of the present invention can be used 5 to 90% by weight of the entire composition when manufacturing varnish, it is preferred to use 10 to 60% by weight in consideration of workability and cured product properties.

The reactive oligomer used in the present invention may be used by mixing one or more of polyurethane acrylate, polyester acrylate, polyepoxy acrylate, polyether acrylate in addition to the compound of the general formula (1).

In addition, the reactive monomers used in the present invention may be polymerized with the reactive oligomers to affect the physical properties of the coating film, and one or more monomers may be used. The mainly used monomers include mono-, bi-, tri-, and poly-functional monomers. The polyfunctional monomers include 2-ethylhexyl acrylate, octyldecyl acrylate, isodecyl acrylate, tridecyl methacrylate, 2-phenoxy ethyl acrylate, nonyl phenol ethoxy lake monoacrylate, and tetrahydrofurfu. Relate, ethoxyethyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate And bifunctional monomers include 1,3-butanedioldiacrylate and 1,4-butanedioldi. Acrylate, 1, 6-hexanediol diacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, neopentyl glycol diacrylate, ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate , Polyethylene glycol dimethacrylate, tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, and the like, and trifunctional monomers include trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, and pentaerythritol. Triacacrylate, glycidyl pentatriacrylate, glycidyl pentatriacrylate, and the like, and polyfunctional monomers include dipentaerythritol pentaacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, and the like. 1, 6-hexanediol diacrylate, tripping in consideration of the physical properties of the coating film Lophylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, and the like are usefully used.

Although the amount of the reactive monomer can be used 5 to 80% by weight of the whole varnish composition, it is preferable to use about 10 to 60% by weight in consideration of the cured material properties and workability.

The photoinitiator uses a conventional polymerization initiator having activity by ultraviolet rays, and 0.1 to 60% by weight of compounds such as benzophenone series, benzyldimethyl ketal series, acetophenone series, anthraquinone series, and thioxoxanthone series are used. do. In particular, such photoinitiators are mainly used hydroxy-cyclohexyl phenyl ketone, 2,2-dimethoxy 2-phenylacetophenone, benzophenone or phenyl-2-hydroxy-2-propyl ketone.

The leveling agent may be silicon-based, fluorine-based, it is appropriate to use about 0 to 10% by weight.

Coating work on plastic molded parts consists of spraying, dipping or roller coating, which can be advantageously selected depending on the material of the plastic, the improvement of the molded part and the film thickness.

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.

In addition, the volatile solvent increases the adhesion of the coating film by giving a chemical impact to the plastic and metal material before curing during painting work.

Solvents that can be used include ketones, alcohols, acetates, aromatic compounds, etc., and may be used by mixing one or more of them. The usage-amount can be used for the varnish / solvent weight ratio as 4/1-1/4.

The additive uses a known compound of silicone or amine amide and can be used by varying the amount of addition according to various requirements.

Using the siloxane-modified epoxy acrylate oligomer of general formula (I) as shown in Table 1 in which the physical properties of the ultraviolet curable coating composition of the present invention were compared and evaluated according to the following examples and comparative examples, abrasion resistance, chemical resistance, scratch resistance It showed excellent physical properties in terms of resistance, chemical resistance and workability.

Example 1

Epoxy acrylate obtained by adding 4 g of triethylamine to 520 g of bisphenol F-type epoxy resin (Korea Chemical Co., Ltd., Korepoxy R8130, Epoxy equivalent: 160 ~ 180) and dropping 208 g of acrylic acid for 2 hours. 20 g of a silane-modified epoxy acrylate oligomer obtained by mixing 252 g of a compound with 270 g of a single-modified epoxy-modified dimethylsiloxane polymer (molecular weight: 1800) for 120 ° C. for 40 hours, 30 g of a bifunctional urethane acrylate (EBECRYL 284, a light diameter UCB company), and trimethyl 24 g of all propane triacrylate, 22.5 g of 1,6-hexanediol diacrylate, 3 g of 2,2-dimethoxy 2-phenylacetophenone, and 0.5 g of silicon pulley acrylate (EBECRYL360, a diameter UCB) were stirred at 50 ° C An ultraviolet curable varnish was prepared.

Example 2

260 g of an epoxy acrylate compound obtained in the same manner as in Example 1 using 640 g of a bisphenol A type epoxy resin (Korea Chemical, trade name: Korepoxy R8828, Epoxy equivalent: 184-194) and 240 g of acrylic acid, and a single-ended epoxy-modified phenyl 20 g of silane-modified epoxy acrylate oligomers obtained by using 300 g of methyl siloxane polymer (molecular weight: 1500) in the same manner as in Example 1, 30 g of bifunctional urethane acrylate (EBECRYL284 manufactured by Sunbushi UCB Co., Ltd.), 24 g of trimethylolpropane triacrylate, 1.6- 22.5 g of hexanediol diacrylate, 3 g of 2,2-dimethoxy 2-phenylacetophenone, and 0.5 g of silicone polyacrylate (EBECRYL360, manufactured by UCB) were stirred at 50 ° C to prepare an ultraviolet curable varnish.

Example 3

260 g of an epoxy acrylate compound obtained in the same manner as in Example 1 using a bisphenol A type epoxy resin (Korea Chemical Co., Ltd. product name: Korepoxy R8828, Epoxy equivalent: 184-194) and 240 g of acrylic acid, and a single-ended epoxy-modified diphenyl siloxane polymer (Molecular weight: 1000) 20 g of a silane-modified epoxy acrylate oligomer obtained in the same manner as in Example 1, 30 g of a bifunctional urethane acrylate (EBECRYL284 from UCB diameter), 24 g of trimethylolpropane triacrylate, and 1.6-hexanediol diacryl An ultraviolet curable varnish was prepared by stirring a rate of 22.5 g, 2,2-dimethoxy-diphenylacetophenone 3g, and 0.5 g of silicone polyacrylate (EBECRYL360, a diameter UCB company) at 50 ° C.

Comparative Example 1

50 g of epoxy acrylate, trimethylolpropanetriacrylate, 24 g, 22.5 g of 1,6-hexanediol dimethyl acrylate, 3 g of 2.2-dimethoxy-phenylacetophenone prepared in the same manner as in Example 1, silylconpolyacrylic 0.5 g of the rate (EBECRYL360 from UCB) was stirred at 50 ° C to prepare an ultraviolet curable varnish.

Comparative Example 2

Epoxyacrylate prepared in the same manner in Example 2 UV curable varnish was prepared in the same composition and content as in Comparative Example 1 except that 50g was used instead of the bifunctional epoxy acrylate of Comparative Example 1.

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

Dry film thickness: 7-15㎛

Dilution with varnish / methyl ethyl ketone = 1 weight ratio and spray coating on plastic molding 1) Use BYK's DUAL-0-TESTER (DUR-0-TESTER)

2) Coating state after 24 hours immersion at room temperature

3) Using a dual wear meter (Dodel 505)

4) Appearance observation after painting on molded products

As shown in Table 1, the physical properties of Examples 1, 2 and 3 were superior to those of Comparative Examples 1 and 2 in all respects. It was better than 3, and Example 1 was the best in workability.

This is for the reactive oligomer of the general formula (1) used in the present invention to exhibit better all the physical properties of the ultraviolet curable paint composition.

Claims (10)

a) General formula (1) prepared by addition reaction of acrylic acid to a bispetol A type epoxy resin, followed by reaction of a hydroxyl group formed in a molecule with a single-terminal epoxy modified siloxane polymer represented by formula (2) with an acid catalyst (1) 5 to 90% by weight of a silane-modified epoxy acrylate oligomer represented by; b) 5-80% by weight of reactive monomer; c) 0.1-20% by weight of photoinitiator; d) 0 to 10% by weight leveling agent; e) small amounts of additives; UV curable coating composition composed of. Wherein R ¹ is a hydrogen atom or a methyl group, R ² is an unsaturated acryloyloxy or methacryloyloxy group having 3 to 8 carbon atoms, R ³ is a siloxane compound and n is an integer of 0 to 20. Here, R <^4> is a methyl group or a phenyl group, m is an integer between 1-40. The ultraviolet curable coating composition according to claim 1, wherein the silane-modified epoxy acrylate oligomer is reacted with an epoxy-modified siloxane polymer in an amount of 0.1 to 0.6 equivalents relative to 1 equivalent of epoxy acrylate. The ultraviolet curable coating composition according to claim 1, wherein the polymer of the general formula (2) is one selected from a single-ended epoxy modified dimethylsiloxane polymer, a single-ended epoxy modified phenylmethylsiloxane polymer, and a single-ended epoxy modified diphenyl siloxane polymer. The ultraviolet curable coating composition according to any one of claims 1 to 3, wherein the single-ended epoxy-modified siloxane polymer has a molecular weight of 250 to 3,000. The method of claim 1, wherein the reactive monomer is 2-ethoxylacrylate, octyldecyl acrylate, isodecyl acrylate, tridecyl methacrylate, 2-phenoxyethyl acrylate, nonylphenol ethoxy lake as monofunctional monomer. Monoacrylate, tetrahydroperfurate, ethoxyethyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxy UV curable coating composition selected from butyl methacrylate. The method of claim 1, wherein the reactive monomer is 1,3-butanediol diacrylate, 1-4-butanediol diacrylate, 1,6-hexanediol diacrylate, diethylene glycol diacrylate, triethylene as a bifunctional monomer. Glycol Dimethacrylate, Neopentyl Glycol Diacrylate, Ethylene Glycol Dimethacrylate, Tetraethylene Glycol Dimethacrylate, Polyethylene Glycol Dimethacrylate, Tripropylene Glycol Diacrylate, 1,6-hexanediol Di UV curable paint composition selected from acrylates. The method according to claim 1, wherein the reactive monomer is selected from trimethylolpropanetriacrylate, trimethylolpropanetrimethacrylate, pentaerythritoltriacrylate, glycidylpentatriacrylate, and glycidylpentatriacrylate as trifunctional monomers. UV curable coating composition selected. The ultraviolet curable coating composition according to claim 1, wherein the reactive monomer is one selected from 1,6-acid diol diacrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, or pentaerythritol tetraacrylate as a polyfunctional monomer. The ultraviolet curable coating composition according to claim 1, wherein the photoinitiator is one selected from benzophenone series, benzyldimethyl ketal series, acetophenone series, anthraquinone series, and thioxoxanthone series. Plastic, metal and non-metallic molded article coated with the chair ultraviolet curable coating composition according to claim 1.