JPH07100431A - Method of forming three-dimensional pattern coating film - Google Patents

Abstract

(57) [Summary] [Structure] A UV-curable coating material containing a coloring pigment is applied on the entire surface or a part of the surface of the article in a pattern form, and a pattern-like cured coating film is formed by irradiating UV rays, Next, a method for forming a three-dimensional pattern coating film, which comprises applying a transparent or opaque coating material using a fluororesin as a binder and curing the coating material. [Effect] The method for forming a three-dimensional pattern coating film of the present invention makes use of the resource-saving and short-time curing characteristics of an ultraviolet curable coating material, and the obtained three-dimensional pattern coating film has excellent weather resistance and stain resistance. There is. Therefore, according to the present invention, it becomes possible to apply the ultraviolet-curable coating material, which has been conventionally applied only to indoor articles, to outdoor articles.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a three-dimensional pattern coating film which is excellent in weather resistance, stain resistance and the like, and is particularly suitable for application to an outdoor article to be coated.

[0002]

2. Description of the Related Art In recent years, in response to social demands such as pollution-free and resource saving, a colored UV-curable coating material having no solvent or a small amount of organic solvent has been attracting attention. The club has come to be adopted. However, UV curable paints have poor weather resistance and poor stain resistance because it is usually not possible to incorporate UV absorbers to improve weather resistance. Therefore, coating materials such as building materials applied outdoors are not suitable. Most of the products have not been put into practical use, and particularly when a patterned coating film was formed using an ultraviolet curable coating composition, the appearance of the coating film deteriorated, and it was difficult to maintain its aesthetic appearance for a long period of time.

In view of the above circumstances, it is an object of the present invention to provide a method for forming a three-dimensional pattern coating film which uses a colored UV-curable coating material and is excellent in weather resistance and stain resistance.

[0004]

That is, according to the present invention, an ultraviolet curable coating material containing a coloring pigment is applied in a pattern on the entire surface or a part of an object to be coated, and the pattern is cured by irradiating with ultraviolet rays. The present invention relates to a method for forming a three-dimensional pattern coating film, in which a transparent or opaque coating containing a fluororesin as a binder is applied and cured.

The present invention will be described in detail below. The UV-curable coating used in the present invention is a UV-polymerizable vehicle,
It comprises a photoreaction initiator and a coloring pigment as essential components, and further contains glass powder, an extender pigment, a solvent, an additive and the like as required. As the vehicle component, a compound having an unsaturated double bond capable of radical polymerization in the molecule can be used. Specifically, unsaturated polyester-based resins, unsaturated acrylic-based resins, unsaturated urethane-based resins, unsaturated epoxy-based resins, unsaturated polyamide-based resins or ethylenic resins used in ordinary UV-curable coatings A typical example is a mixture with a reactive diluent having an unsaturated group. In particular, the following vehicles that are excellent in recoatability, that is, excellent in interlayer adhesion even under a wide range of ultraviolet irradiation conditions are suitable.

The hibicle is mainly composed of an acrylic urethane oligomer, and the acrylic urethane oligomer has a urethane bond in the molecule and an unsaturated double bond capable of radical polymerization to an average molecular weight of several hundreds. Those that are viscous at room temperature of tens of thousands are widely included. For example,
Non-yellowing polyisocyanate and hydroxyl group (meth)
In addition to oligomers obtained by reaction with acrylic acid esters, polyether-based acrylic urethane oligomers,
Polyester-based acrylic urethane oligomers, polybutadiene-based acrylic urethane oligomers and the like are also included.

The vehicle comprises these resins or oligomers and a reactive diluent. 2- as a reactive diluent
Ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, isobornyl (meth) acrylate, tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, tetraethylene glycol diacrylate, trimethylolpropane tri (meth) acrylate , Pentaerythritol tetra (meth) acrylate, ditrimethylolpropane pentaacrylate, dipentaerythritol hexaacrylate, vinyl acetate, N-vinylpyrrolidone,
Typical examples include dimethyl (meth) acrylamide, vinyltoluene, divinylbenzene, etc. These reactive diluents are preferably added in an amount of 10 to 100 parts by weight based on 100 parts by weight of the resin or oligomer.

Examples of the photoreaction initiator include carbonyl compounds such as benzoin, benzophenone and their esters, benzoyl peroxide, azobisisobutyronitrile, diphenyldisulfide, N-methyldiethanolamine and 2,5-diethoxy-4-. Although conventionally used ones such as (p-tolylthio) benzenediazonium hexafluorophosphate can be used as they are, particularly in the present invention, an acylphosphine oxide compound easily forms a cured coating film, and therefore a thick film is obtained. This is preferable because it can be realized and a patterned coating film having a three-dimensional effect can be formed.

Specific examples of the acylphosphine oxide compound include 2,2-dimethylpropioyldiphenylphosphine oxide, 2,2-dimethylpentanoyldiphenylphosphine oxide, 2,2-dimethyloctanoyldiphenylphosphine oxide and methyl. 2,2-dimethyloctanoylphenylphosphinate, 2-methyl-2-ethylhexanoyldiphenylphosphine oxide, 2,6-dimethylbenzoyldiphenylphosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide,
2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, methyl 2,4,6-trimethylbenzoylphenylphosphinate, 2,3,6
-Trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethoxybenzoyldiphenylphosphine oxide, 2,4,6-trichlorobenzoyldiphenylphosphine oxide, 2,4,6
Typical examples include trimethylbenzoylnaphthylphosphonate and the like. The photoreaction initiator is suitably added in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the vehicle component.

As the color pigment used in the present invention, usual inorganic / organic pigments and dyes can be used. In particular,
Representative examples include titanium oxide, zinc sulfide, zinc white, lead white, lithopone, carbon black, oil smoke, dark blue, phthalocyanine blue, ultramarine blue, carmine FB, yellow lead, zinc yellow, Hansa yellow, ocher, red iron oxide, and insoluble metal-containing azo dyes. It can be cited as an example. In the present invention, zinc sulfide, oil smoke, ultramarine blue, phthalocyanine blue, carmine FB, yellow lead, ocher, red iron oxide, insoluble metal-containing azo dye, etc., which have a small ultraviolet absorption rate, are particularly preferable. In addition, metallic pigments, colorant particles, and the like can be used in combination if necessary.

The amount of the coloring pigment blended is 40 in the resulting coating film.
A suitable amount is not more than weight%, and the lower limit is arbitrarily determined according to the desired hiding power and coloring power of the coating film. The transparent glass powder, which is optionally blended, has a function of imparting abrasion resistance to the resulting coating film and also having a function of propagating light energy into the inside of the coating film. It is preferable because a coating film can be formed.

The transparent glass powder preferably has the following conditions in order to have the above-mentioned function. (A) Central particle size is 100 μm or less, preferably 0.5 to
It is 60 μm. When the center particle size exceeds 100 μm, the curability of the coating film is not affected, but the glass powder is likely to stand out in the formed coating film and become rough.
In addition, deterioration of physical properties such as tensile strength is observed. On the other hand, the lower limit of the particle size is not particularly limited, but the transmittance tends to substantially decrease, and it becomes difficult to form a thick film,
It is desirable to set it within the above range. (B) The difference in the refractive index of the transparent glass powder from the refractive index of the clear coating film of the ultraviolet curable coating material excluding the color pigment is within 0.3. If the difference in refractive index exceeds 0.3, the light energy for curing the coating film when it is thickened is greatly attenuated in the deep portion of the coating film, resulting in curing failure, which is not suitable.

Usually, the clear coating film of the UV-curable coating has a refractive index N _D of about 1.4 to 1.6, so that the refractive index N _D is around 1.5, soda lime glass, soda lime,
Specific examples include lead glass, potassium-lead glass, potassium-lead glass, potassium-soda-lead glass, borosilicate glass, high-alumina glass, potassium-soda-barium glass, but are not limited to these. That would be obvious.

The glass powder may have a spherical shape or an indefinite shape, but the spherical shape is preferred when the film thickness is increased to several hundreds μm or more. The content of glass powder is 80% by weight or less in the produced coating film, and particularly, the coating film thickness of 100% is 100%.
When forming a thick film of μm or more, 20 to 70% by weight is suitable. Examples of the extender pigment to be blended as necessary are silica sand, silicate, talc, kaolin, barium sulfate, calcium carbonate, flaky or fibrous or hollow glass, polyurethane, polyester, polyethylene, resin powder such as polystyrene, and the like. Is a typical example.

Further, the solvent is used for appropriately adjusting the coating or printing viscosity, and typical examples thereof include toluene, xylene, acetone, methyl ethyl ketone, ethyl acetate and the like. The colored UV-curable coating material used in the present invention comprises the components described above.

The coating material containing a fluorine-containing resin as a binder used in the present invention is applied on the coating film in order to eliminate the poor weather resistance and stain resistance of the ultraviolet curable coating material. The form is not particularly limited, such as an organic solvent type, an aqueous type, a non-aqueous dispersion type, and a powder type, and the dry form may be any of a room temperature dry type, a bake hardening type, and an ultraviolet ray hardening type. The fluorine-containing resin is preferably a fluorine-containing copolymer in which a fluorine atom is bonded to the main chain obtained by using fluoroolefin as an essential component. Incidentally, even in a fluorine-containing copolymer having a fluorine atom bonded to a side chain having a fluoroalkyl group or a perfluoroalkyl group-containing vinyl monomer as a constituent component, the weather resistance is improved to some extent, but the weather resistance is slightly inferior to the former, Further, the former is preferred because it has poor acid resistance and recoatability. Fluorine-containing copolymers having a fluorine atom bonded to the main chain obtained by using fluoroolefin as an essential component include JP-A-57-34107, JP-A-59-51953, JP-A-60-28458, and JP-A-60-28458. JP-A-61-157609, JP-A-62-104862
JP-A-62-225572 and JP-A-62-292.
Typical examples thereof include the fluorine-containing copolymers described in JP-A-848 and JP-A-1-289874, or modified products thereof, but the invention is not limited thereto.

As the paint using these fluorine-containing resins as binders, in the organic solvent type, for example, a paint comprising the above-mentioned fluorine-containing copolymer having a hydroxyl group and a crosslinking agent such as polyisocyanate or melamine resin (Japanese Patent Publication No. 63-2304). ,
Japanese Patent Publication No. 61-41259, etc.); in the water-based type, for example, a coating comprising the above-mentioned fluorine-containing copolymer having a carbonyl group and an organic hydrazine-based compound (JP-A-2-214756).
No.), a coating obtained by neutralizing a copolymer obtained by grafting an amino group- or carboxyl group-containing ethylenically unsaturated monomer onto the fluorine-containing copolymer (JP-A-2-214755).
No.); in the non-aqueous dispersion type, a coating obtained by polymerizing an ethylenically unsaturated monomer with a fluorine-containing copolymer having a polymerizable unsaturated group as a dispersion stabilizer in an organic liquid (JP-A-1-
66273, JP-A-2-69507, JP-A 2-8
No. 8608, JP-A-2-145603); a powder type coating composition comprising a fluorine-containing copolymer having a crosslinkable reactive group and a cross-linking agent (JP-A-1-103670); and an ultraviolet curing type urethane in the molecule. A coating material containing a fluorine-containing copolymer having a bond and a (meth) acrylic group (JP-A-61-363).
No. 74) is a typical example.

It should be noted that these paints may partially use a binder such as an acrylic resin or a polyester resin having good compatibility. In addition, various additives such as an ultraviolet absorber, an antioxidant, a dispersant, etc., and ordinary coloring pigments for paints, extender pigments, etc. can be blended as necessary. For the paint using fluorine-containing resin as a binder, use the colorless and transparent paint if you want to make the best use of the color of the object to be coated, the color of the ultraviolet curable paint,
When it is desired to make it a composite color with the above color, a colored paint having a small hiding ratio is used, and when it is desired to hide the color, a colored paint having a high hiding ratio is used.

Next, a method for forming a three-dimensional pattern coating film of the present invention will be described. Examples of the object to be coated include various base materials such as metal, wood, plastic, glass, ceramics, mortar, and concrete, and these base materials are subjected to a sealing treatment if necessary,
It is the one that has been subjected to a base treatment such as a polishing treatment and a coloring treatment.
An ultraviolet-curable coating material containing a color pigment is applied to these objects to be coated so as to have a dry film thickness of about 50 to 1000 μm, either entirely or partially in a pattern. As a method of applying in a pattern, a method of applying a paint in a spatter form, a method of screen printing, a method of forming an uneven pattern with a pattern roller after uniformly applying, a granular material such as sand on the applied uncured coating film Typical methods include a method of sprinkling objects, but the method is not limited to these methods.

Next, ultraviolet rays are irradiated to induce a photopolymerization reaction to cure the coating film. When a solvent is added to the ultraviolet curable coating material, it is desirable to flash off for several tens of seconds to several minutes before irradiating with ultraviolet rays. A low-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, a carbon arc lamp, a xenon lamp, a chemical lamp, etc. are used as a light source used for irradiating ultraviolet rays.

Next, a coating material containing a fluorine-containing resin as a binder is applied onto the three-dimensional patterned cured coating film by an arbitrary coating means according to the above-mentioned coating form so that the dry film thickness is about several tens of μm to 100 μm, and the dry form is obtained. 60 to room temperature according to
Bake dry at ~ 240 ° C or irradiate with ultraviolet light to cure.

[0022]

As described above, the method for forming a three-dimensional pattern coating film of the present invention makes use of the resource-saving and short-time curing characteristics of the ultraviolet curable coating material, and the obtained three-dimensional pattern coating film has weather resistance. Excellent in stain resistance. Therefore, according to the present invention,
It becomes possible to apply the ultraviolet-curable coating material, which has been conventionally applied only to indoor articles, to outdoor articles.

[0023]

EXAMPLES The present invention will be described below with reference to examples. In addition,
In the examples, "part" and "%" are shown by weight. <Colored UV-curable coating (1) Note 1)> Acrylic urethane oligomer Note 2) 22 parts N-vinylpyrrolidone 6 parts 2,4,6-Trimethylbenzoyldiphenyl 1 part Phosphine oxide soda glass beads Note 3) 40 parts Zinc sulfide 14 parts Trimethylpropane triacrylate 17 parts Note 1) Refractive index of clear coating film excluding soda glass and zinc sulfide ND = 1.5 Note 2) Isophorone diisocyanate 1 mol and 2-hydroxyethyl acrylate 2 mol by a conventional method Addition-reacted acrylic urethane oligomer with an average molecular weight of about 500 Note 3) Transparent spherical beads with a refractive index ND = 1.52 and a central particle size of 10 μm <Colored UV-curable coating (2) Note 4)> Acrylic urethane oligomer Note 5 ) 25 parts 2-ethylhexyl methacrylate 7 parts 2,6-dimethoxy Benzoyl 1 part Diphenylphosphine oxide soda glass beads Note 6) 55 parts Titanium oxide 12 parts Note 4) Refractive index of clear coating film excluding soda glass beads and titanium oxide ND = 1.5 Note 5) 1,6-hexanediol 2.1 mol, 1 mol of ethylene glycol and 2.4 mol of adipic acid are subjected to a condensation reaction to produce a polyester having a molecular weight of about 1000, 1 mol of the polyester, 2 mol of isophorone diisocyanate,
Polyester type acrylic urethane oligomer having an average molecular weight of about 1700, which is obtained by addition reaction with 2 mol of 2-hydroxyethyl acrylate by a conventional method Note 6) Transparent spherical beads having a refractive index N _D = 1.52 and a central particle size of 60 μm <Fluorine-containing Resin-based clear coating A> 52 parts of chlorotrifluoroethylene, 21 parts of 4-hydroxy-n-butyl vinyl ether, 17 parts of cyclohexyl vinyl ether,
According to the method described in JP-A-57-34107, a 60% xylol solution of a fluorine-containing copolymer (number average molecular weight 6800, hydroxyl value 100) was obtained from a monomer containing 10 parts of ethyl vinyl ether.

To 100 parts of this solution, 1 part of a surface conditioner and a burette of hexamethylene diisocyanate ["Sumijour N-75" (Sumitomo Bayer), solid content 75
%], And 23 parts were added to prepare a fluororesin-based clear coating material A. <Fluorine-containing resin color paint B> A monomer comprising 30 parts of chlorotrifluoroethylene, 25 parts of tetrafluoroethylene, 10 parts of 4-hydroxy-n-butyl vinyl ether, 18 parts of cyclohexyl vinyl ether, and 17 parts of ethyl vinyl ether is disclosed in JP-A-57. Fluorine-containing copolymer (number average molecular weight 45
A 40% cyclohexanone solution having a hydroxyl value of 000 and a hydroxyl value of 52) was obtained.

On the other hand, 55.5 parts of a polyisocyanate having a cyanurate ring, which is a trimer of hexamethylene diisocyanate, is dissolved in 20 parts of methyl ethyl ketone, and 24.5 parts of methyl ethyl ketone oxime is added thereto and reacted to cause a blocked isocyanate compound solution ( NCO equivalent 35
9, non-volatile content 80%) was obtained. A transparent iron oxide pigment (10 parts) and the blocked isocyanate were added to 100 parts of the fluorine-containing copolymer solution to prepare a fluorine-containing resin-based gold color paint B. <Acrylic resin clear paint A> 44 parts of ethyl acrylate, 43 parts of isobutyl methacrylate, 12 parts of hydroxyethyl methacrylate, 0.8 parts of methacrylic acid, 0.2 parts of polymerization catalyst in a solvent consisting of 50 parts of xylol and 50 parts of butyl acetate. Then, the solution is polymerized by an ordinary method, and an acrylic resin having a nonvolatile content of 50% (glass transition temperature 14 ° C.,
A solution having a hydroxyl value of 52 and an acid value of 5) was obtained.

To 90 parts of this solution, 9 parts of the hexamethylene diisocyanate burette was added to prepare an acrylic resin clear paint A. Example 1 A black hard vinyl chloride resin plate was used with a screen plate having a 100-mesh tile pattern of 150 mesh with a joint width of 4 mm and a white UV-curable coating material (1) with a urethane rubber squeegee having a hardness of 82 degrees to form a film having a thickness of 50 μm. Printing was done. Then 12
Ultraviolet rays were irradiated for 5 seconds from a distance of 15 cm with a 0 W / cm Fe.Sn halide lamp to cure the coating film. Then viscosity 2
Fluorine-containing resin clear coating material A adjusted to 0 seconds (FC # 4/20 ° C) was applied to the entire surface so that the dry film thickness was 30 μm, and dried at 80 ° C for 30 minutes, and white 1
A three-dimensional pattern of a 00-square tile pattern was formed. Comparative Example 1 A coated plate was prepared in the same manner as in Example 1 except that the fluororesin-based clear coating material A was not applied. Comparative Example 2 A coated plate was prepared in the same manner as in Example 1 except that the acrylic resin-based clear coating material A was used in place of the fluorine-containing resin-based clear coating material A. Example 2 A white UV-curable coating material (2) was applied to a steel sheet coated with a gray coating film in a scattered manner so as to have a dry film thickness of 500 μm, and the coating film was irradiated with UV rays in the same manner as in Example 1 to cure the coating film. Let Then, the fluororesin-based colored coating material B adjusted to have a viscosity of 20 seconds was applied so as to have a dry film thickness of 30 μm, and baked at 150 ° C. for 30 minutes to prepare a coated plate having a spot-like uneven pattern. Comparative Example 3 A coated plate was prepared in the same manner as in Example 2 except that the fluororesin-based colored coating material B was not applied. The weather resistance and stain resistance performance tests of the coated plate thus obtained were as shown in Table 1. As is clear from Table 1, the coated plate obtained by the method of the present invention has excellent weather resistance and stain resistance, and can maintain the appearance of a three-dimensional pattern for a long period of time.

On the other hand, Comparative Examples 1 and 3, which are pattern-shaped cured coatings formed only by the UV-curable coating, had poor weather resistance and stain resistance, and Comparative Example 2 coated with an acrylic resin clear coating was also poor. . Table 1 ━━━━━━━━━━━━━━━━━━━━━━━━━ Actual example ratio Comparison ━━━━━━━━━━━━━━━━━ ━━━━━━━━━ 1 2 1 2 3 3 ━━━━━━━━━━━━━━━━━━━━━━━━━ Weather resistance Note 7) ○ ○ × △ × ━━ ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Pollution resistance Note 8) ○ ○ × × × ━━━━━━ ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Note 7) Appearance of the coating film after 500 hours of the due cycle test (whether there is any abnormality such as crack chalking) Visual evaluation: ◯: No abnormality, Δ: Some abnormality, ×: Many abnormalities Note 8) After washing and drying the coated plate after the above weather resistance test,
Draw a line with a width of 2 mm with red and black magic, leave it for 24 hours, then wipe it off with lacquer thinner and visually judge the remaining amount of the magic. ○: Completely disappear, △: A little remains, ×: Remains considerably.

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Claims (3)

[Claims] 1. A pattern-like cured coating film is formed by applying a UV-curable coating material containing a color pigment in a pattern on the entire surface or a part of an object to be coated, and then irradiating with ultraviolet rays to form a pattern-like cured coating film. A method for forming a three-dimensional pattern coating film, which comprises applying a transparent or opaque paint using as a binder and curing it. 2. A difference in refractive index between the ultraviolet curable coating material and a clear coating film obtained by removing a color pigment from the coating material.
2. The method for forming a three-dimensional pattern coating film according to claim 1, wherein transparent glass powder having a center particle size of 0.5 to 100 [mu] m within 0.3 is contained in an amount of 20 to 80% by weight in the total solid content of the coating material. 3. The method for forming a three-dimensional pattern coating film according to claim 1, wherein the ultraviolet-curable coating material contains an acrylic urethane oligomer as a main component as a vehicle component and an acylphosphine oxide compound as a photoreaction initiator.