JPH06271805A - Paint for coloring wood and coloring method of wood - Google Patents

Abstract

PURPOSE:To produce a comparatively inexpensive coloring method of wood products such as furniture so that the coated film thereon has excellent adhesion. CONSTITUTION:This color paint 1 for coloring the surfaces of wood 3 is composed of a mixture of an ultraviolet-curable prepolymer as a binder, colorants and solvents. The surface of a wood ware 3 is colored by coating with the color paint 1 and further coated with an ultraviolet-curable top coating 2. Then, the coated ware is irradiated with ultraviolet rays 4 to cure the color paint 1 and the ultraviolet-curable top coating 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coloring paint for wood such as furniture and flooring, which has excellent adhesion of a coating film, and a method for coloring wood.

[0002]

2. Description of the Related Art Conventionally, a method for forming a coating film has been proposed which uses active energy rays such as ultraviolet rays and electron beams as a means for curing the coating film (for example, Japanese Patent Laid-Open No. 4-18968). The above-mentioned method of forming a coating film is also used in woodworking products such as furniture, flooring and doors in order to impart a color different from the texture of wood to improve the appearance and increase the added value. . In the above coating film forming method, the surface of wood is colored with a coloring agent such as a pigment or a dye, and then an ultraviolet curable paint (UV curable paint) is applied and light is irradiated to cure it. There is.

As another method, there is also used a method in which after the surface of the wood is colored, a wood sealer having excellent adhesion to the wood base and the interlayer is applied, and then a coating film of the above-mentioned UV-curable paint is formed thereon. Has been. The above wood sealer is
For example, urethane paint, lacquer, etc. are conventional general paints. There is also a method of promoting internal curing by adding a curing accelerator such as isocyanate to the UV-curable coating material without using the wood sealer.

[0004]

However, the above-mentioned conventional technique has the following problems. That is, in the method of forming a coating film using an ultraviolet curable paint after coloring the surface of the wood, the ultraviolet rays do not sufficiently penetrate to the ultraviolet curable paint impregnated in the wood due to the influence of the coloring agent. Therefore, curing may not proceed to the inside of the coating film. As a result, the adhesion between the coating film and the wood is reduced, and the coating film easily peels off.

On the other hand, in the method of forming the wood sealer layer, the number of steps and the number of paints used increase. Therefore, the cost becomes high. In addition, in the method of adding a curing accelerator to the above-mentioned ultraviolet-curable coating material, the curing proceeds if the curing accelerator is left to stand, and therefore the pot life (working time) of the ultraviolet-curable coating material is shortened.

[0006] Therefore, the amount of unused waste paint increases,
High cost. The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a colored coating material for wood and a method for coloring wood, which is excellent in adhesion of a coating film and is relatively inexpensive.

[0007]

The present invention is a colored paint for coloring the surface of wood, wherein the colored paint is a mixture of an ultraviolet curable prepolymer as a binder, a colorant and a solvent. It is in colored paint for wood.

The above ultraviolet curable prepolymer includes
Examples are oligomers, monomers and mixtures of both.
The above-mentioned oligomer is a general term for a polymer having a low degree of polymerization of a dimer or more of a monomer, and is also called a low polymer, and has a molecular weight of usually 1,000 to 10,000.

Examples of the above-mentioned oligomers include epoxy / acrylic type, epoxidized oil acrylic type, urethane / acrylic type, unsaturated polyester type, polyester type,
There are acrylic type, polyether / acrylic type.
The monomer is, for example, a reaction diluent. Examples of the reactive diluent include monofunctional reactive diluents, polyfunctional reactive diluents, and modified acrylates thereof.

That is, as the monofunctional reactive diluent,
For example, styrene, vinyltoluene, divinyltoluene,
Butyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, tetrahydro (meth) acrylate, isobornyl (meth) acrylate, dicyclopentenyl acrylate, phenoxy EO (ethylene oxide) modified acrylate, phenoxy PO (propylene oxide) A modified acrylate is used.

Examples of the polyfunctional reactive diluents include 1-6 hexanediol diol diacrylate, trimethylol propane triacrylate, pentaerythritol triacrylate, dipentaerythritol.
Hexaacrylate, tripropylene glycol diacrylate, tetraethylene glycol diacrylate are used.

It is also possible to use an acrylate obtained by modifying the above compound with ethylene oxide (EO) or propylene oxide (PO). For example, a photosensitizer (photoinitiator) is added to the ultraviolet curable prepolymer.

Examples of the photosensitizer include benzophenone, acetophenone, diethoxy acetophenone, chloroacetophenone, 2-2 dimethoxyphenyl acetophenone, propiophenone, thioxanthone, benzoin, benzyl, anthraquinone, benzyl ketal, benzoin ethyl ether, benzoin. -Isopropyl ether, benzoin-isopropyl ether,
Dimethoxy phenyl acetophenone and acylphosphine oxide are used.

More specifically, for example, a hydroxyacetophenone compound (for example, Darocure 2959 manufactured by Ciba Geigy), 2-hydroxy-2-methyl-1-phenylpropan-1-one (for example, Darocure 1173 manufactured by Ciba Geigy), 1-hydroxy cyclohexyl phenyl ketone (eg, Ciba Geigy, Irgacure 184), 1- (4-isopropylphenyl) -2
-Hydroxy-2-methylpropan-1-one (for example, Ciba Geigy, Darocure 1116), 2-methyl-1- [4- (methylthio) phenyl] -2-monofolinopropane-1 (for example, Ciba Geigy, Irgacure 907), benzyl dimer ketal (for example, Ciba Geigy, Irgacure 651), and 2,4,6-trimethylbenzoyldiphenylphosphine oxide (for example, BASF, Lucillin TPO).

As the colorant, for example, a color pigment and a dye are used. Examples of the coloring pigment include titanium oxide, zinc sulfide, zinc white, lead white, lithopone, carbon black, oil smoke, dark blue, phthalocyanine blue, ultramarine, carmine FB, yellow lead, zinc yellow, Hansa yellow, ocher,
Use red iron oxide.

Examples of the dyes include insoluble metal azo dyes. Further, the above-mentioned dyes include acid dyes and basic dyes. The former include level dyes, condensation-resistant dyes, acid mordant dyes, and metal complex hydrochloric acid dyes. The latter includes, for example, m-phenylenediamine derivatives. Also,
As the dye, for example, a direct dye, a reactive dye or a naphthol dye is used.

Examples of the solvent include toluene, xylene, ethyl acetate, butyl acetate, ketones (MIBK,
MEK), alcohols (methanol, ethanol, isopropyl alcohol), or thinner is used.

In the colored coating material, it is preferable to use 2 to 50% (weight ratio, the same applies hereinafter) of the ultraviolet curable prepolymer. If it is less than 2%, the adhesion is low, while if it exceeds 50%, the coating workability is deteriorated.

The colorant is preferably used in an amount of 0.1 to 35% (weight ratio, the same applies hereinafter). If it is less than 0.1%, the coloring power is low, while if it exceeds 35%, the adhesion is deteriorated. The solvent is used as the balance.

In the colored coating material of the present invention, for example, an extender, an extender pigment as a sealing agent on the surface of wood, and a paint for improving the coating workability, stability during storage, quality maintenance, etc. Various additives such as a foaming agent, a dispersant, a color separation preventing agent, and an anti-settling agent can be added.

Examples of the wood include wood materials used for making various woodworking products such as various furnitures, building floor materials, ceiling materials and doors. The above wood material is oak,
There are beech, cherry tree, sen, etc.

There are the following methods for coloring wood using the above-mentioned coloring paint. That is, the above-mentioned colored paint is applied to the surface of wood, then the UV-curable paint for the top coating film is applied to the surface of the colored paint, and then the above-mentioned colored paint and the UV-curable paint are cured by irradiation with ultraviolet rays. Let

Examples of the above-mentioned coating include brush coating, roller coating, spray coating, flow coating such as curtain flow coater and flow coater, roller coating such as roller coater and roller bushing, reduced pressure coating method, dip coating method. To use.

As the ultraviolet curable coating material for the upper surface coating film, for example, a conventionally used coating material is used. The above UV-curable paint is, for example, 10 to 500 g on the surface of wood.
/ M ² is applied.

The above-mentioned irradiation of ultraviolet rays is carried out, for example, for 2 to 60 seconds. This ultraviolet ray is generated by using, for example, a high-pressure mercury lamp or a fluorescent lamp type ultraviolet lamp that generates little heat rays. Further, when irradiating with ultraviolet rays, the wood is placed on, for example, a belt conveyor, and the wood is irradiated while being continuously moved.

[0026]

FUNCTION AND EFFECT The colored coating material for wood of the present invention contains an ultraviolet curable prepolymer as a binder, a coloring agent and a solvent. Therefore, the colored paint is sufficiently cured between the lower layer surface of the coating film and the surface of the wood.

Therefore, the adhesion between the cured coating film formed of the colored coating material and the surface of the wood is improved. On the other hand, in the wood coloring method of coloring the surface of wood using the above-mentioned colored paint, the above-mentioned colored paint is applied to the surface of the wood, and then an ultraviolet curable paint for the upper surface coating film is applied.

Therefore, the ultraviolet rays pass through the ultraviolet curable coating material for the upper surface coating film, and the lower layer of the coating film of the colored coating material is sufficiently irradiated with the ultraviolet rays. As a result, the adhesion between the cured coating film of the colored paint and the surface of the wood is improved. Further, the number of coating steps is small and the cost is low as compared with the case where the wood sealer of the conventional example is used. Therefore, according to the present invention, it is possible to provide a colored coating material for wood and a method for coloring wood, which is excellent in adhesion of the coating film and is relatively inexpensive.

[0029]

EXAMPLES Examples according to the present invention will be described together with comparative examples. The following Samples 1 and 2 and Comparative Samples C1 and C2 were adjusted (prepared), coating was performed, and the coating film was subjected to a test for measuring the number of coating film cross-cuts.

Next, Examples 1 and 2 and Comparative Examples 1 and 2 will be described with reference to Table 1. Example 1 according to the present invention
In preparing the colored paint in 2, the UV-curable prepolymer was trimethylol propane
A UV-curable acrylic monomer modified with triacrylate (TMPTA) -ethylene oxide (EO) was used.

As the above colorant, a pigment type "Banchaku PG" manufactured by Gengen Kagaku Co., Ltd. containing 15% of processed pigment was used. As the solvent, a lacquer thinner manufactured by Gengen Chemical Co., Ltd. was also used. In preparing the colored coating composition of Example 1, 10% (weight ratio) of the above-mentioned ultraviolet-curable prepolymer, 10% of colorant, and 80% of solvent were used.
% With a mixture was used.

Further, in the preparation of Example 2, 20 parts of the above ultraviolet curable prepolymer, 30% of a coloring agent,
With a solvent of 70%, 0.5% of a sensitizer "Dicure 1173" was used with respect to the 100%. On the other hand, in preparing the above Comparative Examples C1 and C2, the wiping stain base used in the base colorant for the room temperature drying type paint was used, and 100% of the processed pigment 1 similar to the sample 1 was used.
0% was added. This base colorant does not include the above-mentioned UV-curable prepolymer.

As the wiping stain base, "Z4-10 or Z4-15" manufactured by Gengen Kagaku Co., Ltd. was used. It consists of a lacquer type resin and a solvent. As the wiping stain base, "Z4-10" was used for preparing Comparative Example C1. Moreover, "Z4-15" was used for the preparation of Comparative Example C2. Z4-10 and Z41
5 differs in that the resin composition is different and the adhesion is different.

Next, the coating of the colored paints of Examples 1 and 2 will be described. First, as the wood 3, oak veneer plywood is used. That is, as shown in FIG. 2, 50 g / m ² of the colored paint 1 is applied to the surface of the wood 3 using a brush, and then wiped off with a waste cloth. Then, as shown in FIG. 1, an ultraviolet curable coating material 2 for a top coating film is applied to the coating surface of the colored coating material 1.
20 g / m ^{2 with} a curtain flow coater.

Thereafter, as shown in FIG. 1, 80 w / cm
The ultraviolet ray 4 having the following irradiation intensity is irradiated for 2 seconds to cure the colored coating material 1 and the ultraviolet curable coating material 2. The UV curable coating material 2 is an acrylic UV curable coating material (Ultra V sanding sealer, VS-7 in Table 1).
1), or an unsaturated polyester-based UV curable coating (Ultra V sanding sealer, VS- in Table 1)
29) was used for each.

Next, in Comparative Examples C1 and C2, the above colorant was applied to the same surface of the wood 3 as described above, and thereafter, the UV curable coating material 2 was applied in the same manner as described above and irradiated with UV light. Others are the same as the creation method of the first and second embodiments.

Next, the coating film peeling strength of each of the above-mentioned sample coating films was measured by a 45 ° peeling method according to JIS K-6854 using a film peeling tester. The measurement results are shown in Table 1. In the above measurement, a square of 2 mm square is 1
00 pieces were made, cellophane tape was stuck on it, and it was peeled off at an angle of 45 degrees. This peeling occurs between the surface 31 of the wood 3 and the lower surface 11 of the coating film.

As is known from Table 1, Examples 1 and 2 according to the present invention do not have the above-mentioned number of cross-cuts of the coating film, as is clear from comparison with Comparative Examples C1 and C2. That is, it is known that the coating film is not peeled at all. Therefore, it can be seen that the coating film using the colored coating material of this example has much better adhesion to the wood 3.

[0039]

[Table 1]

[Brief description of drawings]

FIG. 1 is an explanatory view showing a final step of a wood coloring method according to an embodiment.

FIG. 2 is an explanatory diagram showing a first step of the method for coloring wood according to the embodiment.

[Explanation of symbols]

 1. ． ． Color paint, 2. ． ． UV curable paint, 3. ． ． Wood, 4. ． ． Ultraviolet rays,

Claims (2)

[Claims] 1. A coloring paint for coloring the surface of wood, wherein the coloring paint is a mixture of an ultraviolet-curable prepolymer as a binder, a coloring agent and a solvent. Colored paint. 2. A colored coating material is applied to the surface of wood, and then an ultraviolet curable coating material for a top coating film is applied to the surface of the colored coating material. A method for coloring wood, which comprises curing.