JPH02164481A - Forming method for soft feeling film - Google Patents

Abstract

PURPOSE:To form a soft feeling film with micro-voids by coating an ultraviolet curing type coating material composed of dispersed hollow particles not being impregnated with liquid on a base surface, and then irradiating ultraviolet rays and curing the coating material. CONSTITUTION:An ultraviolet curing type coating material is prepared by an ultraviolet polymerizing vehicle, an optical reaction initiating agent and hollow particles without the properties of being impregnated with liquid as essential components, and if necessary, blending a color dyeing pigment, an extender pigment, an additive and the like therein. Said ultraviolet curing type coating material in which hollow particles without the properties of being impregnated with liquid are dispersed is applied on the base surface and ultraviolet rays are irradiated thereon to cure a film and form a film of irregular surface with soft feeling. As for said vehicle component, a compound with radical polymerizable unsaturated double bonds in molecules can be used, and a compound composed of acrylic urethane oligomer as main component is suitable.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for forming a coating film using an ultraviolet curable paint that is attractive in design and has a soft appearance and feel.

<Conventional technology and its issues to be solved> Traditionally, in order to bring out design in the interior of buildings and interior accessories, etc.
Colored ones and ones with an uneven three-dimensional effect are widely used, and in recent years there has been a demand for a soft finished appearance to give a sense of comfort. One way to achieve such a soft finished appearance is to create minute voids in the coating film applied to the surface of the object. As such a method, for example, there is a method of applying a paint containing a porous filler such as vermiculite or shirasu balloon.

However, this method requires a large amount of porous filler to create minute voids in the coating film, and therefore the amount of resin that acts as a binder is relatively small, resulting in poor physical strength of the coating film. Furthermore, the water resistance was poor, and although it had a soft appearance, it felt rough to the touch and had a poor soft touch feeling.

Another method is to apply a paint containing a foaming agent or a paint that entrains a large amount of foam by vigorous stirring, but these methods have poor foam stability and workability.

Further, in all of the above methods, the coating film is cured by natural drying, forced drying or baking drying, and the curing time usually takes several tens of minutes to several days, resulting in poor productivity.

In order to solve the above-mentioned problems, the present inventors conducted extensive research to develop a method for forming a coating film that cures in a short period of time (for example, several tens of seconds) and has a soft feel by creating minute voids in the coating film. This led to the present invention.

<Means for Solving the Problems> The present invention provides an uneven coating in which an ultraviolet curable paint in which hollow particles that are not impregnable with liquid are dispersed is applied to the surface of a base material, and the coating film is cured by irradiation with ultraviolet rays. The present invention relates to a method for forming a coating film with a soft feel.

In the method of the present invention, hollow particles are dispersed in the ultraviolet curable paint, so the hollow particles have a small specific gravity (for example, true specific gravity of 0.5 or less, preferably 0.2 or less), and the coating film after application is floats on the surface of the coating film during the wet state and is mainly distributed on the coating surface, and the resulting coating film has an uneven shape without roughness, giving a soft touch feeling when touched with the hand.

In addition, when the hollow particles are transparent, the thickness of the outer wall of the hollow particle is thin due to the difference in refractive index between the internal gas and the outer wall of the hollow particle, and when the hollow particle is colored, the thickness of the outer wall of the hollow particle is thin (because the hiding power is small, The color of the coating film that is visible through the hollow particles mainly distributed on the surface has a soft tone, and the coating film has a soft appearance.

It is known that in conventional UV-curable paints, the presence of bubbles (air gas) in the coating film inhibits curing due to oxygen, but in the present invention, the air gas is isolated by the outer wall of the hollow particles. Therefore, curing inhibition due to oxygen can be prevented.

The present invention will be explained in detail below.

The ultraviolet curable paint used in the present invention contains an ultraviolet polymerizable bihiknope photoreaction initiator and hollow particles that are not impregnated with liquid as essential components, and further contains coloring dyes and pigments, extender pigments, solvents, additives, etc. as necessary. It consists of a combination of ingredients.

As the vehicle component, a compound that eliminates a radically polymerizable unsaturated double bond in the molecule can be used. Specifically, unsaturated polyester resins, unsaturated acrylic resins, unsaturated urethane resins, unsaturated epoxy resins, unsaturated polyamide resins, or these (nail grease and A typical example is a mixture with a reactive diluent having an ethylenically unsaturated group.

Among these, those containing acrylic urethane oligomer as the main component are preferred from the viewpoints of adhesion to substrates, curing properties (quick drying properties) under a wide range of ultraviolet irradiation conditions, and the like. The acrylic urethane oligomers include a wide range of acrylic urethane oligomers that have a urethane bond in the molecule and have an unsaturated double bond that is capable of radical polymerization, have an average molecular weight of several hundred to several hundred, and are viscous at room temperature.

For example, in addition to oligomers obtained by the reaction of polyisocyanates and (merry) acrylic esters having hydroxyl groups, polyester-based acrylic urethane oligomers are also used.
, polyester-based acrylic urethane oligomers, polybutadiene-based acrylic urethane oligomers, etc. Specific examples include toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, xylene diisocyanate, isomers of these or excess polyisocyanate and polyester. Polyisocyanates (particularly preferably non-yellow Examples include reaction products of a modified polyisocyanate) and a compound having a hydroxyl group and an unsaturated group. The compounds having a hydroxyl group and an unsaturated group include hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate,
Hydroxyethyl (meth)acrylate, glycidyl (
Typical examples include meth)acrylate.

The vehicle consists of these acrylic urethane oligomers and a reactive diluent. As reactive diluents, 2-ethylhexyl (meth)acrylate, 2-hydroxyethyl (
meth)acrylate, inbornyl(meth)acrylate, tripropylene glycol diacrylate, 1,6
-Hexanediol diacrylate, tetraethylene glycol diacrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(
meth)acrylate, ditrimethylolpropane pentaacrylate, dipentaerythritol hexaacrylate, vinylope acetate N-vinylpyrrolidone, dimethyl(
Typical examples include meth)acrylamide, vinyltoluene, divinylbenzene, etc., and these reaction diluents are
It is suitable to mix 10 to 100 parts by weight.

As the photoreaction initiator, when there are a relatively small amount of hollow particles described below and the coating film is transparent, the conventionally commonly used benzophenone type, benzoin ether type, benzyl ketal type, thioxanthone type, It is possible to use photoinitiators such as acetophenone.

However, when a large amount of hollow particles are mixed,
An acylphosphine oxide compound is suitable when a colored dye or pigment is blended or when a thick film (for example, 100 to 500 μm) is formed and the film becomes cloudy and difficult to see through. This acylphosphine oxide compound is a compound represented by the following general formula.

[In the formula, R1 is a linear or branched alkyl group having 1 to 6 carbon atoms, a cyclohexyl group having 6 to 12 carbon atoms in total,
, cyclopentyl-, arylhalogen-, alkyl-
, or an alkoxy-substituted aryl group, or an S- or N-containing 5- or 6-membered heterocyclic group (containing additional carbon atoms), R2 has the meaning of R1, and R1 and R2 may be the same or different, or an alkoxy group having 1 to 6 carbon atoms or a total carbon number of 6 to 1
or R1 and R2 together with the phosphorus atom to which they are bonded form a ring moiety having 2 to 12 carbon atoms; and R3 represents an aryloxy group or arylalkoxy group having a carbon number of a linear or branched alkyl group having 2 to 18 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, a phenyl group or a naphthyl group, or S-10
-1 or N-containing 5- or 6-membered heterocyclic group (containing other carbon atoms), the R3 group being one or more substituents or groups (wherein R1 and R2 are ), and X represents a phenylene group or an aliphatic or alicyclic divalent group having 2 to 6 carbon atoms, and one or more of R1 to R2 is olefinically unsaturated. Good too. ] The acylphosphine oxide compound is suitably blended in an amount of 0.1 to 5 parts by weight, particularly preferably 0.2 to 3 parts by weight, per 100 parts by weight of the vehicle component.

Optionally α,α-dimethyl-α-hydroxyacetophenone, hydroxycyclohexylacetophenone, benzyl dimethyl ketal, α,α-dimethyl-α-morpholineaceto p-methylthiophenone, α,α-diethyl-α-dimethylaminoaceto-p- It is also possible to use common photoreaction initiators such as morpholinophenone.

As mentioned above, the hollow particles must not be impregnated with liquid in order to be able to float on the surface of the coating film.For example, porous particles such as Shirasu balloons can absorb liquid and
It is not suitable because its specific gravity is similar to that of paint, making it difficult to float.

Typical examples of such hollow particles include hollow resin particles such as vinylidene chloride-acrylonitrile copolymer and acrylic acid ester-styrene copolymer, and hollow glass beads. The shape of the hollow particles is
Spherical particles are preferable, and the particle size is 200 μm or less, preferably 10
A thickness of about 100μ is suitable.

The appropriate amount of the hollow particles is 0.01 to 15% by weight (in terms of paint solid content), preferably 0.1 to 10% by weight, and within this range a coating film with a soft feel can be obtained.

The above-mentioned colored dyes and pigments do not necessarily need to be blended, but can be used for the purpose of adjusting the color of the coating film or improving the design.

Coloring dyes and pigments include organic dyes and pigments such as phthalocyanine, anthraquinone, perylene, azo, isoindolinone, and quinacridone, inorganic pigments such as carbon black and transparent iron oxide, other aluminum powders, and mica powders. Typical examples include metallic pigments such as:

The extender pigments are used to improve coating performance or as extenders, and specifically include silica sand, silicates, talc, kaolin, barium sulfate, calcium carbonate,
Typical examples include powder, flake, and fiber glass, and resin powders such as polyurethane, polyester, polyethylene, and polystyrene.

In addition, the above-mentioned solvents are used to appropriately adjust the viscosity of the coating, and include toluene, xylene, acetone,
Typical examples include methyl ethyl ketone, ethyl acetate, isopropyl alcohol, and water.

Next, the method for forming the coating film of the present invention will be explained.

The coating film can be formed on various substrates such as metal, wood, plastic, glass, ceramics, concrete, and paper.

The UV-curable paint used in the present invention not only has a soft feel, heat insulation, and soundproofing properties, but also has the characteristics of a radically polymerizable cured film such as abrasion resistance, scratch resistance, water resistance, and chemical resistance. Since an excellent coating film can be obtained in the process, it can be particularly suitably used for the interior and exterior of buildings. These substrates may be subjected to a surface treatment such as sealing treatment, polishing treatment, coloring treatment, etc. as necessary, and may also have an uneven surface.

A flow coater, roll coater, spray gun, pattern roller knife coater,
The ultraviolet curable paint is applied entirely or partially by a painting method such as a brush or a printing method such as gravure, offset, offset gravure, or screen.

Next, the coating film is cured by irradiation with ultraviolet rays.

Note that light sources that can be used to irradiate ultraviolet rays include low-pressure mercury lamps, high-pressure mercury lamps, metal halide lamps, carbon arc lamps, xenon lamps, chemical lamps, and the like.

Further, in the case of a thick film (for example, 100 to 500 μ), the human power is 80 W/cm or more, preferably L 20 W/am or more, and the metal halide lamp is particularly suitable as the light source.

<Effects of the Invention> Since the paint film forming method of the present invention contains hollow particles with low specific gravity in the paint, the hollow particles are mainly distributed on the paint film surface, and the resulting paint film is difficult to touch by hand. When exposed, it becomes uneven with a soft feel, and the coating film visible through the hollow particles has a soft color tone, resulting in a coating film with a soft appearance.

In addition, the curing strain that normally occurs during curing of UV-curable paints is absorbed by the hollow particles, resulting in a coating film with less distortion and shrinkage.Although it has a soft feel as mentioned above, it has excellent scratch resistance. A coating film with excellent abrasion resistance, water resistance, chemical resistance, etc., as well as excellent heat resistance, soundproofing, dewproofing, etc., can be obtained.

When an acylphosphine oxide compound is used as a photoreaction initiator, there is little decrease in the intensity of light energy even though there is scattering, diffusion, and absorption of light energy incident from the surface layer of the coating film, and therefore the lower layer of the coating film It is possible to obtain a cured coating film.

(Examples) Hereinafter, the present invention will be further explained in detail by examples. In the examples, "parts" are expressed on a weight basis.

[Preparation of acrylic urethane oligomer (I)] 1 mol of isophorone diisocyanate and 2 mol of 2-hydroxyethyl acrylate were subjected to an addition reaction in a conventional manner to prepare an acrylic urethane oligomer (I) having an average molecular weight of about 500.

[Preparation of acrylic urethane oligomer (n)] 1, 6
- 2.1 mol of hexanediol, 1 mol of ethylene glycol
mol and 2.4 mol of adipic acid were subjected to a condensation reaction to produce a polyester having a molecular weight of 1000. The polyester 1 was subjected to an addition reaction with 2 moles of monopeisophorone diisocyanate and 2 moles of 2-hydroxyethyl acrylate to prepare a polyester type acrylic urethane oligomer (n) having an average molecular weight of about 1700.

[Preparation of acrylic epoxy oligomer (I [I)] Bisphenol A type jepoxy compound [trade name "Ebiko" 828 manufactured by Yuka Shell Epoxy Co., Ltd.] molecular weight 38 (by adding mol of DI and 2 moles of acrylic acid by an ordinary method) , an acrylic epoxy oligomer (III) having an acid value of 20 was prepared.

Examples: Acrylic urethane oligomer (It), 60 parts N-vinylpyrrolidone 40 parts Hollow resin particles
Note 1) 1 Evil method 1) Matsumoto Yushi Pharmaceutical Co., Ltd., product name “Microsphere-F-80EDJ (polyvinylidene chloride type: particle size 20-80μ; true specific gravity 0
．． 02) Apply ultraviolet curable paint with the above formulation onto a Hanasha soft vinyl chloride sheet using a sponge roll coater to a film thickness of approximately 50 mm.
Apply it so that it becomes μ, and apply it using a metal halide lamp (input 1
The coating film was cured by ultraviolet irradiation by passing it through the film at a passing speed of 7.5 m/min from a position 100 mm below (20 w/cm).

The obtained coated plate had a matte state with fine irregularities, the floral pattern was thinly veiled, and the appearance and touch were soft, and the adhesion between the coating film and the base sheet was also good. .

Example 2 Acrylic urethane oligomer (1) 60 parts Hollow resin particles Note 1) After turning off 5 parts, use a metal halide lamp (input 1201/+7c)
The coating film was cured by ultraviolet rays by passing the coating film from the position of 100 II [I1] below at a passing speed of 15 m/min.

The obtained coated plate had fine irregularities, was concealed in a color close to pure white, had a soft feel, and had good adhesion between the coated film and the base plate.

In addition, as a photoreaction initiator, α
When using the above-mentioned ultraviolet curable coating containing the same amount of α-dimethyl-α-hydroxyacetophenone, the lower layer of the coating film showed insufficient curing and poor adhesion.

Example 3 Acrylic epoxy oligomer (III) 60 parts Butyl acetate 20 parts An ultraviolet curable paint consisting of the above formulation was applied to a hard vinyl chloride resin board using a knife coater to a film thickness of 100 μm.
0℃, 1 minute flash hollow glass particles Note 2)
10 parts Colored aluminum powder Note 3) Vinyl acetate 10 parts 40 parts Note 2) Product name rQ-C manufactured by Philadelphia Quartz Co.
EL300J (particle size 10-180μ: true specific gravity 0.21) Note 3) Product name: “Astro Flake #5 Silver” manufactured by Fukuda Metal Foil & Powder Industries Co., Ltd. Apply ultraviolet curable paint with the above formulation to a metal plate using an airless sprayer. Apply to a thickness of 300μ, 60μ
After flashing off hot air at °C for 1 minute, it was passed through a metal halide lamp (input 120 W/am) from a position 100 m+ below 0 at a passing speed of 10 m/min, and the coating film was cured by ultraviolet irradiation.

The obtained coated plate had a soft white background with silver powder scattered thereon, had a good design, and had good adhesion between the coated film and the base plate.

In addition, when using the above two types of UV-curable paints containing 3 parts and 10 parts of benzophenone instead of 2,6-simethoxybenzoyldiphenylphosphine oxide as a photoreaction initiator, the lower layer of the paint film was poorly cured. Comparative Example 1 The same ultraviolet curable paint as in Example 3 was used except that vermiculite powder was used instead of the hollow glass powder, and coating was carried out in the same manner as in Example 3.

The coated plate obtained had a rough coating surface and a poor soft feel.

Comparative Example 2 Similar to Example 2, except that instead of the hollow resin particles, a nonionic surfactant foaming agent and foam stabilizer were blended, and an ultraviolet curable paint with minute bubbles formed by disper stirring was used. and painted it.

The resulting coated plate was milky white and had a soft feel.
Both surface tack and internal curing were not sufficient, and the paint film peeled off easily with a fingernail.

Claims (2)

[Claims] (1) A method for forming an uneven, soft-feeling coating film by applying an ultraviolet-curing paint in which hollow particles that are not impregnable with liquid are dispersed onto the surface of a base material, and curing the coating film by irradiating it with ultraviolet rays. . (2) The method for forming a soft-feeling paint film according to claim (1), wherein the photoreaction initiator used in the ultraviolet curable paint is an acylphosphine oxide compound.