JPH02269162A - Method for forming a soft coating film - Google Patents

Abstract

PURPOSE:To form a coating film containing fine pores and having a soft touch on the surface of a substrate by curing a coating film containing dispersed hollow particles free from the impregnation of liquids and further a titanocene compound as an optical reaction initiator with UV rays. CONSTITUTION:An UV ray-curable coating containing liquid impregnation-free hollow particles (e.g. vinylidene chloride-acrylonitrile copolymer dispersed therein and a titanocene compound [e.g. a compound of the formula (R<1> is cyclopentanyl anion, indenyl anion, etc.; R<2> is six-membered carbon ring group or five- membered or six-membered heterocyclic ring group wherein two (or either one) of the ortho positions to the metal-carbon bond are substituted with fluorine atoms; R<3> is R<2>, alkynyl, etc.)] is coated on the surface of a substrate and subsequently cured with the irradiation of UV rays to form an uneven coating film having a soft touch.

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 has excellent design and is soft in appearance and feel.

<Conventional technology and its problems to be solved> Traditionally, in order to bring out the 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 the foam stability and workability are poor.

Furthermore, 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 disperses hollow particles that are not impregnable with liquid,
The present invention also relates to a method for forming an uneven, soft-feeling coating film by applying an ultraviolet curable coating material containing a titanocene compound as a photoreaction initiator to the surface of a substrate, and curing the coating film by irradiating it with ultraviolet rays.

In the method of the present invention, since hollow particles are dispersed in the ultraviolet curable coating, 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 coater coats the coating. 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 difference in refractive index between the internal gas and the outer wall of the hollow particles causes the coating film surface to deteriorate, and when the hollow particles are colored, the thickness of the outer wall of the hollow particles causes a small hiding power. The color of the coating film seen through the hollow particles mainly distributed in the coating 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 vehicle, a 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 mixture of.

As the vehicle component, a compound having an unsaturated double bond capable of radical polymerization in the molecule can be used. Specifically, unsaturated polyester resins, unsaturated acrylic resins, unsaturated urethane resins, unsaturated epoxy resins, unsaturated polyamide resins, or these resins and ethylenic resins are used in ordinary UV-curable paints. A typical example is a mixture with a reactive diluent having an 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 having urethane bonds in the molecule and unsaturated double bonds capable of radical polymerization, having an average molecular weight of several hundred to several hundred, and being viscous at room temperature.

For example, polyisocyanate and hydroxyl group-containing (meth)
In addition to oligomers obtained by reaction with acrylic esters, polyether-based acrylic urethane oligomers,
Also included are polyester-based acrylic urethane oligomers, polybutadiene-based acrylic urethane oligomers, and the like.

Specifically, toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, xylene diisocyanate, isomers of these or excess polyisocyanate and polyester boronopepolyoxymethylene glyconopepolyoxyethylene glycol, polyoxypropylene glycol, Cabrolactone polyonope A combination of a polyisocyanate (particularly preferably a non-yellowing type polyisocyanate), such as a compound having an isocyanate end, which is a reaction product with trimethylolpropane, pentaerythritol, etc., and a compound having a hydroxyl group and an unsaturated group. Examples include reaction products. The compound having a hydroxyl group and an unsaturated group is hydroxypropyl (meth)
Representative examples include acrylate, hydroxybutyl (meth)acrylate, hydroxyethyl (meth)acrylate, and glycidyl (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, 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, dimethyl(
Typical examples include meth)acrylamide, vinyltoluene, and divinylbenzene.
, 10 to 100 parts by weight is suitable.

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 a photoreaction initiator such as acetophenone, but if a large amount of hollow particles is mixed, a colored dye or pigment is mixed, or a thick film (e.g.
When the coating film becomes cloudy and difficult to see through when the coating film is 00μ), it is difficult to cure the inside of the coating film with the above-mentioned in-shell photoreaction initiator, so a titanocene compound is used in the present invention. This titanocene compound is a compound represented by the following general formula.

Formula (I) R'-Ti R2 (I) [wherein the two R1 groups are each independently cyclopentadienyl e1 indenyl et al, 5°6.7-tetrahydroindenyl e, C1-cps-alkyl or CI "" CI 1- even if unsubstituted
Alkoxy, C2-C11-alkenyl, C5-C8-
Cycloalkyl, 08-Cl6-aryl, C7-C4
- aralkynopecyano or substituted with one or more halogens, or the two R1 groups may be linked and unsubstituted or substituted as above, of the formula (II
) [wherein X is (CH2), (n is 1, 2 or 3), 2 substituted with phenyl or not
alkylidene with ~12 carbon atoms, even 5 ~
cycloalkylidene with 7 ring carbon atoms, 5iR3,
or 5nR3 (R' is 01-C1□-alkyl, C
5-C+□-cycloalkyl, C6-cps-aryl or 07-C16-aralkyl. ). ]
is a group in which R2 is a 6-membered carbon ring or a 5- or 6-membered heterocycle in which at least one of the two ortho positions to the metal-carbon bond is substituted with fluorine, and is aromatic. The group ring may further contain a substituent,
Alternatively, R2 and R3 are connected to form the group -Q-Y-Q-(In) of formula (III) [wherein, Q is a carbocyclic aromatic ring, and these two bonds are connected to the Y group. Q is located at the 〇-position, and is substituted with a fluorine atom at the m-position relative to the Y group, and Q may further contain a substituent. Y is CH2, alkylidene with 2 to 12 carbon atoms, cycloalkylidene with 5 to 7 ring carbon atoms, direct bond, NR', 0, S SS
O1S02, C01S+R3 or -3nR3 (R' is as above), R3 has the same meaning as R2, or unsubstituted or substituted phenylalkynyl to alkynino, N3, CN5SIR3t or 5
iR3, and R2 in the titanocene contains one or more free esterified or etherified polyoxaalkylene groups, which are bonded directly or via domineering to the aromatic ring. It is something that exists. ] Titanocene represented by.

Specifically, the titanocene compound is bis(cyclopentadienyl)-bis(4-decyloxy-2,3,5
,6-tetrafluorophenyl)-titanium, bis(
cyclopentagenyl)-bis(pentafluorophenyl)-titanium, bis(cyclopentagenyl)-bisI"4-(1'4',7'-)lioxaundecyl)
-2,3゜5.6-tetrafluorophenyl]-titanium, bis(methylcyclopentagenyl)-bis[4
-(1',4',7'-trioxaundecyl)-2
,3,5,6-tetrafluorophenyl]-titanium, bis(cyclopentagenyl)-bisC4-(1',
4',? ',10'-tetraoxadodecyl)-2,3
,5,6-tetrafluorophenyl]-titanium, bis(methylcyclopentadienyl)-bisC3-(1'
, 4', 7'-trioxahendecyl)-2,6-difluorophenyltwo titanium, bis(cyclopentagenyl)-bis(3-(1', 4', 7', 1
0'-trioxadodecyl)-2,6-)lifluorophenyltwo titanium and bis(cyclopentagenyl)-bis[:3-(1',4'-dioxapentyl)=2,6-difluorophenyl Typical examples include two-titanium.

The titanocene 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, benzyldimethyl ketal, α,α-dimethyl-α-morpholineaceto p-methylthiophenone, α,α-diethyl-α-dimethylaminoaceto-p-morpho It is also possible to use common photoreaction initiators such as linophenone and acylphosphine oxide.

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 to be blended 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 butalocyanine, 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, powder, flake, Typical examples include fibrous glass, resin powders such as polyurethane, polyester, polyethylene, and polystyrene.

The solvent is used to appropriately adjust the viscosity of the coating, and representative examples include toluene, xylene, acetone, methyl ethyl ketone, ethyl acetate, isopropyl alcohol, and water.

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

Various substrates such as metal, wood, plastic, glass, ceramics, concrete, and paper can be used as the substrate on which the coating film is formed.

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 as a light source used for irradiating 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.

Further, in the case of a thick film (for example, 100 to 500 μm), the human power is 80 W/am or more, preferably 120 W/Cff1 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., and also excellent heat resistance, soundproofing property, dewproofing property, etc. can be obtained.

Furthermore, since a titanocene compound is used as a photoreaction initiator, a cured coating film can be obtained despite scattering, diffusion, and absorption of light energy incident on the coating film surface layer.

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

[Acrylic urethane oligomer (I) made by m] Acrylic urethane oligomer (I) having an average molecular weight of about 500 was prepared by adding 1 mole of inphorone diisocyanate and 2 moles of 2-hydroxyethyl acrylate in a conventional manner.

[Preparation of acrylic urethane oligomer (ff) 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 about 1000. 1 mole of the polyester, 2 moles of inphorone diisocyanate, and 2 moles of 2-hydroxyethyl acrylate were subjected to an addition reaction using a conventional method to prepare a polyester type acrylic urethane oligomer (n) having an average molecular weight of about 1,700.

[Preparation of acrylic urethane oligomer (I [I)] Bisphenol A type jepoxy compound [trade name “Epicote 828.,” manufactured by Yuka Shell Epoxy Co., Ltd., + molecular weight approximately 380]
An acrylic epoxy oligomer (III) having an acid value of 20 was prepared by addition reaction of 1 mole and 2 moles of acrylic acid using a conventional method.

[Preparation of bis(cyclopentagenyl)-bis(4-decyloxy-2,3,5,6-tetrafluorophenyl)-titanium] Place 1 mol of sodium metal in 1 mol of 1-decanol, The temperature of the mixture was maintained at approximately 45°C by cooling. After the reaction had subsided, the mixture was heated to 50° C. with stirring until the sodium was completely dissolved. Add this solution to 1
The mixture was poured over a period of time into 1.16 moles of chloropentafluorobenzene at about 42°C. Thereafter, the mixture was heated to 70°C and reacted for 7 hours. After cooling, it was poured into the same amount of water and extracted with the same amount of methylene chloride.

The organic layer was separated, dried over sodium sulfate, purified by vacuum distillation of methylene chloride, and purified with decyl (2,
3,5,6-tetrafluoro-4-chloro)phenyl ether was prepared.

The obtained decyl (2,3,5,6-tetrafluoro-4
-chloro)phenyl ether were dissolved in anhydrous diethyl ether under an argon inert gas atmosphere and the solution was cooled to -75°C.

Next, a hexane solution of lithium butyl was added dropwise, and the mixture was stirred at the same temperature for 15 minutes.

Then 1 mol of bis(cyclopentagenyl)-titanium dichloride was added in powder form and the reaction was terminated by warming the mixture to room temperature over a period of 2 hours.

The reaction product was poured into twice the amount of water, and extracted with ethyl acetate several times. The ethyl acetate phase is dried over sodium sulfate and the residue obtained by vacuum distillation is purified by chromatography on silica gel using a hexane-ether (2:1) mixture as mobile phase, followed by evaporation of the solvent. Bis(cyclopentagenyl)
-bis(4-decyloxy-2,3,5,8-tetrafluorophenyl)-titanium was prepared.

[Decyl 2,
3.5.6-Tetrafluoro-4-chloro)phenyl ether was replaced with 2 mol of chloropentafluorobenzene, but the reaction was carried out in the same manner as above to produce bis(cyclopentagenyl)-bis(pentafluorophenyl). - Prepared titanium.

Example 1 Acrylic urethane oligomer (II) 61N-
Vinylpyrrolidone 40 parts Hollow resin particles Note 1) 1 part Note 1) Matsumoto Yushi Seiyaku Co., Ltd., product name "Microsphere-F-80EDJ (polyvinylidene chloride type 2 particle size 20-80μ; true specific gravity 0
．． 02) Apply an ultraviolet curable paint with the above formulation onto a floral-patterned 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) 5 parts Butyl acetate 20 parts A hard vinyl chloride resin board was coated with an ultraviolet curable paint having the above composition using a knife coater to a film thickness of 100μ. Apply, 6
After flashing off for 1 minute at 0° C., the coating film was cured with ultraviolet light by passing it through a metal halide lamp (manpower: 120 W/cm) from a position 100 mm 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.

Note that α,α-dimethyl-α-hydroxyacetophenone was used instead of bis(cyclopentadienyl)-bis(4-decyloxy-2,3゜5.6-tetrafluorophenyl)-titanium as a photoreaction initiator. When using the UV curable paint with the above-mentioned amount blended, the lower layer of the coater had poor curing and poor adhesion.

Example 3 Acrylic urethane oligomer (I) 60 parts Hollow glass particles Note 2) 10 parts Colored aluminum powder Note 3) 10 parts Vinyl acetate
40 copies Note 2) Product name rQ-CEL 300J manufactured by Philadelphia Quartz Co., Ltd. (Particle size 10-180 μ; true specific gravity 0.21) Note 3) Product name “Astro Flake #5 Silver” manufactured by Fukuda Metal Foil & Powder Industries Co., Ltd. Metal Apply an ultraviolet curable paint consisting of the above formulation to the board using an airless sprayer to a film thickness of approximately 300 μm.
After flashing off hot air at °C for 1 minute, a metal halide lamp (input 120 w/am) was passed through it at a passing speed of 10 m/min from a position 100 below D, 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, coatings using the above two types of UV-curable paints containing 3 parts and 10 parts of benzophenone instead of bis(cyclopentagenyl)-bis(pentafluorophenyl)-titanium as a photoreaction initiator, The lower layer was poorly cured, resulting in poor adhesion.

Comparative Example 1 Painting was carried out in the same manner as in Example 3, except that vermiculite powder was used instead of the hollow glass powder, using the same ultraviolet curable paint.

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. I 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 (1)

[Claims] An uneven, soft texture in which hollow particles that are not impregnated with liquid are dispersed and an ultraviolet curable coating containing a titanocene compound as a photoreaction initiator is applied to the surface of the substrate, and the coating is cured by irradiation with ultraviolet rays. A method of forming a coating film.