JPH02296876A - Composition for forming ultraviolet-curing coating film having hiding power - Google Patents

Abstract

PURPOSE:To form a coating film having hiding power by compounding a vehicle component comprising a polymerizable unsatd. monomer and/or a polymerizable unsatd. polymer with a Leuco color, a photopolymn. initiator, and a white pigment. CONSTITUTION:100 pts.wt. vehicle component comprising a polymerizable unsatd. monomer and/or a polymerizable unsatd. polymer (e.g. a polymerizable unsatd. urethane acrylate resin) is compounded with 0.1-30 pts.wt. Leuco color (e.g. Leucocrystal Violet), 0.1-10 pts.wt. photopolymn. initiator (e.g. hydroxycyclohexyl phenyl ketone) which generate radicals when excited by irradiation with ultraviolet rays, and 1-30 pts.wt. white pigment (e.g. titanium oxide), thus giving a coating compsn. The resulting compsn. is applied to a substrate in a thickness of 10-5000mum and irradiated with ultraviolet rays in a dose of 10-1000mJ/cm<2> to form a colored coating film having hiding power.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to an ultraviolet curable shade film-forming composition.

(Prior art and its problems) When a large amount of colored pigment is blended into an ultraviolet curable composition in order to shade the coating film obtained from the composition, the transmission of light for curing is inhibited; There is a problem in that the curing of the vehicle component does not proceed sufficiently, and there has been a desire for an ultraviolet curable composition that can form a shaded coating film.

(Means for Solving the Problem) As a result of intensive research to obtain an ultraviolet curable composition capable of forming a shaded cured coating film, the present inventors found that by using specific amounts of a leuco dye and a white pigment, The inventors have discovered that the above object can be achieved and have arrived at the present invention.

That is, in the present invention, 0.1 to 3% of the vehicle component, which is either a polymerizable unsaturated monomer or a polymerizable unsaturated polymer, or a mixture of both, is 0.1 to 3 parts by weight based on 100 parts by weight of the vehicle component.
The present invention relates to an ultraviolet curable shaded film-forming composition containing as essential components 0 parts by weight of a leuco dye, 0.1-101 parts by weight of a photopolymerization initiator, and 1-30 parts by weight of a white pigment.

The vehicle component used in the composition of the present invention may be either a polymerizable unsaturated monomer or a polymerizable unsaturated polymer, or a mixture of both.

Specific examples of polymerizable unsaturated materials include esters of acrylic acid or methacrylic acid and monohydric alcohols having 1 to 28 carbon atoms, such as methyl acrylate, methyl methacrylate, ethyl acrylate,
Ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, 1so-butyl acrylate, Lso-butyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, propyl acrylate,
Propyl methacrylate, hexyl acrylate, hexyl methacrylate, octyl acrylate, octyl methacrylate, lauryl acrylate, lauryl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, acrylic acid Includes stearyl, stearyl methacrylate, etc.

In addition, the monomers include styrene, vinyltoluene,
Vinyl aromatic compounds such as methylstyrene, chlorostyrene, divinylbenzene; other vinyl compounds such as vinyl acetate, vinyl chloride, vinyl isobutyl ether, methyl vinyl ether, acrylonitrile, 2-ethylhexyl vinyl ether can also be used. Further, as the monomer, carboxyl group-containing monomers such as acrylic acid and methacrylic acid; hydroxyl group-containing monomers such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, and 2-hydroxypropyl methacrylate; butyl isocyanate, Adducts of polyisocyanates such as phenyl isocyanate and the above hydroxyl group-containing monomers; adducts of phosphoric acid and the above hydroxyl group-containing monomers; unsaturated monomers having nitrogen-containing heterocycles such as vinylpyrrolidone and vinylpyridine can also be used.

Further, as the monomer, diethylene glycol diacrylate, diethylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, propylene glycol diacrylate, propylene glycol dimethacrylate,
1.3-butanediol diacrylate, 1.3-butanediol dimethacrylate, 1.4-butanediol diacrylate, 1,4-butanediol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, 1. 6-hexanediol diacrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, etc. Tri- or tetravinyl compound: A product obtained by reacting the adduct of the polyhydric alcohol and ethylene oxide with acrylic acid and/or methacrylic acid; A product obtained by reacting the adduct of the polyhydric alcohol and propylene oxide with acrylic acid and/or Products obtained by reacting methacrylic acid: Products obtained by reacting the adduct of polyhydric alcohol and ε-caprolactone with acrylic acid and/or methacrylic acid; phosphorus-containing polymerizable unsaturated monomers, etc. are included.

The monomers described above can be used alone or in combination of two or more.

The polymerizable unsaturated polymer used in the method of the present invention includes:
Ethylenically unsaturated group-containing resins are included, and specific examples include the following.

Examples of ethylenically unsaturated group-containing resins include resins obtained by condensing polyester with (meth)acrylic acid, ethylenically unsaturated group-containing polyurethane resins, ethylenically unsaturated group-containing epoxy resins, and ethylenically unsaturated group-containing resins. Examples include phosphorus-containing epoxy resins, acrylic resins containing ethylenically unsaturated groups, silicone resins containing ethylenically unsaturated groups, and melamine resins containing ethylenically unsaturated groups.

A leuco dye, a photopolymerization initiator, and a white pigment are blended as essential components into the vehicle component described above.

The leuco dye used in the present invention is a reduced dye that is colorless or light-colored before excitation and has high light transmittance, and becomes colored when it absorbs light and is excited, and is represented by the following formula. .

In the formula, R1-R4 represent a hydrogen atom or an alkyl group containing 1 to 4 carbon atoms. Moreover, R6 represents the following group.

Typical examples of the leuco dyes used in the present invention include leuco crystal violet and leuco patent blue.
Leuko wool green, leuco naphthalene green, leuco magenc, leuco victoria blue, leuco acid violet, leuco wool fast blue, leuco chrome oxane brilliant violet, leuco chrome oxane pure blue, leuco rhodamine B, leuco sulforhodamine B extra, etc. can.

The photopolymerization initiator used in the present invention is a conventional photopolymerization initiator that is excited by ultraviolet irradiation to generate radicals, such as benzoin,
Benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, benzoin n-butyl ether, α-
Hydroxyisobutylphenone, benzophenone, p-
Methylbenzophenone, Michler's ketone, acetophenone, 1-hydroxy-l-cyclohexylacetophenone, 2-chlorothioxanthone, anthraquinone, 2-
Examples include methylanthraquinone, phenyl disulfide, and 2-nitrofluorene. These photopolymerization initiators can be used alone or in combination of two or more.

The white pigment used in the present invention includes white colored pigments such as titanium white, and extender pigments such as talc, tantalum, silica fine powder, baryta, and meat.

The proportion of each of the above-mentioned components in the composition of the present invention needs to be within the following range relative to 100 parts by weight of the vehicle component.

Leuco dye: 0.1 to 30 parts by weight, preferably 0.5 to 30 parts by weight
10 parts by weight, photopolymerization initiator: O, 1-10 parts by weight, preferably 1-5 parts by weight
f [Oki part, white pigment = 1 to 30 parts by weight, preferably 3 to 20 parts by weight.

If the amount of leuco dye added is less than 0.1 parts by weight, the coloring power will be low and the opacification will tend to be insufficient, while if it exceeds 30 parts by weight, a large amount of the generated radicals will be consumed for color development of the leuco dye, and the vehicle Polymerization of the components is difficult to occur.

If the amount of the photopolymerization initiator is less than 0.1 part by weight, curing will not be performed sufficiently due to the generation of few radicals.
Moreover, if it is used in an amount exceeding 10 parts by weight, a large amount of the photopolymerization initiator remains in the coating film, which causes a decrease in coating film performance.

If the amount of the white pigment is less than 1 part by weight, opacity may not be sufficient (it tends to occur); on the other hand, if it exceeds 30 parts by weight, the transmission of ultraviolet rays will be inhibited by the white pigment during curing by irradiation with ultraviolet rays. , it becomes difficult to cure the inside of the film sufficiently.

In addition to the above-mentioned essential components, the composition of the present invention may contain various paint additives such as an antifoaming agent, a leveling agent, and a thickener, if necessary.

Further, the composition of the present invention is preferably applied to a substrate.

10-5000 microns, more preferably 100-10
A cured film that develops color and hides it can be formed by coating the film to a thickness of 0.00 microns and irradiating the film with ultraviolet light at preferably 10 to 1000 m j /cm''.

(Actions and Effects of the Invention) In the composition of the present invention, polymerization of the vehicle component and color development of the leuco dye occur due to ultraviolet irradiation, and color development of the leuco dye and prevention of light transmission by the white pigment occur together. It is capable of forming a dark coating. Further, since the white pigment does not prevent light transmission so much as to prevent the coating film from curing, polymerization of the vehicle component also proceeds and a darkly cured coating film can be formed.

The composition of the present invention is an epoch-making composition that can form a colored cured coating film shaded by ultraviolet irradiation without going through complicated steps, and can be usefully used as paints, inks, adhesives, etc.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

In addition, hereinafter, "part" means "part by weight".

Example 1 60 parts of polymerizable unsaturated urethane acrylate resin with a solid content of 100%, 21.5 parts represented by the following chemical formula (1), 10 parts of vinylpyrrolidone, 1 part of leuco crystal violet, and 2 parts of hydroxycyclohexylphenyl ketone
．． 5 parts and 5 parts of titanium white have 2 parts by a part gauge.
The mixture was thoroughly stirred until the particle size was 5 microns or less, and a cloudy, translucent liquid was obtained.

Spread this solution on a glass plate with a thickness of 100 μm, a width of 5 cm, and a length of 5 cm.
cm+, then apply ultraviolet rays at 300mj/cIII
After 2 irradiations, a blue shaded coating was obtained.

Example 2 A green shaded coating film was obtained in the same manner as in Example 1 except that 1 part of leuco wool green was used instead of 1 part of leuco crystal violet.

Claims (1)

[Claims] 1. 0.1 to 30 parts by weight of a leuco dye, 0.1 to 10 parts by weight per 100 parts by weight of a vehicle component that is either a polymerizable unsaturated monomer or a polymerizable unsaturated polymer, or a mixture of both. Parts by weight of photoinitiator and 1 to
An ultraviolet-curable shaded film-forming composition containing 30 parts by weight of a white pigment as an essential component.