JPH06298819A - Photocurable composition containing metallic pigment - Google Patents

Abstract

PURPOSE:To obtain a photocurable compsn. having improved metallic feeling such as glass and flip-flop properties by compounding a polymerizable unsatd. compd., a specific cationic dye, a sensitizer, a metallic pigment, and a solvent. CONSTITUTION:A photocurable compsn. is obtd. by compounding a polymerizable unsatd. compd., 0.001wt.% cationic dye of formula I [wherein D<+> is a cation having on absorption in the near-infrared region; and R1 to R4 are each (substd.) alkyl, (substd.) aryl, (substd.) allyl, (substd.) aralky], (substd.) alkenyl, (substd.) alkynyl, (substd.) silyl, or heterocyclic] having an absorption in the hear-infrared region, a sensitizer of formula II (wherein R5 to R8 are each R1; Z<+> is a quaternary ammonium, pyridinium, or quinolinium cation or a phosphonium cation) in a molar ratio of the dye to the sensitizer of (1:10)-(10:1), a metallic pigment having a length of 2-100mum and a thickness of 1/2-1/100 of the length, and 5-50wt.% solvent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photocurable composition containing a metallic pigment, and more specifically, it is photocurable and the cured product has a gloss and flip-flop property peculiar to metallic materials. The present invention relates to a composition having a metallic feeling.

[0002]

2. Description of the Related Art Conventionally, photopolymerization has been used in various fields such as curing, drying and printing of coatings, resin printing, printing substrate preparation, resist or photomask, black and white or color transfer coloring sheet or coloring sheet preparation. It is used for various purposes, especially from the viewpoint of global environmental problems, energy saving, labor saving in response to rising labor costs, etc., it can be polymerized at room temperature, which is a feature of photopolymerization, and can be dried quickly and without solvent. It is being developed with attention paid to sex.

In the development of printing inks, ultraviolet curable inks have been studied for the purpose of solventlessness, improvement of productivity by rapid curing or improvement of physical properties of cured films (for example, Japanese Patent Laid-Open No. 1-229084). , JP-A-1
-271469 and JP-A-2-22370). As for the development of paints, studies on quick-drying and curing of colored coating films have been conducted (for example, JP-A-52-13).
5341, JP-A-52-152436, JP-A-2-296875 and JP-A-3-6265), and JP-A-52-152436,
A method for forming a colored cured coating film containing a pigment or a dye having a high hiding ratio in a system containing a polymerizable unsaturated resin and a photopolymerization initiator is disclosed.

However, curing by ultraviolet light is 200
The polymerizable monomer is rapidly cured by cation polymerization or radical polymerization by irradiating with ultraviolet light of up to 400 nm, and the transmittance of ultraviolet light becomes a problem in a colored coating film containing a pigment having a high hiding rate. In particular, when a flake-like pigment having excellent concealing property like a metallic pigment and having a light-reflecting property is added, there is a problem that the light transmittance is hindered and the coating film is not cured.

Further, as an example of carrying out the polymerization reaction by using near infrared light having a wavelength longer than ultraviolet light, photocuring can be carried out by applying high transmittance of near infrared light even in a system containing a pigment or the like. Application by the present inventors that it is possible (Japanese Patent Application No. 4-175)
767), but in the case of metallic pigments,
The orientation of the metallic pigment was not uniform, and a metallic feeling peculiar to metallic materials was not developed.

[0006]

DISCLOSURE OF THE INVENTION The present invention can be cured by irradiation with near-infrared light even if it contains a flake-like metallic pigment, which has been difficult to carry out by photocuring in the past. It is an object of the present invention to provide a photocurable composition containing a metallic pigment capable of exhibiting the metallic feel.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above problems of the conventional thermosetting material containing a flake metallic pigment, and as a result, a polymerizable unsaturated compound and a flake shape have been obtained. A specific near-infrared polymerization initiator and a boron-based compound as a specific sensitizer are added to a composition containing a metallic pigment, and a solvent is further added in an amount of 5 to 50% by weight, preferably 10 to 40% of the total amount of the essential components. It was found that the composition is cured by irradiating with near-infrared light and the flaky metallic pigment is uniformly oriented, and a cured product having a metallic feeling is obtained by adding it in an amount of wt%, thereby completing the present invention. Came to. When the composition of the present invention is used, the conventional solvent amount required for expressing a metallic feeling of a cured product (for example, 80% by weight of the composition for a metallic base coat for automobiles, 50% for a high solid type).
A material capable of exhibiting a metallic feeling in a cured product by photocuring can be obtained by using a solvent in a much smaller amount (about wt%).

The invention of claim 1 of the present invention is a polymerizable unsaturated compound, a cationic dye having an absorption in the near infrared region represented by the general formula (Formula 3), and a general formula (Formula 4). A sensitizer to be, a metallic pigment, and a solvent are included as essential components,
It is a photocurable composition containing a metallic pigment, characterized in that the solvent is contained in an amount of 5 to 50% by weight with respect to the total of the essential components.

[0009]

[Chemical 3]

(In the formula, D ⁺ is a cation having absorption in the near infrared light region, and R ₁ , R ₂ , R ₃ and R ₄ are each independently an alkyl group, an aryl group, an allyl group, Aralkyl group, alkenyl group, alkynyl group, silyl group, heterocyclic group, substituted alkyl group, substituted aryl group, substituted allyl group, substituted aralkyl group, substituted alkenyl group, substituted alkynyl group or substituted silyl group)

[0011]

[Chemical 4]

(Wherein R ₅ , R ₆ , R ₇ and R ₈ are each independently an alkyl group, an aryl group, an allyl group, an aralkyl group, an alkenyl group, an alkynyl group, a silyl group, a heterocyclic group or a substituted alkyl group. Represents a group, a substituted aryl group, a substituted allyl group, a substituted aralkyl group, a substituted alkenyl group, a substituted alkynyl group or a substituted silyl group, and Z ⁺ represents a quaternary ammonium cation, a quaternary pyridinium cation, a quaternary quinolinium cation or phosphonium. Indicates a cation)

According to a second aspect of the present invention, the metallic pigment is a flake powder selected from aluminum metal or its compound, titanium metal or its compound, stainless steel, nickel or its compound, glass and iron oxide. The photocurable composition according to claim 1.

The polymerizable unsaturated compound used in the present invention is either a polymerizable unsaturated monomer or a polymerizable unsaturated polymer, or a mixture of both.

Specific examples of the polymerizable unsaturated monomer include esterified products of acrylic acid or methacrylic acid and a monohydric alcohol. Examples thereof include methyl acrylate, methyl methacrylate, ethyl acrylate and ethyl methacrylate. , N-butyl acrylate, n-methacrylic acid
Butyl, iso-butyl acrylate, methacrylic acid is
o-butyl, tert-butyl acrylate, tert-butyl methacrylate, propyl acrylate, propyl methacrylate, hexyl acrylate, hexyl methacrylate, octyl acrylate, octyl methacrylate, lauryl acrylate, lauryl methacrylate, acrylic acid −
2-ethylhexyl, 2-ethylhexyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, stearyl acrylate, stearyl methacrylate and the like are included.

As the monomer, vinylbenzenes such as styrene, vinyltoluene, methylstyrene, chlorostyrene and divinylbenzene, vinyl ethers such as vinyl isobutyl ether, methyl vinyl ether and 2-ethylhexyl vinyl ether, (meth) acrylonitrile, ( (Meth) acrylic compounds such as (meth) acrylamide and methylenebisacrylamide; vinyl esters such as vinyl acetate, vinyl propionate and vinyl benzoate; allyl alcohol, allyl acetate, diallyl phthalate, allyl such as trimellitate allyl. Other vinyl compounds such as group-containing monomers can also be used.

Further, as the monomer, a carboxyl group-containing monomer such as acrylic acid or methacrylic acid; 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2
-Hydroxyl group-containing monomer such as hydroxypropyl methacrylate; Addition product of polyisocyanate such as butyl isocyanate and phenyl isocyanate with the above-mentioned hydroxyl group-containing monomer; Addition product of phosphoric acid and the above-mentioned hydroxyl group-containing monomer; N-vinylpyrrolidone, N-vinyl Nitrogen-containing unsaturated monomers such as carbazole, N-vinylacetamide and vinylpyridines 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
Di-, tree- or tetravinyl compounds such as hexanediol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, petaneerythritol tetramethacrylate;

A product obtained by reacting acrylic acid and / or methacrylic acid with the above-mentioned addition product of polyhydric alcohol and ethylene oxide; acrylic acid and / or methacrylic acid with the above-mentioned addition product of polyhydric alcohol and propylene oxide. Reacted product; acrylic acid and / or an addition product of the above polyhydric alcohol and ε-caprolactone
Alternatively, a product obtained by reacting methacrylic acid; a phosphorus-containing polymerizable unsaturated monomer and the like are included.

The above-mentioned monomers may be used alone or in combination with 2
Mixtures of two or more can be used. The polymerizable unsaturated polymer includes an ethylenically unsaturated group-containing resin,
Specific examples include the following. Examples of the ethylenically unsaturated group-containing resin include resins obtained by condensing polyester (meth) acrylic acid, ethylenically unsaturated group-containing polyurethane resins, ethylenically unsaturated group-containing epoxy resins, ethylenically unsaturated group-containing phosphorus. Epoxy resin,
Examples thereof include acrylic resin containing ethylenically unsaturated group, silicone resin containing ethylenically unsaturated group, and melamine resin containing ethylenically unsaturated group. In particular, the (meth) acrylic functional polyorganosilsesquioxane disclosed in JP-A-4-28722 is suitable.

Examples of the cationic dye having the absorption in the near infrared light region represented by the general formula (Formula 3) used in the present invention include those disclosed in JP-A-4-362935 and Japanese Patent Application No.
The thing described in the specification of 175767 can be mentioned.

In the above cationic dye, specific examples of R ₁ , R ₂ , R ₃ and R _{4 in} the general formula (Formula 3) are alkyl group, aryl group, allyl group, aralkyl group and alkenyl group. , Alkynyl group, silyl group, heterocyclic group, substituted alkyl group, substituted aryl group, substituted allyl group,
Examples thereof include a substituted aralkyl group, a substituted alkenyl group, a substituted alkynyl group, a substituted silyl group, and the like.
Specific examples of the anion in the n-butyltriphenylboron ion, n-octyltriphenylboron ion, n-butyltrianisylboron ion, di-n-dodecyldiphenylboron ion, tetraphenylboron ion, triphenylnaphthyl Examples thereof include boron ion, tetrabutylboron ion, and tri-n-butyl (dimethylphenylsilyl) boron ion.

Preferred cations (D ⁺ ) having absorption in the near infrared light region in the general formula (Formula 3) are, for example, cyanine, xanthene, oxazine, thiazine, diallylmethane and triallylmethane. , And cations of pyrylium-based cation dyes.

The cation having absorption in near infrared light as used herein is a cation having absorption in a wavelength region of 740 nm or more, and preferably a compound having absorption in a wavelength region of 780 nm or more.

Examples of the sensitizer represented by the general formula (Formula 4) used in the present invention include, for example, JP-A-4-362.
Examples thereof include those described in Japanese Patent Application No. 935 and Japanese Patent Application No. 4-175767. The general formula (Formula 4)
Examples of the ion (Z ⁺ ) therein include a quaternary ammonium cation, a quaternary pyridinium cation, a quaternary quinolinium cation, and a phosphonium cation.

The above cationic dyes and sensitizers may be used alone or in admixture of two or more. By using the above-mentioned cationic dye and a sensitizer together, decomposition is caused by near-infrared light, the color of the cationic dye is decolored, and polymerization is initiated. It is possible to cure a material containing a metallic pigment, which was impossible by photocuring. The decolorization reaction of the cationic dye is an irreversible reaction, and the color of the cationic dye does not impair the hue of the cured product.

The above-mentioned cationic dye and the above-mentioned sensitizer in the present invention are each 0.0% with respect to the entire photocurable composition of the present invention.
The object of the present invention can be achieved by using it in an amount of 01% by weight or more, preferably 0.01 to 10% by weight. If it is less than 0.001% by weight, the polymerization may not be sufficiently carried out and the curing may be insufficiently completed. It is not preferable from the economical point of view to use too much. It is also possible to use two or more cationic dyes and sensitizers in combination. The ratio of the cationic dye to the sensitizer is arbitrary, but the range of 10: 1 to 1:10 (molar ratio) is preferable.

The metallic pigment used in the present invention is
The shape of the pigment is a scale-like metal pigment, a scale-like metal compound pigment, or a mixture thereof. Specifically, the longitudinal dimension is 2 to 100 μm, and the thickness is 1/2 to 1 / the longitudinal dimension.
The range of 100 is preferable. In order for the cured product to have a good metallic feel, it is necessary that the shape of the pigment is not spherical, but scale-like, and that the pigment is oriented in a layered and uniform manner in the cured product.

Examples of the above metallic pigments include flaky powders of aluminum metal, aluminum oxide, aluminum nitride, titanium metal, titanium nitride, stainless steel, nickel, glass, iron oxide, gold, silver, copper, tin and the like. can give.

As the solvent used in the present invention, a general solvent conventionally used for coating materials can be used as long as it is a compound which does not impair the chemical stability of the cationic dye and the sensitizer. Specific examples of the solvent include aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as heptane, hexane, and pentane, ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, diethylene glycol dimethyl ether, and triethylene glycol dimethyl ether. And the like, esters such as ethyl acetate, butyl acetate and aluminum acetate, and ethylene glycol monoethers such as methyl cellosolve and ethyl cellosolve. These solvents may be used alone or in combination of two or more. Further, it is also possible to use water as a solvent or a dispersion medium. The solvent used in the present invention, viscosity adjustment,
Since it also has a function of improving the compatibility of the composition, an appropriate amount can be added depending on the situation.

A polymerizable unsaturated compound, the above cationic dye,
When the above sensitizer and flake-like metallic pigment are combined and kneaded, and a solvent is added in an amount of 5 to 50% by weight, preferably 10 to 40% by weight, to form a composition, near infrared light is irradiated. As a result, a photocurable composition of the present invention is obtained, and the cured product has a metallic feeling peculiar to the flake material. If the amount of the solvent is 5% by weight or less, the flaky metallic pigment is not uniformly oriented, and the metallic feel of the cured product is impaired. Although there is no practical inconvenience even if the amount of solvent used is 50% by weight or more, the amount of solvent used should be as small as possible from the viewpoints of resource saving from the viewpoint of global environment, prevention of environmental destruction, etc. and cost. desirable. Of course, in the case where the flake pigment is used only for the purpose of reducing the permeability of corrosive liquids or gases, such as heavy-duty anticorrosive paint, it may not be necessary to use a solvent.

In the present invention, the order of mixing the materials is not particularly limited. It may be used as a so-called one-pack type composition, or as a so-called two-pack type composition, a cationic dye and a sensitizer (or a solution thereof) are added to other material compositions immediately before use. There is no problem in adopting.

The method for curing the photocurable composition containing the metallic pigment of the present invention is not particularly limited, and examples thereof include halogen lamps, xenon lamps, and sunlight in the near infrared region with a wavelength of 740 nm or more. It is achieved by irradiation with light having a spectrum, but as already filed by the present inventors (Japanese Patent Application No. 4-175767), an ultraviolet photoinitiator is added to the composition and cured by using ultraviolet light in combination. It is also possible to let. Further, in order to prevent polymerization inhibition due to oxygen, it is preferable to carry out the curing reaction by controlling the oxygen concentration on the surface of the cured product to be low during the curing reaction. Also, appropriate heating may be performed for the purpose of promoting the curing reaction.

Any additives and fillers can be added to the photocurable composition containing the metallic pigment of the present invention without departing from the spirit of the present invention. Examples of the additive here include a thickener, a leveling agent, a thixotropic agent, a dispersant, a plasticizer, an antioxidant, an ultraviolet absorber, and a lubricant which are generally used as additives for coatings, Examples of the filler include organic substances, inorganic substances, and their composites and mixtures.

Examples of organic fillers include finely pulverized polymers, and examples of inorganic fillers include silica, silica-alumina, alumina, quartz, calcium carbonate, kaolin, talc and aluminum sulfate. , Barium sulphate, calcium sulphate, titanium oxide, calcium phosphate, etc. powder and the surface of these powders are polyfunctional (meta)
Examples thereof include those coated with an acrylate monomer or a silane coupling agent. Examples of the composite include those obtained by mixing the above-mentioned inorganic filler with an ethylenically unsaturated compound, polymerizing and curing it, and then finely pulverizing it.
Further, two or more different kinds of fillers may be added separately, or may be added after mixing, without any problem.

In general, in order to develop a metallic feeling in a material, it is necessary that the flake metallic pigment is layered and uniformly oriented in the cured product as described above. In the conventional thermosetting materials, a method has been adopted in which a large amount of solvent is added and the flake-like metallic pigment is uniformly oriented by utilizing the convection phenomenon caused by the evaporation. As described above, a general thermosetting material dissolves a polymer in a solvent,
The materials are insolubilized by various crosslinking methods (melamine crosslinking, isocyanate crosslinking, etc.), and thus a large amount of solvent was required to dissolve the polymer.
However, in the present invention, the solvent only needs to be present in an amount sufficient to uniformly orient the flake metallic pigment, and therefore, the amount of solvent used can be significantly reduced as compared with the conventional thermosetting composition.

Since the pigment in the present invention is in the form of flakes, when it is arranged parallel to the surface of the coating film, it reflects light rays, heat rays, etc., which are harmful to the resin constituting the coating film, and impedes the penetration of liquid or gas that corrodes the substrate. It extends the life of the coating film, protects the substrate from corrosion for a long time, and develops the luster and sharpness peculiar to the flake metallic pigment, which greatly contributes to the improvement of the design of the coating film.

Examples of the use of the photocurable composition containing the metallic pigment of the present invention include the fields of use in which conventional flake-shaped metallic compositions are used. Examples include printing inks, resists, Examples thereof include coating of adhesives, dental materials, woodworking and furniture, coating of metals and plastics, coating of automobile bodies, interiors, bumpers, coating of inorganic materials and the like. The photocurable composition containing the metallic pigment of the present invention has a smaller amount of solvent used, less heating energy for curing, and is applied to a heat-sensitive material as compared with a conventional thermosetting composition. There are features such as being able to.

[0040]

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples without departing from the gist of the present invention. (Example 1) Nonaethylene glycol diacrylate 5
0 g, pentaerythritol triacrylate hexamethylene diisocyanate-urethane prepolymer 50
After thoroughly mixing 4 g of aluminum paste (trade name SAP561PS, manufactured by Showa Aluminum Powder Co., nonvolatile content of about 65% by weight, volatile solvent content of about 35% by weight) with a stirrer,
Near infrared light absorbing cationic dye (Chemical formula 5) 0.1 g, boron sensitizer, tetrabutylammonium n-butyltriphenylboron, 0.1 g n-butyl acetate 4.0 g was added as a solvent (solvent The amount was 5% by weight of the entire composition), and was referred to as Sample 1. R in the formula (Formula 5) is an n-butyl group, A
r represents a phenyl group. The λ _max (TMPT) (absorption wavelength) of the near-infrared light absorbing cationic dye (Chemical formula 5) is 822n.
m. TMPT stands for trimethylolpropane trimethacrylate.

[0041]

[Chemical 5]

(Example 2) Pentaerythritol triacrylate-hexamethylene diisocyanate In the same manner as in Example 1 except that an epoxy acrylate resin (lipoxy SP-4010 manufactured by Showa High Polymer Co., Ltd.) was used instead of the urethane prepolymer. Sample 2 was created.

Example 3 A polyester acrylate resin (manufactured by Toagosei Co., Ltd., trade name M-8030) was used in place of pentaerythritol triacrylate-hexamethylene diisocyanate urethane prepolymer, and the amount of n-butyl acetate was used. Sample 3 was prepared in the same manner as in Example 1 except that the amount was 50 g. The amount of solvent is 32% by weight of the total essential components.

Example 4 Sample 4 was prepared in the same manner as in Example 1 except that n-butyl acetate was used as the solvent and methyl ethyl ketone was used.

Example 5 Instead of the pentaerythritol triacrylate-hexamethylene diisocyanate urethane prepolymer, the polyorganosilsesquioxane described in JP-A-4-28722 (in the general formula,
70 mol% of R ₁ and R ₂ are methyl groups and 30 mol% are methacryloxypropyl groups, and have a number average molecular weight of about 100.
Sample 5 was prepared in the same manner as in Example 1 except that the sample No. 00) was used.

(Example 6) Instead of the aluminum paste of Example 1, a paste composed of flakes of metallic titanium (trade name Tylake TMP-500, manufactured by Showa Aluminum Powder Co., Ltd.,
Sample 6 was prepared in the same manner as in Example 1 using 7 g of a solid content of about 70% by weight and a volatile solvent content of about 30% by weight.

(Example 7) A paste made of flaky titanium nitride was used in place of the paste made of metallic titanium flakes of Example 6 (trade name: Tylake Gold TG).
Sample 7 was prepared in the same manner as in Example 6 except that 8 g of P-500, manufactured by Showa Aluminum Powder Co., Ltd., solid content: about 60% by weight, volatile solvent content: about 40% by weight) was used.

Example 8 Sample 8 was synthesized in the same manner as in Example 1 except that the near infrared ray absorbing cationic dye (Chemical Formula 6) was used. In the formula (Formula 6), R represents an n-hexyl group and Ar represents an anisyl group. The λ _max (TMPT) (absorption wavelength) of the near infrared absorptive cationic dye (Chemical Formula 6) is 785 nm. TMPT stands for trimethylolpropane trimethacrylate.

[0049]

[Chemical 6]

Example 9 Sample 9 was synthesized in the same manner as in Example 1 except that the near infrared ray absorbing cationic dye (Chemical Formula 7) was used. In the formula (Formula 7), R represents an n-hexyl group, Ar represents an anisyl group, and Ph represents a phenyl group. The λ _max (TMPT) (absorption wavelength) of the near infrared light absorbing cationic dye (Chemical Formula 7) is 828 nm. TMPT stands for trimethylolpropane trimethacrylate.

[0051]

[Chemical 7]

Example 10 Sample 10 was synthesized in the same manner as in Example 1 except that ethylpyridinium n-butyltriphenylboron was used as the boron sensitizer.

Comparative Example 1 A comparative sample was prepared in the same manner as in Example 1 except that the amount of the solvent n-butyl acetate added was 2 g (the amount of solvent was about 1.8% by weight of the composition).

Comparative Example 2 A conventional thermosetting resin coating film was prepared. The composition is as follows. Vehicle (Product name Bell Coat 6000, NOF Corporation, solid content 35%)
47g, aluminum paste (trade name; SAP561PS)
3 g, thinner 47 ml (solvent amount is about 79% by weight of the composition). This paint was applied to the same substrate as used in the curing test below in the same manner, and heat-cured at 140 ° C. for 30 minutes,
A coating film was formed.

[Curing test] Aluminum substrate (2.5 cm × 7
cm) was coated with the above sample (Samples 1 to 10 and the comparative sample of Comparative Example 1) to a thickness of 100 μm. The obtained test piece was irradiated with a halogen lamp with an output of 1500 W having a spectral distribution in the wavelength range of 800 nm to 950 nm for 5 minutes in a box in which the oxygen concentration was controlled to 0.1% by volume. Upon irradiation with light, the color of the cationic dye was completely erased and the polymerization reaction proceeded, and all the samples were completely cured. Near-infrared light absorbing pigments are generally dark blue and the composition is also colored deep blue, but the coloration derived from the cationic dye disappears completely by light irradiation, and the cured product is derived from the composition other than the cationic dye. The color of the cationic dye did not affect the color tone of the cured product.

Next, the metallic feeling of the cured product was evaluated by the following method. The results are shown together in Table 1. [Evaluation of Metallic Feeling] The metallic coating film was evaluated using a “metallic feeling measuring device” (trade name ALCOPE LMR-200, manufactured by Kansai Paint Co., Ltd.). The metallic feeling measuring device irradiates a measured object with a laser beam from a specific angle and automatically measures reflected light, scattered light, etc.
The value indicates the intensity of the front reflected light, and the SV value indicates the intensity of the scattered light.
The value represents the flip-flop property calculated from them.
The larger the IV value and the FF value and the smaller the SV value, the better the metallic coating is.

[0057]

[Table 1]

The cured product of the photocurable composition containing the metallic pigment of the present invention achieves a metallic feeling equivalent to that of a conventional thermosetting coating film using a large amount of a solvent (Comparative Example 2). You can see that

[0059]

INDUSTRIAL APPLICABILITY The present invention provides a photocurable composition containing a metallic pigment, wherein a polymerizable unsaturated compound, a composition containing a flake metallic pigment and a specific near-infrared polymerization initiator and By adding a boron compound as a specific sensitizer and further adding a solvent in an amount of 5 to 50% by weight, preferably 10 to 40% by weight based on the total amount of essential components, the composition is irradiated with near infrared light. And the flake-shaped metallic pigment is uniformly oriented, and a cured product having a metallic feeling is obtained. Since conventional thermosetting materials containing flake-like metallic pigments are difficult to photo-cure, a large amount of solvent is used (for example, 80% by weight of the composition in a metallic base coat for automobiles,
The high-solid type is about 50% by weight), and the metallic feel of the cured product was obtained by curing with heat. However, the photocurable composition of the present invention has an extremely small amount compared to conventional thermosetting materials. It is economical as well as resource-saving and environment-friendly because it has the characteristics that a cured product with a metallic feel can be obtained by using a solvent, that there is little heating energy for curing, and that it can be applied to heat-sensitive materials. It can be said that it is a photocurable composition that is friendly to the global environment from the viewpoint of conservation and the like. Since the pigment in the present invention is in the form of flakes, when it is arranged in parallel to the surface of the coating film, it reflects light rays, heat rays, etc., which are harmful to the resin constituting the coating film, and it prevents the penetration of liquids and gases that corrode the substrate. It prolongs the life of the film, protects the substrate from corrosion for a long time, and develops the luster and sharpness peculiar to the flake metallic pigment, which greatly contributes to the improvement of the design of the coating film. The photocurable composition containing the metallic pigment of the present invention is an application field in which a conventional flake-shaped metallic composition is used, for example, printing ink, resist, adhesive, dental material, woodworking, furniture and the like. Painting, painting of metals, plastics, etc.
Since it can be used for painting automobile bodies, interiors, bumpers, etc., coating inorganic materials, etc., it has high industrial utility value.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication location G03F 7/029 (72) Inventor Kiichi Hosoda 5-1 Ogimachi, Kawasaki-ku, Kawasaki-shi, Kanagawa Showa Denko KK Company Chemicals Laboratory (72) Inventor Kaoru Saito, 410, Oza, Osho City, Nara Prefecture Showa Aluminum Powder Co., Ltd.

Claims (2)

[Claims] 1. A polymerizable unsaturated compound, a cationic dye having a near-infrared light region represented by the general formula (Formula 1), a sensitizer represented by the general formula (Formula 2), and a metallic pigment. And a solvent as an essential component, and the solvent is contained in an amount of 5 to 50% by weight based on the total amount of the essential component, a photocurable composition containing a metallic pigment. [Chemical 1] (In the formula, D ⁺ is a cation having absorption in the near infrared light region, R ₁ , R ₂ , R ₃ , and R ₄ are each independently an alkyl group, an aryl group, an allyl group, an aralkyl group, Alkenyl group, alkynyl group, silyl group, heterocyclic group, substituted alkyl group, substituted aryl group, substituted allyl group, substituted aralkyl group, substituted alkenyl group, substituted alkynyl group or substituted silyl group) (In the formula, R ₅ , R ₆ , R ₇ and R ₈ are each independently an alkyl group, an aryl group, an allyl group, an aralkyl group, an alkenyl group, an alkynyl group, a silyl group, a heterocyclic group, a substituted alkyl group and a substituted group. Represents an aryl group, a substituted allyl group, a substituted aralkyl group, a substituted alkenyl group, a substituted alkynyl group or a substituted silyl group, and Z ⁺ represents a quaternary ammonium cation, a quaternary pyridinium cation, a quaternary quinolinium cation or a phosphonium cation. Show) 2. The flake-like powder selected from aluminum metal or its compound, titanium metal or its compound, stainless steel, nickel or its compound, glass and iron oxide, as the metallic pigment. Photocurable composition.