JP2013119598A - Ultraviolet ray-curing photoluminescent ink composition for screen printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultraviolet ray-curing screen ink composition including a photoluminescent pigment suitable for anti-counterfeiting printed matter and forming an ink cured film with high film thickness.SOLUTION: The ultraviolet ray-curing photoluminescent ink composition for screen printing includes at least a photopolymerizable compound, a photopolymerization initiator, and a scale-like photoluminescent pigment. The photopolymerizable compound includes at least one multifunctional ultraviolet ray curable oligomer and at least one ultraviolet ray curable monomer, the photoluminescent pigment is a scale-like photoluminescent pigment, and the ultraviolet ray-curing photoluminescent ink composition for screen printing has a viscosity of 30°C of 0.05 Pa s or more and less than 1.1 Pa s.

Description

  The present invention relates to an ultraviolet curable screen ink composition for forming an ink cured film having a high film thickness containing a glitter pigment suitable for anti-counterfeit printed matter, and in particular, the leafing effect of the glitter pigment in the ink cured film The present invention relates to an ultraviolet curable screen ink composition that reproduces (orientation) and is excellent in ink cured film strength and friction resistance.

Recent advances in digital equipment such as scanners, printers, and color copiers have made it possible to easily produce elaborate copies of valuable prints. As one of the anti-counterfeiting techniques for preventing such duplication and counterfeiting, there is a printed matter having a glittering effect in which an image line is formed with an ultraviolet curable glittering ink composition and the hue changes depending on the observation angle.

The glitter effect that changes the hue is obtained when the solvent (organic solvent / water) evaporation type ink is used, and the thinner the ink cured film printed on the substrate, the better the effect. When an ultraviolet curable ink is used, the ink cured film printed on the substrate becomes thick, so in order to obtain a good glitter effect, use a substrate having an oil absorption of 20 sec or more and less than 6000 sec, It is desirable to orient the glitter pigment on the surface of the ink cured film on the substrate to express the glitter effect by adjusting the viscosity of the ultraviolet curable glitter ink with respect to the oil absorption of the substrate.

  For example, as an example of the ultraviolet curable glitter ink described above, at least 25 to 95 parts by mass of a binder component composed of one or more monomers or oligomers having one or more unsaturated bonds and 5 to 60 parts by mass of a pearl pigment. There has been disclosed a pearl ink for printing characterized by comprising a composition containing the same (for example, see Patent Document 1).

  Further, a photopolymerization initiator, a polymerizable monomer and / or a polymerizable oligomer, a viewing angle-dependent discoloration pigment in which a metal oxide is coated on alumina flake, and / or a viewing angle-dependent discoloration pigment in which a silica oxide is coated with a metal oxide. There is disclosed a highly decorative ultraviolet curable ink characterized in that it contains (see, for example, Patent Document 2).

  In addition, in order to leave the glitter pigment on the surface of the ink cured coating, the surface of the glitter pigment is treated with an aqueous dispersant and the water is coordinated, so that the ink is repelled by the repulsion between water and the UV curable varnish component. An aqueous ultraviolet curable glitter ink that orients a glitter pigment on the upper layer of the cured film is disclosed (for example, see Patent Document 3).

Japanese Patent Laid-Open No. 2001-240786 JP 2004-115759 A JP 2011-6562 A

  However, since the techniques described in Patent Document 1 and Patent Document 2 have an ink viscosity of 2 Pa · s to 30 Pa · s, when used on printing paper having an oil absorption of 20 sec or more and less than 6000 sec, Insufficient penetration, and the glitter pigment is not sufficiently oriented on the surface of the ink-cured film, so even if a thick ink-cured film is formed, a good hue change cannot be obtained. There was a problem that (interference light of the bright pigment) was inhibited.

  In addition, the technique described in Patent Document 3 contains water during ink blending, so the leafing effect (orientation) of the glitter pigment is good, but it is used for a base material having an oil absorption in the above-mentioned range. In this case, the water component penetrates into the base material, so that the penetration of the varnish component into the base material becomes insufficient, resulting in poor adhesion, or the water-dispersed glitter pigment repels the varnish to the varnish surface. By floating, there is a possibility that the glitter pigment may be exposed from the ink cured film, and there is a problem that the pigment removal resistance is lacking.

  The present invention aims to solve the above-mentioned problems, and uses a water and a dispersant to absorb the substrate without aligning the glitter pigment due to the resilience of the ultraviolet curable varnish of the glitter pigment. By adjusting the characteristics of the UV curable varnish with respect to the degree, the exposure of the glitter pigment to the ink cured film is prevented, and lines, solids, halftone dots, etc. (hereinafter referred to as “image”) that have good glitter and pigment detachment resistance. The present invention relates to a glittering ink composition for ultraviolet curable screen printing capable of forming a line or the like.

  The ultraviolet curable screen printing glitter ink composition of the present invention is an ultraviolet curable screen printing glitter ink composition comprising at least a photopolymerizable compound, a photopolymerization initiator, and a scaly glitter pigment. The above-mentioned photopolymerizable compound is composed of at least one multifunctional ultraviolet curable oligomer and at least one ultraviolet curable monomer, and the glitter pigment is a scaly glitter pigment, which is an ultraviolet curing screen printing glitter. A UV-curable screen-printing glitter ink composition characterized in that the viscosity at 30 ° C. of the water-based ink composition is 0.05 Pa · s or more and less than 1.1 Pa · s.

  Further, the glittering ink composition for ultraviolet curable screen printing of the present invention comprises a urethane-based, epoxy-based, polyether-based, polyester-based, UV-curable oligomer having a viscosity at 60 ° C. of 1 Pa · s to 80 Pa · s. An ultraviolet ray that is at least one of an acrylic type and has a viscosity at 25 ° C. of an ultraviolet curable monomer of at least one of a (meth) acrylamide type and a (meth) acrylate type of 0.04 Pa · s or less. A curable ink composition for screen printing.

  Further, the ultraviolet curable screen printing glitter ink composition of the present invention is the use of the ultraviolet curable screen printing glitter ink composition on printing paper having an oil absorption of 20 sec or more and less than 6000 sec.

  Further, the ultraviolet curable screen printing glitter ink composition of the present invention has a plurality of image lines arranged in different arrangement directions on at least a part of the printing paper by the ultraviolet curable screen printing glitter ink composition. By using the fact that the visibility of the print image changes according to the observation angle by forming the print image, it is used for a forgery-preventing printed matter that performs authenticity determination.

  The ultraviolet-curable screen-printing glitter ink composition of the present invention is an arrangement of glitter pigments contained in a high-thickness ink-cured film by adjusting the characteristics of the ultraviolet-curable varnish with respect to the oil absorption of the substrate. Can be formed in the same direction to form a high-thickness image line having an excellent leafing effect and excellent saturation and glitter (interference light of the glitter pigment) inherent to the glitter pigment.

  Moreover, the glittering ink composition for ultraviolet curable screen printing of the present invention prevents the glittering pigment from being exposed from the ink cured film by adjusting the characteristics of the ultraviolet curable varnish with respect to the oil absorption of the substrate. Therefore, the pigment detachment resistance is good.

The figure which shows an example of a mixing | blending of the photopolymerizable compound of this invention. The figure which shows an example of a mixing | blending of the varnish for ultraviolet curing type screen printing of this invention. The figure which shows an example of a mixing | blending of the glittering ink composition for ultraviolet curable screen printing of this invention. The figure which shows an example of the mixing | blending of the ultraviolet curable screen printing glitter ink composition of a comparative example. An example figure of the measurement result of the viscosity of the glittering ink composition for ultraviolet curing type screen printing of the present invention. An example figure which shows evaluation of the printed matter using the glittering ink composition for ultraviolet curing type screen printing of this invention. The example figure which shows the observation result by the electron microscope of the printed matter of this invention. An example figure which shows the observation result by the electron microscope of the printed matter of a comparative example. An example figure which shows the observation result by the electron microscope of the printed matter of a comparative example.

  A mode for carrying out the present invention will be described. However, the present invention is not limited to the embodiments described below, and includes various other embodiments within the scope of the technical idea described in the claims.

  In the ultraviolet curable screen printing glitter ink composition of the present invention, the photopolymerizable compound comprises at least one multifunctional ultraviolet curable oligomer and at least one ultraviolet curable monomer, and the glitter pigment has a thickness. A scaly glittering pigment having a particle size of 0.5 μm or more and 6 μm or less and a particle size of 3 μm or more and 200 μm or less, and having a viscosity at 30 ° C. of 0.05 Pa · s or more and less than 1.1 Pa · s. To do.

(Photopolymerizable compound)
The photopolymerizable compound is polyfunctional and has at least one ultraviolet curable oligomer having a viscosity at 60 ° C. of 1 Pa · s to 80 Pa · s and at least one having a viscosity at 25 ° C. of 0.04 Pa · s or less. Consists of two UV curable monomers.

(UV curable oligomer)
The UV curable oligomer that is multifunctional and has a viscosity at 60 ° C. of 1 Pa · s or more and 80 Pa · s or less has an average molecular weight of 1000 to 40,000 and two or more photopolymerizable functional groups in one molecule. , Urethane-based, epoxy-based, polyether-based, polyester-based and acrylic-based ultraviolet curable oligomers. By using the oligomer, high film strength can be obtained. This is because the monofunctional oligomer cannot provide sufficient curability, cured film strength, flexibility, and the like. A range where the viscosity at 60 ° C. is 1 Pa · s or more and 80 Pa · s or less is a range for obtaining sufficient cured film strength and flexibility and keeping the ink viscosity low. The blending ratio of the polyfunctional ultraviolet curable oligomer to the photopolymerizable compound is 20% by weight to 60% by weight. This is because if it is less than 20% by weight, sufficient film strength and flexibility cannot be obtained. This is because when the amount exceeds 60% by weight, it is not possible to reduce the viscosity of the ink.

  As a polyfunctional urethane-based oligomer, for example, a polyol (a) and an organic polyisocyanate (b) are reacted to prepare a urethane prepolymer, and the urethane prepolymer is reacted with a hydroxyl group-containing (meth) acrylate (c). There is something that can be obtained. Moreover, what is obtained by reacting organic polyisocyanate (b) and hydroxyl group-containing (meth) acrylate (c) can be exemplified. This is because the use of such a polyfunctional urethane-based oligomer improves the elasticity of the ink cured film and prevents the ink cured film from becoming brittle.

  Examples of the polyol (a) include ethylene glycol, propylene glycol, 1,3-butylene glycol, neopentyl glycol, 1,6-hexanediol, polypropylene glycol, bisphenol A polyethylene glycol, polytetramethylene glycol, glycerin, and trimethylol. Examples include propane, polyester polyol, polycarbonate polyol, polycaprolactone polyol, polybutadiene polyol, polymer polyol, and polysiloxane polyol.

  Examples of the organic polyisocyanate (b) include aromatic diisocyanates such as tolylene diisocyanate or diphenylmethane diisocyanate, araliphatic diisocyanates such as tetramethylxylylene diisocyanate, isophorone diisocyanate, bis (4-isocyanatocyclohexyl) methane, hexa Examples thereof include aliphatic or cycloaliphatic diisocyanates such as methylene diisocyanate and trimethylhexamethylene diisocyanate.

  Examples of the hydroxyl group-containing (meth) acrylate (c) include one acrylic group such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and the like. Multifunctional having two or more acrylic groups such as functional (meth) acrylate, trimethylolpropane di (meth) acrylate, glycerin di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate (Meth) acrylate etc. can be mentioned.

(UV curable monomer)
As a UV curable monomer having a viscosity at 25 ° C. of 0.04 Pa · s or less, a (meth) acrylamide type or (meth) acrylate type monofunctional or polyfunctional UV curable monomer having a molecular weight of 70 to 800, etc. It is. In addition, the viscosity at 25 ° C. is set to 0.04 Pa · s or less because the viscosity of the ink is reduced by blending a small amount of monomer, and the film strength and flexibility, curability and permeability to the substrate are ensured. Because.

  In addition, even when two or more ultraviolet curable monomers are blended, the ultraviolet curable monomer has a viscosity at 25 ° C. of at least one monomer of 0.04 Pa · s or less. The viscosity at 30 ° C. of the entire glittering ink composition may be 0.5 Pa · s to less than 1.1 Pa · s. Therefore, at least one ultraviolet curable monomer component having a viscosity at 25 ° C. of 0.04 Pa · s or less may be blended and used in combination with an ultraviolet curable monomer component having 0.04 Pa · s or more. The blending ratio of the ultraviolet curable monomer having a viscosity at 25 ° C. of 0.04 Pa · s or more to the photopolymerization compound is 50% by weight or less. When the amount exceeds 50% by weight, the viscosity at 25 ° C. is a monomer component combined with an ultraviolet curable monomer of 0.04 Pa · s or less, and the blending ratio with respect to the photopolymerizable compound described later exceeds 80% by weight. This is because good ink cured film properties (strength and flexibility) cannot be obtained, and curing failure occurs.

  Examples of the monofunctional photopolymerizable monomer include (meth) acrylic acid, itaconic acid, (meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, and N, N-dimethyl (meth) acrylamide. N, N-diethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-ethylaminoethyl (meth) acrylamide, diacetone (meth) acrylamide, N-vinylpyrrolidone, N- (meth) acryloylpyrrolidone, 2- Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, glycerol (meth) acrylate and (methoxy) polyethylene glycol (meth) acrylate Doors and the like.

  In addition, as the bifunctional photopolymerizable monomer, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, 1,4-butanediol diacrylate, 1, 6-hexanediol diacrylate, 1,9-nonanediol diacrylate, neopentyl glycol diacrylate, dimethylol-tricyclodecane diacrylate, EO (ethylene oxide) adduct diacrylate of bisphenol A, PO (propylene oxide) of bisphenol A Adducts diacrylate, hydroxypivalate neopentyl glycol diacrylate and polytetramethylene glycol diacrylate And the like.

  Examples of the trifunctional photopolymerizable monomer include triacrylates or trimethacrylates of trihydric or higher polyhydric alcohols such as trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate and the like. It is done.

  Examples of the tetra- or higher functional photopolymerizable monomer include tricyclodecane di (meth) acrylate, tripropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1 , 6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane polyethoxytri (meth) acrylate, trimethylolpropane polypropoxytri (meth) acrylate, glycerin polypropoxytri (meth) acrylate Bisphenol A polyethoxydi (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) ) Acrylate, dipentaerythritol penta and hexa (meth) acrylate mixture, dipentaerythritol polyethoxy hexa (meth) acrylate and dipentaerythritol poly propoxy hexa (meth) acrylate and the like. This is because the use of such an acrylic monomer improves the strength of the ink cured film and prevents the ink cured film from becoming brittle.

  In addition, the mixture ratio of the ultraviolet curable monomer whose viscosity in 25 degreeC with respect to a photopolymerizable compound is 0.04 Pa.s or less is 30 to 80 weight%. If the amount is less than 30% by weight, sufficient ink viscosity cannot be expected. If the amount exceeds 80% by weight, good ink cured film properties (strength and flexibility) cannot be obtained, resulting in poor curing. This is because it occurs.

(Scale-like glitter pigment)
The scale-like glitter pigment is not particularly limited as long as it is not soluble in the photopolymerizable compound, and known scale-like glitter such as scale-like pearl pigment, scale-like mica, scale-like metal pigment, glass flake pigment, and cholesteric liquid crystal pigment. Pigments can be used. By using the scaly pigment, high pigment orientation can be obtained due to the leafing effect in the ink. The scaly glittering pigment has a thickness of 0.5 to 6 μm and a particle size of 3 to 200 μm. It is because manufacturability and brightness are inferior if the lower limit is not exceeded. If each upper limit is exceeded, the printability is remarkably deteriorated, transfer defects, plate clogging, etc. occur, which is unsuitable for printing applications.

(Photopolymerization initiator)
As photopolymerization initiators, 4-dimethylaminobenzoic acid, 4-dimethylaminobenzoic acid ester, alkoxyacetophenone, benzophenone and benzophenone derivatives, alkyl benzoylbenzoate, bis (4-dialkylaminophenyl) ketone, benzyl and benzyl derivatives, Known photopolymerization initiators such as benzoin and benzoin derivatives can be used alone or in combination of two or more.

(Luminescent ink composition for UV curable screen printing)
An ultraviolet curable glitter ink composition for screen printing comprises at least the above-mentioned photopolymerizable compound, a photopolymerization initiator, and a glitter material, and has a viscosity at 30 ° C. of 0.05 to 1.1 Pa · s. Is less than. The reason why the viscosity at 30 ° C. is 0.05 or more and less than 1.1 Pa · s is that when it is less than 0.05 Pa · s, it is difficult to obtain a sufficient film thickness, and there is a possibility that printing defects such as bleeding may occur. Because. This is because if it exceeds 1.1 Pa · s, the permeability to the substrate becomes insufficient, and sufficient glitter cannot be expressed.

  The blending ratio of the photopolymerizable compound to the ultraviolet curable screen printing glitter ink composition is 60% by weight to 94% by weight. If it is less than 60% by weight, the curability and the film strength may be poor. When it exceeds 94% by weight, the blending ratio of the glitter pigment is low, and good glitter cannot be obtained. The blending ratio of the photopolymerization initiator is 1 to 15% by weight. If it is 1% by weight or less, curing failure occurs, and the kind of pigment, the amount added, and the ink film thickness are limited. When it exceeds 15% by weight, there is no significant change in curability even if it is added. The blending ratio of the scaly glittering pigment is 5 to 30% by weight. If the amount is less than 5% by weight, sufficient saturation cannot be obtained when the interference light after ink formation is observed. When it exceeds 30% by weight, an effect commensurate with the blending ratio cannot be obtained, and the saturation is not further improved.

  In addition, the organic ink or inorganic pigment can be added to the ultraviolet-curable screen printing glitter ink composition of the present invention within a range that does not affect the viscosity. Further, an antifoaming agent, a leveling agent, a dispersant, a polymerization inhibitor, a wax and the like can be added in order to improve the ink stability and the abrasion resistance of the ink cured film.

(Base material)
The substrate used for printing the glittering ink composition for ultraviolet curable screen printing of the present invention is a printing paper having an oil absorption of 20 sec or more and less than 6000 sec according to the oil absorption measurement method according to JISP8130. When the printing paper having the above-described oil absorption uses the ink of the present invention, the reproducibility is good with a high-thickness image line, and the glitter and anti-pigmentation properties are good. When the oil absorption is less than 20 sec, a sufficient film thickness cannot be obtained and bleeding occurs. In addition, the penetration of the varnish is rapid, the pigment is exposed from the ink cured film, and the pigment detachment resistance is poor. . When the oil absorption is 6000 sec or more, in addition to insufficient orientation of the pigment on the surface of the ink cured film due to penetration of the varnish, glossiness is hindered by varnish gloss.

  In addition, the printing method on the substrate of the ultraviolet curable screen printing glitter ink composition of the present invention is preferably a screen printing method in consideration of anti-counterfeiting effects, printability, high-thickness image lines, etc. . In the present invention, the high-thickness image line refers to a printed image line having a cured film thickness of 3 μm to 40 μm. When the thickness of the cured film is 3 μm or less, there is no clear difference from the solvent evaporation type ink in the line shape, and the advantage of using the ultraviolet curable ink is halved. Moreover, since the luster pigment is more easily exposed than the cured film, it is inferior in pigment detachment resistance. When the thickness of the cured film is 40 μm or more, poor curing is likely to occur, and printability is inferior. As an implementation condition, it is desirable that the thickness of the cured film is in the range of 5 μm to 30 μm.

  Moreover, since the glittering ink composition for ultraviolet curable screen printing of the present invention can form a printed image line having a high film thickness, the ink composition is used for printing paper having an oil absorption of 20 sec or more and less than 6000 sec. Then, the first image line and the second image line are arranged at different angles to form a background portion and a latent image portion, and a printed material (for example, a latent image can be visually recognized by tilting the printed material) Japanese Patent No. 4374446, etc.) can be used to produce printed matter with a high anti-counterfeit effect.

  Further, the glittering ink composition for ultraviolet curable screen printing of the present invention forms a high-thickness printed image line that leaves the glittering pigment, so if the printed material is tilted slightly, the effect unique to the glittering pigment is achieved. Interference light (iris color) can be generated. Therefore, the ink composition is used for printing paper having an oil absorption of 20 sec or more and less than 6000 sec, and the first image line and the second image line are arranged at different angles to form a background portion and a latent image portion, To produce a printed material with a good anti-counterfeit effect by using it for a printed material (for example, WO2003 / 013871 etc.) in which a latent image of an arbitrary gradation can be visually recognized by tilting the printed material. Can do.

(Preparation method of glitter ink composition for UV curable screen printing)
The method for producing a glittering ink composition for ultraviolet curable screen printing according to the present invention comprises a photopolymerizable compound production step and an ink composition production step.

  The production step of the photopolymerizable compound includes at least one kind of polyfunctional and ultraviolet curable oligomer having a viscosity at 60 ° C. of 1 Pa · s to 80 Pa · s, and a viscosity at 25 ° C. of 0.04 Pa · s. The following ultraviolet curable monomers are mixed and heated and stirred. For the stirring, known stirring devices such as a propeller stirrer and a Henschel mixer can be used. As an example of the production process of the photopolymerizable compound, a bifunctional urethane-based oligomer is taken in a glass container and heated to 70 ° C. with a mantle heater and dissolved. Next, the monofunctional acrylamide monomer is put into a glass container and heated and stirred at 70 ° C. using a propeller type stirrer. The heating and stirring conditions are heating and stirring at a rotation speed of 100 rpm for 30 minutes to dissolve the two components.

  In the production process of the ink composition, a photopolymerization initiator is added to the produced photopolymerizable compound, and the mixture is heated and stirred. After the photopolymerization initiator is blended, an additive such as a pigment and wax is blended, and the mixture is kneaded at room temperature with an ink production apparatus such as a propeller stirrer or a ball mill. As an example of the preparation process of the ink composition, a photopolymerization initiator is added to a glass container containing a photopolymerizable compound, and heated using a propeller type agitator and a mantle heater at 70 ° C. and a rotation speed of 100 rpm for 30 minutes. Stir and dissolve the photopolymerization initiator. Next, additives such as pigments, waxes and antifoaming agents are added, and the mixture is stirred for 60 minutes at room temperature and at a rotational speed of 100 rpm to form an ink.

  Hereinafter, the ultraviolet curable screen printing glitter ink composition of the present invention will be described in detail with specific examples. In addition,% in an example shows weight% altogether.

(Preparation of photopolymerizable compound (A1))
A: bifunctional urethane oligomer (manufactured by Nippon Synthetic Chemical Co., Ltd.), B: bifunctional urethane oligomer (manufactured by Kyoeisha Chemical Co., Ltd.), C: monofunctional acrylamide monomer (manufactured by Arakawa Chemical Industries), The photopolymerizable compound A1 was produced by mixing with a propeller-type stirrer at a temperature of 70 ° C. and a rotation speed of 100 rpm for 40 minutes. In addition, the photopolymerizable compound (A2-A4) was obtained by the same method. A summary of the mixing ratio is shown in FIG.

(Preparation of UV curable varnish for screen printing (W1))
A photopolymerization initiator (BASF), a pigment dispersant (Nippon Lubrizol), and an antifoaming agent (BIC Chemie) were agitated with a propeller agitator according to the formulation shown in FIG. A mold screen printing varnish W1 was produced. In addition, the material mentioned above was mix | blended with the photopolymerizable compound (A2-A4) by the same method, and the varnish for ultraviolet curing type screen printing (W2-W4) was obtained. A summary of the compounding ratio is shown in FIG.

(Preparation of glitter ink composition for ultraviolet curable screen printing (I1))
A scaly glitter pigment (manufactured by Merck & Co., Inc.) and a scaly glitter pigment for color adjustment are added to the produced UV curable varnish W1 in accordance with the composition shown in FIG. 3, and a propeller stirrer is used for 60 minutes at a rotation speed of 100 rpm. The mixture was stirred to prepare a glittering ink composition (I1) for ultraviolet curable screen printing. In addition, the material mentioned above was mix | blended with the ultraviolet curable varnish (W2-W4) by the same method, and the glittering ink composition (I2-I4) for ultraviolet curable screen printing was obtained. A summary of the mixing ratio is shown in FIG.

(Preparation of a bright ink composition for comparative ultraviolet curable screen printing)
A commercially available UVA 9117 (viscosity 2.0 Pa · s (30 ° C.) manufactured by Seiko Advance) was used as the ultraviolet curable varnish, and the mixture was stirred with a propeller stirrer using the same method as in Example 1. Thus, a bright ink composition I5 for ultraviolet curable screen printing of Comparative Example was produced. Further, in accordance with the matters described in JP2011-6562, the composition shown in FIG. 4 was prepared using an ultraviolet curable varnish W5 (consisting of a photopolymerizable compound, a photopolymerization initiator and an antifoaming agent), an aqueous pigment dispersant and water. Thus, a bright ink composition I6 for ultraviolet curable screen printing of a comparative example was produced. Moreover, bifunctional urethane type oligomers A and B are 8.8% each, viscosity is 0.2 Pa · s (25 ° C.) (Nippon Kayaku) as a monomer, 70.4%, photopolymerization initiator (manufactured by BASF) 10 %, A pigment dispersant (manufactured by Nihon Lubrizol) 1%, an antifoaming agent (manufactured by BYK Chemie) 1%, and UV curable varnish W6 blended as shown in FIG. A glittering ink composition I7 was produced.

  The viscosity at 30 ° of the produced UV-curable screen printing glitter ink composition (I1 to I4) and the UV-curable screen printing glitter ink compositions (I5, I6, and I7) of the comparative examples is high share. It measured using the cone plate (PK5; 0.5) with the viscosity meter (HATOKE ROTOVISCO RV20). The measurement results are shown in FIG.

  Evaluation of the glittering ink composition for ultraviolet curable screen printing of the present invention was performed as follows.

The printed matter for evaluation was produced by performing screen printing using a urethane squeegee having a mesh surface of 255PW (manufactured by NBC) and a hardness of about 70 ° to obtain a solid print region of 40 × 40 mm. Five seconds after printing, UV irradiation was performed with one metal halide lamp (120 W / cm), and curing was performed at an irradiation amount of 160 mJ / cm ² . The base material is a PET film (transparent material, thickness 50 μm) with an oil absorption of 6000 seconds or more, various papers with an oil absorption of 50 to 150 seconds, and high-quality paper with an oil absorption of 20 seconds or less (Kishu Paper's Kishu Fine) , Basis weight 81.4 g / cm ² , thickness 100 μm) and coated paper (Nippon Paper Aurora Coat, basis weight 209.4 g / cm ² , thickness 190 μm) having an oil absorption of 4500-5800 seconds was used.

  The thickness of the cured film was calculated from the difference between the thickness of the entire printed matter (cured film and substrate) and the measured thickness of the substrate. A digimatic micrometer (No. 293 manufactured by Mitutoyo) was used for the measurement. The evaluation of the penetration rate was obtained by the formula of (ab) × 100 / a, where the thickness of the cured film on the PET film was a μm and the thickness of the cured film on each substrate was b μm.

  The glittering effect was evaluated visually, with the evaluation standard being “◯” when the effect specific to the glittering pigment was good, and “X” when the effect unique to the glittering pigment could not be observed. The lightness L * was the lightness obtained when the incident light was fixed at 45 ° and the light receiving angle was 45 ° with a variable angle spectrocolorimeter (GCMS-4 type manufactured by Murakami Color Research Laboratory). In addition, the saturation C * ab is fixed at 45 ° with a variable angle spectrocolorimeter (GCMS-4, manufactured by Murakami Color Research Laboratory), and the light receiving angle is set to a maximum value of 0 to 80 degrees. did.

Evaluation of pigment detachment resistance was performed by applying an adhesive tape (CT405AP-18, manufactured by NICHIBAN) to the printing surface, and using a laminator (SA-1010, manufactured by Tester Sangyo Co., Ltd., a small desktop test laminator) at a speed of 0.5 m / min and a pressure of 3. After passing through once at 0 kgf / cm ² , the adhesive tape was peeled off and attached to black paper to observe whether the pigment adhered. The evaluation criteria were “No” for adhesion, and “No” for adhesion.

  As shown in FIG. 6, by using the ink of the embodiment of the present invention, high orientation of the glitter pigment on the surface of the ink-cured film, high saturation due to the original color of the pigment is obtained, and gloss due to the varnish component is obtained. Since the feeling (lightness) can be suppressed, a printed matter having excellent glitter and pigment detachment resistance could be obtained.

  Next, the pigment orientation on the printed material surface (ink cured film surface) of the present invention will be described with reference to FIG. 7 showing the observation results with an environmental control electron microscope (SEMEDX Type N, manufactured by Hitachi, Ltd., observation magnification 800 times).

  As shown in FIG. 7 (a), the printed matter (4) of level 1 ink I1 of the present invention is a state in which the glitter pigment (2) is finely arranged on the surface of the ink cured film (1). Since the glitter pigment (2) is not exposed from the surface (1), the glitter pigment (2) is oriented in the ink cured film surface (1) as shown in the schematic diagram of FIG. I was able to confirm that.

  Next, the pigment orientation in the ink cured film of the comparative example will be described with reference to FIGS. 8 and 9, which are observation results with an environmental control electron microscope (SEMEDX Type N, manufactured by Hitachi, Ltd., observation magnification 800 times).

  As shown to Fig.8 (a), the printed matter (4 ') by the level 8 ink I5 of a comparative example is the state in which the glitter pigment (2') was sparsely arranged on the ink cured film surface (1 '). The glitter pigment (2 ') is not exposed from the ink cured film surface (1'), but the glitter pigment (2 ') is submerged in the ink cured film surface (1'). ), It was confirmed that the glitter pigment was not oriented on the surface of the ink cured film (1 ′).

  Further, as shown in FIG. 9A, the printed matter (4 ″) of the level 9 ink I6 of the comparative example has a finely arranged glitter pigment (2 ″) on the surface of the ink cured film (1 ″). In this state, the glitter pigment (2 ″) is exposed from the ink cured film surface (1 ″), and the ink cured film surface (1 ″) is exposed as shown in the schematic diagram of FIG. The bright pigment (2 ″) was oriented, but it was confirmed that the bright pigment (2 ″) was exposed from the surface of the ink cured film (1 ″).

1, 1 ′, 1 ″ ink cured film 2, 2 ′, 2 ″ glitter pigment
3, 3 ′, 3 ″ base material 4, 4 ′, 4 ″ printed matter

Claims (4)

An ultraviolet curable screen printing glitter ink composition comprising at least a photopolymerizable compound, a photopolymerization initiator, and a scaly glitter pigment,
The photopolymerizable compound comprises at least one multifunctional ultraviolet curable oligomer and at least one ultraviolet curable monomer,
An ultraviolet curable screen printing glitter ink composition having a viscosity at 30 ° C. of 0.05 Pa · s or more and less than 1.1 Pa · s.   The ultraviolet curable oligomer is at least one of urethane type, epoxy type, polyether type, polyester type and acrylic type having a viscosity at 60 ° C. of 1 Pa · s to 80 Pa · s, 2. The glitter ink composition for ultraviolet curable screen printing according to claim 1, wherein the viscosity at 25 [deg.] C. is at least one of (meth) acrylamide type and (meth) acrylate type having a viscosity of 0.04 Pa.s or less. object.   Use of the ultraviolet curable screen printing glitter ink composition according to claim 1 or 2 on a printing paper having an oil absorption of 20 sec or more and less than 6000 sec.   A printed image in which a plurality of lines are arranged in the same direction or in different arrangement directions is formed on at least a part of the printing paper by the glittering ink composition for ultraviolet curable screen printing according to claim 1 or 2. As a result, the use of the printed image for anti-counterfeiting that performs authenticity determination using the fact that the visibility of the printed image changes according to the observation angle.

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