TW201425490A - Ink composition for roll printing - Google Patents

Abstract

Disclosed is an ink composition for roll printing with excellent printing properties, which includes a brightening agent represented by Formula 1 to improve whiteness, thus expressing white color more clearly. Therefore, in a case where the ink composition is used in formation of bezel patterns for a touch screen panel, bezel patterns having excellent shielding properties and coloring properties may be formed and the ink coated on a roll during printing is completely transferred to a substrate, thereby attaining excellent printability.

Description

Drum printing ink composition

This invention relates to roller printing ink compositions.

Micropatterns for semiconductor circuit components and display devices (eg, LCDs, PDPs, etc.) are formed by photolithography using photoresist. Photoetching has the advantage of obtaining the desired precise pattern, however, it also bears many disadvantages because multiple processes are required, many materials are used to maximize the photoresist effect, and coating or other processes require a significant amount of Light resistance.

Therefore, in order to overcome the above-mentioned disadvantages of photolithography, a next generation process for forming a micro pattern (for example, roll printing or ink jet printing) has been proposed in recent years.

Many methods, including, for example, offset printing, reverse offset printing, roll-to-roll printing, etc., can be applied to the formation of micropatterns by roller printing, and can also be used in a wide range of applications, that is, the composition of color filters. , for example, R (red), G (green), and B (blue) and black matrix (BM) patterns for forming electrodes in thin film transistors (TFTs) or plasma display panels (PDPs), barriers Etching of rib material (pattern transfer) and so on.

Recently, a method of forming a block diagram of a touch panel by roll printing has been proposed. In this regard, the bezel is the uppermost layer visible to the user, and the white ink used herein must have shielding properties, high resistance, and excellent coloring properties.

White inks generally include a coloring agent containing titanium dioxide, wherein titanium dioxide has reduced reflectivity at 420 nm or shorter wavelengths to cause yellowing, thus bearing the problem of not producing clearer white.

Korean Patent Application Publication No. 2010-39652 discloses a non-solvent type and a UV curable white ink composition, however, there is no proposal to overcome yellowing.

Accordingly, it is an object of the present invention to provide a roller printing ink composition having improved whiteness for a clearer white appearance.

Another object of the present invention is to provide a roll printing ink composition having excellent printing properties.

In order to achieve the above object, the present invention provides the following: (1) A roller printing ink composition comprising the brightening agent represented by Formula 1:

(wherein R ₁ and R ₂ are each a benzoxazole group, and are independently substituted by a hydroxyl group, a halogen, a guanamine group, an amine group, an ester or an alkyl group having 1 to 6 carbon atoms). (2) The ink composition according to (1) above, wherein the compound represented by Formula 1 is included in an amount of 0.01 to 1 wt.% based on the total weight of the ink composition. (3) The ink composition according to (1) above, further comprising a white inorganic pigment, a binder resin, a polymerization initiator, and a solvent. (4) The ink composition according to (3) above, wherein the white inorganic pigment is selected from the group consisting of CI dyes white 4, 5, 6, 6: 1, 7, 18, 18: 1, 19, 20, 22, 25, 26 At least one of the groups consisting of 27, 28, and 32. (5) The ink composition according to (3) above, wherein the white inorganic pigment comprises TiO ₂ . (6) The ink composition according to (3) above, wherein the solvent is at least one selected from the group consisting of glycol ethers, acetates, aromatic hydrocarbons, ketones, alcohols, and cyclic esters. (7) The ink composition according to (3) above, which further comprises a polymerizable compound. (8) The ink composition according to (7) above, wherein the polymerizable compound is selected from the group consisting of decyl phenyl carbitol, 2-hydroxy-3-phenoxypropyl acrylate, 2-ethylhexyl acrylate Alcohol ester, 2-hydroxyethyl acrylate, N-vinyl pyrrolidone, 1,6-hexanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, di(methyl) Neopentyl glycol acrylate, triethylene glycol di(meth)acrylate, bis(acryloyloxyethyl)ether of bisphenol A, 3-methylpentanediol di(meth)acrylate, Trimethylolpropane tris(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol pentyl (meth)acrylate, and dipentaerythritol hexa(meth)acrylate At least one of the group consisting of.

According to the present invention, the whiteness is improved to exhibit a clearer white color.

When the ink composition of the present invention is used to form a surface block diagram of a touch screen panel, a surface block diagram having excellent shielding properties and coloring properties can be formed.

According to the present invention, the ink coated on the drum is completely transferred to the substrate during printing, and thus has excellent printing properties.

The present invention discloses a roll printing ink composition having excellent printing properties, which comprises a brightening agent represented by Formula 1 to improve whiteness, and thus exhibits a clearer white color. Therefore, in the example in which the ink composition is used to form a touch panel of a touch screen panel, a block diagram-like sample having excellent shielding properties and coloring properties can be formed, and the ink coated on the roller can be completely transferred during printing. To the substrate, thereby obtaining excellent printing properties (i.e., printability).

The invention will be explained in more detail below.

The roller printing ink composition of the present invention may comprise a brightening agent represented by Formula 1:

(wherein R ₁ and R _{2 are} each a benzoxazole group, and are independently substituted by a hydroxyl group, a halogen, a guanamine group, an amine group, an ester or an alkyl group having 1 to 6 carbon atoms).

TiO _{2 , which is} typically used for white inorganic pigments, has reduced reflectivity at wavelengths of 420 nm or shorter, and thus has a tendency to accelerate yellowing, resulting in a decrease in whiteness. In such an example, the compound represented by Formula 1 can reflect UV light into visible light in an invisible region by a fluorescent reaction to improve whiteness.

Although brighteners having a benzoxazole structure are known in the art, brighteners having a thiophene structure like the present invention have improved whiteness and compatibility with roller printing inks. Has a remarkable excellent effect.

The content of the compound represented by Formula 1 is not particularly limited, and if it is in the range in which the compound can exert a desired function, the range can be, for example, from 0.01 to 1 wt.%, preferably from the total weight of the ink composition. From 0.03 to 0.5 wt.%, and more preferably from 0.03 to 0.1 wt.%. When the content of the compound represented by Formula 1 is within the above range, the effect of improving the whiteness of the ink composition can be maximized.

The roll printing ink composition of the present invention may further comprise other ingredients of a conventional roll printing ink composition which are generally used in the art to express white without particular limitation. For example, a white inorganic pigment, a binder resin, a polymerization initiator, and a solvent may be further included.

The white inorganic pigment used herein is not particularly limited as long as it is any white inorganic pigment generally used in the art, however, the white inorganic pigment may include, for example, CI dye white 4, 5, 6, and 6: 1, 7, 18, 18: 1, 19, 20, 22, 25, 26, 27, 28, 32, and so on. In terms of reflection efficiency and whiteness, it is preferred to use C.I. Pigment White 6 or White 22, and they may be used singly or in combination of two or more.

The TiO ₂ contained in the CI Pigment White 6 is quite inexpensive and has a high refractive index to exhibit excellent reflection, and thus is used as an effective white colorant. Preferably, TiO ₂ may have a rutile structure.

The white inorganic pigment may be subjected to various treatments as needed, for example, resin treatment, surface treatment with a dye derivative having an acidic group or a basic group introduced therein, surface grafting of a pigment using a polymer compound, and sulfuric acid mist. A method of preparing fine particles, a cleaning treatment for removing impurities by an organic solvent or water, a treatment for removing ionic impurities by ion exchange, and the like.

The colorant may further comprise any other white pigment in the desired range without departing from the object of the present invention.

The content of the white inorganic pigment is not particularly limited, if it is within the range in which the white inorganic pigment can exert a desired function, but the range can be, for example, 10 to 30 wt.% from the total weight of the ink composition, and preferably. It is from 15 to 25 wt.%. When the content of the white inorganic pigment is within the above range, the formed pattern can have excellent whiteness and shielding properties.

The binder resin is used as a pattern support and may include a copolymer formed of a monomer having a carboxyl group and a monomer having an unsaturated bond.

The monomer having a carboxyl group may include an unsaturated carboxylic acid having at least one carboxyl group in one molecule, for example, a mono-carboxylic acid such as acrylic acid, methacrylic acid, crotonic acid or the like; a dicarboxylic acid such as fumaric acid. , methylaconaconic acid (metaconic acid), itaconic acid, etc.; and its anhydride and the like.

The kind of the monomer having an unsaturated bond is not particularly limited as long as it is a monomer having an unsaturated double bond and can be copolymerized with a monomer having a carboxyl group. Specific examples thereof may include: an unsaturated carboxylic acid ester compound such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, or (meth)acrylic acid 2- a hydroxyethyl ester or the like; an unsubstituted or substituted alkyl ester compound, for example, an aminoethyl (meth) acrylate or the like; an unsaturated carboxylic acid ester compound having an alicyclic substituent, for example, (methyl) Cyclopentyl acrylate, cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, cycloheptyl (meth) acrylate, cyclooctyl (meth) acrylate, (methyl) Methylcyclopentenyl acrylate, methylcyclohexenyl (meth) acrylate, methylcycloheptenyl (meth) acrylate, methylcyclooctenyl (meth) acrylate, (A) Isoyl methacrylate, adamantyl (meth) acrylate, decyl (meth) acrylate, etc.; an unsaturated carboxylic acid ester compound having a thermosetting substituent, for example, 3-methyl- 3-(Methyl)propenyloxymethyloxypropylene oxide, 3-ethyl-3-(methyl)propenyloxymethyloxypropylene oxide, 3-methyl-3-(methyl) Acryloxy An oxypropylene oxide compound or the like; an unsaturated epoxypropyl carboxylate compound, for example, a glycidyl (meth)acrylate; and the like; an unsaturated carboxylate compound having an aromatic ring substituent, for example, (A) a benzyl acrylate, a phenoxy (meth) acrylate or the like; an aromatic vinyl compound such as styrene, vinyl toluene, α-methyl styrene, etc.; a vinyl carboxylate such as vinyl acetate And vinyl cyanoacrylate or the like; a vinyl cyanide compound, for example, (meth)acrylonitrile, α-chloroacrylonitrile or the like, which may be used singly or in combination of two or more.

Examples of the copolymer may include 3-ethyl-3-methylpropenyloxymethyloxypropylene oxide/benzyl methacrylate/methacrylic acid copolymer, 3-ethyl-3-methylpropene oxime Oxymethyloxypropylene oxide/benzyl methacrylate/methacrylic acid/styrene copolymer, 3-ethyl-3-methylpropenyloxymethyloxypropylene oxide/methyl methacrylate Ester/methacrylic acid copolymer, 3-ethyl-3-methylpropenyloxymethyloxypropylene oxide/methyl methacrylate/methacrylic acid/styrene copolymer, and the like.

The content of the binder resin is not particularly limited, if it is within the range in which the binder resin can exert a desired function, but the range can be, for example, from 1 to 10 wt.%, based on the total weight of the ink composition, and preferably. It is from 1 to 5 wt.%. When the content of the binder resin is within the above range, it can increase the pattern transfer rate while playing the role of supporting the pattern, thereby improving the yield and enhancing the process efficiency.

The polymerization initiator may be any thermal polymerization initiator known in the art, in particular, a thermal polymerization initiator comprising a phosphonium cation and particularly a ruthenium anion, compared to other types of thermal polymerization initiators. It exhibits excellent stability with time and high shrinkage characteristics, and therefore is preferable from the viewpoint of improvement in adhesion between the ink composition and the article to be printed. Such a polymerization initiator may be used singly or in combination of two or more.

Specific examples of the phosphonium cations contained in the polymerization initiator may include triphenylsulfonium, tris(4-methylphenyl)phosphonium, tris(4-isopropylphenyl)phosphonium, and tris(2,6-dimethyl Phenyl)anthracene, tris(4-cyanophenyl)anthracene, tris(4-chlorophenyl)anthracene, diphenyl(4-hydroxyphenyl)anthracene, methylphenyl(4-hydroxyphenyl)anthracene, Dibenzylphenyl hydrazine, dibenzyl (4-hydroxyphenyl) hydrazine, benzylmethyl (4-hydroxyphenyl) fluorene, benzylmethyl (4-acetoxyphenyl) fluorene, methyl (4-hydroxyphenyl)(2-methylphenyl)phosphonium, dimethyl(methoxy)phosphonium, dimethyl(ethoxy)phosphonium, dimethyl(propoxy)phosphonium, dimethyl (butoxy) hydrazine, dimethyl (octyloxy) hydrazine, dimethyl (octadecyloxy) hydrazine, dimethyl (isopropoxy) hydrazine, dimethyl (third-butoxy)鋶, dimethyl (cyclopentyloxy) hydrazine, dimethyl (cyclohexyloxy) hydrazine, dimethyl (fluoromethoxy) hydrazine, dimethyl (2-chloroethoxy) hydrazine, two Methyl (3-bromopropoxy) fluorene, dimethyl (4-cyanobutoxy) hydrazine, dimethyl (8-nitrooctyloxy) hydrazine, dimethyl (18-trifluoromethyl decene) Octaoxy)anthracene, dimethyl(2-hydroxyisopropoxy)anthracene, dimethyl(tris(trichloromethyl)methyl)anthracene and many more. Among these, triphenylphosphonium, tris(4-methylphenyl)phosphonium, benzylmethyl(4-hydroxyphenyl)phosphonium, benzylmethyl (4-acetoxyphenyl) are preferably used. Indole and methyl (4-hydroxyphenyl) (2-methylphenyl) anthracene, and more preferably tris(4-methylphenyl)anthracene, benzylmethyl(4-ethyloxyphenyl)anthracene And benzylmethyl (4-hydroxyphenyl) fluorene.

Further, the kind of the anion contained in the polymerization initiator is also not particularly limited, but may include, for example, a halogen ion such as F ^- , Cl ^- , Br ^- , I ^- etc.; OH ^- ; ClO ₄ ^- ; Acid ions, for example, FSO ₃ ^- , ClSO ₃ ^- , CH ₃ SO ₃ ^- , C ₆ H ₅ SO ₃ ^- , CF ₃ SO ₃ ^-, etc.; sulfate ions, for example, HSO ₄ ^- , SO ₄ ^{2- ,} etc.; Ions, for example, HCO ₃ ^- , CO ₃ ^{2- ,} etc.; phosphate ions, for example, H ₂ PO ₄ ^- , HPO ₄ ^2- , PO ₄ ^3-, etc.; fluorophosphate ions, for example, PF ₆ ^- , PF ₅ OH ^- And other; boric acid ions, for example, BF ₄ ^- , B(C ₆ F ₅ ) ₄ ^- , B(C ₆ H ₄ CF ₃ ) ₄ ^-, etc.; AlCl ₄ ^- ; BiF ₆ ^- ; fluoroantimonic acid ions, for example, SbF ₆ ^- , SbF ₅ OH ^-, etc.; fluoroarsenic acid ions, for example, ASF ₆ ^- , AsF ₅ OH ^- and the like.

The content of the polymerization initiator is not particularly limited, if it is within a range in which the polymerization initiator can exert a desired function, but the range can be, for example, from 0.1 to 3 wt.%, based on the total weight of the ink composition, and It is preferably from 0.5 to 1.5 wt.%. Within this range, favorable degree of polymerization and coating properties can be ensured, and in addition, adhesion to articles to be printed can be effectively enhanced.

The type of the solvent is not particularly limited, but may include, for example, glycol ethers, acetates, aromatic hydrocarbons, ketones, alcohols, cyclic esters, and the like, which may be used singly or in combination of two or more.

The type of the glycol ether solvent is not particularly limited, but may include, for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, Diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, etc., which may be used alone or in combination of two or more. .

The type of the acetate solvent is not particularly limited, but may include, for example, methylcellosolveacetate, ethyl sarbutazone acetate, ethyl acetate, n-butyl acetate, and second butyl acetate. Base ester, tert-butyl acetate, amyl acetate, methyl lactate, ethyl lactate, butyl lactate, 3-methoxybutyl acetate, 3-methyl-3-methoxy acetate -1-butyl ester, methoxypentyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, Diethylene glycol monoacetate, diethylene glycol diacetate, dibutyl ether diethylene glycol acetate, propylene glycol monoacetate, propylene glycol diacetate, monomethyl ether propylene glycol acetate, monoethyl ether acetate Propylene glycol ester or the like, which may be used singly or in combination of two or more.

The type of the aromatic hydrocarbon solvent is not particularly limited, but may include, for example, benzene, toluene, xylene, and the like, which may be used singly or in combination of two or more.

The type of the ketone solvent is not particularly limited, but may include, for example, methyl ethyl ketone, acetone, methyl amyl ketone, methyl isobutyl ketone, cyclohexanone, etc., which may be used alone or in combination of two types. Use it in multiples.

The type of the alcohol solvent is not particularly limited, but may include, for example, ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol, glycerin, etc., which may be used alone or in combination of two or more. .

The type of the cyclic ester solvent is not particularly limited, but may include, for example, γ-butyrolactone.

The content of the solvent is not particularly limited as long as it is within a range in which the solvent can exert a desired function, but may range, for example, from 40 to 70 wt.%, and preferably from 50 to the total weight of the ink composition. 60 wt.%. When the content of the solvent is within the above range, the ink composition can have an appropriate coloring ability while being easy to print.

Optionally, the roller printing ink composition of the present invention may further comprise a polymerizable compound.

The polymerizable compound is a component that enhances the strength of the pattern and may include, for example, a mono- to hexa-functional monomer. Specific examples thereof may include: a mono-functional monomer such as decyl phenyl carbitol acetate, 2-hydroxy-3-phenoxypropyl acrylate, 2-ethylhexyl carbitol acrylate, 2-hydroxy acrylate Ethyl ester, N-vinylpyrrolidone, etc.; di-functional monomers such as 1,6-hexanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, di(methyl) ) neopentyl glycol acrylate, triethylene glycol di(meth)acrylate, bis(acryloyloxyethyl)ether of bisphenol A, 3-methylpentanediol di(meth)acrylate An ester or the like; a tri-functional monomer such as trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, or the like; a tetra-functional monomer such as pentaerythritol tetra(meth)acrylate; A penta-functional monomer such as dipentaerythritol pentyl (meth)acrylate or the like; a hexa-functional monomer such as dipentaerythritol hexa(meth)acrylate or the like; which may be used singly or in combination of two or more.

The content of the polymerizable compound is not particularly limited as long as it is within a range in which the polymerizable compound can exert a desired function, but may range, for example, from 1 to 10 wt.%, based on the total weight of the ink composition, and It is preferably from 2 to 5 wt.%. When the content of the polymerizable compound is within the above range, favorable pattern strength can be obtained.

The roller printing ink composition of the present invention is more thirsty and includes any additives such as a surfactant, a filler, a curing agent, an adhesion enhancer, an antioxidant, a UV absorber, a dispersant, etc., which can be familiar thereto. The needs of the skilled artisan are used in combination with the above ingredients within the scope not impairing the object of the present invention.

The type of the surfactant is not particularly limited, but may include, for example, a ruthenium surfactant or a fluorosurfactant or a mixture thereof.

Specific examples of 矽 surfactants may include BYK-077, BYK-085, BYK-300, BYK-301, BYK-302, BYK-306, BYK-307, BYK-310, BYK-320, BYK-322, BYK -323, BYK-325, BYK-330, BYK-331, BYK-333, BYK-335, BYK-341v344, BYK-345v346, BYK-348, BYK-354, BYK-355, BYK-356, BYK-358 , BYK-361, BYK-370, BYK-371, BYK-375, BYK-380, BYK-390, etc., which are all manufactured by BYK-Chemi Co., Ltd., and can be used alone or in combination of two or more.

Specific examples of the fluorosurfactant may include F-114, F-177, F-410, F-411, F-450, F-493, F-494, F-443, F-444, F-445, F -446, F-470, F-471, F-472SF, F-474, F-475, F-477, F-478, F-479, F-480SF, F-482, F-483, F-484 , F-486, F-487, F-172D, MCF-350SF, TF-1025SF, TF-1117SF, TF-1026SF, TF-1128, TF-1127, TF-1129, TF-1126, TF-1130, TF -1116SF, TF-1131, TF1132, TF1027SF, TF-1441, TF-1442, TF-1535, all manufactured by DaiNippon Ink & Chemicals (DIC); S-381, S-383, S-393, SC- 101, Sc-105, KH-40, SA-100, S-611, S-386, S-221, S-231, S-243, S-420, S-651, etc., all from AGC Seiji Chemical It is produced and can be used singly or in combination of two or more.

The preferred embodiments are described below to more specifically understand the present invention. However, it is obvious to those skilled in the art that the specific embodiments are provided for the purpose of illustration, and are not intended to limit the scope of the appended claims. Modifications and variations are possible, and such modifications and changes are appropriately incorporated in the invention as defined in the appended claims.

Example

Example 1

After preparing a grinding mother liquor comprising 50% TiO ₂ and 3% polyester dispersant, 30% of the total weight of the ink composition of the grinding mother liquor, 2% of the methacrylic acid and methyl group having a weight average molecular weight (MW) of 15,000 Copolymer formed from benzyl acrylate, 1% dipentaerythritol hexaacrylate (manufactured by TOAGOSEI), 0.5% thermal polymerization initiator and 1% surfactant (TF-1535, manufactured by DIC) ), mixed at 23 ° C with stirring. Thereafter, 0.03% of (2,5-thienyldiylbis(5-tris-butyl-1,3-benzoxazole)) was added as a brightener and the remainder of n-butyl acetate was added to the mixture. To reach a total of 100 wt.%. A roller printing ink composition was prepared by stirring the mixture for 3 hours.

Example 2

The roller printing ink composition was prepared by the same procedure as described in Example 1, but the content of the brightening agent was 0.07%.

Example 3

The drum printing ink composition was prepared by the same procedure as described in Example 1, but the content of the brightening agent was 0.01%.

Comparative Example 1

The drum printing ink composition was prepared by the same procedure as described in Example 1, but did not include a brightening agent.

Comparative Example 2

The drum printing ink composition was prepared by the same procedure as described in Example 1, but including 2,2'-(1,2-ethylenediyldi-4,1-phenylene)bisbenzoxazole as A brightener is used instead of the brightener shown in Formula 1.

Comparative Example 3

The roller printing ink composition was prepared by the same procedure as described in Example 1, but including N-5-chlorobenzoxazol-2-ylethylamine as a brightening agent instead of the brightening shown in Formula 1. Agent.

Test example

1. Evaluation of printability

After printing a print on each of the roll printing ink compositions prepared in Examples 1 to 3 and Comparative Examples 1 to 3 on a glass substrate, the printed substrate was observed under a microscope, and the pattern was finally transferred according to the following criteria. The shape of the pattern in the substrate, the extent of formation, and the presence of holes.

Standard for evaluation ○: The ink applied to the drum is completely transferred. △: The ink applied to the drum was not completely transferred, and some of the ink remained. ×: A large amount of ink remains on the drum. 2. Assessment of whiteness

After printing a print on each of the roll printing ink compositions prepared in Examples 1 to 3 and Comparative Examples 1 to 3 on a glass substrate, the printed substrate was subjected to a whiteness analyzer (Model: X-Rite Premier 8400, USA) The whiteness was measured by X-RITE.

The results of the evaluation are shown in Table 1 below.

[Table 1]

Referring to Table 1 above, it was confirmed that the roll printing ink compositions of the present invention in Examples 1 to 3 have excellent printability because the ink applied to the drum is completely transferred, and extremely high white of about 97 to 98%. Degree, by which the desired white color is more clearly expressed without changing the color (for example, yellowing).

On the other hand, for Comparative Example 1 which did not have the compound represented by Formula 1, white was not clearly expressed because it was caused by a relatively low whiteness of about 88%, although it had excellent printability.

Alternatively, for Comparative Example 2 comprising 2-2'-(1,2-ethylenediyldi-4,1-phenylene)bisbenzoxazole as a brightening agent, and including N-5- In Comparative Example 3, chlorobenzoxazol-2-ylacetamide as a brightening agent, the ink applied to the drum was not completely transferred to the substrate, and some remained, thus showing poor printability and reduction Whiteness.

no.

no.

no.

Claims (8)

A roller printing ink composition comprising a brightening agent represented by Formula 1: [Formula 1] (wherein R ₁ and R _{2 are} each a benzoxazole group, and are independently substituted with a monohydroxy group, a halogen, a guanamine group, an amine group, an ester or an alkyl group having 1 to 6 carbon atoms). The composition of claim 1, wherein the compound represented by Formula 1 is included in an amount of from 0.01 to 1 wt.% of the total weight of the ink composition. The composition of claim 1, further comprising a white inorganic pigment, a binder resin, a polymerization initiator, and a solvent. The composition of claim 3, wherein the inorganic pigment is selected from the group consisting of CI pigments 4, 5, 6, 6: 1, 7, 18, 18: 1, 19, 20, 22, 25, 26 At least one of the groups consisting of 27, 28, and 32. The composition of claim 3, wherein the white inorganic pigment comprises TiO ₂ . The composition of claim 3, wherein the solvent is at least one selected from the group consisting of glycol ethers, acetates, aromatic hydrocarbons, ketones, alcohols, and cyclic esters. The composition of claim 3, further comprising a polymerizable compound. The composition of claim 7, wherein the polymerizable compound is selected from the group consisting of decyl phenyl carbitol, 2-hydroxy-3-phenoxypropyl acrylate, 2-ethylhexyl acrylate Alcohol ester, 2-hydroxyethyl acrylate, N-vinyl pyrrolidone, 1,6-hexanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, di(methyl) ) neopentyl glycol acrylate, triethylene glycol di(meth)acrylate, bis(acryloyloxyethyl)ether of bisphenol A, 3-methylpentanediol di(meth)acrylate , trimethylolpropane tris(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol pentyl (meth)acrylate, and dipentaerythritol hexa(meth)acrylate At least one of the groups consisting of esters.