KR101487789B1 - Inkjet ink - Google Patents

Abstract

(식 중에서, R¹, R², R³, 및 R⁴은 각각 독립적으로 수소 또는 탄소수가 1∼6의 알킬이며, R⁵, R⁶, R⁷ 및 R⁸은 각각 독립적으로 탄소수가 1∼6인 알킬렌이며, k는 0 또는 1이며, l, m, 및 n은 각각 독립적으로 1∼10의 정수다.)It is an object of the present invention to provide an inkjet ink capable of forming a microlens array exhibiting excellent jetting property, photo-curability, adhesion of a cured film to a substrate, high transmittance and high strength, (A), a monofunctional (meth) acrylate (B) and a photopolymerization initiator (C), wherein the transmittance at a wavelength of 400 nm of a cured film And more preferably 96% or more.

Wherein R ¹ , R ² , R ³ , and R ⁴ are each independently hydrogen or alkyl having 1 to 6 carbon atoms; and R ⁵ , R ⁶ , R ^7, and R ⁸ each independently represent a hydrogen atom, K is 0 or 1, and 1, m, and n are each independently an integer of 1 to 10.)

Description

Inkjet ink {INKJET INK}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an ink for inkjet, which can be suitably used for manufacturing an optical apparatus such as a liquid crystal monitor or a display panel. Specifically, the present invention relates to an inkjet ink suitable for a microlens array or the like used in a backlight device.

BACKGROUND ART Transmission-type or transflective-type LCDs which display using a backlight have been used for liquid crystal display devices such as liquid crystal displays. Such a transmissive or semi-transmissive LCD has a structure in which an opening is provided in a reflection plate inside the LCD and a backlight is transmitted through the opening. As described above, a light guide plate having a microlens array disposed between the liquid crystal display panel and the backlight is employed in order to eliminate unevenness of luminance when transmitting backlight. (For example, Patent Document 1).

Conventionally, the injection molding method which has been used as a method of manufacturing such a light guide plate requires a plurality of molds to be manufactured, and it takes much time and cost. In addition, in the case of manufacturing using the above-described manufacturing method, the accuracy of resin lens patterning is poor and luminance unevenness easily occurs.

In order to solve such a problem, recently, a method of forming a microlens array by directly applying a photosensitive material onto a substrate using an inkjet method has been developed (for example, Patent Document 2, Patent Document 3, Patent Document 4) . Since the method of manufacturing a resin lens employing the ink jet method can easily control the patterning with electronic data of a computer or the like without manufacturing a conventional mold, the manufacturing cost can be reduced even for small-volume production and multi-product production It is expectation from point.

In addition, although various ink compositions have been proposed as photosensitive materials for use in the ink-jet method (for example, Patent Document 5, Patent Document 6, Patent Document 7 and Patent Document 8) It does not have the capability of satisfying both of light curability, adhesion to substrate, high transmittance and high strength.

On the other hand, various inks have been proposed as photosensitive materials excellent in photo-curability and adhesion to a substrate (for example, Patent Document 9, Patent Document 10, Patent Document 11, Patent Document 12, Patent Document 13, Patent Document 15, Patent Document 16).

However, Patent Literature 9, Patent Literature 10 and Patent Literature 11 have high transmittance of the cured film estimated in Examples, but do not have sufficient strength.

In addition, in Patent Documents 12, 13, 14, 15, and 16, since a coloring agent such as a dye and a pigment is added to any composition, the transmittance is low and if a composition without the coloring agent of the Example is added It can be inferred that the transmittance is low and thus it does not have sufficient performance.

[Patent Document 1] JP-A-2003-107505

[Patent Document 2] JP-A-05-303017

[Patent Document 3] JP-A-2000-180605

[Patent Document 4] JP-A-2004-240294

[Patent Document 5] JP-A-2004-117955

[Patent Document 6] JP-A-2005-340467

[Patent Document 7] Japanese Laid-Open Patent Publication No. 2006-208734

[Patent Document 8] Japanese Laid-Open Patent Publication No. 2007-024970

[Patent Document 9] JP-A-02-006562

[Patent Document 10] JP-A-07-053892

[Patent Document 11] Japanese Laid-Open Patent Publication No. 07-070472

[Patent Document 12] JP-A-2003-192943

[Patent Document 13] JP-A-2005-162882

[Patent Document 14] International Patent Application Publication 2006-129530 pamphlet

[Patent Document 15] JP-A-2007-231231

[Patent Document 16] Japanese Unexamined Patent Application Publication No. 2007-231233

An object of the present invention is to provide an ink for ink jet which is capable of forming a microlens array exhibiting high photo-curability, adhesion to a substrate, and high transmittance and high strength.

The present inventors have found that a photocurable inkjet ink containing a (meth) acrylic acid ester, a monofunctional (meth) acrylate and a photopolymerization initiator represented by the general formula (1) has excellent photocurability, adhesion to a substrate, It is possible to form a lens array, and based on this view, the present invention has been completed. Further, the present invention provides a microlens array obtained from such an inkjet ink, and uses of the microlens array.

That is, the present invention includes the following items.

[1] A photocurable inkjet ink comprising a (meth) acrylic acid ester (A) represented by the general formula (1), a monofunctional (meth) acrylate (B) and a photopolymerization initiator (C) Thickness: 5 占 퐉) having a transmittance at a wavelength of 400 nm of 96% or more.

Wherein R ¹ , R ² , R ³ , and R ⁴ are each independently hydrogen or alkyl having 1 to 6 carbon atoms, and R ⁵ , R ⁶ , R ^7, and R ⁸ are each independently an alkyl group having 1 to 6 carbon atoms And k is 0 or 1, and 1, m, and n are each independently an integer of 1 to 10.)

(Meth) acrylic acid ester (A) represented by the general formula (1), 20 to 60% by weight of the monofunctional (meth) acrylate (B), the photopolymerization initiator (C) Is contained in an amount of 1 to 20% by weight.

[3] The inkjet ink according to [1] or [2], wherein in the general formula (1), R ⁵ , R ⁶ and R ⁷ each independently represent an alkylene group having 2 or 3 carbon atoms.

[4] The ink-jet ink according to any one of [1] to [3], wherein in Formula 1, R ¹ is hydrogen and k is 0.

[5] The ink-jet ink according to any one of [1] to [4], wherein 1, m and n are 1 in the general formula (1).

[6] The inkjet ink according to any one of [1] to [5], wherein the monofunctional (meth) acrylate (B) is a monofunctional (meth) acrylate having an alkyl of 1 to 6 carbon atoms.

[7] The positive photosensitive resin composition according to any one of [1] to [5], wherein the monofunctional (meth) acrylate (B) is at least one compound selected from the group consisting of cyclohexyl (meth) acrylate, n-hexyl (meth) acrylate, The inkjet ink according to any one of [1] to [6], wherein the ink is at least one selected from the group consisting of propyl (meth) acrylate, ethyl (meth) acrylate and methyl (meth) acrylate.

[8] The inkjet ink according to any one of [1] to [7], wherein the photopolymerization initiator (C) is an? -Hydroxyalkylphenone-based or acylphosphine oxide-based photopolymerization initiator.

[9] The inkjet ink according to any one of [1] to [8], which further contains a polymerization inhibitor.

(10) A process for producing an ethylene-vinyl acetate copolymer, which comprises reacting ethylene oxide-modified glycerin triacrylate (ethylene oxide denatured: 3 mol) as the (meth) acrylic acid ester (A) The inkjet ink according to [9], which contains 2,4,6-trimethylbenzoyldiphenylphosphine oxide as a photopolymerization initiator (C) and phenothiazine as a polymerization inhibitor.

[11] A cured film obtainable by curing the inkjet ink according to any one of [1] to [10].

[12] A microlens array obtained from the cured film according to [11].

[13] An optical device having a microlens array according to [12].

The inkjet ink of the present invention is excellent in jetting property and photo curability of the ink coating film, and the cured film obtained from the ink has excellent adhesion to the substrate. Further, the microlens array obtained from the cured film has high transmittance and high strength.

[One. Inkjet ink of the present invention]

The inkjet ink of the present invention (hereinafter also simply referred to as " ink of the present invention ") comprises 30 to 70% by weight of a (meth) acrylic acid ester (A) (B) in an amount of 20 to 60% by weight based on the total weight of the ink, and a photopolymerization initiator (C) in an amount of 1 to 20% by weight based on the total weight of the ink, wherein the photocurable ink- (Having a thickness of 5 mu m) obtained by forming a coating film having a square shape of 3 cm in width and 3 cm in length by applying inkjet to the central portion on the glass substrate of the glass substrate and photo- Curable ink for ink jet printing showing 96% or more.

Wherein R ¹ , R ² , R ³ , and R ⁴ are each independently hydrogen or alkyl having 1 to 6 carbon atoms, and R ⁵ , R ⁶ , R ^7, and R ⁸ are each independently an alkyl group having 1 to 6 carbon atoms And k is 0 or 1, and 1, m, and n are each independently an integer of 1 to 10.)

The ink of the present invention may be colorless or colored. From the viewpoint of transmittance, colorlessness is preferable, but a colored compound may be contained within a range not hindering the effect of the invention. Further, for example, when checking the state of the cured film, a coloring agent may be included to facilitate identification with the substrate.

In the present specification, '(meth) acrylate' is used to indicate both or one of acrylate and methacrylate.

In addition, the ink of the present invention may contain a phenol resin, a melamine resin, an epoxy resin, an epoxy curing agent, a surfactant, a compound having another radically polymerizable double bond, a solvent, a polymerization inhibitor and the like, if necessary. Here, the 'compound having another radically polymerizable double bond' is a compound other than the (meth) acrylic acid ester (A) and the monofunctional (meth) acrylate (B) represented by the general formula (1).

Hereinafter, the viscosity of each component and the ink of the present invention will be described.

<1.1. Viscosity of inkjet ink of the present invention>

The viscosity of the inkjet ink of the present invention measured at 25 캜 by an E-type viscometer is preferably 200 mPa s or less, more preferably 1 to 200 mPa 상기. When the viscosity is from 1 mPa · s to 200 mPa · s, the jetting property by the inkjet apparatus is improved. The viscosity of the ink of the present invention at 25 占 폚 is more preferably 2 to 150 mPa 占 퐏, and particularly preferably 3 to 100 mPa 占 퐏.

The viscosity of the ink of the present invention at a temperature (preferably 10 to 120 캜) at the time of discharging to an inkjet coating apparatus is preferably 1 to 30 mPa · s, more preferably 2 to 25 mPa · s , And particularly preferably from 3 to 20 mPa · s.

When an ink having a viscosity of more than 30 mPa · s at 25 ° C. is used, more stable discharge can be achieved by heating the ink jet head to lower the viscosity of the ink at the time of discharging. When jetting the inkjet head by heating, the viscosity of the inkjet ink at a heating temperature (preferably 40 to 120 ° C) is preferably 1 to 30 mPa · s, more preferably 2 to 25 mPa · s And particularly preferably from 3 to 20 mPa · s.

When the inkjet head is heated, it is preferable to use an ink that does not contain a solvent.

 1.2. (Meth) acrylic acid ester (A) represented by the general formula (1)

By using the (meth) acrylic acid ester (A) represented by the general formula (1), the ink of the present invention is excellent in photo-curability. The cured film formed of the ink of the present invention has excellent adhesion to a substrate, and exhibits high transmittance and high strength. Further, the microlens array obtained from the cured film has excellent adhesion to the substrate, and exhibits high transmittance and high strength.

Wherein R ¹ , R ² , R ³ and R ⁴ are each independently hydrogen or alkyl having 1 to 6 carbon atoms, and R ⁵ , R ⁶ , R ⁷ and R ⁸ are each independently an alkyl group having 1 to 6 carbon atoms And k is 0 or 1, and 1, m and n are each independently an integer of 1 to 10.

Among them, in particular, when R ¹ is hydrogen, CH ₃ or CH ₂ CH ₃ and k is 0, it is found that the ink of the present invention has good photo-curability and that the resulting cured film exhibits high transmittance and high strength have. Further, it can be seen that, when R ¹ is hydrogen, the transmittance of the cured film becomes higher and more preferable. R ² , R ³ and R ⁴ are preferably hydrogen or CH ₃ from the viewpoint of photo-curability, and more preferably hydrogen. R ⁵ , R ⁶ and R ⁷ are preferably ethylene, propylene or butylene, more preferably ethylene, from the viewpoint of the transmittance and the balance of the strength of the cured film obtained from the ink.

Specific examples of the (meth) acrylic acid ester represented by the formula (1) include trimethylol propane PO modified (3 mol) triacrylate, trimethylol propane PO modified (6 mol) triacrylate, trimethylol propane PO modified Trimethylolpropane EO-modified (3 mol) triacrylate, trimethylolpropane EO-modified (6 mol) triacrylate, trimethylolpropane EO-modified (9 mol) triacrylate, PO-modified (3 mol) glycerin triacrylate (6 mol) glycerin triacrylate, PO modified (9 mol) glycerin triacrylate, EO modified (3 mol) glycerin triacrylate, EO modified (6 mol) glycerin triacrylate, EO modified Mol) glycerin triacrylate. On the other hand, 'EO denaturation' indicates ethylene oxide denaturation, 'PO denaturation' indicates propylene oxide denaturation, and moles in parentheses indicates the number of ethylene oxide or propylene oxide added per molecule.

In particular, when trimethylolpropane PO-modified (3 mol) triacrylate or EO-modified (3 mol) glycerin triacrylate is used, the ink of the present invention is excellent not only in the photocurability, but also in transmittance, , A cured film having a good strength balance can be obtained. Further, when EO-modified (3 mol) glycerol triacrylate is used, the cured film has the highest transmittance and is good.

The (meth) acrylic acid ester (A) represented by the general formula (1) may be one kind of compound selected from the above-mentioned compounds and the like, or may be a mixture of two or more kinds thereof.

The (meth) acrylic acid ester (A) represented by the above-described formula (1) can be produced by a known method and is also commercially available. For example, trimethylolpropane PO-modified (3 mol) triacrylate (M-310: trade name, produced by Toa Gosei Co., Ltd.), trimethylolpropane PO- Trimethylolpropane EO-modified (3 mol) triacrylate (M-350: trade name, produced by Toa Gosei Co., Ltd.), trimethylolpropane EO-modified (6 mol) triacrylate (M-360: trade name, manufactured by Toa Gosei Co., Ltd.), EO-modified (3 mol) glycerin triacrylate (A-GLY-3E: Shin-Nakamura Chemical Industry Co., Ltd.) and EO-modified (9 mol) glycerol triacrylate (A-GLY-9E: trade name; manufactured by Shin-Nakamura Chemical Industry Co., Ltd.).

When the content of the (meth) acrylic acid ester (A) represented by the general formula (1) in the ink of the present invention is 30 to 70 wt%, not only the photocurability is excellent but also the transmittance of the cured film formed by the ink of the present invention, More preferably from 45 to 60% by weight, and particularly preferably from 50 to 60% by weight, based on the total weight of the composition.

1.3. Monofunctional (meth) acrylate (B) &gt;

The monofunctional (meth) acrylate (B) does not affect the jetting property, photocurability of the ink of the present invention and the adhesion, transmittance and strength of the cured film obtained from the ink, &Lt; / RTI &gt;

Further, by using the monofunctional (meth) acrylate (B), the adhesion, transmittance and strength to the substrate required for the microlens array obtained from the cured film can be maintained.

The monofunctional (meth) acrylate (B) is not particularly limited as long as it satisfies the above characteristics, but monofunctional (meth) acrylate having an alkyl moiety is preferable, and more preferably, (Meth) acrylate having an alkyl moiety having 4 carbon atoms, more preferably a monofunctional (meth) acrylate having an alkyl moiety having 2 to 4 carbon atoms, particularly preferably a (Meth) acrylate.

Specific examples of monofunctional (meth) acrylate (B) include cyclohexyl (meth) acrylate, n-hexyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl Acrylate, dicyclopentanyl (meth) acrylate, isobonyl (meth) acrylate, 4-butylcyclohexyl (meth) acrylate, 2- (Meth) acrylate, 3-hydroxy-1-methacryloxyadamantane, 3-hydroxy-1 (Meth) acrylate, ethylcyclopentyl (meth) acrylate, 3, 5-dihydroxy-1-methacryloxyadamantane, methacryloyloxynorbornene methacrylate, tetrahydro Furfuryl (meth) acrylate, caprolactone-modified tetrahydro (Meth) acrylate, methacryloyloxyethyl hexahydrophthalimide, cyclic trimethylolpropane formal acrylate,? -Butyllactone (meth) acrylate, mebanolactone (meth) acrylate (Meth) acrylate, cyclic imido acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, methylphenoxyethyl (Meth) acrylate, 4-t-butylcyclohexyl (meth) acrylate, cyclohexyldimethanol mono (meth) acrylate, 2-hydroxy-3-phenoxypropyl acrylate (Meth) acrylate, isopropyl (meth) acrylate, isoamyl (meth) acrylate, isobutyl (meth) acrylate, n-butyl -part Octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, (Meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, dodecyl (meth) acrylate, Acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 1,4-cyclohexanedimethanol mono (Meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethoxyethoxyethyl Butoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate (Meth) acrylate, methoxydipropylene glycol (meth) acrylate, dipropylene glycol (meth) acrylate, ethyl diglycol (meth) acrylate, glycerol mono (Meth) acrylates such as glycidyl (meth) acrylate, 3,4-epoxycyclohexyl (meth) acrylate, methyl glycidyl Ethyl-3- (meth) acryloxyethyl oxetane, 3-methyl-3- (meth) acryloxyethyl oxetane, 2-trifluoromethyl-3- (meth) acryloxymethyloxetane, 4-trifluoromethyl-2-methyl- (Meth) acryloxymethyloxetane, (3-ethyl-3-oxetanyl) methyl (meth) acrylate, -carboxypolycaprolactone mono (Meth) acryloyloxyethyl phosphate, mono [2- (meth) acryloyloxyethyl] mono [2- (meth) acryloyloxyethyl] .

Of these, cyclohexyl (meth) acrylate, n-hexyl (meth) acrylate, n-butyl (meth) acrylate, Acrylate, or methyl (meth) acrylate, the balance between jetting property and photocurability, transmittance of the cured film obtained from the ink, adhesiveness to the substrate, and high strength are improved. Of these, n-butyl (meth) acrylate, t-butyl (meth) acrylate, isopropyl (meth) acrylate, ethyl (Meth) acrylate, and t-butyl (meth) acrylate.

The monofunctional (meth) acrylate (B) may be a single compound or a mixture of two or more compounds.

If the content of the monofunctional (meth) acrylate (B) is 20 to 60% by weight of the total amount of the ink of the present invention, the ink can be adjusted to a viscosity suitable for the use of the ink, More preferably 25 to 50% by weight, still more preferably 30 to 45% by weight, still more preferably 30 to 40% by weight.

1.4. Photopolymerization initiator (C)

The inkjet ink of the present invention comprises a photopolymerization initiator (C). The photopolymerization initiator (C) is not particularly limited as long as it is a compound capable of generating radicals upon irradiation with ultraviolet rays or visible light rays, but an? The pin oxide compound is more preferable in terms of the photo-curability and the transmittance of the cured film obtained from the ink.

In addition, the transmittance of the microlens array obtainable from the cured film is particularly preferably an acylphosphine oxide-based compound.

Specific examples of the photopolymerization initiator (C) include benzophenone, Michler's ketone, 4,4'-bis (diethylamino) benzophenone, xanthone, thioxanthone, -Diethylthioxanthone, 2-ethyl anthraquinone, acetophenone, 2-hydroxy-2-methylpropiophenone, 2-hydroxy-2-methyl-4'-isopropylpropiophenone, 1- Cyclohexyl phenyl ketone, isopropyl benzoin ether, isobutyl benzoin ether, 2,2-diethoxy acetophenone, 2,2-dimethoxy-2-phenylacetophenone, camphorquinone, benzanthrone, -1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one, 2-benzyl-2-dimethylamino- Diethyl (t-butylperoxycarbonyl) benzophenone, 3,4,4'-tri (t-butylperoxycarbonyl) benzoate, Phenone, 3,3 ', 4,4'-tetra (t-butylperoxy Di (methoxycarbonyl) -4,4'-di (methoxycarbonyl) benzophenone, 3,3 ', 4,4'-tetra (t-hexylperoxycarbonyl) benzophenone, di (t-butylperoxycarbonyl) benzophenone, 3,4'-di (methoxycarbonyl) -4,3'-di Di (t-butylperoxycarbonyl) benzophenone, 2- (4'-methoxystyryl) -4,6-bis (trichloromethyl) -s-triazine , 2- (3 ', 4'-dimethoxystyryl) -4,6-bis (trichloromethyl) -s-triazine, 2- Bis (trichloromethyl) -s-triazine, bis (trichloromethyl) -s-triazine, 2- (2'-methoxystyryl) -4,6- Di (trichloromethyl) -s-triazine, 4- [pN, N-di (ethoxycarbonylmethyl)] - 2,6- (Trichloromethyl) -5- (2'-chlorophenyl) -s-triazine, 1,3-bis (trichloromethyl) -5- (4'-methoxyphenyl) - s-triazine, 2- (p-dimethylaminos 2-mercaptobenzothiazole, 3,3'-carbonylbis (7-diethylaminocoumarin), 2- (o-dimethylaminostyryl) benzothiazole, Chlorophenyl) -4,4 ', 5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis (2-chlorophenyl) -4,4' -Tetrakis (4-ethoxycarbonylphenyl) -1,2'-biimidazole, 2,2'-bis (2,4-dichlorophenyl) -4,4 ', 5,5'-tetraphenyl Bis (2,4-dibromophenyl) -4,4 ', 5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis , 2'-bis (2,4,6-trichlorophenyl) -4,4 ', 5,5'-tetraphenyl-1,2'-biimidazole, 3- propionyl) carbazole, 3,6-bis (2-methyl-2-morpholino-propionyl) -9-n- dodecyl carbazole, 1-hydroxycyclohexyl phenyl ketone, bis (η ⁵ -2, (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium, bis (2,4,6-trimethylbenzoyl) phenylphosphine Oxide and 2,4,6-trimethyl There may be mentioned the one trillion days diphenyl phosphine oxide.

Among these, especially preferred are 2-hydroxy-2-methylpropiophenone, 2-hydroxy-2-methyl-4'-isopropylpropiophenone, 1-hydroxycyclohexyl phenyl ketone, Trimethylbenzoyl) phenylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide are more preferable.

The photopolymerization initiator (C) may be a single compound or a mixture of two or more compounds.

When the content of the photopolymerization initiator (C) is 1 to 20% by weight of the total amount of the ink of the present invention, the ink of the present invention is preferable because it can excellently photocurable against ultraviolet rays and maintains a high transmittance, %, More preferably from 3 to 10% by weight.

<1.5. Other ingredients>

The inkjet ink of the present invention may contain other components such as a phenol resin, a melamine resin, an epoxy resin, an epoxy curing agent, a surfactant, a colorant and a polymerization inhibitor to improve various characteristics.

(1.5.1. Phenolic resin)

The inkjet ink of the present invention may contain a phenol resin in order to improve the strength of the cured film obtained from the ink.

Examples of the phenol resin include novolac resins obtained by condensation reaction of an aromatic compound having a phenolic hydroxyl group with aldehydes, homopolymers (including hydrogenated products) of vinylphenol, and vinylphenol compounds such as vinylphenol Copolymers (including hydrogenated products) and the like are preferably used.

Specific examples of the aromatic compound having a phenolic hydroxyl group include phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, m-ethylphenol, p-ethylphenol, butylphenol, o-chisilanol, 2,3-chisilanol, 2,4-chisilanol, 2,5-chisilanol, 3,4-chisilanol, 3,5- -Trimethylphenol, 3,4,5-trimethylphenol, p-phenylphenol, resorcinol, hydroquinone, hydroquinone monomethyl ether, pyrogallol, bisphenol A, bisphenol F, diphenol containing terpene skeleton, gallic acid ), Gallic ester,? -Naphthol and? -Naphthol.

Specific examples of aldehydes include formaldehyde, paraformaldehyde, furfural, benzaldehyde, nitrobenzaldehyde and acetaldehyde.

Specific examples of the compound copolymerizable with vinylphenol include (meth) acrylic acid or a derivative thereof, styrene or a derivative thereof, maleic anhydride, vinyl acetate and acrylonitrile.

Specific examples of the phenol resin include Resin PSM-6200 (manufactured by Guga Chemical Co., Ltd.), Shonoru BRG-555 (manufactured by Showa High Polymer Co., Ltd.), Marukarin M S-2P, Marukarin CST70 and Marukarinha PHM-C (manufactured by Maruzen Petrochemical Co., Ltd.).

The phenol resin usable in the ink of the present invention may be one kind of compound or a mixture of two or more kinds of compounds.

When the content of the phenol resin is 0.5 to 20 wt% of the total amount of the ink of the present invention, the strength of the cured film obtained from the ink is improved, and 0.5 to 10 wt% is more preferable in view of balance with other properties , And more preferably 0.5 to 7 wt%.

(1.5.2 melamine resin)

The inkjet ink of the present invention may contain a melamine resin in order to improve the strength of the cured film obtained from the ink.

The melamine resin is not particularly limited as long as it is a resin produced by polycondensation of melamine and formaldehyde. Specific examples thereof include methylolmelamine, etherified methylolmelamine, benzoguanamine, methylolbenzoguanamine, etherified methylol Benzoguanamine, and condensates thereof. Of these, methylolmelamine is preferable.

Specific examples of commercially available melamine resins include NIKARAKU MW-30, MW-30HM, MW-390, MW-100LM and MX-750LM (manufactured by Sanwa Chemical Co., Ltd.).

The melamine resin usable for the ink of the present invention may be one kind of compound or a mixture of two or more kinds of compounds.

When the content of the melamine resin is 0.5 to 20 wt% of the total amount of the ink of the present invention, the strength of the cured film obtained from the ink is improved, and 0.5 to 10 wt% is more preferable in view of balance with other properties , And more preferably 0.5 to 7 wt%.

(1.5.3 epoxy resin)

The inkjet ink of the present invention may contain an epoxy resin in order to improve the strength of the cured film obtained from the ink.

The epoxy resin is not particularly limited as long as it is a compound having at least one structure derived from an epoxide represented by the formula (2-1) or (2-2) (hereinafter also referred to as an "epoxy structure") in a molecule.

Specific examples of the epoxy resin include, for example, novolak type (phenol novolak type and cresol novolak type), bisphenol A type, bisphenol F type, hydrogenated bisphenol A type, hydrogenated bisphenol F type, bisphenol S type, Methane type, tetraphenol ethane type, bixylenol type, biphenol type, alicyclic and heterocyclic epoxy compounds, and epoxy compounds having a dicyclopentadienes skeleton or naphthalene skeleton. Include novolac, bisphenol A and bisphenol F type epoxy compounds, and more preferably bisphenol A and bisphenol F type epoxy compounds.

The epoxy resin can be produced by a known method and is also commercially available. Examples of commercially available products include Epikote 828, Epikote 834, Epikote 1001, Epikote 1004 (manufactured by Japan Epoxy Resin Co., Ltd.), Efcuron 840, Efcuron 850, Efcuron 1050, Epitoto YD-013, Epitioto YD-127 and Epitioto YD-128 (manufactured by Tohto Kasei Co., Ltd.), DER317, DER331, DER661, Epoxy resin ESA-011, Sumi-epoxy (trade name) manufactured by Dow Chemical Co., Ltd.), Araludido 6071, Araludido 6084, Araludido GY250 and Ararudaido GY260 AER330, AER661, AER664 (manufactured by Sumitomo Chemical Industry Co., Ltd.), Sumi-epoxy ELA-115, (Manufactured by Asahi Kasei e-materials Co., Ltd.)), and other bisphenol A type epoxy compounds; Epicuron N-770, Epicuron N-865 (DIC (manufactured by Dow Chemical Co., Ltd.), DER431, DER438 (Manufactured by Tohto Kasei Co., Ltd.), ARARUDIDE ECN1235, ARARUDAIDE ECN1273, ARARUDIDE ECN1299 (manufactured by Tiba Japan Co., Ltd. (Japan)), Ephotoot YDCN- Epoxy ESCN-195X, Sumitomo Chemical Co., Ltd.), XPY307, EPPN-201, EOCN-1025, EOCN-1020, EOCN-104S and RE- 306 (manufactured by Nippon Kayaku Co., Epoxy resin such as epoxy ESCN-220 (manufactured by Sumitomo Chemical Industry Co., Ltd.), AERECN-235, AERECN-299 (manufactured by Asahi Kasei E-materials Co., Ltd.) Epoxy compounds; YDF-175, YDF-2001, YDF-170, YDF-170, YDF-170 and YDF-170 available from Nippon Shokubai Co., YDF-2004, and Ararudai XPY306 (manufactured by Chiba Japan Co., Ltd.); Hydrogenated bisphenol A type epoxy compounds such as Epototo ST-2004, Eptoto ST-2007 and Eptoto ST-3000 (manufactured by Tohto Kasei Co., Ltd.); Alicyclic epoxy compounds such as Sekisui Kaido 2021P (manufactured by Daicel Chemical Industries, Ltd.), ARARUDIDE CY175 and ARALUDIDE CY179 (manufactured by Ciba Japan Co., Ltd.); Trihydroxyphenylmethane type epoxy compounds such as YL-933 (manufactured by Japan Epoxy Resin Co., Ltd.), EPPN-501 and EPPN-502 (manufactured by Dow Chemical Japan); (Such as YL-6056, YX-4000, and YL-6121 (manufactured by Japan Epoxy Resin Co., Ltd.), or mixtures thereof; Bisphenol S type epoxy compounds such as EBPS-200 (manufactured by Nippon Kayaku Co., Ltd.), EPX-30 (manufactured by ADEKA Corporation) and EXA-1514 (manufactured by DIC Corporation); Bisphenol A novolak type epoxy compounds such as JER157S (manufactured by Japan Epoxy Resin Co., Ltd.); Tetraphenyl ethane type epoxy compounds such as YL-931 (manufactured by Japan Epoxy Resin Co., Ltd.) and ARALUDIDE 163 (manufactured by Ciba Japan Co., Ltd.); EXA-4750, EXA-4700 (DIC) (manufactured by Nissan Chemical Industries, Ltd.) and the like, such as ARARUDAYO PT810 (manufactured by Chiba Japan Co., Ltd.) and TEPIC )), And other naphthalene group-containing epoxy compounds; Epoxy compounds having a dicyclopentadienes skeleton such as HP-7200, HP-7200H and HP-7200HH (manufactured by DIC Corporation); And xylene bisoxetane.

The epoxy resin usable for the ink of the present invention may be a single compound or a mixture of two or more kinds of compounds.

The content of the epoxy resin is preferably from 0.5 to 20% by weight, more preferably from 0.5 to 10% by weight, still more preferably from 0.5 to 7% by weight, since the strength of the cured film obtained from the ink of the present invention is improved.

(1.5.4 Epoxy curing agent)

When the inkjet ink of the present invention contains an epoxy resin, an epoxy curing agent may be further added to improve the strength of the cured film. As the epoxy curing agent, an acid anhydride curing agent, an amine curing agent and a catalyst type curing agent are preferable.

Specific examples of the acid anhydride-based curing agent include maleic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrotrimellitic anhydride, phthalic anhydride, trimellitic anhydride, Methyltetrahydrophthalic anhydride, 3,6-endomethylentetrahydrophthalic anhydride, hexachloroendomethylenetetrahydrophthalic anhydride, methyl-3,6-endomethylenetetrahydrophthalic anhydride and styrene-maleic anhydride copolymer. have.

Specific examples of the amine-based curing agent include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dicyanediamide, polyamide amine (polyamide resin), ketimine compound, isophoronediamine, m- (Aminomethyl) cyclohexane, N-aminoethylpiperazine, 4,4'-diaminodiphenylmethane, 4,4'-diamino-3,3 '- diethyldiphenylmethane and diaminodiphenylsulfone.

Specific examples of the catalyst-type curing agent include a tertiary amine compound and an imidazole compound.

The epoxy curing agent usable in the ink of the present invention may be one kind of compound or a mixture of two or more kinds of compounds.

When the content of the epoxy curing agent is 0.5 to 20% by weight of the total amount of the ink of the present invention, the cured film obtained from the ink of the present invention has an improved strength, and is preferably 0.5 to 10% by weight, more preferably 0.5 to 7% Is more preferable.

(1.5.5. Surfactant)

The inkjet ink of the present invention may contain a surfactant, for example, to improve the wettability to the base substrate and the uniformity of the surface of the cured film obtained from the ink. As the surfactant, a silicone surfactant, an acrylic surfactant, and a fluorine surfactant can be used.

Specific examples of the surfactant include silicone surfactants such as Byk-300, Byk-306, Byk-335, Byk-310, Byk-341, Byk-344 and Byk-370 DFX-18, Futazanto 250 or Futazento 251 (manufactured by NEOS) and Megaface (trade name) manufactured by Nippon Kayaku Co., Ltd.), and acrylic surfactants such as Byk-354, Byk-358 and Byk- Fluorine surfactants such as F-475, F-477, F-553 and F-554 (manufactured by DIC Corporation).

Surfactants usable in the ink of the present invention may be one kind of compound or a mixture of two or more kinds of compounds.

If the content of the surfactant is 0.001 to 1% by weight of the total amount of the ink of the present invention, the uniformity of the film surface of the cured film obtained from the ink is improved, and from the viewpoint of balance with other properties, 0.001 to 0.1% , And still more preferably 0.001 to 0.05 wt%.

(1.5.6. Other compounds having a radically polymerizable double bond)

The inkjet ink of the present invention can be applied to inkjet ink of the present invention in addition to the (meth) acrylate ester (A) and the monofunctional (meth) acrylate (B) represented by the general formula (1) It is also possible to add a compound having another radical polymerizable double bond within a range that does not impair the adhesion, transmittance and strength of the cured film to the substrate.

Specific examples of the compound having another radically polymerizable double bond include bis (hydroxymethyl) tricyclodecane di (meth) acrylate, tricyclodecane dimethylol di (meth) acrylate, bisphenol F EO- Acrylate, pentaerythritol tri (meth) acrylate, trimethylol (meth) acrylate, bisphenol A EO modified di (meth) acrylate, polypropylene glycol di Acrylate such as propane tri (meth) acrylate, ethylene glycol di (meth) acrylate, tedlaethylene glycol di (meth) acrylate, polyethylene glycol di (meth) , 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, or trimethylolpropane trioxyethyl Acrylate, (meth) acrylic acid dimer, crotonic acid, alpha -chloroacrylic acid, cinnamic acid, maleic acid, fumaric acid, N- vinylformamide, and polymethylmethacrylate macromonomers, N-cyclohexylmaleimide, N- (Meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N-dimethylacrylamide, Isopropyl (meth) acrylamide, and N-hydroxyethyl (meth) acrylamide.

The compound having another radically polymerizable double bond usable in the ink of the present invention may be a single compound or a mixture of two or more kinds of compounds.

When the content of the compound having another radically polymerizable double bond is 0.1 to 20% by weight of the total amount of the ink of the present invention, it is preferable because the photo-curability and balance of the adhesion, transmittance and strength of the cured film to the substrate are good, , More preferably from 0.1 to 5% by weight.

(1.5.7. Solvent)

A solvent may be added to the inkjet ink of the present invention within a range that does not impair the jetting property and photocurability of the ink of the present invention and the adhesion, transmittance and strength of the cured film obtained from the ink.

As the solvent usable in the present invention, a solvent having a boiling point higher than the temperature at which the ink jet head is heated, more specifically, a solvent having a boiling point of 100 to 300 캜, is preferable from the viewpoint of jetting properties. When the ink jet head is heated to a high temperature (for example, 70 to 120 占 폚), a solvent having a boiling point of 200 to 300 占 폚 is preferable.

However, when the inkjet head is heated, it is preferable that the ink of the present invention is basically not contained.

Specific examples of the solvent having a boiling point of 100 to 300 캜 include butyl acetate, butyl propionate, ethyl lactate, methyl oxyacetate, ethyl oxyacetate, butyl oxyacetate, methyl methoxyacetate, ethyl methoxyacetate, butyl methoxyacetate, ethoxy Ethoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, Ethoxypropionate, methyl 2-ethoxypropionate, ethyl 2-ethoxypropionate, methyl 2-ethoxypropionate, ethyl 2-ethoxypropionate, ethyl 2-ethoxypropionate, Methyl 2-methylpropionate, ethyl 2-oxy-2-methylpropionate, methyl 2-methoxy-2-methylpropionate, ethyl 2-ethoxy-2-methylpropionate, methyl pyruvate, Ethyl propionate, propyl propionate, propyl propionate, propyl propionate, propyl propionate, ethyl propionate, propyl propionate, propyl propionate, propyl propionate, Propylene glycol monomethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monopropyl ether acetate, dipropylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, Glycol monoethyl ether acetate, dipropylene glycol monobutyl ether acetate, ethylene glycol monobutyl ether acetate, cyclohexanone, cyclopentanone, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol Monoethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, toluene, xylene , Anisole,? -Butyrolactone, N, N-dimethylacetamide, N-methyl-2-phyloridone and dimethylimidazolidinone.

The solvent usable in the ink of the present invention may be a single compound or a mixture of two or more compounds.

If the content of the solvent is 0.1 to 20 wt% of the total amount of the ink of the present invention, it is preferable because the nozzle is hard to dry during jetting. It is more preferably 0.1 to 10% by weight and more preferably 0.1 to 5% by weight in consideration of the balance with other characteristics.

(1.5.8 polymerization inhibitor)

The inkjet ink of the present invention may contain a polymerization inhibitor to improve storage stability. Specific examples of the polymerization inhibitor include 4-methoxyphenol, hydroquinone, and phenothiazine. Among these, phenothiazine is preferred because the change (increase) in ink viscosity is small even in long-term storage.

The polymerization inhibitor usable in the ink of the present invention may be a single compound or a mixture of two or more kinds of compounds.

When the content of the polymerization inhibitor is 0.01 to 1% by weight of the total amount of the ink of the present invention, the change in viscosity is small even during long-term storage, and 0.01 to 0.5% by weight is more preferable in view of balance with other properties , And more preferably 0.01 to 0.1 wt%.

<1.6. Method of preparing photocurable inkjet ink of the present invention>

The inkjet ink of the present invention can be prepared by mixing the respective ingredients as raw materials by a known method.

In particular, the ink of the present invention is preferably prepared by mixing the above components (A) to (C) and, if necessary, other components, and filtering the obtained solution to degas. The thus prepared ink of the present invention is excellent in jetting property. For the filtration, for example, a membrane filter made of a fluororesin can be employed.

<1.7. Preservation of inkjet ink of the present invention>

When the inkjet ink of the present invention is stored at -20 to 25 占 폚, the viscosity change (increase) during storage is small and storage stability is good.

[2. Application of inkjet ink by inkjet method]

The inkjet ink of the present invention can be applied using a known inkjet application method. Examples of the ink-jet application method include a method in which ink is applied (applied) from an ink-jet head by applying mechanical energy to ink, a method of applying ink by applying thermal energy to ink, Jet (registered trademark) method).

By using the ink-jet coating method, the ink-jet ink can be applied to a predetermined pattern shape.

Examples of the ink-jet head include those having a contact surface of a heat generating portion containing a metal and / or a metal oxide. Specific examples of the metal and / or metal oxide include metals such as Ta, Zr, Ti, Ni and Al, and oxides of these metals.

As a preferred application apparatus for applying by using the ink of the present invention, for example, energy corresponding to a coating signal is given to ink inside an inkjet head having an ink containing section in which ink is contained, and ink droplets are generated (Painting) corresponding to the application signal while performing the application (painting).

The ink jet applying apparatus is not limited to the one in which the ink jet head and the ink containing section are separated from each other, and the ink jet applying apparatus may be integrally formed so that the ink jet head and the ink containing section can not be separated. In addition, the ink containing portion may be provided in the fixing portion of the ink jet recording head, and may be of a type that supplies ink to the ink jet head through a tube, for example, It is possible.

As described above, the heating temperature of the ink-jet head is preferably 40 to 120 占 폚, and the viscosity of the ink of the present invention at the heating temperature is preferably 1 to 30 mPa 占 퐏.

[3. Formation of a cured film]

The cured film of the present invention is obtained by applying the above inkjet ink of the present invention onto a substrate surface by an inkjet method and then curing the coating film by irradiating the ink with light such as ultraviolet rays or visible rays.

When an ultraviolet ray or a visible ray is irradiated, the exposure dose to be irradiated depends on the composition of the ink, but is measured with an integrated UV meter UIT-201 equipped with a photodetector UVD-365PD manufactured by Ushio Inc., / cm ² level are preferred, and 200~4,000mJ / cm ² is about more preferably, 300~3,000mJ / cm ² degree it is even more preferred. The wavelength of ultraviolet light or visible light to be irradiated is preferably 200 to 500 nm, more preferably 300 to 450 nm.

On the other hand, the UV exposure amount described below is a value measured with an integrated light amount meter UIT-201 equipped with a photodetector UVD-365PD manufactured by Ushio Inc.

The exposure machine is not particularly limited as long as it is a device which is equipped with a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a halogen lamp, etc. and irradiates ultraviolet rays or visible light in the range of 250 to 500 nm.

If necessary, the cured film cured by light irradiation may be further heated / fired, and the cured film may be more firmly cured by heating / firing at 80 to 250 캜 for 10 to 60 minutes.

The 'substrate' to which the ink of the present invention can be applied is not particularly limited as long as it can be an object to which the ink of the present invention is applied, and its shape is not limited to a flat plate shape, have.

The material of the substrate is not particularly limited, and examples thereof include polyester resins such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT); polyolefin resins such as polyethylene and polypropylene; polyolefin resins such as polyethylene- A plastic film such as a fluorine resin, an acrylic resin, a polyamide, a polycarbonate and a polyimide, a laminated film of a cellophane, an acetate, a metal foil, a polyimide and a metal foil, , Parchment paper, and paper and glass treated with eyes by polyethylene, clay binders, polyvinyl alcohol, starch or carboxymethylcellulose (CMC).

The substances constituting these substrates may contain additives such as an antioxidant, a deterioration inhibitor, a filler, an ultraviolet absorber, an antistatic agent and / or an electromagnetic wave inhibitor within a range not adversely affecting the effect of the present invention. The surface of the substrate may be subjected to a bonding treatment such as a waterproof treatment, a corona treatment, a plasma treatment, or a blast treatment, or a protective film for a color filter or a hard coat film may be provided on the surface have.

Although the thickness of the substrate is not particularly limited, it is usually about 10 m to 2 mm, and is appropriately adjusted according to the purpose of use, but is preferably 15 m to 1.5 mm, more preferably 20 m to 1 mm.

The use of the substrate is not particularly limited, but the cured film obtained from the inkjet ink of the present invention is excellent in adhesion to a substrate, exhibits high transmittance and high strength, and is particularly preferably used in the production of a microlens array used in a backlight device Do.

The diameter of the dots of the cured film of the present invention functioning as a microlens array or the like used in such a backlight device is not particularly limited, but is preferably 10 to 100 m, more preferably 20 to 60 m, and particularly preferably 30 to 50 m . The height of the dots is not particularly limited, but is usually 0.5 to 10 mu m, more preferably 1 to 8 mu m, and particularly preferably 2 to 6 mu m.

As described above, by implementing the backlight manufactured using the cured film of the present invention, for example, a liquid crystal display for a liquid crystal display element can be manufactured.

[Example]

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto.

<Preparation of Inkjet Ink and Preparation of Cured Film Pattern-Forming Substrate>

First, ink-jet ink relating to Examples 1 to 6 and Comparative Examples 1 to 4 and a cured film pattern-formed substrate obtained therefrom will be described.

[Example 1]

GL-3E (Shin-Nakamura Chemical Industries, Ltd.), which is an EO-modified (3 mol) glycerin triacrylate, as a (meth) acrylic acid ester (A) Butyl methacrylate (manufactured by Tokyo Kasei Kogyo Co., Ltd.) as the (meth) acrylate (B) and 2,4,6-trimethylbenzoyldiphenylphosphine oxide (C) as the photopolymerization initiator (DAROCUR TPO, trade name; product of Chiba Japan) and phenothiazine (Tokyo Kasei Kogyo Co., Ltd.) as a polymerization inhibitor were mixed / dissolved in the following composition ratios, , To prepare an inkjet ink 1.

(A) A-GLY-3E 350.00 g

(B) 200.00 g of n-butyl methacrylate

(C) DAROCUR TPO 55.00 g

(Other) phenothiazine 0.28 g

The viscosity of the inkjet ink 1 at 25 캜 was measured using an E-type viscometer (TV-22, manufactured by TOKI INDUSTRIAL CO., LTD., The same applies hereinafter), and as a result, it was 12 mPa · s.

Two sheets of glass substrates (thickness: 0.7 mm) having a length of 4 cm and a length of 4 cm were prepared and the inkjet ink 1 was injected into an inkjet cartridge and mounted on an inkjet apparatus (DMP-2831 manufactured by FUJIFILM Dimatix Inc.) , A dot pattern having a design value of 40 mu m in diameter was formed on one of the glass substrates with a discharge voltage (piezo voltage) of 16 V, a head temperature of 30 DEG C, a driving frequency of 5 kHz, A square pattern having a width of 3 cm and a width of 3 cm.

UV irradiation apparatus (J-CURE1500, a home-made product) was applied to two substrates on which a dot pattern and a square pattern were drawn using the inkjet ink 1 to irradiate ultraviolet rays at an amount of UV exposure of 2000 mJ / cm ² , A substrate 1a on which dots of 40 占 퐉 and a height of 5.0 占 퐉 were formed, and a substrate 1b on which square patterns of width 3 cm and width 5.0 占 퐉 were formed.

[Example 2]

The following composition ratios were excluded using M-350 (manufactured by Toa Gosei Co., Ltd.), which is trimethylolpropane EO-modified (3 mol) triacrylate, as the (meth) acrylic acid ester (A) The ink 2 for inkjet recording was prepared under the same conditions as in Example 1.

(A) M-350 350.00 g

(B) 200.00 g of n-butyl methacrylate

(C) DAROCUR TPO 55.00 g

(Other) phenothiazine 0.28 g

Using an E-type viscometer, the viscosity of the ink 2 for inkjet at 25 占 폚 was measured and found to be 10 mPa 占 퐏.

A substrate 2a on which a dot pattern with a dot diameter of 40 占 퐉 and a height of 4.9 占 퐉 was formed and a substrate 2b on which a square pattern with a width of 3 cm and a thickness of 4.8 占 퐉 were formed by the same method as in Example 1 using the inkjet ink 2 was obtained.

[Example 3]

Using ethyl methacrylate (manufactured by Tokyo Kasei Kogyo Co., Ltd.) as the monofunctional (meth) acrylate (B), the ink composition was prepared in the same manner as in Example 1, 3 was prepared.

(A) A-GLY-3E 350.00 g

(B) 200.00 g of ethyl methacrylate

(C) DAROCUR TPO 55.00 g

(Other) phenothiazine 0.28 g

Using an E-type viscometer, the viscosity of the inkjet ink 3 at 25 degrees was measured and found to be 9 mPa · s.

Using the inkjet ink 3, a substrate 3a having a dot pattern of a dot diameter of 39 mu m and a height of 4.8 mu m formed thereon and a substrate 3b having a square pattern having a width of 3 cm and a thickness of 4.8 mu m formed thereon were obtained in the same manner as in Example 1.

[Example 4]

Using n-hexyl methacrylate (manufactured by Tokyo Kasei Kogyo Co., Ltd.) as the monofunctional (meth) acrylate (B), an inkjet Was prepared.

(A) A-GLY-3E 350.00 g

(B) 200.00 g of n-hexyl methacrylate

(C) DAROCUR TPO 55.00 g

(Other) phenothiazine 0.28 g

Using an E-type viscometer, the viscosity of the inkjet ink 4 at 25 캜 was measured and found to be 14 mPa s.

A substrate 4a having a dot pattern of a dot diameter of 41 mu m and a height of 5.1 mu m and a substrate 4b having a square pattern having a width of 3 cm and a thickness of 5.1 mu m formed thereon were obtained in the same manner as in Example 1 using the inkjet ink 4.

[Example 5]

An ink-jet ink 5 was prepared under the same conditions as in Example 1 except that A-GLY-3E, which is a (meth) acrylic acid ester (A) represented by the general formula (1)

(A) A-GLY-3E 600.00 g

(B) 200.00 g of n-butyl methacrylate

(C) DAROCUR TPO 80.00 g

(Other) phenothiazine 0.40 g

Using an E-type viscometer, the viscosity of the ink-jet ink 5 at 25 占 폚 was measured and found to be 87 mPa 占 퐏.

A substrate 5a having a dot pattern having a dot diameter of 40 mu m and a height of 5.3 mu m formed thereon and a substrate 5a having a width of 3 cm and a thickness of 5.3 mu m were prepared in the same manner as in Example 1 except that the ink- Thereby obtaining a substrate 5b having a square pattern formed thereon.

[Example 6]

A-GLY-3E, which is a (meth) acrylic acid ester (A) represented by the formula (1), is reduced and instead trimethylolpropane triacrylate M-309 (manufactured by Toa Gosei Co., Ltd.) Was added to adjust the composition ratios to the following ratios. The ink jet ink 6 was prepared under the same conditions as in Example 1.

(A) A-GLY-3E 200.00 g

(Other) M-309 150.00g

(B) 200.00 g of n-butyl methacrylate

(C) DAROCUR TPO 55.00 g

(Other) phenothiazine 0.28 g

Using an E-type viscometer, the viscosity of the ink-jet ink 6 at 25 占 폚 was measured and found to be 10 mPa 占 퐏.

A substrate 6a having a dot pattern having a dot diameter of 40 mu m and a height of 4.9 mu m formed thereon and a substrate 6b having a square pattern having a width of 3 cm and a thickness of 5.0 mu m formed thereon were obtained in the same manner as in Example 1 using the inkjet ink 6. [

[Comparative Example 1]

Except that A-GLY-3E, which is a (meth) acrylic acid ester (A) represented by the formula (1), was further reduced and M-309, trimethylolpropane triacrylate, Ink jet ink 7 was prepared under the same conditions as in Example 1.

(A) A-GLY-3E 100.00 g

(Other) M-309 250.00g

(B) 200.00 g of n-butyl methacrylate

(C) DAROCUR TPO 55.00 g

(Other) phenothiazine 0.28 g

Using an E-type viscometer, the viscosity of the ink for inkjet 7 at 25 占 폚 was measured and found to be 10 mPa 占 퐏.

Using the ink-jet ink 7, a substrate 7a having a dot pattern having a dot diameter of 40 mu m and a height of 4.9 mu m formed thereon and a substrate 7b having a square pattern having a width of 3 cm and a thickness of 5.0 mu m formed thereon were obtained in the same manner as in Example 1.

[Comparative Example 2]

Except that M-309, which is trimethylolpropane triacrylate, was added in place of the (meth) acrylic acid ester (A) represented by the formula (1) to give the following composition ratios: Ink 8 was prepared.

(Other) M-309 350.00g

(B) 200.00 g of n-butyl methacrylate

(C) DAROCUR TPO 55.00 g

(Other) phenothiazine 0.28 g

Using an E-type viscometer, the viscosity of the inkjet ink 8 at 25 占 폚 was measured and found to be 9 mPa 占 퐏.

A substrate 8a having a dot pattern of 39 占 퐉 in dots and a height of 4.8 占 퐉 and a substrate 8b having a square pattern with a width of 3 cm and a thickness of 4.9 占 퐉 were obtained in the same manner as in Example 1 using the inkjet ink 8.

[Comparative Example 3]

Except that SR-9003 (manufactured by Satoruma Japan K.K.), which is a propylene oxide-modified neopentyldiacrylate, was used instead of the (meth) acrylic ester (A) represented by the formula (1) Ink-jet ink 9 was prepared in the same manner as in Example 1.

(Others) SR-9003 600.00g

(B) 200.00 g of n-butyl methacrylate

(C) DAROCUR TPO 60.00 g

(Other) phenothiazine 0.30 g

Using an E-type viscometer, the viscosity of the ink-jet ink 9 at 25 占 폚 was measured and found to be 6 mPa 占 퐏.

Using the ink-jet ink 9, a pattern substrate was tried to be produced in the same manner as in Example 1, but a dot pattern and a cured film could not be obtained due to poor curability.

[Comparative Example 4]

A-GLY-3E, a monofunctional (meth) acrylate (B) which is a (meth) acrylic acid ester (A) represented by the formula (1) and SR-9003 which is a propylene oxide-modified neopentyldiacrylate Ink-jet ink 10 was prepared in the same manner as in Example 1 except that the composition ratio was as follows.

(A) A-GLY-3E 200.00 g

(Other) SR-9003 200.00g

(B) 100.00 g of n-butyl methacrylate

(C) DAROCUR TPO 50.00 g

(Other) phenothiazine 0.25 g

Using an E-type viscometer, the viscosity of the ink-jet ink 10 at 25 占 폚 was measured and found to be 13 mPa 占 퐏.

Using the inkjet ink 10, a substrate 10a having a dot pattern having a dot diameter of 40 mu m and a height of 5.1 mu m formed thereon and a substrate 10b having a square pattern having a width of 3 cm and a thickness of 5.2 mu m formed thereon were obtained in the same manner as in Example 1 .

&Lt; Evaluation of inkjet ink and patterned cured film &

Then, the jetting property, the photo-curability, the adhesion of the cured film to the substrate, the transmittance and the strength of the cured film were evaluated. Each test method is as follows, and the evaluation results are shown in Tables 1 and 2.

(Jetting test of ink)

The jetting property of the ink was evaluated by observing the dot patterns on the substrates 1a to 10a and 1b to 10b obtained in each of the Examples and Comparative Examples, and the disturbance of the square pattern of 3 cm in width and 3 cm and the scratching of printing. The evaluation criteria are as follows.

?: No pattern disturbance or print scratches at all.

?: Distortion of pattern and scratching of print are many.

X: ink can not be ejected (i.e., a pattern can not be formed).

(Photocurability test)

The surface state of the cured film was observed under a microscope while touching the surface of the square pattern substrates 1b to 10b of 3 cm in width and 3 cm obtained in each of the Examples and Comparative Examples. The evaluation criteria are as follows.

○: No touch marks are left on the surface of the cured film.

DELTA: There are a few touch marks on the surface of the cured film.

X: The touch mark remains completely on the surface of the cured film.

(Measurement of Transmittance of Cured Film)

Using the square pattern substrates 1b to 10b of 3 cm in length and length obtained in each of the Examples and Comparative Examples using a transmittance measuring device V-670 (manufactured by Nihon Denshi Co., Ltd.) Was measured. As a reference, a glass substrate (thickness: 0.7 mm) having a length of 4 cm and a length of 4 cm without a cured film was used.

(Adhesion Test of Cured Film to Substrate)

An adhesive tape ("Polyester Tape No. 56: Adhesive force of 5.5 N / cm" manufactured by Sumitomo 3M Co., Ltd.) was attached to the dot pattern substrates 1a to 10a obtained in the respective Examples and Comparative Examples, The state of the dot pattern remaining on the substrate was observed to evaluate the adhesion of the cured film to the substrate. The evaluation criteria are as follows.

?: The dot pattern was not changed at all.

B: Some dots were peeled off.

X: All the dots were peeled off.

(Strength measurement)

The pencil hardness was measured in accordance with JIS 5400 by using the square pattern substrates 1b to 10b of 3 cm in length and 3 cm obtained in each of the Examples and Comparative Examples to examine the strength.

The above evaluation results are shown in Tables 1 and 2 below.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Jetting ability ○ ○ ○ ○ ○ ○ Photocurable ○ ○ ○ ○ ○ ○ Transmittance (%) 98.5 97.2 98.1 97.8 96.4 96.1 Adhesiveness ○ ○ ○ ○ ○ ○ burglar
(Pencil hardness) 3H 3H 3H 3H 3H 3H

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Jetting ability ○ ○ ○ ○ Photocurable ○ ○ × ○ Transmittance (%) 95.0 93.9 - 97.5 Adhesiveness △ △ - ○ burglar
(Pencil hardness) 3H 3H - H

As can be clearly seen from the results shown in Table 1, the substrate 1a to 10a and 1b to 10b obtained using the inkjet ink according to the present invention showed no pattern disturbance or scratching of printing, and had good jetting properties.

Subsequently, evaluation of the photo-curability of the ink on the substrates 1b to 10b showed that no marks were left on the surface of the cured film on all substrates other than the substrate 9b among the evaluated substrates.

On the other hand, in the substrate 9b, since the surface of the cured film remained completely cured and the curability was poor, the subsequent test was stopped.

As a result of measuring the transmittance of light having a wavelength of 400 nm by using the substrates 1b to 8b and 10b, the transmittance was high in the order of substrate 1b> substrate 3b> substrate 4b> substrate 10b> substrate 2b> substrate 6b. On the other hand, the transmittance of the substrate 7b and the substrate 8b was as low as 96% or less.

Furthermore, when the adhesiveness of the cured film was evaluated by employing the substrates 1a to 8a and 10a, the dot patterns of the substrates 1a to 6a and 10a were not changed completely and the adhesiveness was good. On the other hand, in the substrates 7a to 8a, some of the dots were peeled off, and the adhesion was degraded.

Finally, the substrates 1b to 8b and 10b were employed to measure the strength. As a result, the cured films of the substrates 1b to 8b exhibited pencil hardness of 3H. On the other hand, the cured film of the substrate 10b exhibited a pencil hardness of H and a low strength.

As described above, according to the present invention, an inkjet ink capable of forming a cured film exhibiting high jetting properties, photo-curability, and adhesion of a cured film to a substrate can be obtained and high transmittance and high strength can be obtained, It can be suitably used for manufacturing an optical device such as a panel.

Claims (13)

(A), a monofunctional (meth) acrylate (B) and a photopolymerization initiator (C) represented by the general formula (1) Wherein the transmittance at a light wavelength of 400 nm is 96% or more.

Wherein R ¹ , R ² , R ³ , and R ⁴ are each independently hydrogen or alkyl having 1 to 6 carbon atoms, and R ⁵ , R ⁶ , R ^7, and R ⁸ are each independently selected from the group consisting of And k is 0 or 1, and 1, m and n are each independently an integer of 1 to 10.) The ink composition according to claim 1, which comprises 30 to 70% by weight of a (meth) acrylic acid ester (A) represented by the general formula (1), 20 to 60% by weight of a monofunctional (meth) acrylate (B) C) in an amount of 1 to 20% by weight. The inkjet ink according to claim 1 or 2, wherein R ⁵ , R ⁶ and R ⁷ in Formula 1 are each independently alkylene having 2 or 3 carbon atoms. The inkjet ink according to claim 1 or 2, wherein R ^{1 in} the formula ( ¹⁾ is hydrogen and k is 0. The inkjet ink according to Claim 1 or 2, wherein l, m and n in Formula 1 are 1. The inkjet ink according to claim 1 or 2, wherein the monofunctional (meth) acrylate (B) is a monofunctional (meth) acrylate having an alkyl having 1 to 6 carbon atoms. The positive photosensitive resin composition according to claim 1 or 2, wherein the monofunctional (meth) acrylate (B) is cyclohexyl (meth) acrylate, n-hexyl (meth) acrylate, Is at least one member selected from the group consisting of butyl (meth) acrylate, isopropyl (meth) acrylate, ethyl (meth) acrylate and methyl (meth) acrylate. The inkjet ink according to claim 1 or 2, wherein the photopolymerization initiator (C) is an? -Hydroxyalkylphenone-based or acylphosphine oxide-based photopolymerization initiator. The inkjet ink according to claim 1 or 2, further comprising a polymerization inhibitor. 10. The method of claim 9,
(Meth) acrylate as the monofunctional (meth) acrylate (B), ethylene oxide modified glycerin triacrylate (ethylene oxide denatured: 3 mol) as the (meth) acrylic acid ester (A) 2, 4, 6-trimethylbenzoyldiphenylphosphine oxide as a photopolymerization initiator (C), and phenothiazine as a polymerization inhibitor. A cured film obtained by curing the ink jet ink according to claim 9. A microlens array obtained from the cured film according to claim 11. An optical apparatus having the microlens array according to claim 12.