TW201412889A - Inkjet ink, microlens, optical component and device - Google Patents

Abstract

An inkjet ink, a microlens, an optical component and a device are provided. An inkjet ink that can form a microlens having a good shape even without conducting a surface treatment on a substrate is provided. The inkjet ink includes a (meth)acrylamide (A) represented by the following formula (1), a cyclic (meth)acrylamide (B) represented by the following formula (2), an urethane methacrylate (C) and a photopolymerization initiator (D).

Description

Inkjet ink, microlens, optical parts and devices

The present invention relates to an inkjet ink that is suitably used in the manufacture of a light guide plate as a member of a backlight unit incorporated in an optical device such as an image display device. More specifically, the present invention relates to an inkjet ink which can form a microlens having a good shape even without surface treatment of a substrate.

Conventionally, the microlens formed on the light guide plate of the image display device is formed by injection molding using a mold. However, when a small number of microlenses are produced by using this method, it is necessary to re-mold the mold every time the product is designed, and the number of manufacturing steps becomes a problem.

In recent years, as a manufacturing method with a high degree of freedom of design, a method of forming a microlens directly on the surface of a substrate by using an inkjet method has been carried out (see, for example, Patent Document 1 and Patent Document 2).

The method of manufacturing a microlens using such an inkjet method can be easily controlled by a personal computer or the like, so that the number of manufacturing steps can be changed without even a small number of microlenses. Can suppress Manufacturing costs and the like are expected from this.

However, when the microlens is directly formed on the substrate constituting the light guide plate using the conventional inkjet ink, the free energy of the interface between the substrate surface and the ink is small, so there is a problem that a microlens having a large diameter is formed, or the ink is on the substrate. The wettability of the surface appears to be uneven, so there is a problem that a microlens having a poor shape is formed.

In order to solve this problem, a surface treatment for forming a liquid-repellent cured film or the like on the surface of the substrate is performed before the microlens is formed for the purpose of controlling the diameter and height of the microlens. However, this method has a problem in the formation of the microlens: the number of manufacturing steps is increased, and the takt time is increased.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2000-180605

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2004-240294

As one means for solving the above problem, it is conceivable to develop an inkjet ink which can form a microlens having a good shape without performing surface treatment of a substrate, instead of the conventional ink.

In this case, since the surface free energy of the substrate which is not subjected to the surface treatment is low, a microlens having a good shape is formed, and therefore the surface free energy of the ink is required to be high, and in order to increase the surface free energy of the ink, it is considered that the surface tension is high. The compound is used as a raw material.

There are known a plurality of compositions containing such a compound having a high surface tension (refer to Japanese Laid-Open Patent Publication No. 2002-212244 or Japanese Patent Laid-Open No. 2011-132322).

However, the composition described in these documents does not necessarily mean that the interface free energy with the substrate is high, and there is also a composition having a low interface free energy with the substrate due to the compound used.

Further, a photopolymerizable compound having a high surface tension tends to have poor moisture resistance. When a microlens is formed only by a photopolymerizable compound having a high surface tension, there is a problem that optical characteristics are deteriorated after the constant temperature and humidity test.

An object of the present invention is to provide an inkjet ink which can form a microlens having a good shape without performing surface treatment of a substrate. In particular, it is an object of providing an inkjet ink which can form a microlens having a good shape and excellent optical characteristics even after a constant temperature and humidity test on an acrylic substrate without surface treatment.

The present inventors have found that the use of urethane methacrylate, a photopolymerization initiator, and a methylacrylamide having a specific structure and a ring (methyl) When a light-curable inkjet ink made of acrylamide is used, for example, when a light guide plate is manufactured, it can be formed into a shape without performing surface treatment on a substrate, and it is difficult to deteriorate optical characteristics even after a constant temperature and humidity test. The microlens, based on this finding, completed the present invention.

That is, the present invention includes the following items.

[1] An inkjet ink comprising (meth)acrylamide (A) represented by the following formula (1) and a cyclic (methyl) represented by the following formula (2) Inkjet inks of acrylamide (B), (meth)acrylic acid urethane (C) and photopolymerization initiator (D): (In the formula (1), R ¹ is hydrogen or a methyl group, R ² is an organic group having 1 to 10 carbon atoms or an organic group having a hydroxyl group having 1 to 10 carbon atoms, and R ³ is hydrogen and the carbon number is 1 ~10 organic group or organic group containing a hydroxyl group of 1 to 10)

(In the formula (2), R ⁴ is hydrogen or a methyl group, and R ⁵ is a divalent organic group).

[2] The inkjet ink according to [1], characterized in that (meth)acrylamide (A) is contained in an amount of from 5% by weight to 40% by weight based on the total amount of the inkjet ink The amount of 40% by weight to 85% by weight includes the cyclic (meth)acrylamide (B), and the (meth)acrylic acid urethane (C) is contained in an amount of 5% by weight to 20% by weight to 0.5% by weight. The amount of the weight % to 20% by weight includes the photopolymerization initiator (D).

[3] The inkjet ink according to [1] or [2], wherein R ² in the formula (1) is an alkylene group having a carbon number of 1 to 5, and R ³ is hydrogen or a carbon number is 1 to 5 alkyl groups.

[4] The inkjet ink according to any one of [1] to [3] wherein R ⁵ in the formula (2) is a group represented by the following formula (3): -R ⁶ - XR ⁷ - (3)

(In the formula (3), R ⁶ and R ⁷ are each independently an alkylene group having 1 to 3 carbon atoms, and X is oxygen or sulfur).

[5] The inkjet ink according to any one of [1] to [4] wherein the (meth)acrylic acid urethane (C) has a viscosity at 25 ° C of 5,000 mPa. s above.

[6] The inkjet ink according to any one of [1] to [5] wherein the photopolymerization initiator (D) is selected from the group consisting of an acyl phosphine oxide system. At least one of a group consisting of a oxyphenylacetate initiator, a benzoylformic acid initiator, and a hydroxyphenyl ketone initiator Compound.

[7] The inkjet ink according to any one of [1] to [6] wherein it is used for microlens formation.

[8] A microlens obtained by hardening the inkjet ink according to any one of [1] to [7].

[9] An optical component comprising the microlens according to [8].

[10] A device comprising the optical zero according to [9] Pieces.

According to the inkjet ink of the present invention, it is possible to form a microlens having a good shape and having difficulty in deterioration of optical characteristics even after the constant temperature and humidity test, without performing surface treatment on the substrate.

Inkjet ink

The inkjet ink of the present invention (hereinafter also referred to as "ink of the present invention") includes a (meth)acrylamide (A) represented by the following formula (1) and a ring represented by the following formula (2). (Meth) acrylamide (B), (meth)acrylic acid urethane (C), and photopolymerization initiator (D).

The ink of the present invention contains the above-described compound, and a microlens having a good shape can be formed without performing surface treatment for forming a microlens having a good shape on the surface of the substrate.

Further, the ink of the present invention is excellent in photocurability, and the ink can be used to form a microlens which is difficult to deteriorate optical characteristics even after the constant temperature and humidity test.

The ink of the present invention may contain an organic solvent, a polymerization inhibitor, a thermosetting compound, and a thermal polymerization initiation as needed within the scope of the gist of the present invention. Agent, antioxidant, colorant, and other than (meth) acrylamide (A), cyclic (meth) acrylamide (B), and (meth) acrylate (C) Other components such as a compound (E) having a radical polymerizable double bond.

The ink of the present invention may be colorless or colored. It is also possible to contain a trace amount of a colored compound within a range that does not impair the effects of the invention. For example, when the state of the microlens is inspected, a coloring agent may be contained in order to facilitate recognition of the substrate.

In the present specification, "(meth)acrylamide" is used to mean either or both of acrylamide and methacrylamide, and "(meth)acrylate" is used to mean acrylate and methacrylic acid. Either or both of the esters.

1-1. (Meth) acrylamide (A)

The (meth) acrylamide (A) is a compound having a structure of the following formula (1).

The (meth)acrylamide (A) having the structure of the following formula (1) has an extremely high surface tension, and a microlens having a good shape can be formed by using the ink containing the (meth)acrylamide (A).

(In the formula (1), R ¹ is hydrogen or a methyl group, R ² is an organic group having 1 to 10 carbon atoms or an organic group having a hydroxyl group having 1 to 10 carbon atoms, and R ³ is hydrogen and the carbon number is 1 ~10 organic groups or organic groups containing a hydroxyl group of 1 to 10)

The organic group having 1 to 10 carbon atoms in the R ² is preferably a hydrocarbon group having 1 to 10 carbon atoms, more preferably a hydrocarbon group having 1 to 6 carbon atoms.

Examples of the hydrocarbon group having 1 to 10 carbon atoms include a methylene group, a dimethylene group, a trimethylene group, an isopropylidene group, a tetramethylene group, a pentamethylene group, a hexamethylene group and the like, and a methylene group is preferred. Dimethylene.

At least one -CH ₂ - in the hydrocarbyl group in the present specification may also be -CH=CH-, -C≡C-, -O-, -CO-, -COO-, -OCO-, -NR-(R It is substituted by hydrogen, methyl, ethyl, ethoxy or methoxy), -CONH-, or -NHCO-.

The organic group having 1 to 10 carbon atoms in the R ² in the R ² is preferably a hydrocarbon group having a hydroxyl group of 1 to 10, more preferably a hydrocarbon group having 1 to 6 carbon atoms.

The organic group having 1 to 10 carbon atoms in the R ³ and the organic group having 1 to 10 carbon atoms in the hydroxyl group may be an organic group having 1 to 10 carbon atoms as the R ² and containing a hydroxyl group. A group having a hydrogen atom of 1 to 10 and a hydrogen atom or a hydroxyl group is added to one bonding bond of the exemplified group.

In the above, when R ² is an alkylene group having 1 to 5 carbon atoms, and R ³ is hydrogen or an alkyl group having 1 to 5 carbon atoms, it is a compound which is hard to deteriorate optical properties even after a constant temperature and humidity test. , thus better.

Examples of the (meth) acrylamide (A) include N-(hydroxymethyl)(meth)acrylamide, N-(2-hydroxyethyl)(meth)acrylamide, and N-( 3-hydroxypropyl)(meth)acrylamide, N-(2-hydroxypropyl)(meth)acrylamide, N-(1-methyl-1-hydroxyethyl)(methyl)propene Indoleamine, N-(1-methyl-2-hydroxyethyl)(meth)acrylamide, N-(1,1-dimethyl-1-hydroxyethyl)(meth)acrylamide, N-(1-ethyl-2-hydroxyethyl)(meth)acrylamide, N-(1,1-dimethyl-3-hydroxybutyl)(methyl)propenamide, N-[ 1,2-dihydroxy-1-(hydroxymethyl)ethyl](meth)acrylamide, N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl](methyl)propene Indoleamine, N-[1,1-bis(hydroxymethyl)ethyl](methyl)propenylamine, N-[2-hydroxy-2,2-bis(hydroxymethyl)ethyl](methyl Acrylamide, N-(2,2-dihydroxyethyl)(meth)acrylamide, N-[tris(hydroxymethyl)methyl](methyl)propenamide, N-[2- (2-hydroxyethoxy)ethyl](meth)acrylamide, and the hydrogen atom bonded to the nitrogen atom of the compounds are -CH ₃ , -C ₂ H ₅ , -CH ₂ OH, - _{C 2 H 4 -OH, -CH 2} CH (OH) 2, -CH 2 -CH (OH) CH 3 Substituted compound formed.

Among these compounds, N-(hydroxymethyl)(meth)acrylamide and N-(2-hydroxyethyl)(meth)acrylamide are preferred from the viewpoints of ease of availability and the like.

The (meth)acrylamide (A) may be produced by a known production method, or may be a commercially available product.

Specific examples of the (meth) acrylamide (A) include N-(hydroxymethyl) acrylamide (Tokyo Chemical Industry Co., Ltd.), N-(hydroxymethyl)methacrylamide, and N-(hydroxyl group). Ethyl) acrylamide (trade name: HEAA, Xingren Co., Ltd.), N-[tris(hydroxymethyl)methyl] acrylamide (Kanto Chemical Co., Ltd.).

The (meth) acrylamide (A) used in the ink of the present invention may be one type of compound or a mixture of two or more types of compounds.

In the ink of the present invention, the content of the (meth) acrylamide (A) is preferably 5% by weight to 40% by weight, more preferably 5% by weight to 30% by weight based on the total amount of the ink. When the weight % is more preferably 5% by weight to 20% by weight, it is possible to form a microlens having a small change in optical characteristics even after the constant temperature and humidity test.

1-2. Cyclic (meth) acrylamide (B)

The cyclic (meth) acrylamide (B) is a compound having a structure of the following formula (2).

The cyclic (meth)acrylamide (B) having the structure of the following formula (2) has extremely high surface tension, and it is difficult to deteriorate optical characteristics even after the constant temperature and humidity test. By using the ink containing the cyclic (meth)acrylamide (B), it is possible to form a microlens having a good shape and having an optical property which is hard to deteriorate even after the constant temperature and humidity test.

(In the formula (2), R ⁴ is hydrogen or a methyl group, and R ⁵ is a divalent organic group).

The divalent organic group in R ⁵ is preferably a hydrocarbon group having 1 to 10 carbon atoms, and examples thereof include those exemplified in the hydrocarbon group having 1 to 10 carbon atoms in R ² .

Further, the ring containing R ⁵ may be a saturated or unsaturated alicyclic ring or an aromatic ring.

When R ⁵ is a group represented by the following formula (3), it is preferable that the optical characteristics are more difficult to deteriorate even after the constant temperature and humidity test.

-R ⁶ -XR ⁷ - (3)

(In the formula (3), R ⁶ and R ⁷ are each independently an alkylene group having 1 to 3 carbon atoms, and X is oxygen or sulfur).

The cyclic (meth) acrylamide (B) may be produced by a known production method, or may be a commercially available product.

Specific examples of the cyclic (meth) acrylamide (B) include N-propylene hydrazino (trade name: ACMO, Xingren Co., Ltd.), N-methyl propylene hydrazine, and N- propylene oxime. Base thiophene.

The cyclic (meth) acrylamide (B) to be used in the ink of the present invention may be used alone or in combination of two or more.

In the ink of the present invention, the content of the cyclic (meth) acrylamide (B) is preferably 40% by weight to 85% by weight, more preferably 60% by weight to 85% by weight based on the total amount of the ink. Further, the obtained ink can be formed into a microlens having a good shape and which is difficult to deteriorate optical characteristics even after the constant temperature and humidity test.

In addition, when the content of the cyclic (meth) acrylamide (B) is in the above range, it is excellent in discharge property and the like, and has an ink suitable for the viscosity of the inkjet ink, and is required for forming a microlens. The ink which is excellent in photocurability is therefore preferable.

1-3. (Meth)acrylic acid urethane (C)

When (meth)acrylic acid urethane (C) is used, the obtained microlens exhibits particularly high optical characteristics even after the constant temperature and humidity test, which is preferable.

The (meth)acrylic acid urethane (C) is not particularly limited, and is preferably 25 ° C. The viscosity is 5,000mPa. The compound above s, more preferably has a viscosity of 10,000 mPa at 25 ° C. Compounds above s. When the viscosity is within this range, the wetting and diffusion of the ink ejected on the substrate is suppressed, and a microlens having a smaller diameter and a better shape can be formed, which is preferable.

In addition, the upper limit of the viscosity of the (meth)acrylic acid urethane (C) may also be 3,000,000 mPa. s.

The viscosity can be measured using an R/S Plus rheometer (BROOKFIELD).

The (meth)acrylic acid urethane (C) may be produced by a known production method, or may be a commercially available product.

The viscosity at 25 ° C is 10,000 mPa. Specific examples of the (meth)acrylic acid urethane (C) of s or more include the following compounds.

NK Oligo UA-1100H (11,000 mPa.s, 25 ° C), NK Oligo U-6 LPA (149,000 mPa.s, 25 ° C), NK Oligo U-6HA (40,000 mPa.s, 50 ° C) (all are trade names; Shin-Nakamura Chemical Industry Co., Ltd.), CN9001 (46,500mPa.s, 60°C), CN9893 (1,120,000mPa.s, 25°C), CN990 (60,000mPa.s, 25°C) (all are trade names; Sha Duo ( Sartomer), KAYARAD UXE-1000 (525,000 mPa.s, 25 ° C) (trade name; Nippon Kayaku Co., Ltd.).

In addition, among these compounds, the viscosity values of NK Oligo U-6LPA, CN9893, and KAYARAD UXE-1000 are values measured by an R/S Plus rheometer (Bollyfei), and the viscosity values of the other compounds are also added. Is the directory value.

The (meth)acrylic acid urethane (C) used in the ink of the present invention may be used alone or in combination of two or more.

The content of the (meth)acrylic acid urethane (C) in the photocurable inkjet ink of the present invention is preferably 5% by weight to 20% by weight, more preferably 5 parts by weight based on the total amount of the ink. From % to 15% by weight, and more preferably from 5% by weight to 12% by weight, it is an ink having a viscosity suitable for an inkjet ink, and the optical characteristics of the microlens obtained from the ink are changed even after a constant temperature and humidity test. It is also less, so it is better.

1-4. Photopolymerization initiator (D)

The photopolymerization initiator (D) is not particularly limited as long as it is a compound capable of generating a radical by irradiation of ultraviolet rays or visible rays, and is preferably a mercaptophosphine oxide initiator or an oxyphenyl acetate. The initiator, the benzamidinecarboxylic acid-based initiator, and the hydroxyphenylketone-based initiator are particularly preferred from the viewpoints of photocurability of the ink and light transmittance of the obtained microlens. A phosphine oxide-based initiator, an oxyphenylacetate-based initiator, and a benzamidinecarboxylic acid-based initiator.

Specific examples of the photopolymerization initiator (D) which can generate radicals by irradiation of ultraviolet rays or visible rays include benzophenone, Michler's ketone, and 4,4'-bis(diethyl). Amino)benzophenone, xanthone, thioxanthone, isopropyl xanthone, 2,4-diethylthioxanthone, 2-ethylhydrazine, acetophenone, 2-hydroxyl -2-methyl-4'-isopropylpropiophenone, isopropyl benzoin ether, isobutyl benzoin ether, 2,2-diethoxyacetophenone, camphorquinone, benzoxanthone, 4-di Ethyl methylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 4,4'-di(tert-butylperoxycarbonyl)benzophenone, 3,4,4'-tri Tert-butylperoxycarbonyl)benzophenone, 3,3',4,4'-tetrakis(tert-butylperoxycarbonyl)benzophenone, 3,3',4,4'-tetra(tert-hexyl) Peroxycarbonyl)benzophenone, 3,3'-bis(methoxycarbonyl)-4,4'-di(tert-butylperoxycarbonyl)benzophenone, 3,4'-di(methoxy Carbonyl)-4,3'-di(tert-butylperoxycarbonyl)benzophenone, 4,4'-bis(methoxycarbonyl)-3,3'-di(tert-butylperoxycarbonyl) Benzophenone, 2-(4'-methoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(3',4' -dimethoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(2',4'-dimethoxystyryl)-4,6-bis ( Trichloromethyl)-s-triazine, 2-(2'-methoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4'-pentyloxybenzene Vinyl)-4,6-bis(trichloromethyl)-s-triazine, 4-[p-N,N-bis(ethoxycarbonylmethyl)]-2,6-di(trichloromethyl) )-s-triazine, 1,3-bis(trichloromethyl)-5-(2'-chlorophenyl)-s-triazine, 1,3-bis(trichloromethyl)-5-(4' -methoxyphenyl)-s-triazine, 2-(p-dimethylaminostyryl)benzoxazole, 2-(p-dimethylaminostyryl)benzothiazole, 2-mercapto Benzothiazole, 3,3'-carbonyl bis(7-diethylaminocoumarin), 2-(o-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2 '-Biimidazole, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetrakis(4-ethoxycarbonylphenyl)-1,2'-biimidazole, 2 , 2'-bis(2,4-dichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4-di Bromophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4,6-trichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 3-(2-methyl-2-dimethylaminopropionyl)carbazole, 3,6-bis(2-methyl -2-? Oxoprop-acyl) -9-n-dodecyl Long thiazole, bis (η ⁵ -2,4- cyclopentadien-1-yl) - bis (2,6-difluoro-3- (lH-pyrrolo -1-yl)-phenyl)titanium, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenyl 1-acetone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propanone, 2-hydroxy-1-{4-[4-(2 -hydroxy-2-methyl-propenyl)-benzyl]phenyl}-2-methyl-1-propanone, 2-methyl-1-[4-(methylthio)phenyl]-2- Morpholino-1-propanone, 2-(dimethylamino)-1-(4-morpholinophenyl)-2-benzyl-1-butanone, 2-(dimethylamino)- 2-[(4-Methylphenyl)methyl]-1-[4-(4-morphinyl)phenyl]-1-butanone, oxy-phenyl-acetic acid-2-[2-oxygen Benz-2-phenyl-ethoxycarbonyl-ethoxy]-ethyl ester, oxy-phenyl-acetic acid-2-[2-hydroxy-ethoxy]-ethyl ester, methyl benzhydrazinecarboxylate, Bis(2,4,6-trimethylbenzylidene)phenylphosphine oxide, 2,4,6-trimethylbenzimidyldiphenylphosphine oxide, 2,4,6-trimethylbenzene Methyl phenyl diphenylphosphonate, 1-[4-(phenylthio)phenyl]-1,2-octanedione-2-(O-benzamide), 1-[9-ethyl -6-(2-methylbenzimidyl)-9H-indazol-3-yl]-ethanone-1-(O-B醯肟).

Among them, preferred are 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1- [4-(2-Hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propanone, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl) -propenyl)-benzyl]phenyl}-2-methyl-1-propanone, oxy-phenyl-acetic acid-2-[2-oxo-2-phenyl-ethenyloxy-ethoxy Ethyl ester, oxy-phenyl-acetic acid-2-[2-hydroxy-ethoxy]-ethyl ester, methyl benzhydrazide, bis(2,4,6-trimethylbenzhydrazide Phenylphosphine oxide, 2,4,6-trimethylbenzimidyldiphenylphosphine oxide, 2,4,6-trimethylbenzhydryldiphenylphosphonate.

The commercially available product of the photopolymerization initiator (D) is preferably Irgacure 184, Irgacure 651, Irgacure 127, DAROCUR 1173, Irgacure 500, Irgacure 2959, Irgacure 754, DAROCUR MBF, Lucirin TPO (all trade names; BASF Japan) BASF Japan), etc.

Among these commercial products, if Irgacure 754, DAROCUR MBF, and Lucirin TPO are used, the obtained microlens has the highest light transmittance, which is more preferable.

The photopolymerization initiator (D) may be one type of compound or a mixture of two or more types of compounds.

When the content of the photopolymerization initiator (D) is from 0.5% by weight to 20% by weight based on the total amount of the ink of the present invention, it is preferable to obtain an ink having high sensitivity with respect to ultraviolet rays, more preferably 2% by weight. ~20% by weight, still more preferably 5% by weight to 20% by weight.

1-5. Other ingredients

The ink of the present invention may contain an organic solvent, a polymerization inhibitor, a thermosetting compound, a thermal polymerization initiator, an antioxidant, a colorant, and (meth) propylene as needed within the range not impairing the gist of the present invention. Other components such as a compound (E) having a radical polymerizable double bond other than the decylamine (A), the cyclic (meth)acrylamide (B), and the (meth)acrylic acid urethane (C).

1-5-1. Organic solvent

The ink of the present invention may contain an organic solvent for the purpose of adjusting the discharge property. The squirting property can be adjusted by including a solvent to finely adjust the viscosity or surface tension of the ink.

The organic solvent is not particularly limited, and is preferably an organic solvent having a boiling point of from 100 ° C to 300 ° C.

Specific examples of the organic solvent having a boiling point of 100 ° C to 300 ° C include butyl acetate, butyl propionate, ethyl lactate, methyl methoxyacetate, ethyl methoxyacetate, butyl methoxyacetate, and B. Methyl oxyacetate, ethyl ethoxyacetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, 3-ethoxypropionic acid Ethyl ester, methyl pyruvate, ethyl pyruvate, propyl pyruvate, methyl acetate, ethyl acetate, dioxane, 3-methoxybutanol, 3-methoxybutyl acetate Ester, methyl 2-hydroxyisobutyrate, isopropyl 2-hydroxyisobutyrate, isobutyl 2-hydroxyisobutyrate, n-butyl 2-hydroxyisobutyrate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, Propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol monophenyl ether, ethylene glycol monobutyl ether, ethylene glycol monophenyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl Ether, diethylene glycol monobutyl ether, diethylene glycol monophenyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, dipropylene glycol monophenyl ether, ethylene glycol , diethylene glycol, propylene glycol, dipropylene glycol, benzyl alcohol, cyclohexanol, 1,4-butanediol, triethylene glycol, tripropylene glycol, tripropylene glycol methyl ether, tripropylene glycol monobutyl ether, propylene glycol monomethyl ether Acid ester, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, dipropylene Monobutyl ether acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monobutyl ether acetate, cyclohexanone, cyclopentanone, diethylene glycol monomethyl ether acetate, diethylene glycol Monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ether, dipropylene glycol dimethyl ether, toluene, xylene, Anisole, γ-butyrolactone, N,N-dimethylacetamide, N-methyl-2-pyrrolidone and dimethylimidazolidinone.

The organic solvent which can be used in the ink of the present invention may be one type of compound or a mixture of two or more types of compounds.

When the content of the organic solvent is from 0.1% by weight to 20% by weight based on the total amount of the ink of the present invention, an ink having a good balance of discharge property and other characteristics is preferable, and more preferably 0.2% by weight to 10% by weight. Further preferably 0.5% by weight to 8 The weight % is particularly preferably from 1% by weight to 5% by weight.

1-5-2. Polymerization inhibitor

The ink of the present invention may contain a polymerization inhibitor in order to improve storage stability. Specific examples of the polymerization inhibitor include 4-methoxyphenol, hydroquinone, dibutylhydroxytoluene, and phenothiazine. Among these polymerization inhibitors, when phenothiazine is used, it is preferable to obtain an ink which is small in viscosity even during long-term storage.

The polymerization inhibitor which can be used in the ink of the present invention may be one type of compound or a mixture of two or more types of compounds.

When the content of the polymerization inhibitor is 0.01% by weight to 1% by weight based on the total amount of the ink of the present invention, it is preferable to obtain an ink having a small change in viscosity even during long-term storage, and it is preferable to consider the balance with other characteristics. More preferably, it is 0.01% by weight to 0.5% by weight, still more preferably 0.01% by weight to 0.1% by weight.

1-5-3. Free radical polymerizability other than (meth)acrylamide (A), cyclic (meth)acrylamide (B), and (meth)acrylic acid urethane (C) Double bond compound (E)

The ink of the present invention may further comprise (meth) acrylamide (A), cyclic (meth) acrylamide (B), and the like, in order to adjust the viscosity within a range that does not impair the characteristics of the ink. A compound (E) having a radical polymerizable double bond other than the (meth)acrylic acid urethane (C).

The compound (E) is not particularly limited, and examples thereof include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate, and 1,4. - cyclohexanedimethanol mono(meth)acrylate, glycidyl (meth)acrylate, (meth)acrylic acid-3,4-epoxycyclohexyl ester, methyl glycidyl (meth)acrylate ( Methylglycidyl methacrylate), 3-methyl-3-(methyl)propenyloxymethyl propylene oxide, 3-ethyl-3-(methyl) propylene methoxymethyl propylene oxide, 3-methyl -3-(Methyl) propylene oxiranyl ethyl propylene oxide, 3-ethyl-3-(methyl) propylene oxiranyl ethyl propylene oxide, 2-phenyl-3-(methyl) propylene醯oxymethyl propylene oxide, 2-trifluoromethyl-3-(methyl) propylene methoxymethyl propylene oxide, 4-trifluoromethyl-2-(methyl) propylene methoxy group Propylene oxide, (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, (meth)acrylic acid Isobutyl ester, tert-butyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, (meth) propylene Tricyclo [5.2.1.0 ^2,6] decyl (meth) acrylate, dicyclopentenyl oxyethyl (meth) acrylate, isobornyl (meth) acrylate, phenyl acrylate, glycerol (meth)acrylic acid ester, (meth)acrylic acid tetrahydrofuran methyl ester, (meth)acrylic acid-5-tetrahydrofuranmethyloxycarbonylpentyl ester, lauryl alcohol ethylene oxide adduct (meth)acrylic acid Ester, ω-carboxypolycaprolactone mono(meth)acrylate, succinic acid mono[2-(methyl)propenyloxyethyl]ester, maleic acid mono[2-(methyl)propene oxime Ethylethyl]ester, cyclohexene-3,4-dicarboxylic acid mono[2-(methyl)acryloxyethyl)ester, (meth)acrylamide, N,N-dimethyl ( Methyl) acrylamide, N,N-diethyl(meth)acrylamide, N,N-dimethylaminopropyl(meth)acrylamide, N-isopropyl (methyl) Acrylamide, thioglycidyl (meth) acrylate, phenyl thiaethyl (meth) acrylate, ethoxylated o-phenylphenol (meth) acrylate, dicyclopentyl (meth) acrylate Base ester, γ-butyrolactone (meth) acrylate, lauryl (meth) acrylate, methoxyethyl (meth) acrylate, (meth) propylene Ethyl ethoxylate, methoxybutyl (meth)acrylate, phenoxyethyl (meth)acrylate, polyethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate , polypropylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di Methyl) acrylate, 1,4-cyclohexanedimethanol di(meth) acrylate, 2-n-butyl-2-ethyl-1,3-propanediol di(meth) acrylate, trishydroxyl Propane di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, neopentyl Alcohol di(meth)acrylate, bis[2-(methyl)propenyloxyethyl]hydroxyethyl isocyanate, styrene, methylstyrene, chloromethylstyrene, N- Cyclohexylmaleimide, N-phenylmaleimide, vinyl toluene, polystyrene macromonomer, crotonic acid, alpha-chloroacrylic acid, cinnamic acid, maleic acid, fumaric acid, clothing Kang acid, citraconic acid, mesaconic acid, pentaerythritol di(meth) acrylate, season Tetraol di(meth)acrylate monostearate, dipentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(methyl) ) acrylate, dipentaerythritol penta (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethylene oxide modified trimethylolpropane tri (meth) acrylate, propylene oxide Trimethylolpropane tri(meth)acrylate, epichlorohydrin modified trimethylolpropane tri(meth)acrylate, di-trimethylolpropane tetra(meth)acrylate, glycerol Tris(meth)acrylate, epichlorohydrin modified glycerol tri(meth)acrylate, dipropanetriol tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol six (a) Acrylate, caprolactone modified dipentaerythritol hexa(meth) acrylate, ethylene oxide modified tris(meth) acrylate, tris[2-(methyl) propylene oxiranyl] Isophthalocyanate, caprolactone modified tris[(meth)acryloxyethyl]isocyanate, acid modified epoxy (meth) acrylate, Modified (meth) acrylate, bisphenol F ethylene oxide modified di(meth) acrylate, bisphenol A ethylene oxide modified di(meth) acrylate and bisphenol S ethylene oxide Modified di(meth)acrylate and the like.

The compound (E) which can be used in the ink of the present invention may be one type of compound or a mixture of two or more types of compounds.

In the case where the ink of the present invention contains the compound (E), the compound (E) is preferably formulated in an amount of from 1% by weight to 40% by weight based on the total amount of the ink of the present invention, in consideration of the ink of the present invention. The balance of other materials used in the case is particularly preferably from 1% by weight to 15% by weight.

1-5-4. Thermosetting compound

In order to obtain a microlens which is difficult to reduce optical characteristics even after the constant temperature and humidity test, the ink of the present invention may contain a thermosetting compound. The thermosetting compound is not particularly limited as long as it is a compound having a thermosetting functional group, and examples thereof include an epoxy compound, an epoxy curing agent, a bismaleimide, a phenol resin, a phenolic hydroxyl group-containing resin, and melamine. Resin, etc.

The thermosetting compound which can be used in the ink of the present invention may be one type of compound or a mixture of two or more types of compounds.

When the content of the thermosetting compound is 0.01% by weight to 10% by weight based on the total amount of the ink of the present invention, it is preferable to obtain a microlens which is difficult to deteriorate optical characteristics even after the constant temperature and humidity test. 0.1% by weight to 8% by weight, still more preferably 0.5% by weight to 5% by weight.

1-5-4-1. Epoxy compound

The epoxy compound is not particularly limited as long as it has at least one compound represented by the following formula (4-1) or formula (4-2) in one molecule.

Specific examples of the epoxy compound include a phenol type (phenol novolak type and cresol novolak type) epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a trisphenol methane type epoxy resin, and a hydrogenation double Phenolic A type epoxy resin, hydrogenated bisphenol F type epoxy resin, bisphenol S type epoxy resin, tetraphenol ethane type epoxy resin, bixylenol type epoxy resin, biphenyldiol type epoxy Resin, alicyclic and heterocyclic epoxy resin, and epoxy resin having a dicyclopentadiene skeleton or a naphthalene skeleton, preferably a phenolic epoxy resin, a bisphenol A epoxy resin, a bisphenol F type Epoxy resin and trisphenol methane type epoxy resin.

As the epoxy compound, an epoxy resin produced by a known method can be used, and a commercially available product can also be used.

Examples of commercially available products include jER828, jER834, jER1001, and jER1004 (both trade names; Mitsubishi Chemical Corporation), Epiclon 840, and Epiclon 850. Epiclon 1050, Epiclon 2055 (both trade names; Di Ai Sheng (DIC) Co., Ltd.), Epotohto YD-011, Epotohto YD-013, Epotohto YD-127, Epotohto YD-128 (all trade names; Nippon Steel Chemical Co., Ltd.) Club), DER317, DER331, DER661, DER664 (all trade names; Dow Chemical Japan Co., Ltd.), Araldite 6071, Araldite 6084, Araldite GY250, Araldite GY260 (both trade names; Huntsman Japan Club (Huntsman Japan KK), Sumiepoxy ESA-011, Sumiepoxy ESA-014, Sumiepoxy ELA-115, Sumiepoxy ELA-128 (all trade names; Sumitomo Chemical Industries, Ltd.), AER330, AER331, AER661 and AER 664 (all product names; Asahi Kasei Electronic Materials Co., Ltd.) and other bisphenol A type epoxy resins; jER152, jER154 (all trade names; Mitsubishi Chemical Corporation), DER431, DER438 (all trade names; Dow Chemical Japan Co., Ltd., Epiclon N-730, Epiclon N-770, Epiclon N-865 (both trade names; Di Ai Sheng Co., Ltd.), Epotohto YDCN-701, Epotohto YDCN-704 (all are trade names; Nippon Steel Chemical Co., Ltd.), Arald Ite ECN 1235, Araldite ECN 1273, Araldite ECN 1299 (all trade names; Huntsman Japan Co., Ltd.), XPY307, EPPN-201, EOCN-1025, EOCN-1020, EOCN-104S, RE-306 (all goods Name; Nippon Kayaku Co., Ltd., Sumiepoxy ESCN-195X, Sumiepoxy ESCN-220 (both trade names; Sumitomo Chemical Industries, Ltd.), AERECN-235 and AERECN-299 (all are trade names; Asahi Kasei Electronic Materials Co., Ltd. a phenolic epoxy resin; Epiclon 830 (trade name; Di Ai Sheng Co., Ltd.), jER807 (trade name; Mitsubishi Chemical Corporation), Epotohto YDF-170 (trade name; Nippon Steel Chemical Co., Ltd.), YDF-175, YDF-2001, YDF-2004 And bisphenol F-type epoxy resins such as Araldite XPY306 (both trade names; Huntsman Japan Co., Ltd.); Epotohto ST-2004, Epotohto ST-2007, and Epotohto ST-3000 (both trade names; Nippon Steel Chemical Co., Ltd.) Hydrating bisphenol A type epoxy resin; epoxide type epoxy resin such as Celloxide 2021P (trade name; Daicel Co., Ltd.), Araldite CY175 and Araldite CY179 (all trade names; Huntsman Japan Co., Ltd.); YL-6056, YX-4000, YL-6121 (both trade names; Mitsubishi Chemical Corporation) and the like, a bisphenol type or a biphenyl phenol type epoxy resin or a mixture thereof; EBPS-200 (trade name; Nippon Chemical Co., Ltd., EPX-30 (trade name; Aidike Co., Ltd.) and EXA-1514 (trade name; Di Ai Sheng Co., Ltd.) and other bisphenol S-type epoxy resin; jER157S (trade name; Mitsubishi Chemical Corporation Club) and other bisphenol A phenolic epoxy resin; YL-931 (trade name; Mitsubishi Chemical Corporation Tetraphenol ethane type epoxy resin such as Araldite 163 (trade name; Huntsman Japan Co., Ltd.); Araldite PT810 (trade name; Huntsman Japan Co., Ltd.) and TEPIC (trade name; Nissan Chemical Industry Co., Ltd. Heterocyclic epoxy resin; HP-4032, EXA-4750 and EXA-4700 (all are trade names; Di Aisheng Epoxy resin having a naphthalene skeleton, such as an epoxy resin having a naphthalene skeleton, such as HP-7200, HP-7200H, and HP-7200HH (all trade names; Di Ai Sheng Co., Ltd.); Tecmoa VG3101L ( A trisphenol methane type epoxy resin such as a product name; Mitsui Chemicals Co., Ltd., YL-933 (trade name; Mitsubishi Chemical Corporation), EPPN-501, and EPPN-502 (both trade names; Nippon Kayaku Co., Ltd.).

The epoxy compound which can be used in the ink of the present invention may be one type of compound or a mixture of two or more types of compounds.

1-5-4-2. Epoxy hardener

The epoxy curing agent is preferably an acid anhydride curing agent, a polyamine curing agent, a catalyst curing agent or the like.

Examples of the acid anhydride-based curing agent include maleic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrotrimellitic anhydride, and phthalic anhydride. , trimellitic anhydride, and styrene-maleic anhydride copolymer, and the like.

Examples of the polyamine-based hardener include diethylidene triamine, tri-ethylidene tetraamine, tetraethylidene pentaamine, dicyanodiamine, polyamidamine (polyamine resin), and ketone a ketimine compound, isophoronediamine, m-xylylenediamine, m-phenylenediamine, 1,3-bis(aminomethyl)cyclohexane, N-aminoethylpyridazine, 4, 4'-Diaminodiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, and diaminodiphenylanthracene.

The catalyst-based hardener may, for example, be a tertiary amine compound or an imidazole compound, and specific examples thereof include 1,2-dimethylimidazole and 2-ethyl-4-methyl. Imidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 2-phenylimidazoline, 1-cyanoethyl-2-ethyl-4-methylimidazole, and the like.

The epoxy curing agent which can be used in the ink of the present invention may be one type of compound or a mixture of two or more types of compounds.

1-5-4-3. Bismaleimide

The bismaleimide is, for example, a compound represented by the following formula (5).

In the formula (5), R ⁸ and R ¹⁰ each independently represent hydrogen or a methyl group, and R ⁹ is a divalent group represented by the following formula (6).

-R ¹¹ -YR ¹² - (6)

In the formula (6), R ¹¹ and R ¹² are each independently a non-continuous (not adjacent) at least one methylene group which may be substituted by oxygen, and an alkyl group having 1 to 18 carbon atoms, including It may also have a divalent group of an aromatic ring having a substituent or a cycloalkyl group which may have a substituent. Examples of the substituent include a carboxyl group, a hydroxyl group, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms. In terms of obtaining a microlens having high heat resistance, it is preferred that R ¹¹ and R ¹² are each independently a divalent group selected from the group (b) below.

[Chemistry 7]

In the formula (6), Y is one divalent group selected from the group (c) below.

The bismaleimide which can be used in the ink of the present invention may be one compound or a mixture of two or more compounds.

1-5-4-4. Phenolic resin or resin containing phenolic hydroxyl group

The phenol resin is preferably a phenol resin obtained by a condensation reaction of an aromatic compound having a phenolic hydroxyl group and an aldehyde, and a resin containing a phenolic hydroxyl group is preferably a homopolymer (including a hydride) using vinyl phenol, and A vinyl phenol-based copolymer (including a hydride) of a vinyl phenol and a compound copolymerizable therewith.

Examples of the aromatic compound having a phenolic hydroxyl group include phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, m-ethylphenol, p-ethylphenol, o-butylphenol, m-butylphenol, and p-. Butyl phenol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-dimethyl Phenol, 2,3,5-trimethylphenol, 3,4,5-trimethylphenol, p-phenylphenol, resorcinol, hydroquinone, hydroquinone monomethyl ether, o-benzene Phenol, bisphenol A, bisphenol F, containing a terpene skeleton Bisphenol, gallic acid, gallic acid ester, α-naphthol, and β-naphthol.

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

Examples of the compound copolymerizable with the vinyl phenol 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 Resitop PSM-6200 (trade name; Group Chemical Industry Co., Ltd.), Shonol BRG-555 (trade name; Showa Denko Co., Ltd.), and specific examples of the phenolic hydroxyl group-containing resin. Maruka Lyncur M S-2G, Maruka Lyncur CST70 and Maruka Lyncur PHM-C (both trade names; Maruzen Petrochemical Co., Ltd.).

The phenol resin or the phenolic hydroxyl group-containing resin which can be used in the ink of the present invention may be one type of compound or a mixture of two or more types of compounds.

1-5-4-5. Melamine resin

The melamine resin is not particularly limited as long as it is a resin produced by polycondensation of melamine and formaldehyde, and examples thereof include methylol melamine, etherified methylol melamine, benzoguanamine, methylol benzoguanamine, and etherified hydroxyl. A condensate such as methyl benzoguanamine or the like. Among these melamine resins, a condensate of etherified methylol melamine is preferred in terms of the chemical resistance of the obtained microlens becoming good.

Specific examples of the melamine resin include NIKALAC MW-30, NIKALAC MW-30HM, NIKALAC MW-390, NIKALAC MW-100LM, and NIKALAC MX-750LM (trade name; Sanhe Chemical Co., Ltd. Society).

The melamine resin which can be used in the ink of the present invention may be one type of compound or a mixture of two or more types of compounds.

1-5-5. Thermal polymerization initiator

In order to improve the hardenability of the ink by the heating step, the ink of the present invention may further contain a thermal polymerization initiator. Specific examples of the thermal polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2,4-dimethylvaleronitrile), benzammonium peroxide, and peroxidation. Di-tert-butyl, San-Aid SI-60L, San-Aid SI-80L, San-Aid SI-100L, San-Aid SI-110L, San-Aid SI-180L, San-Aid SI-110, San-Aid SI-180 (trade name; Sanshin Chemical Industry Co., Ltd.). Preferred among these are 2,2'-azobisisobutyronitrile and 2,2'-azobis(2,4-dimethylvaleronitrile).

The thermal polymerization initiator which can be used in the ink of the present invention may be one type of compound or a mixture of two or more types of compounds.

The content of the thermal polymerization initiator is preferably 10% by weight or less based on the total amount of the ink of the present invention, and more preferably 0.005% by weight to 10% by weight from the viewpoint of the effect of addition and discharge stability.

1-5-6. Antioxidant

In order to prevent oxidation of the resulting microlens, the ink of the present invention may also contain an antioxidant.

The antioxidant may, for example, be triethylene glycol-bis-[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-( 3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 3 , 5-di-tert A hindered phenol compound such as diethyl 4-hydroxybenzylphosphonate, an amine compound such as n-butylamine, triethylamine or diethylaminomethyl methacrylate.

The antioxidant which can be used in the ink of the present invention may be one type of compound or a mixture of two or more types of compounds.

The content of the antioxidant is preferably 3% by weight or less based on the total amount of the ink of the present invention, and more preferably 0.005% by weight to 2% by weight from the viewpoint of the effect of addition and the stability of discharge.

1-5-7. Colorant

The ink of the present invention may be colored or colorless. For example, when examining the state of the microlens obtained by applying the ink to the substrate or the like, the ink may be colored to facilitate the recognition of the microlens and the substrate. Agent. The colorant is preferably a dye and a pigment.

The coloring agent usable in the ink of the present invention may be one type of compound or a mixture of two or more types of compounds.

When the content of the colorant is from 0.1 part by weight to 5 parts by weight based on 100 parts by weight of the solid matter in the ink of the present invention, the inspection of the microlens obtained from the ink becomes easy and preferable, and other considerations are considered. The balance of the characteristics is more preferably from 0.1 part by weight to 1 part by weight, still more preferably from 0.1 part by weight to 0.5 part by weight.

1-6. Preservation of ink

When the ink of the present invention is stored at 5 ° C to 25 ° C, the change in viscosity during storage is small, and the storage stability is good.

1-7. Viscosity of ink

The viscosity of the ink of the present invention at 25 ° C measured by an E-type viscometer is preferably 2 mPa. s~200mPa. s, more preferably 2mPa. s~100mPa. s. When the viscosity is within this range, the discharge property of the ink jet apparatus becomes good.

1-8. Method for preparing ink

The ink of the present invention can be prepared by mixing various components which are raw materials by a known method.

In particular, the ink of the present invention is preferably prepared by dispersing the (meth) acrylamide (A), cyclic (meth) acrylamide (B), and amine (meth) acrylate. The acid ester (C), the photopolymerization initiator (D), and other components as needed are mixed, and the resulting solution is filtered and degassed, for example, using a membrane filter. The ink prepared as described above is excellent in discharge property.

1-9. Coating ink by inkjet method

The ink of the present invention can be applied by a known inkjet method. Examples of the inkjet method include a piezoelectric method in which mechanical energy is applied to the ink to eject the ink from the inkjet head, and a coating method in which thermal energy is applied to the ink to eject the ink (so-called thermal method). .

By using the inkjet method, the ink of the present invention can be easily applied to a predetermined pattern, and a uniform pattern can be formed on a large substrate.

Examples of the ink jet head include an ink jet head having 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 the metals.

Preferred coating for use in coating using the ink of the present invention The apparatus includes, for example, a device that applies energy corresponding to a coating signal to ink in an inkjet head having an ink containing portion that stores ink, and generates ink droplets from the energy. Coating (drawing) corresponding to the coating signal.

The inkjet coating device is not limited to a device in which the inkjet head is separated from the ink containing portion, and these devices that cannot be separated and integrated may be used. Further, the ink accommodating portion may be detachably or inseparably integrated with respect to the ink jet head, and may be mounted on the bracket or may be provided at a fixed portion of the apparatus. In the latter case, the ink may be supplied to the inkjet head via an ink supply member such as a tube.

2. Microlens

The microlens of the present invention is preferably formed by the above-described ink of the present invention. Specifically, it is preferred that the ink of the present invention is applied to the surface of the substrate by an inkjet method, and then the ink is irradiated with light such as ultraviolet rays or visible rays. The microlens obtained by hardening it.

Since the microlens of the present invention is obtained by curing the ink of the present invention, it has a good shape and is excellent in optical characteristics even after the constant temperature and humidity test.

In the case of irradiating ultraviolet rays, visible rays, or the like, the exposure amount to be irradiated may be appropriately selected depending on the composition of the ink, and is preferably about 100 mJ/cm ² to 5,000 mJ/cm ² , more preferably 150 mJ/cm ^{2 .} It is about 2,000 mJ/cm ² , and more preferably about 180 mJ/cm ² to 1,000 mJ/cm ² . Further, the wavelength of the ultraviolet ray or the visible ray to be irradiated is preferably from 200 nm to 500 nm, more preferably from 250 nm to 450 nm.

In addition, in the present invention, the exposure amount is obtained by using a oxtail motor type A value measured by an integrated light meter UIT-201 (trade name) of a light receiver UVD-365PD (trade name) manufactured by Ushio Inc.

Further, the exposure machine is preferably equipped with a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a halogen lamp, an electrodeless lamp, etc., and irradiates ultraviolet rays or visible rays in a range of 200 nm to 500 nm. Device.

Further, the hardened microlens may be further heated and calcined by light irradiation as needed, and may be heated and calcined at 80 to 250 ° C for 10 minutes to 60 minutes, thereby making the microlens stronger. Hardening.

The "substrate" to which the ink of the present invention is applied is not particularly limited as long as it is a substrate to which the ink of the present invention is applied, and the shape thereof is not limited to a flat plate shape, and may be a curved shape or the like.

The substrate is not particularly limited, and examples thereof include a polyester resin substrate including polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), and polyethylene, polypropylene, and the like. a polyolefin resin substrate; an organic polymer film comprising polyvinyl chloride, a fluororesin, an acrylic resin, a polyamide, a polycarbonate, a polyimine, or the like; a substrate comprising a cellophane; a metal foil; a laminate film of polyimide and metal foil; using glasse paper, parchment paper, polyethylene, clay binder, polyvinyl alcohol, starch or carboxymethyl cellulose with filling effect Paper which has been subjected to filling treatment such as CMC); and a glass substrate.

According to the ink of the present invention, it is preferable to form a microlens having a good shape without performing surface treatment of the substrate even on the acrylic resin substrate.

A substrate containing an additive such as an antioxidant, a deterioration inhibitor, a filler, an ultraviolet absorber, an antistatic agent, and/or an electromagnetic wave inhibitor may be used as the substrate insofar as it does not adversely affect the effects of the present invention. Moreover, the substrate may be a substrate subjected to surface treatment such as corona treatment, plasma treatment or blast treatment on at least a part of the surface of the substrate, or may be provided with an easy adhesion layer or color filter on the surface. A substrate for a protective film or a hard coat film.

As described above, according to the ink of the present invention, a microlens having a good shape can be formed without performing surface treatment of the substrate, but in order to obtain a microlens having a smaller diameter and a higher height, it is also possible to perform liquid dispensing on the surface of the substrate as needed. deal with.

Further, when the ink of the present invention is ejected onto a substrate, particularly an acrylic substrate, it is preferred that the surface state of the substrate is not uneven (partially extremely lyophilic or non-liquid). Therefore, in order to eliminate unevenness on the surface of the substrate, it is preferred to subject the surface of the substrate to surface treatment in advance.

The thickness of the substrate is not particularly limited, but is usually about 10 μm to 4 mm, and can be appropriately adjusted depending on the purpose of use, and is preferably 50 μm to 2 mm, more preferably 100 μm to 1 mm.

The ratio (H/D) of the lens height (H) to the lens diameter (D) of the microlens is appropriately selected depending on the intended use, and is not particularly limited, and optical light having excellent light emission efficiency can be produced. In terms of parts and the like, it is preferably 0.15 or more, and more preferably 0.16 or more.

In the present invention, the "microlens having a good shape" means, for example, a substantially perfect circular shape, and the ratio of the height of the lens to the diameter of the lens is a microlens within the above range.

The light transmittance at a wavelength of 400 nm of the microlens is preferably 98% or more, more preferably 98.5% or more.

3. Optical parts

The optical component of the present invention is not particularly limited as long as it includes the microlens, and is preferably an optical component in which the microlens is provided on a substrate.

Such an optical component can be exemplified by a light guide plate or the like.

4. Device

The device of the present invention comprises the optical component.

Such devices include a display, an illumination lamp, and the like.

By incorporating the light guide plate into a backlight, for example, a liquid crystal display for a liquid crystal display element can be produced, and a configuration in which an LED light source unit including a light guide plate and a high-brightness LED is incorporated in both ends of the light guide plate can be used. Made into LED lighting.

[Examples]

Hereinafter, the present invention will be further described by way of examples, but the invention is not limited to the examples.

Further, the inkjet ink obtained in the examples is sometimes simply referred to as ink. That is, for example, the inkjet ink 1 is sometimes referred to as ink 1.

[Example 1]

HEAA (trade name; Xingren Co., Ltd.) as N-(hydroxyethyl) acrylamide as (meth) acrylamide (A), ACMO as N-propylene hydrazinine (trade name; Nippon Co., Ltd. as a cyclic (meth) acrylamide (B), CN9893 (trade name; Shado 作为) as (meth)acrylic acid urethane (C) Co., Ltd., a difunctional (meth)acrylic acid urethane), and oxy-phenyl-acetic acid-2-[2-oxo-2-phenyl-ethenyloxy-ethoxy] IRGACURE 754 (trade name; Japan BASF Co., Ltd., hereinafter referred to as "Ir754") as a mixture of ethyl ester and oxy-phenyl-acetic acid-2-[2-hydroxy-ethoxy]-ethyl ester as photopolymerization The starting agent (D) was mixed in the following composition ratio, and after completely dissolving, it was filtered with a membrane filter (0.2 μm) of ultrahigh molecular weight polyethylene (UPE) to obtain a filtrate (ink 1).

The viscosity of the ink 1 at 25 ° C was measured using an E-type viscometer (TV-22 of Toki Sangyo Co., Ltd., the same below), and the result was 44 mPa. s.

[Embodiment 2]

KAYARAD UXE-1000 (trade name; Nippon Kayaku Co., Ltd., 4-functional (meth)acrylic acid urethane. Hereinafter referred to as "UXE-1000") was used as the (meth)acrylic acid urethane ( In the same manner as in Example 1, except that the ratio was C), the ink 2 was prepared.

Using an E-type viscometer, the viscosity of the ink 2 at 25 ° C was measured to be 48 mPa. s.

[Example 3]

U-6LPA (trade name; Shin-Nakamura Chemical Co., Ltd., 6-functional (meth)acrylic acid urethane) was used as the (meth)acrylic acid urethane (C), and the ratio was set as follows. In the same manner as in Example 1, except that the ink 3 was prepared.

Using an E-type viscometer, the viscosity of the ink 3 at 25 ° C was measured to be 48 mPa. s.

[Example 4]

N-(hydroxymethyl) acrylamide (hereinafter abbreviated as "HMAA") is used as the (meth) acrylamide (A), and CN9001 (trade name; Sartuo Co., Ltd., 2-functional (methyl)) is used. Ink 4 was prepared in the same manner as in Example 1 except that the urethane acrylate (C) was used as the (meth)acrylic acid urethane (C).

(D) Ir754 7.00g

Using an E-type viscometer, the viscosity of the ink 4 at 25 ° C was measured and found to be 41 mPa. s.

[Example 5]

Using CN2302 (trade name; Shadosuo Co., Ltd., 16-functional (meth)acrylic acid urethane. The viscosity at 25 ° C is 300 mPa.s) as (meth)acrylic acid urethane (C) Ink was prepared in the same manner as in Example 1 except that the ratio was set to the following.

Using an E-type viscometer, the viscosity of the ink 5 at 25 ° C was measured to be 38 mPa. s.

[Comparative Example 1]

Ink 6 was prepared in the same manner as in Example 1 except that the (meth)acrylic acid urethane (C) was not used.

Using an E-type viscometer, the viscosity of the ink 6 at 25 ° C was measured and found to be 33 mPa. s.

[Comparative Example 2]

Instead of using (meth) acrylamide (A), 2-hydroxyethyl methacrylate (hereinafter abbreviated as "HEMA") was used, and the following ratio was used, and In Example 1, the ink 7 was prepared in the same manner.

Using an E-type viscometer, the viscosity of the ink 7 at 25 ° C was measured to be 25 mPa. s.

[Comparative Example 3]

Instead of using (meth) acrylamide (A), N-(butoxymethyl) acrylamide (hereinafter abbreviated as "BMAA") is used, and the following ratio is used, and Ink 8 was prepared in the same manner as in Example 1.

Using an E-type viscometer, the viscosity of the ink 8 at 25 ° C was measured to be 29 mPa. s.

[Comparative Example 4]

Instead of using cyclic (meth) acrylamide (B), instead, Ink 9 was prepared in the same manner as in Example 1 except that N,N-diethyl acrylamide (hereinafter abbreviated as "DEAA") was used.

Using an E-type viscometer, the viscosity of the ink 9 at 25 ° C was measured to be 8 mPa. s.

[Comparative Example 5]

The cyclic (meth) acrylamide (B) was not used, and instead, tetrahydrofurfuryl acrylate (hereinafter abbreviated as "THFA") was used, and the following ratio was used, and Example 1 was used. The ink 10 was prepared in the same manner.

Using an E-type viscometer, the viscosity of the ink 10 at 25 ° C was measured to be 12 mPa. s.

[Comparative Example 6]

Instead of using (meth)acrylic acid urethane (C), IRR214-K (trade name; Daicelinic Co., Ltd.), which is tricyclodecane dimethanol diacrylate, is used instead. The same as in the first embodiment except for the following ratio The ink 11 is prepared by performing.

Using an E-type viscometer, the viscosity of the ink 11 at 25 ° C was measured and the result was 18 mPa. s.

[Comparative Example 7]

Instead of using (meth)acrylic acid urethane (C), instead, EBECRYL 140 (trade name; Daicel cyanotec. hereinafter referred to as "EB-140") is used, and The ink 12 was prepared in the same manner as in Example 1 except for the above.

Using an E-type viscometer, the viscosity of the ink 12 at 25 ° C was measured to be 16 mPa. s.

[Comparative Example 8]

Instead of using (meth)acrylic acid urethane (C), DPHA (trade name; Nippon Oil Co., Ltd.) as dipentaerythritol hexaacrylate was used, and the following ratio was used. Prepared in the same manner as in Example 1 except Ink 13.

Using an E-type viscometer, the viscosity of the ink 13 at 25 ° C was measured and the result was 27 mPa. s.

<Evaluation of ink, microlens and cured film>

The microlens obtained by ejecting the ink obtained by the inkjet method was subjected to shape evaluation and H/D evaluation, and the light transmittance of the cured film obtained by using the ink obtained above at 400 nm and the L ^* a ^* b ^* table were obtained. the measured color value b ^*, the light transmittance 400nm after humidity testing and the film thickness was measured with L ^* a ^* b ^* b ^* values of the color system was measured.

(formation of microlenses)

The ink (1 to 13) obtained above was injected into an inkjet cartridge, and was mounted on an inkjet device DMP-2831 using a 10 pl (picoliter) inkjet head (trade name; FUJIFILM Dimatix Inc.) In the above, the discharge voltage (piezo voltage) and the discharge temperature were set as described in Table 1 in accordance with the ink viscosity. At a driving frequency of 5 kHz, one dot was ejected at intervals of 150 μm on an acrylic substrate Delaglass AD999 (trade name; Asahi Kasei Technoplus Co., Ltd.). Then, the acrylic substrate having a dot pattern formed at equal intervals was irradiated with light having a cumulative exposure amount of 1,000 mJ/cm ² using a UV irradiation device J-CURE 1500 (trade name; JAPAN TECHNOLOGY SYSTEM Corporation) to make the ink (1 to 13) hardening, thereby obtaining an acrylic substrate (1a to 13a) on which microlenses are formed. The following measurement and evaluation were performed using this acrylic substrate (1a-13a).

(evaluation of shape)

The shape of the microlens on the microlens-forming substrate (1a to 13a) obtained as described above was observed using an optical microscope BX51 (trade name; Olympus Co., Ltd.) as shown in Table 1. The shape of the microlens was evaluated.

In addition, the evaluation criteria of the shape of the microlens are as follows.

◎: The shape of all the microlenses is substantially round

○: Most of the microlenses have a substantially perfect circular shape, and few microlenses that are not substantially rounded are rarely seen.

△: the shape of the microlens is mixed with a shape that is not substantially round

×: The shape of all the microlenses is distorted

The term "substantially rounded" as used in the present invention refers to a plan view of a microlens formed on a substrate (a view of a substrate on which a microlens is formed from a direction above the microlens toward the substrate direction (the height direction of the microlens)) In the case where the microlens can be regarded as a circular (or elliptical) shape, it is preferable that the outline of the microlens is depicted as a smooth circular (or elliptical) shape; the shape of a part of the circle is to be shaved, The shape in which a part of the circle is convex or the shape of the microlens is convex or concave is called a shape of the microlens which is not substantially rounded or curved.

(Evaluation of H/D)

The lens diameter of the above microlens was measured using an optical microscope BX51 (trade name; Olympus Co., Ltd.). The value of the lens diameter uses the average of the diameters of any three microlenses. Then, the lens height of the above microlens was measured using a stylus type film thickness meter P-15 (trade name) manufactured by KLA-Tencor Japan Co., Ltd. The value of the lens height uses the average of the heights of any three microlenses.

The height/diameter (H/D) value was calculated by dividing the height of the microlens obtained as described above by the diameter of the microlens. The H/D values of the microlenses on (1a to 13a) are shown in Table 1.

(formation of hardened film)

On a 4 cm square glass substrate (thickness: 0.7 mm), ink (1 to 13) was applied using a spin coater set to the number of revolutions described in Table 2. Then, the glass substrate coated with the ink (1 to 13) is irradiated with light having an integrated exposure amount of 1,000 mJ/cm ² in the same manner as the microlens, and the ink (1 to 13) is cured to obtain a cured film. Substrate (1b~13b). The following measurement and evaluation were performed using the cured film-forming substrate (1b to 13b).

(optical characteristic evaluation)

The light transmittance and b ^* value at a wavelength of 400 nm were measured using the obtained cured film-forming substrate (1b to 13b). The light transmittance and the b ^* value were measured using a transmittance measuring device V-670 (trade name; Japan Spectrophoto Co., Ltd.).

Further, as a reference, a 4 cm square glass substrate in which a cured film was not formed was used. The light transmittance at 400 nm and the b ^* value of the substrate (1b to 13b) on which the cured film was formed are shown in Table 2.

(Evaluation of optical characteristics after constant temperature and humidity test)

The substrate (1b to 13b) on which the cured film was formed was set to a small-temperature constant temperature and humidity tester SH-641 having a furnace temperature of 50 ° C and a relative humidity of 90% (trade name; ESPEC) ))), standing for 65 hours. Thereafter, the substrate (1b to 13b) on which the cured film was formed was taken out from the small-sized constant temperature and humidity tester, and the light transmittance and b ^* value at a wavelength of 400 nm were measured in the same manner as before the constant temperature and humidity test.

The light transmittance at 400 nm and the b ^* value of the cured film-forming substrate (1b to 13b) after the constant temperature and humidity test are shown in Table 2.

(Measurement of film thickness)

A part of the cured film of the cured glass substrate (1b to 13b) after the above constant temperature and humidity test was cut by a cutter, and a stylus type film thickness manufactured by KLA-Tencor Japan Co., Ltd. was used. The film thickness of the step portion was measured in P-15 (trade name), and the average value of the three measurements was calculated.

According to Tables 1 and 2, in Examples 1 to 5, the H/D value of the microlens was large, and the optical characteristics were good even after the constant temperature and humidity test. Example 5 uses a low viscosity (meth)acrylic acid urethane (C), so the H/D is slightly lowered. low.

[Industrial availability]

As described above, according to the present invention, a microlens having a good shape can be formed without performing a surface treatment for easily forming a microlens on the substrate. Further, the optical characteristics of the microlens obtained from the ink of the present invention are excellent in optical characteristics even after the constant temperature and humidity test.

Therefore, the ink of the present invention can be suitably used for manufacturing an optical component such as a light guide plate and a display or an illumination lamp including the same.

Claims (10)

An inkjet ink comprising a (meth)acrylamide (A) represented by the following formula (1) and a cyclic (meth)acrylamide (B) represented by the following formula (2), Inkjet ink of (meth)acrylic acid urethane (C) and photopolymerization initiator (D): In the formula (1), R ¹ is hydrogen or a methyl group, and R ² is an organic group having 1 to 10 carbon atoms or an organic group having 1 to 10 carbon atoms including a hydroxyl group, and R ³ is hydrogen and the carbon number is 1 to An organic group of 10 or an organic group having a hydroxyl group having 1 to 10 carbon atoms; In the formula (2), R ⁴ is hydrogen or a methyl group, and R ⁵ is a divalent organic group. The inkjet ink according to claim 1, wherein the (meth)acrylamide (A) is contained in an amount of 5% by weight to 40% by weight based on the total amount of the inkjet ink, and 40 weight% The amount of % to 85% by weight includes a cyclic (meth)acrylamide (B), and the (meth)acrylic acid urethane (C) is contained in an amount of 5% by weight to 20% by weight to 0.5% by weight. The amount of ~20% by weight contains the photopolymerization initiator (D). The inkjet ink according to claim 1, wherein R ² in the formula (1) is an alkylene group having 1 to 5 carbon atoms, and R ³ is hydrogen or an alkyl group having 1 to 5 carbon atoms. . The inkjet ink according to claim 1, wherein R ⁵ in the formula (2) is a group represented by the following formula (3): -R ⁶ -XR ⁷ - (3) Formula (3) Wherein R ⁶ and R ⁷ are each independently an alkylene group having a carbon number of 1 to 3, and X is oxygen or sulfur. The inkjet ink according to claim 1, wherein the (meth)acrylic acid urethane (C) has a viscosity at 25 ° C of 5,000 mPa. s above. The inkjet ink according to claim 1, wherein the photopolymerization initiator (D) is selected from the group consisting of a mercaptophosphine oxide initiator, an oxyphenyl acetate initiator, and a benzoic acid. At least one compound of the group consisting of a hydrazinecarboxylic acid-based initiator and a hydroxyphenylketone-based initiator. The inkjet ink according to any one of claims 1 to 6, which is used for microlens formation. A microlens obtained by hardening an inkjet ink according to any one of claims 1 to 6. An optical component comprising the microlens of claim 8 of the patent application. A device comprising the optical component of claim 9 in the scope of the patent application.