KR102156658B1 - Inkjet ink, microlens, optical component and apparatus - Google Patents

Abstract

(1)

(2)The present invention relates to inkjet inks, microlenses, optical components and devices. It is an object to provide an inkjet ink capable of forming microlenses having a good shape without surface treatment of a substrate. (Meth)acrylamide (A) represented by the following formula (1), cyclic (meth)acrylamide (B) represented by the following formula (2), urethane (meth)acrylate (C), and a photopolymerization initiator (D) It is an inkjet ink formed including.

(One)

(2)

Description

Inkjet ink, micro lens, optical components and devices {INKJET INK, MICROLENS, OPTICAL COMPONENT AND APPARATUS}

The present invention relates to an inkjet ink that can be suitably used for manufacturing a light guide plate, which is a member of a backlight unit built into an optical device such as an image display device. More specifically, the present invention relates to an inkjet ink capable of forming microlenses having a good shape without surface treatment of a substrate.

In the past, microlenses formed on a light guide plate for an image display device were formed by injection molding using a mold. However, when manufacturing microlenses of a small amount and various kinds using this method, it is necessary to rebuild a mold for each product design, so an increase in the number of manufacturing processes has become a problem.

Recently, as a manufacturing method having a high degree of design freedom, a method of directly forming a microlens on the surface of a substrate by using an inkjet method has been implemented (see, for example, Patent Documents 1 and 2).

Since the microlens manufacturing method using such an inkjet method can easily control patterning with a PC, etc., the number of manufacturing steps does not change even in the production of microlenses of a small amount and a variety of types, and manufacturing costs can be suppressed. I'm looking forward to it.

However, when microlenses are directly formed on the substrate constituting the light guide plate using conventional inkjet ink, the problem of forming a microlens with a large diameter because the interface free energy between the surface of the substrate and the ink is small. There is a problem in that microlenses having an inferior shape are formed because unevenness is seen in the wettability.

In order to solve this problem, before forming the microlens for the purpose of controlling the diameter and height of the microlens, surface treatment such as forming a liquid-repellent cured film on the surface of the substrate is performed. However, such a method has a problem of increasing the tack time by increasing the number of manufacturing steps in the formation of the microlens.

Prior art 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 of solving the above-described problem, development of an inkjet ink capable of forming a microlens having a good shape without performing a surface treatment of the substrate instead of the conventional ink can be considered.

In this case, since the surface free energy of the substrate without surface treatment is low, the surface free energy of the ink is required to be high in order to form a microlens of good shape, and the surface tension as a raw material is required to increase the surface free energy of the ink. You can think of using a high compound.

Several compositions containing such a compound having a high surface tension are known (see Japanese Patent Laid-Open Publication No. 2002-212244 or Japanese Patent Laid-Open Publication No. 2011-132322).

However, it cannot be said that the composition described in these documents necessarily has a high interface free energy with a substrate, and some compounds have a low interface free energy with a substrate.

In addition, since a photopolymerizable compound having a high surface tension generally tends to have poor moisture resistance, if a microlens is formed only with a photopolymerizable compound having a high surface tension, there is a problem that the optical properties deteriorate after a constant temperature and humidity test.

It is an object of the present invention to provide an inkjet ink capable of forming microlenses having good shapes without surface treatment of a substrate. In particular, an object of the present invention is to provide an inkjet ink capable of forming a microlens having good optical properties even after a constant temperature and humidity test on an acrylic substrate, while having a good shape without surface treatment.

According to the photocurable inkjet ink comprising urethane (meth)acrylate, a photopolymerization initiator, and (meth)acrylamide and cyclic (meth)acrylamide having a specific structure, for example, when manufacturing a light guide plate In addition, the present invention was completed based on these findings, finding that it was possible to form a microlens in which the optical properties were not easily deteriorated even after the constant temperature and humidity test in addition to having a good shape without surface treatment of the substrate.

In other words, the present invention includes the following matters.

[1] (meth)acrylamide (A) represented by the following formula (1), cyclic (meth)acrylamide (B) represented by the following formula (2), urethane (meth)acrylate (C), and a photopolymerization initiator ( Inkjet ink comprising D).

......화학식 (1)

......Formula (1)

(In the formula (1), R ¹ is hydrogen or methyl, 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 It is an organic group having 1 to 10 carbon atoms including an organic group or a hydroxyl group.)

......화학식 (2)

......Chemical Formula (2)

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

[2] Based on the total amount of the inkjet ink, the (meth)acrylamide (A) is in an amount of 5% to 40% by weight, and the cyclic (meth)acrylamide (B) is in an amount of 40% to 85% by weight In [1], the urethane (meth)acrylate (C) is included in an amount of 5% to 20% by weight, and the photopolymerization initiator (D) is included in an amount of 0.5% to 20% by weight. Described inkjet ink.

[3] The inkjet ink according to [1] or [2], wherein R ² in the general formula (1) is alkylene having 1 to 5 carbon atoms, and R ³ is hydrogen or alkyl having 1 to 5 carbon atoms.

[4] The inkjet ink according to any one of items [1] to [3], wherein R ⁵ in the general formula (2) is a group represented by the following general formula (3).

-R ⁶ -XR ⁷ -......Formula (3)

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

[5] The ink jet ink according to any one of [1] to [4], wherein the urethane (meth)acrylate (C) has a viscosity of 5,000 mPa·s or more at 25°C.

[6] Matters wherein the photopolymerization initiator (D) is at least one compound selected from the group consisting of an acylphosphine oxide-based initiator, an oxyphenyl acetate-based initiator, a benzoyl formic acid-based initiator, and a hydroxyphenylketone-based initiator [1 The inkjet ink according to any one of [5] to [5].

[7] The inkjet ink according to any one of items [1] to [6] for microlens formation.

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

[9] An optical component having a microlens according to item [8].

[10] A device having the optical component according to item [9].

According to the inkjet ink of the present invention, it is possible to form a microlens that has a good shape even if the substrate is not subjected to surface treatment, and does not deteriorate easily even after a constant temperature and humidity test.

1. Inkjet ink

The inkjet ink of the present invention (hereinafter, also referred to as ``the ink of the present invention'') is (meth)acrylamide (A) represented by the following formula (1), and cyclic (meth)acrylamide (B) represented by the following formula (2). ), urethane (meth)acrylate (C) and a photoinitiator (D).

Since the ink of the present invention contains the above compound, it is possible to form microlenses of good shape even without surface treatment for forming microlenses of good shape on the substrate surface.

Further, the ink of the present invention is excellent in photocurability, and further, according to the ink, it is possible to form a microlens whose optical properties are not easily deteriorated even after a constant temperature and humidity test.

The ink of the present invention is an organic solvent, a polymerization inhibitor, a thermosetting compound, a thermal polymerization initiator, an antioxidant, a colorant, and (meth)acrylamide (A), if necessary, within the scope not impairing the gist of the present invention. Other components, such as a compound (E) having a radically polymerizable double bond other than (meth)acrylamide (B) and urethane (meth)acrylate (C), may be included.

The ink of the present invention may be colorless or colored. You may contain a trace amount of a colored compound in the range which does not impair the effect of the invention. For example, when inspecting the state of the microlens, a colorant may be included in order to facilitate identification with the substrate.

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

1-1. (Meth)acrylamide (A)

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

The surface tension of the (meth)acrylamide (A) having the structure represented by the following formula (1) is extremely high, and thus an ink containing such (meth)acrylamide (A) can form a microlens having a good shape.

......화학식 (1)

......Formula (1)

(In the formula (1), R ¹ is hydrogen or methyl, 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 It is an organic group having 1 to 10 carbon atoms including an organic group or a hydroxyl group.)

As the organic group having 1 to 10 carbon atoms in R ² , a hydrocarbon group having 1 to 10 carbon atoms is preferable, and a hydrocarbon group having 1 to 6 carbon atoms is more preferable.

Examples of the hydrocarbon group having 1 to 10 carbon atoms include methylene, dimethylene, trimethylene, isopropylidene, tetramethylene, pentamethylene, hexamethylene, and the like, preferably methylene and dimethylene.

At least one -CH ₂ -in the hydrocarbon group of the present specification is -CH=CH-, -C≡C-, -O-, -CO-, -COO-, -OCO-, -NR- (R is Hydrogen, methyl, ethyl, ethoxy or methoxy), -CONH-, -NHCO-.

As the organic group having 1 to 10 carbon atoms including a hydroxyl group in the above R ² , a hydrocarbon group having 1 to 10 carbon atoms including a hydroxyl group is preferable, and a hydrocarbon group having 1 to 6 carbon atoms including a hydroxyl group is more preferable.

As the organic group having 1 to 10 carbon atoms including an organic group having 1 to 10 carbon atoms and a hydroxyl group in R ³ above, the organic group having 1 to 10 carbon atoms in the above R ² and an organic group having 1 to 10 carbon atoms including a hydroxyl group Examples of the device include a group in which a hydrogen atom or a hydroxyl group is added to one of the bonded waters among the exemplified groups.

Among these, when R ² is alkylene having 1 to 5 carbon atoms and R ³ is hydrogen or alkyl having 1 to 5 carbon atoms, it is preferable because the optical properties are not easily deteriorated even after a constant temperature and humidity test.

Examples of the (meth)acrylamide (A) include N-(hydroxymethyl)(meth)acrylamide, N-(2-hydroxyethyl)(meth)acrylamide, and N-(3-hydroxy Propyl)(meth)acrylamide, N-(2-hydroxypropyl)(meth)acrylamide, N-(1-methyl-1-hydroxyethyl)(meth)acrylamide, 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)(meth)acrylamide, N-[1,2-dihydroxy-1-(hydroxymethyl)ethyl](meth)acrylamide, N- [1,1-bis(hydroxymethyl)-2-hydroxyethyl](meth)acrylamide, N-[1,1-bis(hydroxymethyl)ethyl](meth)acrylamide, N-[2- Hydroxy-2,2-bis(hydroxymethyl)ethyl](meth)acrylamide, N-(2,2-dihydroxyethyl)(meth)acrylamide, N-[tris(hydroxymethyl)methyl] (Meth)acrylamide, N-[2-(2-hydroxyethoxy)ethyl](meth)acrylamide, and hydrogen atoms bonded to nitrogen atoms of these compounds are -CH ₃ , -C ₂ H ₅ ,- And compounds substituted with CH ₂ OH, -C ₂ H ₄ -OH, -CH ₂ CH(OH) ₂ , -CH ₂ -CH(OH)CH ₃ , and the like.

Among these, N-(hydroxymethyl)(meth)acrylamide and N-(2-hydroxyethyl)(meth)acrylamide are preferable in terms of availability and the like.

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

As specific examples of (meth)acrylamide (A), N-(hydroxymethyl)acrylamide (Tokyo Chemical Industry Co., Ltd.), N-(hydroxymethyl) acrylamide (Tokyo Chemical Industry Co., Ltd.), N-(hydroxymethyl) )Methacrylamide, N-(hydroxyethyl)acrylamide (trade name: HEAA, Kojin Co., Ltd.), N-[tris(hydroxymethyl)methyl]acrylamide (Kanto Chemical Co., Ltd. ) (KANTO CHEMICAL CO., INC.)) etc. are mentioned.

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

In the ink of the present invention, the content of (meth)acrylamide (A) is preferably 5% by weight to 40% by weight, more preferably 5% by weight to 30% by weight, even more preferably with respect to the total amount of the ink. If is 5% by weight to 20% by weight, the change in optical properties is small even after the constant temperature and humidity test, and a microlens having a good shape can be formed.

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

Cyclic (meth)acrylamide (B) is a compound having a structure represented by the following formula (2).

The surface tension of the cyclic (meth)acrylamide (B) having the structure of the following formula (2) is extremely high, and the optical properties are not easily deteriorated even after a constant temperature and humidity test. According to the ink containing the ring-shaped (meth)acrylamide (B), it is possible to form a microlens that has a good shape and does not deteriorate easily even after a constant temperature and humidity test.

......화학식 (2)

......Chemical Formula (2)

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

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

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

If R ⁵ is a group represented by the following general formula (3), it is preferable because it becomes a compound whose optical properties are not easily deteriorated even after a constant temperature and humidity test.

-R ⁶ -XR ⁷ -......Formula (3)

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

Cyclic (meth)acrylamide (B) may be produced by a known production method or may be a commercial product.

As a specific example of cyclic (meth)acrylamide (B), N-acryloylmorpholine (trade name: ACMO, Kojin Co., Ltd.), N-methacryloylmorpholine, N-acrylo Ilthiomorpholine, etc. are mentioned.

The cyclic (meth)acrylamide (B) 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, if 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, The obtained ink is preferable because it can form a microlens that does not deteriorate easily even after a constant temperature and humidity test while having a good shape.

Furthermore, if the content of the cyclic (meth)acrylamide (B) is in the above-described range, it becomes an ink having a viscosity suitable for inkjet ink having excellent ejection properties, and also has excellent photocurability required when forming a microlens. It is preferable because it becomes ink.

1-3. Urethane (meth)acrylate (C)

The use of urethane (meth)acrylate (C) is particularly preferable because the microlens obtained after the constant temperature and humidity test exhibits high optical properties.

The urethane (meth)acrylate (C) is not particularly limited, but a compound having a viscosity of 5,000 mPa·s or more at 25°C is preferable, and more preferably a compound of 10,000 mPa·s or more. When the viscosity is in such a range, the wettability of the ink discharged onto the substrate can be suppressed, and a microlens having a better shape with a smaller diameter can be formed, which is preferable.

And the upper limit of the viscosity of urethane (meth)acrylate (C) may be 3,000,000 mPa·s.

The viscosity can be measured by an R/S plus rheometer (Brookfield).

The urethane (meth)acrylate (C) may be produced by a known production method or may be a commercial product.

Specific examples of the urethane (meth)acrylate (C) having a viscosity of 10,000 mPa·s or more at 25°C include the following compounds.

NK Oligo UA-1100H(11,000mPa·s, 25℃), NK Oligo U-6LPA (149,000mPa·s, 25℃), NK Oligo U-6HA (40,000mPa·s, 50℃) (all brand names: Shinnakamura Shin-Nakamura Chemical Co., Ltd.), CN9001(46,500mPa·s, 60℃), CN9893 (1,120,000mPa·s, 25℃), CN990(60,000mPa·s, 25℃) (All brand names: Sartomer Co.), KAYARAD UXE-1000 (525,000mPa·s, 25℃) (Brand name: Nippon Kayaku Co., Ltd. (NIPPON KAYAKU) Co., Ltd.)).

And among these compounds, the viscosity values of NK Oligo U-6LPA, CN9893 and KAYARAD UXE-1000 are values measured by R/S Plus rheometer (manufactured by Brookfield), and the viscosity of other compounds The value of is the catalog value.

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

The content of urethane (meth)acrylate (C) in the photocurable inkjet ink of the present invention is preferably 5% by weight to 20% by weight, more preferably 5% by weight to 15% by weight based on the total amount of the ink. , More preferably 5% by weight to 12% by weight, an ink having a viscosity suitable for inkjet ink is obtained, and a microlens obtained from the ink is preferable because the change in optical properties is small even after a constant temperature and humidity test.

1-4. Photopolymerization initiator (D)

The photoinitiator (D) is not particularly limited as long as it is a compound capable of generating radicals by irradiation with ultraviolet or visible light, but an acylphosphine oxide-based initiator, an oxyphenyl acetate-based initiator, a benzoyl formic acid-based initiator, and a hydroxyphenylketone-based initiator Are preferable, and among these, an acylphosphine oxide-based initiator, an oxyphenyl acetate-based initiator, and a benzoyl formic acid-based initiator are more preferable from the viewpoints of the photocurability of the ink and the light transmittance of the resulting microlens.

Specific examples of photopolymerization initiators (D) that can generate radicals by irradiation with ultraviolet or visible light include benzophenone, Michler's ketone, 4,4'-bis(diethylamino)benzophenone, xanthone, thioxanthone, iso Propylxanthone, 2,4-diethylthioxanthone, 2-ethylanthraquinone, acetophenone, 2-hydroxy-2-methyl-4'-isopropyl propiophenone, isopropyl benzoin ether, isobutyl benzo Phosphorus ether, 2,2-diethoxyacetophenone, camphorquinone, benzanthrone, ethyl 4-dimethylamino benzoate, isoamyl 4-dimethylamino benzoate, 4,4'-di(t-butyl peroxycarbonyl) Benzophenone, 3,4,4'-tri(t-butyl peroxycarbonyl)benzophenone, 3,3',4,4'-tetra(t-butyl peroxycarbonyl)benzophenone, 3,3',4,4'-tetra(t-hexyl peroxycarbonyl)benzophenone, 3,3'-di(methoxycarbonyl)-4,4'-di(t-butyl peroxycarbonyl)benzophenone, 3,4'-di(methoxycarbonyl)-4,3'-di(t-butyl peroxycarbonyl)benzophenone, 4,4'-di(methoxycarbonyl)-3,3'-di (t-butyl peroxycarbonyl)benzophenone, 2-(4'-methoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(3',4'-dime Toxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(2',4'-dimethoxystyryl)-4,6-bis(trichloromethyl)-s-tri Azine, 2-(2'-methoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4'-pentyloxystyryl)-4,6-bis(trichloro Methyl)-s-triazine, 4-[pN,N-di(ethoxycarbonyl methyl)]-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-dimethyl Aminostyryl)benzoxazole, 2-(p-dimethylaminostyryl)benzthiazole, 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-dibromophenyl)-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-dimethylamino propionyl)carbazole, 3,6-bis(2-methyl-2 -Morpholinopropionyl)-9-n-dodecylcarbazole, bis(η ⁵ -2,4-cyclopentadien-1-yl)-bis(2,6-difluor-3-(1H-pyrrole) -1-yl)-phenyl) titanium, 1-hydroxy cyclohexyl phenylketone, 2,2-dimethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-[4-(2-hydroxy ethoxy)-phenyl]-2-hydroxy-2-methyl-1-propanone, 2-hydroxy-1-{4-[4-(2-hydroxy- 2-Methyl-propionyl)-benzyl]phenyl}-2-methyl-1-propanone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, 2 -(Dimethyl amino)-1-(4-morpholino phenyl)-2-benzyl-1-butanone, 2-(dimethyl amino)-2-[(4-methylphenyl)methyl]-1-[4-( 4-morpholinyl)phenyl]-1-butanone, oxy-phenyl-acetic acid 2-[2-oxo-2-phenyl-acetoxy-ethoxy]-ethyl ester, oxy-phenyl-acetic acid 2-[2- Hydroxy-ethoxy]-ethyl ester, methyl benzoyl formate, bis(2,4,6-trimethyl benzoyl)phenylphosphine oxide, 2,4,6-trimethyl benzoyl diphenylphosphine oxide, 2,4,6- Trimethyl benzoyl diphenylphosphinic acid ester, 1-[4-(phenylthio)phenyl]-1,2-octanedione-2-(O-benzoyloxime), 1-[9-ethyl-6-(2-methylbenzoyl) )-9H-carbazol-3-yl]-ethanone-1-(O-acetyloxime), and the like.

Among these, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-[4-(2 -Hydroxy ethoxy)-phenyl]-2-hydroxy-2-methyl-1-propanone, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl) -Benzyl]phenyl}-2-methyl-1-propanone, oxy-phenyl-acetic acid 2-[2-oxo-2-phenyl-acetoxy-ethoxy]-ethyl ester, oxy-phenyl-acetic acid 2-[2 -Hydroxy-ethoxy]-ethyl ester, benzoyl methyl formate, bis(2,4,6-trimethyl benzoyl)phenylphosphine oxide, 2,4,6-trimethyl benzoyl diphenylphosphine oxide, 2,4,6 -Trimethyl benzoyl diphenylphosphinic acid ester and the like are preferred.

Commercially available products of the photopolymerization initiator (D) include Irgacure 184, Irgacure 651, Irgacure 127, DAROCUR 1173, Irgacure 500, and Irgacure. (Irgacure) 2959, Irgacure 754, DAROCUR MBF, Lucirin TPO (all brand names: BASF Japan Ltd.) and the like are preferred.

Among these, the use of Irgacure 754, DAROCUR MBF, and Lucirin TPO is more preferable because the light transmittance of the resulting microlens is highest.

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

If the content of the photopolymerization initiator (D) is 0.5% to 20% by weight based on the total amount of the ink of the present invention, it is preferable because an ink with high sensitivity to ultraviolet rays can be obtained, and more preferably 2% to 20% by weight. And more preferably 5% to 20% by weight.

1-5. Other ingredients

The ink of the present invention is an organic solvent, a polymerization inhibitor, a thermosetting compound, a thermal polymerization initiator, an antioxidant, a colorant, and (meth)acrylamide (A), a cyclic ( Other components, such as a compound (E) having a radically polymerizable double bond other than meth)acrylamide (B) and urethane (meth)acrylate (C), may be included.

1-5-1. Organic solvent

The ink of the present invention may contain an organic solvent for the purpose of adjusting ejection properties. As it contains a solvent, it is possible to finely adjust the viscosity or surface tension of the ink, so that the ejection property can be adjusted.

The organic solvent is not particularly limited, but it is preferably an organic solvent having a boiling point of 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, methyl ethoxyacetate, ethyl ethoxyacetate, 3- Methoxy methyl propionate, 3-methoxy ethyl propionate, 3-ethoxy methyl propionate, 3-ethoxy ethyl propionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, dioxane, 3-methoxy Butanol, 3-methoxybutyl acetate, 2-hydroxy methyl isobutyrate, 2-hydroxy isobutyric acid i-propyl, 2-hydroxy isobutyric acid i-butyl, 2-hydroxy isobutyric acid n-butyl, propylene glycol mono Methyl 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 mono Ethyl 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 acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, dipropylene glycol 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 ethyl ether, dipropylene glycol dimethyl ether, toluene, xylene, anisole, γ-butyrolactone, N,N-dimethylacetamide, And N-methyl-2-phylolidone and dimethylimidazolidinone.

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

When the content of the organic solvent is 0.1% to 20% by weight based on the total amount of the ink of the present invention, it is preferable because an ink having a good balance between ejection properties and other characteristics can be obtained, and more preferably 0.2% to 10% by weight. %, more preferably 0.5% to 8% by weight, particularly preferably 1% 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, dibutyl hydroxy toluene, and phenothiazine. Among these, the use of phenothiazine is preferable because an ink with a small increase in viscosity can be obtained even in long-term storage.

The polymerization inhibitor that can be used 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 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 because an ink with a small change in viscosity can be obtained even in long-term storage, and considering the balance with other properties, It is more preferably 0.01% by weight to 0.5% by weight, and even more preferably 0.01% by weight to 0.1% by weight.

1-5-3. Compounds having radically polymerizable double bonds other than (meth)acrylamide (A), cyclic (meth)acrylamide (B) and urethane (meth)acrylate (C) (E)

The ink of the present invention has (meth)acrylamide (A), cyclic (meth)acrylamide (B), and urethane (meth)acrylate in that the viscosity is adjusted within a range that does not impair the properties of the ink. A compound (E) having a radical polymerizable double bond other than C) may be included.

Although it does not specifically limit as compound (E), 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 1,4-cyclohexane Dimethanol mono (meth) acrylate, glycidyl (meth) acrylate, 3,4-epoxycyclohexyl (meth) acrylate, methyl glycidyl (meth) acrylate, 3-methyl-3- (meth) Acryloxymethyloxetane, 3-ethyl-3-(meth)acryloxymethyloxetane, 3-methyl-3-(meth)acryloxyethyloxetane, 3-ethyl-3-(meth)acryloxyethyloxetane , 2-phenyl-3-(meth)acryloxymethyloxetane, 2-trifluoromethyl-3-(meth)acryloxymethyloxetane, 4-trifluoromethyl-2-(meth)acryloxymethyloxetane, (Meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, t-butyl (meth) )Acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, tricyclo[5.2.1.0 ^2,6 ]decanyl (meth)acrylate, dicyclopentenyl oxyethyl (meth)acrylate, iso Bornyl (meth)acrylate, phenyl (meth)acrylate, glycerol mono (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 5-tetrahydrofurfuryloxycarbonylpentyl (meth)acrylate, lauryl (Meth)acrylate of ethylene oxide adduct of alcohol, ω-carboxypolycaprolactone mono(meth)acrylate, succinic acid mono[2-(meth)acryloyloxyethyl], maleic acid mono[2-(meth)acrylic Royloxyethyl], cyclohexene-3,4-dicarboxylic acid mono[2-(meth)acryloyloxyethyl], (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N- Diethyl (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, N-isopropyl (meth)acrylamide, thioglycidyl (meth)acrylate, phenylthioethyl (meth)acrylate, Ethoxylated o-phenylphenol (meth)acrylate, dicyclopentanyl (meth)acrylate, γ-butyrolactone (meth)acrylate, lauryl (meth)acrylate, methoxide Cyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, 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(meth)acrylic Rate, 1,4-cyclohexanedimethanol di(meth)acrylate, 2-n-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, trimethylolpropane di(meth)acrylate, Tricyclodecanedimethanol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, bis[2-(meth)acrylo Yloxyethyl]hydroxyethyl isocyanurate, styrene, methylstyrene, chloromethylstyrene, N-cyclohexylmaleimide, N-phenylmaleimide, vinyltoluene, polystyrene macromonomer, crotonic acid, α-chloroacrylic acid, cinnamic acid , Maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, pentaerythritol di(meth)acrylate, pentaerythritol di(meth)acrylate monostearate, dipentaerythritol di(meth)acrylate, pentaerythritol tri (Meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethylene oxide modified trimethyl Roll propane tri(meth)acrylate, propylene oxide modified trimethylolpropane tri(meth)acrylate, epichlorohydrin modified trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, glycerol tri (Meth)acrylate, epichlorohydrin modified glycerol tri(meth)acrylate, diglycerin tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, caprolactone modified Dipentaerythritol hexa(meth)acrylate, ethylene oxide Modified phosphoric acid tri(meth)acrylate, tris[2-(meth)acryloyloxyethyl]isocyanurate, caprolactone modified tris[(meth)acryloxyethyl]isocyanurate, acid-modified epoxy (meth) Acrylate, acid-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. have.

The compound (E) that can be used in the ink of the present invention may be a single compound or a mixture of two or more compounds.

When the ink of the present invention contains the compound (E), the compounding amount of the compound (E) is preferably 1% to 40% by weight, based on the total amount of the ink of the present invention, and can be used in the ink of the present invention. Considering the balance with other materials present, it is particularly preferably 1% to 15% by weight.

1-5-4. Thermosetting compound

The ink of the present invention may contain a thermosetting compound in order to obtain a microlens whose optical properties are not easily deteriorated even after a constant temperature and humidity test. The thermosetting compound is not particularly limited as long as it is a compound having a functional group capable of thermosetting, and examples thereof include an epoxy compound, an epoxy curing agent, a bismaleimide, a phenol resin, a resin containing a phenolic hydroxyl group, and a melamine resin.

The thermosetting compound that can be used 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 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 because a microlens that does not deteriorate easily even after a constant temperature and humidity test can be obtained, more preferably 0.1% by weight. To 8% by weight, more preferably 0.5% to 5% by weight.

1-5-4-1. Epoxy compound

The epoxy compound is not particularly limited as long as it has a structure represented by at least one of the following formulas (4-1) or (4-2) per molecule.

......화학식 (4-1)

......Chemical Formula (4-1)

......화학식 (4-2)

......Chemical formula (4-2)

Specific examples of the epoxy compound include novolak type (phenol novolak type and cresol novolak type) epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, trisphenol methane type epoxy resin, hydrogenated bisphenol A type epoxy Resin, hydrogenated bisphenol F type epoxy resin, bisphenol S type epoxy resin, tetraphenylol ethane type epoxy resin, bixylenol type epoxy resin, biphenol type epoxy resin, alicyclic and heterocyclic epoxy resin, and , An epoxy resin having a dicyclopentadiene skeleton or a naphthalene skeleton, and preferably a novolak type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, and a trisphenol methane type epoxy resin.

As the epoxy compound, an epoxy resin produced by a known method may be used, or a commercial item may be used.

Examples of commercial products include jER 828, jER 834, jER 1001, jER 1004 (all trade names: Mitsubishi Chemical Corporation), Epiclon 840, Epiclon 850, Epiclon 1050, and Epiclon 2055 ( All trade names: DIC Co., Ltd., Epotohto YD-011, Epotohto YD-013, Epotohto YD-127, Epotoh YD-128 (all trade names: Shinnittetsu) Chemical Co., Ltd. (Nippon Steel Chemical CO., LTD.), DER 317, D.E.R. 331, D.E.R. 661, D.E.R. 664 (all brand names: Dow Chemical Nihon Co., Ltd.), Araldite 6071, Araldite 6084, Araldite GY250, Araldite GY260 (all brand names: Huntsman Japan Co., Ltd.), Sumiepoxy ( Sumi-Epoxy) ESA-011, Sumiepoxy ESA-014, Sumiepoxy ELA-115, Sumiepoxy ELA-128 (all brand names: Sumitomo Chemical Industries, Ltd.), AER 330, A.E.R. 331, A.E.R. 661 and A.E.R. Bisphenol A type epoxy resins such as 664 (all brand names: Asahi Kasei E-materials Corp.),

jER 152, jER 154 (all trade names: Mitsubishi Chemical Co., Ltd.), D.E.R. 431, D.E.R. 438 (all brand names: Dow Chemical Nihon Co., Ltd.), Epiclon N-730, Epiclon N-770, Epiclon N-865 (all brand names: DIC), Epotto YDCN-701, Epotto YDCN-704 (all brand names: Shinnittetsu Chemical Co., Ltd.), Araldite ECN1235, Araldite ECN1273, Araldite ECN1299 (all brand names: Huntsman Japan Co., Ltd.), XPY307, EPPN- 201, EOCN-1025, EOCN-1020, EOCN-104S, RE-306 (all trade names: NIPPON KAYAKU Co., Ltd.), Sumiepoxy ESCN-195X, Sumie Epoxy ESCN-220 (all brand names: Sumitomo Chemical Industries, Ltd.), AER ECN-235 and A.E.R. Novolac-type epoxy resins such as ECN-299 (all brand names: Asahi Kasei E-Materials Co., Ltd.),

Epiclon 830 (trade name: DIC Co., Ltd.), jER 807 (trade name: Mitsubishi Chemical Co., Ltd.), Epototo YDF-170 (trade name: Shinnittetsu Chemical Co., Ltd.), YDF-175, Bisphenol F type epoxy resins such as YDF-2001, YDF-2004 and Araldite XPY306 (all brand names: Huntsman Japan),

Hydrogenated bisphenol A type epoxy resins such as Epotto ST-2004, Epotto ST-2007 and Epotto ST-3000 (all trade names: Shinnittetsu Chemical Co., Ltd.),

Aliphatic epoxy resins such as Celloxide 2021P (brand name: Daicel), Araldite CY175 and Araldite CY179 (all brand names: Huntsman Japan),

YL-6056, YX-4000, YL-6121 (all brand names: Mitsubishi Chemical Co., Ltd.), such as bixyleneol type or biphenol type epoxy resin or a mixture thereof,

Bisphenol S type epoxy resins such as EBPS-200 (brand name: Nippon Kayaku Co., Ltd.), EPX-30 (brand name: ADEKA Co., Ltd.) and EXA-1514 (brand name: DIC Co., Ltd.),

bisphenol A novolac type epoxy resins such as jER157S (trade name: Mitsubishi Chemical Co., Ltd.),

Tetraphenylol ethane type epoxy resins such as YL-931 (brand name: Mitsubishi Chemical Co., Ltd.) and Araldite 163 (brand name: Huntsman Japan Co., Ltd.),

Heterocyclic epoxy resins such as Araldite PT810 (trade name: Huntsman Japan) and TEPIC (trade name: Nissan Chemical Co., Ltd.),

Epoxy resins having a naphthalene skeleton such as HP-4032, EXA-4750 and EXA-4700 (all trade names: DIC Corporation),

Epoxy resins having dicyclopentadiene skeletons such as HP-7200, HP-7200H and HP-7200HH (all trade names: DIC Co., Ltd.), and

Techmore VG3101L (trade name: Mitsui Chemicals, Inc.), YL-933 (trade name: Mitsubishi Chemicals, Inc.), EPPN-501 and EPPN-502 (both brand names: Nippon Kayaku Tris phenol methane-type epoxy resins, such as 藥) Co., Ltd. are mentioned.

The epoxy compound that can be used in the ink of the present invention may be a single compound or a mixture of two or more compounds.

1-5-4-2. Epoxy hardener

As the epoxy curing agent, an acid anhydride curing agent, a polyamine curing agent, and a catalyst curing agent are preferable.

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

Examples of the polyamine-based curing agent include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dicyandiamide, polyamideamine (polyamide resin), ketimine compound, isophoronediamine, m-xylenediamine, m-phenyl Rendiamine, 1,3-bis(aminomethyl)cyclohexane, N-aminoethylpiperazine, 4,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenyl Methane, and diaminodiphenyl sulfone.

Examples of the catalyst-based curing agent include tertiary amine compounds and imidazole compounds, and specific examples thereof include 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, and 1-cyanoethyl-2-undee Silimidazolium trimellitate, 2-phenylimidazoline, 1-cyanoethyl-2-ethyl-4-methylimidazole, and the like.

The epoxy curing agent that can be used in the ink of the present invention may be a single compound or a mixture of two or more compounds.

1-5-4-3. Bismaleimide

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

......화학식 (5)

......Chemical Formula (5)

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

-R ¹¹ -YR ¹² -......Chemical Formula (6)

In the formula (6), R ¹¹ and R ¹² are each independently, at least one non-contiguous (non-neighboring) alkylene having 1 to 18 carbon atoms in which at least one methylene may be substituted with oxygen, and an aromatic ring which may have a substituent It is a divalent group having a or cycloalkylene which may have a substituent. Examples of the substituent include carboxyl, hydroxy, alkyl having 1 to 5 carbon atoms, and alkoxy having 1 to 5 carbon atoms. From the viewpoint of obtaining a microlens having high heat resistance, it is preferable that R ¹¹ and R ¹² are each independently one kind of divalent group selected from the following general formula group (b).

In the above formula (6), Y is a divalent group selected from the following formula group (c).

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

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

As the phenolic resin, a novolac resin obtained by condensation reaction of an aromatic compound having a phenolic hydroxyl group and aldehydes can be preferably used, and as a resin containing a phenolic hydroxyl group, a homopolymer of vinyl phenol (including hydrogen additives) And vinyl phenol-based copolymers (including hydrogen additives) of vinyl phenol and a compound capable of copolymerization therewith can be preferably used.

As an aromatic compound having a phenolic hydroxyl group, phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, m-ethylphenol, p-ethylphenol, o-butylphenol, m-butylphenol, p- Butylphenol, 2,3-xyleneol, 2,4-xyleneol, 2,5-xyleneol, 2,6-xyleneol, 3,4-xyleneol, 3,5-xyleneol, 2,3,5 -Trimethylphenol, 3,4,5-trimethylphenol, p-phenylphenol, resorcinol, hydroquinone, hydroquinone monomethyl ether, pyrogallol, bisphenol A, bisphenol F, terpene (terpene) Skeletal-containing diphenol, molybdenum, molybdenum ester, α-naphthol, and β-naphthol.

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

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

As a specific example of a phenolic resin, Resitop PSM-6200 (trade name: GUN EI CHEMICAL INDUSTRY CO., LTD.), Shonol BRG-555 (trade name) : SHOWA DENKO KK), as a specific example of a resin containing a phenolic hydroxyl group, Maruka Lyncur M S-2G, Maruka Linker CST70 and Maruka Linker PHM-C (all brand names: Maruzen Petrochemical Co., LTD.) is mentioned.

The phenolic resin or resin containing a phenolic hydroxyl group that can be used in the ink of the present invention may be a single compound or a mixture of two or more compounds.

1-5-4-5. Melamine resin

The melamine resin is not particularly limited as long as it is a resin prepared by polycondensation of melamine and formaldehyde, and methylol melamine, etherified methylol melamine, benzoguanamine, methylol benzoguanamine and etherified methylol benzoguanamine, etc. Condensates of. Among these, the condensation product of etherified methylol melamine is preferable from the viewpoint of improving the chemical resistance of the resulting microlens.

As a specific example of the melamine resin, Nikarac MW-30, Nikarac MW-30HM, Nikarac MW-390, Nikarac MW-100LM, Nikarac MX-750LM (trade name: Sanwa Chemical Co., Ltd. ., Ltd.)).

The melamine resin that can be used in the ink of the present invention may be a single compound or a mixture of two or more compounds.

1-5-5. Thermal polymerization initiator

The ink of the present invention may contain a thermal polymerization initiator because the curability of the ink is improved by a heating step. Specific examples of the thermal polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis (2,4-dimethyl valeronitrile), benzoyl peroxide, di-t peroxide. -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 ( A brand name: SANSHIN CHEMICAL INDUSTRY CO., LTD.) is mentioned. Among these, 2,2'-azobisisobutyronitrile and 2,2'-azobis (2,4-dimethylvaleronitrile) are preferable.

The thermal polymerization initiator that can be used in the ink of the present invention may be a single compound or a mixture of two or more compounds.

The content of the thermal polymerization initiator is preferably 10% by weight or less with respect to 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 addition effect and ejection stability.

1-5-6. Antioxidant

The ink of the present invention may contain an antioxidant in order to prevent oxidation of the resulting microlens.

As an antioxidant, triethylene glycol-bis-[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5 -Di-t-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 3,5-di- hindered phenol compounds such as t-butyl-4-hydroxy benzyl phosphonate diethyl ester, and amine compounds such as n-butylamine, triethylamine, and diethylamino methyl methacrylate. .

The antioxidant that can be used in the ink of the present invention may be a single compound or a mixture of two or more 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 addition effect and ejection stability.

1-5-7. coloring agent

Although the ink of the present invention may be colored or colorless, for example, when examining the state of the microlens obtained by curing the ink by applying it to a substrate, it is easy to identify the microlens and the substrate. To do this, a colorant may be included. As the colorant, dyes and pigments are preferable.

The colorant that can be used 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 colorant is 0.1 parts by weight to 5 parts by weight based on 100 parts by weight of the solid content in the ink of the present invention, it is preferable because inspection of the microlens obtained from the ink becomes easy, and considering the balance with other characteristics, it is more preferable. Preferably, it is 0.1 parts by weight to 1 part by weight, more preferably 0.1 parts by weight to 0.5 parts 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 storage stability is good.

1-7. Viscosity of ink

The viscosity of the ink of the present invention at 25° C. measured with an E-type viscometer is preferably 2 mPa·s to 200 mPa·s, more preferably 2 mPa·s to 100 mPa·s. When the viscosity is in such a range, the ejection property by the ink jet apparatus becomes good.

1-8. How to prepare ink

The ink of the present invention can be prepared by mixing each component as a raw material by a known method.

In particular, the ink of the present invention, the (meth) acrylamide (A), cyclic (meth) acrylamide (B), urethane (meth) acrylate (C) and a photoinitiator (D), and, if necessary, other It is preferable to prepare the solution obtained by mixing the components by filtering and degassing, for example, using a membrane filter. The ink prepared in this way has excellent ejection properties.

1-9. Application of ink by inkjet method

The ink of the present invention can be applied using a known ink jet method. Examples of the inkjet method include a piezo method in which the ink is ejected from the inkjet head by applying mechanical energy to the ink, and a coating method in which the ink is ejected by applying thermal energy to the ink (ie, a thermal method).

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

Examples of the inkjet head include those having a heat generating portion made of metal and/or metal oxide. Specific examples of the metal and/or metal oxide include metals such as tantalum (Ta), zirconium (Zr), titanium (Ti), nickel (Ni), and aluminum (Al), and oxides of these metals.

As a preferred coating device used when applying the ink of the present invention, for example, an ink in an ink jet head having an ink receiving portion in which the ink is accommodated is given energy corresponding to a coating signal, and the ink An apparatus that performs coating (drawing) corresponding to the coating signal while generating droplets is exemplified.

The inkjet coating apparatus is not limited to a separate inkjet head and an ink receiving portion, and may be one in which the inkjet head and the ink receiving portion are separated. Further, the ink receiving portion may be detachably or non-separably integrated with the inkjet head and mounted on a carriage, or may be provided at a fixed portion of the device. In the latter case, an ink supply member, for example, a type of supplying ink to the inkjet head through a tube may be used.

2. Micro Lens

The microlens of the present invention is formed from the ink of the present invention described above, and specifically, after the ink of the present invention is applied to the surface of a substrate by an inkjet method, the ink is cured by irradiating the ink with light such as ultraviolet rays or visible rays. The microlens obtained by this is preferable.

Since the microlens of the present invention is obtained by curing the ink of the present invention, it has a good shape and at the same time is a microlens having good optical properties even after a constant temperature and humidity test.

When irradiated with ultraviolet rays or visible light, irradiating light exposure is good, but if properly selected according to the composition of the ink, 100mJ / cm ² to 5,000mJ / cm ² level are preferred, and 150mJ / cm ² to 2,000mJ / cm ² and about more preferably, 180mJ / cm ² to 1,000mJ / cm ² degree is more preferred. Further, the wavelength such as ultraviolet rays or visible rays to be irradiated is preferably about 200 nm to 500 nm, more preferably about 250 nm to 450 nm.

In addition, in the present invention, the exposure amount is a value measured with a cumulative photometer UIT-201 (brand name) attached with a light receiver UVD-365PD (brand name) manufactured by Ushio Electric Corporation (USHIO INC.).

And as the exposure machine, 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. are mounted, and is a device that irradiates ultraviolet rays or visible rays in the range of 200 nm to 500 nm. It is desirable.

In addition, if necessary, the microlens cured by irradiation of light may be further heated and fired. By heating and firing at 80°C to 250°C for 10 to 60 minutes, the microlens can be more firmly cured. I can.

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

The substrate is not particularly limited, but examples include a polyester resin substrate made of polyethylene telephthalate (PET) and polybutylene telephthalate (PBT), a polyolefin resin substrate made of polyethylene and polypropylene, and polypropylene. Organic polymer film made of vinyl chloride, fluororesin, acrylic resin, polyamide, polycarbonate, and polyimide, substrate made of cellophane, metal foil, laminated film of polyimide and metal foil, glassine having a filling effect (glassine) paper, parchment paper, polyethylene, clay binder, polyvinyl alcohol, paper filled with starch or carboxymethyl cellulose (CMC), and glass substrates.

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

As the substrate, a substrate containing additives such as an antioxidant, an anti-deterioration agent, a filler, an ultraviolet absorber, an antistatic agent and/or an electromagnetic wave inhibitor may be used within a range that does not adversely affect the effects of the present invention. In addition, the substrate may be a substrate that has undergone surface treatment such as corona treatment, plasma treatment, or blast treatment as necessary on at least a part of the surface of the substrate, and is used for an easily adhesive layer or color filter on the surface. A substrate provided with a protective film or a hard coat film may be used.

As described above, according to the ink of the present invention, a microlens having a good shape can be formed without surface treatment of the substrate, but the surface of the substrate is necessary for the purpose of obtaining a microlens having a smaller diameter and a higher height. You may perform a liquid-repellent treatment.

In addition, when the ink of the present invention is discharged onto a substrate, particularly an acrylic substrate, it is preferable that the surface state of the substrate is spotless (partially extremely lyophilic or not liquid-repellent). Therefore, it is preferable to surface-treat the substrate surface for the purpose of removing stains on the substrate surface.

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

The ratio (H/D) of the lens height (H) to the lens diameter (D) of the microlens may be appropriately selected according to the intended use, and is not particularly limited, but optical components having excellent light extraction efficiency can be manufactured. In terms of presence, it is preferably 0.15 or more, and more preferably 0.16 or more.

In the present invention, the term "microlens of good shape" refers to a microlens having a substantially round shape and the ratio of the height of the lens to the diameter of the lens in the above range.

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

3. Optical components

The optical component of the present invention is not particularly limited as long as it has the microlens, but it is preferable that the microlens is provided on a substrate.

As such an optical component, a light guide plate etc. are mentioned.

4. Device

The device of the present invention has the above optical component.

Examples of such devices include displays and lighting.

By installing the light guide plate on the backlight, for example, a liquid crystal monitor for a liquid crystal display device can be produced, and an LED light source unit with a built-in light guide plate and a high-brightness LED is provided at both ends of the light guide plate, and LED lighting can be produced. have.

Example

Hereinafter, the present invention will be further described by examples, but the present invention is not limited or limited thereto.

In the following, the inkjet ink obtained in the examples may be simply referred to as ink. In other words, inkjet ink 1 may be referred to as ink 1, for example.

Example 1

As (meth)acrylamide (A), as N-(hydroxyethyl)acrylamide, HEAA (trade name: Kojin Co., Ltd.), as cyclic (meth)acrylamide (B), N-acryl ACMO (trade name: Kojin Co., Ltd.), a roilmorpholine, as urethane (meth)acrylate (C), CN9893 (trade name: Satomer Co., Ltd., bifunctional urethane (meth) acrylate ) And as the photopolymerization initiator (D), oxy-phenyl-acetic acid 2-[2-oxo-2-phenyl-acetoxy-ethoxy]-ethyl ester and oxy-phenyl-acetic acid 2-[2-hydroxy-ethoxy ]-Irgacure 754 (trade name: BASF Japan Co., Ltd., hereinafter abbreviated as'Ir754'), a mixture with ethyl ester, was mixed in the following composition ratio and completely dissolved, and then ultra-high molecular weight polyethylene (UPE) Filtration was carried out with an original membrane filter (0.2 µm) to obtain a filtrate (ink 1).

(A) HEAA 10.00g

(B) ACMO 78.00g

(C) CN9893 12.00g

(D) Ir 754 7.00g

As a result of measuring the viscosity of Ink 1 at 25°C using an E-type viscometer (TOKI SANGYO CO., LTD. TV-22, the same below), 44 mPa·s Was.

Example 2

As urethane (meth)acrylate (C), KAYARAD UXE-1000 (trade name: Nippon Kayaku Co., Ltd., tetrafunctional urethane (meth)acrylate, hereinafter abbreviated as'UXE-1000') Ink 2 was prepared in the same manner as in Example 1, except that the following ratio was used using.

(A) HEAA 10.00g

(B) ACMO 78.00g

(C) UXE-1000 12.00g

(D) Ir 754 7.00g

The viscosity of Ink 2 at 25°C was measured using an E-type viscometer and found to be 48 mPa·s.

Example 3

As the urethane (meth)acrylate (C), as in Example 1, except that U-6LPA (trade name: Shinnakamura Chemical Co., Ltd., six-functional urethane (meth)acrylate) was used in the following ratio. Thus, Ink 3 was prepared.

(A) HEAA 10.00g

(B) ACMO 80.00g

(C) U-6LPA 10.00g

(D) Ir 754 7.00g

The viscosity of Ink 3 at 25°C was measured using an E-type viscometer and found to be 48 mPa·s.

Example 4

As (meth)acrylamide (A), using N-(hydroxymethyl)acrylamide (hereinafter abbreviated as'HMAA'), as urethane (meth)acrylate (C), CN9001 (trade name: Sartomer Ink 4 was prepared in the same manner as in Example 1, except that (note) and a bifunctional urethane (meth)acrylate) were used in the following ratio.

(A) HMAA 10.00g

(B) ACMO 80.00g

(C) CN9001 10.00g

(D) Ir 754 7.00g

The viscosity of Ink 4 at 25°C was measured using an E-type viscometer and found to be 41 mPa·s.

Example 5

As urethane (meth)acrylate (C), CN2302 (trade name: Sartomer Co., Ltd., 16-functional urethane (meth)acrylate. Viscosity at 25°C: 300 mPa·s) was used in the following ratio. Other than that, ink 5 was prepared in the same manner as in Example 1.

(A) HEAA 10.00g

(B) ACMO 70.00g

(C) CN2302 20.00g

(D) Ir 754 7.00g

The viscosity of Ink 5 at 25°C was measured using an E-type viscometer and found to be 38 mPa·s.

Comparative Example 1

Ink 6 was prepared in the same manner as in Example 1, except that the urethane (meth)acrylate (C) was not used and the following ratio was used.

(A) HEAA 20.00g

(B) ACMO 80.00g

(D) Ir 754 7.00g

The viscosity of Ink 6 at 25°C was measured using an E-type viscometer and found to be 33 mPa·s.

Comparative Example 2

Ink 7 in the same manner as in Example 1, except that (meth)acrylamide (A) was not used and instead, 2-hydroxyethyl methacrylate (hereinafter abbreviated as'HEMA') was used to make the following ratio. Was prepared.

(Other) HEMA 10.00g

(B) ACMO 80.00g

(C) CN 9893 10.00g

(D) Ir 754 7.00g

The viscosity of Ink 7 at 25°C was measured using an E-type viscometer and found to be 25 mPa·s.

Comparative Example 3

In the same manner as in Example 1, except that (meth)acrylamide (A) was not used and instead of using N-(butoxymethyl)acrylamide (hereinafter, abbreviated as'BMAA') was used in the following ratio. Ink 8 was prepared.

(Others) BMAA 10.00g

(B) ACMO 80.00g

(C) CN 9893 10.00g

(D) Ir 754 7.00g

The viscosity of Ink 8 at 25°C was measured using an E-type viscometer and found to be 29 mPa·s.

Comparative Example 4

As in Example 1, except that cyclic (meth)acrylamide (B) was not used, and instead of using N,N-diethylacrylamide (hereinafter, abbreviated as'DEAA') was used in the following ratio. Thus, Ink 9 was prepared.

(A) HEAA 10.00g

(Others) DEAA 80.00g

(C) CN 9893 10.00g

(D) Ir 754 7.00g

The viscosity of Ink 9 at 25°C was measured using an E-type viscometer and found to be 8 mPa·s.

Comparative Example 5

Ink in the same manner as in Example 1, except that cyclic (meth)acrylamide (B) was not used, and instead of using tetrahydrofurfuryl acrylate (hereinafter, abbreviated as'THFA') was used in the following ratio. 10 was prepared.

(A) HEAA 10.00g

(Other) THFA 80.00g

(C) CN 9893 10.00g

(D) Ir 754 7.00g

The viscosity of Ink 10 at 25° C. was measured using an E-type viscometer and found to be 12 mPa·s.

Comparative Example 6

Instead of using urethane (meth)acrylate (C), tricyclodecane dimethanol diacrylate, IRR214-K (trade name: DAICEL-CYTEC Company LTD) was used as follows: Except having made it the ratio, it carried out similarly to Example 1, and prepared Ink 11.

(A) HEAA 10.00g

(B) ACMO 80.00g

(Others) IRR214-K 10.00g

(D) Ir 754 7.00g

The viscosity of Ink 11 at 25°C was measured using an E-type viscometer and found to be 18 mPa·s.

Comparative Example 7

Do not use urethane (meth)acrylate (C), but instead of using EBECRYL 140 (trade name: Daicel Cytec Co., hereinafter abbreviated as'EB-140'), except for the ratio below. Ink 12 was prepared in the same manner as in Example 1.

(A) HEAA 10.00g

(B) ACMO 75.00g

(Others) EB-140 15.00g

(D) Ir 754 7.00g

The viscosity of Ink 12 at 25°C was measured using an E-type viscometer and found to be 16 mPa·s.

Comparative Example 8

Example 1, except that urethane (meth)acrylate (C) was not used, and instead of using DPHA (trade name: NOF CORPORATION), which is dipentaerythritol hexaacrylate, in the following ratio. In the same way, Ink 13 was prepared.

(A) HEAA 10.00g

(B) ACMO 75.00g

(Others) DPHA 15.00g

(D) Ir 754 7.00g

The viscosity of Ink 13 at 25°C was measured using an E-type viscometer and found to be 27 mPa·s.

Evaluation of ink, micro lens and cured film

In the shape evaluation and H/D evaluation of the microlens obtained by ink jet ejection of the ink obtained as described above, the light transmittance at 400 nm of the cured film obtained from the ink obtained as described above and L ^* a ^* b ^* color system measurement of the b ^* value, the constant temperature and humidity test and after the light transmittance of the 400㎚ of L ^* a ^* b ^* color system b ^* were measured and the film thickness measurement of the value of the.

Formation of micro lenses

Inks (1 to 13) obtained as described above were injected into an inkjet cartridge, mounted on an inkjet apparatus DMP-2831 (trade name: FUJIFILM Dimatix Inc.) using a 10pl (picoliter) inkjet head, and a discharge voltage (piezo). Both (piezo) voltage) and discharge temperature were set as described in Table 1 according to the ink viscosity. At a driving frequency of 5 kHz, one dot was discharged on an acrylic substrate Deraglas AD999 (trade name: ASAHIKASEI TECHNOPLUS Co., Ltd.) at 150 μm intervals. Thereafter, the acrylic substrate with dot patterns formed at equal intervals was irradiated with light having a cumulative exposure of 1,000 mJ/cm ² using a UV irradiation device J-CURE1500 (trade name: JATEC Co., Ltd.), and ink (1 to 13). ) To obtain an acrylic substrate (1a to 13a) with microlenses formed thereon. The following measurement and evaluation were performed using these acrylic substrates 1a to 13a.

Evaluation of shape

The shape of the microlens on the substrates 1a to 13a on which the microlenses obtained as described above are formed is observed using an optical microscope BX51 (trade name: OLYMPUS Co., Ltd.), and the shape of the microlens is shown in Table 1. It was evaluated as.

And the evaluation criteria of the shape of the micro lens are as follows.

(Double-circle): The shape of all microlenses is almost round shape.

○: The shape of most microlenses is almost round, but in rare cases a microlens that is not almost round is seen.

[Delta]: The shape of the microlens is mixed with those that are almost round and not.

■: All microlenses are distorted.

In the present invention, ``nearly round shape'' refers to a plan view of a microlens formed on a substrate (a drawing when the substrate on which the microlens is formed is viewed from above the microlens toward the substrate direction (the height direction of the microlens)), When the microlens looks like a circular (or oval) shape, preferably, the outline of the microlens is a shape such as drawing a smooth circle (or ellipse), and a shape such as a part of a circle is cut off, or It is said that the shape of the microlens is almost not a true circle or is distorted when the shape of a circle is shaped like a jump out or the outline of the microlens is uneven.

H/D evaluation

The diameter of the microlens described above was measured using an optical microscope BX51 (trade name: OLYMPUS Co., Ltd.). As the value of the lens diameter, the average value of the arbitrary three microlens diameters was used. Then, the lens height of the microlens was measured using a contact type thin film thickness meter P-15 (brand name) manufactured by KLA-Tencor Japan. As the value of the lens height, the average value of the heights of any three microlenses was used.

A value of H/D (Height/Diameter) was calculated by dividing the microlens height obtained as described above by the microlens diameter. Table 1 shows the H/D values of the microlenses on the substrates 1a to 13a.

Formation of cured film

Inks (1 to 13) were applied to a 4 cm wide glass substrate (thickness: 0.7 mm) with a spin coater set at the number of rotations shown in Table 2. Thereafter, the glass substrates coated with the inks 1 to 13 are irradiated with light having a cumulative exposure amount of 1,000 mJ/cm ² such as microlens formation to cure the inks 1 to 13, wherein the cured film forming substrates 1b to 13b) was obtained. The following measurement and evaluation were performed using these cured film formation substrates 1b to 13b.

Optical property evaluation

The light transmittance and b ^* value at a wavelength of 400 nm were measured using the obtained cured film forming substrates 1b to 13b. Light transmittance measurement and b ^* value were measured using a transmittance measuring device V-670 (trade name: Nippon Bunko Co., Ltd.).

In addition, as a reference, a glass substrate having a width of 4 cm in which a cured film was not formed was used. Table 2 shows the light transmittance and b ^* value at 400 nm of the cured film forming substrates 1b to 13b.

Evaluation of optical properties after constant temperature and humidity test

The above-described cured film-forming substrates 1b to 13b are set at a furnace temperature of 50°C and a relative humidity of 90% in a small constant temperature and humidity tester SH-641 (trade name: ESPEC CORP.) for 65 hours. Enshrined. Thereafter, the cured film forming substrates 1b to 13b were taken out from the small 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.

Table 2 shows the light transmittance and b ^* value at 400 nm of the cured film-forming substrates 1b to 13b after the constant temperature and humidity test.

Film thickness measurement

A part of the cured film of the glass substrates 1b to 13b with the cured film after the constant temperature and humidity test was cut with a cutter, and the film thickness of the stepped part was measured by KLA-Tencor Japan Co., Ltd., a contact-type film thickness meter P-15 (brand name). It measured using, and calculated the average value of the measurement at three locations.

As can be seen from Tables 1 and 2, in Examples 1 to 5, the H/D values of the microlenses were large, and the optical properties were good even after the constant temperature and humidity test. In Example 5, since urethane (meth)acrylate (C) having a low viscosity was used, H/D was slightly lowered.

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 a substrate. In addition, the optical properties of the microlens obtained from the ink of the present invention are excellent even after the constant temperature and humidity test. Therefore, the ink of the present invention can be suitably used to manufacture optical components such as light guide plates and devices such as displays or lightings having the same.

Claims (10)

In inkjet ink, (meth)acrylamide (A) represented by the following formula (1), cyclic (meth)acrylamide (B) represented by the following formula (2), urethane (meth)acrylate (C), and photopolymerization It includes an initiator (D), and the (meth)acrylamide (A) is in an amount of 5% to 40% by weight, based on the total amount of the inkjet ink, and the cyclic (meth)acrylamide (B) is 40 In an amount of weight% to 85% by weight, the urethane (meth)acrylate (C) in an amount of 5 to 20% by weight, and the photopolymerization initiator (D) in an amount of 0.5 to 20% by weight Inkjet ink, characterized in that.

......Formula (1)
In the above formula (1), R ¹ is hydrogen or methyl, 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, an oil having 1 to 10 carbon atoms. It is an organic group having 1 to 10 carbon atoms including a device or a hydroxyl group.

......Chemical Formula (2)
In the above formula (2), R ⁴ is hydrogen or methyl, and R ⁵ is a divalent organic group. The inkjet ink of claim 1, wherein R ² in the formula (1) is alkylene having 1 to 5 carbon atoms, and R ³ is hydrogen or alkyl 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 -......Formula (3)
In the above formula (3), R ⁶ and R ⁷ are each independently alkylene having 1 to 3 carbon atoms, and X is oxygen or sulfur. The inkjet ink according to claim 1, wherein the urethane (meth)acrylate (C) has a viscosity at 25°C of 5,000 mPa·s or more. The at least one compound according to claim 1, wherein the photoinitiator (D) is an acylphosphine oxide-based initiator, an oxyphenyl acetate-based initiator, a benzoyl formic acid-based initiator, and a hydroxyphenylketone-based initiator. Inkjet ink, characterized in that. The inkjet ink according to any one of claims 1 to 5, for forming microlenses. A microlens obtained by curing the inkjet ink according to any one of claims 1 to 5. An optical component having a micro lens according to claim 7. A device having an optical component according to claim 8. delete