JP2005290133A - Ultraviolet curable low refractive index material composition and antireflection film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a UV curable low refractive index which has good curability even when irradiated with a low amount of light, has excellent scratch resistance, coating property and durability when cured, and has a cured film substantially transparent and excellent in color tone. An index material composition and an antireflection film are provided.
SOLUTION: An ethylenically unsaturated group-containing fluoropolymer, a polyfunctional (meth) acrylate compound containing at least two (meth) acryloyl groups and / or at least one (meth) acryloyl group. A fluorine-containing (meth) acrylate compound to be contained, an extinction coefficient at a wavelength of 365 nm of 5 × 10 ² ml / g · cm or more, and an extinction coefficient at a wavelength of 405 nm of 1 × 10 ² ml / g · cm or less; An ultraviolet curable low refractive index material composition comprising a photopolymerization initiator, wherein the content of the photopolymerization initiator is 0.01 to 15% by weight when the total amount of the composition is 100% by weight.
[Selection] Figure 1

Description

  The present invention relates to an ultraviolet curable low refractive index material composition and an antireflection film. More specifically, the curability is good even at a low irradiation light amount, and when cured, an ultraviolet curable low refractive index material composition capable of obtaining a cured product excellent in scratch resistance, coating property, and durability, And an antireflection film including a low refractive index layer made of such a cured product.

In various display panels such as liquid crystal display panels, cold cathode ray tube panels, plasma displays, etc., in order to prevent reflection of external light and improve image quality, it has low refractive index, scratch resistance, coatability, and durability. There is a need for an antireflection film including a low refractive index layer made of an excellent cured product.
Such an antireflection film is composed of a material for a low refractive index layer, for example, a cured product of a curable composition containing an ethylenically unsaturated group-containing fluoropolymer and a photopolymerization initiator.
As a conventional photopolymerization initiator, one having an extinction coefficient at a wavelength of 365 nm of less than 5 × 10 ² ml / g · cm such as IRGACURE 184 (trade name, manufactured by Ciba Geigy) has been used.
However, such an initiator has a problem that the curing becomes insufficient when the irradiation light quantity is low (for example, about 200 mJ).

  Therefore, the present invention is excellent in curability even with a low irradiation light quantity, excellent in scratch resistance, coating property and durability when cured, and UV cured with a cured film substantially transparent and excellent in color tone. An object of the present invention is to provide a low refractive index material composition and an antireflection film.

According to the present invention, the following ultraviolet curable low refractive index material composition and the like are provided.
1. An ethylenically unsaturated group-containing fluoropolymer,
A polyfunctional (meth) acrylate compound containing at least two (meth) acryloyl groups and / or a fluorine-containing (meth) acrylate compound containing at least one (meth) acryloyl group;
A photopolymerization initiator having an extinction coefficient at a wavelength of 365 nm of 5 × 10 ² ml / g · cm or more and an extinction coefficient at a wavelength of 405 nm of 1 × 10 ² ml / g · cm or less. An ultraviolet curable low refractive index material composition in which the content of the initiator is 0.01 to 15% by weight when the total amount of the composition is 100% by weight.
2. 2. The ultraviolet curable low refractive index material composition according to 1, wherein the total concentration of the (meth) acryloyl group is 1.9 mmol / g or more.
3. An antireflection film comprising a low refractive index layer made of a cured product obtained by curing the ultraviolet curable low refractive index material composition described in 3.1 or 2.

  The ultraviolet curable low refractive index material composition of the present invention has good curability even with a low irradiation light amount, and the cured film is substantially transparent and excellent in color tone. Abrasion property, coating property, and durability can be obtained. The composition of the present invention has a higher ultraviolet curing rate than the conventional one.

  Embodiments of the ultraviolet curable low refractive index material composition and antireflection film of the present invention will be described below.

The ultraviolet curable low refractive index material composition of the present invention includes the following components (A) to (C).
(I) Ethylenically unsaturated group-containing fluorine-containing polymer (b) Polyfunctional (meth) acrylate compound containing at least two (meth) acryloyl groups and / or at least one (meth) acryloyl Fluorine-containing (meth) acrylate compound containing a group (c) The extinction coefficient at a wavelength of 365 nm is 5.0 × 10 ² ml / g · cm or more, and the extinction coefficient at a wavelength of 405 nm is 1 × 10 ² ml / g / cm or less photopolymerization initiator

The ethylenically unsaturated group-containing fluoropolymer used in the present invention preferably comprises a compound containing one isocyanate group, at least one ethylenically unsaturated group, and a hydroxyl group-containing fluoropolymer. It is obtained by reacting at a ratio of isocyanate group / hydroxyl group of 1.1 to 1.9.
By reacting at such a molar ratio, an ethylenically unsaturated group-containing fluorine-containing polymer in which all hydroxyl groups are reacted with isocyanate groups can be obtained. As a result, scratch resistance such as gauze wear resistance and durability such as alkali resistance are enhanced.

The compound containing one isocyanate group and at least one ethylenically unsaturated group is a compound containing one isocyanate group and at least one ethylenically unsaturated group in the molecule. If it is, it will not be restrict | limited in particular.
In addition, when two or more isocyanate groups are contained, there is a possibility of causing gelation when reacting with a hydroxyl group-containing fluoropolymer.
Moreover, since the composition of this invention can be hardened more easily as said ethylenically unsaturated group, the compound which has a (meth) acryloyl group is more preferable.
By making the ethylenically unsaturated group a (meth) acryloyl group, the ethylenically unsaturated group-containing fluoropolymer can be polymerized by a polymerization reaction by radicals generated by ultraviolet rays, and the coating film can be cured.
As such a compound, 2- (meth) acryloyloxyethyl isocyanate and 2- (meth) acryloyloxypropyl isocyanate may be used singly or in combination of two or more.
By using 2- (meth) acryloyloxyethyl isocyanate, an ethylenically unsaturated group can be introduced while maintaining a low refractive index.

Such a compound can also be synthesized by reacting diisocyanate and a hydroxyl group-containing (meth) acrylate.
In this case, examples of the diisocyanate include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, 1,5-naphthalene diisocyanate, m- Phenylene diisocyanate, p-phenylene diisocyanate, 3,3′-dimethyl-4,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, 3,3′-dimethylphenylene diisocyanate, 4,4′-biphenylene diisocyanate, 1, 6-hexane diisocyanate, isophorone diisocyanate, methylene bis (4-cyclohexyl isocyanate), 2,2,4-trimethylhexamethylene diisocyanate, bis (2-isocyanate ethyl) Malate, 6-isopropyl-1,3-phenyl diisocyanate, 4-diphenylpropane diisocyanate, lysine diisocyanate, hydrogenated diphenylmethane diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, tetramethylxylylene diisocyanate, 2,5 (or 6 ) -Bis (isocyanatomethyl) -bicyclo [2.2.1] heptane, or a combination of two or more thereof.
Among these, 2,4-tolylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, methylenebis (4-cyclohexylisocyanate), and 1,3-bis (isocyanatomethyl) cyclohexane are particularly preferable.

Examples of hydroxyl group-containing (meth) acrylates include 2-hydroxyethyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, caprolactone (meth) acrylate, polypropylene glycol (meta ) Acrylate, dipentaerythritol penta (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol di (meth) acrylate monostearate, isocyanuric acid EO-modified di (meth) acrylate, or a combination of two or more Is mentioned.
Among these, 2-hydroxyethyl (meth) acrylate and pentaerythritol tri (meth) acrylate are particularly preferable.
In addition, as a commercial item of a hydroxyl-containing polyfunctional (meth) acrylate, for example, Osaka Organic Chemical Co., Ltd. product name HEA, Nippon Kayaku Co., Ltd. product name KAYARAD DPHA, PET-30, Toagosei Co., Ltd. Product name Aronix M-215, M-233, M-305, M-400 and the like can be obtained.

  When synthesizing from diisocyanate and a hydroxyl group-containing polyfunctional (meth) acrylate, the amount of the hydroxyl group-containing polyfunctional (meth) acrylate added is preferably 1 to 1.2 mol with respect to 1 mol of diisocyanate.

  Examples of a method for synthesizing such a compound include a method in which diisocyanate and a hydroxyl group-containing (meth) acrylate are charged together and a reaction, a method in which diisocyanate is dropped into a hydroxyl group-containing (meth) acrylate, and a reaction method.

［一般式（１）中、Ｒ^１はフッ素原子、フルオロアルキル基、又は−ＯＲ^２で表される基（Ｒ^２はアルキル基、又はフルオロアルキル基を示す）を示す］ The hydroxyl group-containing fluoropolymer used in the present invention preferably contains the following structural unit (a).
(A) A structural unit represented by the following general formula (1).

[In General Formula (1), R ¹ represents a fluorine atom, a fluoroalkyl group, or a group represented by —OR ² (R ² represents an alkyl group or a fluoroalkyl group)]

In the general formula (1), examples of the fluoroalkyl group of R ¹ and R ² include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluorohexyl group, and a perfluorocyclohexyl group. And a C1-C6 fluoroalkyl group. The alkyl group R ^2, a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an alkyl group having 1 to 6 carbon atoms such as a cyclohexyl group.

The structural unit (a) can be introduced by using a fluorine-containing vinyl monomer as a polymerization component. Such a fluorine-containing vinyl monomer is not particularly limited as long as it is a compound having at least one polymerizable unsaturated double bond and at least one fluorine atom. Examples of this include fluoroolefins such as tetrafluoroethylene, hexafluoropropylene and 3,3,3-trifluoropropylene; alkyl perfluorovinyl ethers or alkoxyalkyl perfluorovinyl ethers; perfluoro (methyl vinyl ether), perfluorovinyl ethers; Perfluoro (alkyl vinyl ethers) such as fluoro (ethyl vinyl ether), perfluoro (propyl vinyl ether), perfluoro (butyl vinyl ether), perfluoro (isobutyl vinyl ether); perfluoro (alkoxyalkyl) such as perfluoro (propoxypropyl vinyl ether) Vinyl ethers) may be used singly or in combination of two or more.
Among these, hexafluoropropylene and perfluoro (alkyl vinyl ether) or perfluoro (alkoxyalkyl vinyl ether) are more preferable, and it is more preferable to use these in combination.

In addition, the content rate of a structural unit (a) is 20-70 mol% when the whole quantity of a hydroxyl-containing fluoropolymer is 100 mol%. The reason for this is that when the content is less than 20 mol%, it is sometimes difficult to develop a low refractive index, which is the characteristic of the optically fluorine-containing material intended by the present application. This is because when the ratio exceeds 70 mol%, the solubility of the hydroxyl group-containing fluoropolymer in an organic solvent, transparency, or adhesion to a substrate may be lowered.
For these reasons, the content of the structural unit (a) is more preferably 25 to 65 mol%, and more preferably 30 to 60 mol%, based on the total amount of the hydroxyl group-containing fluoropolymer. Is more preferable.

［一般式（２）中、Ｒ^３は水素原子又はメチル基を、Ｒ^４はアルキル基、−（ＣＨ_２）_ｘ−ＯＲ^５若しくは−ＯＣＯＲ^５で表される基（Ｒ^５はアルキル基、又はグリシジル基を、ｘは０又は１の数を示す）、カルボキシル基、又はアルコキシカルボニル基を示す］ The hydroxyl group-containing fluoropolymer preferably contains the following structural unit (b).
(B) A structural unit represented by the following general formula (2).

[In General Formula (2), R ³ represents a hydrogen atom or a methyl group, R ⁴ represents an alkyl group, a group represented by — (CH ₂ ) _x —OR ⁵ or —OCOR ⁵ (R ⁵ represents an alkyl group, or A glycidyl group, x represents a number of 0 or 1), a carboxyl group, or an alkoxycarbonyl group]

In the general formula (2), examples of the alkyl group represented by R ⁴ or R ⁵ include alkyl groups having 1 to 12 carbon atoms such as a methyl group, an ethyl group, a propyl group, a hexyl group, a cyclohexyl group, and a lauryl group. Examples of the carbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group.

  The structural unit (b) can be introduced by using the above-mentioned vinyl monomer having a substituent as a polymerization component. Examples of such vinyl monomers include methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, tert-butyl vinyl ether, n-pentyl vinyl ether, n-hexyl vinyl ether, n -Alkyl vinyl ethers or cycloalkyl vinyl ethers such as octyl vinyl ether, n-dodecyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexyl vinyl ether; allyl ethers such as ethyl allyl ether, butyl allyl ether; vinyl acetate, vinyl propionate, vinyl butyrate, pivalin Carboxylic acid vinyl ester such as vinyl acid vinyl, vinyl caproate, vinyl vinyl versatate, vinyl stearate Tellurium; methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2- ( (Meth) acrylic acid esters such as n-propoxy) ethyl (meth) acrylate; (meth) acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid and other unsaturated carboxylic acids, etc. The combination of is mentioned.

In addition, the content rate of a structural unit (b) is 10-70 mol% when the whole quantity of a hydroxyl-containing fluoropolymer is 100 mol%. This is because if the content is less than 10 mol%, the solubility of the hydroxyl group-containing fluoropolymer in the organic solvent may be reduced. On the other hand, if the content exceeds 70 mol%, the hydroxyl group This is because optical properties such as transparency and low reflectivity of the fluorinated polymer may be deteriorated.
For such reasons, the content of the structural unit (b) is more preferably 20 to 60 mol%, and more preferably 30 to 60 mol%, based on the total amount of the hydroxyl group-containing fluoropolymer. Is more preferable.

［一般式（３）中、Ｒ^６は水素原子、又はメチル基を、Ｒ^７は水素原子、又はヒドロキシアルキル基を、ｖは０又は１の数を示す］ The hydroxyl group-containing fluoropolymer preferably contains the following structural unit (c).
(C) A structural unit represented by the following general formula (3).

[In General Formula (3), R ⁶ represents a hydrogen atom or a methyl group, R ⁷ represents a hydrogen atom or a hydroxyalkyl group, and v represents a number of 0 or 1]

In the general formula (3), as the hydroxyalkyl group of R ⁷ , 2-hydroxyethyl group, 2-hydroxypropyl group, 3-hydroxypropyl group, 4-hydroxybutyl group, 3-hydroxybutyl group, 5-hydroxypentyl Group, 6-hydroxyhexyl group.

The structural unit (c) can be introduced by using a hydroxyl group-containing vinyl monomer as a polymerization component. Examples of such hydroxyl group-containing vinyl monomers include 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 3-hydroxybutyl vinyl ether, 5-hydroxypentyl vinyl ether, Examples include hydroxyl group-containing vinyl ethers such as 6-hydroxyhexyl vinyl ether, hydroxyl group-containing allyl ethers such as 2-hydroxyethyl allyl ether, 4-hydroxybutyl allyl ether, and glycerol monoallyl ether, allyl alcohol, and the like.
Moreover, as a hydroxyl-containing vinyl monomer, in addition to the above, 2-hydroxyethyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, caprolactone (meth) acrylate, polypropylene Glycol (meth) acrylate or the like can be used.

In addition, it is preferable that the content rate of a structural unit (c) shall be 5-70 mol% when the whole quantity of a hydroxyl-containing fluoropolymer is 100 mol%. This is because if the content is less than 5 mol%, the solubility of the hydroxyl group-containing fluoropolymer in the organic solvent may be reduced. On the other hand, if the content exceeds 70 mol%, the hydroxyl group This is because optical properties such as transparency and low reflectivity of the fluorinated polymer may be deteriorated.
For such reasons, the content of the structural unit (c) is more preferably 5 to 40 mol%, and more preferably 5 to 30 mol%, based on the total amount of the hydroxyl group-containing fluoropolymer. Is more preferable.

［一般式（４）中、Ｒ^８及びＲ^９は、同一でも異なっていてもよく、水素原子、アルキル基、ハロゲン化アルキル基、又はアリール基を示す］
構造単位（ｄ）を含むことにより、耐擦傷性が向上する。
以下、構造単位（ｄ）について説明する。 Further, the hydroxyl group-containing fluoropolymer preferably further comprises the following structural unit (d).
(D) A structural unit represented by the following general formula (4).

[In General Formula (4), R ⁸ and R ⁹ may be the same or different and each represents a hydrogen atom, an alkyl group, a halogenated alkyl group, or an aryl group]
By including the structural unit (d), the scratch resistance is improved.
Hereinafter, the structural unit (d) will be described.

In the general formula (4), the alkyl group of R ⁸ or R ^{9 is} an alkyl group having 1 to 3 carbon atoms such as a methyl group, an ethyl group or a propyl group, and the halogenated alkyl group is a trifluoromethyl group, Examples of the fluoroalkyl group having 1 to 4 carbon atoms such as a fluoroethyl group, a perfluoropropyl group, and a perfluorobutyl group, and examples of the aryl group include a phenyl group, a benzyl group, and a naphthyl group.

  The structural unit (d) can be introduced by using an azo group-containing polysiloxane compound having a polysiloxane segment represented by the general formula (4). Examples of such azo group-containing polysiloxane compounds include compounds represented by the following general formula (5).

［一般式（５）中、Ｒ^１０〜Ｒ^１３は水素原子、アルキル基、又はシアノ基を示し、Ｒ^１４〜Ｒ^１７は水素原子又はアルキル基を示し、ｐ、ｑは１〜６の数、ｓ、ｔは０〜６の数、ｙは１〜２００の数、ｚは１〜２０の数である。］

[In General Formula (5), R ^{10 to} R ¹³ represent a hydrogen atom, an alkyl group, or a cyano group, R ^{14 to} R ¹⁷ represent a hydrogen atom or an alkyl group, and p and q are numbers of 1 to 6, s and t are numbers from 0 to 6, y is a number from 1 to 200, and z is a number from 1 to 20. ]

［一般式（６）中、Ｒ^１０〜Ｒ^１３、Ｒ^１４〜Ｒ^１７、ｐ、ｑ、ｓ、ｔ、ｙは、上記一般式（５）と同じである］ When the compound represented by the general formula (5) is used, the structural unit (d) is included in the hydroxyl group-containing fluoropolymer as a part of the following structural unit (e).
(E) A structural unit represented by the following general formula (6).

[In General Formula (6), R ^{10 to} R ¹³ , R ^{14 to} R ¹⁷ , p, q, s, t, and y are the same as those in General Formula (5) above]

In the general formula (5), examples of the alkyl group represented by R ^{10 to} R ¹³ include alkyl groups having 1 to 12 carbon atoms such as a methyl group, an ethyl group, a propyl group, a hexyl group, and a cyclohexyl group, and R ^{14 to} R ^Examples of the ¹⁷ alkyl group include an alkyl group having 1 to 3 carbon atoms such as a methyl group, an ethyl group, and a propyl group.

［一般式（７）中、ｙ及びｚは、上記一般式（５）と同じである。］ In the present invention, the azo group-containing polysiloxane compound represented by the general formula (5) is particularly preferably a compound represented by the following general formula (7).

[In general formula (7), y and z are the same as the said general formula (5). ]

In addition, it is preferable that the content rate of a structural unit (d) shall be 0.1-10 mol% when the whole quantity of a hydroxyl-containing fluoropolymer is 100 mol%. The reason for this is that when the content is less than 0.1 mol%, the surface slipperiness of the cured coating film is lowered, and the scratch resistance of the coating film may be lowered. If the amount exceeds 10 mol%, the transparency of the hydroxyl group-containing fluoropolymer is inferior, and when used as a coating material, repelling and the like are likely to occur during coating.
For these reasons, the content of the structural unit (d) is more preferably 0.1 to 5 mol% with respect to the total amount of the hydroxyl group-containing fluoropolymer, More preferably, it is mol%. For the same reason, the content of the structural unit (e) is desirably determined so that the content of the structural unit (d) contained therein is in the above range.

［一般式（６）中、Ｒ^１８は乳化作用を有する基を示す］
構造単位（ｆ）を含むことにより、塗工性が向上する。
以下、構造単位（ｆ）について説明する。 Further, the hydroxyl group-containing fluoropolymer preferably further comprises the following structural unit (f).
(F) A structural unit represented by the following general formula (8).

[In General Formula (6), R ¹⁸ represents a group having an emulsifying action]
By including the structural unit (f), the coating property is improved.
Hereinafter, the structural unit (f) will be described.

In the general formula (8), the group having an emulsifying action of R ¹⁸ is a group having both a hydrophobic group and a hydrophilic group, and the hydrophilic group having a polyether structure such as polyethylene oxide and polypropylene oxide. Is preferred.

［一般式（９）中、ｎは１〜２０の数、ｍは０〜４の数、ｕは３〜５０の数を示す］ Examples of the group having such an emulsifying action include a group represented by the following general formula (9).

[In General Formula (9), n is a number from 1 to 20, m is a number from 0 to 4, and u is a number from 3 to 50]

［一般式（１０）中、ｎ、ｍ、及びｕは、上記一般式（９）と同様である］ The structural unit (f) can be introduced by using a reactive emulsifier as a polymerization component. Examples of such reactive emulsifiers include compounds represented by the following general formula (10).

[In general formula (10), n, m, and u are the same as those in general formula (9) above]

In addition, it is preferable that the content rate of a structural unit (f) shall be 0.1-5 mol% when the whole quantity of a hydroxyl-containing fluoropolymer is 100 mol%. The reason for this is that when the content is 0.1 mol% or more, the solubility of the hydroxyl group-containing fluoropolymer in the solvent is improved. On the other hand, if the content is within 5 mol%, the tackiness of the composition is improved. Is not excessively increased, handling becomes easy, and moisture resistance does not decrease even when used as a coating material.
For such reasons, the content of the structural unit (f) is more preferably 0.1 to 3 mol% based on the total amount of the hydroxyl group-containing fluoropolymer, and 0.2 to 3 More preferably, it is mol%.

The hydroxyl group-containing fluoropolymer has a number average molecular weight in terms of polystyrene measured by gel permeation chromatography (hereinafter referred to as “GPC”) using tetrahydrofuran (hereinafter referred to as “THF”) as a solvent. It is preferable that The reason for this is that when the number average molecular weight is less than 5,000, the mechanical strength of the hydroxyl group-containing fluoropolymer may be reduced. On the other hand, when the number average molecular weight exceeds 500,000, the composition This is because the viscosity of the film becomes high and thin film coating may be difficult.
For these reasons, the number average molecular weight in terms of polystyrene of the hydroxyl group-containing fluoropolymer is more preferably 10,000 to 300,000, and even more preferably 10,000 to 100,000.

The ethylenically unsaturated group-containing fluoropolymer used in the present invention comprises the above-described compound containing one isocyanate group and at least one ethylenically unsaturated group, and a hydroxyl group-containing fluoropolymer. Preferably, it is obtained by reacting at a ratio of 1.1 to 1.9 in the molar ratio of isocyanate group / hydroxyl group. The reason for this is that if the molar ratio is less than 1.1, the scratch resistance and durability may be reduced. On the other hand, if the molar ratio exceeds 1.9, the coating film of the composition is immersed in an alkaline aqueous solution. This is because the subsequent scratch resistance may decrease.
For this reason, the molar ratio of isocyanate group / hydroxyl group is preferably 1.1 to 1.5, and more preferably 1.2 to 1.5.

The content of the component (a) is not particularly limited, but is usually 3 to 95% by weight when the total amount of the composition is 100% by weight. The reason for this is that when the addition amount is less than 3% by weight, the refractive index of the cured coating film of the composition becomes high and a sufficient antireflection effect may not be obtained, while the addition amount is 95% by weight. This is because the scratch resistance of the cured coating film of the composition may not be obtained if it exceeds%.
For this reason, the amount of component (a) added is more preferably 5 to 90% by weight, and even more preferably 10 to 80% by weight.

  The polyfunctional (meth) acrylate compound containing at least two (meth) acryloyl groups used in the present invention enhances the scratch resistance of a cured product obtained by curing the composition and an antireflection film using the cured product. Used for.

The compound is not particularly limited as long as it is a compound containing at least two (meth) acryloyl groups in the molecule. Examples include dipentaerythritol tri (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolethane tri (meth) acrylate. , Pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, alkyl-modified dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, alkyl-modified dipentaerythritol penta (meth) acrylate, di Pentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate, ditrimethylolpro Ntetora (meth) acrylate, "U-15HA" (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.) are exemplified alone or in combinations of two or more such.
Of these, dipentaerythritol tri (meth) acrylate, neopentyl glycol di (meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate and Caprolactone-modified dipentaerythritol hexa (meth) acrylate is particularly preferred.

  The fluorine-containing (meth) acrylate compound containing at least one (meth) acryloyl group used in the present invention is used to lower the refractive index of the composition.

  The compound is not particularly limited as long as it is a fluorine-containing (meth) acrylate compound containing at least one (meth) acryloyl group. As such an example, one kind of perfluorooctylethyl (meth) acrylate, octafluoropentyl (meth) acrylate, trifluoroethyl (meth) acrylate, or a combination of two or more kinds can be given.

The content of the component (b) is not particularly limited, but is usually 3 to 95% by weight when the total amount of the composition is 100% by weight. This is because if the amount added is less than 3% by weight, the scratch resistance of the cured coating film of the composition may not be obtained. On the other hand, if the amount added exceeds 95% by weight, This is because the refractive index of the cured coating film becomes high and a sufficient antireflection effect may not be obtained.
For this reason, the amount of component (b) is more preferably 5 to 90% by weight, and even more preferably 10 to 80% by weight.
Furthermore, in the present invention, the total concentration of (meth) acryloyl groups in the composition is preferably 1.9 mmol / g or more, and more preferably 2.0 mmol / g or more.

The photopolymerization initiator used in the present invention is used for curing the composition by ultraviolet irradiation. Specifically, examples of the active species include a photo radical generator that generates radicals.
The photopolymerization initiator used in the present invention has an extinction coefficient at 365 nm of 5 × 10 ² ml / g · cm or more, preferably 7 × 10 ² ml / g · cm or more, more preferably 1 × 10 ³ ml / g · cm. cm or more.
The photopolymerization initiator used in the present invention has an extinction coefficient at 405 nm of 1 × 10 ² ml / g · cm or less, preferably 5 × 10 ¹ ml / g · cm or less, more preferably 1 × 10 ¹ ml / cm. g · cm or less.
By using a photopolymerization initiator having such an extinction coefficient, a cured product having good curability and color tone (not noticeable) can be obtained even with a low irradiation light amount (for example, about 200 mJ).

  Examples of the photoradical generator include 4-benzoyl-4′-methyldiphenyl sulfide, Irgacure 1300 (trade name, manufactured by Ciba Specialty Chemicals), and more preferably 4-benzoyl-4′-methyl. Examples thereof include diphenyl sulfide.

The content of component (c) is 0.01 to 15% by weight, preferably 0.05 to 15% by weight, more preferably 0.1 to 15% by weight, when the total amount of the composition is 100% by weight. . If the content is less than 0.01% by weight, the curing reaction may be insufficient and the scratch resistance may be reduced. On the other hand, if it exceeds 15% by weight, it may act as a plasticizer and impair the scratch resistance, or foreign matter may be generated in the cured film and the appearance may be impaired.
In the composition of the present invention, the content of the initiator having an extinction coefficient at 365 nm of 5 × 10 ² ml / g · cm or more and an extinction coefficient at 405 nm of 1 × 10 ² ml / g · cm or less is as described above. An initiator having an extinction coefficient of less than 5 × 10 ² ml / g · cm (eg, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-1,2-diphenylethane-1-one, etc.) You may use together.

  In the composition of the present invention, a compound that generates active species by heat (hereinafter referred to as “thermal polymerization initiator”) may be used together with a photopolymerization initiator. Examples of such compounds include thermal radical generators that generate radicals as active species.

  Examples of thermal radical generators include benzoyl peroxide, tert-butyl-oxybenzoate, azobisisobutyronitrile, acetyl peroxide, lauryl peroxide, tert-butyl peracetate, cumyl peroxide, tert-butyl peroxide , Tert-butyl hydroperoxide, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), etc. The combination of the above can be mentioned.

The addition amount of the thermal polymerization initiator is not particularly limited, but is preferably 0.01 to 20 parts by weight with respect to 100 parts by weight of the ethylenically unsaturated group-containing fluoropolymer. The reason for this is that when the addition amount is less than 0.01 parts by weight, the curing reaction becomes insufficient, and the scratch resistance and the scratch resistance after immersion in an alkaline aqueous solution may decrease. On the other hand, when the addition amount of the photopolymerization initiator exceeds 20 parts by weight, the refractive index of the cured product increases and the antireflection effect may be lowered.
For these reasons, it is more preferable to add 0.05 to 15 parts by weight of the thermal polymerization initiator with respect to 100 parts by weight of the ethylenically unsaturated group-containing fluoropolymer, More preferably, it is 15 parts by weight.

  Further, it is preferable to add an organic solvent to the composition. Thus, by adding an organic solvent, a thin antireflection film can be formed uniformly. Examples of such an organic solvent include one kind of methyl isobutyl ketone (hereinafter sometimes referred to as “MIBK”), methyl ethyl ketone, methanol, ethanol, t-butanol, and isopropanol, or a combination of two or more kinds.

  The addition amount of the organic solvent is not particularly limited, but is preferably 100 to 100,000 parts by weight with respect to 100 parts by weight of the ethylenically unsaturated group-containing fluoropolymer. This is because when the amount added is less than 100 parts by weight, it may be difficult to adjust the viscosity of the composition. On the other hand, when the amount added exceeds 100,000 parts by weight, the storage stability of the composition is increased. This is because there is a case where it is difficult to handle due to a decrease in viscosity or a decrease in viscosity.

  The composition of the present invention includes a radical photopolymerization initiator, a photosensitizer, a polymerization inhibitor, a polymerization initiator assistant, a leveling agent, a wettability improver, an interface within a range that does not impair the purpose and effect of the present invention It is also preferable to further contain additives such as an activator, a plasticizer, an ultraviolet absorber, an antioxidant, an antistatic agent, a silane coupling agent, an inorganic filler, a pigment, and a dye.

  The composition of the present invention can be prepared by adding the above components (a) to (c) or, if necessary, an organic solvent and an additive and mixing them at room temperature or under heating conditions. Specifically, it can be prepared using a mixer such as a mixer, a kneader, a ball mill, or a three roll. However, when mixing under heating conditions, it is preferable to carry out at or below the decomposition start temperature of the thermal polymerization initiator.

The curing conditions of the composition of the present invention are not particularly limited, but it is preferable that the ultraviolet light exposure is 0.01 to 10 J / cm ² .
The reason for this is that when the exposure amount is less than 0.01 J / cm ² , curing failure may occur. On the other hand, when the exposure amount exceeds 10 J / cm ² , the curing time may become excessively long. Because there is.
For such reasons, the exposure dose is more preferably 0.1 to 5 J / cm ^2, and more preferably 0.2 to 3 J / cm ² .

Next, the antireflection film of the present invention will be described.
The antireflection film of the present invention includes a low refractive index layer made of a cured product obtained by curing the above composition. Furthermore, the antireflection film of the present invention can comprise a high refractive index layer, a hard coat layer, and a substrate under the low refractive index layer.
FIG. 1 shows such an antireflection film 10. As shown in FIG. 1, a hard coat layer 14, a high refractive index layer 16, and a low refractive index layer 18 are laminated on a substrate 12.
At this time, the high refractive index layer 16 may be formed directly on the substrate 12 without providing the hard coat layer 14.
Further, an intermediate refractive index layer (not shown) may be further provided between the high refractive index layer 16 and the low refractive index layer 18 or between the high refractive index layer 16 and the hard coat layer 14.

  The low refractive index layer is composed of a cured product obtained by curing the composition of the present invention. Since the composition and the like of the composition are as described above, a specific description thereof will be omitted, and the refractive index and thickness of the low refractive index layer will be described below.

The refractive index of the cured product obtained by curing the composition of the present invention (the refractive index of Na-D line, measurement temperature 25 ° C.), that is, the refractive index of the low refractive index layer is preferably 1.45 or less. . This is because when the refractive index of the low refractive index layer exceeds 1.45, the antireflection effect may be remarkably lowered when combined with the high refractive index layer.
Therefore, the refractive index of the low refractive index layer is more preferably 1.44 or less, and further preferably 1.43 or less.
In the case where a plurality of low refractive index layers are provided, it is sufficient that at least one of the low refractive index layers has a refractive index value within the above-mentioned range. Therefore, the other low refractive index layers exceed 1.45. It may be a value.

Moreover, when providing a low refractive index layer, since the more excellent antireflection effect is acquired, it is preferable to make the refractive index difference between high refractive index layers into 0.05 or more values. The reason for this is that when the refractive index difference between the low refractive index layer and the high refractive index layer is less than 0.05, a synergistic effect in these antireflective film layers cannot be obtained. This is because there is a case in which the lowering may occur.
Therefore, the refractive index difference between the low refractive index layer and the high refractive index layer is more preferably 0.1 to 0.5, and still more preferably 0.15 to 0.5.

Moreover, although it does not restrict | limit especially also about the thickness of a low-refractive-index layer, For example, it is preferable that it is 50-300 nm. The reason for this is that when the thickness of the low refractive index layer is less than 50 nm, the adhesion to the high refractive index film as the base may be reduced. On the other hand, when the thickness exceeds 300 nm, optical interference occurs. This is because the antireflection effect may be reduced.
Therefore, the thickness of the low refractive index layer is more preferably 50 to 250 nm, and further preferably 60 to 200 nm.
In order to obtain higher antireflection properties, when a plurality of low refractive index layers are provided to form a multilayer structure, the total thickness may be set to 50 to 300 nm.

Although it does not restrict | limit especially as a curable composition for forming a high refractive index layer, As a film formation component, an epoxy resin, phenol resin, melamine resin, alkyd resin, cyanate resin It is preferable to include one kind alone or a combination of two or more kinds such as acrylic resin, polyester resin, urethane resin, and siloxane resin. With these resins, a strong thin film can be formed as the high refractive index layer, and as a result, the scratch resistance of the antireflection film can be remarkably improved.
However, the refractive index of these resins alone is usually 1.45 to 1.62, which may not be sufficient to obtain high antireflection performance. Therefore, it is more preferable to blend high refractive index inorganic particles, for example, metal oxide particles. Moreover, as a hardening form, although the curable composition which can be thermosetting, ultraviolet curing, and electron beam curing can be used, the ultraviolet curable composition with favorable productivity is used more suitably.

The thickness of the high refractive index layer is not particularly limited, but is preferably 50 to 30,000 nm, for example. The reason for this is that when the thickness of the high refractive index layer is less than 50 nm, the antireflection effect and adhesion to the substrate may be reduced when combined with the low refractive index layer, while the thickness is If the thickness exceeds 30,000 nm, optical interference may occur, and the antireflection effect may be reduced.
Therefore, the thickness of the high refractive index layer is more preferably 50 to 1,000 nm, and further preferably 60 to 500 nm.
Further, in order to obtain higher antireflection properties, when a plurality of high refractive index layers are provided to form a multilayer structure, the total thickness may be set to 50 to 30,000 nm.
In addition, when providing a hard-coat layer between a high refractive index layer and a base material, the thickness of a high refractive index layer can be 50-300 nm.

  The constituent material of the hard coat layer used for the antireflection film of the present invention is not particularly limited. Examples of such a material include one kind of siloxane resin, acrylic resin, melamine resin, epoxy resin, or a combination of two or more kinds.

  Moreover, although it does not restrict | limit especially also about the thickness of a hard-coat layer, it is preferable to set it as 1-50 micrometers, and it is more preferable to set it as 5-10 micrometers. The reason for this is that when the thickness of the hard coat layer is less than 1 μm, the adhesion of the antireflection film to the substrate may not be improved. On the other hand, when the thickness exceeds 50 μm, it is uniform. This is because it may be difficult to form.

  Although the kind of base material used for the antireflection film of the present invention is not particularly limited, for example, a base material made of glass, polycarbonate resin, polyester resin, acrylic resin, triacetyl cellulose resin (TAC) or the like. Can be mentioned. By using an antireflection film containing these base materials, excellent reflection can be achieved in a wide range of application areas of antireflection films such as camera lens parts, television (CRT) screen display parts, and color filters in liquid crystal display devices. The prevention effect can be obtained.

  Examples of the present invention will be described in detail below, but the scope of the present invention is not limited to the description of these examples.

Production Example 1
Synthesis of Hydroxyl Group-Containing Fluoropolymer After a 2.0-liter stainless steel autoclave with a magnetic stirrer was sufficiently replaced with nitrogen gas, 400 g of ethyl acetate, 76.3 g of perfluoro (propyl vinyl ether) (FPVE), ethyl vinyl ether (EVE) ) 48.2 g, hydroxyethyl vinyl ether (HEVE) 25.2 g, lauroyl peroxide 1.00 g, azo group-containing polydimethylsiloxane represented by the above general formula (8) (VPS1001 (trade name), Wako Pure Chemical Industries, Ltd.) 6.0 g) and 20.0 g of a nonionic reactive emulsifier (NE-30 (trade name), manufactured by Asahi Denka Kogyo Co., Ltd.) were charged, cooled to -50 ° C with dry ice-methanol, and again The oxygen in the system was removed with nitrogen gas.
Next, 100.0 g of hexafluoropropylene (HFP) was charged, and the temperature increase was started. The pressure when the temperature in the autoclave reached 60 ° C. was 5.3 × 10 ⁵ Pa. Thereafter, the reaction was continued with stirring at 70 ° C. for 20 hours. When the pressure dropped to 1.7 × 10 ⁵ Pa, the autoclave was cooled with water to stop the reaction. After reaching room temperature, unreacted monomers were released and the autoclave was opened to obtain a polymer solution having a solid content concentration of 26.4%. The obtained polymer solution was put into methanol to precipitate a polymer, washed with methanol, and vacuum dried at 50 ° C. to obtain 220 g of a hydroxyl group-containing fluoropolymer. Table 1 shows the monomers and solvents used.
Attached to the obtained hydroxyl group-containing fluoropolymer, the polystyrene-equivalent number average molecular weight by GPC and the fluorine content by the alizarin complexone method were measured. ^{Further, 1 H-NMR, 13 C} -NMR both results of NMR analysis, elemental analysis and fluorine content to determine the percentage of each monomer component constituting the hydroxyl group-containing fluoropolymer. The results are shown in Table 2.

VPS1001 is an azo group-containing polydimethylsiloxane represented by the above general formula (8) having a number average molecular weight of 70 to 90,000 and a polysiloxane portion having a molecular weight of about 10,000. NE-30 is a nonionic reactive emulsifier wherein n is 9, m is 1 and u is 30 in the general formula (10).
Furthermore, in Table 2, the correspondence between the monomer and the structural unit is as follows.
Monomer Structural unit Hexafluoropropylene (a)
Perfluoro (propyl vinyl ether) (a)
Ethyl vinyl ether (b)
Hydroxyethyl vinyl ether (c)
NE-30 (f)
Polydimethylsiloxane skeleton (d)

Production Example 2
Preparation of zirconia-containing hard coat layer composition In a dry air solution, a solution comprising 7.8 parts of mercaptopropyltrimethoxysilane and 0.2 parts of dibutyltin dilaurate is stirred at 50 ° C. with 20.6 parts of isophorone diisocyanate. After dropwise addition over 1 hour, the mixture was stirred at 60 ° C. for 3 hours. 71.4 parts of pentaerythritol triacrylate was added dropwise thereto at 30 ° C. over 1 hour, and the mixture was heated and stirred at 60 ° C. for 3 hours to obtain an organic compound (S1).
Next, 8.2 parts of the synthesized organic compound (S1), 91.8 parts of toluene zirconia sol (number average particle diameter 0.01 μm, zirconia concentration 30%), 41.2 parts of methyl ethyl ketone, 0.1 part of ion-exchanged water After the mixture was stirred at 60 ° C. for 4 hours, 1.3 parts of orthoformate methyl ester was added, and the mixture was further heated and stirred at the same temperature for 1 hour to obtain a crosslinkable particle dispersion (dispersion a). 2 g of this dispersion a was weighed on an aluminum dish, dried on a hot plate at 120 ° C. for 1 hour, and weighed to determine the solid content, which was 25%.
312 parts of the produced dispersion a, 12.0 parts of dipentaerythritol hexaacrylate, 9.0 parts of pentaerythritol triacrylate, 2-methyl-1- [4- A uniform solution hard coat layer composition was obtained by stirring 1.0 part of (methylthio) phenyl] -2-morpholinopropan-1-one at 50 ° C. for 2 hours. 2 g of this composition was weighed in an aluminum dish, dried on a hot plate at 120 ° C. for 1 hour, and weighed to determine the solid content, which was 30%.

Production Example 3
Preparation of base material for coating curable resin composition Zirconia-containing hard material prepared in Production Example 2 on an easy-adhesion treated surface of single-sided easy-adhesive polyethylene terephthalate (PET) film A4100 (manufactured by Toyobo Co., Ltd., film thickness 188 μm) The coating layer composition was applied using a wire bar coater (# 7) and dried in an oven at 80 ° C. for 1 minute to form a coating film. Subsequently, ultraviolet rays were irradiated under the light irradiation conditions of 0.9 mJ / cm ² using a high-pressure mercury lamp in the air to prepare a curable resin composition coating substrate. When the film thickness of the hard coat layer on this substrate was measured with a stylus type surface shape measuring instrument, it was 3 μm.

Production Example 4
Synthesis of Ethylenically Unsaturated Group-Containing Fluoropolymer The hydroxyl group-containing fluoropolymer obtained in Production Example 1 was placed in a separable flask having a capacity of 1 liter equipped with a magnetic stirrer, a glass condenser, and a thermometer. 0 g, 0.01 g of 2,6-di-t-butylmethylphenol and 338 g of MIBK as a polymerization inhibitor were charged, and the hydroxyl group-containing fluoropolymer was dissolved in MIBK at 20 ° C. until the solution became transparent and uniform. Went.
Next, 9.5 g of 2-methacryloyloxyethyl isocyanate was added to this system and stirred until the solution became homogeneous, then 0.1 g of dibutyltin dilaurate was added to start the reaction, and the temperature of the system was changed to 55. By maintaining the temperature at ˜65 ° C. and continuing stirring for 5 hours, a MIBK solution of an ethylenically unsaturated group-containing fluoropolymer was obtained. 2 g of this solution was weighed on an aluminum dish, dried on a hot plate at 150 ° C. for 5 minutes, and weighed to determine the solid content, which was 15.1%. The compounds used, solvent and solid content are shown in Table 3.

Hereinafter, the preparation example of the composition of this invention is shown in Examples 1-3 and Comparative Examples 1-3.
Example 1
As shown in Table 4, 90 g of the ethylenically unsaturated group-containing fluoropolymer synthesized in Production Example 4, a polyfunctional (meth) acrylate compound containing at least two (meth) acryloyl groups (hereinafter “polyfunctional”). 10 g of dipentaerythritol pentaacrylate (manufactured by Nippon Kayaku), and 3 g of 4-benzoyl-4′-methyldiphenyl sulfide (photocatalyst BMS (trade name), Nippon Kayaku) Manufactured, content 2.9 wt% in composition) and MIBK 2575 g were charged into a glass separable flask equipped with a stirrer and stirred at 23 ° C. for 1 hour to obtain a uniform composition. Further, the solid content was determined in the same manner as in Production Example 4.

Examples 2-3 and Comparative Examples 1-3
As shown in Table 4, a composition was obtained in the same manner as in Example 1 except that each component was used.

(Test example)
The scratch resistance (curability) and color tone of the cured products obtained by curing the compositions obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were measured by the following measurement methods.
(1) Scratch resistance Each composition was coated on the composition coating substrate prepared in Production Example 3 using a wire bar coater (# 3), and dried in an oven at 80 ° C. for 1 minute. A coating film was formed. Next, an ultraviolet ray was irradiated under a light irradiation condition of 200 mJ / cm ² using a high-pressure mercury lamp under nitrogen to prepare a sample for evaluation. When the film thickness of the cured product layer was estimated by reflectance measurement, it was about 100 nm.

The surface of the prepared sample for evaluation was rubbed with a cellulose nonwoven fabric soaked in ethanol (trade name Bencott, Asahi Kasei Kogyo Co., Ltd.) 20 times by hand, and the scratch resistance of the surface of the sample for evaluation was determined as follows. Visual evaluation was performed from the reference. The results are shown in Table 4.
○: The sample surface for evaluation is intact.
(Triangle | delta): The fine scratch is attached to the sample surface for evaluation.
X: The surface of the sample for evaluation is scratched.

(2) Color tone The appearance of the evaluation sample surface was visually evaluated from the following criteria. The results are shown in Table 4.
○: colorless and transparent ×: yellowish.

  The cured product of the composition of the present invention is useful as an antireflection film for various display panels such as liquid crystal display panels, cold cathode ray tube panels, and plasma displays.

It is sectional drawing of the antireflection film by one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Antireflection film 12 Base material 16 High refractive index layer 18 Low refractive index layer

Claims (3)

An ethylenically unsaturated group-containing fluoropolymer,
A polyfunctional (meth) acrylate compound containing at least two (meth) acryloyl groups and / or a fluorine-containing (meth) acrylate compound containing at least one (meth) acryloyl group;
A photopolymerization initiator having an extinction coefficient at a wavelength of 365 nm of 5 × 10 ² ml / g · cm or more and an extinction coefficient at a wavelength of 405 nm of 1 × 10 ² ml / g · cm or less. An ultraviolet curable low refractive index material composition in which the content of the initiator is 0.01 to 15% by weight when the total amount of the composition is 100% by weight.   The ultraviolet curable low refractive index material composition according to claim 1, wherein the total concentration of the (meth) acryloyl group is 1.9 mmol / g or more.   An antireflection film comprising a low refractive index layer made of a cured product obtained by curing the ultraviolet curable low refractive index material composition according to claim 1.

Images