JP2000319574A - Coating material composition for reflection-preventing coating, and article treated for reflection-prevention - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition capable of forming a reflection- preventing coating film excellent in abrasion resistance and chemical resistance on the surface of an article having a large area by including a specific fluorine- containing resin, a cationically polymerizable compound, a cationic photopolymerization initiator and an organic solvent. SOLUTION: The objective composition is obtained by including (A) a fluorine-containing resin having >=60 wt.% fluorine content, (B) 10-100 pts.wt. cationically polymerizable compound based on 100 pts.wt. component A, (C) 0.1-10 wt.% cationic photopolymerization initiator based on the so-called solid which is the residue obtained by subtracting the amount of the component D from the amount of the whole composition, and (D) an organic solvent. A compound having at least two or more epoxy groups in one molecule is preferably used as the component B. A compound not degrading at normal temperature but rapidly generating an acid which can efficiently initiate the polymerization of the cationically polymerizable functional group, by the irradiation of energy rays is preferably used as the component C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antireflection coating composition and an antireflection treated article for performing an antireflection treatment on a large area article such as a large display.

[0002]

2. Description of the Related Art Heretofore, as a method for performing antireflection treatment on a large-area article such as a large-sized display, there has been known a method of thinly coating the surface of an article to be treated with a composition containing a fluorine-containing resin having a low refractive index. ing.

In this method, it is desirable to crosslink and cure the coating film in order to impart practical wear resistance and chemical resistance. For example, as described in JP-A-8-100136 and JP-A-8-48935, a coating film is formed by a method such as light irradiation using a compound having a polymerizable ethylenically unsaturated group. Crosslinking and curing have been attempted.

However, since the above curing reaction proceeds by a radical mechanism, curing is likely to be insufficient due to curing inhibition by oxygen in the air. Since the antireflection coating film generally forms a very thin coating film having a thickness of about a quarter of the wavelength of light, the antireflection coating film has a large specific surface area, and particularly has a great influence on oxygen-induced curing inhibition. If the curing is insufficient, there is a problem that the wear resistance of the antireflection coating film is reduced.

In order to prevent curing inhibition by oxygen, a curing reaction is performed in an atmosphere of an inert gas such as nitrogen or in a vacuum.
Alternatively, it is necessary to take measures such as covering with a film or the like having an oxygen barrier property and polymerizing, but such a method has a problem that processing of a large area becomes difficult or costs increase.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned conventional problems, and has a practical wear resistance and a good surface resistance on a large-area article. An object of the present invention is to provide an antireflection coating composition and an antireflection treated article that form an antireflection coating film having excellent chemical resistance.

[0007]

The invention according to claim 1 of the present application (Invention 1) comprises a fluorine-containing resin having a fluorine content of 60% by weight or more, a cationic polymerizable compound, and a cationic photopolymerization initiator. A coating composition for antireflection coating, comprising an agent and an organic solvent.

The invention described in claim 2 of the present application (Invention 2)
Comprises a fluorine-containing resin having a fluorine content of 60% by weight or more, a cationically polymerizable compound, a compound having two or more hydroxyl groups, a photo-cationic polymerization initiator, and an organic solvent. It is a composition for paint for prevention coating.

The invention described in claim 3 of the present application (the present invention 3)
Is a compound for an antireflection coating according to the second aspect of the present invention, wherein the compound having two or more hydroxyl groups is a compound represented by the following general formula.

[0010]

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The invention described in claim 4 of the present application (Invention 4)
Means that at least two cationically polymerizable compounds are present in one molecule.
The coating composition for antireflection coating according to any one of the first to third aspects of the present invention, which is a polymerizable substance having one epoxy group.

The invention according to claim 5 of the present application (the present invention 5)
Is an antireflection-treated article having a cured film of the composition for antireflection coating paint according to any one of the present inventions 1 to 4 formed on the surface thereof, wherein the cured film has a thickness of An antireflection treated article characterized by having a thickness of 0.5 μm or less.

(The inventor's draft has no description explaining the problem of less than 60%.) The fluorine-containing resin used in the present invention takes into consideration the refractive index, transparency and solubility in a solvent. To be elected. That is, the refractive index of the antireflection film is in the range of 1.20 to 1.30,
Since the refractive index of the fluorine-containing resin does not fall below 1.3 even with a resin having a high fluorine content, the lower the refractive index, the better. Generally, as the fluorine content increases, the refractive index decreases and the antireflection effect increases, and the fluorine-containing resin in the present invention desirably has a fluorine content of 60% by weight or more.

Further, since the antireflection-treated article of the present invention is disposed on the surface of a display or the like, it is required that the article has high transparency. Factors that hinder the transparency include light absorption and light scattering. However, since the antireflection coating film is formed to be extremely thin, the influence of the former is relatively small and the latter is problematic. If the compatibility between the fluorine-containing resin and other additives is poor or if the crystallinity of the fluorine-containing resin itself is high, light scattering is likely to occur, and the transparency is deteriorated. Therefore, a resin having an appropriate branched structure and good solubility is suitable.

In the present invention, as the fluorine-containing resin,
Fluoroethylene, vinylidene fluoride, trifluoroethylene, tetrafluoroethylene, chlorotrifluoroethylene, 1,2-dichloro-1,2-difluoroethylene, 2-bromo-3,3,3-trifluoroethylene, 3-bromo- 3,3-difluoropropylene, 3,
A fluorine-containing resin which is a polymer or copolymer such as 3,3-trifluoropropylene, 1,1,2-trichloro-3,3,3-trifluoropropylene, hexafluoropropylene, α-trifluoromethacrylic acid is used. No.

The cationically polymerizable compound is preferably a compound having at least two or more epoxy groups in one molecule. This is because a three-dimensional stitch structure is formed by using a compound having a plurality of functional groups in one molecule, and a strong film can be obtained. As the cationic polymerizable functional group,
An epoxy group and an oxetane group are preferable from the viewpoint of polymerizability, physical properties of a cured product, and availability, and an epoxy group and an oxetane group may be used in combination.

As the cationically polymerizable compound having two or more epoxy groups in one molecule, for example, an alicyclic epoxy compound represented by the following chemical formula is preferably used.

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[0018]

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[0019]

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[0020]

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[0021]

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[0022]

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In addition to the alicyclic epoxy compounds described above, polyglycidyl ether, ethylene glycol, propylene glycol, trimethylol porpane, pentaerythritol, which is a reaction product of a polyhydric phenol such as bisphenol A, bisphenol F, and novolak resin with epichlorohydrin Polyglycidyl ether, which is a reaction product of a polyhydric alcohol such as the above and epichlorohydrin, is also preferably used. These may be used alone or in combination of two or more.

The amount of the cationically polymerizable compound is preferably 10 to 100 parts by weight based on 100 parts by weight of the fluorine-containing resin. If the amount is less than 10 parts by weight, the cured film does not have sufficient strength, and if it is 100 parts by weight or more, the refractive index of the cured film is increased and the antireflection performance is reduced.

The cationic photopolymerization initiator may be an electron beam, an ultraviolet ray,
Various compounds are known which generate an acid component upon irradiation with an activating energy ray such as visible light, and various compounds are known. However, in the present invention, the acid is rapidly decomposed at room temperature without being decomposed at normal temperature. Are preferably used, in which the generated acid efficiently initiates the polymerization of the cationically polymerizable functional group.

Examples of such compounds include aromatic diazonium salts, aromatic iodonium salts, aromatic sulfonium salts, pyridinium salts, iron-allene complex compounds, aluminum complex-silanol compounds, and the like.

The amount of the cationic photopolymerization initiator is based on the so-called solid content of the entire composition excluding the organic solvent.
0.1 to 10% by weight is desirable. If the content is less than 0.1% by weight, the curing speed is slowed down, and the practicality is reduced. If the content is more than 10% by weight, the refractive index of the cured film is increased, the antireflection performance is reduced, and the mechanical strength of the cured product is reduced. Because.

In the invention 2, the curing rate is stabilized by adding a compound having two or more hydroxyl groups.
Generally, in a cross-linking curing reaction, as the cross-linking structure is formed, the molecular motion of the reaction system is restricted, so that the reaction speed gradually decreases. Depending on the reaction conditions, a large amount of functional groups may remain as an actual reaction, and if such a reaction ends incompletely, the strength of the cured film may not be sufficient or a secondary reaction may occur. Problems such as deterioration of the cured film occur.

In order to complete the reaction quickly,
There are means (1) increasing the amount of the polymerization initiator, (2) heating the reaction system, and (3) using a chain transfer agent together.

Regarding (1), as described above, if the blending amount is too large, the antireflection performance and the mechanical strength are hindered, so that it is difficult to blend an amount that achieves a desired reaction rate. In some cases, the effect is limited.
The method (2) requires heating the reaction system at the time of light irradiation or heating the reaction system in an oven or the like after the irradiation, and is not preferable because the substrate to be treated can be restricted in terms of heat resistance. On the other hand, the method (3) in which a chain transfer agent is used in combination is preferable because these problems are not caused.

The chain transfer agent reacts with the active species at the terminal of the polymerization to produce an active species having high mobility. This active species reacts with a functional group whose movement is restricted, so that the reaction is completed quickly. It is valid. On the other hand, since the reaction chain is interrupted by reacting with the active species at the polymerization terminal, if the added amount is too large, it acts as a reaction terminator and inhibits crosslinking and curing.

In the cationic reaction, water acts as a chain transfer agent. Accordingly, the presence of an appropriate amount of water promotes the crosslinking and curing reaction, whereas the presence of excess water inhibits the crosslinking and curing. For this reason, the cured state is likely to be unstable due to the influence of the amount of moisture in the curing atmosphere and the amount of moisture attached to the processing substrate. Excessive moisture can be removed relatively easily by controlling drying conditions and the like, but it is difficult to leave only an appropriate amount of moisture, and the curing rate tends to be slow.

In the invention 2, the compound having a hydroxyl group functions as a chain transfer agent. Therefore, a stable curing rate can be obtained as long as the water is sufficiently removed and dried. In addition, since a compound having two or more hydroxyl groups in the molecule is used, it functions as a cross-linking agent and further improves the strength of the cured film.

In the present invention, the compound having two or more hydroxyl groups in one molecule is not particularly limited.
4-butanediol, 1,6-hexanediol, 1,
8-octanediol, 1,10-decanediol,
1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,2,6-hexanetriol,
Pentaerythritol and the like can be used.

The compounding amount of the compound having two or more hydroxyl groups in one molecule is determined by the molar ratio with the cationically polymerizable functional group, and the molar number of the cationically polymerizable functional group contained in the composition is assumed to be 1. Preferably, the number of moles of hydroxyl groups is in the range of 0.01 to 1. If the amount is too small, the effect of addition cannot be obtained, and if the amount is too large, the reaction chain is interrupted as described above to inhibit curing.

In the invention 3, a compound represented by the following general formula is used as a compound having two or more hydroxyl groups in one molecule. By using a compound with a high fluorine content,
The antireflection effect can be further enhanced. Further, since there are hydroxyl groups at both ends of a carbon chain having an appropriate chain length, it can effectively contribute to crosslinking. When the chain length is shorter than this, when one terminal is incorporated into the cross-linking system, the mobility of the remaining hydroxyl group is suppressed, and the reaction probability is reduced. If the carbon chain is longer than this, the interval between crosslinking points is too long, and the crosslinking effect is reduced.

[0037]

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In the present invention, examples of the organic solvent include aromatic hydrocarbons such as toluene and xylene; ketones such as methyl ethyl ketone and methyl isobutyl ketone; esters such as ethyl acetate; ethers such as ethylene glycol monoethyl ether; General-purpose organic solvents that are widely used industrially can be used.

The preferred amount of the organic solvent is determined depending on the coating method, but generally, the solid content is 0.1%.
It is desirable to dilute so as to be 5 to 30% by weight.
The anti-reflection film must be formed as extremely thin as 0.5 μm or less and without thickness unevenness. This is because it is practical to adopt a method of removing the non-volatile components to a predetermined thickness.

The thickness of the cured film of the composition is 0.5
μm or less is preferable, and it is desirable to adjust the thickness to about な る of the wavelength to be antireflection target. If the thickness is 0.5 μm or more, the interference effect is reduced, the reflectance is increased, and the practical antireflection effect is reduced.

[0041]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. Example 1 [Preparation of paint for antireflection coating] 100 parts by weight of a fluorine-containing resin (manufactured by Daikin Industries, trade name "Daiel G-501", fluorine content 68% by weight) and a cation represented by the following formula (Formula 10) 40 parts by weight of a polymerizable compound (manufactured by Daicel Chemical Industries, Ltd., trade name “Eporide GT-403”) and a photocationic polymerization initiator represented by the following formula (Formula 11) (manufactured by Asahi Denka Co., trade name “SP-170”) 3 parts by weight were dissolved in 4000 parts by weight of methyl isobutyl ketone to obtain a coating composition for antireflection coating.

[0042]

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[0043]

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[Preparation of Anti-Reflection Treated Article] Thickness 100 μm
m on a treated substrate consisting of a polyethylene terephthalate (hereinafter abbreviated as “PET”) film using a “microgravure coater” manufactured by Yasui Seiki Co., Ltd. the coating is .1Myuemu, ultraviolet ultra-high pressure mercury lamp to cure the 500 mJ / cm ² irradiated to the coating film, to obtain a PET film with an antireflection treatment. The obtained antireflection-treated PET film is
As shown in FIG. 1, an antireflection-treated article was obtained by attaching the antireflection layers to both sides of a transparent acrylic plate so as to face outward.

[Evaluation of Antireflection Performance] The reflection spectrum of the surface of the antireflection treated article was measured using a spectrophotometer “UV # 3100” manufactured by Shimadzu Corporation. The bottom of the spectrum was at 570 nm. The reflectance is 1.
5%. When this antireflection-treated article was placed on the front of a large display, a good image without reflection was observed.

[Evaluation of abrasion resistance performance] Further, the surface of the antireflection-treated article was placed on a commercially available cleaning cloth for 500 hours.
When a load of 5 g / cm ² was applied and wiping was performed 300 times in a stroke of 5 cm at a speed of 1 reciprocation / second, no scratch was generated, and a streak was formed only after 400 reciprocations.

[Evaluation of Chemical Resistance] Isopropyl alcohol was dropped on the surface of the antireflection-treated article, and was wiped off after standing for 5 minutes. No abnormality was found on the treated surface.
When a commercially available glass cleaner was sprayed on the surface of the antireflection-treated article and wiped off after standing for 5 minutes,
There were no abnormalities on the treated surface.

Example 2 [ Preparation of antireflection coating liquid] As a compound having two or more hydroxyl groups in one molecule, 1H, 1H, 10H, 1
An antireflection coating composition having the same composition as in Example 1 was obtained except that 10 parts by weight of 0H-perfluoro-1,10-decanediol was added.

[Preparation of Anti-Reflection Treated Article] An anti-reflection treated article was obtained in the same manner as in Example 1 using the obtained anti-reflection coating.

[Evaluation of Antireflection Performance] When the reflection spectrum of the surface of the reflection-treated article was measured in the same manner as in Example 1, the bottom of the spectrum was at 560 nm.
Its reflectivity was 1.4%. When this antireflection-treated article was placed on the front of a large display, a good image without reflection was observed.

[Evaluation of Abrasion Resistance Performance] The antireflection treated article was evaluated for the abrasion resistance performance in the same manner as in Example 1. As a result, no damage was caused by wiping 400 reciprocations. With.

[Evaluation of Chemical Resistance] When the antireflection treated article was evaluated for chemical resistance in the same manner as in Example 1, no abnormalities were observed on the treated surface in the case of isopropyl alcohol and in the case of a commercially available glass cleaner. Was.

Comparative Example The cationic polymerizable compound and the cationic photopolymerization initiator were removed from the composition of Example 1, and a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (trade name, manufactured by Nippon Kayaku Co., Ltd.) The same as in Examples, using a coating composition for antireflection coating comprising 40 parts by weight of "Kayarad DPHA") and 3 parts by weight of a photoradical polymerization initiator benzyldimethyl ketal (trade name "Irgacure 651" manufactured by Ciba Geigy). Thus, an antireflection-treated article was obtained.

The antireflection performance of the obtained antireflection-treated article was evaluated in the same manner as in the example. As a result, the degree of reflection was equal to that of the example 1. Similarly, in the same evaluation of abrasion resistance as in Example 1, scratches were found after 100 reciprocations of wiping. Furthermore, in the same evaluation of chemical resistance as in Example 1, in the case of isopropyl alcohol and the case of glass cleaner, the antireflection coating on the surface of the treated article to which the reagent had adhered was peeled off.

[0055]

The antireflection coating composition of the present invention comprises a fluorine-containing resin, a cationically polymerizable compound, a cationic photopolymerization initiator, and an organic solvent. A film is obtained, and there is no polymerization inhibition by oxygen as in radical polymerization. Further, since the fluorine-containing resin has a fluorine content of 60% by weight or more, the refractive index is low, and the antireflection effect is high.

Further, by blending a compound having two or more hydroxyl groups in one molecule, it is possible to obtain a stable curing rate which is hardly affected by the amount of water in the curing atmosphere.
When the compound having two or more hydroxyl groups in the molecule is a compound represented by the following general formula, the antireflection effect can be further enhanced. In addition, since there are hydroxyl groups at both ends of a carbon chain having an appropriate chain length, an effect coating with high strength can be obtained.

[0057]

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Since the cationically polymerizable compound has two or more epoxy groups, a three-dimensional knitted structure is formed when polymerized using a photo-cationic polymerization initiator, and the abrasion resistance and chemical resistance are reduced. An excellent strong film can be obtained.

The anti-reflection-treated article of the present invention is an anti-reflection-treated article having a cured film of an anti-reflection coating composition formed on its surface, wherein the cured film has a thickness of 0.5 μm or less and a fluorine content. Is excellent in anti-reflection performance because it contains 60% or more of a fluororesin, and excellent in abrasion resistance and chemical resistance because the film has a strong three-dimensional stitch structure made of a cationically polymerizable compound.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view showing a laminated configuration of an antireflection treated article.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Anti-reflection film 2 PET film 3 Adhesive 4 Acrylic plate

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 4J038 CD091 CD111 CD121 CD131 DB031 DB032 DB061 DB062 DB071 DB072 DB261 DB262 DF021 DF022 JA14 JA20 JA21 JB16 JB29 JC17 JC38 KA02 KA03 KA06 MA07 NA04 NA11 NA19 PA17

Claims (5)

[Claims] 1. A coating composition for antireflection coating, comprising a fluorine-containing resin having a fluorine content of 60% by weight or more, a cationically polymerizable compound, a cationic photopolymerization initiator, and an organic solvent. object. 2. A fluorine-containing resin having a fluorine content of 60% by weight or more, a cationically polymerizable compound and a hydroxyl group
A composition for a coating for antireflection coating, comprising a compound having at least one compound, a cationic photopolymerization initiator, and an organic solvent. 3. The coating composition for antireflection coating according to claim 2, wherein the compound having two or more hydroxyl groups is a compound represented by the following general formula. Embedded image 4. The antireflection method according to claim 1, wherein the cationically polymerizable compound is a polymerizable substance having at least two epoxy groups in one molecule. Compositions for coatings for coating. 5. An antireflection-treated article having a cured film of the composition for antireflection coating coating according to claim 1 formed on a surface thereof, wherein the cured film has a thickness of 5%. An antireflection-treated article having a thickness of 0.5 μm or less.