JPH04126784A - Hard coating agent and optical product made of plastics - Google Patents

Abstract

PURPOSE:To obtain a hard coating agent, containing an epoxy group-containing silicon compound, etc., a mixed colloid of cerium oxide and titania and a curing catalyst and capable of forming high-refractive index layers having abrasion and weather resistance, etc., on plastic lenses, etc. CONSTITUTION:The objective hard coating agent containing (A) an epoxy group- containing silicon compound expressed by the formula (R<1> is 2-8C epoxy group- containing organic group; R<2> is 1-6C alkyl, alkenyl or aryl; R<3> us 1-6C alkyl, alkenyl, alkoxyalkyl or acyl; m and n are 0<m<2 and 0<=n<2) or a partial hydrolyzate thereof, (B) a mixed colloid of cerium oxide and titania (preferably a mixed crystal substance of the cerium oxide colloid and titania colloid) and (C) a curing catalyst composed of preferably aluminum perchlorate, etc.

Description

[Detailed description of the invention] Peel, Omega dish! The present invention relates to a hard coating agent capable of forming a high refractive index coating layer (hard coating film) having characteristics such as abrasion resistance and weather resistance on plastic optical articles such as plastic lenses, and the hard coating film. This invention relates to a plastic optical product having a surface formed on the surface thereof.

In recent years, high refractive index lenses have been commonly used for plastic lenses used as eyeglass lenses for the purpose of weight reduction. Materials between .63 and 1.68 have been proposed. If such a high refractive index lens is coated with a hard coating film with a low refractive index, interference fringes will occur significantly, making it undesirable as an optical material. Therefore, a coating with a high refractive index close to that of a plastic lens is required. It is desirable to apply a hard coating agent that gives

However, in order to impart properties such as high hardness, abrasion resistance, and solvent resistance to plastic optical products that generally have excellent processability and impact resistance, alkyltrialkoxysilane hydrolysates and colloidal silica are used. Coating composition (Special Publication No. 52-39691, 62-
55554) is used, but the refractive index of the hard coating film provided by this composition is 1.4.
The refractive index was low, around 6, and was unsuitable for coating the above-mentioned high refractive index substrate.

Furthermore, it is known that if titania sol, which is an inorganic fine particle with a high refractive index, is added to such a coating composition instead of colloidal silica, the refractive index of the coating can be increased.
No. 58-13101 proposes a methylsilane coating agent containing colloidal silica and colloidal titania.

However, this coating agent also did not have a sufficiently high film refractive index, and when applied to a high refractive index substrate, some interference fringes were observed and there was no dyeing property at all. Furthermore, JP-A-63-225635 proposes a coating agent containing anatase-type titania fine particles, but although this coating agent has a sufficiently satisfactory refractive index, the hard coating film yellows when exposed to ultraviolet rays. There were problems in that it was easy to change and had poor durability (weather resistance).

In addition, for the purpose of obtaining a high refractive index coating,
No. 3-223701 proposes a coating agent containing particulate cerium oxide and a hydrolyzate of a disilyl compound.

However, in order to apply this coating agent to a substrate with a refractive index of 1.6 or more, such as the above-mentioned high refractive index lens, it is necessary to increase the content of cerium oxide to a very large extent. The resulting film was brittle, had poor transparency, and was economically disadvantageous.

As described above, conventional hard coating agents have a low refractive index or are of inferior quality. For example, when coating high refractive index lenses such as thiourethane resin or polycarbonate resin, interference fringes are likely to occur. It was unsuitable for coating plastic optical products such as lenses.

The present invention was made in view of the above circumstances, and provides a high refractive index notebook coating film with high hardness, wear resistance, and excellent properties such as solvent resistance, weather resistance, and adhesion. The object of the present invention is to provide a hard coating agent and a plastic optical product on which a hard coating film is formed using the node coating agent.

In order to achieve the above object, the inventors of the present invention have made extensive studies and found that the following general formula (1) % formula % (1) (wherein R1 is an epoxy group having 2 to 8 carbon atoms) R2 is an alkyl group having 1 to 6 carbon atoms.

The alkenyl group or aryl group, R3, is an alkyl group, alkenyl group, alkoxyalkyl group, or acyl group having 1 to 6 carbon atoms, and m and n are positive numbers satisfying O<m<2.0≦n<2. ) By blending a mixed colloid of cerium oxide and titania as inorganic fine particles into a hard coating agent containing an epoxy group-containing silicon compound or its partially hydrolyzed product and a curing catalyst, it is possible to achieve high hardness and durability. It was discovered that a hard coating agent suitable for plastic optical products can be obtained, which has good properties such as abrasion resistance, solvent resistance, adhesion, and weather resistance, and also provides a hard coating film with a high refractive index. However, the present invention has been completed.

In this case, the epoxy group-containing silicon compound of formula (1) can be cured together with the inorganic fine particles to impart properties such as coating hardness and wear resistance, but as the inorganic fine particles, the refractive index is 2.
When a mixture of colloidal cerium oxide (No. 2) and colloidal titania with a refractive index of 2.7 is blended, the refractive index of the coating film containing only colloidal silica is 1.45 to 1.
．． Whereas the refractive index of the coating film was as low as about 49, it is possible to increase the refractive index of the coating film to about 1.55 to 1.65. Furthermore, by changing the amount of the mixed colloid mentioned above, various plastic substrates with different refractive indexes (refractive index of 1.55 to 1.55) can be produced.
(approximately 1.65), a hard coating film can be applied without primer without producing interference fringes. In addition, yellowing due to ultraviolet rays can be prevented by adding colloidal cerium oxide, such as the anatase type titania-containing hard coating film described in JP-A No. 63-225635, which can improve weather resistance. It is.

Therefore, the present invention comprises (a) the epoxy group-containing silicon compound of the above formula (1) or its partial hydrolyzate, (b) a mixed colloid of cerium oxide and titania, and (c) a curing catalyst. To provide a hard coating agent comprising a hard coating agent, and a plastic optical product having a hard coating film formed on the surface of the hard coating agent.

The present invention will be explained in more detail below.

Component (a) constituting the hard coating agent of the present invention contributes to film formation and organic dye adsorption, and is an epoxy group-containing silicon compound or a portion thereof represented by the following general formula (1) % formula % (1) It is a hydrolyzate.

Here, the substituent R' in the formula is an organic group containing an epoxy group having 2 to 8 carbon atoms, such as a glycidoxymethyl group,
Examples thereof include a glycidoxyalkyl group having an alkylene group having 1 to 4 carbon atoms, such as a glycidoxyprobyl group, and an epoxycyclohexylalkyl group. Further, R2 is an alkyl group, an alkenyl group, or an aryl group having 1 to 6 carbon atoms, such as a methyl group, an ethyl group, a propyl group, or a butyl group.

Examples include vinyl group and phenyl group. R3 has 1 carbon number
~6 alkyl, alkenyl, alkoxyalkyl, or acyl groups, such as methyl, ethyl, propyl, and isopropyl groups.

Butyl group, isobutyl group, methoxyethyl group, ethoxyethyl group, butoxyethyl group, acetyl group.

Examples include propionyl group. m and n are each (1
It is a positive number satisfying <m<2.0≦n<2.

Specifically, such silicon compounds of the above formula (1) include 3-glycidoxyprobyltrimethoxysilane, 3-
Glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyljethoxysilane, 3-glycidoxypropyl phenyldimethoxysilane, 2-(3',4
'-Epoxycyclohexyl)ethyltrimethoxysilane, 2-(3',4'-epoxycyclohexyl)ethyltriethoxysilane, 2-(3',4'-epoxycyclohexyl)ethylmethyldimethoxysilane, 2-(
Examples include 3',4'-epoxycyclohexyl)ethylmethyljethoxysilane, and one of these may be used alone or two or more of these may be used in combination.

Furthermore, the above-mentioned epoxy group-containing silicon compound can be used as it is, but it is also possible to use a partially hydrolyzed product by adding the following silanes in advance and co-hydrolyzing it. That is, examples of silanes include tetramethoxysilane and tetraethoxysilane.

Tetraisopropyloxysilane, methylpolysilicate, ethylpolysilicate, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, dimethyldimethoxysilane, dimethyljethoxy Silane, diphenyldimethoxysilane, diphenyljethoxysilane, methylphenyldimethoxysilane, methylphenyldiethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane,
3-methacryloxypropylmethyldimethoxysilane,
Examples include 3-methacryloxypropylmethyljethoxysilane, but 3-glycidoxypropylmethyldialkoxysilane or 2-(3',4'-epoxycyclohexyl) is particularly suitable for increasing adsorption of organic dyes.
It is preferable to use a mixture of ethylmethyldialkoxysilane and tetraalkoxysilane or alkyl polysilicate, or a partial hydrolyzate thereof.

Note that the above-mentioned epoxy group-containing silicon compound is usually preferably used after being dissolved in an organic solvent such as alcohols, ketones, esters, cellosolves, or aromatic compounds.

Next, in the hard coating agent of the present invention, a mixed colloid of cerium oxide and titania is blended as inorganic fine particles.

In this case, the mixing ratio of cerium oxide and titania is 2/98 to 50150 in weight ratio, especially 5/95 to 30/7.
If the content of cerium oxide is less than the above ratio and the content is less than 2% by weight, weather resistance may deteriorate; if the content is more than the above ratio and exceeds 50% by weight, the coating liquid In some cases, the cerium oxide separates and the coating is not uniform. In this case, colloidal titania undergoes a valence change due to ultraviolet rays and is generally prone to yellowing, but this yellowing can be prevented by blending cerium oxide in the above ratio.

Note that as the mixed colloid, a mixed crystal of cerium oxide colloid and titania colloid, etc. can be used.

The mixed colloid preferably has a particle size of 1 to 200 mμ, particularly 2 to 50 mμ, and preferably has a particle size of 1 mμ.
If it is smaller, the surface hardness of the coating may decrease;
If it is larger than 00 mμ, the transparency of the film may decrease.

Furthermore, since the refractive index of the coating film can be adjusted by adjusting the amount of component (B), it is preferable to appropriately select the amount of component (B) depending on the refractive index of the coating film. 10 to 300 parts, especially 20 to 20 parts as solid content of inorganic fine particles based on (parts by weight, the same applies hereinafter)
Preferably, the amount is 0 parts. (b) The amount of ingredients is 10
If the amount is less than 300 parts, a coating with high hardness cannot be obtained and the refractive index of the coating may be low, and if it exceeds 300 parts, the resulting coating may be brittle and have poor coating properties.

Component (iii) of the present invention is a curing catalyst necessary for curing the mixture of the above-mentioned essential components.

In this case, as the curing catalyst, for example, a Lewis acid catalyst, an organic aluminum compound, an organic titanium compound, etc. are preferably used from the viewpoint of stability of the coating agent, hardness of the film, non-yellowing, curability, etc. Examples include aluminum chloride, aluminum perchlorate, aluminum phosphate, aluminum triisopropoxide, aluminum acetylacetonate-1 tetrabutyl titanate, and tetraisopropyl titanate, among which aluminum perchlorate is preferably used. .

Furthermore, the amount of component (c) added can be 0.05 to 10 parts, particularly o, i to 5 parts, with respect to 100 parts of component (a), and the amount added is less than 0.05 part. If the amount exceeds 10 parts, the stability of the coating solution may deteriorate.

Various components can be added to the hard coating agent of the present invention for the purpose of improving adhesion with plastic substrates, weather resistance, coatability, antireflection properties, etc., within a range that does not impede the effects of the present invention. be.

For example, epoxy resins such as polyolefin-based epoxy resins, cyclohexene oxide, polyglycidyl esters, condensation products of epichlorohydrin and bisphenol A, glycidyl methacrylate, copolymers with acrylic compounds, hensifenone-based, benzotriazole-based, phenol-based, etc. Examples include ultraviolet absorbers. Furthermore, various surfactants can be added to improve coating properties, and block copolymers and graft copolymers of dimethylsiloxane and polyether, fluorine-based surfactants, etc. are particularly effective. .

The coating agent of the present invention can be obtained by mixing component (A) and optional components if necessary, and then adding components (B) and (C). When using, mix component (A) and optional components if necessary, add pure water or an acidic aqueous solution such as hydrochloric acid or acetic acid to hydrolyze, and then add components (B) and (C) to coat. agent can be obtained.

In addition, examples of solvents that can be included in the coating agent of the present invention include methanol and ethanol.

Isopropanol, butanol, isobutanol.

Lower alcohols such as diacetone alcohol, cellosolves such as methyl cellosolve, ethyl cellosolve, acetic acid cellosolve, and butyl cellosolve are preferred, and mixtures of these with solvents such as esters, ketones, amides, aromatic compounds, etc. are also preferably used. It will be done.

The hard coating agent of the present invention can be applied to various plastics and the like. Here, the plastic materials to which the hard coating agent of the present invention is applied include, but are not particularly limited to, polycarbonate, polystyrene, polyester,
There are polyurethane and polythiourethane. In this case, the hard coating agent of the present invention is applied to a plastic optical product such as a plastic lens and heat-treated to obtain a highly hard protective coating film. Application methods include brush coating, roll coating, spray coating, flow coating, and dipping coating.

Conventional coating methods such as spin cord can be employed. Furthermore, the curing conditions vary depending on the amount of curing catalyst blended, etc., but the temperature is usually below the softening point of the plastic base material, usually 8.
By curing at 0 to 150°C for 0.6 to 10 hours,
A desired cured film can be obtained. Further, the cured film obtained using the coating agent of the present invention can be dyed, but the dyeing process can be arbitrarily determined depending on the concentration of various disperse dyes, temperature, time, etc. -0.1-1 for boat fishing
Dyeing can be easily carried out by immersing the material in a dye bath in which % by weight of the dye is dispersed at 80 to 100° C. for 5 to 15 minutes.

As explained above, the hard coating agent of the present invention has high hardness and wear resistance, and also has good properties such as solvent resistance, adhesion, and weather resistance, and has a refractive index of 1. .55 or higher, it provides a hard coating film with a high refractive index that does not show interference fringes even when coated on a plastic substrate with a high refractive index such as a thiourethane resin or a polycarbonate resin.

Therefore, by forming a hard coating film on the surface using the hard coating agent of the present invention, a plastic optical product having high transparency and good appearance can be obtained.

<Examples, Comparative Examples> The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[Example 1] 3-glycidoxypropylmethyljethoxysilane 35
5 g of tetramethoxysilane was poured into a flask, and 7.5 g of 0.05N diluted hydrochloric acid was added dropwise over 30 minutes while stirring under water cooling. Furthermore, cerium oxide titania sol (manufactured by Catalysts & Chemicals Industry Co., Ltd., methanol solution, CeOz
/ T i Ox = 2 / 8, non-volatile content 20%
), and after aging at 20 to 25° C. for 16 hours, 20 g of ethanol, 80 g of diacetone alcohol, and 0.6 g of aluminum perchlorate hexahydrate were added to prepare a coating liquid. Next, this coating liquid was applied to CR-39 (diethylene glycol bisallyl carbonate) treated with alkali by a dipping method, and
It was cured for 60 minutes at 0°C.

In addition, the above coating liquid was applied to an extruded polycarbonate flat plate with a refractive index of 1.58 by a dipping method, and
After curing for 0 minutes, the appearance was visually observed and interference fringes were examined.

[Example 2] 60g of cerium oxide titania sol similar to Example 1
After adding and aging in the same manner as in Example 1, ethanol
g, diacetone alcohol 20 g, and aluminum perchlorate hexahydrate 0.6 g to prepare a coating solution, which was applied to a CR-39 polycarbonate flat plate and cured in the same manner as in Example 1.

[Comparative Example 1] Titania sol (manufactured by Nissan Chemical ■, aqueous solution, non-volatile content 10%) 1 instead of the cerium oxide titania sol of Example 1
After adding 20 g and aging in the same manner as in Example 1, 10 g of ethanol, 20 g of diacetone alcohol, and 1.2 g of aluminum chloride hexahydrate were respectively added to prepare a coating liquid. CR-39 was applied to a polycarbonate plate and cured.

[Comparative Example 2] Silica sol (manufactured by Nissan Chemical, methanol solution, nonvolatile content 30
%) 100g and aged in the same manner as in Example 1,
A coating solution was prepared by adding 10 g of ethanol, 20 g of diacetone alcohol, and 0.6 g of aluminum acetylacetonate.
R-39 was applied to a polycarbonate plate and cured.

The properties of the coating films obtained in Examples 1 and 2 and Comparative Example 1.2 were examined using the following method. The results are shown in Table 1.

The coating was rubbed 10 times at a load of 500 g using abrasion-resistant #0000 steel wool, and the appearance of scratches was visually determined.

According to Section 6.15 of 11 size JIS K-5400, the film was made by cutting 11 base lines vertically and horizontally at 1n intervals with a knife, and after adhering Sellotape (manufactured by Chihan Co., Ltd.) to the film, a peel test was performed. The number of squares that did not peel off was determined.

The coating was lightly rubbed 100 times with absorbent cotton impregnated with solvent-resistant acetone, and transparency was visually determined.

After irradiating ultraviolet rays at 70°C for 8 hours using Atlas Nibucon (newly manufactured by Toyo Seiki Seisakusho, accelerated weathering test equipment), and repeating a cycle of 4 hours at 50°C in a humid environment for 200 hours. The degree of coloration of the film was visually determined.

After applying a coating agent on a refractive index polytetrafluoroethylene sheet and curing it at 120°C for 60 minutes, the resulting film was peeled off, and the cured film was sandwiched between methyl salicylate sheets and an Atsbe refractometer (Atago Co., Ltd.) was used. Measurements were made at 25°C using a

The coating solution was applied to an extruded polycarbonate flat plate (refractive index: 1.587), and the coating was rubbed around three times while visually observing the appearance.

From the results in Table 1, the hard coating films (Examples 1 and 2) formed using the hard coating agent of the present invention have good wear resistance, solvent resistance, and adhesion, and yellow even when irradiated with ultraviolet rays. It has been found that it does not change and has excellent weather resistance, has a high refractive index of 1.55 or more, and no interference fringes are observed even when coated on a polycarbonate flat plate.

Sender: Shin-Etsu Chemical Co., Ltd.

Claims (1)

[Claims] 1. (a) The following general formula (1) R^1, R^2_nSi(OR^3)_4_m_n...
...(1) (wherein R^1 is an organic group containing an epoxy group having 2 to 8 carbon atoms, R^2 is an alkyl group having 1 to 6 carbon atoms,
Alkenyl group or aryl group, R^3 is an alkyl group, alkenyl group, alkoxyalkyl group or acyl group having 1 to 6 carbon atoms, m and n are positive numbers of 0<m<2, 0≦n<2. be. A hard coating agent comprising: an epoxy group-containing silicon compound or a partially hydrolyzed product thereof; (b) a mixed colloid of cerium oxide and titania; and (c) a curing catalyst. 2. The hard coating agent according to claim 1, wherein the mixed colloid is a mixed crystal of cerium oxide colloid and titania colloid. 3. A plastic optical product, characterized in that a hard coating film formed from the hard coating agent according to claim 1 or 2 is formed on the surface.