JPH05264806A - Coating composition and plastic lens using the same - Google Patents

Abstract

PURPOSE:To obtain a coating compsn. from which a hard coating film excellent in weather resistance and scratching resistance and free from interference fringes can be formed, and to obtain a plastic lens from this compsn. by combining specified multiple oxide sols and org. silicon compds. CONSTITUTION:The coating compsn. essentially consists of colloidal dispersion and one or more kinds of org. silicon compds. expressed by formula and hydrolyzed compds. of these. The colloidal dispersion contains fine particles of multiple oxides consisting of three components, which are titanium oxide, zirconium oxide and antimony pentoxide. This coating compsn. is applied on a lens base body and hardened to form a hard coating film. In formula, R<1> and R<2> are org. groups of 1-6 carbon number, X is a group which can be hydrolyzed, a is 0 or 1. It is preferable that the weight proportion of the components in the multiple oxide is 1:1:1 and that the fine particles have 1-100mum average particle size.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating composition suitable for forming a hard coat film having a high refractive index and a plastic lens having a hard coat film formed using the same.

[0002]

[Prior Art and its Problems] For plastic lenses,
Various hard coat films are formed on the surface of the lens substrate in order to improve its surface hardness, abrasion resistance and the like.
Generally, for a hard coat film formed on a plastic lens having a high refractive index, a hard coat composition containing antimony pentoxide sol, titanium oxide sol, cerium oxide sol, etc. is used. However, such a hard coat composition has a problem that it cannot be used for a plastic lens substrate having a high refractive index of 1.63 to 1.66 due to generation of interference fringes. Further, the obtained hard coat film lacked weather resistance.

[0003]

It is an object of the present invention to prevent occurrence of interference fringes, weather resistance,
An object of the present invention is to provide a coating composition and a plastic lens capable of forming a hard coat film having excellent scratch resistance and the like.

[0004]

The present invention has achieved the above object by combining a specific composite oxide sol and an organic silicon compound.

That is, the present invention relates to (A) titanium oxide,
Colloidal dispersion of fine particles of complex oxide composed of three components of zirconium oxide and antimony pentoxide, and (B) general formula

[Chemical 1] [Wherein, R ¹ and R ² represent an organic group having 1 to 6 carbon atoms,
X represents a hydrolyzable group, and a is 0 or 1] and one of the organosilicon compounds represented by
The present invention provides a coating composition containing at least one species as a main component, and a plastic lens having a hard coat film obtained by coating the composition on a lens substrate and curing the composition.

As described above, the coating composition of the present invention contains, as the component (A), a colloidal dispersion of fine particles of a composite oxide composed of three components of titanium oxide, zirconium oxide and antimony pentoxide. In this composite oxide, the mixing ratio of titanium oxide, zirconium oxide and antimony pentoxide is generally determined in consideration of dispersibility in a solvent, weather resistance, adhesion and the like. Generally, when titanium oxide increases, cracks tend to occur, or water resistance tends to deteriorate, and when zirconium oxide increases, adhesiveness tends to deteriorate, and yellowing tends to increase, and when antimony pentoxide increases. , There is a tendency that a high refractive index cannot be obtained. The mixing ratio of these varies depending on the organosilicon compound to be mixed. For example, with respect to the organosilicon compound used in the examples described later, the weight ratio of titanium oxide: zirconium oxide: antimony pentoxide is 1: 1 :. It is preferably 1. Generally, it may contain titanium oxide: zirconium oxide: antimony pentoxide in a weight ratio of 1: 1 to 3: 1: 1.

The fine particles of the composite oxide are 1 to 100 μm.
Those having an average particle diameter of m are preferable. If the average particle diameter is less than 1 μm, the weather resistance is deteriorated and the pot life of the coating liquid is shortened. On the other hand, when it exceeds 100 μm, the dispersibility or the transparency when formed into a coating film is deteriorated.

The colloidal dispersion of fine particles of the complex oxide used in the present invention is a dispersion of the fine particles in a colloidal form using water and / or an organic solvent as a dispersion medium. As the organic solvent, alcohols such as methanol and ethanol are preferable. Further, for the purpose of improving the dispersibility of the composite oxide fine particles, it is preferable to add various kinds of surfactants and appropriate alkalis, especially organic amines or acids, especially organic acids. Of the organic acids, it is particularly preferable to add a carboxylic acid. The choice of amine or acid is determined by the compatibility with the organosilicon compound used.

The organosilicon compound used as the component (B) in the coating composition of the present invention has the general formula (I).
Various compounds may be used as long as they are compounds represented by or their hydrolysates. In the general formula (I), R
¹ and R ² represent an organic group having 1 to 6 carbon atoms. Here, examples of the organic group include an alkyl group, an alkenyl group, and a phenyl group, and these groups include an epoxy group, a glycidoxy group, an amino group, an amide group, a mercapto group, a methacryloyloxy group, and a cyano group. It may have a substituent. Examples of the hydrolyzable group represented by X include halogen, an alkoxy group, an alkoxyalkoxy group, and an acyloxy group. In the present invention, the compound of the general formula (I) or a hydrolyzate thereof can be used alone or in combination of two or more.

As the component (B), more specifically,
γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, β-
(3,4-Epoxycyclohexyl) ethyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, a mixture thereof or a hydrolyzate thereof is preferable. Furthermore, if necessary, the compound of the general formula (I)
It may contain an organosilicon compound other than the organosilicon compound represented by.

The coating composition of the present invention comprises, in addition to the above-mentioned components (A) and (B), additives generally used in hard coat compositions such as a curing agent, a surfactant,
An ultraviolet absorber, a dye, and an organic polymer compound such as an epoxy resin or an acrylic resin for the purpose of improving hardness may be contained within a range that does not impair desired properties.

As the curing agent, triethylamine, n-
Organic amines such as butylamine, amino acids such as glycine,
Aluminum acetylacetonate, indium acetylacetonate, chromium acetylacetonate, titanium acetylacetonate, metal acetylacetonate such as cobalt acetylacetonate, sodium acetate,
Organic acid metal salts such as zinc naphthenate, cobalt naphthenate, zinc octylate, tin octylate, Lewis acids such as stannic chloride, aluminum chloride, ferric chloride, titanium chloride, zinc chloride and antimony chloride, peroxides Examples thereof include peroxides such as hydrogen. Of these, aluminum acetylacetonate is particularly preferable.

In the coating composition of the present invention, the compounding ratio of the colloidal dispersion of the complex oxide and the organosilicon compound is such that the colloidal dispersion of the complex oxide (30 wt% methanol dispersion liquid) relative to the organosilicon compound 1. As) 1
-4 (by weight), preferably 1.3-3. When the ratio of the colloidal dispersion is less than 1, sufficient hardness cannot be obtained, the refractive index is not increased, and the weather resistance and scratch resistance are not improved. When it exceeds 4, the coating film is whitened. The film may crack or the film may crack.

Further, the hard coat film formed by applying the high refractive index coating composition of the present invention contains 21 to 46% by weight, preferably 2 to 46% by weight of the above-mentioned organosilicon compound.
6 to 41% by weight, and the complex oxide is present at 23 to 43% by weight, preferably 27 to 39% by weight.
If the amount of the organosilicon compound is too large, the refractive index becomes low, the scratch resistance is lowered, and the dye fading property is deteriorated. On the other hand,
When the amount of complex oxide increases, the film becomes white and cracks occur in the film.

When the coating composition of the present invention is applied, it is preferable to use it after diluting it with various solvents from the viewpoints of workability and adjustment of the thickness of the coating. Examples of the diluent solvent include water, alcohols, esters, ethers, cellosolves, halogenated hydrocarbons, dimethylformamide, dimethylsulfoxide, aromatic hydrocarbons, aliphatic hydrocarbons, ketone compounds, and the like, and if necessary. It is also possible to use a mixed solvent of these. Of these,
Considering the dispersibility of the metal oxide used, water, alcohols, dimethylformamide, ethylene glycols,
Cellosolves and the like are preferable.

The method of applying the coating composition to the lens substrate is not particularly limited, and brush coating, dipping, roll coating, spray coating, spin coating, flow coating, etc.
Various methods can be applied.

The high refractive index coating composition according to the present invention is generally suitable for forming a hard coat film exhibiting a refractive index of n = 1.63 to 1.66, and a high refractive index plastic lens such as, for example, It is suitable for application to urethane resin lenses. The urethane resin may be various urethane resins produced by reacting an isocyanate compound with a hydroxy compound and / or a mercapto compound. For example, a polythiol as described in JP-A-63-130614 may be used. The resin obtained by reaction with polyisocyanate is mentioned.

When the coating composition of the present invention is applied, it is 1 to 10 μm, preferably 1.5 to 10 μm on the lens substrate.
It is applied so as to have a film thickness of 5 μm.

Thus, the lens provided with the hard coat film using the coating composition of the present invention is preferably dyed, and then the antireflection film is applied to the lens by a vacuum deposition method or an organic composition coating method. It is possible and there is little discoloration such as fading or yellowing.

[0020]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited thereto.

Example 1 1) Preparation of coating liquid (a) Preparation of hydrolyzate (A) 210.0 parts by weight of γ-glycidoxypropyltrimethoxysilane was charged into a reactor equipped with a rotor, and the magnet was used. 70.5 parts by weight of a 0.01N hydrochloric acid aqueous solution was gradually added dropwise with stirring with a tic stirrer, and after completion of the addition, the mixture was stirred for 24 hours to obtain a hydrolyzate of γ-glycidoxypropyltrimethoxysilane. This is called a hydrolyzate (A).

(B) Preparation of Hydrolyzate (B) A reactor equipped with a rotor was charged with 180.0 parts by weight of γ-glycidoxypropylmethyldimethoxysilane, and the mixture was stirred with a magnetic stirrer at 0.01. 40.5 parts by weight of a normal hydrochloric acid aqueous solution was gradually added dropwise, and after completion of the addition, the mixture was stirred overnight to obtain a hydrolyzate of γ-glycidoxypropylmethyldimethoxysilane. This is called a hydrolyzate (B).

(C) Preparation of Hydrolyzate (C) In a reactor equipped with a rotor, 100.0 parts by weight of β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane was charged and stirred with a magnetic stirrer. While adding 10.0 parts by weight of ethyl alcohol and confirming that the mixture was mixed, 20.0 parts by weight of a 0.1N hydrochloric acid aqueous solution was added, and the mixture was stirred overnight and β- (3,4-epoxycyclohexyl) ethyltri A hydrolyzate of methoxysilane was obtained.
This is called a hydrolyzate (C).

(D) Preparation of coating composition 15.4 parts by weight of methanol, isopropyl alcohol 1
1.6 parts by weight of aluminum acetylacetonate was dissolved in 7.3 parts by weight and 10.8 parts by weight of ethyl cellosolve, and a 2: 1: 1 (weight ratio) composite oxide of titanium oxide / zirconium oxide / antimony pentoxide was mixed. (Solid content 30.0
% By weight, methanol dispersion) was mixed and stirred for 4 hours. Hydrolyzate (A) 6 with further stirring
0.0 parts by weight, 90.0 parts by weight of the hydrolyzate (B) and 30.0 parts by weight of the hydrolyzate (C) were sequentially added, and the mixture was stirred overnight. Let stand for a whole day and night under the condition of 10 ± 2 ℃,
A coating composition was obtained.

2) Coating and curing A urethane resin lens substrate having a refractive index of 1.66 is treated with a 3% sodium hydroxide aqueous solution, washed, dried and then immersed in the coating composition obtained in 1) above. The film was applied at a pulling rate of 220 mm / min, preliminarily cured at 90 ° C. for 10 minutes, and then heated at 120 ° C. for 2 hours to form a high refractive index hard coat film.

The obtained hard coat film has a refractive index, an appearance,
The interference fringes, scratch resistance, adhesion and weather resistance were evaluated by the following methods, and the results are shown in Table 1. The refractive index is evaluated by the spectral characteristics near 500 nm. Appearance Visually observe the transparency of the coating film and check for uneven coating.

Interference fringes The lens is placed under a mercury fluorescent lamp, and some of the interference fringes due to reflection are observed by visual inspection, and the evaluation is performed according to the following criteria. A: Almost no interference fringes. B: There are some interference fringes. C: There are interference fringes as a whole.

Scratch resistance: The coating surface of the hard coat film is rubbed with # 0000 steel wool to examine the state of scratches and evaluated according to the following criteria. A: The surface of the coating film is scarcely scratched. B: The surface of the coating film is slightly scratched. C: The coating film surface is deeply scratched.

Adhesion: 11 parallel lines are put on the surface of the coating film with a knife or the like at intervals of 1 mm in length and width, and 100 squares are put. A cellophane adhesive tape is strongly adhered onto it, and is rapidly peeled in the direction of 90 degrees, and the number of remaining squares in 100 squares is examined and evaluated according to the following criteria (three times of peeling). Good: 95/100 or higher Poor: 94/100 or lower

Weather resistance The surface condition after exposure to a sunshine weather meter (manufactured by Suga Test Instruments Co., Ltd.) for 300 hours is evaluated.

Examples 2 and 3 Hydrolyzates (A), (B) and (C) in Example 1
Example 1 except that the addition amount of was changed to the ratio shown in Table 1.
The same operation was performed. Table 1 shows the results of performance evaluation of the obtained hard coat film.

Comparative Example 1 In Example 1, instead of the titanium oxide / zirconium oxide / antimony pentoxide composite sol, an antimony pentoxide sol (solid content 30.0% by weight, methanol dispersion) 41 was used.
A hard coat film was formed in the same manner as in Example 1 except that 0.0 part by weight was used. The performance of the obtained hard coat film was evaluated, and the results are shown in Table 1.

Comparative Example 2 The same operation as in Comparative Example 1 was carried out except that the amounts of the hydrolyzates (A), (B) and (C) added in Comparative Example 1 were changed to those shown in Table 1. .. Table 1 shows the results of performance evaluation of the obtained hard coat film.

[0034]

[Table 1]

[0035]

By using the coating composition of the present invention, it is possible to form a high-refractive-index hard coat film having excellent properties such as transparency, scratch resistance, and weather resistance, and free from yellowing, clouding, and interference fringes. The result is a high quality plastic lens.

Claims (8)

[Claims] 1. A colloidal dispersion of (A) fine particles of a composite oxide comprising three components of titanium oxide, zirconium oxide and antimony pentoxide, and (B) a general formula: [Wherein, R ¹ and R ² represent an organic group having 1 to 6 carbon atoms,
X represents a hydrolyzable group, and a is 0 or 1] and one of the organosilicon compounds represented by
A coating composition comprising at least one species as a main component. 2. The coating composition according to claim 1, wherein the ratio of each component in the composite oxide is 1: 1: 1 by weight. 3. The coating composition according to claim 1, wherein the fine particles have an average particle size of 1 to 100 μm. 4. The coating composition according to claim 1, wherein the dispersion medium of the component (A) is water and / or an organic solvent. 5. The coating composition according to claim 1, wherein the dispersion medium of the component (A) is water and / or alcohol. 6. The component (B) is γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-methacryloxypropyl. The coating composition according to claim 1, which is one or more of trimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, and a hydrolyzate thereof. 7. A colloidal dispersion (30% by weight) of the composite oxide of the component (A) with respect to the organosilicon compound 1 of the component (B).
The coating composition according to claim 1, which comprises (as a methanol dispersion) in a ratio (weight ratio) of 1 to 4. 8. A plastic lens having a hard coat film obtained by applying and curing the coating composition according to claim 1 on a plastic substrate.