KR100550883B1 - Low interference and abrasion resistant coating composition - Google Patents

Abstract

Disclosed is a coating composition for spectacle lenses with low interference fringes and excellent wear resistance. Basic resins include aqueous or alcoholic colloidal silica particles, hydrolyzates or partial condensates of organomodified silanes, and aluminum chelate compounds, including solvents and various additives. It has excellent storage stability, so it can be used for long-term storage, shows excellent wear resistance, excellent adhesion, hot water resistance, and shows low interference pattern.

Description

Wear resistant coating composition with low interference pattern {LOW INTERFERENCE AND ABRASION RESISTANT COATING COMPOSITION}

The present invention relates to wear resistant coating compositions, and more particularly, to siloxane based coating compositions having excellent storage stability, adhesion, low interference fringes, and the like.

Transparent plastic materials are widely used as a substitute for glass in many fields because of their light weight and good impact resistance, and are particularly applied as optical lenses, industrial safety glasses or leisure goggles. However, most plastic materials have a soft surface and are easily scratched. In order to overcome these disadvantages, a protective film is generally formed on the surface of the plastic material using an organic material or a silicone coating material.

Coating agents used for this purpose include polyurethane-based or acrylic organic materials and silicone-based coating agents.

In general, the coating composition is required to have all the basic properties such as storage stability, wear resistance, and the like. In particular, plastic spectacle lenses are required to reduce the interference fringes caused by the difference in refractive index. Since the refractive index of the general silicone coating material is 1.46 to 1.48, the refractive index (1.50 to 1.56) of the plastic spectacle lens is significantly different. Accordingly, the presence of the interference fringe (rainbow fringe) due to the difference in refractive index severely hurts the appearance of the product and reduces the value of the product. Therefore, if a silicone-based coating composition is to be applied to the spectacle lens, a refractive index enhancer should be prescribed. In Japanese Patent Laid-Open No. 2000-206305A, the refractive index is improved with the composition of the hydrolysis condensate of titanium dioxide fine particles and organo-modified silane, but this composition has poor storage stability. In addition, although US Patent No. 6,218,494 improves the refractive index with the titanium alkoxide and the organic modified silane composition, wear resistance is bad.

Accordingly, it is an object of the present invention to provide a siloxane-based coating composition having a low interference pattern while maintaining excellent storage stability and wear resistance in view of the above problems.

In order to achieve the above object, the present invention has been found to solve the above-mentioned problems by formulating and formulating a reaction product of bisphenol-type epoxy resin and 3-aminopropylsilane in a basic resin, thereby completing the present invention.

That is, the present invention

(I) Basic resin total amount

  (I-a) 20 to 40% by weight of aqueous or alcoholic colloidal silica particles,

  (I-b) 40-70 weight% of hydrolyzate or partial condensate of organic modified silane represented by following General formula (1)

R ¹ _a R ² _b Si (OR ³ ) _{4- (a + b)} (1)

[Wherein, R ¹ and R ² are each independently β- (3,4-epoxycyclohexyl) ethyl, γ-glycidoxypropyl, γ-methacryloxypropyl, γ-chloropropyl, γ-mercaptopropyl, Or a γ-aminopropyl group, R ³ represents a methyl group, an ethyl group, n-propyl group, isopropyl group, n-butyl group, methoxyethyl group, or 2-ethylhexyl group, a and b represent 0-3 Represents an integer;

  (I-c) 0.1-5 weight% of aluminum chelate compound represented by General formula (2)

AlX _n (OR ³ ) _3-n (2)

[Wherein, R ⁴ represents a methyl group, an ethyl group, n-propyl group, isopropyl group, n-butyl group, methoxyethyl group or 2-ethylhexyl group, X represents acetylacetone, ethyl acetoacetate, lactic acid ammonium salt N is an integer of 1 to 3

And

  (I-d) 5-30 weight% of reaction products of bisphenol-type epoxy resin and 3-aminopropylsilane

Basic resin 20 to 40% by weight,

(II) 60-80 wt% of solvent and

(III) 0.01 to 0.1% by weight of an additive, based on the sum of (I) and (II)

It provides a coating composition comprising a.

In particular, in the general formula (1), R ¹ is preferably at least one of glycidoxypropyl and β- (3,4-epoxycyclohexyl) ethyl, and as the compound of the general formula (2), aluminum trisethylaceto Acetate is preferred.

In addition, the reaction product of the bisphenol-type epoxy resin and 3-aminopropyl silane is preferably obtained by heating the bisphenol-type epoxy resin and 3-aminopropyl silane in an alcohol solvent, additives commonly used in the art as an additive For example, surfactants, pH adjusters and the like can be included.

Hereinafter, the present invention will be described in detail.

The general method of preparing the coating composition of the present invention is as follows. First, an organic or inorganic acid is added to an aqueous or alcoholic silica sol to form acidic colloidal silica particles. Next, at least one organic modified silane is added to proceed hydrolysis and partial condensation. Then, a solution of the reaction product of bisphenol-type epoxy resin and 3-aminopropylsilane, which increases the refractive index, is hydrolyzed and partially condensed, and then an organic solvent, aluminum chelate, and various additives are added to give an appropriate maturation period. do.

Hereinafter, each component contained in the coating composition of the present invention will be described in detail.

(A) Colloidal silica particles

Aqueous or alcoholic colloidal silicas with a pH of 2.0-7.0 usually contain an organic or inorganic acid in a sol or stable dispersion of amorphous silica particles having a particle diameter of 5-50 nm (products such as commercially available Ludox, DuPont). It is prepared by adding. The sol or dispersion of the first colloidal silica preferably has a particle size of 5 to 50 nm, and a pH of 2.0 to 11.0 in terms of storage stability.

The particle content of the colloidal silica is in the range of 20 to 40% by weight relative to the base resin. This is because if the particle content of the colloidal silica is less than 20% by weight, the strength of the coating composition is small, and if it is more than 40% by weight, cracking is caused during the curing process. More preferably, it is 25 to 35% by weight.

(B) Hydrolysates or partial condensates of organomodified silanes.

Examples of the organic modified silane represented by the general formula (1) include methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, dimethyldimethoxysilane, and phenyltrimethoxysilane , Phenyltriethoxysilane, tetraethoxysilane, tetramethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, hexyltrimethoxysilane, butyltrimethoxysilane , β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane , γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxy Silane, N-β- (aminoethyl) -γ-aminopropyltri And the like silane.

Hydrolysates or partial condensates of organo modified silanes are prepared by adding organic or inorganic acids to the organo modified silanes.

The initial dose of the organomodified silane compound is in the range of 40 to 70% by weight relative to the base resin. This is because if the content of the organic modified silane is less than 40% by weight, cracking is caused during the curing process, and if the content of the organically modified silane is more than 70% by weight, the strength of the composition is small. More preferably, it is 50 to 60% by weight.

(C) aluminum chelate compounds

The coating composition of the present invention is thermoset by a heating process. The acid and base neutralization products of the organic or inorganic acid added during the process of the present invention promote the condensation reaction of the silane, but aluminum chelate compounds are required to promote the condensation reaction of the silane with organic functional groups such as epoxy functional groups or carbinol. .

Examples of aluminum chelates that can be used include aluminum trisacetylacetonate, aluminum trisethylacetoacetate, aluminum diisopropoxide monoethylacetoacetate, aluminum diisopropoxide monoacetoacetonate, aluminum dibutoxide monoethylacetoacetate, aluminum Dibutoxyde monoacetoacetonate, aluminum bisethyl acetoacetate monoacetylacetonate, and the like.

This component is to be used in the range of 0.1 to 5% by weight based on the base resin. If the content thereof is less than 0.1% by weight, the time required for sufficient curing is long, and if it exceeds 5% by weight, the storage stability is lowered. More preferably, it is used in the range of 2-3 weight%.

(D) Reaction product of bisphenol type epoxy resin and 3-aminopropylsilane

The coating composition of the present invention comprises a reaction product of bisphenol-type epoxy resin and 3-aminopropylsilane to increase the refractive index of the coating. The reaction product of the bisphenol-type epoxy resin and 3-aminopropylsilane used in the composition of the present invention can be obtained by heating in an alcohol solvent. In the present invention, a bisphenol-type epoxy resin was selected as a typical commercial product of a compound containing an aromatic reactor and an epoxy reactor in one molecule, but there are various kinds of bisphenol-type epoxy resins depending on the molecular weight. In the aromatic reactor, since the refractive index is larger than that of the silicone-based coating composition, when the amount of the component is increased, the refractive index of the composition may be increased. The epoxy reactor also serves to chemically bond with 3-aminopropylsilane, allowing the aromatic reactor to stably participate in curing in the coating composition. 3-aminopropylsilane in the present invention includes 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane and the like. The reaction product has an alkoxysilane reactor while maintaining the strength, adhesiveness and refractive index of the bisphenol-type epoxy resin, and thus has excellent compatibility with the silicone-based coating composition. If the compatibility with the silicone coating composition is insufficient, the coating after curing hardly exhibits abrasion resistance and hot water resistance. The reaction product component of the bisphenol-type epoxy resin and 3-aminopropylsilane is used in the range of 5 to 30% by weight based on the basic resin. This is because if the amount thereof is less than 5% by weight, the interference fringe is severe, and if it exceeds 30% by weight, the viscosity of the resin becomes too high. More preferably, it is 15 to 25weight% of a range.

(E) solvent

As the solvent used in the coating composition of the present invention, alcohol is generally preferred, which serves to significantly improve the storage stability and the transparency of the coating. Examples of such alcohol solvents include methanol, ethanol, isopropyl alcohol, butanol, diacetone alcohol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, cellosolve acetate, ethyl acetoacetate, and the like. Such solvent is added to adjust the amount so that the base resin is in the range of 60 to 80% by weight in the coating composition.

(F) various additives

In addition, the coating composition of this invention can use various additives in the range in which the effect of this invention does not fall for the purpose of improving adhesiveness, smoothness, etc. with a base material. Examples thereof include dyes, ultraviolet absorbers, antioxidants, and the like, and various surfactants may be blended to improve smoothness. As such surfactants, dimethylsiloxane and polyethylene oxide block copolymers, graft copolymers or fluorine-based surfactants may be used.

In addition, the coating composition of the present invention should adjust the pH in consideration of various physical properties such as storage stability, curing rate and abrasion resistance, and use an organic or inorganic acid for this purpose, for example acetic acid, sulfuric acid, hydrochloric acid, p-toluenesulfonic acid Etc. can be mentioned. These acid components may be used alone or in combination of two or more in consideration of the reaction rate according to the final pH or components of the coating solution and the adhesion to the applied substrate.

When the coating composition of the present invention as described above is applied to a plastic substrate such as a vision correcting lens and heat treated, a high hardness protective film can be obtained. In this case, a variety of commonly used methods, such as silk screen, roll coating, spray coating, dip coating or spin coating, are applied without exception. Curing conditions vary slightly depending on the blending ratio and components, but in general, a protective film having a desired hardness can be obtained by curing at a temperature below the softening point of the substrate (about 60 to 150 ° C.) for 20 minutes to several hours.

The following presents preferred synthesis examples, comparative examples and examples to aid in understanding the invention. However, the following examples are provided only to more easily understand the present invention, and the invention is not limited only to the following examples.

Synthesis Example 1

19 g of bisphenol-type epoxy resin (Kukdo Chemical Co., Ltd. YD-128M, 190 g / eq) was added, 148 g of isopropyl alcohol was added, and the mixture was dissolved with stirring. 18 g of 3-aminopropyltrimethoxysilane (Degussa, Dynasylan AMMO, 179 g / mole) is slowly added dropwise. Stirred for 5 hours while maintaining the temperature of the contents at 60 ℃. The obtained solution 185g (20 weight% of solid content) was used as it is, without further processing.

Example 1

While maintaining the temperature inside the reactor at 30 ° C. or less, 60 g of Dupont's colloidal silica Ludox HS-30 (particle size 12 nm, solid content 30 wt%) was added thereto. After adding 3 g of acetic acid thereto, a mixed solution of 30 g of γ-glycidoxypropyltrimethoxysilane was added dropwise while stirring with a magnetic stirrer, and 100 g of the reaction product obtained in Synthesis Example 1 was added dropwise, and the temperature was raised to 60 ° C. It was hydrolyzed for time. After cooling to room temperature, 2 g of aluminum trisethyl acetoacetate, 50 g of ethyl cellosolve, and 0.05 g of a silicone surfactant BYK348 (BYK) were added and stirred for 24 hours. The final composition thus obtained was immersed and coated in a lens for vision correction (CNB Optical Refractive Index 1.56), and then dried at room temperature for 5 minutes and heated at 100 ° C. for 1 hour to obtain a cured coating.

Example 2

While maintaining the temperature inside the reactor at 30 ° C. or less, 60 g of Dupont's colloidal silica Ludox HS-30 (particle size 12 nm, solid content 30 wt%) was added thereto. After adding 3 g of acetic acid thereto, a mixed solution of 40 g of γ-glycidoxypropyltrimethoxysilane was added dropwise while stirring with a magnetic stirrer, and 50 g of the reaction product obtained in Synthesis Example 1 was added dropwise, and the temperature was raised to 60 ° C. for 5 hours. During hydrolysis. After cooling to room temperature, 2 g of aluminum trisethyl acetoacetate, 50 g of ethyl cellosolve, and 0.05 g of a silicone surfactant BYK348 (BYK) were added and stirred for 24 hours. The obtained final composition was immersed and coated in a vision correcting lens (CNB Optical Refractive Index 1.56), dried at room temperature for 5 minutes, and heated at 100 ° C. for 1 hour to obtain a cured coating.

Example 3

While maintaining the temperature inside the reactor at 30 ° C. or less, 60 g of Dupont's colloidal silica Ludox HS-30 (particle size 12 nm, solid content 30 wt%) was added thereto. 3 g of acetic acid was added thereto, and a mixed solution of 45 g of γ-glycidoxypropyltrimethoxysilane was added dropwise while stirring with a magnetic stirrer, and 25 g of the reaction product obtained in Synthesis Example 1 was added dropwise thereto, and the temperature was raised to 60 ° C. for 5 hours. During hydrolysis. After cooling to room temperature, 2 g of aluminum trisethyl acetoacetate, 50 g of ethyl cellosolve, and 0.05 g of a silicone surfactant BYK348 (BYK) were added and stirred for 24 hours. The obtained final composition was immersed and coated in a vision correcting lens (CNB Optical Refractive Index 1.56), dried at room temperature for 5 minutes, and heated at 100 ° C. for 1 hour to obtain a cured coating.

Comparative Example 1

While maintaining the temperature inside the reactor at 30 ° C. or less, 60 g of Dupont's colloidal silica Ludox HS-30 (particle size 12 nm, solid content 30 wt%) was added thereto. After adding 3 g of acetic acid thereto, 50 g of γ-glycidoxypropyltrimethoxysilane was added dropwise while stirring with a magnetic stirrer, and the mixture was hydrolyzed for 5 hours by raising the temperature to 60 ° C. After cooling to room temperature, 2 g of aluminum trisethyl acetoacetate, 50 g of ethyl cellosolve, and 0.05 g of a silicone surfactant BYK348 (by KK) were added thereto, and the mixture was stirred for 24 hours. The obtained final composition was immersed and coated in a lens for correction of vision (CNB Optical Refractive Index 1.56), dried at room temperature for 5 minutes, and heated at 100 ° C. for 1 hour to obtain a cured coating.

Comparative Example 2

While maintaining the temperature inside the reactor at 30 ° C. or less, 60 g of Dupont's colloidal silica Ludox HS-30 (particle size 12 nm, solid content 30 wt%) was added thereto. After adding 3 g of acetic acid thereto, 45 g of γ-glycidoxypropyltrimethoxysilane was added dropwise while stirring with a magnetic stirrer, and the mixture was hydrolyzed for 5 hours at a temperature of 60 ° C. After cooling to room temperature, add 2 g of aluminum trisethyl acetoacetate, 50 g of ethyl cellosolve, and 5 g of bisphenol-type epoxy resin (Yukdo Chemical Co., Ltd. YD-128M, 190 g / eq) and 0.05 g of silicone surfactant BYK348 (BYK Co., Ltd.) for 24 hours. Stir while. The obtained final composition was immersed and coated in a vision correcting lens (CNB Optical Refractive Index 1.56), dried at room temperature for 5 minutes, and heated at 100 ° C. for 1 hour to obtain a cured coating.

Comparative Example 3

While maintaining the temperature inside the reactor at 30 ° C. or less, 60 g of Dupont's colloidal silica Ludox HS-30 (particle size 12 nm, solid content 30 wt%) was added thereto. After adding 3 g of acetic acid thereto, a mixed solution of 30 g of γ-glycidoxypropyltrimethoxysilane and 20 g of phenyltriethoxysilane (Shinwol Chemical Co., Ltd., KBE 103) was added dropwise while stirring with a magnetic stirrer, and 60 ° C. The temperature was raised to hydrolysis for 5 hours. After cooling to room temperature, 2 g of aluminum trisethyl acetoacetate, 50 g of ethyl cellosolve, and 0.05 g of a silicone surfactant BYK348 (BYK) were added and stirred for 24 hours. The final composition thus obtained was immersed and coated in a lens for vision correction (CNB Optical Refractive Index 1.56), and then dried at room temperature for 5 minutes and heated at 100 ° C. for 1 hour to obtain a cured coating.

Hereinafter, the physical properties of the immersion-cured coating were examined by the following method.

(1) storage stability

The viscosity change at the time of storage at 25 degreeC for 1 month was evaluated, and when the change of viscosity was insignificant, it was represented by (double-circle), when the change was small, it represented by (circle) and when there was a significant change, it represented by (triangle | delta).

(2) wear resistance

After tying # 0000 steel wool to a hammer of 1.5 kg and rubbing the cured film 30 times, the scratches were 1, the scratches were 2, and the severe scratches were 3.

(3) adhesion

According to ASTM D3359, 100 squares of 1 mm2 were made by drawing cells with a length of 1 mm on the film, and then peeled off five times using a cellophane tape of 24 mm width of 3M Korea. It was determined by counting the number of spaces present.

(4) Hot water resistance

The coated vision correcting lens was immersed in 80 ° C. brine (10 wt% brine) for 30 minutes and then subjected to an adhesion test.

(5) degree of interference

The coated lens was observed with a three wavelength lamp to evaluate the strength of the rainbow pattern (the intensity of interference). It is rated 5 if the interference is strong and 1 when the interference is weak.

Coating property check table after coating using composition Storage stability Wear resistance Adhesion Hot water resistance Degree of interference Example 1 ◎ One 100 100 2 Example 2 ◎ One 100 100 3 Example 3 ◎ 2 100 90 4 Comparative Example 1 ◎ 2 70 50 5 Comparative Example 2 ◎ 2 90 90 4 Comparative Example 3 ○ 3 70 20 3

Through the results shown in Table 1 it can be seen that the coating composition according to the present invention is very good storage stability, wear resistance, adhesion, hot water resistance and the like, in particular the degree of interference is small.

As described above, the wear-resistant coating composition of the present invention is excellent in storage stability and can be used for long-term storage, exhibits excellent wear resistance, excellent adhesion, and hot water resistance of high hardness and exhibits little interference fringes.

Claims (5)

(I) Basic resin total amount   (I-a) 20 to 40% by weight of aqueous or alcoholic colloidal silica particles,   (I-b) 40-70 weight% of hydrolyzate or partial condensate of organic modified silane represented by following General formula (1) R ¹ _a R ² _b Si (OR ³ ) _{4- (a + b)} (1) [Wherein, R ¹ and R ² each independently represent a β- (3,4-epoxycyclohexyl) ethyl group, a γ-glycidoxypropyl group, a γ-methacryloxypropyl group, a γ-chloropropyl group, and a γ-mer A captopropyl group or a γ-aminopropyl group, R ³ represents a methyl group, an ethyl group, n-propyl group, isopropyl group, n-butyl group, methoxyethyl group, or 2-ethylhexyl group, and a and b are 0 An integer of -3];   (I-c) 0.1-5 weight% of aluminum chelate compound represented by General formula (2) AlX _n (OR ³ ) _3-n (2) [Wherein, R ⁴ represents a methyl group, an ethyl group, n-propyl group, isopropyl group, n-butyl group, methoxyethyl group or 2-ethylhexyl group, X represents acetylacetone, ethyl acetoacetate, lactic acid ammonium salt N is an integer of 1 to 3 And   (I-d) 5 to 30% by weight of reaction product of bisphenol type epoxy resin and 3-aminopropylsilane Basic resin 20 to 40% by weight, (II) 60-80 wt% of solvent and (III) 0.01 to 0.1% by weight of an additive, based on the sum of (I) and (II) Coating composition comprising The coating composition according to claim 1, wherein in formula (1), R ¹ is at least one of glycidoxypropyl and β- (3,4-epoxycyclohexyl) ethyl. The coating composition according to claim 1, wherein the compound of formula (2) is aluminum trisethyl acetoacetate. The coating composition according to claim 1, wherein the reaction product of the bisphenol-type epoxy resin and 3-aminopropylsilane is obtained by heating a bisphenol-type epoxy resin and 3-aminopropylsilane in an alcohol solvent. The coating composition of claim 1, wherein said additive comprises a surfactant and a pH adjuster.