JPH0523294B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD The present invention relates to a coating composition that is applied to the surface of plastic products such as plastic lenses to improve scratch resistance. "Prior Art and its Problems" In recent years, plastics have begun to be used in optical products such as lenses. Compared to glass lenses, plastic lenses are lighter, easier to process, easier to dye, and
It has advantages such as excellent impact resistance, but on the other hand,
It has the major drawback of being easily scratched. For this reason, many methods have been studied to improve the scratch resistance of plastic lenses, and they can be broadly divided into two methods. One method is to apply an inorganic hard coat film to the surface of the plastic lens using vacuum evaporation, sputtering, or other methods.
There is a method of forming by ion plating method etc., and the other method is to form on the surface of plastic lens.
This is a method in which an organic hard coat film of acrylic, melamine, silicone, etc. is formed by dip coating, spray coating, or the like. However, inorganic hard coat films have the disadvantage that impact resistance is significantly reduced when the film is thick enough to provide sufficient scratch resistance.
On the other hand, with organic hard coat films, impact resistance does not decrease even if the film is thick enough to provide scratch resistance (for example, approximately 10μ), but if it is also made to have dyeability, the scratch resistance tends to decrease. be. In addition, products with an inorganic anti-reflection film formed on an organic hard coat film are also commercially available, but the organic hard coat film, which is suitable for coating with an inorganic anti-reflection film, is difficult to dye. I often ended up becoming a thing. Therefore, it is desired to develop an organic hard coat film that has good adhesion to an inorganic antireflection film and is easily dyeable. Further, when an organic hard coat film is dip coated, there is a drawback that the film thickness tends to be uneven within a single lens, and interference fringes occur. Furthermore, the coating liquids used for conventional organic hard coat films have had a significantly short shelf life. Furthermore, as materials for extending the life of the coating liquid, for example, chelate compounds such as indium acetylacetonate and iron hexafluoroacetylacetonate are listed in Japanese Patent Application Laid-open No. 155437/1983.
Even if these were mixed, the lifespan was not extended. Also,
In JP-A-56-99263 and JP-A-59-146001,
Ammonium perchlorate is mentioned, but there are problems in that the coating film yellows and dyeing variations tend to occur. Furthermore, JP-A-59-100401
The issue mentions stannous chloride, but using stannous chloride extends pot life, but has the problem of poor water resistance. Furthermore, if a hardening agent such as dibutylamine, triethanolamine, iron octylate, or sodium acetate is mixed, the life of the hard coating solution will be significantly shortened. "Objective of the Invention" The object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a material that is easy to dye, has excellent scratch resistance, has good adhesion to an inorganic antireflection film, and has a refractive index that is similar to that of a plastic lens. The object of the present invention is to provide a coating composition in which there is almost no difference between the two and the coating liquid has a long shelf life. "Structure of the Invention" The coating composition according to the present invention comprises (A) the general formula
A silicon compound containing at least one epoxy group represented by YRSiX ₃ (in the formula, R is an alkyl group, Y is an organic group having an epoxy group, and X is an alkoxyl group), and (B) a particle size of 1 to 100 nm. (C) an acidic aqueous solution; (D) a mixed solution of one or two of maleic anhydride and dibutyltin dilaurate as a curing catalyst;
When the total of the above components (A), (B), and (C) is 100 parts by weight,
(A) component is 10 to 50 parts by weight, (B) component is 40 to 85 parts by weight,
It is characterized by containing 1 to 10 parts by weight of component (C) and 0.01 to 5.0 parts by weight of component (D). In the present invention, examples of the compound represented by the general formula of component (A) include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β-(3,4epoxycyclohexyl)ethyl Examples include trimethoxysilane. The blending amount of component (A) is 10 to 50 parts by weight when the total of components (A), (B), and (C) is 100 parts by weight. If the amount of component (A) is less than 10 parts by weight, the adhesion between the coating film and the lens will decrease, and if the amount of component (A) exceeds 50 parts by weight, the wettability of the coating liquid on the lens will deteriorate, and furthermore, the staining property will decrease. descend. Component (B) is colloidal silica dispersed in a solution. In this case, examples of the dispersion solvent for colloidal silica include water, metal, ethanol,
Butanol, normal propanol, ethyl cellosolve, ethylene glycol, isopropyl alcohol, etc. are used, but alcohols are particularly preferred. The amount of component (B) is the sum of components (A), (B), and (C).
When 100 parts by weight, it is 40 to 85 parts by weight.
If component (B) is less than 40 parts by weight, the scratch resistance will decrease,
Cracks can easily form in the coating film. On the other hand, (B)
When the component exceeds 85 parts by weight, the silicon content increases, so the refractive index of the coating film decreases, creating a difference with the refractive index of the lens material (n = 1.50), and interference fringes become clear. spoil the appearance. Component (C) is used to hydrolyze the compound represented by the general formula of component (A). Examples of the acidic aqueous solution of component (C) include phosphoric acid, acetic acid, nitric acid, sulfuric acid, hydrochloric acid, water, etc., and an aqueous solution with a pH of 1 to 4 is preferable. The amount of component (C) is the sum of components (A), (B), and (C).
When 100 parts by weight, it is 1 to 10 parts by weight.
If the amount of component (C) is less than 1 part by weight, the compound of the above formula will be insufficiently hydrolyzed, and the coated film will be prone to cracks. Furthermore, if the amount of component (C) exceeds 10 parts by weight, the dyeability and wettability will decrease. Component (D), a curing catalyst, is added to improve the storage stability of the coating liquid. Generally, in a silicone hard coating liquid, a silicon condensation reaction proceeds from the time the liquid is prepared. In the present invention, by using one or both of maleic anhydride and dibutyltin laurylate as a curing catalyst for component (D), it is possible to retard this reaction rate and improve the storage stability of the liquid. The blending amount of component (D) is when the total of components (A), (B), and (C) is 100 parts by weight.
The amount is 0.01 to 5.0 parts by weight. If component (D) is less than 0.01 part by weight, the above effects cannot be obtained sufficiently, and component (D)
If it exceeds 5.0 parts by weight, there will be problems such as short solution life and poor dyeing reproducibility. Incidentally, a surfactant may be added to the coating composition of the present invention in order to obtain smoothness of the cured film. In addition, as a substrate to which the coating composition of the present invention is applied, particularly diethylene glycol bisallyl carbonate resin (trade name CR-39, TS-
16, MR-3) Acrylic resin is preferred, but various other plastics can also be used. "Examples of the Invention" Next, the present invention will be described in more detail with reference to Examples and Comparative Examples. The test method for the characteristic values determined in the Examples and Comparative Examples is as follows. (1) Adhesion After coating the plastic lens with an organic silicon hard coat film or further forming an anti-reflection coat film on it, cross-cut 100 stitches at 1 mm intervals, and peel off with cellophane tape for 3 times.
The number of stitches remaining in the coating film during the 100 stitches was measured. (2) Scratch resistance The coating surface was abraded 50 times with #0000 steel wool under a load of 1 kg to examine its resistance to scratches. The evaluation was as follows. A: No scratches, B:
Slight scratches, C: Significant scratches (3) Weather resistance The surface condition was examined after 150 hours of exposure to a Sunshine Weather Meter using a carbon arc. ◯ indicates that the surface condition is good, △ indicates that the surface condition is somewhat poor, and × indicates that the surface condition is poor. (4) Dyeability Immerse the hard-coated lens in a dye bath at 90℃ for 5 minutes, and the light attenuation rate at 550nm is 20%.
If the above is achieved, it is considered OK. ◯ indicates good dyeability, △ indicates slightly poor dyeability, and × indicates poor dyeability. (5) Chemical resistance After hard-coated lenses were immersed in an aqueous solution containing water, alcohol, and detergent for 24 hours, the condition of the coated surface was examined. ○ indicates that the surface condition is good. (6) Inorganic coating property After applying and curing the organic silicon hard coat film, put it in a vacuum evaporator and apply Al ₂ O ₃ at λ ₀ /4, ZrO ₂ at λ ₀ /2, and SiO ₂ at λ Coat _0/4 sequentially to form an antireflection film. Note that λ ₀ is
It is 550nm. Then, the surface condition of the coat film was examined. ◯ indicates that the coated surface is good, △ indicates that the coated surface is somewhat poor, and × indicates that the coated surface is poor. (7) Coating liquid life After applying the coating film, adhesion test shows 0/100.
The liquid life was defined as the time when . Examples 1 to 4 γ-glycidoxypropyltrimethoxysilane as component (A), methanol silica sol (manufactured by Catalysts Kasei Kogyo, OSCAL-1132) or isopropyl alcohol-dispersed colloidal silica sol (manufactured by Catalysts Kasei Kogyo, OSCAL) as component (B) -1432), a 0.01 N aqueous solution of hydrochloric acid or acetic acid as the component (C), and maleic anhydride or dibutyltin laurylate as the component (D), mixed with the composition shown in Table 1, and kept at room temperature for 24 hours. It was aged and made into a coating liquid. Next, a plastic lens made of diethylene glycol bisallyl carbonate resin (trade name CR-39) was washed in advance, and the above-mentioned coating liquid was applied by dip coating.
The pulling speed was 12 cm/min. Table 1 shows the performance evaluation of the obtained hard coat film and the lifespan of the coating liquid. Examples 5 to 7 β-(3,4 epoxycyclohexyl)ethyltrimethoxysilane as component (A), methanol silica sol (manufactured by Nissan Chemical, Snotex 30) or ethyl alcohol-dispersed colloidal silica sol (manufactured by Catalysts Kasei Kogyo Co., Ltd.) as component (B) Made by OSCAL−
1232), a 0.01N aqueous solution of hydrochloric acid or nitric acid was used as component (C), and a mixture of maleic anhydride and dibutyltin dilaurylate in a weight ratio of 1:1 was used as component (D), and these were prepared in the table below. The composition shown in 1 was mixed and aged at room temperature for 24 hours to obtain a coating liquid. Next, the coating solution was applied to a plastic lens made of diethylene glycol bisallyl carbonate resin (trade name: CR-39) in the same manner as in Examples 1 to 4, and cured.
Table 1 shows the performance evaluation of the obtained hard coat film and the lifespan of the coating liquid. Examples 8 to 10 Component (A) was a mixture of γ-glycidoxypropyltrimethoxysilane and β-(3,4 epoxycyclohexyl)ethyltrimethoxysilane in a weight ratio of 1:1, ( B) As a component, methanol silica sol (manufactured by Nissan Chemical, Snowtex
30) or butyl alcohol-dispersed colloidal silica sol (Catalyst Chemical Industry Co., Ltd., OSCAL-1532), (C)
A 0.01N aqueous hydrochloric acid solution was used as the component, and maleic anhydride was used as the component (D). These were mixed in the composition shown in Table 1, and aged at room temperature for 48 hours to obtain a coating solution. Next, the coating solution was applied to a plastic lens made of diethylene glycol bisallyl carbonate resin (trade name: CR-39) in the same manner as in Examples 1 to 4, and cured. Table 1 shows the performance evaluation of the obtained hard coat film and the lifespan of the coating liquid. Comparative Example 1 Components (A), (B), and (C) had the same composition as in Example 1, and (D)
The coating solution was prepared without mixing the components.
Other treatments were performed in the same manner as in Example 1. The results are shown in Table-1. Comparative Example 2 32 parts by weight of γ-glycidoxypropyltrimethoxysilane as component (A), 356 parts by weight of methanol silica sol as component (B), 12 parts by weight of 0.01N hydrochloric acid aqueous solution as component (C), component (D) The composition is a mixture of 1.6 parts by weight of dibutyltin dilaurylate, 48
The mixture was aged at room temperature for an hour and a coating solution was prepared.
Other treatments were performed in the same manner as in Example 1. The results are shown in Table-1. Comparative Example 3 240 parts by weight of γ-glycidoxypropyltrimethoxysilane as component (A), 140 parts by weight of methanol silica sol as component (B), 20 parts by weight of 0.01N hydrochloric acid aqueous solution as component (C), component (D) The composition was mixed with 1.0 parts by weight of maleic anhydride and aged for 24 hours.
Coating liquid was adjusted. Other treatments were performed in the same manner as in Example 1. The results are shown in Table-1. Comparative Example 4 120 parts by weight of β-(3,4 epoxycyclohexyl)ethyltrimethoxysilane as component (A),
220 parts by weight of isopropyl alcohol-dispersed colloidal silica sol as component (B), 60 parts by weight of 0.01N hydrochloric acid aqueous solution as component (C), and 4.0 parts by weight of maleic anhydride as component (D), aged for 24 hours, Coating liquid was adjusted. Other treatments were performed in the same manner as in Example 1. The results are shown in Table-1. As is clear from Table 1, generally good evaluation results are obtained in Examples 1 to 10. On the other hand, in Comparative Example 1 in which component (D) was not mixed, sufficient scratch resistance was not obtained and the life of the coating liquid was shortened. Furthermore, in Comparative Example 2, in which component (A) was mixed in a smaller amount and component (B) was added in a larger amount than in the scope of the present invention, the adhesion, weather resistance, inorganic coating properties, and life of the coating liquid were all reduced. Furthermore, in Comparative Example 3, in which more component (A) and less component (B) were mixed than in the range of the present invention, the dyeing properties and scratch resistance decreased. Furthermore, in Comparative Example 4, in which component (C) was mixed in a larger amount than the range of the present invention, the adhesion and dyeability decreased. In addition, in Table 1, "M" of component (B) represents methanol silica sol, "E" represents ethyl alcohol-dispersed colloidal silica sol, "B" represents butyl alcohol-dispersed colloidal silica sol, and "I" represents isopropyl alcohol-dispersed colloidal silica sol. , "None" in component (D) is maleic anhydride, "di"
represents dibutyltin dilaurylate, and "co" represents a mixture of maleic anhydride and dibutyltin dilaurylate.

[Table] "Effects of the Invention" As explained above, according to the present invention, the above (A)
By mixing components (B), (C), and (D) in a specific composition, it has excellent adhesion, weather resistance, dyeing properties, chemical resistance, inorganic coating properties, scratch resistance, and coating liquid life. A coating composition can be obtained.

Claims (1)

[Claims] 1 (A) General formula YRSiX ₃ (wherein R is an alkyl group,
(Y represents an organic group having an epoxy group, X represents an alkoxyl group); (B) a silicon compound containing at least one type of epoxy group;
It consists of a 100 nm colloidal silica sol, (C) an acidic aqueous solution, and (D) a mixed solution of one or two of maleic anhydride and dibutyltin dilaurylate as a curing catalyst, and the above (A), (B), and (C) components. When the total of is 100 parts by weight, component (A) is 10 to 50 parts by weight, component (B) is
40 to 85 parts by weight, component (C) 1 to 10 parts by weight, component (D)
A coating composition characterized in that the coating composition contains 0.01 to 5.0 parts by weight.