JPH0321678A - Coating composition and optical article coated with the same - Google Patents

Abstract

PURPOSE:To obtain the title composition free from unevenness of reflecting color when reflection preventing film is formed on rigid coating film formed by applying to plastic glass lens by dispersing diamond fine granules into a coating liquid containing a coating film-forming ingredient. CONSTITUTION:The aimed composition obtained by dispersing diamond fine granules (preferably having 10-100nm granule size) into a coating liquid containing a coating film-forming ingredient (preferably organosilicon compound or hydrolysate thereof) and further as necessary adding a curing catalyst (preferably aluminum chelate compound) thereto. The coating film has excellent scratch resistance, surface hardness, abrasion resistance, flexibility, transparency, heat resistance and antistatic properties, large degree of surface reflection and good adhesion with reflection preventing film, metallized film, etc., and slippery characteristics of coating film surface.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to coating compositions, in particular coating compositions for protecting plastic moldings.

[Conventional technology]

Plastic molded products are used in large quantities due to their advantages such as light weight, easy processability, and impact resistance. However, on the other hand, they do not have sufficient hardness and are easily scratched, are easily attacked by solvents, and are electrostatically charged and dusty. It has drawbacks such as adsorption of water and insufficient heat resistance, and is therefore unsatisfactory in practical terms compared to inorganic glass objects when used as eyeglass lenses and window materials.

Therefore, it has been proposed to apply a protective coat to plastic molded products. Numerous types of coating compositions have been proposed for use in coatings.

Among them, there are "coating compositions whose main component (resin component or film-forming component) is an organosilicon compound or its hydrolyzate", which is expected to provide a hard coating film close to that of an inorganic system (for example, , JP-A-52-1126 No. 1), which has been put into practical use as an eyeglass lens.

However, this coating composition is still unsatisfactory in its scratch resistance (resistance to scratches), so it has been proposed to add colloidally dispersed silica sol to it (for example, see JP-A-53-111336). This has also been put into practical use for eyeglass lenses.

Incidentally, conventionally, plastic eyeglass lenses have been manufactured almost 100% by casting polymerization of a monomer called diethylene glycol bisallyl carbonate (commonly known as CR-39). This lens has a refractive index of approximately 1
．． 50, which is lower than the refractive index of glass lenses, which is approximately 1.52, and therefore myopic lenses have the disadvantage of having thick edges, which is the main reason why they are disliked by wearers.

Therefore, the development of monomers higher than CR-39 has proceeded, for example, JP-A-55-13747, JP-A-5
6-166214, JP-A-57-23611, and JP-A-57-54901 were proposed. Currently, several companies offer na = 1.54 to 1. 60 medium to high refractive index plastic lenses are now commercially available.

These lenses are also coated with the aforementioned coating composition to which silica sol is added.

[Problems to be Solved by the Invention] However, the coating composition to which silica sol is added has the first problem that interference fringes are visible on the coating film and the appearance of the lens is poor.

Furthermore, in lenses, an antireflection film (consisting of a multilayer structure film of inorganic oxide thin films based on optical interference theory) is often formed on the coating film. In this case, the antireflection film exhibits a reflection color of, for example, very pale green, but the second problem is that this reflection color varies depending on the position on the lens surface and is uneven.

Therefore, the first object of the present invention is that na=1.54 to 1.
To provide a coating composition that provides a coating film on a medium to high refractive index plastic molded article of No. 60 in which no interference fringes are visible and the reflective color is uniform.

A second object of the present invention is to provide a coating composition that has excellent scratch resistance, surface hardness, abrasion resistance, flexibility, transparency, antistatic property, dyeability, heat resistance, etc. It is in.

[Means to solve the problem]

Therefore, the present invention provides a "coating composition characterized in that diamond fine particles are dispersed in a coating liquid containing film-forming components, and a curing catalyst is optionally added thereto."

[Effect]

(a) The coating film-forming component (resin component) for coating is not particularly limited as long as it has good adhesion to the substrate and provides a transparent and hard coating, but organosilicon compounds or Hydrolysates thereof are preferred.

As an organosilicon compound, the following general formula: R'a R"
b Si(OR3)4-. +bl・・・−・−・・−(
Formula ■) (However, in the formula, R1 has 4 to 4 carbon atoms and has a functional group or an unsaturated double bond.)
l4 is an organic group, Rt is a hydrocarbon group or halogenated hydrocarbon group having 1 to 6 carbon atoms, R3 is an alkyl group, alkoxyalkyl group, or acyl group having 1 to 4 carbon atoms, and a and b are each 0 or l, and a+b is
1 or 2. ) Organosilicon compounds represented by these are preferred.

Among the compounds of general formula (I), for example, the following compounds are used in which RI has an epoxy group as a functional group.

(1) General formula (■): (However, in the formula, R4 is an alkyl group having 1 to 4 carbon atoms, an alkoxyalkyl group or an acyl group, and R5 is a carbon number 1
~6 hydrocarbon group or halogenated hydrocarbon group, R@ is,
hydrogen or a methyl group, m is 2 or 3, p is 1-6, q is O-2. ).

(2) General formula (■): (However, R7 is an alkyl group or alkoxyalkyl group or an acyl group having 1 to 4 carbon atoms, R5 is a hydrocarbon group or halogenated hydrocarbon group having 1 to 4 carbon atoms, 1 is 2 or 3,
r is 1-4. ).

Since all of the compounds represented by the above general formula have an epoxy group, they are also called epoxysilanes.

Specific examples of epoxysilanes include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxyethoxysilane, γ-glycidoxypropyltriacetoxysilane, and γ-glycidoxypropyltrimethoxyethoxysilane. Examples include glycidoxypylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β-(3.4-epoxycyclohexyl)ethyltriethoxysilane.

Furthermore, among the compounds of general formula (I), those other than those in which Rl has an epoxy group as a functional group (including those where a=0)
For example, the following can be used:

Methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, vinyltrimethoxyethoxysilane, γ-methacrylatetrimethoxysilane, aminomethyltrimethoxysilane, 3- Aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercabutopropyltriethoxysilane, 3,3.3- }Various trialkoxysilanes, triacyloxysilanes, or trialkoxyalkoxysilane compounds such as trifluoropropyltrimethoxysilane.

The exemplified compounds of general formula (I) listed above are all S
There are three OR” groups bonded to the i atom (a+b=1)3
As a functional example, there are two OR'' groups (a+b=2)
Of course, corresponding difunctional compounds can also be used. Examples of corresponding difunctional compounds include dimethyldimethoxysilane, diphenyldimethoxysilane, methylphenyldimethoxysilane, methylvinyldimethoxysilane, and dimethyldiethoxysilane.

The compound of general formula (1) may be used alone, or two or more may be used in combination depending on the purpose.

In particular, when a bifunctional compound is used, it is preferable to use it together with a trifunctional compound. When used together, 2>a+b>1 on average.

Furthermore, it is also possible to use a corresponding tetrafunctional compound of a+b=o in combination. Examples of corresponding tetrafunctional compounds include methyl silicate, ethyl silicate, isoprobyl silicate, n-probyl silicate, n-butyl silicate, t-butyl silicate, sec-butyl silicate, and the like.

The compound of general formula (I) may be used as is, but
It is preferable to use it as a hydrolyzate for the purpose of increasing the reaction rate and lowering the curing temperature. When using two or more compounds with the same functional number among di- to tetrafunctional compounds, or when using two or more compounds with different functional numbers together, they may be used together after hydrolysis, or they may be used together after hydrolysis. It may be used in combination beforehand to carry out co-hydrolysis. Hydrolysis liberates the alcohol HOR'', and the compound of general formula (I) becomes the corresponding silanol: OH R''11 0H-Si-OH or OH-Si-OH1 RI or RIRI. Silanol undergoes rapid dehydration condensation and becomes an oligomer. Therefore, in order for this reaction to proceed sufficiently,
After hydrolysis, it may be allowed to stand (cure) for 1 to 24 hours.

Naminosha ± 2 names Tsui: Diamond fine particles themselves are known (for example, J
．． Cryst. Growth 80 (1987)
p. 417-424, JP-A-61-251506, JP-A-63-103810), its particle size is lnm-1.
CI μm, especially Ion m to 100 nm, is preferred. If it is smaller than this, it will be difficult to manufacture, and if it is larger than this, the stability of the coating composition, the transparency of the coating film, etc.
Smoothness etc. deteriorate.

The diamond fine particles may be used in the form of a colloidal dispersion (generally called a sol) in a suitable liquid dispersion medium such as water, alcohol or other organic solvent, or a mixture of water and organic solvent. It is also possible to add a suitable stabilizer, such as a surfactant, to the sol. In order to shorten the time required for coating, these are used as necessary (however, those that impair the stability of the coating composition are not preferred), and for example, the following are used.

(1) Amines: Monoethanolamine, diethanolamine, isoprobanolamine, ethylenediamine, isopropylamine, diisobutylamine, morpholine, triethanolamine, diaminopropane, aminoethylethanolamine, dicyandiamide, triethylenediamine, 2
-Ethyl-4-methylimidazole.

(2) Various metal complex compounds: General formula: AIX, Y. ．． (However, in the formula, and n is O or 1 or 2).

Particularly useful chelate compounds include solubility, stability,
From the viewpoint of catalytic effect, aluminum acetylacetonate, aluminum bisethyl acetoacetate monoacetylacetonate, aluminum di-n-butoxide monoethyl acetoacetate, aluminum di-i
so-propoxide monomethyl acetoacetate and the like.

In addition, chromium acetylacetonate, titanyl acetylacetonate, cobalt acetylacetonate, iron (
III) Acetylacetonate, manganese acetylacetonate, nickel acetylacetonate.

(3) Metal alkoxides: aluminum triethoxide, aluminum tri-n-propoxide, aluminum tri-n-butoxide, tetraethoxytitanium, tetra-n-butoxytitanium, tetra-i-
Bropoxy titanium.

(4) Organic metal salts: sodium acetate, zinc naphthenate, cobalt naphthenate, zinc octylate, tin octylate.

(5) Perchlorate: Magnesium perchlorate, ammonium perchlorate.

(6) Organic acids or their anhydrides: malonic acid, succinic acid, tartaric acid, adipic acid, azelaic acid, maleic acid, O-phthalic acid, terephthalic acid, fumaric acid, itaconic acid, oxazacetic acid, succinic anhydride, anhydride Maleic acid, itaconic anhydride, 1,2-dimethylmaleic anhydride, phthalic anhydride, hexahydrophthalic anhydride, naphthalic anhydride.

(7) Lewis acid: Ferric chloride, aluminum chloride.

(8) Metal halides: stannous chloride, stannic chloride, tin bromide, zinc chloride, zinc bromide, titanium tetrachloride, titanium bromide, thallium bromide, germanium chloride, hafnium chloride, lead chloride, odor Lead chloride.

The above catalysts may not be used alone, but may be used in combination of two or more. Particularly when component (a) has an epoxy group, a catalyst that also serves as a ring-opening polymerization catalyst for the epoxy group may be used.

In particular, aluminum chelate compounds are one of the preferred catalysts.

``L Sokodan Seiri: The solvent (d) is used as necessary to make the coating composition liquefied or to lower its viscosity. For example, water, lower alcohols, acetone, ethers, ketones, esters, etc. are used.

In the coating composition of the present invention, the amount of component (b) is 1 to 5 per 100 parts by weight (solid content) of component (a).
00 parts by weight (solid content) preferably 10 to 200 parts by weight (
solid content), the total of components (a) and (b) is 100
0.0% of component (c) per part by weight (solid content). 0001
It is appropriate to use up to 50 parts by weight, preferably 0.0005 to 20 parts by weight.

Component (d) is used in an appropriate amount depending on the viscosity of the composition.

In addition to the above components (a) to (d), if necessary, for example, for the purpose of improving adhesion to the substrate (molded object) to be coated, improving weather resistance, etc., or for the purpose of improving the weather resistance of the coating composition, Various additives may be used in combination for the purpose of improving stability.

Examples of additives include pH adjusters, viscosity improvers, leveling agents, matting agents, dyes, pigments, stabilizers, ultraviolet absorbers, antioxidants, and the like.

In addition, an epoxy resin or other organic polymer may be used in combination for the purpose of improving the dyeability of the coating film.

Epoxy resins include polyolefin epoxy, cyclopentadiene oxide, cyclohexene oxide, or alicyclic epoxy resin such as polyglycidyl ester, polyglycidyl ether, epoxidized vegetable oil, and nopolac type, which are commonly used for paints and casting. There are epoxy novolaks made of phenolic resin and shrimp chlorohydrin, and also copolymers of glycidyl methacrylate and methyl methacrylate.

Other organic polymers include, for example, polyol,
There are cellulose resins, melamine resins, etc.

In order to improve the flow during application, improve the smoothness of the coating film, and lower the coefficient of friction on the coating surface, various surfactants can be used in combination with the coating composition, especially dimethylsiloxane. Block or graft copolymers of and alkylene oxide, as well as fluorine-based surfactants, etc., are effective.

In some cases, an inorganic filler such as silica sol, antimony oxide sol, etc. may be used in combination as long as the object of the present invention is not impaired.

The compositions of the invention are applied in particular to plastic moldings. In terms of materials for molded products, examples include polymethyl methacrylate and its copolymers, acrylonitrile styrene copolymers, polycarbonates, cellulose acetate, polyvinyl chloride, polyethylene terephthalate, epoxy resins, unsaturated polyester resins, polyurethane resins, CR The composition of the present invention is applied to a polymer of -39 and the like.

In terms of form, the composition of the present invention is applied to blocks, wires, films, and the like.

In terms of function, molded products include optical products, especially camera lenses,
The composition of the present invention is applied to spectacle lenses, reflective mirrors, prisms, and the like.

The composition of the present invention is particularly useful as a scratch-preventing film for "eyeglass lenses" molded from a resin having a medium to high refractive index of na=1.53 or more.

In addition, the composite material of the present invention can be applied not only to plastic objects but also to inorganic glass, wood, metal articles, and the like.

As the application means, usual coating methods such as brush coating, dipping, roll coating, spray coating, and flow coating can be used.

Furthermore, after applying the composition of the present invention to a mold, cast polymerization of the raw material that will become the base material molding is performed to mold a plastic object, or after applying the composition of the present invention to a molded object, it is still possible to It is also possible to bring the uncured coating surface into close contact with a mold, and then cure the coating thereon.

After being applied, the coating composition of the present invention is often cured by heat treatment to obtain a hard coating film. Heating temperature is about 50-200℃, preferably 80-14℃
A sufficient effect can be obtained at 0°C.

The thickness of the coating film after drying is generally from 0.1 to 30 μm, preferably from 0.5 to 10 μm.

The coating film is transparent and has excellent hardness, particularly scratch resistance, and does not cause deterioration in appearance due to scratches, which is a problem with plastic molded products, and can provide molded products with extremely high commercial value.

Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited to this.

[Examples 1 to 3] (1) 1-minimal bottom ΔL week type: 212.4 parts by weight of γ-glycidoxybrobylmethyltrimethoxysilane was charged into a reaction vessel equipped with a rotor,
While cooling to 10°C and stirring vigorously using a magnetic stirrer, add 0.01N hydrochloric acid aqueous solution 48.6
Parts by weight were added gradually.

Immediately after the completion of the dropwise addition, cooling was stopped to obtain a hydrolyzate corresponding to component (a) in the form of a uniform, colorless and transparent solution.

After adding 77.1 parts by weight of ethanol and 37.7 parts by weight of ethylene glycol as component (d) to the obtained hydrolyzate (a), 7.1 parts by weight of aluminum acetylacetonate as component (C). A preliminary composition A was prepared by adding 65 parts by weight and thoroughly mixing and dissolving the mixture.

(2) Ekebono Seisho Sodan Ushisei type: 248 parts by weight of γ-glycidoxypyldiethoxysilane was charged into a reaction vessel equipped with a rotor, and while stirring vigorously using a magnetic stirrer, the 0.05N 36 parts by weight of an aqueous hydrochloric acid solution was added dropwise at once. Immediately after addition, the solution was non-uniform, but within a few minutes it became a uniform, colorless and transparent solution while generating heat. Continue stirring for another 1 hour, and add component (a)
A hydrolyzate corresponding to .

To the obtained hydrolyzate (a), 56.6 parts by weight of ethanol and 53.4 parts by weight of ethylene glycol were added as component (d), and then 4.7ffiJi parts of aluminum acetylacetonate was added as component (C). , and sufficiently mixed and dissolved to prepare preliminary composition B.

(3) Preparation of Coating 7: In a glass container, add the precompositions A and B prepared in (1) and (2) above in the parts by weight (not solid content) listed in Table 1 below.
Weigh and pour into it, add (b) 40 parts by weight of diamond fine particles (average particle size: 8 to 40 nm) and a small amount of surfactant as part a, and stir and mix thoroughly to form a uniform, colorless and transparent mixture. A solution-like coating composition was prepared.

Keimoku: Commercially available refractive index n d = 1. No. 59 polycarbonate eyeglass lenses (diameter 70 mm) were prepared, and the above coating composition was applied thereto by a dipping method, followed by heat treatment at 100° C. for 2 hours to cure the coating film.

Sky madness: The lens with the cured coating obtained in the previous section (4) was subjected to the following test,
The performance of the coating film was evaluated.

The coating surface was rubbed with #0000 steel wool to examine the scratch resistance. The evaluation was conducted as follows.

◎・・・・・・No scratches even if rubbed strongly.

○...If you rub it quite strongly, it will get a little scratched.

×・・・Even weak friction can cause damage.

By the way, the evaluation of the lens without a coating film was ×.

The surface of the paint film was rubbed with sandpaper x iooo, and the scratch resistance was evaluated in the same manner as ■ Qianji 1.

(2) Appearance A general-purpose antireflection film was formed by vacuum deposition on the coating film cured in the previous item (4), and the unevenness of reflected color was examined with the naked eye and evaluated as follows.

◎・・・・・・No unevenness in reflected color ○・・・・・・〃 Slightly ×−−− −−− // Significant ~) (c)
After immersing a lens with an adhesive cured coating in hot water at 90°C for 2 hours, apply cellophane adhesive tape (trade name: "Cello Tape") to the coating surface.
(manufactured by Nichiban Co., Ltd.) was strongly attached. One end of the tape was held in hand and rapidly peeled off in a 90 degree direction, and the degree of peeling of the coating film was observed with the naked eye.

The results of the above evaluation are shown in Table 1 below.

[Comparative example l]

In the examples, commercially available silica sol (methanol dispersion sol, average particle size = 13
The coating composition of this example was prepared and evaluated in substantially the same manner as in the example except that 20% of the solid content was used.

[Comparative Example 2] A lens itself without a coating film was similarly tested and evaluated as Comparative Example 2.

The results of the above evaluation are also shown in Table I below.

Table (3) The coating film has excellent antistatic properties and is relatively resistant to staining.

(4) The surface reflectance of the coating film is high.

(5) Good adhesion of antireflection films, metal vapor deposition films, etc. to paint films.

(6) The coating film surface has good sliding properties (low coefficient of friction).

Claims (1)

[Scope of Claims] 1. A coating composition characterized in that fine diamond particles are dispersed in a coating liquid containing film-forming components, and further a curing catalyst is optionally added. 2. The coating composition according to claim 1, wherein the coating film-forming component is an organosilicon compound or a hydrolyzate thereof.