JPH0222340A - Molded body having transparent coating layer - Google Patents

Abstract

PURPOSE:To obtain the subject molded body, having a transparent coating layer containing a fine particulate inorganic substance consisting of an Sn oxide with a specific average particle diameter and having a high refractive, surface hardness and electric conductivity without interference fringes of the coating layer. CONSTITUTION:A molded body, obtained by dispersing (A) 5-80wt.%, preferably 10-70wt.% fine particulate inorganic substance consisting of an Sn oxide (which may be used together with other metal oxides) having 1-300mum, preferably 5-200mum average particle diameter in (B) a transparent material (preferably containing an organosilicon polymer and/or organic high polymer compound having a crosslinked structure) and coating the surface of a molded body (preferably transparent glass or plastic) with the resultant coating agent and having a transparent coating layer with transparency thereof expressed in terms of <=80% haze value determined by the formula.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a molded article having a transparent coating layer with a high refractive index.

Furthermore, the present invention relates to a molded article having a transparent coating layer suitable for producing a molded article having low light reflectance, high light transmittance, and electrical conductivity and high surface hardness.

[Prior Art] Reducing the light reflectance of various transparent materials and improving the light transmittance is an extremely important problem, such as effective use of light and eliminating blurring of images due to reflected images, and many methods have been used to date. is proposed.

The idea is to reduce the light reflectance and improve the light transmittance by forming an optical thin layer, mainly made of inorganic material, on the surface of the base material, which has a refractive index different from that of the base material. At this time, in order to maximize the effect, it is possible to coat multiple thin layers with different refractive indexes, control the thickness of each thin layer to match the wavelength level of the corresponding light beam, or continuously apply different refractive indexes. Formation of so-called heterogeneous films is being carried out.

Taking the case of forming a single-layer antireflection thin film on the surface of a substrate as an example, the antireflection thin film provided on the surface of the substrate is made of an inorganic component with a refractive index as low as possible (for example, magnesium fluoride, etc.). , and it is said to be desirable to adjust the optical thickness of the antireflection thin film to 1/4 of the wavelength of the target light beam.

Such optical thin films are subject to limitations regarding the substrates to which they can be applied, depending on the formation process.

To date, antireflection thin layer formation has been most widely applied to transparent materials, mainly glass substrates. The technique of coating a thin inorganic layer on the surface of the substrate, which is often used in this case, has extremely limited application to other techniques.

Examples of the techniques mentioned above include vacuum evaporation, sputtering, and ion beam methods to improve adhesion. However, these techniques are difficult to apply to plastic materials, which have recently become popular among transparent materials, particularly in the field of eyeglass lenses, or to plastic films and sheets, for which it is advantageous to form an antireflection layer. In particular, there are many problems when applied to plastic materials with high hardness coating materials to improve their abrasion resistance.

That is, plastic materials generally have insufficient heat resistance and cannot withstand the above coating process, and in some cases, the plastic material (substrate) may undergo decomposition, melting, thermal deformation, optical distortion, etc. Adhesion is also generally poor. This is mainly due to the difference in expansion coefficient between the plastic material (base material) and the inorganic material coated on its surface, and if the adhesion decreases significantly during heating or humidification, the inorganic material layer may crack or crack. etc. may occur.

An even more serious problem is the significant reduction in impact resistance and flexibility of the plastic material (substrate) that occurs due to the coating with such an inorganic layer. This is thought to be mainly due to the notch effect caused by cracks in the inorganic material on the surface layer.

In other words, this indicates that the superiority of plastic materials over glass materials is lost, and is an important problem.

In addition, conventionally, in corrective lenses etc. with a high refractive index,
There was a problem in that it had poor appearance due to interference fringes.

JP-A-54-87735, JP-A-54-8773
6 and JP-A-53-130732 disclose a technique for forming a coating layer made of silica colloid, but do not describe the refractive index. Furthermore, U.S. Patent No. 2601.123 also describes a technique for coating only inorganic particles;
There was no description regarding refractive index.

[Problems to be Solved by the Invention] The present inventors have made extensive studies to solve these problems and develop a molded product having a transparent coating layer that has a high refractive index, high surface hardness, and conductivity. As a result, the present invention was achieved.

That is, an object of the present invention is to provide a molded article having a conductive transparent coating layer, which has a high refractive index, and is free from problems such as poor appearance due to interference fringes.

[Means to solve the problem] In order to achieve the above object, the present invention consists of the following configuration.

"In a molded article having a transparent coating layer, the transparent layer contains 5 to 80% by weight of a fine particulate inorganic substance made of an oxide of Sn with an average particle size of 1 to 300 mμ. The particulate inorganic material used in the present invention has an average particle diameter of about 1 to 300 mμ, preferably about 5 to 200 mμ.

If the particle size is too small, it is difficult to produce, expensive and impractical, and if the particle size is too large, the transparency generally decreases, so particles within the above range are mainly used.

In the present invention, fine particulates of tin oxide are used as these particulate inorganic substances. It is particularly preferred because it has excellent transparency, conductivity, and surface hardness, and also provides a high refractive index. That is, if the refractive index is high, a corrective lens or the like having a high refractive index will not cause poor appearance due to interference fringes in the coating layer.

Furthermore, these particulate inorganic substances can be used not only alone, but also in combination with other metal oxides. Furthermore, silicon,
A mixed oxide containing antimony, indium, etc. may also be used.

It is necessary that the particulate inorganic substance be contained in at least the surface layer of the transparent substrate.

This is because the premise is to impart hardness to the surface layer of the base material to improve wear resistance and abrasion resistance.

Methods for incorporating inorganic substances into the surface layer include methods such as uniformly dispersing the inorganic substance in the transparent material serving as the base material during the molding process, and methods in which the inorganic substance is dispersed only in the surface layer. Yet another method is to disperse the inorganic material in a transparent coating material and apply it to the surface of the transparent material.

Various known methods can be used to disperse the above-mentioned particulate inorganic material, such as (a) mixing the particulate inorganic material and another base material (transparent material) by heating or at room temperature in the presence or absence of a solvent or other components; how to.

(b) A method in which a dispersion (fine particulate inorganic substance) and a substance serving as a substrate (hereinafter referred to as a vehicle component) are mixed in a volatile dispersion medium, and then the volatile dispersion medium is evaporated.

(C) A method is used in which fine particulate inorganic material is dispersed in a monomer component and then polymerized.

When the present invention is applied to the coating material among the above methods, the method in item (b) is preferred. In this case, the coating film formed by evaporation of the volatile dispersion medium may be cured.

Examples of volatile dispersion media that can be used include water, hydrocarbons, chlorinated hydrocarbons, esters, ketones, alcohols, and organic carboxylic acids.

Moreover, these can be used not only alone but also as a mixture of two or more.

The amount of the particulate inorganic substance of the present invention contained in the transparent material is
At least, preferably in the surface layer part of 1 μm or less, 5 to 5
It is 80% by weight, preferably 10 to 70% by weight. If the amount is less than 5% by weight, the effect of addition will be small, and if the amount exceeds 80% by weight, defects such as cracking and decreased transparency will occur.

Methods for dispersing inorganic substances in transparent materials include the above-mentioned method of directly dispersing them in the base material (transparent material), or the method of dispersing them in a coating material and applying this to the transparent material (hereinafter referred to as coating method). Although it is not particularly important which method is used, the coating method has the following advantages.

In other words, if the fine particulate inorganic substance cannot be easily dispersed in the substrate, or if it can be dispersed but would cause a significant change in the properties of the substrate, the coating method may be used to improve the properties of the substrate. No major changes will occur.

When dispersing the above-mentioned fine particulate inorganic material, it is possible to use a fine powder form before dispersion, but in order to achieve the purpose of the present invention, it is necessary to disperse the fine particulate inorganic material in a colloidal form in a liquid dispersion medium. The ones listed above are particularly effective.

The substrate or vehicle component in which the particulate inorganic material of the present invention is dispersed is not particularly limited. Considering the provision of a thin film, it is preferable that the surface of the inorganic substance is formed by partially or completely volatilizing or disappearing by activated gas treatment, thereby forming a surface containing micropores of the inorganic substance. Compounds containing various elements having organic groups, such as organic compounds and/or organosilicon compounds, can usually be used, and these polymer compounds are particularly useful.

Examples of these are epoxy resins, copolymers of acrylic esters and/or methacrylic esters (including copolymers with other vinyl monomers), polyamides, polyesters (so-called alkyd resins, unsaturated polyester resins). ), various amino resins (including melamine resins, urea resins, etc.), urethane resins, polycarbonates, polyvinyl acetate, polyvinyl alcohol, styrene resins, transparent vinyl chloride resins, silicon resins, cellulose resins, and diethylene glycol bisallyl. Carbonate polymer (CR-39) can be mentioned.

Furthermore, these resins can be used in combination, and cured products obtained by using an appropriate curing agent in combination can also be used.

In addition to plasticizers, various curing agents, curing catalysts, etc., the vehicle component may further contain various additives such as surface conditioners, ultraviolet absorbers, and antioxidants.

The molded article having a transparent coating layer of the present invention preferably has a haze value (percentage) of 80% or less as determined by the following formula.

Haze value (%) = (diffuse light transmittance/total light transmittance) x 10
0 In particular, the coexistence with a silicon-based polymer compound or a polymer compound containing the silicon-based polymer compound used as a coating agent for improving the surface hardness of plastic articles can be effectively used to improve the surface hardness.

Further, the molded article having a transparent coating layer of the present invention may be colorless or colored with dyes and pigments.

Various methods have been proposed for providing a silicon-based polymer coating layer, but a method obtained by curing a compound selected from the group consisting of compounds having the following general formula and/or their hydrolysates is proposed. The method used is particularly effective.

That is, a compound consisting of the formula %() where R1 and R2 are C, %C
, o alkyl, aryl, halogenated alkyl, halogenated aryl, alkenyl, or an organic group having an epoxy group, (meth)acryloxy group, mercapto group, amino group, or cyano group, bonded to silicon through a 5i-C bond R3 is C1- to C6
is an alkyl group, alkoxyalkyl group or acyl group, a and b are 0.1 or 2, and a+b is 1 or 2.

Examples of these compounds include methyltrimethoxysilane, methyltriethoxysilane, methyltrimethoxyethoxysilane, methyltriacetoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyl trimethoxysilane, vinyltriethoxysilane,
Vinyltriacetoxysilane, vinyltrimethoxyethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriacetoxysilane, γ
-Chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, γ-chloropropyltripropoxysilane, 3. 3゜3-Trifluoropropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-(β-glycidoxyethoxy)propyltritoxysilane, β-(3 , 4-epoxycyclohexyl)ethyltriethoxysilane, β-(3゜4-epoxycyclohexyl)ethyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane , γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane,
Trialkoxy or triazyloxysilanes such as N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, β-cyanoethyltriethoxysilane, dimethyldimethoxysilane, phenylmethyldimethoxysilane, dimethyljethoxysilane, phenylmethyljetoxysilane, etc. Toxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyljethoxysilane, γ-glycidoxypropylphenyldimethoxysilane, γ-glycidoxy Propylphenyldiethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropylmethyljethoxysilane, dimethyldiacetoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyljethoxysilane, γ- Dialkoxysilane or diacyloxysilane such as mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyljethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyljethoxysilane, methylvinyldimethoxysilane, methylvinyljethoxysilane An example is

These organosilicon compounds can be used alone or in combination of two or more.

Furthermore, there are various tetraalkoxysilanes or their hydrolysates that can be used in combination with the above-mentioned silane compounds, although they cannot be used alone.

Examples of tetraalkoxysilanes include methyl silicate, ethyl silicate, n-propyl silicate, isopropyl silicate, n-butyl silicate, 5ec-
Examples include butyl silicate and t-butyl silicate.

Although these organosilicon compounds can be cured even in the absence of a catalyst, various curing catalysts can be used to further accelerate curing. Various acids or bases including Lewis acids, Lewis bases, such as organic carboxylic acids, chromic acid, hypochlorous acid, boric acid, bromic acid, selenite, thiosulfuric acid, orthosilicic acid, thiocyanic acid, nitrite, aluminium. Metal salts of acids and carbonates, particularly alkali metal salts or ammonium salts, as well as alkoxides of aluminum, zirconium, titanium, or complex compounds thereof, can be used. Naturally, this material can be used in combination with other organic substances, and among these, epoxy resins and acrylic copolymers, especially those having hydroxyl groups, such as polyvinyl alcohol, are useful.

Furthermore, when used as a coating material, it is possible to use solvents and various additives to facilitate coating work or maintain good storage stability.

Any base material may be used, but from the viewpoint of transparency, glass and transparent plastic materials give particularly effective results. Preferred examples of the above-mentioned plastic materials include polymethyl methacrylate and copolymers thereof, polycarbonate, diethylene glycol bisallyl carbonate polymer (CR-39), polyester, especially polyethylene terephthalate, unsaturated polyester, epoxy resin, polyether sulfone, and the like. The coating method, drying and/or curing method is appropriately selected from those commonly used in the coating field.

In the present invention, the surface of the transparent coating layer containing the particulate inorganic material obtained as described above may be further treated with an activated gas as described above to provide an antireflection thin layer. Furthermore, a single-layer or multilayer anti-reflection film made of an inorganic material may be provided on the transparent coating layer containing a particulate inorganic material by vacuum deposition or sputtering.

[Example] Example 1 (1) Preparation of silane hydrolyzate γ-glycidoxyprobyltrimethoxysilane 23.6
g was cooled to 10° C., 5.4 g of a 0°01 N aqueous hydrochloric acid solution was gradually added dropwise with stirring, and after the dropwise addition was completed, stirring was continued for an additional hour at room temperature to obtain a silane hydrolyzate.

(2) Preparation of coating agent Add 18.7 g of ethyl alcohol to the silane hydrolyzate.
, phenethyl alcohol 100.3g.

After adding and mixing 0.08 g of silicone surfactant and 0.5 g of aluminum acetylacetonate and stirring thoroughly, further indium oxide/tin oxide mixed inorganic metal oxide fine particles with an average particle size of 100 mμ are added. 39.5 g of oxide was added and thoroughly dispersed with paint conditioner. The composition further contains 50% by weight of colloidal antimony pentoxide having an average particle size of 55 mμ.
Aqueous dispersion 33.4 was further added and dispersed and mixed again with a paint conditioner to obtain a coating agent.

(3) Applying the coating agent and curing. Apply the coating agent described in the previous section to a flat inorganic glass substrate with a thickness of 3.0 mm.
Coating was performed using a bar coater No. 1-6. After application, 5
Set the temperature indoors for 1 minute, then heat at 80℃ for 1 minute.
It was heated and cured for 2 minutes and then at 130° C. for 2 hours.

(4) Evaluation method (a) Coating film thickness It was carried out in accordance with JIS BO651.

(b) Specific resistance value The surface resistance value (sheet resistance value) was determined by the four-probe method, and the specific resistance value was obtained by multiplying the surface resistance value by the coating film thickness.

(c) Haze was measured using a direct reading haze computer (manufactured by Suga Test Instruments Co., Ltd.).

(d) Surface hardness Pencil hardness was measured according to JIS K5400 and defined as surface hardness.

(5) Evaluation results The coating thickness was 6.5 μm, the specific resistance value was 228 Ω/mouth, and the haze was 5.3%. Also, the pencil hardness is 9
H, and the surface hardness was excellent.

[Effects of the Invention] The molded product having the transparent coating layer of the present invention has high hardness and good transparency, and does not have the disadvantage of interference fringes of the coating layer (
An extremely high-quality molded product can be obtained. It also has excellent antireflection properties, and when applied to lenses, etc., it can provide an excellent feeling of wearing without causing eye fatigue. Furthermore, because it has conductivity, it has excellent antistatic properties,
It also has features such as not attracting dust or dirt.

Claims (5)

[Claims] (1) A molded article having a transparent coating layer, characterized in that the transparent layer contains 5 to 80% by weight of a fine particulate inorganic substance made of an oxide of Sn with an average particle diameter of 1 to 300 mμ. A molded body having (2) The molded article having a transparent coating layer according to claim (1), wherein the transparency of the molded article is 80% or less in haze value determined by the following formula. Haze value (%) = (diffuse light transmittance/total light transmittance) x 10
0 (3) The molded article having a transparent coating layer according to claim (1), wherein the transparent layer contains an organosilicon polymer. (4) The molded article having a transparent coating layer according to claim (1), wherein the transparent layer contains an organic polymer compound having a crosslinked structure. (5) The molded article having a transparent coating layer according to claim (1), wherein the base material of the molded article is transparent glass or transparent plastic.