JPS63308069A - Transparent material - Google Patents

Abstract

PURPOSE:To provide a transparent material having excellent optical characteristics and high surface hardness and composed of fine particles of inorganic material having a specific particle diameter and a vehicle. CONSTITUTION:Fine particles of an inorganic material (e.g. zinc oxide, silica or alumina) having an average particle diameter of 1-300mmu, preferably 5-200mmu are compounded with a vehicle [e.g. epoxy polymer, (meth)acrylate polymer or polyamide polymer]. The amount of the inorganic material is 5-80wt.%, preferably 10-70wt.% based on the transparent material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a transparent material with excellent optical properties and high surface hardness.

[Prior art] Plastic materials generally have insufficient heat resistance, so
When exposed to heat, it may undergo thermal decomposition, melting, thermal deformation,
Optical distortion may occur.

In order to improve these drawbacks, attempts have been made to strengthen plastics with glass fibers, or to add inorganic oxide fine particles with a particle size of 1 μm or more as fillers to plastics.

[Problems to be Solved by the Invention] However, although these conventional techniques can certainly improve mechanical properties, they have insufficient transparency and cannot be used for optical purposes.

In order to improve upon such prior art, the present invention provides a transparent material with high optical properties and surface hardness by preparing a composition consisting of fine particles of a specific size and a vehicle.

[Means for solving problems] In order to achieve the above object, the present invention consists of the following configuration.

"A transparent material comprising a particulate inorganic substance having an average particle diameter of 1 to 300 mμ and a vehicle, and characterized in that the amount of the particulate inorganic substance contained in the transparent material is 5 to 80% by weight." The present invention The fine particulate inorganic substance used for this purpose 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 prepare, and if the particle size is too large, the transparency will generally deteriorate and the object of the present invention regarding the antireflection effect cannot be achieved, so particles within the above range are mainly used. It will be done.

Examples of particulate inorganic materials include zinc oxide, silicon oxide,
One or more selected from aluminum oxide, titanium oxide, zirconium oxide, tin oxide, beryllium oxide, and antimony oxide can be preferably used. This is because it has excellent transparency and surface hardness.

Among these, aluminum oxide, titanium oxide, zirconium oxide, tin oxide, beryllium oxide, and antimony oxide are particularly preferred in that they provide a high refractive index. That is, when the refractive index is high, it becomes easy to manufacture corrective lenses and the like having a high refractive index, and it becomes possible to manufacture lenses with thinner edges and larger diameters than conventional plastic lenses.

Moreover, these particulate inorganic substances can be used not only alone but also in combination of two or more types. Furthermore, the above-mentioned oxide may be a mixed oxide containing silicon or the like.

It is necessary that the particulate inorganic substance be contained in at least a part of the transparent material. Examples of means for containing an inorganic substance in at least a part of the transparent material include a method of uniformly dispersing the inorganic substance in the transparent material during the molding process, or a method of dispersing the inorganic substance only in a part of the transparent material.

Various known methods are known for dispersing the above-mentioned particulate inorganic materials, such as the following methods.

(a) A method of mixing a particulate inorganic substance and another base material (transparent material) under heating or at room temperature in the presence or absence of a solvent or other components.

(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 of rapid polymerization in which fine particulate inorganic substances are dispersed in monomer components.

Among the above methods, when the present invention is applied to casting, the method (b) or (C) is preferred.

In the case of (b) or (C), the resin produced 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
It is 5 to 80% by weight, preferably 10 to 70% by weight.

If the amount is less than this, the effect of addition will be small, and if it is more than this, defects such as cracking and decreased transparency will occur.

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

The substrate, that is, the vehicle component in which the particulate inorganic material of the present invention is dispersed, is one that forms a microporous-containing surface of the inorganic material by being partially or completely diffused or eliminated by activated gas treatment. Although there are no particular limitations, compounds containing various elements having organic groups such as organic compounds and/or organosilicon compounds can usually be used, and these high molecular 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 resin, urea resin, etc.), urethane resin,
Mention may be made of polycarbonate, polyvinyl acetate, polyvinyl alcohol, styrene resins, transparent vinyl chloride resins, silicon-based resins, gIiM family resins and diethylene glycol-rubisallyl carbonate polymers (CR-39>).

Furthermore, these resins can be used in combination, and cured products of these resins which can be cured by 1q by using in combination with an appropriate curing agent can also be used.

The vehicle component may contain various additives such as surface conditioners, ultraviolet absorbers, and antioxidants in addition to plasticizers, various curing agents, and curing catalysts.

The transparent material referred to in the present invention has a haze value (percentage) determined by the following formula of 80% or less, and may be colorless or colored with dyes and pigments.

Haze value (percentage) - (diffuse light transmittance/total light transmittance) X100 For optical applications as intended by the present invention, more transparent materials are preferred. In particular, silicon-based polymer compounds or polymer compounds containing them, which are used as coating materials for improving the surface hardness of plastic articles, can be effectively used to improve the surface hardness. Compositions in which the above compounds are combined with silicon oxide-based fine particles, especially their dispersions in alcoholic solvents and/or aqueous solvents, can be used to improve surface hardness in the field of transparent materials where light transmittance is particularly required. It is particularly useful as a device that simultaneously improves light transmittance. Various methods have been proposed for providing silicon-based polymer coatings, but methods obtained by curing a compound selected from the group consisting of compounds having the following general formula and/or their hydrolysates are used. The method is particularly effective.

That is, the general formula, RatRb2S! (OR3) A compound consisting of 4-(a+b), where R1 and R2 are C1 to C1o alkyl, aryl, halogenated alkyl, halogenated aryl, alkenyl, or epoxy group, (meth)acryloxy group, An organic group having a mercapto group, an amine group, or a cyano group, which is bonded to silicon through a S;-C bond, and R3 is a C1 to C6 alkyl group,
It is an alkoxyalkyl group or an 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, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, vinyl triethoxysilane, vinyltriacetoxysilane,
Vinyltrimethoxyethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriacetoxysilane, γ-diOropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, T-
Chloropropyltriacetoxysilane, 3,3.3-trifluoropropyltrimethoxysilane, γ-glycidoxyprobyltrimethoxysilane, γ-glycidoxyprobyltriethoxysilane, γ-(β-glycidoxyethoxy ) Propyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, β
-(3,4-epoxycyclohexyl)ethyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-7minopropyltrimethoxysilane, γ
Trialkoxy or Triazyloxysilanes and methyldimethoxysilane, phenylmethyldimethoxysilane, dimethyldiethoxysilane, phenylmethyljethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyljethoxysilane, γ- Glycidoxypropylphenyldimethoxysilane, γ-glycidoxypropylphenyldiethoxysilane, 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.

Although not used alone, there are various tetraalkoxysilanes or their hydrolysates that can be used in combination with the above-mentioned silane compounds.

Examples of tetraalkoxysilanes include methyl silicate, ethyl silicate, n-propyl silicate, i-
Propyl 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 that have been proposed so far can be used to further accelerate curing. various acids or bases, including, for example, Lewis acids, Lewis bases, and the neutral or basic salts formed therefrom, such as organic carboxylic acids, chromic acid, subzinconic acid, boric acid, bromic acid, selenite, thiosulfate; , orthosilicic acid, thiocyanic acid, nitrous acid, aluminic acid, metal salts of carbonic acid, especially alkali metal salts or ammonium salts, alkoxides of aluminum, zirconium, titanium, or complex compounds thereof. Naturally, these can be used in combination with other organic substances,
Among these, useful are epoxy resins, acrylic copolymers, especially those having hydroxyl groups, and polyvinyl alcohol.

An antireflection thin layer is obtained by treating the surface of a base material whose main components are the fine particulate inorganic material obtained as described above and a vehicle component in which the fine particulate inorganic material is dispersed, with an activated gas.

The activated gas here refers to ions, electrons, or excited gas generated under normal pressure or reduced pressure.

Examples of methods for generating these activated gases include corona discharge, direct current under reduced pressure, high voltage discharge using low frequency, high frequency, or microwave.

Further, as the gas for generating the activated gas, for example, oxygen, air, nitrogen, argon, freon, etc. are preferably used.

For the purposes of the present invention, an activated gas obtained by high voltage discharge using direct current, low frequency, high frequency or microwave under a pressure of 10@-2 Torr to 10 rorr is particularly preferred from the viewpoint of processing efficiency. The activated gas obtained here is what is called low-temperature plasma, and its characteristics and generation method are described in detail in Low-Temperature Plasma Chemistry (Edited by Keiichi Hozumi, 1976: Nankodo).

The conditions for performing activated gas treatment include the shape of the treatment equipment, the type of gas used, the material, composition, shape of the target surface,
Conditions differ depending on the size, etc., and conditions must be determined experimentally to maximize the purpose of the present invention.

[Example] The present invention will be explained in more detail with reference to Examples below.

Example 1 (1) Preparation of silane hydrolyzate γ-glycidoxyprobyltrimethoxysilane 2124CI was charged into a reactor equipped with a rotor, and the liquid temperature was adjusted to 10°C.
0.0 while stirring with a magnetic stirrer.
486 g of 1N hydrochloric acid aqueous solution was gradually added dropwise. After the dropwise addition was completed, cooling was stopped to obtain a silane compound.

(2) Preparation of dispersion for molding Methanol-dispersed colloidal silica (Nissan Chemical Co., Ltd. product, “Methanol Silica Sol”°, solid content 30%, average particle diameter 13 ±
1 μm>600 g was added with stirring. To this mixed dispersion was added 207.991 g of methanol and 60 g of diethyl glycol dimer ether.

1.8 g of a silicone surfactant was added, and further 6 g of aluminum acetylacetonate was added and mixed with sufficient stirring to prepare a dispersion for molding.

(3) Molding and evaluation of transparent material Using the dispersion obtained in the previous section, mold a cylindrical glass container (inner diameter 5
0mm>200 was weighed out. Leave it at that room temperature,
The top of the glass container was left open to air dry for one week to evaporate most of the dispersion medium.

It was roughly heated at 50°C for 5 hours, and then the temperature was raised to 90°C, and heat curing was performed for 10 hours.

The resulting transparent material was completely transparent, and the resin had good surface hardness and did not show any scratches even in an abrasion test with steel wool.

Example 2 (1) Preparation of dispersion liquid for molding To 47.0Q of the γ-glycidoxypropyltrimethoxysilane hydrolyzate of Example 1, 155.0Q of epoxy resin ("Epicote 827", manufactured by Shell Chemical Co., Ltd.) was added. 4g,
223.8 g of diacetone alcohol and 111.6 CI of benzyl alcohol were mixed to obtain a homogeneous solution.

Methanol silica sol 1423q of Example 1 was added to this solution.
, methanol 597.50. Silicone surfactant 3
．． 840 was added and mixed well.

6 g of aluminum acetylacetonate was added to this mixed solution and thoroughly stirred and mixed to obtain a molding dispersion.

(2) Molding and evaluation of transparent material A molded product of transparent material was obtained in the same manner as in Example 1. This resin also had good surface hardness as in Example 1.

Example 3 (1) Preparation of dispersion for molding Polyvinyl alcohol (average degree of polymerization 600, degree of saponification 9)
1.0 to 94.0 mol%) 15% by weight aqueous solution 500
After weighing g into a beaker, add 53.3C1 of water under stirring,
18.2 q of the γ-glycidoxypropyltrimethoxysilane hydrolyzate of Example 1 and 215 q of the methanol silica sol of Example 1 were added, respectively.

To this mixed dispersion, 210 g of 1,4 dioxane, 0.5 Q of fluorosurfactant, and 3 g of aluminum acetylacetonate were added and thoroughly stirred and mixed to obtain a molding dispersion.

(2) Molding and evaluation of transparent material A colorless transparent material was obtained in the same manner as in Example 1 except that the final curing temperature in Example 1 was changed to 130°C.

The obtained molded product was a transparent material that was insoluble in water and had antifogging properties. Also, even when worn with steel wool, it remained virtually undamaged.

Example 4 (1) Preparation of dispersion liquid for molding Polyvinyl alcohol (average degree of polymerization 600, degree of saponification 9
A molding dispersion was obtained in the same manner as in Example 3, except that the amount of the 15% by weight aqueous solution (1.0 to 94.0 mol%) added was changed to 20,000.

(2) Molding and evaluation of transparent materials A colorless transparent material was obtained in the same manner as in Example 3.

The obtained molded product was a transparent material that was insoluble in water and had antifogging properties.

Example 5 (1) Preparation of monomer for molding 10 g of a sol subjected to hydrophobic treatment on the surface of a silica sol was dispersed in 90 g of styrene monomer with stirring. The dispersion became an almost colorless and transparent liquid.

0.5 g of azobisisobutyronitrile was added and mixed as a polymerization initiator to this dispersion to obtain a molding dispersion.

<2> Molding and evaluation of transparent materials A space was created between two circular glass plates (thickness 1 mm, outer diameter 70 mm), the area around the two glasses was fixed with polyester film adhesive tape, and cast polymerization was performed. As a formwork,
The dispersion liquid described in the previous section was poured into it. After sealing the next injection port, Shun heated it to 60℃ for 5 hours, then slowly raised the temperature to 90℃.
Heating polymerization was carried out at ``C'' for 5 hours.

Although the obtained molded plate was slightly cloudy, it was a molded product with sufficient transparency for practical use. This molded product did not break even when dropped naturally from a height of 1 m, and had strong impact resistance.

Example 6 (1) Preparation of dispersion for molding 86.8 g of the γ-glycidoxypropyltrimethoxysilane hydrolyzate of Example 1 was added with an epoxy resin ("Epicote 827", manufactured by Shell Chemical Co., Ltd. > 50.0 g). ni l,
Dimethylformamide 155゜0g, benzyl alcohol 70. OQ, and methanol 120. OQ was mixed to obtain a homogeneous solution.

To this solution was added antimony pentoxide aqueous sol (solid content > 208.4 g, silicone surfactant 1.10% by weight, and mixed well. To this mixed solution was added aluminum acetylacetonate 10.OCJ and sufficient The mixture was stirred and mixed to obtain a dispersion for molding.

(2) Molding and evaluation of transparent material A molded product of transparent material was obtained in the same manner as in Example 1. Although this product had a slight haze under strong light, it was substantially colorless and transparent, and had sufficient transparency for practical use.

Furthermore, the obtained molded product had a refractive index of 1.59, which was unprecedentedly high.

[Effects of the Invention] By creating a composition consisting of fine particles of a specific size and a vehicle, the present invention was able to provide a transparent material with high optical properties and surface hardness. In general, when specific inorganic fine particles are used as the fine particles, there is a remarkable effect that a transparent material with a high refractive index can be obtained. By roughly changing the distribution state of the fine particles, the refractive index can be changed partially or continuously within one molded product.

Claims (4)

[Claims] (1) A transparent material comprising a particulate inorganic material having an average particle diameter of 1 to 300 mμ and a vehicle, and characterized in that the amount of the particulate inorganic material contained in the transparent material is 5 to 80% by weight. (2) The particulate inorganic substance is selected from zinc oxide, silicon oxide, aluminum oxide, titanium oxide, zirconium oxide, tin oxide, beryllium oxide, and antimony oxide.
The transparent material according to claim (1), which is a compound of more than one species. (3) Vehicle is epoxy resin, (meth)acrylate resin, polyamide resin, polyester resin, amino resin, urethane resin, polycarbonate resin, polyvinyl acetate resin, polyvinyl alcohol resin, styrene resin, transparent vinyl chloride resin, silicon-based The transparent material according to claim 1, wherein the transparent material is one or more resins selected from resins and cellulose resins. (4) The transparent material according to claim (1), wherein the vehicle is a resin obtained from an organic silane compound and/or a hydrolyzate thereof, and the particulate inorganic substance is made of silicon oxide. .