JPH05279630A - Transparent ultraviolet ray absorbing organic-inorganic complex and coating agent containing the same - Google Patents

Abstract

PURPOSE:To obtain an organic-inorganic complex having ultraviolet ray absorbing ability which is stable for a long period and an ultraviolet ray absorbing coating agent containing the complex. CONSTITUTION:The objective transparent organic-inorganic complex contains 10-99.9% organic polymer containing carboxyl group and/or hydroxyl group and 0.1-90% metal oxide having an ultraviolet ray absorbing ability. This metallic oxide is produced by hydrolyzing and polycondensing a metal alkoxide in the above-mentioned organic polymer. The objective ultraviolet absorbing coating agent contains this complex.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an ultraviolet-absorbing organic-inorganic composite and an ultraviolet-absorbing coating agent containing the same.

[0002]

2. Description of the Related Art Ultraviolet ray absorbing materials are used as coating agents for window glass of houses and automobiles, cathode ray tubes of televisions, fluorescent lamps, spectacle lenses, etc. in order to eliminate the harmful effects of ultraviolet rays on the human body, and foods in transparent containers. It is an extremely useful material that is used as a coating agent for the outer surface of a product in order to prevent deterioration of the product. Conventionally, an ultraviolet absorbing material is obtained by kneading an organic compound having an ultraviolet absorbing ability such as benzotriazole or benzophenone into a resin,
There is one in which inorganic particles having an ultraviolet absorbing ability such as titanium oxide and cerium oxide are kneaded into a resin as a filler. However, in the case of kneading an organic compound, some of the organic molecules having an ultraviolet absorbing ability are volatilized by the heat at the time of kneading, and these organic molecules emerge on the material surface after a long time ( Bleed-out phenomenon). Further, the one in which inorganic particles are kneaded as a filler does not cause a problem like the one in which an organic compound is kneaded in terms of sustainability, but visible light can be obtained because it has a structure in which inorganic particles are dispersed in a resin. It becomes scattered and becomes opaque. Therefore, it cannot be used for coating although it requires transparency. Recently, attempts have been made to miniaturize the inorganic particles to improve the transparency as much as possible, but as the particles become finer, it becomes difficult to disperse them in the resin, and sufficient transparency has not been achieved.

On the other hand, JP-A-53-11951 and 53-
JP 11952 discloses a method for producing a transparent organic-inorganic composite. These methods produce a transparent composite material by heating and mixing a silicon alkoxide with a vinyl polymer under specific conditions.
It is not disclosed that the obtained composite has an ultraviolet absorbing ability. Further, in Japanese Patent Application No. 4-18453, an organic-inorganic composite in which inorganic fine particles surface-treated with a specific silane coupling agent are dispersed in a monomer containing (meth) acrylate as a main component and polymerized Although a method for producing a body is disclosed, there is no disclosure that the obtained organic-inorganic composite is transparent and has an ultraviolet absorbing ability.

[0004]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide an organic-inorganic composite having a long-term stable ultraviolet absorbing ability and an ultraviolet absorbing coating agent containing the same.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to provide an organic-inorganic composite having a long-term stable ultraviolet absorbing ability and an ultraviolet absorbing coating agent containing the same. By hydrolyzing and polycondensing an alkoxide in a specific organic polymer, a transparent complex of a metal oxide and an organic polymer is obtained, and at that time, a metal oxide having an ultraviolet absorbing ability is formed. It was found that the intended ultraviolet absorbing organic-inorganic composite can be obtained by using a metal alkoxide, and has completed the present invention. That is, the present invention provides organic polymers containing a carboxyl group and / or a hydroxyl group in an amount of 10 to 9
9.9% and 0.1% metal oxide having an ultraviolet absorbing ability
It is an invention of a transparent organic-inorganic composite, wherein the content of the metal oxide is about 90% and the metal oxide is obtained by hydrolyzing and polycondensing a metal alkoxide in the organic polymer.

Examples of the organic polymer containing a carboxyl group and / or a hydroxyl group used in the production of the transparent ultraviolet absorbing organic-inorganic composite of the present invention include an acrylic resin containing a carboxyl group and / or a hydroxyl group. Examples thereof include resins, urethane resins, epoxy resins, polystyrene resins, polyimide resins, polycarbonate resins, polyamide resins, polyvinyl chloride resins, polyethylene terephthalate resins and the like.

This organic polymer has a carboxyl group and / or
Alternatively, the form containing a hydroxyl group is not particularly limited, and for example, a monomer having a carboxyl group and / or a hydroxyl group may be mixed in a raw material monomer for producing a resin to be copolymerized. After the coalescence is produced, it may be blended with a polymer having a carboxyl group and / or a hydroxyl group. As the monomer having a carboxyl group, acrylic acid,
Examples thereof include carboxylic acid monomers such as methacrylic acid, crotonic acid, itaconic acid and maleic anhydride. In addition, as the monomer having a hydroxyl group, hydroxyalkyl (meth) acrylate such as hydroxyethyl (meth) acrylate, hydroxy-n-butyl (meth) acrylate, hydroxylauryl (meth) acrylate and polyoxyethylene (meth) acrylate is used. Can be mentioned. Further, examples of the monomer having a carboxyl group and a hydroxyl group include monohydroxyethyl maleate and monohydroxypropyl fumarate.

The content of the monomer unit having a carboxyl group and / or a hydroxyl group in the organic polymer is at least 1% by weight of the organic polymer, preferably when the monomer has only a carboxyl group and no hydroxyl group. It is 5 to 60% by weight. This is because if it is less than 1% by weight, the transparency of the organic-inorganic composite is lost. Also,
When the monomer has only a hydroxyl group and no carboxyl group, it is at least 5% by weight, preferably 10 to 100% by weight of the organic polymer. This is because if it is less than 5% by weight, the transparency of the obtained organic-inorganic composite is lost. If the monomer has both hydroxyl and carboxyl groups, it is at least 5% by weight of the organic polymer, preferably 10-60%. These monomer units having only a carboxyl group, monomer units having only a hydroxyl group and monomer units having both a hydroxyl group and a carboxyl group can be present in the organic polymer in an appropriate combination, and each monomer unit in that case The ratio of can be appropriately determined in consideration of the above content.

The metal alkoxide used in the present invention means an alkyl group bonded to a metal atom through an oxygen atom. The alkyl group includes methyl, ethyl,
Lower alkyl groups such as n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, isopentyl, sec-pentyl and the like can be mentioned. Further, the metal of the metal alkoxide needs to be a compound whose oxide has absorption in the ultraviolet region, and examples thereof include titanium, cerium, zinc, zirconium, and vanadium. Particularly, titanium alkoxide, cerium alkoxide, zinc alkoxide or a mixture thereof is preferable. Specific examples include titanium tetraisopropoxide, titanium tetrabutoxide, cerium tetraethoxide, zinc diethoxide, zirconium tetraisopropoxide, vanadium pentapropoxide and the like.

The transparent ultraviolet-absorbing organic-inorganic composite of the present invention is produced as follows, using the above-mentioned organic polymer and metal alkoxide as the main raw materials. First,
Mix the metal alkoxide and organic polymer. At this time, when the organic polymer is a liquid or can be mixed uniformly with the metal alkoxide even without a solvent, the metal alkoxide and the organic polymer can be directly mixed, or when the organic polymer is a solid, If it is difficult to uniformly mix even a liquid, it is necessary to use a solvent. Alternatively, the organic polymer and the metal alkoxide may be dissolved separately and then mixed. Examples of the solvent include common alcohols such as methanol, ethanol, n-propyl alcohol and isopropyl alcohol; 2-methoxyethanol, 2
-Alkoxy alcohols such as ethoxyethanol; aromatic hydrocarbons such as benzene, toluene and xylene; amide solvents such as dimethylformamide and dimethylacetamide; and dimethylsulfoxide.

The ratio of the organic polymer to the metal alkoxide in the mixed solution is such that, when the metal alkoxide is converted into the corresponding metal oxide, the weight ratio of the organic polymer to the metal oxide is 10:90 to 99. 9: 0.1, preferably 70:30
~ 98: 2. If the ratio of the metal alkoxide converted to the metal oxide is less than 0.1% by weight, the ultraviolet absorption ability of the obtained organic-inorganic composite will be insufficient. On the other hand, if it exceeds 90% by weight, the resulting material becomes brittle, which is not preferable. When the solvent is used, the concentration of the total amount of the organic polymer and the metal alkoxide in the mixed solution is 5 to
It is 80% by weight, preferably 20 to 50% by weight.

Next, the metal alkoxide in this mixed solution is hydrolyzed and polycondensed. By this reaction, a metal oxide is produced and alcohol is by-produced. The particle size of the produced metal oxide is preferably 100 nm or less. Water in the atmosphere may be sufficient as water necessary for hydrolysis, but water may be added when water is insufficient. This hydrolysis or polycondensation reaction varies depending on the metal alkoxide used, but is generally carried out at 0 to 90 ° C. for 10 minutes to 96 hours, preferably 10 to 50 ° C. for 1 to 24 hours. For example, when titanium tetraisopropoxide is used as the metal alkoxide, the reaction proceeds simply by mixing it with the organic polymer and stirring in the atmosphere. When used as a coating agent, a mixture of an organic polymer and a metal alkoxide is applied to a material to be coated, such as glass, and left in the atmosphere to hydrolyze and polycondense to give a transparent and uniform film. Can be obtained.

In parallel with the hydrolysis and polycondensation of the metal alkoxide, the solvent and the by-produced alcohol are volatilized. To completely remove them, heating or depressurizing is performed at the end or after the hydrolysis of the metal alkoxide. It is necessary to remove these by evaporation. The organic-inorganic composite of the present invention thus obtained is a transparent material having a visible light transmittance of 90% or more.

The present invention is also an invention of an ultraviolet absorbing coating agent containing the transparent ultraviolet absorbing organic-inorganic composite thus obtained. The coating agent is produced by dissolving the ultraviolet absorbing organic-inorganic composite of the present invention in a suitable solvent. Suitable solvents include n-butanol, toluene, isopropanol, ethanol, tetrahydrofuran, 2-methoxyethanol, 2-ethoxyethanol. Further, the solvent of the mixture obtained by hydrolyzing and polycondensing the above metal alkoxide can be used as it is without distilling off the solvent. The concentration of the organic-inorganic composite in the coating agent is 5 to 90% by weight, preferably 20/5
It is 0% by weight. You may add a 3rd component as needed. When the coating agent of the present invention is used as a spray, LPG, chlorofluorocarbon, etc. can be mentioned as the spray filling gas.

EXAMPLES Examples 1 to 3 Various amounts of titanium tetraisopropoxide (TTIP) and poly-2-hydroxyethyl methacrylate (HEMA) shown in Table 1 were each dissolved in 20 ml of toluene,
Mix with stirring. After stirring at room temperature for 20 minutes, put the mixture into a Teflon beaker to a depth of 1 cm, and let it stand at room temperature for 24 hours.
After stirring for an hour, in a vacuum dryer at 80 ° C, 1-5 torr
After drying for 2 hours, the residual solvent was removed to obtain a transparent disc having a thickness of 4 mm. The characteristics of this disc are shown in Table 1.

[0015]

[Table 1] ─────────────────────────────────── Charged weight, g Ultraviolet absorption capacity ¹⁾ ,% Visible light transmission ²⁾ ,% Example TTIP HEMA Before and after weather resistance test ³⁾ Before and after weather resistance test ─────────────────────────── ───────── 1 1.8 9.5 0 0 100 100 100 3.6 3.6 9.0 0 0 100 100 100 3 7.1 8.0 8.0 0 100 100 100 ──────── ─────────────────────────── 1) λ = 300 nm transmittance (%) 2) λ = 600 nm transmittance (%) 3 ) 200 in a carbon arc weather meter
Left for 0 hours

Examples 4 to 5 Various metal alkoxides shown in Table 2 were dissolved in 5 ml of a mixed solvent of toluene / butanol (volume ratio 1: 1) so as to be 1.0 g in terms of metal oxide. . On the other hand, acrylic resin for paint [A-136-5 manufactured by Dainippon Ink and Chemicals, Inc.
5, acrylic acid content 5% by weight] 8.0 g of the same solvent 1
Dissolved in 0 ml. While stirring the metal alkoxide solution, the acrylic resin solution was quickly added and mixed. Apply this to a glass plate with a thickness of 3 mm, leave it at room temperature for 48 hours,
A transparent coating film was obtained. The characteristics of this film are shown in Table 2.

[0017]

[Table 2] ─────────────────────────────────── Example Metal alkoxide UV absorption capacity,% Visible light Permeability,% ─────────────────────────────────── 4 Titanium tetrabutoxide 0 100 5 Cerium tetrapropoxide 0 100 ───────────────────────────────────

Examples 6 to 7 TTIP (3.6 g) and methyl methacrylate (MMA) / hydroxyethyl methacrylate (HEMA) mixed monomers (9.0 g) having various compositions shown in Table 3 were respectively added to 20 g each.
It was dissolved in ml of toluene and mixed with stirring. After that, a transparent disc having a thickness of 4 mm was obtained in the same manner as in Example 1. The characteristics of this disc are shown in Table 3.

[0019]

[Table 3] ─────────────────────────────────── Weight of charged monomer, g UV absorption capacity Visible light transmission Properties Example MMA HEMA %% ─────────────────────────────────── 6 8 1 100 100 7 6 3 0 100 ───────────────────────────────────

Comparative Examples 1 and 2 Titanium oxide powders having various particle diameters shown in Table 4 were used, and the same resin solution as the resin used in Example 4 was added thereto and ultrasonically treated for 10 minutes. Using this solution, a coating film was formed on a glass plate in the same manner as in Example 4. The characteristics of the film are shown in Table 4.

[0021]

[Table 4] ─────────────────────────────────── Comparative example Titanium oxide powder UV absorption capacity,% visible Light transmittance,% ─────────────────────────────────── 4 Particle size 0.1 μm 0 7 5 Particle size 0.01 to 0.02 μm 11 21 ────────────────────────────────────

[0022]

EFFECT OF THE INVENTION The UV-absorbing organic-inorganic composite of the present invention is transparent and has stable UV-absorbing ability for a long period of time, and since it can be molded into any size and shape, it can be used for various purposes. In addition, by coating the window glass of homes and automobiles, the cathode ray tube of TVs, fluorescent lamps, spectacle lenses, contact lenses, etc. as a UV absorbing coating agent, the adverse effect of UV rays on the human body can be eliminated. The effect of preventing discoloration of carpets, tatami mats, etc. can be obtained. Further, by coating the outer surface of a transparent container for food or chemicals, it is possible to prevent deterioration of the contents due to ultraviolet rays.

Claims (3)

[Claims] 1. An organic polymer having a carboxyl group and / or a hydroxyl group is contained in an amount of 10 to 99.9% and a metal oxide having an ultraviolet absorbing ability is included in an amount of 0.1 to 90%, and the metal oxide is A transparent organic-inorganic composite obtained by hydrolyzing and polycondensing a metal alkoxide in an organic polymer. 2. The transparent organic-inorganic composite according to claim 1, wherein the metal alkoxide is a titanium alkoxide, a cerium alkoxide, a zinc alkoxide or a mixture thereof. 3. An ultraviolet-absorbing coating agent containing the transparent organic-inorganic composite according to claim 1.