JPS63145370A - Coating solution for use in forming transparent film - Google Patents

Abstract

PURPOSE:To form a coating soln. for use in forming a transparent film, which can form a silicon oxide film having excellent durability and transparency and has excellent shelf stability, by homogeneously mixing an oxy compound of zirconium with a silicon alkoxide or its derivative in a solvent mixture of water with an org. solvent. CONSTITUTION:An oxy compound of zirconium and a silicon alkoxide or its derivative are homogeneously mixed in a solvent mixture of water with an org. solvent. When the silicon oxide or its derivative is used together with a non-precipitating silica soln., the whole light transmittance of the resulting zirconium oxide/silicon oxide film is increased and the transparency is improved. Preferred examples of the oxy compound of zirconium are zirconium oxychloride and zirconium oxynitrate. As the silicon alkoxide or its derivative, compds. of Si(RO)4 (wherein R is CH3, C2H5, n- or iso-C2H5 etc.) and mixtures of two or more of them are preferred.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a coating solution for forming a transparent film, and more particularly, it relates to a coating solution for forming a transparent film on a substrate such as glass or plastic.
The present invention relates to a transparent film-forming rough coating Qi liquid capable of forming a transparent film with excellent adhesion to a substrate.

Technical Priority of the Invention and Problems Thereof It is widely practiced to form inorganic oxide films on substrates such as plastics, glass, ceramics, metals, etc. for various purposes. Such an inorganic oxide film has specific electrical properties, optical properties, chemical properties, mechanical properties, etc. depending on the metal element contained in the film,
It has functions such as conductive film, insulating film, alignment film, photomask, alkali elution prevention film, visible light non-reflection film, infrared reflection film, ultraviolet absorption film, mechanical heat insulation film, etc., and is used in the electronics field and optical equipment. It is used in a wide range of fields, including the

As a method for forming such an inorganic oxide film on a substrate, a vapor phase method such as a CVD method, a PVD method, or an evaporation method, or a liquid phase method using an alkoxide compound is used. On the other hand, vapor phase methods such as the CVD method require a vacuum evaporation device, and there is a problem in that the area or shape of the substrate on which the film is formed is limited depending on the size of the device.

On the other hand, in the so-called sol-gel method using an alkoxide compound, a film is generally obtained by hydrolysis of an alkoxide compound, so 1 q of a film can be formed by applying a coating liquid in which the alkoxide compound is dispersed or dissolved onto a substrate. It has the advantage of being able to However, since the rate of hydrolysis of alkoxide compounds, except for silicon alkoxide, is extremely fast, it is difficult to control the rate. When applied, the alkoxide compound is hydrolyzed by moisture in the air. Therefore, the properties of the resulting coating may depend on the amount of moisture in the air, making it difficult to obtain a coating with constant properties.

For the reasons mentioned above, a coating liquid in which silicon alkoxide is dispersed or dissolved in a solvent has been mainly used to form a metal oxide film on a substrate. However, the silicon oxide (S!02) film obtained using such silicon alkoxide is easily attacked by acids, alkalis, and organic solvents, or easily peels off from the substrate when it comes into contact with water vapor, seawater, etc. In addition, in order to form a silicon oxide film, the film obtained by applying a coating liquid onto a substrate had to be baked at a temperature of at least 450'C.

In order to solve the problem that the silicon oxide coating has poor durability as described above, JP-A-57-100943 proposes a silicon oxide coating containing 1 to 30 mol % of zirconium oxide. In the zirconium oxide-silicon oxide coating described in JP-A-57-100943,
Zirconium compounds include ZrCl2, ZrCl3,
Zirconium chloride such as ZrC1, Zr(NO3>4・5
It is stated that zirconium nitrate, zirconium alkoxide, zirconium diketonate, etc., can be used.

However, when attempting to form a zirconium oxide-silicon oxide film using a coating solution containing zirconium chloride, zirconium nitrate, zirconium alkoxide, or zirconium diketonate and silicon alkoxide, zirconium chloride and zirconium nitrate are unstable to water. The inventors of the present invention have discovered that, as a result, the coating solution cannot be stored for a long period of time, and the pot life is short, which is a major problem. Moreover, when attempting to form a zirconium oxide-silicon oxide coating using a coating solution containing the above-mentioned dihydric zirconium salt, the coating must be baked at a temperature of at least 450 DEG C. or higher.

In addition, the above-mentioned coating solution has a problem in that when hydrolyzing silicon alkoxide, a mineral acid such as hydrochloric acid must be newly added to the coating solution to adjust the number of leaves 1 to 2 to 6.

Purpose of the Invention The present invention aims to solve the problems associated with the prior art as described above, and is capable of forming a silicon oxide film with excellent durability and transparency, as well as being stable. Formation of a transparent film that has excellent properties and can be stored for a long period of time, does not require the addition of new acid when forming a silicon oxide film, and does not require baking the coated film at high temperatures. The purpose is to provide a coating solution for

Summary of the Invention The first transparent film-forming coating according to the present invention is a liquid in which a zirconium oxyacid salt and a silicon alkoxide or a derivative thereof are uniformly mixed in a mixed solvent consisting of water and an organic solvent. It is characterized by the fact that

Further, in the second coating liquid for forming a transparent film according to the present invention, a zirconium oxyacid salt, a silicon alkoxide or a derivative thereof, and a non-precipitating silica are uniformly mixed in a mixed solvent consisting of water and an organic solvent. It is characterized by being done.

The coating solution for forming a transparent film according to the present invention includes a zirconium oxyacid, silicon alkoxy or a derivative thereof, and optionally non-precipitating silica in a mixed solvent consisting of water and an organic solvent. - Since it is mixed with
This coating solution has excellent stability and can be stored for a long period of time, and there is no need to add new acid to the coating solution when forming a film, and it is not necessary to bake the coating film at a high temperature of 450°C. In addition, the coating has excellent durability and transparency.

DETAILED DESCRIPTION OF THE INVENTION The transparent crotch-forming coating liquid according to the present invention will be specifically explained below.

The coating liquid for forming a transparent l film according to the present invention includes a zirconium oxyacid salt, a silicon alkoxide or a derivative thereof, and optionally a non-sedimentable silica liquid dissolved in a mixed solvent consisting of water and an organic solvent. Although the composition is uniformly dispersed, each component will be explained below.

Examples of zirconium oxyacids include zirconium oxychloride, zirconium oxynitrate, and oxy! Zirconium Il yate, zirconium oxyoxalate, etc. are used, and among these, zirconium oxychloride and zirconium oxynitrate are particularly preferred. Such zirconium oxylates dissolve in organic solvents such as water and alcohol,
It becomes acidic when water is present in the solution.

Examples of silicon alkoxides or derivatives thereof include SiH, (O
R>b (a=o~3.b=1~4゜a+b=4.R is an alkyl group) or (R'''0)aS i (RO>b
, R-aS i (RO > b (a = 4) or a condensate (up to a pentamer) or a derivative in which a part of H in the above formula is replaced with C1 or a vinyl group, etc. is used. .

Among these, especially 5i(RO> (wherein, R is Cl-1
3, C2H5,n and 1so-C3H7,n-,1s
A mixture of one or more of the compounds represented by o-, 5ec-, and tert-C4 is preferred.

The non-precipitating silica liquid is used together with the above-mentioned zirconium oxylate and silicon alkoxide or its derivative, if necessary. When this non-sedimenting silica liquid is used in place of a part of the silicon alkoxide, the total light transmittance of the resulting zirconium oxide-silicon oxide coating increases and the transparency improves, but the durability of the coating is also impaired. There is no.

The non-precipitating silica liquid used in the present invention is S i O
2 When an aqueous solution with a concentration of 20% by weight was centrifuged at 250.0OOG for 1 hour, the sediment was 30Iff of the total SiO2.
1 copy or less. Such a non-precipitating silica solution is made by adding a growth inhibitor to a non-precipitating silica dispersion obtained by removing most of the alkali from an aqueous alkali silicate solution, and dispersing this in a diluent. Growth inhibitors include ethylene glycol, N-methyl-2-pyrrolidone, morpholine, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, dimethyl formamide, etc. alone or in combination with non-precipitating silica.
It is used in amounts of at least 0.5 mole or more.

In this non-precipitating silica liquid, 5i02/M20 (
The amount of residual alkali (in the formula, M indicates total alkali concentration) is desirably 200 or more, preferably 1000 or more.

Such a non-sedimentable silica solution is produced by, for example, contacting an aqueous alkali silicate solution with a hydrogen-type cation exchange resin to remove most of the alkali, then adding a growth inhibitor, and then removing most of the water. It can be produced by adding and dispersing a diluent without removing the sieve.

Examples of diluents used for non-precipitating silica solutions include alcohols such as methanol, ethanol, n-propatool, i-propatool, n-butanol, i-butanol, and t-butanol, methyl acetate, ethyl acetate, etc. Acidic esters, ethers such as diethyl ether, acetone, etc. can be used alone or in combination.

The above-mentioned non-precipitated silica solution is described in detail in Application No. 11, No. 187835, filed earlier by the present applicant.

Examples of the organic solvent used in the coating solution for forming a transparent film according to the present invention include alcohols such as methanol, ethanol, n-propertool, i-propertool, n-butanol, i-butanol, and t-butanol; Esters such as methyl acetate and ethyl acetate, ethers such as diethyl ether, ketones such as acetone and methyl ethyl ketone, and ethylene glycol monomethyl ether are used alone or in combination.

In the coating liquid for forming a transparent film according to the present invention, the zirconium oxyacid salt and the silicon alkoxide or its derivative each have Z r 02 /S in terms of oxide.
+02 (Mo/L/ratio) is used in an amount such that the ratio is in the range of 0.05 to 2.0, preferably 0.2 to 1.0.

This Z r02 /S i 02 (molar ratio) is 0.05
If the ZrO2/5102 (molar ratio) is less than 2.0, it is not preferable because the durability of the obtained film is insufficient.
If the value is exceeded, the adhesion of the film to the substrate and the optical properties of the film (
This is not preferable because the haze and total light transmittance decrease.

In addition, the total amount of zirconium oxylate and silicon alkoxide or its derivative in the above coating solution is 0.5 to 2 as 5i02+ZrO2 in terms of oxide.
0% by weight, preferably 2 to 10% by weight. However, if the above-mentioned value exceeds 20% by weight, the pot life of the coating solution 5 will be shortened, and it will not be able to withstand long-term storage, and the obtained coating will become too thick, which may cause cracks, which is not preferable. On the other hand, if the above-mentioned value is less than 0.5% by weight, it is not preferable because it becomes necessary to repeat coating several times in order to form a film with a desired thickness.

When a non-precipitating silica solution is used, it is a small ratio of SiO in the non-precipitating silica solution to S i O2 converted to silicon alkoxy] or its derivatives (S in the non-precipitating silica solution). + 02 > / (3i02 in silicon alkoxide or its derivatives) is preferably 9 or less. If this value exceeds 9, the transparency of the film will increase dramatically, but the durability of the film will improve. This is not preferable because a new problem arises in that the firing temperature of the coated film must be set to about 300'C or higher to cause agitation.

Even when non-sedimenting silica is used, Z in the coating solution
Conditions such as the ratio of rO2 to total 5iQ2 are the same as in the case where only silicon alkoxide or its derivatives are used.

In the present invention, a non-sedimenting silica solution containing a growth inhibitor is used, but in some cases, the growth inhibitor may be added to DI.
The non-sedimented silica liquid is treated with zirconium oxylate, silicon alkoxide or its derivatives, water,
This growth inhibitor may be added to the resulting mixed solution mixed with an organic solvent.

In the coating liquid for forming a transparent film according to the present invention, water is necessary for the hydrolysis reaction of silicon alkoxide.

The amount of water in the coating solution 5 is preferably determined depending on the amount of silicon alkoxide or its derivative in the mixed solution, and the amount of water in the mixed solution is determined depending on the amount of silicon alkoxide or its derivative (7) in the mixed solution. %[s i 02 ,! =(
7)-E/L, ratio 820/S! It is preferable that water is contained in the coating liquid in an amount such that 02 is at least 2 or more. If this value is less than 2, undecomposed silicon alkoxide or its derivative remains undecomposed even after the first pattern is formed, so that no film can be obtained.

In addition, since the coating liquid according to the present invention contains organic solvents such as water and alcohol as described above, the zirconium oxyacid salt dissolves in these, and the coating liquid exhibits acidity of pf-12 or less. become. Therefore, it is not necessary to add an acid catalyst such as hydrochloric acid or nitric acid to the coating solution to hydrolyze the silicon alkoxide or its derivative.

Next, a method for producing a coating liquid for forming a transparent film according to the present invention will be explained.

The zirconium oxylate and the silicon alkoxide or its derivative are dissolved or dispersed in water and an organic solvent. The dissolution or dispersion order at this time is not particularly limited; for example, an aqueous solution of zirconium oxylate and an organic solvent such as alcohol are mixed, and the resulting mixture is added to an alcohol solution of silicon alkoxide or its derivative. may be added, or the above solutions may be mixed all at once.

In this way, the 141 coating solution F is coated onto a substrate such as glass or plastic by a conventionally known method such as a spinner method, a spray method, a bar code method, a roll coater method, etc. Next, by drying and curing the coated Ui film formed on the substrate at a temperature of about room temperature to 120°C, a film with excellent adhesion to the substrate, scratch resistance, and transparency can be obtained. If this coating is further fired at a temperature of up to about 250'C, a coating with further improved durability such as alkali resistance ↑ (1) can be obtained. It is also possible to sinter the coating at a temperature of .

In this way, in the present invention, it is possible to form a film with excellent properties by drying or baking the film at a temperature of about 250'C or less, so it is possible to form a film with excellent properties, which does not have excellent heat resistance such as plastics. A coating can also be formed on the substrate.

The optical properties of the transparent film obtained by applying the coating solution 5 according to the present invention to a transparent substrate such as glass include, for example, when a film is formed using silicon alkoid or its derivative as a SiO2 source, Light transmittance 85% or more,
A film with a glossiness (G value) of 190% or less and a haze of 2% or less can be obtained, and if a non-sedimentable silica solution is added to form a film, for example, a total light transmittance of 90% or more and a glossiness of 1.
70% or less, resulting in a coating with even higher transparency and less glare.

The coating liquid according to the present invention exhibits excellent effects when applied to applications such as an alkali ion elution prevention film for glass substrates and a transparent insulation coating for liquid crystal cells.

Effects of the Invention The coating solution for forming a transparent film according to the present invention contains a zirconium oxyacid salt, a silicon alkoxide or a derivative thereof, and optionally non-precipitating silica in a mixed solvent consisting of water and an organic solvent. Because it is uniformly mixed, this coating solution has excellent stability and can be stored for a long period of time.Moreover, there is no need to add new acid to the coating solution when forming a film, and the coating solution can be maintained for up to 450 minutes. There is no need to bake at temperatures as high as C, and the resulting coating has excellent durability and transparency. Therefore, a film can be formed even on a substrate having poor heat resistance such as plastic.

EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples.

Example 1 112 g of 25% by weight aqueous zirconium oxychloride solution as 7rO2, 696 J of ethanol and 126 cJ of water
8f1 were combined to prepare a water-alcoholic solution of zirconium oxychloride.

1 oog of ethyl silicate 2B to ethanol 833
Add g and j! The above zirconium oxychloride solution was added to the alcohol solution of ethyl silicate prepared above to prepare a coating solution for forming a transparent film.

Table 1 shows the composition of this coating liquid.

Example 2 A 25% by weight ZrO2 aqueous solution of zirconium oxynitrate 1609, ethanol 5803 and 60 g of water were mixed to prepare a water-alcoholic solution of zirconium oxynitrate.

To an alcoholic solution of ethylsilicate obtained by adding 350g of ethanol to 50y of ethylsilicate 40,
A coating solution for forming a transparent film was prepared by adding the above-mentioned zirconium oxynitrate solution.

The composition of the five coating liquids is shown in Table 1.Examples 3 to 5 As a diluent, a 1:1 mixture of methanol and ethanol was used instead of the ethanol in Example 1. Example 3), a 1:1 mixture of methanol-〇-butanol (Example 4), and a 1:1 mixture of ethylene glycol monomethyl ether-ethyl acetate (Example 5) were used. A coating solution for forming a transparent film is prepared using the method described in 17.

Table 1 shows the composition of this coating liquid.

Example 6 5% by weight aqueous sodium silicate solution (S102)
! 02 / Na20 = 3 mol 1 mol) to 15
It was passed through a hydrogen type cation exchange resin column maintained at °C at a space velocity (SV) of -5 to obtain a non-sedimentable silica solution. After adding 44.5 g of N-methyl-2-pyrrolidone per 100 g of the above solution and mixing with stirring, the mixture was heated to 80°C using a rotary evaporator to distill off water, and the non-sedimentable silica A liquid (liquid A) was obtained. S i of this liquid
022Xi degree is 10% by weight, water content is 1.0% by weight
Met.

Separately, 112 g of a 25 strain% zirconium oxynitrate aqueous solution, 696 g of ethanol and 126 g of water were used as ZrO2.
A mixed solution (solution B) of g was prepared.

(2) Solution B was mixed with a solution prepared by adding and mixing 100 g of Pursiligoo 1 to 28 and 31 g of Solution A to 916 g of ethanol (Liquid B), and the coating solution for forming a transparent film was removed.

Table 1 shows the composition of this coating liquid.

Practical Examples 7 to 9 The amount of liquid A used was 93g (Example 7) and 280g (
Example 8), 2.5209 (Example 9) and the amount of ethanol in liquid B were each 1,060 g (Example 7).
, j, 497 g (Example 8) and 6.7239 g (Example 9), a coating liquid for forming a transparent film was obtained in the same manner as in Example 6.

Table 1 shows the composition of this coating liquid.

Example 10 Using the coating liquids subjected to IH in Examples 1 to 9, a transparent coating was provided on a glass plate in the following manner.

Apply each coat using a spinner, 2.
After coating on a glass plate at OO rpm, it was dried at 110'C and fired at 250'C for 1 m. The following tests were conducted on the 1q coated film to evaluate its properties. The results are shown in Table 2.

・Total light transmittance (Tt) and haze (H) 2 haze computer (manufactured by Suga Test Instruments) ・Glossiness (G value): JI
Evaluation was made using the gloss measurement method of SK7105-81 at a measurement angle of 60'.

・Adhesion test 2 A part of commercially available 12-body width cellophane tape was attached to the film, the rest was held perpendicular to the film, and the film was instantly peeled off and the presence or absence of the film on the glass was visually observed.

- Pencil hardness: Evaluated based on JIS DO202-71.

・Durability test: The following test was conducted to compare the adhesion and total light transmittance before and after the test.

■Alkali resistance: Soaked in 15ffiff1% ammonia water for 120 hours at room temperature.

■ Salt water resistance: 120% by weight in NaCl aqueous solution at room temperature
Time soaking.

Claims (1)

[Scope of Claims] 1) A coating liquid for forming a transparent film, in which a zirconium oxyacid salt and a silicon alkoxide or a derivative thereof are uniformly mixed in a mixed solvent consisting of water and an organic solvent. 2) A coating liquid for forming a transparent film, which is obtained by uniformly mixing a zirconium oxylate, a silicon alkoxide or a derivative thereof, and a non-precipitating silica liquid in a mixed solvent consisting of water and an organic solvent.