JPH02210401A - Formation of antireflection layer - Google Patents

Abstract

PURPOSE:To decrease the generation of cracks and to form the antireflection films which consists of the thin films of metal oxides having excellent heat resistance and adhesiveness by applying a liquid contg. the partial condensation product of a specific silane compd. and metal alkoxide on a substrate and curing the coating by heating to form the 1st layer A. CONSTITUTION:The liquid contg. the partial condensation product of the silane compd. expressed by the formula SiRm<1>Rn<2>(OR<3>)4-m-n and the metal alkoxide is applied on the substrate and is cured by heating, then the liquid contg. the metal alkoxide and a solvent is applied thereon and is cured by heating; thereafter, the liquid contg. the metal alkoxide different in metal species and the solvent is applied thereon and is cured by heating. Both functions of the 1st layer of the three-layered antireflection film on the high-polymer substrate side and an under coating layer are provided by using the combination of the partial condensation product of the specific silane compd. and the metal alkoxides in such a manner.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for forming an antireflection layer on a substrate made of an organic polymer. Organic polymer plates with anti-reflection layers are used for display front panels, optical lenses, automobile window glass,
Used for front panels of instruments, etc.

(Prior Art) One of the methods for forming an antireflection layer on an organic polymer substrate is to form a thin film of metal alkoxide on the substrate and harden it by heating to form a thin metal oxide film. , is preferred because it has relatively excellent adhesion to the substrate, has a wide selection of metal species of metal oxide, and can easily control film thickness and refractive index.

However, if a thin film of metal alkoxide is simply formed and then heated and cured to form a metal oxide, the adhesion of this thin film to the organic substrate is not sufficient, and higher adhesion is required depending on the application. has been done.

Furthermore, when a thin film is laminated onto an organic substrate using this technology, cracks are likely to occur in the thin film, and cracks are particularly likely to occur in the case of forming thin films for antireflection because multiple thin films are laminated. It becomes a bigger problem.

Aiming at improving this adhesion and crack resistance, a metal alkoxide, a trifunctional silane, or a trifunctional silane are used together to create an organic group component bonded to a metal atom, as seen in JP-A No. 61-236501. There are a lot of things left behind,
Furthermore, the present applicant proposed in Japanese Patent Application No. 84340/1984 a method for producing a metal oxide thin film using a mixture of an alcohol having 5 or more carbon atoms and an alcohol having 4 or less carbon atoms as a solvent for diluting the metal alkoxide.

(Problems to be Solved by the Invention) However, when a large amount of organic group components bonded to metal atoms remain, it is necessary to use a large amount of expensive metal alkoxide when preparing a coating solution, resulting in high cost. Not only does the process become complicated, but since it contains trifunctional silane and colloidal silica, such coating solutions deteriorate quickly, tend to leave bubbles due to their high viscosity, and lack transparency due to poor dispersibility. There were also problems such as the tendency to decrease. Regarding the latter, there is a problem in that it is difficult to obtain a thin film with an excellent appearance because alcohols having 5 or more carbon atoms have poor compatibility with water. In addition, a composition mainly composed of bifunctional silane, trifunctional silane, etc. is provided on the polymer substrate to form an undercoat layer, and a three-layer antireflection film is formed by repeatedly applying metal alkoxide and curing with heat. This method can form an anti-reflection film using a metal oxide thin film with excellent heat resistance and adhesion, but it requires an undercoat layer in addition to the anti-reflection layer, so it is possible to form an anti-reflection film with less cracking. This increases the number of calendars to be done, making it costly and time-consuming.
There is a need for the development of a method for forming an antireflection film made of a metal oxide that has excellent adhesion and crack resistance more easily.

In view of this situation, the inventors of the present invention have made extensive studies and found that if a combination of a partial condensate of a specific silane compound and a metal alkoxide is used, the first layer and underlayer on the polymer substrate side of a three-layer anti-reflection film will The inventors have discovered that it is possible to provide both functions of the coating layer, and that one layer can be omitted while maintaining good adhesion and crack resistance, thereby resulting in cost reduction, and have thus arrived at the present invention.

That is, the gist of the present invention is to provide a method for forming an antireflection layer consisting of three thin films A, B, and C in order from the substrate side on a substrate made of an organic polymer.
n (o R3L-m-n (where RI R2 each represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or an aryl or aralkyl group having 6 to 12 carbon atoms, and the substituent is vinyl group, an amino group, a (meth)acryloyl group, a mercapto group, a halogen, and an epoxy group, R1 and R2 may be the same or different, and R3 is A liquid containing a partial condensate of a silane compound (representing an alkyl group having 1 to 4 carbon atoms, m is 1 or 2, n is O or 1, and m+n is 1 or 2) and a metal alkoxide is applied to the substrate. Layer A is formed by applying the liquid on top of the core layer A and heating and curing it, and then layer B is formed by applying a liquid containing a metal alkoxide and a solvent onto the core layer A and heating and curing it. The metal alkoxide contained in the liquid used to form layer B is a liquid containing a metal alkoxide of a different metal type and a solvent, which is applied onto the three layers and cured by heating to form a zero layer. The feature lies in the method of forming an antireflection layer.

In the present invention, in order for the three layers consisting of ABC to function as a three-layer antireflection film, each of na+nbnc must be
, B, C layer refractive index, d, , db, de are AB, C, respectively.
Thickness of layer (nm), m is a positive integer, 1. n is a positive odd number,
Let λ be an arbitrary reference wavelength selected within the visible peripheral region (unit: n
m), A: 1.55<n, <1.80, na'da =
1λ/4B: 1.65<nb<2.25, n
b'db "9 m/4, 715>naC:
1.40<n,<1.50, n+,'de "F
It is desirable to satisfy the condition n/4.

In addition, since layer A can relieve the stress caused by the difference in thermal expansion coefficient between the substrate made of organic polymer and layer B, the coefficient of thermal expansion of layer A is calculated by comparing the coefficient of thermal expansion of layer A with that of the substrate made of organic polymer and that of layer B. It is preferable to set the value to be an intermediate value.

The thermal expansion coefficient of layer A is determined by the mixing ratio of the partial polycondensate of the silane compound, which is a component with a high coefficient of thermal expansion, and the metal oxide component from metal alkoxide, which is a component with a low coefficient of thermal expansion. The mixing ratio of the partial polycondensate of the silane compound and the metal alkoxide in the coating composition can be adjusted. That is, it is preferable that the coating composition for layer A contains 50 to 2000 parts by weight of metal alkoxide based on 100 parts by weight of the silane compound partial polycondensate. If the content of the metal alkoxide is less than the above-mentioned lower limit, it becomes difficult for the layer A to play the role of stress relaxation, the hardness and solvent resistance decrease, and the appearance becomes poor, which is not preferable.

Further, if the content exceeds the above upper limit, it is not preferable because cracks are likely to occur and the adhesion to a substrate made of an organic polymer decreases. The metal alkoxide contained in the coating composition for layer A has a refractive index of 1.55 to 1.55.
1.80, and for this reason, it is preferable to use a metal alkoxide with a relatively high refractive index, a silicon alkoxide with a low refractive index, and a trifunctional or trifunctional silane in an appropriate ratio within the above condition range, Metal species of metal alkoxides with high refractive index include aluminum, titanium, strontium, scandium, yttrium, thorium, zirconium, hafnium, vanadium, niobium, tantalum,
Chromium, molybdenum, tungsten, tin, indium,
Lead, zinc, antimony, bismuth, manganese, iron, cobalt, nickel, cerium, lanthanum, and the like are preferably used. Further, as the alkoxide component of the metal alkoxide, an alcohol having 1 to 5 carbon atoms is preferably used in layers A, B, and C. When the number of carbon atoms is 6 or more, the compatibility with water is poor and the viscosity becomes high, so it tends to be difficult to obtain a coating film with an excellent appearance.

A chelating agent may also be added to the layer A coating composition. Addition of the chelating agent converts the metal alkoxide into a metal chelate compound, which is more water-stable than the original metal alkoxide and thus facilitates the preparation of the coating composition. It has the effect of slowing deterioration. Examples of chelating agents that can be used include β-diketones such as 2,4-pentanedione and 24-hebutanedione, ketoesters such as methyl acetoacetate, ethyl acetoacetate, butyl acetoacetate,
Lactic acid, methyl lactate, ethyl lactate, ammonium lactate salt,
Hydroxycarboxylic acids or their esters or salts, such as salicylic acid, methyl salicylate, ethyl salicylate, phenyl salicylate, malic acid, ethyl malate, tartaric acid, methyl tartrate, ethyl tartrate, 4-hydroxy-4-
Keto alcohols such as methyl-2-pentanone, 4-hydroxy-2-pentanone, 4-hydroxy-2-heptanone, 4-hydroxy-4-methyl-2-heptanone,
Monoethanolamine, jetanolamine, triethanolamine, N-methyl-monoethanolamine, N
Examples include amyl alcohols such as -ethyl-monoethanolamine, N,N-dimethylethanolamine, and N,N-diethylethanolamine, and enolic active hydrogen compounds such as malonic acid diethyl ester, methylolmelamine, methylolurea, and methylol acrylamide. . When adding a chelating agent, the mixing ratio of metal alkoxide and chelating agent is 3 to 1 mole of metal alkoxide.
It is preferably less than 1 mole, more preferably 1 to 3 moles. 1 chelating agent per mole of metal
If the amount is less than 3 moles, the effect of adding the chelating agent will not be sufficient (on the contrary, if more than 3 moles of the chelating agent is added, no further improvement of the above-mentioned effect will be observed.

The silane compound used in the present invention is S i R'mR”n (OR3L-m-0 (however, R
', R2 each represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or an aryl or aralkyl group having 6 to 12 carbon atoms, and the substituent is a vinyl group, an amino group, (
one or more selected from meth)acryloyl group, mercapto group, halogen and epoxy group, R1 and R2 may be the same or different, and R3 represents an alkyl group having 1 to 4 carbon atoms. , m is l or 2, n is 0 or 1, and m+n is 1 or 2). Specific examples of this silane compound include methyltrimethoxysilane, methyltriethoxysilane, methyltrimethoxyethoxysilane, methyltriacetoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, vinyl triethoxysilane, vinyltriacetoxysilane, vinyltrimethoxyethoxysilane,
Phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriacetoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, γ-chloropropyltriacetoxysilane, 3.3.3-trifluoropropyltrimethoxy Silane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, N-β-(aminoethyl )-γ-aminopropyltrimethoxysilane, β-cyanoethyltriethoxysilane, methyltriphenoxysilane, chloromethyltrimethoxysilane, chloromethyltriethoxysilane, dimethyldimethoxysilane, phenylmethyldimethoxysilane, dimethyljethoxysilane, phenyl Methyljethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropylmethyljethoxysilane, dimethyldiacetoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyljethoxysilane, γ-mercaptopropyl Methyldimethoxysilane, γ-mercaptobrobylmethyldiethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyljethoxysilane, methylvinyldimethoxysilane, methylvinyljethoxysilane, glycidyloxymethyltrimethoxy Silane, glycidyloxymethyltriethoxysilane, β-glycidyloxyethyltrimethoxysilane, β-glycidyloxyethyltriethoxysilane, γ-glycidyloxybrobyltrimethoxysilane, γ-glycidyloxybrobyltriethoxysilane, γ-glycidyl Oxypropyltri(methoxyethoxy)silane, γ-glycidyloxypropyltriacetoxysilane, δ-glycidyloxybutyltrimethoxysilane, δ-glycidyloxybutyltriethoxysilane, glycidyloxymethyldimethoxysilane, glycidyloxymethyl(methyl)dimethoxy Silane, glycidyloxymethyl (ethyl) dimethoxysilane, glycidyloxymethyl (phenyl) dimethoxysilane, glycidyloxymethyl (vinyl) dimethoxysilane, glycidyloxymethyl (dimethyl) methoxysilane, β-glycidyloxyethyl (methyl) dimethoxysilane, β -glycidyloxyethyl(ethyl)dimethoxysilane, β-glycidyloxyethyl(dimethyl)methoxysilane, γ-glycidyloxypropyl(methyl)dimethoxysilane, γ-glycidyloxybrobyl(ethyl)dimethoxysilane, γ
-Glycidyloxypropyl(dimethyl)methoxysilane, δ-glycidyloxybutyl(methyl)dimethoxysilane, δ-glycidyloxybutyl(ethyl)dimethoxysilane, δ-glycidyloxybutyl(dimethyl)
Methoxysilane, bis(glycidyloxymethyl)dimethoxysilane, bis(glycidyloxymethyl)jethoxysilane, bis(glycidyloxyethyl)dimethoxysilane, bis(glycidyloxypropyl)jethoxysilane, tris(glycidyloxymethyl)methoxysilane , tris(glycidyloxymethyl)ethoxysilane, tris(glycidyloxyethyl)methoxysilane, tris(glycidyloxyethyl)ethoxysilane, tris(glycidyloxypropyl)methoxysilane, tris(glycidyloxypropyl)ethoxysilane, glycidylmethyl Trimethoxysilane, glycidylmethyltrimethoxysilane, β-glycidylethyltrimethoxysilane, β-glycidylethyltriethoxysilane, γ-glycidylpropyltrimethoxysilane, γ-
Glycidylpropyltriethoxysilane, γ-glycidylpropyltri(methoxyethoxy)silane, γ-glycidylpropyltriacetoxysilane, 3,4-epoxycyclohexylmethyltrimethoxysilane, 3,4epoxycyclohexylmethyltriethoxysilane, 34
- epoxycyclohexylethyltrimethoxysilane,
Examples include 3,4-epoxycyclohexylpropyltrimethoxysilane and 3,4-epoxycyclohexylbutyltrimethoxysilane. The silane compound may be a mixture of two or more types as long as it falls within the above composition range. This partial condensate of a silane compound can be obtained by treating the silane compound with an aqueous acid solution such as hydrochloric acid, acetic acid, or sulfuric acid. The amount of the acid aqueous solution used for hydrolysis is preferably 1.5 to 10 times the mole of the silane compound. If the amount of the acid aqueous solution is less than the above lower limit, cracks will easily occur in layer A, and if it exceeds the upper limit, the appearance of layer A will deteriorate. The viscosity of the partial condensate of the silane compound is preferably 5 to 20 centipoise.

The liquid applied to form layer A may contain a solvent, and examples of the solvent include alcohols, hydrocarbons, ketones, esters, ethers, cellosolves,
Examples include halides, carboxylic acids, aromatic compounds, etc., and two or more of these can also be used as a mixture. Among these, lower alcohols such as methanol, ethanol, propatool, and butanol, cellosolves such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve, lower carboxylic acids such as formic acid, acetic acid, and propionic acid, and aromatic alcohols such as toluene and xylene It is preferable to use the compound and esters such as ethyl acetate and butyl acetate alone or as a mixed solvent.

Next, since the metal alkoxide contained in the liquid used to coat layer A to form layer B has a high refractive index, in order to increase the medium refractive index of the composition for forming phase A, Alkoxides of those shown as the high refractive index metal species used are preferably used. As the alkoxide component, those having 1 to 5 carbon atoms are preferably used.

Furthermore, the metal type of the metal alkoxide contained in the liquid applied to form layer C is different from the metal type of the metal alkoxide used for forming layer B, and has a low refractive index. Silane is preferably used for certain reasons. As the alkoxide, those based on alcohols having 1 to 5 carbon atoms are preferably used.

Examples of the solvent used in the liquid for forming layer 111B and layer C include alcohols, hydrocarbons, ketones, esters, ethers, cellosolves, halides, carboxylic acids, aromatic compounds, etc. It is also possible to use a mixture of the above.

Among these, lower alcohols such as methanol, ethanol, propatool, and butanol, cellosolves such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve, lower carboxylic acids such as formic acid, acetic acid, and propionic acid, and aromatic alcohols such as toluene and xylene It is preferable to use the compound and esters such as ethyl acetate and butyl acetate alone or as a mixed solvent.

The concentration of the metal alkoxide contained in the layer B and layer C forming liquids is preferably 5 to 40% by weight, and if the concentration is less than this lower limit, the thickness of the coated film at one time will be too thin and the thickness will not reach the specified level. A problem arises in that coating and drying must be repeated to obtain a film thickness, which is cumbersome, and if the concentration exceeds the above upper limit, the coating liquid tends to gel and lack stability.

In order to hydrolyze the metal alkoxide, 3 to 10% by weight of water and 0.3 to 1% by weight of acid are added to the layer B and layer C forming liquids based on the metal alkoxide. As this acid, inorganic acids such as hydrochloric acid and sulfuric acid, and organic acids such as acetic acid can be used.

As the liquid for forming layers B and C, a mixed solvent in which metal alkoxide, water, and acid are added to a solvent may be used, and this solution is thoroughly stirred to undergo some hydrolysis and partial condensation beforehand. May be used. When using a product that has undergone some degree of hydrolysis and partial condensation, it is necessary to hold the reaction so that the solution after the reaction has a uniform and coatable viscosity, and the viscosity should be kept at 10 centipoise or less. It is preferable to leave it there.

In the present invention, after the liquid for layer A is applied onto the substrate, the solvent is evaporated, the metal alkoxide is converted to a metal oxide condensate by heating, and then the liquid for layer B is applied thereon. The antireflection layer is formed by heating and curing to form layer B, and then applying a layer C forming liquid thereon and heating and curing to form layer C.

(Example) The present invention will be further explained below using Examples.

The measurement methods and evaluation criteria for each characteristic of the laminate are as follows.

1) Cross-cut the surface of the adhesive laminate with a razor, 1n+n+X
After making 100 squares of 1 mm in size, applying Chiban 405) to commercially available cellophane adhesive tape, and then peeling off the cellophane tape three times, the number of squares where the surface film had not peeled off was determined. was used as a measure of adhesion.

2) Film thickness was measured using an ellipsometer (manufactured by Shojo Kogaku Kogyo Co., Ltd.).

3) Viscosity Measured at 25°C using a rotational viscometer (manufactured by Tokyo Keiki).

4) Occurrence of Cracks A metal oxide was coated, a thin film was formed and cured by heating, and the presence or absence of cracks in the thin film portion was observed using an optical microscope at a magnification of 400 times.

5) Heat the laminate having the heat-resistant metal oxide thin film layer to 80°C for 5 minutes.
After keeping it for a minute, it was placed in ice water and rapidly cooled, and the presence or absence of cracks was observed using an optical microscope.

6) The laminate having the hot water-resistant metal oxide thin film layer was placed in hot water at 60°C for 2 hours.
After 4 hours of immersion, the presence or absence of cracks was observed using an optical microscope.

7) Total light transmittance Measured according to JIS K 7105.

Example 1 γ-glycidyloxybrobyltrimethoxysilane8.
1.3 g of 0.05N hydrochloric acid aqueous solution was added dropwise to 5 g at 10°C.
After mixing and dropping, stirring was continued for an additional hour at room temperature to prepare a silane hydrolyzate.

Next, 7.0 g of tetrapropylorthotitanate was mixed with 5.0 g of acetylacetone and stirred at room temperature for 1 hour to prepare a titanium chelate compound, and a mixture of 10.4 g of this and 2.6 g of the above silane hydrolyzate was mixed. A mixture of 0.33 g of water, 1 g of salt Mo, and 30 g of isopropyl alcohol was added dropwise to this mixture, and after stirring at room temperature for 10 minutes, 2.6 g of the previously prepared silane hydrolyzate was mixed. A layer-A forming liquid was obtained. The viscosity of this liquid was 2.7 centiboads.

Also, tetra n-butyl orthotitanate tetramer 11
．． 5 g, isopropyl alcohol 25 m I2, n-butyl alcohol 25 m A mixed solution of 2N hydrochloric acid aqueous solution 1.5 g, isopropyl alcohol 25 mρ, n-butyl alcohol 25 m I! were added and stirred to perform hydrolysis and partial condensation to obtain a B layer forming liquid.

The viscosity of this liquid was 3.5 centipoise.

Separately, 9.0 g of water, 1 g of hydrochloric acid, 60 mβ of isopropyl alcohol were added to a mixed solution of 20.8 g of tetraethyl silicate and 65 mβ of isopropyl alcohol, and the mixture was stirred to perform hydrolysis and partial condensation to prepare a C layer forming liquid. did. The viscosity of this liquid was 2.8 centipoise.

Polymethyl methacrylate AR board (manufactured by Mitsubishi Rayon)
The A layer forming liquid was applied using a dipping method at a pulling speed of 5.7 cm for 7 minutes, and then heated and cured at room temperature for 5 minutes and then at 80° C. for 1 hour. Next, the B layer forming liquid was applied thereon using a dipping method at a pulling speed of 9.7 cm for 7 minutes, and then heated and cured at room temperature for 5 minutes and then at 80° C. for 1 hour. Next, a C layer forming liquid was applied on top of this using a dipping method at a pulling rate of 6.5 cm/min, and then
It was then heated and cured at 80°C for 1 hour.

The total light transmittance of the obtained laminate was 98%, the refractive index of the A layer was 1,62, the film thickness was 850, and the refractive index of the B layer was 1.
．． 81, film thickness is 1520 people, refractive index of 0 layer is 1.44,
The film thickness was 955 people. Further, the refractive index of the substrate in contact with layer A was 1.49. The adhesion of the obtained laminate was 10
0%, no cracks were generated in the obtained laminate (no cracks were observed in the heat resistance test and hot water resistance test).

Example 2 A layer forming liquid (viscosity 2.8 centipoise), and the pulling rate from the A layer forming solution was 5.5 centipoise.
A laminate was obtained in the same manner as in Example 1 except that the binding was performed at cm/min. The total light transmittance of the laminate is 98%, and the refractive index of layer A is 1.
The film thickness was 770 mm, the adhesion was 100%, there were no cracks, and both heat resistance and hot water resistance were good.

Example 3 A layer forming solution (viscosity 2.8 centipoise ) was obtained, and a laminate was obtained in the same manner as in Example 1, except that the pulling rate from the A-layer forming liquid was 5.1 cm/min. The total light transmittance of the obtained laminate was 97%, the refractive index of the A layer was 1.68, the film thickness was 820 mm, the adhesion was 100%, and there were no cracks (no heat resistance). , and hot water resistance were both good.

Example 4 A layer forming solution (viscosity 2.6 centiboaz) was prepared in the same manner as in Example 1 except that the same molar amount of methyltriethoxysilane was used instead of γ-glycidyloxypropyltrimethoxysilane as the silane compound. A laminate was obtained in the same manner as in Example 1 except that the pulling rate from the A-layer forming liquid was 5.4 cm/min. The total light transmittance of the obtained laminate was 98%, the refractive index of the A layer was 1.63, the film thickness was 840 mm, the adhesion was 100%, there were no cracks, and it had good heat resistance. Both types of hot water resistance were good.

Example 5 The same molar amount of phenyltrimethoxysilane was used instead of γ-glycidyloxypropyltrimethoxysilane as the silane compound, but All
A laminate was obtained in the same manner as in Example 1, except that a forming liquid (viscosity 2.8 centipoise) was obtained and the pulling rate from the A layer forming liquid was 5.2 cm/min. The total light transmittance of the obtained laminate was 98%, and the refractive index of layer A was 1.65.
The film thickness was 830, and the adhesion was 100%, with no cracks (and both heat resistance and hot water resistance were good).

Example 6 A metal chelate compound was prepared in the same manner as in Example 1 except that 32.7 g of zirconium tetraisopropoxide and 20.0 g of acetylacetone were used instead of 5.0 g of acetylacetone in 7.0 g of tetrapropylorthotitanate. Using this, a layer A forming liquid (viscosity 2.6 centiboad) was obtained, and the pulling rate from the A layer forming liquid was set to 6.
A laminate was obtained in the same manner as in Example 1 except that the speed was 3 cm/min.

The total light transmittance of the obtained laminate was 98%, the refractive index of the A layer was 1.56, the film thickness was 880%, and the adhesion was 100%.
%, no cracks occurred (and both heat resistance and hot water resistance were good.

Example 7 A metal chelate compound was prepared in the same manner as in Example 1, except that 20.4 g of aluminum isopropoxide and 30.0 g of acetylacetone were used instead of 5.0 g of acetylacetone in 7.0 g of tetrapropylorthotitanate. to obtain the A layer forming liquid (viscosity 2.7 centiboads), and the pulling speed from the A layer forming liquid was 6.2 cm.
A laminate was obtained in the same manner as in Example 1, except that the heating time was changed to /min.

The total light transmittance of the obtained laminate was 97%, the refractive index of the A layer was 1.54, the film thickness was 890%, and the adhesion was 100%.
%, no cracks occurred, and both heat resistance and hot water resistance were good.

(Effects of the Invention) As described above, the present invention provides an excellent method for easily obtaining a three-layer antireflection film that is crack-free, has excellent heat resistance, and has excellent adhesion without using an undercoat layer. It is.

Patent applicant: Mitsubishi Rayon Co., Ltd. Agent Patent Attorney Yoshizawa Disappeared

Claims (1)

[Claims] 1) A and B are placed on a substrate made of an organic polymer in order from the substrate side.
In a method for forming an antireflection layer consisting of three thin films of C, the general formula SiR^1_mR^2_n(OR^3)_4_-
_m_-_n (However, R^1 and R^2 each represent hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or an aryl or aralkyl group having 6 to 12 carbon atoms, and the substituent is vinyl group, an amino group, a (meth)acryloyl group, a mercapto group, a halogen, and an epoxy group, and R^1 and R^2 may be the same or different, and R^ 3 represents an alkyl group having 1 to 4 carbon atoms, m is 1 or 2, n is 0 or 1, and m+n is 1 or 2) A liquid containing a partial condensate of a silane compound and a metal alkoxide. is coated on a substrate and heated and cured to form a layer A, and then a liquid containing a metal alkoxide and a solvent is coated on the layer A,
Layer B is formed by heating and curing, and then a liquid containing a metal alkoxide of a different metal type from the metal alkoxide contained in the liquid used to form layer B and a solvent is applied onto layer B. A method for forming an antireflection layer, which comprises heating and curing this to form a C layer.