JPS6153365A - Composition for forming thin film of silicon oxide - Google Patents

Abstract

PURPOSE:To obtain the titled composition having excellent film-forming property, and giving an optical interference film free from cracks and interlaminar separation, by dissolving or dispersing an organic silicon compound and a silica sol in an organic solvent. CONSTITUTION:The objective composition can be produced by dissolving or dispersing an organic silicon compound (preferably alkoxysilane and/or alkoxysilane polymer) and a silica sol (preferably water-based silica sol and/or organosol having particle diameter of 5-100mmu) in an organic solvent (preferably methanol, etc.). The sum of the organic silicon compound and the silica sol is preferably 5-30wt% in terms of silicon oxide, and the amount of silica sol is preferably 1-50wt% in terms of silicon oxide.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to silicon oxide (hereinafter referred to as "rSiO2" and a ligand).
It relates to a composition for forming a thin film, and more specifically, it includes an 8702 thin film and a transparent metal oxide with a high refractive index, such as TiO2Ta.
Thin films such as 20s l Zr0z l HfO (hereinafter referred to as r
It is called a high refractive index "4 film". ) The present invention relates to a composition suitable for forming a 5in2 thin film layer of an optical interference film consisting of a multilayer film laminated alternately. Two or more transparent thin films with different refractive indexes? Depending on the order of lamination, it has an optical interference property that reflects or absorbs light in a specific wavelength range, and is formed on a heat-resistant substrate such as glass, ceramic, metal, etc. (: more light reflective). It is used as a film, antireflection film, and light absorption film.Therefore,
The present invention can be used in the field of manufacturing mirrors using optical interference films, cold mirrors, solar heat collecting mirrors, solar heat absorption devices, solar cells, optical filters, and the like. [Prior art] As a method for manufacturing an optical interference film, metal oxide thin film formation methods such as vacuum evaporation, sputtering, and CVD are used on a substrate C; a high refractive index film and a low refractive index film are alternately formed. Laminated on
There is a method of forming a multilayer film. Although these methods are semi-finished technologies, they require a large amount of manufacturing equipment, are difficult to process large-area substrates, and are not suitable for mass production, so the product cost is extremely high. Become. As a metal oxide thin film forming method that allows a large amount of C2 treatment to be applied to a large-area substrate, there is a coating-baking method in which a coating solution containing a solvent-soluble organometallic compound is applied to the substrate and baked. It is possible to produce an optical interference film by alternately stacking low refractive index films and high refractive index films on a substrate to form a multilayer film.
In Publication No. 09, Tie, which adopted this method, /
SiO. A method for manufacturing an optical interference film consisting of a three-layer film of /Tie has been disclosed. In this publication, SiO. As a coating liquid for forming a thin film layer, a siloxane obtained by reacting tetramethoxysilane or tetraethoxysilane in a reaction system in the presence of a lower alcohol and acetic acid in the presence of a mineral acid (C) is used. Problem] 8iL) 1 thin film, high refractive index film such as Tie2, and t alternating I:
When an optical interference film consisting of a laminated multilayer film is formed on a substrate using a coating and baking method, the thermal expansion coefficient of StO is 7×1.
0-For C: On the other hand, the coefficient of thermal expansion of Tie2 is 6×
10 - '/' Stress is accumulated in each thin film layer. Also, stress is accumulated in each thin film layer due to thermal decomposition of the organic 8i compound. Defects specific to multilayer film C2 such as peeling and cracking occur, and special C: Cracks are likely to occur in thin film layers.The aforementioned coating solution for forming a 5in2 thin film eliminates these defects by containing PgOiY. However, when forming a multilayer film of two or more layers with improved selectivity in the light reflection or absorption wavelength region, although it can be adopted in a three-layer film, t: is an improvement on the multilayer film defects. The present invention aims to provide a SiO2 thin film type thin film forming product suitable for forming a SiO□ thin film layer in a method for producing an optical interference film using coating and baking method C: [Means for Solving the Problems] The present invention provides an i for forming a silicon oxide thin film, which is prepared by dissolving and dispersing an organosilicon compound S and a silica sol in an organic solvent.
It is an acid. In the present invention (2), the organic 8i compound can be used without any limitation as long as it is soluble in organic solvents. , for example, tetrabutoxysilanes having the same or different substituents, such as methitrahydroxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, dimethoxydiisopropoxysilane, jetoxydiisopropoxysilane, shedoxydibutoxysilane, etc. methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropo-disilane, ethyltriethoxysilane, ethyltriptoxysilane, phenyl), trialkoxysilanes such as IJ ethoxysilane ν, and the above-mentioned al;xysilanes 13) Also 11 B type or higher v,
Reaction system I in the presence of lower alcohol and carboxone:
Condensation polymerization is carried out in the presence of a mineral acid such as hydrochloric acid, phosphoric acid, etc., or in a lower alcoholic solvent (in the presence of an acidic catalyst such as hydrochloric acid, nitric acid, phosphoric acid, acetic acid, etc. or a basic catalyst such as sodium hydroxide, Preferably used are alkoxysilane polymers having a degree of polymerization of 2 to 20, which are obtained by dropping C diwater in the presence of potassium hydroxide or the like, followed by hydrolysis and condensation polymerization. Preferably, the average particle size is 5 to 1. When using a permanent silica sol, considering the hydrolytic stability of the organic 3i compound, a sol with a pH of 7 or less is preferably used.
-Use 4 for convenience. These aqueous silica sols include Snorax [F] 0, Snorax OL (8 San Kagaku@J'E, ), and Catahydride [F] 8.
N (catalyst chemical industry

[Effect]

In the present invention, SiO. The composition for forming a thin film consists of an organic solvent bath solution of an organic St compound that has been used conventionally.
In, by adding and mixing silica sol with Thin Film Forming Composition C2, the film formability during 5i02 thin film formation was improved.Characteristics. In other words, by thermally decomposing the coating film of the uninvented composition,
By containing silica sol when producing g,
Coating film that does not contain silica sol (compared to the other, volumetric shrinkage is small, which is one of the causes of cracks, delamination, etc.)
SiO! It is presumed that stress accumulation due to volumetric contraction C2 during production is reduced. In addition, even when fine racks occur in a thin film, the dispersed silica sol acts as a barrier and prevents peeling (i.e., growth of racks like type 2). When forming χ, it is possible to form a thick film with no defects in a single coating and baking process compared to when using a composition that does not contain silica sol. When forming a coating film, it is assumed that the silica sol with dispersion of C in the coating film absorbs the difference in thermal expansion, and the total number of layers is 5 or more without delamination or cracks. If the silica sol is too large, the smoothness of the surface of the 5in2 thin film will decrease.Therefore, the preferred particle size of the silica sol is 5in2.
~100 mμ. [Example] The present invention will be explained in more detail with reference to an uninvented example. However, the scope of the present invention is not limited to the following examples. Preparation of thin film forming composition (IJ Tie, thin film forming composition Tetraisopropoxy titanium: 42.69Y ethanol: 284 g (: dissolved, acetylacetone: ao9
A solution of an organic titanium compound in which part of the isopropoxy group was replaced with an acetylacetone residue was obtained. Separately, tetraisopropoxy titanium: 56.2Llil
v Ethanol: Dissolved in 850F, in the presence of a catalytic amount of hydrochloric acid, gradually added 1:1 to 3.1' and stirred (
Two reactions were performed. Then, acetylacetone 74011Y: was added to this reaction solution and reacted to obtain a titanate polymer solution. The synthesized organic titanium compound solution: 30,9 and the titanate polymer solution: 4009Y were mixed, and P2O,:
0.49'2 Added as a glass forming agent - Tie2 equivalent concentration: 3. (5 wt% TiO□ thin film forming composition W tetraethoxysilane: 186 g, ethanol:
648.9, acetic acid: 20t$, P and concentrated hydrochloric acid: 0
．． 8Ji' and reacted under reflux for 45 hours.
102 conversion concentration 5. % of alkoxysilane polymer solution. Composition for forming a thin film; A? It was adjusted. (B) 5i02'4 m composition for film formation; A: 1
000g C1100O: Add 1.2511 tons, mix uniformly at room temperature, 8iQ2 standard tea 2.5wt% (7)
P2O,y2-containing T63)02 Thin FIX forming composition: B was prepared. (q Methyltriethoxysilane: 20011, Tetraethoxysilane: 250g, Ethanol: 880.
li+, and 20% hydrochloric acid: Mix 1.5 g,
After gradually dropping 150 g of water at a temperature of 0°0, the mixture was further maintained at a temperature of 70°0 for 5 hours to complete the reaction.
A composition for forming a 5io2 thin film; C consisting of a combined solution of alkoxysilane 1 having a concentration of 5in2 equivalent IQwt% was prepared. (To) Etraethoxysilane: 186. ! ? , ethanol: 126. L Acetic acid: 20t$g#, mhi concentrated salt a
s, :0-8Ji'Y mixed and under reflux C; kept for 45 hours to complete the reaction, 8iQ, 5i02 thin film forming composition solution consisting of an alkoxysilane polymer solution with a converted concentration of 10 wt%; D adjusted. Example 1 and Comparative Example 1 Ti0. /Si- Formation of alternating multilayer filmSiO. Each commercially available mild silica sol was added to Thin Film Forming Composition-A, diluted with a mixed solvent of ethyl acetate/ethanol (1/l), and the concentration in terms of 5tO2: 5. Owt% of uninvented SiO. A composition for forming a thin film was prepared. After dipping a quartz glass plate with the prepared Tie, a thin film forming composition, and forming a coating film of the composition, it was held at a temperature of 500°C for 80 minutes and fired, and then the composition was coated on a quartz glass plate ( = Tie2TiO2 thin film.Then, the quartz glass plate on which the TiO2 thin film was formed was dipped in the prepared silica sol-containing sio, thin film forming composition or StO, thin film forming composition; A to form a coating film. ℃ for a0 minutes to form a thin film on the Tie thin film.The above operation was repeated to form a Tie/3) on the quartz glass plate.
02/Ti02/3)0g/T102/3
)02/'rto2 was formed. The film thickness of each layer is adjusted to adjust the pulling speed during dipping.Thus, the TiO2 thin film is approximately 60OA', SiO. The thin film was 100 oa''. The film formation results are shown in the first coating. Example 2 and Comparative Example 2 T102/3) Formation of 0z alternating multilayer film The 5i02 thin film forming composition prepared above, B: 10100O Organosilica sol, 08CAL-1482 (J:
17. ! Add i+ 8 and mixed solvent (ethyl acetate/ethanol = 1/1): 3), 8 i02 equivalent concentration H5,
9wt%, 3) 02 standard silica sol content: g, 1w
t% of the 5in2 thin film forming composition according to the present invention, B'
adjusted. The TiQ2 thin film forming composition prepared above, the composition B and the SiO2 thin film forming composition without silica sol;
A multilayer MXyt of i02 repetitions was formed. When a silica sol-containing composition was used, a good G-layer film with no defects such as peeling or cracking was obtained, but what about the comparative composition containing no silica sol? When used, peeling occurred in the sixth SiO2 layer. Example 8 and Comparative Example 8 SiO. Formation of thick film 8iQ2 thin film forming composition prepared above; C and Dc
, 08CAL-1482 (above) and mixed solvent (ethyl acetate/ethanol: 1/1) Y added, SiO2 equivalent concentration 10 wt%, silica sil content based on 5102 = 50
wt% of sio, thin film forming composition according to the present invention; C'
and D/ were adjusted. Prepared compositions: ♂ S and D' and C A composition without addition of disilica sol: C8 and Dg. After applying these compositions on a soda glass plate using a spinner method, they were calcined, and further τ: Calcined at a high temperature. 5in2 with a film thickness of approximately 400OA'
A film was formed on a soda glass plate. The above operation was repeated for the purpose of forming a 5tO2 film with a film thickness of 8000 A'. The results are shown in Table 2. The optical interference film is free from defects such as cracks and delamination, and is composed of a multilayer film in which metal oxide thin films other than SiQ, SiO2 thin films, and C2 are laminated alternately as shown in the above examples. In addition, a thick film of 5J02 without defects can be formed by one coating and baking process.Although no examples are shown, the composition of the present invention can be used at low temperature or 1) By heat treatment in a medium temperature range, a cured coating mainly composed of SiO2 with high surface hardness can be formed on glass, metal, plastic, etc. It provides an excellent SIO2 thin film formation assembly,
Its industrial significance is extremely significant.

Claims (5)

[Claims] (1) A composition for forming a silicon oxide thin film, which is obtained by dissolving and dispersing an organosilicon compound and silica sol in an organic solvent. (2) The organosilicon compound is an alkoxysilane and/or
or the composition according to claim (1), which is an alkoxysilane polymer. (3) The composition according to claim (1), wherein the silica sol is an aqueous silica sol and/or organosol with a particle size of 5 to 100 mμ. (4) The total amount of organosilicon compound and silica sol is
Contains 5 to 30% by weight in terms of O_2, and contains SiO_
A composition according to claim (1) containing 1 to 50% by weight of silica sol on a 2 basis. (5) Claim No. 1 containing a vitreous forming agent
) The composition described in item