JP2006342340A - Siliceous film, composition for forming siliceous film, method for forming siliceous film and laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a siliceous film sufficiently preventing reflection and sufficiently suppressing absorption of water when formed on the surface of a transparent substrate. <P>SOLUTION: The siliceous film is used for forming the film on the transparent substrate. The siliceous film has ≤1.41 refractive index and ≥0.8 to ≤1.5 g/cm<SP>3</SP>density. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a silica-based coating, a composition for forming a silica-based coating, a method for forming a silica-based coating, and a laminate.

  Conventionally, glass or transparent plastic is an optical component, lens, prism, optical disk, camera lens, glasses, liquid crystal panel, plasma display, cathode ray tube, instrument meter hood, solar cell panel, solar concentrator, window glass, vehicle glass. In addition, it is used as a transparent member material such as show window glass. In order to prevent reflection on the surface of the transparent member (transparent substrate), an antireflection film is formed on the surface. The antireflection film is usually a single layer or multilayer film made of a low refractive index material. The antireflection film is formed by being applied to the surface of the transparent substrate by vacuum deposition, dip coating spin coating, slit coating, or the like.

In order to obtain a good antireflection effect with a single-layer antireflection film, if the refractive index of the transparent substrate is nG, the refractive index n of the single-layer antireflection film is √nG, that is, relative to the refractive index of the transparent substrate. Need to be 1/2 power. For example, since the refractive index of the optical glass is 1.47 to 1.92, n of the single-layer antireflection film formed on the optical glass needs to be 1.21 to 1.38. Among the inorganic materials, MgF ₂ has the lowest refractive index of 1.38. However, considering that the refractive index of ordinary glass and transparent plastic is about 1.5, a material having a lower refractive index is desired.

In response to such a demand, Patent Documents 1 to 12 and the like have proposed attempts to lower the refractive index by making the antireflection film porous. However, none of these proposals are sufficient in terms of the refractive index and strength of the antireflection film, or there are difficulties in the process. As a result, a satisfactory antireflection film has not been obtained. In addition, the conventional inorganic thin film is formed by the CVD method, and the restrictions on the process are large.
JP 58-116507 A Japanese Patent Laid-Open No. 62-226840 JP-A-1-312501 JP-A-3-199043 JP-A-5-157902 JP-A-6-3501 Japanese Unexamined Patent Publication No. 6-157076 JP 7-140303 A Japanese Patent Laid-Open No. 7-150356 JP 7-333403 A JP-A-9-249411 JP 2000-147750 A

  However, when the present inventors examined in detail about the conventional method of forming an antireflection film, in order to achieve a desired low refractive index, a very large number of pores (voids) are formed in the film of the antireflection film. Found that it needs to be introduced in. In this case, the mechanical strength of the film tends to be further reduced due to excessive increase in the porosity in the film. In particular, when the mechanical film strength or film hardness of the base material of the antireflection film is inherently insufficient, the tendency becomes remarkable. Further, the conventional antireflection film has a high moisture absorption property (hygroscopicity) and tends to deteriorate the adhesion, and has a big problem from the viewpoint of process compatibility.

  Therefore, the present invention has been made in view of such circumstances, and an object thereof is to provide a silica-based coating film that can sufficiently prevent reflection when provided on the surface of a transparent substrate and that can sufficiently suppress moisture absorption. . It is another object of the present invention to provide a composition for forming a silica-based film, a method for forming a silica-based film, and a laminate for forming such a silica-based film.

The present invention is a silica-based film for forming on a transparent substrate, having a refractive index of 1.41 or less and a density of 0.8 g / cm ³ or more and 1.5 g / cm ³ or less. The present invention relates to a silica-based film. This refractive index range is useful for antireflection.

  The present invention relates to the above silica-based coating used as an antireflection film.

In the present invention, a refractive index value R1 immediately after formation and a refractive index value R2 after standing in an air atmosphere at a temperature of 23 ± 1 ° C. and a relative humidity of 45 ± 5% for one week (B1);
R2-R1 <0.1 (B1)
It is related with the said silica-type film which satisfies the conditions represented by these.

  Such a silica-based coating is considered to have sufficiently suppressed moisture absorption (hygroscopicity), and is further excellent in adhesiveness.

  Moreover, this invention is a composition for silica type film formation for forming the said silica type film, Comprising: (a) component: Siloxane resin and (b) component: The said (a) component can be melt | dissolved. The present invention relates to a composition for forming a silica-based film comprising a solvent and a component (c): a curing accelerating catalyst.

  Moreover, this invention relates to the said composition for silica-type film formation formed by further containing the thermal decomposition volatile compound which thermally decomposes or volatilizes at (d) component: 200-600 degreeC.

  The present invention also relates to a method for forming a silica-based film, wherein a silica-based film is formed on a transparent substrate, wherein the composition for forming a silica-based film is applied onto the surface of the transparent substrate to form a coating film. The present invention relates to a method for forming a silica-based film, which includes a step, a step of removing a solvent contained in the coating film to obtain a dry film, and a step of baking the dry film.

  The present invention relates to a laminate comprising a transparent substrate and the above-described silica-based film formed on the surface of the transparent substrate.

  According to the present invention, a silica-based film capable of sufficiently preventing reflection when provided on the surface of a transparent substrate and sufficiently suppressing moisture absorption, and a composition for forming a silica-based film for forming the silica-based film Product, a method for forming a silica-based film, and a laminate.

  Hereinafter, embodiments of the present invention will be described in detail.

  The silica-based film of the present invention preferably has a refractive index of 1.41 or less, more preferably 1.38 or less, further preferably 1.35 or less, and 1.30 or less. Is very preferred. This is for improving optical characteristics such as an antireflection effect on the transparent substrate. In addition, when the refractive index of a silica type coating exceeds 1.41, there exists a tendency for an optical characteristic to deteriorate. Further, the lower limit of the refractive index of the silica-based coating is about 1.25. When the refractive index is below this lower limit, the strength of the coating is remarkably lowered, which is not realistic.

  The refractive index can be measured, for example, with an ellipsometer under the following conditions. Specifically, first, a silica-based film forming composition for forming a silica-based film is applied onto a silicon wafer by a spin coating method. Thereafter, the silicon wafer coated with the composition is placed on a hot plate heated to 200 ° C., and the solvent in the composition is sufficiently removed. Finally, a film is formed on the silicon wafer by final curing in a nitrogen atmosphere at 350 ° C. for 30 minutes. After the film is formed, the film is irradiated with a 633 nm He—Ne laser with an ellipsometer L116B (trade name) manufactured by Gartner, and the refractive index is obtained from the phase difference generated by the irradiation.

The silica-based coating of the present invention has a refractive index value R1 immediately after formation and a refractive index value R2 after standing for 1 week in an air atmosphere at a temperature of 23 ± 1 ° C. and a relative humidity of 45 ± 5%. And the following formula (B1);
R2-R1 <0.1 (B1)
It is preferable to satisfy the condition represented by the following formula (B2);
R2-R1 ≦ 0.03 (B2)
It is more preferable to satisfy the condition represented by the following formula (B3);
R2-R1 ≦ 0.01 (B3)
It is more preferable to satisfy the condition represented by the following formula (B4);
R2-R1 ≦ 0.00 (B4)
It is particularly preferable that the condition represented by When (R2-R1) satisfies the condition represented by the above formula (B1), it can be said that the standing stability of the silica-based coating is further sufficient. This standing stability depends mainly on the hygroscopicity of the silica-based coating, and it is considered that the standing stability decreases as the hygroscopicity of the silica-based coating increases.

  The “refractive index immediately after being formed” means a refractive index measured after 10 minutes to 3 hours after forming a silica-based film on a silicon wafer as described above.

  As a method for controlling the refractive index to 1.41 or less, for example, a method of reducing the amount of silanol groups of the siloxane resin, increasing the porosity in the coating, or introducing a fluorine atom or the like into the siloxane resin. Is mentioned.

  The silica-based coating of the present invention preferably has an average pore size (average pore diameter) of pores in the coating of 100 nm or less, more preferably 50 nm or less, and even more preferably 30 nm or less. It is very preferable that it is 10 nm or less. When the average pore size of the pores exceeds 100 nm, the refractive index of the silica-based film tends to increase due to moisture absorption (moisture absorption). Or there exists a tendency for the film | membrane intensity | strength of a silica type coating to become weak and process tolerance deteriorate. Furthermore, a transparent substrate provided with such a silica-based coating on the surface tends to have low light transmittance. There is no particular lower limit value for the average pore size, and there is no problem as long as the pore size can sufficiently reduce the refractive index. In other words, even if the pore size is a size that cannot be measured by an X-ray diffractometer described later, there is no problem as long as the refractive index is sufficiently low.

  In the present specification, the average pore size of pores means a size including both closed pores and open pores.

  Examples of a method for reducing the average pore size of pores in the coating, preferably 100 nm or less, include, for example, reducing the blending amount of component (d), decreasing the molecular weight of component (d), (d And a method of selecting a solvent or a siloxane resin capable of uniformly dispersing / dissolving the component. If the blending amount of the component (d) is too large, the components (d) may be aggregated, resulting in an increase in average pore size. Moreover, when controlling the average pore size of the airport of the coating column, it is preferable to take into consideration the high compatibility and the strength of interaction between the component (d) and the solvent and / or siloxane resin.

The silica-based film of the present invention preferably has a density of 0.8 g / cm ³ or more and 1.5 g / cm ³ or less, and 0.9 g / cm ³ or more and 1.2 g / cm ³ or less. More preferably. When the density is less than 0.8 g / cm ³ , moisture absorption (absorption) or film strength tends to deteriorate. On the other hand, if the density exceeds 1.5 g / cm ³ , the refractive index may not be lowered sufficiently, which is not realistic.

  Examples of the method for controlling the density of the silica-based coating include a method of adjusting the amount of pores in the silica-based coating.

  The average pore size and density of the silica-based film can be measured by, for example, an X-ray diffractometer.

  Specifically, first, a composition for forming a silica-based film for forming a silica-based film is applied onto a silicon wafer by adjusting the rotation speed so as to have a film thickness of 200 nm by a spin coating method. Thereafter, the silicon wafer coated with the composition is placed on a hot plate heated to 200 ° C., and the solvent in the composition is sufficiently removed. Finally, a film is formed on the silicon wafer by final curing in a nitrogen atmosphere at 350 ° C. for 30 minutes. After the coating is formed, measurement is performed using the Rigaku Co., Ltd. product name "X-ray diffractometer ATX-G for thin film structure evaluation" system according to the following procedure and conditions.

Procedure (a) Measurement of X-ray reflectivity X-ray source: Rotating anti-cathode type Cu50KV300mA
High-resolution optical multilayer mirror Ge (220) 4-crystal monochromator Slit (S1) 1.0 mmW x 10 mmH
Slit (S2) 0.1mmW × 10mmH
Slit (RS) 0.2mmW × 10mmH
Slit (GS) 0.2mmW × 20mmH
Scanning axis 2θ / ω continuous Sampling width 0.002 °
Scan speed 0.15 ° / min
Scan range 0-2.0 °

Procedure (b) Analysis of X-ray reflectivity First, profile fitting is performed. Next, the density and film thickness are calculated by analyzing with X-ray reflectivity analysis software GXRR.

Procedure (c) Measurement of diffuse X-ray scattering X-ray source: Rotating anti-cathode type Cu50KV300mA
High resolution optical system multilayer mirror Slit Collimation
Slit (S1) 0.1mmW × 10mmH
Slit (S2) 0.1mmW × 10mmH
Slit (RS) 0.2mmW × 10mmH
Slit (GS) 0.1mmW × 20mmH
Scanning axis 2θ / ω continuous Sampling width 0.02 °
Scan speed 0.2 ° / min
Scanning range 0.2 to 6.0 °
Offset angle 0.1 °

Procedure (d) Analysis of hole size First, profile fitting of an X-ray small angle scattering pattern is performed. Subsequently, the pore size is determined by analysis with analysis software Nano-Solver (trade name).

  The silica-based coating of the present invention preferably has an elastic modulus of 5 GPa or more, more preferably 8 GPa or more. Thereby, the silica-type film of this invention can have more sufficient mechanical strength. If it is less than 5 GPa, the process resistance tends to deteriorate because the film strength is weak. The upper limit is not particularly limited, and there is no problem as long as it is an elastic modulus that can sufficiently lower the refractive index.

  The “elastic modulus” of the silica-based coating is an elastic modulus in the vicinity of the surface of the silica-based coating, and is a value of the elastic modulus obtained using a nanoindenter DCM (SA-2, trade name) manufactured by MTS. Means. The method for forming a silica-based film for measuring the elastic modulus is as follows. First, a composition for forming a silica-based film for forming a silica-based film on a silicon wafer is spin-coated so that the film thickness becomes 0.5 μm to 0.6 μm. Next, the silicon wafer coated with the composition is placed on a heated hot plate, and the solvent in the composition is sufficiently removed. Finally, a silica-based coating film cured on 350 ° C. for 30 minutes and formed on the silicon wafer is used. At this time, if the film thickness is excessively thin, it is not preferable because it is affected by the base (silicon wafer). “Near the surface” means a depth position within 1/10 of the film thickness from the coating surface. Specifically, the elastic modulus indicates the elastic modulus at a depth of 15 nm to 50 nm from the coating surface.

  In addition, a Barkovic indenter (material: diamond) is used as an indenter for pushing in when measuring the elastic modulus. The amplitude frequency of the indenter is set to a frequency that is not affected by the surrounding environment, for example, 60 Hz, and is measured.

  Examples of a method of increasing the elastic modulus of the silica-based film and adjusting it to 5 GPa or more include a method of increasing the crosslinking point of the siloxane resin or decreasing the amount of silanol groups of the siloxane resin. . In order to increase the number of crosslinking points of the siloxane resin, for example, it is effective to reduce the value of the total number (M) of specific bonding atoms. In order to reduce the amount of silanol groups in the siloxane resin, for example, it is effective to add a curing accelerating catalyst or an aprotic solvent to the silica-based film forming composition.

  When the silica-based coating according to the present invention is provided on a transparent substrate, it is preferable to improve the reflectance by 1.1 times or more with respect to the above-described transparent substrate not provided with the silica-based coating. It is more preferable to improve it twice or more. Here, the degree of improvement in reflectance is measured as follows. First, a silica-based film having a film thickness of 175 ± 10 nm is provided on a slide glass having a thickness of 1 mm. Next, a black paint is applied to the surface of the slide glass on the side opposite to the side on which the silica-based coating is provided to obtain a laminate for evaluation in which back surface reflection is suppressed. With respect to this evaluation laminate, the reflectance of the reflected light with respect to the irradiation light is measured with a spectrophotometer with an integrating sphere. The reflectance is a value with a wavelength of 900 nm, and the degree of improvement in reflectance is expressed as a relative ratio when the reflectance of a slide glass without a silica-based coating is 1.

  The silica-based coating according to the present invention preferably has a transmittance of more than 90%, more preferably more than 94%, and particularly preferably 96% or more. Here, the transmittance of the silica-based film is measured as follows. First, a silica-based film having a film thickness of 175 ± 10 nm is provided on a slide glass having a thickness of 1 mm. Next, set the slide glass without the silica-based coating on the reference side and the slide glass with the silica-based coating on the sample side, and measure the transmittance of the transmitted light with respect to the irradiation light with a double beam spectrophotometer. . The transmittance of the silica-based film is a value with a wavelength of 900 nm. In addition, the relative ratio of the slide glass provided with the silica coating when the transmittance of the slide glass not provided with the silica coating is 100% is expressed as the transmittance of the silica coating.

  The composition for forming a silica-based film of the present invention is not particularly limited as long as it can form the above-described silica-based film. The composition for forming a silica-based film of the present invention contains (a) component: a siloxane resin, (b) component: a solvent capable of dissolving the component (a), and (c) component: a curing accelerating catalyst. It is preferable that it is.

<(A) component>
The component (a) is a siloxane resin, and a known one can be used, but it is preferable to have an OH group at the end or side chain of the resin. This is because the hydrolysis condensation reaction for curing the composition for forming a silica-based film is further advanced.

  The siloxane resin preferably has a weight average molecular weight (Mw) of 500 to 1,000,000, more preferably 500 to 500,000 from the viewpoints of solubility in a solvent, mechanical properties, moldability, and the like. More preferably, it is 100,000, particularly preferably 500-10000, and most preferably 500-5000. If this weight average molecular weight is less than 500, the film formability of the silica-based film tends to be inferior. When the weight average molecular weight exceeds 1,000,000, the compatibility with the solvent tends to decrease. In the present specification, the weight average molecular weight is measured by gel permeation chromatography (hereinafter referred to as “GPC”) and converted using a standard polystyrene calibration curve.

The weight average molecular weight (Mw) can be measured, for example, by GPC under the following conditions.
Sample: 10 μL of silica-based film forming composition
Standard polystyrene: Standard polystyrene manufactured by Tosoh Corporation (molecular weight: 190,000, 17,900, 9,100, 2,980, 578, 474, 370, 266)
Detector: RI-monitor manufactured by Hitachi, Ltd., trade name “L-3000”
Integrator: GPC integrator manufactured by Hitachi, Ltd., trade name “D-2200”
Pump: manufactured by Hitachi, Ltd., trade name “L-6000”
Degassing device: Showa Denko Co., Ltd., trade name "Shodex DEGAS"
Column: Hitachi Chemical Co., Ltd., trade names “GL-R440”, “GL-R430”, “GL-R420” connected in this order and used as eluent: tetrahydrofuran (THF)
Measurement temperature: 23 ° C
Flow rate: 1.75 mL / min Measurement time: 45 minutes

Moreover, as a preferable siloxane resin, for example, the following general formula (1);
R ¹ _n SiX _4-n (1)
And a resin obtained by hydrolysis and condensation using the compound represented by formula (I) as an essential component. Here, in the formula, R ¹ is an H atom or F atom, or a group containing a B atom, an N atom, an Al atom, a P atom, a Si atom, a Ge atom, or a Ti atom, or an organic compound having 1 to 20 carbon atoms. X represents a hydrolyzable group, n represents an integer of 0 to 2, and when n is 2, each R ¹ may be the same or different, and when n is 0 to 2, X may be the same or different.

  Examples of the hydrolyzable group X include an alkoxy group, a halogen atom, an acetoxy group, an isocyanate group, and a hydroxyl group. Among these, an alkoxy group is preferable from the viewpoint of liquid stability of the composition itself, coating characteristics, and the like.

  Examples of the compound (alkoxysilane) of the general formula (1) in which the hydrolyzable group X is an alkoxy group include tetraalkoxysilane, trialkoxysilane, and diorganodialkoxysilane.

  Examples of the tetraalkoxysilane include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-iso-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, and tetra-tert-butoxysilane. Etc.

  Examples of the trialkoxysilane include trimethoxysilane, triethoxysilane, tripropoxysilane, fluorotrimethoxysilane, fluorotriethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-propoxysilane, and methyltri-iso. -Propoxysilane, methyltri-n-butoxysilane, methyltri-iso-butoxysilane, methyltri-tert-butoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltri-n-propoxysilane, ethyltri-iso-propoxysilane, ethyltri N-butoxysilane, ethyltri-iso-butoxysilane, ethyltri-tert-butoxysilane, n-propyltrimethoxysilane, n-propyltrie Xysilane, n-propyltri-n-propoxysilane, n-propyltri-iso-propoxysilane, n-propyltri-n-butoxysilane, n-propyltri-iso-butoxysilane, n-propyltri-tert-butoxy Silane, iso-propyltrimethoxysilane, iso-propyltriethoxysilane, iso-propyltri-n-propoxysilane, iso-propyltri-iso-propoxysilane, iso-propyltri-n-butoxysilane, iso-propyltri -Iso-butoxysilane, iso-propyltri-tert-butoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, n-butyltri-n-propoxysilane, n-butyltri-iso-propoxysilane, n- Tiltly-n-butoxysilane, n-butyltri-iso-butoxysilane, n-butyltri-tert-butoxysilane, sec-butyltrimethoxysilane, sec-butyltriethoxysilane, sec-butyltri-n-propoxysilane, sec- Butyltri-iso-propoxysilane, sec-butyltri-n-butoxysilane, sec-butyltri-iso-butoxysilane, sec-butyltri-tert-butoxysilane, t-butyltrimethoxysilane, t-butyltriethoxysilane, t- Butyltri-n-propoxysilane, t-butyltri-iso-propoxysilane, t-butyltri-n-butoxysilane, t-butyltri-iso-butoxysilane, t-butyltri-tert-butoxysilane, phenyl Limethoxysilane, phenyltriethoxysilane, phenyltri-n-propoxysilane, phenyltri-iso-propoxysilane, phenyltri-n-butoxysilane, phenyltri-iso-butoxysilane, phenyltri-tert-butoxysilane, tri Examples include fluoromethyltrimethoxysilane, pentafluoroethyltrimethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, and 3,3,3-trifluoropropyltriethoxysilane.

  Examples of the diorganodialkoxysilane include dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldi-n-propoxysilane, dimethyldi-iso-propoxysilane, dimethyldi-n-butoxysilane, dimethyldi-sec-butoxysilane, and dimethyldi-tert. -Butoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diethyldi-n-propoxysilane, diethyldi-iso-propoxysilane, diethyldi-n-butoxysilane, diethyldi-sec-butoxysilane, diethyldi-tert-butoxysilane, di- n-propyldimethoxysilane, di-n-propyldiethoxysilane, di-n-propyldi-n-propoxysilane, di-n-propyldi-iso-propoxysilane, di- -Propyldi-n-butoxysilane, di-n-propyldi-sec-butoxysilane, di-n-propyldi-tert-butoxysilane, di-iso-propyldimethoxysilane, di-iso-propyldiethoxysilane, di-iso -Propyldi-n-propoxysilane, di-iso-propyldi-iso-propoxysilane, di-iso-propyldi-n-butoxysilane, di-iso-propyldi-sec-butoxysilane, di-iso-propyldi-tert-butoxy Silane, di-n-butyldimethoxysilane, di-n-butyldiethoxysilane, di-n-butyldi-n-propoxysilane, di-n-butyldi-iso-propoxysilane, di-n-butyldi-n-butoxy Silane, di-n-butyldi-sec-butoxysilane Di-n-butyldi-tert-butoxysilane, di-sec-butyldimethoxysilane, di-sec-butyldiethoxysilane, di-sec-butyldi-n-propoxysilane, di-sec-butyldi-iso-propoxysilane, Di-sec-butyldi-n-butoxysilane, di-sec-butyldi-sec-butoxysilane, di-sec-butyldi-tert-butoxysilane, di-tert-butyldimethoxysilane, di-tert-butyldiethoxysilane, Di-tert-butyldi-n-propoxysilane, di-tert-butyldi-iso-propoxysilane, di-tert-butyldi-n-butoxysilane, di-tert-butyldi-sec-butoxysilane, di-tert-butyldi- tert-Butoxysilane, Diphenyl Rudimethoxysilane, diphenyldiethoxysilane, diphenyldi-n-propoxysilane, diphenyldi-iso-propoxysilane, diphenyldi-n-butoxysilane, diphenyldi-sec-butoxysilane, diphenyldi-tert-butoxysilane, bis (3,3,3-trifluoropropyl) dimethoxysilane, methyl (3,3,3-trifluoropropyl) dimethoxysilane and the like can be mentioned.

In addition, the compound of the general formula (1) in which R ¹ is an organic group having 1 to 20 carbon atoms, and other compounds than the above include, for example, bis (trimethoxysilyl) methane, bis (triethoxysilyl) methane, bis (Tri-n-propoxysilyl) methane, bis (tri-iso-propoxysilyl) methane, bis (trimethoxysilyl) ethane, bis (triethoxysilyl) ethane, bis (tri-n-propoxysilyl) ethane, bis ( Tri-iso-propoxysilyl) ethane, bis (trimethoxysilyl) propane, bis (triethoxysilyl) propane, bis (tri-n-propoxysilyl) propane, bis (tri-iso-propoxysilyl) propane, bis (tri Methoxysilyl) benzene, bis (triethoxysilyl) benzene, bis (tri-n-pro Examples thereof include bissilylalkanes such as (poxysilyl) benzene and bis (tri-iso-propoxysilyl) benzene, and bissilylbenzene.

Examples of the compound of the general formula (1) in which R ¹ is a group containing Si atom include hexaalkoxydisilanes such as hexamethoxydisilane, hexaethoxydisilane, hexa-n-propoxydisilane, and hexa-iso-propoxydisilane. And dialkyltetraalkoxydisilanes such as 1,2-dimethyltetramethoxydisilane, 1,2-dimethyltetraethoxydisilane, 1,2-dimethyltetrapropoxydisilane, and the like.

  Moreover, as a compound (halogenated silane) of General formula (1) whose hydrolyzable group X is a halogen atom (halogen group), the alkoxy group in each alkoxysilane molecule mentioned above is substituted with a halogen atom, for example. And the like. Furthermore, examples of the compound (acetoxysilane) of the general formula (1) in which the hydrolyzable group X is an acetoxy group include those in which the alkoxy group in each alkoxysilane molecule described above is substituted with an acetoxy group. It is done.

  Furthermore, examples of the compound (isocyanate silane) of the general formula (1) in which the hydrolyzable group X is an isocyanate group include those in which the alkoxy group in each alkoxysilane molecule described above is substituted with an isocyanate group. . Furthermore, examples of the compound (hydroxysilane) of the general formula (1) in which the hydrolyzable group X is a hydroxyl group include those in which the alkoxy group in each alkoxysilane molecule described above is substituted with a hydroxyl group. Can be mentioned.

  These compounds represented by the general formula (1) are used singly or in combination of two or more.

  Further, a resin obtained by hydrolytic condensation of a partial condensate such as a multimer of the compound represented by the general formula (1), a partial condensate such as a multimer of the compound represented by the general formula (1) and the general Resin obtained by hydrolytic condensation of the compound represented by formula (1), resin obtained by hydrolytic condensation of the compound represented by general formula (1) and other compounds, general formula (1) It is also possible to use a resin obtained by hydrolytic condensation of a partial condensate such as a multimer of the compound represented by general formula (1) and another compound.

  Examples of partial condensates such as multimers of the compound represented by the general formula (1) include hexamethoxydisiloxane, hexaethoxydisiloxane, hexa-n-propoxydisiloxane, hexa-iso-propoxydisiloxane, and the like. Examples include hexaalkoxydisiloxane, trisiloxane having advanced partial condensation, tetrasiloxane, and oligosiloxane.

  Examples of the “other compounds” include compounds having a polymerizable double bond or triple bond. Examples of the compound having a polymerizable double bond include ethylene, propylene, isobutene, butadiene, isoprene, vinyl chloride, vinyl acetate, vinyl propionate, vinyl caproate, vinyl stearate, methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether. , Acrylonitrile, styrene, methacrylic acid, methyl methacrylate, ethyl methacrylate, methacrylate-n-propyl, methacrylate-iso-propyl, methacrylate-n-butyl, acrylic acid, methyl acrylate, ethyl acrylate, acrylic acid Examples thereof include phenyl, vinylpyridine, vinylimidazole, acrylamide, allylbenzene, diallylbenzene and the like, and those obtained by partial condensation of these compounds. Examples of the compound having a triple bond include acetylene and ethynylbenzene.

  The resins thus obtained are used alone or in combination of two or more.

  The amount of water used when hydrolyzing and condensing the compound represented by the general formula (1) is preferably 0.1 to 1000 mol, more preferably 1 mol per mol of the compound represented by the general formula (1). Is 0.5 to 100 mol. If the amount of water is less than 0.1 mol, the hydrolysis-condensation reaction tends not to proceed sufficiently. If the amount of water exceeds 1000 mol, gelation tends to occur during hydrolysis or condensation.

  Moreover, it is also preferable to use a catalyst in the hydrolysis condensation of the compound represented by the general formula (1). Examples of such a catalyst include an acid catalyst, an alkali catalyst, and a metal chelate compound.

  Examples of the acid catalyst include organic acids and inorganic acids. Examples of organic acids include formic acid, maleic acid, fumaric acid, phthalic acid, malonic acid, succinic acid, tartaric acid, malic acid, lactic acid, citric acid, acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid , Octanoic acid, nonanoic acid, decanoic acid, oxalic acid, adipic acid, sebacic acid, butyric acid, oleic acid, stearic acid, linoleic acid, linolenic acid, salicylic acid, benzenesulfonic acid, benzoic acid, p-aminobenzoic acid, p- Examples thereof include toluenesulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, trifluoroethanesulfonic acid, and the like. Examples of the inorganic acid include hydrochloric acid, phosphoric acid, nitric acid, boric acid, sulfuric acid, and hydrofluoric acid. These are used singly or in combination of two or more. Among these, maleic acid is preferable as the organic acid and / or nitric acid is preferable as the inorganic acid.

  Examples of the alkali catalyst include inorganic alkalis and organic alkalis. Examples of the inorganic alkali include sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide and the like. Examples of the organic alkali include pyridine, monoethanolamine, diethanolamine, triethanolamine, dimethylmonoethanolamine, monomethyldiethanolamine, ammonia, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, methylamine, and ethylamine. Propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, cyclopentylamine, cyclohexylamine, N, N-dimethylamine, N, N-diethylamine, N , N-dipropylamine, N, N-dibutylamine, N, N-dipentylamine, , N-dihexylamine, N, N-dicyclopentylamine, N, N-dicyclohexylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, tricyclopentylamine, tricyclohexylamine, etc. It is done. These are used singly or in combination of two or more.

  Examples of the metal chelate compound include trimethoxy mono (acetylacetonato) titanium, triethoxy mono (acetylacetonato) titanium, tri-n-propoxy mono (acetylacetonato) titanium, tri-iso-propoxy mono ( Acetylacetonato) titanium, tri-n-butoxy mono (acetylacetonato) titanium, tri-sec-butoxy mono (acetylacetonato) titanium, tri-tert-butoxy mono (acetylacetonato) titanium, dimethoxy Di (acetylacetonato) titanium, diethoxy-di (acetylacetonato) titanium, di-n-propoxy-di (acetylacetonato) titanium, diiso-propoxy-di (acetylacetonato) titanium, di-n-butoxy-di (Acetylacetonato) titanium, dise -Butoxy di (acetylacetonato) titanium, ditert-butoxy di (acetylacetonato) titanium, monomethoxy tris (acetylacetonato) titanium, monoethoxy tris (acetylacetonato) titanium, mono n-propoxy Tris (acetylacetonato) titanium, monoiso-propoxy-tris (acetylacetonato) titanium, mono-n-butoxy-tris (acetylacetonato) titanium, mono-sec-butoxy-tris (acetylacetonato) titanium, mono-tert -Butoxy tris (acetylacetonato) titanium, tetrakis (acetylacetonato) titanium, trimethoxy mono (ethyl acetoacetate) titanium, triethoxy mono (ethyl acetoacetate) titanium, tri-n-propoxy mono (ethyl) Cetoacetate) titanium, tri-iso-propoxy mono (ethyl acetoacetate) titanium, tri-n-butoxy mono (ethyl acetoacetate) titanium, tri-sec-butoxy mono (ethyl acetoacetate) titanium, tri-tert -Butoxy mono (ethyl acetoacetate) titanium, dimethoxy di (ethyl acetoacetate) titanium, diethoxy di (ethyl acetoacetate) titanium, di-n-propoxy di (ethyl acetoacetate) titanium, diiso-propoxy di (Ethyl acetoacetate) titanium, di-n-butoxy di (ethyl acetoacetate) titanium, disec-butoxy di (ethyl acetoacetate) titanium, di tert-butoxy di (ethyl acetoacetate) titanium, monomethoxy tris (Ethyl acetoacetate) titanium, monoethoxy tris (ethyl acetoacetate) titanium, mono n-propoxy tris (ethyl acetoacetate) titanium, monoiso-propoxy tris (ethyl acetoacetate) titanium, mono n-butoxy tris (Ethyl acetoacetate) titanium, mono-sec-butoxy-tris (ethyl acetoacetate) titanium, mono-tert-butoxy-tris (ethyl acetoacetate) titanium, tetrakis (ethyl acetoacetate) titanium and other metal chelate compounds having the above, Examples thereof include compounds in which titanium of a metal chelate compound having titanium is replaced with zirconium, aluminum, or the like. These are used singly or in combination of two or more.

  In the hydrolysis condensation of the compound represented by the general formula (1), it is preferable to perform hydrolysis using such a catalyst. However, there are cases where the stability of the composition deteriorates or the influence of corrosion or the like on other materials may be caused by including a catalyst. In such a case, for example, after the hydrolysis, the catalyst may be removed from the composition, or may be reacted with another compound to deactivate the function as a catalyst. There is no particular limitation on the method of removing or reacting, but it may be removed using distillation, ion chromatography column or the like.

  Moreover, the hydrolyzate obtained from the compound represented by the general formula (1) may be taken out of the composition by reprecipitation or the like. In addition, as a method of deactivating the function as a catalyst by reaction, for example, when the catalyst is an alkali catalyst, a method of adding an acid catalyst and neutralizing it by an acid-base reaction or bringing the pH to the acidic side can be mentioned. It is done. In addition, when the catalyst is an acid catalyst, a method of adding an alkali catalyst and neutralizing by an acid-base reaction can also be mentioned.

  The amount of the catalyst used is preferably in the range of 0.0001 to 1 mol with respect to 1 mol of the compound represented by the general formula (1). When the amount used is less than 0.0001 mol, the reaction does not substantially proceed. If the amount of the catalyst used exceeds 1 mol, gelation tends to be promoted during hydrolysis condensation.

  Furthermore, since the alcohol by-produced by this hydrolysis is a protic solvent, it is preferably removed using an evaporator or the like.

  The resin thus obtained preferably has a weight average molecular weight of 500 to 1,000,000, more preferably 500 to 500,000 from the viewpoints of solubility in a solvent, mechanical properties, moldability, and the like. More preferably, it is 100,000, particularly preferably 500-10000, and most preferably 500-5000. If this weight average molecular weight is less than 500, the film formability of the silica-based film tends to be inferior. When the weight average molecular weight exceeds 1,000,000, the compatibility with the solvent tends to decrease.

When adhesion to the substrate and mechanical strength are required, H atom, F atom, B atom, N atom, Al atom, P atom, Si atom, Ge atom with respect to 1 mol of Si atom in the general formula (1) , The total content of at least one atom selected from the group consisting of Ti atoms and C atoms (this is the total number (M) of specific bonding atoms (R ¹ in the general formula (1)). 1.3-0.2 mol, more preferably 1.0-0.2 mol, particularly preferably 0.90-0.2 mol, 0.8-0. Very preferably 2 moles. That is, H atom, F atom, B atom, N atom, Al atom, P atom, Si atom, Ge atom, Ti atom, and C atom bonded to each Si atom forming the siloxane bond of the siloxane resin. The total number of at least one atom selected from the group consisting of atoms is preferably 1.3 to 0.2, more preferably 1.0 to 0.2, and 0.90 to 0.2. It is particularly preferable that the ratio is 0.8 to 0.2. If it does in this way, the adhesiveness to the other film | membrane (layer) of a silica-type film and the fall of mechanical strength can be suppressed.

  When the total number (M) of these specific bonding atoms is less than 0.20 mol, the dielectric properties tend to be inferior when a silica-based coating is used as an insulating film. When M exceeds 1.3 mol, the adhesion with other films (layers) of the silica-based film finally obtained tends to be inferior. Among the specific bonding atoms described above, at least one selected from the group consisting of H atoms, F atoms, N atoms, Si atoms, Ti atoms, and C atoms in terms of film-forming properties of the silica-based film. It is preferable that it contains these atoms. Further, among them, it is more preferable that at least one kind of atom selected from the group consisting of H atom, F atom, N atom, Si atom and C atom is contained in terms of dielectric properties and mechanical strength.

In addition, the total number (M) of a specific bond atom can be calculated | required from the preparation amount of a siloxane resin, for example, following formula (A);
_{M = (M 1 + (M} 2/2) + (M 3/3)) / M si (A)
It can be calculated using the relationship represented by In the formula, M ₁ represents the total number of atoms bonded to a single (only one) Si atom among the specific bonded atoms, and M ₂ is bonded to two silicon atoms among the specific bonded atoms. M ₃ represents the total number of atoms bonded to three silicon atoms among the specific bonded atoms, and M _si represents the total number of Si atoms.

  Such siloxane resins are used alone or in combination of two or more. As a method of combining two or more types of siloxane resins, for example, a method of combining two or more types of siloxane resins having different weight average molecular weights, or two or more types of siloxane resins obtained by hydrolytic condensation using different compounds as essential components The method of combining, etc. are mentioned.

<(B) component>
Examples of the solvent capable of dissolving the component (a) include aprotic solvents and protic solvents. These may be used alone or in combination of two or more.

  Examples of the aprotic solvent include acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-iso-propyl ketone, methyl-n-butyl ketone, methyl-iso-butyl ketone, methyl-n-pentyl ketone, methyl-n- Hexyl ketone, diethyl ketone, dipropyl ketone, di-iso-butyl ketone, trimethylnonanone, cyclohexanone, cyclopentanone, methylcyclohexanone, 2,4-pentanedione, acetonyl acetone, γ-butyrolactone, γ-valerolactone, etc. Ketone solvents; diethyl ether, methyl ethyl ether, methyl-n-di-n-propyl ether, di-iso-propyl ether, tetrahydrofuran, methyltetrahydrofuran, dioxane, dimethyldioxane, ethyl Glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol di-n-propyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol methyl mono-n-propyl ether, diethylene glycol methyl mono-n- Butyl ether, diethylene glycol di-n-propyl ether, diethylene glycol di-n-butyl ether, diethylene glycol methyl mono-n-hexyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol methyl ethyl ether, triethylene glycol methyl Non-n-butyl ether, triethylene glycol di-n-butyl ether, triethylene glycol methyl mono-n-hexyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, tetradiethylene glycol methyl ethyl ether, tetraethylene glycol methyl mono-n -Butyl ether, diethylene glycol di-n-butyl ether, tetraethylene glycol methyl mono-n-hexyl ether, tetraethylene glycol di-n-butyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol di-n-propyl ether, propylene glycol Dibutyl ether, dipropylene glycol dimethyl ether, Propylene glycol diethyl ether, dipropylene glycol methyl ethyl ether, dipropylene glycol methyl mono-n-butyl ether, dipropylene glycol di-n-propyl ether, dipropylene glycol di-n-butyl ether, dipropylene glycol methyl mono-n-hexyl Ether, tripropylene glycol dimethyl ether, tripropylene glycol diethyl ether, tripropylene glycol methyl ethyl ether, tripropylene glycol methyl mono-n-butyl ether, tripropylene glycol di-n-butyl ether, tripropylene glycol methyl mono-n-hexyl ether, Tetrapropylene glycol dimethyl ether, tetrapropylene glycol diethyl ether, Ether type such as tetradipropylene glycol methyl ethyl ether, tetrapropylene glycol methyl mono-n-butyl ether, dipropylene glycol di-n-butyl ether, tetrapropylene glycol methyl mono-n-hexyl ether, tetrapropylene glycol di-n-butyl ether Solvent: methyl acetate, ethyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, acetic acid Methylpentyl, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methyl cyclohexyl acetate, nonyl acetate, methyl acetoacetate, ethyl acetoacetate, diethylene glycol monomethyl acetate Ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, glycol diacetate, methoxytriglycol acetate, ethyl propionate, n-butyl propionate, Ester solvents such as i-amyl propionate, diethyl oxalate, di-n-butyl oxalate; ethylene glycol methyl ether propionate, ethylene glycol ethyl ether propionate, ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate , Diethylene glycol methyl ether acetate, diethylene glycol ethyl ether acetate, diethylene glycol ether acetate solvents such as n-butyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, dipropylene glycol methyl ether acetate, dipropylene glycol ethyl ether acetate; acetonitrile, N-methylpyrrolidinone, N-ethylpyrrolidinone, N-propylpyrrolidinone, N-butylpyrrolidinone, N-hexylpyrrolidinone, N-cyclohexylpyrrolidinone, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-dimethylsulfoxide and the like can be mentioned. Among these, an ether solvent, an ether acetate solvent, and a ketone solvent are preferable from the viewpoint of increasing the film thickness.

  Among these, the inventors consider that an ether acetate solvent is preferred first, an ether solvent is preferred second, and a ketone solvent is preferred third, from the viewpoint of suppressing coating unevenness and repellency. These are used singly or in combination of two or more.

  Examples of protic solvents include methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, sec-butanol, t-butanol, n-pentanol, i-pentanol, and 2-methylbutanol. , Sec-pentanol, t-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, n-octanol, 2-ethylhexanol, sec- Octanol, n-nonyl alcohol, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec-heptadecyl alcohol, phenol, cyclohexanol, methylcyclohexano , Benzyl alcohol, ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, and other alcohol solvents; ethylene glycol methyl ether, ethylene glycol ethyl ether , Ethylene glycol monophenyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol mono-n-hexyl ether, ethoxytriglycol, tetraethylene glycol mono-n-butyl ether, propylene glycol monomethyl ether, propylene Glycol propyl ether, dipropylene Recall monomethyl ether, dipropylene glycol monoethyl ether, ether solvents such as tripropylene glycol monomethyl ether; methyl lactate, ethyl lactate, n- butyl, ester solvents such as lactic acid n- amyl and the like. Among these, alcohol-based solvents are preferable from the viewpoint of storage stability. Among these, the inventors consider that ethanol, isopropyl alcohol, propylene glycol propyl ether, and the like are preferable from the viewpoint of suppressing coating unevenness and repellency.

  These are used singly or in combination of two or more.

  The method of using the component (b) is not particularly limited. For example, the method of using the component (a) as a solvent when preparing the component, the method of adding the component after preparing the component (a), the method of exchanging the solvent, (a) There is a method in which components are taken out by solvent distillation or the like and (b) a solvent is added.

  Furthermore, the composition for forming a silica-based film of the present invention may contain water as necessary, but it is preferably within a range that does not impair the intended properties.

  The amount of the solvent used is preferably such that the concentration of the component (a) (siloxane resin) is 5 to 35% by weight with respect to the total amount of the components (a) and (b). More preferably, the amount is such that it is ˜30% by weight, particularly preferably the amount is such that it is 8% to 30% by weight, and it is very particularly preferred that the amount is 8% to 25% by weight, The amount is most preferably 10 to 20% by weight. If the amount of the solvent is excessive and the concentration of the component (a) is less than 5% by weight, it tends to be difficult to form a silica-based film having a desired film thickness. When the amount of the solvent is too small and the concentration of the component (a) exceeds 35% by weight, the film formability of the silica-based film is deteriorated and the stability of the composition itself tends to be lowered.

<(C) component>
The component (c) in the present invention is a curing accelerating catalyst and is different from a normal photoacid generator or photobase generator. Therefore, it is usually distinguished from onium salts such as those used as photoacid generators or photobase generators. However, any material that has both photoacid generation ability or photobase generation ability and curing acceleration catalytic ability can be used.

  This curing accelerating catalyst does not show a catalytic action in a solution, and is considered to be a unique one showing activity in a coated film.

Means for examining the curing acceleration catalytic ability of the curing acceleration catalyst are shown in 1-4 below.
1. A composition comprising the component (a) and the component (b) is prepared.
2. The composition prepared in 1 above is applied to a silicon wafer so that the film thickness after baking is 1.0 ± 0.1 μm, and the film is baked at a predetermined temperature for 30 seconds to measure the film thickness of the film.
3. The silicon wafer on which the film is formed is immersed in a 2.38 wt% tetramethylammonium hydroxide (TMAH) aqueous solution at 23 ± 2 ° C. for 30 seconds, and the film thickness of the film after water washing and drying is observed. At this time, the minimum temperature at the time of baking at which the change in film thickness before and after immersion in the TMAH aqueous solution is within 20% is defined as the insoluble temperature.
4). In the composition prepared in 1 above, 0.01% by weight of the compound whose curing acceleration catalytic ability is to be confirmed is added to the total amount of the component (a) to obtain a composition. Determine the insoluble temperature. If the insolubility temperature is lowered by adding a compound for which curing acceleration catalytic ability is desired, the compound has curing acceleration catalytic ability.

  Examples of the curing accelerating catalyst that is component (c) include alkali metals such as sodium hydroxide, sodium chloride, potassium hydroxide, potassium chloride, and onium salts. These are used singly or in combination of two or more.

  Among these, an onium salt is preferable and a quaternary ammonium salt is preferable from the viewpoint that the silica-based coating film obtained can be reduced in refractive index and mechanical strength and can further improve the stability of the composition. More preferred.

  Examples of the onium salt include a salt formed from (c-1) a nitrogen-containing compound and (c-2) at least one selected from an anionic group-containing compound and a halogen atom. The atoms bonded to nitrogen of the (c-1) nitrogen-containing compound are composed of H atom, F atom, B atom, N atom, Al atom, P atom, Si atom, Ge atom, Ti atom, and C atom. It is preferably at least one selected from the group. Examples of the anionic group include a hydroxyl group, a nitrate group, a sulfate group, a carbonyl group, a carboxyl group, a carbonate group, and a phenoxy group.

  Examples of these onium salts include ammonium hydroxide, ammonium fluoride, ammonium chloride, ammonium bromide, ammonium iodide, ammonium phosphate salt, ammonium nitrate salt, ammonium borate salt, ammonium sulfate salt, ammonium formate salt, ammonium maleate salt, Ammonium fumarate, ammonium phthalate, ammonium malonate, ammonium succinate, ammonium tartrate, ammonium malate, ammonium lactate, ammonium citrate, ammonium acetate, ammonium propionate, ammonium butanoate Salt, ammonium pentanoate, ammonium hexanoate, ammonium heptanoate, ammonium octanoate, ammonium nonanoate Salt, ammonium decanoate, ammonium oxalate, ammonium adipate, ammonium sebacate, ammonium butyrate, ammonium oleate, ammonium stearate, ammonium linoleate, ammonium linolenate, ammonium salicylate, Benzenesulfonic acid ammonium salt, benzoic acid ammonium salt, p-aminobenzoic acid ammonium salt, p-toluenesulfonic acid ammonium salt, methanesulfonic acid ammonium salt, trifluoromethanesulfonic acid ammonium salt, trifluoroethanesulfonic acid ammonium salt, etc. An ammonium salt compound is mentioned.

  Further, the ammonium moiety of the ammonium salt compound is methylammonium, dimethylammonium, trimethylammonium, tetramethylammonium, ethylammonium, triethylammonium, tetraethylammonium, propylammonium, dipropylammonium, tripropylammonium, tetrapropylammonium, Examples also include ammonium salt compounds substituted with butylammonium, dibutylammonium, tributylammonium, tetrabutylammonium, ethanolammonium, diethanolammonium, triethanolammonium, and the like.

  In these onium salt compounds, ammonium such as tetramethylammonium nitrate, tetramethylammonium acetate, tetramethylammonium propionate, tetramethylammonium maleate, and tetramethylammonium sulfate is used from the viewpoint of accelerating the curing of the silica-based film. Salts are preferred.

  These are used singly or in combination of two or more.

  Further, the blending ratio of the component (c) is preferably 0.001 to 1.0% by weight, that is, 0.001 to 1.0 part by weight based on the total amount of the component (a), and 0.005% by weight. % To 1.0% by weight, ie 0.005 to 1.0 part by weight, more preferably 0.005 to 0.5% by weight, ie 0.05 to 0.5 part by weight. preferable. If the blending ratio is less than 0.001% by weight, the curability tends to deteriorate, and if it exceeds 1.0% by weight, the storage stability of the solution tends to decrease.

  These onium salts can be added to a desired concentration after being dissolved or diluted in water or a solvent as necessary. Moreover, although the time to add is not specifically limited, For example, there exists a case where (a) component is hydrolyzed, during hydrolysis, at the end of the reaction, and before and after solvent distillation.

<(D) component>
The component (d) in the present invention is a pyrolytic volatile compound that thermally decomposes or volatilizes at 200 to 600 ° C., that is, a pore forming material. The hole forming material is not particularly limited as long as it can form holes in the silica-based coating.

  Specific examples of the pore forming material (void forming agent) include, for example, vinyl ether compounds, vinyl compounds having a polyethylene oxide structure, vinyl compounds having a polypropylene oxide structure, vinyl pyridine compounds, styrene compounds, alkyl esters. Examples thereof include vinyl compounds, (meth) acrylate compounds, polymers having a polyalkylene oxide structure, polyesters, polyanhydrides, and polycarbonate polymers. From the viewpoint of the decomposition characteristics of the polymer and the mechanical strength of the film, a polymer having a polyalkylene oxide structure is preferred, and a polymer having a polypropylene oxide structure is particularly preferred.

  Examples of the polyalkylene oxide structure include a polyethylene oxide structure, a polypropylene oxide structure, a polytetramethylene oxide structure, and a polybutylene oxide structure.

  Specifically, polyethylene oxide alkyl ether, polyoxyethylene sterol ether, polyoxyethylene lanolin derivative, ethylene oxide derivative of alkylphenol formalin condensate, polyoxyethylene polyoxypropylene block copolymer, polypropylene oxide alkyl ale, polyoxyethylene polyoxy Ether type compounds such as propylene alkyl ether, polyoxyethylene glycerin fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyoxyethylene fatty acid alkanolamide sulfate and other ether ester type compounds, polyethylene glycol fatty acid ester, ethylene glycol fatty acid ester, fatty acid monoglyceride , Polyglycerol fatty acid ester, sorbitan fatty acid ester Le, ether ester type compounds such as propylene glycol fatty acid esters, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, and polyethylene glycol, glycol-type compounds such as polypropylene glycol.

  In addition, examples of the (meth) acrylate acid compound include acrylic acid alkyl ester, methacrylic acid alkyl ester, acrylic acid alkoxyalkyl ester, methacrylic acid alkyl ester, and methacrylic acid alkoxyalkyl ester.

  Examples of the alkyl acrylate ester include 1 to 6 carbon atoms such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, pentyl acrylate, and hexyl acrylate. Examples of the alkyl ester and alkyl methacrylate ester include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, pentyl methacrylate, hexyl methacrylate and the like. ~ 6 alkyl esters, acrylic acid alkoxyalkyl esters as methoxymethyl acrylate, ethoxyethyl acrylate, methacrylic acid alkoxyalkyl esters as methoxymethyl methacrylate It can be mentioned methacrylic acid ethoxyethyl, and the like.

  Moreover, the (meth) acrylate acid compound can use a copolymer with a compound having a hydroxyl group. Specific examples of the compound include 2-hydroxyethyl acrylate, diethylene glycol acrylate, 2-hydroxypropyl acrylate, dipropylene glycol acrylate, methacrylic acid, 2-hydroxyethyl methacrylate, diethylene glycol methacrylate, 2-hydroxypropyl methacrylate, and dipropylene glycol methacrylate. Is mentioned.

  Examples of polyesters include hydroxycarboxylic acid polycondensates, lactone ring-opening polymers, and polycondensates of aliphatic polyols and aliphatic polycarboxylic acids.

  Examples of the polycarbonate include polycondensates of carbonic acid and alkylene glycol such as polyethylene carbonate, polypropylene carbonate, polytrimethylene carbonate, polytetramethylene carbonate, polypentamethylene carbonate, and polyhexamethylene carbonate.

  Examples of the polyanhydride include polycondensates of dicarboxylic acids such as polymalonyl oxide, polyadipoyl oxide, polypimeyl oxide, polysuberoyl oxide, polyazelayl oxide, and polysebacoyl oxide. .

  The pore-forming material preferably has a weight average molecular weight of 200 to 10,000 from the viewpoint of solubility in a solvent, compatibility with a siloxane resin, mechanical properties of the film, moldability of the film, and the like. -5000 is more preferable, and 400-2000 is more preferable. This weight average molecular weight is a value measured by gel permeation chromatography (GPC) and converted using a standard polystyrene calibration curve.

Further, the silica-based film forming composition of the present invention may contain porous particles as a pore-forming material as the component (d). Examples of the porous particles include silica particles containing Si element and O element, inorganic compound particles other than silica such as Al ₂ O ₃ , organic polymers, and activated carbon. From the viewpoint of mechanical strength and transparency of the coating film to be formed, porous silica particles containing Si element and O element are preferable.

  As the structure of the porous particles, particles having an open structure in which voids are present everywhere from the particle surface or from the surface to the inside, and particles having a closed pore structure having outer walls and voids in the particles can be used.

  The porous particles preferably have a particle size (particle diameter) of less than 100 nm, and more preferably 50 nm. The lower limit is about 1 nm. When the particle size is 100 nm or more, the transparency may decrease due to light scattering, the dispersibility of the composition may decrease, or the stability of the solution may decrease. When the particle size is less than 1 nm, the refractive index of the resulting film may not be sufficiently reduced.

  The above component (d) is used singly or in combination of two or more.

  In the composition for forming a silica-based film according to the present invention, the content of the pore-forming material of the component (d) is 10 to 50% by weight with respect to the total amount of the component (a) and the component (d). It is preferably 15 to 45% by weight. When the content of the component (d) is within the above range, the mechanical strength and storage stability of the resulting silica-based coating are further improved.

<Other ingredients>
In addition, a dye, a surfactant, a silane coupling agent, a thickener, an inorganic filler, and the like may be added as long as the object and effect of the present invention are not impaired. Moreover, you may provide void | hole (hole) formation ability to the siloxane resin which is (a) component. Moreover, a photoacid generator or a photobase generator can be contained to form a silica-based film forming composition.

  The composition for forming a silica-based film of the present invention can be used in the vicinity of an electrode such as a TFT as necessary. In that case, it is desirable that the composition does not contain an alkali metal or an alkaline earth metal. Moreover, even when those metals are contained, the metal ion concentration in the composition is preferably 1000 ppm or less, and more preferably 1 ppm or less. When these metal ion concentrations exceed 1000 ppm, metal ions easily flow into transistor portions such as TFTs having a silica-based film obtained from the composition, which may adversely affect the performance itself.

  Therefore, it is effective to remove alkali metal or alkaline earth metal from the composition using an ion exchange filter or the like, if necessary. However, when used for optical waveguides, other uses, etc., this is not limited as long as the purpose is not impaired.

  Next, a method for forming a silica-based film according to the present invention will be described. The method for forming a silica-based film of the present invention comprises a step of applying the above-mentioned composition for forming a silica-based film on the surface of a substrate to form a coating film, and a solvent for removing the solvent contained in the coating film to dry And a step of firing the dry film. The substrate may be a light-shielding substrate such as a silicon wafer, but is preferably a transparent substrate because the effects of the present invention can be more effectively exhibited.

  As a method for forming a silica-based film on a transparent substrate using the composition for forming a silica-based film of the present invention, spray coating, lip coater, slit coater, printing method and the like can be employed in addition to spin coating. In general, a spin coating method having excellent film formability and film uniformity will be described as an example, but the present invention is not limited to this spin coating method. Further, the transparent substrate may be one having a flat surface, or one having electrodes or the like and having a rough surface.

  In addition to glass substrates, organic polymers such as polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyacryl, nylon, polyethersulfone, polyvinyl chloride, polypropylene, and triacetyl cellulose can be used as these substrates.

  First, the composition for forming a silica-based film is spin-coated on a transparent substrate such as a glass substrate, preferably at 300 to 3000 rotations / minute, more preferably at 400 to 2000 rotations / minute, to form a coating film. If the rotational speed is less than 300 revolutions / minute, the film uniformity tends to deteriorate, and if it exceeds 3000 revolutions / minute, the film formability may deteriorate.

  Further, the film thickness of the silica-based coating varies depending on the use application, and for example, in the antireflection film application, it is preferably 0.01 to 10 μm, and the film thickness when used for an interlayer insulating film such as LSI is 0.01. It is preferable that it is -2micrometer, and it is preferable that the film thickness at the time of using it for a passivation layer is 2-40 micrometers.

  The film thickness when used for liquid crystal is preferably 0.1 to 20 μm, the film thickness when used for a photoresist is preferably 0.1 to 2 μm, and the film when used for an optical waveguide The thickness is preferably 1 to 50 μm. In particular, the antireflection film may have a laminated structure in combination with a high refractive material, for example, a film containing titanium-based fine particles.

  In order to adjust the film thickness of the silica-based film, for example, the concentration of the component (a) in the composition may be adjusted. When using the spin coating method, the film thickness can be adjusted by adjusting the number of rotations and the number of coatings. When the film thickness is controlled by adjusting the concentration of the component (a), for example, when the film thickness is increased, the concentration of the component (a) is increased, and when the film thickness is decreased, the component (a) It can be controlled by lowering the concentration of. In addition, when adjusting the film thickness using the spin coating method, for example, when increasing the film thickness, the rotation speed is decreased or the number of coatings is increased, and when the film thickness is decreased, the rotation speed is decreased. It can be adjusted by raising or reducing the number of times of application.

  Next, the organic solvent in the coating film is removed with a hot plate or the like preferably at 50 to 350 ° C., more preferably at 100 to 300 ° C. to obtain a dry film. If this drying temperature is less than 50 ° C., the organic solvent tends not to be sufficiently removed. Also, depending on the conditions of the next final curing, this drying step can be omitted.

  Next, the coating film (dry film) from which the organic solvent has been removed is baked at a heating temperature of 200 to 600 ° C. to perform final curing, and a silica-based film formed on the surface of the transparent substrate and the transparent substrate. Is obtained. If the heating temperature is less than 200 ° C, sufficient curing tends not to be achieved, and if it exceeds 600 ° C, it is disadvantageous in terms of energy cost.

  In addition, the heating time during the curing is preferably 2 to 60 minutes, and more preferably 2 to 30 minutes.

  FIG. 1 is a schematic cross-sectional view of a laminate having a silica-based film formed as described above. The laminate 100 includes a transparent substrate 10 and a silica-based coating 20 formed on the surface of the transparent substrate 10. Such laminates include optical components, lenses, prisms, optical disks, camera lenses, glasses, liquid crystal panels, plasma displays, cathode ray tubes, equipment meter hoods, solar cell panels, solar concentrators, window glass, vehicle glass and It can be used as a transparent member such as show window glass.

  Silica-based coatings according to the present invention include liquid crystal panels, plasma displays, solar cell panels, solar concentrators, window glass, vehicle glass and other antireflection films, surface protective films (passivation films), buffer coat films, interlayers. It can be suitably used as an insulating film or the like. In particular, the antireflection film is not limited in application, and can be used in common for all members that require the antireflection film. In addition, the substrate on which the silica-based film is formed by applying the composition for forming a silica-based film according to the present invention may be a silicon wafer or the like.

  Hereinafter, specific examples according to the present invention will be described, but the present invention is not limited thereto.

(Synthesis of siloxane resin (I))
The synthesis | combination of the raw material siloxane resin used for Example 1 is shown.
In a solution prepared by dissolving 22.29 g of tetraethoxysilane and 9.49 g of methyltriethoxysilane in 58.64 g of propylene glycol methyl ether acetate, 9.58 g of an aqueous nitric acid solution adjusted to 0.644% by weight was added under stirring. Added dropwise over a period of minutes. After completion of the dropwise addition, the mixture was reacted for 3 hours with stirring, and then a portion of the produced ethanol and propylene glycol methyl ether acetate was distilled off in a 60 ° C. warm bath under reduced pressure to obtain a polysiloxane solution having a solid content of 15.21%. 65.75 g was obtained. It was 870 when the weight average molecular weight of polysiloxane was measured by GPC method.

(Synthesis of siloxane resin (b))
The synthesis | combination of the raw material siloxane resin used for Examples 2-8 and Comparative Example 2 is shown.
In a solution obtained by dissolving 91.07 g of tetraethoxysilane and 71.03 g of methyltriethoxysilane in 319.91 g of propylene glycol methyl ether acetate, 47.9 g of an aqueous nitric acid solution adjusted to 0.644% by weight was added with stirring. Added dropwise over a period of minutes. After completion of the dropwise addition, the mixture was reacted for 3 hours with stirring, and then a part of the produced ethanol and propylene glycol methyl ether acetate was distilled off in a warm bath at 60 ° C. under reduced pressure to obtain a polysiloxane solution having a solid content of 16.35%. 324.16 g was obtained. It was 920 when the weight average molecular weight of polysiloxane was measured by GPC method.

(Synthesis of siloxane resin (c))
The synthesis | combination of the raw material siloxane resin used for the comparative example 1 is shown.
In a solution obtained by dissolving 17.34 g of tetraethoxysilane in 27.24 g of propylene glycol methyl ether acetate, 5.43 g of an aqueous nitric acid solution adjusted to 0.644% by weight was added dropwise over 10 minutes with stirring. After completion of the dropwise addition, the mixture was reacted for 3 hours with stirring, and then part of the produced ethanol and propylene glycol methyl ether acetate was distilled off in a 60 ° C. warm bath under reduced pressure to obtain a polysiloxane solution having a solid content of 14.32%. 34.92 g was obtained. The weight average molecular weight of the polysiloxane measured by the GPC method was 1,010.

(Synthesis of siloxane resin (d))
The synthesis | combination of the raw material siloxane resin used for Example 9 is shown.
In a solution prepared by dissolving 15.35 g of tetraethoxysilane and 11.14 g of dimethyldiethoxysilane in 66.27 g of propylene glycol methyl ether acetate, 7.25 g of an aqueous nitric acid solution adjusted to 0.644% is stirred for 30 minutes. It was dripped over. After completion of the dropwise addition, the mixture was reacted for 3 hours with stirring, and then a part of the produced ethanol and propylene glycol methyl ether acetate were distilled off in a 60 ° C. warm bath under reduced pressure to obtain a polysiloxane solution having a solid concentration of 16.5%. 60.6 g was obtained. The weight average molecular weight of the polysiloxane measured by the GPC method was 950.

(Synthesis of siloxane resin (e))
The synthesis | combination of the raw material siloxane resin used for Example 10 is shown.
In a solution prepared by dissolving 17.18 g of tetraethoxysilane and 13.4 g of methyltriethoxysilane in 60.37 g of propylene glycol monopropyl ether, 9.04 g of an aqueous nitric acid solution adjusted to 0.644% was stirred for 30 minutes. It was dripped over. After completion of the dropwise addition, the mixture was allowed to react for 3 hours with stirring, and then a part of the produced ethanol and propylene glycol monopropyl ether was distilled off in a 60 ° C. warm bath under reduced pressure to obtain a polysiloxane solution having a solid content of 16.7%. 59.9 g was obtained. It was 920 when the weight average molecular weight of polysiloxane was measured by GPC method.

(Synthesis of siloxane resin (f))
The synthesis | combination of the raw material siloxane resin used for Example 11 is shown.
To a solution obtained by dissolving 17.18 g of tetraethoxysilane and 13.4 g of methyltriethoxysilane in 60.37 g of diethylene glycol dimethyl ether, 9.04 g of an aqueous nitric acid solution adjusted to 0.644% was added dropwise over 30 minutes with stirring. did. After completion of the dropwise addition, the mixture was reacted for 3 hours with stirring, and a portion of the generated ethanol and diethylene glycol dimethyl ether were distilled off in a 60 ° C. warm bath under reduced pressure to obtain 63.69 g of a polysiloxane solution having a solid concentration of 15.7%. Obtained. The weight average molecular weight of the polysiloxane measured by the GPC method was 930.

(Synthesis of siloxane resin (g))
The synthesis | combination of the raw material siloxane resin used for Example 12 is shown.
In a solution obtained by dissolving 17.18 g of tetraethoxysilane and 13.4 g of methyltriethoxysilane in 60.37 g of propylene glycol methyl ether acetate, 9.04 g of an aqueous nitric acid solution adjusted to 0.644% is stirred for 30 minutes. It was dripped over. After completion of the dropwise addition, the mixture was reacted for 3 hours with stirring, and then a part of the produced ethanol and propylene glycol methyl ether acetate was distilled off in a warm bath at 60 ° C. under reduced pressure to obtain a polysiloxane solution 67 having a solid content concentration of 14.8%. .57 g was obtained. The weight average molecular weight of the polysiloxane measured by the GPC method was 950.

(Synthesis of siloxane resin (h))
The synthesis | combination of the raw material siloxane resin used for Example 13 is shown.
In a solution prepared by dissolving 27.09 g of tetraethoxysilane and 5.81 g of methyltriethoxysilane in 57.04 g of propylene glycol methyl ether acetate, 10.06 g of an aqueous nitric acid solution adjusted to 0.644% was stirred for 30 minutes. It was dripped over. After completion of the dropwise addition, the mixture was reacted for 3 hours with stirring, and then part of the produced ethanol and propylene glycol methyl ether acetate was distilled off in a warm bath at 60 ° C. under reduced pressure to obtain a polysiloxane solution 68 having a solid content of 14.7%. 0.02 g was obtained. The weight average molecular weight of the polysiloxane measured by the GPC method was 970.

(Synthesis of siloxane resin (re))
The synthesis | combination of the raw material siloxane resin used for Example 14 is shown.
In a solution obtained by dissolving 13.0 g of tetraethoxysilane and 16.6 g of methyltriethoxysilane in 61.78 g of propylene glycol methyl ether acetate, 8.61 g of an aqueous nitric acid solution adjusted to 0.644% is stirred for 30 minutes. It was dripped over. After completion of the dropwise addition, the reaction was allowed to proceed for 3 hours with stirring, and then a portion of the produced ethanol and propylene glycol methyl ether acetate was distilled off in a warm bath at 60 ° C. under reduced pressure to obtain a polysiloxane solution 66 having a solid content concentration of 15.1%. .23 g was obtained. The weight average molecular weight of the polysiloxane measured by the GPC method was 930.

(Synthesis of siloxane resin (nu))
The synthesis | combination of the raw material siloxane resin used for Example 15 is shown.
In a solution prepared by dissolving 3.10 g of tetraethoxysilane and 24.19 g of methyltriethoxysilane in 65.12 g of propylene glycol methyl ether acetate, 7.6 g of an aqueous nitric acid solution adjusted to 0.644% is stirred for 30 minutes. It was dripped over. After completion of the dropwise addition, the mixture was reacted for 3 hours with stirring, and then part of the produced ethanol and propylene glycol methyl ether acetate was distilled off in a warm bath at 60 ° C. under reduced pressure to obtain a polysiloxane solution 68 having a solid concentration of 14.5%. .97 g was obtained. The weight average molecular weight of the polysiloxane measured by the GPC method was 940.

Example 1
To 59.17 g of the polysiloxane solution obtained in the synthesis of siloxane resin (ii), 30.19 g of propylene glycol methyl ether acetate, 0.19 g of 2.38% tetramethylammonium nitrate aqueous solution (pH 3.6) and 1% maleic 0.45 g of an acid aqueous solution was added and dissolved by stirring at room temperature (25 ° C.) for 30 minutes to obtain 90.0 g of a polysiloxane solution for forming a silica-based film having a solid content concentration of 10%.

(Example 2)
To 55.05 g of the polysiloxane solution obtained in the synthesis of siloxane resin (b), 34.32 g of propylene glycol methyl ether acetate, 0.19 g of 2.38% tetramethylammonium nitrate aqueous solution (pH 3.6) and 1% maleic 0.45 g of an acid aqueous solution was added and dissolved by stirring at room temperature (25 ° C.) for 30 minutes to obtain 90.0 g of a polysiloxane solution for forming a silica-based film having a solid content concentration of 10%.

(Example 3)
44.04 g of the polysiloxane solution obtained in the synthesis of siloxane resin (b), 43.56 g of propylene glycol methyl ether acetate, 1.8 g of polypropylene glycol (manufactured by Aldrich, PPG725), 2.38% tetramethylammonium nitrate 0.15 g of aqueous solution (pH 3.6) and 0.45 g of 1% maleic acid aqueous solution were added, respectively, and stirred and dissolved at room temperature (25 ° C.) for 30 minutes to obtain a silica-based film forming polysiloxane solution having a solid content concentration of 10%. 90.0 g was obtained.

Example 4
35.78 g of the polysiloxane solution obtained in the synthesis of siloxane resin (b), 50.50 g of propylene glycol methyl ether acetate, 3.15 g of polypropylene glycol (manufactured by Aldrich, PPG725), 2.38% tetramethylammonium nitrate 0.12 g of aqueous solution (pH 3.6) and 0.45 g of 1% maleic acid aqueous solution were added, respectively, and stirred and dissolved at room temperature (25 ° C.) for 30 minutes to form a polysiloxane solution for forming a silica-based film having a solid content concentration of 10%. 90.0 g was obtained.

(Example 5)
To 46.79 g of the polysiloxane solution obtained in the synthesis of siloxane resin (b), 41.25 g of propylene glycol methyl ether acetate, 1.35 g of hollow SiO ₂ particles having an inner diameter of 90 nm, 2.38% tetramethylammonium nitrate aqueous solution ( pH 3.6) 0.16 g and 1% maleic acid aqueous solution 0.45 g were added, respectively, and stirred and dissolved at room temperature (25 ° C.) for 30 minutes to obtain a silica-based coating-forming polysiloxane solution 90. 0 g was obtained.

(Example 6)
To 44.04 g of the polysiloxane solution obtained in the synthesis of siloxane resin (b), 43.56 g of propylene glycol methyl ether acetate, 1.8 g of hollow SiO ₂ particles having an inner diameter of 40 nm, 2.38% tetramethylammonium nitrate aqueous solution ( pH 3.6) 0.15 g and 1% maleic acid aqueous solution 0.45 g were added respectively, and stirred and dissolved at room temperature (25 ° C.) for 30 minutes to obtain a silica-based film forming polysiloxane solution 90. 0 g was obtained.

(Example 7)
To 41.28 g of the polysiloxane solution obtained in the synthesis of siloxane resin (b), 45.87 g of propylene glycol methyl ether acetate, 2.25 g of hollow SiO ₂ particles with an inner diameter of 20 nm, 2.38% tetramethylammonium nitrate aqueous solution ( pH 3.6) 0.14 g and 1% maleic acid aqueous solution 0.45 g were added, respectively, and stirred and dissolved at room temperature (25 ° C.) for 30 minutes to obtain a silica-based film forming polysiloxane solution 90. 0 g was obtained.

(Comparative Example 1)
To 62.85 g of the polysiloxane solution obtained in the synthesis of siloxane resin (c), 26.51 g of propylene glycol methyl ether acetate, 0.19 g of 2.38% tetramethylammonium nitrate aqueous solution (pH 3.6) and 1% maleic 0.45 g of an acid aqueous solution was added and dissolved by stirring at room temperature (25 ° C.) for 30 minutes to obtain 90.0 g of a polysiloxane solution for forming a silica-based film having a solid content concentration of 10%.

(Comparative Example 2)
27.52 g of the polysiloxane solution obtained in the synthesis of siloxane resin (b) was added to 57.43 g of propylene glycol methyl ether acetate, 4.5 g of polypropylene glycol (manufactured by Aldrich, PPG725), 2.38% tetramethylammonium nitrate. 0.09 g of an aqueous solution (pH 3.6) and 0.45 g of a 1% maleic acid aqueous solution were added, respectively, and stirred and dissolved at room temperature (25 ° C.) for 30 minutes to form a polysiloxane solution for forming a silica-based film having a solid content concentration of 10%. 90.0 g was obtained.

(Example 8)
To 49.54 g of the polysiloxane solution obtained in the synthesis of siloxane resin (b), 38.94 g of propylene glycol methyl ether acetate, 0.9 g of hollow SiO ₂ particles with an inner diameter of 150 nm, 2.38% tetramethylammonium nitrate aqueous solution ( pH 3.6) 0.17 g and 1% maleic acid aqueous solution 0.45 g were added, respectively, and stirred and dissolved at room temperature (25 ° C.) for 30 minutes to obtain a silica-based coating-forming polysiloxane solution 90. 0 g was obtained.

Example 9
To 30.3 g of the polysiloxane solution obtained in the synthesis of siloxane resin (d), 19.34 g of propylene glycol methyl ether acetate, 0.11 g of 2.38% tetramethylammonium nitrate aqueous solution (pH 3.6) and 1% malee 0.25 g of an acid aqueous solution was added and dissolved by stirring at room temperature (25 ° C.) for 30 minutes to obtain 50.0 g of a polysiloxane solution which is a composition for forming a silica-based film having a solid content concentration of 10%.

(Example 10)
To the polysiloxane solution 29.9 g obtained in the synthesis of siloxane resin (e), 19.7 g of propylene glycol monopropyl ether, 0.11 g of 2.38% tetramethylammonium nitrate aqueous solution (pH 3.6) and 1% maleic 0.25 g of an acid aqueous solution was added and dissolved by stirring at room temperature (25 ° C.) for 30 minutes to obtain 50.0 g of a polysiloxane solution which is a composition for forming a silica-based film having a solid content concentration of 10%.

(Example 11)
To 31.85 g of the polysiloxane solution obtained in the synthesis of siloxane resin (f), 17.8 g of diethylene glycol dimethyl ether, 0.11 g of 2.38% tetramethylammonium nitrate aqueous solution (pH 3.6) and 1% maleic acid aqueous solution 0 .25 g was added and stirred and dissolved at room temperature (25 ° C.) for 30 minutes to obtain 50.0 g of a polysiloxane solution which is a silica-based film forming composition having a solid content concentration of 10%.

Example 12
5.0 g of a 20% solution obtained by dissolving polymethyl methacrylate (PMMA) in propylene glycol methyl ether acetate in 27.03 g of the polysiloxane solution obtained in the synthesis of siloxane resin (g), and propylene glycol methyl ether acetate 17. 6 g, 0.11 g of 2.38% tetramethylammonium nitrate aqueous solution (pH 3.6) and 0.25 g of 1% maleic acid aqueous solution were added, respectively, and stirred and dissolved at room temperature (25 ° C.) for 30 minutes to obtain a solid content concentration. 50.0 g of a polysiloxane solution which is a 10% silica-based film forming composition was obtained.

(Example 13)
To 34.01 g of the polysiloxane solution obtained in the synthesis of siloxane resin (x), 15.63 g of propylene glycol methyl ether acetate, 0.11 g of a 2.38% tetramethylammonium nitrate aqueous solution (pH 3.6) and 1% maleic 0.25 g of an acid aqueous solution was added and dissolved by stirring at room temperature (25 ° C.) for 30 minutes to obtain 50.0 g of a polysiloxane solution which is a composition for forming a silica-based film having a solid content concentration of 10%.

(Example 14)
To 33.11 g of the polysiloxane solution obtained by the synthesis (i) of the siloxane resin, 16.53 g of propylene glycol methyl ether acetate, 0.11 g of a 2.38% tetramethylammonium nitrate aqueous solution (pH 3.6) and 1% malee 0.25 g of an acid aqueous solution was added and dissolved by stirring at room temperature (25 ° C.) for 30 minutes to obtain 50.0 g of a polysiloxane solution which is a composition for forming a silica-based film having a solid content concentration of 10%.

(Example 15)
To 34.48 g of the polysiloxane solution obtained in the synthesis of siloxane resin (nu), 15.16 g of propylene glycol methyl ether acetate, 0.11 g of 2.38% tetramethylammonium nitrate aqueous solution (pH 3.6) and 1% malee 0.25 g of an acid aqueous solution was added and dissolved by stirring at room temperature (25 ° C.) for 30 minutes to obtain 50.0 g of a polysiloxane solution which is a composition for forming a silica-based film having a solid content concentration of 10%.

(Reference Example 1)
To 17.83 g of monomethyltriethoxysilane, 13.82 g of ethanol and 22.24 g of 1-butanol were added and mixed to obtain a uniform solution. To this solution, 10.8 g of water and 0.49 g of phosphoric acid were further added, followed by stirring at room temperature for 60 minutes. 13.82 g of ethanol, 22.24 g of butanol and 3.3 g of polyethylene glycol were added to the solution after stirring, and stirring was further performed for 10 minutes to obtain a composition for forming a silica-based film.

[Evaluation coating production]
The composition for forming a silica-based film produced according to Examples 1 to 15, Comparative Examples 1 and 2 and Reference Example 1 was adjusted by adjusting the rotation speed so that the film thickness of the silica-based film was 175 ± 10 nm. A coating film was formed by spin coating on a wafer and a slide glass having a thickness of 1 mm. After spin coating, the solvent in the coating film was removed at 250 ° C. for 3 minutes, and the coating film was finally cured in a quartz tube furnace at 350 ° C./30 minutes to produce a silica-based coating (film formation).

[Film evaluation]
The silica-based film formed by the film forming method was evaluated by the following method. The results are shown in Table 1.

[Measurement method of refractive index]
The refractive index of the silica-based coating on the silicon wafer was measured with an ellipsometer.

[Measurement method of density and average pore size]
The density and average pore size of the coating on the silicon wafer were measured by a product name “X-ray diffractometer ATX-G for thin film structure evaluation” manufactured by Rigaku Corporation.

[Measurement method of Young's modulus (elastic modulus)]
About the silica-type film formed on the silicon wafer, the Young's modulus (elastic modulus) which shows film | membrane intensity | strength was measured by the above-mentioned method using nanoindenter SA2 (DCM) made from MTS.

[Evaluation of antireflection film performance]
<Measurement method of reflectance>
For the antireflection film on the obtained slide glass, a black paint was applied to the glass surface opposite to the silica-based film to suppress back surface reflection. The reflectance was measured with a spectrophotometer with an integrating sphere. The reflectance was expressed as a relative ratio when the wavelength was 900 nm and the reflectance of the untreated glass was 1.

<Measurement method of transmittance>
With respect to the antireflection film on the obtained slide glass, the transmittance was measured with a double beam spectrophotometer, with the glass on which the silica-based coating was not formed as the reference side and the glass with the silica-based coating as the sample side. The transmittance was a value with a wavelength of 900 nm. The transmittance was expressed as a relative ratio when the transmittance of the untreated glass was 100%.

[Stability test of coating film]
The film formed on the silicon wafer was left in a clean room controlled at 23 ± 1 ° C. and 45 ± 5% for one week, and then the refractive index of the film on the silicon wafer was measured by an ellipsometer.

[Coating adhesion test]
First, the film formed on the silicon wafer is cross-cut vertically and horizontally with a razor blade, and then peeled off with a tape (trade name “Scotch Tape” manufactured by 3M Company). (Adhesion) was evaluated. In Table 1, the case where no peeling of the film was observed is described as “no peeling”. Moreover, the case where peeling of a film is recognized even partially is described as “peeling”.

  The silica-based film, the composition for forming a silica-based film, the method for forming a silica-based film, and the laminate of the present invention are useful as an antireflection film, for example.

It is a schematic cross section which shows the laminated body which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Transparent substrate, 20 ... Silica-type film, 100 ... Laminated body.

Claims (7)

A silica-based coating for forming on a transparent substrate, having a refractive index of 1.41 or less and a density of 0.8 g / cm ³ or more and 1.5 g / cm ³ or less.   The silica-based film according to claim 1, which is used as an antireflection film. The refractive index value R1 immediately after formation and the refractive index value R2 after standing for 1 week in an air atmosphere at a temperature of 23 ± 1 ° C. and a relative humidity of 45 ± 5% are expressed by the following formula (B1);
R2-R1 <0.1 (B1)
The silica-type coating film of Claim 1 or 2 which satisfies the conditions represented by these. A silica-based film forming composition for forming a silica-based film according to any one of claims 1 to 3,
(A) component: siloxane resin;
(B) component: a solvent capable of dissolving the component (a),
(C) component: a curing accelerating catalyst;
A composition for forming a silica-based film comprising:   (D) Component: The composition for silica-type film formation of Claim 4 which further contains the pyrolysis volatile compound which thermally decomposes or volatilizes at 200-600 degreeC. A method for forming a silica-based film, which forms a silica-based film on a transparent substrate,
Applying the silica-based film forming composition according to claim 4 or 5 on the surface of the transparent substrate to form a coating film;
Removing the solvent contained in the coating film to obtain a dry film;
And a step of firing the dried film.   A laminate comprising: a transparent substrate; and the silica-based coating according to any one of claims 1 to 3, which is formed on a surface of the transparent substrate.

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