KR102276499B1 - Composition for forming silica-based coating film, and method for formation of a silica-based coating film using the same - Google Patents

Abstract

(assignment)
Provided are a composition for forming a silica-based film, which is excellent in compatibility between components, and provides a silica-based film having good transparency, crack resistance, and flatness by firing, and a method for producing a silica-based film using the same.
(Solution)
The composition for forming a silica-based film according to the present invention contains polysiloxane represented by the following general formula (1) and silica having an average particle diameter of 10 to 50 nm. In the formula, R ¹ to R ³ independently represent a methyl group or an ethyl group, and the subscripts p, q and r represent the molar percentage of the subscripted structural units relative to the total structural units in the polysiloxane, respectively, p > 0 mol% , q ≥ 0 mol%, r > 0 mol%, provided that the sum of p, q and r is 100 mol%, and the ^{content of the sum of R 1} to R ³ with respect to the polysiloxane is 10 to 30 mass% to be.

Description

A composition for forming a silica-based film and a method for manufacturing a silica-based film using the same {COMPOSITION FOR FORMING SILICA-BASED COATING FILM, AND METHOD FOR FORMATION OF A SILICA-BASED COATING FILM USING THE SAME}

The present invention relates to a composition for forming a silica-based film and a method for producing a silica-based film using the same.

Conventionally, in manufacture of optical-semiconductor elements, such as a light emitting diode (LED), the transparent sealing agent composition used for sealing, such as an optical-semiconductor element, is known (refer patent document 1). The composition disclosed in Patent Document 1 contains a specific alkoxysilane-modified polysiloxane obtained by dealcoholization of a polysiloxane having silanol groups at both terminals and a partial condensate of tetraalkoxysilane, and a curing catalyst.

International Publication No. 2010/090280

Generally, optical devices, such as an optical semiconductor element, and a solar cell are protected by the silica-type film formed from the composition etc. of patent document 1 mentioned above. This silica-based film is required to have high durability and flatness so that it can be preferably used as a protective film. Moreover, high transparency is also requested|required so that the said silica-based film may transmit sufficient light.

As a method of improving the durability of the silica-based coating film, a method of forming a silica-based coating film by firing a composition for forming a silica-based coating film at a high temperature can be considered. By calcining the composition at a high temperature, impurities in the composition that may cause deterioration of the silica-based film can be removed by burning, so that the durability of the silica-based film can be improved. However, when the composition for forming a silica-based film is fired at a high temperature, there is a problem that cracks are easily generated in the silica-based film. In particular, as the thickness of the silica-based film increases, cracks are more likely to occur. Therefore, the improvement of crack resistance is calculated|required by the silica-type film. In addition, the composition for forming a silica-based film, which forms a silica-based film by firing, is required to have excellent compatibility between components.

The present invention has been made in view of the above problems, and a composition for forming a silica-based film, which is excellent in compatibility between components, and imparts a silica-based film having good transparency, crack resistance, and flatness by firing, and silica using the same An object of the present invention is to provide a method for producing a cinnamon film.

The present inventors discovered that the said subject was solved by combining the specific polysiloxane which has a branched structure, and the silica whose average particle diameter is 10-50 nm, and came to complete this invention. Specifically, the present invention provides the following.

A first aspect of the present invention is a composition for forming a silica-based film comprising a polysiloxane represented by the following general formula (1) and silica having an average particle diameter of 10 to 50 nm.

[Formula 1]

(Wherein, R ¹ to R ³ independently represent a methyl group or an ethyl group, and the subscripts p, q and r represent the molar percentage of the structural units with the subscripts relative to the total structural units in the polysiloxane, respectively, p > 0 mol %, q≥0 mol%, r>0 mol%, provided that the sum of p, q and r is 100 mol%, and the content of the total of ^{R 1} to R ^{3 with respect to the polysiloxane is 10 to 30 mass} % to be)

A second aspect of the present invention is a method for producing a silica-based film, comprising a composition layer forming step of forming a composition layer comprising the composition for forming a silica-based film on a substrate, and a firing step of firing the composition layer.

According to the present invention, there is provided a composition for forming a silica-based film, which provides a silica-based film having excellent compatibility between components and good transparency, crack resistance, and flatness by firing, and a method for producing a silica-based film using the same. can provide

1(A) to 1(D) are schematic cross-sectional views for explaining a method for producing a silica-based coating film according to an embodiment of the present invention.

<Composition for forming a silica-based film>

The composition for forming a silica-based film according to the present invention contains the polysiloxane represented by the general formula (1) and silica having an average particle diameter of 10 to 50 nm. The composition for forming a silica-based film according to the present invention has excellent compatibility between components, and by firing the composition for forming a silica-based film, a silica-based film having good transparency, crack resistance, and flatness can be obtained. The composition for forming a silica-based film according to the present invention can be suitably used for sealing an optical device such as an optical semiconductor element or a solar cell.

[Polysiloxane Represented by General Formula (1)]

The composition for forming a silica-based film according to the present invention contains the polysiloxane represented by the general formula (1). The polysiloxane may be used alone or in combination of two or more.

In the general formula (1), the subscripts p, q and r represent the molar percentage of the structural unit with the subscript relative to the total structural units in the polysiloxane, respectively, p > 0 mol%, q ≥ 0 mol%, and r > 0 mol%, provided that the sum of p, q and r is 100 mol%. It is preferable that p is 40-80 mol%, q is 0-50 mol%, and r is 5-60 mol%. In particular, when q>0, p is 45 to 65 mol%, q is 10 to 45 mol%, and r is more preferably 5 to 35 mol%, p is 50 to 60 mol%, and q is 15 to 40 It is still more preferable that mol% and r are 7-30 mol%. Moreover, when q=0, it is more preferable that p is 40-80 mol%, r is 20-60 mol%, It is still more preferable that p is 45-75 mol%, and r is 25-55 mol%. .

^{The content of the total of R 1} to R ³ with respect to the polysiloxane represented by the general formula (1), that is, the content of the total of the methyl groups and ethyl groups directly bonded to silicon atoms in the polysiloxane with respect to the polysiloxane is 10 to 30 mass% . In general, in a silica-based coating film, an organic group directly bonded to a silicon atom in polysiloxane constituting the silica-based coating film has a function of relieving stress due to shrinkage during firing of the polysiloxane. And the larger the chain length of this organic group or the larger the volume, the greater the stress relaxation function is expected. On the other hand, in the silica-based coating film, the transparency of the carbon-carbon bonding portion in the polysiloxane is lowered by the reaction at high temperature. Then, in the composition for silica-type film formation which concerns on this invention, the organic group couple|bonded with a silicon atom is made into a methyl group and/or an ethyl group, and the content is 10-30 mass %. When the organic group directly bonded to the silicon atom is a methyl group and/or an ethyl group, and the total content of the methyl group and the ethyl group is 30 mass% or less, the carbon-carbon bonding portion in the polysiloxane does not increase too much, so the transparency of the silica-based film is reduced is likely to be suppressed. Moreover, when content of the total of a methyl group and an ethyl group is 10 % or more, generation|occurrence|production of the crack in a silica-type film is easy to be suppressed. The content of the sum of R ¹ ~ R ³ to the polysiloxane represented by the general formula (1) is more preferably 18 to 28% by weight.

In view of the flatness of the silica-based coating film obtained, according to the above general formula (1), q is a number that satisfies ^{q> 0, R 1 ~ R} 3 is preferably a methyl group.

The mass average molecular weight of polysiloxane represented by the said General formula (1) is not specifically limited unless the effect of this invention is impaired, Preferably it is 500-40000, More preferably, it is 1000-20000. When the said mass average molecular weight is 500-40000, compatibility with the said polysiloxane and the silica whose average particle diameter is 10-50 nm becomes more favorable more easily.

In addition, in this specification, a mass average molecular weight means that it is standard polystyrene conversion measured by gel permeation chromatography (GPC).

The polysiloxane represented by the said General formula (1) is hydrolyzed and dehydrated, for example in the presence of an acid catalyst, water, and organic solvent by the alkoxysilanes corresponding to each structural unit to which the subscript p, q, or r is attached. It can be prepared by the method of condensing.

[Silica having an average particle diameter of 10 to 50 nm]

The composition for forming a silica-based film according to the present invention contains silica having an average particle diameter of 10 to 50 nm together with the polysiloxane represented by the general formula (1), thereby providing a silica-based film excellent in crack resistance. The silica may be used alone or in combination of two or more. In addition, the average particle diameter can be measured with a laser diffraction scattering type particle size distribution meter.

As said silica, a conventionally well-known thing can be used. It does not specifically limit as a manufacturing method of the said silica, A conventionally well-known method is employable. Specifically, for example, the silica can be obtained by hydrolysis and dehydration condensation of one or two or more alkoxysilanes in the presence of water, an organic solvent, and a catalyst.

Even if the surface of the said silica is untreated, it may be processed with surface treatment agents, such as a silane coupling agent which has an acryloyl group, a methacryloyl group, etc. When the surface of the silica is untreated, it has a hydroxyl group. On the other hand, when the surface of the silica is treated with a surface treatment agent, it has a functional group such as an acryloyl group or a methacryloyl group depending on the type of the surface treatment agent.

In the composition for forming a silica-based film according to the present invention, the mass ratio of the polysiloxane represented by the general formula (1) to the silica is preferably 80/20 to 35/65, more preferably 80/20 to 50/50 desirable. When the mass ratio is 80/20 to 35/65, the resulting silica-based coating film tends to be excellent in transparency and crack resistance.

[Organic solvent]

The composition for forming a silica-based film according to the present invention may contain an organic solvent. By containing an organic solvent, it becomes easy to adjust the applicability|paintability of the composition for silica-type film formation, and the film thickness of the silica-type film manufactured from the composition for silica-type film formation. Organic solvents can be used individually or in combination of 2 or more types.

Although it does not specifically limit as an organic solvent, For example, Alcohol, such as methanol, ethanol, isopropanol (IPA), and a butanol; Ketones, such as acetone, diethyl ketone, and methyl ethyl ketone; esters such as methyl acetate, ethyl acetate, and butyl acetate; polyhydric alcohols such as propylene glycol, glycerin, and dipropylene glycol; ethers such as dipropylene glycol dimethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol dimethyl ether, and propylene glycol diethyl ether; Monomethyl ether, such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, 3-methoxy-3-methyl-1- butanol (sol pit) ether glycols; Cyclic ethers, such as tetrahydrofuran and a dioxane; and ether-based esters such as propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether acetate, 3-methoxybutyl acetate (MBA), and ethyl diglycol acetate (EDGAC).

The content of the organic solvent is such that the solid content concentration of the composition for forming a silica-based film is preferably 5 to 40 mass%, more preferably 10 to 30 mass%.

[Surfactants]

The composition for forming a silica-based film according to the present invention may contain a surfactant. By containing a surfactant, the applicability|paintability, planarization property, and developability of the composition for silica-type film formation are improved easily, and generation|occurrence|production of the coating unevenness of the composition layer formed after application|coating becomes easy to reduce. As surfactant, a conventionally well-known thing can be used and a silicone type surfactant is preferable. The content of the surfactant is preferably 10 to 10000 mass ppm, more preferably 100 to 10000 mass ppm, and still more preferably 500 to 5000 mass ppm with respect to the entire composition for forming a silica-based film. Surfactant may be used independently and may be used in combination of 2 or more type.

[Other Ingredients]

The composition for forming a silica-based film according to the present invention may contain additives such as known viscosity modifiers as necessary in order to adjust properties such as viscosity of the composition for forming a silica-based film.

<Method for producing a silica-based coating film>

The method for producing a silica-based film according to the present invention includes a composition layer forming step of forming a composition layer comprising the composition for forming a silica-based film according to the present invention on a substrate, and a firing step of firing the composition layer. Hereinafter, with reference to FIG.1(A) - FIG.1(D), the manufacturing method of a silica-based film is demonstrated. 1(A) to 1(D) are schematic cross-sectional views for explaining a method for producing a silica-based coating film according to an embodiment of the present invention.

First, as shown in Fig. 1A, the substrate 2 on which the optical device 1 is mounted is prepared. The optical device 1 is, for example, an LED (light emitting diode), organic EL, or the like. The board|substrate 2 is a back surface side protective layer etc., for example. Further, the substrate 2 may be a surface-side protective layer or the like laminated on the light-receiving surface side or the light-emitting surface side of the optical device 1 . Moreover, a solar cell etc. may be mounted on the board|substrate 2 .

Next, as shown in FIG. 1(B), the composition for forming a silica-based film according to the present invention is applied to the surface of the substrate 2 on the side on which the optical device 1 is mounted, and the composition layer 3 to form The coating method of the composition for forming a silica-based film is not particularly limited, and a known method can be employed. Thereby, the optical device 1 is coated with the composition layer 3 .

Next, as shown in FIG.1(C), the board|substrate 2 on which the composition layer 3 was laminated|stacked is mounted in the heating furnace 4, such as an electric furnace, and the composition layer 3 is baked. do. As a result, as shown in FIG. 1(D), the composition for forming a silica-based film is thermoset, and a silica-based film 5 is formed on the surface of the substrate 2 . The optical device 1 is sealed by a silica-based film 5 . As a calcination temperature, the temperature of 500 degreeC or more is mentioned, for example, The temperature of 580 degreeC or more is preferable. By setting the sintering temperature of the composition for forming a silica-based film to 500° C. or higher, impurities that may cause deterioration of the silica-based film 5 can be effectively burned and removed, so that the durability of the silica-based film 5 is improved. , the silica-based coating film 5 can be preferably used as the protective film.

The silica-based coating film can be manufactured by the above process. The silica-based film produced in this way is excellent in transparency, crack resistance, and flatness.

Example

Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples.

[Examples 1-35 and Comparative Examples 1-15]

(Preparation of a composition for forming a silica-based film)

As shown in Tables 1 to 5, a polymer and silica having a predetermined mass ratio were mixed in a solvent to prepare a composition for forming a silica-based film having a solid content concentration of 18 mass%.

The detail of each component in Tables 1-5 is as follows. In addition, organic group content means content of the methyl group with respect to a polymer, or an ethyl group.

Polymer A: A polymer represented by the following formula (organic group content = 20.6 mass%)

[Formula 2]

(Wherein, the subscripts p1, q1, and r1 represent the molar percentage of the structural unit with the subscript relative to the total structural units in the polymer A, and p1 = 54.5 mol%, q1 = 18.2 mol%, r1 = 27.3 mol% )

Polymer B: A polymer represented by the following formula (organic group content = 16.2 mass%)

[Formula 3]

(Wherein, the subscripts p2 and r2 represent the molar percentage of the structural unit with the subscript relative to the total structural units in the polymer B, p2 = 70 mol%, r2 = 30 mol%)

Polymer C: A polymer represented by the following formula

[Formula 4]

(wherein, the subscript n1 represents the number of repetitions of the structural unit to which the subscript is attached)

Polymer D: A polymer represented by the following formula

[Formula 5]

(Wherein, the subscript n2 represents the number of repetitions of the structural unit to which the subscript is attached.)

Polymer E: Polymer represented by the following formula (organic group content = 27.7 mass%)

[Formula 6]

(Wherein, the subscripts p3, q3, and r3 represent the molar percentage of the structural unit with the subscript relative to the total structural unit in the polymer E, p3 = 54.5 mol%, q3 = 36.4 mol%, r3 = 9.1 mol% )

Polymer F: Polymer represented by the following formula (organic group content = 11.8 mass%)

[Formula 7]

(Wherein, the subscripts p4 and r4 represent the molar percentage of the structural unit with the subscript relative to the total structural units in the polymer F, and p4 = 50 mol%, r4 = 50 mol%)

Polymer G (organic group content = 22.8 mass%)

[Formula 8]

(Wherein, the subscripts p5 and r5 represent the molar percentage of the structural unit with the subscript relative to the total structural units in the polymer G, p5 = 50 mol%, r5 = 50 mol%)

Silica A: Untreated silica (terminal group: hydroxyl group, average particle diameter: 12, 25, or 45 nm)

Silica B: surface-treated silica (terminal group: methacryloyloxy group, average particle diameter: 10, 50, or 100 nm)

Solvent A: 3-methoxybutyl acetate

Solvent B: propylene glycol monomethyl ether acetate

Solvent C: 3-methoxy-3-methyl-1-butanol

Solvent D: isopropanol

Solvent E: ethyl diglycol acetate

(Compatibility evaluation)

The prepared composition for forming a silica-based film was visually observed, and compatibility was evaluated based on the following criteria. A result is shown to Tables 1-5.

Good (double-circle): The composition for forming a silica-based film was transparent, and no precipitate was observed in this composition.

Slightly good (circle): The composition for forming a silica-based film was cloudy, but no precipitate was observed in this composition.

Defect (x): A precipitate was observed in the composition for forming a silica-based film.

(Manufacture of silica-based film)

The prepared composition for forming a silica-based film was applied onto a sample substrate using a spin coater (trade name: Opticoat MS-A150, manufactured by Mikasa Corporation) so that the final film thickness was 0.5 to 5.0 µm. Next, the sample was mounted on the hotplate, and the prebaking process was performed at 80 degreeC for 5 minute(s), then, at 130 degreeC for 5 minute(s). Thereafter, either by calcining in a vertical bake furnace (trade name: TS8000MB, manufactured by Tokyo Oka Kogyo Co., Ltd.) in N ₂ at 500°C for 30 minutes, or in a muffle furnace (trade name: Muffle Furnace FP-41, manufactured by Yamato Science Co., Ltd.) ) to N ₂ of, by firing at 580 ℃ for 10 minutes, and heat cured to obtain a silica-based coating film.

(Evaluation of crack resistance)

For the obtained silica-based coating film, the presence or absence of cracks was confirmed by optical microscopy, and the crack limit film thickness (that is, the maximum film thickness at which a silica-based coating film can be formed without generating cracks) was measured with a surface shape measuring device (brand name). : Dektak 3ST, manufactured by ALVAK) was used. A result is shown to Tables 1-5.

(Evaluation of flatness)

In the crack resistance evaluation, the crack limit film thickness was measured and the surface roughness (Ra) of the silica-based coating film was measured with the above-mentioned surface shape measuring device. A result is shown to Tables 1-5.

(Transparency evaluation)

For the silica-based coating having a crack limit film thickness, the light transmittance was measured. The light transmittance was measured using a spectrophotometer (trade name: MCPD-3000, manufactured by Otsuka Electronics Co., Ltd.). In any wavelength of 400 to 800 nm, the case where the light transmittance was 95% or more was considered good (double-circle), and the case where the light transmittance was less than 95% at any wavelength of 400 to 800 nm was regarded as poor (x). A result is shown to Tables 1-5.

As shown in Tables 1 to 5, the composition for forming a silica-based film according to an embodiment containing polymers A, B, or E to G, which are polysiloxanes represented by the general formula (1), and silica having an average particle diameter of 10 to 50 nm. It was excellent in compatibility with silver components, and also provided the silica-type film with favorable transparency, crack resistance, and flatness by baking. On the other hand, the compositions of Comparative Examples 1 to 4 or 6 to 9 using the polymer C having a phenyl group as an organic group have poor compatibility between components or excellent compatibility between components, but have poor transparency due to firing. An inferior silica-based coating was provided. The silica-based film obtained by calcining the composition of Comparative Example 5 using polymer D had a crack limiting film thickness of 0.5 µm and was inferior in crack resistance. The silica-based film obtained by calcining the composition of Comparative Example 10 in which the mass ratio of the polymer (polysiloxane) to the silica was 100/0 had a crack limiting film thickness of 0.5 µm and was inferior in crack resistance. The composition of Comparative Example 11 in which the mass ratio of polymer (polysiloxane) to silica was 20/80 gave a silica-based coating film having poor transparency by calcination. The composition of Comparative Example 12 in which the mass ratio of polymer (polysiloxane) to silica was 0/100 did not form a film. The silica-based coating films obtained by calcining the compositions of Comparative Examples 13 to 15 using silica having an average particle diameter of 100 nm had an Ra of more than 200 Å and were inferior in flatness.

1: Optical device
2: substrate
3: composition layer
4: heating furnace
5: Silica-based film

Claims (6)

A composition for forming a silica-based transparent encapsulation film comprising a polysiloxane represented by the following general formula (1) and silica having an average particle diameter of 10 to 50 nm, wherein the polysiloxane is The mass ratio is 35 to 80%,
After applying the silica-based transparent encapsulation film-forming composition to a final film thickness of 0.5 to 5.0 μm on a substrate and pre-baking, the fired film obtained under the firing condition 1 and the fired film obtained under the firing condition 2 For each, the composition for forming a silica-based transparent sealing film having a light transmittance of 95% or more at any wavelength of 400 to 800 nm.
Firing conditions 1: Firing in N _{2 at} 500°C for 30 minutes
Firing condition 2: Firing in N _{2 at} 580°C for 10 minutes
[Formula 1]

(Wherein, R ¹ to R ³ independently represent a methyl group or an ethyl group, and the subscripts p, q and r represent the molar percentage of the structural units with the subscripts relative to the total structural units in the polysiloxane, respectively, p > 0 mol %, q>0 mol%, r>0 mol%, provided that the sum of p, q and r is 100 mol%, and the content of the total of ^{R 1} to R ^{3 with respect to the polysiloxane is 10 to 30 mass} % to be) The method of claim 1,
A composition for forming a silica-based transparent sealing film, wherein R ¹ to R ^{3 are a methyl group.} A composition for forming a silica-based film comprising a polysiloxane represented by the following general formula (1) and silica having an average particle diameter of 10 to 50 nm, wherein the mass ratio of the polysiloxane to the total of the polysiloxane and the silica is 35 to 80% A composition for forming a silica-based film.
[Formula 2]

(Wherein, R ¹ to R ³ independently represent a methyl group or an ethyl group, and the subscripts p, q and r represent the molar percentage of the subscripted structural units relative to the total structural units in the polysiloxane, and each p is 40 to 60 mol% (except for 60 mol%), q satisfies 10-50 mol%, r > 0 mol%, provided that the sum of p, q, and r is 100 mol%, with respect to the polysiloxane The total content of R ¹ to R ³ is 10 to 30 mass%) 4. The method of claim 3,
A composition for forming a silica-based film, wherein R ¹ to R ^{3 are a methyl group.} A composition layer forming step of forming a composition layer comprising the composition for forming a silica-based transparent sealing film according to claim 1 or 2 on a substrate;
A method for producing a silica-based coating film, comprising a firing step of firing the composition layer. A composition layer forming step of forming a composition layer comprising the composition for forming a silica-based film according to claim 3 or 4 on a substrate;
A method for producing a silica-based coating film, comprising a firing step of firing the composition layer.

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