CN102399372B - Method for forming curing laminated film of siloxane resin compound - Google Patents

Abstract

The present invention relates to a method for forming a cured film of a silicone resin composition. Using a silicone resin composition, it has excellent transparency, high scratch hardness, high insulation, low dielectric constant, and excellent flatness. There is no film reduction during firing, and no cracks will occur even if it is formed into a thick film. There is no peeling of the film at the substrate interface and a fired cured film with excellent adhesion. Coating the siloxane resin composition containing silanol group or alkoxysilyl group on the substrate, pre-baking, treating with alkaline aqueous solution, rinsing and firing to form silanol group-containing or alkoxysilyl-based siloxane resin composition firing cured film.

Description

Method for forming cured film of silicone resin composition

technical field

The invention relates to a method for forming a cured film of a silicone resin composition containing a silanol group or an alkoxysilyl group, and more particularly relates to a method for forming a silicone resin composition containing a silanol group or an alkoxysilyl group. A method of curing a film of an oxane resin composition, the cured film is excellent in transparency, has high scratch hardness, high insulation, low dielectric constant and excellent flatness, and does not generate cracks even when a thick film is formed , and there is no peeling of the film on the substrate interface, and the adhesion is excellent.

Background technique

Silicone resins are known as materials with high heat resistance, high hardness, high insulation, and high transparency, and are used in various applications. As one of these applications, a coating containing a silicone resin is cured (hereinafter, sometimes referred to as "fire-cured") coating, which has excellent insulation due to durability and low dielectric properties, and has high Using these properties, hardness is used as an insulating film, planarizing film, protective film, semiconductor sealing material, etc. in semiconductor elements and liquid crystal display elements. In addition, due to its high transparency, it is not only used in the field of such electronic materials, but also used as a surface protection film for optical parts and vehicles.

When forming a cured film using a silicone resin composition using a silicone resin as a binder, known methods include preparing a composition containing a polyfunctional polysiloxane, applying the composition, and drying with heat, etc. This is cured to form a coating (see Patent Document 1). The polyfunctional polysiloxane composition has an alkoxy group or a hydroxyl group. At this time, as a curing agent (also called a "catalyst"), an acidic compound or a basic compound, a metal alkoxide, a metal chelate compound, etc. are used, but when the viscosity of the polyfunctional polysiloxane is high or the solid content concentration is high When adding the above-mentioned curing agent to the polyfunctional polysiloxane, the problem of immediate thickening or gelling will occur. In addition, even if it does not thicken or gel immediately after addition, thickening will occur during storage, and if the catalyst is weakly acidic, there will also be a problem of difficulty in curing. In addition, when such a material is used to form a cured film, the coating film must be processed at high temperature, and there is also a problem that the amount of film loss at this time is large.

In order to solve such a problem, it has also been proposed to use an acidic compound and a basic compound having a different boiling point from the acidic compound as a curing agent (see Patent Document 2). This composition does not cure immediately even if a curing agent containing an acidic compound and a basic compound having a different boiling point from the acidic compound is added to the polyfunctional polysiloxane having a plurality of alkoxy groups and/or hydroxyl groups , In addition, when the boiling points of the acidic compound and the basic compound are different, by heating the polysiloxane compound at a temperature between these boiling points, the acidic compound or the basic compound acts as a curing agent, which is excellent in storage stability. The siloxane composition can be condensed at low temperature to achieve curing of the film, but since the curing agent is used, there are problems that cracks are easy to occur and the decrease in stability over time cannot be sufficiently suppressed.

In addition, silanol-based curable silicone resins can cure coating films at low temperatures and have high hardness properties. Furthermore, in addition to these, silanol-based curable silicone resins have attracted attention due to the high transparency of the coating film, and properties such as high heat resistance, low dielectric properties, and insulating properties. In particular, among the four bonds of the silicon atom, silsesquioxane in which one carbon atom is connected to three oxygen atoms, and a silicone resin in which all four bonds of the silicon atom are connected to oxygen atoms, due to the formation of Strong three-dimensional cross-linking shows the above-mentioned properties more significantly, so it is particularly expected to be used as a coating agent on a plastic substrate for a flexible display and a barrier film or a planarizing agent on a thin-film transistor (hereinafter also referred to as TFT), but If the cured film is formed at 250°C or higher, especially the electrical properties of TFT will decrease, so curing must be performed at less than 250°C. So far, it has been disclosed that a coating solution for forming a silica-based coating containing an alkoxysilane hydrolyzate and a silicone-based surfactant is heat-treated at a temperature of 250 to 500°C to form a silica-based coating. method (refer to Patent Document 3). According to this method, although a film with excellent adhesion is formed without impairing the properties of flatness and crack boundaries, it must be cured at a high temperature of 250°C or higher, or an organic Silicone surfactants also have the problem that only materials with a large weight average molecular weight (Mw) can be selected when forming a thick film. On the other hand, if it is a thin film, the Mw may be small, but the sublimation during firing increases, the amount of film loss increases, and the range of Mw that does not sublimate during curing is narrow, so it cannot be used for practical use.

The thicker the three-dimensional siloxane resin film is formed or exposed to higher temperatures (even if it is less than 250°C), the more the stress increases when the film returns to normal temperature, and the more prone to cracks. In order to make the cured coating of the silicone resin less prone to cracking, it is possible to use a silicone resin in which 2 of the 4 linkages of silicon atoms are linked to carbon atoms and 2 to be linked to oxygen atoms, or to add methods of organic resins (for example, acrylic resins), but these methods tend to hinder the above-mentioned film properties. In addition, if a silicone resin is added separately or added to the polymer repeating unit of the silicone resin, since the sublimation property is also improved while the fluidity is improved, there is a risk of polluting the oven during film formation, forming wrinkles according to the flow trace, or There is a problem that the film hardness after curing becomes low.

[Prior art literature]

[Patent Document]

[Patent Document 1] Japanese Unexamined Patent Publication No. 2004-99879

[Patent Document 2] Japanese Unexamined Patent Publication No. 2008-208200

[Patent Document 3] Japanese Invention Patent Publication No. 4079383

Contents of the invention

The object of the present invention is to provide a method for forming a cured film of a silicone resin composition that does not have the above-mentioned conventional problems, that is, when forming a cured film of a silicone resin in a semiconductor element or a liquid crystal element, the temperature is lower than 250°C. Or fired at a temperature exceeding 250°C, it can also form excellent transparency, high scratch hardness, high insulation, low dielectric constant, no film reduction and excellent flatness, and no cracks will occur even if a thick film is formed, and A coating with excellent adhesion without film peeling at the substrate interface.

After serious research, the present inventors found that after coating the silicone resin composition containing silanol groups or alkoxysilyl groups on the substrate, pre-baking is performed, and the pre-baked film is treated with an alkaline aqueous solution. , firing and curing, so that firing at a temperature below 250 ° C or even exceeding 250 ° C, and regardless of the thickness of the film, can form excellent transparency, high scratch hardness, high insulation, low dielectric constant, The present invention was accomplished based on the knowledge that a cured film with excellent adhesion does not generate cracks even when a thick film is applied.

That is, the present invention relates to a method for forming a cured film of a silicone resin composition by using a silicone resin composition containing a silanol group or an alkoxysilyl group at least through a silanol group or an alkoxysilyl group. A method for forming a cured film of a silicone resin composition formed by polymerizing and curing an alkoxysilyl group, which is characterized in that the composition is applied to a base material and prebaked, After treatment with alkaline aqueous solution, rinse and fire.

In addition, the present invention is characterized in that in the above method, the treatment of the alkaline aqueous solution is performed by immersing in the alkaline aqueous solution, or by spin-drying or immersion (padol) or showering.

In addition, the present invention is characterized in that in the above method, the alkaline aqueous solution is an aqueous tetramethylammonium hydroxide solution.

In addition, the present invention is characterized in that, in the above method, the firing is performed at a temperature of 120 to 400°C.

In the present invention, a resin containing a silanol group or an alkoxysilyl group is used as the silicone resin. In addition, after coating the silicone resin composition containing a silanol group or an alkoxysilyl group, Pre-baking of the coating film, the pre-baking film is treated with an alkaline aqueous solution, so that it is not affected by the subsequent firing temperature and film thickness, and has excellent transparency, high scratch hardness, high insulation, and low dielectric Constant, and there is no film reduction, even when thick film is coated, there is no crack, and the cured film is excellent in adhesion. Therefore, it is preferably used for forming an insulating film or a planarizing film, a protective film, an optical component, a surface protective film of a car, and the like in a semiconductor element and a liquid crystal display element.

Detailed ways

Hereinafter, the method for forming a cured film of the silanol group- or alkoxysilyl group-containing silicone resin composition of the present invention will be described in more detail.

As described above, the method for forming a cured film of a siloxane resin composition containing a silanol group or an alkoxysilyl group according to the present invention is characterized by coating a substrate containing a silanol group or an alkoxysilyl group. Based on the silicone resin composition, after pre-baking treatment, after treatment with an alkaline aqueous solution, rinse and fire the film, for the materials used in the method for forming a cured film of the silicone resin composition of the present invention, The method will be described in detail sequentially as follows.

(i) Silicone resin composition containing silanol group or alkoxysilyl group

First, it is a siloxane resin composition containing a silanol group or an alkoxysilyl group for forming the cured film of the present invention, which is composed of (a) a silanol group or an alkoxysilyl group It consists of a silicone resin, (b) organic solvent, and (c) additives used as needed.

(a) Silicone resin containing silanol group or alkoxysilyl group

As the siloxane resin containing silanol group or alkoxysilyl group used in the present invention, it can be any currently known silicone resin containing silanol group and/or alkoxysilyl group as reactive groups. The structure of the oxane resin, polysiloxane is not particularly limited. Examples of typical silanol group- or alkoxysilyl-containing siloxane resins that can be used in the present invention include alkoxysilanes represented by the following general formula (1). One or more siloxane resins (polysiloxanes) obtained by hydrolysis in an organic solvent.

(R ¹ ) _n Si(OR ² ) _4-n (1)

(In the formula, ^R1 represents a hydrogen atom, an alkyl group with 1 to 6 carbon atoms that may have a substituent, a cycloalkyl group with 3 to 6 carbon atoms, and a carbon atom at the α position with 15 or less carbon atoms An aralkyl group not connected to a hydrogen atom, an aryl group with 6 to 15 carbon atoms, or an alkenyl group with 1 to 6 carbon atoms, ^R2 represents an alkyl group with 1 to 6 carbon atoms that may have a substituent, n is an integer of 0 to 3).

In the above-mentioned general formula, the alkyl group having 1 to 6 carbon atoms that may have a substituent as ^R1 can include, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-hexyl, n-decyl, trifluoromethyl, 2,2,2-trifluoroethyl, 3,3,3-trifluoropropyl, 3-hydroxypropyl, 3-glycidyloxypropyl, 2 -(3,4-epoxycyclohexyl)ethyl, 3-aminopropyl, 3-mercaptopropyl, 3-isocyanatopropyl, 4-hydroxy-5-(p-hydroxyphenylacyloxy)pentyl wait. In addition, examples of a cycloalkyl group having 3 to 6 carbon atoms that may have a substituent include cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl; the carbon atom at the α-position that may have a substituent The aralkyl group having 15 or less carbon atoms that is not bonded to a hydrogen atom includes phenylisopropyl group, etc.; the aryl group that may have a substituent includes phenyl, tolyl, p-hydroxyphenyl, Naphthyl, etc.; examples of alkenyl groups having 1 to 6 carbon atoms that may have substituents include vinyl, allyl, 3-acryloyloxypropyl, and 3-methacryloyloxypropyl wait.

On the other hand, the alkyl group having 1 to 6 carbon atoms that may have a substituent as ^R2 can be exemplified the same group as the alkyl group that may have a substituent for ^R1 , and preferably has no substituent An alkyl group with 1 to 4 carbon atoms.

As specific examples of the alkoxysilane compound represented by the general formula (1), the following compounds can be illustrated.

(1) Tetraalkoxysilane: tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, etc.,

(2) Monoalkyltrialkoxysilane: Monomethyltrimethoxysilane, Monomethyltriethoxysilane, Monoethyltrimethoxysilane, Monoethyltriethoxysilane, Monopropyltrimethoxysilane Oxysilane, Monopropyltriethoxysilane, etc.,

(3) Monoaryltrialkoxysilane: monophenyltrimethoxysilane, monophenyltriethoxysilane, mononaphthyltrimethoxysilane, etc.,

(4) Trialkoxysilane: Trimethoxysilane, Triethoxysilane, Tripropoxysilane, Tributoxysilane, etc.,

(5) Dialkyldialkoxysilane: dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, dipropylene dimethoxysilane, dipropyldiethoxysilane, etc.,

(6) Diphenyldialkoxysilane: diphenyldimethoxysilane, diphenyldiethoxysilane, etc.,

(7) Alkylphenyldialkoxysilane: methylphenyldimethoxysilane, methylphenyldiethoxysilane, ethylphenyldimethoxysilane, ethylphenyldiethoxysilane base silane, propylphenyldimethoxysilane, propylphenyldiethoxysilane, etc.,

(8) Trialkylalkoxysilane: trimethylmethoxysilane, tri-n-butylethoxysilane, and the like.

Preferred compounds among them are tetramethoxysilane, tetraethoxysilane, monomethyltrimethoxysilane, monomethyltriethoxysilane, mononaphthyltrimethoxysilane, monophenyltrimethoxy silane.

The siloxane resin containing a silanol group or an alkoxysilyl group used in the present invention is preferably a siloxane resin whose reactive group consists only of a silanol group or consists of a silanol group or an alkoxysilyl group. (polysiloxane). That is, the silicone resin may contain an alkoxysilyl group that has not reacted when the silicone resin is synthesized. The silanol group-containing siloxane resin whose reactive group consists of only silanol groups or silanol groups and alkoxysilyl groups can use the alkoxysilane represented by the aforementioned general formula (1). One or more than two kinds of manufacture. In addition, as the siloxane resin containing a silanol group or an alkoxysilyl group used in the present invention, if necessary, as the alkoxysilane, an alkoxysilane that does not contain a reactive group such as a hydroxyl group among the aforementioned R ¹ and R ² can be used. A mixture of one or two or more alkoxysilanes and one or more alkoxysilanes with reactive groups such as hydroxyl groups in ^R1 and/or ^R2 , using the siloxane resin obtained by hydrolyzing and condensing them . In addition, in the present invention, as a raw material alkoxysilane, an alkoxysilane in which n is 0 or 1 in the above-mentioned general formula (1) is preferred, and at this time, an alkoxysilane in which n is 2 or 3 can be further used as needed. .

The molecular weight is preferably a weight average molecular weight (Mw) of 400 to 20,000, more preferably 400 to 10,000. When the weight-average molecular weight is less than 400, it may volatilize together with the solvent during prebaking, and when it exceeds 20,000, hardening becomes difficult.

The hydrolytic condensation reaction of alkoxysilane is usually carried out in an organic solvent. The solvent component of the alkoxysilane solution is not particularly limited as long as it is an organic solvent capable of dissolving or dispersing the formed resin. As such a solvent, well-known organic solvents can be suitably used, and for example, monohydric alcohols such as methanol, ethanol, propanol, butanol, isobutanol, and isoamyl alcohol; ethylene glycol, diethylene glycol, propylene glycol, propane Triol, trimethylolpropane, hexanetriol and other polyols; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, di Ethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropylene Monoethers of polyhydric alcohols such as base ether, propylene glycol monobutyl ether, 3-methyl-3-methoxybutanol, and their acetates; esters such as methyl acetate, ethyl acetate, and butyl acetate; Acetone, methyl ethyl ketone, methyl isoamyl ketone and other ketones; ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dipropyl ether, ethylene glycol dibutyl ether, Hydroxyl group of polyols such as propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, etc. All alkyl etherified polyol ethers, etc. The solvent used for the reaction of the alkoxysilane can also generally be used as a solvent for the siloxane resin composition coated on the base material later.

The organic solvent is preferably a liquid having a boiling point of 100 to 300° C., and preferably a liquid having at least one hydroxyl group and/or an ether bond in the molecule, or an acetate having at least one ether bond in the molecule. These organic solvents may be used alone or in combination of two or more. In addition, when forming a cured film of silicone resin on a flat panel display or the like, ethers of polyhydric alcohols such as propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), etc. are generally used. Ether esters of polyols. Therefore, when using a silicone resin composition in this field, it is preferable to use ethers and ether esters of polyols such as PGME or PGMEA. Moreover, 3-methyl-3-methoxybutanol, 3-methyl-3-methoxybutyl acetate, etc. are also mentioned as a preferable solvent. The organic solvent is usually used in a ratio of 10 to 30 molar times with respect to 1 mol of alkoxysilane.

The hydrolysis condensation reaction of alkoxysilane can proceed to some extent even without a catalyst, but it is preferable to use a catalyst in order to impart coatability and storage stability. As the catalyst, any conventionally known catalyst can be used, but it is preferable to use an acid catalyst in view of the stability of the resin. As the acid catalyst, either organic acid or inorganic acid can be used. Examples of the organic acid include organic carboxylic acids such as acetic acid, propionic acid, and butyric acid. Examples of the inorganic acid include inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid. The acid catalyst may be added after adding water to the solution, or may be mixed with water and added as an aqueous acid solution. The addition amount of an acid catalyst can be selected suitably. The hydrolysis reaction is usually completed in about 5 to 100 hours, and it can also be heated at a temperature not exceeding 60 to 70 ° C, and the acid catalyst aqueous solution is added dropwise in an organic solvent containing an alkoxysilane compound to react. complete the reaction within.

The degree of hydrolysis can be adjusted according to the amount of water added in the presence of a catalyst. Generally, water is desirably reacted in a ratio of 20 to 1000 mol%, preferably 50 to 500 mol%, based on the total number of moles of alkoxy groups in the alkoxysilane compound represented by the general formula (1). If the amount of water added is less than the above range, the degree of hydrolysis will be low, making it difficult to form a film, so it is not suitable. On the other hand, if it is too large, gelation will easily occur, so it is not suitable.

In addition, as other representative silanol group-containing or alkoxysilyl siloxane resins, those obtained by hydrolyzing one or more halosilanes represented by the following general formula (2) in an organic solvent can be mentioned. Silicone resin (polysiloxane).

(R ¹ ) _n Si X _4-n (2)

(In the formula, ^R1 represents a hydrogen atom, an alkyl group with 1 to 6 carbon atoms that may have a substituent, a cycloalkyl group with 3 to 6 carbon atoms, and a carbon atom at the α position with 15 or less carbon atoms An aralkyl group not connected to a hydrogen atom, an aryl group with 6 to 15 carbon atoms, or an alkenyl group with 1 to 6 carbon atoms, X represents a halogen atom, and n is an integer of 0 to 3).

In addition, as R ¹ in the general formula (2), the same group as the group represented by R ¹ in the above general formula (1) can be cited as a preferable group. In addition, examples of X include a chlorine atom, a bromine atom, and an iodine atom. In addition, n is preferably 0 to 1 similarly to the above general formula (1), so this can be used together with a halosilane compound in which n is 2 or 3 as needed. By using such a halosilane compound, a silanol group-containing siloxane resin can be produced by the same method as when using such an alkoxysilane represented by the general formula (1). For example, in a trihalosilane compound, a part of the chlorosilyl groups undergoes hydrolysis and condensation reaction to form Si—O—Si bonds, and the rest are hydrolyzed to turn the chlorosilyl groups into silanol groups. The content of silanol groups in the formed siloxane resin can be adjusted by controlling the type, amount, reaction conditions, and the like of the halosilane compound used. When a halosilane compound is used, all the reactive groups of the obtained silanol group-containing siloxane resin form silanol groups.

(b) Organic solvents

In the silanol group- or alkoxysilyl group-containing silicone resin composition of the present invention, an organic solvent for dissolving or dispersing the silanol group- or alkoxysilyl group-containing silicone resin is used. As an organic solvent, the same thing as the organic solvent used when performing the hydrolysis condensation reaction of the said alkoxysilane can be used. As mentioned above, as the organic solvent of the siloxane resin composition containing silanol group or alkoxysilyl group of the present invention, the solvent during the hydrolysis and condensation reaction of alkoxysilane can be directly used as a solvent containing silanol The organic solvent utilization of the siloxane resin composition of base or alkoxysilyl group, or can further add other solvents therein, or separate solvent from the siloxane resin obtained by reaction, the siloxane without solvent The resin is dissolved or dispersed in a new solvent, etc., and used as a composition. As mentioned above, since ether esters such as PGMEA and ethers such as PGME are used for general flat panel displays, it is preferable to use ethers such as PGME or PGMEA or ether esters when using silicone resin compositions in this field. solvent. Moreover, 3-methyl-3-methoxybutanol, 3-methyl-3-methoxybutyl acetate, etc. are mentioned as a preferable solvent.

(c) Additives

As an additive, surfactant, a thickener, etc. are mentioned, for example. Surfactants are used to improve coating properties, wettability to substrates, and the like of silanol group- or alkoxysilyl group-containing silicone resin compositions. As surfactants, known nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, etc., anionic, cationic surfactants, and amphoteric surfactants act as catalysts to promote silicon Since the oxane resin composition deteriorates over time, nonionic surfactants are preferable. Examples of nonionic surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, polyoxyethylene cetyl ether, and polyoxyethylene fatty acid diesters. , polyoxy fatty acid monoester, polyoxyethylene polyoxypropylene block copolymer, acetylene alcohol, acetylene glycol, polyethoxylate of acetylene alcohol, polyethoxylate of acetylene glycol and other acetylenic alcohol derivatives, containing Fluorosurfactants, for example, Florad (trade name, manufactured by Sumitomo 3M Co., Ltd.), Megafac (trade name, manufactured by DIC Corporation), Sulflon (trade name, manufactured by Asahi Glass Co., Ltd.), or organic Silicone surfactants, such as KF-53, KF-54 (both are manufactured by Shin-Etsu Chemical Co., Ltd.), SH7PA, SH21PA, SH28PA, SH30PA, ST94PA (all are manufactured by Toray Dou Corning (KK) )wait. Examples of the acetylenic alcohol include 3-methyl-1-butyn-3-ol, 3-methyl-1-pentyn-3-ol, 3,6-dimethyl-4-octyne-3 , 6-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,5-dimethyl-1-hexyn-3-ol, 2,5 - Dimethyl-3-hexyne-2,5-diol, 2,5-dimethyl-2,5-hexanediol and the like.

The content of the siloxane resin containing a silanol group or an alkoxysilyl group in the silicone resin composition containing a silanol group or an alkoxysilyl group is preferably 1 to 100 parts by weight of the solvent. 40 parts by weight. If it exceeds 40 parts by weight, the time-dependent deterioration rate of the resin will be accelerated, which is not preferable.

Moreover, content of surfactant is 50 ppm - 100,000 ppm in a composition, Preferably it is the range of 100 ppm - 50,000 ppm. If it is too small, it will be difficult to obtain surface activity and wettability will be poor; if it is too large, severe foaming will occur, and foam accumulation will occur on the coater, making handling difficult.

(ii) coating

The siloxane resin composition containing silanol group or alkoxysilyl group is coated on the substrate to form a siloxane resin coating film containing silanol group or alkoxysilyl group. The base material is not particularly limited, and various substrates such as a silicon substrate, a glass plate, a metal plate, and a ceramic plate can be cited. In particular, the TFT surface of a liquid crystal display that requires an insulating film is a preferred substrate of the present invention. . The coating method is not particularly limited, and various methods such as spin coating, dip coating, blade coating, roll coating, spray coating, and slit coating can be used. In addition, the concentration of the silanol group- or alkoxysilyl-containing silicone resin in the coating solution depends on the type of silanol-group- or alkoxysilyl-containing silicone resin used (for example, R ¹ type, difference in molecular weight, etc.), coating method, desired coating film thickness, etc., are not particularly limited and can be selected arbitrarily.

(iii) Pre-baking

The silanol group- or alkoxysilyl group-containing siloxane resin composition film thus formed on the substrate is then prebaked to remove the organic solvent in the composition. The prebaking temperature varies depending on the type of organic solvent used in the composition, but if the temperature is too low, the residual components of the organic solvent will increase, which may cause damage to substrate conveying equipment, etc.; on the other hand, if the temperature is too high, If it dries rapidly, it will cause foggy spots, or the siloxane resin containing silanol group or alkoxysilyl group may sublime, so it is preferably 60-200°C, more preferably 70-180°C. The prebaking is performed, for example, using a heating device such as a hot plate or an oven. The prebaking time varies depending on the type of organic solvent used and the prebaking temperature, but is preferably 30 seconds to 10 minutes, more preferably 1 to 5 minutes.

(iv) Alkaline aqueous solution treatment

After pre-baking, the coating is treated with an alkaline aqueous solution. The alkaline aqueous treatment is not particularly limited, and can be performed by general methods such as immersion (immersion) in an alkaline aqueous solution, spin immersion, showering, slit coating, cap coating, and spraying. When the composition contains a surfactant, it is preferably performed by immersion (dipping). In addition, even if a surfactant is contained, water immersion treatment may be performed, or other methods such as spin-dip coating may be used.

The base may be an inorganic base or an organic base. Examples of the inorganic base include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal metasilicates (hydrates), alkali metal phosphates (hydrates), and the like, preferably sodium hydroxide and hydroxide Alkali metal hydroxides such as potassium.

Moreover, examples of organic bases include quaternary ammonium compounds, amino alcohols (alkanolamines), ammonia water, alkylamines, heterocyclic amines, and the like. Examples of the quaternary ammonium compound include tetramethylammonium hydroxide (tetramethylammonium hydroxide, hereinafter also referred to as "TMAH"), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, trimethylammonium hydroxide Trimethyl(2-hydroxyethyl)ammonium hydroxide (choline), triethyl(2-hydroxyethyl)ammonium hydroxide, tripropyl(2-hydroxyethyl)ammonium hydroxide , trimethyl(2-hydroxypropyl)ammonium hydroxide as a preferred substance. Among them, TMAH and choline are particularly preferred.

Examples of amino alcohols (alkanolamines) include monoethanolamines such as 2-ethanolamine and 2-aminoethanolamine, diethanolamine, triethanolamine, monopropanolamine, dipropanolamine, tripropanolamine, monoiso Propanolamine, Diisopropanolamine, Triisopropanolamine, Monobutanolamine, Dibutanolamine, Neopentanolamine, N,N-Dimethylethanolamine, N,N-Diethylethanolamine, N , N-dimethylpropanolamine, N, N-diethylpropanolamine, N-(β-aminoethyl)ethanolamine, N-methylethanolamine, N-methyldiethanolamine, N-n-butyl Ethanolamine, N-tert-butylethanolamine, N-tert-butyldiethanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, N,N-di-n-butylethanolamine, N-ethylethanolamine Among them, ethanolamines are preferably used, and monoethanolamine is particularly preferable.

However, the treatment with an aqueous TMAH solution is preferable in view of the route of acquisition and the convenience of biotoxicity or gasification if solidified.

In the present invention, the concentration of the alkaline aqueous solution used in the alkaline aqueous treatment depends on various factors such as the type and concentration of the alkali used, the type of silanol group or silyl group-containing siloxane resin to be treated, and the film thickness. And the change is not particularly limited. Since the silanol group- or silyl group-containing siloxane resin may be dissolved when the alkali concentration is high, it is preferable to use an alkaline aqueous solution at a concentration where it does not dissolve. In general, when the ratio of silanol groups is increased relative to the molecular weight of a silanol group- or silyl-group-containing siloxane resin, it becomes easier to dissolve in an alkaline aqueous solution. In addition, the solubility varies depending on the type of alkali. Generally, the alkali concentration range of the alkaline aqueous solution is preferably 0.1 to 10%, more preferably 0.1 to 7.5%, and still more preferably 0.1 to 5%. In addition, as mentioned above, when the proportion of silanol groups is high relative to the molecular weight of silanol group or silyl group-containing siloxane resin, since the resin dissolves in an alkaline aqueous solution, it is preferable depending on the strength of the alkali. Reduce the concentration of the alkaline aqueous solution. In addition, the film reduction by alkaline aqueous solution treatment is preferably 10% or less. If it exceeds 10%, the difference in the amount of dissolution in the film will increase and unevenness will occur, so it is not suitable.

The treatment time also varies greatly depending on the type of alkali used, the alkali concentration of the alkaline aqueous solution, the type of silanol group or silyl group-containing siloxane resin to be treated, and the film thickness, etc., and is not particularly limited. The treatment time is preferably about 15 seconds to 3 minutes. If the processing time is short, the process may be uneven, and if it is long, the efficiency will be poor. In addition, the treatment was performed at normal temperature.

In the present invention, by alkali treatment, as mentioned above, it can be formed regardless of the thickness of the coating film. Excellent transparency, high scratch hardness, high insulation, low dielectric constant, and no film reduction, even after coating Even when it is a thick film, no cracks occur, and the cured film has excellent adhesion. One of the reasons for this may be that the alkoxysilyl group remaining in the film becomes a silanol group, and there is no sufficiently polymerized compound to polymerize, and the molecular weight increases. Compounds with large and small molecular weights disappear, thereby reducing the amount of sublimation of compounds in the coating film caused by heating during firing and curing, thereby reducing the amount of film reduction of the cured film, but the present invention is not limited thereto.

In addition, inorganic alkaline aqueous solutions can also be used in hard coatings and other applications where there is no problem with electrical properties and semiconductor properties, but because the aqueous solution contains metal ions such as sodium and potassium, it is not suitable for interlayer insulating films of TFTs and It is used in applications where electrical properties and semiconductor properties must be taken into consideration, such as a planarizing film.

(v) Washing treatment

The rinsing treatment is performed by rinsing away the residual alkaline aqueous solution on the coating surface treated with the alkaline aqueous solution with water. Therefore, any method may be used as long as it is an alkaline aqueous solution for rinsing the coating surface. For example, an appropriate method known as a conventional rinsing method, such as immersing the film in water, flowing water over the film surface, and rinsing with water, can be used. The rinsing time is not particularly limited as long as the alkaline aqueous solution on the coating can be removed, for example, it can be performed for about 30 seconds to 5 minutes when dipping, and about 15 seconds to 3 minutes for running water. In addition, ion-exchanged water or pure water is preferable for applications requiring electrical properties or semiconducting properties as the water used in the rinsing treatment. In addition, in rinsing by immersion, water washing may be changed and immersion rinsing may be performed several times.

(vi) Firing (curing) treatment

Firing treatment is preferably under an inert atmosphere such as nitrogen, helium, argon or in air, using a heating device such as a hot plate or an oven, at a temperature of 120 to 400°C for 15 minutes to 3 hours, more preferably at 150 Perform at ~350°C for 30 minutes to 2 hours. It is better to reduce the film thickness reduction during firing as little as possible. Generally, the film thickness reduction rate before and after firing is 7.5% or less, preferably 5% or less, more preferably 3% or less. If the firing film thickness reduction rate is about 7.5%, the unevenness of the film becomes large, and the compound derived from the film is much sublimated during firing, so there is a problem that the sublimated compound contaminates the machine.

The film thickness after curing varies depending on the application and is not particularly limited, but may be 20 μm or less, preferably 15 μm or less. Furthermore, in order to form such a cured film thickness, the concentration of the silicone resin in the silanol group- or alkoxysilyl group-containing silicone resin composition and the coating amount of the composition must be determined. If the film thickness is too thick, layer separation may occur between the resins in the film during curing (curing), so it is not suitable.

The siloxane resin fired coating containing silanol group or alkoxysilyl group formed in this way has almost no film loss caused by firing, excellent transparency, high scratch hardness, high insulation, and low dielectric constant , In addition, the planarity is excellent, even if a thick film is formed, there is no crack, and there is no film peeling at the substrate interface, and the adhesion is excellent.

[Example]

Hereinafter, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited to these Examples and a comparative example at all.

Manufacturing example 1

47.6g (0.35mol) methyltrimethoxysilane, 29.7g (0.15mol) phenyltrimethoxysilane, 4.83g (0.015mol) 3,3',4,4'-benzophenone tetracarboxylic acid The dianhydride was dissolved in 200 g of 3-methyl-3-methoxybutanol, and 34.2 g of distilled water was added with stirring at 45° C., followed by heating and stirring for 1 hour to perform hydrolysis and condensation. Thereafter, it was washed with water five or more times, and the ethyl acetate oil layer was recovered. Next, the ethyl acetate oil layer was concentrated and replaced with propylene glycol monomethyl ether acetate to obtain a 40% solution of a polycondensate of methylphenylsilsesquioxane.

The obtained siloxane resin was methylphenylsilsesquioxane (methyl:phenyl=7:3 molar ratio) having a weight average molecular weight (Mw) of 1,000.

The measurement of the weight average molecular weight (Mw) was performed using the following apparatus and conditions (for example, in the following examples, it measured also under the same conditions).

Apparatus and method of use: HPLC (GPC system) manufactured by Shimadzu Corporation

Column: GPC column (G2000HXL 1 piece, G4000HXL 1 piece) manufactured by Tosohichi Co., Ltd.

Using the above-mentioned apparatus, measurement was performed by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard under the analysis conditions of a flow rate of 0.7 ml/min, an elution solvent tetrahydrofuran, and a column temperature of 40°C.

Manufacturing example 2

In Production Example 1, except that the reaction temperature was changed from 45°C to 60°C, the same method as in Production Example 1 was carried out, thereby obtaining methylphenylsilsesquioxane (methylphenylsilsesquioxane) with a weight average molecular weight (Mw) of 2,000. base: phenyl = 7:3 molar ratio).

Manufacturing example 3

In Production Example 1, except that the reaction temperature was changed from 45°C to 60°C, and the reaction time was changed from 1 hour to 6 hours, the same method as in Production Example 1 was carried out, thereby obtaining formazan with a weight average molecular weight (Mw) of 4,000. phenyl silsesquioxane (methyl:phenyl=7:3 molar ratio).

Manufacturing example 4

In a 300mL 4-neck flask with a stirrer, reflux condenser, dropping funnel and thermometer, add 14.8g of water, 1.4g of 35% by mass hydrochloric acid and 44.8g of toluene, and dissolve 11.1g (0.05mol) of 3-acetyl Oxypropyltrimethoxysilane, 40.8g (0.3mol) methyltrimethoxysilane, 29.7g (0.15mol) phenyltrimethoxysilane were dissolved in 30g toluene, and the mixture was heated at 15-25°C Added dropwise to the 4-necked flask. After completion of the dropwise addition, at the same temperature, after stirring for 30 minutes, adding water and standing still, liquid separation was carried out, and the oil layer was recovered.

Thereafter, it was washed with water three times, and the toluene oil layer was recovered. Next, this toluene oil layer was put into an eggplant-shaped flask, concentrated by an evaporator, diluted with methanol, and the solvent was replaced with methanol, and the whole volume was adjusted to 250 g. 50 g of water was added to this solution, and 30.8 g (0.22 mol) of potassium carbonate was added at room temperature. Thereafter, the mixture was stirred for 1 hour, and after the stirring was completed, ethyl acetate and water were added for liquid separation, and an oil layer was recovered.

Thereafter, it was washed with water five or more times, and the ethyl acetate oil layer was recovered. Next, the ethyl acetate oil layer was concentrated and replaced with propylene glycol monomethyl ether acetate to obtain a 40% solution of a polycondensate of 3-hydroxypropylsilsesquioxane.

The obtained polycondensate of 3-hydroxypropyl silsesquioxane is methyl, 3-hydroxypropyl, phenyl silsesquioxane (methyl: 3-hydroxypropyl: Phenyl = 6:1:3 molar ratio).

Manufacturing Example 5

600ml of water was added to the reactor, and a mixture of 283.5g (1mol) of p-methoxybenzyltrichlorosilane and 300ml of toluene was added dropwise in 2 hours while stirring at 30°C for hydrolysis. Thereafter, the aqueous layer was removed by liquid separation operation, and the solvent was distilled off from the organic layer with an evaporator. The concentrated solution was heated at 200° C. for 2 hours under reduced pressure to conduct a polymerization reaction. 200 g of acetonitrile was added to the obtained polymer to obtain a p-methoxybenzylsilsesquioxane solution.

In the solution obtained in this way, 240 g of trimethylsilyl iodide was dripped at 60 degreeC or less, and it was made to react at 60 degreeC for 10 hours. After completion of the reaction, 200 g of water was added to perform hydrolysis, and then poured out to obtain a polymer layer. The polymer layer was vacuum dried to yield 165 g of p-hydroxybenzylsilsesquioxane. The molecular weight of this polymer was measured using GPC (Gel Permeation Chromatography), and Mw in terms of polystyrene was 3,000.

Manufacturing example 6

In a reaction vessel having a reflux condenser, a dropping funnel and a stirrer, 400 ml of water was added, stirred, and 400 ml of n-butyl acetate was added thereto. The outside of the reaction vessel was ice-cooled, and the stirring speed was low enough to maintain the organic layer and the water layer. Next, 52.2 g (0.35 mol) of methyltrichlorosilane and 31.7 g (0.15 mol) of phenyltrichlorosilane were added dropwise from the dropping funnel for 10 minutes. At this point, the temperature of the reaction mixture rose to 40°C. Then, stir directly for 30 minutes. After the reaction, the organic layer was washed until the washing water was neutral. Then, the solvent in the organic layer was distilled off under reduced pressure and diluted to 40% with PGMEA to obtain the target methylphenylsilsesquioxane. The molecular weight of this polymer measured by GPC (gel permeation chromatography) was Mw=2,000 (methyl:phenyl=7:3 molar ratio) in terms of polystyrene.

Example 1

To propylene glycol monomethyl ether acetate (PGMEA), add 10 g of methyl phenyl silsesquioxane (methyl: phenyl = 7: 3 mole 1,000 ppm of the solution and 0.08 g of surfactant KF-54 (manufactured by Shin-Etsu Chemical Co., Ltd.) (5% PGMEA solution) were stirred and dissolved to prepare a 35% solution. This solution was passed through a syringe filter ( , PTFE, filtration accuracy 0.20 μm) to prepare a silicone composition. This composition was spin-coated on a 6-inch silicon wafer at 600 rpm/10 sec using a Mikasa spin coater (manufactured by Mikasa Co., Ltd.), and prebaked on a hot plate at 110° C. for 2 minutes to obtain a silicon wafer with a thickness of 5 μm. oxane resin film. The resin film was immersed in a 0.4% by weight tetramethylammonium hydroxide (TMAH) aqueous solution for 30 seconds, rinsed with ion-exchanged water, and then fired in an oven at 250° C. for 60 minutes after completely shutting off the water. .

The evaluation results of the transmittance (400nm), pencil hardness, film thickness reduction rate after firing (hereinafter referred to as "fired film reduction rate"), and the presence or absence of cracks in the fired film are shown in Table 1. express. In addition, each evaluation was performed by the following method.

(transmittance)

The ultraviolet-visible absorption spectrum of the obtained cured film was measured using MultiSpec-1500 manufactured by Shimadzu Corporation, and the transmittance at a wavelength of 400 nm was obtained.

(pencil hardness)

Measured according to JIS K5600-5-4. If the pencil hardness is less than HB, the substrate may be damaged during transportation, etc., so the pencil hardness is desirably H or more, preferably 3H or more.

(Firing film thickness reduction rate)

The film thickness before firing and the film thickness after firing were carried out using Lambda Aeros VM-1200 (manufactured by Dainippon Sculin). The parameters of the sample measurement parameters whose absolute film thickness was known were used in advance, and the parameters were used for optical measurement. The film thickness reduction rate after firing was calculated by the following formula.

Firing film thickness reduction rate (%)=[(film thickness before firing-film thickness after firing)/film thickness before firing]×100

(whether the fired film has cracks)

Whether there are cracks in the fired film is that after the film is fired, it is left to stand for a day and night, and the cracks in the center of the 4-inch wafer In the circle of , check visually for cracks.

Example 2

The same procedure as in Example 1 except that methylphenylsilsesquioxane with a molecular weight of 2,000 obtained in Production 2 was used as the siloxane resin, and a 2.38% by weight tetramethylammonium hydroxide (TMAH) aqueous solution was used as the alkali treatment solution. Accordingly, a silicone resin fired cured film is formed. The obtained fired cured film was evaluated in the same manner as in Example 1, and the results in Table 1 were obtained.

Example 3

In addition to using methyl, 3-hydroxypropyl, and phenylsilsesquioxane (methyl: 3-hydroxypropyl:phenyl = 6:1:3 molar ratio) with a molecular weight of 3,000 obtained in Production 4 as the siloxane For the resin, except that a 2.38% by weight tetramethylammonium hydroxide (TMAH) aqueous solution was used as the alkali treatment liquid, a silicone resin fired cured film was formed in the same manner as in Example 1. The obtained fired cured film was evaluated in the same manner as in Example 1, and the results in Table 1 were obtained.

Example 4

Except having used 0.3 weight% ethanolamine aqueous solution as an alkaline aqueous solution, it carried out similarly to Example 1, and formed the siloxane resin firing cured film. The obtained fired cured film was evaluated in the same manner as in Example 1, and the results in Table 1 were obtained.

Example 5

Except not having used surfactant KF-54, it carried out similarly to Example 1, and formed the silicone resin firing cured film. The obtained fired cured film was evaluated in the same manner as in Example 1, and the results in Table 1 were obtained.

Example 6

In addition to using methylphenylsilsesquioxane with a molecular weight of 4,000 obtained in Production 3 as the siloxane resin, using a 5% by weight tetramethylammonium hydroxide (TMAH) aqueous solution as an alkaline aqueous solution, and making the firing temperature 300°C Except that, in the same manner as in Example 1, a silicone resin fired cured film was formed. The obtained fired cured film was evaluated in the same manner as in Example 1, and the results in Table 1 were obtained.

Example 7

A siloxane resin fired cured film was formed in the same manner as in Example 1 except that the firing temperature was set to 180°C. The obtained fired cured film was evaluated in the same manner as in Example 1, and the results in Table 1 were obtained.

Example 8

A siloxane resin fired cured film was formed in the same manner as in Example 1 except that the firing temperature was set to 300°C. The obtained fired cured film was evaluated in the same manner as in Example 1, and the results in Table 1 were obtained.

Example 9

A siloxane resin fired cured film was formed in the same manner as in Example 2 except that the film thickness was 7 μm. The obtained fired cured film was evaluated in the same manner as in Example 1, and the results in Table 1 were obtained.

Example 10

Except having used the methylphenyl silsesquioxane of molecular weight 2,000 obtained in manufacture 6 as a siloxane resin, it carried out similarly to Example 2, and formed the siloxane resin firing cured film. The obtained fired cured film was evaluated in the same manner as in Example 1, and the results in Table 1 were obtained.

Comparative example 1

A siloxane resin fired cured film was formed in the same manner as in Example 1 except that the alkaline aqueous solution treatment was not performed. The obtained fired cured film was evaluated in the same manner as in Example 1, and the results in Table 1 were obtained.

Comparative example 2

A siloxane resin fired cured film was formed in the same manner as in Example 2 except that the alkaline aqueous solution treatment was not performed. The obtained fired cured film was evaluated in the same manner as in Example 1, and the results in Table 1 were obtained.

Comparative example 3

A siloxane resin fired cured film was formed in the same manner as in Example 1, except that the alkali aqueous solution treatment was not performed and the siloxane resin with a weight average molecular weight of 3,000 obtained in Production Example 5 was used. The obtained fired cured film was evaluated in the same manner as in Example 1, and the results in Table 1 were obtained.

Comparative example 4

A siloxane resin fired cured film was formed in the same manner as in Example 6 except that the alkaline aqueous solution treatment was not performed. The obtained fired cured film was evaluated in the same manner as in Example 1, and the results in Table 1 were obtained.

Comparative Example 5

A siloxane resin fired cured film was formed in the same manner as in Example 1, except that a 1N aqueous saline solution was used instead of the tetramethylammonium hydroxide (TMAH) aqueous solution. Evaluation of the obtained baked cured film obtained in the same manner as in Example 1 was performed, and the results in Table 1 were obtained.

Comparative example 6

A siloxane resin fired cured film was formed in the same manner as in Example 10 except that the alkaline aqueous solution treatment was not performed. The obtained fired cured film was evaluated in the same manner as in Example 1, and the results in Table 1 were obtained.

Comparative Example 7

A siloxane resin fired cured film was formed in the same manner as in Example 1, except that ion-exchanged water was used instead of the tetramethylammonium hydroxide (TMAH) aqueous solution. The obtained fired cured film was evaluated in the same manner as in Example 1, and the results in Table 1 were obtained.

Table 1

It can be seen from Table 1 that by treating with alkaline aqueous solution, it can be formed with excellent transparency, high scratch hardness, high insulation, low dielectric constant and excellent flatness. Even if a thick film is formed, no cracks will occur, and the substrate interface A cured film of a silanol group- or alkoxysilyl-containing silicone resin composition with excellent adhesion without film peeling.

Claims (5)

1. the curing overlay film formation method of a silicone resin composition, the method uses by (a) silicone resin containing silanol group or alkoxysilyl, (b) organic solvent, the composition that c additive that () uses as required is formed, at least pass through the polymerization of silanol group or alkoxysilyl, be cured, form the curing overlay film formation method of the silicone resin composition of overlay film, wherein the aforementioned additive used as required is selected from tensio-active agent and thickening material, it is characterized in that: foregoing is applied on base material, after carrying out pre-bake treatment, after alkaline aqueous solution process, rinse, fire.

2. the curing overlay film formation method of the silicone resin composition described in claim 1, is characterized in that: the process of the aforementioned base aqueous solution is by being impregnated in alkaline aqueous solution, or covers that submergence or shower carry out by revolving.

3. the curing overlay film formation method of the silicone resin composition described in claim 1 or 2, is characterized in that: the aforementioned base aqueous solution is organic alkaline aqueous solutions.

4. the curing overlay film formation method of the silicone resin composition described in claim 3, is characterized in that: the aforementioned base aqueous solution is the tetramethyl ammonium hydroxide aqueous solution.

5. the curing overlay film formation method of the silicone resin composition described in any one of Claims 1 to 4, is characterized in that: aforementioned firing is carried out at the temperature of 120 ~ 400 DEG C.