KR20120022616A - Method of forming a cured coating film of siloxane resin composition - Google Patents

Abstract

PURPOSE: A manufacturing method of a cured coating film of a siloxane resin composition is provided to form a coating film having excellent flatness and adhesion without delamination in substrate interface and the generation of crack even through thick membrane. CONSTITUTION: A manufacturing method of a cured coating film of a siloxane resin composition using a silanol group or alkoxysilyl group-containing siloxane resin composition comprises: a step of spreading the siloxane resin composition on a substrate; a step of pre-baking treatment; a step of treating the outcome by alkali water solution, and rinsing and firing the same. The treatment by alkali water solution is conducted by immersing, paddling or showering to the alkali water solution. The alkali water solution is organic alkali water solution.

Description

Method of forming a cured coating film of siloxane resin composition

The present invention relates to a method for forming a cured coating film of a silanol group or an alkoxysilyl group-containing siloxane resin composition, and more particularly, has excellent transparency, high scratch hardness, high insulation, low dielectric constant, and excellent flatness. The present invention relates to a method for forming a cured film of a silanol group or an alkoxysilyl group-containing siloxane resin composition which is excellent in adhesion without cracking and film peeling at the substrate interface even with a thick film.

The siloxane resin is known as a material having high heat resistance, high hardness, high insulation, and high transparency, and is used in various applications. As one of such uses, hardening of the composition containing a siloxane resin (Hereinafter, it may be called "baking hardening") is a semiconductor element using the thing which is excellent in insulation, durability, and low dielectric constant, and has high hardness. It is used as an insulating film, a flattening film, a protective film, a semiconductor sealing material, etc. in a liquid crystal display element etc. In addition, since it is highly transparent, it is used not only in such an electronic material field but also as surface protection film of optical members, automobiles, etc.

When forming a cured film using the siloxane resin composition which used siloxane resin as a binder, the film is formed by preparing the composition containing the polyfunctional polysiloxane which has an alkoxy group or a hydroxyl group, apply | coating this, heat-drying, etc., and hardening it. The method of making is known (refer patent document 1). At this time, as the curing agent (also referred to as a "catalyst"), an acidic compound, a basic compound, a metal alkoxide, a metal chelate compound and the like are used. However, when the viscosity of the polyfunctional polysiloxane is high or the solid content concentration is high, the curing agent is used. When added to polyfunctional polysiloxanes, there was a problem that they immediately thickened or gelled. In addition, even when no thickening or gelation occurs immediately after the addition, there is a problem that thickening may occur during storage, and that the catalyst is hardly hardened if it is weakly acidic. Moreover, in order to form the cured film using such a material, it is necessary to process a coating film at high temperature, and also there existed a problem that the film reduction amount was large at that time.

In order to solve this problem, it is also proposed to use an acidic compound and a basic compound having a boiling point different from the acidic compound as a curing agent (see Patent Document 2). This composition does not immediately cure even if an acidic compound and a curing agent containing a basic compound having a boiling point different from the acidic compound are added to the polyfunctional polysiloxane having a plurality of alkoxy groups and / or hydroxyl groups. A polysiloxane composition having excellent storage stability using a point where an acidic compound or a basic compound acts as a curing agent by heating a polysiloxane compound at a temperature between these boiling points when the boiling point of the compound is different, and condensation at low temperatures and further curing of the film Although it becomes possible, there exists a problem that a cracking phenomenon tends to occur because of using a hardening | curing agent, and the problem that the inhibition of the fall of stability with time is inadequate.

By the way, a silanol-group curable siloxane resin can harden | cure a coating film at low temperature, and has the characteristic that hardness is high. Moreover, in addition to this, a silanol-group curable siloxane resin attracts attention from the point that transparency of a film is high, and also has characteristics, such as high heat resistance, low dielectric property, and insulation. Among these, the silsesquioxane resin which one carbon atom and three oxygen atoms couple | bond with four bonding water of a silicon atom, and the silica resin which the oxygen atom couple | bonds with all four bonding water of a silicon atom, In order to form a strong three-dimensional crosslink by silicon and oxygen, and to exhibit the above characteristics more remarkably, especially on a coating agent or a thin film transistor (hereinafter sometimes abbreviated as TFT) on a plastic substrate for flexible display. Although expected as a barrier film and a planarizing agent, when a cured film is formed at 250 degreeC or more, since the electrical property of TFT especially falls, it is necessary to perform hardening below 250 degreeC. Until now, a method of forming a silica-based coating by heating a coating liquid for forming a silica-based coating film containing a hydrolysis product of an alkoxysilane and a silicone-based surfactant at a temperature of 250 to 500 ° C. has been disclosed (see Patent Document 3). According to this method, it is possible to form a film having excellent adhesion without impairing the properties of flatness and crack limit, but it is necessary to cure at a high temperature of 250 ° C. or higher, and a silicone-based surfactant is essential and a thick film. When it is set as the above, there is a problem that only a material having a large weight average molecular weight (Mw) can be selected. On the other hand, in the case of a thin film, the Mw may be small, but the sublimation during firing increases and the amount of film reduction increases, so that the Mw range is narrow.

The film of the three-dimensional siloxane resin has a tendency to increase in stress when the film is returned to room temperature as the thickness of the formed film is thicker and to be exposed to high temperature (below 250 ° C), so that cracking tends to occur. . In order to make it hard to produce the cracking phenomenon of the hardened film of a siloxane resin, the silicon resin which the carbon atom and the oxygen atom couple to two of four bond numbers of a silicon atom is used, or organic resin ( For example, although there exists a method similar to adding an acrylic resin), all these methods tend to inhibit the said film characteristics. In addition, when the silicone resin is added separately or added in the repeating unit of the polymer of the siloxane resin, the fluidity is improved and the sublimation property is also increased. Thus, contamination of the oven during film formation and wrinkles due to flow marks are formed, and after curing There was a problem that the film hardness was lowered.

Patent Document 1: Japanese Unexamined Patent Publication No. 2004-99879 Patent Document 2: Japanese Unexamined Patent Publication No. 2008-208200 Patent Document 3: Japanese Patent No. 4079383

The object of the present invention is excellent in transparency even when firing at a temperature of less than 250 ° C or more than 250 ° C when the siloxane resin cured film is formed without the above conventional problems, that is, in a semiconductor device or a liquid crystal device, A film having high scratch hardness, high insulation, low dielectric constant, no film reduction, excellent flatness, no cracking even with a thick film, no film peeling at the substrate interface, and excellent adhesion It is providing the hardening film formation method of the siloxane resin composition which can be provided.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining, after apply | coating a silanol group or an alkoxy silyl group containing siloxane resin composition to a base material, it carries out prebaking, and after baking this hardening | curing process with an aqueous alkali solution, it is 250 degrees C or less, or 250 Regardless of the thickness of the film, it is also excellent in transparency, high scratching hardness, high insulation, low dielectric constant, and excellent adhesion even when a thick film is applied, regardless of the thickness of the film. It turns out that a cured film can be formed and this invention is made | formed based on this knowledge.

That is, this invention uses the silanol group or the alkoxysilyl group containing siloxane resin composition, The hardening film formation method of the siloxane resin composition which hardens | cures by superposition | polymerization of a silanol group or an alkoxysilyl group to form a film, The said composition is described. The present invention relates to a method for forming a cured coating film of a siloxane resin composition, which is coated on the resin, prebaked, and treated with an aqueous alkali solution, followed by rinsing and baking.

The present invention is also characterized in that in the above method, the treatment in the aqueous alkali solution is performed by immersion in an aqueous alkali solution, a paddle or a shower.

The present invention is also characterized in that in the above method, the aqueous alkali solution is an aqueous tetramethylammonium hydroxide solution.

Moreover, this invention is the said method WHEREIN: It is characterized by the said baking performed at the temperature of 120-400 degreeC.

In the present invention, a silanol group or an alkoxysilyl group-containing resin is used as the siloxane resin, and after the silanol group or the alkoxysilyl group-containing siloxane resin composition is applied, prebaking of the coating film is carried out, and the prebaking film is made of an aqueous alkali solution. By the treatment, it is excellent in transparency regardless of the subsequent firing temperature and film thickness, has high scratch hardness, high insulation, low dielectric constant, and the film does not shrink, and no adhesion occurs even when a thick film is applied. An excellent cured film can be formed. For this reason, it can use suitably for formation of insulating films, flattening films, protective films, optical members, surface protection films, such as an automobile in a semiconductor element, a liquid crystal display element, etc.

Hereinafter, the hardened film formation method of the silanol group or the alkoxy silyl group containing siloxane resin composition of this invention is demonstrated in detail.

As mentioned above, the hardening film formation method of the silanol group or the alkoxy silyl group containing siloxane resin composition of this invention apply | coats a silanol group or the alkoxy silyl group containing siloxane resin composition to a base material, and after prebaking, it is made into alkaline aqueous solution. Although it is characterized by rinsing and baking the film after the treatment, the materials and methods used in the cured film-forming method of the siloxane resin composition of the present invention will be described in detail below.

(i) Silanol group or alkoxysilyl group containing siloxane resin composition

First, it is a silanol group or the alkoxy silyl group containing siloxane resin composition used in order to form the cured film of this invention, Comprising: (a) silanol group or the alkoxy silyl group containing siloxane resin, (b) organic solvent, (c ) Consists of additives used as needed.

(a) Silanol group or alkoxysilyl group containing siloxane resin

The silanol group or alkoxysilyl group-containing siloxane resin used in the present invention may be any siloxane resin containing a conventionally known silanol group and / or alkoxysilyl group as a reactive group, and the structure of the polysiloxane is not particularly limited. Representative silanol groups or alkoxysilyl group-containing siloxane resins that can be used in the present invention include, for example, siloxane resins (polysiloxanes) obtained by hydrolyzing one or more of the alkoxysilanes of the following general formula (1) in an organic solvent. Can be mentioned.

In Chemical Formula 1,

R ¹ is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an aralkyl group having no hydrogen atom bonded to a carbon atom at an α-position having 15 or less carbon atoms, and having 6 to 15 carbon atoms. An aryl group or an alkenyl group having 1 to 6 carbon atoms,

R ² is an alkyl group having 1 to 6 carbon atoms which may have a substituent,

n is an integer of 0-3.

As said C1-C6 alkyl group which may have a substituent of R <^{1> in} the said general formula, For example, a methyl group, an ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group, n-hexyl group , n-decyl group, trifluoromethyl group, 2,2,2-trifluoroethyl group, 3,3,3-trifluoropropyl group, 3-hydroxypropyl group, 3-glycidoxypropyl group, 2 -(3,4-epoxycyclohexyl) ethyl group, 3-aminopropyl group, 3-mercaptopropyl group, 3-isocyanatopropyl group, 4-hydroxy-5- (p-hydroxyphenylcarbonyloxy Pentyl group etc. are mentioned. Moreover, as a C3-C6 cycloalkyl group which may have a substituent, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, etc. are mentioned, The hydrogen in the C-position carbon atom which may have a substituent is mentioned. Examples of the aralkyl group having no carbon atoms of 15 or less include a phenyl isopropyl group and the like, and examples of the aryl group which may have a substituent include a phenyl group, tolyl group, p-hydroxyphenyl group, naphthyl group, and the like. As a C1-C6 alkenyl group which may have a substituent, a vinyl group, an allyl group, 3-acryloxypropyl group, 3-methacryloxypropyl group, etc. are mentioned.

In addition, as a C1-C6 alkyl group which may have a substituent of R <^2>, the group similar to what was illustrated as an alkyl group which may have a substituent of R <^1> can be illustrated, A C1-C4 alkyl group which does not have a substituent is preferable. Do.

As a specific example of the alkoxysilane compound of the said General formula (1), the following compound is illustrated, for example.

(A) Tetraalkoxysilane: Tetramethoxysilane, Tetraethoxysilane, Tetrapropoxysilane, etc.

(B) Monoalkyltrialkoxysilane: monomethyltrimethoxysilane, monomethyltriethoxysilane, monoethyltrimethoxysilane, monoethyltriethoxysilane, monopropyltrimethoxysilane, monopropyltriethoxysilane Etc

(C) monoaryltrialkoxysilane: monophenyltrimethoxysilane, monophenyltriethoxysilane, mononaphthyltrimethoxysilane, etc.

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

(E) dialkyl dialkoxysilanes: dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, dipropyldimethoxysilane, dipropyldiethoxysilane and the like.

(E) diphenyl dialkoxysilane: diphenyl dimethoxysilane, diphenyl diethoxysilane, etc.

Alkylphenyl dialkoxysilanes: methylphenyldimethoxysilane, methylphenyldiethoxysilane, ethylphenyldimethoxysilane, ethylphenyldiethoxysilane, propylphenyldimethoxysilane, propylphenyldiethoxysilane, etc.

(A) Trialkyl alkoxysilane: trimethylmethoxysilane, trin-butylethoxysilane, etc.

Preferred compounds among them are tetramethoxysilane, tetraethoxysilane, monomethyltrimethoxysilane, monomethyltriethoxysilane, mononaphthyltrimethoxysilane and monophenyltrimethoxysilane.

As for the siloxane resin containing the silanol group or the alkoxysilyl group used in this invention, the siloxane resin (polysiloxane) which a reactive group consists only of a silanol group, or consists of a silanol group and an alkoxy silyl group is preferable. That is, in the siloxane resin, the unreacted alkoxysilyl group at the time of synthesize | combining siloxane resin may be contained. The silanol group-containing siloxane resin composed of only a silanol group or a silanol group and an alkoxysilyl group can be produced using one kind or two or more kinds of alkoxysilanes represented by the general formula (1). In addition, the silanol group or the alkoxysilyl group containing siloxane resin used in this invention is an alkoxysilane if needed, 1 type or 2 types of the alkoxysilane which does not contain reactor, such as a hydroxyl group, in said R <^1> and R <^2> . The siloxane resin obtained by hydrolytically condensing these and using 1 or 2 or more types of alkoxysilanes which have a reactor, such as a hydroxyl group, in R <^1> and / or R <^2> may be used. In addition, in this invention, it is preferable to use the alkoxysilane whose n is 0 or 1 in the said General formula (1) as a raw material alkoxysilane, At this time, the alkoxysilane whose n is 2 or 3 may also be used as needed. .

The weight average molecular weight (Mw) of the molecular weight is preferably 400 to 20,000, more preferably 400 to 10,000. When the weight average molecular weight is less than 400, it may volatilize with the solvent at the time of prebaking, and when larger than 20,000, it is hard to harden.

Hydrolytic condensation reaction of an alkoxysilane is normally performed 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 resin to be formed. As such a solvent, a well-known organic solvent can be used suitably, For example, monohydric alcohols, such as methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, isobutyl alcohol, amyamyl alcohol; Polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, glycerin, trimethylolpropane and hexane triol; Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl Monoethers of polyhydric alcohols such as ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, 3-methyl-3-methoxybutanol and acetates thereof; Esters such as methyl acetate, ethyl acetate and butyl acetate; Ketones such as acetone, methyl ethyl ketone and methyl isoamyl ketone; ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dipropyl ether, ethylene glycol dibutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene The polyhydric alcohol ether etc. which alkylated all the hydroxyl groups of polyhydric alcohols, such as glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, and diethylene glycol diethyl ether, are mentioned. It is common that the solvent used in reaction of alcoholic silane is used also as a solvent of the siloxane resin composition apply | coated to a base material continuously.

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 ether bond in the molecule, or an acetate ester having at least one ether bond in the molecule. Do. These organic solvents may be used independently, or may be used in combination of 2 or more type. Moreover, when forming the cured film of a siloxane resin on a flat panel display etc., ether ester of polyhydric alcohols, such as polypropylene alcohol, such as propylene glycol monomethyl ether (PGME), and propylene glycol monomethyl ether acetate (PGMEA) conventionally Since is generally used, when using a siloxane resin composition in such a field, it is preferable to use ethers and ether esters of polyhydric alcohols, such as PGME or PGMEA. In addition, 3-methyl-3-methoxybutanol, 3-methyl-3-methoxybutyl acetate, etc. are also mentioned as a preferable solvent. The organic solvent is usually used at a ratio of 10 to 30 molar volume with respect to 1 mole of alkoxysilane.

Although hydrolysis condensation reaction of an alkoxysilane advances to some extent even without a catalyst, in order to provide applicability | paintability and storage stability, it is preferable to use a catalyst. Although any conventionally well-known catalyst can be used as a catalyst, it is preferable to use an acid catalyst from the point of stability of resin. As the acid catalyst, both an organic acid and an inorganic acid can be used. Examples of the organic acid include organic carboxylic acids such as acetic acid, propionic acid and butyric acid. As an inorganic acid, inorganic acids, such as hydrochloric acid, nitric acid, a sulfuric acid, phosphoric acid, are mentioned. An acid catalyst may be added after adding water to a liquid, or may be mixed with water and added as an acid aqueous solution. The amount of acid catalyst added is appropriately selected. The hydrolysis reaction is usually completed in about 5 to 100 hours, but is heated to a temperature not exceeding 60 to 70 ° C, and an acid catalyst aqueous solution is added dropwise to the organic solvent containing the alkoxysilane compound to react with a short reaction time. You can also complete

The degree of hydrolysis can be adjusted by the amount of water added in the presence of a catalyst. Generally, it is preferable to react water at a ratio of 20 to 1000 mol%, preferably 50 to 500 mol%, based on the total moles of alkoxy groups of the alkoxysilane compound of the formula (1). When the addition amount of water is too small than the said range, since hydrolysis degree becomes low and film formation becomes difficult, on the other hand, it is unpreferable because it is easy to cause gelatinization.

Moreover, as another typical silanol group or the alkoxy silyl group containing siloxane resin, the siloxane resin (polysiloxane) obtained by hydrolyzing one or more types of halosilanes of following General formula (2) in an organic solvent is mentioned.

In Chemical Formula 2,

R ¹ is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an aralkyl group having no hydrogen atom bonded to a carbon atom at an α-position having 15 or less carbon atoms, and having 6 to 15 carbon atoms. An aryl group or an alkenyl group having 1 to 6 carbon atoms,

X is a halogen atom,

n is an integer of 0-3.

Moreover, as R <^1> in general formula (2), the thing similar to what was shown as R <^1> of the said general formula (1) is mentioned as a preferable thing. Moreover, as X, a chlorine atom, a bromine atom, and an iodine atom are mentioned. In addition, n is preferably 0 to 1, as in the general formula (1), and a halosilane compound in which n is 2 or 3 may be used together with necessity. By using such a halosilane compound, a silanol group-containing siloxane resin can be produced in the same manner as in the case of using an alkoxysilane as shown in the general formula (1). For example, in a trichlorosilane compound, some chlorosilyl groups hydrolyze and condense to form a bond of Si-O-Si, and the rest hydrolyzes and a chlorosilyl group turns into a silanol group. Content of the silanol group in the siloxane resin formed can be adjusted by controlling the kind, quantity, reaction conditions, etc. of the halosilane compound to be used. When using a halosilane compound, all the reactors of the silanol group containing siloxane resin obtained become silanol groups.

(b) organic solvent

In the silanol group or the alkoxysilyl group-containing siloxane resin composition of the present invention, an organic solvent is used to dissolve or disperse the silanol group or the alkoxysilyl group-containing siloxane resin. As an organic solvent, the same thing as the organic solvent used at the time of performing the hydrolysis condensation reaction of the said alkoxysilane can be used. As mentioned above, as an organic solvent of the silanol group or the alkoxy silyl group containing siloxane resin composition of this invention, the solvent at the time of the hydrolysis condensation reaction of an alkoxysilane is used as an organic solvent of a silanol group or an alkoxy silyl group containing siloxane resin composition as it is. Another solvent may be added here, and the siloxane resin obtained by reaction may be isolated from a solvent, and the siloxane resin which does not contain a solvent may be used as a composition, for example, to melt | dissolve or disperse | distribute in a new solvent. As mentioned above, since ether esters, such as PGMEA, and ethers, such as PGME, are used for general flat panel displays, when using a siloxane resin composition in such a field, ethers, such as PGME or PGMEA, or ether esters, are used. It is preferable to use a system solvent. In addition, 3-methyl-3-methoxybutanol, 3-methyl-3-methoxybutyl acetate, etc. are also mentioned as a preferable solvent.

(c) additives

As an additive, surfactant, a thickener, etc. are mentioned, for example. Surfactant is used in order to improve the application | coating characteristic of a silanol group or an alkoxy silyl group containing siloxane resin composition, the wettability to a base material, etc. As surfactants, nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and the like are known, but anionic and cationic surfactants and amphoteric surfactants are catalyzed by the aging degradation of the siloxane resin composition. In order to accelerate | stimulate, nonionic surfactant is preferable. As a nonionic surfactant, For example, polyoxyethylene alkyl ethers, such as polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, polyoxyethylene cetyl ether, polyoxyethylene fatty acid diester, and polyoxy fatty acid monoester , Acetylene glycol derivatives such as polyoxyethylene polyoxypropylene block polymer, acetylene alcohol, acetylene glycol, polyethoxylate of acetylene alcohol, polyethoxylate of acetylene glycol, fluorine-containing surfactants such as Florade [see: Trade name, manufactured by Sumitomo 3M Co., Ltd., MegaPac (refer to Trade Name, manufactured by DIC Corporation), sulfon (trade name: manufactured by Asahigaras Corporation), or an organic siloxane surfactant such as KF -53, KF-54 (reference: all manufactured by Shin-Etsu Chemical Co., Ltd.), SH7PA, SH21PA, SH28PA, SH30PA, S T94PA (refer: all are manufactured by Toray Dow Corning Co., Ltd.) etc. are mentioned. Examples of the acetylene glycols include 3-methyl-1-butyn-3-ol, 3-methyl-1-pentin-3-ol, 3,6-dimethyl-4-octin-3,6-diol, 2,4,7 , 9-tetramethyl-5-decine-4,7-diol, 3,5-dimethyl-1-hexyn-3-ol, 2,5-dimethyl-3-hexine-2,5-diol, 2,5- Dimethyl-2,5-hexanediol etc. are mentioned.

It is preferable that content of the silanol group or the alkoxy silyl group containing siloxane resin in a silanol group or the alkoxy silyl group containing siloxane resin composition is 1-40 weight part with respect to 100 weight part of solvents. If it exceeds 40 parts by weight, the aged deterioration rate of the resin is increased, which is undesirable.

Moreover, content of surfactant is 50-100,000 ppm in a composition, Preferably it is the range of 100-50,000 ppm. When too small, surface activity is hard to be obtained and wettability does not become good, When too large, foam generate | occur | produces violently, foaming occurs in an applicator, etc., and handling is difficult.

(ii) application

A silanol group or an alkoxysilyl group containing siloxane resin composition is apply | coated to a base material, and becomes a silanol group or an alkoxy silyl group containing siloxane resin film. Although it does not specifically limit as a base material, Various board | substrates, such as a silicon substrate, a glass plate, a metal plate, and a ceramic plate, are mentioned, Especially the TFT surface of a liquid crystal display which requires an insulating film, etc. are preferable as a board | substrate of this invention. A coating method is not specifically limited, For example, various methods, such as a spin coat method, the dip coat method, the knife coat method, the roll coat method, the spray coat method, the slit coat method, can be employ | adopted. In addition, the density | concentration of the silanol group or the alkoxy silyl group containing siloxane resin in a coating solution is a kind of silanol group or alkoxy silyl group containing siloxane resin used (for example, the difference of the kind of R <^1> , molecular weight, etc.), and application | coating It changes with a method, desired coating film thickness, etc., and is not specifically limited, It may be arbitrary.

(iii) prebaking

Thus, the silanol group or the alkoxysilyl group containing siloxane resin composition film formed on the board | substrate is then prebaked, and the organic solvent in a composition is removed. The prebaking temperature also varies depending on the type of organic solvent used in the composition. However, if the temperature is too low, the residual amount of the organic solvent may increase, which may cause the substrate transporting device or the like to invade. 60-200 degreeC is preferable and 70-180 degreeC is more preferable at the point which may dry rapidly and a fog stain may occur, or a silanol group or an alkoxy silyl group containing siloxane resin may sublimate. Prebaking is performed using heating apparatuses, such as a hotplate and oven, for example, Although the time of prebaking changes with kinds of the organic solvent used and the temperature of a prebaking, 30 second-10 minutes are preferable, 1 to 5 minutes are more preferred.

(iv) aqueous alkali solution treatment

After prebaking, the coating is treated with an aqueous alkali solution. The aqueous alkali solution is not particularly limited and can be carried out by general methods such as immersion (dip) in an aqueous alkali solution, paddles, showers, slits, cap coats, and sprays. When the said composition contains surfactant, it is preferable to carry out by immersion (dip). Moreover, even if it contains surfactant, another method, for example, paddle application is also possible, if immersion treatment is given.

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

Examples of the organic alkali include quaternary ammonium compounds, aminoalcohols (alkanolamines), ammonia water, alkylamines, heterocyclic amines, and the like. As the quaternary ammonium compound, for example, tetramethylammonium hydroxide (tetramethylammonium hydroxide; sometimes referred to as "TMAH"), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, trimethylethylammonium hydroxide , Trimethyl (2-hydroxyethyl) ammonium (choline), triethyl (2-hydroxyethyl) ammonium hydroxide, tripropyl (2-hydroxyethyl) ammonium hydroxide, trimethyl (2-hydroxypropyl) ammonium hydroxide It is mentioned as a preferable thing. Among these, TMAH and choline are particularly preferable.

As amino alcohols (alkanolamines), for example, monoethanolamine, such as 2-ethanolamine and 2-aminoethanol, diethanolamine, triethanolamine, monopropanolamine, dipropanolamine, tripropanolamine, and monoisopropanolamine , 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, Nn-butylethanolamine, N-tert-butylethanolamine, N-tertiary- Butyldiethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, N, N-di-n-butylethanolamine, N-ethylethanolamine, etc. are mentioned, Among these, ethanolamines are mentioned. It is preferable to use, and monoethanolamine is especially preferable.

However, it is preferable to process with TMAH aqueous solution from the point of availability, the biotoxicity, and the convenience of vaporizing when hardened | cured.

In the present invention, the concentration of the aqueous alkali solution used for the aqueous alkali solution is varied depending on various factors such as the type and concentration of the alkali used, the type of silanol group or alkoxysilyl group-containing siloxane resin to be treated, and the film thickness. It is not. When an alkali concentration is high, since a silanol group or an alkoxy silyl group containing siloxane resin may melt | dissolve, it is preferable to use the aqueous alkali solution of the insoluble density | concentration. Generally, when the ratio of the silanol group to the silanol group or the alkoxysilyl group-containing siloxane resin molecular weight is increased, it becomes easy to dissolve in the aqueous alkali solution. In addition, there is a difference in dissolving power depending on the type of alkali. In general, the alkali concentration range of the aqueous alkali solution is preferably 0.1 to 10%, more preferably 0.1 to 7.5%, still more preferably 0.1 to 5%. As described above, when the ratio of the silanol groups to the silanol groups or the alkoxysilyl group-containing siloxane resin molecular weight is high, the resin is dissolved in an aqueous alkali solution. It is preferable. Moreover, as for the film reduction by aqueous alkali solution treatment, 10% or less is preferable. If it exceeds 10%, it is not preferable because the difference in the amount of dissolution in the film is large and leads to staining.

Although it changes drastically according to the processing time, the kind of alkali used, the alkali concentration of aqueous alkali solution, the kind and film thickness of the silanol group or alkoxysilyl group containing siloxane resin to be processed, etc., it is not specifically limited, Generally, it is 15 second- It is preferable that the treatment time is about 3 minutes. If the processing time is short, there is a deviation of the process, and if it is long, the efficiency is bad. In addition, processing temperature can be performed at normal temperature.

In the present invention, in the case of applying a thick film by alkali treatment as described above, regardless of the thickness of the coating film, excellent transparency, high scratch hardness, high insulation, low dielectric constant, and the film is not reduced, In this case, a cured film having excellent adhesion can be formed without cracking. However, the alkoxysilyl group remaining in the film is used as a silanol, and a compound which is not sufficiently polymerized is polymerized to increase the molecular weight, thereby reducing the molecular weight. It is speculated that one of the causes is that the compound disappears, and thereby the amount of reduction in the film reduction of the cured film is reduced by reducing the sublimation amount of the compound in the coating film due to heating at the time of plastic curing. However, the present invention is limited thereto. It is not.

In addition, the inorganic alkali aqueous solution may be used for applications without problems in electrical characteristics and semiconductor characteristics such as hard coat films. However, since the metal ions such as sodium and potassium are contained in the aqueous solution, the interlayer insulating film and planarization of the TFT are used. It is not preferable to use it for the application | use which should consider an electrical characteristic and semiconductor characteristics, such as a film | membrane.

(v) rinse treatment

The rinse treatment is performed in order to wash away the aqueous alkali solution remaining on the coated surface treated with the aqueous alkali solution. Therefore, any method may be used as long as the aqueous alkali solution on the coating surface is washed away. For example, a suitable method known as a conventional rinsing method can be employed, such as dipping the film in water, pouring water over the film surface, or spraying the water over a shower. The rinse treatment time may be a time for removing the aqueous alkali solution on the film, and is not particularly limited. For example, the rinse treatment time is about 30 seconds to 5 minutes in case of immersion, and about 15 seconds to 3 minutes in case of running water. Do it. As water used in the rinse treatment, ion-exchanged water or pure water is preferable as long as it is an application requiring electrical characteristics or semiconductor characteristics. In addition, in rinsing by immersion, immersion rinsing may be performed several times by changing a bath.

(vi) firing (curing) treatment

The firing treatment is preferably carried out in an inert gas atmosphere such as nitrogen, helium, argon or the like for 15 minutes to 3 hours at a temperature of 120 to 400 ° C. using a heating device such as a hot plate or an oven. It is preferable to carry out for 30 minutes-2 hours at the temperature of 150-350 degreeC. The decrease in the film thickness during firing is preferably as small as possible, and in general, the film thickness reduction rate before and after firing is 7.5% or less, preferably 5% or less, and more preferably 3% or less. If the rate of reduction of the thickness of the fired film is larger than 7.5%, there is a problem that the unevenness of the film is large and the sublimation of the compound from the film is large at the time of firing.

Although the film thickness after hardening differs with a use and it does not specifically limit, 20 micrometers or less, Preferably it is 15 micrometers or less. Then, the concentration of the siloxane resin in the silanol group or the alkoxysilyl group-containing siloxane resin composition and the coating amount of the composition are determined so as to be such a cured film thickness. If the film thickness is too thick, the resins in the film may cause layer separation during curing (cure), which is not preferable.

The thus-formed silanol group or alkoxysilyl group-containing siloxane resin calcined film has almost no film reduction due to calcining, is excellent in transparency, has high scratch hardness, high insulation, low dielectric constant, is excellent in flatness, and is thick. Even if it is a film, there is no cracking, no film peeling at the substrate interface, and excellent adhesion.

Example

Although an Example and a comparative example are shown to the following and this invention is demonstrated to it further more concretely, this invention is not limited at all by these Examples and a comparative example.

Preparation Example 1

47.6 g (0.35 mol) of methyltrimethoxysilane, 29.7 g (0.15 mol) of phenyltrimethoxysilane, and 4.83 g (0.015 mol) of 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride It melt | dissolved in 200 g of 3-methoxybutanol, and stirring at 45 degreeC, 34.2 g of distilled water was added, and it heated and stirred for 1 hour, and hydrolyzed and condensed. Thereafter, the mixture was washed five times or more with water to recover an ethyl acetate oil layer. Next, the ethyl acetate oil layer was concentrated and replaced with propylene glycol monomethyl ether acetate to obtain a 40% solution of a methylphenylsilsesquioxane condensation product.

The obtained siloxane resin was methylphenyl silsesquioxane (methyl group: phenyl group = 7: 3 mol ratio) of weight average molecular weight (Mw) 1,000.

The measurement of the weight average molecular weight (Mw) was performed on the following apparatuses and conditions (In addition, the measurement was performed on the same conditions also in the following examples).

Apparatus, method: Shimadzu Sesakusho HPLC (GPC system)

Column: GPC column (1 G2000HXL, 1 G4000HXL) manufactured by Tosoh Corporation

Using this apparatus, it measured by gel permeation chromatography (GPC) which makes monodisperse polystyrene the standard on the conditions of the flow volume of 0.7 mL / min, the elution solvent tetrahydrofuran, and column temperature 40 degreeC.

Production Example 2

In Production Example 1, the same method as in Production Example 1 was conducted except that the reaction temperature was set at 45 ° C to 60 ° C. This obtained the methylphenyl silsesquioxane (methyl group: phenyl group = 7: 3 mol ratio) of weight average molecular weight (Mw) 2,000.

Production Example 3

In Production Example 1, the same procedure as in Production Example 1 was conducted except that the reaction temperature was set at 45 ° C to 60 ° C and the reaction time was 1 hour to 6 hours, and the methylphenylsilsesqui having a weight average molecular weight (Mw) of 4,000 was obtained. Oxane (methyl group: phenyl group = 7: 3 mol ratio) was obtained.

Preparation Example 4

Into a 300 mL four-necked flask equipped with a stirrer, a reflux cooler, a dropping funnel, and a thermometer, 14.8 g of water, 1.4 g of 35 mass% hydrochloric acid, and 44.8 g of toluene were charged, and 3-acetoxypropyltrime 11.1 g (0.05 mol) of oxysilane, 40.8 g (0.3 mol) of methyltrimethoxysilane, and 29.7 g (0.15 mol) of phenyltrimethoxysilane were dissolved in 30 g of toluene, and the mixed solution was added dropwise at 15 to 25 ° C. After completion of the dropwise addition, the mixture was stirred at the same temperature for 30 minutes, and then allowed to stand by adding water, followed by liquid separation to recover the oil layer.

Thereafter, the mixture was washed three times with water to recover the toluene oil layer. Next, the toluene oil layer was placed in a branched flask, concentrated by an evaporator, and diluted with methanol to replace the solvent with methanol, and the total amount 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. Then it was stirred for 1 hour. After stirring was completed, ethyl acetate and water were added to separate the liquid, and the oil layer was recovered.

Thereafter, the mixture was washed five times or more with water to recover an ethyl acetate oil layer. Next, the ethyl acetate oil layer was concentrated and substituted with propylene glycol monomethyl ether acetate to obtain a 40% solution of 3-hydroxypropylsilsesquioxane condensation polymer.

The obtained 3-hydroxypropyl silsesquioxane polycondensate has a weight average molecular weight (Mw) of 3,000 methyl, 3-hydroxypropyl, and phenylsilsesquioxane (methyl group: 3-hydroxypropyl: phenyl group = 6: 1). : 3 mol ratio).

Preparation Example 5

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

240 g of trimethylsilyl iodide was dripped at 60 degreeC or less in the solution obtained in this way, and it was made to react at 60 degreeC for 10 hours. After the reaction was completed, 200 g of water was added to hydrolyze, and then a polymer layer was obtained by decant. 165 g of p-hydroxybenzylsilsesquioxane was obtained by vacuum drying the polymer layer. When the molecular weight of this polymer was measured using GPC (gel permeation chromatography), Mw was 3,000 in polystyrene conversion.

Preparation Example 6

400 ml of water was put into the reaction vessel provided with a reflux condenser, a dropping funnel and a stirrer, and 400 ml of n-butyl acetate was added thereto. The reaction vessel exterior was ice-cooled, and the stirring speed was made low so that an organic layer and an aqueous layer could be hold | maintained. Next, 52.2 g (0.35 mol) of methyl trichlorosilane and 31.7 g (0.15 mol) of phenyltrichlorosilane were dripped over 10 minutes from the dropping funnel. At this time, the temperature of the reaction mixture rose to 40 ° C. It was further stirred for 30 minutes. After the completion of the reaction, the organic layer was washed until the wash water became neutral, and then the solvent of the organic layer was distilled off under reduced pressure, and diluted to 40% with PGMEA to obtain the desired methylphenylsilsesquioxane. When the molecular weight of this polymer was measured using GPC (gel permeation chromatography), it was Mw = 2,000 (methyl group: phenyl group = 7: 3 mol ratio) in polystyrene conversion.

Example 1

10 g of a methylphenylsilsesquioxane (methyl group: phenyl group = 7: 3 mol ratio) solution having a weight average molecular weight (Mw) of 1,000 prepared in Production Example 1 to propylene glycol monomethyl ether acetate (PGMEA), and surfactant KF-54 [see : 0.08 g of Shin-Etsu Chemical Co., Ltd. (5% PGMEA solution) was added so that it might be set to 1,000 ppm, and it melt | dissolved by stirring, and produced the 35% solution by this. This solution was filtered with the Advantech Toyo Co., Ltd. syringe filter (25 mm (phi), PTFE, filtration accuracy 0.20 micrometer), and the siloxane composition was prepared. This composition was spin-coated at 600 rpm / 10 sec on a 6-inch silicon wafer using a Mikasa spin coater (manufactured by MIKASA Co., Ltd.), and then prebaked at 110 ° C. for 2 minutes in a hot plate, and having a thickness of 5 μm. The siloxane resin film of was obtained. The resin film was immersed in 0.4 wt% tetramethylammonium hydroxide (TMAH) aqueous solution for 30 seconds, then rinsed with ion-exchanged water, drained well, and calcined at 250 ° C. for 60 minutes in an oven.

Table 1 shows the results of evaluation of the transmittance (400 nm), pencil hardness, reduction rate of film thickness due to firing (hereinafter referred to as "sintering film reduction rate"), and the presence or absence of cracks in the fired film. In addition, each evaluation was performed with the following method.

Transmittance

The ultraviolet visible absorption spectrum of the obtained cured film was measured using Multi Spec-1500 by Shimadzu Corporation, and the transmittance | permeability in wavelength 400nm was calculated | required.

(Pencil hardness)

It measured based on JISK5600-5-4. If the pencil hardness is less than or equal to HB, there is a possibility that scratches may occur at the time of transporting the substrate or the like.

(Film thickness reduction rate)

The film thickness before firing and the film thickness after firing are performed using Lambda Ace VM-1200 (manufactured by Dainiphon Screen), and the parameters are measured in advance using a sample whose known absolute film thickness is known and the parameters are used. And optically measured, the reduction rate of the film thickness due to baking was calculated by the following equation.

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

(With or without cracks in the plastic film)

The presence or absence of cracking of the fired film was allowed to stand for 1 day and night after the film was fired, and it was visually confirmed whether or not there was a crack in a circle of 4 cmφ in the center of the 4-inch wafer.

Example 2

As in Example 1, except that methylphenylsilsesquioxane having a molecular weight of 2,000 obtained in Production Example 2 was used as the siloxane resin, and an aqueous 2.38% by weight tetramethylammonium hydroxide (TMAH) aqueous solution was used as the alkaline treatment liquid. A siloxane resin plastic hardened film was formed. Evaluation of the obtained cured cured film was performed like Example 1, and the result of Table 1 was obtained.

Example 3

As the siloxane resin, methyl, 3-hydroxypropyl and phenylsilsesquioxane (methyl group: 3-hydroxypropyl group: phenyl group = 6: 1: 3 mol ratio) having a molecular weight of 3,000 obtained in Production Example 4 were used, and also alkali. A siloxane resin calcined cured film was formed in the same manner as in Example 1 except that a 2.38 wt% tetramethylammonium hydroxide (TMAH) aqueous solution was used as the treatment liquid. Evaluation of the obtained baked cured film was performed like Example 1, and the result of Table 1 was obtained.

Example 4

A siloxane resin calcined cured film was formed in the same manner as in Example 1 except that a 0.3 wt% aqueous ethanolamine solution was used as the aqueous alkali solution. Evaluation of the obtained baked cured film was carried out similarly to Example 1, and the result of Table 1 was obtained.

Example 5

A siloxane plastic cured film was formed in the same manner as in Example 1 except that the surfactant KF-54 was not used. Evaluation of the obtained cured cured film was performed like Example 1, and the result of Table 1 was obtained.

Example 6

A methyl phenyl silsesquioxane having a molecular weight of 4,000 obtained in Production Example 3 was used as the siloxane resin, and a 5 wt% tetramethylammonium hydroxide (TMAH) aqueous solution was used as the aqueous alkali solution, and the firing temperature was 300 ° C. A siloxane resin calcined cured film was formed in the same manner as in Example 1 except that. Evaluation of the obtained cured cured film was performed like Example 1, and the result of Table 1 was obtained.

Example 7

A siloxane resin baking hardened film was formed like Example 1 except having set baking temperature to 180 degreeC. Evaluation of the obtained cured cured film was performed like Example 1, and the result of Table 1 was obtained.

Example 8

A siloxane resin baking hardened film was formed like Example 1 except having set baking temperature to 300 degreeC. Evaluation of the obtained cured cured film was performed like Example 1, and the result of Table 1 was obtained.

Example 9

A siloxane resin baking cured film was formed like Example 2 except having set the film thickness to 7 micrometers. Evaluation of the obtained cured cured film was performed like Example 1, and the result of Table 1 was obtained.

Example 10

A siloxane resin calcined cured film was formed in the same manner as in Example 2 except that methylphenylsilsesquioxane having a molecular weight of 2,000 obtained in Production Example 6 was used as the siloxane resin. Evaluation of the obtained cured cured film was performed like Example 1, and the result of Table 1 was obtained.

Comparative Example 1

A siloxane resin plastic hardened film was formed like Example 1 except not treating with aqueous alkali solution. Evaluation of the obtained cured cured film was performed like Example 1, and the result of Table 1 was obtained.

Comparative Example 2

A siloxane resin plastic hardened film was formed like Example 2 except not having processed with aqueous alkali solution. Evaluation of the obtained cured cured film was performed like Example 1, and the result of Table 1 was obtained.

Comparative Example 3

A siloxane resin calcined cured film was formed in the same manner as in Example 1 except that the alkali solution was not treated and the siloxane resin having a weight average molecular weight of 3,000 obtained in Production Example 5 was used. Evaluation of the obtained cured cured film was performed like Example 1, and the result of Table 1 was obtained.

Comparative Example 4

A siloxane resin plastic hardened film was formed like Example 6 except not having treated with aqueous alkali solution. Evaluation of the obtained cured cured film was performed like Example 1, and the result of Table 1 was obtained.

Comparative Example 5

A siloxane resin calcined cured film was formed in the same manner as in Example 1 except that the aqueous 1N hydrochloric acid solution was treated instead of the aqueous tetramethylammonium hydroxide (TMAH) solution. Evaluation of the obtained cured cured film was performed like Example 1, and the result of Table 1 was obtained.

Comparative Example 6

A siloxane resin plastic hardened film was formed like Example 10 except not having treated with aqueous alkali solution. Evaluation of the obtained cured cured film was performed like Example 1, and the result of Table 1 was obtained.

Comparative Example 7

A siloxane resin calcined cured film was formed in the same manner as in Example 1 except that treatment was performed with ion-exchanged water instead of tetramethylammonium hydroxide (TMAH) aqueous solution treatment. Evaluation of the obtained cured cured film was performed like Example 1, and the result of Table 1 was obtained.

As apparent from Table 1, by performing aqueous alkali solution treatment, it is excellent in transparency, has high scratch hardness, high insulation and low dielectric constant, and has excellent flatness, and does not cause cracks even with a thick film. There is no film peeling off, and the cured film of the silanol group or the alkoxy silyl group containing siloxane resin composition which is excellent in adhesiveness can be formed.

Claims (5)

In the hardening film formation method of the siloxane resin composition which hardens by superposition | polymerization of a silanol group or an alkoxy silyl group using a silanol group or an alkoxy silyl group containing siloxane resin composition, and forms a film, the said composition is apply | coated to a base material and is free After baking, it processes with alkali aqueous solution, and then rinses and bakes, The cured film formation method of the siloxane resin composition characterized by the above-mentioned. The method of forming a cured film of the siloxane resin composition according to claim 1, wherein the treatment with the aqueous alkali solution is performed by immersion in an aqueous alkali solution, a paddle, or a shower. The said alkali aqueous solution is an organic alkali aqueous solution, The cured film formation method of the siloxane resin composition of Claim 1 or 2 characterized by the above-mentioned. The said aqueous alkali solution is tetramethylammonium hydroxide aqueous solution, The cured film formation method of the siloxane resin composition of Claim 3 characterized by the above-mentioned. The said baking is performed at the temperature of 120-400 degreeC, The cured film formation method of the siloxane resin composition of any one of Claims 1-4 characterized by the above-mentioned.