KR101985547B1 - Agent for forming electrode protective film - Google Patents

Abstract

An electrode protecting film forming agent capable of forming an electrode protecting film of sufficient hardness even at a low temperature baking of 150 DEG C or less, an electrode protecting film, and an electronic device having the electrode protecting film. The present invention provides an electrode protecting film forming agent capable of forming a liquid crystal alignment film suppressing the occurrence of craters and pinholes, particularly when used in a liquid crystal display device.
An electrode protecting film forming agent comprising a polysiloxane obtained by polycondensation of an alkoxysilane containing at least one compound selected from the group consisting of a compound of the formula (1) and a compound of the formula (2).
R^OneSi (OR²)₃ (One)
(R^One Is a hydrocarbon group having 1 to 8 carbon atoms containing an ureido group, and R² Represents an alkyl group having 1 to 5 carbon atoms)
(R³)_nSi (OR⁴)_4-n(2)
(R³ Is a substituted or unsubstituted hydrocarbon group having 1 to 8 carbon atoms, R⁴ Is an alkyl group of 1 to 5 carbon atoms and n is an integer of 0 to 3)

Description

AGENT FOR FORMING ELECTRODE PROTECTIVE FILM [0001]

The present invention relates to an electrode protecting film forming agent containing a polysiloxane, an electrode protecting film and an electronic device having the electrode protecting film. And more particularly, to an electrode protective film forming agent, an electrode protecting film, and a liquid crystal display element having the electrode protecting film used in a liquid crystal display element.

In the production of a liquid crystal display element, an oxide film is formed between the transparent electrode and the liquid crystal alignment film for the purpose of insulating and protecting the transparent electrode. As a method for forming an oxide film, there is known a vapor phase method represented by a vapor deposition method, a sputtering method, and a coating method using a coating liquid for forming an oxide film. Of these, a coating method is widely used because of productivity and ease of film formation on a large substrate. As the coating liquid, a complex of a hydrolyzate of tetraalkoxysilane and other metal alkoxides or metal chelate compounds is known. When a coating solution is prepared by using a metal alkoxide, the metal alkoxide generally has a high hydrolysis rate except for silicon, and it is difficult to control the reaction. Therefore, it has been attempted to cause a chelating agent such as acetylacetone to act on the alkoxide to adjust the hydrolysis rate of the alkoxide. However, in general, a chelated compound has a high thermal decomposition temperature, and calcination at 450 DEG C or more is considered to be preferable (see, for example, Patent Document 1).

As another method, it has been attempted to prepare a transparent coating agent without adding stabilizing means such as chelation by adding a mineral acid to the hydrolyzate of silicon alkoxide and titanium alkoxide in the silica-titania coating liquid. In this case, too, baking at least 300 DEG C is required (see, for example, Patent Document 2).

In recent years, a display using a plastic plate or a plastic film on a substrate such as a plastic LCD or an electronic paper has been proposed, and it has been proposed that sufficient hardness can be obtained even at a low temperature of 200 캜 or lower and the upper layer alignment agent can be applied without defects Is required.

Japanese Patent Application Laid-Open No. 63-258959 Japanese Patent Application Laid-Open No. 55-25487

In the methods of Patent Documents 1 and 2, an electrode protective film of sufficient hardness can not be obtained at a firing temperature of 200 ° C or less. When a liquid crystal alignment film is formed on the electrode protective film, there is a problem that craters and pinholes are generated in the alignment film.

An object of the present invention is to provide an electrode protecting film forming agent, an electrode protecting film, and an electronic device having the electrode protecting film which can form an electrode protecting film of sufficient hardness even when baked at a low temperature of 150 캜 or less. It is an object of the present invention to provide an electrode protective film forming agent capable of forming a liquid crystal alignment film in which the generation of craters and pinholes is suppressed in the upper layer of the electrode protective film when used in a liquid crystal display device.

Means for Solving the Problems The present inventors have made intensive studies in view of the above circumstances, and have completed the present invention.

That is, the gist of the present invention is as follows.

1. An electrode protection film formation method, characterized by comprising a polysiloxane obtained by polycondensation of an alkoxysilane containing at least one compound selected from the group consisting of an alkoxysilane represented by the formula (1) and an alkoxysilane represented by the formula (2) My.

R ¹ {Si (OR ² ) ₃ } _P (1)

(R ¹ is a hydrocarbon group of 1 to 12 carbon atoms substituted with an ureido group, R ² is an alkyl group of 1 to 5 carbon atoms, and p is an integer of 1 or 2)

(R³)_nSi (OR⁴)_4-n (2)

(Wherein R ³ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms which may be substituted with a hetero atom, a halogen atom, a vinyl group, an amino group, a glycidoxy group, a mercapto group, a methacryloxy group, an isocyanate group or an acryloxy group A hydrocarbon group, R ⁴ is an alkyl group having 1 to 5 carbon atoms, and n is an integer of 0 to 3)

2. The electrode protecting film forming agent according to 1 above, wherein the alkoxysilane represented by the formula (2) is tetraalkoxysilane wherein n in the formula (2) is 0.

3. The alkoxysilane represented by the above formula (1) is contained in an amount of 0.5 to 60 mol% of the total alkoxysilane and the alkoxysilane represented by the formula (2) is contained in the total alkoxysilane in an amount of 40 to 99.5 mol% And the like.

4. The alkoxysilane represented by the above formula (1) is at least one selected from the group consisting of? -Ureidopropyltriethoxysilane,? -Ureidopropyltrimethoxysilane and? -Ureidopropyltripropoxysilane The electrode protecting film forming agent according to any one of 1 to 3 above.

5. An electrode protective film obtained by applying the liquid crystal aligning agent according to any one of 1 to 4 above to a substrate and firing.

6. A method for forming an electrode protective film, comprising applying the electrode protective film forming agent according to any one of 1 to 4 above to a substrate, drying the coated film at a temperature from room temperature to 120 deg.

7. The method for forming an electrode protective film according to 6 above, wherein the baking temperature is 100 to 180 占 폚.

(8) An electronic device having the electrode protection film according to (5) above.

9. A liquid crystal display element having an electrode protective film as described in 5 above.

The electrode protective film obtained from the electrode protecting film forming agent of the present invention has sufficient hardness under low temperature curing conditions of 150 DEG C or lower and can be applied to a substrate having low heat resistance such as a plastic substrate. When used in a liquid crystal display device, a liquid crystal alignment film suppressing cratering or pinholes can be formed on the formed electrode protective film. Therefore, it is useful for the production of a liquid crystal display element having excellent display characteristics even on a substrate having low heat resistance such as a plastic substrate.

The electrode protective film forming agent of the present invention is characterized by containing a polysiloxane having a ureido group. Therefore, an electrode protective film having sufficient hardness even at a low temperature of 100 to 150 캜 can be formed.

Conventionally, when an oxide thin film formed from a siloxane polymer or an oxide precursor has a low firing temperature, alkoxy groups remaining in the coating film are not sufficiently decomposed. Therefore, when used in a liquid crystal display device, sufficient affinity and adhesiveness can not be obtained with a polyimide alignment film having different interfacial characteristics, and it is presumed that when the alignment film is formed, cratering or pinholes are generated have. In the present invention, by containing an ureido group in the electrode protecting film forming agent, affinity with the polyimide type aligning agent can be improved, so that cratering and pinholes can be suppressed. In addition, It is presumed that even if calcined at a low temperature, it is sufficiently cured.

Hereinafter, the present invention will be described in detail.

[Polysiloxane]

The electrode protecting film forming agent of the present invention is a polysiloxane obtained by polycondensation of an alkoxysilane containing an alkoxysilane represented by the following formula (1).

R ¹ {Si (OR ² ) ₃ } _P (1)

In the formula (1), R ¹ is a hydrocarbon group of 1 to 12 carbon atoms substituted with a ureido group, and more specifically, a group in which any hydrogen atom of a hydrocarbon group of 1 to 12 carbon atoms is substituted with a ureido group . R ¹ is preferably 1 to 7 carbon atoms in the hydrocarbon group substituted with a ureido group. R ² is an alkyl group having 1 to 5 carbon atoms, preferably an alkyl group having 1 to 3 carbon atoms, more preferably a methyl group or an ethyl group. p represents an integer of 1 or 2; R ¹ and R ² may be a linear chain structure or a branched structure.

In the alkoxysilane represented by the formula (1), when p is 1, it is an alkoxysilane represented by the formula (1-1).

R ¹ Si (OR ² ) ₃ (1-1)

When p is 2, it is an alkoxysilane represented by the formula (1-2).

(R ² O) ₃ Si-R ¹ -Si (OR ² ) ₃ (1-2)

Specific examples of the alkoxysilane represented by the formula (1-1) include, but are not limited to, the following. (R) -N-1-phenylethyl-N ' -triethoxysilane, [gamma] -ureidopropyltrimethoxysilane, [gamma] -ureidopropyltripropoxysilane, (R) -N-1-phenylethyl-N'-trimethoxysilylpropylurea, and the like.

Among them, γ-ureidopropyltriethoxysilane or γ-ureidopropyltrimethoxysilane is particularly preferable because it is readily available as a commercial product.

Specific examples of the alkoxysilane represented by the formula (1-2) include, but are not limited to, the following. For example, there may be mentioned bis [3- (triethoxysilyl) propyl] urea, bis [3- (triethoxysilyl) ethyl] urea, bis [3- (trimethoxysilyl) (Tripropoxysilyl) propyl] urea. Among them, bis [3- (triethoxysilyl) propyl] urea is particularly preferable because it is commercially available and easy to obtain.

When the alkoxysilane represented by the formula (1) is used in an amount of less than 0.5 mol% in the total alkoxysilane used for obtaining the electrode protecting film forming agent, the printing property of a good liquid crystal alignment film may not be obtained. desirable. More preferably, it is 1.0 mol% or more. More preferably, it is 2.0 mol% or more. On the other hand, if it exceeds 60 mol%, the electrode protective film to be formed may not be sufficiently cured, so that it is preferably 60 mol% or less. More preferably, it is 50 mol% or less. More preferably, it is 40 mol% or less.

The electrode protecting film forming agent of the present invention can be obtained by polycondensation of an alkoxysilane represented by the formula (1) and an alkoxysilane containing at least one alkoxysilane represented by the following formula (2).

(R³)_nSi (OR⁴)_4-n (2)

(Wherein R ³ is a hydrogen atom or a group selected from the group consisting of a hetero atom, a halogen atom, a vinyl group, an amino group, a glycidoxy group, a mercapto group, a methacryloxy group, an isocyanate group or an acryloxy group, Preferably a hydrocarbon group having 1 to 6 carbon atoms, R ⁴ is an alkyl group having 1 to 5 carbon atoms, preferably 1 to 3 carbon atoms, and n is an integer of 0 to 3, preferably 0 to 2 )

R ³ of the alkoxysilane represented by the formula (2) may be a hydrogen atom or a hetero atom, a halogen atom, a vinyl group, an amino group, a glycidoxy group, a mercapto group, a methacryloxy group, an isocyanate group or an acryloxy group , And a hydrocarbon group having 1 to 8 carbon atoms, preferably 1 to 6 carbon atoms. R ⁴ has the same meaning as R ² described above, and the preferable range thereof is also the same. Examples of R ³ include aliphatic hydrocarbons; A cyclic structure such as an aliphatic ring, an aromatic ring or a heterocyclic ring; Unsaturated bonds; A hetero atom such as an oxygen atom, a nitrogen atom or a sulfur atom, or an organic group having 1 to 6 carbon atoms, which may have a branched structure. Further, R ³ may be substituted with a halogen atom, a vinyl group, an amino group, a glycidoxy group, a mercapto group, a methacryloxy group, an isocyanate group, an acryloxy group and the like.

Specific examples of the alkoxysilane represented by the formula (2) are shown below, but the invention is not limited thereto.

Specific examples of the alkoxysilane in which R ³ is a hydrogen atom in the alkoxysilane of the formula (2) include trimethoxysilane, triethoxysilane, tripropoxysilane and tributoxysilane.

Specific examples of other alkoxysilanes of the formula (2) include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, Aminopropyltrimethoxysilane, N-2 (aminoethyl) 3-aminopropyltriethoxysilane, N-2 (aminoethyl) Aminoethylaminomethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3- (2-aminoethylaminopropyl) trimethoxysilane, 3- (2-aminoethylaminopropyl) Vinyltriethoxysilane, vinyltrimethoxysilane, allyltriethoxysilane, vinyltrimethoxysilane, vinyltrimethoxysilane, vinyltrimethoxysilane, vinyltrimethoxysilane, vinyltrimethoxysilane, vinyltrimethoxysilane, vinyltrimethoxysilane, , 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, Acryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, 3-isocyanatopropyltriethoxysilane, trifluoropropyltrimethoxysilane, chloropropyltriethoxysilane, bromopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, dimethyldiethoxysilane, dimethyldimethoxysilane, diethyldiethoxysilane, diethyldimethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, 3-aminopropyltrimethoxysilane, Propyl methyldiethoxysilane, 3-aminopropyldimethylethoxysilane, trimethylethoxysilane, trimethylmethoxysilane, and the like.

The electrode protective film forming agent of the present invention may contain one or more such specific organic groups as long as the effects of the present invention, such as adhesion with the substrate, hardness of the film, and printability of the upper liquid crystal alignment film, are not impaired.

In the alkoxysilane represented by the formula (2), the alkoxysilane wherein n is 0 is tetraalkoxysilane. Since tetraalkoxysilane is easily condensed with an alkoxysilane represented by the formula (1), it is preferable to obtain the polysiloxane of the present invention.

As the alkoxysilane in which n is 0 in the formula (2), tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane or tetrabutoxysilane is more preferable, and tetramethoxysilane or tetraethoxysilane Is particularly preferable.

When the alkoxysilane represented by the formula (2) is used in combination, the alkoxysilane represented by the formula (2) is preferably contained in an amount of 40 to 99.5 mol% in the total alkoxysilane used for obtaining the electrode protective film forming agent. And more preferably 50 to 99.5 mol%. And more preferably 60 to 99.5 mol%.

In the present invention, the electrode protecting film forming agent is preferably a polysiloxane obtained by polycondensation of an alkoxysilane represented by formula (1) and at least one compound selected from an alkoxysilane represented by formula (2).

The electrode protective film forming agent of the present invention may be used in combination with one or more of such alkoxysilanes as long as the effects of the present invention such as hardness of the film and printing property of the upper liquid crystal alignment film are not impaired.

[Production method of polysiloxane]

The method for obtaining the polysiloxane to be used in the present invention is not particularly limited, but the present invention can be obtained by condensing an alkoxysilane containing the alkoxysilane of the above formula (1) as an essential component in an organic solvent. Generally, the polysiloxane is obtained as a solution in which such alkoxysilane is polycondensed and uniformly dissolved in an organic solvent.

Examples of the polycondensation method in the present invention include a method of hydrolyzing and condensing the above alkoxysilane in a solvent such as an alcohol or a glycol. At this time, the hydrolysis-condensation reaction may be either partial hydrolysis or complete hydrolysis. In the case of complete hydrolysis, theoretically, 0.5-fold molar water of the total alkoxide group in the alkoxysilane may be added, and it is usually preferable to add an excess amount of water in excess of 0.5-molar mol.

In the present invention, the amount of water used in the reaction can be appropriately selected according to the desired amount. The amount of water is usually 0.5 to 2.5 times, more preferably 0.75 to 1.5 times, mole of the total alkoxy groups in the alkoxysilane.

For the purpose of promoting the hydrolysis and condensation reaction, an acid such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, formic acid, oxalic acid, maleic acid, and fumaric acid; Alkali such as ammonia, methylamine, ethylamine, ethanolamine, triethylamine and the like; A catalyst such as a metal salt of hydrochloric acid, sulfuric acid, nitric acid or the like is used. In addition, it is also common to accelerate the hydrolysis / condensation reaction by heating the solution in which the alkoxysilane is dissolved. At that time, the heating temperature and the heating time can be appropriately selected according to the desired one. For example, heating and stirring at 50 ° C for 24 hours, or heating and stirring for 1 hour under reflux.

As another method, a method of polycondensing a mixture of an alkoxysilane, a solvent and an organic acid such as formic acid, oxalic acid, maleic acid, and fumaric acid may be mentioned. For example, a method of polycondensing a mixture of alkoxysilane, a solvent and oxalic acid by heating may be mentioned. Specifically, oxalic acid is added to the alcohol in advance to prepare an alcohol solution of oxalic acid, and then the alkoxysilane is mixed while heating the solution. At this time, the amount of oxalic acid to be used is preferably 0.2 to 2 mol based on 1 mol of the total alkoxy group of the alkoxysilane. The heating in this method can be carried out at a liquid temperature of 50 to 180 ° C. Preferably, this is a method of heating for several ten minutes to several ten hours under reflux so as not to evaporate or volatilize the liquid.

When a plurality of alkoxysilanes are used in obtaining the polysiloxane, a mixture of a plurality of types of alkoxysilanes may be used in advance, or a plurality of types of alkoxysilanes may be used in sequence.

The solvent used for polycondensing the alkoxysilane (hereinafter also referred to as a polymerization solvent) is not particularly limited as long as it dissolves the alkoxysilane. In addition, even when the alkoxysilane is not dissolved, it may be any one that dissolves along with the progress of the polycondensation reaction of the alkoxysilane. Generally, an organic solvent having good compatibility with alcohols, glycols, glycol ethers, or alcohols is used because alcohol is produced by the polycondensation reaction of alkoxysilane.

Specific examples of such polymerization solvents include alcohols such as methanol, ethanol, propanol, butanol, and diacetone alcohol; Ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, hexylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, , 2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 2,4-pentanediol, 2,3-pentanediol, 1,6- Ryu; Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dipropyl ether, ethylene glycol dibutyl ether, diethylene glycol Monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl Propylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dipropyl ether, propylene glycol dibutyl ether Glycol ethers such as t-butyl ether; N-dimethylformamide, N, N-dimethylacetamide,? -Butyrolactone, dimethylsulfoxide, tetramethylurea, hexamethylphosphoric triamide, m-cresol, etc. .

In the present invention, a plurality of the polymerization solvents may be mixed and used.

The polymerization solution of the polysiloxane (hereinafter also referred to as a polymerization solution) obtained by the above-mentioned method is added to the polymerization solution in such a manner that the concentration of the silicon atoms of the entire alkoxysilane injected as the raw material in terms of SiO ₂ (hereinafter referred to as SiO ₂ concentration) . By selecting an arbitrary concentration in this concentration range, generation of gel can be suppressed and a homogeneous solution can be obtained.

In the present invention, the polymerized polysiloxane solution obtained by the above method may be used as an electrode protective film forming agent as it is. If necessary, the solution obtained by the above method may be concentrated or diluted with a solvent or replaced with another solvent to form an electrode protective film It may be zero.

At this time, the solvent to be used (hereinafter also referred to as an addition solvent) may be the same as or different from the polymerization solvent. This addition solvent is not particularly limited as long as the polysiloxane is uniformly dissolved, and even a single kind or plural kinds of solvents can be arbitrarily selected and used.

Specific examples of such an addition solvent include ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; And esters such as methyl acetate, ethyl acetate and ethyl lactate.

These solvents can improve the applicability when the electrode protective film forming agent is applied onto the substrate by adjusting the viscosity of the electrode protective film forming agent, or by spin coating, flexographic printing, ink jet, slit coating or the like.

[Other components]

In the present invention, as long as the effects of the present invention are not impaired, other components other than the polysiloxane such as inorganic microfine particles, metaloxyl oligomers, metaloxyl polymers, leveling agents, and surfactants .

As the inorganic fine particles, fine particles such as silica fine particles, alumina fine particles, titania fine particles, or magnesium fluoride fine particles are preferable, and in particular, they are preferably in a colloid solution state. The colloidal solution may be a dispersion of inorganic fine particles in a dispersion medium, or a colloidal solution of a commercial product. In the present invention, incorporation of the inorganic fine particles makes it possible to adjust the surface shape and the refractive index of the formed cured coating, and to impart other functions. The inorganic fine particles preferably have an average particle diameter of 0.001 to 0.2 mu m, more preferably 0.001 to 0.1 mu m. When the average particle diameter of the inorganic fine particles exceeds 0.2 탆, the transparency of the cured coating formed using the coating liquid to be prepared may be lowered.

Examples of the dispersion medium of the inorganic fine particles include water and an organic solvent. As the colloid solution, it is preferable that pH or pKa is adjusted to 1 to 10 from the viewpoint of stability of the electrode protecting film forming agent. The pH or pKa is more preferably 2 to 7.

Examples of the organic solvent for use in the dispersion medium of the colloid solution include alcohols such as methanol, propanol, butanol, ethylene glycol, propylene glycol, butanediol, pentanediol, hexyleneglycol, diethylene glycol, dipropylene glycol and ethylene glycol monopropyl ether ; Ketones such as methyl ethyl ketone and methyl isobutyl ketone; Aromatic hydrocarbons such as toluene and xylene; Amides such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone; Esters such as ethyl acetate, butyl acetate and? -Butyrolactone; And ethers such as tetrahydrofuran and 1,4-dioxane. Of these, alcohols and ketones are preferred. These organic solvents may be used alone or as a dispersion medium by mixing two or more kinds thereof.

As the metal oxalic oligomer and the metal oxalic polymer, a single or complex oxide precursor such as silicon, titanium, aluminum, tantalum, antimony, bismuth, tin, indium or zinc is used. The metal acid oligomer and the metal acid polymer may be commercially available products or may be obtained from monomers such as metal alkoxides, nitrates, hydrochlorides and carboxylates by a conventional method such as hydrolysis.

Specific examples of commercially available metaloxyl oligomers and metal oxalic polymers include siloxane oligomers such as methyl silicate 51, methyl silicate 53A, ethyl silicate 40, ethyl silicate 48, EMS-485 and SS-101, , And titanoxane oligomers such as titanium-n-butoxide tetramer manufactured by Kanto Chemical Co., Ltd. These may be used alone or in combination of two or more.

In addition, known leveling agents and surfactants can be used, and commercially available products are particularly preferred because they are readily available.

The method of mixing the above other components with the polysiloxane may be carried out simultaneously with or after the polysiloxane, and is not particularly limited.

[Electrode protective film]

A desired electrode protective film can be obtained by applying the electrode protecting film forming agent of the present invention to a substrate on which an electrode or an electrode is formed and thermally curing it. As a method for applying the electrode protecting film forming agent, a known or well-known method may be employed. For example, a dip coating method, a flow coating method, a spraying method, a bar coating method, a gravure coating method, a roll coating method, a blade coating method, an air knife coating method, a flexo printing method, an ink jet method, have. Among them, a good coating film can be formed by the flexo printing method, the slit coat method, the ink jet method, the spray coat method, and the gravure coat method.

At this time, the substrate used is plastic; Glass ; Glass formed with transparent electrodes such as ATO, fluorine-doped tin oxide (FTO), ITO, and IZO; Ceramics, and the like. As the plastic, there may be used a plastic such as polycarbonate, poly (meth) acrylate, polyethersulfone, polyarylate, polyurethane, polysulfone, polyether, polyetherketone, polyolefin, polyethylene terephthalate, polyacrylonitrile, triacetylcellulose, Diacetylcellulose, acetate butyrate cellulose, and the like. The shape of the substrate may be a plate or a film.

The electrode protective film forming agent is generally filtered using a filter or the like before application.

The coating film formed on the substrate is dried at a temperature of room temperature to 120 ° C, preferably 60 to 90 ° C, and then thermally cured at a temperature of preferably 100 to 180 ° C, more preferably 150 to 180 ° C. At that time, the time required for drying may be 30 seconds or more, but 10 minutes or less is sufficient.

The time required for thermal curing can be appropriately selected, but it may be 5 minutes or more. When a low curing temperature is selected, it is easy to obtain an electrode protective film having sufficient hardness by lengthening the curing time.

Further, the electrode protective film forming agent of the present invention can obtain a cured film having sufficient hardness even at a curing temperature exceeding 180 캜.

It is also effective to irradiate an energy ray (ultraviolet ray or the like) using a mercury lamp, a metal halide lamp, a xenon lamp, an excimer lamp or the like prior to thermosetting. By irradiating the dried coating film with an energy ray, the curing temperature can be further lowered or the hardness of the coating film can be increased. The irradiation amount of the energy ray can be appropriately selected in accordance with the need, and is usually several hundreds to several thousand mJ / cm 2.

The electrode protective film of the present invention has good printability of the liquid crystal alignment material on the film, and therefore, a liquid crystal alignment film suppressing cratering and pinholes can be formed.

Therefore, the electrode protective film forming agent of the present invention can form an electrode protective film having the above-described characteristics, and is therefore very useful for improving the display characteristics of a liquid crystal display element.

Example

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

In the present embodiment, the abbreviations of the used compounds are as follows.

TEOS: tetraethoxysilane

APS: 3-aminopropyltriethoxysilane

GPS: 3-glycidoxypropyltrimethoxysilane

MPS: 3-mercaptopropyltrimethoxysilane

UPS: 3-ureidopropyltriethoxysilane

MPMS: 3-methacryloxypropyltrimethoxysilane

TET: Tetraethoxy titanium

AN: aluminum nitrate 9 hydrate

HG: Hexylene glycol (also known as 2-methyl-2,4-pentanediol)

PGME: Propylene glycol monomethyl ether (also known as 1-methoxy-2-propanol)

BCS: butyl cellosolve (aka 1-butoxy-2-ethanol)

PB: propylene glycol monobutyl ether (aka 1-butoxy-2-propanol)

NMP: N-methyl-2-pyrrolidone

1,4-BDO: 1,4-butanediol

MeOH: methanol

EtOH: ethanol

[Synthesis Example 1]

To a 200 ml four-neck reaction flask equipped with a thermometer and a reflux tube, 39.0 g of MeOH was added and a small amount of 18.0 g of oxalic acid was added to the MeOH under stirring to prepare a methanol solution of oxalic acid. Then, this solution was heated to the reflux temperature, and 8.6 g of a methanol solution containing 10.4 g of tetraethoxysilane, 1.1 g of APS, 2.4 g of GPS, 1.0 g of MPS and 92% of UPS in a refluxing solution (UPS content: 7.9 g) and 19.5 g of MeOH was added dropwise over 45 minutes. After completion of the dropwise addition, the solution (L1) of the polysiloxane was prepared by heating under reflux for 5 hours and cooling.

In a 300 ml flask, 100 g of the polysiloxane solution L1 and 64.0 g of HG, 48.0 g of NMP and 32.0 g of 1,4-BDO were mixed as a solvent. Subsequently, the solvent was distilled off under reduced pressure gradually from 60 DEG C to 20 mmHg (2.67 m &liter;) by a NEW rotary rotary pressurizer (NE-1, manufactured by Tokyo Ehwa Machinery), and 184.0 g of the solvent was replaced with NMP (Hereinafter, also referred to as a substitution solution). Thereafter, 184.0 g of this substituted solution was mixed with 16.0 g of PGME to obtain a polysiloxane diluted solution (LA1) having a solid content concentration of 3 mass% in terms of SiO ₂ .

[Synthesis Example 2]

(Methanol content: 8.8 g) containing 92% of methanol and 34.8 g of MeOH, 27.8 g of TEOS and a UPS was charged into a 200 ml four-necked flask equipped with a reflux condenser, a thermometer and a reflux condenser, Was prepared. To this solution, a solution prepared by previously mixing 17.64 g of MeOH, 9.00 g of water and 1.50 g of oxalic acid as a catalyst was added dropwise over 30 minutes at room temperature, and the mixture was stirred for 30 minutes at room temperature for 30 minutes. Thereafter, after heating for 1 hour under reflux, the solution was cooled to obtain a polysiloxane solution having a solid content in terms of SiO ₂ of 10 mass%.

To 30.0 g of the obtained polysiloxane solution, 35.0 g of HG and 35.0 g of BCS were mixed to obtain a polysiloxane diluted solution (LA2) having a solid content concentration of 3 mass% in terms of SiO ₂ .

[Synthesis Example 3]

31.8 g of PGME and 33.0 g of TEOS were added to a 200 ml four-neck reaction flask equipped with a stirrer, a thermometer and a reflux tube, and stirred to prepare a solution of the alkoxysilane monomer. To this solution, a solution prepared by previously mixing 15.9 g of PGME, 15.0 g of water and 0.2 g of oxalic acid as a catalyst was added dropwise over 30 minutes at room temperature, and the mixture was stirred for 30 minutes at room temperature for 30 minutes. Thereafter, after heating for 30 minutes under reflux, a solution prepared by mixing 2.4 g of a methanol solution containing 92% of UPS (2.2 g of UPS content) and 1.8 g of PGME was added, and further heated for 30 minutes under reflux, To obtain a polysiloxane solution having a solid content in terms of SiO ₂ of 10 mass%.

The resulting polysiloxane solution, 30.0 g, PGME 60.0 g, and a mixture of HG 10.0 g, SiO ₂ in terms of solid content concentration of 3 mass% to obtain a polysiloxane solution is diluted (LA3).

[Synthesis Example 4]

31.5 g of PGME, 31.2 g of TEOS and 2.1 g of MPMS were added to a 200 ml four-neck reaction flask equipped with a reflux condenser, a thermometer and a reflux condenser, and stirred to prepare a solution of the alkoxysilane monomer. To this solution, a solution prepared by previously mixing 15.7 g of PGME, 15.0 g of water and 0.3 g of oxalic acid as a catalyst was added dropwise over 30 minutes at room temperature, and the mixture was stirred for 30 minutes at room temperature for 30 minutes. Thereafter, after heating for 30 minutes under reflux, a solution prepared by mixing 2.4 g of a methanol solution containing 92% of UPS (2.2 g of UPS content) and 1.8 g of PGME was added, and further heated for 30 minutes under reflux, To obtain a polysiloxane solution having a solid content in terms of SiO ₂ of 10 mass%.

To 30.0 g of the obtained polysiloxane solution, 60.0 g of PGME and 10.0 g of HG were mixed to obtain a polysiloxane dilute solution (LA4) having a solid content concentration of 3 mass% in terms of SiO ₂ .

[Synthesis Example 5]

20.6 g of HG, 6.9 g of BCS and 37.5 g of TEOS were added to a 200 ml four-neck reaction flask equipped with a reflux condenser, a thermometer and a reflux tube, and stirred to prepare a solution of an alkoxysilane monomer. To this solution, a solution prepared by previously mixing 10.3 g of HG, 3.4 g of BCS, 10.8 g of water and 0.5 g of oxalic acid as a catalyst was added dropwise over 30 minutes at room temperature, and the mixture was stirred for 30 minutes at room temperature for 30 minutes. Thereafter, after heating for 30 minutes under reflux, a solution prepared by mixing 5.8 g (UPS content: 5.3 g) of a methanol solution containing 92% of UPS, 3.2 g of HG and 1.1 g of BCS was added and further refluxed for 30 minutes After heating, the solution was allowed to cool to obtain a polysiloxane solution having a solid content in terms of SiO ₂ of 12 mass%.

To 30.0 g of the obtained polysiloxane solution, 41.9 g of HG, 7.1 g of BCS and 40.9 g of PB were mixed to obtain a polysiloxane diluted solution (LA5) having a solid content concentration of 3 mass% in terms of SiO ₂ .

[Synthesis Example 6]

90 g of the polysiloxane diluent solution (LA2) obtained in Synthesis Example 2, 3.0 g of colloidal silica fine particles (product name: methanol silica sol, manufactured by Nissan Chemical Industries, Ltd., solid concentration in terms of SiO _2: 30 mass%) and 7.0 g of MeOH The mixture was stirred at room temperature for 30 minutes to obtain a polysiloxane diluted solution (LA6) having a solid content in terms of SiO ₂ of 3 mass%.

[Comparative Synthesis Example 1]

An ethanol solution of oxalic acid was prepared by adding 40.3 g of EtOH to a 200 ml four-neck reaction flask equipped with a reflux condenser, a thermometer and a reflux condenser, and adding 18.0 g of oxalic acid to the EtOH in small amounts. Subsequently, this solution was heated to the reflux temperature, and a mixture of 20.8 g of TEOS and 20.8 g of EtOH was added dropwise to this refluxing solution over 45 minutes. After completion of the dropwise addition, heating was continued for 5 hours under reflux and then cooled to prepare a solution of polysiloxane.

In a 300 ml flask, 100 g of the polysiloxane solution and 64.0 g of HG, 48.0 g of NMP and 32.0 g of 1,4-BDO were mixed as a solvent. Subsequently, the solvent was distilled off under reduced pressure gradually from 60 DEG C to 20 mmHg (2.67 m &liter;) by a NEW rotary rotary pressurizer (NE-1 manufactured by Tokyo Ehwa Machinery Co., Ltd.) to obtain a replacement solution of 184.0 g. Thereafter, 18.0 g of this substituted solution was mixed with 16.0 g of PGME to obtain a polysiloxane diluted solution (LB1) having a solid content concentration of 3 mass% in terms of SiO ₂ .

[Comparative Synthesis Example 2]

23.7 g of HG, 7.9 g of BCS and 41.7 g of TEOS were added to a 200 ml four-neck reaction flask equipped with a reflux condenser, a thermometer and a reflux condenser, and stirred to prepare a solution of the alkoxysilane monomer. To this solution, a solution prepared by previously mixing 11.8 g of HG, 3.9 g of BCS, 10.8 g of water and 0.2 g of oxalic acid as a catalyst was added dropwise over 30 minutes at room temperature, and the mixture was stirred for 30 minutes at room temperature for 30 minutes. Thereafter, after heating for 60 minutes under reflux, the solution was cooled to obtain a polysiloxane solution having a solid content in terms of SiO ₂ of 12 mass%.

To 30.0 g of the obtained polysiloxane solution, 55.2 g of HG, 9.2 g of BCS and 55.6 g of PB were mixed to obtain a polysiloxane diluted solution (LB2) having a solid content concentration of 3 mass% in terms of SiO ₂ .

[Comparative Synthesis Example 3]

2.5 g of pure water, 64.8 g of ethanol and 2.7 g of AN as a catalyst were introduced into a 300 ml flask, and stirred to obtain a homogeneous solution. To this solution was added 14.3 g of TEOS and the mixture was stirred at room temperature for 30 minutes. Thereafter, 15.7 g of TET was added, and the mixture was stirred at room temperature for 30 minutes. This solution was used as a solution (pre-replacement solution) before the solvent was replaced with HG.

In a 300 ml flask, 24.0 g of the obtained pre-substitution solution and 25.87 g of HG were mixed. Next, the solvent was distilled off by gradually reducing the pressure from 60 占 폚 to 20 mmHg (2.67 占 ㎪) by a NEW rotary rotary pressurizer (NE-1 manufactured by Tokyo Ehwa Machinery Co., Ltd.) to obtain 28.9 g of a displacement solution. Thereafter, 28.9 g of the substitution solution was mixed with 11.1 g of PGME to prepare a polytitanosiloxane dilute solution (LB3) having a solid content concentration of 3 mass% in terms of SiO ₂ .

[Evaluation of electrode protective film]

The electrode protective film formed from the obtained solutions (LA1 to LA6) and (LB1 to LB3) was evaluated for pencil hardness, water contact angle and liquid crystal alignment film printability using a method described later. The results are shown in Table 1.

From the results shown in Table 1, it can be seen that the electrode protective film obtained by the present invention is generally considered to have a sufficient hardness when the film is used as an electrode protective film (insulating film) of a liquid crystal display element even at a low temperature curing temperature of 150 DEG C or lower 5 H or more.

Further, even when a polyamic acid type as well as a soluble polyimide type liquid crystal aligning agent were used on this film, excellent film formation without cratering and pinholes was exhibited.

[Pencil hardness]

The polysiloxane solution (coating liquid) of the synthetic examples (LA1 to LA6) and the comparative synthetic examples (LB1 to LB3) was filtered using a chromatography disk (pore size 0.45 mu m, manufactured by Kurashiki Shimbun). Thereafter, the glass substrate was dropped onto an ITO-adhered glass substrate (ITO film thickness: 140 nm) having a thickness of 0.7 mm, and a preliminary rotation for 5 seconds at 300 rpm using a spin coater (1H- Thereafter, the film was rotated at a rotation number of 2000 to 5000 rpm for 20 seconds to form a coating film. Subsequently, after drying for 3 minutes on a hot plate at a temperature of 80 ° C, the cured coating was heated on a hot plate at a curing temperature of 150 ° C for 15 minutes. The pencil hardness of the obtained cured film was measured according to the test method (JIS K5400).

[Water contact angle]

The contact angle when 3 microliters of pure water was dropped using an automatic contact angle caliper type CA-Z manufactured by Kyowa Interface Science Co., Ltd. was measured. The mode of the substrate used and the method of manufacturing the protective film are the same as in the case of [pencil hardness] measurement.

[Liquid crystal alignment film printability]

Anilox roll (300 #) manufactured by Inuma Kogyo Seisakusho Co., Ltd., a convex plate (400 L 30% 75% dot) was used on a cured film formed by the same method as the above-mentioned [Pencil hardness] , A liquid crystal aligning agent (SANEVA (registered trademark) SE-3140 0735 (trade name, polyamide acid type), SE-7492 062M (trade name; polyamide acid / soluble polyimide blend type) 062B (trade name: soluble polyimide type)). Thereafter, the substrate was dried on a hot plate at 80 캜 for 3 minutes to form a liquid crystal alignment film. The formed liquid crystal alignment film was observed with naked eyes to see if the liquid crystal alignment film had a good case without cratering, pinholes and unevenness, a case where pinholes or unevenness occurred, and a case where cratering was generated, .

Industrial availability

The electrode protective film forming agent of the present invention can form an electrode protective film excellent in the coating film forming ability in the flexo printing method, the slit coat method, the ink jet method, the spray coat method and the gravure coat method, have. Further, the formed electrode protective film can form a liquid crystal alignment film suppressing craters or pinholes on the upper layer thereof. Therefore, it is useful as an electrode protecting film for a liquid crystal display device using a plastic substrate requiring firing at a low temperature, or an electronic paper of liquid crystal type.

On the other hand, the entire contents of the specification, claims and summary of Japanese Patent Application No. 2009-274662 filed on December 2, 2009 are incorporated herein by reference and accepted as the disclosure of the specification of the present invention.

Claims (9)

An electrode protective film forming agent for obtaining an electrode protective film for a liquid crystal display element in which a liquid crystal alignment film is formed on an electrode protective film,
Characterized in that it contains polysiloxane obtained by polycondensation of an alkoxysilane containing at least one compound selected from the group consisting of an alkoxysilane represented by the formula (1) and an alkoxysilane represented by the formula (2)
Wherein the alkoxysilane represented by the formula (1) is contained in an amount of 0.5 to 60 mol% of the total alkoxysilane and the alkoxysilane represented by the formula (2) is contained in the total alkoxysilane in an amount of 40 to 99.5 mol%.
R ¹ {Si (OR ² ) ₃ } _P (1)
(R ¹ is a hydrocarbon group of 1 to 12 carbon atoms substituted with an ureido group, R ² is an alkyl group of 1 to 5 carbon atoms, and p is an integer of 1 or 2)
(R ³ ) _n Si (OR ⁴ ) _4-n (2)
(Wherein R ³ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms which may be substituted with a hetero atom, a halogen atom, a vinyl group, an amino group, a glycidoxy group, a mercapto group, a methacryloxy group, an isocyanate group, A hydrocarbon group, R ⁴ is an alkyl group having 1 to 5 carbon atoms, and n is an integer of 0 to 3) The method according to claim 1,
Wherein n in the formula (2) is 0 tetraalkoxysilane. delete 3. The method according to claim 1 or 2,
Wherein the alkoxysilane represented by the formula (1) is at least one selected from the group consisting of? -Ureidopropyltriethoxysilane,? -Ureidopropyltrimethoxysilane and? -Ureidopropyltripropoxysilane, Forming agent. An electrode protecting film obtained by applying the electrode protecting film forming agent according to claim 1 or 2 to a substrate and firing, wherein a liquid crystal alignment film is formed on the electrode protecting film. A method for forming an electrode protective film, comprising applying the electrode protective film forming agent according to any one of claims 1 to 3 on a substrate, drying the coated film at a temperature of from room temperature to 120 deg. The method according to claim 6,
And the firing temperature is 100 to 180 占 폚. delete A liquid crystal display element having the electrode protective film according to claim 5.