JP2009235358A - Polysilane resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition high in water repellency, heat resistance, and transparency. <P>SOLUTION: The resin composition includes a polysilane and a hydrophobic alkyl compound. The polysilane may contain at least one selected from polymonoaryl silane units, polydiaryl silane units, and polyalkyl aryl silane units. Further, the polysilane may contain at least one selected from mono 6-20C arylsilane units, and 1-6C alkyl 6-20C aryl saline units. The hydrophobic alkyl compound may contain a 6-24C alkyl group and at least one selected from a polymeric unsaturated group, a hydrolytically condensable group, a hydroxyl group, an alkoxy group, a mercapto group, an alkylthio group, a halogen atom, a carboxyl group, an alkoxycarbonyl group, a carbonyl halide group, an epoxy group and an isocyanate group. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a resin composition having high characteristics such as water repellency, heat resistance, light resistance, and transparency, which is useful for liquid crystal displays such as image display devices (televisions, personal computers, etc.), mobile phones, digital cameras, and game machines. The present invention relates to a liquid crystal alignment film formed of the resin composition, a method for forming the liquid crystal alignment film, and a liquid crystal element including the liquid crystal alignment film.

  A liquid crystal element is used in a display portion of an electronic device such as a television or a projector. The liquid crystal element has a structure in which liquid crystal is sandwiched between a pair of substrates, and an alignment film is formed on the inner surface of the substrate in contact with the liquid crystal in order to control the initial alignment state of liquid crystal molecules. As the alignment film, an organic alignment film such as polyimide is generally used.

  For example, in Japanese Patent Laid-Open No. 10-161133 (Patent Document 1), a liquid crystal alignment film formed by applying a polyimide polymer material to a substrate, performing a heat treatment, and then performing a rubbing process has a thin film having a thickness of 13 nm. A liquid crystal alignment film having a thickness of 20 nm or less is described. However, the alignment film made of polyimide has insufficient heat resistance, and may cause photodegradation depending on the use environment, use time, and the like. When such photodegradation occurs, the alignment film is decomposed, and the decomposition product may adversely affect the performance of the liquid crystal.

In particular, the long-term reliability of the liquid crystal alignment film is a problem in applications such as display devices (for example, liquid crystal televisions, personal computers), mobile phones, and the like that are currently in widespread use. Therefore, it has been proposed to use an inorganic alignment film made of an inorganic material such as silicon oxide as an alignment film that is not easily affected by heat, light, and wet heat environments. For example, Japanese Patent Laid-Open No. 10-339876 (Patent Document 2) discloses a liquid crystal in which an electrode is formed and a monomolecular film-like film is formed on the surface of a substrate that is rubbed after the electrode surface is formed into a thin film. An alignment film is described. In addition, this document describes that a mixture of a plurality of silane-based surfactants having different critical surface energies is used as a molecule constituting the film. However, the alignment film of this document may not have sufficient water repellency. Further, since the silicon oxide film formed using the sol-gel method is rubbed and a film is formed on the surface thereof, the material use efficiency in the process of forming the silicon oxide film is low. Further, since the silicon oxide film is formed at an unnecessary position on the substrate, a process for partially removing the coating and a surface modification process are required, which causes an increase in manufacturing cost and a complicated process. Furthermore, when the rubbing treatment is performed, the yield decreases due to rubbing cloth pieces attached to the surface of the coating.
JP-A-10-161133 (Claim 1) JP-A-10-339876 (Claims 1 and 3)

  Accordingly, an object of the present invention is to provide a resin composition having high characteristics such as water repellency, heat resistance, light resistance, and transparency, a liquid crystal alignment film formed with this resin composition, a method for forming the same, and the liquid crystal alignment film. It is in providing the liquid crystal element provided.

  Another object of the present invention is to provide a resin composition having a high solvent resistance, a liquid crystal alignment film formed from this resin composition, a method for forming the same, and a liquid crystal device including the liquid crystal alignment film.

  Still another object of the present invention is to provide a method for forming a liquid crystal alignment film simply and efficiently without performing a rubbing treatment.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventor has a high heat resistance, light resistance, transparency and the like, and can improve water repellency when a resin composition is composed of polysilane and a hydrophobic alkyl compound. The present inventors have found that an effective liquid crystal alignment film can be formed and completed the present invention.

That is, the resin composition of the present invention is composed of polysilane and a hydrophobic alkyl compound. The polysilane may contain at least one selected from a polymonoarylsilane unit, a polydiarylsilane unit, and a polyalkylarylsilane unit. The polysilane may contain at least one selected from a mono C _6-20 aryl silane unit and a C _1-6 alkyl C _6-20 aryl silane unit. The hydrophobic alkyl compound includes a C _6-24 alkyl group, a polymerizable unsaturated group, a hydrolytic condensable group, a hydroxyl group, an alkoxy group, a mercapto group, an alkylthio group, a halogen atom, a carboxyl group, an alkoxycarbonyl group, a carbonyl group. You may have at least 1 type selected from the halide group, the epoxy group, and the isocyanate group. Further, the hydrophobic alkyl compound is at least one member selected from the group consisting of an epoxy compound having a silane compound having a linear C _6-24 alkyl group, and a linear C _6-24 alkyl group and an epoxy group Also good. The ratio (weight ratio) between the polysilane and the hydrophobic alkyl compound may be about polysilane / hydrophobic alkyl compound = 5/95 to 95/5. The resin composition may further contain a crosslinking agent. When the resin composition contains a crosslinking agent, the solvent resistance can be improved.

  The liquid crystal alignment film comprised with the said resin composition is also contained in this invention. The liquid crystal alignment film may be formed on a transparent substrate.

  Furthermore, the present invention also includes a liquid crystal element including the liquid crystal alignment film formed to face each other and a liquid crystal sealed between these liquid crystal alignment films. The liquid crystal may be homeotropic or homogeneous alignment liquid crystal.

  Furthermore, the present invention includes a method of applying the resin composition to a transparent substrate and forming the liquid crystal alignment film without performing a rubbing treatment.

  In the present invention, since the resin composition is composed of polysilane and a hydrophobic alkyl compound, heat resistance, light resistance, transparency and the like are high, and in particular, water repellency can be improved. Moreover, the resin composition of this invention can improve especially solvent resistance by including a crosslinking agent. Furthermore, the resin composition can form an effective liquid crystal alignment film.

  The resin composition (polysilane resin composition) of the present invention is composed of polysilane and a hydrophobic alkyl compound.

[Polysilane]
The polysilane may have at least one structural unit selected from structural units represented by formula (1a), formula (1b), and formula (1c).

^(Wherein, R 1 to R ³ represents a substituent.)
In the formula (1a) and the formula (1b), examples of the substituent represented by R ^{1 to} R ³ include a hydrocarbon group (alkyl group, alkenyl group, cycloalkyl group, cycloalkenyl group, aryl group, aralkyl group, etc. ), Hydroxyl group, alkoxy group, cycloalkyloxy group, aryloxy group, aralkyloxy group, amino group, silyl group, halogen atom and the like.

As the alkyl group, a C _1-14 alkyl group such as methyl, ethyl, propyl, isopropyl, butyl, s-butyl, t-butyl, pentyl, hexyl (preferably a C _1-10 alkyl group, more preferably C _{1 -6} alkyl group, etc.). Examples of the alkenyl group include C _2-14 alkenyl groups such as vinyl, allyl, butenyl, pentenyl (preferably C _2-10 alkenyl group, more preferably C _2-6 alkenyl group). Examples of the cycloalkyl group include C _5-14 cycloalkyl groups such as cyclopentyl, cyclohexyl and methylcyclohexyl (preferably a C _5-10 cycloalkyl group, more preferably a C _5-8 cycloalkyl group). Examples of the cycloalkenyl group include C _5-14 cycloalkenyl groups such as cyclopentenyl and cyclohexenyl (preferably a C _5-10 cycloalkenyl group, more preferably a C _5-8 cycloalkenyl group). As the aryl group, a C _6-20 aryl group which may have a substituent such as phenyl, methylphenyl (tolyl), dimethylphenyl (xylyl) or naphthyl (preferably an _optionally substituted C). _6-15 aryl group, more preferably C _6-12 aryl group _optionally having substituent (s) and the like. Examples of the aralkyl group include C _6-20 aryl-C _1-4 alkyl groups (preferably C _6-10 aryl-C _1-2 alkyl groups) such as benzyl, phenethyl, and phenylpropyl. Examples of the alkoxy group include C _1-14 alkoxy groups such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, t-butoxy and pentyloxy (preferably C _1-10 alkoxy groups, more preferably C _1-6 alkoxy groups). Is mentioned. The cycloalkyl group, cyclopentyloxy, C _5-14 cycloalkyl group (preferably a C _5-10 cycloalkyloxy group, more preferably C _5-8 cycloalkyl group), such as cyclohexyloxy, and the like . Examples of the aryloxy group include C _6-20 aryloxy groups such as phenoxy and naphthyloxy (preferably a C _6-15 aryloxy group, more preferably a C _6-12 aryloxy group). Examples of the aralkyloxy group include C _6-20 aryl-C _1-4 alkyloxy groups (preferably C _6-10 aryl-C _1-2 alkyloxy groups) such as benzyloxy, phenethyloxy, and phenylpropyloxy. It is done. As an amino group, an amino group (—NH ₂ ), a substituted amino group (N-mono or N, N-disubstituted amino group substituted with the alkyl group, cycloalkyl group, aryl group, aralkyl group, acyl group, etc.) Etc.). Examples of the silyl group include Si _1-10 silanyl groups (preferably Si _1-6 silanyl groups) such as silyl group, disiranyl group, and trisilanyl group, substituted silyl groups (eg, alkyl groups, cycloalkyl groups, aryl groups, aralkyl groups). , Substituted silyl groups substituted with alkoxy groups, and the like. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Further, when the substituent represented by R ^{1 to} R ³ is a hydrocarbon group, an alkoxy group, a cycloalkyloxy group, an aryloxy group, an aralkyloxy group, an amino group, or a silyl group, these substituents are Furthermore, it may have a substituent such as the exemplified alkyl group, aryl group, and alkoxy group.

Among the substituents represented by R ^{1 to} R ³ , a hydrocarbon group such as an alkyl group (for example, a methyl group); a substituent containing an aromatic ring such as an aryl group, an aralkyl group, and an aryloxy group (particularly, An aryl group such as a phenyl group) is preferable.

Preferable polysilane includes a structural unit represented by the formula (1a) in which at least one of the substituents R ¹ and R ² is an aryl group (particularly a C _6-20 aryl group), and the substituent R ³ is an aryl group ( particularly polysilane [e.g. having at least one selected from the structural unit represented by the formula is a _{C 6-20} aryl group) (1b), the substituent ^{R 1} is an aryl group (especially _{C 6-20} aryl group) And a structural unit represented by the formula (1a) in which R ² is an alkyl group (particularly a C _1-6 alkyl group), and a formula in which the substituent R ³ is an aryl group (particularly a C _6-10 aryl group) ( And the like having a structural unit represented by 1b).

  The ratio (molar ratio) between the structural unit represented by the formula (1a) and the structural unit represented by the formula (1b) is the former / the latter = 1/99 to 90/10, preferably 5/95 to 80 /. 20, More preferably, it may be about 10/90 to 70/30 (10/90 to 50/50).

  Moreover, the ratio of the structural unit represented by Formula (1c) is the conversion of the silicon atom (molar conversion) which comprises polysilane, and the ratio of the structural unit represented by Formula (1a), Formula (1b), and Formula (1c). 15 mol% or less (for example, 0.01 to 13 mol%), preferably 10 mol% or less (for example, 0.05 to 8 mol%), more preferably 5 mol% or less (for example, 0.1 mol% or less) based on the total amount. 1 to 4 mol%).

  Typical polysilanes include, for example, homopolymers such as polydimethylsilane, poly (methylpropyl) silane, poly (methylbutyl) silane, poly (methylpentyl) silane, poly (dibutyl) silane, and poly (dihexyl) silane. Dialkyl silanes; polymonoaryl silanes such as polyphenyl silanes (polyaryl silanes); polydiaryl silanes such as poly (diphenyl) silanes, poly (alkyl aryl) silanes such as poly (methylphenyl) silanes, etc.] copolymers [dimethyl silanes A copolymer of a dialkylsilane such as a methylhexylsilane copolymer and another dialkylsilane; an arylsilane-alkylarylsilane copolymer such as a phenylsilane-methylphenylsilane copolymer; a dimethylsilane-methylphenol Silane silane copolymer, dimethyl silane-phenyl hexyl silane copolymer, dimethyl silane-methyl naphthyl silane copolymer, dipropyl silane-alkyl aryl silane copolymer such as methyl propyl silane-methyl phenyl silane copolymer, etc.] It can be illustrated. For details, see, for example, R.A. D. Miller, J.M. Michl; Chemical Review, 89, 1359 (1989); Matsumoto; Japan Journal of Physics, Volume 37, p. 5425 (1998). These polysilanes can be used alone or in combination of two or more.

Of these, monoaryl silane units, diaryl silane units, polysilane, including alkylaryl silane units, such as poly monoaryl silane (Porimono C _6-12 aryl silanes, etc.), polydiene aryl silane (polydiene C _6-20 aryl silane Homopolymers such as polyalkylaryl silanes (such as poly C _1-6 alkyl C _6-20 aryl silanes); diaryl silane units (such as di C _6-20 aryl silane units) and alkyl aryl silane units (C _{1- 6} alkyl C _6-20 aryl silane units), aryl silane units (C _6-20 aryl silane units, etc.) and alkyl aryl silane units (C _1-6 alkyl C _6-20 aryl silane units, etc.) Containing copolymers, in particular ants C _6-20 aryl silane-C _1-6 alkyl C _6-20 aryl silane copolymers such as C _6-20 aryl silane-C _1-3 alkyl C _6-20 Arylsilane copolymers and the like are preferred.

  The average degree of polymerization (for example, the number average degree of polymerization) of the polysilane may be, for example, about 5 to 400, preferably about 10 to 350, and more preferably about 20 to 300.

  The polysilane may have a weight average molecular weight of about 300 to 100,000, preferably about 400 to 50,000, and more preferably about 500 to 20,000.

  The form of the polysilane (such as a polysilane having at least one structural unit among the structural units represented by the formula (1a) to the formula (1c)) is not particularly limited. For example, the copolymer is a random copolymer. It may be a polymer, a block copolymer, an alternating copolymer, a comb copolymer, or the like.

  The polysilane may be an acyclic polysilane (such as a linear polysilane, a branched polysilane, or a network polysilane), or may be a cyclic polysilane. When the polysilane is an acyclic polysilane, the terminal group (terminal substituent) of the polysilane may be a hydrogen atom, a halogen atom (such as a chlorine atom), an alkyl group, a hydroxyl group, an alkoxy group, or a silyl group. Usually, it is often a halogen atom (such as a chlorine atom), a hydroxyl group, an alkoxy group, particularly a hydroxyl group.

  When the polysilane has a hydroxyl group at the terminal and / or side chain, the hydroxyl equivalent of the polysilane is 100 to 50,000 g / eq, preferably 200 to 30,000 g / eq, more preferably 300 to 10,000 g / eq. It may be a degree.

(Polysilane production method)
The polysilane can be prepared using various known methods. As a method for producing these polysilanes, for example, a method of dehalogenating polycondensation of halosilanes using magnesium as a reducing agent using a silicon-containing monomer having a specific structural unit (“magnesium reduction method”, WO 98/29476). And the like, a method of dehalogenating polycondensation of halosilanes in the presence of an alkali metal ("Kipping method", J. Am. Chem. Soc., 110, 124 (1988), Macromolecules, 23, 3423 (1990), etc. ), Dehalogenation condensation polymerization of halosilanes by electrode reduction (J. Chem. Soc., Chem. Commun., 1161 (1990), J. Chem. Soc., Chem. Commun. 897 (1992), etc.), Hydrazines in the presence of metal catalysts Dehydrocondensation polymerization method (JP-A-4-334551, etc.), anionic polymerization method of disilene crosslinked with biphenyl or the like (Macromolecules, 23, 4494 (1990), etc.), ring-opening polymerization method of cyclic silanes Etc.

  Among these production methods, the purity of the resulting polysilane, the molecular weight distribution, the compatibility with the resin, the low sodium and chlorine content, and the industrial aspects such as production cost and safety, the magnesium reduction method Is most preferred. In such a magnesium reduction method, polysilane can be synthesized by polymerizing halosilanes in the presence of at least a magnesium metal component. In the magnesium reduction method, a magnesium metal component and other metal components [for example, lithium compounds, halides that are not lithium compounds (lithium halides, lithium halides) are used as catalysts in order to obtain high-performance polysilanes more efficiently. ] In many cases. Details of such a magnesium reduction method are described in JP-A-2007-77190. The polysilane of the present invention can be produced according to the method described in JP 2007-77190 A using at least one selected from the compounds represented by the following formulas (2a) to (2c).

(In the formula, X ^{1 to} X ⁹ are halogen atoms, and R ^{1 to} R ³ are the same as above.)
In the formulas (2a) to (2c), the halogen atom (chlorine atom, bromine atom, iodine atom, etc.) represented by X ^{1 to} X ⁹ is preferably a chlorine atom or a bromine atom (particularly a chlorine atom), The same or different halogen atoms may be used.

[Hydrophobic alkyl compounds]
Hydrophobic alkyl compound, usually, the hydrophobic alkyl group, for example, hexyl group, octyl group, decyl group, dodecyl group, tetradecyl group, hexadecyl group, octadecyl group, eicosyl group, a linear C such docosyl group _{6- 24} alkyl groups (preferably a linear C _6-20 alkyl group, more preferably a linear C _6-18 alkyl group) and the like. The hydrophobic alkyl group may be cyclic, but is usually acyclic (linear or branched). Some or all of these hydrophobic alkyl groups may be fluorine-substituted. Hydrophobicity can be improved by using an alkyl compound having a fluorine-substituted hydrophobic alkyl group. The hydrophobic alkyl compound may have such a hydrophobic alkyl group at the terminal and / or side chain.

  The hydrophobic alkyl compound may be a substituent that can react with a functional group or a reactive group (for example, a residual hydroxyl group of polysilane), such as a polymerizable unsaturated group [vinyl group, allyl group, (meth) acryloyl. Group], hydrolytic condensable group (silanol group, alkoxysilyl group, mercaptosilyl group, alkylthiosilyl group, substituted silyl group such as halosilyl group), hydroxyl group, alkoxy group, mercapto group, alkylthio group, halogen atom, It may have a carboxyl group, an alkoxycarbonyl group, a carbonyl halide group, an epoxy group, an isocyanate group, or the like. Of these, hydrolyzable condensable groups (such as silanol groups, alkoxysilyl groups, mercaptosilyl groups, alkylthiosilyl groups, halosilyl groups), epoxy groups, and isocyanate groups are preferred.

Specific examples of the hydrophobic alkyl compound include a silane compound having a hydrophobic alkyl group (for example, a C _6-24 alkyl group, preferably a C _10-20 alkyl group) [having a hydrophobic alkyl group and an alkoxyl group. Silane compounds (C _6-24 alkyldiC _1-2 alkoxysilanes such as n-octadecyldimethoxysilane, n-octadecylmethyldimethoxysilane, 1H, 1H, 2H, 2H-perfluorooctylmethoxydimethoxysilane; n-hexyltrimethoxysilane N-octyltrimethoxysilane, n-decyltrimethoxysilane, n-hexadecyltrimethoxysilane, n-octadecyltrimethoxysilane, n-hexyltriethoxysilane, n-octyltriethoxysilane, n-decyltriethoxysilane , N-hex C _6-24 alkyltri-C ₁ such as _{sadecyltriethoxysilane} , n-octadecyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorooctyltrimethoxysilane, 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane _-2 alkoxysilane, etc.]]; an epoxy compound (1,2-epoxyheptane, etc.) having the hydrophobic alkyl group (for example, a C _6-24 alkyl group, preferably a C _6-20 alkyl group) and an epoxy group; 1,2-epoxyeicosane, 1,2-epoxydodecane, 1,2-epoxydecane, 3-perfluorohexyl-1,2-epoxypropane, 3-perfluorooctyl-1,2-epoxypropane, 3-perfluorodecyl _{C 6-12} alkyl group such as 1,2-epoxypropane , And epoxy compound having an epoxy group); glycidyl ethers of higher aliphatic alcohols (octyl alcohol, such as C _6-24 alcohols such as decyl alcohol); higher fatty acids (octanoic acid, C _6-24 alkanoic acids such as decanoic acid Etc.); glycidyl amines of higher aliphatic amines (C _6-24 alkylamines such as octylamine and decylamine) and the like.

These hydrophobic alkyl compounds can be used alone or in combination of two or more. Of these, silane compounds having a hydrophobic alkyl group such as C _6-20 alkyltri C _1-2 alkoxysilane (C _15-20 alkyltrimethoxysilane such as n-octadecyltrimethoxylane) are preferred.

  The molecular weight of the hydrophobic alkyl compound may be about 100 to 1,500, preferably about 200 to 1,200, and more preferably about 300 to 1,000.

  If such a hydrophobic alkyl compound is used, the terminal group of the polysilane (for example, hydroxyl group, alkoxy group, halogen atom) and the terminal group of the hydrophobic alkyl compound may be cross-linked, or the water repellency of the resin composition Can be improved.

  The ratio (weight ratio) between the polysilane and the hydrophobic alkyl compound can be selected from a range that does not impair the coating property and liquid crystal orientation of the resin composition. The former / the latter = 5/95 to 95/5, preferably 30 / It may be about 70 to 90/10, more preferably about 40/60 to 85/15.

The resin composition may contain a catalyst. When the catalyst is used, a hydrolysis reaction (such as a reaction between polysilane and a hydrophobic alkyl compound) can be promoted. The catalyst is usually an acid catalyst in many cases. The acid catalyst is not particularly limited, and is an inorganic acid [eg, protonic acid (sulfuric acid, hydrogen chloride (or hydrochloric acid), phosphoric acid, etc.), Lewis acid (boron trifluoride, aluminum chloride, zinc chloride, etc.), etc.] Organic acids {eg sulfonic acids (alkane sulfonic acids such as methane sulfonic acid, arene sulfonic acids such as p-toluene sulfonic acid), aliphatic carboxylic acids [eg alkanoic acids (eg formic acid, acetic acid, propionic acid etc. Carboxylic acids such as aliphatic oxycarboxylic acids such as glycolic acid, lactic acid and oxypropionic acid, and aromatic oxycarboxylic acids such as oxybenzoic acid} Etc. These acid catalysts may be used alone or in combination of two or more. Of these, inorganic acids (such as protonic acids) and organic acids (such as _C1-3 alkanoic acids such as acetic acid) are often used.

  The amount of the catalyst used is not particularly limited and is, for example, 0.01 to 50 parts by weight, preferably 0.02 to 30 parts by weight with respect to 100 parts by weight of the base resin component (total amount of polysilane and hydrophobic alkyl compound). More preferably, it may be about 0.03 to 10 parts by weight (particularly 0.05 to 5 parts by weight).

  The resin composition may contain a crosslinking agent. Examples of the crosslinking agent include silane coupling agents, polyvalent carboxylic acids or acid anhydrides, polyvalent epoxy compounds, and polyisocyanates.

Examples of the silane coupling agent include C _1-4 alkoxysilanes (tetraethoxysilane, tetramethoxysilane, etc.) having a polymerizable unsaturated group, hydrolysis-condensable group and the like exemplified in the section of the hydrophobic alkyl compound. C _1-4 alkoxysilane etc.).

  Examples of the polyvalent carboxylic acid include aliphatic polycarboxylic acids (aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, maleic acid and fumaric acid; aliphatic tricarboxylic acids such as butanetricarboxylic acid; heptanetetracarboxylic acid; Aliphatic tetracarboxylic acids such as, etc.), aromatic polycarboxylic acids (such as aromatic dicarboxylic acids such as phthalic acid), or acid anhydrides thereof.

  Examples of the polyvalent epoxy compound include diglycidyl ethers (bisphenol type diglycidyl ethers such as bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, and bisphenol AD diglycidyl ether; phenol novolak diglycidyl ether, cresol novolak diglycidyl Novolac-type glycidyl ethers such as ethers; alkylene glycol diglycidyl ethers such as ethylene glycol diglycidyl ether and propylene glycol diglycidyl ether); triglycidyl ethers [glycerin triglycidyl ether, triglycidyl ethers having a triazine ring (triglycidyl) Isocyanurate, etc.); glycidyl ester having two or more glycidyl groups (Diglycidyl esters such as diglycidyl phthalate and diglycidyl phthalate); glycidylamines having two or more glycidyl groups (diglycidylamines such as diglycidylaniline, triglycidylaminophenol, etc.) Triglycidylamines, tetraglycidylamines such as tetraglycidyldiaminodiphenylmethane) and the like.

  Examples of the polyisocyanate include polyisocyanates having two or more isocyanate groups [tolylene diisocyanate (TDI), diphenylmethane-4,4′-diisocyanate (MDI), xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI). And the like].

  Of these, polyvalent epoxy compounds, particularly triglycidyl ethers [triglycidyl ethers having a triazine ring (such as triglycidyl isocyanate)] are often used. These crosslinking agents can be used alone or in combination of two or more. When these crosslinking agents are used, the solvent resistance of the resin composition can be improved.

  The amount of the crosslinking agent used is not particularly limited, and is, for example, 0.01 to 50 parts by weight, preferably 0.03 to 30 parts by weight with respect to 100 parts by weight of the base resin component (total amount of polysilane and hydrophobic alkyl compound). Part, more preferably about 0.06 to 10 parts by weight (particularly 0.1 to 5 parts by weight).

  Furthermore, the resin composition may contain conventional additives (stabilizers, curing agents, plasticizers, surfactants, dissolution accelerators, colorants, etc.). These additives can be used alone or in combination of two or more.

  The amount of the additive used is not particularly limited, and is, for example, 0.01 to 100 parts by weight, preferably 0.1 to 50 parts by weight with respect to 100 parts by weight of the base resin component (total amount of polysilane and hydrophobic alkyl compound). It can select suitably from the range of about a part.

Moreover, in order to improve the coating property (coating property) of the resin composition, the resin composition may contain a solvent. Examples of the solvent include ethers (cyclic C _4-6 ethers such as 1,4-dioxane and tetrahydrofuran; chain C _4-6 alkyl ethers such as diethyl ether, diisopropyl ether, and dimethoxyethane), ketones ( C _3-6 dialkyl ketones such as acetone and methyl ethyl ketone, cycloalkanones such as cyclohexanone), esters (carboxylic acid C _1-4 such as ethyl formate, methyl acetate, ethyl acetate, ethyl propionate, ethyl lactate, butyl lactate) Alkyl esters; ethoxyethyl propionate, etc.), hydrocarbons [aliphatic hydrocarbons (pentane, hexane, heptane, octane, etc.), alicyclic hydrocarbons (cyclohexane, methylcyclohexane, etc.), aromatic hydrocarbons (Benzene, toluene , Xylene, ethylbenzene, etc.), halogenated hydrocarbons (methylene chloride, etc.)], alcohols (monohydric alcohols such as methanol, ethanol, n-propanol, isopropanol, polyhydric alcohols such as ethylene glycol, diethylene glycol, etc.) Cellosolves (C _1-4 alkyl cellosolves such as methyl cellosolve and ethyl cellosolve), carbitols (C _1-4 alkyl carbitols such as methyl carbitol, ethyl carbitol, propyl carbitol, butyl carbitol, etc.) Etc.), glycol ether esters (cellosolve acetate, propylene glycol monomethyl ether acetate, etc.) and the like. These solvents may be used alone or in combination of two or more as a mixed solvent.

  The amount of the solvent used may be about 10 to 500 parts by weight, preferably 20 to 300 parts by weight, and more preferably about 30 to 200 parts by weight with respect to 1 part by weight of the solid content in the resin composition.

[Liquid crystal alignment film]
Since the resin composition has high characteristics such as heat resistance, light resistance, transparency, and water repellency, it is useful as a liquid crystal alignment film. The liquid crystal alignment film may be formed on a transparent substrate.

  The thickness of the liquid crystal alignment film may be about 10 to 300 nm, preferably about 20 to 200 nm, and more preferably about 30 to 100 nm.

  Examples of the material for the transparent substrate include glass [silicate glass such as oxide glass (silica glass (quartz glass), soda lime glass, lead alkali silicate glass, borosilicate glass, aminosilicate glass; Borate glass; phosphate glass, etc.), non-oxide glass (chalcogenide glass, fluoride glass, alloy glass, oxyhalide glass, etc.)], ceramics, transparent plastic [cyclic olefin resin (Polymers containing cycloalkadiene such as cyclopentadiene as a polymerization component), acrylic resins (polyalkyl methacrylates such as polymethyl methacrylate), polystyrene resins, polycarbonate resins, etc.]. Of these, silicate glass (such as oxide glass) is often used.

  The surface of the transparent substrate may be covered with a transparent conductive film. The transparent conductive film may be made of a metal having transparency and conductivity (metal oxide such as indium tin oxide, tin oxide, titanium oxide, and zinc oxide).

  The liquid crystal alignment film can be formed by applying the resin composition to a transparent substrate and, if necessary, performing a heat treatment or the like by a conventional method. Since the resin composition is used, a liquid crystal alignment film can be easily and efficiently formed without performing a rubbing treatment.

  Examples of the method for applying the resin composition include spin coating, roll coating, curtain coating, dip coating, spray coating, casting, bar coating, and gravure coating.

  The heating temperature may be about 40 to 250 ° C, preferably 80 to 200 ° C, more preferably about 100 to 190 ° C (particularly 120 to 180 ° C). When a solvent is used, the heating temperature (drying temperature) may be 40 to 200 ° C., preferably 60 to 180 ° C., more preferably about 80 to 160 ° C., depending on the type of solvent. Moreover, when using a crosslinking agent, heating temperature (curing temperature) may be 100-250 degreeC according to the kind of crosslinking agent, Preferably it is about 110-230 degreeC, More preferably, about 120-200 degreeC may be sufficient. .

  The heating time (or drying time or curing time) may be about 10 seconds to 5 hours, preferably about 30 seconds to 3 hours, and more preferably about 1 minute to 1 hour.

  In addition, the present invention includes a liquid crystal element including the liquid crystal alignment films formed to face each other and the liquid crystal sealed between the liquid crystal alignment films.

  Examples of the liquid crystal include nematic liquid crystal, cholesteric liquid crystal, discotic liquid crystal, lyotropic liquid crystal polymer, and thermotropic liquid crystal polymer.

  The liquid crystal may be homeotropic alignment liquid crystal (vertical alignment liquid crystal), homogeneous alignment liquid crystal (parallel alignment liquid crystal), tilt alignment liquid crystal, or the like. Of these, homeotropic alignment liquid crystals, homogeneous alignment liquid crystals, and the like are often used.

  Further, in order to accurately and uniformly control the thickness of the liquid crystal layer, a spacer may be used between the liquid crystal alignment films. Examples of the spacer include glass, silica, and a photospacer (a spacer formed by a photocuring reaction, such as a spacer formed of a photocurable resin). Of these, photo spacers are often used. You may use a spacer individually or in combination of 2 or more types.

  The spacer only needs to be formed between the liquid crystal alignment films opposed to each other. When a photospacer is used, for example, a composition composed of a photocurable resin and a solvent is applied to the liquid crystal alignment film. The photo spacer can be formed by photocuring. Since the liquid crystal alignment film has high characteristics such as water repellency and solvent resistance, it can be suitably used even if a solvent is used.

  Examples of the solvent include the solvents exemplified in the section of the resin composition, such as ketones (such as methyl ethyl ketone), esters (such as ethyl lactate and ethoxyethyl propionate), aromatic hydrocarbons (such as xylene), glycols. Ether esters (such as propylene glycol monomethyl ether acetate) are often used.

  Since the resin composition of the present invention has high properties such as water repellency, heat resistance, light resistance, and transparency, an image display device (television, personal computer, etc.), mobile phone, digital camera, game machine (portable game machine) Etc.), and can be used for liquid crystal alignment films of liquid crystal displays such as electronic dictionaries.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

[Solvent resistance]
The prepared liquid crystal alignment film (3 cm × 3 cm) was immersed in 20 mL of propylene glycol monomethyl ether acetate to evaluate the solvent resistance.

[Heat-resistant]
Using a “TGA-50” device manufactured by Shimadzu Corporation, thermogravimetric analysis (TGA) was performed at a heating rate of 5 ° C./min in an air atmosphere and a nitrogen atmosphere (flow rate 100 ml / min), and liquid crystal alignment The heat resistance of the film was evaluated.

[Water repellency]
The contact angle of water was measured using a contact angle measuring device (Kyowa Interface Science Co., Ltd., DropMaster).

Example 1
(1) Preparation of resin composition 10 parts by weight of phenylsilane-methylphenylsilane copolymer (Ossol SI-20-10, manufactured by Osaka Gas Chemical Co., Ltd.) was dissolved in 40 parts by weight of propylene glycol monomethyl ether acetate. To this solution, 3 parts by weight of n-octadecyltrimethoxysilane (manufactured by Amax Co.) and 1 part by weight of acetic acid as a catalyst were added and stirred at room temperature for 3 days. To this solution was added 1.25 parts by weight of an epoxy crosslinking agent (Tris- (2,3-epoxypropyl) -isocyanurate, manufactured by Nissan Chemical Industries, TEPIC), and diluted with 45 parts by weight of propylene glycol monomethyl ether acetate. And filtered to obtain a resin composition.

(2) Preparation of liquid crystal alignment film The obtained resin composition was applied to an ITO (indium tin oxide) vapor-deposited glass substrate by a spin coating method and dried by heating at a temperature of 160 ° C. for 30 minutes to obtain a liquid crystal alignment film. It was. The film thickness was about 100 nm. The water repellency of the liquid crystal distribution film was measured. Further, when the solvent resistance of the liquid crystal alignment film was evaluated, it showed solvent resistance to propylene glycol monomethyl ether acetate. Furthermore, when the heat resistance of the liquid crystal alignment film was evaluated, the weight loss was about 2% even at a high temperature of about 200 ° C., indicating high heat resistance.

(3) Production of liquid crystal cell Two substrates on which an alignment film was formed were prepared. A cell gap was set to 6 μm, two substrates were placed opposite to each other, and liquid crystal (MLC-2038, liquid crystal transition temperature: 79.9 ° C.) was injected therebetween to produce a liquid crystal cell. When the orientation of the obtained liquid crystal cell was examined between two orthogonal polarizing plates, it showed good homeotropic orientation. Furthermore, by applying a voltage of 3 V, transmission of visible light was confirmed, indicating that an orientation change occurred.

Example 2
A liquid crystal alignment film was obtained in the same manner as in Example 1 except that 5 parts by weight of n-octadecyltrimethoxysilane was used instead of 3 parts by weight. The film thickness was about 100 nm. The water repellency of the liquid crystal distribution film was measured. Further, when the solvent resistance of the liquid crystal alignment film was evaluated, it was insoluble in propylene glycol monomethyl ether acetate and exhibited high solvent resistance. Further, a liquid crystal cell was prepared in the same manner as in Example 1, and the orientation was examined. As a result, a good homeotropic alignment was shown.

Example 3
A liquid crystal alignment film was obtained in the same manner as in Example 1 except that 10 parts by weight of n-octadecyltrimethoxysilane was used instead of 3 parts by weight. The film thickness was about 100 nm. The water repellency of the liquid crystal distribution film was measured. Further, when the solvent resistance of the liquid crystal alignment film was evaluated, it was insoluble in propylene glycol monomethyl ether acetate and exhibited high solvent resistance. Further, a liquid crystal cell was prepared in the same manner as in Example 1, and the orientation was examined. As a result, a good homeotropic alignment was shown.

Comparative Example 1
A liquid crystal alignment film was obtained in the same manner as in Example 1 except that n-octadecyltrimethoxysilane and a catalyst were not used. The film thickness was about 100 nm. The water repellency of the liquid crystal alignment film was measured. Moreover, when the liquid crystal cell was produced similarly to Example 1 and the orientation was investigated, it was not uniaxially aligned.

Comparative Example 2
Except not using polysilane and a catalyst, the resin composition was apply | coated to the ITO vapor deposition glass substrate by the spin-coating method like Example 1, but film formation was not able to be performed.

  The results are shown in Table 1.

  As is clear from Table 1, in the example, a liquid crystal alignment film having high water repellency was obtained because the resin composition was composed of polysilane and a hydrophobic alkyl compound in comparison with the comparative example. Moreover, in the Example, the liquid crystal cell whose liquid crystal molecule is homeotropic alignment was obtained. Furthermore, in the examples, a liquid crystal alignment film having high solvent resistance and high heat resistance even at a high temperature of about 200 ° C. was obtained.

Claims (12)

  A resin composition composed of polysilane and a hydrophobic alkyl compound.   The resin composition according to claim 1, wherein the polysilane includes at least one selected from a monoarylsilane unit, a diarylsilane unit, and an alkylarylsilane unit. The resin composition according to claim 1 or 2, wherein the polysilane contains at least one selected from a mono C _6-20 aryl silane unit and a C _1-6 alkyl C _6-20 aryl silane unit. The hydrophobic alkyl compound is a C _6-24 alkyl group, a polymerizable unsaturated group, a hydrolytic condensable group, a hydroxyl group, an alkoxy group, a mercapto group, an alkylthio group, a halogen atom, a carboxyl group, an alkoxycarbonyl group, a carbonyl halide. The resin composition according to any one of claims 1 to 3, comprising at least one selected from a group, an epoxy group, and an isocyanate group. Hydrophobic alkyl compound, silane compound having a C _6-24 alkyl group, and according to claim 1 is at least one selected from an epoxy compound having a C _6-24 alkyl group and an epoxy group Resin composition.   The resin composition according to any one of claims 1 to 5, wherein a ratio (weight ratio) between the polysilane and the hydrophobic alkyl compound is polysilane / hydrophobic alkyl compound = 5/95 to 95/5.   Furthermore, the resin composition in any one of Claims 1-6 containing a crosslinking agent.   The liquid crystal aligning film comprised with the resin composition in any one of Claims 1-7.   The liquid crystal alignment film according to claim 8, which is formed on a transparent substrate.   The liquid crystal element comprised by the liquid crystal aligning film of Claim 8 or 9 formed facing each other, and the liquid crystal enclosed between these liquid crystal aligning films.   The liquid crystal element according to claim 10, wherein the liquid crystal is a homeotropic or homogeneous alignment liquid crystal.   A method for forming a liquid crystal alignment film according to claim 8 or 9 by applying the resin composition according to claim 1 to a transparent substrate and performing a rubbing treatment.