JP5206413B2 - Silicon-based liquid crystal aligning agent and liquid crystal aligning film - Google Patents

Description

  The present invention relates to a liquid crystal aligning agent containing polysiloxane obtained by polycondensation of alkoxysilane and a specific glycol compound, a liquid crystal aligning film obtained from the liquid crystal aligning agent, and a liquid crystal having the liquid crystal aligning film. The present invention relates to a display element.

  The liquid crystal display element has a structure in which two substrates, each having a liquid crystal alignment film mainly composed of polyamic acid and / or polyimide on a transparent electrode, are arranged to face each other, and a liquid crystal material is filled in a gap between the substrates. It is generally known. The most well-known method is a TN (Twisted Nematic) type liquid crystal display element, but an STN (Super Twisted Nematic) type that can realize a higher contrast ratio than this, and an IPS (Insert) with less viewing angle dependency. Development of a -plane switching (VA) type, a vertical alignment (VA) type, and the like has been made.

  Among them, a vertical alignment type liquid crystal display element driven by a thin film transistor (TFT) has a fast response speed, an ultra-wide viewing angle, and a high contrast, and MVA demands higher quality. New vertical alignment type liquid crystal display devices such as (Multi-domain Vertical Alignment), ASV (Advanced Super View), and PVA (Patterned Vertical Alignment) have been proposed.

It is known that the liquid crystal alignment film provided in these liquid crystal display elements orients the liquid crystal and greatly affects various characteristics such as electric characteristics of the liquid crystal display element. Therefore, a liquid crystal alignment film suitable for such a new vertical alignment type display element has been developed.
For example, as a liquid crystal alignment film for obtaining good vertical alignment properties, a method of introducing a long alkyl chain into polyamic acid and / or polyimide (see, for example, Patent Document 1), a method of introducing a cyclic substituent, and the like have been proposed. ing. (For example, see Patent Document 2.)
Furthermore, in order to realize a high and stable vertical alignment, it is said that it is necessary to introduce a large amount of long-chain alkyl groups to make the film water repellent and reduce the surface energy.

In addition, a method for introducing a specific cyclic substituent into polyamic acid and / or polyimide has been proposed for the purpose of imparting an electrical property of high voltage holding ratio and / or low residual DC to the device together with good vertical alignment. Yes. (For example, refer to Patent Document 3.)
Recently, a metal halide lamp with high irradiation intensity has been used as a light source for a liquid crystal projector for business use and home theater (a rear pro TV referred to as a third thin TV), and a liquid crystal made of an organic polymer that has been used conventionally. In addition to the alignment film material, other liquid crystal alignment film materials having not only high heat resistance but also high light resistance have become necessary. As one of the solutions, it has been proposed to apply a liquid crystal alignment film material based on an inorganic polymer to this application.

  However, research and development on liquid crystal alignment film materials based on inorganic polymers are mainly vapor deposition materials (see, for example, Patent Documents 4 and 5), and there are almost no reports on coating materials that are advantageous for manufacturing large-screen displays. Absent. For this reason, liquid crystal alignment film materials based on inorganic polymers have been rarely used so far.

  The report of using a coating-based inorganic polymer as a liquid crystal alignment film material has been proposed, for example, as a liquid crystal aligning agent composition containing a reaction product of tetraalkoxysilane, trialkoxysilane and water and a glycol ether solvent. . These compositions prevent liquid crystal alignment films that prevent display defects, have good afterimage characteristics even after long-time driving, do not decrease the ability to align liquid crystals, and have little decrease in voltage holding ratio against light and heat. There is nothing that can be formed (for example, see Patent Documents 6 and 7), and there has never been a liquid crystal alignment film material made of a coating-type inorganic polymer at a practical level.

Apart from this trend, technological innovations in liquid crystal display elements such as liquid crystal TVs are remarkable, and in order to achieve this, improvement of the reliability of the elements has become a bigger issue than ever.
One of the reliability of the element is the electrical reliability of the element. The reliability, particularly electrical reliability, of a conventional TFT type liquid crystal display element has been confirmed by the voltage holding ratio corresponding to the 30 Hz operation of the liquid crystal display element and its temperature characteristics. It is difficult to detect such a difference, and the above problem cannot be solved.

Therefore, as a method for confirming higher reliability, a method has been proposed in which the voltage holding ratio is measured by driving the element at a low frequency so as to widen the interval between pulse voltages applied to the liquid crystal display element. (For example, refer to Patent Document 8.)
Another reliability of the element is reliability at the time of manufacturing the element. That is, the reliability of the liquid crystal display element is very important because it directly affects the yield improvement in the manufacturing process as well as the reliability with respect to the display characteristics of monitors, televisions and the like.

  Furthermore, in recent years, in a situation where the liquid crystal display element is enlarged, it is said that the yield in the manufacturing process has a greater influence on the productivity of the liquid crystal display element than before. The applicability when applying the liquid crystal alignment film by flexographic printing or the like not only greatly affects the image quality of the liquid crystal display element, but also causes the yield to deteriorate.

In particular, in the case of a vertical alignment type display element, it is necessary to align the liquid crystal vertically, and it is necessary to introduce a long-chain alkyl group into the inorganic polymer skeleton. (For example, refer to Patent Documents 6 and 7.)
However, there is a problem that as the amount of the long-chain alkyl group to be introduced increases, the coating property deteriorates. In addition, as the amount of alkoxysilane containing a long-chain alkyl group is increased, the denseness of the film is lowered, and there are adverse effects such as a display defect due to a decrease in hardness and a display short circuit due to a tunnel current.
Accordingly, there is an increasing demand for a liquid crystal alignment film material based on an inorganic polymer that can solve the above-described problems and is excellent in applicability such as printability for vertical alignment.
Japanese Patent Laid-Open No. 06-3678 JP 09-278724 A JP 2001-311080 A JP 2003-50397 A JP 2004-126463 A JP 2005-250244 A JP 09-281502 A JP 2001-264805 A

  An object of the present invention is first to provide a silicon-based liquid crystal aligning agent that can form a liquid crystal alignment film having good liquid crystal alignment and high hardness, and excellent in applicability such as flexographic printing. Secondly, it is to provide a liquid crystal alignment film obtained from a silicon-based liquid crystal alignment agent. Thirdly, it is to provide a liquid crystal display element having the liquid crystal alignment film.

As a result of intensive studies in view of the above situation, the present inventors have completed the present invention.
That is, the present invention has the following gist.
1. Total containing the following polysiloxane (A) and glycol compound (B) , wherein the glycol compound (B) is converted to SiO ₂ with silicon atoms of all alkoxysilanes used to obtain the polysiloxane (A). The liquid crystal aligning agent characterized by containing 2.5-19,800 mass parts with respect to 100 mass parts .
Polysiloxane (A): polysiloxane obtained by polycondensation of alkoxysilane containing at least one of alkoxysilanes represented by the following formula (1).
R ¹ _n Si (OR ² ) _4-n (1)
(R ¹ is an organic group having 7 to 30 carbon atoms, R ² represents a hydrocarbon group having 1 to 5 carbon atoms, and n represents an integer of 1 to 3)
Glycol compound (B): having two carbon atoms to which a hydroxy group and a hydrogen atom are bonded, and having the structure in which the two carbon atoms are bonded via an aliphatic group that may contain a hetero atom A glycol compound having 3 to 6 consecutive carbon atoms.
2. Furthermore, the liquid crystal aligning agent of Claim 1 containing the following solvent (C).
Solvent (C): A solvent having a hydroxy group, which is a compound different from the glycol compound (B) defined in 1 above.
3. The above 1 or 2 wherein the polysiloxane (A) is a polysiloxane obtained by polycondensation of an alkoxysilane containing 0.1 to 30 mol% of the alkoxysilane represented by the formula (1) in the total alkoxysilane. Liquid crystal aligning agent as described in.
4). The polysiloxane (A) is a polysiloxane obtained by polycondensation of an alkoxysilane using at least one alkoxysilane represented by the formula (1) and at least one alkoxysilane represented by the formula (2). The liquid crystal aligning agent of any one of said 1-3.
R ³ _m Si (OR ⁴ ) _4-m (2)
(R ³ represents a hydrogen atom, a halogen atom or an organic group having 1 to 6 carbon atoms, R ⁴ represents a hydrocarbon group having 1 to 5 carbon atoms, and m represents an integer of 0 to 3)
5. The glycol compound (B) is 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 2, 5. The liquid crystal aligning agent according to any one of the above 1 to 4, which is at least one selected from the group consisting of 4-pentanediol, 1,6-hexanediol, diethylene glycol, and dipropylene glycol.
6). Polysiloxane in the liquid crystal aligning agent (A) is, SiO ₂ concentration in terms of silicon atoms of the total alkoxysilane in terms of SiO ₂ was used to obtain the polysiloxane (A) is 0.5 to 20 wt% The liquid crystal aligning agent of any one of said 1-5.
7 . The liquid crystal aligning film obtained using the liquid crystal aligning agent of any one of said 1-6 .
8). 8. A liquid crystal display device having the liquid crystal alignment film as described in 7 above.

  The silicon-based liquid crystal aligning agent of the present invention contains a specific glycol compound, so that it is easier to increase the water repellency of the film during film formation than when a liquid crystal aligning agent not containing it is used, As a result, a liquid crystal alignment film having high density, high hardness, good liquid crystal alignment of the film, and excellent coating properties can be obtained. Therefore, a liquid crystal display element with high reliability and high image quality can be provided.

The present invention is described in detail below.
<Polysiloxane A>
The polysiloxane (A) used in the present invention is obtained by polycondensation of an alkoxysilane having an alkoxysilane represented by the following formula (1) as an essential component.
R ¹ _n Si (OR ² ) _4-n (1)
(R ¹ is an organic group having 7 to 30 carbon atoms, R ² represents a hydrocarbon group having 1 to 5 carbon atoms, and n represents an integer of 1 to 3)
R ¹ (hereinafter also referred to as a first organic group) in the formula (1) is preferably 8 to 20, particularly preferably 8 to 18, and the polysiloxane (A) has the first organic group. As a result, the liquid crystal is aligned in one direction.

  Examples of the first organic group include alkyl group, perfluoroalkyl group, alkenyl group, allyloxyalkyl group, phenethyl group, perfluorophenylalkyl group, phenylaminoalkyl group, styrylalkyl group, naphthyl group, benzoyloxy Alkyl group, alkoxyphenoxyalkyl group, cycloalkylaminoalkyl group, epoxycycloalkyl group, N- (aminoalkyl) aminoalkyl group, N- (aminoalkyl) aminoalkylphenethyl group, bromoalkyl group, diphenylphosphino group, N -(Methacryloxyhydroxyalkyl) aminoalkyl group, N- (acryloxyhydroxyalkyl) aminoalkyl group, optionally substituted and monovalent organic group having at least one norbornane ring, optionally substituted and A monovalent organic group having at least one steroid skeleton, or a monovalent organic group having a substituent selected from the group consisting of a fluorine atom, a trifluoromethyl group and a trifluoromethoxy group and having 7 or more carbon atoms Examples thereof include a photosensitive group that is an organic group, a cinnamoyl group, or a chalconyl group. Among these, an alkyl group and a perfluoroalkyl group are preferable because they are easily available. The polysiloxane (A) used in the present invention may have a plurality of such first organic groups.

  When the first organic group is less than 0.1 mol with respect to 100 mol of silicon atoms of the polysiloxane (A), good liquid crystal alignment may not be obtained. 1 mol or more is preferable, More preferably, it is 0.5 mol or more, More preferably, it is 1 mol or more. Moreover, since it may not fully harden | cure the liquid crystal aligning film formed when it exceeds 30 mol, 30 mol or less is preferable, More preferably, it is 22 mol or less, More preferably, it is 15 mol or less.

  In other words, in all alkoxysilanes used to obtain the polysiloxane (A), if it is less than 0.1 mol%, good liquid crystal alignment may not be obtained, so 0.1 mol% or more Is preferable, more preferably 0.5 mol% or more, and still more preferably 1 mol or more. Further, when it exceeds 30 mol%, the liquid crystal alignment film to be formed may not be sufficiently cured. Therefore, it is preferably 30 mol% or less, more preferably 22 mol% or less, still more preferably 15 mol% or less. It is.

Although the specific example of the alkoxysilane represented by such Formula (1) is given, it is not limited to this.
For example, heptyltrimethoxysilane, heptyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, hexadecyltrimethoxysilane, hexadecyl Triethoxysilane, heptadecyltrimethoxysilane, heptadecyltriethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, nonadecyltrimethoxysilane, nonadecyltriethoxysilane, undecyltriethoxysilane, undecyltrimethoxysilane, 21-docosenyltriethoxysilane, allyloxyundecyltriethoxysilane, tridecafluorooctyltrimethoxysilane, tride Fluorooctyltriethoxysilane, isooctyltriethoxysilane, phenethyltriethoxysilane, pentafluorophenylpropyltrimethoxysilane, N-phenylaminopropyltrimethoxysilane, N- (triethoxysilylpropyl) dansyriamid, styrylethyltriethoxysilane, ( R) -N-1-phenylethyl-N′-triethoxysilylpropylurea, (1-naphthyl) triethoxysilane, (1-naphthyl) trimethoxysilane, m-styrylethyltrimethoxysilane, p-styrylethyltri Methoxysilane, N- [3- (triethoxysilyl) propyl] phthalamic acid, 1-trimethoxysilyl-2- (p-aminomethyl) phenylethane, 1-trimethoxysilyl-2- (m-aminomethyl) ) Phenylethane, benzoyloxypropyltrimethoxysilane, 3- (4-methoxyphenoxy) propyltrimethoxysilane, N-triethoxysilylpropylquinine urethane, 3- (N-cyclohexylamino) propyltrimethoxysilane, 1-[( 2-triethoxysilyl) ethyl] cyclohexane-3,4-epoxide, N- (6-aminohexyl) aminopropyltrimethoxysilane, aminoethylaminomethylphenethyltrimethoxysilane, 11-bromoundecyltrimethoxysilane, 2- (Diphenylphosphino) ethyltriethoxysilane, N- (3-methacryloxy-2-hydroxypropyl) -3-aminopropyltriethoxysilane, N- (3-acryloxy-2-hydroxypropyl) -3-amino- B pills triethoxysilane and the like. Examples of the alkoxysilane represented by the formula (1) include dodecyltriethoxysilane, octadecyltriethoxysilane, octyltriethoxysilane, tridecafluorooctyltriethoxysilane, dodecyltrimethoxysilane, octadecyltrimethoxysilane, or octyltrimethoxy. Silane is preferred.

In the present invention, a plurality of alkoxysilanes represented by the formula (1) can be used in combination.
Moreover, in this invention, alkoxysilane other than the alkoxysilane represented by Formula (1) can be used together. In particular, a group different from the first organic group (hereinafter also referred to as a second organic group) is used for the purpose of improving adhesion with a substrate, affinity with liquid crystal molecules, and the like, as long as the effects of the present invention are not impaired. ) Can be used in combination.

The second organic group is an organic group having 1 to 6 carbon atoms. Examples of the second organic group include an aliphatic hydrocarbon; a ring structure such as an aliphatic ring, an aromatic ring or a hetero ring; an unsaturated bond; or a hetero atom such as an oxygen atom, a nitrogen atom or a sulfur atom. It is an organic group having 1 to 3 carbon atoms, which may be included and may have a branched structure. The second organic group may have a halogen atom, vinyl group, amino group, glycidoxy group, mercapto group, ureido group, methacryloxy group, isocyanate group, acryloxy group, or the like.
The polysiloxane (A) used in the present invention may have one or more second organic groups.
Examples of the alkoxysilane having the second organic group include alkoxysilanes represented by the following formula (2).
R ³ _m Si (OR ⁴ ) _4-m (2)
(R ³ represents a hydrogen atom, a halogen atom or an organic group having 1 to 6 carbon atoms, R ⁴ represents a hydrocarbon group having 1 to 5 carbon atoms, and m represents an integer of 0 to 3)
In the alkoxysilane of the formula (2), alkoxysilane in which m is 0 represents tetraalkoxysilane. Tetraalkoxysilane is preferable for obtaining polysiloxane (A) because it easily condenses with the alkoxysilane represented by formula (1). Specific examples of the alkoxysilane in which m is 0 in the formula (2) include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane and the like, among which tetramethoxysilane and tetraethoxysilane are preferable. .
Moreover, when R < ³ > of Formula (2) is a C1-C6 organic group, the same group as the 2nd organic group mentioned above is represented. Accordingly, the example of R ³ in this case is the same as described as the second organic group above.

Examples of the alkoxysilane having 1 to 6 carbon atoms represented by R ³ represented by the formula (2) include the following examples.
When m = 1, methyltrimethoxysilane, methyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, methyltripropoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2 (Aminoethyl) 3-aminopropyltriethoxysilane, N-2 (aminoethyl) 3-aminopropyltrimethoxysilane, 3- (2-aminoethylaminopropyl) trimethoxysilane, 3- (2-aminoethylaminopropyl) ) Triethoxysilane, 2-aminoethylaminomethyltrimethoxysilane, 2- (2-aminoethylthioethyl) triethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptomethyltrimethoxysilane, 3-ureidopropyl Reethoxysilane, 3-ureidopropyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, allyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyl Trimethoxysilane, 3-acryloxypropyltriethoxysilane, 3-isocyanatopropyltriethoxysilane, trifluoropropyltrimethoxysilane, chloropropyltriethoxysilane, bromopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, phenyltri Examples include ethoxysilane and phenyltrimethoxysilane.

  When m = 2, dimethyldiethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, diphenyldimethoxysilane, methyldiethoxysilane, methyldimethoxysilane, methylphenyldiethoxysilane, methylphenyldimethoxysilane, 3-aminopropyl Examples include methyldiethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-ureidopropylmethyldiethoxysilane, and 3-ureidopropylmethyldimethoxysilane.

  Further, when m = 3, trimethylethoxysilane, trimethylmethoxysilane, dimethylphenylethoxysilane, dimethylphenylmethoxysilane, 3-aminopropyldimethylethoxysilane, 3-aminopropyldimethylmethoxysilane, 3-ureidopropyldimethylethoxysilane, Examples include 3-aminopropyldimethylmethoxysilane.

In the alkoxysilane of the formula (2), specific examples of the alkoxysilane when R ³ is a hydrogen atom or a halogen atom include trimethoxysilane, triethoxysilane, tripropoxysilane, tributoxysilane, chlorotrimethoxysilane, And chlorotriethoxysilane.
When the alkoxysilane represented by the above formula (2) is used, one kind or a plurality of kinds can be appropriately used as necessary.

  When using together the alkoxysilane represented by Formula (2), in all the alkoxysilanes used in order to obtain polysiloxane (A), the alkoxysilane represented by Formula (2) is 99.9 mol% or less. More preferably, it is 99.5 mol% or less, More preferably, it is 99 mol%. Moreover, 70 mol% or more is preferable, as for the alkoxysilane represented by Formula (2), More preferably, it is 78 mol% or more, More preferably, it is 85 mol% or more.

  The polysiloxane (A) used in the present invention is obtained by condensing an alkoxysilane having an alkoxysilane represented by the above formula (1) as a preferred component in an organic solvent. In that case, the alkoxysilane containing the alkoxysilane represented by Formula (1) and (2) is preferable. Usually, the polysiloxane (A) is obtained as a solution obtained by polycondensation of such an alkoxysilane and uniformly dissolved in an organic solvent.

The method for condensing the polysiloxane (A) used in the present invention is not particularly limited, and examples thereof include a method of hydrolyzing and condensing alkoxysilane in an alcohol or glycol solvent. At that time, the hydrolysis / condensation reaction may be either partial hydrolysis or complete hydrolysis. In the case of complete hydrolysis, theoretically 0.5 times mole of water of all alkoxy groups in the alkoxysilane may be added, but usually an excess amount of water is added more than 0.5 times mole.
In the present invention, the amount of water used in the above reaction can be appropriately selected as desired, but it is usually 0.5 to 2.5 moles of all alkoxy groups in the alkoxysilane.

  Usually, for the purpose of promoting hydrolysis / condensation reaction, acids such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, formic acid, succinic acid, maleic acid, fumaric acid, alkalis such as ammonia, methylamine, ethylamine, ethanolamine, triethylamine, etc. Alternatively, a catalyst such as a metal salt of an inorganic acid such as hydrochloric acid, sulfuric acid, or nitric acid is used. In addition, it is also common to further promote 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 as desired. Examples thereof include heating and stirring at 50 ° C. for 24 hours and heating and stirring for 1 hour under reflux.

As another method, for example, a method of heating and polycondensing a mixture of alkoxysilane, a solvent and oxalic acid can be mentioned. Specifically, after adding succinic acid to alcohol in advance to obtain an alcohol solution of succinic acid, alkoxysilane is mixed while the solution is heated. In that case, the amount of succinic acid used is generally 0.2 to 2 mol with respect to 1 mol of all alkoxy groups of the alkoxysilane. The heating in this method can be performed at a liquid temperature of 50 to 180 ° C., and preferably, for example, several tens of minutes under reflux in a container equipped with a reflux pipe so as not to cause evaporation or volatilization of the liquid. It is done for more than ten hours.
When using multiple types of alkoxysilanes when obtaining polysiloxane (A), you may mix as a mixture which mixed alkoxysilane beforehand, and may mix multiple types of alkoxysilanes sequentially.

  The solvent used for polycondensation of alkoxysilane (hereinafter also referred to as polymerization solvent) is not particularly limited as long as it can dissolve alkoxysilane. Moreover, even when alkoxysilane does not melt | dissolve, what is melt | dissolved should just melt | dissolve with the progress of the polycondensation reaction of alkoxysilane. In general, since an alcohol is generated by a polycondensation reaction of alkoxysilane, an organic solvent having good compatibility with alcohols, glycols, glycol ethers and alcohols is used.

  Specific examples of such a polymerization solvent include methanol, ethanol, propanol, n-butanol, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, hexylene glycol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl. Carbitol, 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 Ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl 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 Examples include dibutyl ether, N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, γ-butyrolactone, dimethyl sulfoxide, tetramethylurea, hexamethylphosphotriamide, m-cresol and the like. Furthermore, the glycol compound (B) mentioned later can also be used as a polymerization solvent. Among these, methanol, ethanol, butyl cellosolve, hexylene glycol, 1,3-butanediol, 1,4-butanediol or a mixed solvent thereof is preferable as the polymerization solvent. In the present invention, a plurality of the above polymerization solvents may be mixed and used.

The polysiloxane (A) polymerization solution (hereinafter also referred to as polymerization solution) obtained by such a method has a concentration obtained by converting silicon atoms of all alkoxysilanes charged as raw materials into SiO ₂ (hereinafter referred to as SiO ₂ conversion). The concentration is generally 0.5 to 20% by mass. By selecting an arbitrary concentration within this concentration range, gel formation can be suppressed and a homogeneous solution can be obtained.

<Solution of polysiloxane (A)>
In the present invention, the polymerization solution obtained by the above-described method may be used as it is as the polysiloxane (A) solution. If necessary, the solution obtained by the above-described method may be concentrated or a solvent may be added. The solution may be diluted or substituted with another solvent to form a solution of polysiloxane (A).
In this case, the solvent used (hereinafter also referred to as additive solvent) may be the same solvent used for the polycondensation or may be another solvent. This solvent is not particularly limited as long as the polysiloxane (A) is uniformly dissolved, and one kind or a plurality of kinds can be arbitrarily selected and used.

Specific examples of such an additive solvent include alcohols such as methanol, ethanol, 2-propanol, butanol, and diacetone alcohol; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ethylene glycol, diethylene glycol, propylene glycol, and the like. Glycols such as xylene glycol; methyl cellosolve, ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, 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, polyethylene Glycol ethers such as glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether; methyl acetate, ethyl acetate And esters such as ethyl lactate; N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, γ-butyrolactone, dimethyl sulfoxide, tetramethylurea, hexamethylphosphotriamide, m- Examples include cresol. Especially, as an addition solvent, methanol, ethanol, butyl cellosolve, hexylene glycol, or those mixed solvents are preferable.
In the present invention, one or more of the polysiloxane (A) solutions obtained as described above may be used.

<Glycol compound (B)>
The glycol compound (B) used in the present invention has two carbon atoms to which a hydroxy group and a hydrogen atom are bonded, and the two carbon atoms described above are bonded via an aliphatic group which may contain a hetero atom. It is a glycol compound having the structure described above and having 3 to 6 consecutive carbon atoms, preferably 3 to 5 and particularly preferably 3 or 4. When the glycol compound (B) contains a hetero atom, it means a glycol compound having 3 to 6 consecutive carbon atoms excluding the hetero atom. For example, diethylene glycol has 4 consecutive carbon atoms and is a particularly preferred specific example of the glycol compound (B).

  The glycol compound (B) is not particularly limited as long as it is a compound as described above, but specific examples thereof include 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1, Examples include 3-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 2,4-pentanediol, 1,6-hexanediol, diethylene glycol, and dipropylene glycol.

  Since such a glycol compound (B) is usually in a liquid state, it can also be used as a solvent. Therefore, you may use as all or one part of the polymerization solvent at the time of polycondensation of polysiloxane (A) or an addition solvent, and you may add to polysiloxane (A) synthesize | combined with another solvent later.

The amount of the glycol compound (B) used in the present invention is _2. for the total 100 parts by mass of the silicon atoms of all alkoxysilanes used for obtaining the polysiloxane (A) converted to SiO 2. The amount is 5 to 19,800 parts by mass, preferably 5 to 6,000 parts by mass, and more preferably 25 to 4,000 parts by mass. When the amount of the glycol compound is less than 2.5 parts by mass, the effect of increasing the water repellency of the liquid crystal alignment film may not be sufficient.

  The glycol compound (B) used in the present invention can easily increase the water repellency of the liquid crystal alignment film, and can reduce the organic groups of the polysiloxane (A) in the liquid crystal alignment agent, resulting in a denseness. It is possible to obtain a liquid crystal alignment film that is high in hardness, high in hardness, excellent in liquid crystal alignment of the film, and excellent in coatability.

<Solvent (C)>
In the present invention, a solvent (C) which is a solvent having a hydroxy group and having a structure different from that of the glycol compound (B) can also be used.
Specific examples of the solvent (C) include alcohols such as methanol, ethanol, 2-propanol, butanol, diacetone alcohol, ethylene glycol, 1,2-propanediol, 1,2-butanediol, and 2,3-butane. Glycols such as diol, 1,2-pentanediol, 2,3-pentanediol, and 2-methyl-2,4-pentanediol; Glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene Glycol ether acetates such as glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monophenyl ether acetate, ethylene glycol monotolyl ether acetate And the like. Among them, ethanol, hexylene glycol, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, and propylene glycol monobutyl ether are preferable as the solvent (C).

The solvent (C) used in the present invention may be used as all or a part of the polymerization solvent or additive solvent for polycondensation of the polysiloxane (A). ) May be added later.
These solvents (C) can improve the applicability when the liquid crystal aligning agent is applied onto the substrate by adjusting the viscosity of the liquid crystal aligning agent or by spin coating, flexographic printing, ink jetting or the like.

In the present invention, the amount of the solvent (C) is a silicon atom of the total alkoxysilanes used to obtain polysiloxane (A) with respect to 100 parts by weight of the total in terms of SiO _2, 0~19,700 It is 0 mass parts, Preferably it is 0-19,600 mass parts, More preferably, it is 0-18,800 mass parts.

<Other ingredients>
In the present invention, as long as the effects of the present invention are not impaired, other components other than polysiloxane (A), glycol compound (B) and solvent (C), for example, inorganic fine particles, metalloxane oligomers, metalloxane polymers, Components such as a leveling agent and a surfactant may be contained.

As the inorganic fine particles, fine particles such as silica fine particles, alumina fine particles, titania fine particles, and magnesium fluoride fine particles are preferable, and those of a colloidal solution are particularly preferable. This colloidal solution may be a dispersion of inorganic fine particle powder in a dispersion medium or a commercially available colloidal solution. In the present invention, the inclusion of inorganic fine particles makes it possible to impart the surface shape of the formed cured film and other functions. The inorganic fine particles preferably have an average particle diameter of 0.001 to 0.2 μm, more preferably 0.001 to 0.1 μm. When the average particle diameter of the inorganic fine particles exceeds 0.2 μm, the transparency of the cured film formed using the prepared coating liquid may be lowered.
Examples of the dispersion medium for the inorganic fine particles include water and organic solvents. As a colloidal solution, it is preferable that pH or pKa is adjusted to 1-10 from the viewpoint of the stability of the coating liquid for forming a film. More preferably, it is 2-7.

  Organic solvents used for the dispersion medium of colloidal solutions include alcohols such as methanol, isopropyl alcohol, butanol, ethylene glycol, propylene glycol, butanediol, pentanediol, hexylene glycol, 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 γ-butyrolactone And ethers such as tetrahydrofuran and 1,4-dioxane. Of these, alcohols and ketones are preferred. These organic solvents can be used alone or in admixture of two or more as a dispersion medium.

  As the metalloxane oligomer and metalloxane polymer, single or composite oxide precursors such as silicon, titanium, aluminum, tantalum, antimony, bismuth, tin, indium, and zinc are used. The metalloxane oligomer or metalloxane polymer may be a commercially available product or may be obtained from a monomer such as a metal alkoxide, nitrate, hydrochloride, or carboxylate by a conventional method such as hydrolysis. In the present invention, by containing a metalloxane oligomer and a metalloxane polymer, it is possible to improve the refractive index of the cured film or to impart photosensitivity. When using a metalloxane oligomer or a metalloxane polymer, it may be used simultaneously when synthesizing the polysiloxane (A) or may be added later to the polysiloxane (A).

  Specific examples of commercially available metalloxane oligomers and metalloxane polymers are siloxane oligomers or siloxane polymers such as methyl silicate 51, methyl silicate 53A, ethyl silicate 40, ethyl silicate 48, EMS-485, SS-101 manufactured by Colcoat Co., Ltd. And titanoxane oligomers such as titanium-n-butoxide tetramer manufactured by Kanto Chemical Co., Inc. You may use these individually or in mixture of 2 or more types.

Moreover, a leveling agent, surfactant, etc. can use a well-known thing, and since a commercial item is easy to acquire especially, it is preferable.
In addition, the method of mixing the above-mentioned other components with the polysiloxane (A) may be simultaneous with or after the solution of the polysiloxane (A) and the glycol compound (B), and is not particularly limited. .

<Preparation of liquid crystal aligning agent>
The method for preparing the liquid crystal aligning agent of the present invention is not particularly limited. It is sufficient that the polysiloxane (A) and the glycol compound (B) and, if necessary, the solvent (C) and / or other components are uniformly mixed.

  Usually, polysiloxane (A) is polycondensed in a solvent, and thus is obtained in a solution state. Therefore, the method of using the polysiloxane (A) polymerization solution already described above as it is is simple. When the polymerization solvent for polysiloxane (A) is glycol compound (B), glycol compound (B) may not be added later. Moreover, when the solution of polysiloxane (A) does not contain a glycol compound (B), when preparing a liquid crystal aligning agent, a glycol compound (B) can be added and used.

Moreover, when using together a solvent (C), you may use as a polymerization solvent at the time of synthesize | combining polysiloxane (A), or an addition solvent, and may mix and use it when preparing a liquid crystal aligning agent.
When preparing the liquid crystal aligning agent, the polysiloxane (A) has a SiO ₂ equivalent concentration obtained by converting silicon atoms of all alkoxysilanes used for obtaining the polysiloxane (A) into SiO ₂ in the liquid crystal aligning agent. It is 0.5-20 mass%, Preferably it is 0.5-15 mass%, Most preferably, it is 0.5-8 mass%. Within such a SiO ₂ equivalent concentration range, it is easy to obtain a desired film thickness by a single application, and a sufficient pot life of the solution is easily obtained.
Note that this time, the solvent used to adjust the terms of SiO ₂ concentration, the polymerization solvent of the polysiloxane (A), it is possible to use a solvent selected from the group consisting of entrainer and glycol compounds (B).

<Formation of liquid crystal alignment film>
The liquid crystal aligning agent of this invention can be made into a cured film by drying and baking after apply | coating to a board | substrate.
Examples of the method for applying the liquid crystal aligning agent include spin coating, printing, ink jet, spraying, roll coating, and the like.In terms of productivity, the transfer printing method is widely used industrially. The liquid crystal aligning agent of this invention is also used suitably.
The drying process after applying the liquid crystal aligning agent is not necessarily required, but if the time from application to baking is not constant for each substrate, or if baking is not performed immediately after application, a drying process is included. Is preferred. The drying is not particularly limited as long as the solvent is removed to such an extent that the shape of the coating film is not deformed by transporting the substrate or the like. For example, a method of drying on a hot plate at a temperature of 40 ° C. to 150 ° C., preferably 60 ° C. to 100 ° C. for 0.5 to 30 minutes, preferably 1 to 5 minutes can be mentioned.

  The coating film formed by applying the liquid crystal aligning agent by the above method can be baked to obtain a cured film. At that time, the firing temperature can be carried out at an arbitrary temperature of 100 ° C. to 350 ° C., preferably 140 ° C. to 300 ° C., more preferably 150 ° C. to 230 ° C., further preferably 160 ° C. to 220 ° C. It is. Firing can be performed at an arbitrary time of 5 minutes to 240 minutes. Preferably it is 10 to 90 minutes, More preferably, it is 20 to 90 minutes. For the heating, a generally known method such as a hot plate, a hot air circulation oven, an IR oven, a belt furnace or the like can be used.

  The polysiloxane (A) in the liquid crystal alignment film undergoes polycondensation in the firing step. However, in the present invention, it is not necessary to completely polycondense unless the effects of the present invention are impaired. However, firing is preferably performed at a temperature higher by 10 ° C. or more than the heat treatment temperature required for the liquid crystal cell production process, such as curing of the sealant.

  The thickness of the cured film can be selected as necessary. When the thickness of the cured film is 5 nm or more, it is preferable because the reliability of the liquid crystal display element is easily obtained. More preferably, it is 10 nm or more. Moreover, the case of 300 nm or less is preferable because the power consumption of the liquid crystal display element does not become extremely large. More preferably, it is 150 nm or less.

  Such a cured film can be used as a liquid crystal alignment film as it is, but the cured film is rubbed, irradiated with polarized light or light of a specific wavelength, processed with an ion beam, etc. An alignment film can also be used.

<Liquid crystal alignment film>
The liquid crystal alignment film of the present invention formed by the method as described above is considered to have a structure in which the specific organic group of the polysiloxane (A) is unevenly distributed in the vicinity of the surface layer of the liquid crystal alignment film. This can be confirmed by measuring the water contact angle of the liquid crystal alignment film of the present invention. This is presumed to be due to the effect of the glycol compound (B) that is a component of the liquid crystal aligning agent of the present invention, and when the glycol compound (B) is contained in the liquid crystal aligning agent, the glycol compound (B) is not included. Compared to the case, the water contact angle can be increased.

  That is, the specific organic group of the polysiloxane (A) is unevenly distributed near the surface layer of the liquid crystal alignment film due to the effect of the glycol compound (B), so that the liquid crystal molecules can be easily aligned in one direction, particularly in the vertical direction. It is thought that there is an effect. Therefore, since the liquid crystal alignment film of the present invention exhibits high water repellency, good liquid crystal vertical alignment can be obtained.

Furthermore, the liquid crystal alignment film of the present invention is a good liquid crystal because the water repellency of the liquid crystal alignment film is high even when the amount of the specific organic group contained in the polysiloxane (A) which is a component of the liquid crystal alignment agent of the present invention is small. It has vertical alignment, high density, and high hardness. In addition, since the liquid crystal alignment film is obtained from the liquid crystal aligning agent of the present invention having excellent coating properties, it also has an effect of high uniformity. Therefore, a liquid crystal display element with high reliability and high image quality can be provided. Specifically, in the liquid crystal aligning agent of the present invention, the specific organic group that the polysiloxane (A) has is 0.1 to 30 moles relative to 100 moles of silicon atoms that the polysiloxane (A) has. In addition, the obtained liquid crystal alignment film has high water repellency, good liquid crystal vertical alignment, high density, high hardness, and excellent uniformity.
Furthermore, the display element having the liquid crystal alignment film can reduce the content of the specific organic group of the polysiloxane (A) by the action of the glycol compound (B) contained in the liquid crystal alignment agent. It is considered that the absolute value of the accumulated charge of the display element can be reduced.

<Liquid crystal display element>
The liquid crystal display element of the present invention can be obtained by forming a liquid crystal alignment film on a substrate by the method described above and then preparing a liquid crystal cell by a known method. As an example of producing a liquid crystal cell, a method is generally employed in which a pair of substrates on which a liquid crystal alignment film is formed are fixed with a sealant with a spacer interposed therebetween, and liquid crystal is injected and sealed. In this case, the size of the spacer used is 1 to 30 micrometers, preferably 2 to 10 micrometers.

The method for injecting the liquid crystal is not particularly limited, and examples thereof include a vacuum method for injecting liquid crystal after the inside of the manufactured liquid crystal cell is decompressed, and a dropping method for sealing after dropping the liquid crystal.
The substrate used for the liquid crystal display element is not particularly limited as long as it is a highly transparent substrate, but is usually a substrate in which a transparent electrode for driving liquid crystal is formed on the substrate.

  Specific examples include glass plate, polycarbonate, poly (meth) acrylate, polyethersulfone, polyarylate, polyurethane, polysulfone, polyether, polyetherketone, trimethylpentene, polyolefin, polyethylene terephthalate, (meth) acrylonitrile, tri Examples thereof include a substrate in which a transparent electrode is formed on a plastic plate such as acetyl cellulose, diacetyl cellulose, and acetate butyrate cellulose.

As a high-performance element such as a TFT type element, an element in which an element such as a transistor is formed between an electrode for driving a liquid crystal and a substrate is used.
In the case of a transmissive liquid crystal element, it is common to use a substrate as described above. However, in a reflective liquid crystal display element, an opaque substrate such as a silicon wafer can be used if only one substrate is used. It is. At that time, a material such as aluminum that reflects light may be used for the electrode formed on the substrate.
As described above, the liquid crystal alignment film obtained using the liquid crystal aligning agent of the present invention has high density, high hardness, high water repellency, and good liquid crystal vertical alignment. In addition, a liquid crystal alignment film having excellent uniformity can be obtained. Furthermore, an element produced using the liquid crystal alignment film has good accumulated charge characteristics.

Hereinafter, although a synthesis example, an Example, and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example.
Explanation of abbreviations in this embodiment.
TEOS: Tetraethoxysilane C8: Octyltriethoxysilane C12: Dodecyltriethoxysilane C18: Octadecyltriethoxysilane F13: Tridecafluorooctyltrimethoxysilane MTES: Methyltriethoxysilane MPS: 3-Mercaptopropyltrimethoxysilane MAPS: 3 -Methacryloxypropyltrimethoxysilane HG: hexylene glycol (2-methyl-2,4-pentanediol)
BCS: butyl cellosolve EtOH: ethanol 1,3-PrDO: 1,3-propanediol 1,3-BDO: 1,3-butanediol 1,4-BDO: 1,4-butanediol 1,3-PeDO: 1, 3-pentanediol 1,6-HDO: 1,6-hexanediol DEG: diethylene glycol DPG: dipropylene glycol

<Synthesis Example 1>
Into a 1 L four-necked reaction flask equipped with a thermometer and a reflux tube, 164.3 g of HG, 164.9 g of TEOS and 13.9 g of C12 were added and stirred to prepare a solution of an alkoxysilane monomer. To this solution, an oxalic acid solution in which 82.1 g of HG, 74.1 g of water and 0.8 g of oxalic acid as a catalyst were mixed in advance was added dropwise over 30 minutes at room temperature, and stirred at room temperature for 30 minutes after the completion of the addition. Then, after heating for 1 hour under reflux, the mixture was allowed to cool to obtain a polysiloxane solution (K1) having a SiO ₂ equivalent solid content concentration of 10% by mass.

<Preparation Examples 1-7>
By mixing and stirring the amounts of HG, BCS and solvent (X) shown in Table 1 to 10 g of the polysiloxane solution (K1) obtained in Synthesis Example 1, the solvent composition is shown in Table 1. and it was obtained in terms of SiO ₂ solid content concentration of 4 mass% of the liquid crystal alignment agent (KL1~KL7).

<Preparation Example 8>
10 g of the polysiloxane solution (K1) obtained in Synthesis Example 1, 11.0 g of HG, and 4.0 g of BCS are mixed and stirred, so that the solvent composition is HG: BCS = 80: 20, and the solid content concentration in terms of SiO ₂ Obtained 4 mass% liquid crystal aligning agent (KM1).

<Synthesis Example 2>
A 1 L four-necked reaction flask equipped with a thermometer and a reflux tube was charged with BCS 164.3 g, TEOS 164.9 g and C12 13.9 g, and stirred to prepare an alkoxysilane monomer solution. To this solution, an oxalic acid solution in which 82.1 g of BSC, 74.1 g of water and 0.8 g of oxalic acid as a catalyst were mixed in advance was added dropwise over 30 minutes at room temperature, and stirred at room temperature for 30 minutes after the completion of the addition. Then, after heating for 1 hour under reflux, the mixture was allowed to cool to obtain a polysiloxane solution (K2) having a solid content concentration of 10% by mass as SiO ₂ .

<Preparation Example 9>
13.0 g of BCS and 2.0 g of DEG are added to 10 g of the polysiloxane solution (K2) obtained in Synthesis Example 2, mixed and stirred, and the solvent composition is set to BCS: DEG = 90: 10, converted to SiO ₂ A liquid crystal aligning agent (KL8) having a solid content concentration of 4% by mass was obtained.
<Preparation Example 10>
15.0 g of BCS was mixed with 10 g of the polysiloxane solution (K2) obtained in Synthesis Example 2 and stirred to obtain a liquid crystal aligning agent (KM2) having a SiO ₂ equivalent solid content concentration of 4 mass%.

<Synthesis Example 3>
Into a 1 L four-necked reaction flask equipped with a thermometer and a reflux tube, 164.3 g of DEG, 164.9 g of TEOS, and 13.9 g of C12 were charged and stirred to prepare a solution of an alkoxysilane monomer. To this solution, 82.1 g of DEG, 74.1 g of water and 0.8 g of oxalic acid as a catalyst were mixed dropwise over 30 minutes at room temperature, and the mixture was stirred at room temperature for 30 minutes after completion of the dropwise addition. Then, after heating under reflux for 1 hour, the mixture was allowed to cool to obtain a polysiloxane solution (K3) having a solid content concentration of 10% by mass as SiO ₂ .

<Preparation Example 11>
15.0 g of DEG was mixed with 10 g of the polysiloxane solution (K3) obtained in Synthesis Example 3 and stirred to obtain a liquid crystal aligning agent (KL9) having a solid content concentration of 4% by mass as SiO ₂ .
<Preparation Example 12>
13.0 g of DEG and 2.0 g of BCS are added to and mixed with 10 g of the polysiloxane solution (K3) obtained in Synthesis Example 3 so that the solvent composition becomes BCS: DEG = 10: 90, and converted to SiO ₂ A liquid crystal aligning agent (KL10) having a solid content concentration of 4% by mass was obtained.
<Synthesis Example 4>
EtOH 164.3 g, TEOS 164.9 g, and 13.9 g of C12 were charged into a 1 L four-necked reaction flask equipped with a thermometer and a reflux tube, and stirred to prepare an alkoxysilane monomer solution. To this solution, an oxalic acid solution in which 82.1 g of EtOH, 74.1 g of water and 0.8 g of oxalic acid as a catalyst were mixed in advance was added dropwise over 30 minutes at room temperature, and stirred at room temperature for 30 minutes after the completion of the addition. Then, after heating for 1 hour under reflux, the mixture was allowed to cool to obtain a polysiloxane solution (K4) having a solid content concentration in terms of SiO ₂ of 10% by mass.

<Preparation Example 13>
1 g of EtOH and 2.0 g of DEGOH were added to 10 g of the polysiloxane solution (K4) obtained in Synthesis Example 4, mixed and stirred, and converted to SiO ₂ such that the solvent composition was EtOH: DEG = 90: 10. A liquid crystal aligning agent (KL11) having a solid content concentration of 4% by mass was obtained.
<Preparation Example 14>
EtOH 15.0 g was mixed with 10 g of the polysiloxane solution (K4) obtained in Synthesis Example 4 and stirred to obtain a liquid crystal aligning agent (KM3) having a SiO ₂ equivalent solid content concentration of 4 mass%.
<Synthesis Example 5>
A 1 L four-necked reaction flask equipped with a thermometer and a reflux tube was charged with 121.0 g of HG, 40.3 g of BCS, 164.9 g of TEOS, and 17.4 g of C18, and stirred to prepare an alkoxysilane monomer solution. To this solution, an oxalic acid solution prepared by mixing 60.5 g of HG, 20.2 g of BCS, 75.0 g of water and 0.8 g of oxalic acid as a catalyst in advance over 30 minutes at room temperature, and stirred for 30 minutes at room temperature after completion of the addition. did. Then, after heating for 1 hour under reflux, the mixture was allowed to cool to obtain a polysiloxane solution (K5) having a solid content concentration in terms of SiO ₂ of 10% by mass.

<Preparation Examples 15 to 19>
By mixing and stirring the amounts of HG, BCS and DEG shown in Table 2 to 10 g of the polysiloxane solution (K5) obtained in Synthesis Example 5, the solvent composition is shown in Table 2, and SiO 2 The liquid crystal aligning agent (KL12-KL15 and KM4) whose ₂ conversion solid content concentration is 4 mass% was obtained.

<Synthesis Example 6>
A 1 L four-neck reaction flask equipped with a thermometer and a reflux tube was charged with 121.5 g of HG, 41.5 g of BCS, 164.9 g of TEOS, and 11.5 g of C8 and stirred to prepare an alkoxysilane monomer solution. To this solution, an oxalic acid solution in which 62.2 g of HG, 20.7 g of BCS, 74.1 g of water and 0.8 g of oxalic acid as a catalyst were mixed dropwise over 30 minutes at room temperature, and stirred at room temperature for 30 minutes after completion of the dropwise addition. did. Then, after heating for 1 hour under reflux, the mixture was allowed to cool to obtain a polysiloxane solution (K6) having a solid content concentration in terms of SiO ₂ of 10% by mass.

<Preparation Example 20>
HG 10.2 g, BCS 2.8 g, and DEG 2.0 g were added to 10 g of the polysiloxane solution (K6) obtained in Synthesis Example 6, mixed and stirred, and the solvent composition was HG: BCS: DEG = 70: 20: 10. Thus, a liquid crystal aligning agent (KL16) having a solid content concentration in terms of SiO ₂ of 4% by mass was obtained.
<Preparation Example 21>
12.2 g of HG and 2.8 g of BCS were added to 10 g of the polysiloxane solution (K6) obtained in Synthesis Example 6, mixed and stirred, so that the solvent composition was HG: BCS = 80: 20, and the SiO ₂ equivalent solid A liquid crystal aligning agent (KM5) having a partial concentration of 4% by mass was obtained.

<Synthesis Example 7>
A 1 L four-necked reaction flask equipped with a thermometer and a reflux tube was charged with 118.1 g of HG, 39.4 g of BCS, 207.3 g of TEOS, and 1.7 g of C12, and stirred to prepare a solution of an alkoxysilane monomer. To this solution, an oxalic acid solution in which HG 59.0 g, BCS 19.7 g, water 53.9 g and 0.9 g of oxalic acid as a catalyst were mixed in advance was added dropwise over 30 minutes at room temperature, and stirred at room temperature for 30 minutes after completion of the addition. did. Then, after heating for 1 hour under reflux, the mixture was allowed to cool to obtain a polysiloxane solution (K7) having a SiO ₂ equivalent solid content concentration of 12% by mass.

<Preparation Example 22>
HG 13.8 g, BCS 3.8 g and DEG 2.5 g were added to 10 g of the polysiloxane solution (K7) obtained in Synthesis Example 7, mixed and stirred, and the solvent composition was HG: BCS: DEG = 70: 20: 10. As a result, a liquid crystal aligning agent (KL17) having a solid content concentration of 4% by mass in terms of SiO ₂ was obtained.
<Preparation Example 23>
HG16.2 g and BCS 3.8 g were added to 10 g of the polysiloxane solution (K7) obtained in Synthesis Example 7, mixed and stirred, the solvent composition was HG: BCS = 80: 20, and the SiO ₂ equivalent solid A liquid crystal aligning agent (KM6) having a partial concentration of 4% by mass was obtained.

<Synthesis Example 8>
A 1 L four-necked reaction flask equipped with a thermometer and a reflux tube was charged with 124.9 g of HG, 41.6 g of BCS, 171.9 g of TEOS, and 2.8 g of C12 and stirred to prepare an alkoxysilane monomer solution. To this solution, an oxalic acid solution in which 62.5 g of HG, 20.8 g of BCS, 74.8 g of water and 0.8 g of oxalic acid as a catalyst were mixed in advance was added dropwise over 30 minutes at room temperature, and stirred at room temperature for 30 minutes after completion of the addition. did. Then, after heating under reflux for 1 hour, the mixture was allowed to cool to obtain a polysiloxane solution (K8) having a solid content concentration of 10% by mass as SiO ₂ .

<Preparation Example 24>
HG 10.2 g, BCS 2.8 g and DEG 2.0 g were added to 10 g of the polysiloxane solution (K8) obtained in Synthesis Example 8, mixed and stirred, and the solvent composition was HG: BCS: DEG = 70: 20: 10. Thus, a liquid crystal aligning agent (KL18) having a solid content concentration of 4% by mass in terms of SiO ₂ was obtained.
<Preparation Example 25>
12.2 g of HG and 2.8 g of BCS are added to 10 g of the polysiloxane solution (K8) obtained in Synthesis Example 8, mixed and stirred, and the solvent composition is set to HG: BCS = 80: 20 to obtain a solid in terms of SiO ₂ A liquid crystal aligning agent (KM7) having a partial concentration of 4% by mass was obtained.

<Synthesis Example 9>
A 1 L four-necked reaction flask equipped with a thermometer and a reflux tube was charged with 123.2 g of HG, 41.1 g of BCS, 164.9 g of TEOS, and 13.9 g of C12 and stirred to prepare an alkoxysilane monomer solution. To this solution, an oxalic acid solution in which 61.6 g of HG, 20.5 g of BCS, 74.1 g of water and 0.8 g of oxalic acid as a catalyst were mixed in advance was added dropwise over 30 minutes at room temperature, and stirred at room temperature for 30 minutes after the completion of the addition. did. Then, after heating at 65 ° C. for 1 hour, the mixture was allowed to cool to obtain a polysiloxane solution (K9) having a solid content concentration in terms of SiO ₂ of 10% by mass.

<Preparation Example 26>
HG 10.2 g, BCS 2.8 g and DEG 2.0 g were added to 10 g of the polysiloxane solution (K9) obtained in Synthesis Example 9, mixed and stirred, and the solvent composition was HG: BCS: DEG = 70: 20: 10. Thus, a liquid crystal aligning agent (KL19) having a solid content concentration in terms of SiO ₂ of 4% by mass was obtained.
<Preparation Example 27>
12.2 g of HG and 2.8 g of BCS were added to and mixed with 10 g of the polysiloxane solution (K9) obtained in Synthesis Example 9 so that the solvent composition was HG: BCS = 80: 20, and the solid was converted to SiO _2. A liquid crystal aligning agent (KM8) having a partial concentration of 4% by mass was obtained.

<Synthesis Example 10>
A 1 L four-necked reaction flask equipped with a thermometer and a reflux tube was charged with 111.6 g of HG, 39.6 g of BCS, 147.6 g of TEOS, and 41.6 g of C12, and stirred to prepare an alkoxysilane monomer solution. To this solution, an oxalic acid solution in which HG 59.5 g, BCS 19.8 g, water 72.2 g and 0.8 g of oxalic acid as a catalyst were mixed in advance was added dropwise over 30 minutes at room temperature, and stirred at room temperature for 30 minutes after the completion of the addition. did. Then, after heating for 1 hour under reflux, the mixture was allowed to cool to obtain a polysiloxane solution (K10) having a solid content concentration in terms of SiO ₂ of 10% by mass.

<Preparation Example 28>
HG 10.3 g, BCS 2.8 g and DEG 2.0 g were added to 10 g of the polysiloxane solution (K10) obtained in Synthesis Example 10, mixed and stirred, and the solvent composition was HG: BCS: DEG = 70: 20: 10. Thus, a liquid crystal aligning agent (KL20) having a solid content concentration of 4% by mass in terms of SiO ₂ was obtained.
<Preparation Example 29>
12.2 g of HG and 2.8 g of BCS were added to 10 g of the polysiloxane solution (K10) obtained in Synthesis Example 10, mixed and stirred, and the solvent composition was adjusted to HG: BCS = 80: 20 to obtain a solid in terms of SiO ₂ A liquid crystal aligning agent (KM9) having a partial concentration of 4% by mass was obtained.

<Synthesis Example 11>
Into a 1 L four-necked reaction flask equipped with a thermometer and a reflux tube, 116.8 g of HG, 39.0 g of BCS, 138.9 g of TEOS, and 55.4 g of C12 were added and stirred to prepare an alkoxysilane monomer solution. To this solution, an oxalic acid solution in which 58.4 g of HG, 19.5 g of BCS, 71.2 g of water and 0.8 g of oxalic acid as a catalyst were mixed dropwise over 30 minutes at room temperature, and stirred at room temperature for 30 minutes after completion of the dropwise addition. did. Then, after heating for 1 hour under reflux, the mixture was allowed to cool to obtain a polysiloxane solution (K11) having a SiO ₂ equivalent solid content concentration of 10% by mass.

<Preparation Example 30>
HG 10.3 g, BCS 2.8 g and DEG 2.0 g were added to 10 g of the polysiloxane solution (K11) obtained in Synthesis Example 11, mixed and stirred, and the solvent composition was HG: BCS: DEG = 70: 20: 10. Thus, a liquid crystal aligning agent (KL21) having a solid content concentration of 4% by mass in terms of SiO ₂ was obtained.
<Preparation Example 31>
12.2 g of HG and 2.8 g of BCS were added to 10 g of the polysiloxane solution (K11) obtained in Synthesis Example 11, mixed and stirred, so that the solvent composition was HG: BCS = 80: 20, and a solid in terms of SiO ₂ A liquid crystal aligning agent (KM10) having a partial concentration of 4% by mass was obtained.

<Synthesis Example 12>
A 1 L four-necked reaction flask equipped with a thermometer and a reflux tube was charged with 123.2 g of HG, 41.1 g of BCS, 164.9 g of TEOS, and 13.9 g of C12 and stirred to prepare an alkoxysilane monomer solution. To this solution, an oxalic acid solution in which 61.6 g of HG, 20.5 g of BCS, 74.1 g of water and 0.8 g of oxalic acid as a catalyst were mixed in advance was added dropwise over 30 minutes at room temperature, and stirred at room temperature for 30 minutes after the completion of the addition. did. Then, after heating for 1 hour under reflux, the mixture was allowed to cool to obtain a polysiloxane solution (K12) having a SiO ₂ equivalent solid content concentration of 10% by mass.

<Preparation Example 32>
HG 10.2 g, BCS 2.8 g, and DEG 2.0 g were added to 10 g of the polysiloxane solution (K12) obtained in Synthesis Example 12, mixed and stirred, and the solvent composition was HG: BCS: DEG = 70: 20: 10. Thus, a liquid crystal aligning agent (KL22) having a solid content concentration of 4% by mass in terms of SiO ₂ was obtained.
<Preparation Example 33>
12.2 g of HG and 2.8 g of BCS were added to 10 g of the polysiloxane solution (K12) obtained in Synthesis Example 12, mixed and stirred, so that the solvent composition was HG: BCS = 80: 20, and a solid in terms of SiO ₂ A liquid crystal aligning agent (KM11) having a partial concentration of 4% by mass was obtained.

<Synthesis Example 13>
A 1 L four-necked reaction flask equipped with a thermometer and a reflux tube was charged with 124.3 g of HG, 41.4 g of BCS, 156.3 g of TEOS, 13.9 g of C12, and 7.4 g of MTES, and stirred to obtain a solution of the alkoxysilane monomer. Prepared. To this solution, oxalic acid solution in which 62.1 g of HG, 20.7 g of BCS, 73.1 g of water and 0.8 g of oxalic acid as a catalyst were mixed in advance was added dropwise over 30 minutes at room temperature, and stirred at room temperature for 30 minutes after completion of the addition. did. Then, after heating for 1 hour under reflux, the mixture was allowed to cool to obtain a polysiloxane solution (K13) having a SiO ₂ equivalent solid content concentration of 10% by mass.

<Preparation Example 34>
HG 10.2 g, BCS 2.8 g, and DEG 2.0 g were added to 10 g of the polysiloxane solution (K13) obtained in Synthesis Example 13, mixed and stirred, and the solvent composition was HG: BCS: DEG = 70: 20: 10. Thus, a liquid crystal aligning agent (KL23) having a solid content concentration in terms of SiO ₂ of 4% by mass was obtained.
<Preparation Example 35>
12.2 g of HG and 2.8 g of BCS are added to 10 g of the polysiloxane solution (K13) obtained in Synthesis Example 13, mixed and stirred, so that the solvent composition is HG: BCS = 80: 20, and a solid in terms of SiO ₂ A liquid crystal aligning agent (KM12) having a partial concentration of 4% by mass was obtained.

<Synthesis Example 14>
A 1 L four-necked reaction flask equipped with a thermometer and a reflux tube was charged with 130.1 g of HG, 43.4 g of BCS, 147.6 g of TEOS, 13.9 g of C12, 8.18 g of MPS and 10.4 g of MAPS, stirred, and alkoxysilane. A solution of the monomer was prepared. To this solution, an oxalic acid solution in which HG 65.1 g, BCS 21.7 g, water 69.4 g and 0.8 g of oxalic acid as a catalyst were mixed in advance was added dropwise over 30 minutes at room temperature, and stirred at room temperature for 30 minutes after completion of the addition. did. Then, after heating for 1 hour under reflux, the mixture was allowed to cool to obtain a polysiloxane solution (K14) having a SiO ₂ equivalent solid content concentration of 10% by mass.

<Preparation Example 36>
HG 10.2 g, BCS 2.7 g and DEG 2.0 g were added to 10 g of the polysiloxane solution (K14) obtained in Synthesis Example 14, mixed and stirred, and the solvent composition was HG: BCS: DEG = 70: 20: 10. Thus, a liquid crystal aligning agent (KL24) having a solid content concentration of SiO ₂ of 4% by mass was obtained.
<Preparation Example 37>
HG 12.3 g and BCS 2.7 g were added to 10 g of the polysiloxane solution (K14) obtained in Synthesis Example 14, mixed and stirred, the solvent composition was HG: BCS = 80: 20, and the SiO ₂ equivalent solid A liquid crystal aligning agent (KM13) having a partial concentration of 4% by mass was obtained.

<Synthesis Example 15>
A 1 L four-necked reaction flask equipped with a thermometer and a reflux tube was charged with 120.4 g of HG, 40.1 g of BCS, 164.9 g of TEOS, and 19.5 g of F13, and stirred to prepare an alkoxysilane monomer solution. To this solution, an oxalic acid solution in which 60.2 g of HG, 20.1 g of BCS, 74.1 g of water and 0.8 g of oxalic acid as a catalyst were mixed in advance was added dropwise over 30 minutes at room temperature, and stirred at room temperature for 30 minutes after completion of the addition. did. Then, after heating for 1 hour under reflux, the mixture was allowed to cool to obtain a polysiloxane solution (K15) having a solid content concentration in terms of SiO ₂ of 10% by mass.

<Preparation Example 38>
12.2 g of HG and 2.8 g of BCS were added to 10 g of the polysiloxane solution (K15) obtained in Synthesis Example 15, mixed and stirred, so that the solvent composition was HG: BCS = 80: 20, and a solid in terms of SiO ₂ A liquid crystal aligning agent (KM14) having a partial concentration of 4% by mass was obtained.
<Preparation Example 39>
HG 10.3 g, BCS 2.7 g, and DEG 2.0 g were added to 10 g of the polysiloxane solution (K15) obtained in Synthesis Example 15, mixed and stirred, and the solvent composition was HG: BCS: DEG = 70: 20: 10. Thus, a liquid crystal aligning agent (KL25) having a solid content concentration in terms of SiO ₂ of 4% by mass was obtained.
<Preparation Example 40>
A silica sol (SiO ₂ ) in which 9 g of a liquid crystal aligning agent (KL22) obtained by the same method as in Preparation Example 32 and colloidal silica having a particle system of 18 nm are dispersed in an organic solvent (HG: BCS: DEG = 70: 20: 10). 1 g of the converted solid content concentration was added and mixed and stirred to obtain a liquid crystal aligning agent (KL26) having a SiO ₂ converted solid content concentration of 4 mass%.
<Preparation Example 41>
Silica sol (SiO ₂ equivalent solid content concentration) in which 9 g of liquid crystal aligning agent (KM11) obtained by the same method as in Preparation Example 33 and colloidal silica having a particle system of 18 nm are dispersed in an organic solvent (HG: BCS = 80: 20) Was added, mixed and stirred to obtain a liquid crystal aligning agent (KM15) having a SiO ₂ conversion solid content concentration of 4% by mass.

<Synthesis Example 16>
Into a 1 L four-necked reaction flask equipped with a thermometer and a reflux tube, 300.6 g of EtOH was added, and 90.0 g of oxalic acid was added little by little to this EtOH with stirring to prepare an EtOH solution of oxalic acid. The solution was then heated to its reflux temperature, and a mixture of 99.0 g TEOS and 10.4 g C18 was added dropwise over 30 minutes to the solution under reflux. Even after completion of the dropwise addition, heating was continued under reflux for 5 hours, and then allowed to cool to obtain a polysiloxane solution (K16) having a solid content concentration of 6% by mass as SiO ₂ .

<Preparation Example 42>
Polysiloxane solution obtained in Synthesis Example 16 (K16) BCS1.1g to 10 g, and stirred and mixed by adding EtOH3.9G, solvent composition EtOH: BCS = 90: as a 10, SiO ₂ in terms of solid A liquid crystal aligning agent (KM16) having a partial concentration of 4% by mass was obtained.
<Preparation Example 43>
1.1 g of DEG and 3.9 g of EtOH were added to 10 g of the polysiloxane solution (K16) obtained in Synthesis Example 16, mixed and stirred, so that the solvent composition was EtOH: DEG = 90: 10, and a solid in terms of SiO ₂ was obtained. A liquid crystal aligning agent (KL27) having a partial concentration of 4% by mass was obtained.

<Examples 1-27>
The liquid crystal aligning agents KL1 to KL27 were subjected to pressure filtration with a membrane filter having a pore diameter of 0.45 micrometers, and then formed into a film on a glass substrate with an ITO transparent electrode by a spin coating method. The substrate was dried on a hot plate at 80 ° C. for 5 minutes and then baked in a hot air circulation clean oven at 180 ° C. for 60 minutes to form a liquid crystal alignment film having a thickness of about 80 nm. Further, the water contact angle of the liquid crystal alignment film was measured by the method described later. The results are shown in Table 3.
<Comparative Examples 1-16>
The liquid crystal aligning agents KM1 to KM16 were subjected to pressure filtration with a membrane filter having a pore diameter of 0.45 micrometers, and then formed on a glass substrate with an ITO transparent electrode by a spin coating method. The substrate was dried on a hot plate at 80 ° C. for 5 minutes and then baked in a hot air circulation clean oven at 180 ° C. for 60 minutes to form a liquid crystal alignment film having a thickness of about 80 nm. Further, the water contact angle of the liquid crystal alignment film was measured by the method described later. The results are shown in Table 3.

[Water contact angle]
3 μL of pure water was dropped on the liquid crystal alignment films obtained from Examples 1-27 and Comparative Examples 1-16, and contact was made using an automatic contact angle meter CA-Z type manufactured by Kyowa Interface Science Co., Ltd. The corner was measured.

  From Table 3, 1,3-PrDO, 1,3-BDO, 1,4-BDO, 1,3-PeDO, 1,6-HDO, DEG as liquid crystal aligning agents while using the same polysiloxane solution. When a specific glycol compound such as DPG is contained, the water contact angle of the film during film formation is higher than when a liquid crystal aligning agent not containing it is used. For example, it is clear from comparison between Examples 1 to 7 and Comparative Example 1 using K1 of a polysiloxane solution. That is, it was found that the water repellency of the film can be easily increased by containing the specific glycol compound as a liquid crystal aligning agent.

<Example 27>
Using the liquid crystal aligning agent KL18 obtained in Preparation Example 24, a liquid crystal cell was produced by the method described later. The liquid crystal alignment of the obtained liquid crystal cell was confirmed by the method described later. The results are shown in Table 4.
<Comparative Example 16>
Using the liquid crystal aligning agent KM7 obtained in Preparation Example 25, a liquid crystal cell was prepared by the method described later. The liquid crystal alignment of the obtained liquid crystal cell was confirmed by the method described later. The results are shown in Table 4.

[Creation of liquid crystal cell]
Prepare two substrates with a liquid crystal alignment film obtained as described above, spray a spacer with a particle diameter of 6 micrometers on the surface of the liquid crystal alignment film of one substrate, and then apply epoxy to the outer edge of the substrate by screen printing. After applying the system adhesive, the liquid crystal alignment films were laminated so as to face each other and cured after pressure bonding to create an empty cell. MLC-6608 (trade name) manufactured by Merck was injected into the empty cell by a vacuum injection method, and then the injection hole was sealed with a UV curable resin to prepare a liquid crystal cell (element).
[Liquid crystal orientation]
The liquid crystal cell prepared by the above-mentioned [Preparation of liquid crystal cell] method was observed with a polarizing microscope, and the alignment state of the liquid crystal was confirmed. In the case where the entire liquid crystal cell shows a uniform alignment state having no defects, the mark is “◯”. The results are shown in Table 4.

  As described in Table 3 above, even when the same polysiloxane solution is used, a liquid crystal alignment film prepared using a liquid crystal aligning agent (Comparative Example 16) that does not contain a specific glycol compound such as DEG is DEG. The water contact angle is not higher than that of a liquid crystal alignment film prepared using a liquid crystal alignment agent (Example 27) containing a specific glycol compound. And from Table 4, in the liquid crystal cell produced using these liquid crystal aligning films, the liquid crystal cell using the liquid crystal aligning film produced using the liquid crystal aligning agent containing specific glycol compounds like DEG is sufficient vertical. It was found that liquid crystal alignment was obtained and sufficient vertical liquid crystal alignment could not be obtained in a liquid crystal cell using a liquid crystal alignment film produced using a liquid crystal alignment agent not containing a specific glycol compound such as DEG. .

<Examples 28 to 29>
The liquid crystal aligning agent KL19 obtained in Preparation Example 26 or the liquid crystal aligning agent KL20 obtained in Preparation Example 28 is pressure filtered through a membrane filter having a pore diameter of 0.45 micrometers, and then spin-coated on a glass substrate with an ITO transparent electrode. The film was formed by the method and the printing method. The substrate was dried on a hot plate at 80 ° C. for 5 minutes and then baked in a hot air circulation clean oven at 180 ° C. for 60 minutes to form a liquid crystal alignment film having a thickness of about 80 nm. At this time, the applicability in obtaining a film was evaluated by the methods described later (applicability for spin coating, applicability for flexographic printing). The pencil hardness was measured by the method described later. Further, a liquid crystal cell was prepared from the substrate with a liquid crystal alignment film in accordance with the above-described method for preparing a liquid crystal cell, and accumulated charge was measured by the method described later. The results are shown in Table 5.

<Comparative Examples 17-18>
Using the liquid crystal aligning agent KM9 obtained in Preparation Example 29 or the liquid crystal aligning agent KM8 obtained in Preparation Example 27, the coating property, pencil hardness, and accumulated charge measurement are performed by the methods described later in the same manner as in Examples 28 to 29. went. The results are shown in Table 5.
[Pencil hardness]
The liquid crystal alignment films obtained from Examples 28 to 29 and Comparative Examples 17 to 18 were measured by a pencil hardness test method (JIS K5400). The results are shown in Table 5.
[Applicability of spin coat]
The liquid crystal aligning agent was filtered using a chromatodisc (pore diameter 0.45 micrometer), and then formed into a film on a glass substrate with an ITO transparent electrode by spin coating. The substrate was dried on a hot plate at 80 ° C. for 5 minutes and then baked in a hot air circulation clean oven at 180 ° C. for 60 minutes to form a liquid crystal alignment film having a thickness of about 80 nm. Visual observation of the obtained liquid crystal alignment film, ○ when the cured film is good with no pinholes / unevenness, △ when pinholes / unevenness occurs in part, pinholes / unevenness occurs on the entire surface When it is, it was set as x. The results are shown in Table 5.
[Applicability of flexographic printing]
After the liquid crystal aligning agent was filtered using a chromatodisc (pore diameter 0.45 micrometer), a Nihon Photo Printing Co., Ltd. DR type printing machine anilox roll (360 #) letterpress (halftone dot 400L 30% 70 degrees) was used. A coating film was formed on a glass substrate with a transparent electrode. The coating film was dried on a hot plate at a temperature of 80 ° C. for 5 minutes and then baked in a hot air circulation clean oven at 180 ° C. for 60 minutes to form a liquid crystal alignment film. Visual observation of the obtained liquid crystal alignment film, ○ when the cured film is good with no pinholes / unevenness, △ when pinholes / unevenness occurs in part, pinholes / unevenness occurs on the entire surface When it is, it was set as x. The results are shown in Table 5.
[Measurement of accumulated charge]
A rectangular wave of 30 Hz / ± 2.8 V in which a DC voltage of 10 V is superimposed on a liquid crystal cell has a temperature of 23
The accumulated voltage remaining in the liquid crystal cell was measured by an optical flicker erasing method immediately after the DC voltage of 10 V was cut off at 20 ° C. for 20 hours. The results are shown in Table 5.

  From Table 5, as a liquid crystal aligning agent, the coating property of the liquid crystal aligning film composed of a liquid crystal aligning agent not containing a specific glycol compound such as DEG (Comparative Example 17) is a pinhole regardless of the spin coating method or flexographic printing.・ Unevenness was seen, which proved to be insufficient. It was also found that the pencil hardness of the film was as low as H. Furthermore, it was found that the amount of change in accumulated charge was small immediately after DC application for 20 hours and 10 minutes after DC off, and the rate at which accumulated charge was released was slow. On the other hand, as a liquid crystal aligning agent, the applicability of the liquid crystal aligning film made of a liquid crystal aligning agent (Example 28) containing a specific solvent such as DEG is not limited to the spin coat method and flexographic printing. It was found that there was no unevenness and it was sufficient. It was also found that the film had a high pencil hardness of 6H. Furthermore, the absolute value of the accumulated charge also decreased greatly immediately after DC application for 20 hours and 10 minutes after the DC was turned off, indicating that the accumulated charge removal rate was fast. That is, it is presumed that problems such as image sticking and afterimage can be reduced as element characteristics.

  As a result, when a vertical liquid crystal alignment film having a high water contact angle is obtained by containing a specific glycol compound such as DEG as a liquid crystal aligning agent, it has good coatability, high hardness, and good residual DC characteristics. It was found that a vertical liquid crystal alignment film having the same can be obtained. This means that a high-reliability and high-quality vertical liquid crystal display element can be provided by containing a specific solvent such as DEG as the liquid crystal aligning agent.

Since the liquid crystal aligning agent of the present invention contains a specific solvent, it is easier to increase the water repellency of the film at the time of film formation than when a liquid crystal aligning agent not containing it is used. A liquid crystal alignment film having high density, high hardness, and good liquid crystal alignment can be formed. Furthermore, since the liquid crystal aligning agent of this invention is excellent in applicability | paintability, a highly uniform liquid crystal aligning film can be obtained. Therefore, a highly reliable liquid crystal display element with high image quality can be provided.
In addition, a long-chain alkyl group-containing silane used for obtaining a liquid crystal alignment film exhibiting a desired water repellency can be improved by adding a specific glycol compound during preparation of the liquid crystal alignment agent. It is economical because the amount of use can be reduced.
Therefore, it can be suitably used in various liquid crystal alignment elements, particularly in the vertical alignment type (VA). In addition, it can also be used in polarizing films, retardation films, and alignment films for viewing angle widening films.

The entire contents of the specification, claims, and abstract of Japanese Patent Application No. 2006-275713 filed on October 6, 2006 are incorporated herein as the disclosure of the specification of the present invention. Is.

Claims (8)

Total containing the following polysiloxane (A) and glycol compound (B) , wherein the glycol compound (B) is converted to SiO ₂ with silicon atoms of all alkoxysilanes used to obtain the polysiloxane (A). The liquid crystal aligning agent characterized by containing 2.5-19,800 mass parts with respect to 100 mass parts .
Polysiloxane (A): polysiloxane obtained by polycondensation of alkoxysilane containing at least one of alkoxysilanes represented by the following formula (1).
R ¹ _n Si (OR ² ) _4-n (1)
(R ¹ is an organic group having 7 to 30 carbon atoms, R ² represents a hydrocarbon group having 1 to 5 carbon atoms, and n represents an integer of 1 to 3)
Glycol compound (B): having two carbon atoms to which a hydroxy group and a hydrogen atom are bonded, and having the structure in which the two carbon atoms are bonded via an aliphatic group that may contain a hetero atom A glycol compound having 3 to 6 consecutive carbon atoms. Furthermore, the liquid crystal aligning agent of Claim 1 containing the following solvent (C).
Solvent (C): A solvent having a hydroxy group, which is a compound having a structure different from that of the glycol compound (B) defined in claim 1.   The polysiloxane (A) is a polysiloxane obtained by polycondensation of an alkoxysilane represented by the formula (1) with an alkoxysilane containing 0.1 to 30 mol% in all alkoxysilanes. Or the liquid crystal aligning agent of 2. The polysiloxane (A) is a polysiloxane obtained by polycondensation of an alkoxysilane using at least one alkoxysilane represented by the formula (1) and at least one alkoxysilane represented by the formula (2). The liquid crystal aligning agent of any one of Claims 1-3 .
R ³ _m Si (OR ⁴ ) _4-m (2)
(R ³ represents a hydrogen atom, a halogen atom or an organic group having 1 to 6 carbon atoms, R ⁴ represents a hydrocarbon group having 1 to 5 carbon atoms, and m represents an integer of 0 to 3) The glycol compound (B) is 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 2, The liquid crystal aligning agent according to any one of claims 1 to 4 , which is at least one selected from the group consisting of 4-pentanediol, 1,6-hexanediol, diethylene glycol, and dipropylene glycol.
Polysiloxane in the liquid crystal aligning agent (A) is, SiO ₂ concentration in terms of silicon atoms of the total alkoxysilane in terms of SiO ₂ was used to obtain the polysiloxane (A) is 0.5 to 20 wt% The liquid crystal aligning agent of any one of Claims 1-5. The liquid crystal aligning film obtained using the liquid crystal aligning agent of any one of Claims 1-6 . The liquid crystal display element which has a liquid crystal aligning film of Claim 7 .