JP2007047806A - Alignment layer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an alignment film having a polymer layer having characteristics that can easily align a liquid crystalline compound, particularly, a discotic liquid crystalline compound. <P>SOLUTION: Inorganic oxide fine particles having a particle size of 5 nm to 1 μm are produced by hydrolysis and condensation reaction of an inorganic oxide precursor in a W/O emulsion having an aqueous phase emulsified in an oil phase and containing a cationic surfactant dissolved in the oil phase. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an alignment film provided on a transparent support.

  CRT (cathode ray tube) has been mainly used as a display device for OA equipment such as desktop personal computers and word processors. Recently, liquid crystal display devices (hereinafter referred to as LCDs) are widely used in place of CRTs because of their thinness, light weight, and low power consumption. The LCD generally comprises a liquid crystal cell and a pair of polarizing plates provided on both sides thereof.

  The liquid crystal cell is composed of a pair of transparent substrates provided with a transparent electrode and a liquid crystal compound sealed therebetween. The transparent substrate generally has an alignment film on the surface. The alignment film is formed by rubbing a polymer layer such as polyimide, polyvinyl alcohol or gelatin, or by obliquely depositing an inorganic compound. The alignment film has a function of defining the alignment direction of the liquid crystalline compound. The alignment film is preferably a polymer layer subjected to rubbing treatment from the viewpoint of productivity. For this reason, the appearance of a polymer that can easily and stably incline and align a liquid crystalline compound by rubbing treatment is eagerly desired.

Many LCDs having the above structure use twisted nematic liquid crystals. The LCD display method can be roughly divided into a birefringence mode and an optical rotation mode. A super twisted nematic liquid crystal display device (hereinafter referred to as STN-LCD) using a birefringence mode uses a super twisted nematic liquid crystal having a twist angle exceeding 90 degrees and steep electro-optical characteristics. . For this reason, such an STN-LCD can display a large capacity by time-division driving. However, STN-LCD has a problem that response speed is slow (several hundred milliseconds) and gradation display is difficult, so that liquid crystal display devices using active elements (eg, TFT-LCD and MIM-LCD) are used. It is inferior to the display characteristics.
In TFT-LCD and MIM-LCD, a twisted nematic liquid crystal having a twist angle of 90 degrees and positive birefringence is used to display an image. In the display mode of the TN-LCD, high-speed response (several tens of milliseconds) and high contrast can be obtained. Therefore, the optical rotation mode is advantageous in many respects compared to the birefringence mode and other modes. However, since the display color and display contrast of the TN-LCD change depending on the angle when viewing the liquid crystal display device (viewing angle characteristic), the display characteristic does not reach the CRT level.

In order to improve the viewing angle characteristics (that is, widening the viewing angle), it has been proposed to provide a retardation plate (optical compensation sheet) between a pair of polarizing plates and a liquid crystal cell. The proposed retardation plate has almost no phase difference in the vertical direction with respect to the liquid crystal cell, so it does not give any optical action from the front, but the phase difference appears when tilted. This compensates for the phase difference generated in step (b). This phase difference brings about undesirable viewing angle characteristics such as coloring or disappearance of the display image. As such an optical compensation sheet, a sheet having negative birefringence and an inclined optical axis so as to compensate for positive birefringence of the nematic liquid crystal is effective.
Patent Document 1 discloses an optical compensation sheet having negative birefringence and an inclined optical axis. That is, the sheet is produced by stretching a polymer such as polycarbonate or polyester, and has a main refractive index direction inclined from the normal line of the sheet. In order to manufacture the said sheet | seat by an extending | stretching process, since an extremely complicated extending | stretching process is required, it is very difficult to manufacture the optical compensation sheet | seat of a large area by the disclosed method.

On the other hand, an optical compensation sheet using a liquid crystalline polymer is also known. For example, Patent Document 2 and Patent Document 3 disclose optical compensation sheets obtained by applying a liquid crystalline polymer to the alignment film surface on a supporting film. Polyimide is used as the polymer for the alignment film. As other polymer examples, polyamide such as nylon (Patent Document 2) and polyvinyl alcohol (Patent Document 3) are also described. The polymers having liquid crystal properties described in these publications have a problem that they are not suitable for mass production because their aging requires a long period of time at a high temperature for alignment.
Patent Document 4 discloses an optical compensation sheet (birefringent plate) comprising a support and a polymerizable rod-like compound having liquid crystallinity and positive birefringence. This optical compensation sheet is obtained by applying a solution of a polymerizable rod-shaped compound to a support, orienting the compound with an electric or magnetic field, and then curing. Further, this publication describes the use of a rubbed polyimide film, a silane coupling agent layer having a long-chain alkyl group, and a silicon oxide vapor-deposited film in order to orient the compound. Since the cured film having liquid crystallinity obtained above is optically positive uniaxial, the omnidirectional viewing angle can hardly be enlarged.

JP-A-6-75115 Japanese Patent Laid-Open No. 3-9326 JP-A-3-291601 Japanese Patent Application Laid-Open No. 5-215921

As described above, various polymers for alignment films are known. However, in an alignment film obtained by rubbing these polymer layers, it is difficult to tilt and align the liquid crystalline compound easily and stably. Therefore, a known optical compensation sheet composed of a support film, an alignment film, and a liquid crystal compound layer cannot significantly increase the omnidirectional viewing angle.
The present applicant has already filed an application for an optical compensatory sheet in which the viewing angle in all directions is greatly expanded (Japanese Patent Application No. 6-118963). This optical compensation sheet comprises a transparent support, an alignment film of rubbing-treated polyvinyl alcohol provided thereon, and an optically anisotropic layer of a discotic liquid crystal compound formed on the alignment film. In this sheet, an enlarged viewing angle is obtained by using a discotic liquid crystalline compound. However, it cannot be said that the alignment film can easily and stably perform the tilt alignment of the discotic liquid crystalline compound. Furthermore, it has been found that when the optical compensation sheet is stored for a long period of time, the optical anisotropic layer is occasionally peeled off from the alignment film.

  An object of the present invention is to provide an alignment film having a polymer layer having a characteristic that a liquid crystal compound, particularly a discotic liquid crystal compound, can be easily aligned by orienting the surface thereof. There is.

  The present invention provides an alignment film provided on a transparent support, the alignment film comprising polyvinyl alcohol in which at least one hydroxyl group is substituted with a group having a vinyl moiety, an oxiranyl moiety, or an aziridinyl moiety. It is in the characteristic alignment film.

Preferred embodiments of the alignment film of the present invention are as follows.
1) A group having a vinyl moiety, an oxiranyl moiety or an aziridinyl moiety is bonded to a polymer chain of polyvinyl alcohol via an ether bond, a urethane bond, an acetal bond or an ester bond.
2) A group having a vinyl moiety, an oxiranyl moiety or an aziridinyl moiety does not have an aromatic ring.
3) The substituted polyvinyl alcohol has the following general formula (I):

(However, L ¹¹ represents an ether bond, a urethane bond, an acetal bond or an ester bond;
R ¹¹ represents an alkylene group or an alkyleneoxy group;
L ¹² represents a linking group connecting R ¹¹ and Q ¹¹ ;
Q ¹¹ represents vinyl, oxiranyl or aziridinyl;
and x1 + y1 + z1 = 100, x1 is 10-99.9 mol%, y1 is 0.01-80 mol%, and z1 is 0-70 mol%; and k and h are 0 or 1, respectively. is there)
It is represented by

  4) The substituted polyvinyl alcohol has the following general formula (II):

(Wherein R ²¹ represents an alkyl group or an alkyl group substituted with alkyl, alkoxy, aryl, halogen, vinyl, vinyloxy, oxiranyl, acryloyloxy, methacryloyloxy or crotonoyloxy;
W ²¹ is an alkyl group, alkyl, alkoxy, aryl, halogen, vinyl, vinyloxy, oxiranyl, acryloyloxy, methacryloyloxy or crotonoyloxy substituted alkyl group, alkoxy group, or alkyl, alkoxy, aryl, halogen, vinyl Represents an alkoxy group substituted with vinyloxy, oxiranyl, acryloyloxy, methacryloyloxy or crotonoyloxy;
q is 0 or 1; and n is an integer from 0 to 4)
It consists of polyvinyl alcohol in which at least one hydroxyl group is substituted with a group represented by:

5) R ²¹ represents an alkyl group, or an alkyl group substituted with alkyl, alkoxy, aryl or halogen; and W ²¹ represents an alkyl group, alkoxy group substituted with an alkyl group, alkyl, alkoxy, aryl or halogen, or an alkoxy group Or an alkoxy group substituted with alkyl, alkoxy, aryl or halogen.

6) R ²¹ represents an alkyl group substituted by vinyl, vinyloxy, oxiranyl, acryloyloxy, methacryloyloxy or crotonoyloxy; and W ²¹ is an alkyl group, alkyl, alkoxy, aryl, halogen, vinyl, vinyloxy, Alkyl group, alkoxy group substituted with oxiranyl, acryloyloxy, methacryloyloxy or crotonoyloxy, or alkoxy substituted with alkyl, alkoxy, aryl, halogen, vinyl, vinyloxy, oxiranyl, acryloyloxy, methacryloyloxy or crotonoyloxy Represents a group.

  7) The polyvinyl alcohol has a repeating unit having a group having a vinyl moiety, an oxiranyl moiety or an aziridinyl moiety in the range of 0.1 to 10 mol% of all repeating units.

  In addition, the compound used for this invention does not have any problem even if the hydrogen atom in a compound is a deuterium atom.

  The element comprising the transparent support of the present invention and a specific polymer layer provided thereon can easily align a liquid crystal compound (particularly a discotic liquid crystal compound) by subjecting the polymer layer to an alignment treatment. . Therefore, the above element is useful not only as an optical compensation sheet but also as a substrate of a liquid crystal cell.

  In the optical compensation sheet of the present invention, the polymer of the alignment film and the liquid crystalline compound of the optical anisotropic layer are chemically bonded at the interface of these layers. For this reason, since the said optical compensation sheet shows high adhesiveness between alignment film and an optical anisotropic layer, it can be said that this sheet | seat also has the outstanding durability with the enlarged viewing angle.

  Further, the optical compensation sheet is formed by coating an optically anisotropic layer made of a discotic compound having a polymerizable group on an alignment film made of a specific polymer having a polymerizable group (eg, vinyl group). Is cured by applying UV light or heat. Therefore, the element of the present invention can be advantageously used for the production of the sheet.

The alignment film of the present invention comprises elements of a transparent support and a polymer layer comprising a specific polymer.
A typical configuration of the above elements is shown in FIG. In FIG. 1, a polymer layer 12 is provided on a transparent support 11 to constitute an element having a polymer layer.
The polymer layer 12 can easily align the liquid crystalline compound by subjecting the surface thereof to an alignment treatment such as a rubbing treatment. The polymer of the polymer layer is a specific polymer having a polymerizable group having a vinyl moiety, an oxiranyl moiety or an aziridinyl moiety, or an aryl group. Preferred polymers are specific polyvinyl alcohols of the general formula (I), (II) or (III) (wherein (II) represents only those specific groups).

The optical compensation sheet of the present invention comprises a transparent support, an alignment film provided thereon, and an optical anisotropic layer provided on the alignment film.
A typical configuration of the above elements is shown in FIG. In FIG. 2, a transparent support 21, an alignment film 22, and an optical anisotropic layer 23, which is a liquid crystal compound layer, are provided in this order to constitute an optical compensation sheet. The alignment film 22 is a layer obtained by aligning the polymer layer of FIG.
The optical compensation sheet of the present invention is characterized in that the polymer of the alignment film 22 and the liquid crystalline compound of the optical anisotropic layer 23 are chemically bonded via an interface between these layers. Such a chemical bond between two layers is generally formed by a reaction between a polymerizable group of a polymer and a polymerizable group of a liquid crystal compound. In this case, the optically anisotropic layer is preferably a discotic liquid crystalline compound having negative birefringence. Alternatively, the alignment film (or polymer layer) may be made of polyvinyl alcohol having no polymerizable group and having an aryl group that can easily align the liquid crystalline compound.

Any material can be used as the material for the transparent support of the present invention as long as it is transparent. A material having a light transmittance of 80% or more is preferable, and a material having optical isotropy when viewed from the front is particularly preferable.
Therefore, the transparent support is preferably manufactured from a material having a small intrinsic birefringence. Commercially available products such as ZEONEX (manufactured by Nippon Zeon Co., Ltd.), ARTON (manufactured by Nippon Synthetic Rubber Co., Ltd.) and FUJITAC (manufactured by Fuji Photo Film Co., Ltd.) can be used as such materials. Furthermore, even a material having a large intrinsic birefringence such as polycarbonate, polyarylate, polysulfone and polyethersulfone can be obtained by appropriately setting conditions such as solution casting and melt extrusion.

When the main refractive index in the plane of the transparent support (film) is nx, ny, the main refractive index in the thickness direction is nz, and the thickness of the film is d, the relationship between the triaxial main refractive indexes is nz <ny = nx. (Negative uniaxiality) is satisfied, and the retardation represented by the formula {(nx + ny) / 2-nz} × d is preferably 20 nm to 400 nm (preferably 30 to 150 nm).
However, the values of nx and ny do not have to be strictly equal, and are almost equal. Specifically, if | nx−ny | / | nx−nz | ≦ 0.2, there is no practical problem. The front retardation represented by | nx−ny | × d is preferably 50 nm or less, and more preferably 20 nm or less.

  An undercoat layer is preferably provided on the transparent support in order to increase the adhesive strength between the transparent support and the alignment film. Generally gelatin is used.

The alignment film of the present invention is provided on a transparent support. The alignment film has a function of defining the alignment direction of a liquid crystal compound such as a discotic liquid crystal compound provided thereon by coating or the like, and the alignment gives an optical axis inclined from the optical compensation sheet.
In the present invention, the alignment film is a polymer layer subjected to an alignment treatment such as a rubbing treatment, and the polymer has a group having vinyl, oxiranyl, aziridinyl, or aryl. The polymer is preferably polyvinyl alcohol. The alignment film will be described below using polyvinyl alcohol as an example.
In the polyvinyl alcohol of the present invention, at least one hydroxyl group is substituted with a group having a vinyl moiety, an oxiranyl moiety or an aziridinyl moiety. In general, the above-described moiety is composed of a polymer chain (carbon atom) of polyvinyl alcohol, an ether bond (—O—), a urethane bond (—OCONH—), an acetal bond ((—O—) ₂ CH—) or an ester bond (— OCO-) [ie linking group]. A urethane bond, an acetal bond or an ester bond is preferred. It is preferable that vinyl, oxiranyl, aziridinyl or aryl is indirectly bonded to polyvinyl alcohol via the above bond, that is, a group having the above moiety is bonded to polyvinyl alcohol together with the bonding group as described below. Preferably it is.

  The polyvinyl alcohol of the present invention is generally represented by the following general formula (I), (II) or (III) (wherein (II) represents only the group).

(However, L ¹¹ represents an ether bond, a urethane bond, an acetal bond or an ester bond;
R ¹¹ represents an alkylene group or an alkyleneoxy group;
L ¹² represents a linking group connecting R ¹¹ and Q ¹¹ ;
Q ¹¹ represents vinyl, oxiranyl or aziridinyl;
and x1 + y1 + z1 = 100, x1 is 10-99.9 mol%, y1 is 0.01-80 mol%, and z1 is 0-70 mol%; and k and h are 0 or 1, respectively. is there)
It is represented by

In the general formula (I), R ¹¹ is generally an alkylene group having 1 to 24 carbon atoms, and at least one non-adjacent CH ₂ group is —O—, —CO—, —NH—, —NR ⁷ — (R ⁷ ) represents an alkyl or aryl having 6 to 15 carbon atoms having 1 to 4 carbon atoms - S -, - SO ₂ - or alkylene carbon atoms 3 to 24 which replaced arylene having 6 to 15 carbon atoms Group, or alkyl, aryl, alkoxy, aryloxy, alkylthio, arylthio, halogen, alkylcarbonyl, arylcarbonyl, alkylsulfonyl, arylsulfonyl, hydroxyl, mercapto, amino, alkylcarbonyloxy, arylcarbonyloxy, alkylsulfonyloxy, arylsulfonyloxy , Alkylcarbonylthio, a It represents any of the above alkylene groups substituted with reelcarbonylthio, alkylsulfonylthio, arylsulfonylthio, alkylcarbonylamino, arylcarbonylamino, alkylsulfonylamino, arylsulfonylamino, carboxy or sulfo.

R ¹¹ represents —R ² —, —R ³ — (O—R ⁴ ) _t —OR ⁵ —, —R ³ —CO—R ⁶ —, —R ³ —NH—R ⁶ —, —R ³ —NR. ^{7 -R 6 -, - R 3} -S-R 6 -, - R 3 -SO 2 -R 6 - or ^-R 3 ^-A 2 ^{-R 6} - ^{(where, R 2, R 3, R} 4, R ⁵ and R ⁶ each represent alkylene having 1 to 24 carbon atoms, R ⁷ represents alkyl having 1 to 12 carbon atoms or aryl having 6 to 15 carbon atoms, and A ² represents 6 to 6 carbon atoms. Preferably represents 24 arylenes, and t represents an integer of 0-4). Further, R ¹¹ is —R ² — or —R ³ — (O—CH ₂ CH ₂ ) _t — (wherein R ² and R ³ are each alkylene having 1 to 12 carbon atoms, and t is 0 to 2) In particular, R ¹¹ is preferably alkylene having 1 to 12 carbon atoms.

  The alkylene group may have a substituent. Examples thereof include alkyl having 1 to 24 carbon atoms, aryl having 6 to 24 carbon atoms, alkoxy having 1 to 24 carbon atoms, aryloxy having 6 to 24 carbon atoms, and alkylthio having 1 to 24 carbon atoms. Arylthio having 6 to 24 carbon atoms, halogen (F, Cl, Br), alkylcarbonyl having 2 to 24 carbon atoms, arylcarbonyl having 7 to 24 carbon atoms, alkylsulfonyl having 1 to 24 carbon atoms, carbon Arylsulfonyloxy having 6 to 24 atoms, hydroxyl, mercapto, amino, alkylcarbonyloxy having 2 to 24 carbon atoms, arylcarbonyloxy having 7 to 24 carbon atoms, alkylsulfonyloxy having 1 to 24 carbon atoms, carbon atom Arylsulfonyloxy having 6 to 24 carbon atoms, alkylcarbonylthio having 2 to 24 carbon atoms, carbon Arylcarbonylthio having 7 to 24 children, alkylsulfonylthio having 1 to 24 carbon atoms, arylsulfonylthio having 6 to 24 carbon atoms, alkylcarbonylamino having 2 to 24 carbon atoms, 7 to 24 carbon atoms Examples thereof include arylcarbonylamino, alkylsulfonylamino having 1 to 24 carbon atoms, arylsulfonylamino having 6 to 24 carbon atoms, carboxy and sulfo.

  Preferred examples of the substituent for the alkylene group include alkyl having 1 to 24 carbon atoms (particularly 1 to 12 carbon atoms), aryl having 6 to 24 carbon atoms (particularly 6 to 14 carbon atoms), and carbon atoms 2 -24 alkoxyalkyl (especially 2-12 carbon atoms). Examples of alkyl include methyl, ethyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, i-propyl, i-butyl, Mention may be made of sec-butyl, t-amyl and 2-ethylhexyl. Examples of alkyl substituted with 1-4 alkoxy include 2-methoxyethyl, 2- (2-methoxyethoxy) ethyl, 2- [2- (2-methoxyethoxy) ethoxy] ethyl, 2-n- Mention may be made of butoxyethyl, 2-ethoxyethyl, 2- (2-ethoxyethoxy) ethyl, 3-methoxypropyl, 3-ethoxypropyl, 3-n-propyloxypropyl and 2-methylbutyloxymethyl. Examples of aryl include phenyl, 2-tolyl, 3-tolyl, 4-tolyl, 2-anisyl, 3-anisyl, 4-anisyl, 2-biphenyl, 3-biphenyl, 4-biphenyl, 2-chlorophenyl, 3- Mention may be made of chlorophenyl, 4-chlorophenyl, 1-naphthyl and 2-naphthyl. Examples of the heterocyclic group include pyridyl, pyrimidyl, thiazolyl and oxazolyl.

L ¹² is —O—, —S—, —CO—, —O—CO—, —CO—O—, —O—CO—O—, —CO—O—CO—, —NRCO—, —CONR. -, -NR-, -NRCONR-, -NRCO-O- or -OCONR- (wherein R represents a hydrogen atom or a lower alkyl group) are preferred.
- ^{(L ₁₂₎} h ^-Q ₁₂ are vinyl, vinyloxy, acryloyl, methacryloyl, crotonoyl, acryloyloxy, methacryloyloxy, crotonoyloxy oxy, vinyl phenoxy, vinyl benzoyloxy, styryl, 1,2-epoxy ethyl, 1,2 -Epoxypropyl, 2,3-epoxypropyl, 1,2-iminoethyl, 1,2-iminopropyl or 2,3-iminopropyl are preferred. Furthermore, vinyl, vinyloxy, acryloyl, methacryloyl, acryloyloxy, methacryloyloxy, crotonoyloxy, vinylbenzoyloxy, 1,2-epoxyethyl, 1,2-epoxypropyl, 2,3-epoxypropyl, 1,2-iminoethyl 1,2-iminopropyl or 2,3-iminopropyl is preferred. In particular, acryloyl, methacryloyl, acryloyloxy and methacryloyloxy are preferred.

  Under the condition of x1 + y1 + z1 = 100, x1 is preferably 50 to 99.9 mol%, and y1 is preferably 0.01 to 50 mol% (more preferably 0.01 to 20 mol%, particularly 0.01 to 10 mol%). %, Most preferably 0.01 to 5 mol%) and z1 is preferably 0.01 to 50 mol%.

In the above general formula (I), when L ¹¹ is an acetal bond, the polyvinyl alcohol of the general formula (I) can be represented by the following general formula (Ia).

(However, R ¹¹ , L ¹² , Q ¹¹ , x 1, y 1, z 1, k, and h are synonymous with the general formula (I).)

  The polyvinyl alcohol of the present invention can also be represented by the following general formula (III).

(However, L ³¹ represents an ether bond, a urethane bond, an acetal bond or an ester bond;
A ³¹ represents an arylene group or an arylene group substituted with halogen, alkyl, alkoxy or substituted alkoxy (substituents of substituted alkoxy include alkoxy, aryl, halogen, vinyl, vinyloxy, acryloyl, methacryloyl, crotonoyl, Acryloyloxy, methacryloyloxy, crotonoyloxy, vinylphenoxy, vinylbenzoyloxy, styryl, 1,2-epoxyethyl, 1,2-epoxypropyl, 2,3-epoxypropyl, 1,2-iminoethyl, 1,2- Mention may be made of iminopropyl or 2,3-iminopropyl);
R ³¹ represents the same group as R ¹¹ ;
L ³² represents the same group as L ¹² ;
Q ³¹ represents the same group as Q ¹¹ ;
x2 is 10 to 99.9 mol%, y2 is 0.01 to 80 mol%, and z2 is 0 to 70 mol%, and k1 and h1 are 0 or 1, respectively, under the condition of x2 + y2 + z2 = 100 is there)
In particular, A ³¹ is an arylene group having 6 to 24 carbon atoms, or an arylene group having 6 to 24 carbon atoms substituted with halogen, alkyl having 1 to 4 carbon atoms, or alkoxy having 1 to 4 carbon atoms. It is preferable.

In the group A ^31, the number of carbon atoms of the arylene group is generally 6 to 24, preferably 6 to 12. Examples of the arylene group include 1,4-phenylene, 1,3-phenylene, 1,2-phenylene and 1,5-naphthylene, and 1,4-phenylene is particularly preferable. As the substituent for the arylene group, a halogen atom (F, Cl, Br or I), an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and an alkoxy having 1 to 4 carbon atoms, C6-C15 aryl, halogen, vinyl, vinyloxy, oxiranyl (1,2-epoxyethyl, 1,2-epoxypropyl, 2,3-epoxypropyl), aziridinyl (1,2-iminoethyl, 1,2 -Iminopropyl or 2,3-iminopropyl), acryloyl, methacryloyl, crotonoyl, acryloyloxy, methacryloyloxy, crotonoyloxy, vinylphenoxy, vinylbenzoyloxy or styryl substituted alkoxy groups having 1 to 4 carbon atoms Can be mentioned. A halogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms is preferable, and F, Cl, or methyl is particularly preferable.
Under the condition of x2 + y2 + z2 = 100, x2 is preferably 50 to 99.9 mol%, and y2 is preferably 0.01 to 50 mol% (more preferably 0.01 to 20 mol%, particularly 0.01 to 10 mol%). %, Most preferably 0.01 to 5 mol%) and z2 is preferably 0.01 to 50 mol%.

In the above general formula (III), when L ³¹ is an acetal bond, the polyvinyl alcohol of the general formula (III) can be represented by the following general formula (IIIa).

(However, A ³¹ , R ³¹ , L ³² , Q ³¹ , x 2, y 2, z 2, k 1, and h 1 are synonymous with the general formula (III).)

  Furthermore, the polyvinyl alcohol of the present invention is preferably one in which at least one hydroxyl group is substituted with a group of the following general formula (II).

(Wherein R ²¹ represents an alkyl group or an alkyl group substituted with alkyl, alkoxy, allyl, halogen, vinyl, vinyloxy, oxiranyl, acryloyloxy, methacryloyloxy or crotonoyloxy;
W ²¹ is an alkyl group, alkyl, alkoxy, aryl, halogen, vinyl, vinyloxy, oxiranyl, acryloyloxy, methacryloyloxy or crotonoyloxy substituted alkyl group, alkoxy group, or alkyl, alkoxy, aryl, halogen, vinyl Represents an alkoxy group substituted with vinyloxy, oxiranyl, acryloyloxy, methacryloyloxy or crotonoyloxy;
q is 0 or 1; and n is an integer from 0 to 4 (preferably 0 or 1, especially 0))

R ²¹ represents an alkyl group, or an alkyl group substituted with alkyl, alkoxy, aryl or halogen; and W ²¹ represents an alkyl group, alkyl group, alkoxy, aryl or halogen-substituted alkyl group, alkoxy group, or It preferably represents an alkoxy group substituted with alkyl, alkoxy, allyl or halogen.

R ²¹ represents an alkyl group substituted by vinyl, vinyloxy, oxiranyl, acryloyloxy, methacryloyloxy or crotonoyloxy; and W ²¹ is an alkyl group, alkyl, alkoxy, aryl, halogen, vinyl, vinyloxy, Alkyl group, alkoxy group substituted with oxiranyl, acryloyloxy, methacryloyloxy or crotonoyloxy, or alkoxy substituted with alkyl, alkoxy, aryl, halogen, vinyl, vinyloxy, oxiranyl, acryloyloxy, methacryloyloxy or crotonoyloxy It preferably represents a group.

The number of carbon atoms of the alkyl group or alkoxy group is preferably 1-24, and particularly preferably 1-12.
Examples of the alkyl group include unsubstituted alkyl groups (eg, methyl, ethyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n- Dodecyl, i-propyl, i-butyl, sec-butyl, t-amyl and 2-ethylhexyl);
Alkyl groups substituted with 1 to 4 alkoxy (eg, 2-methoxyethyl, 2- (2-methoxyethoxy) ethyl, 2- [2- (2-methoxyethoxy) ethoxy] ethyl, 2-n-butoxyethyl) 2-ethoxyethyl, 2- (2-ethoxyethoxy) ethyl, 3-methoxypropyl, 3-ethoxypropyl, 3-n-propyloxypropyl, 3-benzyloxypropyl and 2-methylbutyloxymethyl);
Aralkyl groups (eg 2-phenylethyl and 2- (4-n-butyloxyphenyl) ethyl);
Vinylalkyl groups (eg, vinylmethyl, 2-vinylethyl, 5-vinylpentyl, 6-vinylhexyl, 7-vinylheptyl and 8-vinyloctyl);
Vinyloxyalkyl groups (eg 2-vinyloxyethyl, 5-vinyloxypentyl, 6-vinyloxyhexyl, 7-vinyloxyheptyl and 8-vinyloxyoctyl);
Oxiranyl alkyl groups (for example, 3,4-epoxybutyl, 4,5-epoxypentyl, 5,6-epoxyhexyl, 6,7-epoxyheptyl, 7,8-epoxyoctyl and 6,7-epoxyoctyl) ;
Acryloyloxyalkyl groups (eg 2-acryloyloxyethyl, 3-acryloyloxypropyl, 4-acryloyloxybutyl, 5-acryloyloxypentyl, 6-acryloyloxyhexyl, 7-acryloyloxyheptyl and 8-acryloyloxyoctyl);
Methacryloyloxyalkyl groups (eg 2-methacryloyloxyethyl, 3-methacryloyloxypropyl, 4-methacryloyloxybutyl, 5-methacryloyloxypentyl, 6-methacryloyloxyhexyl, 7-methacryloyloxyheptyl and 8-methacryloyloxyoctyl);
Crotonoyloxyalkyl groups (eg 2-crotonoyloxyethyl, 3-crotonoyloxypropyl, 4-crotonoyloxybutyl, 5-crotonoyloxypentyl, 6-crotonoyloxyhexyl, 7-crotonoyloxyheptyl and 8-crotonoyloxyoctyl).

The substitution position of OR ^{21 with} the benzene ring is preferably the 3 or 4 position.
The polyvinyl alcohol having the group of the general formula (II) has a repeating unit having the group of the general formula (II) in a range of 0.1 to 10 mol% (particularly 0.1 to 5 mol%) of all repeating units. In the range).

  The group of general formula (II) can be introduced into polyvinyl alcohol by reacting a carboxylic acid derivative having the following general formula (IIa) group with polyvinyl alcohol.

In the general formula (IIa), R ²¹ , W ²¹ , n and q have the same meanings as those in the general formula (II), and X is necessary for forming a carboxylic acid site activated form (X—CO— Represents a group that can be activated.
The group represented by X is described, for example, in “Peptide Synthesis (Chapter 5, published by Maruzen 1975)” by Nobuo Izumiya et al. For example, when an active ester is formed, examples of X include 4-nitrophenoxy and N-oxysuccinimide. In the case of forming an acid anhydride, a symmetric acid anhydride and a mixed acid anhydride can be mentioned. Examples of X in the case of a mixed acid anhydride include methanesulfonyloxy, trifluoroacetyloxy, ethyloxy Mention may be made of carbonyloxy. Examples of X in the case of an acid halide include a chlorine atom and a bromine atom. These compounds having an atomic group represented by X are not necessarily isolated, and those generated in the reaction system may be used as they are. As the carboxylic acid derivative, mixed acid anhydrides and acid halides are preferable, and methanesulfonyloxy type mixed acid anhydrides and acid chlorides are particularly preferable.

  Examples of compounds of the general formula (IIa) when X is OH (ie in the acid form) are shown below.

  In the present invention, the substituent introduced into the polymer chain (carbon atom) of polyvinyl alcohol is particularly preferably a substituent represented by the following general formula (IV).

In the general formula (IV), L ⁴¹ represents an atomic group necessary for forming a urethane bond, an acetal bond or an ester bond, and R ⁴¹ represents vinyl, acryloyl, methacryloyl, crotonoyl group, styryl, oxiranyl or aziridinyl (especially Acryloyl or methacryloyl), j and e each represent 0 or 1, d represents an integer from 2 to 24 (particularly an integer from 2 to 10), and u represents an integer from 0 to 4.

By reacting a compound having a group to be introduced into polyvinyl alcohol or modified polyvinyl alcohol (eg, the general formula (IIa)) with polyvinyl alcohol, the polyvinyl alcohol having a specific group of the present invention can be obtained. .
The polyvinyl alcohol or modified polyvinyl alcohol used in the reaction with the compound having the specific group generally has a saponification degree of 70 to 100%. Examples thereof include unmodified polyvinyl alcohol, copolymerized polyvinyl alcohol (modified groups such as —COONa, —Si (OH) ₃ , —N (CH ₃ ) ₃ .Cl, —C ₉ H ₁₉ COO, —SO ₃ Na or —C ₁₂ H ₂₅ or the like is introduced), polyvinyl alcohol modified by chain transfer (for example, —COONa, —SH or C ₁₂ H ₂₅ S— etc. cited or _-C 6 _{H 5} or the like is introduced): it is introduced), and (alkyl as modifying groups, for example, _-COOH, -CONH 2, -COOR (R) modified polyvinyl alcohol by block polymerization be able to. The polymerization degree is preferably in the range of 100 to 3000. The saponification degree is preferably in the range of 80 to 100%, particularly preferably 85 to 95%. Moreover, as a polymerization degree, the range of 100-3000 is preferable.

  Examples of the polyvinyl alcohol of the present invention are shown below.

In the general formula V-1, examples of x, y and z are shown below.
───────────────────────────────────
x y z
(Mol%) (mol%) (mol%)
───────────────────────────────────
Polymer No. 1 86.3 1.7 12
Polymer No. 2 85.0 3.0 12
Polymer No. 3 87.7 0.3 12
Polymer No. 4 70.0 18.0 12
Polymer No. 5 86.9 1.1 12
Polymer No. 6 98.5 0.5 1
Polymer No. 7 97.8 0.2 2
Polymer No. 8 96.5 2.5 1
Polymer No. 9 94.9 4.1 1
───────────────────────────────────

In the general formula V-2, examples of x, y and z are shown below.
───────────────────────────────────
x y z
(Mol%) (mol%) (mol%)
──────────────────────────────────────
Polymer No. 10 86.3 1.7 12
Polymer No. 11 81.7 0.3 18
Polymer No. 11a 87.7 0.3 12
Polymer No. 12 83.0 5.0 12
Polymer No. 13 89.0 10.0 1
Polymer No. 13a 78.0 10.0 12
───────────────────────────────────

In the general formula V-3, examples of n, x, y and z are shown below.
───────────────────────────────────
n x y z
(Mol%) (mol%) (mol%)
───────────────────────────────────
Polymer No. 14 2 80.3 1.7 18
Polymer No. 15 3 87.5 0.5 12
Polymer No. 16 4 94.0 5.0 1
Polymer No. 16a 4 83.0 5.0 12
Polymer No. 17 5 86.9 1.1 12
Polymer No. 18 6 87.7 0.3 12
───────────────────────────────────

In the general formula V-4, examples of n, x, y and z are shown below.
───────────────────────────────────
n x y z
(Mol%) (mol%) (mol%)
───────────────────────────────────
Polymer No. 19 2 87.8 0.2 12
Polymer No. 20 2 87.5 0.5 12
Polymer No. 21 3 94.4 0.6 5
Polymer No. 21a 3 87.4 0.6 12
Polymer No. 22 4 86.4 1.6 12
Polymer No. 23 5 96.0 2.0 2
Polymer No. 23a 5 86.0 2.0 12
Polymer No. 24 6 84.8 3.2 12
───────────────────────────────────

In the general formula V-5, examples of n, x, y, and z are shown below.
───────────────────────────────────
n x y z
(Mol%) (mol%) (mol%)
───────────────────────────────────
Polymer No. 25 2 87.5 0.5 12
Polymer No. 26 3 97.4 0.6 2
Polymer No. 26a 3 87.4 0.6 12
Polymer No. 27 4 86.4 1.6 12
Polymer No. 28 5 80.0 2.0 18
Polymer No. 29 6 84.8 3.2 12
───────────────────────────────────

In the general formula V-6, examples of Y, x, y, and z are shown below.
───────────────────────────────────
Y x y z
(Mol%) (mol%) (mol%)
───────────────────────────────────
Polymer No. 30 No. 30-Y 86.3 1.7 12
Polymer No. 31 No. 31-Y 97.3 1.7 1
Polymer No. 32 No. 32-Y 87.4 0.6 12
Polymer No. 33 No. 33-Y 80.8 1.2 18
Polymer No. 34 No. 34-Y 86.3 1.7 12
───────────────────────────────────

In the above general formula V-7, examples of x, y and z are shown below.
───────────────────────────────────
x y z
(Mol%) (mol%) (mol%)
───────────────────────────────────
Polymer No. 35 87.8 0.2 12
Polymer No. 36 88.0 0.003 12
Polymer No. 37 87.86 0.14 12
Polymer No. 38 87.94 0.06 12
Polymer No. 39 87.2 0.8 12
Polymer No. 40 98.5 0.5 1
Polymer No. 41 97.8 0.2 2
Polymer No. 42 96.5 2.5 1
Polymer No. 43 94.9 4.1 1
Polymer No. E 86.9 1.1 12
Polymer No. F 98.5 0.5 1
───────────────────────────────────

In the above general formula V-8, examples of n, x, y and z are shown below.
───────────────────────────────────
n x y z
(Mol%) (mol%) (mol%)
───────────────────────────────────
Polymer No. 44 3 87.8 0.2 12
Polymer No. 45 5 87.85 0.15 12
Polymer No. 46 6 87.7 0.3 12
Polymer No. 47 8 87.7 0.3 12
───────────────────────────────────

In the general formula V-9, examples of Y, x, y and z are shown below.
───────────────────────────────────
Y x y z
(Mol%) (mol%) (mol%)
───────────────────────────────────
Polymer No. 48 No. 48-Y 96.2 1.8 2
Polymer No. 49 No. 49-Y 84.2 0.8 15
Polymer No. 50 No. 50-Y 84.9 3.1 12
Polymer No. 51 No. 51-Y 87.5 2.5 10
───────────────────────────────────

In the general formula V-10, examples of n, R, x, y, and z are shown below.
───────────────────────────────────
n R x y z
(Mol%) (mol%) (mol%)
───────────────────────────────────
Polymer No. 52 6 H 86.4 1.6 12
Polymer No. 53 4 H 87.2 0.8 12
Polymer No. 54 4 H 84.7 3.3 12
Polymer No. 55 5 CH ₃ 78.8 6.2 15
Polymer No. 56 9 CH ₃ 94.2 3.8 2
Polymer No. 57 3 H 85.0 5.0 10
───────────────────────────────────

In the general formula V-11, examples of n, R, x, y, and z are shown below.
───────────────────────────────────
n R x y z
(Mol%) (mol%) (mol%)
───────────────────────────────────
Polymer No. 58 2 H 87.5 2.5 10
Polymer No. 59 4 H 84.5 0.5 15
Polymer No. 60 5 CH ₃ 97.8 0.2 2
Polymer No. 61 6 CH ₃ 94.5 4.1 1
Polymer No. 62 9 H 97.3 1.7 1
───────────────────────────────────

The above-mentioned specific polyvinyl alcohol is a compound having a group of the specific unit (y or y1) of the general formula (I) or (III) or the group of the general formula (II) (eg, of the general formula (IIa) Compound) can be obtained by reacting with polyvinyl alcohol. Such groups can react with polyvinyl alcohol to form ester bonds, urethane bonds, acetal bonds, and the like.
As a solvent (reaction solvent) for dissolving polyvinyl alcohol and the compound having the specific group, various solvents from polar solvents to nonpolar solvents can be used. Examples thereof include polar solvents such as N, N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N, N-dimethylacetamide, pyridine, ethers such as tetrahydrofuran and 1,2-dimethoxyethane, dichloromethane, chloroform. And non-polar solvents such as benzene and hexane. These may be used alone or in combination. DMSO and ethers are particularly preferable.

  A catalyst can be used for the reaction as necessary. The base catalyst used in esterification with a mixed acid anhydride and acid halide may be either organic or inorganic. For example, hydroxide (eg, sodium hydroxide, potassium hydroxide, ammonium hydroxide), alkoxide (eg, sodium methoxide, sodium ethoxide, potassium tert-butoxide), metal hydride (eg, sodium hydride, Calcium hydride), amines (eg, pyridine, triethylamine, piperidine, 1,8-diazabicyclo [5,4,0] -7-undecene (DBU)), carbonates (eg, sodium carbonate, potassium carbonate, sodium bicarbonate) ), Acetate salts (eg, sodium acetate, potassium acetate). In particular, amines are preferable, and these may be used as a solvent.

  Catalysts used in the urethanization with isocyanate include alkoxides (eg, sodium methoxide, sodium ethoxide, potassium tert-butoxide), metal compounds (eg, di-n-butyltin dilaurate, tin octoate, Zinc acetylacetonate), amines (eg, pyridine, triethylamine, piperidine, 1,8-diazabicyclo [5,4,0] -7-undecene (DBU), tetramethylbutanediamine (TMBDA), 1,4-diaza [ 2,2,2] bicyclooctane (DABCO)).

  Catalysts used for aldehyde acetalization include mineral acids (eg, sulfuric acid, hydrochloric acid), carboxylic acids (eg, chloroacetic acid, trifluoroacetic acid, salicylic acid and derivatives thereof), sulfonic acids (eg, methanesulfonic acid, Benzenesulfonic acid, p-toluenesulfonic acid), boron trifluoride, phosphorus pentoxide, and ion exchange resin (eg, Amberlyst).

The reaction temperature at the time of reacting the compound having the specific group and polyvinyl alcohol is generally in the range of -80 to 150 ° C, preferably in the range of -20 to 120 ° C, particularly preferably in the range of -5 to 90 ° C. A range is preferred. In the reaction, the ratio (preparation ratio) between the compound having the specific group and the repeating unit of polyvinyl alcohol is preferably 1/100 to 1/1 (compound / repeating unit) in terms of molar ratio, and particularly 1/50. ~ 1/5 is preferred.
In order to obtain the desired polymer from the reaction mixture, the polymer is usually purified by reprecipitation by adding a poor solvent to the reaction mixture, dialysis, or freeze-drying. These operations can be repeated as appropriate and / or combined appropriately.

Below, the synthesis example of the specific polyvinyl alcohol of this invention is shown.
[Synthesis Example 1]
(Synthesis of Polymer No. 1)
Dimethyl sulfoxide previously dehydrated in a 300 ml three-necked flask equipped with a stirrer using 14.7 g of polyvinyl alcohol (trade name: MP polymer MP-203; manufactured by Kuraray Co., Ltd .; degree of saponification 88 mol%) and molecular sieve 4A 100 ml was added and dissolved with stirring at room temperature. The temperature was raised to 70 ° C., and a solution of 0.776 g of methacryloyloxyethyl isocyanate in 15 ml of dimethyl sulfoxide was added dropwise. Stirring was continued for 2 hours, followed by filtration using a paper towel to remove impurities such as dust, and then dropwise added to 1.25 liters of ethyl acetate with stirring to precipitate the polymer. The precipitate (polymer) was collected by filtration, soaked in 600 ml of methanol, washed with stirring, collected again by filtration, and dried to obtain 14.0 g of a bulk polymer (No. 1) (yield 91%).

NMR spectrum (solvent DMSO-d ₆ )
The obtained polymer no. In 1, in addition to the main chain proton, the hydroxyl proton, and the acetyl group proton, the following protons that are not recognized in the raw material MP-203 were recognized with a weak intensity. δ = 5.7, 6.1 ppm: assigned to vinyl group proton

(Measurement of visible absorption spectrum of polymer No. 1 and determination of introduction rate y of methacrylolyl group)
In a 50 ml volumetric flask, polymer no. 0.015 g of 1 was accurately weighed and distilled water was added to prepare a 0.03% aqueous solution. Using this solution, the visible absorption spectrum was measured with a visible absorption ultraviolet-visible spectrophotometer (UV-2200, manufactured by Shimadzu Corporation).
Maximum absorption wavelength (λmax) = 202 nm
Absorbance (202 nm) = 0.839

On the other hand, in the same manner, polymer no. The absorption spectrum of polyvinyl alcohol (MP-203, manufactured by Kuraray Co., Ltd.) used as the raw material 1 was measured. The absorbance at 202 nm was 0.504.
Furthermore, the urethane compound 1 * 10 <^-4> M methanol solution obtained when the isocyanate compound which has the methacryloyl group used for the said synthesis | combination was made to react with methanol was prepared, and the absorption spectrum was measured similarly.
Maximum absorption wavelength (λmax) = 202 nm
Absorbance = 0.903
Molecular extinction coefficient (ε) = 8.42 × 10 ⁴ M ⁻¹ · cm
Therefore, polymer no. It is apparent that the increase in absorbance at λmax = 202 nm of 1 was due to the introduction of methacryloyloxyethyl isocyanate into the hydroxyl group of polyvinyl alcohol. The introduction rate (y) was determined from the measured value of the absorbance (y = 1.7).

[Synthesis Examples 2, 3, and 4]
(Synthesis of polymer No. 2, No. 3, No. 4)
In the same manner as in Synthesis Example 1, polymer no. 2, 3 and 4 were synthesized.
Polymer No. The results of measuring the visible absorption spectra of 2, 3 and 4 are as follows, and the introduction rate y was determined from this.
λmax Abs210 y
Polymer No. 2 202nm 1.423 3.0
3 202 nm 0.653 0.3
4 202 nm 1.532 (0.001% aqueous solution) 18.0

[Synthesis Example 5]
(Synthesis of Polymer No. 5)
In Synthesis Example 1, the same procedure as in Synthesis Example 1 was conducted except that the reaction temperature was changed from 70 ° C. to room temperature. 5 was obtained.
[Synthesis Examples 6 to 34]
(Synthesis of polymer Nos. 6 to 34)
Basically, in the same manner as in Synthesis Example 1, polymer no. 6-34 were obtained.

[Synthesis Example 35]
(Synthesis of Polymer No. 35)
26.4 g of polyvinyl alcohol (MP-203, manufactured by Kuraray Co., Ltd.) and 225 ml of dimethyl sulfoxide (DMSO) previously dehydrated using molecular sieve 4A were added to a 500 ml three-necked flask equipped with a stirrer and stirred at room temperature. The resulting solution was dissolved to prepare a polyvinyl alcohol / DMSO solution.
On the other hand, in another 50 ml three-necked flask equipped with a stirrer, 1.55 ml (20 mmol) of methanesulfonyl chloride and 20 ml of tetrahydrofuran (THF) were added, and compound 2-2 (the above compound number; 4- (4-acryloyloxy) was added. A solution of 5.28 g (20 mmol) of butoxy) benzoic acid) and 3.42 ml (20 mmol) of diisopropylethylamine in 20 ml of THF was added dropwise with stirring under ice cooling. Stirring was continued for 30 minutes under ice-cooling after the dropwise addition to prepare a mixed acid anhydride of Compound 2-2 and methanesulfonic acid.

  To the polyvinyl alcohol / DMSO solution, 3.42 ml (20 mmol) of diisopropylethylamine and 0.24 g (2 mmol) of dimethylaminopyridine were added, and the above mixed acid anhydride was slowly added with stirring at room temperature. Stirring was continued for 6 hours at room temperature, and then left overnight. The reaction solution was slightly yellow. The mixture was filtered using a paper towel to remove impurities such as dust, and then dropped into 2.25 liters of ethyl acetate with stirring to precipitate the polymer. The precipitate (polymer) was white cotton-like. The precipitate was collected by filtration and dried to obtain 22.1 g (yield 84%) of a bulk polymer (No. 35).

NMR spectrum (solvent DMSO-d ₆ )
Polymer No. In 35, in addition to main chain protons, hydroxyl group protons, and acetyl group protons, the following protons, which are not observed in the raw material MP-203, were observed with weak intensity.
δ = 7.9, 7.0 ppm: assigned to phenylene group proton δ = 6.3, 6.2, 5.9 ppm: assigned to vinyl group proton (measurement of ultraviolet absorption spectrum of polymer No. 35 and determination of introduction rate y) )
In a 100 ml volumetric flask, polymer no. 35 of 0.1 was accurately weighed and distilled water was added to prepare a 0.1% aqueous solution. Using this solution, the absorption spectrum was measured using an ultraviolet-visible spectrophotometer (UV-2200, manufactured by Shimadzu Corporation).
Maximum absorption wavelength (λmax) = 260 nm
Absorbance (Abs260) = 0.788

On the other hand, in the same manner, polymer no. The absorption spectrum of polyvinyl alcohol (MP-203, manufactured by Kuraray Co., Ltd.) used for 35 raw materials was measured. Absorption maximum was not observed in the wavelength range of 220 to 400 nm, and weak absorption was observed with a tail extending from the short wavelength side to the long wavelength side. The absorbance at 260 nm was 0.011.
Furthermore, a methyl ester 1 × 10 ⁻⁴ M methanol solution of compound 2-2 was prepared, and an absorption spectrum was measured in the same manner.
Maximum absorption wavelength (λmax) = 260 nm
Absorbance (Abs260) = 1.84
Molecular extinction coefficient (ε) = 1.84 × 10 ⁴ M ⁻¹ · cm
Met.
Therefore, polymer no. The absorption band of λmax = 260 nm of 35 clearly shows that compound 2-2 was introduced into the hydroxyl group of polyvinyl alcohol by an ester bond. The introduction rate (y) was determined from the measured absorbance value (y = 0.21).

[Synthesis Examples 36, 37 and 38]
(Synthesis of polymer No. 36, 37, 38)
In the same manner as in Synthesis Example 35, polymer no. 36, 37 and 38 were synthesized. However, the amounts of reagents used are as shown in the table below. The yield and yield are also shown in the table below.

────────────────────────────────────
Polymer No. 36 No. 37 No. 38
────────────────────────────────────
[Esterification of PVA]
PVA MP-203 (g) 26.4 26.4 26.4
DMSO (ml) 225 225 225
Diisopropylethylamine (ml) 0.34 1.71 10.3
Dimethylaminopyridine (g) 0.024 0.12 0.72
────────────────────────────────────
[Preparation of mixed acid anhydride]
Methanesulfonyl chloride (g) 0.16 0.78 4.65
Tetrahydrofuran (ml) 2 10 60
Compound 2-2 (g) 0.53 2.64 15.84
Diisopropylethylamine (ml) 0.34 1.71 10.3
Tetrahydrofuran (ml) 2 10 60
────────────────────────────────────
Yield (g /%) 21.1 / 80 23.5 / 89 22.3 / 84
────────────────────────────────────

Polymer No. The ultraviolet absorption spectrum measurement results of 36, 37, and 38 are as follows. The introduction rate y was determined from this.
λmax Abs260 y
Polymer No. 36 260 nm 0.023 0.003
37 260 nm 0.553 0.14
38 260 nm 0.132 0.06

[Synthesis Example E]
(Synthesis of polymer No. E)
In the same manner as in Synthesis Example 38 except that the reaction conditions were changed from room temperature 6 hours to 45 ° C. 8 hours in Synthesis Example 38, polymer no. E was obtained.

[Synthesis Example 39]
(Synthesis of polymer No. 39)
To a 500 ml three-necked flask equipped with a stirrer, 26.4 g of polyvinyl alcohol (MP-203, manufactured by Kuraray Co., Ltd.) and 168 ml of DMSO previously dehydrated using molecular sieve 4A were added and dissolved while stirring at room temperature. Of DMSO was prepared.
On the other hand, to another 200 ml three-necked flask equipped with a stirrer, 3.24 ml (42 mmol) of methanesulfonyl chloride and 21 ml of THF were added, and compound 2-211.1 g (42 mmol) and 7.32 ml (42 mmol) of diisopropylethylamine were dissolved in 42 ml of THF. The resulting solution was added dropwise with stirring under ice cooling. Stirring was continued under ice-cooling for 30 minutes after the dropwise addition to prepare a mixed acid anhydride of compound 2-2 and methanesulfonic acid.

To the DMSO solution of polyvinyl alcohol, 7.32 ml (42 mmol) of diisopropylethylamine and 0.51 g (4.2 mmol) of 4-N, N-dimethylaminopyridine were added, and the mixed acid was stirred with heating at 45 ° C. The anhydride was added dropwise evenly over 1 hour. After completion of the dropwise addition, the mixture was further stirred at 45 ° C. for 3 hours, cooled to room temperature, and filtered using a paper towel. To this reaction liquid, 134 ml of 2-propanol was added, and the resulting mixture was added dropwise to 1.68 l of ethyl acetate with stirring to precipitate the polymer. The precipitate (polymer) was collected by filtration, then poured into 700 ml of methanol, washed with stirring, and then collected again by filtration. It was dried under reduced pressure at room temperature to obtain 24.0 g (yield 91%) of a slightly yellow small polymer (No. 39).
The above-mentioned polymer No. The ultraviolet absorption spectrum was measured in the same manner as in 35, and the introduction rate y was determined from the absorbance at 260 nm (y = 0.80).

[Synthesis Examples 40, 41, 42 and 43]
(Synthesis of polymer Nos. 44, 45, 46 and 47)
In Synthesis Example 35, synthesis was performed in the same manner as in Synthesis Example 35 using Compound 2-1, Compound 2-3, Compound 2-4, and Compound 2-6 instead of Compound 2-2. 44, 45, 46 and 47 were obtained.

[Synthesis Examples 44 and 45]
(Synthesis of polymer Nos. 53 and 54)
In a 500 ml three-necked flask equipped with a stirrer, 44 g of polyvinyl alcohol (MP-203, manufactured by Kuraray Co., Ltd.) 44 g, p-toluenesulfonic acid monohydrate 4.4 g (23 mmol), and molecular sieve 4 A were previously dehydrated in 200 ml DMSO. Was dissolved with stirring at room temperature. To this solution was added a solution consisting of 4- (4-acryloyloxybutyloxy) benzaldehyde (2.0 g for polymer No. 53, 8.0 g for polymer No. 54) and 80 ml of DMSO for 5 hours at room temperature. Stirring was continued.
The reaction mixture was added dropwise with stirring to 3 l (liter) of ethyl acetate to precipitate the polymer. The precipitate (polymer) was collected by filtration, then poured into 1 l of methanol, washed with stirring, and then collected again by filtration. The polymer was dried under reduced pressure at room temperature to obtain a white lumpy polymer.
Polymer No. 53 Yield 41g (Yield 89%)
Polymer No. 54 Yield 43g (Yield 83%)

NMR spectrum (solvent DMSO-d ₆ )
Polymer No. In 53 and 54, in addition to main chain protons, hydroxyl protons, and acetyl group protons, the following protons that are not found in the raw material MP-203 were observed with a weak intensity.
δ = 7.3, 6.9 ppm: attributed to phenylene group protons δ = 6.3, 6.2, 5.9 ppm: attributed to vinyl group protons δ = 5.5 ppm: attributed to acetal protons In some cases, no signal was observed in the vicinity of δ = 10 ppm. Therefore, it is clear that the obtained polymer was acetalized as intended.

Furthermore, an acetal of 4- (4-acryloyloxybutyloxy) benzaldehyde and trimethylenediol was prepared, and then a 1 × 10 ⁻⁴ M methanol solution of this acetal was prepared, and its absorption spectrum was measured.
Maximum absorption wavelength (λmax) = 272 nm
Absorbance (Abs272) = 1.66
Molecular extinction coefficient (ε) = 1.66 × 10 ⁴ M ⁻¹ · cm
Met.
Polymer No. For 53 and 54, the above-mentioned polymer no. The ultraviolet absorption spectrum was measured in the same manner as in Example 35, and the introduction rate y was determined from the absorbance at 272 nm. They were 0.8 and 3.3, respectively.

  The alignment film of the present invention may be composed of the specific polyvinyl alcohol of the present invention alone or may be composed of a mixture with a conventionally known alignment film polymer. In the case of a mixture, generally known polymers can be used at 90% by weight or less of the total polymer, but it is particularly preferred to be used at 70% by weight or less.

Examples of the polymer having a polymerizable group that can be used in the alignment film of the present invention other than the specific polyvinyl alcohol of the present invention include a polyimide having vinyl, oxiranyl or aziridinyl, and a gelatin having vinyl, oxiranyl or aziridinyl. Can be mentioned.
These polymers can be synthesized using a polymer having a hydroxyl group or an amino group introduced in the same manner as the synthesis of the specific polyvinyl alcohol. For example, the introduction of a polymerizable group into polyimide has a polymerizable group used in the synthesis of the specific polyvinyl alcohol by reacting a polyhydric alcohol with a carboxyl group of a polyamic acid to introduce a hydroxyl group into the polyamic acid. The reaction can be carried out by reacting a compound (eg, a compound of the general formula (IIa) or an isocyanate compound thereof) with the hydroxyl group of the polyamic acid and then polymerizing the polyamic acid having this polymerizable group. Introduction of a polymerizable group into gelatin can be carried out by reacting an ε-amino group of a lysine residue of gelatin with a compound having a polymerizable group used in the synthesis of the specific polyvinyl alcohol.

  Examples of other known polymers that can be used in the alignment film of the present invention include polymethyl methacrylate, acrylic acid / methacrylic acid copolymer, styrene / maleimide copolymer, polyvinyl alcohol and modified polyvinyl alcohol, poly ( N-methylolacrylamide), styrene / vinyl toluene copolymer, chlorosulfonated polyethylene, nitrocellulose, polyvinyl chloride, chlorinated polyolefin, polyester, polyimide, vinyl acetate / vinyl chloride copolymer, ethylene / vinyl acetate copolymer , Carboxymethylcellulose, polyethylene, polypropylene and polycarbonate.

The alignment film of the present invention is formed by applying a coating liquid containing the above-mentioned specific polyvinyl alcohol, which is an alignment film forming material, onto a transparent support, followed by heating and drying to form a polymer layer, and then rubbing the polymer layer It can form by performing orientation processing, such as.
Examples of the coating method include a spin coating method, a dip coating method, an extrusion coating method, and a bar coating method. The E-type coating method is particularly preferable. The film thickness is preferably 0.1 to 10 μm.
Heat drying can be performed at 20 ° C. to 110 ° C., preferably 60 ° C. to 100 ° C., particularly preferably 80 ° C. to 100 ° C. The drying time can be 1 minute to 36 hours. Preferably, it is 5 minutes to 30 minutes.

  The alignment film can be obtained by subjecting the polymer layer to an alignment treatment such as a rubbing treatment using a treatment method widely adopted as a liquid crystal alignment treatment step of LCD as described above. The alignment film functions to define the alignment direction of a liquid crystal compound such as a liquid crystal discotic compound provided thereon. The rubbing treatment is generally performed by rubbing the surface of the polymer layer in a certain direction using paper, gauze, felt, rubber, velvet, fibers of polyamide, polyester, or the like. Preferably, it is performed by rubbing the surface of the polymer layer using a rubbing roll wound with a rubbing cloth such as velvet. The rubbing may be performed by a batch method or a continuous method.

The optical compensation sheet of the present invention can be obtained by forming a liquid crystal compound layer (optically anisotropic layer) on the alignment film. The liquid crystal compound may be a rod-like liquid crystal compound or a discotic liquid crystal compound. A discotic liquid crystalline compound is preferred. The liquid crystalline compound preferably has a polymerizable group in order to chemically bond with the polymer of the alignment film.
With respect to these liquid crystal compounds, for example, the Chemical Society of Japan, quarterly chemistry review, No. 22. It is described in the chemistry of liquid crystals (published in 1994). Examples of rod-like liquid crystalline compounds include biphenyl derivatives, benzoic acid phenyl ester derivatives, benzylidene aniline derivatives, azobenzene derivatives, azoxybenzene derivatives, stilbene derivatives, and those whose benzene rings are saturated or substituted with heterocyclic rings. Can be mentioned. Examples of these are C _a H _{2a + 1} -Ph-Ph-CN, C _a H _{2a + 1} -Cy-Ph-CN, C _a H _{2a + 1} -Ph-COO-Ph-CN, C _a H _{2a + 1} -Ph-COO-Ph (F) -CN, C _a H _{2a + 1} -Cy-COO-Ph-O (C _b H _{2b + 1} ), C _a H _{2a + 1} -Cy-Ph-O (C _b H _{2b + 1} ), C _a H _{2a + 1} -Cy-Ph _{-Ph-O (C b H 2b} + 1), or _{C a H 2a + 1 -Cy-} C 2 H 4 -Ph-Ph (F) -C b H 2b + 1 ( where, Ph is phenylene, Cy is cyclohexene, Ph (F) Is a F-substituted phenylene, and a and b each represent an integer of 1 to 24), and a polymerizable group (eg, acryloyloxy, methacryloyloxy, vinyl, vinyloxy, styryl or chloroacryloxy) is introduced. Compounds and D.I. J. et al. Broer et al., Makromol. Chem. , 189, 185 (published in 1988) and the same magazine, 190, 2255 (published in 1989).

The above discotic (discotic) liquid crystalline compounds generally have a discotic structure as a mother nucleus at the center of the molecule, and linear alkyl groups, alkoxy groups, substituted benzoyloxy groups, and the like are linearly radiated. It has a substituted structure, exhibits liquid crystallinity, and includes what is generally called a discotic liquid crystal.
The disk-like morphological characteristics of the mother nucleus part excluding the side chain part can be expressed, for example, as follows for the hydrogen substitution product that is the original compound.
First, the molecular size of the mother nucleus is obtained as follows.
1) For a molecule (mother nucleus molecule), design a plane molecular structure that is as close to the plane as possible, preferably a plane. In this case, as the bond distance and bond angle, it is preferable to use standard values according to the orbital mixture. For example, the Chemical Society of Japan, Chemical Handbook 4th Edition, Chapter II, Volume 15 (1993 published by Maruzen) You can refer to it.
2) Using the structure obtained in 1) as an initial value, the structure is optimized by the molecular orbital method or the molecular force field method. Examples of the method include Gaussian 92, MOPAC 93, CHARMm / QUANTA, and MM3, and Gaussian 92 is preferable.
3) A sphere defined by the van der Waals radius is given to each atom whose structure has been optimized, thereby describing the shape of the molecule.
4) Let a, b, and c be the three edges of the smallest rectangular parallelepiped in which the molecular part obtained in 3) can enter.
In order to reduce the arbitraryness, it is preferable to perform the above 3) and after. 3 ′) Move the center of gravity of the structure obtained by the structure optimization to the origin, and change the coordinate axis to the inertial main axis (inertia tensor ellipse). The main axis of the body).
4 ') Each atom is given a sphere defined by the van der Waals radius, thereby describing the shape of the molecule.
5 ′) Measure the length in the direction of each coordinate axis on the van der Waals surface, and let them be a, b and c, respectively.
The form of the mother nucleus of the discotic compound obtained by the above procedure can be defined as a structure satisfying a ≧ b> c and a ≧ b ≧ a / 2. The structure preferably satisfies a ≧ b> c and a ≧ b ≧ 0.7a. Further, it is more preferable that b / 2> c.

  As the discotic liquid crystalline compounds that can be used in the present invention, the Chemical Society of Japan, Quarterly Chemical Review, No. 22, benzene derivatives, triphenylene derivatives, truxene derivatives, phthalocyanine derivatives, porphyrin derivatives, anthracene derivatives, azacrown derivatives, cyclohexane derivatives, β-diketone metal complex derivatives, and phenyl, which are described in Liquid Crystal Chemistry (1994) Further, the cyclic compounds described in the Chemical Society of Japan, “Chemical Review No. 15 New Aromatic Chemistry” (published by the University of Tokyo Press, 1977), and their electronic structures such as hetero atom substitutions, are acetylene macrocycles. Can be mentioned. In addition, as in the case of the metal complex, a plurality of molecules may be formed by a hydrogen bond, a coordinate bond, or the like to form a disk-like molecule.

A discotic liquid crystal compound has a structure in which a discotic structure is used as a mother nucleus at the center of a molecule, and a linear alkyl group, an alkoxy group, a substituted benzoyloxy group, or the like is radially substituted as a side chain thereof. . The mother nucleus compound is preferably one that forms a discotic nematic (N _D ) phase, and particularly preferably triphenylene and truxene. Examples of the side chain include an alkyl group, an alkoxy group, an alkylthio group, an acyloxy group, an alkoxycarbonyl group, and a halogen, and an alkyl group, an alkoxy group, an alkylthio group, and an acyloxy group are particularly preferable. These groups are C.I. Hansch, A.M. Leo, R.A. W. Taft, Chemical Review (Chem. Rev.) 1991, 91, 165-195 (American Chemical Society). Further, the side chain may contain, for example, a functional group such as an ether group, an ester group, a carbonyl group, a thioether group, a sulfoxide group, a sulfonyl group or an amide group, and an aryl group or a heterocyclic group in the side chain. .

  The discotic liquid crystalline compound of the present invention can form a new bond in itself as a substituent, or can bind to another compound (same or different), and the polymer of the alignment film It is preferable to have a group that can be chemically bonded. Such a group reacts with the same type of group to form a new bond, or reacts with a different type of group to form a new bond. Examples of such groups are S. R. Sandler and W.W. By S. R. Sandler, W. Karo, Organic Functional Group Preparations Volumes 1 and 2 (Academic Press, New York, London, 1968). Among them, a polymerizable group is preferable, and for example, a multiple bond (a constituent atom may be a carbon atom or a non-carbon atom), a hetero-membered ring such as oxirane, aziridine and the like are preferable. A. M.M. Hikmet et al. [Macromolecules, 25, 4194 (1992)] and [Polymer, 34, 8, 1763 (1993)]; J. et al. Double bonds, ie acrylic groups, vinyl ether groups and epoxy groups are preferred, as described in a research report by Broer et al. [Macromolecules, Vol. 26, page 1244 (1993)].

  Preferred examples of the discotic liquid crystalline compound include the following.

Examples of R ⁶¹ , R ⁶² , R ⁶⁴ , R ⁶⁵ , R ⁶⁶ and J in the above D-1-1 are shown below.
────────────────────────────────────────
Compound R ⁶¹ R ⁶² R ⁶⁴ R ⁶⁵ R ⁶⁶ J
────────────────────────────────────────
TP-1 HHHHH-(CH ₂ ) ₂ OCO-
TP-2 HHHHH-(CH ₂ ) ₃ OCO-
_{TP-3 HHHHH - (CH 2} ) 4 OCO-
TP-4 HHHHH-(CH ₂ ) ₅ OCO-
TP-5 HHHHH-(CH ₂ ) ₆ OCO-
TP-6 HHHHH-(CH ₂ ) ₇ OCO-
TP-7 HHHHH-(CH ₂ ) ₈ OCO-
TP-8 HHHH CH _3- (CH ₂ ) ₉ OCO-
TP-9 HHHHC ₂ H _5- (CH ₂ ) ₆ OCO-
TP-10 CH ₃ HHHC ₂ H _5- (CH ₂ ) ₆ OCO-
TP-11 CH ₃ CH ₃ HHH-(CH ₂ ) ₂ OCO-
TP-12 H CH ₃ HHH-(CH ₂ ) ₃ OCO-
_{TP-13 CH 3 HHHH - (} CH 2) 4 OCO-
TP-14 CH ₃ HHHH-(CH ₂ ) ₅ OCO-
TP-15 CH ₃ HHHH-(CH ₂ ) ₆ OCO-
TP-16 CH ₃ CH ₃ HHH-(CH ₂ ) ₇ OCO-
TP-17 H CH ₃ HHH-(CH ₂ ) ₈ OCO-
TP-18 CH ₃ HHH CH _3- (CH ₂ ) ₉ OCO-
TP-19 CH HHHC ₂ H _5- (CH ₂ ) ₆ OCO-
TP-20 H CH ₃ HH CH _3- (CH ₂ ) ₆ OCO-
_{TP-21 HHHH nC 3 H 7} - (CH 2) 2 OCO-
TP-22 HHHHH-(CH ₂ ) ₃ OC ₂ H ₄ OCO-
_{TP-23 HHHHH - (C 2} H 4 O) 2 C 3 H 6 OCO-
TP-24 CH HHHH-(C ₂ H ₄ O) ₂ CO-
TP-25 HHHHH-(C ₂ H ₄ O) ₃ CO-
TP-26 HHH CH ₃ CH _3- (CH ₂ ) ₄ CO-
TP-27 HH CH ₃ HH-(CH ₂ ) ₅ OCO-
TP-28 HH CH ₃ HH-(CH ₂ ) ₆ OCO-
TP-29 HH CH ₃ HH-(CH ₂ ) ₇ OCO-
TP-30 HH CH ₃ HH-(CH ₂ ) ₈ OCO-
────────────────────────────────────────

  Moreover, these discotic liquid crystalline compounds can be used not only independently but also as a mixed composition. As a compound that can be added to the discotic liquid crystalline compound, a discotic liquid crystalline compound that does not have liquid crystallinity, or other compounds (low molecular, high molecular, liquid crystalline, or non-liquid crystalline may be used. Any of those capable of forming a new bond and those not capable of forming; eg, plasticizer, polymerizable monomer, surfactant, polymer).

As described above, the optical compensation sheet of the present invention is generally a film obtained by rubbing a layer of a polymer having a functional group such as a polymerizable group (eg, the specific polyvinyl alcohol of the present invention) on a transparent support. It can be obtained by forming an alignment film and then forming an optically anisotropic layer on the alignment film.
The optically anisotropic layer of the present invention is formed from a liquid crystal compound, preferably a discotic liquid crystal compound. As described above, these compounds preferably have a functional group such as vinyl, oxiranyl or aziridinyl.
The optically anisotropic layer is generally formed by applying a solution obtained by dissolving a liquid crystal compound (and other compounds) such as a discotic liquid crystal compound in a solvent onto the alignment film, drying it, and then forming a discotic nematic phase formation temperature (disco In the case of a tick liquid crystalline compound), and then cooled by maintaining the alignment state (discotic nematic phase). Alternatively, the optically anisotropic layer is formed by applying a solution in which a discotic liquid crystalline compound having a polymerizable group (and other compounds (for example, polymerizable monomer, photopolymerization initiator)) is dissolved in a solvent on the alignment film, It is obtained by drying, then heating to the discotic nematic phase formation temperature, polymerization (by irradiation with UV light, etc.), and further cooling. The discotic liquid crystalline compound having a polymerizable group loses liquid crystallinity after being polymerized and cured as described above.
The discotic nematic liquid crystal phase-solid phase transition temperature of the discotic (discotic) liquid crystal compound used in the present invention is preferably 70 to 300 ° C, particularly preferably 70 to 170 ° C. The film thickness of the optically anisotropic layer is preferably 0.1 μm to 20 μm and can be applied in the same manner as the polyvinyl alcohol described above.

In the present invention, the alignment film is made of a polymer having a functional group such as vinyl, oxiranyl, or aziridinyl. For this reason, when the optically anisotropic layer having the above functional group is formed on the alignment film, and these two layers are irradiated with, for example, UV light, the functional groups (eg, vinyl) of the alignment film and the optically anisotropic layer are formed. By reacting with each other, these two layers become chemically bonded. Even when the optical compensation sheet thus obtained is stored or used for a long period of time, the optically anisotropic layer hardly peels off from the alignment film.
Accordingly, the functional groups of the alignment film and the optically anisotropic layer are preferably those that react with each other, and in particular, polymerizable groups such as vinyl, oxiranyl, and aziridinyl (especially the same polymerizable group) are preferable.

The optically anisotropic layer of the present invention generally has a minimum absolute value of retardation other than 0 (having no optical axis) in a direction inclined from the normal direction of the optical compensation sheet. A typical configuration example of an optical compensation sheet including the optically anisotropic layer of the present invention is shown in FIG. In FIG. 3, a transparent support 31, an alignment film 32, and a discotic compound layer (an optically anisotropic layer) 33 are sequentially laminated to constitute an optical compensation sheet. R represents the rubbing direction of the alignment film. n ₁ n ₂ and n ₃ represent the refractive index in the triaxial direction of the optical compensation sheet, and satisfy the relationship of n ₁ ≦ n ₃ ≦ n ₂ when viewed from the front. β is the inclination from the normal 34 of the optically anisotropic layer in the direction indicating the minimum value of Re (retardation).
The negative uniaxiality that the optical compensation sheet of the present invention normally has generally satisfies n ₁ <n ₂ = n ₃ . Actually, it is only necessary to satisfy | n ₂ −n ₃ | / | n ₂ −n ₁ | ≦ 0.2.
In order to improve the viewing angle characteristics of TN-LCD and TFT-LCD, the direction showing the minimum value of Re is inclined 5 to 50 degrees (average value of inclination) from the normal 34 of the optical anisotropic layer. It is preferably 10 to 40 degrees (the above β).
Further, the sheet has the following conditions:
50 ≦ [(n ₃ + n ₂ ) / 2−n ₁ ] × D ≦ 400 (nm)
(Where D is the thickness of the sheet) is preferably satisfied, and the following conditions are further satisfied:
100 ≦ [(n ₃ + n ₂ ) / 2−n ₁ ] × D ≦ 400 (nm)

FIG. 4 shows a typical configuration example of a liquid crystal display device provided with the optical compensation sheet of the present invention. In FIG. 4, a liquid crystal cell TNC comprising a pair of substrates with transparent electrodes and a twisted nematic liquid crystal sealed between the substrates, a pair of polarizing plates A and B provided on both sides of the liquid crystal cell, and a liquid crystal cell The optical compensation sheets RF ₁ and RF ₂ and the backlight BL arranged between the polarizing plate and the polarizing plate are combined to form a liquid crystal display device. Only one of the optical compensation sheets may be disposed (that is, RF ₁ or RF ₂ ). R ₁ indicates the rubbing direction of the optical compensation sheet RF ₁ when viewed from the front, and R ₂ indicates the rubbing direction of the optical compensation sheet RF ₂ . The solid line arrow of the liquid crystal cell TNC represents the rubbing direction of the substrate on the polarizing plate B side of the liquid crystal cell, and the dotted line arrow of the liquid crystal cell TNC represents the rubbing direction of the substrate on the polarizing plate A side of the liquid crystal cell. PA and PB represent the polarization axes of the polarizing plates A and B, respectively.

Next, the present invention will be described in more detail based on examples.
[Examples 1 to 4 and Comparative Example 1]
(Formation of alignment film)
On the glass substrate, the following coating solution containing polyvinyl alcohol shown in Table 1 described later was applied with a bar coater and dried by heating at 80 ° C. for 10 minutes to form a polymer layer having a thickness of 0.8 μm. (Hereinafter, “part” means “part by weight”.)
[Coating solution]
Polyvinyl alcohol shown in Table 1 1.0 part Water 18.0 parts Methanol 6.0 parts The surface of the polymer layer obtained was rubbed roll outer diameter: 80 mm, glass substrate transport speed: 100 m / min, rubbing roll rotation A rubbing process was performed under the conditions of several: 1000 rpm and substrate transport tension: 1 kgf / cm substrate width to form an alignment film.

(Formation of discotic liquid crystalline compound layer (optically anisotropic layer))
A 10% by weight methylethylketone solution of TP-3 (the triphenylene compound) is applied at 3000 rpm on the alignment film of the glass substrate that has been subjected to rubbing treatment, and dried to obtain a discotic liquid crystalline compound layer ( An optically anisotropic layer) was formed.

(Evaluation of orientation of layer of discotic liquid crystalline compound)
Using a polarizing microscope (OPTIPHOT-POL, manufactured by Nippon Optics Co., Ltd.) while heating a glass plate provided with an alignment film and an optically anisotropic layer on a hot stage (FP82 type, manufactured by METTLER) The orientation state of the anisotropic layer was observed. The optically anisotropic layers obtained in Examples 1 to 4 and Comparative Example 1 appeared bright even under crossed Nicols and exhibited optical anisotropy. Table 1 shows the observation results of the obtained optical anisotropic layer.

Table 1
───────────────────────────────────
Example Polymer layer Orientation
The polymer number ───────────────────────────────────
Example 1 1 Uniform Orientation Example 2 35 Uniform Orientation Example 3 39 Uniform Orientation Example 4 53 Uniform orientation ────────────────────────────────────
Comparative Example 1 MP-203 Schlieren structure remaining
(Made by Kuraray Co., Ltd.)
───────────────────────────────────

[Examples 5-34 and Comparative Examples 2-3]
(Preparation of alignment film)
A triacetyl cellulose film (thickness 100 μm, manufactured by Fuji Photo Film Co., Ltd., Fujitac) was coated with the following coating solution containing polyvinyl alcohol shown in Table 2 to be described later with a bar coater, and heated and dried at 80 ° C. for 10 minutes. Thus, a polymer layer having a thickness of 0.8 μm was formed.
[Coating solution]
Polyvinyl alcohol shown in Table 2 1.0 part Water 18.0 parts Methanol 6.0 parts The surface of the polymer layer obtained was rubbed roll outer diameter: 80 mm, film transport speed: 100 m / min, rubbing roll rotational speed. The film was rubbed under the conditions of: 1000 rpm and film transport tension: 1 kgf / cm substrate width to form an alignment film.

(Formation of discotic liquid crystalline compound layer (optically anisotropic layer))
On the alignment film on the rubbed film, a discotic liquid crystalline compound layer forming coating solution having the following composition is applied by a bar coater and dried to form a discotic liquid crystalline compound coating layer. Formed.
[Coating solution]
12 parts of cellulose acetate butyrate (CAB531, manufactured by Eastman Chemical Co.)
Discotic liquid crystalline compound TP-3 (the above compound) 100 parts Tripropylene glycol diacrylate 10 parts (SR306, manufactured by Somaru Corporation)
Photopolymerization initiator 2 parts (Irgacure 907, manufactured by Ciba Geigy Japan Ltd.)
400 parts of methyl ethyl ketone The film having this coating layer is passed through a heating zone at 140 ° C. for 2 minutes, and then the coating layer is irradiated with UV light to be cured, thereby fixing the alignment state of the aligned discotic liquid crystalline compound. The thin film (optical anisotropic layer, layer thickness 2 μm) was formed to obtain an optical compensation sheet.

(Evaluation of orientation of discotic liquid crystalline compound layer (optical anisotropic layer) before and after wet heat resistance test)
Using a polarizing microscope (OPTIPHOT-POL, Nippon Optical Co., Ltd.) while heating the film provided with the alignment film and the optically anisotropic layer on a hot stage (FP82 type, manufactured by METTLER) The orientation state of the direction layer was observed. The optical anisotropic layers obtained in Examples 5 to 34 and Comparative Examples 2 to 3 appeared bright even under crossed Nicols, and exhibited optical anisotropy. Table 2 shows the observation results of the obtained optical anisotropic layer.
Further, the orientation of the obtained film was observed in the same manner as described above after being allowed to stand for 100 hours under the conditions of 75 ° C. and 95% humidity, and the heat and moisture resistance was evaluated. The obtained results are shown in Table 2.
The orientation was evaluated as follows.
AA: Uniform orientation BB: Remaining schlieren structure The evaluation of wet heat resistance was performed as follows.
AA: Uniform orientation BB: Generation of reticulation after 20 hours of wet heat resistance test CC: Generation of reticulation after 5 hours of heat resistance test

Table 2
───────────────────────────────────
Example Polymer layer Orientation
Before polymer heat resistance After heat resistance ────────────────────────────────────
Example 5 1 AA AA
Example 6 2 AA AA
Example 7 3 AA AA
Example 8 4 AA AA
Example 9 5 AA AA
Example 10 5 / ^* MP-203 = 3/1 AA AA
Example 11 5 / ^** PVA-117 = 4/1 AA AA
Example 12 10 AA AA
Example 13 14 AA AA
Example 14 20 AA AA
Example 15 25 AA AA
Example 16 26 AA AA
Example 17 29 AA AA
Example 18 35 AA AA
Example 19 36 AA AA
Example 20 37 AA AA
Example 21 38 AA AA
Example 22 39 AA AA
Example 23 39 / ^* MP-203 = 3/1 AA AA
Example 24 39 / ^** PVA-117 = 4/1 AA AA
Example 25 44 AA AA
Example 26 45 AA AA
Example 27 48 AA BB
Example 28 49 AA AA
Example 29 51 AA AA
Example 30 53 AA AA
Example 31 35 / ^* MP-203 = 1/1 AA-
Example 32 E AA-
Example 33 E / ^* MP-203 = 1/3 AA-
Example 34 E / ^** PVA-117 = ^4/1 AA-
───────────────────────────────────
Comparative Example 2 ^* MP-203 AA CC
Comparative Example 3 ^** PVA-117 AA CC
───────────────────────────────────
Remarks: *, ** Made by Kuraray Co., Ltd.

[Examples 35 to 46 and Comparative Examples 4 to 9]
In Example 5, a discotic liquid crystalline compound shown in Table 3 was used instead of TP-3, and polymer No. An optical compensation sheet was prepared in the same manner as in Example 5 except that the polymer shown in Table 3 was used instead of 1.
About the sheet | seat obtained in Examples 35-46 and Comparative Examples 4-9, it carried out similarly to Example 5, and evaluated the orientation before and behind a wet heat test.
Moreover, the obtained optical anisotropic layer showed high permeability under crossed Nicols, and optical anisotropy was observed. The results are shown in Table 3.

Table 3
───────────────────────────────────
Example Polymer layer Discotic orientation
Polymer number Compound number Before heat and moisture resistance After heat and humidity resistance ---------------------
Example 35 1 TP-4 AA AA
Example 36 1 TP-5 AA AA
Example 37 1 TP-8 AA AA
Example 38 1 TP-17 AA AA
Example 39 1 TP-23 AA AA
Example 40 1 TP-28 AA AA
Example 41 39 TP-4 AA AA
Example 42 39 TP-5 AA AA
Example 43 39 TP-8 AA AA
Example 44 39 TP-17 AA AA
Example 45 39 TP-23 AA AA
Example 46 39 TP-28 AA AA
───────────────────────────────────
Comparative Example 4 Polyimide TP-4 BB CC
Comparative Example 5 Polyimide TP-5 BB CC
Comparative Example 6 Polyimide TP-8 BB CC
Comparative Example 7 ^* MP-203 TP-17 AA CC
Comparative Example 8 ^* MP-203 TP-23 AA CC
Comparative Example 9 ^* MP-203 TP-28 AA CC
───────────────────────────────────
Remarks: * Made by Kuraray Co., Ltd.

[Examples 47 to 52 and Comparative Examples 10 to 11]
On a triacetyl cellulose film (thickness: 100 μm, manufactured by Fuji Photo Film Co., Ltd.) coated with a gelatin thin film (0.1 μm), the following coating solution containing polyvinyl alcohol shown in Table 4 described below was applied with a bar coater. The polymer layer was applied and dried with hot air at 90 ° C. to form a polymer layer having a thickness of 0.8 μm.
[Coating solution]
Polyvinyl alcohol shown in Table 4 1.0 part Water 18.0 parts Methanol 6.0 parts The surface of the polymer layer obtained was rubbed roll outer diameter: 80 mm, film transport speed: 100 m / min, rubbing roll rotational speed. The film was rubbed under the conditions of: 1000 rpm and film transport tension: 1 kgf / cm substrate width to form an alignment film.
When the in-plane main refractive index is nx, ny, the refractive index in the thickness direction is nz, and the thickness is d, the triacetyl cellulose film is | nx−ny | × d = 6 nm, {(nx + ny) / 2. −nz} × d = 40 nm, almost negative uniaxiality, and the optical axis was almost in the normal direction of the film.

(Formation of discotic liquid crystalline compound layer (optically anisotropic layer))
On the alignment film on the rubbed film, a disk-shaped liquid crystalline compound layer-forming coating solution having the following composition is applied with a wire bar (using # 3 bar) and dried to form a disk-shaped liquid crystal. A coating layer of the active compound was formed.
[Coating solution]
Cellulose acetate butyrate 4 parts (CAB551-0.2, manufactured by Eastman Chemical Co.)
Discotic liquid crystalline compound TP-3 182 parts Ethylene glycol-modified totimethylolpropane 18 parts Triacrylate (V # 360, manufactured by Osaka Organic Chemical Co., Ltd.)
Photopolymerization initiator 6 parts (Irgacure 907, manufactured by Ciba Geigy Japan Ltd.)
Sensitizer 2 parts (Kayacure-DETX, manufactured by Nippon Kayaku Co., Ltd.)
343 parts of methyl ethyl ketone The film having this coating layer is attached to a metal frame and heated in a constant temperature bath at 120 ° C. for 3 minutes to orient the discotic liquid crystalline compound, and then the high pressure of 120 W / cm remains at 120 ° C. The film is irradiated with UV for 1 second using a mercury lamp, and then allowed to cool to room temperature, thereby forming a thin film (optical anisotropic layer, layer thickness 2 μm) in which the alignment state of the aligned discotic liquid crystalline compound is fixed, and an optical compensation sheet Got.

The optically anisotropic layers of the sheets obtained in Examples 47 to 52 and Comparative Examples 10 to 11 showed high permeability under crossed Nicols, and optical anisotropy was observed.
Furthermore, about the obtained sheet | seat, the cellophane tape (adhesive tape) was used and the adhesiveness between an orientation film and an optically anisotropic layer was evaluated. That is, the cellophane tape was applied to the surface of the optical anisotropic layer, and the tape was peeled off by being pulled parallel to the optical anisotropic layer. And adhesiveness was evaluated as follows.
AA: No layer was attached to the surface of the peeled tape.
CC: An optically anisotropic layer was adhered to the surface of the peeled tape.
The results are shown in Table 4.

Table 4
────────────────────────────────────
Examples Polymer layer Discotic Adhesion
Polymer number Compound number
────────────────────────────────────
Example 47 1 TP-3 AA
Example 48 39 TP-3 AA
Example 49 53 TP-3 AA
Example 50 1 / No. 39 = 1/1 TP-3 AA
Example 51 1 / No. 53 = 1/1 TP-3 AA
Example 52 39 / No. 53 = 1/1 TP-3 AA
────────────────────────────────────
Comparative Example 10 ^* MP-203 TP-3 CC
Comparative Example 11 ^** PVA-117 TP-3 CC
────────────────────────────────────
Remarks: *, ** Made by Kuraray Co., Ltd.

  In the optical compensation sheets of Examples 47 to 52, an optically anisotropic layer made of a discotic liquid crystalline compound having a polymerizable group was applied on an alignment film made of a polymer having a polymerizable group, and these layers were cured. Has been created. For this reason, these layers are strongly bonded. On the other hand, in the optical compensation sheets of Comparative Examples 10 to 11, an optically anisotropic layer made of a discotic liquid crystalline compound having a polymerizable group was applied and formed on an alignment film made of a polymer having no polymerizable group. It is created by curing only the side layer. These layers are easily peeled off. Therefore, it was confirmed that the two layers of the optical compensation sheets of Examples 47 to 52 were chemically bonded to each other.

  When the discotic liquid crystalline compounds used in the above-mentioned examples are collated with the above-mentioned disk-like morphological characteristics, when a = 1, b and c are 0.89 and 0.29, respectively. .

It is sectional drawing which shows the typical structure of the alignment film of this invention. It is sectional drawing which shows the typical structure of the optical compensation sheet | seat of this invention. It is a schematic diagram which shows the typical structure of the optically anisotropic layer of the optical compensation sheet | seat of this invention. It is a schematic diagram which shows the typical structure of the liquid crystal display device which has the optical compensation sheet | seat of this invention.

Explanation of symbols

11, 21, 31 Transparent support 12 Polymer layer 22, 32 Alignment film 23, 33 Optical anisotropic layer 34 Normal of optical anisotropic layer A, B Polarizing plate PA Polarizing axis of polarizing plate A PB Polarizing axis of polarizing plate B RF ₁ , RF ₂ optical compensation sheet BL backlight R ₁ rubbing direction of optical compensation sheet RF ₁ R ₂ rubbing direction of optical compensation sheet RF ₂ TNC liquid crystal cell

Claims (5)

  An alignment film provided on a transparent support, wherein the alignment film is made of polyvinyl alcohol in which at least one hydroxyl group is substituted with a group having a vinyl part, an oxiranyl part or an aziridinyl part. film.   The alignment film according to claim 1, wherein the group having a vinyl moiety, an oxiranyl moiety or an aziridinyl moiety is bonded to a polymer chain of polyvinyl alcohol through an ether bond, a urethane bond, an acetal bond or an ester bond.   The alignment film according to claim 1, wherein the group having a vinyl moiety, an oxiranyl moiety or an aziridinyl moiety does not have an aromatic ring. The substituted polyvinyl alcohol is represented by the following general formula (I):

(However, L ¹¹ represents an ether bond, a urethane bond, an acetal bond or an ester bond;
R ¹¹ represents an alkylene group or an alkyleneoxy group;
L ¹² represents a linking group connecting R ¹¹ and Q ¹¹ ;
Q ¹¹ represents vinyl, oxiranyl or aziridinyl;
and x1 + y1 + z1 = 100, x1 is 10-99.9 mol%, y1 is 0.01-80 mol%, and z1 is 0-70 mol%; and k and h are 0 or 1, respectively. is there)
The alignment film according to claim 1, represented by: The substituted polyvinyl alcohol has the following general formula (II):

(Wherein R ²¹ represents an alkyl group or an alkyl group substituted with alkyl, alkoxy, aryl, halogen, vinyl, vinyloxy, oxiranyl, acryloyloxy, methacryloyloxy or crotonoyloxy;
W ²¹ is an alkyl group, alkyl, alkoxy, aryl, halogen, vinyl, vinyloxy, oxiranyl, acryloyloxy, methacryloyloxy or crotonoyloxy substituted alkyl group, alkoxy group, or alkyl, alkoxy, aryl, halogen, vinyl Represents an alkoxy group substituted with vinyloxy, oxiranyl, acryloyloxy, methacryloyloxy or crotonoyloxy;
q is 0 or 1; and n is an integer from 0 to 4)
The alignment film according to claim 1, which comprises polyvinyl alcohol in which at least one hydroxyl group is substituted with a group represented by the formula:

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