JP2019043995A - Filtration method and storage method for polymerizable liquid crystal composition liquid, and method for producing liquid crystal cured layer - Google Patents

Abstract

To provide a polymerizable liquid crystal composition liquid that suppresses the occurrence and precipitation of fine foreign matter derived from a polymerizable liquid crystal compound in the polymerizable liquid crystal composition liquid, and prevents the occurrence of alignment defects when making a liquid crystal cured layer.SOLUTION: A filtration method for a polymerizable liquid crystal composition liquid includes filtering a polymerizable liquid crystal composition liquid containing a solvent, and a polymerizable liquid crystal compound dissolved in the solvent, with a filter with a bore diameter of 0.4 μm or less.SELECTED DRAWING: None

Description

  The present invention relates to a filtration method and storage method of a polymerizable liquid crystal composition liquid containing a polymerizable liquid crystal compound dissolved in a solvent. The present invention also relates to a method for producing a cured liquid crystal layer using a polymerizable liquid crystal composition liquid filtered by a specific filtration method.

  In recent years, with the thinning of image display devices, an optical film such as a retardation film comprising a cured liquid crystal layer (film) obtained by applying a polymerizable liquid crystal compound onto a substrate or an alignment film and curing in an aligned state Is being developed. In the production of such an optical film, a polymerizable liquid crystal compound is usually coated on a substrate or an alignment film as a solution obtained by dissolving the polymerizable liquid crystal compound in a solvent from the viewpoint of film formability, handleability, etc. (E.g., Patent Documents 1 and 2).

Patent No. 6055569 JP, 2016-014869, A

  In the production site of an optical film, a polymerizable liquid crystal composition liquid prepared by dissolving a polymerizable liquid crystal compound in a solvent may be temporarily or permanently stored before being used for the production of a liquid crystal cured layer. At this time, fine foreign substances derived from the polymerizable liquid crystal compound may be precipitated in the polymerizable liquid crystal composition liquid. It has been found that such fine foreign matter may cause the disturbance of the molecular orientation of the polymerizable liquid crystal compound when obtaining the liquid crystal cured layer from the polymerizable liquid crystal composition liquid, and may cause an alignment defect of the optical film.

  Therefore, the present invention is directed to a polymerizable liquid crystal composition liquid which suppresses generation and precipitation of fine foreign particles originating from a polymerizable liquid crystal compound in a polymerizable liquid crystal composition liquid, and hardly produces an alignment defect when producing a liquid crystal cured layer. Intended to provide.

The present invention provides the following preferred embodiments.
[1] A method of filtering a polymerizable liquid crystal composition liquid, comprising filtering a polymerizable liquid crystal composition liquid containing a solvent and a polymerizable liquid crystal compound dissolved in the solvent with a filter having a pore size of 0.4 μm or less.
[2] The filtration method according to [1], wherein the polymerizable liquid crystal composition liquid contains a polymerization initiator.
[3] The polymerizable liquid crystal compound comprises the following (1) to (4):
(1) a compound capable of forming a nematic phase;
(2) having π electrons on the major axis direction (a) of the polymerizable liquid crystal compound;
(3) has π electrons in the direction (b) intersecting with the long axis direction (a); and (4) the sum of π electrons existing in the long axis direction (a) is N (πa), long axis The total of the molecular weights present in the direction is N (Aa): π electron density in the major axis direction (a) of the polymerizable liquid crystal compound defined by the following formula (i):
D (πa) = N (πa) / N (Aa) (i)
And the total of the π electrons present in the cross direction (b) as N (πb), and the sum of the molecular weights present in the cross direction (b) as N (Ab). Π electron density in the cross direction (b) of
D (πb) = N (πb) / N (Ab) (ii)
And
0 ≦ [D (πa) / D (πb)] ≦ 1
In relation to
The filtration method according to the above [1] or [2], which is a compound satisfying all the above.
[4] The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition liquid is at least 0.5 times the saturation concentration of the polymerizable liquid crystal compound at 25 ° C. of the solvent dissolving the polymerizable liquid crystal compound. The filtration method as described in said [1]-[3].
[5] A polymerizable liquid crystal composition liquid containing a solvent and a polymerizable liquid crystal compound dissolved in the solvent, which is filtered through a filter having a pore diameter of 0.4 μm or less and then stored. Method.
[6] The storage method according to [5], wherein the polymerizable liquid crystal composition liquid contains a polymerization initiator.
[7] The storage method according to [5] or [6], wherein the polymerizable liquid crystal composition liquid after filtration is stored at a temperature of 20 ° C. or more.
[8] The storage method according to any one of the above [5] to [7], wherein the polymerizable liquid crystal composition liquid after filtration is stored in the dark.
[9] The polymerizable liquid crystal compound comprises the following (1) to (4):
(1) a compound capable of forming a nematic phase;
(2) having π electrons on the major axis direction (a) of the polymerizable liquid crystal compound;
(3) has π electrons in the direction (b) intersecting with the long axis direction (a); and (4) the sum of π electrons existing in the long axis direction (a) is N (πa), long axis The total of the molecular weights present in the direction is N (Aa): π electron density in the major axis direction (a) of the polymerizable liquid crystal compound defined by the following formula (i):
D (πa) = N (πa) / N (Aa) (i)
And the total of the π electrons present in the cross direction (b) as N (πb), and the sum of the molecular weights present in the cross direction (b) as N (Ab). Π electron density in the cross direction (b) of
D (πb) = N (πb) / N (Ab) (ii)
And
0 ≦ [D (πa) / D (πb)] ≦ 1
In relation to
The storage method according to any one of the above [5] to [8], which is a compound satisfying all the above.
[10] The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition liquid is at least 0.5 times the saturation concentration of the polymerizable liquid crystal compound at 25 ° C. of the solvent dissolving the polymerizable liquid crystal compound. The storage method according to any one of the above [5] to [9].
[11] A step of filtering a polymerizable liquid crystal composition liquid containing a solvent and a polymerizable liquid crystal compound dissolved in the solvent with a filter having a pore size of 0.4 μm or less,
Applying the polymerizable liquid crystal composition liquid after filtration onto a substrate to obtain a coated layer;
And removing the solvent from the coating layer to orient the polymerizable liquid crystal compound, and curing the polymerizable liquid crystal layer by polymerizing the aligned polymerizable liquid crystal compound to obtain a liquid crystal cured layer. , A method of manufacturing a liquid crystal hardened layer.
[12] The production method according to [11], wherein the polymerizable liquid crystal composition liquid contains a polymerization initiator.
[13] The production method according to the above [11] or [12], which comprises storing the polymerizable liquid crystal composition liquid after filtration at a temperature of 20 ° C. or more.
[14] The production method according to any one of the above [11] to [13], which comprises storing the polymerizable liquid crystal composition liquid after filtration in a dark place.
[15] The polymerizable liquid crystal compound comprises the following (1) to (4):
(1) a compound capable of forming a nematic phase;
(2) having π electrons on the major axis direction (a) of the polymerizable liquid crystal compound;
(3) has π electrons in the direction (b) intersecting with the long axis direction (a); and (4) the sum of π electrons existing in the long axis direction (a) is N (πa), long axis The total of the molecular weights present in the direction is N (Aa): π electron density in the major axis direction (a) of the polymerizable liquid crystal compound defined by the following formula (i):
D (πa) = N (πa) / N (Aa) (i)
And the total of the π electrons present in the cross direction (b) as N (πb), and the sum of the molecular weights present in the cross direction (b) as N (Ab). Π electron density in the cross direction (b) of
D (πb) = N (πb) / N (Ab) (ii)
And
0 ≦ [D (πa) / D (πb)] ≦ 1
In relation to
The manufacturing method in any one of said [11]-[14] which is a compound which satisfy | fills all.
[16] The production method according to any one of the above [11] to [15], wherein an alignment film is formed on the substrate.
[17] The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition liquid is at least 0.5 times the saturation concentration of the polymerizable liquid crystal compound at 25 ° C. of the solvent dissolving the polymerizable liquid crystal compound. The manufacturing method in any one of said [11]-[16].
[18] A polymerizable liquid crystal composition liquid comprising a solvent and a polymerizable liquid crystal compound dissolved in the solvent, and being filtered by a filter having a pore size of 0.4 μm or less.
[19] The polymerizable liquid crystal composition liquid as described in the above [18], which contains a polymerization initiator.
[20] The polymerizable liquid crystal compound comprises the following (1) to (4):
(1) a compound capable of forming a nematic phase;
(2) having π electrons on the major axis direction (a) of the polymerizable liquid crystal compound;
(3) has π electrons in the direction (b) intersecting with the long axis direction (a); and (4) the sum of π electrons existing in the long axis direction (a) is N (πa), long axis The total of the molecular weights present in the direction is N (Aa): π electron density in the major axis direction (a) of the polymerizable liquid crystal compound defined by the following formula (i):
D (πa) = N (πa) / N (Aa) (i)
And the total of the π electrons present in the cross direction (b) as N (πb), and the sum of the molecular weights present in the cross direction (b) as N (Ab). Π electron density in the cross direction (b) of
D (πb) = N (πb) / N (Ab) (ii)
And
0 ≦ [D (πa) / D (πb)] ≦ 1
In relation to
The polymerizable liquid crystal composition liquid according to the above [18] or [19], which is a compound satisfying all the above.
[21] The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition liquid is at least 0.5 times the saturation concentration of the polymerizable liquid crystal compound at 25 ° C. of the solvent dissolving the polymerizable liquid crystal compound. The polymerizable liquid crystal composition liquid according to any one of the above [18] to [20].

  According to the present invention, a polymerizable liquid crystal composition liquid which suppresses generation and precipitation of fine foreign particles originating from the polymerizable liquid crystal compound in the polymerizable liquid crystal composition liquid, and which hardly causes an alignment defect when producing the liquid crystal cured layer Can be provided.

  Hereinafter, embodiments of the present invention will be described in detail. The scope of the present invention is not limited to the embodiments described herein, and various modifications can be made without departing from the spirit of the present invention.

<Filtration method>
The method of filtering a polymerizable liquid crystal composition liquid of the present invention includes filtering a polymerizable liquid crystal composition liquid containing a solvent and a polymerizable liquid crystal compound dissolved in the solvent with a filter having a pore diameter of 0.4 μm or less. In the present invention, the polymerizable liquid crystal composition liquid means a solution containing at least a polymerizable liquid crystal compound and a solvent capable of dissolving the polymerizable liquid crystal compound as its constituent components.

When the polymerizable liquid crystal composition liquid prepared by dissolving the polymerizable liquid crystal compound in a solvent is stored temporarily or for a long time, fine foreign particles originating from the polymerizable liquid crystal compound are generated in the polymerizable liquid crystal composition liquid, May precipitate out. Although the actual condition and the cause are not clear, it is considered that fine molecules of the polymerizable liquid crystal compound are formed by association of the molecules of the polymerizable liquid crystal compound, and they are precipitated as fine foreign matter. Such association of the polymerizable liquid crystal compound is likely to have already occurred at the stage of preparing the polymerizable liquid crystal composition solution by dissolving the polymerizable liquid crystal compound in a solvent, and a fine aggregate existing immediately after the preparation In the case where the polymerizable liquid crystal composition liquid is stored temporarily or over a long period of time, it is thought that it precipitates as fine foreign matter by growing with time.
In the filtration method of the present invention, even when the polymerizable liquid crystal composition liquid is stored by filtering the polymerizable liquid crystal composition liquid with a filter with a fine pore diameter, generation of fine foreign matter derived from the polymerizable liquid crystal compound And precipitation can be suppressed, and when used in the preparation of an optical film, a polymerizable liquid crystal composition liquid with less alignment defects can be provided.

  In the filtration method of the present invention, the pore diameter of the filter used to filter the polymerizable liquid crystal composition liquid is 0.4 μm or less, preferably 0.3 μm or less, more preferably 0.2 μm or less, and still more preferably 0 .15 μm or less. The molecular association of the polymerizable liquid crystal compound present in the polymerizable liquid crystal composition liquid can be sufficiently separated as the pore size of the filter is not more than the above upper limit value. The lower limit of the pore size of the filter is not particularly limited, but is usually 0.03 μm or more from the viewpoint of filtration efficiency. The thickness of the filter is usually 1 to 1000 μm, preferably 10 to 100 μm.

  The material of the filter is not particularly limited, and may be appropriately selected according to the type of solvent used and the like. For example, cellulose, nitrocellulose, cellulose mixed ester, cellulose acetate, polypropylene, nylon, polytetrafluoroethylene (PTFE), hydrophilic PTFE, polyvinylidene fluoride, polyether sulfone, glass fiber, paper, cloth, non-woven fabric, etc. And from the viewpoint of solvent resistance, PTFE is preferred.

  In the filtration method of the present invention, filtration of the polymerizable liquid crystal composition liquid can be performed by natural filtration, vacuum filtration, pressure filtration or the like. From the viewpoint of filtration rate, vacuum filtration or pressure filtration is preferred.

  The filtration of the polymerizable liquid crystal composition liquid may be performed only once or plural times. When filtration is performed multiple times, a filter with a pore diameter of 0.4 μm or less may be used in all filtrations, or a filter with a pore diameter of 0.4 μm or less may be used in at least one filtration among multiple filtrations. The relatively large foreign matter such as general foreign matter (garbage etc.) taken from the outside is removed from the outside of the polymerizable liquid crystal composition liquid by filtering with a filter having a pore size of larger than 0.4 μm first, and then 0.4 μm. The filtration can be performed more efficiently by performing filtration with the following small pore size filters.

  In addition, the filtration method of the present invention is carried out by using the polymerizable liquid crystal composition liquid after preparation of the polymerizable liquid crystal composition liquid to obtain a liquid crystal cured layer (for example, applying to a base material etc.). Since fine foreign substances derived from the liquid crystal compound can be removed, an optical film with few alignment defects can be obtained. For this reason, the filtration method of the present invention can be carried out at any time before using the polymerizable liquid crystal composition liquid to obtain the liquid crystal cured layer after preparation of the polymerizable liquid crystal composition liquid, but the polymerizable liquid crystal composition liquid When the composition liquid is stored after preparation of the liquid crystal composition, it is performed before storage to separate the molecular association of the polymerizable liquid crystal compound and to suppress the growth of fine foreign matter derived from the polymerizable liquid crystal compound, thereby forming the polymerizable liquid crystal composition. The generation and precipitation of fine foreign substances in the liquid can be effectively suppressed, and the effects of the present invention can be obtained more advantageously.

  When the amount of the polymerizable liquid crystal compound is relatively large relative to the saturation concentration of the polymerizable liquid crystal compound in the solvent dissolving the polymerizable liquid crystal compound, fine foreign matter derived from the polymerizable liquid crystal compound in the polymerizable liquid crystal composition liquid Development, growth and / or precipitation tend to be promoted. In the filtration method of the present invention, the growth of fine foreign matter can be suppressed by filtering the polymerizable liquid crystal composition liquid with a filter having a fine pore diameter, and therefore, the polymerizability with a relatively large content of the polymerizable liquid crystal compound A liquid crystal composition liquid, specifically, preferably used for a polymerizable liquid crystal composition liquid having a concentration of 0.5 times or more the saturation concentration of the polymerizable liquid crystal compound at 25 ° C. of a solvent for dissolving the polymerizable liquid crystal compound It is possible to expect a high suppression effect on the generation, growth and precipitation of fine foreign substances derived from the polymerizable liquid crystal compound. In the present invention, the content of the polymerizable liquid crystal compound is more preferably 0.8 times or more and still more preferably 0.9 times or more with respect to the saturation concentration. In the filtration method of the present invention, the upper limit of the content of the polymerizable liquid crystal compound is not particularly limited, and it is possible to apply even in the supersaturated state, and the filtration method of the present invention is more effective. .

  The filtration method of the present invention can be widely applied to polymerizable liquid crystal composition liquids using polymerizable liquid crystal compounds conventionally known in the field of optical films. In the present invention, the polymerizable liquid crystal compound means a liquid crystal compound having a polymerizable functional group, particularly a photopolymerizable functional group. The photopolymerizable functional group means a group capable of participating in the polymerization reaction by active radicals or acids generated from the photopolymerization initiator. Examples of the photopolymerizable functional group include vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxiranyl group, oxetanyl group and the like. Among them, acryloyloxy group, methacryloyloxy group, vinyloxy group, oxiranyl group and oxetanyl group are preferable, and acryloyloxy group is more preferable. The liquid crystallinity may be a thermotropic liquid crystal or a lyotropic liquid crystal, and the phase order structure may be a nematic liquid crystal or a smectic liquid crystal. As the polymerizable liquid crystal compound, only one type may be used, or two or more types may be used in combination.

  Among various polymerizable liquid crystal compounds, compounds having characteristics such as a relatively large molecular structure, a rigid structure, and a structure including a high π electron density structure have low solubility in a solvent, and in a polymerizable liquid crystal composition group The molecules tend to associate with each other. In general, such association often occurs in discotic liquid crystals, but the compounds listed below have a structure with high π electron density as described above, and association occurs even though they are nematic liquid crystal compounds. It is easier. According to the filtration method of the present invention, the growth of fine foreign matter can be suppressed by filtering the polymerizable liquid crystal composition liquid with a filter having a fine pore diameter, and therefore, a polymerizable liquid crystal having such a molecular structural feature It can apply especially suitably to the polymerization liquid crystal constituent liquid which uses a compound.

As a polymeric liquid crystal compound which has the said molecular structure, the compound which satisfy | fills all the following (1)-(4) is mentioned.
(1) a compound capable of forming a nematic phase;
(2) It has π electrons on the major axis direction (a) of the polymerizable liquid crystal compound.
(3) π electrons are present in the direction intersecting with the long axis direction (a) [cross direction (b)].
(4) A polymerizable liquid crystal compound defined by the following formula (i) with N (πa) as the total of π electrons existing in the long axis direction (a) and N (Aa) as the total of molecular weights existing in the long axis direction Π electron density in the long axis direction (a) of:
D (πa) = N (πa) / N (Aa) (i)
And the total of the π electrons present in the cross direction (b) as N (πb), and the sum of the molecular weights present in the cross direction (b) as N (Ab). Π electron density in the cross direction (b) of
D (πb) = N (πb) / N (Ab) (ii)
And
0 ≦ [D (πa) / D (πb)] ≦ 1
(Ie, the π electron density in the cross direction (b) is greater than the π electron density in the long axis direction (a)).
The polymerizable liquid crystal compound satisfying all the above (1) to (4) can be applied on an alignment film formed by rubbing treatment and heated to a temperature higher than the phase transition temperature to form a nematic phase. is there. In the nematic phase formed by the alignment of the polymerizable liquid crystal compound, alignment is usually performed so that the long axis directions of the polymerizable liquid crystal compound are parallel to each other, and the long axis direction is the alignment direction of the nematic phase.

で表される化合物が挙げられる。 In general, the polymerizable liquid crystal compound having the above-mentioned properties often exhibits reverse wavelength dispersion. Specific examples of the compound satisfying the above properties (1) to (4) include the compounds represented by the following formula (I):

The compound represented by these is mentioned.

  In formula (I), Ar represents a divalent aromatic group which may have a substituent. The term "aromatic group" as used herein refers to a group having a planar ring structure, and the ring structure has [4n + 2] [pi] electrons in accordance with the Hückel rule. Here, n represents an integer. When the ring structure is formed by containing a hetero atom such as -N = or -S-, the case where the non-covalent electron pair on these hetero atoms is included to satisfy the Hückel rule and has aromaticity is also included. The divalent aromatic group preferably contains at least one or more of a nitrogen atom, an oxygen atom and a sulfur atom.

G ¹ and G ² each independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group. Here, a hydrogen atom contained in the divalent aromatic group or divalent alicyclic hydrocarbon group is a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, carbon The carbon atom which may be substituted by the alkoxy group of the number 1-4, a cyano group, or a nitro group and which comprises this bivalent aromatic group or a bivalent alicyclic hydrocarbon group is an oxygen atom, a sulfur atom Or may be substituted by a nitrogen atom.

L ¹ , L ² _, B ¹ and B ² are each independently a single bond or a divalent linking group.

k and l each independently represent an integer of 0 to 3 and satisfy the relationship 1 ≦ k + 1. Here, when 2 ≦ k + 1, B ¹ and B ² , G ¹ and G ² may be identical to or different from each other.

E ¹ and E ² each independently represent an alkanediyl group having 1 to 17 carbon atoms, wherein a hydrogen atom contained in the alkanediyl group may be substituted by a halogen atom, and the alkanediyl group may be substituted is, -O - - _-CH 2 contained, - S -, - may be substituted with Si-. Each of P ¹ and P ² independently represents a polymerizable group or a hydrogen atom, and at least one is a polymerizable group.

G ¹ and G ² are each independently preferably a 1,4-phenylenediyl group which may be substituted by at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms And a 1,4-cyclohexanediyl group which may be substituted by at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms, and more preferably 1 substituted by a methyl group , 4-phenylenediyl group, unsubstituted 1,4-phenylenediyl group, or unsubstituted 1,4-trans-cyclohexanediyl group, particularly preferably unsubstituted 1,4-phenylenediyl group, or unsubstituted It is a substituted 1,4-trans-cyclohexanediyl group. In addition, it is preferable that at least one of the plurality of G ¹ and G ² is a divalent alicyclic hydrocarbon group, and at least one of G ¹ and G ² bonded to L ¹ or L ^2. More preferably, one is a divalent alicyclic hydrocarbon group.

L ¹ and L ² are each independently preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R ^a1 OR ^a2- , -R ^a3 COOR ^a4- , -R ^{a5 OCOR a6 -, R a7 OC =} OOR a8 -, - N = N -, - CR c = CR d -, or C≡C-. Here, R ^{a1 to} R ^a8 each independently represent a single bond or an alkylene group having 1 to 4 carbon atoms, and R ^c and R ^d each represent an alkyl group having 1 to 4 carbon atoms or a hydrogen atom. L ¹ and ^{L 2} are each independently more preferably a single _{^{bond, -OR a2-1 -, - CH 2}} -, - CH 2 CH 2 -, - COOR a4-1 -, or ^{OCOR a6-1} - a . Here, R ^a2-1 , R ^a4-1 and R ^a6-1 each independently represent a single bond, -CH _2- or -CH ₂ CH _2- . L ¹ and L ² are each independently more preferably a single bond, —O—, —CH ₂ CH ₂ —, —COO—, —COOCH ₂ CH ₂ —, or OCO—.

In a preferred embodiment of the present invention, at least one of G ¹ and G ² in the formula (I) is a divalent alicyclic hydrocarbon group, and the divalent alicyclic hydrocarbon group is polymerizable liquid crystal compound bound by L ¹ and / or L ² is -COO- and aromatic groups Ar of which may bivalent have a substituent is used.

Each of B ¹ and B ² is preferably independently a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R ^a9 OR ^a10- , -R ^a11 COOR ^a12- , -R ^a13 OCOR ^a14 -, or ^R a15 OC ^{= OOR a16} - a. Here, R ^{a9 to} R ^a16 each independently represent a single bond or an alkylene group having 1 to 4 carbon atoms. B ¹ and B ² are each independently more preferably a single bond, -OR ^{a10 -1-} , -CH _2- , -CH ₂ CH _2- , ^{-COOR a12 -1-} or OCOR ^a14-1- . Here, R ^a10-1 , R ^a12-1 and R ^a14-1 each independently represent a single bond, -CH _2- or -CH ₂ CH _2- . B ¹ and B ² are each independently more preferably a single bond, -O-, -CH ₂ CH _2- , -COO-, -COOCH ₂ CH _2- , -OCO-, or OCOCH ₂ CH _2- .

  k and l are preferably in the range of 2 ≦ k + 1 ≦ 6 from the viewpoint of reverse wavelength dispersive expression, preferably k + 1 = 4, and more preferably k = 2 and l = 2. It is further preferable that k = 2 and l = 2 because of a symmetrical structure.

Each of E ¹ and E ² is preferably independently an alkanediyl group having 1 to 17 carbon atoms, and more preferably an alkanediyl group having 4 to 12 carbon atoms.

The polymerizable group represented by P ¹ or P ² is, for example, an epoxy group, a vinyl group, a vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxiranyl And oxetanyl groups and the like. Among these, acryloyloxy group, methacryloyloxy group, vinyloxy group, oxiranyl group and oxetanyl group are preferable, and acryloyloxy group is more preferable.

  Ar preferably has at least one selected from an aromatic hydrocarbon ring which may have a substituent, an aromatic heterocyclic ring which may have a substituent, and an electron-withdrawing group. As the said aromatic hydrocarbon ring, a benzene ring, a naphthalene ring, an anthracene ring etc. are mentioned, for example, A benzene ring and a naphthalene ring are preferable. As the aromatic heterocyclic ring, furan ring, benzofuran ring, pyrrole ring, indole ring, thiophene ring, benzothiophene ring, pyridine ring, pyrazine ring, pyrimidine ring, triazole ring, triazine ring, pyrroline ring, imidazole ring, pyrazole ring And thiazole ring, benzothiazole ring, thienothiazole ring, oxazole ring, benzoxazole ring, phenanthroline ring and the like. Among these, it is preferable to have a thiazole ring, a benzothiazole ring, or a benzofuran ring, and it is more preferable to have a benzothiazole group. When Ar contains a nitrogen atom, the nitrogen atom preferably has a π electron.

The total number N of _π electrons contained in the divalent aromatic group represented by Ar in the formula (I) is preferably 8 or more, more preferably 10 or more, still more preferably 14 or more, and particularly preferably Preferably it is 16 or more. Moreover, it is preferably 30 or less, more preferably 26 or less, and still more preferably 24 or less.

  Examples of the aromatic group represented by Ar include the following groups.

In formulas (Ar-1) to (Ar-22), the symbol * represents a linking moiety, and Z ⁰ , Z ¹ and Z ² each independently represent a hydrogen atom, a halogen atom, or an alkyl having 1 to 12 carbon atoms. Group, cyano group, nitro group, alkylsulfinyl group having 1 to 12 carbon atoms, alkylsulfonyl group having 1 to 12 carbon atoms, carboxyl group, fluoroalkyl group having 1 to 12 carbon atoms, alkoxy group having 1 to 6 carbon atoms, C1-C12 alkylthio group, C1-C12 N-alkylamino group, C2-C12 N, N-dialkylamino group, C1-C12 N-alkylsulfamoyl group or carbon 2 to 12 N, N-dialkylsulfamoyl groups are represented.

Q ¹ and Q ² each independently represent —CR ^{2 ′} R ^3′— , —S—, —NH—, —NR ^{2 ′} —, —CO— or O—, and R ^{2 ′} and R ^{3 ′} Each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

J ¹ and J ² each independently represent a carbon atom or a nitrogen atom.

Y ¹ , Y ² and Y ³ each independently represent an aromatic hydrocarbon group or aromatic heterocyclic group which may be substituted.

W ¹ and W ² each independently represent a hydrogen atom, a cyano group, a methyl group or a halogen atom, and m represents an integer of 0 to 6.

Examples of the aromatic hydrocarbon group in Y ¹ , Y ² and Y ³ include aromatic hydrocarbon groups having 6 to 20 carbon atoms such as phenyl group, naphthyl group, anthryl group, phenanthryl group and biphenyl group, and a phenyl group And a naphthyl group is preferable, and a phenyl group is more preferable. The aromatic heterocyclic group has 4 to 20 carbon atoms which contains at least one hetero atom such as nitrogen atom such as furyl group, pyrrolyl group, thienyl group, pyridinyl group, thiazolyl group, benzothiazolyl group, oxygen atom and sulfur atom An aromatic heterocyclic group is mentioned, and a furyl group, a thienyl group, a pyridinyl group, a thiazolyl group and a benzothiazolyl group are preferable.

Y ¹ and Y ² may be each independently an optionally substituted polycyclic aromatic hydrocarbon group or a polycyclic aromatic heterocyclic group. The polycyclic aromatic hydrocarbon group refers to a condensed polycyclic aromatic hydrocarbon group or a group derived from an aromatic ring assembly. The polycyclic aromatic heterocyclic group means a group derived from a fused polycyclic aromatic heterocyclic group or an aromatic ring assembly.

Z ⁰ , Z ¹ and Z ² are each independently preferably a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, a nitro group, or an alkoxy group having 1 to 12 carbon atoms; ⁰ is more preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a cyano group, and Z ¹ and Z ² are more preferably a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group or a cyano group.

Q ¹ and Q ² are preferably -NH-, -S-, -NR ^{2 '} -or -O-, and R ^2' is preferably a hydrogen atom. Among them, -S-, -O- and -NH- are particularly preferable.

  Among formulas (Ar-1) to (Ar-22), formulas (Ar-6) and (Ar-7) are preferable from the viewpoint of molecular stability.

In formulas (Ar-16) to (Ar-22), Y ¹ may form an aromatic heterocyclic group together with the nitrogen atom to which it is attached and Z ⁰ . Examples of the aromatic heterocyclic group include those described above as the aromatic heterocyclic ring which Ar may have, and examples thereof include pyrrole ring, imidazole ring, pyrroline ring, pyridine ring, pyrazine ring, pyrimidine ring, indole And rings, quinoline ring, isoquinoline ring, purine ring, pyrrolidine ring and the like. The aromatic heterocyclic group may have a substituent. Y ¹ may be, together with the nitrogen atom to which it is attached and Z ⁰ , an optionally substituted polycyclic aromatic hydrocarbon group or a polycyclic aromatic heterocyclic group as described above. For example, benzofuran ring, benzothiazole ring, benzoxazole ring and the like can be mentioned. In addition, the compound represented by said Formula (I) can be manufactured according to the method as described in Unexamined-Japanese-Patent No. 2010-31223, for example.

In the present invention, the solvent used for the polymerizable liquid crystal composition liquid is preferably a solvent which can dissolve the polymerizable liquid crystal compound to be used and is inert to the polymerization reaction of the polymerizable liquid crystal compound, and the polymerizable liquid crystal used It may be appropriately selected according to the compound.
Specifically, for example, alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, methyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether and phenol; ester solvents such as ethyl acetate and butyl acetate; acetone, methyl ethyl ketone, Ketone solvents such as cyclopentanone, cyclohexanone, cycloheptanone, methyl amyl ketone, methyl isobutyl ketone, N-methyl-2-pyrrolidinone; non-chlorinated aliphatic hydrocarbon solvents such as pentane, hexane and heptane; toluene, xylene and the like Non-chlorinated aromatic hydrocarbon solvents of the following: nitrile solvents such as acetonitrile; ether solvents such as propylene glycol monomethyl ether, tetrahydrofuran, dimethoxyethane; Fine chloroform, chlorinated hydrocarbon solvents such as chlorobenzene and the like. More preferably, ester solvents such as ethyl acetate and butyl acetate, methyl ethyl ketone, cyclopentanone, cyclohexanone, cycloheptanone, methyl amyl ketone, methyl isobutyl ketone, ketone solvents such as N-methyl-2-pyrrolidinone, pentane, hexane, heptane And non-chlorinated aliphatic hydrocarbon solvents such as toluene and xylene; propylene glycol monomethyl ether; and chlorinated hydrocarbon solvents such as chloroform and chlorobenzene. These solvents may be used alone or in combination.

  In the present invention, the content of the solvent in the polymerizable liquid crystal composition liquid may be appropriately determined in relation to the polymerizable liquid crystal compound to be used, but generally, 10 parts by weight of the solid content of the polymerizable liquid crystal composition liquid It is 10 parts by mass to 10000 parts by mass, preferably 50 parts by mass to 5000 parts by mass, and more preferably 500 parts by mass to 3000 parts by mass.

  In the present invention, the polymerizable liquid crystal composition liquid may contain, in addition to the polymerizable liquid crystal compound and the solvent, a polymerization initiator for initiating the polymerization reaction of the polymerizable liquid crystal compound. When a polymerization initiator is contained in the polymerizable liquid crystal composition liquid, not only association between the molecules of the polymerizable liquid crystal compound but also polymerization of the polymerizable liquid crystal compound tends to occur, and the polymerizable liquid crystal is kept during storage of the composition liquid. It is considered that a slight amount of dimer, trimer, other oligomers and the like derived from the compound are generated, and precipitation of fine foreign substances in the polymerizable liquid crystal composition liquid tends to occur more easily. The filtration method of the present invention can be suitably used for a polymerizable liquid crystal composition liquid containing a polymerization initiator, and can effectively suppress the generation and precipitation of fine foreign substances derived from the polymerizable liquid crystal compound. .

  The polymerization initiator may be appropriately selected according to the polymerizable liquid crystal compound to be used. For example, in the case of using a polymerizable liquid crystal compound having a photopolymerizable functional group described above, a photopolymerization initiator can be used. Examples of the photopolymerization initiator include benzoin compounds, benzophenone compounds, alkylphenone compounds, acyl phosphine oxide compounds, triazine compounds, iodonium salts and sulfonium salts. The polymerization initiators can be used alone or in combination of two or more.

  Examples of benzoin compounds include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether and benzoin isobutyl ether.

  As a benzophenone compound, benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3,3 ', 4,4'-tetra (tert-butylperoxycarbonyl) benzophenone And 2,4,6-trimethylbenzophenone and the like.

  As the alkyl phenone compound, diethoxyacetophenone, 2-methyl-2-morpholino-1- (4-methylthiophenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butane -1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1,2-diphenyl-2,2-dimethoxyethane-1-one, 2-hydroxy-2-methyl-1- [1 4- (2-hydroxyethoxy) phenyl] propan-1-one, 1-hydroxycyclohexyl phenyl ketone and 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propan-1-one Oligomers etc. are mentioned.

  The acyl phosphine oxide compounds include 2,4,6-trimethyl benzoyl diphenyl phosphine oxide and bis (2,4,6-trimethyl benzoyl) phenyl phosphine oxide.

  As a triazine compound, 2,4-bis (trichloromethyl) -6- (4-methoxyphenyl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- (4-methoxynaphthyl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- (4-methoxystyryl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- [2 -(5-Methylfuran-2-yl) ethenyl] -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- [2- (furan-2-yl) ethenyl] -1,3 5-triazine, 2,4-bis (trichloromethyl) -6- [2- (4-diethylamino-2-methylphenyl) ethenyl] -1,3,5-triazine and 2,4-bis (trichloromethyl) -6-[ - (3,4-dimethoxyphenyl) ethenyl] -1,3,5-triazine.

  A commercially available thing can be used as a polymerization initiator. As a commercially available polymerization initiator, for example, “Irgacure (registered trademark) 907”, “Irgacure (registered trademark) 184”, “Irgacure (registered trademark) 651”, “Irgacure (registered trademark) 819”, “Irgacure (registered trademark) 819”, Irgacure (registered trademark) 250, Irgacure (registered trademark) 369 (Ciba Japan Co., Ltd.); "Seikol (registered trademark) BZ", "Seikool (registered trademark) Z", "Seikool (registered trademark) BEE" (Seiko Chemical Co., Ltd.); "Kayacure (registered trademark) BP 100" (Nippon Kayaku Co., Ltd.); "Kayacure (registered trademark) UVI-6992" (manufactured by Dow); "Adeka Optomer SP" -152 "," ADEKA OPTOMER SP-170 "(trade name ADEKA);" TAZ-A "," TAZ-P " "(Nippon SiberHegner Company); and" TAZ-104 "(Sanwa Chemical Co., Ltd.).

  When the polymerizable liquid crystal composition liquid contains a polymerization initiator, the content can be appropriately adjusted according to the type and amount of the polymerizable liquid crystal compound contained in the composition liquid, but 100 parts by mass of the polymerizable liquid crystal compound 0.1 to 30 parts by mass is preferable, and 0.5 to 10 parts by mass is more preferable. When the content of the polymerizable initiator is within the above range, the reaction of the polymerizable group sufficiently proceeds, and the orientation of the polymerizable liquid crystal compound is hardly disturbed.

  Furthermore, the polymerizable liquid crystal composition liquid may contain additives such as a polymerization inhibitor, a photosensitizer, and a leveling agent. These additives can be used alone or in combination of two or more.

  By using the polymerization inhibitor, the progress of the polymerization reaction of the polymerizable liquid crystal compound can be easily controlled. As a polymerization inhibitor, hydroquinones having a substituent such as hydroquinone and alkyl ether; catechols having a substituent such as alkyl ether such as butyl catechol; pyrogallols, 2,2,6,6-tetramethyl-1- Radical scavengers such as piperidinyloxy radical; thiophenols; β-naphthylamines and β-naphthols. The content of the polymerization inhibitor is usually 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass, and more preferably 0.1 to 3 with respect to 100 parts by mass of the polymerizable liquid crystal compound. It is a mass part. The polymerization inhibitors can be used alone or in combination of two or more.

  By using a photosensitizer, it is possible to sensitize the photopolymerization initiator. Examples of the photosensitizer include xanthones such as xanthone and thioxanthone; anthracenes having a substituent such as anthracene and alkyl ether; phenothiazine; rubrene. The photosensitizers can be used alone or in combination of two or more. The content of the photosensitizer is usually 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, more preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound. 3 parts by mass.

  The leveling agent is an additive having the function of adjusting the flowability of the polymerizable liquid crystal composition liquid and making the liquid crystal cured layer obtained by applying the composition liquid flatter, and, for example, silicone such as a silane coupling agent And leveling agents of polyacrylate type and perfluoroalkyl type. Specifically, DC3PA, SH7PA, DC11PA, SH28PA, SH29PA, SH30PA, ST80PA, ST86PA, SH8400, SH8700, FZ2123 (all manufactured by Toray Dow Corning Co., Ltd.), KP 321, KP 323, KP 324, KP 326, KP 340, KP341, X22-161A, KF6001, KBM-1003, KBE-1003, KBM-303, KBM-402, KBM-403, KBE-402, KBE-403, KBM-1403, KBM-502, KBM-503, KBE- 502, KBE-503, KBM-5103, KBM-602, KBM-603, KBM-903, KBE-903, KBE-9103, KBM-573, KBM-575, KBE-585, KBM-80 , KBM-802, KBM-803, KBE-846, KBE-9007 (all from Shin-Etsu Chemical Co., Ltd.), TSF 400, TSF 401, TSF 410, TSF 4300, TSF 4440, TSF 4445, TSF 4446, TSF 4452, TSF 4460 (above , All Momentive Performance Materials Japan Ltd.), Fluorinert (registered trademark) FC-72, FC-40, FC-43, FC-3283 (all manufactured by Sumitomo 3M Co., Ltd.), Megafuck (registered trademark) R-08, R-30, R-90, F-410, F-443, F-445, F-470, F-477, F-479, F-482, F-483 (all of which are DIC ), F-top (trade name) EF301, the same EF303, the same EF351, the same EF352 (all of which are all made by Mitsubishi Materials Electronic Chemicals Co., Ltd.), Surfron (registered trademark) S-381, S-382, and S -383, the S-393, the SC-101, the SC-105, the KH-40, and the SA-100 (all of which are all AGC Seimi Chemical Co., Ltd.), trade names E1830 and E5844 (Daikin Fine Chemical Co., Ltd.) BM-1000, BM-1100, BYK-352, BYK-353 and BYK-361N (all trade names: manufactured by BM Chemie) and the like. The leveling agents can be used alone or in combination of two or more. 0.01-5 mass parts is preferable with respect to 100 mass parts of polymerizable liquid crystal compounds, and, as for content of a leveling agent, 0.05-3 mass parts is more preferable.

  The polymerizable liquid crystal composition liquid used in the filtration method of the present invention may be prepared by stirring and mixing the polymerizable liquid crystal compound and the solvent, and, if necessary, the polymerization initiator and other additives by a known method. it can.

<Storage method>
The storage method of the polymerizable liquid crystal composition liquid of the present invention is to store the polymerizable liquid crystal composition liquid containing the solvent and the polymerizable liquid crystal compound dissolved in the solvent after filtering it with a filter having a pore diameter of 0.4 μm or less. including.

  In the storage method of the present invention, for the filtration of the polymerizable liquid crystal composition liquid with a filter having a pore diameter of 0.4 μm or less, the same methods and conditions as those described above as the filtration method of the present invention can be adopted. The polymerizable liquid crystal compound, the solvent, the polymerization initiator and other additives constituting the polymerizable liquid crystal composition liquid used in the storage method of the present invention are the same as those exemplified in the filtration method of the present invention described above. Can be used.

  Fineness derived from the polymerizable liquid crystal compound when stored in an environment where the temperature can be 20 ° C. or higher, such as storage at room temperature, as compared to when the polymerizable liquid crystal composition liquid is stored at low temperature (eg, 15 ° C. or less) Growth and precipitation of foreign substances are likely to be promoted, but the growth of fine foreign substances can be suppressed by filtering the polymerizable liquid crystal composition liquid with a filter with a fine pore size before storage, and storage for a long period of time Even in this case, it becomes difficult to cause the precipitation of fine foreign matter. Therefore, the storage method of the present invention can obtain the effects of the present invention particularly advantageously when the polymerizable liquid crystal composition liquid after filtration is stored at a temperature of 20 ° C. or higher. According to the storage method of the present invention, even when the polymerizable liquid crystal composition liquid is stored at a temperature of 25 ° C. or higher, or at a temperature of 30 ° C. or higher, the effect of suppressing the growth of fine foreign matter You can get it. In the storage method of the present invention, “storage at a temperature of 20 ° C. or higher” means storage at room temperature in addition to storage under an environment controlled to a specific temperature of always 20 ° C. or higher. This includes the case where the storage period is 20 ° C. or higher.

  In addition, by storing the polymerizable liquid crystal composition liquid after filtration in a dark place, it is possible to more effectively suppress the growth and precipitation of fine foreign substances derived from the polymerizable liquid crystal compound. Storage in a dark place includes storage in a room shielded from light such as sunlight, storage in a light-shielding container, and the like.

<Method of manufacturing liquid crystal hardened layer>
Furthermore, the present invention
Filtering the polymerizable liquid crystal composition liquid containing the solvent and the polymerizable liquid crystal compound dissolved in the solvent with a filter having a pore diameter of 0.4 μm or less (hereinafter, also referred to as “filtration step”)
Applying the polymerizable liquid crystal composition liquid after filtration onto a substrate to obtain a coated layer (hereinafter also referred to as “coating step”),
A step of orienting the polymerizable liquid crystal compound by removing the solvent from the obtained coated layer (hereinafter also referred to as "drying step"), and curing the polymerizable liquid crystal layer by polymerizing the aligned polymerizable liquid crystal compound To obtain a cured liquid crystal layer (hereinafter referred to as "curing step")
The present invention also relates to a method for producing a liquid crystal cured layer comprising
Suppressing generation, growth, precipitation and the like of fine foreign matter derived from the polymerizable liquid crystal compound in the polymerizable liquid crystal composition liquid by filtering the polymerizable liquid crystal composition liquid with a filter with a fine pore diameter of 0.4 μm or less The cured liquid crystal layer obtained from such a polymerizable liquid crystal composition liquid is less likely to cause alignment defects, and an optical film having excellent optical characteristics can be produced.

  In the method for producing a cured liquid crystal layer according to the present invention, the same method, conditions and the like as those described above as the filtration method according to the present invention can be employed in the filtration step. Further, as the polymerizable liquid crystal compound, the solvent, the polymerization initiator and the other additives constituting the polymerizable liquid crystal composition liquid, the same ones as exemplified in the filtration method of the present invention described above can be used. .

  In the method for producing a cured liquid crystal layer according to the present invention, as a method for applying the polymerizable liquid crystal composition liquid after filtration onto a substrate, extrusion coating, direct gravure coating, reverse gravure coating, CAP coating, slit coating And die coating methods. Moreover, the method etc. of coating using coaters, such as a dip coater, a bar coater, a spin coater, etc. are mentioned. Among them, the CAP coating method, the inkjet method, the dip coating method, the slit coating method, the die coating method and the coating method using a bar coater are preferable in that they can be applied continuously in the Roll to Roll format. In the case of coating by a roll to roll method, a composition for forming a photoalignment film or the like is coated on a substrate to form an alignment film, and a polymerizable liquid crystal composition liquid is continuously applied on the obtained alignment film. You can also.

  The substrate is preferably a resin substrate. As a resin which comprises a base material, For example, Polyolefins, such as polyethylene, a polypropylene, norbornene-type polymer; Polyvinyl alcohol; Polyethylene terephthalate; Polymethacrylate ester; Polyacrylate ester; Cellulose ester; Polyethylene naphthalate; Polycarbonate; And polyether sulfone; polyether ketone; polyphenylene sulfide; and polyphenylene oxide. Among them, a base material made of a polyolefin such as polyethylene, polypropylene and norbornene-based polymer is preferable.

An alignment film may be formed on the surface of the substrate on which the polymerizable liquid crystal composition liquid is applied. The alignment film has an alignment regulating force to align the polymerizable liquid crystal compound in a desired direction.
It is preferable that the alignment film has solvent resistance which is not dissolved by application of a polymerizable liquid crystal composition liquid and the like, and has heat resistance in heat treatment for removal of a solvent described later or alignment of a polymerizable liquid crystal compound. Examples of the alignment film include an alignment film containing an alignment polymer, a photo alignment film, and a glue alignment film having a concavo-convex pattern and a plurality of grooves on the surface.

  When the orientation polymer is contained, examples of the orientation polymer include polyamide and gelatin having an amide bond, polyimide having an imide bond and polyamic acid which is a hydrolyzate thereof, polyvinyl alcohol, alkyl-modified polyvinyl alcohol and polyacrylamide Polyoxazoles, polyethylene imines, polystyrenes, polyvinyl pyrrolidones, polyacrylic acids and polyacrylic esters are included. Among them, polyvinyl alcohol is preferred. Two or more orientation polymers may be combined.

  An alignment film containing an alignment polymer is usually coated on a substrate with an alignment polymer composition in which the alignment polymer is dissolved in a solvent, the solvent is removed to form a coated film, or the alignment polymer composition is used. It apply | coats to material, removes a solvent, forms a coating film, and is obtained by rubbing this coating film.

  The concentration of the orientable polymer in the orientable polymer composition may be in the range in which the orientable polymer is completely dissolved in the solvent. The content of the orientable polymer based on the orientable polymer composition is preferably 0.1 to 20% by mass, and more preferably 0.1 to 10% by mass.

  A commercially available alignment film material may be used as it is as an alignment polymer composition. Examples of commercially available alignment film materials include Sun Ever (registered trademark, manufactured by Nissan Chemical Industries, Ltd.), Optomer (registered trademark, manufactured by JSR Corporation), and the like.

  As a method of applying the oriented polymer composition to a substrate, spin coating method, extrusion method, gravure coating method, die coating method, slit coating method, bar coating method, coating method such as applicator method, flexo method And other known methods such as printing methods. Examples of the method for removing the solvent contained in the oriented polymer composition include a natural drying method, a ventilation drying method, a heat drying and a reduced pressure drying method.

  The coating film formed from the oriented polymer composition may be subjected to rubbing treatment. By applying the rubbing process, the coating film can be provided with an orientation regulating force.

  As a method of rubbing treatment, for example, a method in which the coating film is brought into contact with a rotating rubbing roll on which a rubbing cloth is wound is mentioned. When the rubbing process is performed, masking may be performed to form a plurality of regions (patterns) having different orientation directions in the alignment film.

  The photoalignment film is usually coated on a substrate with a composition for forming a photoalignment film containing a polymer or monomer having a photoreactive group and a solvent, and irradiated with polarized light (preferably polarized UV) after removing the solvent. It is obtained by The photo alignment film can arbitrarily control the direction of the alignment regulation force by selecting the polarization direction of the polarized light to be irradiated.

  The photoreactive group refers to a group that generates liquid crystal alignment ability by light irradiation. Specific examples thereof include groups involved in the photoreaction that is the source of the alignment ability such as alignment induction reaction, isomerization reaction, photodimerization reaction, photocrosslinking reaction or photolysis reaction of molecules generated by light irradiation. The photoreactive group is preferably a group having an unsaturated bond, particularly a double bond, a carbon-carbon double bond (CCC bond), a carbon-nitrogen double bond (C = N bond), nitrogen-nitrogen Particularly preferred is a group having at least one member selected from the group consisting of a double bond (N = N bond) and a carbon-oxygen double bond (C = O bond).

  Examples of the photoreactive group having a C = C bond include vinyl group, polyene group, stilbene group, stilbazole group, stilbazolium group, chalcone group and cinnamoyl group. As a photoreactive group which has a C = N bond, the group which has structures, such as aromatic Schiff base and aromatic hydrazone, is mentioned, for example. Examples of the photoreactive group having an N = N bond include an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bisazo group, a formazan group, and a group having an azoxybenzene structure. Examples of the photoreactive group having a C = O bond include benzophenone group, coumarin group, anthraquinone group and maleimide group. These groups may have a substituent such as an alkyl group, an alkoxy group, an aryl group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group or a halogenated alkyl group.

  The group which participates in the photodimerization reaction or the photocrosslinking reaction is preferable in that the orientation is excellent. Among them, a cinnamoyl group is preferable in that a photoreactive group involved in the photodimerization reaction is preferable, a light irradiation amount necessary for alignment is relatively small, and a photoalignment film excellent in thermal stability and temporal stability is easily obtained. And chalcone groups are preferred. As the polymer having a photoreactive group, those having a cinnamoyl group which has a cinnamic acid structure at the end of the polymer side chain are particularly preferable.

  The content of the polymer or monomer having a photoreactive group in the composition for forming a photoalignment film can be controlled by the type of the polymer or monomer and the thickness of the target photoalignment film, and is at least 0.2% by mass or more Preferably, the range of 0.3 to 10% by mass is more preferable. The composition for forming a photoalignment film may contain a polymer material such as polyvinyl alcohol or polyimide or a photosensitizer within a range that the characteristics of the photoalignment film are not significantly impaired.

  As a method of apply | coating the composition for photo-alignment film formation to a base material, the method similar to the method of apply | coating the oriented polymer composition mentioned above to a base material is mentioned. The method for removing the solvent from the applied composition for forming a photo alignment film may be the same method as the method for removing the solvent from the alignment polymer composition.

  In order to irradiate polarized light, the composition for forming a photo alignment film coated on a base material may be irradiated with polarized light directly from the base material side, even if it is irradiated with polarized light directly to the solvent-removed composition. It may be in the form of being transmitted through the material for irradiation. In addition, the polarized light is preferably substantially parallel light. The wavelength of the polarized light to be irradiated is preferably in the wavelength range in which the photoreactive group of the polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet light) having a wavelength of 250 nm to 400 nm is particularly preferable. As a light source for irradiating the polarized light, an ultraviolet light laser such as a xenon lamp, a high pressure mercury lamp, an ultra high pressure mercury lamp, a metal halide lamp, KrF, ArF or the like can be mentioned. Among them, a high pressure mercury lamp, an ultrahigh pressure mercury lamp and a metal halide lamp are preferable because the emission intensity of the ultraviolet light having a wavelength of 313 nm is large. Polarized UV can be irradiated by irradiating the light from the light source through an appropriate polarizing layer. Polarizing layers include polarizing filters, polarizing prisms such as Glan-Thomson, and Glan-Taylor, and polarizing layers of the wire grid type.

  Note that when rubbing or polarized irradiation is performed, masking can be performed to form a plurality of regions (patterns) having different liquid crystal alignment directions.

  The groove alignment layer is a film having a concavo-convex pattern or a plurality of grooves (grooves) on the film surface. When a polymerizable liquid crystal compound is applied to a film having a plurality of linear grooves aligned at equal intervals, liquid crystal molecules are aligned in the direction along the groove.

  As a method of obtaining a globular alignment layer, a method of forming a concavo-convex pattern by performing development and rinsing after exposure through an exposure mask having slits of a pattern shape on the surface of a photosensitive polyimide film, a plate having grooves on the surface A method of forming a layer of UV curable resin before curing on the master disk and transferring the formed resin layer to a substrate and curing, and a film of UV curable resin before curing formed on the substrate, There is a method of pressing a roll-shaped master having a plurality of grooves to form asperities and then curing.

  In the drying step, as a method of removing the solvent from the coating layer obtained in the coating step, for example, natural drying, through-flow drying, heat drying, reduced-pressure drying and a method combining these may be mentioned. Among these, natural drying or heat drying is preferable. The drying temperature is preferably in the range of 0 to 200 ° C, more preferably in the range of 20 to 150 ° C, and still more preferably in the range of 50 to 130 ° C. The drying time is preferably 10 seconds to 20 minutes, more preferably 30 seconds to 10 minutes.

  In the curing step, the polymerization of the polymerizable liquid crystal compound oriented in the drying step can be carried out by a known method for polymerizing a compound having a polymerizable functional group, and for example, photopolymerization by irradiation of active energy rays is adopted can do.

  The active energy ray to be irradiated is appropriately selected according to the type of the polymerizable liquid crystal compound, the type of the photopolymerization initiator when the photopolymerization initiator is contained, and the amount thereof. Specifically, one or more types of light selected from the group consisting of visible light, ultraviolet light, infrared light, X-rays, α-rays, β-rays, and γ-rays can be mentioned. Among them, ultraviolet light is preferable in that it is easy to control the progress of the polymerization reaction, and in that it can be used widely in the field as a photopolymerization device, polymerization is possible so that it can be photopolymerized by ultraviolet light. It is preferable to select the type of the liquid crystal compound.

  As a light source of the active energy ray, for example, low pressure mercury lamp, medium pressure mercury lamp, high pressure mercury lamp, super high pressure mercury lamp, xenon lamp, halogen lamp, carbon arc lamp, tungsten lamp, gallium lamp, excimer laser, wavelength range An LED light source which emits 380 to 440 nm, a chemical lamp, a black light lamp, a microwave excitation mercury lamp, a metal halide lamp and the like can be mentioned.

The ultraviolet irradiation intensity is usually 10 to 3,000 mW / cm ² . The ultraviolet irradiation intensity is preferably an intensity in a wavelength range effective for activating the photopolymerization initiator. The light irradiation time is usually 0.1 seconds to 10 minutes, preferably 0.1 seconds to 5 minutes, more preferably 0.1 seconds to 3 minutes, and still more preferably 0.1 seconds to 1 minute. is there. When it is irradiated with the ultraviolet irradiation intensity once or plural times, the integrated light quantity is 10 to 3,000 mJ / cm ² , preferably 50 to 2,000 mJ / cm ² , more preferably 100 to 1,000 mJ / cm. ²

  In the method of producing a cured liquid crystal layer according to the present invention, the polymerizable liquid crystal composition liquid after filtration may be used as it is in the coating step, but in the polymerizable liquid crystal composition liquid after filtration with a fine filter of 0.4 μm or less Even when stored temporarily or for a long time, generation, growth and precipitation of fine foreign substances derived from the polymerizable liquid crystal compound can be suppressed. For this reason, in a preferred embodiment, the method for producing a cured liquid crystal layer of the present invention includes a step of storing the polymerizable liquid crystal composition liquid after filtration for a certain period (hereinafter, also referred to as "storage step").

  A storage step is usually provided between the filtration step and the coating step. As the storage step, the same method and conditions as those described above as the storage method of the present invention can be adopted.

<Polymerizable liquid crystal composition liquid>
As described above, by filtering the polymerizable liquid crystal composition liquid with a filter with a fine pore diameter of 0.4 μm or less, the polymerizable liquid crystal in the polymerizable liquid crystal composition liquid may be stored temporarily or over a long period of time It is possible to suppress the generation, growth, precipitation and the like of fine foreign matter derived from the compound. By using such a polymerizable liquid crystal composition liquid, it is possible to produce an optical film which is hard to produce alignment defects and which is excellent in optical characteristics. Accordingly, the present invention also relates to a polymerizable liquid crystal composition liquid comprising a solvent and a polymerizable liquid crystal compound dissolved in the solvent, which is filtered by a filter having a pore size of 0.4 μm or less.

  In the polymerizable liquid crystal composition liquid of the present invention, for example, the polymerizable liquid crystal compound and the solvent, and if necessary, the polymerization initiator and other additives are stirred and mixed according to a known method, and the polymerizable liquid crystal compound is After the polymerizable liquid crystal composition liquid is obtained by dissolution, it can be prepared by filtering the obtained polymerizable liquid crystal composition liquid with a filter of 0.4 μm or less according to the filtration method of the present invention described above. . As the polymerizable liquid crystal compound, the solvent, the polymerization initiator and other additives constituting the polymerizable liquid crystal composition liquid of the present invention, the same one as described above in the description of the filtration method of the present invention may be used. it can.

  Hereinafter, the present invention will be described in more detail by way of examples. Unless otherwise indicated, "%" and "parts" in the examples are% by mass and parts by mass.

Example 1
[Preparation of composition for forming photo alignment film]
Composition (1) for forming a photoalignment film by mixing 5 parts of the photoalignment material having the following structure and 95 parts of cyclopentanone (solvent) as components, and stirring the obtained mixture at 80 ° C. for 1 hour I got

[Preparation of Polymerizable Liquid Crystal Composition Liquid]
100 parts of a polymerizable liquid crystal compound A having the following structure, 0.01 part of a polyacrylate compound (leveling agent) (BYK-361N; manufactured by BYK-Chemie), and 7.5 parts of Irgacure OXE-03 (manufactured by BASF Japan Ltd.) And 3 parts of 2-dimethylamino-2-benzyl-1- (4-morpholinophenyl) butan-1-one (IRGACURE 369 (Irg369); manufactured by BASF Japan Ltd.) as a component, and the solid content concentration is N-methyl-2-pyrrolidone (NMP) was added so as to be 13%, and the mixture was stirred at 80 ° C. for 1 hour to obtain a polymerizable liquid crystal composition liquid containing a polymerizable liquid crystal compound. The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition liquid was 2.4 times the saturation concentration of the polymerizable liquid crystal compound A at 25 ° C. of the solvent (NMP). The saturated concentration was measured and calculated according to the following method.

<Method of measuring saturation concentration>
In a sample tube, 1 g of a solvent (NMP) and 1 g of a polymerizable liquid crystal compound were weighed, and stirred in a water bath set at 23 ° C. for 24 hours to prepare a saturated concentration solution. The supernatant was sampled and dissolved in tetrahydrofuran together with 10 mL of the standard solution to prepare a measurement solution. This measurement solution is injected into a liquid chromatograph (manufactured by Shimadzu Corporation; LC-10AT), and the saturation of the polymerizable liquid crystal compound to a predetermined solvent at 23 ° C. based on the ratio of each peak area value and a calibration curve separately prepared. The concentration was calculated. As a standard solution, one prepared from 7.5 g of hexylbenzene and 1000 ml of tetrahydrofuran was used.
Liquid chromatograph (LC) measurement was performed under the following conditions.
Measurement condition:
Column (L-Column ODS, inner diameter 3.0 mm, length 150 mm, particle diameter 3 μm)
Temperature; 40 ° C
Mobile phase A; 0.1% (v / v) -TFA / water Mobile phase B; 0.1% (v / v) -TFA / acetonitrile gradient; 0 min 70% -B
30min 100%-B
60 min 100%-B
60.01 min 70%-B
75 min 70%-B
Flow rate: 0.5 mL / min
Injection volume: 5 μL
Detection wavelength: 254 nm

  The obtained polymerizable liquid crystal composition liquid was filtered with a 0.2 μm membrane filter (material: PTFE, manufactured by Advantec Co., Ltd.). The polymerizable liquid crystal composition liquid after filtration was used as a polymerizable liquid crystal composition liquid (1). In addition, the polymeric liquid crystal compound A was synthesize | combined by the method of Unexamined-Japanese-Patent No. 2010-31223.

Polymerizable liquid crystal compound A:

[Temporal stability evaluation of polymerizable liquid crystal composition liquid]
The polymerizable liquid crystal composition liquid after filtration was allowed to stand at room temperature (25 ° C.) in the dark for 1 month. The cycloolefin polymer (COP) film as a substrate was corona treated using a corona processor. Next, the composition (1) for forming a photoalignment film described above is applied to the surface of a corona-treated COP film (base material) using a bar coater, dried at 80 ° C. for 1 minute, and then polarized UV irradiation Polarized UV exposure was carried out with an integrated light quantity of 100 mJ / cm ² using an apparatus to obtain an alignment film.
Subsequently, a polymerizable liquid crystal composition liquid (1) stored for one month after filtration is applied on the alignment film using a bar coater, dried at 120 ° C. for one minute, and then using a high pressure mercury lamp. The liquid crystal cured layer was formed by irradiating ultraviolet rays from the coated surface side of the polymerizable liquid crystal composition liquid (1) (in nitrogen atmosphere, wavelength: 313 nm, integrated light quantity at wavelength 313 nm is 500 mJ / cm ² ). The obtained liquid crystal cured layer was observed at a magnification of 400 using a polarization microscope (BX51, manufactured by Olympus Corporation). Those with no orientation defect on the surface were marked with “o”, those with slight orientation defects with “Δ”, and those with orientation defects with “x”. The results are shown in Table 1.

Example 2
A polymerizable liquid crystal composition liquid (2) was prepared in the same manner as in Example 1 except that the pore size of the membrane filter was changed to 0.05 μm, and after storage under the same conditions, the stability over time was evaluated. The results are shown in Table 1.

[Example 3]
A polymerizable liquid crystal composition liquid (3) is prepared in the same manner as in Example 1 except that the polymerizable liquid crystal compound A is changed to a polymerizable liquid crystal compound B having the following structure, and stored under the same conditions A stability assessment was made. The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition liquid was 0.52 times the saturation concentration of the polymerizable liquid crystal compound B at 25 ° C. of the solvent (NMP). The results are shown in Table 1. In addition, the polymerizable liquid crystal compound B was synthesize | combined by the method of Unexamined-Japanese-Patent No. 2010-31223.

Polymerizable liquid crystal compound B:

Comparative Example 1
A polymerizable liquid crystal composition liquid (4) was prepared in the same manner as in Example 1 except that the pore size of the membrane filter was changed to 0.45 μm, and after storage under the same conditions, the stability over time was evaluated. The results are shown in Table 1.

Comparative Example 2
A polymerizable liquid crystal composition liquid (5) was prepared in the same manner as in Example 1 except that filtration through a membrane filter was not performed, and after storage under the same conditions, the stability over time was evaluated. The results are shown in Table 1.

[Reference Example 1]
A polymerizable liquid crystal composition liquid (6) was prepared in the same manner as in Comparative Example 2 except that the polymerizable liquid crystal compound A was changed to LC242 (a liquid crystal compound commercially available from BASF), and stored under the same conditions. After that, temporal stability evaluation was performed. The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition liquid was 0.25 times the saturation concentration of LC 242 at 25 ° C. of the solvent (NMP). The results are shown in Table 1.

Claims (21)

  A method for filtering a polymerizable liquid crystal composition liquid, comprising filtering a polymerizable liquid crystal composition liquid containing a solvent and a polymerizable liquid crystal compound dissolved in the solvent with a filter having a pore diameter of 0.4 μm or less.   The filtration method according to claim 1, wherein the polymerizable liquid crystal composition liquid contains a polymerization initiator. The polymerizable liquid crystal compound has the following (1) to (4):
(1) a compound capable of forming a nematic phase;
(2) having π electrons on the major axis direction (a) of the polymerizable liquid crystal compound;
(3) has π electrons in the direction (b) intersecting with the long axis direction (a); and (4) the sum of π electrons existing in the long axis direction (a) is N (πa), long axis The total of the molecular weights present in the direction is N (Aa): π electron density in the major axis direction (a) of the polymerizable liquid crystal compound defined by the following formula (i):
D (πa) = N (πa) / N (Aa) (i)
And the total of the π electrons present in the cross direction (b) as N (πb), and the sum of the molecular weights present in the cross direction (b) as N (Ab). Π electron density in the cross direction (b) of
D (πb) = N (πb) / N (Ab) (ii)
And
0 ≦ [D (πa) / D (πb)] ≦ 1
In relation to
The filtration method of Claim 1 or 2 which is a compound which satisfy | fills all.   The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition liquid is at least 0.5 times the saturation concentration of the polymerizable liquid crystal compound at 25 ° C. of the solvent for dissolving the polymerizable liquid crystal compound. The filtration method in any one of -3.   A method for storing a polymerizable liquid crystal composition liquid, which comprises storing a polymerizable liquid crystal composition liquid containing a solvent and a polymerizable liquid crystal compound dissolved in the solvent with a filter having a pore diameter of 0.4 μm or less, and storing it.   The storage method according to claim 5, wherein the polymerizable liquid crystal composition liquid contains a polymerization initiator.   The storage method according to claim 5 or 6, wherein the polymerizable liquid crystal composition liquid after filtration is stored at a temperature of 20 ° C or more.   The storage method according to any one of claims 5 to 7, wherein the polymerizable liquid crystal composition liquid after filtration is stored in the dark. The polymerizable liquid crystal compound has the following (1) to (4):
(1) a compound capable of forming a nematic phase;
(2) having π electrons on the major axis direction (a) of the polymerizable liquid crystal compound;
(3) has π electrons in the direction (b) intersecting with the long axis direction (a); and (4) the sum of π electrons existing in the long axis direction (a) is N (πa), long axis The total of the molecular weights present in the direction is N (Aa): π electron density in the major axis direction (a) of the polymerizable liquid crystal compound defined by the following formula (i):
D (πa) = N (πa) / N (Aa) (i)
And the total of the π electrons present in the cross direction (b) as N (πb), and the sum of the molecular weights present in the cross direction (b) as N (Ab). Π electron density in the cross direction (b) of
D (πb) = N (πb) / N (Ab) (ii)
And
0 ≦ [D (πa) / D (πb)] ≦ 1
In relation to
The storage method according to any one of claims 5 to 8, which is a compound satisfying all the above.   The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition liquid is at least 0.5 times the saturation concentration of the polymerizable liquid crystal compound at 25 ° C. of the solvent dissolving the polymerizable liquid crystal compound. The storage method according to any one of to 9. Filtering a polymerizable liquid crystal composition liquid containing a solvent and a polymerizable liquid crystal compound dissolved in the solvent with a filter having a pore size of 0.4 μm or less;
Applying the polymerizable liquid crystal composition liquid after filtration onto a substrate to obtain a coated layer;
And removing the solvent from the coating layer to orient the polymerizable liquid crystal compound, and curing the polymerizable liquid crystal layer by polymerizing the aligned polymerizable liquid crystal compound to obtain a liquid crystal cured layer. , A method of manufacturing a liquid crystal hardened layer.   The method according to claim 11, wherein the polymerizable liquid crystal composition liquid contains a polymerization initiator.   The manufacturing method according to claim 11 or 12, which comprises storing the polymerizable liquid crystal composition liquid after filtration at a temperature of 20 ° C or more.   The production method according to any one of claims 11 to 13, comprising storing the liquid crystal composition liquid after filtration in a dark place. The polymerizable liquid crystal compound has the following (1) to (4):
(1) a compound capable of forming a nematic phase;
(2) having π electrons on the major axis direction (a) of the polymerizable liquid crystal compound;
(3) has π electrons in the direction (b) intersecting with the long axis direction (a); and (4) the sum of π electrons existing in the long axis direction (a) is N (πa), long axis The total of the molecular weights present in the direction is N (Aa): π electron density in the major axis direction (a) of the polymerizable liquid crystal compound defined by the following formula (i):
D (πa) = N (πa) / N (Aa) (i)
And the total of the π electrons present in the cross direction (b) as N (πb), and the sum of the molecular weights present in the cross direction (b) as N (Ab). Π electron density in the cross direction (b) of
D (πb) = N (πb) / N (Ab) (ii)
And
0 ≦ [D (πa) / D (πb)] ≦ 1
In relation to
The production method according to any one of claims 11 to 14, which is a compound satisfying all the above.   The manufacturing method according to any one of claims 11 to 15, wherein an alignment film is formed on the base material.   12. The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition liquid is at least 0.5 times the saturation concentration of the polymerizable liquid crystal compound at 25 ° C. of the solvent dissolving the polymerizable liquid crystal compound. The manufacturing method in any one of -16.   A polymerizable liquid crystal composition liquid comprising a solvent and a polymerizable liquid crystal compound dissolved in the solvent, and being filtered by a filter having a pore size of 0.4 μm or less.   The polymerizable liquid crystal composition liquid according to claim 18, containing a polymerization initiator. The polymerizable liquid crystal compound has the following (1) to (4):
(1) a compound capable of forming a nematic phase;
(2) having π electrons on the major axis direction (a) of the polymerizable liquid crystal compound;
(3) has π electrons in the direction (b) intersecting with the long axis direction (a); and (4) the sum of π electrons existing in the long axis direction (a) is N (πa), long axis The total of the molecular weights present in the direction is N (Aa): π electron density in the major axis direction (a) of the polymerizable liquid crystal compound defined by the following formula (i):
D (πa) = N (πa) / N (Aa) (i)
And the total of the π electrons present in the cross direction (b) as N (πb), and the sum of the molecular weights present in the cross direction (b) as N (Ab). Π electron density in the cross direction (b) of
D (πb) = N (πb) / N (Ab) (ii)
And
0 ≦ [D (πa) / D (πb)] ≦ 1
In relation to
The polymerizable liquid crystal composition liquid according to claim 18 or 19, which is a compound satisfying all the above.   The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition liquid is at least 0.5 times the saturation concentration of the polymerizable liquid crystal compound at 25 ° C. of the solvent dissolving the polymerizable liquid crystal compound. Polymeric liquid crystal composition liquid in any one of -20.