JP2014189630A - Film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film having aeolotropy in adhesion force and having unique adhesion characteristic.SOLUTION: Provided is the film including a liquid crystal film, especially a liquid crystal film in which one orientation state of nematic orientation or nematic hybrid orientation is stabilized. The film can be produced by expanding a liquid crystalline composition on an orientation base plate and orienting the liquid crystalline composition, and then stabilizing the orientation state by performing light radiation and/or heating processing.

Description

  The present invention relates to a film having specific adhesive properties having anisotropy in adhesive force.

With an adhesive tape, the stronger the adhesive strength, the lower the peelability, which may seriously damage the adherend during peeling. Today, the performance required for pressure-sensitive adhesive tapes varies depending on the application, but depending on the application, a strong adhesive force and excellent peelability may be required.
Patent Document 1 discloses a pressure-sensitive adhesive product (pressure-sensitive adhesive tape) having a pressure-sensitive adhesive layer containing a partially oriented and partially crystallized elastomer. This pressure-sensitive adhesive tape exhibits different peelability depending on the peeling direction. Such a pressure-sensitive adhesive tape exhibiting anisotropic releasability can achieve both strong adhesiveness in a specific direction and excellent releasability in directions other than the specific direction. Thereby, while being able to implement | achieve strong adhesion | attachment with a to-be-adhered body, it can peel easily by peeling from the direction excellent in peelability after use.
However, this pressure-sensitive adhesive tape requires the blending of specific elastomers, and it is not easy to partially orient and partially crystallize these elastomers.
Therefore, there has been a demand for an adhesive tape exhibiting anisotropic peelability that can be produced by a simpler method.

JP 2002-161256 A

  The present invention provides a pressure-sensitive adhesive tape having a unique pressure-sensitive adhesive characteristic that has not been achieved so far, depending on the peeling direction.

As a result of intensive studies to solve the above problems, the present inventors have completed the present invention.
That is, this invention relates to the film characterized by including a liquid crystal film.
In addition, the present invention relates to the film described above, wherein the liquid crystal film has a fixed alignment state of either nematic alignment or nematic hybrid alignment.

  The film of the present invention has unique adhesive properties that have never been seen, and the peel force varies depending on the peel direction.

¹ shows the ¹ H-NMR spectrum of acrylic compound 3 obtained in Reference Example 3. The horizontal axis represents the chemical shift based on tetramethylsilane (TMS) (hereinafter the same). The ¹ H-NMR spectrum of acrylic compound 4 obtained in Reference Example 4 is shown. The ¹ H-NMR spectrum of acrylic compound 5 obtained in Reference Example 5 is shown. The ¹ H-NMR spectrum of the dioxetane compound 14 obtained in Reference Example 14 is shown. ¹ shows the ¹ H-NMR spectrum of dioxetane compound 15 obtained in Reference Example 15.

Hereinafter, the present invention will be described in detail.
The liquid crystal film according to the present invention is obtained by aligning a liquid crystalline composition and fixing the liquid crystal alignment state.
As the liquid crystalline composition referred to in the present invention, for example, a composition comprising a (meth) acrylic compound having an oxetane group and a liquid crystalline compound having an oxetane group can be used.
The (meth) acrylic compound having an oxetane group here is a compound represented by any one of the following general formulas (1), (2) or (3).

In Formula (1), Formula (2), and Formula (3), R ¹ each independently represents hydrogen or a methyl group, R ² each independently represents hydrogen, a methyl group, or an ethyl group, and L ¹ independently represents a single bond, —O—, —O—CO— or —CO—O—, m is each independently an integer of 1 to 10, and n is each independently , An integer from 0 to 10.

  Although various compounds corresponding to these formulas (1), (2) and (3) can be mentioned, it is not always necessary to have liquid crystallinity. More specifically, the following compounds can be mentioned as preferred examples.

The method for synthesizing these (meth) acrylic compounds having an oxetane group is not particularly limited, and can be synthesized by applying a method used in ordinary organic chemistry synthesis methods.
For example, by connecting a site with an oxetane group and a site with a (meth) acrylic group by means such as Williamson's ether synthesis or ester synthesis using a condensing agent, the oxetane group and the (meth) acrylic group are completely A (meth) acrylic compound having an oxetane group having two different reactive groups can be synthesized.
In the synthesis, since the oxetane group has cationic polymerizability, it is necessary to select reaction conditions in consideration of causing side reactions such as polymerization and ring opening under strong acidic conditions. These reaction conditions will be described in detail in the synthesis of the compound represented by the general formula (5) described later.

The liquid crystalline compound having an oxetane group of the present invention may be a main chain type liquid crystalline compound having an oxetane group or a side chain type polymeric liquid crystalline compound having an oxetane group.
Examples of the main chain polymer liquid crystalline compound having an oxetane group include polyesters, polyesteramides, polyamides, and polyamideimides having an oxetane group and exhibiting liquid crystallinity. Polyester is preferred.

  The main chain type liquid crystalline polyester having an oxetane group used in the present invention is an aromatic diol unit (hereinafter referred to as a structural unit (A)), an aromatic dicarboxylic acid unit (hereinafter referred to as a structural unit (B)), and It includes at least two kinds of aromatic hydroxycarboxylic acid units (hereinafter referred to as structural units (C)) as essential units, and includes structural units having an oxetane group that is a cationically polymerizable group at least at one end of the main chain. Main chain type liquid crystalline polyester. Hereinafter, the structural units (A), (B), and (C) will be sequentially described.

  The compound for introducing the structural unit (A) is preferably a compound represented by the following general formula, specifically, catechol, resorcin, hydroquinone or the like or a substituted product thereof, 4,4′-biphenol, 2, 2 ', 6,6'-tetramethyl-4,4'-biphenol, 2,6-naphthalenediol and the like can be mentioned, and in particular, catechol, resorcin, hydroquinone, and the like or substituted products thereof are preferable.

However, -X in the _{formula, -H, -CH 3, -C 2} H 5, -CH 2 CH 2 CH 3, -CH (CH 3) 2, -CH 2 CH 2 CH 2 CH 3, -CH _{2 CH (CH 3) CH 3} , -CH (CH 3) CH 2 CH 3, -C (CH 3) 3, -OCH 3, -OC 2 H 5, -OC 6 H 5, -OCH 2 C 6 H ₅ , —F, —Cl, —Br, —NO ₂ , or —CN, particularly preferably a compound represented by the following formula.

  The compound for introducing the structural unit (B) is preferably a compound represented by the following general formula, specifically, terephthalic acid, isophthalic acid, phthalic acid or the like, or a substituted product thereof, 4,4′-stilbene Examples thereof include dicarboxylic acid or a substituted product thereof, 2,6-naphthalenedicarboxylic acid, 4,4′-biphenyldicarboxylic acid and the like, and terephthalic acid, isophthalic acid, phthalic acid and the like, or a substituted product thereof are particularly preferable.

However, -X in the _{formula, -H, -CH 3, -C 2} H 5, -CH 2 CH 2 CH 3, -CH (CH 3) 2, -CH 2 CH 2 CH 2 CH 3, -CH _{2 CH (CH 3) CH 3} , -CH (CH 3) CH 2 CH 3, -C (CH 3) 3, -OCH 3, -OC 2 H 5, -OC 6 H 5, -OCH 2 C 6 H ₅ , -F, -Cl, -Br, -NO ₂ , or -CN.

  The compound for introducing the structural unit (C) is preferably a compound represented by the following general formula, specifically, hydroxybenzoic acid or a substituted product thereof, 4′-hydroxy-4-biphenylcarboxylic acid or a substituted product thereof. , 4′-hydroxy-4-stilbene carboxylic acid or a substituted product thereof, 6-hydroxy-2-naphthoic acid, 4-hydroxycinnamic acid and the like. In particular, hydroxybenzoic acid and a substituted product thereof, 4′-hydroxy -4-Biphenylcarboxylic acid or a substituted product thereof, 4′-hydroxy-4-stilbenecarboxylic acid or a substituted product thereof is preferred.

However, -X in the _formula, -X 1, -X ₂ are each _{individually, -H, -CH 3, -C 2} H 5, -CH 2 CH 2 CH 3, -CH (CH 3) 2, _{-CH 2 CH 2 CH 2 CH 3} , -CH 2 CH (CH 3) CH 3, -CH (CH 3) CH 2 CH 3, -C (CH 3) 3, -OCH 3, -OC 2 H 5, -OC ₆ H _5, represents _{-OCH 2 C 6 H 5, -F} , -Cl, -Br, any group of -NO _2, or -CN,.

  The main-chain liquid crystalline polyester has, as a structural unit, at least two of (A) an aromatic diol unit, (B) an aromatic dicarboxylic acid unit, and (C) an aromatic hydroxycarboxylic acid unit, and Any structural unit having an oxetane group at least one end of the main chain (hereinafter referred to as structural unit (D)) as an essential structural unit and exhibiting a thermotropic liquid crystallinity may be used. There is no particular limitation as long as these conditions are satisfied.

  The proportion of the structural units (A), (B) and (C) constituting the main chain type liquid crystalline polyester in the total structural units is such that the structural units (A), (B) and (C) are diols or dicarboxylic acids or When expressed as a ratio of the sum of the weights of all the monomers as the hydroxycarboxylic acid, it is usually 20 to 99%, preferably 30 to 95%, particularly preferably 40 to 90%. If the amount is less than 20%, the temperature range for exhibiting liquid crystallinity may be extremely narrow, and if it exceeds 99%, a cationically polymerizable group essential for the main-chain liquid crystalline polyester of the present invention may be added. There are relatively few units, and there is a possibility that the orientation retention ability and the mechanical strength cannot be improved, which is not preferable in either case.

  Next, the structural unit (D) having an oxetane group will be described. Examples of the compound for introducing the structural unit (D) include compounds in which an oxetane group is bonded to an aromatic compound having a phenolic hydroxyl group or a carboxyl group as shown in the following general formula. An appropriate spacer portion may be provided between the aromatic ring and the oxetane group. Moreover, you may use together cationically polymerizable groups other than an oxetane group, for example, an epoxy group, a vinyloxy group, etc. in the range which does not impair the effect of this invention.

However, _-X in the formula, -X _1, -X 2, -Y, -Z represents any of the following groups each independently for each structural unit.
However, _-X in the formula, -X _1, -X 2, -Y, -Z represents any of the following groups each independently for each structural unit.
_{(1) -X, -X 1,} -X 2: -H, -CH 3, -C 2 H 5, -CH 2 CH 2 CH 3, -CH (CH 3) 2, -CH 2 CH 2 CH 2 _{CH 3, -CH 2 CH (CH} 3) CH 3, -CH (CH 3) CH 2 CH 3, -C (CH 3) 3, -OCH 3, -OC 2 H 5, -OC 6 H 5, - _{OCH 2 C 6 H 5, -F} , -Cl, -Br, -NO 2 or -CN,
(2) -Y: single _{bond, - (CH 2) n -} , - O -, - O- (CH 2) n -, - (CH 2) n -O -, - O- (CH 2) n - O -, - O-CO - , - CO-O -, - O-CO- (CH 2) n -, - CO-O- (CH 2) n -, - (CH 2) n -O-CO- , — (CH ₂ ) _n —CO—O—, —O— (CH ₂ ) _n —O—CO—, —O— (CH ₂ ) _n —CO—O—, —O—CO— (CH ₂ ) _{n -O -, - CO-O-} (CH 2) n -O -, - O-CO- (CH 2) n -O-CO -, - O-CO- (CH 2) n -CO-O- _{, -CO-O- (CH 2)} n -O-CO- or _{-CO-O- (CH 2) n} -CO-O-, ( where, n is an integer of 1-12.)
(3) Z:

  In the structural unit (D), the bonding position of a substituent containing an oxetane group and a phenolic hydroxyl group or a carboxylic acid group has a positional relationship of 1,4-when the skeleton to which these groups are bonded is a benzene ring, In the case of a naphthalene ring, a 2,6-positional relationship is preferable, and in the case of a biphenyl skeleton or a stilbene skeleton, a 4,4′-positional relationship is preferable from the viewpoint of liquid crystallinity. More specifically, 4-vinyloxybenzoic acid, 4-vinyloxyphenol, 4-vinyloxyethoxybenzoic acid, 4-vinyloxyethoxyphenol, 4-glycidyloxybenzoic acid, 4-glycidyloxyphenol, 4- (oxetanyl) Methoxy) benzoic acid, 4- (oxetanylmethoxy) phenol, 4′-vinyloxy-4-biphenylcarboxylic acid, 4′-vinyloxy-4-hydroxybiphenyl, 4′-vinyloxyethoxy-4-biphenylcarboxylic acid, 4′- Vinyloxyethoxy-4-hydroxybiphenyl, 4′-glycidyloxy-4-biphenylcarboxylic acid, 4′-glycidyloxy-4-hydroxybiphenyl, 4′-oxetanylmethoxy-4-biphenylcarboxylic acid, 4′-oxetanylmethoxy- 4-hi Droxybiphenyl, 6-vinyloxy-2-naphthalenecarboxylic acid, 6-vinyloxy-2-hydroxynaphthalene, 6-vinyloxyethoxy-2-naphthalenecarboxylic acid, 6-vinyloxyethoxy-2-hydroxynaphthalene, 6-glycidyloxy 2-naphthalenecarboxylic acid, 6-glycidyloxy-2-hydroxynaphthalene, 6-oxetanylmethoxy-2-naphthalenecarboxylic acid, 6-oxetanylmethoxy-2-hydroxynaphthalene, 4-vinyloxycinnamic acid, 4-vinyloxyethoxy cinnamic Acid, 4-glycidyloxycinnamic acid, 4-oxetanylmethoxycinnamic acid, 4'-vinyloxy-4-stilbenecarboxylic acid, 4'-vinyloxy-3'-methoxy-4-stilbenecarboxylic acid, 4'-vinyloxy-4- Hydro Cystilbene, 4′-vinyloxyethoxy-4-stilbenecarboxylic acid, 4′-vinyloxyethoxy-3′-methoxy-4-stilbenecarboxylic acid, 4′-vinyloxyethoxy-4-hydroxystilbene, 4′-glycidyloxy -4-stilbenecarboxylic acid, 4'-glycidyloxy-3'-methoxy-4-stilbenecarboxylic acid, 4'-glycidyloxy-4-hydroxystilbene, 4'-oxetanylmethoxy-4-stilbenecarboxylic acid, 4'- Preference is given to oxetanylmethoxy-3′-methoxy-4-stilbene carboxylic acid, 4′-oxetanylmethoxy-4-hydroxystilbene and the like.

  The ratio of the structural unit (D) having an oxetane group to the total structural units constituting the main-chain liquid crystalline polyester is similarly expressed by the weight ratio in the composition charged with the structural unit (D) as carboxylic acid or phenol. The range is usually 1 to 60%, preferably 5 to 50%. If it is less than 1%, there is a possibility that the improvement of the orientation holding ability and the mechanical strength may not be obtained. If it exceeds 60%, the crystallinity is increased and the liquid crystal temperature range is narrowed. Is also not preferable.

  Each structural unit of (A) to (D) has one or two carboxyl groups or phenolic hydroxyl groups, but the carboxyl groups and phenolic hydroxyl groups of (A) to (D) are charged. It is desirable that the total number of equivalents of the respective functional groups be roughly aligned at this stage. That is, when the structural unit (D) is a unit having a free carboxyl group, (number of moles of (A) × 2) = (number of moles of (B) × 2) + number of moles of (D) ), When the structural unit (D) is a unit having a free phenolic hydroxyl group, (number of moles of (A) × 2) + (number of moles of (D)) = (number of moles of (B) × 2) It is desirable to generally satisfy the relationship In the case of a charged composition greatly deviating from this relational expression, carboxylic acid or phenol other than the unit involved in cationic polymerization, or a derivative thereof becomes the molecular end, and not only sufficient cationic polymerizability cannot be obtained, The presence of these acidic residues is not preferable because a polymerization reaction or a decomposition reaction may occur at a stage other than the desired stage in the process.

The main chain type liquid crystalline polyester can contain structural units other than (A), (B), (C) and (D). Other structural units that can be contained are not particularly limited, and compounds (monomers) known in the art can be used. For example, naphthalene dicarboxylic acid, biphenyl dicarboxylic acid, aliphatic dicarboxylic acid, compounds in which halogen groups or alkyl groups are introduced into these compounds, biphenols, naphthalenediol, aliphatic diols, and compounds in which halogen groups or alkyl groups are introduced into these compounds Etc. Further, when an optically active compound is used as a raw material for the units constituting the main chain type liquid crystalline polyester, it is possible to impart a chiral phase to the main chain type liquid crystalline polyester. The optically active compound is not particularly limited. For example, an optically active aliphatic alcohol (C _n H _{2n + 1} OH, where n represents an integer of 4 to 14), an optically active aliphatic group is bonded. alkoxy benzoate _{(C n H 2n + 1 O} -Ph-COOH, where n is 4 to 14 integer, Ph represents a phenylene group.), menthol, camphor acid, naproxen derivatives, binaphthol, 1,2-propanediol, 1 , 3-butanediol, 2-methylbutanediol, 2-chlorobutanediol, tartaric acid, methylsuccinic acid, 3-methyladipic acid, isosorbide, isomannide and the like.

The molecular weight of the main-chain liquid crystalline polyester is preferably 0.03 to 0.50 dl / g in logarithmic viscosity η measured at 30 ° C. in a phenol / tetrachloroethane mixed solvent (mass ratio 60/40). Is 0.05 to 0.15 dl / g. When η is smaller than 0.03 dl / g, the solution viscosity of the main-chain liquid crystalline polyester is low, and there is a possibility that a uniform coating film cannot be obtained when forming into a film. On the other hand, if it is larger than 0.50 dl / g, the alignment treatment temperature required for aligning the liquid crystal becomes high, and there is a risk that alignment and polymerization are likely to occur at the same time and the alignment is lowered.
The molecular weight control of the main-chain liquid crystalline polyester is determined solely by the charged composition. Specifically, the main chain obtained by the relative content in the total charge composition of the monofunctional monomer that reacts in such a manner that both ends of the molecule are sealed, that is, the compound for introducing the structural unit (D) described above. The average degree of polymerization of the liquid crystal polyester (average number of bonds of the structural units (A) to (D)) is determined. Therefore, in order to obtain a main-chain liquid crystalline polyester having a desired logarithmic viscosity, it is necessary to adjust the charged composition according to the type of charged monomer.

As a method for synthesizing the main-chain liquid crystalline polyester, a method used when synthesizing a normal polyester can be adopted, and the method is not particularly limited. For example, a method in which a carboxylic acid unit is activated into an acid chloride or a sulfonic acid anhydride and reacted with a phenol unit in the presence of a base (acid chloride method), or a carboxylic acid unit and a phenol unit are converted into DCC (dicyclohexylcarbodiimide). A method of directly condensing using a condensing agent such as the above, a method of acetylating a phenol unit, and a method of deaceticating polymerization of this with a carboxylic acid unit under melting conditions can be used. However, when using deacetic acid polymerization under melting conditions, the monomer unit having an oxetane group may undergo polymerization or decomposition under the reaction conditions, so it may be necessary to strictly control the reaction conditions. In many cases, it may be desirable to use a method such as using an appropriate protecting group or reacting a compound having another functional group once and then introducing an oxetane group later. The crude main chain type liquid crystalline polyester obtained by the polymerization reaction may be purified by a method such as recrystallization or reprecipitation.
The main-chain liquid crystalline polyester thus obtained is identified by the analytical means such as NMR (nuclear magnetic resonance method) at what ratio each monomer is present in the main-chain liquid crystalline polyester. can do. In particular, the average number of bonds of the main-chain liquid crystalline polyester can be calculated from the amount ratio of the oxetane group.

Further, a side chain type polymer liquid crystalline compound may be used instead of the main chain type polymer liquid crystalline compound, and the side chain type polymer liquid crystalline compound may be a liquid crystal represented by the following formula (4). Can be mentioned.

In the formula (4), each R ³ independently represents hydrogen or a methyl group, and each R ⁴ independently represents hydrogen, methyl group, ethyl group, butyl group, hexyl group, octyl group, nonyl group, decyl group. Group, dodecyl group, methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group, dodecyloxy group, cyano group, bromine, chlorine, fluorine or carboxyl R ⁵ represents a hydrogen group, a methyl group or an ethyl group, R ⁶ represents a hydrocarbon group having 1 to 24 carbon atoms, and L ² each independently represents a single bond, -O-, -O-CO-, -CO-O-, -CH = CH- or -C≡C-, p represents an integer of 1 to 10, and q represents 0 to 10 Represents an integer, a, b, c, d, e and f represent the mole ratio of each unit in the polymer (a + b + c + d + e + f = 1.0, however, not the c + d + e = 0.).

The molar ratio of each component constituting the side chain type polymer liquid crystalline compound represented by the formula (4) is not a + b + c + d + e + f = 1.0 and c + d + e = 0, and needs to exhibit liquid crystallinity. The molar ratio of each component may be arbitrary as long as this requirement is satisfied, but is preferably as follows.
a: Preferably 0 to 0.80, more preferably 0.05 to 0.50
b: preferably 0 to 0.90, more preferably 0.10 to 0.70
c: preferably 0 to 0.50, more preferably 0.10 to 0.30
d: preferably 0 to 0.50, more preferably 0.10 to 0.30
e: preferably 0 to 0.50, more preferably 0.10 to 0.30
f: Preferably 0 to 0.30, more preferably 0.01 to 0.10

R ⁴ is preferably hydrogen, methyl group, butyl group, methoxy group, cyano group, bromine, or fluorine, particularly preferably hydrogen, methoxy group, or cyano group, and L ² is preferably A single bond, —O—, —O—CO— or —CO—O—. R ⁶ is preferably a hydrocarbon group having 2, 3, 4, ⁶ , 8 or 18 carbon atoms.

  The side chain type polymer liquid crystalline compound has a birefringence that varies depending on the ratio of each component a to f and the orientation form, but the birefringence when nematic orientation is 0.001 to 0.300. It is preferable that it is 0.05 to 0.25.

  The side chain type polymer liquid crystalline compound can be easily synthesized by copolymerizing the (meth) acrylic group of each (meth) acrylic compound corresponding to each component by radical polymerization or anionic polymerization. Polymerization conditions are not particularly limited, and normal conditions can be employed.

  As an example of radical polymerization, a (meth) acrylic compound corresponding to each component is dissolved in a solvent such as dimethylformamide (DMF) or diethylene glycol dimethyl ether, and 2,2′-azobisisobutyronitrile (AIBN) or benzoyl peroxide is dissolved. The method of making it react for several hours at 60-120 degreeC by using (BPO) etc. as an initiator is mentioned. Moreover, in order to make the liquid crystal phase appear stably, copper bromide (I) / 2,2′-bipyridyl series, 2,2,6,6-tetramethylpiperidinooxy free radical (TEMPO) series, etc. are used. A method of controlling the molecular weight distribution by conducting living radical polymerization as an initiator is also effective. These radical polymerizations need to be performed under deoxygenated conditions.

  An example of anionic polymerization is a method in which a (meth) acrylic compound corresponding to each component is dissolved in a solvent such as tetrahydrofuran (THF) and reacted with a strong base such as an organic lithium compound, an organic sodium compound, or a Grignard reagent as an initiator. Can be mentioned. In addition, the molecular weight distribution can be controlled by optimizing the initiator and the reaction temperature for living anionic polymerization. These anionic polymerizations need to be performed under dehydration and deoxygenation conditions.

  The side chain polymer liquid crystalline compound preferably has a weight average molecular weight of 1,000 to 200,000, particularly preferably 3,000 to 50,000.

  The liquid crystalline composition of the present invention preferably further contains a dioxetane compound represented by the following general formula (5). The dioxetane compound represented by the general formula (5) can be used regardless of the presence or absence of liquid crystallinity, but preferably exhibits liquid crystallinity.

In Formula (5), each R ⁷ independently represents hydrogen, a methyl group or an ethyl group, and each L ³ independently represents — (CH ₂ ) _n — (n is an integer of 1 to 12). , X ¹ each independently represents a single bond, —O—, —O—CO—, or —CO—O—, and M ¹ is any one represented by formula (6) or formula (7) Yes, P ¹ in Formula (6) and Formula (7) each independently represents a group selected from Formula (8), P ² represents a group selected from Formula (9), and L ⁴ represents Each independently represents a single bond, —CH═CH—, —C≡C—, —O—, —O—CO— or —CO—O—.
^{-P 1 -L 4 -P 2 -L 4} -P 1 - (6)
^{-P 1 -L 4 -P 1 - (} 7)

  In formula (8) and formula (9), Et, iPr, nBu and tBu represent an ethyl group, an isopropyl group, a normal-butyl group and a tertiary-butyl group, respectively.

More specifically, the linking groups connecting the left and right oxetane groups as viewed from the M ¹ group may be different (asymmetric type) or the same (symmetric type), and the liquid crystallinity may vary depending on the structure, but not shown. Good.

The compound represented by the general formula (5), many of the compounds is illustrated by the combination of L ^3, X ¹ and M ^1, preferably, may be mentioned the following compounds.

These compounds can be synthesized according to a usual synthesis method in organic chemistry, and the synthesis method is not particularly limited.
In the synthesis, since the oxetane group has cationic polymerizability, it is necessary to select reaction conditions in consideration of causing side reactions such as polymerization and ring opening under strong acidic conditions. Oxetane groups are less likely to cause side reactions than oxirane groups, which are similar cationically polymerizable functional groups. Further, various compounds such as similar alcohols, phenols, and carboxylic acids may be reacted successively, and utilization of protecting groups may be considered as appropriate.

As a more specific synthesis method, for example, hydroxybenzoic acid is used as a starting compound, an oxetane group is bound by Williamson's ether synthesis method, etc., and then the resulting compound and a diol suitable for the present invention are converted to acid chloride. Or by condensing using a carbodiimide condensation method or the like, or conversely protecting the hydroxyl group of hydroxybenzoic acid with an appropriate protecting group in advance, condensing with a diol suitable for the present invention, removing the protecting group, and And a method of reacting a hydroxyl group with a oxetane compound such as a haloalkyloxetane.
For the reaction between the oxetane compound and the hydroxyl group, a reaction condition suitable for the form and reactivity of the compound used may be selected. Usually, the reaction temperature is -20 ° C to 180 ° C, preferably 10 ° C to 150 ° C. The reaction time is 10 minutes to 48 hours, preferably 30 minutes to 24 hours. Outside these ranges, the reaction does not proceed sufficiently or side reactions occur, which is not preferable. Moreover, the mixing ratio of both is preferably 0.8 to 1.2 equivalents of the oxetane compound per equivalent of hydroxyl group.

  The reaction can be carried out without solvent, but is usually carried out in a suitable solvent. The solvent used is not particularly limited as long as it does not interfere with the intended reaction. For example, aromatic hydrocarbons such as benzene, toluene and xylene, amides such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone, methyl ethyl ketone, Examples thereof include ketones such as methyl isobutyl ketone, ethers such as dibutyl ether, ethylene glycol dimethyl ether and diethylene glycol dimethyl ether, esters such as ethyl acetate and ethyl benzoate, and mixtures thereof.

  In addition, you may refine | purify the compound represented by General formula (1)-(3) and General formula (5) by recrystallization, a chromatography, etc. as needed after a synthesis | combination. In particular, recrystallization is an effective means for those having a certain degree of crystallinity, and even a compound that cannot be recrystallized at room temperature can be recrystallized by cooling to a low temperature such as −20 ° C. is there.

  In the liquid crystalline composition of the present invention, the compound having an oxetane group represented by the formulas (1) to (3), the liquid crystalline compound having an oxetane group, and a formula (5) added as necessary The composition (mass ratio) of each component of the dioxetane compound represented is a compound having an oxetane group represented by formulas (1) to (3): a liquid crystal compound having an oxetane group: represented by formula (5). Dioxetane compound = 1-30: 100: 0-40, preferably 3-20: 100: 5-30. Outside this range, the adhesiveness between the liquid crystalline composition and the adhesive / adhesive becomes insufficient, and the liquid crystal film becomes unfavorable.

  After the liquid crystalline composition is subjected to an alignment treatment, the liquid crystalline state is fixed by polymerizing a cationic polymerizable group contained in the composition and crosslinking. Thereby, the heat resistance of a liquid crystal film improves. Therefore, in order to easily and rapidly proceed cationic polymerization, it is preferable that the liquid crystal composition contains a photocation generator and / or a thermal cation generator that generates cations by external stimuli such as light and heat. . If necessary, various sensitizers may be used in combination.

The photo cation generator means a compound capable of generating a cation by irradiating with light having an appropriate wavelength, and examples thereof include organic sulfonium salt systems, iodonium salt systems, and phosphonium salt systems. Antimonates, phosphates, borates and the like are preferably used as counter ions of these compounds. Specific examples of the compound include Ar ₃ S ⁺ SbF ₆ ⁻ , Ar ₃ P ⁺ BF ₄ ⁻ and Ar ₂ I ⁺ PF ₆ ⁻ (wherein Ar represents a phenyl group or a substituted phenyl group). In addition, sulfonate esters, triazines, diazomethanes, β-ketosulfone, iminosulfonate, benzoinsulfonate, and the like can also be used.

  The thermal cation generator is a compound capable of generating a cation by being heated to an appropriate temperature, for example, benzylsulfonium salts, benzylammonium salts, benzylpyridinium salts, benzylphosphonium salts, hydrazinium salts, carboxylic acid esters, Examples thereof include sulfonic acid esters, amine imides, antimony pentachloride-acetyl chloride complexes, diaryliodonium salts-dibenzyloxycopper, and boron halide-tertiary amine adducts.

  The amount of these cation generators added to the liquid crystalline composition depends on the structure of the mesogenic part or spacer part constituting the main chain type or side chain type liquid crystalline polymer compound used, the oxetane group equivalent, the liquid crystalline composition. However, it is usually 100 mass ppm to 20 mass%, preferably 1000 mass ppm to 10 mass%, more preferably, based on the main chain type or side chain type liquid crystalline polymer compound. Is in the range of 0.5% to 8% by weight, most preferably 1% to 6% by weight. If the amount is less than 100 mass ppm, the amount of cations generated may not be sufficient and polymerization may not proceed. If the amount is more than 20 mass%, the remaining cation generator remains in the liquid crystal film. It is not preferable because there is a risk that the light resistance and the like may deteriorate due to an increase in the number of objects.

  In the liquid crystalline composition used in the present invention, various compounds that can be mixed without impairing liquid crystallinity can be contained in addition to the main chain type or side chain type polymer liquid crystalline compound. Examples of the compound that can be contained include compounds having a cationic polymerizable functional group such as an oxetane group, an epoxy group, and a vinyloxy group, and various polymer substances having film-forming ability.

  Next, a method for producing a liquid crystal film using the liquid crystalline composition referred to in the present invention will be described. Although it does not limit as a manufacturing method of a liquid crystal film, after developing a liquid crystalline composition on an orientation board | substrate and orienting the said liquid crystalline composition, light irradiation and / or heat processing are carried out. It can manufacture by fixing the said orientation state.

  First, the liquid crystalline composition according to the present invention is spread on an alignment substrate to align the liquid crystalline composition. Examples of the alignment substrate include films of polyimide, polyphenylene sulfide, polyphenylene oxide, polyether ketone, polyethylene naphthalate, polyethylene terephthalate, polyarylate, triacetyl cellulose, and the like. Depending on the production method, these films may exhibit sufficient alignment ability for the liquid crystalline composition and can be used as an alignment substrate as they are, but many of them are rubbing, stretching, polarized light irradiation, oblique light irradiation, etc. By performing the above operations, the orientation ability is expressed or enhanced. In addition, a known alignment film such as polyimide, polyvinyl ether, polyvinyl cinnamate, and polyvinyl alcohol is provided on these substrate films, and alignment ability is exhibited by performing operations such as rubbing, stretching, polarized light irradiation, and oblique light irradiation. You can also Furthermore, the method by the oblique vapor deposition process of a silicon oxide can be illustrated. These operations and processes can be performed in combination as appropriate.

As a method for forming a liquid crystalline composition layer by spreading the liquid crystalline composition on an alignment substrate, a method in which the liquid crystalline composition is directly applied on the alignment substrate in a molten state, or a solution of the liquid crystalline composition is aligned. The method of drying a coating film and distilling a solvent after apply | coating on a board | substrate is mentioned.
The solvent used for preparing the solution is not particularly limited as long as it is a solvent that can dissolve the components constituting the liquid crystal composition of the present invention and various compounds that may be appropriately added and can be distilled off under appropriate conditions. Acetone, methyl ethyl ketone, isophorone, cyclohexanone and other ketones, butoxyethyl alcohol, hexyloxyethyl alcohol, ether alcohols such as methoxy-2-propanol, glycol ethers such as ethylene glycol dimethyl ether and diethylene glycol dimethyl ether, ethyl acetate, ethyl lactate , Esters such as γ-butyrolactone, phenols such as phenol and chlorophenol, amides such as N, N-dimethylformamide, N, N-dimethylacetamide and N-methylpyrrolidone, chloroform , Tetrachloroethane, halogenated such or a mixture of these systems, such as dichlorobenzene are preferably used. These solvents may be single or a mixture of a plurality of types may be used. Examples of the aforementioned various compounds include surfactants, antifoaming agents, leveling agents and the like used for forming a uniform coating film on the alignment substrate. The amount of these various compounds to be added varies depending on the structure of the constituents of the liquid crystal composition of the present invention and the composition ratio thereof, but cannot be determined unconditionally, but is usually about 0.01 to 10% by mass. is there.

  There is no particular limitation on the application method, either a method of directly applying a liquid crystalline composition or a method of applying a solution, as long as the uniformity of the coating film is ensured, and a known method is adopted. be able to. Examples thereof include spin coating, die coating, curtain coating, dip coating, and roll coating.

  The liquid crystal composition layer may be applied on the surface of one alignment substrate, that is, the liquid crystal composition layer may be in a state where the surface is exposed to air, or after the solvent is removed, The surface may be covered with another substrate, and the liquid crystal composition layer may be sandwiched between two substrates. At this time, the other substrate is not necessarily the same as the original alignment substrate.

  In the method of applying the liquid crystal composition solution, it is preferable to include a drying step for removing the solvent after the application. As long as the uniformity of a coating film is maintained, this drying process can employ | adopt a well-known method, without being specifically limited. For example, a method such as a heater (furnace) or hot air blowing may be used.

  The coating thickness is not generally determined because it is adjusted depending on the liquid crystal composition to be used and the intended use of the liquid crystal film to be obtained. However, the thickness after drying is 0.05 to 20 μm, preferably 0.2 to 10 μm. It is. Alternatively, since the liquid crystalline composition of the present invention exhibits refractive index anisotropy by being oriented, it is not always sufficient to simply define the coating film thickness only by the film thickness. In some cases, it is preferable to define the value (Δnd = refractive index anisotropy (Δn) × film thickness (d)). The retardation value at that time is 10 to 1000 nm, preferably 20 to 800 nm. If the film thickness and / or retardation value is outside this range, it is not preferable because it becomes difficult to achieve the desired effect and the orientation becomes insufficient.

  Subsequently, the liquid crystalline composition layer formed on the alignment substrate is formed into a liquid crystal alignment by a method such as heat treatment, and is cured and fixed by light irradiation and / or heat treatment. In the first heat treatment, the liquid crystal composition layer used is heated to a liquid crystal phase expression temperature range, so that the liquid crystal is aligned by the self-alignment ability inherent in the liquid crystal composition. As the conditions for the heat treatment, the optimum conditions and limit values differ depending on the liquid crystal phase behavior temperature (transition temperature) of the liquid crystal composition to be used, but it cannot be generally stated, but is usually 10 to 250 ° C., preferably 30 to 160 ° C. It is preferable that the heat treatment be performed at a temperature not lower than the glass transition point (Tg) of the liquid crystalline composition, more preferably not lower than 10 ° C. higher than Tg. If the temperature is too low, the liquid crystal alignment may not proceed sufficiently, and if the temperature is high, the cationic polymerizable reactive group in the liquid crystalline composition and the alignment substrate may be adversely affected. Moreover, about heat processing time, it is 3 seconds-30 minutes normally, Preferably it is the range of 10 seconds-10 minutes. If the heat treatment time is shorter than 3 seconds, the liquid crystal alignment may not be completed sufficiently, and if the heat treatment time exceeds 30 minutes, the productivity is deteriorated.

Examples of orientation states that can be developed by heat treatment include nematic orientation and nematic hybrid orientation. Of these, nematic hybrid orientation is preferred. In the case of twisted nematic orientation, an optically active compound is required. The optically active compound may be added separately, or may be incorporated into the main chain type or side chain type polymer liquid crystalline compound as a co-weighted (condensed) synthetic component, and the optically active compound is not particularly limited. no. for example, optically active aliphatic alcohols _{(C n H 2n + 1 OH} , wherein n represents an integer from 4 to 14.), alkoxy benzoic acid linked an optically active aliphatic group _{(C n H 2n} + 1 O- Ph-COOH, where n represents an integer of 4 to 14, and Ph represents a phenylene group.), Menthol, camphoric acid, naproxen derivative, binaphthol, 1,2-propanediol, 1,3-butanediol, 2-methylbutane Diols, 2-chlorobutanediol, tartaric acid, methylsuccinic acid, 3-methyladipic acid, isosorbide, isomannide, etc. That.
Of these, binaphthol, isosorbide, isomannide and the like, which are effective in a small amount, are preferable.

  After the liquid crystal composition layer is formed into a liquid crystal alignment by a method such as heat treatment, the liquid crystal composition layer is cured by a polymerization reaction of a cationic polymerizable reactive group in the composition while maintaining the liquid crystal alignment state. The curing step is aimed at fixing the liquid crystal alignment state of the completed liquid crystal alignment by a curing (crosslinking) reaction and modifying it into a stronger film.

Since the liquid crystalline composition referred to in the present invention has a cationic polymerizable reactive group, it is preferable to use a cationic polymerization initiator (cation generator) for polymerization (crosslinking) of the reactive group as described above. . As the polymerization initiator, it is preferable to use a photo cation generator rather than a thermal cation generator.
When a photo cation generator is used, the liquid crystalline composition can be obtained if the steps from the addition of the photo cation generator to the heat treatment for liquid crystal alignment are performed under dark conditions (light blocking conditions that do not cause the photo cation generator to dissociate). The product can be liquid crystal aligned with sufficient fluidity without being cured until the alignment stage. Thereafter, the liquid crystal composition layer is cured by generating cations by irradiating light from a light source that emits light of an appropriate wavelength.

As a light irradiation method, a photocation is generated by irradiating light from a light source such as a metal halide lamp, a high pressure mercury lamp, a low pressure mercury lamp, a xenon lamp, an arc lamp, or a laser having a spectrum in the absorption wavelength region of the photocation generator used. Cleave the generator. The dose per square centimeter is usually in the range of 1 to 2000 mJ, preferably 10 to 1000 mJ as the cumulative dose. However, this is not the case when the absorption region of the photocation generator and the spectrum of the light source are significantly different, or when the liquid crystalline composition itself has the ability to absorb the light source wavelength. In these cases, it is possible to adopt a method such as using a suitable photosensitizer or a mixture of two or more photocation generators having different absorption wavelengths.
The temperature at the time of light irradiation needs to be in a temperature range in which the liquid crystalline composition takes liquid crystal alignment. In order to sufficiently enhance the curing effect, it is preferable to perform light irradiation at a temperature equal to or higher than Tg of the liquid crystalline composition.

  The liquid crystalline composition layer produced by the above process is a sufficiently strong film. Specifically, the mesogens are three-dimensionally bonded by the curing reaction, and not only the heat resistance (the upper limit temperature for maintaining the liquid crystal alignment) is improved as compared to before curing, but also scratch resistance, abrasion resistance, crack resistance. The mechanical strength such as property is also greatly improved. The present invention is industrially significant in the sense that it provides a method capable of simultaneously achieving the conflicting objectives of easily controlling the precise alignment of liquid crystal alignment and improving the thermal and mechanical strength.

  The liquid crystal composition layer (liquid crystal film) in which the liquid crystal alignment is fixed is in a form as it is formed on the alignment substrate (alignment substrate / (alignment film) / liquid crystal composition layer), a substrate different from the alignment substrate It can be used in a form in which a liquid crystal film is transferred to a film or the like (substrate film / liquid crystalline composition layer), or in a liquid crystalline composition layer single layer form.

  In addition, as a film used for transfer in the present invention, for example, a triacetyl cellulose film such as Fujitac (product of Fujifilm), Konicatak (product of Konica), TPX film (product of Mitsui Chemicals), Arton film ( JSR products), Zeonex films (Nippon Zeon products), acrylprene films (Mitsubishi Rayon products), and other transparent films, polyethylene terephthalate films, polyethylene with an easy release layer on the surface A terephthalate film etc. are mentioned. Moreover, various optical glass, quartz glass, a polarizing element, and a polarizing plate can also be mentioned as needed.

The adhesive / adhesive used in the above transfer and bonding is not particularly limited as long as it has an appropriate adhesive force at both interfaces to be transferred and bonded, for example, an acrylic polymer system, an epoxy resin system, Examples include ethylene-vinyl acetate copolymer systems, rubber systems, urethane systems and mixtures thereof, and various reactive systems such as thermosetting and / or photocuring and electron beam curing. A mold is preferable because of ease of processing.
Radical polymerization systems and cationic polymerization systems are known as photocurable adhesives / adhesives. However, in the present invention, adhesives / adhesives mainly composed of a compound having a (meth) acryloyl group, which are radical polymerization systems ( (Hereinafter referred to as “acrylic adhesive / adhesive”) is preferable, and the acrylic adhesive / adhesive is suitable for the adhesion of ordinary commercially available ultraviolet (UV) curable adhesives and liquid crystalline compositions. Those modified as appropriate can be used.

Depending on the adhesiveness of the liquid crystal composition, appropriate modification may be made by using various (meth) acrylic monofunctional monomers, polyfunctional monomers, polyesters commercially available from Toa Gosei Co., Ltd., Osaka Organic Chemical Co., Ltd., etc. Photopolymerization initiators, viscosity modifiers (thickeners), additives such as surfactants and dispersants, and the like can be appropriately added to oligomers such as (meth) acrylates and polyurethane (meth) acrylates. Further, (fine) particles having a refractive index different from that of the acrylic adhesive / adhesive may be added for the purpose of light diffusion and scattering. Examples of the material of the (fine) particles include silica, alumina, ITO, silver, and various (crosslinked) plastics.
The amount of these additives cannot be determined unconditionally depending on the type, components, functions, etc., but is usually preferably 0.01% by mass to 20% by mass with respect to the acrylic adhesive / adhesive.
Since the reaction (curing) conditions for the reactive substances vary depending on the components constituting the adhesive / adhesive, the viscosity, the reaction temperature, and the like, conditions suitable for each may be selected. In the case of an acrylic-based adhesive / adhesive, for example, a light source similar to that in the case of the above-described photocation generator is used, and a similar irradiation amount may be used. The acceleration voltage in the case of the electron beam curable type is usually 10 kV to 200 kV, preferably 25 kV to 100 kV.

  A known method can be employed as the transfer method. For example, as described in JP-A-4-57017 and JP-A-5-333313, after laminating a target substrate different from the alignment substrate through a pressure-sensitive adhesive or an adhesive, Examples include a method of transferring only the liquid crystal film by performing a curing treatment (UV crosslinking) of the pressure-sensitive adhesive or adhesive as necessary, and peeling the alignment substrate from the laminate.

The pressure-sensitive adhesive tape of the present invention includes the liquid crystal film thus obtained. Specifically, it is obtained by forming an adhesive / adhesive on one side or both sides of the obtained liquid crystal film. Further, a release film may be formed on the outer side. As the adhesive / adhesive, those mentioned above can be used. The liquid crystal film is particularly preferably a liquid crystal film in which the alignment state of either nematic alignment or nematic hybrid alignment is fixed.
The pressure-sensitive adhesive tape of the present invention has a unique property that the peeling force varies depending on the peeling direction. Specifically, when peeling in the reverse direction of the rubbing treatment used when aligning the liquid crystal film, an extremely large peeling force is exhibited as compared with the case where peeling is performed in the forward direction. The pressure-sensitive adhesive tape of the present invention exhibiting such anisotropic releasability can achieve both strong adhesion in a specific direction and excellent releasability in directions other than the specific direction. Can be easily peeled off by peeling from a direction (rubbing direction) excellent in peelability after use.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In addition, each analysis method used in the Example is as follows.
(1) Measurement of ¹ H-NMR The compound was dissolved in deuterated chloroform or deuterated dimethyl sulfoxide and measured with INOVA400 manufactured by VARIAN.
(2) Observation of phase behavior The phase behavior was observed with a BH2 polarizing microscope manufactured by Olympus Optical Co., Ltd. while heating the sample on a hot stage FP82HT manufactured by Mettler.
The phase transition temperature was measured with a differential scanning calorimeter DSC7 manufactured by Perkin-Elmer. In the description of the phase behavior, C represents a crystalline phase, Ch represents a cholesteric phase, Nm represents a nematic phase, and Iso represents an isotropic liquid phase.
(3) Measurement of logarithmic viscosity of polymer liquid crystalline compound Using a Ubbelohde viscometer, measurement was performed at 30 ° C. in a phenol / tetrachloroethane (60/40: mass ratio) mixed solvent.
(4) Parameter measurement of optical film The retardation value (Δnd) of the aligned liquid crystal composition layer and the like was measured with KOBRA-20ADH manufactured by Oji Scientific Instruments using light having a wavelength of 550 nm.
Further, the average tilt angle of the nematic hybrid alignment was obtained from a simulation in which Δnd in increments of 10 ° from −40 ° to 40 ° was measured and assumed that the tilt angle changed linearly.
(5) Measurement of GPC The compound was dissolved in tetrahydrofuran, and TSK-GELSuperH1000, SuperH2000, SuperH3000, and SuperH4000 were connected in series with a Tosoh 8020GPC system and measured using tetrahydrofuran as an eluent. Polystyrene standards were used for molecular weight calibration.
(6) Film thickness measurement SURFACE TEXTUREALYSIS SYSTEM Dektak3030ST manufactured by SLOAN was used. Moreover, the method of calculating | requiring a film thickness from the data of interference wave measurement (The JASCO Corporation UV / visible / near infrared spectrophotometer V-570) and refractive index data was used together.

The abbreviations described in the following Reference Examples, Examples and Comparative Examples respectively represent the following.
DCC: 1,3-dicyclohexylcarbodiimide DMAP: 4-dimethylaminopyridine DCM: dichloromethane PPTS: pyridinium-p-toluenesulfonate THF: tetrahydrofuran DMF: dimethylformamide BHT: 2,6-di-t-butyl-4-methylphenol PEN : Polyethylene naphthalate TAC: Triacetyl cellulose

[Reference Example 1 (Synthesis of Intermediate Compound 1 having Oxetane Group)]
According to scheme 1, intermediate compound 1 having an oxetane group was synthesized.

[Reference Example 2 (Synthesis of Intermediate Compound 2 Having Oxetane Group)]
According to scheme 2, intermediate compound 2 having an oxetane group was synthesized.

[Reference Example 3 (Synthesis of Acrylic Compound 3)]
According to the following scheme 3, acrylic compound 3 was synthesized.
A ¹ H-NMR spectrum of the resulting acrylic compound 3 is shown in FIG.

[Reference Example 4 (Synthesis of Acrylic Compound 4)]
According to the following scheme 4, acrylic compound 4 was synthesized.
The ¹ H-NMR spectrum of the resulting acrylic compound 4 is shown in FIG.

[Reference Example 5 (Synthesis of acrylic compound 5)]
According to the following scheme 5, acrylic compound 5 was synthesized.
A ¹ H-NMR spectrum of the resulting acrylic compound 5 is shown in FIG.

[Reference Example 6 (Synthesis of acrylic compound 6)]
According to the following scheme 6, acrylic compound 6 was synthesized.

[Reference Example 7 (Synthesis of acrylic compound 7)]
Acrylic compound 7 was synthesized according to Scheme 7.

[Reference Example 8 (Synthesis of acrylic compound 8)]
Acrylic compound 8 was synthesized according to Scheme 8.

[Reference Example 9 (Synthesis of acrylic compound 9)]
Acrylic compound 9 was synthesized according to Scheme 9.

[Reference Example 10 (Synthesis of Liquid Crystalline Polyester 10)]
97.188 g (722 mmol) of 3-chloromethyl-3-ethyloxetane, 9.70 g (30.1 mmol) of tetrabutylammonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd., reagent) and ethyl 4-hydroxybenzoate (Tokyo Chemical Co., Ltd.) ), Reagent) 100.00 g (602 mmol) was reacted by stirring and mixing in N-methylpyrrolidone solvent at 120 ° C. for 3 hours, and the resulting reaction solution was diluted with water, extracted with ethyl acetate, and the solvent was distilled off. By leaving, crude ethyl 4- (3-ethyloxetane-1-yl-methoxy) benzoate was obtained. Next, an aqueous solution of 43.69 g (662 mmol) of 85% pure potassium hydroxide was added to the ester and reacted at 100 ° C. for 4 hours to hydrolyze, and then 91.40 g (662 mmol) of an aqueous solution of sodium hydrogensulfate monohydrate. By diluting and precipitating, crude crystals of 4- (3-ethyloxetane-1-yl-methoxy) benzoic acid were obtained. The crude crystals were dissolved in acetonitrile and recrystallized to obtain crystals of 4- (3-ethyloxetane-1-yl-methoxy) benzoic acid.
A mixture of 12.00 g (50.8 mmol) of 4- (3-ethyloxetane-1-yl-methoxy) benzoic acid and 6.56 g (50.8 mmol) of N, N-diisobutylethylamine was dissolved in distilled tetrahydrofuran. This solution was dropped into a distilled tetrahydrofuran solution of methanesulfonyl chloride at 0 ° C. to obtain 4- (3-ethyloxetane-1-yl-methoxy) benzoic acid methanesulfonic anhydride. Here, 9.37 g (46.2 mmol) of terephthalic acid chloride, 4.30 g (34.6 mmol) of methylhydroquinone and 3.81 g (34.6 mmol) of catechol were dissolved, and then 15.18 g (150.0 mmol) of triethylamine, A tetrahydrofuran solution of 1.41 g (11.5 mmol) of N, N-dimethylaminopyridine was added dropwise, and the mixture was reacted at 0 ° C. for 2 hours and then at 60 ° C. for further 4 hours. Thereafter, the reaction solution was poured into an excessive amount of methanol at room temperature, the reaction product was precipitated by reprecipitation, washed and dried to obtain liquid crystalline polyester 10. The obtained liquid crystalline polyester 10 has a logarithmic viscosity of 0.090 dL / g, a C-Nm phase transition temperature of 68 ° C., and an Nm-Iso transition temperature of 268 ° C. as observed with a polarization microscope on a hot stage. It was.

[Reference Example 11 (Synthesis of side chain liquid crystalline polyacrylate 11)]
From 2 parts (molar ratio) of acrylic compound 4 and 8 parts (molar ratio) of acrylic compound 7, 2,2′-azobisisobutyronitrile was used as an initiator and DMF as a solvent at 90 ° C. under nitrogen. Side chain liquid crystalline polyacrylate 11 was synthesized by performing radical polymerization for 6 hours, reprecipitating in methanol and purifying.
The weight average molecular weight of the side chain type liquid crystalline polyacrylate 11 measured by GPC was 9,100.
From the DSC measurement, the glass transition point (Tg) was 82 ° C. From a polarizing microscope observation on a hot stage, a nematic liquid crystal phase was developed at a temperature of Tg or higher, and the Nm-Iso transition temperature was 248 ° C.

[Reference Example 12 (Synthesis of side chain liquid crystalline polyacrylate 12)]
From 2 parts (molar ratio) of acrylic compound 5, 6 parts (molar ratio) of acrylic compound 7 and 2 parts (molar ratio) of acrylic compound 8, 2,2′-azobisisobutyronitrile is used as an initiator, Side chain liquid crystalline polyacrylate 12 was synthesized by radical polymerization under nitrogen at 90 ° C. for 6 hours using DMF as a solvent, reprecipitation in methanol and purification.
The weight average molecular weight of the side chain type liquid crystalline polyacrylate 12 measured by GPC was 9,700.
From the DSC measurement, the glass transition point (Tg) was 78 ° C. From a polarizing microscope observation on a hot stage, a nematic liquid crystal phase was developed at a temperature of Tg or higher, and the Nm-Iso transition temperature was 229 ° C.

[Reference Example 13 (Synthesis of side chain liquid crystalline polyacrylate 13)]
1 part (molar ratio) of acrylic compound 3, 1 part (molar ratio) of acrylic compound 6, 7 parts (molar ratio) of acrylic compound 7, 0.5 part (molar ratio) of acrylic compound 9 and 0 of stearyl acrylate .5 parts (molar ratio) from 2,2′-azobisisobutyronitrile as initiator and DMF as solvent, perform radical polymerization at 90 ° C. for 6 hours under nitrogen, and reprecipitate in methanol for purification By doing so, the side chain type liquid crystalline polyacrylate 13 was synthesized. The weight average molecular weight of the side chain type liquid crystalline polyacrylate 13 measured by GPC was 9,700.
From the DSC measurement, Tg was 79 ° C. From Mettler observation, it was confirmed that a liquid crystal phase was developed at a temperature of Tg or higher and the Nm-Iso transition temperature was 190 ° C.

[Reference Example 14 (Synthesis of dioxetane compound 14)]
The dioxetane compound 14 was synthesized according to scheme 10. The ¹ H-NMR spectrum of the resulting dioxetane compound 14 is shown in FIG.

[Reference Example 15 (synthesis of dioxetane compound 15)]
The dioxetane compound 15 was synthesized according to the following scheme 11. The ¹ H-NMR spectrum of the obtained dioxetane compound 15 is shown in FIG.

[Example 1]
0.10 g of the acrylic compound 4 synthesized in Reference Example 4 and 0.90 g of the main-chain type liquid crystal polymer 10 synthesized in Reference Example 10 were dissolved in 9 ml of cyclohexanone, and triallylsulfonium hexafluoroantimonate in the dark. After adding 0.10 g of a 50% propylene carbonate solution (manufactured by Aldrich, reagent), the solution was filtered through a polytetrafluoroethylene filter having a pore size of 0.45 μm to prepare a solution of a liquid crystalline composition.
This solution was applied onto a 50 μm thick PEN film “Teonex Q-51” (manufactured by Teijin Ltd.) whose surface was rubbed with a rayon cloth using a spin coating method. The solvent was removed by gently spraying, followed by heating in an oven at 150 ° C. for 3 minutes to form a uniform liquid crystal alignment. Then, after irradiating ultraviolet light with an integrated irradiation amount of 300 mJ / cm ^{2 with} a high-pressure mercury lamp in an air atmosphere, a liquid crystal composition layer cured by cooling was obtained.
The obtained film was transferred to a TAC film via a commercially available UV curable acrylic adhesive UV-3400 (product of Toa Gosei Co., Ltd.) to obtain a liquid crystal film. That is, an ultraviolet curable acrylic adhesive UV-3400 is applied on the cured liquid crystalline composition layer on the PEN film so as to have a thickness of 5 μm, laminated with a TAC film, and 400 mJ / cm from the TAC film side. ^The PEN film was peeled off after the adhesive was cured by irradiating the ultraviolet light of No. ² . The obtained liquid crystal film was a monodomain nematically oriented liquid crystal film having no peeling failure portion. The film thickness of the liquid crystalline composition layer was 0.85 μm.
Further, an acrylic polymer-based pressure-sensitive adhesive was applied on the liquid crystalline composition layer of the liquid crystal film, and laminated with a polyethylene terephthalate film. A film having a layer structure of TAC / UV-3400 / liquid crystal composition layer / acrylic polymer adhesive / polyethylene terephthalate film was obtained.
The film was subjected to a 180 ° peel test using a strograph E-L manufactured by Toyo Seiki Co., Ltd. The measurement was performed at a temperature of 23 ° C. and a peeling speed of 300 mm / min.
When the TAC film was peeled from the rubbing forward direction, the peel force was 25 gf / inch. On the other hand, when peeled from the reverse direction of rubbing, the peel force was 230 gf / inch.

[Example 2]
9 ml of 0.05 g of acrylic compound 4 synthesized in Reference Example 4, 0.75 g of side chain type liquid crystalline polyacrylate 11 synthesized in Reference Example 11 and 0.2 g of dioxetane compound 14 synthesized in Reference Example 14 In a dark place, add 0.10 g of a 50% propylene carbonate solution of triallylsulfonium hexafluoroantimonate (manufactured by Aldrich) and filter through a polytetrafluoroethylene filter with a pore size of 0.45 μm. Thus, a liquid crystal composition solution was prepared.
This solution was applied onto a 50 μm thick PEN film “Teonex Q-51” (manufactured by Teijin Ltd.) whose surface was rubbed with a rayon cloth using a spin coating method. The solvent was removed by gently spraying, followed by heating in an oven at 150 ° C. for 3 minutes to form a uniform liquid crystal alignment. Then, after irradiating ultraviolet light with an integrated irradiation amount of 300 mJ / cm ^{2 with} a high-pressure mercury lamp in an air atmosphere, a liquid crystal composition layer cured by cooling was obtained.
The obtained film was transferred to a TAC film via a commercially available UV curable acrylic adhesive UV-3400 (product of Toa Gosei Co., Ltd.) to obtain a liquid crystal film. That is, UV-3400 was applied on the cured liquid crystalline composition layer on the PEN film so as to have a thickness of 5 μm, laminated with a TAC film, and irradiated with ultraviolet light of 400 mJ / cm ² from the TAC film side. Then, the PEN film was peeled off. The obtained liquid crystal film had no poorly peeled portion, and when observed under a polarizing microscope, monodomain uniform liquid crystal alignment without disclination was observed. Δnd when viewed from the front was 120 nm. Further, Δnd when viewed from a position inclined by 40 ° from the vertical along the rubbing axis is 153 nm, and Δnd when viewed from a position inclined by −40 ° on the opposite side is 61 nm, which is asymmetric. Since there was no point of 0 nm, it was found that the liquid crystalline composition layer had a nematic hybrid alignment structure. The average tilt angle was 28 degrees. The film thickness of this liquid crystalline composition layer was 0.84 μm.
Further, an acrylic polymer-based pressure-sensitive adhesive was applied on the liquid crystal composition layer of the liquid crystal film and laminated with a polyethylene terephthalate film. A film having a layer structure of TAC / UV-3400 / liquid crystal composition layer / acrylic polymer adhesive / polyethylene terephthalate film was obtained.
This film was subjected to a 180 ° peel test using a strograph E-L manufactured by Toyo Seiki Co., Ltd. at a measurement temperature of 23 ° C. and a peel rate of 300 mm / min.
When the TAC film was peeled from the rubbing forward direction, the peel force was 30 gf / inch. On the other hand, when peeled from the reverse direction of rubbing, the peel force was 460 gf / inch.

[Example 3]
9 ml of 0.08 g of acrylic compound 5 synthesized in Reference Example 5, 0.80 g of side chain type liquid crystalline polyacrylate 12 synthesized in Reference Example 12, and 0.12 g of dioxetane compound 15 synthesized in Reference Example 15 In a dark place, add 0.10 g of a 50% propylene carbonate solution of triallylsulfonium hexafluoroantimonate (manufactured by Aldrich) and filter through a polytetrafluoroethylene filter with a pore size of 0.45 μm. Thus, a liquid crystal composition solution was prepared.
A PEN film was peeled off in the same manner as in Example 1 except that this solution was used. As a result, a uniform monodomain liquid crystal film without a defective peeling portion was obtained.
When the obtained liquid crystal film was observed under a polarizing microscope, monodomain uniform liquid crystal alignment without disclination was observed. Δnd when viewed from the front was 97 nm. Further, Δnd when viewed from a position tilted 40 ° from the vertical along the rubbing axis is 140 nm, and Δnd when viewed from a position tilted −40 ° opposite thereto is 41 nm, and Δnd is asymmetric at any angle. Since there was no point of 0 nm, it was found that this liquid crystalline composition layer had a nematic hybrid alignment structure. The average tilt angle was 39 degrees. Moreover, the thickness of the liquid crystalline composition layer of the obtained liquid crystal film was 1.08 μm.
Furthermore, on the liquid crystal composition layer of this liquid crystal film, an acrylic polymer-based pressure-sensitive adhesive was applied to a thickness of 5 μm and laminated with a polyethylene terephthalate film. A film of TAC / UV-3400 / liquid crystal composition layer / acrylic polymer adhesive / polyethylene terephthalate was obtained.
The film was subjected to a 180 ° peel test using a strograph E-L manufactured by Toyo Seiki.
When the TAC film was peeled from the rubbing forward direction, the peel force was 38 gf / inch. On the other hand, when peeled from the reverse direction of rubbing, the peel force was 680 gf / inch.

[Example 4]
9 ml of 0.15 g of acrylic compound 3 synthesized in Reference Example 3, 0.77 g of side chain type liquid crystalline polyacrylate 13 synthesized in Reference Example 13, and 0.08 g of dioxetane compound 15 synthesized in Reference Example 15 In a dark place, add 0.10 g of a 50% propylene carbonate solution of triallylsulfonium hexafluoroantimonate (manufactured by Aldrich) and filter through a polytetrafluoroethylene filter with a pore size of 0.45 μm. Thus, a liquid crystal composition solution was prepared.
A PEN film was peeled off in the same manner as in Example 1 except that this solution was used. As a result, a uniform monodomain liquid crystal film without a defective peeling portion was obtained.
When the obtained liquid crystal film was observed under a polarizing microscope, monodomain uniform liquid crystal alignment without disclination was observed. Δnd when viewed from the front was 92 nm. In addition, Δnd when viewed from a position tilted 40 ° from the vertical along the rubbing axis is 120 nm, and Δnd when viewed from a position tilted by −40 ° on the opposite side is 43 nm, which is asymmetric. Since there was no point of 0 nm, it was found that this liquid crystalline composition layer had a nematic hybrid alignment structure. The average tilt angle was 31 degrees. The thickness of the liquid crystal composition layer of the obtained liquid crystal film was 0.82 μm.
Furthermore, on the liquid crystal composition layer of this liquid crystal film, an acrylic polymer-based pressure-sensitive adhesive was applied to a thickness of 5 μm and laminated with a polyethylene terephthalate film.
A film of TAC / UV-3400 / liquid crystal / acrylic polymer adhesive / polyethylene terephthalate was obtained.
The film was subjected to a 180 ° peel test using a strograph E-L manufactured by Toyo Seiki.
When the TAC film was peeled from the rubbing forward direction, the peel force was 42 gf / inch. On the other hand, when peeled from the reverse direction of rubbing, the peel force was 540 gf / inch.

Claims (2)

  A film comprising a liquid crystal film.   The film according to claim 1, wherein the liquid crystal film has a fixed alignment state of either nematic alignment or nematic hybrid alignment.

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