JP5708972B2 - Polymerizable liquid crystal composition, cholesteric reflective film and reflective polarizing plate using the same - Google Patents

Description

  The present invention relates to a polymerizable liquid crystal composition useful as a liquid crystal device, a display, an optical component, a colorant, a security marking, a laser light emitting member, and the like, and a cholesteric polarizing film obtained from the polymerized liquid crystal composition, a reflective polarization Regarding the board.

  The development of polarizing plates utilizing the selective reflection characteristics of cholesteric liquid crystals has been actively performed since the 1990s. In order to use the cholesteric liquid crystal as a polarizing plate, it is necessary to set the wavelength region of selective reflection to the visible light region, and the polarization characteristics can be obtained by setting the pitch of the cholesteric liquid crystal to a predetermined value. However, when a chiral compound is added to a nematic liquid crystal, the pitch generally keeps a constant pitch, and only selective reflection in a specific narrow wavelength region corresponding to this can be obtained. Therefore, attempts have been made to widen the selective reflection wavelength region by devising a cholesteric liquid crystal composition.

  As one of the methods, in a polymerizable cholesteric liquid crystal, a method of sequentially controlling the width of the pitch by controlling the polymerization rate on the light irradiation surface and the non-irradiation surface is disclosed (Patent Document 1 and Patent Document 2). . This method suppresses absorption of the photoinitiator contained in the cholesteric liquid crystal composition by adding a dye having an absorption wavelength that overlaps with the absorption wavelength of the photoinitiator in the polymerizable cholesteric liquid crystal composition. The pitch is controlled by the difference in polymerization rate between the irradiated surface and the non-irradiated surface. However, with this method, it takes a long time to obtain a cholesteric reflective film in which the wavelength range of selective reflection is expanded, and there is a problem in productivity. In addition, since the dye is not a liquid crystal compound, there is a problem that defects such as coloring of the film and occurrence of alignment defects are likely to occur with an increase in the addition amount.

As another method, there is a method of making the pitch easily change by making the chiral compound in the cholesteric liquid crystal composition non-polymerization type (Non-Patent Document 1). In this method, the pitch is dispersed by irradiating weak light onto the irradiation surface and gradually photopolymerizing the cholesteric liquid crystal composition from the irradiation surface.
However, when expanding the wavelength region of selective reflection, it takes a long time to produce a cholesteric reflective film in these methods, and there is a problem in productivity.

Japanese Patent No. 3224467 Japanese Patent No. 4271729

Liquid Crystal, Vol. 34, no. 9, 1009-1018 (2007)

  The problem to be solved by the present invention is to provide a polymerizable liquid crystal composition that easily expands the selective reflection wavelength region of the cholesteric reflective film and is excellent in productivity, and combines the polymerizable liquid crystal composition with the polymerizable liquid crystal composition. An object of the present invention is to provide a cholesteric reflective film and a reflective polarizing plate having an excellent appearance.

The inventors of the present invention add a compound having a function close to that of a dye and capable of forming a liquid crystal because alignment defects occur with an increase in the amount of the dye disclosed in the prior art. Focusing on the fact that alignment defects hardly occur even when the amount is increased, the present invention has been achieved.
The present invention
a) General formula (1)

（式中、Ｒ_１及びＲ_２はそれぞれ独立してフッ素原子、塩素原子、シアノ基、炭素数１〜１２のアルキル基、又は炭素数２〜１２のアルケニル基を表し、これらの基中に含まれる水素原子の１個又はそれ以上がフッ素原子に置換されても良く、Ｚ_１は単結合、−Ｏ−、−Ｓ−、−ＣＯＯ−、−ＯＣＯ−、−ＯＣＨ_２−、−ＣＨ＝ＣＨ−、−ＣＨ＝ＣＨ−ＣＯＯ−、又は−ＯＣＯ−ＣＨ＝ＣＨ−を表し、Ｚ_２は単結合、−Ｏ−、−Ｓ−、−ＣＯＯ−、−ＯＣＯ−、−ＣＨ_２Ｏ−、−ＣＨ＝ＣＨ−、−ＣＨ＝ＣＨ−ＣＯＯ−、又は−ＯＣＯ−ＣＨ＝ＣＨ−を表し、Ａは−Ｃ≡Ｃ−、−Ｃ＝Ｎ−、−Ｎ＝Ｎ−、若しくは−Ｃ＝Ｎ−Ｎ＝Ｃ−、又は以下の何れかの環構造

(In the formula, R ₁ and R ₂ each independently represent a fluorine atom, a chlorine atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms, and these are included in these groups. One or more of hydrogen atoms may be substituted with a fluorine atom, and Z ₁ may be a single bond, —O—, —S—, —COO—, —OCO—, —OCH ₂ —, —CH═CH. -, - CH = CH-COO- , or an -OCO-CH = CH-, _{Z 2} is a single bond, -O -, - S -, - COO -, - OCO -, - CH 2 O -, - CH = CH—, —CH═CH—COO—, or —OCO—CH═CH—, and A represents —C≡C—, —C═N—, —N═N—, or —C═N—. N = C-, or any of the following ring structures

を表し、Ｒ_３は、フッ素原子、塩素原子、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、又はシアノ基を表し、Ｂは以下の環構造

R ₃ represents a fluorine atom, a chlorine atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cyano group, and B represents the following ring structure

R ₄ represents a fluorine atom, a chlorine atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cyano group. 1) or 2 or more types of liquid crystal compounds represented by b), b) 1 or 2 types of liquid crystal compounds having only one polymerizable functional group, and c) 2 or more polymerizable functional groups. 1) or 2 or more kinds of liquid crystal compounds, d) 1 or 2 kinds of chiral compounds having one or more polymerizable functional groups, and e) 1 or more kinds of polymerization initiators. A polymerizable liquid crystal composition characterized by
A cholesteric reflective film composed of a cured product of a planar aligned polymerizable liquid crystal composition, the polymerizable liquid crystal composition providing the cholesteric reflective film as the polymerizable liquid crystal composition;
Provided is a reflective polarizing plate in which a base material, a cholesteric reflective film and a retardation film are sequentially laminated, wherein the retardation film is the retardation film,
Provided is a reflective polarizing plate in which a base material, a cholesteric reflective film, a retardation film, and a linear polarizing film are sequentially laminated, wherein the retardation film is the retardation film. .

  The polymerizable liquid crystal composition of the present invention has a function close to that of a dye and contains a compound that can be a liquid crystal, whereby alignment defects are less likely to occur and the wavelength range of selective reflection can be easily expanded. Have Moreover, the polymerizable liquid crystal crude product of the present invention can produce a cholesteric reflective film by a simple method and is excellent in productivity. Therefore, the polymerizable liquid crystal composition, cholesteric reflective film, and reflective polarizing plate of the present invention can be applied to liquid crystal devices, displays, optical components, colorants, security markings, and laser emission members.

3 is a diagram showing a polarization reflection band of a cholesteric reflection film produced in Example 1. FIG. It is a figure which shows the polarization | polarized-light reflective zone | band of the cholesteric reflective film produced in Example 17. FIG.

The present invention is described in detail below.
a) (Liquid crystal compound represented by the general formula (1))
The polymerizable liquid crystal composition of the present invention uses the liquid crystal compound represented by the general formula (1). By adding a dye having an absorption wavelength that overlaps with the absorption wavelength of the photoinitiator, a cholesteric liquid crystal is used. From the viewpoint of suppressing absorption of the photoinitiator contained in the composition, a compound having a large overlap of conjugated bonds of the liquid crystal compound is preferable.
From such a viewpoint, in the liquid crystal compound represented by the general formula (1), R ₁ and R ₂ are each independently a fluorine atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, or an alkyl group having 2 to 12 carbon atoms. An alkenyl group is preferable, and a fluorine atom, an alkyl group having 3 to 8 carbon atoms, or an alkenyl group having 2 to 8 carbon atoms is particularly preferable.

Z ₁ is preferably a single bond, —O—, —S—, —COO—, —OCO— or —OCH ₂ —, and particularly preferably a single bond, —O—, —COO— or —OCO—. Z ₂ is preferably a single bond, —O—, —S—, —COO—, —OCO— or —OCH ₂ —, and particularly preferably a single bond, —O—, —COO— or —OCO—.
A is -C≡C-, -C = N-, -N = N-, -C = N-N = C-,

が好ましく、特に−Ｃ≡Ｃ−、−Ｃ＝Ｎ−Ｎ＝Ｃ−、

In particular, —C≡C—, —C═N—N═C—,

が好ましい。Ｒ_３は、フッ素原子、塩素原子、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、シアノ基が好ましく、特にフッ素原子、炭素数１〜６のアルキル基が好ましい。
一般式（１）で表される液晶化合物のＢは、

Is preferred. R ₃ is preferably a fluorine atom, a chlorine atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cyano group, and particularly preferably a fluorine atom or an alkyl group having 1 to 6 carbon atoms.
B of the liquid crystal compound represented by the general formula (1) is

が好ましく、特に、

Are preferred, in particular

が好ましい。Ｒ_４は、フッ素原子、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基又はシアノ基が好ましく、特にフッ素原子又は炭素数１〜６のアルキル基が好ましい。

Is preferred. R ₄ is preferably a fluorine atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cyano group, and particularly preferably a fluorine atom or an alkyl group having 1 to 6 carbon atoms.

  Specific examples of the general formula (1) include the following liquid crystal compounds, but are not limited thereto.

(In the formula, m and n each independently represent an integer of 0 to 7, and R represents a hydrogen atom, a fluorine atom or an alkyl group having 1 to 6 carbon atoms.)
0.1-20 mass% is preferable and, as for the content rate of the compound represented by General formula (1), 0.5-10 mass% is more preferable.
b) (Liquid crystal compound having only one polymerizable functional group)
The liquid crystal compound having only one polymerizable functional group used in the polymerizable liquid crystal composition of the present invention exhibits liquid crystallinity alone or in a composition with another liquid crystal compound. If it is a compound which has only 1 polymeric functional group, there will be no limitation in particular and a well-known and usual thing can be used.

  For example, Handbook of Liquid Crystals (D. Demus, JW Goodby, GW Gray, H. W. Spies, V. Vill, edited by Wiley-VCH, 1998), Quarterly Chemical Review No. 22, Liquid Crystal Chemistry (edited by the Chemical Society of Japan, 1994), or JP-A-7-294735, JP-A-8-3111, JP-A-8-29618, JP-A-11-80090, A rigid part called a mesogen in which a plurality of structures such as 1,4-phenylene group and 1,4-cyclohexylene group are connected as described in Kaihei 11-116538, JP-A-11-148079, etc. And a rod-like polymerizable liquid crystal compound having a polymerizable functional group such as (meth) acryloyl group, vinyloxy group, glycidyl group, or maleimide as described in JP-A Nos. 2004-2373 and 2004-99446 Examples thereof include a rod-like polymerizable liquid crystal compound having a group. Among these, a rod-like liquid crystal compound having a polymerizable group is preferable because it can easily produce a liquid crystal having a temperature range around room temperature.

Examples of the polymerizable functional group include a vinyl group, a vinyloxy group, an acryloyl group, a (meth) acryloyl group, a glycidyl group, a glycidyl ether group, an oxetanyl group, and a maleimide group. From the viewpoint of productivity, an acryloyl group or ( ) An acryloyl group is preferred.
Specific examples of the liquid crystal compound having only one polymerizable functional group used in the polymerizable liquid crystal composition of the present invention include the following liquid crystal compounds, but are not limited thereto. Absent.

(In the formula, l and m each independently represent an integer of 1 to 9, and n represents an integer of 0 to 10.)
These liquid crystal compounds can be used alone or in combination of two or more.

  A liquid crystal compound having only one polymerizable functional group is represented by the general formula (2)

(In the formula, L represents a hydrogen atom or a methyl group, Sp represents a single bond or an alkyl group having 1 to 10 carbon atoms, X represents a single bond, —O—, —S—, —COO—, —OCO—). , —OCH ₂ —, —CH═CH—, —CH═CH—COO— or —OCO—CH═CH—, G ₁ is a single bond, 1,4-phenylene group, naphthalene-2,6-diyl Group or a 1,4-cyclohexylene group, and one or two or more hydrogen atoms present in these groups are a fluorine atom, a chlorine atom, an alkyl group having 1 to 6 carbon atoms, and 1 to 2 carbon atoms. 6 may be substituted with an alkoxy group or a cyano group, and M represents a single bond, —O—, —S—, —COO—, —OCO—, —OCH ₂ —, —CH═CH—, —CH. = CH-COO- or -OCO-CH = CH- to represent, _{if G 1} is a single bond, M It represents a single bond, representing the _{G 1} is 1,4-phenylene group, naphthalene-2,6-diyl group or a 1,4-cyclohexylene group, -O -, - S -, - COO -, - OCO- , —OCH ₂ —, —CH═CH—, —CH═CH—COO— or —OCO—CH═CH—, G ₂ represents a hydrogen atom, a phenyl group, a cyclohexyl group, a naphthyl group, or a carbon number of 1 to 10. Represents an alkyl group, an alkoxy group having 1 to 10 carbon atoms, a carboxyl group, a carbamoyl group, a cyano group, a nitro group or a halogen atom, but the hydrogen atom in the phenyl group, cyclohexyl group or naphthyl group is unsubstituted. Or may be substituted with one or two or more halogen atoms, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cyano group, and the carboxyl group or carbamoyl Each hydrogen atom good .Y ₁ and Y ₂ may be substituted with an alkyl group having 1 to 10 carbon atoms which may be unsubstituted or substituted independently represent a hydrogen atom, a halogen atom in the cyano group, a nitro group, carbon In the case of a compound represented by the formula (1) represents an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms), the wavelength region of selective reflection can be further expanded, which is particularly preferable.

L of the liquid crystal compound represented by the general formula (2) is preferably a hydrogen atom.
Sp of the liquid crystal compound represented by the general formula (2) is preferably a single bond or an alkyl group having 3 to 6 carbon atoms, and particularly preferably an alkyl group having 3 to 6 carbon atoms.
X in the liquid crystal compound represented by the general formula (2) is preferably a single bond, —O—, —COO—, —OCO— or —OCO—CH═CH—, and is preferably a single bond, —O— or —OCO—. Are particularly preferred.

M is a liquid crystal compound represented by the general formula (2), when representing the _{G 1} is 1,4-phenylene group, naphthalene-2,6-diyl group or a 1,4-cyclohexylene group, -O -, - COO—, —OCO—, —CH═CH—, —CH═CH—COO— or —OCO—CH═CH— are preferred, and —O—, —COO— and —OCO— are particularly preferred.
G _{2 of the} liquid crystal compound represented by the general formula (2) is hydrogen atom, phenyl group, cyclohexyl group, naphthyl group, alkyl group having 1 to 10 carbon atoms, alkoxy group having 1 to 10 carbon atoms, carboxyl group, carbamoyl. Group, a cyano group, a fluorine atom or a chlorine atom is preferable, and an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group or a fluorine atom is particularly preferable.
Y _{1 of the} liquid crystal compound represented by the general formula (2) is preferably a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group, an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, a hydrogen atom, A fluorine atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms is particularly preferable.
Y _{2 of the} liquid crystal compound represented by the general formula (2) is preferably a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group, an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, A fluorine atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms is particularly preferable.
5-80 mass% is preferable and, as for the content rate of the liquid crystal compound represented by General formula (2), 10-70 mass% is especially preferable. Moreover, the liquid crystal compound represented by General formula (2) can also be used independently, and can also be used in mixture of 2 or more types.
Specific examples of the liquid crystal compound represented by the general formula (2) include the following liquid crystal compounds, but are not limited thereto.

(In the formula, m represents an integer of 1 to 6, and R represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a carboxyl group, a carbamoyl group, a halogen atom, a cyano group, or a nitro group. Represents a group, but when these groups are carboxyl groups or carbamoyl groups, the terminal hydrogen atom may be unsubstituted or substituted with an alkyl group having 1 to 10 carbon atoms.)
Furthermore, a liquid crystal compound having only one polymerizable functional group is represented by the general formula (3)

(In the formula, L ₁ represents a hydrogen atom or a methyl group, Sp ₁ represents a single bond or an alkyl group having 1 to 10 carbon atoms, and X ₁ and X ₂ are each independently a single bond, —O—, Represents —S—, —COO—, —OCO—, —OCH ₂ —, —CH═CH—, —CH═CH—COO— or —OCO—CH═CH—, and represents Y ₃ , Y ₄ , Y ₅ and Y ₆ each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a carboxyl group, a carbamoyl group, a cyano group, a nitro group, or a halogen atom, The hydrogen atom in the alkoxy group may be substituted with one or more halogen atoms, and even if the hydrogen atom in the carboxyl group or carbamoyl group is not substituted, it is substituted with an alkyl group having 1 to 10 carbon atoms. May be.)
Is particularly preferable because the wavelength range of selective reflection can be further expanded.

L _{1 of the} liquid crystal compound represented by the general formula (3) is preferably a hydrogen atom.
Sp _{1 of the} liquid crystal compound represented by the general formula (3) is preferably an alkyl group having 1 to 10 carbon atoms, and particularly preferably an alkyl group having 2 to 6 carbon atoms.
X _{1 of the} liquid crystal compound represented by the general formula (3) is preferably —O—, —COO—, —OCO—, —CH═CH—, —CH═CH—COO— or —OCO—CH═CH—. -O-, -COO- or -OCO- are particularly preferred.
X _{2 of the} liquid crystal compound represented by the general formula (3) is preferably —O—, —COO—, —OCO—, —CH═CH—, —CH═CH—COO— or —OCO—CH═CH—. , —COO—, —OCO—, —CH═CH— or —O— are particularly preferred.

Y ₃ , Y ₄ , Y ₅ and Y _{6 in the} liquid crystal compound represented by the general formula (3) are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a carboxyl group. Group, a carbamoyl group, a cyano group or a fluorine atom is preferable, and a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms or a cyano group is particularly preferable.
These liquid crystal compounds can be used alone or in combination of two or more.
Specific examples of the liquid crystal compound represented by the general formula (3) include the following liquid crystal compounds, but are not limited thereto.

(In the formula, m represents an integer of 1 to 10, and R represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a carboxyl group, a carbamoyl group, a cyano group, a nitro group, or a halogen. Represents an atom, but when these groups are alkyl groups having 1 to 6 carbon atoms or alkoxy groups having 1 to 6 carbon atoms, they are all unsubstituted or substituted by one or more halogen atoms When these groups are a carboxyl group or a carbamoyl group, the terminal hydrogen atom may be unsubstituted or substituted with an alkyl group having 1 to 10 carbon atoms.)
In these formulas, R preferably represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, or a cyano group.
These liquid crystal compounds can be used alone or in combination of two or more.

c) (Liquid crystal compound having two or more polymerizable functional groups)
The liquid crystal compound having two or more polymerizable functional groups used in the polymerizable liquid crystal composition of the present invention exhibits liquid crystallinity alone or in a composition with another liquid crystal compound. If it is a compound which has two or more polymerizable functional groups, there will be no limitation in particular and a well-known and usual thing can be used.
For example, Handbook of Liquid Crystals (D. Demus, JW Goodby, GW Gray, H. W. Spies, V. Vill, edited by Wiley-VCH, 1998), Quarterly Chemical Review No. 22, Liquid Crystal Chemistry (Edited by Chemical Society of Japan, 1994), or Japanese Patent Laid-Open Nos. 4-227684, 11-80090, 11-116538, 11-148079, 1,4-phenylene group 1,4-cyclohexane as described in JP-A-2000-178233, JP-A-2002-308831, JP-A-2002-145830, JP-A-2004-125842, and the like. A rod-like polymerizable liquid crystal compound having a rigid site called a mesogen in which a plurality of structures such as a len group are connected and a polymerizable functional group such as an acryloyl group, a (meth) acryloyl group, a vinyloxy group, or a glycidyl group, or JP-A-2004-2373 And a maleimide group as described in JP-A-2004-99446 Jo polymerizable liquid crystal compound. Among these, a rod-like liquid crystal compound having a polymerizable group is preferable because it can easily produce a liquid crystal having a temperature range around room temperature.

Examples of the polymerizable functional group include a vinyl group, a vinyloxy group, an acryloyl group, a (meth) acryloyl group, a glycidyl group, a glycidyl ether group, an oxetanyl group, and a maleimide group. From the viewpoint of productivity, an acryloyl group or ( ) An acryloyl group is preferred.
Specific examples of the liquid crystal compound having two or more polymerizable functional groups used in the polymerizable liquid crystal composition of the present invention include the following liquid crystal compounds.

(In the formula, m and n each independently represent an integer of 1 to 10, and R represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a carboxyl group, a carbamoyl group, cyano. Represents a group, a nitro group or a halogen atom, but when these groups are alkyl groups having 1 to 6 carbon atoms or alkoxy groups having 1 to 6 carbon atoms, they are all unsubstituted or one or two When these groups are a carboxyl group or a carbamoyl group, the terminal hydrogen atom may be unsubstituted or substituted with an alkyl group having 1 to 10 carbon atoms. Good.)
R is preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, or a cyano group.
These liquid crystal compounds can be used alone or in combination of two or more.
d) (chiral compound having at least one polymerizable functional group)
There is no particular limitation as long as it is a chiral compound having at least one polymerizable functional group, which is used in the polymerizable liquid crystal composition of the present invention, and known and commonly used compounds can be used.
For example, it describes in Unexamined-Japanese-Patent No. 11-193287, Unexamined-Japanese-Patent No. 2001-158788, JP-T-2006-52669, Unexamined-Japanese-Patent No. 2007-269639, Unexamined-Japanese-Patent No. 2007-269640, 2009-84178 etc. And a chiral saccharide such as isosorbide, isomannite, glucoside, etc., and a rigid site such as 1,4-phenylene group, 1,4-cyclohexylene group, (meth) acryloyl group, vinyloxy group, A polymerizable chiral compound having a polymerizable functional group such as a glycidyl group, a polymerizable chiral compound comprising a terpenoid derivative as described in JP-A-8-239666, NATURE VOL35, pages 467 to 469 (November 30, 1995) Issued), NATURE VOL392 476-4 79 pages (published on April 2, 1998), etc., a polymerizable chiral compound comprising a mesogenic group and a spacer having a chiral moiety, or JP-T-2004-504285, JP-A-2007-248945 Examples thereof include polymerizable chiral compounds containing a binaphthyl group as described in the publication. Among them, a chiral compound having a large helical twisting power (HTP) is preferable because the polymerizable liquid crystal composition of the present invention can be easily produced.
Specific examples of the chiral compound having at least one polymerizable functional group used in the polymerizable liquid crystal composition of the present invention include the following liquid crystal compounds, but are not limited thereto. is not.

(In the formula, m and n each independently represent an integer of 1 to 10, and R represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a carboxyl group, a carbamoyl group, cyano. A group, a nitro group, or a halogen atom, and when these groups are alkyl groups having 1 to 6 carbon atoms or alkoxy groups having 1 to 6 carbon atoms, they are all unsubstituted or one or two When these groups are a carboxyl group or a carbamoyl group, the terminal hydrogen atom may be unsubstituted or substituted with an alkyl group having 1 to 10 carbon atoms. Good.)
These chiral compounds can be used alone or in combination of two or more.
e) (polymerization initiator)
The polymerization initiator used in the polymerizable liquid crystal composition of the present invention is used for polymerizing the polymerizable liquid crystal composition of the present invention. As the photopolymerization initiator used when the polymerization is carried out by light irradiation, known and conventional ones can be used.

  For example, 2-hydroxy-2-methyl-1-phenylpropan-1-one (“Darocur 1173” manufactured by Merck), 1-hydroxycyclohexyl phenyl ketone (“Irgacure 184” manufactured by Ciba Specialty Chemicals), 1- ( 4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one ("Darocur 1116" manufactured by Merck & Co.), 2-methyl-1-[(methylthio) phenyl] -2-morpholinopropane-1 ( “Irgacure 907” manufactured by Ciba Specialty Chemicals). Benzylmethylketal ("Irgacure 651" manufactured by Ciba Specialty Chemicals) 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone ("Irgacure 369" manufactured by Ciba Specialty Chemicals) ), 2-dimethylamino-2- (4-methylbenzyl) -1- (4-morpholin-4-yl-phenyl) butan-1-one (“Irgacure 379” manufactured by Ciba Specialty Chemicals), 2 , 2-dimethoxy-1,2-diphenylethane-1-one, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (Darocur TPO), 2,4,6-trimethylbenzoyl-diphenyl-phosphine Oxide ("Irgaku" manufactured by Ciba Specialty Chemicals) 819 "), 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], ethanone (" Irgacure OXE01 "manufactured by Ciba Specialty Chemicals), 1- [9 -Ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime) ("Irgacure OXE02" manufactured by Ciba Specialty Chemicals). A mixture of 2,4-diethylthioxanthone (“Kayacure DETX” manufactured by Nippon Kayaku Co., Ltd.) and ethyl p-dimethylaminobenzoate (“Kayacure EPA” manufactured by Nippon Kayaku Co., Ltd.) -ITX ") and a mixture of ethyl p-dimethylaminobenzoate, acylphosphine oxide (" Lucirin TPO "manufactured by BASF), and the like.

  1-10 mass is preferable and, as for the content rate of a photoinitiator, 2-7 mass% is especially preferable. These can be used alone or in combination of two or more.

In addition, as the thermal polymerization initiator used in the thermal polymerization, known and conventional ones can be used, for example, methyl acetoacetate peroxide, cumene hydroperoxide, benzoyl peroxide, bis (4-t-butylcyclohexyl). Peroxydicarbonate, t-butylperoxybenzoate, methyl ethyl ketone peroxide, 1,1-bis (t-hexylperoxy) 3,3,5-trimethylcyclohexane, p-pentahydroperoxide, t-butylhydro Organic peroxides such as peroxide, dicumyl peroxide, isobutyl peroxide, di (3-methyl-3-methoxybutyl) peroxydicarbonate, 1,1-bis (t-butylperoxy) cyclohexane, 2, 2'-azobisisobutyronitrile, Azonitrile compounds such as 2,2′-azobis (2,4-dimethylvaleronitrile), azoamidin compounds such as 2,2′-azobis (2-methyl-N-phenylpropion-amidin) dihydrochloride, 2,2 ′ Azoamide compounds such as azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide} and alkylazo such as 2,2′azobis (2,4,4-trimethylpentane) Compounds and the like can be used. The content of the thermal polymerization initiator is preferably 1 to 10 mass%, particularly preferably 2 to 6 mass%. These can be used alone or in combination of two or more.
The photopolymerization initiator and the thermal polymerization initiator may be used in combination according to the application and production method.

f) (Solvent)
The composition of the present invention contains the polymerizable liquid crystal composition and a solvent, and the solvent used in the composition is a base material or an alignment film formed on the base material when applied on the base material. As long as the polymerizable liquid crystal composition of the present invention can be aligned without defects, the solvent used is not particularly limited, but a solvent in which the polymerizable liquid crystal compound exhibits good solubility is preferable.
Examples of such solvents include aromatic hydrocarbons such as toluene, xylene, cumene, and mesitylene, ester solvents such as methyl acetate, ethyl acetate, propyl acetate, and butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Ketone solvents, ether solvents such as tetrahydrofuran, 1,2-dimethoxyethane, anisole, amide solvents such as N, N-dimethylformamide, N-methyl-2-pyrrolidone, propylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether Examples include acetate, γ-butyrolactone, and chlorobenzene. These can be used alone or in combination of two or more.
The ratio of the solvent is not particularly limited as long as the polymerizable liquid crystal composition used in the present invention is usually applied by coating, so long as the applied state is not significantly impaired, but the solid content of the polymerizable liquid crystal composition and the solvent The ratio is preferably 0.1: 99.9 to 80:20, and more preferably 1:99 to 60:40 in view of applicability.

g) (surfactant or polymer that promotes planar alignment)
Since the polymerizable liquid crystal composition of the present invention is polymerized in a planar aligned state, a surfactant or a polymer that promotes the planar alignment is used as necessary.
The surfactant for promoting planar alignment used in the polymerizable liquid crystal composition of the present invention is soluble in the polymerized liquid crystal composition, and is opposite to the substrate when the polymerizable liquid crystal composition is coated and dried. The surfactant to be used is not particularly limited as long as it segregates at the air interface, but a surfactant having a smaller surface tension than the liquid crystal compound having a polymerizable functional group is preferable. Examples of such surfactants include fluorine-containing nonionic surfactants, organosilane surfactants, polyacrylate surfactants, and the like. The surfactant may have a polymerizable group in order to form a stronger film when polymerized.

The polymer that promotes planar alignment used in the polymerizable liquid crystal composition of the present invention is also soluble in the polymerized liquid crystal composition, and the air on the side opposite to the substrate when the polymerizable liquid crystal composition is applied and dried. The polymer to be used is not particularly limited as long as it segregates at the interface, but a polymer having a smaller surface tension than a liquid crystal compound having a polymerizable functional group is preferable. Examples of such a polymer include polyethylene, polypropylene, polyisobutylene, paraffin, liquid paraffin, chlorinated polypropylene, chlorinated paraffin, chlorinated liquid paraffin, and polyvinylidene fluoride.
The polymer preferably has a mass average molecular weight of 200 to 1,000,000, more preferably 300 to 100,000, and particularly preferably 400 to 10,000.
The content of surfactant or polymer that promotes planar alignment is preferably 0.01 to 3% by mass, particularly preferably 0.05 to 1.0% by mass.

h) (stabilizer)
The polymerizable liquid crystal composition of the present invention can be applied uniformly, to obtain a cholesteric reflective film having a uniform film thickness, or a general-purpose additive can be used according to each purpose. For example, leveling agents, thixotropic agents, surfactants, ultraviolet absorbers, infrared absorbers, antioxidants, surface treatment agents, polymerization inhibitors and the like can be added to such an extent that the liquid crystal alignment ability is not significantly reduced. .
(Cholesteric reflective film)
The cholesteric reflective film of the present invention is a cholesteric reflective film composed of a cured product of a planar aligned polymerizable liquid crystal composition, wherein the polymerizable liquid crystal composition is
a) General formula (1)

(In the formula, R ₁ and R ₂ each independently represent a fluorine atom, a chlorine atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms, and these are included in these groups. One or more of hydrogen atoms may be substituted with a fluorine atom, and Z ₁ may be a single bond, —O—, —S—, —COO—, —OCO—, —OCH ₂ —, —CH═CH. -, - CH = CH-COO- , or an -OCO-CH = CH-, _{Z 2} is a single bond, -O -, - S -, - COO -, - OCO -, - CH 2 O -, - CH = CH—, —CH═CH—COO—, or —OCO—CH═CH—, and A represents —C≡C—, —C═N—, —N═N—, or —C═N—. N = C-, or any of the following ring structures

を表す。Ｒ_３は、Ｆ、Ｃｌ、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、シアノ基を表す。Ｂは

Represents. R ₃ represents F, Cl, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cyano group. B is

R ₄ represents a fluorine atom, a chlorine atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cyano group. 1) or 2 or more types of liquid crystal compounds represented by b), b) 1 or 2 types of liquid crystal compounds having only one polymerizable functional group, and c) 2 or more polymerizable functional groups. 1) or 2 or more kinds of liquid crystal compounds, d) 1 or 2 kinds of chiral compounds having one or more polymerizable functional groups, and e) 1 or more kinds of polymerization initiators. It is characterized by.
The cholesteric reflective film of the present invention is preferably a cholesteric reflective film having a polarization reflection band of 300 nm or more.

(Cholesteric reflective film manufacturing method)
(Base material)
The substrate used for the cholesteric reflective film of the present invention is a substrate usually used for liquid crystal devices, displays, optical components and optical films, and when dried after application of the polymerizable liquid crystal composition of the present invention, or If it is the material which has heat resistance which can endure the heating at the time of liquid crystal device manufacture, there will be no restriction | limiting in particular. Examples of such a substrate include organic materials such as a glass substrate, a metal substrate, a ceramic substrate, and a plastic substrate. In particular, when the substrate is an organic material, cellulose derivatives, polyolefins, polyesters, polyolefins, polycarbonates, polyacrylates, polyarylates, polyether sulfones, polyimides, polyphenylene sulfides, polyphenylene ethers, nylons, polystyrenes, and the like can be given.

Of these, plastic substrates such as polyester, polystyrene, polyolefin, cellulose derivatives, polyarylate, and polycarbonate are preferable.
In order to improve the applicability and adhesiveness of the polymerizable liquid crystal composition of the present invention, these substrates may be subjected to surface treatment. Examples of the surface treatment include ozone treatment, plasma treatment, corona treatment, silane coupling treatment, and the like. In addition, in order to adjust the light transmittance and reflectance, an organic thin film, an inorganic oxide thin film, a metal thin film, etc. are provided on the surface of the substrate by a method such as vapor deposition, or in order to add optical added value. The material may be a pickup lens, a rod lens, an optical disk, a retardation film, a light diffusion film, a color filter, or the like. Among these, a pickup lens, a retardation film, a light diffusion film, and a color filter that have higher added value are preferable.

  In addition, the substrate is usually subjected to an alignment treatment or provided with an alignment film so that the polymerizable liquid crystal composition is aligned when the polymerizable liquid crystal composition of the present invention is applied and dried. Also good. Examples of the alignment treatment include stretching treatment, rubbing treatment, polarized ultraviolet visible light irradiation treatment, ion beam treatment, and the like. When the alignment film is used, a known and conventional alignment film is used. Such alignment films include polyimide, polysiloxane, polyamide, polyvinyl alcohol, polycarbonate, polystyrene, polyphenylene ether, polyarylate, polyethylene terephthalate, polyether sulfone, epoxy resin, epoxy acrylate resin, acrylic resin, coumarin compound, chalcone. Examples of the compound include compounds, cinnamate compounds, fulgide compounds, anthraquinone compounds, azo compounds, and arylethene compounds. The compound subjected to the alignment treatment by rubbing is preferably an alignment treatment or a compound in which crystallization of the material is promoted by inserting a heating step after the alignment treatment. Among the compounds that perform alignment treatment other than rubbing, it is preferable to use a photo-alignment material.

(Application)
Examples of the coating method for obtaining the cholesteric reflective film of the present invention include applicator method, bar coating method, spin coating method, gravure printing method, flexographic printing method, ink jet method, die coating method, cap coating method, dipping, etc. Can be done. Usually, since the polymerizable liquid crystal composition diluted with a solvent is applied, it is dried after the application.
(Polymerization process)
The polymerization operation of the polymerizable liquid crystal composition of the present invention is generally carried out by removing light from the polymerizable liquid crystal composition by drying or the like and then irradiating it with light such as ultraviolet rays or heating in a planar alignment state. When the polymerization is performed by light irradiation, specifically, it is preferable to irradiate ultraviolet light having a wavelength of 390 nm or less, and it is most preferable to irradiate light having a wavelength of 250 to 370 nm. However, when the polymerizable liquid crystal composition causes decomposition or the like due to ultraviolet light of 390 nm or less, it may be preferable to perform polymerization treatment with ultraviolet light of 390 nm or more. This light is preferably diffused light and unpolarized light.

  On the other hand, the polymerization by heating is preferably performed at a temperature at which the polymerizable liquid crystal composition exhibits a liquid crystal phase or at a temperature lower than that. In particular, when a thermal polymerization initiator that releases radicals by heating is used, the cleavage temperature is the above. It is preferable to use the one in the temperature range. When the thermal polymerization initiator and the photopolymerization initiator are used in combination, the polymerization temperature and the polymerization temperature are set so that the polymerization speeds of both the photo-alignment film and the polymerizable liquid crystal film are not greatly different together with the limitation of the temperature range. It is preferred to select each initiator. Although the heating temperature depends on the transition temperature from the liquid crystal phase to the isotropic phase of the polymerizable liquid crystal composition, the heating temperature is preferably lower than the temperature at which inhomogeneous polymerization is induced by heat. However, if the glass transition point of the base material made of an organic material is exceeded, thermal deformation of the base material becomes remarkable, and therefore, the glass transition point of the room temperature to the base material is preferable. For example, when a polymeric group is a (meth) acryloyl group, it is preferable to carry out at a temperature lower than 90 degreeC.

  The cholesteric reflective film can also be heat-treated in order to stabilize the solvent resistance and heat resistance of the obtained cholesteric reflective film. In this case, it is preferable to heat above the glass transition point of the prepolymerizable liquid crystal film. Usually, heating within a range not exceeding the glass transition point of a base material made of an organic material is preferable. In addition, for the above purpose, light irradiation treatment can also be performed. In this case, it is preferable that the liquid crystal compound component in the cholesteric reflective film is not photodegraded by light irradiation.

(Reflective polarizing plate)
The reflective polarizing plate of the present invention is a reflective polarizing plate or base material in which a base material, a cholesteric reflective film, a retardation film are sequentially laminated, a reflective type in which a cholesteric reflective film, a retardation film, and a linearly polarizing film are sequentially laminated. A polarizing plate, wherein the cholesteric reflective film uses the cholesteric reflective film of the present invention.
Moreover, the aspect which has two or more retardation films in a reflection type polarizing plate, and this retardation film used the retardation film from which retardation differs is also preferable.
The lamination of the base material and the cholesteric reflective film is as described in the method for producing the cholesteric reflective film. The lamination | stacking of retardation film can mention the method shown below.

(When directly laminated on cholesteric reflective film)
It is obtained by forming an alignment film on the cholesteric reflective film of the present invention, applying and drying a solution containing the liquid crystal compound thereon, and polymerizing the liquid crystal compound in a uniaxially aligned state. When the liquid crystal compound is uniaxially aligned without forming an alignment film, it is obtained by coating and drying a solution containing the liquid crystal compound directly on the cholesteric film of the present invention and polymerizing. In the case of using an alignment film, a known and conventional alignment film is used as described in the section of the base material.

(When pasting on cholesteric reflective film)
A coating film is dried on the substrate by the coating method, and a retardation film is obtained by the same method as in the polymerization step. After bonding an adhesive or an adhesive film to the obtained retardation film, the cholesteric reflective film of the present invention and the retardation film are bonded by bonding via an adhesive or an adhesive film. It is done. In the case of using an adhesive or an adhesive film, known adhesives and adhesive films for optical film use are used.

Further, the retardation film may be provided with two different retardation films. As a combination of two different retardation films, the alignment of liquid crystal compounds is homogeneous (positive A plate), homogeneous (positive A plate), homogeneous (positive A plate), homeotropic (positive C plate), and homogeneous (positive A plate). ) And hybrid (O plate).
Furthermore, when providing a linearly-polarizing film on the said retardation film, it laminates | stacks by a bonding system normally.
The lamination method is the same as the method of laminating a retardation film on the cholesteric reflective film.

  By subjecting the cholesteric reflective film of the present invention to an X-ray irradiation treatment or an electron beam irradiation treatment, the adhesion between the substrate and the polymer of the polymerizable liquid crystal composition of the present invention is improved. X-rays are electromagnetic waves having a wavelength of 0.1 to 100 Å (angstrom) and energy of about 0.1 to 100 keV, and a commercially available X-ray irradiation apparatus is usually used. The energy of X-rays may be such that the cholesteric reflective film of the present invention is not decomposed by the X-ray irradiation treatment, and specifically, 1 to 100 kGy (gray) is preferable. On the other hand, an electron beam (EB) is a flow of electrons accelerated by a large energy given by an accelerator, and a commercially available electron beam irradiation apparatus is usually used. The output of an electron beam should just be a grade which the cholesteric reflective film of this invention does not decompose | disassemble by an electron beam irradiation process, and 10-200 kGy is specifically preferable.

Hereinafter, the present invention will be described with reference to synthesis examples, examples, and comparative examples, but the present invention is not limited to these examples. Unless otherwise specified, “part” and “%” are based on mass.
(Preparation of polymerizable liquid crystal composition (1))
Liquid crystal compound represented by formula (A-1), Liquid crystal compound represented by formula (B-1), Liquid crystal compound represented by formula (C-1), Liquid crystal represented by formula (C-2) Compound, chiral compound represented by formula (D-1), polymerization initiator represented by formula (E-1), polymerization initiator represented by formula (E-2), liquid paraffin (G-1) The polymerizable liquid crystal composition (1) of the present invention was obtained by mixing 0.5 part. After adding 0.07 part of 4-methoxy-1-naphthol (H-1) and 60 parts of cyclohexanone (F-1) to the obtained polymerizable liquid crystal composition, it was dissolved at 60 ° C. to obtain the polymerizable property of the present invention. A liquid crystal composition (2) was obtained.

(Preparation of polymerizable liquid crystal compositions (3) to (25))
In the same manner as the preparation of the polymerizable liquid crystal composition (2) of the present invention, the polymerizable liquid crystal compositions (3) to (21) of the present invention and the polymerizable liquid crystal compositions (22) to (25) of the comparative examples are obtained. It was. Tables 1 to 6 show specific compositions of the polymerizable liquid crystal compositions (1) to (21) of the present invention and the polymerizable liquid crystal compositions (22) to (25) of the comparative examples.

  The compounds shown in Tables 1 to 6 are as shown below.

Cyclopentanone (F-2)
Toluene (F-3)
Polypropylene having a weight average molecular weight of 2200 (G-2)
4-methoxyphenol (H-2)

Example 1
The polyimide solution for alignment film was applied to a glass substrate having a thickness of 0.7 mm using a spin coating method, dried at 100 ° C. for 10 minutes, and then baked at 200 ° C. for 60 minutes to obtain a coating film. The obtained coating film was rubbed to obtain a cholesteric reflective film substrate of the present invention. The rubbing treatment was performed using a commercially available rubbing apparatus.
The polymerizable liquid crystal composition (2) of the present invention was applied to a rubbed substrate by a spin coating method and dried at 80 ° C. for 2 minutes. The obtained coating film was placed on a hot plate at 60 ° C., and a 15 mW / cm ² high-pressure mercury lamp adjusted so that ultraviolet light (UV light) of only around 365 nm was obtained with a band-pass filter. Irradiated with UV light for 10 seconds at intensity. Next, the bandpass filter was removed, and UV light was irradiated for 20 seconds at an intensity of 70 mW / cm ² to obtain a cholesteric reflective film of the present invention.
When the selective reflection wavelength of the obtained cholesteric reflection film was measured using a spectrophotometer (U-4100 “manufactured by Hitachi, Ltd.”), the polarization reflection band was about 350 nm as shown in FIG.
(Examples 2 to 16)
In the same manner as in Example 1, cholesteric reflective films of Examples 2 to 16 were obtained. As shown in Table 7, the polarization reflection band of the obtained cholesteric reflection film was 300 nm or more. Therefore, the cholesteric reflective film produced using the polymerizable liquid crystal composition of the present invention can be said to be an excellent cholesteric reflective film capable of reflecting the entire visible light. Moreover, it can be said that application | coating, drying, and irradiation at the time of producing a cholesteric reflective film can be performed in a shorter time than before, and it is excellent also in productivity.

(Comparative Examples 1-3)
Cholesteric reflective films of Comparative Examples 1 to 3 were obtained in the same manner as in Example 1 except that the polymerizable liquid crystal compositions (21) to (23) were used. As shown in Table 8, the polarization reflection bands of the obtained reflection films were all 150 nm or less.

(Comparative Examples 4-5)
In the same manner as in Example 1, an attempt was made to obtain the cholesteric reflective films of Comparative Examples 4 and 5 using the polymerizable liquid crystal compositions (24) and (25). A predetermined cholesteric reflective film could not be obtained.
(Example 17)
The polymerizable liquid crystal composition (4) of the present invention was applied to a rubbed PET film with a bar coater and dried at 90 ° C. for 2 minutes. The obtained coating film was held at 60 ° C., and UV light was applied for 10 seconds at an intensity of 15 mW / cm ² using a high-pressure mercury lamp adjusted so that UV light of only around 365 nm was obtained with a bandpass filter. Irradiated. Next, the bandpass filter was removed, and the cholesteric reflective film of Example 17 was obtained by irradiating with UV light at an intensity of 70 mW / cm ² for 20 seconds.

When the selective reflection wavelength of the obtained cholesteric reflection film was measured, the polarization reflection band was about 360 nm as shown in FIG.
(Examples 18 to 32)
Cholesteric reflective films of Examples 18 to 32 were obtained in the same manner as Example 17. As shown in Table 9, the polarization reflection band of the obtained cholesteric reflection film was 300 nm or more.

(Example 33)
2 parts of polyvinyl butyral (product name “ESREC BM-2” manufactured by Sekisui Chemical Co., Ltd.) were dissolved in 49 parts of ethanol and 49 parts of 2-butoxyethanol. The obtained polyvinyl butyral solution was applied to the cholesteric reflective film obtained in Example 1 by a spin coat method and dried at 80 ° C. for 2 minutes. The obtained coating film was rubbed. The rubbing treatment was performed using a commercially available rubbing apparatus.
Next, a toluene solution (solid content ratio: 20%) of a polymerizable liquid crystal composition (product name: UV curable liquid crystal “UCL-017” manufactured by DIC Corporation) for retardation film is spin-coated on the rubbing-treated substrate. And then dried at 80 ° C. for 2 minutes. The obtained coating film was irradiated with UV light at an intensity of 30 mW / cm ² for 15 seconds using a high-pressure mercury lamp to obtain a reflective polarizing plate of Example 33.
The spectral characteristics of the obtained reflective polarizing plate were measured using a spectrophotometer (U-4100 “manufactured by Hitachi, Ltd.”. The measurement was performed between the reflective polarizing plate of Example 33 and the detector. A linear polarizing plate was placed, and the transmittance was measured when the polarization directions of the reflective polarizing plate of Example 33 and the commercially available linear polarizing plate were parallel (parallel Nicol) and vertical (cross Nicol). In the case of parallel Nicol, the transmittance was 90% or more in the visible light region, and in the case of crossed Nicol, the transmittance was almost 0% in the visible light region.

(Example 34)
The toluene solution of UCL-017 used in Example 33 was applied to a surface-rubbed polyacetylcellulose film and dried at 60 ° C. for 3 minutes. The obtained coating film was irradiated with UV light for 15 seconds at an intensity of 30 mW / cm ² using a high-pressure mercury lamp to obtain a retardation film made of a polymerizable liquid crystal composition. After peeling off the release layer on one side of the commercially available transparent double-sided pressure-sensitive adhesive tape, it was pasted on the obtained retardation film, and after peeling off the other release layer, it was pasted on the cholesteric reflective film of Example 17 and carried out. The reflective polarizing plate of Example 34 was obtained. When the spectral characteristics of the obtained reflective polarizing plate were measured by the same method as in Example 33, good polarization characteristics were obtained as in Example 33.

(Example 35)
The polyvinyl butyral solution of Example 33 was applied on the reflective polarizing plate of Example 33 by spin coating, and dried at 80 ° C. for 2 minutes.
Next, a xylene solution (solid content ratio: 25%) of a polymerizable liquid crystal composition (product name: UV curable liquid crystal “UCL-018” manufactured by DIC Corporation) for a retardation film is applied to the reflective polarizing plate by a spin coating method. And dried at 80 ° C. for 2 minutes. The obtained coating film was irradiated with UV light for 20 seconds at an intensity of 30 mW / cm ² using a high-pressure mercury lamp to obtain a reflective polarizing plate of Example 35.

(Example 36)
The xylene solution of UCL-018 used in Example 35 was applied to a surface-treated polyacetylcellulose film and dried at 60 ° C. for 3 minutes. The obtained coating film was irradiated with UV light at an intensity of 30 mW / cm ² for 20 seconds using a high-pressure mercury lamp to obtain a retardation film made of a polymerizable liquid crystal composition. After peeling off the release layer on one side of the commercially available transparent double-sided pressure-sensitive adhesive tape, it was pasted on the obtained retardation film, and after peeling off the other release layer, it was stuck on the reflective polarizing plate of Example 34, A reflective polarizing plate of Example 36 was obtained.

(Example 37)
A peelable release layer on one side of a commercially available transparent double-sided pressure-sensitive adhesive tape was applied on the cholesteric reflective film of Example 17, and then the other release layer was peeled off, and then the cholesteric reflective film of Example 17 was pasted together. A cholesteric reflective film was obtained.
When the selective reflection wavelength of the cholesteric reflection film of Example 37 was measured, the polarization reflection band was about 400 nm as in Example 2. Further, the transmittance was almost 50% or less over the entire visible light range.

(Example 38)
A cholesteric reflective film of Example 38 was obtained by irradiating the cholesteric reflective film of Example 17 with 5 kGy of X-rays at room temperature using a commercially available X-ray irradiation apparatus.
Evaluation of the adhesiveness of the obtained cholesteric reflective film was performed by the crosscut test described in JIS-K5400. In the cross-cut test, 25 squares were made using a cutter to make cuts vertically and horizontally at intervals of 2 mm. When cellophane tape was affixed on the squares and the squares were counted, 24 squares remained.

(Example 39)
The cholesteric reflective film of Example 17 was irradiated with an electron beam of 10 kGy at room temperature using a commercially available electron beam irradiation apparatus to obtain a cholesteric reflective film of Example 39.
When adhesion was evaluated in the same manner as in Example 38, 20 cells remained.

Claims (19)

a) General formula (1)

(In the formula, R ₁ and R ₂ each independently represent a fluorine atom, a chlorine atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms, and these are included in these groups. One or more of hydrogen atoms may be substituted with a fluorine atom, and Z ₁ may be a single bond, —O—, —S—, —COO—, —OCO—, —OCH ₂ —, —CH═CH. -, - CH = CH-COO- , or an -OCO-CH = CH-, _{Z 2} is a single bond, -O -, - S -, - COO -, - OCO -, - CH 2 O -, - CH = CH—, —CH═CH—COO—, or —OCO—CH═CH—, and A represents —C≡C—, —C═N—, —N═N—, or —C═N—. N = C-, or any of the following ring structures

R ₃ represents a fluorine atom, a chlorine atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cyano group, and B represents the following ring structure

R ₄ represents a fluorine atom, a chlorine atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cyano group. 1) or 2 or more types of liquid crystal compounds represented by b), b) 1 or 2 types of liquid crystal compounds having only one polymerizable functional group, and c) 2 or more polymerizable functional groups. 1) or 2 or more kinds of liquid crystal compounds, d) 1 or 2 kinds of chiral compounds having one or more polymerizable functional groups, and e) 1 or more kinds of polymerization initiators. A polymerizable liquid crystal composition characterized by the above. The polymerizable liquid crystal composition according to claim 1, wherein the content of the compound represented by the general formula (1) is 0.1 to 20% by mass. The polymerizable liquid crystal composition according to claim 1 or 2, comprising a) two or more liquid crystal compounds having only one polymerizable functional group. The polymerizable liquid crystal composition according to claim 1, 2 or 3, comprising two or more liquid crystal compounds having two polymerizable functional groups. A liquid crystal compound having only one polymerizable functional group is represented by the general formula (2)

(In the formula, L represents a hydrogen atom or a methyl group, Sp represents a single bond or an alkyl group having 1 to 10 carbon atoms, X represents a single bond, —O—, —S—, —COO—, —OCO—). , —OCH ₂ —, —CH═CH—, —CH═CH—COO— or —OCO—CH═CH—, G ₁ is a single bond, 1,4-phenylene group, naphthalene-2,6-diyl Group or a 1,4-cyclohexylene group, and one or two or more hydrogen atoms present in these groups are a fluorine atom, a chlorine atom, an alkyl group having 1 to 6 carbon atoms, and 1 to 2 carbon atoms. 6 may be substituted with an alkoxy group or a cyano group, and M represents a single bond, —O—, —S—, —COO—, —OCO—, —OCH ₂ —, —CH═CH—, —CH. = CH-COO- or -OCO-CH = CH- to represent, _{if G 1} is a single bond, M It represents a single bond, representing the _{G 1} is 1,4-phenylene group, naphthalene-2,6-diyl group or a 1,4-cyclohexylene group, -O -, - S -, - COO -, - OCO- , —OCH ₂ —, —CH═CH—, —CH═CH—COO— or —OCO—CH═CH—, G ₂ represents a hydrogen atom, a phenyl group, a cyclohexyl group, a naphthyl group, or a carbon number of 1 to 10. Represents an alkyl group, an alkoxy group having 1 to 10 carbon atoms, a carboxyl group, a carbamoyl group, a cyano group, a nitro group or a halogen atom, but the hydrogen atom in the phenyl group, cyclohexyl group or naphthyl group is unsubstituted. Or may be substituted with one or two or more halogen atoms, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cyano group, and the carboxyl group or carbamoyl Each hydrogen atom good .Y ₁ and Y ₂ may be substituted with an alkyl group having 1 to 10 carbon atoms which may be unsubstituted or substituted independently represent a hydrogen atom, a halogen atom in the cyano group, a nitro group, carbon The polymerizable liquid crystal composition according to any one of claims 1 to 4, which is represented by: an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms. The polymerizable liquid crystal composition according to claim 1, wherein the content of the compound represented by the general formula (2) is 5 to 80% by mass. A liquid crystal compound having only one polymerizable functional group is represented by the general formula (3)

(In the formula, L ₁ represents a hydrogen atom or a methyl group, Sp ₁ represents a single bond or an alkyl group having 1 to 10 carbon atoms, and X ₁ and X ₂ are each independently a single bond, —O—, Represents —S—, —COO—, —OCO—, —OCH ₂ —, —CH═CH—, —CH═CH—COO— or —OCO—CH═CH—, and represents Y ₃ , Y ₄ , Y ₅ and Y ₆ each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a carboxyl group, a carbamoyl group, a cyano group, a nitro group, or a halogen atom, The hydrogen atom in the alkoxy group may be substituted with one or more halogen atoms, and even if the hydrogen atom in the carboxyl group or carbamoyl group is not substituted, it is substituted with an alkyl group having 1 to 10 carbon atoms. May be.)
The polymerizable liquid crystal composition according to any one of claims 1 to 6 represented by: The polymerizable liquid crystal composition according to claim 1, wherein the content of the polymerization initiator is 1 to 10% by mass. The polymerizable liquid crystal composition according to any one of claims 1 to 8, comprising one or more surfactants or polymers for promoting planar alignment. The polymerizable liquid crystal composition according to claim 9, wherein the content of a surfactant or polymer that promotes planar alignment is 0.01 to 3% by mass. The composition containing 1 type (s) or 2 or more types of the polymeric liquid crystal composition and solvent as described in any one of Claims 1-10. A cholesteric reflective film composed of a cured product of a planar aligned polymerizable liquid crystal composition, the polymerizable liquid crystal composition comprising:
a) General formula (1)

(In the formula, R ₁ and R ₂ each independently represent a fluorine atom, a chlorine atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms, and these are included in these groups. One or more of hydrogen atoms may be substituted with a fluorine atom, and Z ₁ may be a single bond, —O—, —S—, —COO—, —OCO—, —OCH ₂ —, —CH═CH. -, - CH = CH-COO- , or an -OCO-CH = CH-, _{Z 2} is a single bond, -O -, - S -, - COO -, - OCO -, - CH 2 O -, - CH = CH—, —CH═CH—COO—, or —OCO—CH═CH—, and A represents —C≡C—, —C═N—, —N═N—, or —C═N—. N = C-, or any of the following ring structures

R ₃ represents a fluorine atom, a chlorine atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cyano group, and B represents the following ring structure

R ₄ represents a fluorine atom, a chlorine atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cyano group. 1) or 2 or more types of liquid crystal compounds represented by b), b) 1 or 2 types of liquid crystal compounds having only one polymerizable functional group, and c) 2 or more polymerizable functional groups. 1) or 2 or more kinds of liquid crystal compounds, d) 1 or 2 kinds of chiral compounds having one or more polymerizable functional groups, and e) 1 or more kinds of polymerization initiators. A cholesteric reflective film characterized by The cholesteric reflective film according to claim 12, wherein the polarization reflection band is 300 nm or more. The cholesteric reflective film having a substrate, wherein the substrate is a plastic film. A reflective polarizing plate in which a base material, a cholesteric reflective film and a retardation film are sequentially laminated, wherein the cholesteric reflective film is the cholesteric reflective film according to any one of claims 12 to 14. Reflective polarizing plate. A reflective polarizing plate in which a substrate, a cholesteric reflective film, a retardation film, and a linear polarizing film are sequentially laminated, and the cholesteric reflective film is the cholesteric reflective film according to any one of claims 12 to 14. A reflective polarizing plate characterized by the above. The reflective polarizing plate according to claim 15 or 16, wherein the reflective polarizing plate has two or more retardation films, and the retardation films have retardation films having different retardations. The cholesteric reflective film according to any one of claims 12 to 14, which has been subjected to an X-ray irradiation treatment or an electron beam irradiation treatment. The reflective polarizing plate according to claim 15 , wherein the base material is a light diffusion film.

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