KR20240072041A - Retardation film-forming composition, method for producing retardation film and retardation plate - Google Patents

Abstract

(Problem) It is possible to form a film by employing a process for removing the solvent at a lower temperature than before, for example, below 100°C, and suppress the occurrence of unevenness during film formation to form a retardation film with excellent optical properties. Providing a composition for forming a phase contrast film that can be formed.
(Solution) A polymerizable liquid crystal compound having a nematic liquid crystal phase transition temperature of 100°C or higher and 200°C or lower, and at least two organic solvents A and organic solvent B having different boiling points from each other,
When the nematic liquid crystal phase transition temperature of the polymerizable liquid crystal compound is set to 3):
Tb - Ta ≥ 10 (℃) (1)
Ta < X - 30 (℃) (2)
Tb > X - 70 (℃) (3)
A composition for forming a phase contrast film that satisfies the above.

Description

Composition for forming a phase contrast film, a method for manufacturing a phase contrast film, and a retardation plate {RETARDATION FILM-FORMING COMPOSITION, METHOD FOR PRODUCING RETARDATION FILM AND RETARDATION PLATE}

The present invention relates to a composition for forming a retardation film, a method for producing a retardation film using the composition for forming a retardation film, and a retardation plate comprising a cured film of the composition for forming a retardation film.

Retardation films (retardation films) used in various image display devices are required to be able to convert polarization in the full-wave range as one of their characteristics, for example, [Re(450)/Re(550)] < 1. It is known that, in theory, uniform polarization conversion is possible in a wavelength range showing reverse wavelength dispersion. For example, polymerizable liquid crystal compounds having so-called T-shaped or H-shaped molecular structures tend to exhibit reverse wavelength dispersion when polymerized and cured, and are used as materials for forming retardation films (e.g., Patent Document 1).

Japanese Patent Publication No. 2019-191504

The retardation film formed from a polymerizable liquid crystal compound is, for example, formed by applying a coating solution obtained by dissolving a polymerizable liquid crystal compound in a solvent to a support substrate to form a coating film, and then forming a coating film by placing the polymerizable liquid crystal compound contained in the coating film in a liquid crystalline state. It can be obtained by transferring to and distilling off the solvent. Usually, such a film forming method includes a heat drying process to distill off the solvent, but in recent years, there has been a demand for lowering the temperature during film forming from the viewpoint of reducing environmental load.

However, according to studies by the present inventors and others, in the conventional composition for forming a retardation film using a polymerizable liquid crystal compound with a relatively high nematic phase transition temperature, for example, the nematic phase transition temperature exceeding 100°C, solvent removal is required. It was found that when the drying temperature of the poem is lowered, the distribution of the in-plane retardation of the obtained retardation film tends to deteriorate, causing retardation non-uniformity in some cases.

The present invention makes it possible to form a film by employing a process for removing the solvent at a lower temperature than before, for example, less than 100°C, and also suppresses the occurrence of unevenness during film formation, thereby producing a phase difference film with excellent optical properties. The purpose is to provide a composition for forming a phase contrast film that can form a film.

The present invention provides the following preferred aspects.

[1] A polymerizable liquid crystal compound having a nematic liquid crystal phase transition temperature of 100°C or higher and 200°C or lower, and at least two organic solvents A and organic solvent B having different boiling points from each other,

When the nematic liquid crystal phase transition temperature of the polymerizable liquid crystal compound is set to ) :

Tb - Ta ≥ 10 (℃) (One)

Ta < X - 30 (℃) (2)

Tb > X - 70 (℃) (3)

A composition for forming a phase contrast film that satisfies the above.

[2] The composition for forming a retardation film according to [1] above, wherein the polymerizable liquid crystal compound contains a polymerizable liquid crystal compound (I) represented by the following formula (I).

[Formula 1]

P ¹ -E ¹ -(B ¹ -G ¹ ) _k -L ¹ -Ar-L ² -(G ² -B ² ) _l -E ² -P ² (I)

[In formula (I),

L ¹ , L ² , B ¹ and B ² each independently represent a single bond or a divalent linking group,

G ¹ and G ² each independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group, and the hydrogen atom contained in the divalent aromatic group or divalent alicyclic hydrocarbon group is a halogen atom or a C 1 to C 4 hydrocarbon group. It may be substituted with an alkyl group, a fluoroalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, or a nitro group, and the carbon atom constituting the divalent aromatic group or divalent alicyclic hydrocarbon group, oxygen atom, or sulfur It may be substituted with an atom or a nitrogen atom,

k and l each independently represent an integer from 0 to 3 and satisfy the relationship of 1 ≤ k + l,

E ¹ and E ² each independently represent an alkanediyl group having 1 to 17 carbon atoms, the hydrogen atom contained in the alkanediyl group may be substituted with a halogen atom, and -CH ₂ contained in the alkanediyl group - may be substituted with -O-, -S-, -C(=O)-,

P ¹ and P ² independently represent a polymerizable group or a hydrogen atom (provided that at least one of P ¹ and P ² is a polymerizable group),

Ar is a group represented by any of the formulas (Ar-1) to (Ar-5)

[Formula 2]

[In formula (Ar-1) to (Ar-5),

* indicates a coupling part;

Q ¹ represents -S-, -O- or -NR ¹¹ -, R ¹¹ represents a hydrogen atom or an alkyl group of 1 to 6 carbon atoms which may have a substituent,

Q ² represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may have a substituent;

W ¹ and W ² each independently represent -O-, -S-, -CO-, and -NR ¹¹ -, and R ¹¹ represents a hydrogen atom or an alkyl group of 1 to 6 carbon atoms which may have a substituent;

Y ¹ represents an alkyl group having 1 to 6 carbon atoms, an aromatic hydrocarbon group that may have a substituent, or an aromatic heterocyclic group,

Y ² represents a CN group or an alkyl group having 1 to 12 carbon atoms which may have a substituent, the hydrogen atom contained in the alkyl group may be substituted with a halogen atom, and -CH ₂ - contained in the alkyl group is -O- , -CO-, -O-CO- or -CO-O- may be substituted;

Z ¹ , Z ² and Z ³ are each independently a hydrogen atom, an aliphatic hydrocarbon group or an alkoxy group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, represents a halogen atom, a cyano group, a nitro group, -NR ¹² R ¹³ or -SR ¹⁴ , Z ¹ and Z ² may combine with each other to form an aromatic ring or an aromatic heterocycle, and R ¹² to R ¹⁴ each represent Independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms;

Ax represents an organic group of 2 to 30 carbon atoms having at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocycle, and Ay is a hydrogen atom, an alkyl group of 1 to 6 carbon atoms that may have a substituent, or represents an organic group of 2 to 30 carbon atoms having at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocycle; Ax and Ay may combine to form a ring;

Y ³ and Y ⁴ are each independently represented by the following formula (Y ³ -1):

[Formula 3]

[In equation (Y ³ -1),

R ^Y1 represents a hydrogen atom or an alkyl group having 1 to 6 carbon ^atoms , and the alkyl ^group may be substituted by one or more substituents Fluorosulfuranyl group, nitro group, cyano group, isocyano group, amino group, hydroxyl group, mercapto group, methylamino group, dimethylamino group, diethylamino group, diisopropylamino group, trimethylsilyl group, dimethylsilyl group, thioi Isocyano group, or one -CH ₂ - or two or more non-adjacent -CH ₂ - are each independently -O-, -S-, -CO-, -COO-, -OCO-, -CO-S -, -S-CO-, -O-CO-O-, -CO-NH-, -NH-CO-, -CH=CH-COO-, -CH=CH-OCO-, -COO-CH=CH -, -OCO-CH=CH-, -CH=CH-, -CF=CF- or -C≡C- represents a linear or branched alkyl group having 1 to 20 carbon atoms that may be substituted, and any of the alkyl groups The hydrogen atom may be substituted with a fluorine atom, or may be a group represented by -B ³ -F ³ -P ³ (where B ³ is -CR ¹⁶ R ¹⁷ -, -CH ₂ -CH ₂ -, -O- , -S-, -CO-O-, -O-CO-, -O-CO-O-, -C(=S)-O-, -OC(=S)-, -OC(=S)- O-, -CO-NR ¹⁸ -, -NR ¹⁸ -CO-, -O-CH ₂ -, -CH ₂ -O-, -S-CH ₂ -, -CH ₂ -S- or a single bond, R ¹³ and R ¹⁴ each independently represent a hydrogen atom, a fluorine atom, or an alkyl group with 1 to 4 carbon atoms; F ³ represents an alkanediyl group with 1 to 12 carbon atoms, and the hydrogen atom contained in the alkanediyl group may be substituted with -OR ¹⁹ or a halogen atom, R ¹⁹ represents an alkyl group having 1 to 4 carbon atoms, and the hydrogen atom contained in the alkyl group may be substituted with a fluorine atom, or -CH contained in the alkanediyl group. _2- may be substituted with -O- or -CO-; P ³ represents a hydrogen atom or a polymerizable group),

U ¹ represents an organic group having 2 to 30 carbon atoms having an aromatic hydrocarbon group, any carbon atom of the aromatic hydrocarbon group may be substituted with a hetero atom, and the aromatic hydrocarbon group may be substituted with one or more of the above ^substituents become ;

T ¹ is -O-, -S-, -COO-, -OCO-, -OCO-O-, -NU ² -, -N=CU ² -, -CO-NU ² -, -OCO-NU ² - or O-NU ² -, and U ² is a hydrogen atom, an alkyl group with 1 to 20 carbon atoms, a cycloalkyl group with 3 to 12 carbon atoms, a cycloalkenyl group with 3 to 12 carbon atoms, or an aromatic hydrocarbon group (any of the aromatic hydrocarbon groups). The carbon atom of may be substituted with a hetero atom), an organic group having 2 to 30 carbon atoms, or (E ³ -A ³ ) _q -B ³ -F ³ -P ³ , and its alkyl group, cycloalkyl group, or cycloalke The nyl group and the aromatic hydrocarbon group may _each be unsubstituted or substituted with one or more ^substituents Or two or more non-adjacent -CH ₂ - are each independently -O-, -S-, -CO-, -COO-, -OCO-, -CO-S-, -S-CO-, -SO ₂ -, -O-CO-O-, -CO-NH-, -NH-CO-, -CH=CH-COO-, -CH=CH-OCO-, -COO-CH=CH-, - OCO-CH=CH-, -CH=CH-, -CF=CF- or -C≡C- may be substituted, and one -CH ₂ - in the cycloalkyl group or cycloalkenyl group or two non-adjacent ones. The above -CH ₂ - may each independently be substituted with -O-, -CO-, -COO-, -OCO- or O-CO-O-, E ³ is defined the same as B ³ above, and A ³ represents a divalent alicyclic hydrocarbon group having 3 to 16 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 20 carbon atoms, and the hydrogen atoms contained in the alicyclic hydrocarbon group and the aromatic hydrocarbon group are a halogen atom, -R ²⁰ , -OR ²¹ may be substituted with a cyano group or a nitro group, R ²⁰ represents a hydrogen atom, a fluorine atom, or an alkyl group with 1 to 4 carbon atoms, and R ²¹ represents an alkyl group with 1 to 4 carbon atoms, and the alkyl group contains The hydrogen atom may be substituted with a fluorine atom, B ³ , F ³ and P ³ each have the same meaning as B ³ , F ³ and P ³ above, q represents an integer from 0 to 4, and E ³ and/or when there are multiple A ^3s , they may be the same or different, and U ¹ and U ² may combine to form a ring]

Indicates the group selected from.]

[3] The Hansen solubility parameter distance calculated using the Hansen solubility parameters (δD _A , δP _A , δH _A ) of organic solvent A and the Hansen solubility parameters (δD _B , δP _B , δH _B ) of organic solvent B is 10. The composition for forming a retardation film according to [1] or [2] above.

[4] The composition for forming a retardation film according to [2] or [3] above, wherein the polymerizable liquid crystal compound further contains a rod-shaped polymerizable liquid crystal compound.

[5] The composition for forming a retardation film according to any one of [1] to [4] above, wherein the composition has a solid content of 5% by mass or more.

[6] Retardation film formation according to any one of [1] to [5] above, wherein the total content of organic solvent A and organic solvent B relative to the total mass of solvents contained in the composition for forming a retardation film is 80% by mass or more. Composition for.

[7] The composition for forming a retardation film according to any one of [1] to [6] above, wherein the organic solvent A is an ether-based organic solvent or a ketone-based solvent.

[8] The composition for forming a retardation film according to any one of [1] to [7] above, comprising a leveling agent.

[9] A process of forming a coating film of the composition for forming a retardation film according to any one of [1] to [8] above,

A process of drying the coating film at a drying temperature Td (°C) to obtain a dry coating film, and

A process of curing the dried coating film to obtain a retardation film,

, and the drying temperature Td (°C) is expressed in equations (4) and (5):

Ta < Td < Tb (4)

X - 80 ≤ Td ≤ X - 20 (5)

A method for manufacturing a phase contrast film that satisfies the following.

[10] The production method according to [9] above, wherein the drying temperature Td is 70°C or more and less than 130°C.

[11] A retardation plate comprising a cured film of the composition for forming a retardation film according to any one of [1] to [8] above.

According to the present invention, it is possible to form a film by employing a process for removing the solvent at a lower temperature than before, for example, less than 100° C., and the occurrence of unevenness during film formation is suppressed, resulting in excellent optical properties. A composition for forming a phase contrast film capable of forming a phase contrast film can be provided.

Hereinafter, embodiments of the present invention will be described in detail. In addition, the scope of the present invention is not limited to the embodiments described herein, and various changes can be made without impairing the spirit of the present invention.

<Composition for forming phase contrast film>

The composition for forming a retardation film of the present invention includes a polymerizable liquid crystal compound having a nematic liquid crystal phase transition temperature of 100°C or more and 200°C or less, and at least two types of organic solvent A and organic solvent B having different boiling points from each other. The composition for forming a retardation film of the present invention has the following formula ( 1) ~ (3) are satisfied.

Tb - Ta ≥ 10 (℃) (One)

Ta < X - 30 (℃) (2)

Tb > X - 70 (℃) (3)

In addition, in the present disclosure, among the solvents contained in the composition for forming a retardation film, the organic solvent with a lower boiling point is referred to as “organic solvent A,” and the organic solvent with a higher boiling point is referred to as “organic solvent B.” When the composition for forming a retardation film contains three or more organic solvents, in the relationship with the nematic liquid crystal phase transition temperature ) It is necessary to include at least two organic solvents in a relationship that satisfy all of the following.

In addition, when the composition for forming a retardation film includes a plurality of polymerizable liquid crystal compounds, the nematic liquid crystal phase transition temperature of the polymerizable liquid crystal compound is such that all polymerizable liquid crystal compounds constituting the composition for forming a retardation film are used for forming a retardation film. It means the temperature measured using a mixture of polymerizable liquid crystal compounds mixed in the same ratio as the composition.

Normally, when the drying temperature for removing the organic solvent from the coating film of the composition (coating solution) containing the polymerizable liquid crystal compound and the organic solvent is lowered, the volatilization rate of the organic solvent becomes slower, and the effect of air volume, etc. in the drying furnace is reduced. It becomes easy to get scratches, and it becomes easy for appearance defects to occur, such as scratches and irregularities on the coated surface. Many of the organic solvents conventionally used to dissolve polymerizable liquid crystal compounds having molecular structures such as T-type or H-type that can exhibit reverse wavelength dispersion have a high boiling point exceeding 100°C, and when forming a film, It was difficult to lower the drying temperature without causing appearance defects such as uneven winding. In contrast, the composition for forming a retardation film of the present invention contains an organic solvent A and an organic solvent B that satisfy the above formulas (1) to (3) in the relationship with the polymerizable liquid crystal compound, thereby performing the same polymerization as in the past. Compared to the case of using a liquid crystal compound, even if the drying process of solvent removal is performed at a low temperature, a retardation film with excellent appearance and optical properties can be formed while suppressing the occurrence of unevenness or orientation defects on the coated surface.

Formula (1) means that the boiling point of the organic solvent B is 10°C or more higher than the boiling point of the organic solvent A. By containing at least two organic solvents whose boiling points differ by 10°C or more, a difference occurs in the volatilization rate of each organic solvent, making it easier to control the volatilization rate of the solvent as a whole with respect to the drying temperature. As a result, even if the drying temperature is low, it is difficult to be influenced by wind in the drying furnace, etc., and the occurrence of wind unevenness resulting from this can be suppressed. In addition, volatilization of the organic solvent is prevented from becoming more rapid than necessary, and the solvent It is possible to suppress the crystallization of liquid crystal compounds and the occurrence of orientation defects caused by volatilization. If there is an appropriate difference between Ta and Tb, the timing at which organic solvent A and organic solvent B are removed can be controlled in the drying process, and the above effect is easily obtained. Therefore, the difference is preferably 20° C. or more, more preferably. Typically, it may be 30°C or higher, for example, 40°C or higher or 50°C or higher. On the other hand, if the difference between Ta and Tb becomes too large, sufficient removal of each organic solvent may become difficult in the preferred drying temperature range. Therefore, the difference between Ta and Tb is usually 150°C or less, preferably 120°C or less, more preferably 100°C or less, further preferably 90°C or less, and may be, for example, 80°C or less. In addition, when the composition for forming a retardation film contains three or more types of organic solvents, at least one of the combination of two organic solvents in the relationship of an organic solvent satisfying Formula (2) and an organic solvent satisfying Formula (3) It is preferable that the difference in boiling point in dogs is within the above range.

In addition to satisfying the above equation (1), in the relationship with the nematic liquid crystal phase transition temperature of the polymerizable liquid crystal compound contained in the composition for forming a retardation film, the boiling point of the organic solvent A satisfies equation (2), and the organic If the boiling point of solvent B satisfies equation (3), a solvent (organic solvent A) with a boiling point that is at least a certain degree lower than the phase transition temperature of the polymerizable liquid crystal compound, and a solvent (organic solvent B) with a boiling point that is at least a certain degree higher than that of the solvent. becomes a mixed state. As a result, solvent removal proceeds appropriately during the drying process at the time of film formation, suppressing crystallization of the liquid crystal compound and the occurrence of orientation defects, suppressing unevenness of airflow caused by hot air in the drying furnace, and producing a retardation film with excellent appearance and optical properties. You can get it.

The boiling point Ta of the organic solvent A may be lower than the nematic liquid crystal phase transition temperature If Ta is too low, the volatilization rate of the solvent increases within the preferred drying temperature range, and crystallization and orientation defects in the polymerizable liquid crystal compound tend to occur easily. On the other hand, if Ta is too high, appearance defects such as wind unevenness tend to occur easily in the preferred drying temperature range. For this reason, although it varies depending on the nematic liquid crystal phase transition temperature of the polymerizable liquid crystal compound, Ta is usually 40°C or higher, preferably 50°C or higher, and may be, for example, 60°C or higher.

The boiling point Tb of the organic solvent B is preferably smaller than the difference between Ta and It is more preferable that it is within ℃, and it is even more preferable that it is within 50℃. Moreover, if Tb is too low, crystallization or orientation defects of the polymerizable liquid crystal compound in the drying process tend to occur easily, and if Tb is too high, it becomes difficult to proceed with solvent removal in the preferred drying temperature range. , appearance defects such as irregularities in wind marks tend to occur easily. For this reason, although Tb varies depending on the nematic liquid crystal phase transition temperature of the polymerizable liquid crystal compound, it is preferably lower than the phase transition temperature

The above-mentioned suppressing effect of crystallization, winding irregularity, etc. is particularly achieved by the organic solvent A rather than the drying temperature (hereinafter sometimes referred to as "Td") for solvent removal when forming a phase contrast film from the composition for forming a phase contrast film. When the boiling point Ta of the organic solvent B is low and the boiling point Tb of the organic solvent B is higher than the drying temperature Td, it becomes easier to obtain. Therefore, in one embodiment of the present invention, the boiling point Ta of the organic solvent A and the boiling point Tb of the organic solvent B are in the relationship with the drying temperature Td, using the formula (4):

Ta < Td < Tb (4)

It is desirable to have a relationship that satisfies. In other words, the composition for forming a retardation film of the present invention is suitable for application to a film forming process in which the drying temperature for solvent removal is higher than Ta and lower than Tb.

In one embodiment of the present invention, in the drying process, from the viewpoint of improving optical properties such as orientation and low haze, the nematic liquid crystal phase transition temperature of the polymerizable liquid crystal compound in the coating film is lower than the boiling point of the organic solvent B. It is preferable, and it is more preferable that it is below the drying temperature. Here, since the nematic liquid crystal phase transition temperature of the polymerizable liquid crystal compound tends to decrease in an organic solvent, the nematic liquid crystal phase transition temperature measured with the polymerizable liquid crystal compound (alone) is in the coating film (including the organic solvent). ) tends to be higher than the nematic liquid crystal phase transition temperature of the polymerizable liquid crystal compound.

In the present invention, the drying temperature Td can be appropriately determined in consideration of the nematic phase transition temperature of the polymerizable liquid crystal compound used and the boiling point of the organic solvent contained in the composition for forming a retardation film. The drying temperature is assumed to be, for example, a temperature range that is approximately 20 to 80°C lower than the nematic phase transition temperature of the polymerizable liquid crystal compound used, and is specifically preferably 70 to 140°C, more preferably 80°C. It is within the range of -130°C, and may be, for example, 120°C or less, 110°C or less, and further 100°C or less, less than 100°C, 95°C or less, or 90°C or less. For forming a retardation film of the present invention comprising at least two organic solvents having different boiling points so that the boiling point of each organic solvent and the nematic phase transition temperature of the polymerizable liquid crystal compound satisfy the above equations (1) to (3). In the composition, when a drying process is performed in the above temperature range, the volatilization and removal of the organic solvent A and the organic solvent B progress appropriately in relation to the drying temperature, thereby suppressing crystallization of the liquid crystal compound and the occurrence of orientation defects. While doing so, it is particularly easy to obtain the effect of suppressing wind unevenness caused by hot air in the drying furnace.

The organic solvent A may be appropriately selected in consideration of the nematic liquid crystal phase transition temperature of the polymerizable liquid crystal compound used, the solubility of the polymerizable liquid crystal compound, the temperature conditions of the desired drying process, etc. In one aspect of the present invention, the temperature range of the boiling point Ta of the organic solvent A may be specifically, for example, 100°C or lower, preferably 40 to 100°C, more preferably 50 to 100°C. Preferably it is 60 to 90°C, and even more preferably 65 to 80°C. When containing the organic solvent A having a boiling point in the above range, for example, a relatively low boiling point such as 100°C or lower, preferably 95°C or lower, more preferably 90°C or lower, which is considered desirable from the viewpoint of reducing environmental load. Even if film forming is performed at a drying temperature, the effect of suppressing the occurrence of wind unevenness during drying is obtained.

The organic solvent B may be appropriately selected in consideration of the nematic liquid crystal phase transition temperature of the polymerizable liquid crystal compound used, the solubility of the polymerizable liquid crystal compound, the temperature conditions of the desired drying process, etc. In one aspect of the present invention, the temperature range of the boiling point Tb of the organic solvent B specifically may be, for example, greater than 100°C, preferably greater than 100°C and less than or equal to 300°C, more preferably 120 to 250°C. ℃, more preferably 120 to 200 ℃, even more preferably 120 to 150 ℃. When the organic solvent B having a boiling point in the above range is included, for example, even in combination with the organic solvent A having a low boiling point such as 100° C. or lower, crystallization of the liquid crystal compound and the occurrence of orientation defects can be suppressed, reducing environmental impact. Even if film formation is performed at a relatively low drying temperature, such as 100°C or lower, preferably 95°C or lower, and more preferably 90°C or lower, which is considered desirable from the viewpoint of reduction, a retardation film with excellent appearance characteristics can be obtained.

Hansen solubility parameter distance (hereinafter referred to as “HSP”) calculated using the Hansen solubility parameters (δD _A , δP _A , δH _A ) of organic solvent A and the Hansen solubility parameters (δD _B , δP _B , δH _B ) of organic solvent B It is preferable that the distance (sometimes abbreviated as “distance”) is 10 or less. If the compatibility between solvents is low, the solvent will be in a state of partial separation during the solvent drying process, and mesh-like unevenness due to low solvent compatibility will easily occur. , there is a possibility of causing appearance defects different from the wind unevenness caused by the influence of wind in the drying furnace described above. When the HSP distance is 10 or less, the compatibility between the organic solvent A and the organic solvent B increases, and the occurrence of mesh-like unevenness resulting from the compatibility of the solvents can be effectively suppressed. From the viewpoint of suppressing network unevenness, the HSP distance is preferably 9.5 or less, more preferably 9.0 or less. The lower limit of the HSP distance is not particularly limited and is usually 1.0 or more, preferably 2.0 or more.

The Hansen solubility parameter divides the solubility parameter introduced by Hildebrand into three components: the dispersion term (δD), the polarity term (δP), and the hydrogen bonding term (δH), and is expressed in three-dimensional space. It is shown. The dispersion term (δD) represents the effect due to the dispersion force, the polarity term (δP) represents the effect due to the inter-dipole force, and the hydrogen bonding term (δH) represents the effect of the hydrogen bonding force.

The definition and calculation of Hansen solubility parameters are described in Charles M. Hansen, Hansen Solubility Parameters: A Users Handbook (CRC Press, 2007). Additionally, by using the computer software Hansen Solubility Parameters in Practice (HSPiP), the Hansen solubility parameter can be easily estimated from its chemical structure even for solvents for which literature values, etc. are unknown. In the present invention, when determining the Hansen solubility parameters of organic solvent A and organic solvent B, the values of the registered Hansen solubility parameters for solvents registered in the database were used.

For example, if the coordinates of the Hansen solubility parameters of organic solvent A are δD _A , δP _A , and δH _A , and the coordinates of the Hansen solubility parameters of organic solvent B are δD _B , δP _B , and δH _B , the HSP distance is: It can be calculated using the formula below.

HSP distance = [4(δD _A - δD _B ) ² + (δP _A - δP _B ) ² + (δH _A - δH _B ) ² ] ^1/2

In the present invention, organic solvent A and organic solvent B are each added to the polymerizable liquid crystal compound to be used so that the above-mentioned formulas (1) to (3) are satisfied, and preferably, the HSP distance is within the above range. Accordingly, based on the phase transition temperature, the assumed drying temperature, etc., the polymerizable liquid crystal compound can be appropriately selected from known organic solvents capable of dissolving it. Organic solvents A and B include, for example, the following solvents (numbers in () are boiling points):

Methyl isobutyl ketone (116 ℃), cyclohexanone (156 ℃), cyclopentanone (130 ℃), methyl amyl ketone (151 ℃), isophorone (215 ℃), γ-butyrolactone (GBL) (204 ℃) and other ketone-based solvents;

Xylene (144 ℃), mesitylene (165 ℃), cumene (152 ℃), ethylbenzene (136 ℃), anisole (154 ℃), aniline (184 ℃), benzaldehyde (178 ℃), benzyl alcohol (205 ℃) ℃), methyl benzoate (199 ℃), ethyl benzoate (213 ℃), propyl benzoate (230 ℃), butyl benzoate (250 ℃), nitrobenzene (211 ℃), tetralin (207 ℃), etc. ;

long-chain hydrocarbon solvents such as octane (125°C), nonane (151°C), decane (174°C), undecane (196°C), and dodecane (216°C);

Ethylene glycol monomethyl ether (124 ℃), ethylene glycol monoethyl ether (135 ℃), ethylene glycol-n-propyl ether (151 ℃), ethylene glycol-i-propyl ether (141 ℃), ethylene glycol-n-butyl Ether (171 ℃), diethylene glycol dimethyl ether (162 ℃), diethylene glycol diethyl ether (189 ℃), dipropylene glycol dimethyl ether (171 ℃), diethylene glycol monomethyl ether (194 ℃), diethylene Glycol monoethyl ether (202 ℃), diethylene glycol monobutyl ether (230 ℃), diethylene glycol ethyl methyl ether (176 ℃), diethylene glycol butyl methyl ether (212 ℃), propylene glycol monomethyl ether (120 ℃) ), propylene glycol dimethyl ether (97 ℃), dipropylene glycol monomethyl ether (188 ℃), dipropylene glycol dimethyl ether (171 ℃), tripropylene glycol dimethyl ether (215 ℃), triethylene glycol monomethyl ether (249 ℃) ℃), triethylene glycol dimethyl ether (216 ℃), tetraethylene glycol dimethyl ether (276 ℃), propylene glycol monomethyl ether acetate (146 ℃), ethylene glycol monomethyl ether acetate (145 ℃), diethylene glycol monoethyl Glycol-based solvents such as ether acetate (217°C) and diethylene glycol monobutyl ether acetate (245°C);

Propyl acetate (102 ℃), butyl acetate (126 ℃), amyl acetate (142 ℃), ethyl lactate (155 ℃), methyl methoxypropionate (143 ℃), ethyl ethoxypropionate (170 ℃), Isoamyl propionate (156 ℃), isoamyl isobutyrate (170 ℃), ethyl butyrate (121 ℃), propyl butyrate (143 ℃), butyl butyrate (165 ℃), ethylene carbonate (244 ℃), propylene carbonate Ester solvents such as (242°C);

Amides such as N,N-dimethylformamide (153°C), N,N-dimethylacetamide (165°C), N-methyl-2-pyrrolidone (202°C), and γ-butyrolactam (245°C) System solvent; and

Halogenated solvents such as monochlorobenzene (132 ℃) and 1,1,2,2,-tetrachloroethane (147 ℃)

Sulfur-containing solvents such as dimethyl sulfoxide (189 ℃) and dimethyl sulfone (238 ℃),

Tetrahydrofuran (66 ℃), 1,3-dioxolane (77 ℃), 2-methyltetrahydrofuran (80 ℃), 1,4-dioxane (101 ℃), cyclopentylmethyl ether (106 ℃), Ether-based solvents such as tetrahydropyran (88°C).

It is more advantageous to select organic solvents A and B that have high solubility in the polymerizable liquid crystal compound to be used and are inert in the polymerization reaction of the polymerizable liquid crystal compound. In a preferred embodiment of the present invention, the organic solvent A is an ether-based organic solvent or a ketone-based solvent, more preferably an ether-based solvent, and even more preferably a cyclic ether-based solvent. In a preferred embodiment of the present invention, the organic solvent B is selected from the group consisting of ketone solvents, aromatic solvents, halogen solvents, and amide solvents, and is more preferably a ketone solvent or a halogen solvent, More preferably, it is a ketone-based solvent. In addition, in a preferred embodiment of the present invention, a combination in which organic solvent A is an ether-based solvent and organic solvent B is a ketone-based solvent is preferred.

The content ratio of organic solvent A and organic solvent B can be set appropriately according to the types of organic solvent A and organic solvent B used, their boiling points, assumed drying temperature and drying conditions, etc. Although it may vary depending on the types of organic solvent A and organic solvent B, their boiling points, drying conditions, etc., in general, the effect of suppressing the occurrence of wind unevenness tends to improve as the proportion of organic solvent A increases, and the proportion of organic solvent B tends to improve. As this increases, the effect of suppressing the crystallization of the liquid crystal compound and the occurrence of orientation defects tends to improve. In one embodiment of the present invention, the content ratio (mass ratio, organic solvent A:organic solvent B) of organic solvent A and organic solvent B is preferably 20:80 to 80:20, more preferably 30:70. to 70:30, more preferably 35:65 to 65:35, and particularly preferably 40:60 to 60:40.

The composition for forming a retardation film of the present invention may contain an organic solvent other than organic solvent A and organic solvent B (hereinafter also referred to as “other organic solvent”) as long as it does not affect the effect of the present invention. When the composition for forming a retardation film contains three or more types of organic solvents, as long as there is a relationship that satisfies equations (1) to (3), both of the two types of solvents in the relationship are organic solvent A and organic solvent B. It can be. In the present disclosure, among the combination of two organic solvents in a relationship, an organic solvent satisfying Formula (2) and an organic solvent satisfying Formula (3), the total mass of all solvents contained in the composition for forming a retardation film is The combination of the two types with the largest ratio can be regarded as organic solvent A and organic solvent B, and organic solvents other than those can be regarded as other organic solvents. In this case, it is preferable that the organic solvent A and the organic solvent B are next to each other in order from lowest boiling point. Since control of boiling points, etc. between multiple types of solvents may become complicated, the types of organic solvents contained in the composition for forming a retardation film of the present invention are usually 4 types or less, preferably 3 types or less, and more. Preferably there are two types.

The other organic solvent is an organic solvent different from the organic solvent A and organic solvent B used, and can be selected from known organic solvents such as the organic solvents previously exemplified as organic solvent A and organic solvent B, for example. As for other organic solvents, it is more advantageous to select one that has high solubility in the polymerizable liquid crystal compound and is inert to the polymerization reaction of the polymerizable liquid crystal compound.

From the viewpoint of sufficiently obtaining the effect of the present invention, the total content of organic solvent A and organic solvent B relative to the total mass of solvents contained in the composition for forming a retardation film is preferably 80% by mass or more, more preferably 85% by mass. % or more, more preferably 90 mass% or more, and may be 100 mass% (that is, the organic solvent contained in the composition for forming a retardation film may be only organic solvent A and organic solvent B). In other words, the content of other organic solvents relative to the total mass of the solvent contained in the composition for forming a retardation film is preferably 20 mass% or less, more preferably 15 mass% or less, and still more preferably 10 mass% or less. , it is not necessary to substantially contain other organic solvents. If the content of the other organic solvent is within the above range, the solvent can be removed in the drying process without unnecessary heating, and the amount of residual solvent can be reduced, so that a retardation film with excellent appearance can be obtained.

The composition for forming a retardation film of the present invention preferably contains an organic solvent in an amount such that the solid content concentration is 5% by mass or more. When the solid content concentration is 5% by mass or more, the effect of suppressing the occurrence of wind unevenness is likely to be improved. From this viewpoint, the solid content concentration in the composition for forming a retardation film of the present invention is more preferably 8% by mass or more, and even more preferably 10% by mass or more. The upper limit of the solid content concentration is not particularly limited, but is usually 40% by mass or less, preferably 30% by mass or less, from the viewpoint of coatability and the like. In other words, the content of the organic solvent (the total amount of organic solvents A and B and, if included, other organic solvents) in the composition for forming a phase contrast film of the present invention is 60% with respect to the total mass of the composition for forming a phase contrast film. It is preferable that it is ~95% by mass or less. If the content of the organic solvent is within the above range, it is difficult for wind unevenness to occur, and in the drying process, the solvent can be dried and removed without using unnecessary heating, and the amount of residual solvent can be reduced, so the appearance and optical properties. This excellent phase contrast film can be obtained.

The composition for forming a retardation film of the present invention contains a polymerizable liquid crystal compound (hereinafter also referred to as “polymerizable liquid crystal compound (x)”) having a nematic liquid crystal phase transition temperature of 100°C or more and 200°C or less. The polymerizable liquid crystal compound (x) is a liquid crystal compound having a polymerizable group, especially a photopolymerizable group, and as the polymerizable liquid crystal compound (x), a polymerizable liquid crystal compound conventionally known in the field of optical films can be used. The liquid crystallinity shown by the polymerizable liquid crystal compound (x) may be thermotropic liquid crystal or lyotropic liquid crystal, but thermotropic liquid crystal is preferable because it allows precise film thickness control. The polymerizable liquid crystal compound (x) exhibits nematic liquid crystallinity as a phase-order structure, and thus has the advantage of being easy to control orientation.

Examples of the polymerizable liquid crystal compound (x) include compounds that satisfy all of the following (a) to (d).

(a) It is a compound capable of forming a nematic phase;

(b) The polymerizable liquid crystal compound has π electrons in the long axis direction (a).

(c) It has π electrons in the direction [crossing direction (b)] that crosses the major axis direction (a).

(d) The long axis of the polymerizable liquid crystal compound defined by the formula (i) below, with the sum of π electrons existing in the long axis direction (a) being N(πa) and the sum of molecular weights existing in the long axis direction being N(Aa). π electron density in direction (a):

D(πa) = N(πa)/N(Aa) (i)

and a polymerizable liquid crystal compound defined by the following formula (ii) where the sum of π electrons existing in the crossing direction (b) is N(πb) and the sum of molecular weights existing in the crossing direction (b) is N(Ab). π electron density in the cross direction (b):

D(πb) = N(πb)/N(Ab) (ii)

go,

0 ≤ [D(πa)/D(πb)] ≤ 1

There is a relationship [that is, the π electron density in the cross direction (b) is greater than the π electron density in the long axis direction (a)].

In addition, the polymerizable liquid crystal compound that satisfies all of the above (a) to (d) can form a nematic phase by, for example, applying it on an alignment film and heating it above the phase transition temperature. In the nematic phase formed by aligning the polymerizable liquid crystal compounds, the major axes of the polymerizable liquid crystal compounds are generally aligned to be parallel to each other, and this major axis direction becomes the orientation direction of the nematic phase.

In general, the polymerizable liquid crystal compound having the above properties often exhibits reverse wavelength dispersion in the liquid crystal cured film obtained by polymerizing it alone. As the polymerizable liquid crystal compound, from the viewpoint of developing reverse wavelength dispersion, a liquid crystal having a T-shaped or H-shaped mesogenic structure with additional birefringence in the direction perpendicular to the long axis direction of the molecule is preferable, and stronger dispersion is obtained. From this point of view, T-shaped liquid crystal is more preferable. Specifically, a compound that satisfies the properties (a) to (d) above includes, for example, the following formula (I):

[Formula 4]

P ¹ -E ¹ -(B ¹ -G ¹ ) _k -L ¹ -Ar-L ² -(G ² -B ² ) _l -E ² -P ² (I)

Compounds represented by can be mentioned.

In a retardation film showing reverse wavelength dispersion, uniform polarization conversion is easy to be obtained and the optical properties are excellent. Therefore, in the composition for forming a retardation film of the present invention, the polymerizable liquid crystal compound (x) has the formula (I) It is preferable to include a polymerizable liquid crystal compound (hereinafter also referred to as “polymerizable liquid crystal compound (I)”) represented by . These polymerizable liquid crystal compounds can be used individually or in combination of two or more types.

In formula (I), L ¹ , L ² , B ¹ and B ² each independently represent a single bond or a divalent linking group.

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

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

G ¹ and G ² each independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group. The hydrogen atom contained in the divalent aromatic group or divalent alicyclic hydrocarbon group is a halogen atom, an alkyl group with 1 to 4 carbon atoms, a fluoroalkyl group with 1 to 4 carbon atoms, an alkoxy group with 1 to 4 carbon atoms, a cyano group, or a nitro group. It may be substituted, and the carbon atom constituting the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom, or a nitrogen atom. G ¹ and G ² are each independently, preferably a 1,4-phenylenediyl group, a halogen atom, and It is a 1,4-cyclohexanediyl group which may be substituted with at least one substituent selected from the group consisting of alkyl groups having 1 to 4 carbon atoms, more preferably a 1,4-phenylenediyl group substituted with a methyl group, or an unsubstituted group. 1,4-phenylenediyl group or unsubstituted 1,4-trans-cyclohexanediyl group, especially preferably unsubstituted 1,4-phenylenediyl group or unsubstituted 1,4-trans-cyclo It is a hexanediyl group.

Moreover, it is preferable that at least one of the plurality of G ¹ and G ² is a divalent alicyclic hydrocarbon group, and at least one of G ¹ and G ² bonded to L ¹ or L ² is a divalent alicyclic hydrocarbon group. It is more preferable to be

k and l each independently represent an integer from 0 to 3 and satisfy the relationship of 1 ≤ k + l. From the viewpoint of developing reverse wavelength dispersion, k and l are preferably in the range of 2 ≤ k + l ≤ 6, preferably k + l = 4, and more preferably k = 2 and l = 2. k = 2 and l = 2 are also desirable because it results in a symmetrical structure.

E ¹ and E ² each independently represent an alkanediyl group having 1 to 17 carbon atoms, the hydrogen atom contained in the alkanediyl group may be substituted with a halogen atom, and -CH ₂ contained in the alkanediyl group - may be substituted with -O-, -S-, or -C(=O)-. E ¹ and E ² are each independently preferably an alkanediyl group having 1 to 17 carbon atoms, and more preferably an alkanediyl group having 4 to 12 carbon atoms.

P ¹ and P ² independently represent a polymerizable group or a hydrogen atom. However, it is preferable that at least one of P ¹ and P ² is a polymerizable group, and that both P ¹ and P ² are polymerizable groups from the viewpoint of the film hardness of the resulting retardation film. The polymerizable group represented by P ¹ or P ² includes epoxy group, vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, and oxiranyl group. , and oxetanyl group. Among them, a radical polymerizable group or a cationic polymerizable group is preferable, and from the viewpoint of handling and ease of manufacture, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group, and an oxetanyl group are preferable. , an acryloyloxy group is more preferable.

Ar is a group represented by any of the formulas (Ar-1) to (Ar-5). In the polymerizable liquid crystal compound represented by formula (I), these groups impart a bulky molecular structure in the direction crossing the major axis direction, the absorption wavelength in the minor axis direction becomes a long wavelength, and the absorption wavelength generated by the aligned liquid crystal molecules They have something in common in that the phase difference tends to have reverse wavelength dispersion.

[Formula 5]

The total number of π electrons N _π contained in the divalent group containing an aromatic hydrocarbon ring or aromatic heterocycle represented by formula (Ar-1) to formula (Ar-5) is preferably 12 or more, more preferably 16. or more, more preferably 18 or more, particularly preferably 20 or more. Moreover, it is preferably less than 36, more preferably 32 or less, further preferably 30 or less, and particularly preferably 26 or less.

In formulas (Ar-1) to (Ar-5), * represents a bonding portion with L ¹ or L ² in formula (I).

In the formula (Ar-1), Q ¹ represents -S-, -O-, or -NR ¹¹ -, and R ¹¹ represents a hydrogen atom or an alkyl group of 1 to 6 carbon atoms which may have a substituent. In formulas (Ar-3) and (Ar-4), Q ² represents a hydrogen atom or an alkyl group of 1 to 6 carbon atoms which may have a substituent.

In the formula (Ar-2), W ¹ and W ² each independently represent -O-, -S-, -CO-, and -NR ¹¹ -, and R ¹¹ is a hydrogen atom or a carbon number that may have a substituent. Represents an alkyl group of 1 to 6.

In formula (Ar-1), Y ¹ represents an alkyl group having 1 to 6 carbon atoms, an aromatic hydrocarbon group that may have a substituent, or an aromatic heterocyclic group. In formula (Ar-2), Y ² represents a CN group or an alkyl group having 1 to 12 carbon atoms which may have a substituent. Here, the hydrogen atom contained in the alkyl group may be substituted with a halogen atom, and -CH ₂ - contained in the alkyl group may be substituted with -O-, -CO-, -O-CO-, or -CO-O-. It can be done.

In formulas (Ar-1) to (Ar-5), Z ¹ , Z ² and Z ³ are each independently a hydrogen atom, an aliphatic hydrocarbon group or an alkoxy group having 1 to 20 carbon atoms, or an alicyclic group having 3 to 20 carbon atoms. Represents a hydrocarbon group, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, a halogen atom, a cyano group, a nitro group, -NR ¹² R ¹³ or -SR ¹⁴ , and Z ¹ and Z ² are bonded to each other to form an aromatic ring or aromatic complex. You may form a ring. R ¹² to R ¹⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

In formulas (Ar-3) and (Ar-4), Ax represents an organic group of 2 to 30 carbon atoms having at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocycle, and Ay is a hydrogen atom. , an alkyl group having 1 to 6 carbon atoms which may have a substituent, or an organic group having 2 to 30 carbon atoms having at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocycle, and Ax and Ay are combined You may form a ring.

In the formula (Ar-1), Y ¹ is preferably an aromatic hydrocarbon group or an aromatic heterocyclic group that may have a substituent, and is an aromatic hydrocarbon group with 6 to 12 carbon atoms or an aromatic group with 3 to 12 carbon atoms that may have a substituent. Heterocyclic groups are more preferred. The aromatic hydrocarbon group or aromatic heterocyclic group that may have a substituent is preferably a polycyclic aromatic hydrocarbon group or polycyclic aromatic heterocyclic group that may be substituted. In the present disclosure, “polycyclic aromatic hydrocarbon group” refers to an aromatic hydrocarbon group having at least two aromatic rings, a condensed aromatic hydrocarbon group formed by condensation of two or more aromatic rings, and a condensed aromatic hydrocarbon group formed by condensation of two or more aromatic rings. An aromatic hydrocarbon group formed may be mentioned. “Polycyclic aromatic heterocyclic group” means an aromatic heterocyclic group having at least one heteroaromatic ring, having at least one ring selected from the group consisting of aromatic rings and heteroaromatic rings, and having at least one aromatic heterocyclic ring. An aromatic heterocyclic ring group formed by condensation of one or more rings selected from the group consisting of a ring, an aromatic ring, and a heteroaromatic ring, and at least one heteroaromatic ring and at least one group selected from the group consisting of an aromatic ring and a heteroaromatic ring An aromatic heterocyclic group formed by combining rings can be mentioned.

Substituents that the aromatic hydrocarbon group or aromatic heterocyclic group may have include, for example, a halogen atom, an alkyl group with 1 to 6 carbon atoms, a cyano group, a nitro group, a nitroso group, an alkylsulfinyl group with 1 to 6 carbon atoms, and 1 carbon atom. Alkylsulfonyl group with 6 to 6 carbon atoms, carboxyl group, fluoroalkyl group with 1 to 6 carbon atoms, alkoxy group with 1 to 6 carbon atoms, alkylsulfanyl group with 1 to 6 carbon atoms, N-alkylamino group with 1 to 4 carbon atoms, and 2 to 8 carbon atoms. Examples include N,N-dialkylamino group, sulfamoyl group, N-alkylsulfamoyl group with 1 to 6 carbon atoms, and N,N-dialkylsulfamoyl group with 2 to 12 carbon atoms.

Examples of Y ¹ include groups represented by the following formulas (Y ¹ -1) to (Y ¹ -7).

[Formula 6]

In formulas (Y ¹ -1) to (Y ¹ -7), * represents a connection part.

In formulas (Y ¹ -1) to (Y ¹ -7), Z ⁴ each independently represents a halogen atom or an organic group having 1 to 20 carbon atoms, for example, a fluorine atom, a chlorine atom, or a bromine atom. , methyl group, ethyl group, isopropyl group, sec-butyl group, cyano group, nitro group, sulfone group, nitroxyl group, carboxyl group, trifluoromethyl group, methoxy group, thiomethyl group, N, N-dimethylamino group, N- Methylamino group is preferable, halogen atom, methyl group, ethyl group, isopropyl group, sec-butyl group, cyano group, nitro group, trifluoromethyl group are more preferable, methyl group, ethyl group, isopropyl group, sec-butyl group, Pentyl group and hexyl group are particularly preferable.

In formulas (Y ¹ -1) to (Y ¹ -7), V ¹ and V ² are each independently -CO-, -S-, -NR ¹⁵ -, -O-, -Se- or - It represents SO ₂ - and is preferably -S-, -NR ¹⁵ - or -O-. R ¹⁵ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

In formulas (Y ¹ -1) to (Y ¹ -7), W ³ to W ⁷ each independently represent -C= or -N=.

In formulas (Y ¹ -1) to (Y ¹ -7), at least one of V ¹ , V ² and W ³ to W ⁷ preferably represents a group containing S, N or O.

In formulas (Y ¹ -1) to (Y ¹ -7), a each independently represents an integer of 0 to 3, and is preferably 0 or 1. b each independently represents an integer of 0 to 2, and is preferably 0.

Any group represented by the formula (Y ¹ -1) to (Y ¹ -7) is preferably any group represented by the following formula (Y ¹ -8) to (Y ¹ -13), and is represented by the formula (Y ¹ -8 ) is more preferable. Additionally, * indicates a connection part.

[Formula 7]

In formulas (Y ¹ -8) to (Y ¹ -13), Z ⁴ , a, b, V ¹ , V ² and W ³ are Z in (Y ¹ -1) to formulas (Y ¹ -7) ⁴ , a, b, V ¹ , V ² and W ³ have the same meaning.

Specific examples of Y ¹ include groups represented by formulas (ar-1) to (ar-840) described in Japanese Patent Application Publication No. 2019-003177. Among these, groups represented by the following formula are preferable.

[Formula 8]

In one embodiment of the present invention, the group represented by the formula (Ar-1) specifically includes groups represented by the following formulas (Ar ^1-1 ) to (Ar ^1-126 ). The * part in the formula represents a connection portion with L ¹ or L ² in the formula (I).

[Formula 9]

[Formula 10]

[Formula 11]

[Formula 12]

[Formula 13]

[Formula 14]

In one embodiment of the present invention, specific examples of the group represented by the formula (Ar-2) include groups represented by the following formulas (Ar ² -1) to (Ar2-13). The * part in the formula represents a connection portion with L ¹ or L ² in the formula (I).

[Formula 15]

In one embodiment of the present invention, specific examples of the group represented by the formula (Ar-3) include groups represented by the following formulas (Ar3-1) to (Ar3-23). The * part in the formula represents a connection portion with L ¹ or L ² in the formula (I).

[Formula 16]

[Formula 17]

Groups represented by formulas (Ar-1) to (Ar-4) include, in addition to the groups specifically exemplified above, for example, Japanese Patent Application Laid-Open No. 2011-207765, Japanese Patent Application Publication No. 2008-107767, and WO2014/010325. Contributions listed in etc. may also be made.

In formula (Ar-5), Y ³ and Y ⁴ are each independently represented by the following formula (Y ³ -1):

[Formula 18]

It is selected from the group represented by .

In the formula (Y ³ -1), R ^Y1 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. The alkyl group may be substituted with one or more ^substituents

^Substituent Diethylamino group, diisopropylamino group, trimethylsilyl group, dimethylsilyl group, thioisocyano group, or one -CH ₂ - or two or more non-adjacent -CH ₂ - are each independently -O-, -S -, -CO-, -COO-, -OCO-, -CO-S-, -S-CO-, -O-CO-O-, -CO-NH-, -NH-CO-, -CH=CH Carbon number that may be substituted with -COO-, -CH=CH-OCO-, -COO-CH=CH-, -OCO-CH=CH-, -CH=CH-, -CF=CF- or -C≡C- It represents a 1 to 20 linear or branched alkyl group, and any hydrogen atom in the alkyl group may be substituted with a fluorine atom, or may be represented by -B ³ -F ³ -P ³ . B ³ is -CR ¹⁶ R ¹⁷ -, -CH ₂ -CH ₂ -, -O-, -S-, -CO-O-, -O-CO-, -O-CO-O-, -C( =S)-O-, -OC(=S)-, -OC(=S)-O-, -CO-NR ¹⁸ -, -NR ¹⁸ -CO-, -O-CH ₂ -, -CH ₂ - O-, -S-CH ₂ -, -CH ₂ -S- or a single bond, and R ¹⁶ to R ¹⁸ each independently represent a hydrogen atom, a fluorine atom or an alkyl group having 1 to 4 carbon atoms; F ³ represents an alkanediyl group having 1 to 12 carbon atoms, the hydrogen atom contained in the alkanediyl group may be substituted with -OR ¹⁹ or a halogen atom, and R ¹⁹ represents an alkyl group having 1 to 4 carbon atoms, and The hydrogen atom contained in the alkyl group may be substituted with a fluorine atom, and -CH ₂ - contained in the alkanediyl group may be substituted with -O- or -CO-; P ³ represents a hydrogen atom or a polymerizable group.

The substituent X ³ is preferably a fluorine atom, a chlorine atom, -CF ₃ , -OCF ₃ or a cyano group. R ^Y1 is preferably an alkyl group of 1 to 6 carbon atoms that is unsubstituted or substituted with a hydrogen atom or one or more fluorine atoms, and more preferably is a hydrogen atom.

In the formula (Y ³ -1), U ¹ represents an organic group having 2 to 30 carbon atoms and having an aromatic hydrocarbon group. Any carbon atom of the aromatic hydrocarbon group may be substituted with a hetero atom, and U ¹ is an organic group having 2 to 30 carbon atoms, which has at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocycle. . The aromatic hydrocarbon group may be substituted with one or more of the above ^substituents

U ¹ is preferably an organic group having an aromatic heterocycle in which at least one carbon atom is substituted with a hetero atom because wavelength dispersion is improved. U ¹ is more preferably an organic group having an aromatic heterocycle, which is a condensed ring of a 5-membered ring and a 6-membered ring, because it has good wavelength dispersion and exhibits high birefringence.

Specifically, U ¹ preferably has a group represented by the following formula. In addition, in the formula below, these groups have a bond with T ¹ at an arbitrary position.

[Formula 19]

In the formula (Y ³ -1), T ¹ is -O-, -S-, -COO-, -OCO-, -OCO-O-, -NU ² -, -N=CU ² -, -CO- Represents NU ² -, -OCO-NU ² - or O-NU ² -, and U ² is a hydrogen atom, an alkyl group with 1 to 20 carbon atoms, a cycloalkyl group with 3 to 12 carbon atoms, a cycloalkenyl group with 3 to 12 carbon atoms, or aromatic. represents an organic group having 2 to 30 carbon atoms and a hydrocarbon group (any carbon atom of the aromatic hydrocarbon group may be substituted with a hetero atom), or (E ³ -A ³ ) _q -B ³ -F ³ -P ³ . The alkyl group, cycloalkyl group, cycloalkenyl group and aromatic hydrocarbon group may each be unsubstituted or substituted with one or more ^substituents One -CH ₂ - or two or more non-adjacent -CH ₂ - in the alkyl group are each independently -O-, -S-, -CO-, -COO-, -OCO-, -CO- S-, -S-CO-, -SO ₂ -, -O-CO-O-, -CO-NH-, -NH-CO-, -CH=CH-COO-, -CH=CH-OCO-, -COO-CH=CH-, -OCO-CH=CH-, -CH=CH-, -CF=CF- or -C≡C- may be substituted, and one -CH in the cycloalkyl group or cycloalkenyl group ₂ - or two or more nonadjacent -CH ₂ - may each independently be substituted with -O-, -CO-, -COO-, -OCO-, or O-CO-O-. E ³ is defined in the same way as B ³ above, and A ³ represents a divalent alicyclic hydrocarbon group having 3 to 16 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 20 carbon atoms, and the alicyclic hydrocarbon group and the aromatic hydrocarbon group are The hydrogen atom contained may be substituted with a halogen atom, -R ²⁰ , -OR ²¹ , a cyano group, or a nitro group. R ²⁰ represents a hydrogen atom, a fluorine atom, or an alkyl group with 1 to 4 carbon atoms, and R ²¹ represents an alkyl group with 1 to 4 carbon atoms, and the hydrogen atom contained in the alkyl group may be substituted with a fluorine atom. B ³ , F ³ and P ³ each have the same meaning as B ³ , F ³ and P ³ above, and q represents an integer of 0 to 4. When multiple E ³ and/or A ³ exist, they may be the same or different.

T ¹ is preferably -O-, -S-, -N=CU ² - or -NU ² - because it has good birefringence and is easy to synthesize, and because it is easy to improve wavelength dispersion and birefringence, -O-, -S- or -NU ² - is more preferable.

U ² may _be substituted ^by one or more _of the above substituents An alkyl group or alkenyl group with 1 to 20 carbon atoms, a cycloalkyl group with 3 to 12 carbon atoms, or a cycloalkenyl group with 3 to 12 carbon atoms, which may be substituted by -, -OCO- or -O-CO-O-, or, It is preferable that it is the said alkyl group or alkenyl group which may be substituted with the said cycloalkyl group, cycloalkenyl group, or an aryl group.

Among them, in terms of birefringence and solvent solubility, U ² may have a hydrogen atom substituted with a fluorine atom, and one -CH ₂ - or two or more non-adjacent -CH ₂ - are each independently -O-, -CO It is more preferable that it is a linear alkyl group having 1 to 20 carbon atoms which may be substituted with -, -COO- or -OCO-.

U ¹ and U ² may combine to form a ring. In that case, examples include a cyclic group represented by -NU ¹ U ² or a cyclic group represented by -N=CU ¹ U ² .

Since the raw materials are easy to obtain, have good solubility, and exhibit high birefringence, Y ³ and Y ⁴ each represent a group selected from the following formulas (Y ^3' -1) to (Y ^3' -47). Particularly desirable.

[Formula 20]

[Formula 21]

[Formula 22]

From the viewpoint of improving the orientation of the polymerizable liquid crystal compound (x), making it easy to manufacture industrially, and improving productivity, the following groups can be specifically mentioned as the group represented by the formula (Ar-5). . * in (Ar ⁵ -1) to (Ar ⁵ -20) below represents a bonding portion with L ¹ or L ² in formula (I).

[Formula 23]

[Formula 24]

[Formula 25]

Among formulas (Ar-1) to (Ar-5), a group represented by any of formulas (Ar-1), formula (Ar-2) and formula (Ar-5) is more preferable, and is represented by formula (Ar-1) The group represented is more preferable. Examples of the polymerizable liquid crystal compound represented by formula (I) include compounds described in JP2019-003177, JP2019-073496, etc.

The polymerizable liquid crystal compound (I) preferably has a nematic liquid crystal phase transition temperature of 100°C or more and 200°C or less when measured alone. The nematic liquid crystal phase transition temperature of the polymerizable liquid crystal compound (I) is preferably 110°C or higher, more preferably 120°C or higher, and may be, for example, 130°C or higher, and further may be 140°C or higher.

In the present invention, the nematic liquid crystal phase transition temperature can be measured using, for example, a polarizing microscope equipped with a temperature control stage, differential scanning calorimetry (DSC), thermogravimetric differential thermal analysis (TG-DTA), etc. You can.

In the present invention, the composition for forming a retardation film may contain a polymerizable liquid crystal compound other than the polymerizable liquid crystal compound (I). Examples of polymerizable liquid crystal compounds other than polymerizable liquid crystal compound (I) include rod-shaped polymerizable liquid crystal compounds. Here, the rod-shaped polymerizable liquid crystal compound refers to a polymerizable liquid crystal compound whose molecular structure can be considered to be rod-shaped, and in the present disclosure, a polymer where the phase difference generated by generally aligned liquid crystal molecules exhibits constant wavelength dispersion. refers to a liquid crystal compound.

As the polymerizable liquid crystal compound that forms the liquid crystal cured film in the present invention, for example, a compound containing a group represented by the following formula (II) (hereinafter also referred to as “polymerizable liquid crystal compound (II)”) may be used. Polymerizable liquid crystal compound (II) generally tends to exhibit constant wavelength dispersion. These polymerizable liquid crystal compounds can be used individually or in combination of two or more types.

P ⁴ -B ⁴ -E ⁴ -B ⁵ -A ⁴ -B ⁶ - (II)

[In formula (Y), P ⁴ represents a polymerizable group.

A ⁴ represents a divalent alicyclic hydrocarbon group or a divalent aromatic hydrocarbon group.

B ⁴ is -O-, -S-, -CO-O-, -O-CO-, -O-CO-O-, -CO-NR ²² -, -NR ²² -CO-, -CO-, -CS- or represents a single bond. R ²² represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

B ⁵ and B ⁶ are each independently -C≡C-, -CH=CH-, -CH ₂ -CH ₂ -, -O-, -S-, -C(=O)-, -C( =O)-O-, -OC(=O)-, -OC(=O)-O-, -CH=N-, -N=CH-, -N=N-, -C(=O)- NR ²² -, -NR ²² -C(=O)-, -OCH ₂ -, -OCF ₂ -, -CH ₂ O-, -CF ₂ O-, -CH=CH-C(=O)-O- , -OC(=O)-CH=CH-, -H, -C≡N or represents a single bond.

E ⁴ represents an alkanediyl group having 1 to 12 carbon atoms, the hydrogen atom contained in the alkanediyl group may be substituted with an alkoxy group having 1 to 5 carbon atoms, and the hydrogen atom contained in the alkoxy group may be substituted with a halogen atom. It can be done. Additionally, -CH ₂ - constituting the alkanediyl group may be substituted with -O- or -CO-.]

The carbon number of the aromatic hydrocarbon group and the alicyclic hydrocarbon group of A4 is preferably in the range of 3 to 18, more preferably in the range of 5 to 12, and especially preferably in the range of 5 or 6. The hydrogen atom contained in the divalent alicyclic hydrocarbon group and divalent aromatic hydrocarbon group represented by A ⁴ may be substituted with a halogen atom, an alkyl group with 1 to 6 carbon atoms, an alkoxy group with 1 to 6 carbon atoms, a cyano group, or a nitro group. The hydrogen atom contained in the alkyl group having 1 to 6 carbon atoms and the alkoxy group having 1 to 6 carbon atoms may be substituted with a fluorine atom. A ⁴ is preferably cyclohexane-1,4-diyl group or 1,4-phenylene group.

As E ⁴ , a linear alkanediyl group having 1 to 12 carbon atoms is preferable. -CH ₂ - constituting the alkanediyl group may be substituted with -O-.

Specifically, methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, hepta-1, 7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group and dodecane-1,12-diyl group. linear alkanediyl groups having 1 to 12 carbon atoms, such as diyl groups; -CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -, -CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -O-CH ₂ -CH ₂ - and -CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -O-CH ₂ -CH ₂ - and the like.

As B ⁴ , -O-, -S-, -CO-O-, and -O-CO- are preferable, and among these, -CO-O- is more preferable.

B ⁵ and B ⁶ are each independently -O-, -S-, -C(=O)-, -C(=O)-O-, -OC(=O)-, -OC(= O)-O- is preferable, and among these, -O- or -OC(=O)-O- is more preferable.

The polymerizable group represented by P ⁴ may be any group that can polymerize with the polymerizable liquid crystal compound (I), for example, vinyl group, vinyloxy group, p-stilbene group, acryloyl group, acryloyloxy group, Metachloryl group, metachloryloxy group, carboxyl group, acetyl group, hydroxyl group, carbamoyl group, amino group, alkylamino group having 1 to 4 carbon atoms, epoxy group, oxetanyl group, formyl group, -N=C=O or -N=C =S, etc. From the viewpoint of high polymerization reactivity, especially photopolymerization reactivity, a radical polymerizable group or a cationic polymerizable group is preferable. Since it is easy to handle and the production of the liquid crystal compound itself is easy, the group represented by P4-B4- is preferably an acryloyloxy group, a methachloryloxy group, or a vinyloxy group.

Polymerizable liquid crystal compound (II) includes formula (II-1), formula (II-2), formula (II-3), formula (II-4), formula (II-5), or formula (II-6). Compounds represented by can be mentioned.

P⁴-B⁴-E⁴-B⁵-A⁴-B⁶-A⁵-B⁷-A⁶-B⁸-A⁷-B⁹-E⁵-B¹⁰-P⁵ (II-1)

P ⁴ -B ⁴ -E ⁴ -B ⁵ -A ⁴ -B ⁶ -A ⁵ -B ⁷ -A ⁶ -B ⁸ -A ⁷ -F ⁴ (II-2)

P⁴-B⁴-E⁴-B⁵-A⁴-B⁶-A⁵-B⁷-A⁶-B⁸-E⁵-B¹⁰-P⁵ (II-3)

P ⁴ -B ⁴ -E ⁴ -B ⁵ -A ⁴ -B ⁶ -A ⁵ -B ⁷ -A ⁶ -F ⁴ (II-4)

P⁴-B⁴-E⁴-B⁵-A⁴-B⁶-A⁵-B⁷-E⁵-B¹⁰-P⁵ (II-5)

P ⁴ -B ⁴ -E ⁴ -B ⁵ -A ⁴ -B ⁶ -A ⁵ -F ⁴ (II-6)

[During the ceremony,

A ⁴ , B ⁴ to B ⁶ and P ⁴ have the same meaning as above,

A ⁵ to A ⁷ each independently have the same meaning as A ⁴ , B ⁷ to B ⁹ each independently have the same meaning as B ⁵ , B ¹⁰ has the same meaning as B ⁴ , and E ⁵ has the same meaning as E ⁴ . It has the same meaning, and P ⁵ has the same meaning as P ⁴ .

F ⁴ is a hydrogen atom, an alkyl group having 1 to 13 carbon atoms, an alkoxy group having 1 to 13 carbon atoms, cyano group, nitro group, trifluoromethyl group, dimethylamino group, hydroxyl group, methylol group, formyl group, sulfo group ( -SO ₃ H), represents a carboxyl group, an alkoxycarbonyl group having 1 to 10 carbon atoms, or a halogen atom, and -CH ₂ - constituting the alkyl group and alkoxy group may be substituted with -O-.]

Specific examples of the polymerizable liquid crystal compound (II) include “3.8.6 Network (fully cross-linked)” and “6.5” in the Liquid Crystal Handbook (Liquid Crystal Handbook Editorial Committee edition, published by Maruzen Co., Ltd., October 30, 2000). .1 liquid crystal material b. Among the compounds described in "Polymerizable nematic liquid crystal materials", compounds having a polymerizable group, JP2010-31223, JP2010-270108, JP2011-6360 and JP2011-A Examples include polymerizable liquid crystals described in No. 207765.

The polymerizable liquid crystal compound (II) is preferably a liquid crystal compound that exhibits nematic liquid crystallinity. When the polymerizable liquid crystal compound (II) exhibits nematic liquid crystallinity, its nematic liquid crystal phase transition temperature when measured alone may be 100°C or more and 200°C or less, and outside the above range may be, for example, less than 100°C. .

In the present invention, when the composition for forming a retardation film includes a plurality of polymerizable liquid crystal compounds, the nematic liquid crystal phase transition temperature of the mixture of polymerizable liquid crystal compounds may be 100°C or more and 200°C or less. The nematic liquid crystal phase transition temperature of the mixture is preferably 110°C or higher, more preferably 120°C or higher, and may be, for example, 130°C or higher, and even 140°C or higher.

The content of the polymerizable liquid crystal compound (I) in the composition for forming a retardation film of the present invention can be appropriately determined depending on the type or combination of the polymerizable liquid crystal compounds used, but the polymerizable liquid crystal contained in the composition for forming a retardation film With respect to 100 parts by mass of the compound, the amount is preferably 20 to 100 parts by mass, more preferably 40 to 100 parts by mass, further preferably 50 to 100 parts by mass, and particularly preferably 55 to 100 parts by mass. When the content of the polymerizable liquid crystal compound (I) is within the above range, the resulting retardation film is likely to have reverse wavelength dispersion, which can be advantageous in terms of optical properties. In addition, when the composition for forming a retardation film contains two or more types of polymerizable liquid crystal compounds (I), it is preferable that the total amount of all polymerizable liquid crystal compounds (I) contained in the composition for forming a retardation film is within the above content range. .

The content of the polymerizable liquid crystal compound other than the polymerizable liquid crystal compound (I) in the composition for forming a retardation film of the present invention is preferably 50 parts by mass based on 100 parts by mass of the polymerizable liquid crystal compound contained in the composition for forming a retardation film. It is less than 40 parts by mass, more preferably 40 parts by mass or less, still more preferably 20 parts by mass or less, especially preferably 10 parts by mass or less, and may be substantially 0 parts by mass. In one aspect of the present invention, the content of polymerizable liquid crystal compound (II) is preferably within the above range.

The total content of the polymerizable liquid crystal compound in the composition for forming a retardation film is, for example, 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass, and more preferably 80 to 99 parts by mass, based on 100 parts by mass of solid content of the composition for forming a retardation film. Preferably it is 85 to 99 parts by mass, and more preferably 90 to 98 parts by mass. If the content of the polymerizable liquid crystal compound is within the above range, it is advantageous from the viewpoint of the alignment accuracy of the resulting retardation film. Additionally, when the composition for forming a retardation film includes two or more types of polymerizable liquid crystal compounds, it is preferable that the total amount of all liquid crystal compounds included in the composition for forming a retardation film is within the above content range. In addition, in this specification, the solid content of the composition for forming a retardation film means all components excluding volatile components such as organic solvents from the composition for forming a retardation film.

The composition for forming a retardation film of the present invention may contain a polymerization initiator. The polymerization initiator is a compound capable of initiating a polymerization reaction of a polymerizable liquid crystal compound or the like, and a photopolymerization initiator that generates active radicals by the action of light is preferable from the viewpoint of not being dependent on the phase state of the thermotropic liquid crystal.

As the photopolymerization initiator, any known photopolymerization initiator can be used as long as it is a compound capable of initiating the polymerization reaction of the polymerizable liquid crystal compound. Specifically, photopolymerization initiators that can generate active radicals or acids by the action of light can be mentioned, and among these, photopolymerization initiators that can generate radicals by the action of light are preferable. Photopolymerization initiators can be used individually or in combination of two or more types.

As a photopolymerization initiator, a known photopolymerization initiator can be used. For example, photopolymerization initiators that generate active radicals include self-cleavable benzoin-based compounds, acetophenone-based compounds, and hydroxyacetophenone-based compounds. , α-aminoacetophenone-based compounds, oxime ester-based compounds, acylphosphine oxide-based compounds, azo-based compounds, etc. can be used, and hydrogen abstraction-type benzophenone-based compounds, alkylphenone-based compounds, benzoin ether-based compounds, Benzylketal-based compounds, dibenzosuberone-based compounds, anthraquinone-based compounds, xanthone-based compounds, thioxanthone-based compounds, halogenoacetophenone-based compounds, dialkoxyacetophenone-based compounds, halogenobisimidazole-based compounds, Halogenotriazine-based compounds, triazine-based compounds, etc. can be used. As photopolymerization initiators that generate acid, iodonium salts, sulfonium salts, etc. can be used. From the viewpoint of excellent reaction efficiency at low temperatures, self-cleavage type photopolymerization initiators are preferable, and acetophenone-based compounds, hydroxyacetophenone-based compounds, α-aminoacetophenone-based compounds, and oxime ester-based compounds are particularly preferable.

The content of the photopolymerization initiator can be appropriately adjusted depending on the type and amount of the polymerizable liquid crystal compound, but is usually 0.1 parts by mass or more, 30 parts by mass, based on the total amount of 100 parts by mass of the polymerizable liquid crystal compound contained in the composition for forming a retardation film. It is 0.5 parts by mass or more and 10 parts by mass or less, and more preferably 0.5 parts by mass or more and 8 parts by mass or less. If it is within the above range, the reaction of the polymerizable group sufficiently proceeds without disturbing the orientation of the polymerizable liquid crystal compound.

Moreover, the composition for forming a retardation film may contain a leveling agent. A leveling agent is an additive that has the function of adjusting the fluidity of the composition and making the film obtained by applying the composition more flat. For example, organic modified silicone oil-based, polyacrylate-based, and perfluoroalkyl-based leveling agents. can be mentioned. Among them, polyacrylate-based leveling agents and perfluoroalkyl-based leveling agents are preferable.

The content of the leveling agent in the composition for forming a retardation film is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, based on 100 parts by mass of the total amount of the polymerizable liquid crystal compound. When the content of the leveling agent is within the above range, it becomes easy to horizontally align the polymerizable liquid crystal compound, and the resulting cured film tends to become smoother. If the content of the leveling agent in the polymerizable liquid crystal compound exceeds the above range, there is a tendency for unevenness to occur in the resulting cured film. Additionally, the composition for forming a retardation film may contain two or more types of leveling agents.

The composition for forming a retardation film of the present invention may further contain additives such as antioxidants, photosensitizers, and reactive additives, in addition to an organic solvent and a polymerizable liquid crystal compound, and, if necessary, a polymerization initiator or leveling agent. These components may be used individually, or may be used in combination of two or more. When the composition for forming a phase contrast film contains an additive, the content is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass, based on the solid content of the composition for forming a phase contrast film.

The composition for forming a retardation film can be obtained by mixing organic solvent A and organic solvent B, a polymerizable liquid crystal compound, and, if necessary, components such as a polymerization initiator and a leveling agent at a predetermined temperature.

<Method for manufacturing phase contrast film>

The composition for forming a retardation film of the present invention can be formed into a film by employing a process for removing the solvent at a lower temperature than before, for example, lower than 100°C, and has the effect of suppressing the occurrence of unevenness during film forming. Because it is excellent, it is preferable as a material (composition) for forming a retardation film with excellent optical properties.

When forming a retardation film using the composition for forming a retardation film of the present invention, for example,

A process of forming a coating film of the composition for forming a retardation film of the present invention,

A process of drying the coating film at a drying temperature Td (°C) to obtain a dry coating film, and

A process of curing the dried coating film to obtain a retardation film,

, and the drying temperature Td (°C) is expressed in equations (4) and (5):

Ta < Td < Tb (4)

X - 80 ≤ Td ≤ X - 20 (5)

It is advantageous to adopt a method that satisfies .

Therefore, the present invention,

A process of forming a coating film of the composition for forming a retardation film of the present invention,

A process of drying the coating film at a drying temperature Td (°C) to obtain a dry coating film, and

A process of curing the dried coating film to obtain a retardation film,

, and the drying temperature Td (°C) is expressed in equations (4) and (5):

Ta < Td < Tb (4)

X - 80 ≤ Td ≤ X - 20 (5)

A method for manufacturing a retardation film that satisfies is also targeted.

A coating film of the composition for forming a retardation film can be formed by applying the mixed composition onto a substrate or an alignment film. As the substrate, a substrate known in the field, such as a glass substrate or a resin film substrate, can be appropriately selected and used. From the viewpoint of processability, a resin film substrate is preferable. Examples of the resin constituting the resin film base material include polyolefins such as polyethylene, polypropylene, and norbornene polymers; Cyclic olefin resin; polyvinyl alcohol; polyethylene terephthalate; Polymethacrylic acid ester; Polyacrylic acid ester; Cellulose esters such as triacetyl cellulose, diacetyl cellulose, and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyethersulfone; polyether ketone; Resins such as polyphenylene sulfide and polyphenylene oxide can be mentioned.

In addition, the alignment film preferably has solvent resistance that does not dissolve in organic solvents A and B, such as when applying a composition for forming a retardation film, and also has heat resistance to heat treatment in the drying process described later. Examples of the alignment film include a rubbing alignment film containing an orientation polymer, a photo-alignment film, a groove alignment film having an uneven pattern or a plurality of grooves on the surface, and a stretched film. A photo-alignment film is preferable because it is easy to control the orientation direction more precisely. As such an alignment film, an alignment film generally used in the production of optical films (particularly retardation films) can be appropriately selected and used. Specifically, for example, a rubbing alignment film or photo-alignment film described in Japanese Patent Application Laid-Open No. 2019-191504, etc., a structural unit having a photoreactive group and a structural unit having a polymerizable group described in Japanese Patent Application Laid-Open No. 2021-196514, etc. A photo-alignment film formed of a (co)polymer containing a photo-alignment film, etc. may be employed.

Methods for applying the composition for forming a retardation film to a substrate, etc. include known coating methods such as spin coating, extrusion, gravure coating, die coating, bar coating, and applicator methods, and printing methods such as flexography. Here are some ways to do it.

Next, the organic solvent is dried and removed to form a dry coating film. Drying methods include natural drying, ventilation drying, heat drying, and reduced pressure drying. However, heat drying is preferred because it can efficiently form a phase contrast film, and the composition for forming a phase contrast film of the present invention prevents airborne unevenness. Since the suppressing effect is excellent, heat drying using hot air such as a drying furnace can be preferably adopted. In the present invention, the drying temperature Td (°C) at this time is determined by the boiling point Ta (°C) of the organic solvent A constituting the composition for forming a retardation film, the boiling point Tb (°C) of the organic solvent B, and the nema of the polymerizable liquid crystal compound. In the relationship between the tick liquid crystal phase transition temperature

Ta < Td < Tb (4)

X - 80 ≤ Td ≤ X - 20 (5)

By setting the drying temperature to be higher than Ta and lower than Tb, and within a certain range from the phase transition temperature of the polymerizable liquid crystal compound, the occurrence of wind unevenness due to the influence of wind in the drying furnace described above or caused by volatilization of the solvent An effect of suppressing the crystallization of the liquid crystal compound and the occurrence of orientation defects is obtained. As a result, a retardation film with excellent appearance and optical properties can be obtained.

In the drying process, by heating the coating film obtained from the composition for forming a retardation film, the solvent can be dried and removed from the coating film, and the polymerizable liquid crystal compound can be oriented in a desired direction (for example, horizontal direction) with respect to the coating film plane. there is. In the present invention, the drying temperature for bringing the polymerizable liquid crystal compound into the desired orientation state while removing the solvent contained in the composition for forming a retardation film is the liquid crystal phase transition temperature (nematic liquid crystal) of the polymerizable liquid crystal compound contained in the composition. It is preferable to adopt a temperature lower than the phase transition temperature, for example, about 20 to 80° C. lower than the phase transition temperature of the polymerizable liquid crystal compound used. By carrying out the drying process under these conditions, the volatilization and removal of the organic solvent A and the organic solvent B proceed appropriately in relation to the drying temperature, suppressing crystallization of the liquid crystal compound and the occurrence of orientation defects, and It is particularly easy to obtain the effect of suppressing unevenness of airflow caused by hot air.

The drying temperature Td can be appropriately determined in consideration of materials such as the polymerizable liquid crystal compound used and the base material forming the coating film. In one embodiment of the present invention, the drying temperature Td is preferably 70°C or more and less than 130°C. From the viewpoint of suppressing excessive consumption of heat energy and improving production efficiency, the drying temperature Td is more preferably 120°C or lower, further preferably 110°C or lower, and particularly preferably 100°C or lower. , for example, may be less than 100°C, and may even be less than 90°C. By employing a relatively low heating temperature, there is also an advantage that the selection of support substrates on which the composition for forming a retardation film is applied is expanded.

The drying time can be appropriately determined depending on the heating temperature, the type of polymerizable liquid crystal compound contained, the type of organic solvent, its boiling point and its amount, etc., but is usually 15 seconds to 10 minutes, and preferably 0.5 to 5 minutes.

Next, in the obtained dried coating film, the polymerizable liquid crystal compound is polymerized while maintaining the orientation state of the polymerizable liquid crystal compound, thereby forming a liquid crystal cured film (phase contrast film) that is a polymer of the polymerizable liquid crystal compound existing in the desired orientation state. do. As a polymerization method, a photopolymerization method is usually used. In photopolymerization, the light irradiated to the dry coating film is appropriately selected depending on the type of polymerization initiator contained in the dry coating film and the type and amount of the polymerizable liquid crystal compound. Specific examples include one or more types of light or active electron beams selected from the group consisting of visible light, ultraviolet light, infrared light, X-ray, α-ray, β-ray, and γ-ray. Among them, ultraviolet light is preferable because it is easy to control the progress of the polymerization reaction and because it is possible to use a photopolymerization device that is widely used in the field, and a retardation film is used to enable photopolymerization by ultraviolet light. It is desirable to select the type of polymerizable liquid crystal compound or polymerization initiator contained in the forming composition. Also, during polymerization, the polymerization temperature can be controlled by irradiating the dried coating film with light while cooling it using an appropriate cooling means. By employing such a cooling means to polymerize the polymerizable liquid crystal compound at a lower temperature, a retardation film can be appropriately formed even if a material with relatively low heat resistance is used as the substrate. Additionally, the polymerization reaction can be promoted by raising the polymerization temperature within a range that does not cause problems due to heat during light irradiation (such as deformation due to heat of the substrate). During photopolymerization, a patterned cured film can also be obtained by masking or developing.

Light sources of the active energy rays include, for example, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, halogen lamps, carbon arc lamps, tungsten lamps, gallium lamps, excimer lasers, and wavelength range 380. Examples include LED light sources that emit light at ~440 nm, chemical lamps, black light lamps, microwave-excited mercury lamps, and metal halide lamps.

The ultraviolet irradiation intensity is usually 10 to 3,000 mW/cm2. The ultraviolet irradiation intensity is preferably an intensity in the wavelength range effective for activation of the photopolymerization initiator. The time to irradiate light is usually 0.1 second to 10 minutes, preferably 0.1 second to 5 minutes, more preferably 0.1 second to 3 minutes, and still more preferably 0.1 second to 1 minute. When irradiated with such ultraviolet irradiation intensity once or multiple times, the accumulated light amount is 10 to 3,000 mJ/cm2, preferably 50 to 2,000 mJ/cm2, and more preferably 100 to 1,000 mJ/cm2.

The thickness of the retardation film can be appropriately selected depending on the display device to be applied, etc. Preferably it is 0.2 to 5 ㎛, more preferably 0.2 to 3 ㎛. Additionally, the thickness can be measured using an interference film thickness meter, a laser microscope, or a stylus film thickness meter.

Since the composition for forming a retardation film of the present invention can form a retardation film in a relatively low temperature range, the optical properties that the polymerizable liquid crystal compound can naturally exhibit are reduced by using the composition for forming a retardation film of the present invention. It becomes possible to form a film at a low temperature without having to do anything, and a retardation film with excellent optical properties can be obtained. Therefore, the present invention also relates to a retardation plate including a retardation film formed by curing the polymerizable liquid crystal compound in the composition in an oriented state as a cured film of the composition for forming a retardation film of the present invention. A retardation plate composed of a cured film of the composition for forming a retardation film can sufficiently express the optical properties originally exhibited by the polymerizable liquid crystal compound used, and can be a retardation plate with high optical performance.

The liquid crystal cured film (retardation film) constituting the retardation film of the present invention may be composed of a homopolymer of polymerizable liquid crystal compound (I) in an aligned state, and may be composed of polymerizable liquid crystal compound (I) and polymerizable liquid crystal compound (II) ) may be composed of a copolymer in an aligned state of a mixture of other polymerizable liquid crystal compounds such as ).

In one aspect of the present invention, the retardation film constituting the retardation film of the present invention is a cured film of the composition for forming a retardation film of the present invention, and has optical properties expressed by the following formulas (a), (b), and (c). It is desirable to be satisfied. Such a liquid crystal cured film is usually a cured film formed by curing a polymerizable liquid crystal compound in a state oriented in a horizontal direction with respect to the plane of the liquid crystal cured film.

Re(450)/Re(550) ≤ 1.00 (a)

1.00 ≤ Re(650)/Re(550) (b)

100 nm ≤ Re(550) ≤ 180 nm (c)

[In the formula, Re(λ) represents the in-plane retardation value at the wavelength λ nm of the retardation film, and Re = (nx(λ) - ny(λ)) × d (d represents the thickness of the retardation film, and nx is , in the refractive index ellipsoid formed by the retardation film, represents the main refractive index at a wavelength λ nm in a direction parallel to the plane of the retardation film, and ny is parallel to the plane of the retardation film in the refractive index ellipsoid formed by the retardation film, and , represents the refractive index at the wavelength λ nm in the direction orthogonal to the direction of nx).]

When the retardation film satisfies equations (a) and (b), the retardation film exhibits so-called reverse wavelength dispersion, in which the in-plane retardation value at a short wavelength becomes smaller than the in-plane retardation value at a long wavelength. Since reverse wavelength dispersion is improved and the optical properties of the retardation film are further improved, Re(450)/Re(550) is preferably 0.80 or more and less than 1.0, and more preferably 0.80 or more and less than 0.92. Moreover, Re(650)/Re(550) is preferably 1.00 or more, more preferably 1.01 or more.

The in-plane retardation value can be adjusted by the thickness d of the retardation film. Since the in-plane retardation value is determined by the above equation Re(λ) = (nx(λ) - ny(λ)) × d, the desired in-plane retardation value (Re(λ): of the retardation film at the wavelength λ (nm) To obtain the in-plane retardation value, the three-dimensional refractive index and film thickness d can be adjusted.

In addition, when the retardation film satisfies equation (c), the retardation film including the retardation film functions as a λ/4 plate, and front reflection occurs when a circularly polarizing plate including the retardation film including the retardation film is applied to an optical display, etc. The color improvement effect (effect of suppressing coloring) is excellent. A more preferable range of the in-plane retardation value is 120 nm ≤ Re(550) ≤ 170 nm, and a more preferable range is 130 nm ≤ Re(550) ≤ 150 nm.

The retardation plate of the present invention, for example, can be used as a circularly polarizing plate in combination with a polarizing film having a polarizing function, such as a liquid crystal display device, an organic electroluminescence (EL) display device, an inorganic electroluminescence (EL) display device, Flexible image display devices, touch panel displays, electronic emission display devices (e.g. electric field emission display devices (FED), surface field emission displays (SED)), electronic paper (display devices using electronic ink or electrophoretic elements, In particular, the present invention can be used in various display devices such as plasma display devices, projection display devices (for example, display devices with a grating light valve (GLV) display device, and digital micromirror device (DMD)) and piezoelectric ceramic displays. The retardation plate can be suitably used in organic electroluminescence (EL) display devices and inorganic electroluminescence (EL) display devices (optical displays) using the retardation plate of the present invention having excellent optical properties. By providing this, good image display characteristics can be achieved.

Various members (eg, polarizing film, display elements, etc.) and structures in a circularly polarizing plate or a display device can be appropriately selected and employed using known materials and techniques.

Example

Hereinafter, the present invention will be described in more detail through examples. In addition, “%” and “part” in the examples mean mass% and mass part, respectively, unless otherwise specified.

[Preparation of composition for forming photo-alignment film]

A photo-alignment material with the following structure (weight average molecular weight: 50000, m:n = 50:50) was manufactured according to the method described in Japanese Patent Application Publication No. 2021-196514. 2 parts of the photo-alignment material and 98 parts of cyclopentanone (solvent) were mixed as components, and the resulting mixture was stirred at 80°C for 1 hour to prepare a composition for forming a photo-alignment film.

Photo-alignable materials:

[Formula 26]

[Manufacture of polymerizable liquid crystal compound]

Polymerizable liquid crystal compounds (A1) to (A3) each having the structures shown below were prepared. Polymerizable liquid crystal compound (A1) was prepared in the same manner as described in Japanese Patent Application Publication No. 2010-31223. The polymerizable liquid crystal compound (A2) was prepared in the same manner as the method described in Japanese Patent Application Publication No. 2019-73496. Polymerizable liquid crystal compound (A3) was prepared in the same manner as described in Japanese Patent Application Publication No. 2016-81035.

Polymerizable liquid crystal compound (A1)

[Formula 27]

Polymerizable liquid crystal compound (A2)

[Formula 28]

Polymerizable liquid crystal compound (A3)

[Formula 29]

[Measurement of nematic liquid crystal phase transition temperature of polymerizable liquid crystal compound]

1 g of each of the prepared polymerizable liquid crystal compounds (A1) to (A3) was weighed into a vial tube and dissolved by adding 2 g of chloroform. The obtained solution was applied to a glass substrate with a rubbing treatment and a PVA alignment film formed thereon, and dried. This substrate was placed on a cooling and heating device (“LNP94-2” manufactured by Japan Hi-Tech Co., Ltd.), the temperature was raised from room temperature to 180°C, and then cooled to room temperature. The state at the time of temperature change was observed with a polarizing microscope (LEXT, manufactured by Olympus Corporation), and the temperature at which the nematic liquid crystal phase was formed was measured and set as the nematic liquid crystal phase transition temperature. The obtained results are shown in Table 1.

In addition, when two or more types of polymerizable liquid crystal compounds are used in combination in an embodiment, the nematic liquid crystal phase transition temperature is determined by adding all of the polymerizable liquid crystal compounds constituting the composition for forming a retardation film to the composition for forming a retardation film. A mixture of polymerizable liquid crystal compounds mixed in the same ratio as the composition was used to measure the same as in the case of using one type of polymerizable liquid crystal compound.

<Example 1>

[Preparation of composition (1) for forming a phase contrast film]

According to Table 2, based on 100 parts of polymerizable liquid crystal compound (A1), 0.1 part of leveling agent "BYK-361N" (manufactured by BM Chemie) and "Irgacure OXE-03" (BASF Japan Co., Ltd.) as a photopolymerization initiator. preparation) 3 parts were added. Additionally, a mixed solvent of organic solvent A: tetrahydrofuran (Ta: 66°C)/organic solvent B: cyclopentanone (Tb: 130°C) (20/80 by mass ratio) was added so that the solid content concentration was 9%. Composition (1) for forming a retardation film was prepared by stirring this mixture at a temperature of 50°C for 1 hour. Additionally, when the HSP distance between tetrahydrofuran and cyclopentanone was calculated according to the method below, it was 7.1.

[How to calculate HSP distance]

The HSP distance is based on the Hansen solubility parameters of tetrahydrofuran (δD _A : 16.8, δP _A : 5.7, δH _A : 8.0) and the Hansen solubility parameters of cyclopentanone (δD _B : 17.9, δP _B : 11.9, δH _B) registered in the database. : 5.2) was used to calculate it using the formula below.

HSP distance = [4(δD _A - δD _B ) ² + (δP _A - δP _B ) ² + (δH _A - δH _B ) ² ] ^1/2

[Manufacture of retardation film]

The composition for forming a photo-alignment film was applied to a biaxially stretched polyethylene terephthalate (PET) film (manufactured by Diafoil Mitsubishi Plastics Co., Ltd.) as a substrate using a bar coater. The obtained coating film was dried in a drying oven at 120°C for 2 minutes, and then cooled to room temperature to form a dry film. Then, using a UV irradiation device (SPOT CURE SP-9; manufactured by Ushio Electric Co., Ltd.), 100 mJ/cm2 (based on 313 nm) of polarized ultraviolet light was irradiated to obtain a photo-alignment film. The film thickness of the photo-alignment film measured using an ellipsometer M-220 manufactured by Nippon Spectroscope Co., Ltd. was 200 nm.

On the obtained photo-alignment film, the composition (1) for forming a retardation film was applied using a bar coater to form a coating film. This coating film was heated and dried in a 90°C drying oven for 1 minute, and then cooled to room temperature to obtain a dry film. Next, using a high-pressure mercury lamp (“Unicure VB-15201BY-A” manufactured by Ushio Electric Co., Ltd.), the dried film is irradiated with ultraviolet light at an exposure dose of 500 mJ/cm2 (based on 365 nm) in a nitrogen atmosphere, thereby producing polymerizable liquid crystal. A cured retardation film was formed with the compound oriented horizontally with respect to the substrate surface, thereby obtaining a retardation film (1) consisting of a substrate/photo-alignment film/retardation film. The film thickness of the phase contrast film measured using a laser microscope LEXT OLS4100 manufactured by Olympus Corporation was 2.0 μm.

<Evaluation of unevenness due to hearsay>

On the light table, a pair of linear polarizers were overlapped so that they were crossed nicol. The retardation plates obtained in Examples and Comparative Examples were placed between linear polarizers installed on a light table as described above. At this time, the slow axis of the retardation film was set to be substantially 45° with respect to the absorption axis of the polarizer when viewed in the thickness direction. After that, it was observed with the naked eye, and the degree of unevenness due to wind noise was observed based on the uniformity (uniformity of phase difference) in the observed image. The results are shown in Table 4.

≪Evaluation criteria≫

A: No unevenness of wind pattern is visible at all.

B: Slight wind irregularity was observed in less than 30% of the area of the retardation plate.

C: Wind irregularity was observed in less than 30% of the area of the retardation plate.

D: Wind pattern unevenness was seen throughout the retardation plate.

E: Strong wind irregularity was seen throughout the retardation plate.

<Evaluation of orientation>

The obtained retardation plate was observed at a magnification of 400 times using a polarizing microscope (BX51, manufactured by Olympus Corporation). Orientation was evaluated according to the following criteria. The results are shown in Table 4.

≪Evaluation criteria≫

A: There is no crystallization or orientation disturbance of the liquid crystal compound.

B: Crystallization and orientation of the liquid crystal compound were slightly disturbed.

C: Crystallization and orientation of the liquid crystal compound were strongly disturbed.

<Evaluation of mesh unevenness>

A pair of linear polarizers were overlapped on a light table so that they were crossed Nicols. The retardation plates obtained in Examples and Comparative Examples were placed between linear polarizers installed on a light table as described above. At this time, the slow axis of the retardation film was set to be substantially 45° with respect to the absorption axis of the polarizer when viewed in the thickness direction. After that, it was observed with the naked eye, and the degree of mesh unevenness was observed based on the uniformity (uniformity of phase difference) in the observed image. The results are shown in Table 4.

≪Evaluation criteria≫

A: No unevenness is visible on the mesh screen.

B: Slight mesh unevenness was observed.

C: Strong mesh unevenness was observed.

<Wavelength dispersion measurement>

After bonding the adhesive layer (adhesive containing an acrylic polymer) and the glass substrate in this order to the surface on the side opposite to the photo-alignment film side among the planes perpendicular to the thickness direction of the retardation plate, the phase difference The base material (PET film) constituting the plate and the photo-alignment film were peeled together, and then the adhesive layer and the corona-treated COP film (transfer target) were bonded to the surface of the retardation plate in this order. As a result, a laminate having the glass substrate, adhesive layer, retardation film, adhesive layer, and COP film (transfer target) in this order was obtained. The in-plane retardation value of this laminate for light with a wavelength of 450 nm, 550 nm, and 650 nm was measured using KOBRA-WR manufactured by Oji Measuring Equipment Co., Ltd. In addition, the in-plane retardation values for light with wavelengths of 450 ㎚, 550 ㎚, and 650 ㎚ are obtained from the measurement results of the in-plane retardation values for light with wavelengths of 448.2 ㎚, 498.6 ㎚, 548.4 ㎚, 587.3 ㎚, 628.7 ㎚, and 748.6 ㎚. poetry It was obtained from the dispersion formula.

The measured value of Re(450)/Re(550) [Re(450) represents the in-plane retardation value for light with a wavelength of 450 nm, and Re(550) represents the in-plane retardation value for light with a wavelength of 550 nm] In relation to this, those between 0.80 and less than 0.92 were evaluated as A, those between 0.92 and less than 1.0 were evaluated as B, and those above 1.0 were evaluated as C. The results are shown in Table 4.

<Example 2 and 3>

According to the description in Table 4, the compositions (2) and (3) for forming a retardation film and the retardation plate (2) were prepared in the same manner as in Example 1 except that the mixing ratio of organic solvent A and organic solvent B was changed, ( 3) obtained. The obtained retardation plate was evaluated in the same manner as in Example 1. The results are shown in Table 4.

<Example 4>

According to the description in Table 4, the mixing ratio of organic solvent A and organic solvent B was changed to 40/60 (mass ratio) and the solid content concentration was changed to 5%, and the same procedure as in Example 1 was performed to obtain a composition for forming a retardation film. (4) and retardation plate (4) were obtained. The obtained retardation plate was evaluated in the same manner as in Example 1. The results are shown in Table 4.

<Example 5>

According to the description in Table 4, the mixing ratio of organic solvent A and organic solvent B was changed to 40/60 (mass ratio), and the solid content concentration was changed to 12%. In the same manner as in Example 1, a composition for forming a retardation film was prepared. (5) and retardation plate (5) were obtained. The obtained retardation plate was evaluated in the same manner as in Example 1. The results are shown in Table 4.

<Examples 6 to 9>

As a solvent, organic solvent A: tetrahydrofuran/organic solvent B in the mixing ratio shown in Table 4; Cyclopentanone/other organic solvent: A mixed solvent containing N-methyl-2-pyrrolidone (NMP, boiling point: 202°C) was used, and the same procedure as in Example 1 was carried out except that the solid concentration was set to 12%. , compositions (6) to (9) for forming a retardation film and retardation plates (6) to (9) were obtained. The obtained retardation plate was evaluated in the same manner as in Example 1. The results are shown in Table 4.

<Examples 10 to 12>

Compositions (10) to (12) for forming a retardation film were prepared in the same manner as in Example 1 except that the mixing ratio of organic solvent A and organic solvent B was changed according to the description in Table 4 and the solid content concentration was changed to 12%. and retardation plates (10) to (12) were obtained. The obtained retardation plate was evaluated in the same manner as in Example 1. The results are shown in Table 4.

<Examples 13 to 18>

According to the description in Table 4, the type and mixing ratio of the organic solvent were changed and the solid content concentration was changed to 12%. In the same manner as in Example 1, the retardation film forming compositions (13) to (18) and the retardation plate were prepared. (13) to (18) were obtained. The obtained retardation plate was evaluated in the same manner as in Example 1. The results are shown in Table 4.

In addition, the boiling points of the solvents used are as follows.

2-Methyltetrahydrofuran: 80℃

1,3-dioxolane: 77℃

Monochlorobenzene: 132℃

Anisole: 154℃

Dimethyl sulfoxide (DMSO): 189 °C

In addition, the HSP distance of organic solvent A and organic solvent B in each example was calculated. The calculation results are as shown in Table 4.

<Examples 19 and 20>

In the same manner as in Example 5, except that polymerizable liquid crystal compound (A2) and polymerizable liquid crystal compound (A3) were used as the polymerizable liquid crystal compounds, respectively, compositions (19) and (20) for forming a retardation film and a retardation film were prepared. Plates (19) and (20) were obtained. The obtained retardation plate was evaluated in the same manner as in Example 1. The results are shown in Table 4.

<Examples 21 to 24>

As the polymerizable liquid crystal compound, liquid crystal compound LC242 (registered trademark of BASF Corporation) represented by the following formula (LC242) was used. Additionally, the nematic liquid crystal phase transition temperature of LC242 was 63°C.

[Formula 30]

The compositions (21) to (24) for forming a retardation film and the retardation plate were prepared in the same manner as in Example 5, except that the polymerizable liquid crystal compound (A1) and the polymerizable liquid crystal compound (LC242) were mixed and used in the mass ratio shown in Table 3. (21) to (24) were obtained. The obtained retardation plate was evaluated in the same manner as in Example 1. In addition, the nematic liquid crystal phase transition temperature of the mixture of polymerizable liquid crystal compounds was as shown in Table 4.

<Reference example>

In the same manner as in Example 1 except that LC242 was used as a polymerizable liquid crystal compound, the solvent was only tetrahydrofuran, the solid content concentration was 12%, and the drying temperature was 70°C, a composition for forming a retardation film (25) was prepared. and a retardation plate (25) was obtained. The obtained retardation film was evaluated in the same manner as in Example 1. The results are shown in Table 4.

<Comparative Example 1>

A composition for forming a retardation film (26) and a retardation plate (26) were obtained in the same manner as in Example 1 except that the solvent was NMP only, the solid content concentration was 12%, and the drying temperature was 120°C. The obtained retardation film was evaluated in the same manner as in Example 1. The results are shown in Table 4.

<Comparative Examples 2 to 5>

According to the description in Table 4, compositions (27) to (30) for forming a retardation film and retardation plates (27) to (30) were obtained in the same manner as in Example 1 except that the type of solvent and the solid content concentration were changed. The obtained retardation film was evaluated in the same manner as in Example 1. The results are shown in Table 4.

Claims (11)

A polymerizable liquid crystal compound having a nematic liquid crystal phase transition temperature of 100°C or higher and 200°C or lower, and at least two organic solvents A and B having different boiling points,
When the nematic liquid crystal phase transition temperature of the polymerizable liquid crystal compound is set to ):
Tb - Ta ≥ 10 (℃) (1)
Ta < X - 30 (℃) (2)
Tb > X - 70 (℃) (3)
A composition for forming a phase contrast film that satisfies the above. According to claim 1,
A composition for forming a retardation film, wherein the polymerizable liquid crystal compound contains a polymerizable liquid crystal compound (I) represented by the following formula (I).
P ¹ -E ¹ -(B ¹ -G ¹ ) _k -L ¹ -Ar-L ² -(G ² -B ² ) _l -E ² -P ² (I)
[In formula (I),
L ¹ , L ² , B ¹ and B ² each independently represent a single bond or a divalent linking group,
G ¹ and G ² each independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group, and the hydrogen atom contained in the divalent aromatic group or divalent alicyclic hydrocarbon group is a halogen atom or a C 1 to C 4 hydrocarbon group. It may be substituted with an alkyl group, a fluoroalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, or a nitro group, and the carbon atom constituting the divalent aromatic group or divalent alicyclic hydrocarbon group, oxygen atom, or sulfur It may be substituted with an atom or a nitrogen atom,
k and l each independently represent an integer from 0 to 3 and satisfy the relationship of 1 ≤ k + l,
E ¹ and E ² each independently represent an alkanediyl group having 1 to 17 carbon atoms, the hydrogen atom contained in the alkanediyl group may be substituted with a halogen atom, and -CH ₂ contained in the alkanediyl group - may be substituted with -O-, -S-, -C(=O)-,
P ¹ and P ² independently represent a polymerizable group or a hydrogen atom (provided that at least one of P ¹ and P ² is a polymerizable group),
Ar is a group represented by any of the formulas (Ar-1) to (Ar-5)

[In formula (Ar-1) to (Ar-5),
* indicates a coupling part;
Q ¹ represents -S-, -O- or -NR ¹¹ -, R ¹¹ represents a hydrogen atom or an alkyl group of 1 to 6 carbon atoms which may have a substituent,
Q ² represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may have a substituent;
W ¹ and W ² each independently represent -O-, -S-, -CO-, and -NR ¹¹ -, and R ¹¹ represents a hydrogen atom or an alkyl group of 1 to 6 carbon atoms which may have a substituent;
Y ¹ represents an alkyl group having 1 to 6 carbon atoms, an aromatic hydrocarbon group that may have a substituent, or an aromatic heterocyclic group,
Y ² represents a CN group or an alkyl group having 1 to 12 carbon atoms which may have a substituent, the hydrogen atom contained in the alkyl group may be substituted with a halogen atom, and -CH ₂ - contained in the alkyl group is -O- , -CO-, -O-CO- or -CO-O- may be substituted;
Z ¹ , Z ² and Z ³ are each independently a hydrogen atom, an aliphatic hydrocarbon group or an alkoxy group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, represents a halogen atom, a cyano group, a nitro group, -NR ¹² R ¹³ or -SR ¹⁴ , Z ¹ and Z ² may combine with each other to form an aromatic ring or an aromatic heterocycle, and R ¹² to R ¹⁴ each represent Independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms;
Ax represents an organic group of 2 to 30 carbon atoms having at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocycle, and Ay is a hydrogen atom, an alkyl group of 1 to 6 carbon atoms that may have a substituent, or represents an organic group of 2 to 30 carbon atoms having at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocycle; Ax and Ay may combine to form a ring;
Y ³ and Y ⁴ are each independently represented by the following formula (Y ³ -1):

[In equation (Y ³ -1),
R ^Y1 represents a hydrogen atom or an alkyl group having 1 to 6 carbon ^atoms , and the alkyl ^group may be substituted by one or more substituents Fluorosulfuranyl group, nitro group, cyano group, isocyano group, amino group, hydroxyl group, mercapto group, methylamino group, dimethylamino group, diethylamino group, diisopropylamino group, trimethylsilyl group, dimethylsilyl group, thioi An isocyano group, or one -CH ₂ - or two or more non-adjacent -CH ₂ - are each independently -O-, -S-, -CO-, -COO-, -OCO-, -CO- S-, -S-CO-, -O-CO-O-, -CO-NH-, -NH-CO-, -CH=CH-COO-, -CH=CH-OCO-, -COO-CH= CH-, -OCO-CH=CH-, -CH=CH-, -CF=CF- or -C≡C- represents a straight-chain or branched alkyl group having 1 to 20 carbon atoms, which may be substituted by Any hydrogen atom may be substituted with a fluorine atom, or may be a group represented by -B ³ -F ³ -P ³ (where B ³ is -CR ¹⁶ R ¹⁷ -, -CH ₂ -CH ₂ -, -O -, -S-, -CO-O-, -O-CO-, -O-CO-O-, -C(=S)-O-, -OC(=S)-, -OC(=S) -O-, -CO-NR ¹⁸ -, -NR ¹⁸ -CO-, -O-CH ₂ -, -CH ₂ -O-, -S-CH ₂ -, -CH ₂ -S- or a single bond , R ¹³ and R ¹⁴ each independently represent a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 4 carbon atoms; F ³ represents an alkanediyl group having 1 to 12 carbon atoms, and hydrogen contained in the alkanediyl group The atom may be substituted with -OR ¹⁹ or a halogen atom, R ¹⁹ represents an alkyl group having 1 to 4 carbon atoms, and the hydrogen atom contained in the alkyl group may be substituted with a fluorine atom, or - contained in the alkanediyl group. CH ₂ - may be substituted with -O- or -CO-; P ³ represents a hydrogen atom or a polymerizable group),
U ¹ represents an organic group having 2 to 30 carbon atoms having an aromatic hydrocarbon group, any carbon atom of the aromatic hydrocarbon group may be substituted with a hetero atom, and the aromatic hydrocarbon group may be substituted with one or more of the above ^substituents become ;
T ¹ is -O-, -S-, -COO-, -OCO-, -OCO-O-, -NU ² -, -N=CU ² -, -CO-NU ² -, -OCO-NU ² - or O-NU ² -, and U ² is a hydrogen atom, an alkyl group with 1 to 20 carbon atoms, a cycloalkyl group with 3 to 12 carbon atoms, a cycloalkenyl group with 3 to 12 carbon atoms, or an aromatic hydrocarbon group (any of the aromatic hydrocarbon groups). The carbon atom of may be substituted with a hetero atom), an organic group having 2 to 30 carbon atoms, or (E ³ -A ³ ) _q -B ³ -F ³ -P ³ , and its alkyl group, cycloalkyl group, or cycloalke The nyl group and the aromatic hydrocarbon group may _each be unsubstituted or substituted with one or more ^substituents Or two or more -CH ₂ - that are not adjacent are each independently -O-, -S-, -CO-, -COO-, -OCO-, -CO-S-, -S-CO-, -SO ₂ -, -O-CO-O-, -CO-NH-, -NH-CO-, -CH=CH-COO-, -CH=CH-OCO-, -COO-CH=CH-, - OCO-CH=CH-, -CH=CH-, -CF=CF- or -C≡C- may be substituted, and one -CH ₂ - in the cycloalkyl group or cycloalkenyl group or two non-adjacent ones. The above -CH ₂ - may each independently be substituted with -O-, -CO-, -COO-, -OCO- or O-CO-O-, E ³ is defined the same as B ³ above, and A ³ represents a divalent alicyclic hydrocarbon group having 3 to 16 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 20 carbon atoms, and the hydrogen atoms contained in the alicyclic hydrocarbon group and the aromatic hydrocarbon group are a halogen atom, -R ²⁰ , -OR ²¹ may be substituted with a cyano group or a nitro group, R ²⁰ represents a hydrogen atom, a fluorine atom, or an alkyl group with 1 to 4 carbon atoms, and R ²¹ represents an alkyl group with 1 to 4 carbon atoms, and the alkyl group contains The hydrogen atom may be substituted with a fluorine atom, B ³ , F ³ and P ³ each have the same meaning as B ³ , F ³ and P ³ above, q represents an integer from 0 to 4, and E ³ and/or when there are multiple A ^3s , they may be the same or different, and U ¹ and U ² may combine to form a ring]
Indicates the group selected from.] According to claim 1,
Phase difference where the Hansen solubility parameter distance calculated using the Hansen solubility parameters (δD _A , δP _A , δH _A ) of organic solvent A and the Hansen solubility parameters (δD _B , δP _B , δH _B ) of organic solvent B is 10 or less. Composition for film formation. According to claim 2,
A composition for forming a retardation film, wherein the polymerizable liquid crystal compound further includes a rod-shaped polymerizable liquid crystal compound. According to claim 1,
A composition for forming a phase contrast film having a solid content concentration of 5% by mass or more. According to claim 1,
A composition for forming a phase contrast film, wherein the total content of organic solvent A and organic solvent B is 80% by mass or more with respect to the total mass of solvents contained in the composition for forming a phase contrast film. According to claim 1,
A composition for forming a retardation film, wherein the organic solvent A is an ether-based organic solvent or a ketone-based solvent. According to claim 1,
A composition for forming a phase contrast film, comprising a leveling agent. A process of forming a coating film of the composition for forming a retardation film according to any one of claims 1 to 8,
A process of drying the coating film at a drying temperature Td (°C) to obtain a dry coating film, and
A process of curing the dried coating film to obtain a retardation film,
, and the drying temperature Td (°C) is expressed in equations (4) and (5):
Ta < Td < Tb (4)
X - 80 ≤ Td ≤ X - 20 (5)
A method for manufacturing a phase contrast film that satisfies the following. According to clause 9,
A manufacturing method wherein the drying temperature Td is 70°C or more and less than 130°C. A retardation plate comprising a cured film of the composition for forming a retardation film according to any one of claims 1 to 8.