Retardation material composition and retardation material

Abstract

The purpose of the present invention is to provide a retardation material which has a high retardation value and withstands transfer to a glass substrate or the like, that is, is less susceptible to cracks (cracking) during transfer. In addition, the purpose of the present invention is to provide a retardation material composition for producing said retardation material. The retardation material composition contains a component (A) and a component (B). Component (A): a polymer having, in a side chain, a structure including a photoreactive moiety that is photodimerized or photoisomerized by ultraviolet rays. Component (B): an organic peroxide.

Description

Composition for phase difference material and phase difference material

[0001] The present invention relates to a composition for phase difference materials used to manufacture phase difference materials used in phase difference films and the like, and to a phase difference material obtained from the phase difference material composition.

[0002] In response to the demands for improved display quality and weight reduction in flat panel displays such as liquid crystal displays and organic EL displays, polymer materials with controlled internal molecular orientation structures are being used as optical compensation components for these displays, such as polarizing films (polarizers) and phase difference films (phase difference plates). These polymer materials play a role in changing the polarization state of light and are given birefringence (hereinafter, polymer materials will also be referred to as "phase difference materials").

[0003] Currently, development is underway on phase difference materials that utilize the optical anisotropy of polymerizable liquid crystal compounds. The polymerizable liquid crystal compounds used here have polymerizable groups and liquid crystal structural parts (structural parts having spacer structures and mesogenic structures), and acrylic groups are widely used as polymerizable groups.

[0004] Polymerizable liquid crystal compounds exhibit optical anisotropy when brought into contact with an orientation-treated substrate, utilizing both their orientation-regulating force and the self-organizing properties of liquid crystals. Prior art includes methods such as supporting a specific polymerizable liquid crystal compound having an acrylic group between supports on which an orientation-treated polymer film (hereinafter also referred to as "orientation film") is formed, and irradiating with radiation (see, for example, Patent Document 1), or using a composition comprising two types of polymerizable liquid crystal compounds having acrylic groups, chiral liquid crystals, and a photopolymerization initiator (see, for example, Patent Document 2).

[0005] Furthermore, phase difference films using polymerizable liquid crystal compounds or their polymers without using alignment films (see, for example, Patent Documents 3 and 4), and phase difference films using polymers having photocrosslinking sites (see, for example, Patent Documents 5 and 6) have also been reported.

[0006] JP-A-62-70407, JP-A-9-208957, Special Publication No. 2002-517605, WO2008 / 031243, JP-A 2008-164925, JP-A 11-189665

[0007] When attaching phase difference materials to display elements or polarizing plates, it is sometimes necessary to use a material that has been peeled from the substrate and transferred to an adhesive film. Therefore, depending on the process, the phase difference material needs to be able to withstand transfer to glass substrates, that is, it needs to be resistant to cracking during the transfer process.

[0008] Therefore, the present invention aims to provide a phase difference material that has a high phase difference and is less prone to cracking during transfer. Furthermore, it aims to provide a composition for producing the phase difference material.

[0009] As a result of diligent research to achieve the above objective, the inventors have completed the present invention, which has the following gist.

[0010] Specifically, it is a phase difference material composition containing the following components (A) and (B). Component (A): A polymer having a side chain containing a photoreactive moiety that undergoes photodimerization or photoisomerization by ultraviolet light (hereinafter also referred to as "specific structure") (hereinafter also referred to as "specific polymer"). Component (B): An organic peroxide (hereinafter also referred to as "specific peroxide").

[0011] According to the present invention, a phase difference material is obtained that has a high phase difference and is less prone to cracking during transfer to a glass substrate or the like. Therefore, it is possible to provide liquid crystal display elements and organic EL elements with high yield and excellent display quality. The mechanism by which the present invention yields liquid crystal display elements with the above-mentioned excellent characteristics is not entirely clear, but it is presumed to be approximately as follows.

[0012] To enhance the optical properties of phase-difference materials, it is necessary to promote the photodimerization or photoisomerization reaction of the photoreactive sites in the specific polymer during the orientation treatment process, specifically the ultraviolet irradiation process, when forming the phase-difference material using a phase-difference material composition. To suppress cracks associated with the transfer of the phase-difference material, it is necessary to increase the crosslinking density of the phase-difference material. In other words, crosslinking reactions are required at sites other than the photoreactive sites in the specific polymer.

[0013] The specific peroxide of this invention decomposes upon heat, generating radicals. The temperature at which the specific peroxide undergoes thermal decomposition can be arbitrarily selected by referring to its 10-hour half-life temperature.

[0014] From the above points, when the phase difference material composition of the present invention is used, thermal decomposition of specific peroxides does not occur during ultraviolet irradiation during the formation of the phase difference material, and only the reaction of photoreactive sites in the specific polymer occurs selectively. Then, in the subsequent heat treatment, thermal decomposition of specific peroxides occurs and crosslinking reactions occur between specific polymers, thereby obtaining a phase difference material that has a high phase difference and can suppress the occurrence of cracks associated with transfer.

[0015] The following describes in detail a phase difference material composition containing a specific polymer and a specific peroxide, and a phase difference material obtained using said phase difference material composition. However, the description of the constituent elements described is merely an example of one embodiment of the present invention and is not limited to these contents.

[0016] In this invention, the main chain of a polymer (specific polymer) refers to the "stem" portion of the polymer, which consists of the longest chain of atoms. The side chains of a polymer (specific polymer) refer to the portions that branch off from the "stem" of the polymer.

[0017] <Component (A): Specific Polymer> The specific polymer of component (A) is a polymer having a specific structure. The specific polymer is photosensitive and exhibits liquid crystalline properties within a predetermined temperature range. Specifically, it is preferable that it undergoes photodimerization or photoisomerization with ultraviolet light in the wavelength range of 250 to 400 nm and exhibits liquid crystalline properties at a temperature of 100 to 300°C.

[0018] The specific polymer preferably has a main chain composed of at least one radical polymerizable group selected from (meth)acrylate, (meth)acrylamide, itaconate, fumarate, maleate, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide, or norbornene, and siloxane.

[0019] The specific structure preferably has a rigid mesogenic structure along with a photoreactive site that undergoes photodimerization or photoisomerization by ultraviolet light.

[0020] In the present invention, the specific structure is preferably a structure represented by the following formula [1].

[0021] X １ represents a divalent organic group. Among these, a divalent organic group having an alkylene group with 1 to 12 carbon atoms is preferable. X ２ represents a structure represented by the following formula [1-A] or formula [1-B]. * represents a bonding hand to the main chain of the polymer.

[0022] X ３ represents a hydrogen atom, a benzene ring, or a benzene ring substituted with a hydroxy group, -(CH ２ ) ａ -COOH (a represents an integer of 0 to 4), an alkyl group having 1 to 8 carbon atoms or an alkoxy group having 1 to 8 carbon atoms. Among these, a hydrogen atom, a benzene ring, or a benzene ring substituted with a hydroxy group, -(CH ２ ) ａ -COOH (a represents an integer of 0 to 4), an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms is preferable. More preferably, it is a hydrogen atom or a benzene ring in which a ring hydrogen atom is substituted with -(CH ２ ) ａ -COOH (a represents an integer of 0 to 4). X ４ represents a structure comprising at least one selected from the following formulas [1-a] to [1-c]. Among these, formula [1-a] or formula [1-b] is preferable. X ５ represents a hydrogen atom, a hydroxy group, -(CH ２ ) ｂ -COOH (b represents an integer of 0 to 4), a halogen atom, an alkyl group having 1 to 8 carbon atoms or an alkoxy group having 1 to 8 carbon atoms. Among these, a hydrogen atom, a hydroxy group, -(CH ２ ) ｂ -COOH (b represents an integer of 0 to 4), an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms is preferable. X Ａ and X ＢEach of these independently represents a hydrogen atom, a halogen atom, a cyano group, or a C1-C3 alkyl group. Among these, each independently represents a hydrogen atom or a methyl group. * represents X １ This shows a bonding relationship. Examples of "halogen atoms" include fluorine, chlorine, bromine, and iodine atoms.

[0023] mA represents an integer between 1 and 12, with integers between 2 and 8 being preferred. * indicates a combination.

[0024] A specific example of the structure shown in formula [1] is the structure shown in formula [1a] below.

[0025] X １ａ and X ２ａ These are, independently, single bonds, -O-, -CO-, -COO-, -OCO-, -NH-, -N(CH) ３ )-, -NHCONH-, -CONH-, -CON(CH ３ )-,-NHCO- or-N(CH ３ ) indicates CO-. Among these, a single bond, -O-, -COO-, or -OCO- are preferred, each independently. More preferred are a single bond or -O-, each independently. X ３ａ This represents a single bond, a structure shown by the following formula [1a-A] or formula [1a-B]. ４ａ X in formula [1-A] represents the structure shown by formula [1-A] or formula [1-B] above. ３ and X Ａ The preferred ones are as described above. X in formula [1-B] ４ , X ５ and X Ｂ The preferred ones are as described above. * in formulas [1-A] and [1-B] represents X ３ａ This indicates a bond with the polymer's main chain. ma is an integer from 1 to 12, with integers from 2 to 8 being preferred. * indicates a bond with the polymer's main chain.

[0026] X １Ａ These are single bonds, -O-, -CO-, -COO-, -OCO-, -NH-, -N(CH３ )-, -CONH-, -CON(CH ３ )-,-NHCO- or-N(CH ３ ) Indicates CO-. Among these, single bonds, -O-, -COO-, or -OCO- are preferred. * indicates X ２ａ This shows the combination with **. ** represents X ４ａ This shows the combination.

[0027] More specifically, examples include structures represented by any of the following formulas [1aa] to [1aj], and it is preferable to use one of these in the present invention.

[0028]

[0029] X ５ａ and X ６ａ Each of these independently represents a single bond, -O-, -COO-, or -OCO-. Among these, a single bond or -O- is preferred. ７ａ This represents a single bond or an alkylene group having 1 to 12 carbon atoms. Among these, a single bond or an alkylene group having 2 to 8 carbon atoms is preferred. ８ａ This refers to a hydrogen atom, a benzene ring, or a hydrogen atom on a ring that forms a hydroxyl group, -(CH ２ ) ａ -COOH (where a is an integer from 0 to 4), represents a benzene ring substituted with an alkyl group having 1 to 8 carbon atoms or an alkoxy group having 1 to 8 carbon atoms. In particular, a hydrogen atom, a benzene ring, or a hydrogen atom on the ring being a hydroxyl group, -(CH ２ ) ａ A benzene ring substituted with -COOH (where a is an integer from 0 to 4), an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms is preferred. More preferably, a hydrogen atom or a cyclic hydrogen atom is -(CH ２ ) ａ This is a benzene ring substituted with -COOH (where a is an integer from 0 to 4). ９ａ is a hydrogen atom, a hydroxyl group, -(CH ２ ) ｂ -COOH (where b is an integer from 0 to 4), halogen atom, C1-C8 alkyl group, or C1-C8 alkoxy group. In particular, hydrogen atom, hydroxyl group, -(CH２ ) ｂ -COOH (where b is an integer from 0 to 4), a C1-C3 alkyl group, or a C1-C3 alkoxy group are preferred. maa is an integer from 1 to 12, with 2 to 8 being preferred. * indicates a bond to the polymer's main chain.

[0030] To introduce a specific structure into a specific polymer, it is preferable to carry out a polymerization reaction using a compound having the specific structure (hereinafter also referred to as "specific compound") as part of the raw materials. In particular, it is preferable to use the compound represented by the following formula [1a-1].

[0031] X １ａ ~X ４ａ Details and preferred combinations of and ma are as shown in formula [1a] above. ＡＡ This represents a structure shown by any of the following formulas [1a-a] to [1a-d], [1a-h], or [1a-i]. Among these, formulas [1a-a], [1a-b], [1a-c], or [1a-h] are preferred. More preferred are formulas [1a-a] or [1a-b].

[0032] A １ is -O-, -NH-, or -N(CH ３ ) indicates -. Among these, -O- is preferred. A ａ Each of these independently represents either a hydrogen atom or a methyl group. Of these, a hydrogen atom is preferred. * represents X １ａ This shows the combination.

[0033] A more preferred compound than the one represented by formula [1a-1] is the compound represented by any of the following formulas [1aa-1] to [1aj-1].

[0034]

[0035] X ５ａ ~X ９ａ Details and preferred combinations of maa are as shown in the above formulas [1aa] to [1aj].

[0036] X ＡＡDetails and preferred examples are shown in formula [1a-1] above. Specific examples of the specific compound include compounds represented by any of the following formulas [1-1a] to [1-20a], and it is preferable to use these from the viewpoint of suitably obtaining the effects of the present invention.

[0037]

[0038]

[0039]

[0040] (m represents an integer from 2 to 8. R represents a hydrogen atom, a hydroxyl group, -(CH ２ ) ｄ -COOH (where d is an integer from 0 to 4), represents an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms.

[0041] The proportion of a specific structure (specific compound) used in a specific polymer is preferably 5 to 99.9 mol%, more preferably 20 to 99.9 mol%, even more preferably 30 to 99.9 mol%, and particularly preferably 40 to 99.9 mol%, from the viewpoint of the reactivity of the photoreactive site. Furthermore, one or more types of specific structures (specific compounds) can be used in combination, depending on the characteristics.

[0042] From the viewpoint of the optical properties of the phase difference material, it is preferable that the specific polymer further has a structure represented by the following formula [2a] (hereinafter also referred to as the "second structure") in its side chains.

[0043]

[0044] Y １ａ and Y ２ａ These are, independently, single bonds, -O-, -CO-, -COO-, -OCO-, -NH-, -N(CH) ３ )-, -NHCONH-, -CONH-, -CON(CH ３ )-,-NHCO- or-N(CH ３ ) indicates CO-. Among these, a single bond, -O-, -COO-, or -OCO- are preferred, each independently. More preferred are a single bond or -O-, each independently. Y ３ａThe structure is represented by any of the following formulas [2a-A] to [2a-G]. Among these, formulas [2a-A], [2a-D] to [2a-G] are preferred. More preferred are formulas [2a-A], [2a-D], or [2a-F]. na represents an integer from 0 to 12. Among these, an integer from 2 to 8 is preferred. * indicates a bond with the main chain of the polymer.

[0045]

[0046] Y Ａ is a hydrogen atom, a hydroxyl group, -(CH ２ ) ｃ -COOH (where c is an integer from 0 to 4), cyano group, C1-C8 alkyl group, or C1-C8 alkoxy group. In particular, hydrogen atom, hydroxyl group, -(CH ２ ) ｃ -COOH (where c is an integer from 0 to 4), a C1-C3 alkyl group, or a C1-C3 alkoxy group are preferred. Ｂ These are single bonds, -O-, -CO-, -COO-, -OCO-, -NH-, -N(CH ３ )-, -CONH-, -CON(CH ３ )-,-NHCO- or-N(CH ３ ) indicates CO-. Among these, single bonds, -O-, -CO-, -COO-, or -OCO- are preferred. More preferred are single bonds, -O-, -COO-, or -OCO-. * indicates Y ２ａ This shows the combination.

[0047] More specifically, examples include structures represented by any of the following formulas [2aa] to [2ag], and it is preferable to use one of these in the present invention.

[0048]

[0049] Y ４ａ and Y ５ａ Each of these independently represents a single bond, -O-, -COO-, or -OCO-. Among these, a single bond or -O- is preferred. ６ａ is a hydrogen atom, a hydroxyl group, -(CH ２ ) ｃ-COOH (c represents an integer of 0 to 4), an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms. Among these, a hydrogen atom, a hydroxy group, or -(CH ２ ) ｃ -COOH (c represents an integer of 0 to 4) is preferable. naa represents an integer of 1 to 12. Among these, an integer of 2 to 8 is preferable. * represents a bonding site to the main chain of the polymer.

[0050] To introduce the second structure into the specific polymer, it is preferable to carry out a polymerization reaction using a compound having the second structure (hereinafter also referred to as "the second compound") as a part of the raw materials. In particular, it is preferable to use a compound represented by the following formula [2a-1].[

[0051]

[0052] Y １ａ to Y ３ａ The details and preferred combinations of na are as described in the above formula [2a]. X ＡＡ The details and preferred examples thereof are as described in the above formula [1a-1].[

[0053] More preferred are compounds represented by any one of the following formulas [2aa-1] to [2ag-1].[

[0054] Y ４ａ to Y ６ａ The details and preferred combinations of naa are as described in the above formulas [2aa] to [2ag].[

[0055] X ＡＡ The details and preferred examples thereof are as described in the above formula [1a-1].[

[0056] Specific examples of the second compound include compounds represented by any one of the following formulas [2-1a] to [2-14a], and it is preferable to use these from the viewpoint of suitably obtaining the effects of the present invention.

[0057]

[0058]

[0059] (R is a hydrogen atom, a hydroxy group, or -(CH ２) ｃ -COOH (where c is an integer from 0 to 4). n is an integer from 2 to 8.

[0060] The proportion of the second structure (second compound) used in a specific polymer is preferably 99 mol% or less, from the viewpoint of the reactivity of the photoreactive site and the optical properties of the phase difference material. More preferably, it is 5 to 95 mol%. Particularly preferred is 10 to 90 mol%. Furthermore, one or more types of the second structure (second compound) can be used in combination, depending on the characteristics.

[0061] The specific polymer may also incorporate structures other than the specific structure and the second structure (hereinafter also referred to as "other structures"). In this case, it is preferable to use the following compounds (hereinafter also referred to as "other compounds").

[0062] Specific examples include methyl acrylate, ethyl acrylate, isopropyl acrylate, benzyl acrylate, naphthyl acrylate, anthyl acrylate, anthyl methyl acrylate, phenyl acrylate, 2,2,2-trifluoroethyl acrylate, tert-butyl acrylate, cyclohexyl acrylate, isobornyl acrylate, 2-methoxyethyl acrylate, methoxytriethylene glycol acrylate, 2-ethoxyethyl acrylate, tetrahydrofurfuryl acrylate, 3-methoxybutyl acrylate, 2-methyl-2-adamantyl acrylate, 2-propyl-2-adamantyl acrylate, 8-methyl-8-tricyclodecyl acrylate, 8-ethyl-8-tricyclodecyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, benzyl methacrylate, naphthyl methacrylate, anthyl methacrylate, anthyl methyl methacrylate Examples include methacrylate, phenyl methacrylate, 2,2,2-trifluoroethyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, 2-methoxyethyl methacrylate, methoxytriethylene glycol methacrylate, 2-ethoxyethyl methacrylate, tetrahydrofurfuryl methacrylate, 3-methoxybutyl methacrylate, 2-methyl-2-adamantyl methacrylate, 2-propyl-2-adamantyl methacrylate, 8-methyl-8-tricyclodecyl methacrylate, 8-ethyl-8-tricyclodecyl methacrylate, vinyl ether, methyl vinyl ether, benzyl vinyl ether, 2-hydroxyethyl vinyl ether, phenyl vinyl ether, propyl vinyl ether, styrene, methylstyrene, chlorostyrene, bromostyrene, maleimide, N-methylmaleimide, N-phenylmaleimide, and N-cyclohexylmaleimide.

[0063] Furthermore, examples include glycidyl (meth)acrylate, glycidyl α-ethylacrylate, glycidyl α-n-propylacrylate, glycidyl α-n-butylacrylate, 3,4-epoxybutyl (meth)acrylate, 3,4-epoxybutyl α-ethylacrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, 6,7-epoxyheptyl (meth)acrylate, 6,7-epoxyheptyl α-ethylacrylate, 3-methyl-3-oxetanylmethyl (meth)acrylate, (3-ethyloxetan-3-yl)methyl (meth)acrylate, 4-hydroxybutyl glycidyl ether (meth)acrylate, and compounds having crosslinking groups such as those shown in formulas [K-1] to [K-3] below. In the present invention, it is preferable to use compounds having these crosslinking groups from the viewpoint of the curability and optical properties of the phase difference material.

[0064]

[0065] The proportion of other structures (other compounds) used in a specific polymer is the remaining proportion when the proportion of the specific structure and the second structure used is less than 100 mol%. Furthermore, one or more types of other structures (other compounds) can be used in combination, depending on their respective properties.

[0066] The polymerization method for a specific polymer is not particularly limited, but it can be synthesized by, for example, free radical polymerization or living radical polymerization (nitroxide-mediated radical polymerization (NMP) using nitroxide as the dormant species), atom transfer radical polymerization (ATRP) using metal complexes, reversible addition-cleavage chain transfer (RAFT) polymerization using sulfur compounds as the dormant species, reversible transfer catalytic polymerization (RTCP) using alkyl iodide compounds as the dormant species and phosphorus compounds or alcohols as catalysts, etc.), or chain transfer polymerization. In this case, when using living radical polymerization, it is preferable to use RAFT polymerization because the inclusion of metal residues or halogen compounds may adversely affect each property.

[0067] A specific polymer can be obtained by a radical polymerization reaction using a specific compound, or a specific compound and a second compound. Known radical initiators can be used in this reaction. Specific examples include azo compounds such as 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), and 2,2'-azobis(isobutyric acid)dimethyl; organic peroxides such as benzoyl peroxide, lauroyl peroxide, tert-butylperoxypivalate, and 1,1'-bis(tert-butylperoxy)cyclohexane; and redox initiators consisting of these peroxides and reducing agents. Among these, azo compounds are preferred, and more preferably, 2,2'-azobis(isobutyronitrile) or 2,2'-azobis(isobutyric acid)dimethyl.

[0068] The proportion of the radical initiator used is preferably 0.0001 to 50 parts by mass, relative to 100 parts by mass of all compounds used in the radical polymerization reaction. More preferably, it is 0.0005 to 40 parts by mass.

[0069] Radical polymerization reactions are preferably carried out in an organic solvent. Examples of organic solvents include alcohols, ethers, ketones, amides, esters, and hydrocarbon compounds. Specific examples include tetrahydrofuran, cyclopentanone, cyclohexanone, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylformamide, N,N-diethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methyl-ε-caprolactam, dimethyl sulfoxide, tetramethylurea, dimethyl sulfone, hexamethyl sulfoxide, γ-butyrolactone, methoxymethylpentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene Propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, 1,Examples include 4-dioxane, n-hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol acetate monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentanone, 3-methoxy-N,N-dimethylpropanamide, 3-ethoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide. These organic solvents can be used individually or in combination of two or more.

[0070] The amount of organic solvent used (a) is preferably such that the total amount of all compounds used in the radical polymerization reaction (b) is 0.1 to 50 parts by mass relative to the total amount of polymerization reaction solution used (a + b). Furthermore, since the radical polymerization reaction is inhibited by oxygen, it is preferable to use an organic solvent that has been degassed to the greatest extent possible.

[0071] The reaction temperature for the radical polymerization reaction is preferably 30 to 120°C, more preferably 60 to 110°C. The reaction time is preferably 1 to 36 hours, more preferably 2 to 24 hours.

[0072] The specific polymer can be obtained directly from the reaction solution of the radical polymerization reaction, but it is preferable to remove unreacted compounds and excess radical initiators. Specifically, methods include recovering the specific polymer by adding the reaction solution to a solvent, or using adsorbents such as activated carbon or ion exchange resins. Known methods can be used for these purposes.

[0073] From the viewpoint of the strength of the resulting phase difference material, workability during phase difference material formation, and uniformity of the coating film, the specific polymer preferably has a weight-average molecular weight of 2,000 to 2,000,000 as measured by the GPC (Gel Permeation Chromatography) method. More preferably, it is 2,000 to 1,000,000. Particularly preferred is 5,000 to 500,000.

[0074] <Component (B): Specific Peroxide> The specific peroxide in component (B) is an organic peroxide, and radicals are generated when heated. These are appropriately selected according to the curing process of the phase difference material composition.

[0075] Examples of specific peroxides include compounds having a ketone peroxide structure, a peroxyketal structure, a hydroperoxide structure, a dialkyl peroxide structure, a diacyl peroxide structure, a peroxyester structure, or a peroxydicarbonate structure. However, if a substance that generates gas during radical generation is used, voids may be created in the phase difference material. Therefore, it is preferable that the specific peroxide has a ketone peroxide structure, a peroxyketal structure, a hydroperoxide structure, a dialkyl peroxide structure, a diacyl peroxide structure, a peroxyester structure, or a peroxydicarbonate structure.

[0076] In the present invention, from the viewpoint of storage stability of the phase difference material composition and the optical properties of the phase difference material, it is preferable that the 10-hour half-life temperature of the specific peroxide is 60°C or higher and 150°C or lower. More preferably, it is 70°C or higher and 120°C or lower.

[0077] Specific examples of specific peroxides include diisobutyryl peroxide, cumyl peroxyneodecanoate, di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, 1,1,3,3-tetramethylbutyl peroxyneodecanate, bis(4-tert-butylcyclohexyl) peroxydicarbonate, bis(2-ethylhexyl) peroxydicarbonate, tert-hexyl peroxyneodecanoate, tert-butyl peroxyneodecanoate, ter t-butyl peroxyneoheptanoate, tert-hexyl peroxypivalate, tert-butyl peroxypivalate, bis(3,5,5-trimethylhexanoyl) peroxide, dilauryl peroxide, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, disuccinate peroxide, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, tert-hexyl peroxy-2-ethylhexanoate, di(4-methylbenzoyl) peroxide, tert-butyl Peroxy-2-ethylhexanoate, dibenzoyl peroxide, 1,1-bis(t-butylperoxy)-2-methylcyclohexane, 1,1-bis(tert-hexylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-hexylperoxy)cyclohexane, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis(4,4-di-(tert-butylperoxy)cyclohexyl)propane, tert-hexylperoxyisopropyl monocarbonate, tert-butylperoxy Oxymaleic acid, tert-butylperoxy-3,5,5-trimethylhexanoate, tert-butylperoxylaurate, tert-butylperoxyisopropyl monocarbonate, tert-butylperoxy-2-ethylhexyl monocarbonate, tert-hexylperoxybenzoate, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane, tert-butylperoxyacetate, 2,2-bis(tert-butylperoxy)butane, tert-butylperoxybenzoate, n-butyl-4,Examples include 4-bis(tert-butylperoxy)valerate, 1,4-bis(tert-butylperoxyisopropyl)benzene, dicumyl peroxide, di-tert-hexyl peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, tert-butylcumyl peroxide, di-tert-butyl peroxide, p-menthane hydroperoxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)-3-hexine, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, and tert-butyl hydroperoxide.

[0078] More specifically, Perloyl IB, Perloyl ND, Perloyl NPP, Perloyl IPP, Perloyl SBP, Perocta ND, Perloyl TCP, Perloyl OPP, Perhexyl ND, Perbutyl ND, Perbutyl NHP, Perhexyl PV, Perbutyl PV, Perloyl 355, Perloyl L, Perocta O, Perloyl SA, Perhexa 25O, Perhexyl O, Naiper PMB, Perbutyl O, Naiper BMT, Naiper BW, Perhexa MC, Perhexa TMH, Perhexa HC Examples include Perhexa C, Pertetra A, Perhexyl I, Perbutyl MA, Perbutyl 355, Perbutyl L, Perbutyl I, Perbutyl E, Perhexyl Z, Perhexa 25Z, Perbutyl A, Perhexa 22, Perbutyl Z, Perhexa V, Perbutyl P, Permil D, Perhexyl D, Perhexa 25B, Perbutyl C, Perbutyl D, Permenta H, Perhexin 25B, Permil P, Perocta H, Permil H, Perbutyl H, and Nofmer BC (all manufactured by NOF Corporation).

[0079] In particular, from the above perspective, tert-hexyl peroxypivalate, tert-butyl peroxypivalate, bis(3,5,5-trimethylhexanoyl) peroxide, dilauryl peroxide, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, disuccinate peroxide, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, tert-hexyl peroxy-2-ethylhexanoate, di(4-methylbenzoyl) peroxide, tert-butyl peroxy C-2-ethylhexanoate, dibenzoyl peroxide, 1,1-bis(t-butylperoxy)-2-methylcyclohexane, 1,1-bis(tert-hexylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-hexylperoxy)cyclohexane, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis(4,4-di-(tert-butylperoxy)cyclohexyl)propane, tert-hexylperoxyisopropyl monocarbonate, tert-butylperoxy Simaleic acid, tert-butylperoxy-3,5,5-trimethylhexanoate, tert-butylperoxylaurate, tert-butylperoxyisopropyl monocarbonate, tert-butylperoxy-2-ethylhexyl monocarbonate, tert-hexylperoxybenzoate, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane, tert-butylperoxyacetate, 2,2-bis(tert-butylperoxy)butane, tert-butylperoxybenzoate, n-butyl-4 ,4-bis(tert-butylperoxy)valerate, 1,4-bis(tert-butylperoxyisopropyl)benzene, dicumyl peroxide, di-tert-hexyl peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, tert-butylcumyl peroxide, di-tert-butyl peroxide, p-menthane hydroperoxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)-3-hexine, or diisopropylbenzene hydroperoxide are preferred.

[0080] More preferably are tert-butylperoxy-2-ethylhexanoate, dibenzoyl peroxide, 1,1-bis(t-butylperoxy)-2-methylcyclohexane, 1,1-bis(tert-hexylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-hexylperoxy)cyclohexane, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis(4,4-di-(tert-butylperoxy)cyclohexyl)propane, tert-hexylperoxyisopropyl monocarbonate, tert-butylperoxymaleic acid, tert-butylperoxy-3,5,5-trimethylhexanoate, tert-butylperoxylaurate, ter These are t-butylperoxyisopropyl monocarbonate, tert-butylperoxy-2-ethylhexyl monocarbonate, tert-hexylperoxybenzoate, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane, tert-butylperoxyacetate, 2,2-bis(tert-butylperoxy)butane, tert-butylperoxybenzoate, n-butyl-4,4-bis(tert-butylperoxy)valerate, 1,4-bis(tert-butylperoxyisopropyl)benzene, dicumyl peroxide, di-tert-hexyl peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, or tert-butylcumyl peroxide.

[0081] Radical crosslinking compounds used to enhance the curability of specific polymers and phase difference materials may contain residual radical initiators used in their production; however, these do not provide the effects of the present invention. Therefore, the present invention requires the use of specific peroxides.

[0082] From the viewpoint of storage stability of the phase difference material composition and optical properties of the phase difference material, the proportion of specific peroxide used is preferably 0.01 to 10 parts by mass per 100 parts by mass of the specific polymer. More preferably, it is 0.05 to 5 parts by mass. In addition, one or more types of specific peroxides can be used in combination, depending on the specific peroxide.

[0083] <Composition for Phase Difference Material> The composition for phase difference material is a solution for forming a phase difference material, and is a solution containing a specific polymer, a specific peroxide, and a solvent.

[0084] The polymer components do not have to be all specific polymers; other polymers may be mixed in. Specifically, examples include poly(meth)acrylates that do not contain the specific structure and the second structure, as well as polysiloxanes, polyesters, polyamides, polyureas, polyorganosiloxanes, cellulose derivatives, polyacetals, polystyrene derivatives, poly(styrene-maleic anhydride) copolymers, poly(isobutylene-maleic anhydride) copolymers, poly(vinyl ether-maleic anhydride) copolymers, or poly(styrene-phenylmaleimide) derivatives. Specific examples of poly(styrene-maleic anhydride) copolymers include SMA1000, SMA2000, SMA3000 (manufactured by Cray Valley Co., Ltd.), and GSM301 (manufactured by Gifu Cerates Manufacturing Co., Ltd.). Specific examples of poly(isobutylene-maleic anhydride) copolymers include Isoban-600 (manufactured by Kuraray Co., Ltd.). A specific example of a poly(vinyl ether-maleic anhydride) copolymer is Gantrez AN-139 (methyl vinyl ether maleic anhydride resin, manufactured by Ashland).

[0085] When a specific polymer and other polymers are used as polymer components, the proportion of the other polymer used is preferably 90 parts by mass or less, relative to 100 parts by mass of the total polymers contained in the phase difference material composition. More preferably, it is 10 to 90 parts by mass. Most preferably, it is 20 to 80 parts by mass.

[0086] The solvent content in the phase difference material composition can be appropriately selected from the viewpoint of the application method of the phase difference material composition and the desired film thickness. In particular, from the viewpoint of forming a uniform phase difference material by application, the solvent content in the phase difference material composition is preferably 50 to 99.9% by mass. More preferably 60 to 99% by mass. Particularly preferred is 65 to 99% by mass.

[0087] The solvent used in the phase difference material composition is not particularly limited as long as it is a solvent that dissolves the specific polymer and the specific peroxide. In particular, the following solvents (hereinafter also referred to as "solvent A") are preferred. For example, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyllactamide, N,N-dimethylpropionamide, tetramethylurea, N,N-diethylacetamide, N,N-diethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, γ-valerolactone, 1,3-dimethyl-2-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 3-methoxy-N,N-dimethyl Examples include lupropanamide, 3-butoxy-N,N-dimethylpropanamide, N-(n-propyl)-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-(n-butyl)-2-pyrrolidone, N-(tert-butyl)-2-pyrrolidone, N-(n-pentyl)-2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N-methoxybutyl-2-pyrrolidone, and N-cyclohexyl-2-pyrrolidone (hereinafter collectively referred to as "good solvents"). Among these, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, or γ-butyrolactone are particularly favored. Furthermore, these solvents can be used individually or in combination of two or more types.

[0088] If the specific polymer and specific peroxide have high solubility in the solvent, the following solvents (hereinafter also referred to as "solvents of type B") may be used.For example, diisopropyl ether, diisobutyl ether, diisobutylcarbinol (2,6-dimethyl-4-heptanol), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-dibutoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, 1-(2-butoxyethoxy)-2-propanol, 2-(2-butoxyethoxy) Examples include xy)-1-propanol, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol monopropyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy)ethyl acetate, diethylene glycol acetate, propylene glycol diacetate, ethylene glycol monoethyl ether, n-butyl acetate, propylene glycol monoethyl ether acetate, cyclohexyl acetate, 4-methyl-2-pentyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, n-butyl lactate, isoamyl lactate, diethylene glycol monoethyl ether, or diisobutyl ketone (2,6-dimethyl-4-heptanone).In particular, it is preferable to use diisobutylcarbinol, propylene glycol monobutyl ether, propylene glycol diacetate, diethylene glycol diethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, or diisobutyl ketone. Furthermore, these solvents can be used individually or in combination of two or more types.

[0089] In this invention, from the viewpoint of the coating properties of the phase difference material, it is preferable to use a solvent that combines solvent A and solvent B.

[0090] When solvent A and solvent B are used in combination, solvent B is preferably present in an amount of 1 to 99% by mass of the total solvent contained in the phase difference material composition. More preferably, it is 10 to 99% by mass. Particularly preferred is 20 to 95% by mass.

[0091] In order to enhance the film strength of the phase difference material composition, it is preferable to introduce a compound having at least one structure selected from epoxy groups, isocyanate groups, oxetanyl groups, oxazoline groups, cyclocarbonate groups, hydroxyl groups, hydroxyalkyl groups, lower alkoxyalkyl groups, and polymerizable unsaturated groups (hereinafter collectively referred to as "crosslinkable compounds").

[0092] Specific examples of crosslinkable compounds having epoxy groups or isocyanate groups include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, dibromo neopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, bisphenol A type epoxy resins such as Epicote 828 (manufactured by Mitsubishi Chemical Corporation), bisphenol F type epoxy resins such as Epicote 807 (manufactured by Mitsubishi Chemical Corporation), and YX-8000 (manufactured by Mitsubishi Chemical Corporation). Compounds in which a tertiary nitrogen atom is bonded to an aromatic carbon atom, such as hydrogenated bisphenol A epoxy resins like YX6954BH30 (manufactured by Mitsubishi Chemical Corporation), biphenyl skeleton-containing epoxy resins like EPPN-201 (manufactured by Nippon Kayaku Co., Ltd.), (o,m,p-) cresol novolac epoxy resins like EOCN-102S (manufactured by Nippon Kayaku Co., Ltd.), tetrakis(glycidyloxymethyl)methane, N,N,N',N'-tetraglycidyl-1,4-phenylenediamine, N,N,N',N'-tetraglycidyl-2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2-bis[4-(N,N-diglycidyl-4-aminophenoxy)phenyl]propane, and N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane;N,N,N',N'-tetraglycidyl-1,2-diaminocyclohexane, N,N,N',N'-tetraglycidyl-1,3-diaminocyclohexane, N,N,N',N'-tetraglycidyl-1,4-diaminocyclohexane, bis(N,N-diglycidyl-4-aminocyclohexyl)methane, bis(N,N-diglycidyl-2-methyl-4-aminocyclohexyl)methane, bis(N,N-diglycidyl-3-methyl-4-aminocyclohexyl)methane, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,4-bis(N,N-diglycidylaminomethyl)cyclohexane, 1 Examples include compounds in which a tertiary nitrogen atom is bonded to an aliphatic carbon atom, such as 3-bis(N,N-diglycidylaminomethyl)benzene, 1,4-bis(N,N-diglycidylaminomethyl)benzene, 1,3,5-tris(N,N-diglycidylaminomethyl)cyclohexane, and 1,3,5-tris(N,N-diglycidylaminomethyl)benzene; isocyanurate compounds such as triglycidyl isocyanurate (manufactured by Nissan Chemical Corporation); and those described in paragraph

[0037] of Japanese Patent Publication No. 10-338880 and paragraphs

[0051] to

[0054] of WO2017 / 170483.

[0093] Specific examples of crosslinkable compounds having an oxetanyl group include 1,4-bis{[(3-ethyl-3-oxetanyl)methoxy]methyl}benzene (Aronoxetane OXT-121 (XDO)), bis[2-(3-oxetanyl)butyl]ether (Aronoxetane OXT-221 (DOX)), 1,4-bis[(3-ethyloxetan-3-yl)methoxy]benzene (HQOX), 1,3-bis[(3-ethyloxetan-3-yl)methoxy]benzene (RSOX), 1,2-bis[(3-ethyloxetan-3-yl)methoxy]benzene (CTOX), and those described in paragraphs

[0170] to

[0175] of WO2011 / 132751.

[0094] Specific examples of crosslinkable compounds having an oxazoline group include compounds such as 2,2'-bis(2-oxazoline) and 2,2'-bis(4-methyl-2-oxazoline), polymers and oligomers having an oxazoline group such as Epocross (manufactured by Nippon Shokubai Co., Ltd.), and those described in paragraph

[0115] of Japanese Patent Publication 2007-286597.

[0095] Specific examples of crosslinkable compounds having a cyclocarbonate group include N,N,N',N'-tetra[(2-oxo-1,3-dioxolan-4-yl)methyl]-4,4'-diaminodiphenylmethane, N,N'-di[(2-oxo-1,3-dioxolan-4-yl)methyl]-1,3-phenylenediamine, and those described in paragraphs

[0025] to

[0030] and paragraph

[0032] of WO2011 / 155577.

[0096] Specific examples of crosslinkable compounds having a blocked isocyanate group include Coronate AP Stable M, Coronate 2503, 2515, 2507, 2513, 2555, Millionate MS-50 (all manufactured by Tosoh Corporation), Takenate B-830, B-815N, B-820NSU, B-842N, B-846N, B-870N, B-874N, B-882N (all manufactured by Mitsui Chemicals, Inc.), and those described in paragraphs

[0046] to

[0047] of Japanese Patent Publication No. 2014-224978 and paragraphs

[0119] to

[0120] of WO2015 / 141598.

[0097] Specific examples of crosslinkable compounds having a hydroxyl group, a hydroxyalkyl group, and a lower alkoxyalkyl group include N,N,N',N'-tetrakis(2-hydroxyethyl)adipoamide, 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethoxyphenyl)propane, 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)-1,1,1,3,3,3-hexafluoropropane, and those described in paragraph

[0058] of Japanese Patent Publication No. 2016-118753, paragraph

[0055] of Japanese Patent Publication No. 2016-200798, and paragraphs

[0017] to

[0029] of WO2010 / 074269.

[0098] Specific examples of crosslinkable compounds having polymerizable unsaturated groups include glycerin mono(meth)acrylate, glycerin di(meth)acrylate (1,2-,1,3-compound mixture), glycerin tris(meth)acrylate, glycerol 1,3-diglycerolate di(meth)acrylate, pentaerythritol tri(meth)acrylate, diethylene glycol mono(meth)acrylate, triethylene glycol mono(meth)acrylate, tetraethylene glycol mono(meth)acrylate, pentaethylene glycol mono(meth)acrylate, and hexaethylene glycol mono(meth)acrylate.

[0099] In particular, from the viewpoint of the optical properties of the phase difference material, it is preferable to use the following crosslinkable compounds. Specifically, these include NK ester A-DCP, A-BPE-4, A-BPE-10, APG-100, APG-200, APG-400, A-9300, A-DPH, A-GLY-9E, A-GLY-20E, DCP, 4G, 9G, BPE-100, BPE-200, 9PG, and TMPT (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.).

[0100] The amount of crosslinkable compound used in the phase difference material composition is preferably 0.1 to 100 parts by mass per 100 parts by mass of all polymer components. More preferably, from the viewpoint of allowing the crosslinking reaction to proceed and the desired effect to be achieved, it is 0.1 to 50 parts by mass. Particularly preferred is 1 to 30 parts by mass.

[0101] The composition for the phase difference material may also include compounds that improve the uniformity of the film thickness and surface smoothness of the phase difference material, as well as compounds that improve the adhesion between the phase difference material and the substrate.

[0102] Compounds that enhance the uniformity of the film thickness and surface smoothness of the phase difference material include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants. Specific examples include the surfactant described in paragraph

[0122] of WO2014 / 171493. The preferred usage ratio is 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass, per 100 parts by mass of all polymer components.

[0103] Specific examples of compounds that improve the adhesion between the phase difference material and the substrate include the compounds described in paragraph

[0123] of WO2014 / 171493. The preferred usage ratio is 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, based on 100 parts by mass of all polymer components.

[0104] <Phase difference material> A phase difference material can be manufactured, for example, by a method including the following steps (1) to (3).

[0105] [Step (1): Step of applying the phase difference material composition onto the substrate to form a coating film] Step (1) is the step of applying the phase difference material composition onto the substrate.

[0106] The substrate is not particularly limited, and examples include silicon / silicon dioxide coated substrates, silicon nitride substrates, glass substrates coated with aluminum, molybdenum, or chromium, quartz substrates, and ITO (Indium Tin Oxide) substrates. Furthermore, plastic substrates such as TAC (triacetylcellulose) substrates, cycloolefin polymer substrates, PET (polyethylene terephthalate) substrates, acrylic substrates, and polycarbonate substrates, as well as films thereof, can be used.

[0107] The method of applying the phase difference material composition is not particularly limited. Industrially, examples include the dip method, flow coating method, roll coating method, bar coating method, slit coating method, spinner method, spray method, screen printing, offset printing, flexographic printing, and inkjet method. These application methods are used according to the purpose, such as the film thickness of the phase difference material.

[0108] After applying the phase difference material composition to the substrate, the solvent can be evaporated using a heating means such as a hot plate, a hot air circulation oven, or an IR (infrared) oven to form a coating film. The temperature at which this is applied can be selected from 50 to 200°C, preferably 50 to 150°C, depending on the type of substrate and the solvent used in the phase difference material composition.

[0109] [Step (2): Step of irradiating the coating film with polarized ultraviolet light] Step (2) is a step of irradiating the coating surface of the coating film obtained in step (1) with polarized ultraviolet light, and is a step of irradiating the coating film with polarized ultraviolet light from a certain direction via a polarizing plate.

[0110] Ultraviolet light with a wavelength of 100 to 400 nm can be used. In this case, ultraviolet light with a wavelength of 290 to 400 nm is preferred so that the photocrosslinking reaction of specific polymers can be selectively induced. Furthermore, it is preferable to use a filter that can select the optimal wavelength depending on the phase difference material used. Specifically, this could be a bandpass filter with a central wavelength of 365 nm or a long-wave pass filter that transmits wavelengths longer than 313 nm.

[0111] The ultraviolet light source is not particularly limited and can include low-pressure mercury lamps, high-pressure mercury lamps, deep UV lamps, deuterium lamps, metal halide lamps, argon resonance lamps, xenon lamps, mercury xenon lamps, excimer lasers, fluorescent lamps, LED lamps, halogen lamps, or microwave-excited electrodeless lamps.

[0112] [Step (3): Step of heating the ultraviolet-irradiated coating] Step (3) is a step of heating the ultraviolet-irradiated coating obtained in step (2). This heating can impart orientation control ability to the phase difference material. The heating means of step (1) above can be used to heat the coating. The heating temperature can be appropriately selected according to the temperature at which the liquid crystalline properties of the phase difference material are exhibited. In particular, it is preferable that the temperature is within the temperature range at which a specific polymer exhibits liquid crystalline properties (hereinafter also referred to as the "liquid crystal exhibiting temperature"). More preferably, the temperature range is set with the lower limit of the liquid crystal exhibiting temperature range as the lower limit and the upper limit as 10°C lower than the upper limit of the liquid crystal exhibiting temperature range.

[0113] The liquid crystal emergence temperature is defined as a temperature above the liquid crystal transition temperature at which a specific polymer or phase difference material surface undergoes a phase transition from the solid phase to the liquid crystal phase, and below the isotropic phase transition temperature (Tiso) at which a phase transition occurs from the liquid crystal phase to the isotropic phase. For example, exhibiting liquid crystal properties at 130°C or below means that the liquid crystal transition temperature at which the phase transition from the solid phase to the liquid crystal phase occurs is 130°C or below.

[0114] The thickness of the phase difference material obtained in step (3) can be appropriately selected depending on the step height of the substrate used and the optical properties of the phase difference material. Among these, 0.5 to 10 μm is preferred.

[0115] The phase difference material of the present invention can also be manufactured by a method that includes the following step (4) in addition to the above steps (1) to (3). In this method, the thickness of the phase difference material obtained by step (3) is preferably 5 to 300 nm. More preferably, it is 10 to 200 nm.

[0116] [Step (4): Step to form the liquid crystal layer] Step (4) is a step in which polymerizable liquid crystal is applied to the phase difference material obtained in step (3) and cured to form a liquid crystal layer.

[0117] Polymerizable liquid crystals are polymerizable liquid crystal compounds or liquid crystal compositions that polymerize by at least one of the following treatments: heat treatment or ultraviolet irradiation. Known materials such as nematic liquid crystals, cholesteric liquid crystals, discotic liquid crystals, and twisted nematic oriented liquid crystals containing chiral agents can be used.

[0118] Polymerizable liquid crystal compounds preferably have polymerizable functional groups that can be three-dimensionally crosslinked within the molecule.

[0119] Polymerizable functional groups include those that polymerize by ionizing radiation such as ultraviolet light or electron beams, or by heat. Specifically, these include radical polymerizable functional groups and cationic polymerizable functional groups. Radical polymerizable functional groups include functional groups having at least one addition polymerizable ethylenically unsaturated double bond, such as vinyl groups with or without substituents, and acrylate groups (a general term encompassing acryloyl groups, methacryloyl groups, acryloyloxy groups, and methacryloyloxy groups). Cationic polymerizable functional groups include epoxy groups. Other polymerizable functional groups include isocyanate groups and unsaturated triple bonds.

[0120] In the present invention, from the viewpoint of manufacturing a phase difference material, the polymerizable functional group is preferably a functional group having an ethylenically unsaturated double bond, and it is preferable to use a polymerizable liquid crystal compound having a polymerizable functional group at its terminal end.

[0121] The polymerizable liquid crystal may be a mixture of multiple liquid crystal compounds, and may also contain liquid crystal compounds other than the polymerizable liquid crystal compound, polymerizable compounds, polymerization initiators, surfactants, photosensitizers, chain transfer agents, antioxidants, ultraviolet absorbers, radical scavengers, light stabilizers, optically active compounds, silane coupling agents, or solvents.

[0122] Examples of commercially available polymerizable liquid crystals include RMS03-013C and RMS16-089 (both manufactured by Merck).

[0123] The coating method of the above step (1) can be used for applying the polymerizable liquid crystal. After applying the polymerizable liquid crystal, a liquid crystal layer is formed by a curing treatment of heating or ultraviolet irradiation. In this case, favorable alignment can be obtained by performing both heating and ultraviolet irradiation treatments. The conditions for the heat treatment are appropriately selected depending on the type of the polymerizable liquid crystal. For example, the conditions are 0.5 to 5 minutes at 40 to 80°C. For the ultraviolet irradiation conditions, non-polarized ultraviolet light having a wavelength of 200 to 500 nm is used, and an irradiation dose of 50 to 10,000 mJ / cm ２ is preferred. More preferably, it is 100 to 5,000 mJ / cm ２ .

[0124] The retardation material of the present invention has optical properties suitable for applications such as display elements and recording materials, and is particularly suitable for optical compensation films such as polarizing plates and retardation plates for liquid crystal displays and organic EL.

[0125] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

[0126] The abbreviations used in Synthesis Examples, Examples and Comparative Examples, and the measurement methods for each physical property are as follows. <Solvent> CPN: Cyclopentanone NMP: N-methyl-2-pyrrolidone <Polymerization Initiator> AIBN: 2,2'-azobisisobutyronitrile <Polymerization Control Agent> T1: dodecane-1-thiol R1: a compound represented by the following formula [R1]

[0127]

[0128] <Specific Compounds> 1-1M to 1-11M: compounds represented by the following formulas [1-1M] to [1-11M]

[0129]

[0130] <Second Compounds> 2-1M to 2-5M: compounds represented by the following formulas [2-1M] to [2-5M]

[0131]

[0132] <Other Compounds> 3-1M to 3-2M: compounds represented by the following formulas [3-1M] to [3-2M]

[0133]

[0134] <Cross-linkable compounds> K1 to K16: Compounds represented by the following formulas [K1] to [K16] K17: NK ester A-DCP (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) K18: NK ester A-BPE-4 (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) K19: NK ester APG-400 (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) K20: NK ester A-GLY-9E (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) K21: NK ester A-8300 (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) K22: NK ester A-DPH (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) K23: NK ester TPOA-50 (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)

[0135]

[0136]

[0137] <Specific Peroxides> W1 to W6: Compounds represented by the following formulas [W1] to [W6]

[0138]

[0139] "Synthesis of Polymers" <Synthesis Example 1> 1-1M (1.70 g, 5.12 mmol), 2-1M (8.88 g, 29.0 mmol), AIBN (56.0 mg, 0.341 mmol) and NMP (19.7 g) were added to a 50 mL two-necked flask and stirred at 25°C for 20 minutes to dissolve.

[0140] The reaction solution was purged with nitrogen and heated and stirred for 24 hours in an oil bath set to 60°C. Then, methanol (300 g) was added to the reaction solution, and the resulting precipitate was filtered off. The obtained precipitate was washed three times with methanol and dried to obtain polymer powder (P-1). The weight-average molecular weight (hereinafter also referred to as "Mw") of this polymer powder was 162,500, and the polydispersity (hereinafter also referred to as "PDI"), calculated from the weight-average molecular weight / number-average molecular weight ratio, was 3.0.

[0141] <Synthesis Examples 2-13 and 15-20> As shown in Table 1 below, polymer powders (P-2) to (P-13) and (P-15) to (P-20) were obtained by performing the same procedure as in Synthesis Example 1, except that the type and amount of compounds used, the type and amount of polymerization control agent, and the amount of AIBN were changed.

[0142] <Synthesis Example 14> Polymer powder (P-10) (2.00 g) obtained by the method of Synthesis Example 10 was dissolved in THF (5.50 g), dibutyl phosphate (15.3 mg, 0.0728 mmol) and Karenz AOI (manufactured by Resonaq) (0.411 g, 2.91 mmol) were added, and the mixture was stirred at 40 degrees Celsius for 2 hours. Then, ethanol (20 g) was added to the reaction solution, and the resulting precipitate was filtered off. The obtained precipitate was washed three times with ethanol and dried to obtain polymer powder (P-14). The Mw of this polymer powder was 139,200 and the PDI was 2.7.

[0143] The specifications of the polymer powder are shown in Tables 1 and 2.

[0144]

[0145] "Manufacturing of Phase Difference Compositions" Examples 1 to 50 and Comparative Examples 1 to 16 described below illustrate examples of the manufacturing of phase difference composition. These phase difference composition is used for "production of phase difference material," "evaluation of phase difference," and "evaluation of cracks."

[0146] The specifications for the phase difference material compositions are shown in Tables 2 to 8.

[0147] "Preparation of Phase Difference Materials" Phase difference materials were prepared using the phase difference material compositions prepared by the methods described in the examples and comparative examples.

[0148] The phase difference material composition obtained by the synthesis method was applied to a COP (cycloolefin polymer) film using a bar coater to a film thickness of 3.6 μm. The film was then baked in a 70°C hot air circulating oven for 3 minutes to obtain the coating. Polarized ultraviolet light at 365 nm, filtered through a 325 nm low-cut filter and polarizer, was applied to the surface of the obtained coating using a high-pressure mercury lamp at a rate of 100 mJ / cm². ２The film was irradiated and then heated in an infrared heating furnace at 120°C for 5 minutes to obtain a COP film with a phase difference material.

[0149] "Evaluation of Phase Difference" The phase difference of the phase difference material was evaluated using a COP film with a phase difference material prepared by the above method. Specifically, the linear phase difference at a wavelength of 550 nm was measured using AxoScan (manufactured by Axometrics).

[0150] Furthermore, a higher value for this phase difference was considered to indicate superior performance in this evaluation.

[0151] The results are shown in Tables 9 to 14.

[0152] "Crack Evaluation" The crack resistance of the phase difference material was evaluated using the phase difference material-attached COP film prepared by the above method. Specifically, the phase difference material (40 x 40 mm) obtained by the above method was attached to a glass substrate with an adhesive layer (35 x 35 mm) using a roller. Optical double-sided adhesive sheet M3D49 (manufactured by Mitate Imaging Co., Ltd.) was used for this adhesive layer. Next, the excess phase difference material-attached COP film was cut off using a cutter, and the COP film was peeled off the glass substrate to obtain a glass substrate with phase difference material.

[0153] The obtained glass substrates with phase difference material were visually inspected, and the number of cracks within the phase difference material was confirmed. In this evaluation, substrates with fewer cracks were considered to perform better.

[0154] The results are shown in Tables 9 to 14.

[0155] <Example 1> Polymer powder (P-1) (0.70 g) and W1 (7.00 mg) obtained by the method of Synthesis Example 1 were mixed with CPN (4.30 g), stirred at 25°C for 3 hours, and filtered through a 5.0 μm pore size filter to obtain a phase difference material composition (PD-1). No abnormalities such as turbidity or precipitate formation were observed in this phase difference material composition, and it was confirmed to be a homogeneous solution. Furthermore, the obtained phase difference material composition (PD-1) was used to perform "preparation of phase difference material," "evaluation of phase difference," and "evaluation of cracks."

[0156] <Examples 2 to 50, Comparative Examples 1 to 16> As shown in Tables 2 to 5 below, phase difference material compositions (PD-2) to (PD-66) were obtained by performing the same procedure as in Example 1, except that the type of polymer powder used, specific peroxides, crosslinkable compounds, and other compounds were changed. No abnormalities such as turbidity or precipitate formation were observed in any of the obtained phase difference material compositions, and it was confirmed that they were uniform solutions. Furthermore, "preparation of phase difference materials," "evaluation of phase difference," and "evaluation of cracks" were performed using the phase difference material compositions (PD-2) to (PD-66).

[0157]

[0158]

[0159]

[0160]

[0161]

[0162]

[0163]

[0164]

[0165] The phase difference material obtained using the phase difference material composition of the embodiment of the present invention showed a high value of phase difference. Furthermore, even after transferring the phase difference material to a glass substrate, the number of cracks within the phase difference material was small. Specifically, this is a comparison between the embodiment using the specific compound and the comparative example without it, i.e., a comparison between Example 1 and Comparative Example 1, Example 3 and Comparative Example 2, Example 4 and Comparative Example 3, Example 5 and Comparative Example 4, Example 8 and Comparative Example 5, Example 9 and Comparative Example 6, Example 12 and Comparative Example 7, and Example 13 and Comparative Example 8.

[0166] Furthermore, in Comparative Example 9, which used a polymerization initiator that generates radicals, the above effects were not obtained.

[0167] In this invention, similar effects can be obtained even if the polymer synthesis method is changed. Specifically, the same effects as described above were obtained in Example 1 using the free radical polymerization method, Example 12 using the raft polymerization method, and Example 13 using the chain transfer polymerization method.

[0168] By using the phase difference material composition containing the specific polymer and specific peroxide of the present invention, it is possible to provide a phase difference material that exhibits high phase difference and is less prone to cracking during transfer to glass substrates and the like. Therefore, the phase difference material of the present invention is useful for display elements such as organic EL elements.

[0169] Furthermore, the entire contents of the specification, claims, and abstract of Japanese Patent Application No. 2025-054621, filed on March 27, 2025, are incorporated herein by reference as disclosure of the present invention.

Claims

1. A phase difference material composition containing the following components (A) and (B). (A) A polymer having a side chain structure containing a photoreactive moiety that undergoes photodimerization or photoisomerization by ultraviolet light. (B) An organic peroxide.

2. The composition for a retardation material according to claim 1, wherein the structure comprising a photoreactive site of the component (A) is a structure represented by the following formula [1]. (X １ represents a divalent organic group. X ２ represents a structure represented by the following formula [1-A] or formula [1-B]. * represents a bonding site to the main chain of the polymer.) (X ３ represents a hydrogen atom, a benzene ring, or a benzene ring substituted with a hydroxy group, -(CH ２ ) ａ -COOH (a represents an integer of 0 to 4), an alkyl group having 1 to 8 carbon atoms, or an alkoxy group having 1 to 8 carbon atoms. X ４ represents a structure comprising at least one selected from the following formulas [1-a] to [1-c]. X ５ represents a hydrogen atom, a hydroxy group, -(CH ２ ) ｂ -COOH (b represents an integer of 0 to 4), a halogen atom, an alkyl group having 1 to 8 carbon atoms, or an alkoxy group having 1 to 8 carbon atoms. X Ａ and X Ｂ each independently represent a hydrogen atom, a halogen atom, a cyano group, or an alkyl group having 1 to 3 carbon atoms. * represents a bonding site to X １ .) (mA represents an integer of 1 to 12. * represents a bonding site.) 3. The phase difference material composition according to claim 2, wherein the structure represented by formula [1] is the structure represented by formula [1a] below. (X １ａ and X ２ａ These are, independently, single bonds, -O-, -CO-, -COO-, -OCO-, -NH-, -N(CH) ３ )-, -NHCONH-, -CONH-, -CON(CH ３ )-,-NHCO- or-N(CH ３ ) Indicates CO-. X ３ａ This represents a single bond, a structure shown by the following formula [1a-A] or formula [1a-B]. ４ａ This represents the structure shown by formula [1-A] or formula [1-B]. ma is an integer from 1 to 12. * indicates a bond with the polymer's main chain. (X １Ａ These are single bonds, -O-, -CO-, -COO-, -OCO-, -NH-, -N(CH ３ )-, -CONH-, -CON(CH ３ )-,-NHCO- or-N(CH ３ ) indicates CO-. * is X ２ａ This shows the combination with **. ** represents X ４ａ (This shows the combination.) 4. The phase difference material composition according to claim 3, wherein the structure represented by formula [1a] is a structure represented by any of the following formulas [1aa] to [1aj]. (X ５ａ and X ６ａ Each of these independently represents a single bond, -O-, -COO-, or -OCO-. ７ａ This represents a single bond or an alkylene group having 1 to 12 carbon atoms. ８ａ This refers to a hydrogen atom, a benzene ring, or a hydrogen atom on a ring that forms a hydroxyl group, -(CH ２ ) ａ -COOH (where a is an integer from 0 to 4), represents a benzene ring substituted with an alkyl group having 1 to 8 carbon atoms or an alkoxy group having 1 to 8 carbon atoms. X ９ａ is a hydrogen atom, a hydroxyl group, -(CH ２ ) ｂ -COOH (where b is an integer from 0 to 4), halogen atom, C1-C8 alkyl group, or C1-C8 alkoxy group. maa is an integer from 1 to 12. * indicates a bond to the polymer's main chain.

5. The phase difference composition according to any one of claims 1 to 4, wherein the polymer of component (A) further has a structure represented by the following formula [2a] in its side chains. (Y １ａ and Y ２ａ These are, independently, single bonds, -O-, -CO-, -COO-, -OCO-, -NH-, -N(CH) ３ )-, -NHCONH-, -CONH-, -CON(CH ３ )-,-NHCO- or-N(CH ３ ) Indicates CO-. Y ３ａ The structure is represented by one of the following formulas [2a-A] to [2a-G]. na represents an integer from 0 to 12. * indicates a bond to the polymer's main chain. (Y Ａ is a hydrogen atom, a hydroxyl group, -(CH ２ ) ｃ -COOH (where c is an integer from 0 to 4), cyano group, C1-C8 alkyl group, or C1-C8 alkoxy group. Y Ｂ These are single bonds, -O-, -CO-, -COO-, -OCO-, -NH-, -N(CH ３ )-, -CONH-, -CON(CH ３ )-,-NHCO- or-N(CH ３ ) indicates CO-. * is Y ２ａ (This shows the combination.) 6. The phase difference material composition according to claim 5, wherein the structure represented by formula [2a] is a structure represented by any of the following formulas [2aa] to [2ag]. (Y ４ａ and Y ５ａ These independently represent a single bond, -O-, -COO-, or -OCO-. ６ａ is a hydrogen atom, a hydroxyl group, -(CH ２ ) ｃ -COOH (where c is an integer from 0 to 4), represents an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms. naa represents an integer from 1 to 12. * indicates a bond to the polymer's main chain.

7. The phase difference composition according to claim 1 or 2, wherein the proportion of the structure containing the photoreactive site in the polymer of component (A) is 5 to 99.9 mol%.

8. The phase difference composition according to claim 1 or 2, wherein the polymer has a main chain composed of (meth)acrylate.

9. The phase difference composition according to claim 1 or 2, wherein the 10-hour half-life temperature of the organic peroxide of component (B) is 60°C or higher and 150°C or lower.

10. The phase difference composition according to claim 1 or 2, wherein the organic peroxide of component (B) is a compound having a ketone peroxide structure, a peroxyketal structure, a hydroperoxide structure, a dialkyl peroxide structure, a diacyl peroxide structure, a peroxyester structure, or a peroxydicarbonate structure.

11. The phase difference material composition according to claim 1 or 2, wherein the organic peroxide of component (B) is 0.01 to 10 parts by mass per 100 parts by mass of the polymer of component (A).

12. A phase difference material obtained from the phase difference material composition according to claim 1 or 2.

13. A method for manufacturing a phase difference material, comprising the following steps (1) to (3). (1) A step of applying the phase difference material composition according to claim 1 or 2 onto a substrate to form a coating film. (2) A step of irradiating the coating film with polarized ultraviolet light. (3) A step of heating the coating film that has been irradiated with ultraviolet light.

14. A method for manufacturing a phase difference material, comprising the following steps (1) to (4). (1) A step of applying the phase difference material composition according to claim 1 or 2 onto a substrate to form a coating film. (2) A step of irradiating the coating film with polarized ultraviolet light. (3) A step of heating the coating film that has been irradiated with ultraviolet light. (4) A step of forming a liquid crystal layer on the coating film.

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