JP2011017932A - Optical compensation film and polarizing plate using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical compensation film in which phase differences with respect to wavelengths of light can be easily controlled at low cost without the need of a complicated process such as a process for laminating two retardation films while aligning optical axes; and to provide a polarizing plate with an optical compensation film produced by using the optical compensation film.SOLUTION: The optical compensation film is a stretched film containing 1 to 30 parts by weight of polyesterpolyol based on 100 parts by weight of a cellulose ester, and satisfying specified optical characteristics.

Description

  The present invention relates to an optical compensation film that can be suitably used for an optical device such as a liquid crystal display device and an optical pickup. Or it is related with the polarizing plate using this.

  In a liquid crystal display device, an optical compensation film for compensating for birefringence caused by other components in the device is generally used. Such an optical compensation film is used, for example, for widening the viewing angle and preventing light leakage during black display.

  By the way, in order to use the optical compensation film for preventing the color change of the display screen of the liquid crystal display device, it is necessary to control the phase difference (wavelength dispersion of the phase difference) with respect to each wavelength of light. As an example of such, there is a retardation plate (a quarter wavelength plate) or the like whose phase difference is 1/4 of the wavelength for each wavelength of light. Examples of such a controlled phase difference in a wide band include, for example, (retardation in light with a wavelength of 450 nm) / (retardation in light with a wavelength of 550 nm) and films having different retardations and their optical axes intersect. In this state, there are retardation plates that are laminated in a state (see, for example, Patent Document 1).

  Another example is a ¼ wavelength film produced by uniaxially stretching a film formed from a mixture of a polymer having a positive intrinsic birefringence value and a polymer having a negative intrinsic birefringence value ( For example, see Patent Document 2 and Non-Patent Document 1). Here, a polymer having a positive intrinsic birefringence value means that when the main chain of the polymer extends to the ideal state (refractive index related to the polarization component in the direction parallel to the alignment direction of the polymer main chain) − (Refractive index related to polarization component in a direction perpendicular to the orientation direction of the polymer main chain)> 0, for example, polyvinyl chloride. In addition, a polymer having a negative intrinsic birefringence value means that when the main chain of the polymer is extended and oriented to an ideal state (refractive index related to a polarization component in a direction parallel to the orientation direction of the polymer main chain) − ( The refractive index of the polarization component in the direction perpendicular to the orientation direction of the polymer main chain) is <0, for example, polymethyl methacrylate.

  In addition, examples of films composed of a polymer compound including a monomer unit of a polymer compound having positive refractive index anisotropy and a monomer unit of a polymer compound having negative refractive index anisotropy are also mentioned ( For example, see Patent Document 3).

  Another example is a surface relief hologram using structural birefringence (see, for example, Patent Document 4).

  Further, in an optical device such as an optical pickup, a quarter wavelength plate is used in combination with a polarizing beam splitter. In order to read information from an optical disk medium such as a compact disk or a DVD, a light beam emitted from a laser diode is passed through a polarizing beam splitter and a quarter-wave plate in this order, and then reflected by the reflecting surface of the optical disk medium to be again 1 / When the light beam is incident in the order of the four-wavelength plate and the polarizing beam splitter, that is, when the light beam is reciprocated into the polarizing beam splitter and the quarter-wave plate, the combination of the quarter-wave plate and the polarizing beam splitter is as follows: An isolator function for blocking the light beam reflected from the optical disk medium without passing it to the laser diode side in the return path is developed, and the oscillation of the laser diode is stabilized. In order to read information from the optical disk medium, light having a wavelength of 780 nm is used for a compact disk, and light having a wavelength of 650 nm is used for a DVD. In addition to these, Blu-ray Disks (BD) that can store a larger amount of information than compact discs and DVDs have recently been used, and light with a wavelength of 405 nm is used. Therefore, a reproducing apparatus that can use all of these optical disk media has a phase difference of 195 nm which is a quarter wavelength of light having a wavelength of 780 nm, and 162.5 nm of light having a wavelength of 650 nm. There is a need for a single broadband quarter-wave plate having a phase difference and having a phase difference of 101.3 nm for light having a wavelength of 405 nm.

JP-A-5-27118 JP 56-125702 A International Publication No. 00/26705 Pamphlet JP-A-62-212940

Takashi Inoue, Taku Saito, “Design of Low Birefringent Plastics”, Functional Materials, Vol. 7, No. 3, p21-29, 1987

In the case of a liquid crystal display device, for example, in order to compensate for the birefringence of a recent VA (Vertical Alignment) mode liquid crystal cell, it is necessary to match the wavelength dispersion of the phase difference of the optical compensation film to the wavelength dispersion of the phase difference of the liquid crystal cell. There is. When the in-plane retardation of the optical compensation film with respect to light of wavelength λ (nm) is R (λ) (nm), for example, R (447) for light of wavelength 447 nm, light of wavelength 548 nm, and light of wavelength 628 nm. ), R (548), R (628)
R (447) <R (548) <R (628) (Formula A)
In other words, an optical compensation film showing reverse chromatic dispersion in which R (λ) increases as the wavelength of light in the visible light region increases, and the degree of reverse chromatic dispersion is controlled. It is important that In this specification,
R (447)> R (548)> R (628) (Formula B)
The relationship in which R (λ) decreases as the wavelength of light in the visible light region increases is referred to as “positive chromatic dispersion”, and the relationship of Formula A opposite to this is referred to as “reverse chromatic dispersion”. ". In addition, the value of R (447) / R (548) of the optical compensation film having the relationship of Formula A is referred to as “inverse chromatic dispersion degree”, and the two types of optical compensation films having the relationship of Formula A are reversed. When the degree of chromatic dispersion is compared, the smaller value is expressed as “the reverse chromatic dispersion is high”.

  In the film described in Patent Document 1, although the reverse degree of chromatic dispersion can be changed by the crossing angles of the optical axes of a plurality of films, there is a troublesome adjustment of the crossing angles of the optical axes.

  In addition, in the films described in Patent Document 2 and Non-Patent Document 1, when the film is uniaxially stretched, the phase difference of each polymer unit is reversed, so that the phase difference of the entire film is reduced as a result of the addition, In order to obtain a necessary phase difference, it is necessary to increase the film thickness. As a result, problems such as high material costs and increased thickness of the display device arise.

  Further, even in the film described in Patent Document 3, since the sign of the phase difference of each monomer unit is reversed, the phase difference of the entire film is reduced as a result of addition, and the necessary phase difference is obtained in the same manner as in the above example. In order to obtain this, it is necessary to increase the film thickness.

  In the case of the technique described in Patent Document 4, it is necessary to finely process to the wavelength level size of light, and it is difficult to produce a seamless roll film by processing.

  The present invention has been made in view of the above problems, and its purpose is not to require a complicated process of laminating two retardation films with the optical axis aligned, and inexpensively. An object of the present invention is to provide an optical compensation film in which the phase difference for each wavelength of light can be easily controlled.

  In order to solve such problems, the present inventor has found that the above-mentioned problems can be solved as a result of intensive studies, and has reached the present invention.

  Cellulose ester film does not have much birefringence, and in order to obtain the necessary in-plane retardation, a film thickness exceeding the constraint may be required (in-plane retardation is (in-plane retardation) = (bipolar retardation). Refractive) × (film thickness)). In order to increase the in-plane retardation, in addition to increasing the film thickness, there is a method of using a resin or an additive that exhibits high in-plane retardation, but in general, the in-plane retardation is exhibited. High-resin resins often exhibit positive chromatic dispersion, and the combined use often leads to the chromatic dispersion of the retardation of the film containing cellulose ester in the positive chromatic dispersion direction. However, it has also been found that by using a mixture of cellulose ester and polyester polyol, the reverse wavelength dispersibility can be improved even in a combination system of resins and additives having high in-plane retardation. It was found that wavelength dispersion opposite to the internal phase difference can be controlled simultaneously.

  That is, the present invention relates to the following.

  [1] An optical compensation film which is a stretched film containing 1 to 30 parts by weight of polyester polyol with respect to 100 parts by weight of cellulose ester and satisfies the following formulas 1 and 2.

1 ≦ R (548) ≦ 600 (Formula 1)
[R (447) / R (548)] <[R ₀ (447) / R ₀ (548)] (Formula 2)
(Where R (447) is the in-plane phase difference (nm) for light having a wavelength of 447 nm, R (548) is the in-plane phase difference for light having a wavelength of 548 nm, and R ₀ (447) and R ₀ (548) are respectively And represents an in-plane retardation for light having a wavelength of 447 nm and an in-plane retardation for light having a wavelength of 548 nm in a film stretched by removing the polyester polyol from the composition of the optical compensation film of the present invention.
[2] In the cellulose ester, at least one hydroxyl group per glucose residue of cellulose is substituted with an ester group, and the plurality of ester groups are the same or different and are groups selected from the following general formula (1). [1] The optical compensation film according to [1].

(In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.)
[3] The polyester polyol is a polycondensate of dibasic acid, alkylene glycol, and polyalkylene glycol. Dibasic acid, alkylene glycol, and polyalkylene glycol are represented by the following general formulas (2), (3), The optical compensation film according to [1] or [2], which is a compound represented by (4) and having a number average molecular weight of 400 to 20000.

(In the formula, R ² represents an alkylene group having 1 to 10 carbon atoms.)

(In the formula, R ³ represents an alkylene group having 1 to 10 carbon atoms.)

(In the formula, R ⁴ represents an alkylene group having 1 to 10 carbon atoms, and n represents an integer of 2 to 20).
[4] Any one of [1] to [3], wherein the polyester polyol is a compound containing at least one of the following general formulas (5), (6), and (7): The optical compensation film according to item.

(Wherein R ² , R ³ and R ⁴ are the same or different and represent an alkylene group having 1 to 10 carbon atoms, n represents an integer of 2 to 20; p and q are the same or different; Represents an integer of ˜40.)

(Wherein R ² , R ³ and R ⁴ are the same or different and represent an alkylene group having 1 to 10 carbon atoms, n represents an integer of 2 to 20; and r and s are the same or different; Represents an integer of ˜40.)

(Wherein R ² , R ³ and R ⁴ are the same or different and represent an alkylene group having 1 to 10 carbon atoms, n represents an integer of 2 to 20; t and u are the same or different; Represents an integer of ˜40.)
[5] A polarizing plate with an optical compensation layer, comprising the optical compensation film according to any one of [1] to [4].

  According to the present invention, an optical compensation film excellent in reverse wavelength dispersion can be obtained, and a complicated process of bonding two retardation films with the optical axis aligned is not required and is inexpensive. It is possible to provide an optical compensation film in which the phase difference for each wavelength of light can be easily controlled.

  Hereinafter, the present invention will be described in detail.

  The present invention is a stretched film containing 1 to 30 parts by weight of a polyester polyol with respect to 100 parts by weight of a cellulose ester, and is an optical compensation film characterized by satisfying the following formulas 1 and 2.

1 ≦ R (548) ≦ 600 (Formula 1)
[R (447) / R (548)] <[R ₀ (447) / R ₀ (548)] (Formula 2)
(Where R (447) is the in-plane phase difference (nm) for light having a wavelength of 447 nm, R (548) is the in-plane phase difference for light having a wavelength of 548 nm, and R ₀ (447) and R ₀ (548) are respectively And represents an in-plane retardation for light having a wavelength of 447 nm and an in-plane retardation for light having a wavelength of 548 nm in a film stretched by removing the polyester polyol from the composition of the optical compensation film of the present invention.
First, the cellulose ester will be described. The cellulose ester used in the present invention is, for example, a cellulose obtained from various wood pulp, cotton linter, cotton lint, etc. as a raw material, in the presence of an acid catalyst such as sulfuric acid, monocarboxylic acid, monocarboxylic acid anhydride, or Production by a known method of reacting these mixtures or a known method of reacting monocarboxylic acid anhydrides and monocarboxylic acid halides in the presence of a base catalyst such as pyridine and triethylamine using cellulose as a raw material. (See, for example, US Pat. No. 2,033,820).

  Examples of the monocarboxylic acid to be reacted include a compound represented by the following general formula (8).

(In the formula, R ⁵ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.)
In the present invention, the alkyl group having 1 to 20 carbon atoms is, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an isobutyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, An n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, cyclopentyl group, cyclohexyl group and the like are indicated.

  The compound represented by General formula (8) may be used independently and may use 2 or more types together.

In the present invention, from the viewpoint of availability of the monocarboxylic acid, R ⁵ is a hydrogen atom, preferably an alkyl group having 1 to 20 carbon atoms, R ⁵ is a hydrogen atom, an alkyl group having 1 to 16 carbon atoms More preferably, R ⁵ is more preferably a hydrogen atom or an alkyl group having 1 to 12 carbon atoms.

  Specific examples of the compound represented by the general formula (8) include formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid and decanoic acid. , Undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid and the like.

  The cellulose ester obtained by reacting these and the monocarboxylic acid may be used alone or in combination of two or more.

  Moreover, the compound represented by following General formula (9) is mentioned as an example of the anhydride of the monocarboxylic acid made to react.

(Wherein R ⁶ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.)
The compound represented by General formula (9) may be used independently and may use 2 or more types together.

In the present invention, from the viewpoint of availability of the anhydrides of monocarboxylic acids, R ⁶ is a hydrogen atom, preferably an alkyl group having 1 to 20 carbon atoms, R ⁶ is a hydrogen atom, C1-16 It is more preferably an alkyl group, and R ⁶ is more preferably a hydrogen atom or an alkyl group having 1 to 12 carbon atoms.

  Specific examples of the compound represented by the general formula (9) include formic anhydride, acetic anhydride, propionic anhydride, butyric anhydride, isobutyric anhydride, valeric anhydride, isovaleric anhydride, hexanoic anhydride, heptanoic anhydride Octanoic anhydride, nonanoic anhydride, decanoic anhydride, undecanoic anhydride, dodecanoic anhydride, tridecanoic anhydride, tetradecanoic anhydride, pentadecanoic anhydride, hexadecanoic anhydride, heptadecanoic anhydride, octadecanoic anhydride and the like.

  The cellulose ester obtained by reacting these and the monocarboxylic acid anhydride may be used alone or in combination of two or more.

  Examples of monocarboxylic acid halides to be reacted include compounds represented by the following general formula (10).

(Wherein R ⁷ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and R ⁸ represents a halogen atom.)
In the present invention, the halogen atom means, for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom or the like.

  The compound represented by General formula (10) may be used independently and may use 2 or more types together.

In the present invention, from the viewpoint of availability of the monocarboxylic acid halide, R ⁷ is preferably a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, R ⁸ is preferably a halogen atom, and R ⁷ is a hydrogen atom. More preferably, it is an alkyl group having 1 to 16 carbon atoms, R ⁸ is preferably a halogen atom, R ⁷ is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, and R ⁸ is a halogen atom. Further preferred.

  Specific examples of the compound represented by the general formula (10) include formyl fluoride, acetyl fluoride, propionyl fluoride, butyryl fluoride, isobutyryl fluoride, valeroyl fluoride, isovaleroyl fluoride, hexanoyl fluoride, fluorine Heptanoyl fluoride, octanoyl fluoride, nonanoyl fluoride, decanoyl fluoride, undecanoyl fluoride, dodecanoyl fluoride, tridecanoyl fluoride, tetradecanoyl fluoride, pentadecanoyl fluoride, hexadecanoyl fluoride, heptadecanoyl fluoride, fluorine Octadecanoyl chloride, formyl chloride, acetyl chloride, propionyl chloride, butyryl chloride, isobutyryl chloride, valeroyl chloride, isovaleroyl chloride, hexanoyl chloride, heptanoyl chloride, octanoyl chloride, nonanoyl chloride, decanoyl chloride, Decanoyl, dodecanoyl chloride, tridecanoyl chloride, tetradecanoyl chloride, pentadecanoyl chloride, hexadecanoyl chloride, heptadecanoyl chloride, octadecanoyl chloride, formyl bromide, acetyl bromide, propionyl bromide, butyryl bromide, isobutyryl bromide , Valeroyl bromide, Isovaleroyl bromide, Hexanoyl bromide, Heptanoyl bromide, Octanoyl bromide, Nonanoyl bromide, Decanoyl bromide, Undecanoyl bromide, Dodecanoyl bromide, Tridecanoyl bromide, Tetradecanoyl bromide, Penta bromide Decanoyl, hexadecanoyl bromide, heptadecanoyl bromide, octadecanoyl bromide, formyl iodide, acetyl iodide, propionyl iodide, butyryl iodide, isobutyryl iodide, valeroyl iodide, isovaleroyl iodide, heptiodide iodide Sanoyl, heptanoyl iodide, octanoyl iodide, nonanoyl iodide, decanoyl iodide, undecanoyl iodide, dodecanoyl iodide, tridecanoyl iodide, tetradecanoyl iodide, pentadecanoyl iodide, hexadecanoyl iodide, iodide Examples include heptadecanoyl and octadecanoyl iodide.

  The cellulose ester obtained by reacting these and the monocarboxylic acid halide may be used alone or in combination of two or more.

  Cellulose has three hydroxyl groups per glucose residue, which is its structural unit. Therefore, when these hydroxyl groups are substituted, the degree of substitution per glucose residue (hereinafter referred to as DS) is 3 at maximum. In the present invention, the lower limit of DS is preferably 1.0, more preferably 1.5, still more preferably 1.9, and the upper limit is more preferably 3. When DS is lower than 1.0, for example, when a film before stretching is formed by solution casting, it tends to be difficult to dissolve in a solvent. In the present invention, two or more cellulose esters having different DSs may be used in combination, or may be used alone.

  In the cellulose ester of the present invention, at least one hydroxyl group per glucose residue of cellulose is substituted with an ester group, and the plurality of ester groups are the same or different and are groups selected from the following general formula (1) Is preferred.

(In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.)
Furthermore, the lower limit of the number average molecular weight of the cellulose ester is preferably 5000, more preferably 8000, still more preferably 10,000, and the upper limit is preferably 1000000, more preferably 500000, and further preferably 300000. If the number average molecular weight is less than 5,000, the strength of the film tends to decrease, and if the number average molecular weight is greater than 1,000,000, the workability during film formation tends to be inferior. The number average molecular weight is a value measured by gel permeation chromatography (GPC). In this invention, 2 or more types of the cellulose ester from which a number average molecular weight differs may be used together, and may be used independently.

  Next, the polyester polyol will be described. The polyester polyol used in the present invention is produced by a known method in which a dibasic acid, an alkylene glycol, and a polyalkylene glycol are subjected to a polycondensation reaction in the presence of a catalyst such as an organic titanate such as tetrapropyl titanate or tetrabutyl titanate. (See, for example, JP-A-47-25295).

  As an example of a dibasic acid, the compound represented by following General formula (2) is mentioned.

(In the formula, R ² represents an alkylene group having 1 to 10 carbon atoms.)
In the present invention, the alkylene group having 1 to 10 carbon atoms includes, for example, a methylene group, 1,1-ethylene group, 1,2-ethylene group, 1,1-propylene group, 1,2-propylene group, , 3-propylene group, 2,2-propylene group, 1,1-butylene group, 1,2-butylene group, 1,3-butylene group, 1,4-butylene group, 2,2-butylene group, 2, 3-butylene group, 1,1-pentylene group, 1,2-pentylene group, 1,3-pentylene group, 1,4-pentylene group, 1,5-pentylene group, 1,1-hexylene group, 1,2 -Hexylene group, 1,3-hexylene group, 1,4-hexylene group, 1,5-hexylene group, 1,6-hexylene group, 1,7-heptylene group, 1,8-octylene group, 1,9 -Nonylene group, 1,10-decylene group, 1,2-cyclohexene Len group, 1,3-cyclohexylene group, 1,4-cyclohexylene group, 1,2-cyclohexanedimethylene group, 1,3-cyclohexanedimethylene group, 1,4-cyclohexanedimethylene group, etc. .

In the present invention, from the viewpoint of availability of the compound represented by the general formula (2), R ² is preferably an alkylene group having 1 to 10 carbon atoms, and R ² is an alkylene group having 1 to 8 carbon atoms. More preferably, R ² is more preferably an alkylene group having 1 to 6 carbon atoms.

  Specific examples of the compound represented by the general formula (2) include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid and the like. Can be mentioned.

  Examples of alkylene glycols include compounds represented by the following general formula (3).

(In the formula, R ³ represents an alkylene group having 1 to 10 carbon atoms.)
In the present invention, from the viewpoint of availability of the compound represented by the general formula (3), R ³ is preferably an alkylene group having 1 to 10 carbon atoms, and R ³ is an alkylene group having 1 to 8 carbon atoms. More preferably, R ³ is more preferably an alkylene group having 1 to 6 carbon atoms.

  Specific examples of the compound represented by the general formula (3) include ethylene glycol, propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, and 2,3-butylene glycol. 1,2-pentylene glycol, 1,3-pentylene glycol, 1,4-pentylene glycol, 1,5-pentylene glycol, 1,2-hexylene glycol, 1,3-hexylene glycol, , 4-hexylene glycol, 1,5-hexylene glycol, 1,6-hexylene glycol, 1,7-heptylene glycol, 1,8-octylene glycol, 1,9-nonylene glycol, 1, 10-decylene glycol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-silane B hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, and the like.

  Moreover, as an example of polyalkylene glycol, the compound represented by following General formula (4) is mentioned.

(In the formula, R ⁴ represents an alkylene group having 1 to 10 carbon atoms, and n represents an integer of 2 to 20).
In the present invention, from the viewpoint of availability of the compound represented by the general formula (4), R ⁴ is preferably an alkylene group having 1 to 10 carbon atoms, and R ⁴ is an alkylene group having 1 to 8 carbon atoms. More preferably, R ⁴ is more preferably an alkylene group having 1 to 6 carbon atoms. Similarly, from the viewpoint of availability of the compound, n is preferably an integer having a lower limit of 2 and an upper limit of 20, more preferably n is an integer having a lower limit of 3 and an upper limit of 15, and n is a lower limit of 4 and an upper limit of 10. More preferably, it is an integer.

  Specific examples of the compound represented by the general formula (4) include polyethylene glycol, polypropylene glycol, polytrimethylene glycol, polytetramethylene glycol, polypentamethylene glycol, polyhexamethylene glycol, polyheptamethylene glycol, polyocta Examples include methylene glycol, polynonamethylene glycol, and polydecamethylene glycol.

  Polyester polyols obtained by polycondensation reaction of the above dibasic acid, alkylene glycol, and polyalkylene glycol may be used alone or in combination of two or more.

  Examples of the structure of the polyester polyol are represented by the following general formulas (5), (6), and (7). In the present invention, compounds having these structures are used alone or as a mixture of two or more. Can do.

(Wherein R ² , R ³ and R ⁴ are the same or different and represent an alkylene group having 1 to 10 carbon atoms, n represents an integer of 2 to 20; p and q are the same or different; Represents an integer of ˜40.)

(Wherein R ² , R ³ and R ⁴ are the same or different and represent an alkylene group having 1 to 10 carbon atoms, n represents an integer of 2 to 20; and r and s are the same or different; Represents an integer of ˜40.)

(Wherein R ² , R ³ and R ⁴ are the same or different and represent an alkylene group having 1 to 10 carbon atoms, n represents an integer of 2 to 20; t and u are the same or different; Represents an integer of ˜40.)
The compounds represented by the general formulas (5), (6), and (7) have an alkylene glycol-derived end group and / or a polyalkylene glycol-derived end group shown in the structural formula at both ends. If so, the arrangement of the dibasic acid in the molecular chain and the ester bond of alkylene glycol and polyalkylene glycol may be random or regular.

In the present invention, from the viewpoint of availability of the compound at the time of production, R ² , R ³ and R ⁴ are preferably the same or different and are preferably 1 to 10 alkylene groups, and R ² , R ³ and R ⁴ are It is more preferably the same or different and an alkylene group having 1 to 8 carbon atoms, and R ² , R ³ and R ⁴ are the same or different, and more preferably an alkylene group having 1 to 6 carbon atoms.

  Similarly, from the viewpoint of availability of the compound during production, n is preferably an integer having a lower limit of 2 and an upper limit of 20, more preferably n is an integer having a lower limit of 3 and an upper limit of 15, and n is a lower limit of 4. More preferably, the upper limit is an integer of 10.

  Further, p and q are the same or different and are preferably integers having a lower limit of 1 and an upper limit of 40, more preferably p and q are the same or different and have an integer of lower limit of 2 and an upper limit of 30, and p, q Are more preferably the same or different and an integer having a lower limit of 3 and an upper limit of 20. When p and q are larger than 40, the compatibility with the cellulose ester tends to decrease.

  Further, r and s are the same or different and are preferably integers having a lower limit of 1 and an upper limit of 40, more preferably r and s are the same or different and have an integer of lower limit of 2 and an upper limit of 30; Are more preferably the same or different and an integer having a lower limit of 3 and an upper limit of 20. When r and s are larger than 40, the compatibility with the cellulose ester tends to decrease.

  Further, t and u are preferably the same or different and are preferably integers having a lower limit of 1 and an upper limit of 40, more preferably t and u are the same or different and have an integer of lower limit of 2 and an upper limit of 30, and t, u Are more preferably the same or different and an integer having a lower limit of 3 and an upper limit of 20. When t and u are larger than 40, the compatibility with the cellulose ester tends to decrease.

Specific examples of the compounds represented by the general formulas (5), (6) and (7) are as follows: R ² is 1,2-ethylene group, R ³ is 1,2-ethylene group, R ⁴ is 1, 2-ethylene group, n is 2 compound, R ² is 1,2-ethylene group, R ³ is 1,2-ethylene group, R ⁴ is 1,2-ethylene group, n is 4 compound, R ² is 1,2-ethylene group, R ³ is 1,2-ethylene group, R ⁴ is 1,2-ethylene group, n is a compound of 6, R ² is 1,2-ethylene group, R ³ is 1,2-ethylene A compound in which an ethylene group, R ⁴ is a 1,2-ethylene group, n is 8, R ² is a 1,2-ethylene group, R ³ is a 1,2-propylene group, R ⁴ is a 1,2-ethylene group, n Is a compound of ² , R ² is a 1,2-ethylene group, R ³ is a 1,2-propylene group, R ⁴ is a 1,2-ethylene group, n is a compound of 4, R ² is a 1,2-ethylene group R ³ is 1,2-propy Rene group, R ⁴ is 1,2-ethylene group, n is 6 compound, R ² is 1,2-ethylene group, R ³ is 1,2-propylene group, R ⁴ is 1,2-ethylene group, n Is a compound of 8, R ² is a 1,2-ethylene group, R ³ is a 1,3-propylene group, R ⁴ is a 1,2-ethylene group, n is a compound of ² , R ² is a 1,2-ethylene group R ³ is 1,3-propylene group, R ⁴ is 1,2-ethylene group, n is 4 compound, R ² is 1,2-ethylene group, R ³ is 1,3-propylene group, R ⁴ is 1,2-ethylene group, n is 6 compound, R ² is 1,2-ethylene group, R ³ is 1,3-propylene group, R ⁴ is 1,2-ethylene group, n is 8 compound, R ² is a 1,2-ethylene group, R ³ is a 1,4-butylene group, R ⁴ is a 1,2-ethylene group, n is a compound of ² , R ² is a 1,2-ethylene group, R ³ is 1, 4-butylene group, R ⁴ 1,2-ethylene radical, n is the compound of 4, R ² is 1,2-ethylene group, R ³ is 1,4-butylene group, the compound of R ⁴ is 1,2-ethylene radical, n is 6, R ² is a 1,2-ethylene group, R ³ is a 1,4-butylene group, R ⁴ is a 1,2-ethylene group, n is a compound of 8, R ² is a 1,2-ethylene group, R ³ is 1, 6-hexylene group, R ⁴ is 1,2-ethylene group, n is 2 compound, R ² is 1,2-ethylene group, R ³ is 1,6-hexylene group, R ⁴ is 1,2-ethylene group N is 4, R ² is 1,2-ethylene, R ³ is 1,6-hexylene, R ⁴ is 1,2-ethylene, n is 6, and R ² is 1,2- An ethylene group, R ³ is a 1,6-hexylene group, R ⁴ is a 1,2-ethylene group, n is a compound of 8, R ² is a 1,2-ethylene group, R ³ is a 1,8-octylene group, R ⁴ is 1,2-eth Rene group, compound with n of 2, R ² is 1,2-ethylene group, R ³ is 1,8-octylene group, R ⁴ is 1,2-ethylene group, compound with n is 4, R ² is 1, 2-ethylene group, R ³ is 1,8-octylene group, R ⁴ is 1,2-ethylene group, n is a compound of 6, R ² is 1,2-ethylene group, R ³ is 1,8-octylene group R ⁴ is a 1,2-ethylene group, n is a compound of 8, R ² is a 1,2-ethylene group, R ³ is a 1,2-ethylene group, R ⁴ is a 1,2-propylene group, and n is 2 R ² is a 1,2-ethylene group, R ³ is a 1,2-ethylene group, R ⁴ is a 1,2-propylene group, n is a compound 4, R ² is a 1,2-ethylene group, R ³ is a 1,2-ethylene group, R ⁴ is a 1,2-propylene group, n is a compound of 6, R ² is a 1,2-ethylene group, R ³ is a 1,2-ethylene group, R ⁴ is 1, 2-propylene group, Compounds of but 8, R ² is 1,2-ethylene group, R ³ is 1,2-propylene group, R ⁴ is 1,2-propylene radical, n is 2 the compound, R ² is 1,2-ethylene R ³ is 1,2-propylene group, R ⁴ is 1,2-propylene group, n is 4 compound, R ² is 1,2-ethylene group, R ³ is 1,2-propylene group, R ⁴ is 1,2-propylene group, n is 6 compound, R ² is 1,2-ethylene group, R ³ is 1,2-propylene group, R ⁴ is 1,2-propylene group, n is 8 compound, R ² is a 1,2-ethylene group, R ³ is a 1,3-propylene group, R ⁴ is a 1,2-propylene group, n is a compound ² , R ² is a 1,2-ethylene group, R ³ is 1, 3-propylene group, the compound of R ⁴ is 1,2-propylene radical, n is 4, R ² is 1,2-ethylene group, R ³ is 1,3-propylene group, R ⁴ is 1,2-propylene Group, the compound of n is 6, R ² is 1,2-ethylene group, R ³ is 1,3-propylene group, the compound of R ⁴ is 1,2-propylene group, n is 8, R ² is 1,2 An ethylene group, R ³ is 1,4-butylene group, R ⁴ is 1,2-propylene group, n is a compound ² , R ² is 1,2-ethylene group, R ³ is 1,4-butylene group, R ⁴ is 1,2-propylene group, n is 4 compound, R ² is 1,2-ethylene group, R ³ is 1,4-butylene group, R ⁴ is 1,2-propylene group, n is 6 Compound, R ² is 1,2-ethylene group, R ³ is 1,4-butylene group, R ⁴ is 1,2-propylene group, n is 8 compound, R ² is 1,2-ethylene group, R ³ Is a 1,6-hexylene group, R ⁴ is a 1,2-propylene group, n is a compound ² , R ² is a 1,2-ethylene group, R ³ is a 1,6-hexylene group, R ⁴ is 1,2 -Propylene group N is 4, R ² is 1,2-ethylene group, R ³ is 1,6-hexylene group, R ⁴ is 1,2-propylene group, n is 6 compound, R ² is 1,2- An ethylene group, R ³ is a 1,6-hexylene group, R ⁴ is a 1,2-propylene group, n is a compound of 8, R ² is a 1,2-ethylene group, R ³ is a 1,8-octylene group, R Compound in which ⁴ is 1,2-propylene group, n is 2, R ² is 1,2-ethylene group, R ³ is 1,8-octylene group, R ⁴ is 1,2-propylene group, n is 4 R ² is a 1,2-ethylene group, R ³ is a 1,8-octylene group, R ⁴ is a 1,2-propylene group, n is a compound of 6, R ² is a 1,2-ethylene group, and R ³ is 1,8-octylene group, R ⁴ is 1,2-propylene group, n is a compound of 8, R ² is 1,4-butylene group, R ³ is 1,2-ethylene group, R ⁴ is 1,2- ethylene , The compound of n is 2, R ² is 1,4-butylene group, R ³ is 1,2-ethylene group, R ⁴ is 1,2-ethylene group, a compound of n is 4, R ² is 1,4 Butylene group, R ³ is 1,2-ethylene group, R ⁴ is 1,2-ethylene group, n is 6 compound, R ² is 1,4-butylene group, R ³ is 1,2-ethylene group, R Compound in which ⁴ is 1,2-ethylene group, n is 8, R ² is 1,4-butylene group, R ³ is 1,2-propylene group, R ⁴ is 1,2-ethylene group, and n is 2 , R ² is 1,4-butylene group, R ³ is 1,2-propylene group, R ⁴ is 1,2-ethylene group, n is 4 compound, R ² is 1,4-butylene group, R ³ is 1,2-propylene group, R ⁴ is 1,2-ethylene group, n is 6 compound, R ² is 1,4-butylene group, R ³ is 1,2-propylene group, R ⁴ is 1,2- Ethylene group, n is 8 Things, R ² is 1,4-butylene group, R ³ is 1,3-propylene group, R ⁴ is 1,2-ethylene radical, n is 2 the compound, R ² is 1,4-butylene group, R ³ Is a 1,3-propylene group, R ⁴ is a 1,2-ethylene group, n is a compound 4, R ² is a 1,4-butylene group, R ³ is a 1,3-propylene group, R ⁴ is 1,2 A compound having an ethylene group, n is 6, R ² is a 1,4-butylene group, R ³ is a 1,3-propylene group, R ⁴ is a 1,2-ethylene group, n is a compound 8 and R ² is 1 , 4-butylene group, R ³ is 1,4-butylene group, R ⁴ is 1,2-ethylene group, n is 2 compound, R ² is 1,4-butylene group, R ³ is 1,4-butylene Group, R ⁴ is 1,2-ethylene group, n is 4 compound, R ² is 1,4-butylene group, R ³ is 1,4-butylene group, R ⁴ is 1,2-ethylene group, n is compound of 6, R ² is 1, - butylene group, R ³ is 1,4-butylene group, the compound of R ⁴ is 1,2-ethylene radical, n is 8, R ² is 1,4-butylene group, R ³ is 1,6-hexylene group, R ⁴ is 1,2-ethylene group, n is 2 compound, R ² is 1,4-butylene group, R ³ is 1,6-hexylene group, R ⁴ is 1,2-ethylene group, n is 4 Compound, R ² is 1,4-butylene group, R ³ is 1,6-hexylene group, R ⁴ is 1,2-ethylene group, n is 6 compound, R ² is 1,4-butylene group, R ³ Is a 1,6-hexylene group, R ⁴ is a 1,2-ethylene group, n is a compound of 8, R ² is a 1,4-butylene group, R ³ is a 1,8-octylene group, R ⁴ is 1,2 A compound having an ethylene group, n is 2, R ² is a 1,4-butylene group, R ³ is a 1,8-octylene group, R ⁴ is a 1,2-ethylene group, n is 4 and R ² is 1 , 4-Butile Group, R ³ is 1,8-octylene group, a compound of R ⁴ is 1,2-ethylene radical, n is 6, R ² is 1,4-butylene group, R ³ is 1,8-octylene group, R ⁴ Is a 1,2-ethylene group, n is a compound of 8, R ² is a 1,4-butylene group, R ³ is a 1,2-ethylene group, R ⁴ is a 1,2-propylene group, and n is a compound of 2, R ² is 1,4-butylene group, R ³ is 1,2-ethylene group, R ⁴ is 1,2-propylene group, n is 4 compound, R ² is 1,4-butylene group, R ³ is 1 , 2-ethylene group, R ⁴ is 1,2-propylene group, n is 6 compound, R ² is 1,4-butylene group, R ³ is 1,2-ethylene group, R ⁴ is 1,2-propylene Group, n is a compound of 8, R ² is 1,4-butylene group, R ³ is a 1,2-propylene group, R ⁴ is a 1,2-propylene group, n is a compound of ² , R ² is 1,4 -Butylene group, R ³ is a 1,2-propylene group, R ⁴ is a 1,2-propylene group, n is a compound 4, R ² is a 1,4-butylene group, R ³ is a 1,2-propylene group, R ⁴ is 1, 2-propylene group, n = 6 compound, R ² = 1,4-butylene group, R ³ = 1,2-propylene group, R ⁴ = 1,2-propylene group, n = 8 compound, R ² = 1,4-butylene group, R ³ is 1,3-propylene group, R ⁴
Is a compound having 1,2-propylene group, n is 2, R ² is 1,4-butylene group, R ³ is 1,3-propylene group, R ⁴ is 1,2-propylene group, n is 4 compound, R ² is 1,4-butylene group, R ³ is 1,3-propylene group, R ⁴ is 1,2-propylene group, n is a compound of 6, R ² is 1,4-butylene group, R ³ is 1 , 3-propylene group, R ⁴ is 1,2-propylene group, n is 8 compound, R ² is 1,4-butylene group, R ³ is 1,4-butylene group, R ⁴ is 1,2-propylene A group, a compound in which n is 2, R ² is a 1,4-butylene group, R ³ is a 1,4-butylene group, R ⁴ is a 1,2-propylene group, a compound in which n is 4 and R ² is 1,4 - butylene group, R ³ is 1,4-butylene group, the compound of R ⁴ is 1,2-propylene radical, n is 6, R ² is 1,4-butylene group, R ³ is 1,4-butylene group, R ⁴ is , 2-propylene group, the compound of n is 8, R ² is 1,4-butylene group, R ³ is 1,6-hexylene group, R ⁴ is 1,2-propylene group, n is 2 the compound, R ² Is 1,4-butylene group, R ³ is 1,6-hexylene group, R ⁴ is 1,2-propylene group, n is 4 compound, R ² is 1,4-butylene group, R ³ is 1,6 A compound in which -hexylene group, R ⁴ is 1,2-propylene group, n is 6, R ² is 1,4-butylene group, R ³ is 1,6-hexylene group, R ⁴ is 1,2-propylene group, n is a compound of 8, R ² is a 1,4-butylene group, R ³ is a 1,8-octylene group, R ⁴ is a 1,2-propylene group, n is a compound of ² , R ² is 1,4-butylene group, R ³ is 1,8-octylene group, a compound of R ⁴ is 1,2-propylene radical, n is 4, R ² is 1,4-butylene group, R ³ is 1,8-octylene group, ⁴ is 1,2-propylene group, the compound of n is 6, the compound of R ² is 1,4-butylene group, R ³ is 1,8-octylene group, R ⁴ is 1,2-propylene group, n is 8 R ² is 1,6-hexylene group, R ³ is 1,2-ethylene group, R ⁴ is 1,2-ethylene group, n is 2 compound, R ² is 1,6-hexylene group, R ³ is 1,2-ethylene group, R ⁴ is 1,2-ethylene group, n is 4 compound, R ² is 1,6-hexylene group, R ³ is 1,2-ethylene group, R ⁴ is 1,2- A compound having an ethylene group, n is 6, R ² is a 1,6-hexylene group, R ³ is a 1,2-ethylene group, R ⁴ is a 1,2-ethylene group, n is a compound 8, and R ² is 1, 6-hexylene group, R ³ is 1,2-propylene group, R ⁴ is 1,2-ethylene group, n is 2 compound, R ² is 1,6-hexylene group, R ³ is 1,2-propylene group , ⁴ is 1,2-ethylene group, a compound of n is 4, R ² is 1,6-hexylene group, R ³ is 1,2-propylene group, the compound of R ⁴ is 1,2-ethylene group, n is 6 R ² is a 1,6-hexylene group, R ³ is a 1,2-propylene group, R ⁴ is a 1,2-ethylene group, n is a compound of 8, R ² is a 1,6-hexylene group, R ³ is 1,3-propylene group, R ⁴ is 1,2-ethylene group, n is 2 compound, R ² is 1,6-hexylene group, R ³ is 1,3-propylene group, R ⁴ is 1,2- Compound having ethylene group, n is 4, R ² is 1,6-hexylene group, R ³ is 1,3-propylene group, R ⁴ is 1,2-ethylene group, compound having n is 6, R ² is 1, 6-hexylene group, R ³ is 1,3-propylene group, R ⁴ is 1,2-ethylene group, n is a compound of 8, R ² is 1,6-hexylene group, R ³ is 1,4-butylene group R ⁴ is a 1,2-ethylene group, n is a compound 2, R ² is a 1,6-hexylene group, R ³ is a 1,4-butylene group, R ⁴ is a 1,2-ethylene group, and n is 4 R ² is 1,6-hexylene group, R ³ is 1,4-butylene group, R ⁴ is 1,2-ethylene group, n is 6 compound, R ² is 1,6-hexylene group, R ³ is a 1,4-butylene group, R ⁴ is a 1,2-ethylene group, n is a compound of 8, R ² is a 1,6-hexylene group, R ³ is a 1,6-hexylene group, R ⁴ is 1, 2-ethylene group, n is 2 compound, R ² is 1,6-hexylene group, R ³ is 1,6-hexylene group, R ⁴ is 1,2-ethylene group, n is 4 compound, R ² is 1,6-hexylene group, R ³ is 1,6-hexylene group, R ⁴ is 1,2-ethylene group, n is 6 compound, R ² is 1,6-hexylene group, R ³ is 1,6- Hexylene group R ⁴ is 1,2-ethylene group, a compound of n is 8, R ² is 1,6-hexylene group, R ³ is 1,8-octylene group, R ⁴ is 1,2-ethylene group, n is 2 Compound, R ² is 1,6-hexylene group, R ³ is 1,8-octylene group, R ⁴ is 1,2-ethylene group, n is 4 compound, R ² is 1,6-hexylene group, R ³ Is a 1,8-octylene group, R ⁴ is a 1,2-ethylene group, n is a compound of 6, R ² is a 1,6-hexylene group, R ³ is a 1,8-octylene group, R ⁴ is 1,2 A compound having an ethylene group, n is 8, R ² is a 1,6-hexylene group, R ³ is a 1,2-ethylene group, R ⁴ is a 1,2-propylene group, n is a compound ² , R ² is 1 , 6-hexylene group, R ³ is 1,2-ethylene group, a compound of R ⁴ is 1,2-propylene radical, n is 4, R ² is 1,6-hexylene group, R ³ is 1,2-ethylene Group, R ⁴ is 1,2-propylene group, the compound of n is 6, R ² is 1,6-hexylene group, R ³ is 1,2-ethylene group, R ⁴ is 1,2-propylene group, n is 8 compound, R ² is 1,6-hexylene group, R ³ is 1,2-propylene group, R ⁴ is 1,2-propylene group, n is 2 compound, R ² is 1,6-hexylene group, R ³ is 1,2-propylene group, R ⁴ is 1,2-propylene group, n is 4 compound, R ² is 1,6-hexylene group, R ³ is 1,2-propylene group, R ⁴ is 1 , 2-propylene group, n is 6 compound, R ² is 1,6-hexylene group, R ³ is 1,2-propylene group, R ⁴ is 1,2-propylene group, n is 8 compound, R ² Is a 1,6-hexylene group, R ³ is a 1,3-propylene group, R ⁴ is a 1,2-propylene group, n is a compound ² , R ² is a 1,6-hexylene group, R ³ is 1,3-propylene group, R ⁴ is 1,2-propylene group, n is 4 compound, R ² is 1,6-hexylene group, R ³ is 1,3-propylene group, R ⁴ is 1,2- Propylene group, n = 6 compound, R ² is 1,6-hexylene group, R ³ is 1,3-propylene group, R ⁴ is 1,2-propylene group, n is 8 compound, R ² is 1, 6-hexylene group, R ³ is 1,4-butylene group, R ⁴ is 1,2-propylene group, n is 2 compound, R ² is 1,6-hexylene group, R ³ is 1,4-butylene group , R ⁴ is 1,2-propylene group, n is 4 compound, R ² is 1,6-hexylene group, R ³ is 1,4-butylene group, R ⁴ is 1,2-propylene group, n is 6 R ² is 1,6-hexylene group, R ³ is 1,4-butylene group, R ⁴ is 1,2-propylene group, n is 8 compound, R ² is 1,6-hexyl group R ³ is 1,6-hexylene group, R ⁴ is 1,2-propylene group, n is 2 compound, R ² is 1,6-hexylene group, R ³ is 1,6-hexylene group, R Compound in which ⁴ is 1,2-propylene group and n is 4, R ² is 1,6-hexylene group, R ³ is 1,6-hexylene group, R ⁴ is 1,2-propylene group and n is 6 R ² is a 1,6-hexylene group, R ³ is a 1,6-hexylene group, R ⁴ is a 1,2-propylene group, n is a compound of 8, R ² is a 1,6-hexylene group, R ³ is 1,8-octylene group, R ⁴ is 1,2-propylene group, n is a compound ² , R ² is 1,6-hexylene group, R ³ is 1,8-octylene group, R ⁴ is 1,2- A propylene group, a compound wherein n is 4, R ² is a 1,6-hexylene group, R ³ is a 1,8-octylene group, R ⁴ is a 1,2-propylene group, n is a compound of 6, R ² is a 1,6-hexylene group, R ³ is a 1,8-octylene group, R ⁴ is a 1,2-propylene group, n is a compound of 8, R ² is a 1,8-octylene group, R ³ is 1, 2-ethylene group, R ⁴ is 1,2-ethylene group, n is 2 compound, R ² is 1,8-octylene group, R ³ is 1,2-ethylene group, R ⁴ is 1,2-ethylene group N is 4, R ² is 1,8-octylene group, R ³ is 1,2-ethylene group, R ⁴ is 1,2-ethylene group, n is 6 compound, R ² is 1,8- Octylene group, R ³ is 1,2-ethylene group, R ⁴ is 1,2-ethylene group, n is 8 compound, R ² is 1,8-octylene group, R ³ is 1,2-propylene group, R Compound in which ⁴ is 1,2-ethylene group and n is 2, R ² is 1,8-octylene group, R ³ is 1,2-propylene group, R ⁴ is 1,2-ethylene group and n is 4 , R ² is a 1,8-octylene group, R ³ is a 1,2-propylene group, R ⁴ is a 1,2-ethylene group, n is a compound of 6, R ² is a 1,8-octylene group, R ³ is 1, 2-propylene group, R ⁴ is 1,2-ethylene group, n is a compound of 8, R ² is 1,8-octylene group, R ³ is 1,3-propylene group, R ⁴ is 1,2-ethylene group , N is 2, R ² is 1,8-octylene group, R ³ is 1,3-propylene group, R ⁴ is 1,2-ethylene group, n is 4 compound, R ² is 1,8- Octylene group, R ³ is 1,3-propylene group, R ⁴ is 1,2-ethylene group, n is 6 compound, R ² is 1,8-octylene group, R ³ is 1,3-propylene group, R ⁴ is 1,2-ethylene group, a compound of n is 8, R ² is 1,8-octylene group, R ³ is 1,4-butylene group, R ⁴ is 1,2-ethylene group, n is 2 compound R ² is 1,8-octylene group, R ³ is 1,4-butylene group, R ⁴ is 1,2-ethylene radical, n is the compound of 4, R ² is 1,8-octylene group, R ³ is 1 , 4-butylene group, R ⁴ is 1,2-ethylene group, n is 6 compound, R ² is 1,8-octylene group, R ³ is 1,4-butylene group, R ⁴ is 1,2-ethylene A group wherein n is 8, R ² is 1,8-octylene group, R ³ is 1,6-hexylene group, R ⁴ is 1,2
A compound having an ethylene group, n is 2, R ² is a 1,8-octylene group, R ³ is a 1,6-hexylene group, R ⁴ is a 1,2-ethylene group, n is a compound 4 and R ² is 1 , 8-octylene group, R ³ is 1,6-hexylene group, R ⁴ is 1,2-ethylene group, n is a compound of 6, R ² is 1,8-octylene group, R ³ is 1,6-hexylene Group, R ⁴ is 1,2-ethylene group, n is 8 compound, R ² is 1,8-octylene group, R ³ is 1,8-octylene group, R ⁴ is 1,2-ethylene group, n is 2 compound, R ² is 1,8-octylene group, R ³ is 1,8-octylene group, R ⁴ is 1,2-ethylene group, n is 4 compound, R ² is 1,8-octylene group, R ³ is 1,8-octylene group, a compound of R ⁴ is 1,2-ethylene radical, n is 6, R ² is 1,8-octylene group, R ³ is 1,8-octylene group, R ⁴ is , 2-ethylene group, a compound of n is 8, R ² is 1,8-octylene group, R ³ is 1,2-ethylene group, R ⁴ is 1,2-propylene group, n is 2 the compound, R ² Is 1,8-octylene group, R ³ is 1,2-ethylene group, R ⁴ is 1,2-propylene group, n is 4 compound, R ² is 1,8-octylene group, R ³ is 1,2 An ethylene group, a compound in which R ⁴ is 1,2-propylene group, n is 6, R ² is 1,8-octylene group, R ³ is 1,2-ethylene group, R ⁴ is 1,2-propylene group, n is a compound of 8, R ² is a 1,8-octylene group, R ³ is a 1,2-propylene group, R ⁴ is a 1,2-propylene group, n is a compound of ² , R ² is 1,8-octylene group, R ³ is 1,2-propylene group, R ⁴ is 1,2-propylene group, the compound of n is 4, R ² is 1,8-octylene group, R ³ is 1,2-propylene The compound of R ⁴ is 1,2-propylene radical, n is 6, R ² is 1,8-octylene group, R ³ is 1,2-propylene group, R ⁴ is 1,2-propylene radical, n is 8 R ² is a 1,8-octylene group, R ³ is a 1,3-propylene group, R ⁴ is a 1,2-propylene group, n is a compound ² , R ² is a 1,8-octylene group, R ³ is 1,3-propylene group, R ⁴ is 1,2-propylene group, n is 4 compound, R ² is 1,8-octylene group, R ³ is 1,3-propylene group, R ⁴ is 1, 2-propylene group, n = 6 compound, R ² = 1,8-octylene group, R ³ = 1,3-propylene group, R ⁴ = 1,2-propylene group, n = 8 compound, R ² = 1,8-octylene group, R ³ is 1,4-butylene group, R ⁴ is 1,2-propylene group, the compound of n is 2, R ² is 1,8-octylene group, R ³ is , 4-butylene group, R ⁴ is 1,2-propylene radical, n is the compound of 4, R ² is 1,8-octylene group, R ³ is 1,4-butylene group, R ⁴ is 1,2-propylene Group, n is 6 compound, R ² is 1,8-octylene group, R ³ is 1,4-butylene group, R ⁴ is 1,2-propylene group, n is 8 compound, R ² is 1,8 -Octylene group, R ³ is 1,6-hexylene group, R ⁴ is 1,2-propylene group, n is a compound of ² , R ² is 1,8-octylene group, R ³ is 1,6-hexylene group, R ⁴ is 1,2-propylene group, n is 4 compound, R ² is 1,8-octylene group, R ³ is 1,6-hexylene group, R ⁴ is 1,2-propylene group, n is 6 compound, R ² is 1,8-octylene group, R ³ is 1,6-hexylene group, R ⁴ is 1,2-propylene group, the compound of n is 8, R ² is 1,8-octylene Down group, R ³ is 1,8-octylene group, R ⁴ is 1,2-propylene radical, n is 2 the compound, R ² is 1,8-octylene group, R ³ is 1,8-octylene radical, R Compound in which ⁴ is 1,2-propylene group, n is 4, R ² is 1,8-octylene group, R ³ is 1,8-octylene group, R ⁴ is 1,2-propylene group, and n is 6 R ² is a 1,8-octylene group, R ³ is a 1,8-octylene group, R ⁴ is a 1,2-propylene group, and n is an 8 compound.

  In the present invention, the polyester polyol needs to be used in the range of a lower limit of 1 part by weight and an upper limit of 30 parts by weight with respect to 100 parts by weight of the cellulose ester. More preferably, the lower limit is 2 parts by weight and the upper limit is 25 parts by weight, and the lower limit is 3 parts by weight and the upper limit is 20 parts by weight. When the amount of polyester polyol is less than 1 part by weight, the degree of reverse wavelength dispersion tends to be difficult to increase compared to a stretched film that does not use polyester polyol. The in-plane retardation of the film tends to be difficult to increase.

  Moreover, the minimum of the number average molecular weight of polyester polyol is 400, More preferably, it is 500, More preferably, it is 600, and an upper limit is 20000, More preferably, it is 15000, More preferably, it is 10,000. If the number average molecular weight is less than 400, the strength of the cellulose ester film tends to be reduced when used in combination, and if the number average molecular weight is more than 20000, the compatibility with the cellulose ester tends to be reduced. The number average molecular weight is a value measured by gel permeation chromatography (GPC). In the present invention, two or more polyester polyols having different number average molecular weights may be used in combination, or may be used alone.

  In addition, said polyester polyol can also obtain a commercial item as a raw material at the time of urethane resin manufacture.

  Next, the optical compensation film of the present invention (in the present specification, the film refers to a thin plate regardless of the thickness) will be described.

  First, a method for producing the optical compensation film of the present invention will be described.

  As a production method, a melt casting method or a solution casting method can be used. In the case of using the melt casting method, the present invention is performed by melt extrusion and forming into a film, and then performing stretching such as longitudinal uniaxial stretching, transverse uniaxial stretching, longitudinal and transverse simultaneous biaxial stretching, longitudinal and transverse sequential biaxial stretching, and oblique stretching. It can be set as an optical compensation film. When using the solution casting method, the cellulose ester is dissolved in a solvent in which the cellulose ester can be dissolved, and after the solution is applied and dried on a peelable substrate, the formed film is peeled off, and longitudinal uniaxial stretching and lateral uniaxial stretching are performed. The optical compensation film of the present invention can be obtained by performing stretching such as longitudinal and lateral simultaneous biaxial stretching, longitudinal and lateral sequential biaxial stretching, and oblique stretching. Without stripping the film formed on the peelable substrate, the film is stretched together with the peelable substrate, such as longitudinal uniaxial stretching, transverse uniaxial stretching, longitudinal and transverse simultaneous biaxial stretching, longitudinal and transverse sequential biaxial stretching, and oblique stretching. The optical compensation film of the present invention can also be peeled off from the peelable substrate.

  Examples of the solvent at the time of solution casting include hydrocarbon solvents such as benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, isopropylbenzene, diethylbenzene isomer mixture; methanol, ethanol, 1- Alcohol solvents such as propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, furfuryl alcohol, benzyl alcohol; ethyl ether, isopropyl ether, 1,3-dioxolane, 1,4- Dioxane, tetrahydropyran, tetrahydrofuran, 1,2-dimethoxyethane, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl Ether solvents such as ether; ketone solvents such as acetone, 2-butanone, 4-methyl-2-pentanone, cyclohexanone; methylene chloride, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,1,1-trichloroethane 1,1,2-trichloroethane, 1,1,1,2-tetrachloroethane, 1,1,2,2-tetrachloroethane, pentachloroethane, hexachloroethane, 1-chloropropane, 2-chloropropane, 1,1-di Chloropropane, 1,2-dichloropropane, 1,3-dichloropropane, 2,2-dichloropropane, 1,2,3-trichloropropane, chlorobenzene, 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1, 4-dichlorobenzene, 1,2,3-trichlorobenzene, 1,2,4-to Halogen solvents such as chlorobenzene and 1,3,5-trichlorobenzene; methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, tert-butyl acetate, n-acetate Ester solvents such as pentyl, n-hexyl acetate, n-heptyl acetate, n-octyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate; N Amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide and 1-methyl-2-pyrrolidinone; amine solvents such as pyrrolidine, piperidine and pyrrole. Among these, methylene chloride and chloroform are preferable from the viewpoint of solubility of the cellulose ester. These solvents may be used alone or in combination of two or more.

  As for the amount of the solvent, the ratio of the cellulose ester to the total weight of the cellulose ester and the solvent is preferably used in the range of the lower limit of 1% by weight and the upper limit of 50% by weight, and the lower limit of 2% by weight and the upper limit of 40% by weight. More preferably, the lower limit is 3% by weight and the upper limit is 30% by weight. When the ratio of the cellulose ester is less than 1% by weight, the film thickness at the time of solution casting tends to be thin, and the required film thickness tends to be difficult to obtain. When it is greater than 50% by weight, the viscosity of the solution at the time of solution casting Tends to be high and workability tends to be inferior.

  Further, the peelable substrate is not particularly limited as long as it has peelability of a film after coating and drying or a film after stretching, and the physical properties of the substrate are not impaired during film formation. . Specific examples of compounds that form a release substrate include polycarbonate polymers; polyacrylic esters such as polymethyl acrylate and polymethyl methacrylate; adipic acid, phthalic acid, isophthalic acid, terephthalic acid, 1, Condensates of dibasic acids such as 4-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid and glycols such as ethylene glycol, diethylene glycol, propylene glycol, tetramethylene glycol, and neopentyl glycol Polyester polymers obtained by ring-opening polymerization of lactones; styrene polymers such as polystyrene and poly (α-methylstyrene); copolymers of acrylates and styrene; polyethylene, polypropylene, norbornene resins, cyclo Olefin Polyolefin polymers such as hydrogenated polymer, polyisoprene, and hydrogenated polybutadiene; polyamides such as nylon 6 and nylon 66; polyimides; polyamideimides; polyetherimides; polyvinyl alcohol; polyvinyl chloride; Examples include sulfone, polyether ketone, polyether ether ketone, polyphenylene sulfide, polyphenylene oxide, polyarylate, polyacetal, epoxy resin, phenol resin, silicone resin, metals such as iron, aluminum, and copper, and glass.

  These materials are formed into a sheet shape by, for example, a solution casting method, a melt casting method, an extrusion method, a calendar method, rolling, melt molding, and the like, and are stretched by a non-stretching method, a uniaxial stretching method, a biaxial stretching method, or the like. It can be used as a peelable substrate. Among the above compounds, polyethylene terephthalate (polycondensate of terephthalic acid and ethylene glycol), polyethylene-2,6, since the heat shrinkage rate of the molded product when used at high temperature is low or relatively low and the stability is good. -Naphthalenedicarboxylate (polycondensate of 2,6-naphthalenedicarboxylic acid and ethylene glycol), polyimide, polyamideimide, polyetherimide, polysulfone, polyethersulfone, polyetherketone; polyetheretherketone; polyphenylene sulfide; poly Preferred are arylate; epoxy resin; phenol resin; metal such as iron, aluminum, copper, glass, and the like.

  In addition, after preparation of the peelable substrate, fluorine surfactant, silicone surfactant, alkyl quaternary ammonium salt, phosphate ester, liquid paraffin, wax, higher fatty acid and higher fatty acid metal salt, higher fatty acid ester, higher fatty acid An external release agent such as alcohol, bisamides, polysiloxanes, and aliphatic amine ethylene oxide adducts can be applied on one or both sides to provide a peelable substrate with improved peelability of the formed film. Furthermore, after the external release agent is added as an internal release agent to the peelable substrate preparation compound, the above-described molding can be performed to provide a peelable substrate with improved film peelability.

  Further, as a method of forming a film by applying a solution in which the cellulose ester is dissolved on a peelable substrate, a gravure roll coating method, a Mayer bar coating method, a doctor blade coating method, a reverse roll coating method, a dip coating method, Examples thereof include an air knife coating method, a calendar coating method, a skies coating method, a kiss coating method, a bar coating method, a slot die coating method, and a spin coating method.

  In addition, as a drying method after this coating, for example, a method of leaving (air drying) in an inert gas such as air or nitrogen, a method of heating and drying in a hot air oven, an infrared heating furnace, or the like, drying under reduced pressure using a vacuum dryer or the like It can carry out by the method to carry out, etc. or combining these.

  As the drying temperature condition, either constant temperature or multistage temperature increase can be used. In the case of constant temperature, a temperature range of a lower limit of 5 ° C and an upper limit of 200 ° C is preferable, a lower limit of 10 ° C and an upper limit of 190 ° C are more preferable, and a lower limit of 15 ° C and an upper limit of 180 ° C are more preferable. If the drying temperature is lower than 5 ° C, the drying time tends to be longer, and if it is higher than 200 ° C, thermal deterioration of the formed film or the peelable substrate tends to occur. Although such constant temperature drying can be used, in order to dry effectively, it is preferable to raise the temperature in multiple stages, and from the economical viewpoint, primary drying and secondary drying are particularly preferable.

  When performing two-stage drying, the primary drying preferably has a temperature range of a lower limit of 5 ° C and an upper limit of 40 ° C, more preferably a lower limit of 10 ° C and an upper limit of 35 ° C, and even more preferably a lower limit of 15 ° C and an upper limit of 30 ° C. The drying time is preferably 3 minutes or more. When the primary drying temperature is lower than 5 ° C., the initial drying time for preventing the formed film from foaming tends to be long, and when it is higher than 40 ° C., the foam tends to be easily foamed.

  In secondary drying, a temperature range with a lower limit of 60 ° C. and an upper limit of 200 ° C. is preferred, a lower limit of 70 ° C. and an upper limit of 190 ° C. are more preferred, and a lower limit of 80 ° C. and an upper limit of 180 ° C. are more preferred. When the secondary drying temperature is lower than 60 ° C., the drying time tends to be longer, and when it is higher than 200 ° C., the formed film and the peelable substrate tend to be thermally deteriorated.

  Furthermore, after the solution in which the cellulose ester is dissolved is applied to a peelable substrate, the film formed by exposure to solvent vapor is annealed, and then the drying is performed as described above, whereby the film can be formed before stretching. .

  Next, in the optical compensation film of the present invention, a resin that can be used in combination in order to easily develop an in-plane retardation will be described. Examples of the resin that can be added include polycarbonate polymers; polyolefin polymers such as polyethylene, polypropylene, norbornene resins, cycloolefin polymers, hydrogenated polyisoprene, and hydrogenated polybutadiene; methyl cellulose Cellulose-based resins such as ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose; polyamides such as nylon 6 and nylon 66; polyimides; polyamideimides; polyvinyl alcohol; polyvinyl chloride; polysulfone; polyethersulfone; polyarylate; Etc.

  In this invention, 2 or more types of the said resin may be used together, and may be used independently. These resins can be added as long as the object of the present invention and the transparency of the optical compensation film are not impaired.

  The lower limit of the number average molecular weight of the resin is preferably 5000, more preferably 8000, and still more preferably 10,000, and the upper limit is preferably 1000000, more preferably 500000, and further preferably 300000. When the number average molecular weight is less than 5,000, the strength of the film tends to decrease when used together, and when the number average molecular weight is greater than 1,000,000, the workability during film formation tends to be inferior. The number average molecular weight is a value measured by gel permeation chromatography (GPC). In the present invention, two or more of the same types of resins having different number average molecular weights may be used in combination, or may be used alone.

  Next, additives that can be added for the purpose of modifying the properties of the optical compensation film of the present invention will be described. Additives include antioxidants (eg, hindered phenols such as IRGANOX 1010, IRGANOX 1135, IRGANOX 1330, etc. manufactured by Ciba Specialty Chemicals), processing stabilizers (eg, HP-136, IRGANOX manufactured by Ciba Specialty Chemicals). E201, IRGAFOS 168, etc.), light stabilizers (eg, hindered amines such as Sanol LS-765 and Sanol LS-770 manufactured by Sankyo Lifetech), ultraviolet absorbers (eg, TINUVIN P, TINUVIN 213 manufactured by Ciba Specialty Chemicals) Benzotriazoles such as TINUVIN 326), adhesion improvers (eg, silane compounds such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane) Coupling agent), silanol condensation catalyst (for example, aluminum tris (ethyl acetoacetate) manufactured by Kawaken Fine Chemicals, aluminum chelate M, etc.), plasticizer (for example, dimethyl adipate, diethyl adipate, dipropyl adipate, adipine) Dibutyl acid, bis (2-ethylhexyl) adipate, dimethyl phthalate, diethyl phthalate, dipropyl phthalate, dibutyl phthalate, dipentyl phthalate, dihexyl phthalate, diheptyl phthalate, di-n-octyl phthalate, bis phthalate (Esters such as 2-ethylhexyl)), surfactants (for example, fluorine compounds such as Fluorad FC-430 and Fluorad FC-4430 manufactured by Sumitomo 3M), antistatic agents (for example, Ciba Specialty Chemi) Kalz IRGASTAT P18, IRGASTAT P22, etc.) and the like, and these can be added within a range that does not impair the object and effect of the present invention.

  Next, the characteristics of the optical compensation film of the present invention will be described.

When optically compensating for the retardation due to birefringence in a liquid crystal cell or the like, the in-plane retardation of the optical compensation film of the present invention is preferably 1 nm for the lower limit and 600 nm for the upper limit, more preferably 10 nm for the lower limit and 500 nm for the upper limit in the measurement with 548 nm light. More preferably, the lower limit is 20 nm and the upper limit is 400 nm. If the in-plane retardation is smaller than 1 nm or larger than 600 nm, it tends to be difficult to compensate for the retardation due to birefringence of a liquid crystal cell or the like. Further, when the in-plane retardation with respect to light having a wavelength of 447 nm of the optical compensation film of the present invention is R (447) (nm), and the in-plane retardation with respect to light having a wavelength of 548 nm is R (548) (nm),
[R (447) / R (548)] <[R ₀ (447) / R ₀ (548)] (Formula 2)
(In the formula, R ₀ (447) and R ₀ (548) are respectively the in-plane retardation with respect to the light having a wavelength of 447 nm and the light having a wavelength of 548 nm in the film stretched by removing the polyester polyol from the composition of the optical compensation film of the present invention. In-plane phase difference with respect to.)
Satisfy the relationship. When [R (447) / R (548)] is equal to or greater than [R ₀ (447) / R ₀ (548)], it tends to be difficult to compensate for the birefringence of a liquid crystal cell exhibiting reverse wavelength dispersion. is there.

  Next, the polarizing plate of the present invention will be described. As a polarizing plate, for example, a protective material is bonded to both surfaces of a polarizer using an adhesive such as a polyester adhesive, a polyacrylic adhesive, an epoxy adhesive, a cyanoacrylic adhesive, or a polyurethane adhesive. And the like. Examples of polarizers are polarizers prepared by adsorbing and orienting iodine and / or dichroic dyes on hydrophilic polymer films, polyenes formed by dehydration treatment of polyvinyl alcohol films, and prepared by orientation. Examples include polarizers and polyvinyl chloride films prepared by dehydrochlorination treatment to form polyene and orientation. Examples of the hydrophilic polymer film used for the polarizer include a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film, a saponified film of an ethylene-vinyl acetate copolymer, and the like. As the protective material, the optical compensation film of the present invention can be used on both sides, the optical compensation film of the present invention can be used on one side, and another translucent film can be used on the opposite side.

  As the translucent film, various films can be used as long as they are transparent and have an in-plane retardation of 10 nm or less. Specific examples of the compound that forms a light-transmitting film include polycarbonate polymers; polyacrylic esters such as polymethyl acrylate and polymethyl methacrylate; adipic acid, phthalic acid, isophthalic acid, terephthalic acid, 1 Condensates of dibasic acids such as 1,4-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid and 2,6-naphthalenedicarboxylic acid with glycols such as ethylene glycol, diethylene glycol, propylene glycol, tetramethylene glycol and neopentyl glycol Or a polyester polymer obtained by ring-opening polymerization of lactones; a styrene polymer such as polystyrene and poly (α-methylstyrene); a copolymer of acrylic acid ester and styrene; polyethylene, polypropylene, norbornene resin, Cycloole Polyolefin polymers such as hydrogenated polypolymer, polyisoprene, hydrogenated polybutadiene, etc .; cellulose ester resins such as cellulose acetate having a degree of substitution with acetyl groups of 2 to 3; polyamides such as nylon 6 and nylon 66; polyimides Polyamideimide; Polyvinyl alcohol; Polyvinyl chloride; Polysulfone; Polyethersulfone; Polyarylate; Epoxy resin; Silicone resin; and compounds described in International Publication No. 01/37007 pamphlet.

  Further, the optical compensation film of the present invention can be separately provided on these polarizing plates or polarizing plates in which a translucent film is used as a protective material on both surfaces.

  As the protective material, the above-described translucent film is used on one side, and a ¼ wavelength plate, which is one of the optical compensation films of the present invention, is provided on the opposite side to ¼ the absorption axis of the polarizer. A quarter wavelength that is one of the optical compensation films of the present invention for a polarizing plate in which the slow axis of the wave plate is 45 degrees or a polarizing plate in which a translucent film is used as a protective material on both sides A combination of a polarizing plate (polarizer) and a quarter-wave plate, such as a plate bonded so that the slow axis of the quarter-wave plate is 45 degrees with respect to the absorption axis of the polarizing plate Is also called a circularly polarizing plate.

  Next, an example of a liquid crystal display device in which the optical compensation film and polarizing plate of the present invention can be used will be described. Examples of the liquid crystal display device include a display device configured in the order of light source / light guide plate / light diffusion film / lens film / brightness enhancement film / polarizing plate / liquid crystal cell / polarizing plate. The polarizing plate of the present invention can be mounted on the polarizing plate on the incident light side and / or the outgoing light side of the liquid crystal cell by mounting the optical compensation film of the present invention on the side and / or on the outgoing light side. Examples of the liquid crystal cell method include a TN (Twisted Nematic) method, a VA (Vertical Alignment) method, an IPS (In-Plane Switching) method, an OCB (Optically Compensated Birefringence) method, and the like.

  The optical compensation film of the present invention and the polarizing plate produced using the optical compensation film are a liquid crystal display device using a liquid crystal cell of TN mode, VA mode, IPS mode, OCB mode, etc. It can be used for light leakage prevention. In order to sufficiently exhibit the performance of the optical characteristics of the optical compensation film in the present invention, the VA method and the IPS method are particularly preferable. Also, the optical compensation film of the present invention and the polarizing plate produced using the optical compensation film are suitably used for liquid crystal display device production parts such as video, cameras, mobile phones, personal computers, televisions, monitors and automobile instrument panels. it can.

  Examples are shown below to describe the present invention in more detail, but the present invention is not limited to these examples.

(1) Measurement of in-plane retardation (R (447), R (548), R (628), R ₀ (447), R ₀ (548), R ₀ (628)) Automatic birefringence manufactured by Oji Scientific Instruments Using a total KOBRA-WR, measurement was performed at 25 ° C. with light having a wavelength of 447 nm, light having a wavelength of 548 nm, and light having a wavelength of 628 nm. R (λ) represents the in-plane retardation of the optical compensation film of the present invention with respect to light having a wavelength of λ (nm), and R ₀ (λ) excludes polyester polyol from the composition of the optical compensation film of the present invention. The in-plane retardation of the stretched film is shown.

(2) Measurement of film thickness The thickness of the film was determined using an Anritsu electronic micrometer.

Example 1
Cellulose acetate propionate (CAP-482-20 manufactured by Eastman Chemical, acetyl group substitution degree: 0.1, propionyl group substitution degree DS: 2.6), propylene glycol (hereinafter referred to as PG), polyethylene glycol (Hereinafter referred to as PEG), a commercially available polyester polyol comprising succinic acid (hereinafter referred to as SA) (number average molecular weight: 3500, PG: PEG ethylene glycol unit to SA molar ratio of 12:67:21) 1.0 g Were mixed, and 56.7 g of methylene chloride was added and dissolved at 25 ° C.

  Next, this coating solution was coated on a 50 μm thick polyethylene terephthalate film using a bar coater to form a coated substrate, and then allowed to stand and dry in air at 25 ° C. for 17 hours. Thereafter, the coated film is peeled off from the coated substrate, dried at 60 ° C. for 5 minutes, and then at 120 ° C. for 30 minutes in the air. After forming a film, physical properties were measured. The results are shown in Table 1. The reverse wavelength dispersion is higher than the result of Comparative Example 1 which does not use the polyester polyol shown in Table 2.

(Example 2)
3.726 g of cellulose acetate propionate (CAP-482-20 manufactured by Eastman Chemical, acetyl group substitution degree DS: 0.1, propionyl group substitution degree DS: 2.6), ethyl cellulose (ETHOCEL STD type Premium FP manufactured by Dow Chemical) Grade, product number: 100, number average molecular weight: 63400, ethyl group substitution degree: 2.5) 0.324 g, 0.405 g of the polyester polyol shown in Example 1 were mixed, 24.0 g of methylene chloride was added, and 25 ° C. Dissolved below.

  Next, this coating solution was coated on a 50 μm thick polyethylene terephthalate film using a bar coater to form a coated substrate, and then allowed to stand and dry in air at 25 ° C. for 17 hours. Then, the coated film is peeled off from the coated substrate, dried in air at 60 ° C. for 5 minutes, then at 120 ° C. for 30 minutes, and then stretched uniaxially at 155 ° C. by 1.60 times and optically compensated for optical compensation. After forming a film (¼ wavelength plate), physical properties were measured. The results are shown in Table 1. The reverse wavelength dispersion is higher than the result of Comparative Example 2 that does not use the polyester polyol shown in Table 2. From the results of Comparative Example 3 shown in Table 2, it can be seen that the ethyl cellulose used in Example 2 shows slightly positive wavelength dispersion and does not increase the reverse wavelength dispersion. This indicates that when a stretched film of cellulose acetate propionate mixed with ethyl cellulose (Comparative Example 2) and a stretched film of cellulose acetate propionate (Comparative Example 1) are compared, Comparative Example 2 has the opposite wavelength dispersion. It can also be seen from the decline in sex.

(Comparative Example 1)
Add 56.7 g of methylene chloride to 10.0 g of cellulose acetate propionate (CAP-482-20 manufactured by Eastman Chemical, acetyl group substitution degree DS: 0.1, propionyl group substitution degree DS: 2.6) at 25 ° C. Dissolved below.

  Next, this coating solution was coated on a 50 μm thick polyethylene terephthalate film using a bar coater to form a coated substrate, and then allowed to stand and dry in air at 25 ° C. for 17 hours. Thereafter, the coated film is peeled off from the coated substrate, dried in the air at 60 ° C. for 5 minutes, then at 120 ° C. for 30 minutes, and then stretched uniaxially at 1.34 times at 160 ° C. to measure the physical properties. Went. The results are shown in Table 2.

(Comparative Example 2)
3.726 g of cellulose acetate propionate (CAP-482-20 manufactured by Eastman Chemical, acetyl group substitution degree DS: 0.1, propionyl group substitution degree DS: 2.6), ethyl cellulose (ETHOCEL STD type Premium FP manufactured by Dow Chemical) Grade, product number: 100, number average molecular weight: 63400, ethyl group substitution degree: 2.5) 0.324 g was mixed, and 24.0 g of methylene chloride was added and dissolved at 25 ° C.

  Next, this coating solution was coated on a 50 μm thick polyethylene terephthalate film using a bar coater to form a coated substrate, and then allowed to stand and dry in air at 25 ° C. for 17 hours. Thereafter, the coated film is peeled off from the coated substrate, dried in air at 60 ° C. for 5 minutes, then at 120 ° C. for 30 minutes, then stretched uniaxially at 155 ° C. by 1.31 times, and measured for physical properties. Went. The results are shown in Table 2.

(Comparative Example 3)
47.8 g of methylene chloride was added to 3.37 g of ethyl cellulose (ETHOCEL STD type Premium FP grade, manufactured by Dow Chemical Co., Ltd., product number: 100, number average molecular weight: 63400, ethyl group substitution degree: 2.5), and dissolved at 25 ° C.

  Next, this coating solution was applied to a 50 μm thick polyethylene terephthalate film using a bar coater to obtain a coated substrate. Thereafter, the coated substrate was left to dry in air at 25 ° C. for 17 hours, and then dried in air at 60 ° C. for 5 minutes and further at 120 ° C. for 30 minutes. Thereafter, together with the polyethylene terephthalate film, the film was stretched uniaxially at a free end length of 1.18 times at 155 ° C., and the physical properties were measured by peeling the coated film. The results are shown in Table 2.

(Example 3)
A polyvinyl alcohol film was impregnated with iodine and stretched to prepare a polarizer. A commercially available cellulose acetate film (polarizer protective film) having a thickness of 80 μm was bonded to both surfaces of the polarizer using a polyacrylic adhesive to obtain a polarizing plate. Further, the quarter wave plate produced in Example 2 on one side of the polarizing plate is polyacrylic so that the slow axis of the quarter wave plate is at an angle of 45 degrees with respect to the absorption axis of the polarizing plate. A circularly polarizing plate (a polarizing plate with an optical compensation layer) was prepared by bonding using an adhesive.

  The performance of the produced circularly polarizing plate was confirmed by placing the circularly polarizing plate on a mirror surface, and incident natural light from the polarizing plate side and observing the reflected light. The reflected light was neither bluish nor reddish but blackish brown, and had an antireflection function for the entire visible light range.

Claims (5)

An optical compensation film characterized by being a stretched film containing 1 to 30 parts by weight of a polyester polyol with respect to 100 parts by weight of cellulose ester and satisfying the following formulas 1 and 2.
1 ≦ R (548) ≦ 600 (Formula 1)
[R (447) / R (548)] <[R ₀ (447) / R ₀ (548)] (Formula 2)
(Where R (447) is the in-plane phase difference (nm) for light having a wavelength of 447 nm, R (548) is the in-plane phase difference for light having a wavelength of 548 nm, and R ₀ (447) and R ₀ (548) are respectively And represents an in-plane retardation for light having a wavelength of 447 nm and an in-plane retardation for light having a wavelength of 548 nm in a film stretched by removing the polyester polyol from the composition of the optical compensation film of the present invention. The cellulose ester is characterized in that at least one hydroxyl group per glucose residue of cellulose is substituted with an ester group, and the plurality of ester groups are the same or different and are groups selected from the following general formula (1). The optical compensation film according to claim 1.

(In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.) The polyester polyol is a polycondensate of dibasic acid, alkylene glycol, and polyalkylene glycol. Dibasic acid, alkylene glycol, and polyalkylene glycol are represented by the following general formulas (2), (3), and (4), respectively. The optical compensation film according to claim 1, wherein the optical compensation film is a compound having a number average molecular weight of 400 to 20000.

(In the formula, R ² represents an alkylene group having 1 to 10 carbon atoms.)

(In the formula, R ³ represents an alkylene group having 1 to 10 carbon atoms.)

(In the formula, R ⁴ represents an alkylene group having 1 to 10 carbon atoms, and n represents an integer of 2 to 20). The said polyester polyol is a compound containing at least 1 sort (s) represented by following General formula (5), (6), (7), The optical of any one of Claim 1 to 3 characterized by the above-mentioned. Compensation film.

(Wherein R ² , R ³ and R ⁴ are the same or different and represent an alkylene group having 1 to 10 carbon atoms, n represents an integer of 2 to 20; p and q are the same or different; Represents an integer of ˜40.)

(Wherein R ² , R ³ and R ⁴ are the same or different and represent an alkylene group having 1 to 10 carbon atoms, n represents an integer of 2 to 20; and r and s are the same or different; Represents an integer of ˜40.)

(Wherein R ² , R ³ and R ⁴ are the same or different and represent an alkylene group having 1 to 10 carbon atoms, n represents an integer of 2 to 20; t and u are the same or different; Represents an integer of ˜40.) A polarizing plate with an optical compensation layer, comprising the optical compensation film according to any one of claims 1 to 4.