JP4810674B2 - Optical film manufacturing method, optical compensation film manufacturing method - Google Patents

Description

  The present invention relates to an optical film, a method for producing an optical film, an optical compensation film, a method for producing an optical compensation film, a polarizing plate and a liquid crystal display device, and more particularly, an optical film having a small variation in retardation due to long-term use, Furthermore, by using this as a support, transparency and flatness are not easily impaired even by thermal stretching, the retardation uniformity is excellent, and the retardation of the retardation due to environmental fluctuations is small. Further, heat is generated by the optical LED backlight. In particular, the present invention relates to a polarizing plate and a liquid crystal display device in which changes in visibility due to environmental changes are significantly reduced and color reproducibility is excellent.

  A liquid crystal display (LCD) has low voltage and low power consumption, and can be particularly thinned. Therefore, it is widely used as a display device for personal computers, televisions, monitors, portable information terminals, and the like. The basic configuration of this LCD is, for example, a polarizing plate provided on both sides of a liquid crystal cell.

  By the way, the polarizing plate allows only light having a polarization plane in a certain direction to pass through, and plays an important role in visualizing a change in liquid crystal orientation in the LCD. That is, the performance of the LCD is greatly influenced by the performance of the polarizing plate. The polarizing plate generally has a configuration in which both sides of a polarizing film made of a polyvinyl alcohol film or the like on which iodine or dye is adsorbed and oriented are laminated with a transparent resin layer. As this transparent resin layer, a cellulose ester film such as triacetyl cellulose is suitable as a protective film because of its low birefringence, and is often used.

  In recent years, liquid crystal displays have been developed for a large screen and high image quality as a monitor to replace CRT. Along with this, the demand for protective films for polarizing plates for liquid crystals has become stricter. In particular, since cellulose ester films are water-absorbing, they are easily affected by the environment. As a result, liquid crystal display devices are affected by fluctuations in optical properties. In the case of being incorporated in the device, there is a problem that characteristics such as visibility are likely to fluctuate. In particular, when the cellulose ester film is an optical compensation film or a support film for widening the viewing angle, there is a strong demand for improving the stability of retardation with respect to environmental fluctuations.

  On the other hand, a solution casting method is generally used as a method for producing a cellulose ester film. In this method, a so-called dope solution in which cellulose ester is dissolved in a solvent such as a halogen solvent is cast on a rotating endless belt or drum as a metal support to form a film. After casting, a part of the solvent is dried on the support, the film obtained by solidification is peeled off from the support, and the remaining solvent is dried to obtain a cellulose ester film.

  Since this method must remove the solvent remaining inside the film, the equipment and manufacturing costs, such as the drying line, drying energy, and the recovery and regeneration device for the evaporated solvent, are enormous, and these are reduced. That is also an issue.

  As means for solving the above problems, for example, the optical film described in Patent Document 1 has a cellulose ester film formed by melt casting. With this configuration, an optical film excellent in optical, physical, and dimensional stability can be obtained, but further improvement in the stability of the retardation against environmental fluctuations is required.

  As for the optical compensation film, a triacetylcellulose film formed by solution casting is used as a support, and a polymer layer having an optical compensation function is coated on the support and stretched together with the support at a high temperature. A technique that can easily provide an optical compensation film to which a desired phase difference is imparted has been disclosed (for example, see Patent Document 2), but a solution casting film that has been conventionally used as a polarizing plate protective film. In the triacetyl cellulose film according to, when a polymer layer having an optical compensation function is provided separately from the film forming step and then stretched at a high temperature, there is a problem that retardation nonuniformity is likely to occur due to uneven stretching. For this reason, there is a demand for an optical film that is not easily impaired in transparency and flatness even by hot stretching by high-temperature treatment as a support and has excellent retardation uniformity.

In addition, when the optical compensation film is incorporated in a liquid crystal display device, improvement in visibility due to heat generation or environmental variation due to a direct optical LED backlight used in the liquid crystal display device is also required.
JP 2000-352620 A JP 2004-4474 A

  Accordingly, the present invention has been made in view of the above problems, and its object is to provide an optical film with little variation in retardation due to long-term use, and by using this as a support, it is also transparent by hot stretching. The optical compensation film is less susceptible to loss of retardation and flatness, is excellent in retardation uniformity, and has little retardation fluctuation due to environmental fluctuations.Furthermore, the change in visibility due to heat generation and environmental fluctuations due to the optical LED backlight is significantly reduced. The object is to provide a polarizing plate and a liquid crystal display device excellent in color reproducibility.

  Another object of the present invention is to provide a high-performance optical film and an optical compensation film manufactured without using a halogen-based solvent having a high environmental load.

  The above object of the present invention is achieved by the following configurations.

1. In the method for producing an optical film for melt casting a composition containing a cellulose resin and a plasticizer, the cellulose resin has a residual sulfuric acid content in the range of 0.1 to 50 ppm, and the composition is ethylenically unsaturated. method for producing an optical film having a weight average molecular weight obtained by polymerizing a monomer is characterized by containing the polymer over is 500 to 30,000.

  2. 2. The method for producing an optical film as described in 1 above, wherein the cellulose resin is a mixed fatty acid ester having a total acyl group substitution degree of 2.5 to 2.9 and a number average molecular weight (Mn) of 70000 to 200000.

  3. 3. The above 1 or 2, wherein at least one of the plasticizers is selected from a polyhydric alcohol ester plasticizer, a polyester plasticizer, a citrate ester plasticizer, and a phthalate ester plasticizer. Manufacturing method of the optical film.

  4). 4. The method for producing an optical film as described in any one of 1 to 3, wherein the amount of residual sulfuric acid is in the range of 0.1 to 45 ppm.

  5. 5. The method for producing an optical film as described in any one of 1 to 4, wherein the composition contains an ultraviolet absorber, and the ultraviolet absorber has a weight average molecular weight in the range of 490 to 50,000.

  6). The said composition contains 0.01-5 mass% of hindered amine type | system | group or a hindered phenol type compound, The manufacturing method of the said optical film of any one of the said 1-5 characterized by the above-mentioned.

7). An optical film is manufactured by the manufacturing method of any one of said 1-6, a polymer layer is provided on this optical film, and it extends | stretches, The manufacturing method of the optical compensation film characterized by the above-mentioned.

8). 8. The method for producing an optical compensation film as described in 7 above, wherein the polymer layer comprises at least one selected from polyether ketone, polyamide, polyester, polyimide, polyamideimide, and polyesterimide.

9. 9. The method for producing an optical compensation film according to 7 or 8, wherein the stretching temperature B at the time of stretching is represented by the following formula (I).
Formula (I) Melting temperature A-100 ° C. ≦ Extension temperature B ≦ Melting temperature A-40 ° C.
(However, the melting temperature A represents the temperature at the time of melt casting of the optical film)

  According to the present invention, it is possible to provide an optical film with little variation in retardation due to long-term use. Further, by using this as a support, transparency and flatness are hardly impaired even by thermal stretching, an optical compensation film having excellent retardation uniformity and less retardation variation due to environmental variation is provided, and an optical LED backlight It is possible to provide a polarizing plate and a liquid crystal display device that are remarkably reduced in visibility due to heat generation and environmental fluctuations, and excellent in color reproducibility.

  In addition, it is possible to provide a high-performance optical film manufactured without using a halogen-based solvent having a high environmental load.

  The best mode for carrying out the present invention will be described in detail below, but the present invention is not limited thereto.

  The first object of the present invention is to obtain an optical film (also referred to as a cellulose ester film in the present invention) that has little retardation fluctuation due to long-term use, and further by using the optical film as a support, The second object is to obtain an optical compensation film which can easily obtain a phase difference, is excellent in transparency, flatness and uniformity of retardation, and has little retardation fluctuation due to environmental fluctuation. Furthermore, by using the optical film and the optical compensation film, it is possible to obtain a polarizing plate and a liquid crystal display device that are remarkably reduced in visibility due to heat generation and environmental fluctuations due to an optical LED backlight and excellent in color reproducibility. The purpose of 3 is.

As a result of intensive studies on the above-mentioned problems, the present inventor has found that the above-mentioned problem is a method for producing an optical film for melt casting a composition containing a cellulose resin and a plasticizer, wherein the cellulose resin contains residual sulfuric acid. the amount is in the range of 0.1 to 50 ppm, the composition optical film, characterized in that the weight average molecular weight obtained by polymerizing ethylenically unsaturated monomers contains a polymer over is 500 to 30,000 It has been found that this can be achieved by the production method.

  That is, as a result of detailed studies, the present inventors have excellent optical characteristics and moisture permeability in a thermal melting method, that is, a method of forming a film by a melt casting method that does not use a halogen-based solvent with a large environmental load. In order to obtain an optical film having a high retardation stability even after long-term use, a leap is achieved by selecting a specific cellulose resin and a specific compound as a polymer contained in the cellulose resin during casting. In particular, it has been found that the retardation stability of an optical film is improved.

  Furthermore, on the optical film, an optical compensation film prepared by providing a polymer layer composed of at least one selected from polyetherketone, polyamide, polyester, polyimide, polyamideimide, and polyesterimide, and stretching the entire support, The present inventors have found that an optical compensation film having excellent transparency, flatness, and uniformity of retardation and less retardation fluctuation due to environmental fluctuations can be achieved.

  In particular, the optical compensation film of the present invention is characterized in that a polymer layer is provided on an optical film formed by melt casting, and the stretching temperature B when stretching the entire support is represented by the following formula (I): It has also been found that the optical compensation film is preferably produced by the method for producing an optical compensation film.

Formula (I) Melting temperature A-100 ° C. ≦ Extension temperature B ≦ Melting temperature A-40 ° C.
(However, the melting temperature A represents the temperature at the time of melt casting of the optical film)
The melt casting in the present invention is to melt and melt a cellulose resin to a temperature showing fluidity without using a solvent, and then casting a melt containing the fluid cellulose resin. Define. More specifically, the heating and melting molding method can be classified into a melt extrusion molding method, a press molding method, an inflation method, an injection molding method, a blow molding method, a stretch molding method, and the like. Among these, in order to obtain an optical compensation film having excellent mechanical strength and surface accuracy, the melt extrusion method is excellent. Here, after the film constituent material is heated to exhibit its fluidity, extrusion film formation on a drum or an endless belt is included in the melt film production method of the present invention as a melt casting film formation method.

  Hereinafter, the present invention will be described in detail for each element.

(polymer)
The optical film of the present invention is characterized by containing a polymer having a weight average molecular weight of 500 to 30000 obtained by polymerizing an ethylenically unsaturated monomer, a plasticizer, and a cellulose resin.

Furthermore, the optical film of the present invention preferably contains an acrylic polymer having a weight average molecular weight of 500 or more and 30000 or less, a plasticizer, and a cellulose resin. The acrylic polymer has an acrylic ring having an aromatic ring in the side chain. An acrylic polymer having a polymer or a cyclohexyl group in the side chain is preferred.

  When the weight average molecular weight of the polymer of the present invention is 500 to 30,000, the compatibility with the cellulose resin is good, and neither evaporation nor volatilization occurs during film formation. In particular, an acrylic polymer, an acrylic polymer having an aromatic ring in the side chain, or an acrylic polymer having a cyclohexyl group in the side chain, preferably has a weight average molecular weight of 500 to 10,000, more preferably a weight average molecular weight of 500 to 5000. If it is a thing, in addition to the above, the transparency of the cellulose-ester film after film forming is excellent, and a water vapor transmission rate is also very low, and the performance excellent as a protective film for polarizing plates is shown.

  Since the polymer of the present invention has a weight average molecular weight of 500 or more and 30000 or less, it is considered to be between the oligomer and the low molecular weight polymer. In order to synthesize such a polymer, it is difficult to control the molecular weight in normal polymerization, and it is desirable to use a method that can align the molecular weight as much as possible by a method that does not increase the molecular weight so much. Such polymerization methods include a method using a peroxide polymerization initiator such as cumene peroxide and t-butyl hydroperoxide, a method using a polymerization initiator in a larger amount than normal polymerization, and a mercapto compound in addition to the polymerization initiator. And a method of using a chain transfer agent such as carbon tetrachloride, a method of using a polymerization terminator such as benzoquinone and dinitrobenzene in addition to the polymerization initiator, and further, Japanese Patent Application Laid-Open No. 2000-128911 or 2000-344823. Examples thereof include a compound having one thiol group and a secondary hydroxyl group, or a bulk polymerization method using a polymerization catalyst in which the compound and an organometallic compound are used in combination. Although used, the method described in the publication is particularly preferable.

  Although the monomer as a monomer unit which comprises the polymer useful for this invention is mentioned below, it is not limited to this.

  The ethylenically unsaturated monomer unit constituting the polymer obtained by polymerizing the ethylenically unsaturated monomer is as a vinyl ester, for example, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl valerate, vinyl pivalate, caproic acid. Vinyl, vinyl caprate, vinyl laurate, vinyl myristate, vinyl palmitate, vinyl stearate, vinyl cyclohexanecarboxylate, vinyl octylate, vinyl methacrylate, vinyl crotonate, vinyl sorbate, vinyl benzoate, vinyl cinnamate Etc .; As acrylate ester, for example, methyl acrylate, ethyl acrylate, propyl acrylate (i-, n-), butyl acrylate (n-, i-, s-, t-), pentyl acrylate (n -, I-, s-), hexyl acrylate (n I-), heptyl acrylate (n-, i-), octyl acrylate (n-, i-), nonyl acrylate (n-, i-), myristyl acrylate (n-, i-), acrylic Cyclohexyl acid, acrylic acid (2-ethylhexyl), benzyl acrylate, phenethyl acrylate, acrylic acid (ε-caprolactone), acrylic acid (2-hydroxyethyl), acrylic acid (2-hydroxypropyl), acrylic acid (3- Hydroxypropyl), acrylic acid (4-hydroxybutyl), acrylic acid (2-hydroxybutyl), acrylic acid-p-hydroxymethylphenyl, acrylic acid-p- (2-hydroxyethyl) phenyl, etc .; The above acrylic acid ester is changed to methacrylic acid ester; Examples thereof include acrylic acid, methacrylic acid, maleic anhydride, crotonic acid, itaconic acid and the like. The polymer composed of the above monomers may be a copolymer or a homopolymer, and is preferably a vinyl ester homopolymer, a vinyl ester copolymer, or a copolymer of vinyl ester and acrylic acid or methacrylic acid ester.

  In the present invention, an acrylic polymer (simply referred to as an acrylic polymer) refers to a homopolymer or copolymer of acrylic acid or methacrylic acid alkyl ester having no monomer unit having an aromatic ring or a cyclohexyl group. An acrylic polymer having an aromatic ring in the side chain is an acrylic polymer that always contains an acrylic acid or methacrylic acid ester monomer unit having an aromatic ring. The acrylic polymer having a cyclohexyl group in the side chain is an acrylic polymer containing an acrylic acid or methacrylic acid ester monomer unit having a cyclohexyl group.

  Examples of the acrylate monomer having no aromatic ring and cyclohexyl group include, for example, methyl acrylate, ethyl acrylate, propyl acrylate (i-, n-), butyl acrylate (n-, i-, s-, t-), pentyl acrylate (n-, i-, s-), hexyl acrylate (n-, i-), heptyl acrylate (n-, i-), octyl acrylate (n-, i-) , Nonyl acrylate (n-, i-), myristyl acrylate (n-, i-), acrylic acid (2-ethylhexyl), acrylic acid (ε-caprolactone), acrylic acid (2-hydroxyethyl), acrylic acid (2-hydroxypropyl), acrylic acid (3-hydroxypropyl), acrylic acid (4-hydroxybutyl), acrylic acid (2-hydroxybutyl), acrylic acid 2-methoxy-ethyl) acrylate (2-ethoxyethyl), etc., or the acrylic acid ester can be exemplified those obtained by changing the methacrylic acid ester.

  The acrylic polymer is a homopolymer or copolymer of the above-mentioned monomers, but the acrylic acid methyl ester monomer unit preferably has 30% by mass or more, and the methacrylic acid methyl ester monomer unit has 40% by mass or more. Is preferred. In particular, a homopolymer of methyl acrylate or methyl methacrylate is preferred.

  Examples of acrylic acid or methacrylic acid ester monomers having an aromatic ring include phenyl acrylate, phenyl methacrylate, acrylic acid (2 or 4-chlorophenyl), methacrylic acid (2 or 4-chlorophenyl), and acrylic acid (2 or 3 Or 4-ethoxycarbonylphenyl), methacrylic acid (2 or 3 or 4-ethoxycarbonylphenyl), acrylic acid (o or m or p-tolyl), methacrylic acid (o or m or p-tolyl), benzyl acrylate, Examples include benzyl methacrylate, phenethyl acrylate, phenethyl methacrylate, and acrylic acid (2-naphthyl), but benzyl acrylate, benzyl methacrylate, phenethyl acrylate, and phenethyl methacrylate are preferably used. That.

  In the acrylic polymer having an aromatic ring in the side chain, the acrylic acid or methacrylic acid ester monomer unit having an aromatic ring has 20 to 40% by mass, and the acrylic acid or methacrylic acid methyl ester monomer unit is 50 to 80% by mass. It is preferable to have. The polymer preferably has 2 to 20% by mass of acrylic acid or methacrylic acid ester monomer units having a hydroxyl group.

  Examples of the acrylate monomer having a cyclohexyl group include cyclohexyl acrylate, cyclohexyl methacrylate, acrylic acid (4-methylcyclohexyl), methacrylic acid (4-methylcyclohexyl), acrylic acid (4-ethylcyclohexyl), and methacrylic acid. (4-ethylcyclohexyl) and the like can be mentioned, but cyclohexyl acrylate and cyclohexyl methacrylate can be preferably used.

  In the acrylic polymer having a cyclohexyl group in the side chain, the acrylic acid or methacrylic acid ester monomer unit having a cyclohexyl group has 20 to 40% by mass and preferably 50 to 80% by mass. Moreover, it is preferable to have 2-20 mass% of acrylic acid or methacrylic acid ester monomer units having a hydroxyl group in the polymer.

  Polymers obtained by polymerizing the above ethylenically unsaturated monomers, acrylic polymers, acrylic polymers having an aromatic ring in the side chain, and acrylic polymers having a cyclohexyl group in the side chain are all compatible with the cellulose resin. Excellent, without evaporation and volatilization in the film-forming process by melt casting, excellent productivity, good retention as a protective film for polarizing plates, low moisture permeability, and excellent dimensional stability.

  The acrylic acid or methacrylic acid ester monomer having a hydroxyl group according to the present invention is not a homopolymer but a constituent unit of a copolymer. In this case, it is preferable that the acrylic acid or methacrylic acid ester monomer unit having a hydroxyl group is contained in an acrylic polymer in an amount of 2 to 20% by mass.

  In the present invention, a polymer having a hydroxyl group in the side chain can also be preferably used. The monomer unit having a hydroxyl group is the same as the monomer described above, but acrylic acid or methacrylic acid ester is preferable. For example, acrylic acid (2-hydroxyethyl), acrylic acid (2-hydroxypropyl), acrylic acid (3 -Hydroxypropyl), acrylic acid (4-hydroxybutyl), acrylic acid (2-hydroxybutyl), acrylic acid-p-hydroxymethylphenyl, acrylic acid-p- (2-hydroxyethyl) phenyl, or these acrylic acids. The thing replaced by methacrylic acid can be mentioned, Preferably, it is acrylic acid-2-hydroxyethyl and methacrylic acid-2-hydroxyethyl. The acrylic acid ester or methacrylic acid ester monomer unit having a hydroxyl group in the polymer is preferably contained in the polymer in an amount of 2 to 20% by mass, more preferably 2 to 10% by mass.

  A polymer containing 2 to 20% by mass of the above-mentioned monomer unit having a hydroxyl group, of course, has excellent compatibility with cellulose resin, retention, dimensional stability, low moisture permeability, and polarization. It is particularly excellent in adhesiveness with a polarizer as a protective film for plates, and has the effect of improving the durability of the polarizing plate.

  Moreover, in this invention, it is preferable to have a hydroxyl group in the at least one terminal of the polymer principal chain. The method of having a hydroxyl group at the end of the main chain is not particularly limited as long as it has a hydroxyl group at the end of the main chain, but radical polymerization having a hydroxyl group such as azobis (2-hydroxyethylbutyrate). A method of using an initiator, a method of using a chain transfer agent having a hydroxyl group such as 2-mercaptoethanol, a method of using a polymerization terminator having a hydroxyl group, a method of having a hydroxyl group at the terminal by living ion polymerization, A method of bulk polymerization using a compound having one thiol group and a secondary hydroxyl group as disclosed in JP-A No. 2000-128911 or 2000-344823, or a polymerization catalyst using the compound and an organometallic compound in combination The method described in the publication is particularly preferable. The polymer produced by the method related to the description in this publication is commercially available as Act Flow Series manufactured by Soken Chemical Co., Ltd., and can be preferably used.

  In the present invention, the polymer having a hydroxyl group at the terminal and / or the polymer having a hydroxyl group in a side chain has an effect of significantly improving the compatibility and transparency of the polymer.

  These polymers are preferably contained in the optical film in an amount of 1 to 20% by mass, particularly preferably 3 to 15% by mass.

(Cellulose resin)
Next, the cellulose resin used in the present invention will be described in detail.

  The optical film of the present invention is produced by a melt casting method. Since the melt casting method can significantly reduce the amount of organic solvent used during film production, the film is much more environmentally friendly than conventional solution casting methods that use a large amount of organic solvent. Is obtained.

  The melt casting in the present invention is a method in which a cellulose resin is heated and melted to a temperature showing fluidity without substantially using a solvent, and a film is formed using this, for example, a fluid cellulose resin is extruded from a die. And forming a film.

  The cellulose resin constituting the optical film is not particularly limited as long as it is a meltable film-forming cellulose resin. For example, an aromatic carboxylic acid ester or the like is used, but considering the characteristics of the obtained film such as optical characteristics. It is preferable to use a lower fatty acid ester of cellulose. In the present invention, the lower fatty acid in the lower fatty acid ester of cellulose means a fatty acid having 5 or less carbon atoms. For example, cellulose acetate, cellulose propionate, cellulose butyrate, cellulose pivalate and the like are preferable lower cellulose esters of cellulose. It is mentioned as a thing. In order to achieve both mechanical properties and melt film-forming properties, mixed fatty acid esters such as cellulose acetate propionate, cellulose acetate propionate butyrate, cellulose propionate butyrate and cellulose acetate butyrate are used. Also good. Triacetyl cellulose, which is a cellulose resin generally used in solution casting film formation, is a cellulose resin having a decomposition temperature higher than the melting temperature, and thus is difficult to use for melt film formation.

  Therefore, the most preferable lower fatty acid ester of cellulose has an acyl group having 2 to 4 carbon atoms as a substituent, the substitution degree with acetic acid, that is, the substitution degree of acetyl group is X, and the organic acid has 3 to 5 carbon atoms. When the substitution degree, that is, the substitution degree with an acyl group derived from an aliphatic organic acid having 3 to 5 carbon atoms, for example, an acyl group such as a propionyl group or a butyryl group, is Y, the following formulas (2) and (3 A cellulose ester satisfying the above is preferred.

Formula (2) 2.5 <= X + Y <= 2.9
Formula (3) 0.1 <= Y <= 2.0
Among these, cellulose acetate propionate is particularly preferably used, and among them, a cellulose ester satisfying 1.5 ≦ X ≦ 2.5 and 0.5 ≦ Y ≦ 1.0 is preferably used. The portion not substituted with an acyl group usually exists as a hydroxyl group. These can be synthesized by known methods.

  The total acyl group substitution degree of the acyl groups at the 2nd, 3rd and 6th positions of the glucose unit of the cellulose ester is in the range of 2.0 to 2.9, and the average substitution degree of the 6th acyl group is 0.5. A cellulose ester of ~ 0.9 is preferably used.

  The cellulose resin used in the present invention preferably has a weight average molecular weight Mw / number average molecular weight Mn ratio of 1.0 to 5.5, particularly preferably 1.4 to 5.0, and more preferably. 2.0-3.0. Mw is preferably 100,000 to 500,000, and more preferably 200,000 to 400,000.

  The average molecular weight and molecular weight distribution of the cellulose resin can be measured by a known method using high performance liquid chromatography. Using this, the number average molecular weight and the weight average molecular weight are calculated.

The measurement conditions are as follows.
Solvent: Methylene chloride column: Shodex K806, K805, K803 (used by connecting 3 products manufactured by Showa Denko KK)
Column temperature: 25 ° C
Sample concentration: 0.1% by mass
Detector: RI Model 504 (manufactured by GL Sciences)
Pump: L6000 (manufactured by Hitachi, Ltd.)
Flow rate: 1.0ml / min
Calibration curve: Standard polystyrene STK standard polystyrene (manufactured by Tosoh Corp.) Mw = 100000-500 calibration curves with 13 samples were used. It is preferable that the 13 samples are substantially equally spaced.

  The raw material cellulose of the cellulose resin used in the present invention may be wood pulp or cotton linter, and the wood pulp may be softwood or hardwood, but softwood is more preferable. A cotton linter is preferably used from the viewpoint of peelability during film formation. Cellulose resins made from these can be mixed appropriately or used alone.

  For example, the ratio of cellulose resin derived from cotton linter: cellulose resin derived from wood pulp (coniferous): cellulose resin derived from wood pulp (hardwood) is 100: 0: 0, 90: 10: 0, 85: 15: 0, 50:50: 0, 20: 80: 0, 10: 90: 0, 0: 100: 0, 0: 0: 100, 80:10:10, 85: 0: 15, 40:30:30.

  The cellulose resin can be obtained, for example, by substituting the hydroxyl group of the raw material cellulose with acetic anhydride, propionic anhydride and / or butyric anhydride into the above range by acetyl group, propionyl group and / or butyl group by a conventional method. . The method for synthesizing such a cellulose resin is not particularly limited, and for example, it can be synthesized with reference to the method described in JP-A-10-45804 or JP-A-6-501040. Or the cellulose ester of Unexamined-Japanese-Patent No. 2005-281645 can be used.

  The degree of substitution of acyl groups such as acetyl, propionyl, and butyl groups can be measured according to ASTM-D817-96.

  In addition, industrially, cellulose resins are synthesized using sulfuric acid as a catalyst, but this sulfuric acid is not completely removed, and the residual sulfuric acid causes various decomposition reactions during melt film formation, resulting in cellulose esters obtained. In order to affect the quality of the film, the residual sulfuric acid content in the cellulose resin used in the present invention is characterized by being in the range of 0.1 to 50 ppm in terms of elemental sulfur, and further 0.1 to 45 ppm. A range is preferable. These are considered to be contained in the form of salts. If the residual sulfuric acid content exceeds 50 ppm, the effect of the present invention cannot be obtained, and if it is 45 ppm or less, in addition to the effect of the present invention, the deposit on the die lip during heat melting is preferred. Moreover, since it becomes difficult to fracture | rupture at the time of slitting at the time of hot drawing or after hot drawing, it is preferable. The residual sulfuric acid content is preferably as low as possible. However, if it is less than 0.1 ppm, it is not preferable because the burden of the washing step of the cellulose resin becomes too large. This may be due to the fact that the number of washings increases, but the reason is not well understood. Furthermore, the range of 0.1-30 ppm is preferable. The residual sulfuric acid content can be measured by the following measurement method.

(Residual sulfuric acid content measurement method)
<Preprocessing>
500 mg (M) of a sample is weighed into a polypropylene container, and 10 ml of ultrapure water is added.

  This is dispersed with an ultrasonic cleaner for 30 minutes and then filtered with an aqueous chromatodisc (0.45 μm). This is used as a sample.

(Quantification of SO ₄ )
<Apparatus> DX-120 made by ion chromatograph DIONEX
<Column> IonPac AG14 (4 mm) + IonPac AS14 (4 mm)
<Suppressor> ASRS-ULTRAII (4mm)
<Eluent> 3.5 mM-Na ₂ CO ₃ 1.0 mM-NaHCO ₃
<SRS current> 50 mA
<Flow rate> 1.0 ml / min
<Injection volume> 25 μl
<Conversion method>
Content (ppm) = Measured value (mg / l) / 1000 × 10 / M (mg) × 1000000
By washing the synthesized cellulose resin more sufficiently than when used in the solution casting method, the residual sulfuric acid content can be within the above range, and when producing a film by the melt casting method. Further, adhesion to the lip portion is reduced, and a film having excellent flatness can be obtained, and a film having favorable dimensional change, mechanical strength, transparency, moisture resistance, Rt value and Ro value described later can be obtained.

Further, the intrinsic viscosity of the cellulose resin is preferably 1.5 to 1.75 g / cm ^{3, and} more preferably 1.53 to 1.63.

  Moreover, it is preferable that the cellulose resin used by this invention is a thing with few bright spot foreign materials when it is set as a film. A bright spot foreign material is an arrangement in which two polarizing plates are arranged orthogonally (crossed Nicols), a cellulose ester film is arranged between them, light from the light source is applied from one side, and the cellulose ester film is applied from the other side. This is the point where the light from the light source appears to leak when observed. At this time, the polarizing plate used for the evaluation is desirably composed of a protective film having no bright spot foreign matter, and a polarizing plate using a glass plate for protecting the polarizer is preferably used. The bright spot foreign matter is considered to be one of the causes of unacetylated or low acetylated cellulose contained in the cellulose resin, using a cellulose resin with few bright spot foreign substances, filtering the melted cellulose resin, or In at least one of the process in the latter stage of synthesis of the cellulose resin and the process of obtaining a precipitate, the bright spot foreign matter can also be removed once in the solution state through the filtration step. Since the molten resin has a high viscosity, the latter method is more efficient.

As the film thickness decreases, the number of bright spot foreign matter per unit area decreases, and as the cellulose resin content in the film decreases, the bright spot foreign matter tends to decrease. 0.01 mm or more is preferably 200 pieces / cm ² or less, more preferably 100 pieces / cm ² or less, further preferably 50 pieces / cm ² or less, and 30 pieces / cm ² or less. Preferably, it is preferably 10 pieces / cm ² or less, but most preferably none. Moreover, it is preferable that it is 200 pieces / cm < ² > or less also about a bright spot of 0.005-0.01 mm or less, Furthermore, it is preferable that it is 100 pieces / cm < ² > or less, and it is 50 pieces / cm < ² > or less. The number is preferably 30 pieces / cm ² or less, more preferably 10 pieces / cm ² or less, and most preferably none.

  When removing bright spot foreign matter by melt filtration, filtering a composition containing a plasticizer, an anti-degradation agent, an antioxidant and the like is more effective than filtering a melted cellulose resin alone. This is preferable because of its high removal efficiency. Of course, it may be dissolved in a solvent during the synthesis of the cellulose resin and reduced by filtration. It is possible to filter a mixture of UV absorbers and other additives as appropriate. Filtration is preferably performed with a melt containing cellulose resin having a viscosity of 10,000 P or less, more preferably 5000 P or less, even more preferably 1000 P or less, and even more preferably 500 P or less. As the filter medium, conventionally known materials such as glass fibers, cellulose fibers, filter paper, and fluorine resins such as tetrafluoroethylene resin are preferably used, and ceramics and metals are particularly preferably used. The absolute filtration accuracy is preferably 50 μm or less, more preferably 30 μm or less, still more preferably 10 μm or less, and even more preferably 5 μm or less. These can be used in combination as appropriate. The filter medium can be either a surface type or a depth type, but the depth type is preferably used because it is relatively less clogged.

  In another embodiment, a cellulose resin obtained by dissolving a raw material cellulose resin at least once in a solvent and then drying the solvent may be used. In that case, a cellulose resin which is dissolved in a solvent together with at least one of a plasticizer, an ultraviolet absorber, a deterioration inhibitor, an antioxidant and a matting agent and then dried is used. As the solvent, a good solvent used in a solution casting method such as methylene chloride, methyl acetate or dioxolane can be used, and a poor solvent such as methanol, ethanol or butanol may be used at the same time. In the process of dissolution, it may be cooled to -20 ° C or lower, or heated to 80 ° C or higher. When such a cellulose resin is used, each additive when melted can be easily made uniform, and optical characteristics can be made uniform.

(Plasticizer)
It is necessary to add a plasticizer in combination with the polymer to the optical film of the present invention from the viewpoint of film modification such as improvement of mechanical properties, imparting flexibility, imparting water absorption resistance, and reducing moisture permeability. It is. In addition, the purpose of adding a plasticizer in the melt casting method performed in the present invention is to lower the melting temperature of the film constituting material by adding a plasticizer than the glass transition temperature of the cellulose resin used alone, or at the same heating temperature. It includes that the viscosity of the film constituting material containing a plasticizer can be lowered than that of cellulose resin alone.

  Here, in the present invention, the melting temperature of the film constituent material means a temperature at which the material is heated in a state where the material is heated and fluidity is developed.

  When the cellulose resin is used alone, fluidity for forming a film is not exhibited when the temperature is lower than the glass transition temperature. However, the cellulose resin has a lower elastic modulus or viscosity due to the absorption of heat and exhibits fluidity above the glass transition temperature. In order to melt the film constituent material, the plasticizer to be added preferably has a melting point or glass transition temperature lower than the glass transition temperature of the cellulose resin in order to satisfy the above-mentioned purpose.

  The plasticizer according to the present invention is not particularly limited, but a functional group capable of interacting with a cellulose derivative or other additive by hydrogen bonding or the like so as not to cause haze in the film or bleed out or volatilize from the film. It is preferable to have.

  Examples of such functional groups include hydroxyl groups, ether groups, carbonyl groups, ester groups, carboxylic acid residues, amino groups, imino groups, amide groups, imide groups, cyano groups, nitro groups, sulfonyl groups, sulfonic acid residues, Examples thereof include a phosphonyl group and a phosphonic acid residue, and a carbonyl group, an ester group and a phosphonyl group are preferred.

  Examples of such plasticizers include phosphate ester plasticizers, phthalate ester plasticizers, trimellitic acid ester plasticizers, pyromellitic acid plasticizers, polyhydric alcohol ester plasticizers, glycolate plasticizers. Agents, citric acid ester plasticizers, fatty acid ester plasticizers, carboxylic acid ester plasticizers, polyester plasticizers and the like can be preferably used, but polyhydric alcohol ester plasticizers, polyester plasticizers are particularly preferable. Non-phosphate plasticizers such as citrate plasticizers and phthalate plasticizers. These are also preferably used in combination with an ultraviolet absorber having a molecular weight of 490 to 50,000 described later.

  The polyhydric alcohol ester is composed of an ester of a dihydric or higher aliphatic polyhydric alcohol and a monocarboxylic acid, and preferably has an aromatic ring or a cycloalkyl ring in the molecule.

  The polyhydric alcohol used in the present invention is represented by the following general formula (1).

Formula (1) R _1- (OH) _n
(However, R ₁ represents an n-valent organic group, and n represents a positive integer of 2 or more.)
Examples of preferred polyhydric alcohols include the following, but the present invention is not limited to these. Adonitol, arabitol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2-butanediol, 1,3- Butanediol, 1,4-butanediol, dibutylene glycol, 1,2,4-butanetriol, 1,5-pentanediol, 1,6-hexanediol, hexanetriol, galactitol, mannitol, 3-methylpentane- Examples include 1,3,5-triol, pinacol, sorbitol, trimethylolpropane, trimethylolethane, and xylitol. In particular, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, sorbitol, trimethylolpropane, and xylitol are preferable.

  Of these, polyhydric alcohol esters using polyhydric alcohols having 5 or more carbon atoms are preferred. Most preferably, it is C5-C20.

  There is no restriction | limiting in particular as monocarboxylic acid used for the polyhydric alcohol ester of this invention, Well-known aliphatic monocarboxylic acid, alicyclic monocarboxylic acid, aromatic monocarboxylic acid, etc. can be used. Use of an alicyclic monocarboxylic acid or aromatic monocarboxylic acid is preferred in terms of improving moisture permeability and retention.

  Examples of preferred monocarboxylic acids include the following, but the present invention is not limited thereto.

  As the aliphatic monocarboxylic acid, a fatty acid having a straight chain or a side chain having 1 to 32 carbon atoms can be preferably used. The number of carbon atoms is more preferably 1-20, and particularly preferably 1-10. When acetic acid is contained, the compatibility with the cellulose derivative is increased, and it is also preferable to use a mixture of acetic acid and another monocarboxylic acid.

  Preferred aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2-ethyl-hexanecarboxylic acid, undecylic acid, lauric acid, tridecylic acid , Saturated fatty acids such as myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, heptacosanoic acid, montanic acid, melicic acid, laccelic acid, undecylenic acid, Examples thereof include unsaturated fatty acids such as oleic acid, sorbic acid, linoleic acid, linolenic acid and arachidonic acid.

  Examples of preferable alicyclic monocarboxylic acids include cyclopentanecarboxylic acid, cyclohexanecarboxylic acid, cyclooctanecarboxylic acid, and derivatives thereof.

  Examples of preferred aromatic monocarboxylic acids include those in which an alkyl group is introduced into the benzene ring of benzoic acid such as benzoic acid and toluic acid, and two or more benzene rings such as biphenylcarboxylic acid, naphthalenecarboxylic acid, and tetralincarboxylic acid. Examples thereof include aromatic monocarboxylic acids and derivatives thereof, and benzoic acid is particularly preferable.

  The molecular weight of the polyhydric alcohol ester is not particularly limited, but is preferably 300 to 3000, and more preferably 350 to 1500. A higher molecular weight is preferable because it is less likely to volatilize, and a lower molecular weight is preferable in terms of moisture permeability and compatibility with cellulose derivatives.

  The carboxylic acid used for the polyhydric alcohol ester may be one kind or a mixture of two or more kinds. Moreover, all the OH groups in the polyhydric alcohol may be esterified, or a part of the OH groups may be left as they are.

  The specific compound of a polyhydric alcohol ester is shown below.

  A polyester plasticizer having an aromatic ring or a cycloalkyl ring in the molecule can be preferably used. Although it does not specifically limit as a preferable polyester plasticizer, For example, the plasticizer represented by following General formula (2) is preferable.

General formula (2) B- (GA) n-GB
(In the formula, B is a benzene monocarboxylic acid residue, G is an alkylene glycol residue having 2 to 12 carbon atoms, an aryl glycol residue having 6 to 12 carbon atoms, or an oxyalkylene glycol residue having 4 to 12 carbon atoms, A represents an alkylene dicarboxylic acid residue having 4 to 12 carbon atoms or an aryl dicarboxylic acid residue having 6 to 12 carbon atoms, and n represents an integer of 0 or more.)
In the general formula (2), a benzene monocarboxylic acid residue represented by B and an alkylene glycol residue, oxyalkylene glycol residue or aryl glycol residue represented by G, an alkylene dicarboxylic acid residue or aryl dicarboxylic group represented by A It is composed of an acid residue and can be obtained by a reaction similar to that of a normal polyester plasticizer.

  Examples of the benzene monocarboxylic acid component of the polyester plasticizer used in the present invention include benzoic acid, para-tert-butylbenzoic acid, orthotoluic acid, metatoluic acid, p-toluic acid, dimethylbenzoic acid, ethylbenzoic acid, and normalpropyl. There exist benzoic acid, aminobenzoic acid, acetoxybenzoic acid, etc., and these can be used as 1 type, or 2 or more types of mixtures, respectively.

  Examples of the alkylene glycol component having 2 to 12 carbon atoms of the polyester plasticizer of the present invention include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, and 1,3-butanediol. 2-methyl 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 2,2-diethyl-1 , 3-propanediol (3,3-dimethylolpentane), 2-n-butyl-2-ethyl-1,3-propanediol (3,3-dimethylolheptane), 3-methyl-1,5-pentanediol 1,6-hexanediol, 2,2,4-trimethyl 1,3-pentanediol, 2-ethyl 1,3-hexanediol , 2-methyl 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-octadecanediol, etc., and these glycols are used as one kind or a mixture of two or more kinds Is done.

  In addition, examples of the oxyalkylene glycol component having 4 to 12 carbon atoms of the aromatic terminal ester of the present invention include diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, and tripropylene glycol. It can be used as one kind or a mixture of two or more kinds.

  Examples of the alkylene dicarboxylic acid component having 4 to 12 carbon atoms of the aromatic terminal ester of the present invention include succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid. These are each used as one or a mixture of two or more. Examples of the arylene dicarboxylic acid component having 6 to 12 carbon atoms include phthalic acid, terephthalic acid, 1,5 naphthalene dicarboxylic acid, 1,4 naphthalene dicarboxylic acid, and the like.

  The polyester plasticizer used in the present invention has a number average molecular weight of preferably 250 to 2000, more preferably 300 to 1500. The acid value is preferably 0.5 mgKOH / g or less, the hydroxyl value is 25 mgKOH / g or less, more preferably the acid value is 0.3 mgKOH / g or less, and the hydroxyl value is 15 mgKOH / g or less.

  Hereinafter, the synthesis example of the aromatic terminal ester plasticizer used for this invention is shown.

<Sample No. 1 (Aromatic terminal ester sample)>
In a reaction vessel, 365 parts of adipic acid (2.5 moles), 418 parts of 1,2-propylene glycol (5.5 moles), 610 parts of benzoic acid (5 moles) and 0.30 part of tetraisopropyl titanate as a catalyst Then, while stirring in a nitrogen stream, a reflux condenser is attached to reflux excess monohydric alcohol, and heating is continued at 130 to 250 ° C. until the acid value becomes 2 or less. Removed. Subsequently, the distillate was removed under reduced pressure of 1.33 × 10 ⁴ to 4 × 10 ² Pa or less at 200 to 230 ° C., followed by filtration to obtain an aromatic terminal ester having the following properties. .

Viscosity (25 ° C., mPa · s); 815
Acid value: 0.4
<Sample No. 2 (Aromatic terminal ester sample)>
Sample No. 5 was used except that 365 parts (2.5 moles) of adipic acid, 610 parts (5 moles) of benzoic acid, 583 parts (5.5 moles) of diethylene glycol and 0.45 parts of tetraisopropyl titanate as a catalyst were used in the reaction vessel. In the same manner as in No. 1, an aromatic terminal ester having the following properties was obtained.

Viscosity (25 ° C., mPa · s); 90
Acid value: 0.05
<Sample No. 3 (Aromatic terminal ester sample)>
Sample No. except that 410 parts (2.5 moles) of phthalic acid, 610 parts (5 moles) of benzoic acid, 737 parts (5.5 moles) of dipropylene glycol and 0.40 parts of tetraisopropyl titanate as the catalyst were used in the reaction vessel. . In the same manner as in No. 1, an aromatic terminal ester plasticizer having the following properties was obtained.

Viscosity (25 ° C., mPa · s); 43400
Acid value: 0.2
Although the specific compound of an aromatic terminal ester plasticizer is shown below, this invention is not limited to this.

  The content of the polyester plasticizer used in the present invention is preferably 1 to 20% by mass, and particularly preferably 3 to 11% by mass in the optical film.

  The optical film of the present invention preferably contains a plasticizer other than the plasticizer.

  By including two or more plasticizers, elution of the plasticizer can be reduced. The reason is not clear, but it seems that elution is suppressed by the ability to reduce the amount added per type and the interaction between the two plasticizers and the cellulose resin.

  Examples of the phthalate ester plasticizer include diethyl phthalate, dimethoxyethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, dioctyl phthalate, dicyclohexyl phthalate, dicyclohexyl terephthalate or derivatives. The phthalate dimer represented by the general formula (1) described in JP-A No. 11-349537 is preferably used. Specifically, the compound-1, compound- described in paragraphs 23 and 26 are used. 2 is preferably used.

  The phthalate-based dimer compound is a compound having the structural formula represented by the general formula (1), and can be obtained by mixing and heating two phthalic acids with a dihydric alcohol to cause dehydration esterification. . The average molecular weight of the phthalate ester dimer and the terminal hydroxyl group-containing bisphenol compound is preferably about 250 to 3,000, particularly preferably 300 to 1,000. If it is 250 or less, there is a problem in the heat stability and the volatility and migration of the plasticizer, and if it exceeds 3000, the compatibility as a plasticizer and the plasticizing ability are lowered, and the processability of the fatty acid cellulose ester resin composition, Adversely affects transparency and mechanical properties;

  The citrate ester plasticizer is not particularly limited, and examples thereof include acetyl trimethyl citrate, acetyl triethyl citrate, and acetyl tributyl citrate. A citrate ester compound represented by the following general formula (3) is preferable.

In the general formula (3), the aliphatic acyl group for R ¹ is not particularly limited, but preferably has 1 to 12 carbon atoms, particularly preferably 1 to 5 carbon atoms. Specific examples include formyl, acetyl, propionyl, butyryl, valeryl, palmitoyl, oleyl and the like. The alkyl group for R ² is not particularly limited, and may be either linear or branched, but is preferably an alkyl group having 1 to 24 carbon atoms, particularly preferably an alkyl group having 1 to 4 carbon atoms. It is a group. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group. Particularly preferred as a plasticizer for cellulose acetate ester resins are those in which R ¹ is a hydrogen atom, R ² is a methyl group or an ethyl group, and R ¹ is an acetyl group, and R ² is a methyl group or It is an ethyl group.

<Method for producing citrate compound in which R ¹ is a hydrogen atom>
Among the citrate ester compounds used in the present invention, those in which R ¹ is a hydrogen atom can be produced by applying known methods. As a known method, for example, a method for producing a phthalyl glycolic acid ester from a phthalic acid half ester and an α-halogenated acetic acid alkyl ester described in British Patent Publication 931,781 can be mentioned. Specifically, trisodium citrate, tripotassium citrate or citric acid (hereinafter abbreviated as citric acid raw materials), preferably an alkyl ester corresponding to R ² with respect to 1 mol of trisodium citrate. Certain α-monohalogenated alkyl acetates such as methyl monochloroacetate, ethyl monochloroacetate and the like are reacted in a stoichiometric amount or more, preferably 1 to 10 moles, more preferably 2 to 5 moles. When water is present in the reaction system, the yield of the target compound is lowered, and therefore, an anhydrous product is used as much as possible. For the reaction, a chain or cyclic aliphatic tertiary amine such as trimethylamine, triethylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, dimethylcyclohexylamine can be used as a catalyst, and triethylamine is particularly preferable. The usage-amount of a catalyst is 0.01-1.0 mol with respect to 1 mol of citric acid raw materials, Preferably it is the range of 0.2-0.5 mol. The reaction temperature is 60-150 ° C. for 1-24 hours. A reaction solvent is not particularly required, but toluene, benzene, xylene, methyl ethyl ketone and the like can be used. After the reaction, for example, water is added to remove by-products and catalysts, the oil layer is washed with water, and then separated from unreacted raw material compounds by distillation to isolate the target product.

<Method for producing citrate compound in which R ¹ is an aliphatic acyl group>
The citrate compound of the present invention in which R ¹ is an aliphatic acyl group and R ² is an alkyl group can be produced using the citrate ester compound in which R ¹ is a hydrogen atom. That is, 1 to 10 moles of an acyl halide corresponding to the aliphatic acyl group of R ¹ , for example, formyl chloride, acetyl chloride, etc. are reacted with 1 mole of the citrate compound. As the catalyst, 0.1 to 2 mol of basic pyridine or the like can be used with respect to 1 mol of the citrate compound. The reaction may be solventless and is carried out at a temperature of 80-100 ° C. for 1-5 hours. After the reaction, water and an organic solvent insoluble in water, such as toluene, are added to the reaction mixture to dissolve the target product in the organic solvent, the aqueous layer and the organic solvent layer are separated, and the organic solvent layer is washed with water, and then distilled. The target product can be isolated by a conventional method.

  The citrate ester compound used in the present invention is preferable for obtaining the effects of the present invention in combination with an ultraviolet absorber having a weight average molecular weight of 490 to 50,000.

  The amount of the citrate ester compound added to the cellulose resin is preferably 5 to 200 parts by mass, particularly 10 to 200 parts by mass with respect to 100 parts by mass of the cellulose resin.

  Moreover, 1-30 mass% is preferable and, as for content in the film of a citrate ester compound, 2-20 mass% is preferable especially.

  The glycolate plasticizer is not particularly limited, and a glycolate plasticizer having an aromatic ring or a cycloalkyl ring in the molecule can be used. Examples of the glycolate plasticizer include butyl phthalyl butyl glycolate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, and the like.

  Examples of phosphate plasticizers include triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate, etc. The content of the plasticizer is preferably 40% by mass or less of the total plasticizer content, and particularly preferably the content of the phosphate ester plasticizer is less than 1% by mass. More preferably, it is not added.

  Ethylene glycol ester plasticizer: Specifically, ethylene glycol alkyl ester plasticizers such as ethylene glycol diacetate and ethylene glycol dibutyrate, ethylene glycol dicyclopropyl carboxylate, ethylene glycol dicyclohexyl carboxylate and the like Examples include ethylene glycol cycloalkyl ester plasticizers and ethylene glycol aryl ester plasticizers such as ethylene glycol dibenzoate and ethylene glycol di4-methylbenzoate. These alkylate groups, cycloalkylate groups, and arylate groups may be the same or different, and may be further substituted. Further, a mixture of alkylate group, cycloalkylate group and arylate group may be used, and these substituents may be covalently bonded. Further, the ethylene glycol part may be substituted, the ethylene glycol ester partial structure may be part of the polymer or regularly pendant, and may be an antioxidant, an acid scavenger, an ultraviolet absorber, etc. May be introduced into a part of the molecular structure of the additive.

  Glycerin ester plasticizers: Specifically, glycerol alkyl esters such as triacetin, tributyrin, glycerol diacetate caprylate, glycerol oleate propionate, and glycerin cycloalkyl esters such as glycerol tricyclopropyl carboxylate and glycerol tricyclohexyl carboxylate Glyceryl aryl esters such as glycerin tribenzoate and glycerin 4-methylbenzoate, diglycerin tetraacetylate, diglycerin tetrapropionate, diglycerin acetate tricaprylate, diglycerin alkyl esters such as diglycerin tetralaurate, di Diglycerides such as glycerin tetracyclobutylcarboxylate and diglycerin tetracyclopentylcarboxylate Emissions cycloalkyl esters, diglycerin tetrabenzoate, diglycerin aryl ester such as diglycerin 3-methylbenzoate or the like. These alkylate groups, cycloalkylcarboxylate groups, and arylate groups may be the same or different, and may be further substituted. Further, it may be a mix of alkylate group, cycloalkylcarboxylate group, and arylate group, and these substituents may be bonded by a covalent bond. Furthermore, the glycerin or diglycerin part may be substituted, and the partial structure of the glycerin ester or diglycerin ester may be part of the polymer or regularly pendant, and may be an antioxidant or an acid scavenger. Or may be introduced into a part of the molecular structure of an additive such as an ultraviolet absorber.

  Dicarboxylic acid ester plasticizers: Specifically, alkyldocarboxylic acid alkyl ester plasticizers such as didodecyl malonate (C1), dioctyl adipate (C4), dibutyl sebacate (C8), dicyclopentyl succinate, Alkyl dicarboxylic acid cycloalkyl ester plasticizers such as dicyclohexyl adipate, alkyl dicarboxylic acid aryl ester plasticizers such as diphenyl succinate and di4-methylphenyl glutarate, dihexyl-1,4-cyclohexanedicarboxylate, Cycloalkyldicarboxylic acid alkyl ester plasticizers such as didecylbicyclo [2.2.1] heptane-2,3-dicarboxylate, dicyclohexyl-1,2-cyclobutanedicarboxylate, dicyclopropyl-1,2 Cycloalkyldicarboxylic acid cycloalkyl ester plasticizers such as cyclohexyl dicarboxylate, aryl cycloalkyldicarboxylates such as diphenyl-1,1-cyclopropyldicarboxylate, di2-naphthyl-1,4-cyclohexanedicarboxylate Ester plasticizers, aryl dicarboxylic acid alkyl ester plasticizers such as diethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate and di-2-ethylhexyl phthalate, and aryl dicarboxylic acid cycloalkyls such as dicyclopropyl phthalate and dicyclohexyl phthalate Examples include ester plasticizers and aryl dicarboxylic acid aryl ester plasticizers such as diphenyl phthalate and di4-methylphenyl phthalate. These alkoxy groups and cycloalkoxy groups may be the same or different, may be mono-substituted, and these substituents may be further substituted. The alkyl group and cycloalkyl group may be mixed, and these substituents may be bonded together by a covalent bond. Further, the aromatic ring of phthalic acid may be substituted, and a multimer such as a dimer, trimer or tetramer may be used. In addition, the partial structure of phthalate ester may be part of the polymer or regularly pendant to the polymer, and may be part of the molecular structure of additives such as antioxidants, acid scavengers, and UV absorbers. It may be introduced.

  Polycarboxylic acid ester plasticizers: Specifically, alkyl polycarboxylic acid alkyl ester plastics such as tridodecyl tricarbarate and tributyl-meso-butane-1,2,3,4-tetracarboxylate Agents, alkyl polyvalent carboxylic acid cycloalkyl ester type plasticizers such as tricyclohexyl tricarbarate, tricyclopropyl-2-hydroxy-1,2,3-propanetricarboxylate, triphenyl 2-hydroxy-1,2 Alkyl polycarboxylic acid aryl ester plasticizers such as 1,3-propanetricarboxylate, tetra-3-methylphenyltetrahydrofuran-2,3,4,5-tetracarboxylate, tetrahexyl-1,2,3,4 -Cyclobutane tetracarboxylate, tetrabutyl-1,2, 1,4-cyclopentanetetracarboxylate and other cycloalkyl polycarboxylic acid alkyl ester plasticizers, tetracyclopropyl-1,2,3,4-cyclobutanetetracarboxylate, tricyclohexyl-1,3,5-cyclohexyl Cycloalkyl polycarboxylic acid cycloalkyl ester plasticizers such as tricarboxylate, triphenyl-1,3,5-cyclohexyl tricarboxylate, hexa-4-methylphenyl-1,2,3,4,5,6 -Cycloalkyl polycarboxylic acid aryl ester plasticizers such as cyclohexyl hexacarboxylate, tridodecylbenzene-1,2,4-tricarboxylate, tetraoctylbenzene-1,2,4,5-tetracarboxylate, etc. Aryl polycarboxylic acid Ester polyplasticizers, aryl polyvalent carboxylic acid cycloalkyl ester plasticizers such as tricyclopentylbenzene-1,3,5-tricarboxylate, tetracyclohexylbenzene-1,2,3,5-tetracarboxylate, Aryl polycarboxylic acid aryl ester based plasticizers such as triphenylbenzene-1,3,5-tetracartoxylate, hexa-4-methylphenylbenzene-1,2,3,4,5,6-hexacarboxylate Is mentioned. These alkoxy groups and cycloalkoxy groups may be the same or different, may be mono-substituted, and these substituents may be further substituted. The alkyl group and cycloalkyl group may be mixed, and these substituents may be bonded together by a covalent bond. Further, the aromatic ring of phthalic acid may be substituted, and a multimer such as a dimer, trimer or tetramer may be used. In addition, the partial structure of phthalate ester may be part of the polymer or regularly pendant to the polymer, and may be part of the molecular structure of additives such as antioxidants, acid scavengers, and UV absorbers. It may be introduced.

  Polymer plasticizer: Specifically, aliphatic hydrocarbon polymers, alicyclic hydrocarbon polymers, vinyl polymers such as polyvinyl isobutyl ether and poly N-vinyl pyrrolidone, styrene polymers such as polystyrene and poly 4-hydroxystyrene Examples thereof include polymers, polybutylene succinates, polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyethers such as polyethylene oxide and polypropylene oxide, polyamides, polyurethanes and polyureas. The number average molecular weight is preferably about 1,000 to 500,000, particularly preferably 5,000 to 200,000. If it is 1000 or less, a problem arises in volatility, and if it exceeds 500,000, the plasticizing ability is lowered, which adversely affects the mechanical properties of the cellulose resin derivative composition. These polymer plasticizers may be a homopolymer composed of one type of repeating unit or a copolymer having a plurality of repeating structures. Two or more of the above polymers may be used in combination, and other plasticizers, antioxidants, acid scavengers, ultraviolet absorbers, slip agents, matting agents, and the like may be included.

  These plasticizers can be used alone or in admixture of two or more. If the total content of the plasticizer in the film is less than 1% by mass relative to the cellulose resin, the effect of reducing the moisture permeability of the film is small, which is not preferable. If it exceeds 30% by mass, problems such as compatibility and bleed out occur. Since it is easy and the physical property of a film deteriorates, 1-30 mass% is preferable. 3 to 25% by mass is more preferable, and particularly preferably 5 to 20% by mass, but the addition amount is the total amount with the polymer or acrylic polymer obtained by polymerizing the ethylenically unsaturated monomer according to the present invention. In order to obtain the effect of the present invention, it is determined as appropriate.

(UV absorber)
The ultraviolet absorber according to the present invention is preferably an ultraviolet absorber having a weight average molecular weight in the range of 490 to 50,000, and is preferably a compound having at least two benzotriazole skeletons as an ultraviolet absorbing skeleton. The ultraviolet absorber preferably contains a compound having a weight average molecular weight of 490 to 2,000 and an ultraviolet absorber having a weight average molecular weight of 2,000 to 50,000.

  Hereinafter, the ultraviolet absorbent according to the present invention will be described in detail.

  As an ultraviolet absorber, from the viewpoint of preventing deterioration of a polarizer or a display device with respect to ultraviolet rays, the ultraviolet absorber has an excellent ability to absorb ultraviolet rays having a wavelength of 370 nm or less, and from the viewpoint of liquid crystal display properties, absorption of visible light having a wavelength of 400 nm or more is absorbed. Less is preferred. Examples include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, cyanoacrylate compounds, triazine compounds, nickel complex compounds, etc., but benzophenone compounds and less colored benzotriazole compounds preferable. Moreover, you may use the ultraviolet absorber of Unexamined-Japanese-Patent No. 10-182621, Unexamined-Japanese-Patent No. 8-337574, and the polymeric ultraviolet absorber of Unexamined-Japanese-Patent No. 6-148430.

  Among these ultraviolet absorbers, an ultraviolet absorber having a weight average molecular weight in the range of 490 to 50,000 is preferable for exhibiting the effects of the present invention. Since the compatibility with the cellulose resin deteriorates as the molecular weight increases, an ultraviolet absorber having a molecular weight of 490 or less is usually used. At the same time, there was a tendency to color over time. When the weight average molecular weight exceeds 50,000, the compatibility with the film resin tends to be remarkably deteriorated.

  Moreover, it is also a preferable aspect that the ultraviolet absorber according to the present invention contains an ultraviolet absorber (A) having a weight average molecular weight of 490 to less than 2,000 and an ultraviolet absorber (B) having a weight average molecular weight of 2,000 to 50,000. . Use of ultraviolet absorbers having different molecular weights is a preferable method for enhancing the effects of the present invention and satisfying the exudation property and compatibility. The mixing ratio of the ultraviolet absorbers (A) and (B) is preferably selected as appropriate in the range of 1:99 to 99: 1.

  Examples of UV absorbers that are compounds having a weight average molecular weight within the scope of the present invention and having at least two benzotriazole skeletons as UV absorbing skeletons include bisbenzotriazoles represented by the following general formula (4): Phenol is preferred.

[Wherein, R ₁ and R ₂ are each a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, R ₃ and R ₄ are each a hydrogen atom, a halogen atom, and L is 1 to 4 carbon atoms. Represents an alkylene group. ]
As a substituent atom or substituent of the alkyl group, a halogen atom such as a chloro atom, a bromine atom or a fluorine atom, a hydroxyl group or a phenyl group (this phenyl group may be substituted with an alkyl group or a halogen atom) ) And the like.

  Specific examples of the bisbenzotriazolylphenol compound represented by the general formula (4) include the following. However, it is not limited to these.

1) RUVA-100 / 110 (manufactured by Otsuka Chemical)
2) RUVA-206 (Otsuka Chemical)
3) Tinuvin-360 (manufactured by Ciba Specialty Chemicals)
4) ADK STAB LA-31 (manufactured by Asahi Denka)
5) ADK STAB LA-31RG (Asahi Denka)
Further, at least one of the ultraviolet absorbers according to the present invention is a copolymer of an ultraviolet-absorbing monomer having an molar absorption coefficient at 380 nm of 4000 or more and an ethylenically unsaturated monomer, and further comprising the ethylenically unsaturated monomer component It is preferable to have an ethylenically unsaturated monomer component having at least one hydrophilic group.

  That is, the present invention relates to a copolymer of an ultraviolet-absorbing monomer having an molar absorption coefficient of 4,000 or more at 380 nm and an ethylenically unsaturated monomer, wherein the copolymer has a weight average molecular weight of 490 to 50,000. If an absorptive copolymer is contained, an optical compensation film that can improve the above-described problems can be obtained.

  When the molar extinction coefficient at 380 nm is 4000 or more, it indicates that the ultraviolet absorption performance is good, and an effect sufficient to block the ultraviolet light is obtained, so that the optical compensation film itself is colored yellow. Problems such as sag are improved, and the transparency of the optical compensation film itself is improved.

  As the ultraviolet absorbing monomer used in the ultraviolet absorbing copolymer in the present invention, a monomer having a molar extinction coefficient at 380 nm of 4000 or more, preferably 8000 or more, more preferably 10,000 or more is used. When the molar extinction coefficient at 380 nm is less than 4000, it is necessary to add a large amount in order to obtain the desired UV absorption performance. It tends to decrease.

  Further, as the UV-absorbing monomer used in the UV-absorbing copolymer, the ratio of the molar extinction coefficient at 400 nm to the molar extinction coefficient at 380 nm is preferably 20 or more.

  That is, in order to suppress the absorption of light near 400 nm, which is closer to the visible range, and to obtain the desired UV absorption performance, the present invention contains an ultraviolet absorbing monomer having a performance capable of absorbing ultraviolet light as much as possible. Is preferable.

a. UV Absorbing Monomer UV absorbing monomer (ultraviolet absorber) has a molar extinction coefficient at 380 nm of 4000 or more, and in particular, the ratio of the molar extinction coefficient at 400 nm to the molar extinction coefficient at 380 nm is 20 or more. It is preferable.

  Examples of the UV absorbing monomer include salicylic acid UV absorbers (phenyl salicylate, p-tert-butyl salicylate, etc.) or benzophenone UV absorbers (2,4-dihydroxybenzophenone, 2,2′-dihydroxy-4,4 ′). -Dimethoxybenzophenone, etc.), benzotriazole ultraviolet absorbers (2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3) ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3', 5'-di-tert-amyl-phenyl) benzotriazole, etc.), cyanoacrylate ultraviolet Absorbent (2'-ethylhexyl-2-cyano-3,3-dipheny Acrylate, ethyl-2-cyano-3- (3 ′, 4′-methylenedioxyphenyl) -acrylate, etc.), triazine ultraviolet absorber (2- (2′-hydroxy-4′-hexyloxyphenyl)- 4,6-diphenyltriazine, etc.) or compounds described in JP-A Nos. 58-185677 and 59-149350 are known.

  As the ultraviolet absorbing monomer in the present invention, a basic skeleton is appropriately selected from various known types of ultraviolet absorbers as shown above, a substituent containing an ethylenically unsaturated bond is introduced, It is preferable to select and use a polymerizable compound having a molar extinction coefficient at 380 nm of 4000 or more. As the ultraviolet absorbing monomer of the present invention, a benzotriazole compound is preferably used from the viewpoint of storage stability. A particularly preferred ultraviolet absorbing monomer is represented by the following general formula (5).

In the general formula (5), each substituent represented by R _{11 to} R ₁₆ may further have a substituent unless otherwise specified.

In the general formula (5), any one of the groups represented by R _{11 to} R ₁₆ has a polymerizable group represented by the group having the above structure as a partial structure.

In the formula, L represents a divalent linking group or a simple bond, and R ₁ represents a hydrogen atom or an alkyl group. R ₁ is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. The group containing the polymerizable group may be any of the groups represented by R _{11 to} R ₁₆ , but R ₁₁ or R ₁₃ , R ₁₄ , and R ₁₅ are preferable, and R ₁₄ is particularly preferable.

In the general formula (5), R ₁₁ represents a group substituted on the benzene ring via a halogen atom, an oxygen atom, a nitrogen atom, or a sulfur atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom, and a chlorine atom is preferable.

  Examples of the group that substitutes on the benzene ring through an oxygen atom include a hydroxyl group, an alkoxy group (for example, a methoxy group, an ethoxy group, a t-butoxy group, and a 2-ethoxyethoxy group), an aryloxy group (for example, a phenoxy group, 2 , 4-di-t-amylphenoxy group, 4- (4-hydroxyphenylsulfonyl) phenoxy group, etc.), heterocyclic oxy groups (for example, 4-pyridyloxy group, 2-hexahydropyranyloxy group, etc.), carbonyloxy Groups (for example, alkylcarbonyloxy groups such as acetyloxy group, trifluoroacetyloxy group and pivaloyloxy group, aryloxy groups such as benzoyloxy group and pentafluorobenzoyloxy group), urethane groups (for example, N, N-dimethylurethane group) Alkyl urethane groups such as N-phenylurethane group, N- aryl urethane groups such as p-cyanophenyl) urethane groups), sulfonyloxy groups (for example, methanesulfonyloxy groups, trifluoromethanesulfonyloxy groups, alkylsulfonyloxy groups such as n-dodecanesulfonyloxy groups, benzenesulfonyloxy groups, p- Arylsulfonyloxy groups such as toluenesulfonyloxy group) and the like, and alkoxy groups having 1 to 6 carbon atoms are preferable, and alkoxy groups having 2 to 4 carbon atoms are particularly preferable.

  Examples of the group substituted on the benzene ring through the nitrogen atom include nitro group, amino group (for example, dimethylamino group, cyclohexylamino group, alkylamino group such as n-dodecylamino group, anilino group, pt-octylaniline. Arylamino groups such as lino group), sulfonylamino groups (eg alkylsulfonylamino groups such as methanesulfonylamino group, heptafluoropropanesulfonylamino group, hexadecylsulfonylamino group, p-toluenesulfonylamino group, pentafluorobenzenesulfonyl) Arylsulfonylamino groups such as amino), sulfamoylamino groups (eg, alkylsulfamoylamino groups such as N, N-dimethylsulfamoylamino group, arylsulfamoylamino groups such as N-phenylsulfamoylamino group) Group), acyl Mino group (eg alkylcarbonylamino group such as acetylamino group, myristoylamino group, arylcarbonylamino group such as benzoylamino group), ureido group (eg alkylureido group such as N, N-dimethylaminoureido group, N-phenylureido) Group, arylureido groups such as N- (p-cyanophenyl) ureido group) and the like, and acylamino groups are preferred.

  Examples of the group substituted on the benzene ring via a sulfur atom include an alkylthio group (for example, methylthio group, t-octylthio group, etc.), an arylthio group (for example, phenylthio group), and a heterocyclic thio group (for example, 1-phenyltetrazole-5). -Thio group, 5-methyl-1,3,4-oxadiazole-2-thio group, etc.), sulfinyl group (for example, alkylsulfinyl group such as methanesulfinyl group, trifluoromethanesulfinyl group, and p-toluenesulfinyl group) Arylsulfinyl group), sulfonyl groups (for example, alkylsulfonyl groups such as methanesulfonyl group and trifluoromethanesulfonyl group, and arylsulfonyl groups such as p-toluenesulfonyl group), sulfamoyl groups (for example, dimethylsulfamoyl group, 4- ( 2,4-Di-t-amylfe Carboxymethyl) butyl alkylsulfamoyl group such as aminosulfonyl group, an aryl sulfamoyl group such as a phenyl sulfamoyl groups), sulfinyl group, and particularly preferably an alkylsulfinyl group having 4 to 12 carbon atoms.

In the general formula (5), n represents an integer of 1 to 4, preferably 1 or 2. When n is 2 or more, the plurality of groups represented by R ₁₁ may be the same or different. The substitution position of the substituent represented by R ₁₁ is not particularly limited, but the 4-position or 5-position is preferred.

In the general formula (5), R ₁₂ is a hydrogen atom, an aliphatic group (for example, an alkyl group, an alkenyl group, an alkynyl group, etc.), an aromatic group (for example, a phenyl group, a p-chlorophenyl group, etc.), or a heterocyclic group. (For example, 2-tetrahydrofuryl group, 2-thiophenyl group, 4-imidazolyl group, indolin-1-yl group, 2-pyridyl group, etc.). R ₁₂ is preferably a hydrogen atom or an alkyl group.

In the general formula (5), R ₁₃ represents a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group, and as R ₁₃ , a hydrogen atom or an alkyl group having 1 to 12 carbon atoms is preferable. A branched alkyl group such as a -propyl group, t-butyl group, or t-amyl group is preferable because of its excellent durability.

In the general formula (5), R ₁₄ represents a group which substitutes on the benzene ring via an oxygen atom or a nitrogen atom, and specifically, on the benzene ring via an oxygen atom or a nitrogen atom represented by R _11. And the same groups as those for the substituent. R ₁₄ is preferably an acylamino group or an alkoxy group. When R ₁₄ includes the polymerizable group as a partial structure, as R ₁₄ ,

Is preferred.

In the formula, L ₂ represents an alkylene group having 1 to 12 carbon atoms, preferably a linear, branched or cyclic alkylene group having 3 to 6 carbon atoms. R ₁ represents a hydrogen atom or a methyl group, and R ₂ represents an alkyl group having 1 to 12 carbon atoms, preferably an alkyl group having 2 to 6 carbon atoms.

In the general formula (5), R ₁₅ represents a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group, and as R ₁₅ , a hydrogen atom or an alkyl group having 1 to 12 carbon atoms is preferable. A branched alkyl group such as -propyl group, t-butyl group, and t-amyl group is preferred.

In the general formula (5), R ₁₆ represents a hydrogen atom, an aliphatic group, an aromatic group or a heterocyclic group, and R ₁₆ is preferably a hydrogen atom.

  Although the preferable ultraviolet-absorbing monomer used by this invention is illustrated below, it is not limited to these.

b. Description of polymer The UV-absorbing copolymer used in the present invention is a copolymer of the UV-absorbing monomer and the ethylenically unsaturated monomer, and the copolymer has a weight average molecular weight in the range of 490 to 50,000. It is characterized by being.

  By using a copolymer, an optical compensation film with reduced haze and excellent transparency can be obtained. In the present invention, the weight average molecular weight is in the range of 490 to 50000, preferably 2000 to 20000, and more preferably 7000 to 15000. When the weight average molecular weight was less than 490, there was a tendency for oozing to the film surface and at the same time a tendency to color over time. Moreover, when larger than 50000, it exists in the tendency for compatibility with resin to worsen.

  Examples of the ethylenically unsaturated monomer copolymerizable with the ultraviolet absorbing monomer include methacrylic acid and ester derivatives thereof (methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, i-butyl methacrylate, methacrylic acid). t-butyl, octyl methacrylate, cyclohexyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, tetrahydrofurfuryl methacrylate, benzyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, etc.), or Acrylic acid and its ester derivatives (methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, i-butyl acrylate, t-butyl acrylate, octyl acrylate Cyclohexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, 2-ethoxyethyl acrylate, diethylene glycol ethoxylate acrylate, 3-methoxybutyl acrylate, benzyl acrylate, Dimethylaminoethyl acrylate, diethylaminoethyl acrylate, etc.), alkyl vinyl ether (methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, etc.), alkyl vinyl ester (vinyl formate, vinyl acetate, vinyl butyrate, vinyl caproate, vinyl stearate, etc.), Examples include acrylonitrile, vinyl chloride, and styrene.

  Among these ethylenically unsaturated monomers, an acrylic acid ester having a hydroxyl group or an ether bond, or a methacrylic acid ester (for example, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, tetrahydrofurfuryl methacrylate, acrylic acid 2 -Hydroxyethyl, 2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, 2-ethoxyethyl acrylate, diethylene glycol ethoxylate acrylate, 3-methoxybutyl acrylate) are preferred. These can be used alone or in combination of two or more to be copolymerized with the ultraviolet absorbing monomer.

  The proportion of the ethylenically unsaturated monomer that can be copolymerized with the UV-absorbing monomer takes into account the compatibility of the resulting UV-absorbing copolymer polymer with the transparent resin, the effect on the transparency and mechanical strength of the optical film. To be selected. Preferably, both are blended so that the UV-absorbing monomer is contained in the copolymer in an amount of 20 to 70% by mass, more preferably 30 to 60% by mass. When the content of the UV-absorbing monomer is less than 20% by mass, a large amount of addition is necessary to obtain the desired UV-absorbing performance, and transparency tends to decrease due to an increase in haze or precipitation, and the film strength tends to decrease. It becomes. When the content of the UV-absorbing monomer is larger than 70% by mass, the compatibility with the transparent resin tends to be poor, and the workability when forming a film is poor.

c. Description of Polymerization Method The method for polymerizing the UV-absorbing copolymer in the present invention is not particularly limited, but conventionally known methods can be widely employed, and examples thereof include radical polymerization, anionic polymerization, and cationic polymerization. . Examples of the initiator for the radical polymerization method include azo compounds and peroxides, and examples thereof include azobisisobutyronitrile (AIBN), azobisisobutyric acid diester derivatives, and benzoyl peroxide. The polymerization solvent is not particularly limited. For example, aromatic hydrocarbon solvents such as toluene and chlorobenzene, halogenated hydrocarbon solvents such as dichloroethane and chloroform, ether solvents such as tetrahydrofuran and dioxane, and amide solvents such as dimethylformamide. And alcohol solvents such as methanol, ester solvents such as methyl acetate and ethyl acetate, ketone solvents such as acetone, cyclohexanone and methyl ethyl ketone, and water solvents. Depending on the selection of the solvent, solution polymerization for polymerization in a homogeneous system, precipitation polymerization for precipitation of the produced polymer, and emulsion polymerization for polymerization in a micellar state can also be performed.

  The weight average molecular weight of the ultraviolet-absorbing copolymer can be adjusted by a known molecular weight adjusting method. Examples of such a molecular weight adjusting method include a method of adding a chain transfer agent such as carbon tetrachloride, lauryl mercaptan, octyl thioglycolate, and the like. The polymerization temperature is usually from room temperature to 130 ° C, preferably 50 to 100 ° C.

  The UV-absorbing copolymer is preferably mixed in a proportion of 0.01 to 20% by mass, more preferably in a proportion of 0.1 to 10% by mass with respect to the transparent resin forming the optical film. preferable. At this time, the haze is not particularly limited as long as the haze when the optical film is formed is 0.5 or less, but the haze is preferably 0.2 or less. More preferably, the haze when the optical film is formed is 0.2 or less and the transmittance at 380 nm is 10% or less.

  Furthermore, it is also preferable that at least one of the ultraviolet absorbers contains a polymer derived from an ultraviolet absorbing monomer represented by the following general formula (6).

[Wherein, n represents an integer of 0 to 3, R _{1 to} R ₅ represent a hydrogen atom, a halogen atom or a substituent, and X represents —COO—, —CONR ₇ —, —OCO— or —NR ₇ CO R ₆ represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group or an aryl group, and R ₇ represents a hydrogen atom, an alkyl group or an aryl group. However, the group represented by R ₆ has a polymerizable group as a partial structure. ]
In the general formula (6), when n is 2 or more, the plurality of R ₅ may be the same or different, and may be connected to each other to form a 5- to 7-membered ring. .

R _{1 to} R ₅ each represents a hydrogen atom, a halogen atom or a substituent. As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned, for example, Preferably they are a fluorine atom and a chlorine atom. Examples of the substituent include an alkyl group (for example, methyl group, ethyl group, isopropyl group, hydroxyethyl group, methoxymethyl group, trifluoromethyl group, t-butyl group), alkenyl group (for example, vinyl group). , Allyl group, 3-buten-1-yl group, etc.), aryl group (eg, phenyl group, naphthyl group, p-tolyl group, p-chlorophenyl group, etc.), heterocyclic group (eg, pyridyl group, benzimidazolyl group) , Benzthiazolyl group, benzoxazolyl group, etc.), alkoxy group (eg methoxy group, ethoxy group, isopropoxy group, n-butoxy group etc.), aryloxy group (eg phenoxy group etc.), heterocyclic oxy group (eg For example, 1-phenyltetrazol-5-oxy group, 2-tetrahydropyranyloxy group, etc.), Ruoxy group (for example, acetoxy group, pivaloyloxy group, benzoyloxy group, etc.), acyl group (for example, acetyl group, propanoyl group, butyroyl group, etc.), alkoxycarbonyl group (for example, methoxycarbonyl group, ethoxycarbonyl group, etc.), aryl Oxycarbonyl group (for example, phenoxycarbonyl group), carbamoyl group (for example, methylcarbamoyl group, ethylcarbamoyl group, dimethylcarbamoyl group, etc.), amino group, alkylamino group (for example, methylamino group, ethylamino group, diethylamino group) Anilino group (for example, anilino group, N-methylanilino group, etc.), acylamino group (for example, acetylamino group, propionylamino group, etc.), hydroxyl group, cyano group, nitro group, sulfonamide (Eg, methanesulfonamide group, benzenesulfonamide group, etc.), sulfamoylamino group (eg, dimethylsulfamoylamino group, etc.), sulfonyl group (eg, methanesulfonyl group, butanesulfonyl group, phenylsulfonyl group, etc.) , Sulfamoyl group (eg, ethylsulfamoyl group, dimethylsulfamoyl group, etc.), sulfonylamino group (eg, methanesulfonylamino group, benzenesulfonylamino group, etc.), ureido group (eg, 3-methylureido group, 3 , 3-dimethylureido group, 1,3-dimethylureido group etc.), imide group (eg phthalimide group etc.), silyl group (eg trimethylsilyl group, triethylsilyl group, t-butyldimethylsilyl group etc.), alkylthio group (Eg methylthio Group, ethylthio group, n-butylthio group and the like), arylthio group (for example, phenylthio group and the like), and the like, preferably an alkyl group and an aryl group.

In General Formula (6), when each group represented by R _{1 to} R ₅ is a further substitutable group, it may further have a substituent, and adjacent R _{1 to} R ₄ are They may be connected to each other to form a 5- to 7-membered ring.

R ₆ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic ring. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, n- Examples thereof include a butyl group, an isobutyl group, a t-butyl group, an amyl group, an isoamyl group, and a hexyl group. The alkyl group may further have a halogen atom or a substituent, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the substituent include An aryl group (eg, phenyl group, naphthyl group, p-tolyl group, p-chlorophenyl group, etc.), acyl group (eg, acetyl group, propanoyl group, butyroyl group, etc.), alkoxy group (eg, methoxy group, ethoxy group, Isopropoxy group, n-butoxy group, etc.), aryloxy group (eg, phenoxy group, etc.), amino group, alkylamino group (eg, methylamino group, ethylamino group, diethylamino group etc.), anilino group (eg, anilino group) Group, N-methylanilino group, etc.), acylamino group (for example, acetylamino group, propioni) Amino group, etc.), hydroxyl group, cyano group, carbamoyl group (eg, methylcarbamoyl group, ethylcarbamoyl group, dimethylcarbamoyl group, etc.), acyloxy group (eg, acetoxy group, pivaloyloxy group, benzoyloxy group, etc.), alkoxycarbonyl group (For example, a methoxycarbonyl group, an ethoxycarbonyl group, etc.) and an aryloxycarbonyl group (for example, a phenoxycarbonyl group, etc.) are mentioned.

  Examples of the cycloalkyl group include saturated cyclic hydrocarbons such as a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group, which may be unsubstituted or substituted.

  Examples of the alkenyl group include a vinyl group, an allyl group, a 1-methyl-2-propenyl group, a 3-butenyl group, a 2-butenyl group, a 3-methyl-2-butenyl group, and an oleyl group. Is a vinyl group, 1-methyl-2-propenyl group.

  Examples of the alkynyl group include ethynyl group, butadiyl group, phenylethynyl group, propargyl group, 1-methyl-2-propynyl group, 2-butynyl group, 1,1-dimethyl-2-propynyl group, Preferably, they are an ethynyl group and a propargyl group.

  Examples of the aryl group include a phenyl group, a naphthyl group, and an anthranyl group. The aryl group may further have a halogen atom or a substituent. Examples of the halogen atom include a fluorine atom and chlorine. Atoms, bromine atoms, iodine atoms and the like. Examples of the substituent include alkyl groups (for example, methyl group, ethyl group, isopropyl group, hydroxyethyl group, methoxymethyl group, trifluoromethyl group, t-butyl group). Etc.), acyl groups (eg acetyl group, propanoyl group, butyroyl group etc.), alkoxy groups (eg methoxy group, ethoxy group, isopropoxy group, n-butoxy group etc.), aryloxy groups (eg phenoxy group etc.) ), Amino group, alkylamino group (for example, methylamino group, ethylamino group, diethyl) Mino group etc.), anilino group (eg anilino group, N-methylanilino group etc.), acylamino group (eg acetylamino group, propionylamino group etc.), hydroxyl group, cyano group, carbamoyl group (eg methylcarbamoyl group, Ethylcarbamoyl group, dimethylcarbamoyl group, etc.), acyloxy group (eg, acetoxy group, pivaloyloxy group, benzoyloxy group, etc.), alkoxycarbonyl group (eg, methoxycarbonyl group, ethoxycarbonyl group, etc.), aryloxycarbonyl group (eg, Phenoxycarbonyl group and the like).

Examples of the heterocyclic group include a pyridyl group, a benzimidazolyl group, a benzthiazolyl group, and a benzoxazolyl group. R ₆ is preferably an alkyl group.

In Formula (6), X is _{-COO -, - CONR 7 -,} - OCO- or an -NR ₇ CO-.

R ₇ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a heterocyclic group, and examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, Examples thereof include a t-butyl group, an amyl group, an isoamyl group, and a hexyl group. Such an alkyl group may further have a halogen atom or a substituent. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the substituent include an aryl group. Group (for example, phenyl group, naphthyl group, p-tolyl group, p-chlorophenyl group, etc.), acyl group (for example, acetyl group, propanoyl group, butyroyl group, etc.), alkoxy group (for example, methoxy group, ethoxy group, iso group) Propoxy group, n-butoxy group, etc.), aryloxy group (eg, phenoxy group, etc.), amino group, alkylamino group (eg, methylamino group, ethylamino group, diethylamino group, etc.), anilino group (eg, anilino group) N-methylanilino group), acylamino group (for example, acetylamino group, propionyl) Mino group, etc.), hydroxyl group, cyano group, carbamoyl group (eg methylcarbamoyl group, ethylcarbamoyl group, dimethylcarbamoyl group etc.), acyloxy group (eg acetoxy group, pivaloyloxy group, benzoyloxy group etc.), alkoxycarbonyl group (For example, a methoxycarbonyl group, an ethoxycarbonyl group, etc.) and an aryloxycarbonyl group (for example, a phenoxycarbonyl group, etc.) are mentioned.

  Examples of the cycloalkyl group include saturated cyclic hydrocarbons such as a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group, which may be unsubstituted or substituted.

  Examples of the aryl group include a phenyl group, a naphthyl group, and an anthranyl group. The aryl group may further have a halogen atom or a substituent, and the halogen atom includes a fluorine atom, a chlorine atom, Examples of the substituent include an alkyl group (for example, methyl group, ethyl group, isopropyl group, hydroxyethyl group, methoxymethyl group, trifluoromethyl group, t-butyl group). An acyl group (for example, acetyl group, propanoyl group, butyroyl group, etc.), an alkoxy group (for example, methoxy group, ethoxy group, isopropoxy group, n-butoxy group, etc.), an aryloxy group (for example, phenoxy group, etc.), Amino group, alkylamino group (for example, methylamino group, ethylamino group, diethylamino group) ), Anilino group (for example, anilino group, N-methylanilino group, etc.), acylamino group (for example, acetylamino group, propionylamino group, etc.), hydroxyl group, cyano group, carbamoyl group (for example, methylcarbamoyl group, ethylcarbamoyl group) Group, dimethylcarbamoyl group, etc.), acyloxy group (eg acetoxy group, pivaloyloxy group, benzoyloxy group etc.), alkoxycarbonyl group (eg methoxycarbonyl group, ethoxycarbonyl group etc.), aryloxycarbonyl group (eg phenoxycarbonyl) Group).

Examples of the heterocyclic group include a pyridyl group, a benzimidazolyl group, a benzthiazolyl group, and a benzoxazolyl group. R ₇ is preferably a hydrogen atom.

  The polymerizable group in the present invention means an unsaturated ethylene-based polymerizable group or a bifunctional polycondensable group, and preferably an unsaturated ethylene-based polymerizable group. Specific examples of the unsaturated ethylene polymerizable group include vinyl group, allyl group, acryloyl group, methacryloyl group, styryl group, acrylamide group, methacrylamide group, vinyl cyanide group, 2-cyanoacryloxy group, 1,2 -An epoxy group, a vinylbenzyl group, a vinyl ether group and the like can be mentioned, and a vinyl group, an acryloyl group, a methacryloyl group, an acrylamide group, and a methacrylamide group are preferable. Moreover, having a polymerizable group as a partial structure means that the polymerizable group is bonded directly or by a divalent or higher valent linking group, and the divalent or higher valent linking group is, for example, an alkylene group. (Eg, methylene, 1,2-ethylene, 1,3-propylene, 1,4-butylene, cyclohexane-1,4-diyl, etc.), alkenylene groups (eg, ethene-1,2-diyl, butadiene-1, 4-diyl, etc.), alkynylene groups (eg, ethyne-1,2-diyl, butane-1,3-diyne-1,4-diyl, etc.), linking groups derived from compounds containing at least one aromatic group (Eg, substituted or unsubstituted benzene, condensed polycyclic hydrocarbons, aromatic heterocycles, aromatic hydrocarbon ring assemblies, aromatic heterocycle assemblies, etc.), heteroatom linking groups (oxygen, sulfur, nitrogen, silicon Although such phosphorus atoms) are exemplified, preferably an alkylene group and a group linking a heteroatom. These linking groups may be further combined to form a composite group. The polymer derived from the ultraviolet absorbing monomer preferably has a weight average molecular weight of 2,000 to 30,000, more preferably 5,000 to 20,000.

  The weight average molecular weight of the ultraviolet absorbing polymer used in the present invention can be adjusted by a known molecular weight adjusting method. Examples of such a molecular weight adjusting method include a method of adding a chain transfer agent such as carbon tetrachloride, lauryl mercaptan, octyl thioglycolate, and the like. The polymerization temperature is usually from room temperature to 130 ° C, preferably from 50 ° C to 100 ° C.

  The UV-absorbing polymer used in the present invention is preferably a copolymer of an UV-absorbing monomer and another polymerizable monomer. Examples of other polymerizable monomers that can be copolymerized include styrene derivatives (for example, , Styrene, α-methyl styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, vinyl naphthalene, etc.), acrylate derivatives (eg, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate) , I-butyl acrylate, t-butyl acrylate, octyl acrylate, cyclohexyl acrylate, benzyl acrylate, etc.), methacrylate derivatives (eg, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, I-Butyl methacrylate T-butyl methacrylate, octyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, etc.), alkyl vinyl ether (eg, methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, etc.), alkyl vinyl ester (eg, vinyl formate, vinyl acetate, vinyl butyrate) And unsaturated compounds such as crotonic acid, maleic acid, fumaric acid, itaconic acid, acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, acrylamide, and methacrylamide. Preferred are methyl acrylate, methyl methacrylate, and vinyl acetate.

  It is also preferred that the copolymer component other than the ultraviolet absorbing monomer in the polymer derived from the ultraviolet absorbing monomer contains at least one hydrophilic ethylenically unsaturated monomer.

  The hydrophilic ethylenically unsaturated monomer is not particularly limited as long as it is hydrophilic and has an unsaturated double bond polymerizable in the molecule. For example, unsaturated carboxylic acid such as acrylic acid or methacrylic acid. Or acrylic acid or methacrylic acid ester having a hydroxyl group or an ether bond (for example, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, tetrahydrofurfuryl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl acrylate, Hydroxypropyl, 2,3-dihydroxy-2-methylpropyl methacrylate, tetrahydrofurfuryl acrylate, 2-ethoxyethyl acrylate, diethylene glycol ethoxylate acrylate, 3-methoxybutyl acrylate, etc.), acrylamide, N N- dimethyl (meth) acrylamide, (N- substituted) (meth) acrylamide, N- vinylpyrrolidone, N- vinyloxazolidone and the like.

  As the hydrophilic ethylenically unsaturated monomer, (meth) acrylate having a hydroxyl group or a carboxyl group in the molecule is preferable, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxyethyl acrylate, acrylic acid 2-hydroxypropyl is particularly preferred.

  These polymerizable monomers can be used alone or in combination of two or more to be copolymerized with the ultraviolet absorbing monomer.

  Although the polymerization method of the ultraviolet-absorbing copolymer used in the present invention is not particularly limited, conventionally known methods can be widely employed, and examples thereof include radical polymerization, anionic polymerization, and cationic polymerization. Examples of radical polymerization initiators include azo compounds and peroxides, and examples include azobisisobutyronitrile (AIBN), azobisisobutyric acid diester derivatives, benzoyl peroxide, and hydrogen peroxide. . The polymerization solvent is not particularly limited. For example, aromatic hydrocarbon solvents such as toluene and chlorobenzene, halogenated hydrocarbon solvents such as dichloroethane and chloroform, ether solvents such as tetrahydrofuran and dioxane, and amide solvents such as dimethylformamide. And alcohol solvents such as methanol, ester solvents such as methyl acetate and ethyl acetate, ketone solvents such as acetone, cyclohexanone and methyl ethyl ketone, and water solvents. Depending on the selection of the solvent, solution polymerization for polymerization in a homogeneous system, precipitation polymerization for precipitation of the produced polymer, emulsion polymerization for polymerization in a micelle state, and suspension polymerization for polymerization in a suspension state can also be performed.

  The use ratio of the above-mentioned UV-absorbing monomer, polymerizable monomer copolymerizable therewith and hydrophilic ethylenically unsaturated monomer is compatible with the obtained UV-absorbing copolymer polymer and other transparent polymer, optical compensation film Is appropriately selected in consideration of the effect on transparency and mechanical strength.

  The content ratio of the ultraviolet absorbing monomer in the polymer derived from the ultraviolet absorbing monomer is preferably 1 to 70% by mass, and more preferably 5 to 60% by mass. When the content ratio of the ultraviolet monomer in the ultraviolet absorbing polymer is less than 1% by mass, a large amount of the ultraviolet absorbing polymer must be used when trying to satisfy the desired ultraviolet absorbing performance. As a result, the transparency is lowered and the film strength is lowered. On the other hand, when the content ratio of the ultraviolet monomer in the ultraviolet absorbing polymer exceeds 70% by mass, the compatibility with other polymers is lowered, and it may be difficult to obtain a transparent optical compensation film.

  It is preferable that 0.1-50 mass% of hydrophilic ethylenically unsaturated monomers are contained in the said ultraviolet absorptive copolymer. If it is 0.1% by mass or less, the effect of improving the compatibility with the hydrophilic ethylenically unsaturated monomer does not appear, and if it exceeds 50% by mass, it is difficult to isolate and purify the copolymer. A more preferable content of the hydrophilic ethylenically unsaturated monomer is 0.5 to 20% by mass. When the UV-absorbing monomer itself is substituted with a hydrophilic group, the total content of the hydrophilic UV-absorbing monomer and the hydrophilic ethylenically unsaturated monomer is preferably within the above range.

  In order to satisfy the preferable contents of the UV-absorbing monomer and the hydrophilic monomer, it is preferable to copolymerize an ethylenically unsaturated monomer having no hydrophilic group in the molecule in addition to both.

  Two or more kinds of UV-absorbing monomers and (non) hydrophilic ethylenically unsaturated monomers may be mixed and copolymerized.

  Hereinafter, representative examples of the ultraviolet absorbing monomer preferably used in the present invention are exemplified, but the invention is not limited thereto.

  The ultraviolet absorbent, ultraviolet absorbent monomer and intermediate thereof used in the present invention can be synthesized with reference to known literature. For example, U.S. Pat. Nos. 3,072,585, 3,159,646, 3,399,173, 3,761,272, 4,028,331, 5,683,861 No., European Patent No. 86,300,416, JP-A Nos. 63-227575, 63-185969, Polymer Bulletin. V. 20 (2), 169-176, and Chemical Abstracts V.I. 109, no. 191389 and the like can be synthesized.

  The ultraviolet absorbent and ultraviolet absorbent polymer used in the present invention can be used together with a low molecular compound, a high molecular compound, an inorganic compound, or the like, if necessary, when mixed with another transparent polymer. For example, the UV-absorbing polymer used in the present invention and other relatively low-molecular UV absorbers may be mixed with other transparent polymers simultaneously, or the UV-absorbing polymer used in the present invention and other relatively low-molecular UV absorbers may be mixed. It is also one of preferred embodiments that the ultraviolet absorber is mixed with other transparent polymer at the same time. Similarly, it is one of preferred embodiments to simultaneously mix additives such as an antioxidant, a plasticizer, and a flame retardant.

  The method for adding the ultraviolet absorber and the ultraviolet absorbing polymer used in the present invention is not particularly limited, but the resin may be kneaded with a resin, or once dissolved in a solvent together with the resin and dried and solidified.

The amount of the ultraviolet absorber and the ultraviolet absorbing polymer used in the present invention is not uniform depending on the type of compound, usage conditions, etc., but in the case of an ultraviolet absorber, 0.1 to 0.1 m ² per 1 m ² of the optical film. 5.0 g is preferable, 0.1 to 3.0 g is more preferable, 0.4 to 2.0 is more preferable, and 0.5 to 1.5 is particularly preferable. In the case of an ultraviolet absorbing polymer, 0.1 to 10 g per 1 m ² of the optical film is preferable, 0.6 to 9.0 g is more preferable, 1.2 to 6.0 g is further preferable, and 1.5 to 3.0 g is particularly preferred.

  Furthermore, as described above, those having excellent ultraviolet absorption performance at a wavelength of 380 nm or less from the viewpoint of preventing deterioration of the liquid crystal and having less visible light absorption of 400 nm or more from the viewpoint of good liquid crystal display properties are preferable. In the present invention, the transmittance at a wavelength of 380 nm is particularly preferably 8% or less, more preferably 4% or less, and particularly preferably 1% or less.

  As a commercially available UV absorber monomer that can be used in the present invention, UVM-1 1- (2-benzotriazole) -2-hydroxy-5- (2-vinyloxycarbonylethyl) benzene, manufactured by Otsuka Chemical Co., Ltd. 1- (2-benzotriazole) -2-hydroxy-5- (2-methacryloyloxyethyl) benzene of the reactive ultraviolet absorber RUVA-93, or an analog thereof. A polymer or copolymer obtained by singly or copolymerizing these is also preferably used, but is not limited thereto. For example, as a commercially available polymer ultraviolet absorber, PUVA-30M manufactured by Otsuka Chemical Co., Ltd. is preferably used. Two or more kinds of ultraviolet absorbers may be used.

(Mixing of cellulose resin and additives)
In the present invention, it is preferable to mix a cellulose resin and additives such as a polymer, a plasticizer, and an ultraviolet absorber before being melted by heating.

  Examples of the method of mixing the additive include a cellulose resin, a method of finely mixing the additive, and a method of dissolving the cellulose resin in a solvent and then dissolving or finely dispersing the additive in this to remove the solvent. Can be mentioned. As a method for removing the solvent, a known method can be applied, for example, in-liquid drying method, in-air drying method, solvent coprecipitation method, freeze-drying method, solution casting method, and the like. The mixture of additives can be adjusted to shapes such as powders, granules, pellets, and films.

  The mixing of the additive is performed by dissolving the cellulose resin solid as described above, but may be performed simultaneously with the precipitation and solidification in the cellulose resin synthesis step.

  In the in-liquid drying method, for example, an aqueous solution of an activator such as sodium lauryl sulfate is added to a solution in which a cellulose resin and additives are dissolved, and emulsified and dispersed. Subsequently, the solvent is removed by distillation under normal pressure or reduced pressure, and a dispersion of the cellulose resin mixed with the additive can be obtained. Furthermore, it is preferable to perform centrifugation or decantation to remove the active agent. As the emulsification method, various methods can be used, and it is preferable to use an emulsification dispersion apparatus using ultrasonic waves, high-speed rotational shearing, and high pressure.

  In the emulsification dispersion using ultrasonic waves, so-called batch type and continuous type can be used. The batch method is suitable for producing a relatively small amount of sample, and the continuous method is suitable for producing a large amount of sample. In the continuous type, for example, an apparatus such as UH-600SR (manufactured by SMT Co., Ltd.) can be used. In the case of such a continuous type, the ultrasonic irradiation time can be obtained by the volume of the dispersion chamber / flow velocity × the number of circulations. In the case where there are a plurality of ultrasonic irradiation apparatuses, the total irradiation time is obtained. The irradiation time of ultrasonic waves is practically 10000 seconds or less. Further, if it is necessary for 10000 seconds or more, the load on the process is large, and in practice, it is necessary to shorten the emulsification dispersion time by reselecting the emulsifier. Therefore, more than 10,000 seconds are not necessary. More preferably, it is 10 seconds or more and 2000 seconds or less.

  Disperser mixers, homomixers, ultramixers, and the like can be used as the emulsifying and dispersing apparatus by high-speed rotational shearing. These types can be used properly depending on the liquid viscosity at the time of emulsifying dispersion.

For emulsification and dispersion at high pressure, LAB2000 (manufactured by SMT) can be used, but the emulsification and dispersion capacity depends on the pressure applied to the sample. The pressure is preferably in the range of 10 ⁴ kPa to ⁵ × 10 ⁵ kPa.

  As the active agent, a cationic surfactant, an anionic surfactant, an amphoteric surfactant, a polymer dispersant, and the like can be used, and can be determined according to the particle size of the solvent or the target emulsion. .

  In the air drying method, for example, a solution in which a cellulose resin and an additive are dissolved is sprayed and dried using a spray dryer such as GS310 (manufactured by Yamato Scientific Co., Ltd.).

  In the solvent coprecipitation method, a solution in which a cellulose resin and an additive are dissolved is added to a solution that is a poor solvent for the cellulose resin and the additive and is precipitated. The poor solvent can be arbitrarily mixed with the solvent for dissolving the cellulose resin. The poor solvent may be a mixed solvent. Moreover, you may add a poor solvent in the solution of a cellulose resin and an additive.

  The mixture of the precipitated cellulose resin and additives can be separated by filtration, drying and separation.

  In the mixture of cellulose resin and additive, the particle size of the additive in the mixture is preferably 1 μm or less, more preferably 500 nm or less, and particularly preferably 200 nm or less. The smaller the particle size of the additive, the more preferable is the uniform distribution of mechanical and optical properties of the melt-formed product.

  The mixture of the cellulose resin and the additive and the additive added at the time of heating and melting are desirably dried before or at the time of heating and melting. Here, drying is the removal of either the water or solvent used in preparing the mixture of the cellulose resin and additive, or the solvent mixed during synthesis of the additive, in addition to the moisture absorbed by any of the molten materials. Sure.

  As this removal method, a known drying method can be applied, and it can be performed by a method such as a heating method, a decompression method, a heating decompression method, or the like, and may be performed in air or in an atmosphere where nitrogen is selected as an inert gas. When performing these known drying methods, it is preferable in terms of film quality to be performed in a temperature range where the material does not decompose.

  For example, the moisture or solvent remaining after the removal in the drying step is 5% by mass or less, preferably 1% by mass or less, more preferably 0.1% by mass or less, based on the total mass of the film constituting material. More preferably, it is 0.01 mass% or less. The drying temperature at this time is preferably 100 ° C. or higher and Tg or lower of the material to be dried. Including the viewpoint of avoiding fusion between the materials, the drying temperature is more preferably 100 ° C. or higher (Tg-5) ° C. or lower, and still more preferably 110 ° C. or higher (Tg-20) ° C. or lower. A preferable drying time is 0.5 to 24 hours, more preferably 1 to 18 hours, and still more preferably 1.5 to 12 hours. Below these ranges, the degree of drying may be low, or the drying time may be too long. Also, when Tg is present in the material to be dried, heating to a drying temperature higher than Tg may cause the material to fuse and make handling difficult.

  The drying process may be separated into two or more stages. For example, the film may be melted and formed through storage of the material in the preliminary drying process and the immediately preceding drying process performed immediately before the melt film formation to 1 week before.

(Other additives)
Other additives include the above-mentioned polymers, plasticizers, UV absorbers, antioxidants, acid scavengers, light stabilizers, peroxide decomposers, radical scavengers, metal deactivators, matting agents, etc. Examples include metal compounds, retardation adjusting agents, dyes, and pigments. Moreover, if it has the said function, the additive which is not classified into this is also used.

  It is represented by coloring and molecular weight reduction, including decomposition reactions that have not been elucidated, such as oxidation prevention of film constituent materials, capture of acid generated by decomposition, suppression or prohibition of decomposition reaction due to radical species due to light or heat, etc. Additives are used in order to suppress the generation of volatile components due to deterioration or material decomposition, and to impart functions such as moisture permeability and slipperiness.

  On the other hand, when the film constituent material is heated and melted, the decomposition reaction becomes remarkable, and this decomposition reaction may be accompanied by strength deterioration of the constituent material due to coloring or molecular weight reduction. Moreover, generation | occurrence | production of an unfavorable volatile component may occur by the decomposition reaction of a film constituent material.

  When the film constituent material is heated and melted, it preferably contains the above-mentioned additives, which is excellent in terms of suppressing the deterioration of the strength based on the deterioration or decomposition of the material or maintaining the inherent strength of the material. .

  Moreover, the above-mentioned additive is effective in suppressing coloring, maintaining high transmittance and low haze value during heating and melting. This includes the use of nitrogen or argon as an inert gas as a known technique, degassing operation under reduced pressure to vacuum, and operation under a sealed environment, and at least one of these three methods includes the above additives. It can be used in combination with the method. By reducing the probability that the film constituent material comes into contact with oxygen in the air, deterioration of the material can be suppressed, which is preferable for the purpose of the present invention.

  Since the optical film or the optical compensation film of the present invention is used as a polarizing plate protective film, it is also included in the film constituent material from the viewpoint of improving the storage stability with respect to the polarizing plate and the polarizer constituting the polarizing plate of the present invention. It is preferable that the above-mentioned additives are present.

  In the liquid crystal display device using the polarizing plate of the present invention, since the above-mentioned additive is present in the optical film or the optical compensation film of the present invention, the aging of the optical film or the optical compensation film is performed from the viewpoint of suppressing the above-mentioned deterioration and deterioration. In addition to improving the storage stability, it is excellent in improving the display quality of the liquid crystal display device in that an optical compensation design provided with an optical film or an optical compensation film can exhibit a function over a long period.

  Hereinafter, the additive will be described in more detail.

(Antioxidant)
The antioxidant used in the present invention will be described.

  Antioxidants include phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants, heat-resistant processing stabilizers, oxygen scavengers, etc. Among them, phenolic antioxidants, particularly alkyl-substituted phenolic compounds Antioxidants are preferred. By blending these antioxidants, it is possible to prevent coloration and strength reduction of the molded product due to heat during molding or oxidative degradation without lowering transparency, heat resistance and the like. These antioxidants can be used alone or in combination of two or more, and the blending amount thereof is appropriately selected within a range not impairing the object of the present invention, but the polymer 100 according to the present invention. Preferably it is 0.001-5 mass parts with respect to a mass part, More preferably, it is 0.01-1 mass part.

  As the antioxidant, a hindered phenol antioxidant compound is preferable, for example, a 2,6-dialkylphenol such as those described in columns 12 to 14 of US Pat. No. 4,839,405. Derivative compounds are included. Such compounds include those of the following general formula (7).

  In the above formula, R 1, R 2 and R 3 represent a further substituted or unsubstituted alkyl substituent. Specific examples of hindered phenol compounds include n-octadecyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) -propionate, n-octadecyl 3- (3,5-di-t-butyl- 4-hydroxyphenyl) -acetate, n-octadecyl 3,5-di-tert-butyl-4-hydroxybenzoate, n-hexyl 3,5-di-tert-butyl-4-hydroxyphenylbenzoate, n-dodecyl 3, 5-di-t-butyl-4-hydroxyphenylbenzoate, neo-dodecyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, dodecyl β (3,5-di-t-butyl- 4-hydroxyphenyl) propionate, ethyl α- (4-hydroxy-3,5-di-t-butylphenyl) isobutyrate, octa Sil α- (4-hydroxy-3,5-di-t-butylphenyl) isobutyrate, octadecyl α- (4-hydroxy-3,5-di-t-butyl-4-hydroxyphenyl) propionate, 2- (n -Octylthio) ethyl 3,5-di-t-butyl-4-hydroxy-benzoate, 2- (n-octylthio) ethyl 3,5-di-t-butyl-4-hydroxy-phenylacetate, 2- (n- Octadecylthio) ethyl 3,5-di-t-butyl-4-hydroxyphenyl acetate, 2- (n-octadecylthio) ethyl 3,5-di-t-butyl-4-hydroxy-benzoate, 2- (2- Hydroxyethylthio) ethyl 3,5-di-t-butyl-4-hydroxybenzoate, diethyl glycol bis- (3,5-di-t-butyl- -Hydroxy-phenyl) propionate, 2- (n-octadecylthio) ethyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, stearamide N, N-bis- [ethylene 3- (3 5-di-t-butyl-4-hydroxyphenyl) propionate], n-butylimino N, N-bis- [ethylene 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2- (2-stearoyloxyethylthio) ethyl 3,5-di-tert-butyl-4-hydroxybenzoate, 2- (2-stearoyloxyethylthio) ethyl 7- (3-methyl-5-tert-butyl-4- Hydroxyphenyl) heptanoate, 1,2-propylene glycol bis- [3- (3,5-di-t-butyl-4-hydroxy Enyl) propionate], ethylene glycol bis- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], neopentyl glycol bis- [3- (3,5-di-t-butyl-) 4-hydroxyphenyl) propionate], ethylene glycol bis- (3,5-di-t-butyl-4-hydroxyphenyl acetate), glycerin-1-n-octadecanoate-2,3-bis- (3 5-di-t-butyl-4-hydroxyphenyl acetate), pentaerythritol-tetrakis- [3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate], 1,1,1 -Trimethylolethane-tris- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], sorbite Hexa- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2-hydroxyethyl 7- (3-methyl-5-t-butyl-4-hydroxyphenyl) propionate, 2- Stearoyloxyethyl 7- (3-methyl-5-t-butyl-4-hydroxyphenyl) heptanoate, 1,6-n-hexanediol-bis [(3 ′, 5′-di-t-butyl-4-hydroxy Phenyl) propionate], pentaerythritol-tetrakis (3,5-di-t-butyl-4-hydroxyhydrocinnamate). Hindered phenolic antioxidant compounds of the above type are commercially available, for example, from Ciba Specialty Chemicals under the trade names “Irganox 1076” and “Irganox 1010”.

  Specific examples of other antioxidants include phosphorus antioxidants such as trisnonylphenyl phosphite, triphenyl phosphite, tris (2,4-di-tert-butylphenyl) phosphite, and dilauryl-3. , 3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, pentaerythrityltetrakis (3-laurylthiopropionate), etc. System antioxidant, 2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2- [1- (2-hydroxy-3,5- Di-tert-pentylphenyl) ethyl] -4,6-di-tert-pentylphenyl acrylate 3,4-dihydro-2H-1-benzopyran compound, 3,3′-spirodichroman compound, 1,1-spiroindane compound, morpholine, thiomorpholine, thiomorpholine oxide described in JP-B-8-27508, Examples include thiomorpholine dioxide, compounds having a piperazine skeleton in the partial structure, oxygen scavengers such as dialkoxybenzene compounds described in JP-A-3-174150, and the like. These antioxidant partial structures may be part of the polymer or may be regularly pendant to the polymer and introduced into part of the molecular structure of additives such as plasticizers, acid scavengers, UV absorbers, etc. May be.

(Acid scavenger)
The acid scavenger preferably comprises an epoxy compound as an acid scavenger described in US Pat. No. 4,137,201. Epoxy compounds as such acid scavengers are known in the art and are derived by condensation of various polyglycol diglycidyl ethers, particularly about 8-40 moles of ethylene oxide per mole of polyglycol. Glycol, diglycidyl ether of glycerol, metal epoxy compounds (such as those conventionally used in and together with vinyl chloride polymer compositions), epoxidized ether condensation products, diphenols of bisphenol A Glycidyl ether (i.e., 4,4'-dihydroxydiphenyldimethylmethane), epoxidized unsaturated fatty acid ester (especially an ester of an alkyl of about 4 to 2 carbon atoms of a fatty acid of 2 to 22 carbon atoms (e.g. butyl Epoxy stearate) ), And various epoxidized long chain fatty acid triglycerides and the like (e.g., epoxidized vegetable oils and other unsaturated natural oils, which may be represented and exemplified by compositions such as epoxidized soybean oil, sometimes epoxidized natural) These are referred to as glycerides or unsaturated fatty acids, which generally contain 12 to 22 carbon atoms)). Particularly preferred are commercially available epoxy group-containing epoxide resin compounds EPON815c (produced by miller-stephenson chemical company, Inc.) and other epoxidized ether oligomer condensation products of the general formula (8).

  In the above formula, n is equal to 0-12. Further possible acid scavengers that can be used include those described in paragraphs 87 to 105 of JP-A-5-194788.

(Light stabilizer)
Light stabilizers include hindered amine light stabilizer (HALS) compounds, which are known compounds, such as columns 5-11 of US Pat. No. 4,619,956 and US Pat. , 839,405, as described in columns 3 to 5, including 2,2,6,6-tetraalkylpiperidine compounds, or acid addition salts thereof or complexes of them with metal compounds It is. Such compounds include those of the following general formula (9).

  In the above formula, R1 and R2 are H or a substituent. Specific examples of hindered amine light stabilizer compounds include 4-hydroxy-2,2,6,6-tetramethylpiperidine, 1-allyl-4-hydroxy-2,2,6,6-tetramethylpiperidine, 1-benzyl. -4-hydroxy-2,2,6,6-tetramethylpiperidine, 1- (4-tert-butyl-2-butenyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine, 4-stearoyl Oxy-2,2,6,6-tetramethylpiperidine, 1-ethyl-4-salicyloyloxy-2,2,6,6-tetramethylpiperidine, 4-methacryloyloxy-1,2,2,6 6-pentamethylpiperidine, 1,2,2,6,6-pentamethylpiperidin-4-yl-β (3,5-di-t-butyl-4-hydroxyphenyl) -propionate, -Benzyl-2,2,6,6-tetramethyl-4-piperidinyl maleate, (di-2,2,6,6-tetramethylpiperidin-4-yl) -adipate, (di- 2,2,6,6-tetramethylpiperidin-4-yl) -sebacate, (di-1,2,3,6-tetramethyl-2,6-diethyl-piperidin-4-yl) -sebacate, (di -1-allyl-2,2,6,6-tetramethyl-piperidin-4-yl) -phthalate, 1-acetyl-2,2,6,6-tetramethylpiperidin-4-yl-acetate, trimellitic acid- Tri- (2,2,6,6-tetramethylpiperidin-4-yl) ester, 1-acryloyl-4-benzyloxy-2,2,6,6-tetramethylpiperidine, dibutyl-malonic acid-di -(1,2,2,6,6-pentamethyl-piperidin-4-yl) -ester, dibenzyl-malonic acid-di- (1,2,3,6-tetramethyl-2,6-diethyl-piperidine- 4-yl) -ester, dimethyl-bis- (2,2,6,6-tetramethylpiperidine-4-oxy) -silane, tris- (1-propyl-2,2,6,6-tetramethylpiperidine- 4-yl) -phosphite, tris- (1-propyl-2,2,6,6-tetramethylpiperidin-4-yl) -phosphate, N, N′-bis- (2,2,6,6- Tetramethylpiperidin-4-yl) -hexamethylene-1,6-diamine, N, N′-bis- (2,2,6,6-tetramethylpiperidin-4-yl) -hexamethylene-1,6- Diacetamide, 1-acetyl -4- (N-cyclohexylacetamide) -2,2,6,6-tetramethyl-piperidine, 4-benzylamino-2,2,6,6-tetramethylpiperidine, N, N'-bis- (2, 2,6,6-tetramethylpiperidin-4-yl) -N, N′-dibutyl-adipamide, N, N′-bis- (2,2,6,6-tetramethylpiperidin-4-yl) -N , N′-dicyclohexyl- (2-hydroxypropylene), N, N′-bis- (2,2,6,6-tetramethylpiperidin-4-yl) -p-xylylene-diamine, 4- (bis-2 -Hydroxyethyl) -amino-1,2,2,6,6-pentamethylpiperidine, 4-methacrylamide-1,2,2,6,6-pentamethylpiperidine, α-cyano-β-methyl-β- [N- (2,2 6,6-tetramethyl-piperidin-4-yl)] - amino - acrylic acid methyl ester. Examples of preferred hindered amine light stabilizers include the following HALS-1 and HALS-2.

  These hindered amine light resistance stabilizers can be used alone or in combination of two or more, and used in combination with these hindered amine light resistance stabilizers and additives such as plasticizers, acid scavengers, and UV absorbers. Alternatively, it may be introduced into a part of the molecular structure of the additive. The blending amount is appropriately selected within a range not impairing the object of the present invention, but is preferably 0.01 to 10% by mass, more preferably 0.01 to 5% by mass, and particularly preferably 0.05 in the film. ˜1% by mass.

(Retardation adjuster)
In order to improve the liquid crystal display quality, the optical film or the optical compensation film of the present invention is provided with a liquid crystal layer by adding a retardation adjusting agent or forming an alignment film in the optical compensation film. And optical retardation can be imparted by combining the retardation derived from the liquid crystal layer. In particular, the retardation adjusting agent can be expected to be effective in coloring the film and reducing haze in that it can provide a desired phase difference without excessive stretching.

  As the compound to be added for adjusting the retardation, an aromatic compound having two or more aromatic rings as described in the specification of European Patent 911,656A2 can be used as a retardation adjusting agent. For example, the following rod-shaped compounds are mentioned. Two or more aromatic compounds may be used in combination. The aromatic ring of the aromatic compound includes an aromatic heterocyclic ring in addition to the aromatic hydrocarbon ring. In particular, an aromatic heterocyclic ring is preferable, and the aromatic heterocyclic ring is generally an unsaturated heterocyclic ring. Of these, a 1,3,5-triazine ring is preferred.

<Bar compound>
The optical film or optical compensation film of the present invention, particularly the optical compensation film, preferably contains a rod-shaped compound having a maximum absorption wavelength (λmax) of the ultraviolet absorption spectrum of the solution shorter than 250 nm.

  From the viewpoint of the function of the retardation adjusting agent, the rod-like compound preferably has at least one aromatic ring, and more preferably has at least two aromatic rings. The rod-like compound preferably has a linear molecular structure. The linear molecular structure means that the molecular structure of the rod-like compound is linear in the most thermodynamically stable structure. The most thermodynamically stable structure can be obtained by crystal structure analysis or molecular orbital calculation. For example, molecular orbital calculation is performed using molecular orbital calculation software (for example, WinMOPAC2000, manufactured by Fujitsu Limited), and a molecular structure that minimizes the heat of formation of a compound can be obtained. The molecular structure being linear means that the angle of the molecular structure is 140 degrees or more in the thermodynamically most stable structure obtained by calculation as described above. The rod-shaped compound preferably exhibits liquid crystallinity. More preferably, the rod-like compound exhibits liquid crystallinity upon heating (has thermotropic liquid crystallinity). The liquid crystal phase is preferably a nematic phase or a smectic phase.

  As the rod-like compound, a trans-1,4-cyclohexanedicarboxylic acid ester compound represented by the following general formula (10) is preferable.

Formula (10) Ar ¹ -L ¹ -Ar ²
In Formula (10), Ar ¹ and Ar ² are each independently an aromatic group. In the present specification, the aromatic group includes an aryl group (aromatic hydrocarbon group), a substituted aryl group, an aromatic heterocyclic group, and a substituted aromatic heterocyclic group. An aryl group and a substituted aryl group are more preferable than an aromatic heterocyclic group and a substituted aromatic heterocyclic group. The heterocycle of the aromatic heterocyclic group is generally unsaturated. The aromatic heterocycle is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring. Aromatic heterocycles generally have the most double bonds. As a hetero atom, a nitrogen atom, an oxygen atom or a sulfur atom is preferable, and a nitrogen atom or a sulfur atom is more preferable. Examples of aromatic heterocycles include furan ring, thiophene ring, pyrrole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, pyrazole ring, furazane ring, triazole ring, pyran ring, pyridine Rings, pyridazine rings, pyrimidine rings, pyrazine rings, and 1,3,5-triazine rings are included. As the aromatic ring of the aromatic group, a benzene ring, a furan ring, a thiophene ring, a pyrrole ring, an oxazole ring, a thiazole ring, an imidazole ring, a triazole ring, a pyridine ring, a pyrimidine ring and a pyrazine ring are preferable, and a benzene ring is particularly preferable. .

  Examples of substituents for substituted aryl groups and substituted aromatic heterocyclic groups include halogen atoms (F, Cl, Br, I), hydroxyl, carboxyl, cyano, amino, alkylamino groups (eg, methylamino, ethylamino) , Butylamino, dimethylamino), nitro, sulfo, carbamoyl, alkylcarbamoyl groups (eg, N-methylcarbamoyl, N-ethylcarbamoyl, N, N-dimethylcarbamoyl), sulfamoyl, alkylsulfamoyl groups (eg, N- Methylsulfamoyl, N-ethylsulfamoyl, N, N-dimethylsulfamoyl), ureido, alkylureido groups (eg, N-methylureido, N, N-dimethylureido, N, N, N′-trimethyl) Ureido), alkyl groups (eg, methyl, ethyl, propyl, butyl, pentyl, Butyl, octyl, isopropyl, s-butyl, t-amyl, cyclohexyl, cyclopentyl), alkenyl groups (eg, vinyl, allyl, hexenyl), alkynyl groups (eg, ethynyl, butynyl), acyl groups (eg, formyl, acetyl, Butyryl, hexanoyl, lauryl), acyloxy groups (eg, acetoxy, butyryloxy, hexanoyloxy, lauryloxy), alkoxy groups (eg, methoxy, ethoxy, propoxy, butoxy, pentyloxy, heptyloxy, octyloxy), aryloxy groups (Eg, phenoxy), alkoxycarbonyl group (eg, methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, pentyloxycarbonyl, heptyloxycarbonyl), aryloxycarbo Group (eg, phenoxycarbonyl), alkoxycarbonylamino group (eg, butoxycarbonylamino, hexyloxycarbonylamino), alkylthio group (eg, methylthio, ethylthio, propylthio, butylthio, pentylthio, heptylthio, octylthio), arylthio group (eg, , Phenylthio), alkylsulfonyl groups (eg, methylsulfonyl, ethylsulfonyl, propylsulfonyl, butylsulfonyl, pentylsulfonyl, heptylsulfonyl, octylsulfonyl), amide groups (eg, acetamide, butylamide group, hexylamide, laurylamide) and non- Aromatic heterocyclic groups (eg, morpholyl, pyrazinyl) are included.

  Substituents for substituted aryl groups and substituted aromatic heterocyclic groups include halogen atoms, cyano, carboxyl, hydroxyl, amino, alkyl-substituted amino groups, acyl groups, acyloxy groups, amide groups, alkoxycarbonyl groups, alkoxy groups, alkylthios. And groups and alkyl groups are preferred. The alkyl moiety of the alkylamino group, alkoxycarbonyl group, alkoxy group, and alkylthio group and the alkyl group may further have a substituent. Examples of alkyl moieties and substituents of alkyl groups include halogen atoms, hydroxyl, carboxyl, cyano, amino, alkylamino groups, nitro, sulfo, carbamoyl, alkylcarbamoyl groups, sulfamoyl, alkylsulfamoyl groups, ureido, alkylureido Group, alkenyl group, alkynyl group, acyl group, acyloxy group, alkoxy group, aryloxy group, alkoxycarbonyl group, aryloxycarbonyl group, alkoxycarbonylamino group, alkylthio group, arylthio group, alkylsulfonyl group, amide group and non-aromatic An aromatic heterocyclic group is included. As the substituent for the alkyl moiety and the alkyl group, a halogen atom, hydroxyl, amino, alkylamino group, acyl group, acyloxy group, acylamino group, alkoxycarbonyl group and alkoxy group are preferable.

In Formula (10), L ¹ is a divalent linking group selected from the group consisting of an alkylene group, an alkenylene group, an alkynylene group, a divalent saturated heterocyclic group, —O—, —CO—, and combinations thereof. is there. The alkylene group may have a cyclic structure. As the cyclic alkylene group, cyclohexylene is preferable, and 1,4-cyclohexylene is particularly preferable. As the chain alkylene group, a linear alkylene group is more preferable than a branched alkylene group. The number of carbon atoms of the alkylene group is preferably 1-20, more preferably 1-15, still more preferably 1-10, still more preferably 1-8, 6 is most preferred.

  The alkenylene group and the alkynylene group preferably have a chain structure rather than a cyclic structure, and more preferably have a linear structure rather than a branched chain structure. The number of carbon atoms in the alkenylene group and the alkynylene group is preferably 2 to 10, more preferably 2 to 8, still more preferably 2 to 6, and still more preferably 2 to 4. Most preferred is 2 (vinylene or ethynylene). The divalent saturated heterocyclic group preferably has a 3- to 9-membered heterocyclic ring. The hetero atom of the hetero ring is preferably an oxygen atom, a nitrogen atom, a boron atom, a sulfur atom, a silicon atom, a phosphorus atom or a germanium atom. Examples of saturated heterocycles include piperidine ring, piperazine ring, morpholine ring, pyrrolidine ring, imidazolidine ring, tetrahydrofuran ring, tetrahydropyran ring, 1,3-dioxane ring, 1,4-dioxane ring, tetrahydrothiophene ring, 1 , 3-thiazolidine ring, 1,3-oxazolidine ring, 1,3-dioxolane ring, 1,3-dithiolane ring and 1,3,2-dioxaborolane. Particularly preferred divalent saturated heterocyclic groups are piperazine-1,4-diylene, 1,3-dioxane-2,5-diylene and 1,3,2-dioxaborolane-2,5-diylene.

  The example of the bivalent coupling group which consists of a combination is shown.

L-1: —O—CO-alkylene group —CO—O—
L-2: -CO-O-alkylene group -O-CO-
L-3: —O—CO—alkenylene group —CO—O—
L-4: -CO-O-alkenylene group -O-CO-
L-5: -O-CO-alkynylene group -CO-O-
L-6: -CO-O-alkynylene group -O-CO-
L-7: -O-CO-divalent saturated heterocyclic group -CO-O-
L-8: -CO-O-divalent saturated heterocyclic group -O-CO-
In the molecular structure of the general formula (10), the angle formed by Ar ¹ and Ar ² across L ¹ is preferably 140 degrees or more. As the rod-like compound, a compound represented by the following general formula (11) is more preferable.

Formula (11) Ar ¹ -L ² -XL ³ -Ar ²
In formula (11), Ar ¹ and Ar ² are each independently an aromatic group. The definition and examples of the aromatic group are the same as those for Ar ¹ and Ar ² in formula (10).

In Formula (11), L ² and L ³ are each independently a divalent linking group selected from the group consisting of an alkylene group, —O—, —CO—, and combinations thereof. The alkylene group preferably has a chain structure rather than a cyclic structure, and more preferably has a linear structure rather than a branched chain structure. The number of carbon atoms of the alkylene group is preferably 1 to 10, more preferably 1 to 8, still more preferably 1 to 6, still more preferably 1 to 4, and 1 or Most preferred is 2 (methylene or ethylene). L ² and L ³ are particularly preferably —O—CO— or —CO—O—.

  In the formula (11), X is 1,4-cyclohexylene, vinylene or ethynylene. Specific examples of the compound represented by formula (10) are shown below.

  Specific examples (1) to (34), (41), (42), (46), (47), (52), (53) are two asymmetric carbons at the 1st and 4th positions of the cyclohexane ring. Has atoms. However, the specific examples (1), (4) to (34), (41), (42), (46), (47), (52), (53) have a symmetric meso type molecular structure. Therefore, there is no optical isomer (optical activity) and only geometric isomers (trans and cis forms) exist. The trans type (1-trans) and cis type (1-cis) of specific example (1) are shown below.

  As described above, the rod-like compound preferably has a linear molecular structure. Therefore, the trans type is preferable to the cis type. Specific examples (2) and (3) have optical isomers (a total of four isomers) in addition to geometric isomers. As for geometric isomers, the trans type is similarly preferable to the cis type. The optical isomer is not particularly superior or inferior, and may be D, L, or a racemate. In specific examples (43) to (45), the central vinylene bond includes a trans type and a cis type. For the same reason as above, the trans type is preferable to the cis type.

  Two or more rod-shaped compounds having a maximum absorption wavelength (λmax) shorter than 250 nm in the ultraviolet absorption spectrum of the solution may be used in combination. The rod-shaped compound can be synthesized with reference to methods described in the literature. As literature, Mol. Cryst. Liq. Cryst. 53, 229 (1979), 89, 93 (1982), 145, 111 (1987), 170, 43 (1989); Am. Chem. Soc. 113, p. 1349 (1991), p. 118, p. 5346 (1996), p. 92, p. 1582 (1970). Org. Chem. 40, 420 (1975), Tetrahedron, 48, 16, 3437 (1992).

  In addition, as the discotic compound used in the present invention, a compound having a 1,3,5-triazine ring can be preferably used.

  Among them, the compound having a 1,3,5-triazine ring is preferably a compound represented by the following general formula (12).

In the general formula (12), X ¹ is a single bond, —NR ₄ —, —O— or —S—; X ² is a single bond, —NR ₅ —, —O— or —S—; X ³ is a single bond, —NR ₆ —, —O— or —S—; R ¹ , R ² and R ³ are an alkyl group, an alkenyl group, an aryl group or a heterocyclic group; and R ₄ , R ₅ and R ₆ are a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, or a heterocyclic group. The compound represented by the general formula (12) is particularly preferably a melamine compound.

In the melamine compound, in the general formula (12), X ¹ , X ² and X ³ are —NR ₄ —, —NR ₅ — and —NR ₆ —, respectively, or X ¹ , X ² and X 3 ³ is a single bond, and R ¹ , R ² and R ³ are heterocyclic groups having a free valence on the nitrogen atom. ^{-X 1 -R 1, -X 2 -R} 2 and -X ³ -R ³ are preferably the same substituents. R ¹ , R ² and R ³ are particularly preferably aryl groups. R ₄ , R ₅ and R ₆ are particularly preferably a hydrogen atom.

  The alkyl group is preferably a chain alkyl group rather than a cyclic alkyl group. A linear alkyl group is preferred to a branched alkyl group.

  The number of carbon atoms of the alkyl group is preferably 1-30, more preferably 1-20, still more preferably 1-10, still more preferably 1-8, 6 is most preferred. The alkyl group may have a substituent.

  Specific examples of the substituent include a halogen atom, an alkoxy group (for example, each group such as methoxy, ethoxy, and epoxyethyloxy) and an acyloxy group (for example, acryloyloxy, methacryloyloxy). The alkenyl group is preferably a chain alkenyl group rather than a cyclic alkenyl group. A linear alkenyl group is preferable to a branched chain alkenyl group. The number of carbon atoms in the alkenyl group is preferably 2 to 30, more preferably 2 to 20, still more preferably 2 to 10, still more preferably 2 to 8, 6 is most preferred. The alkenyl group may have a substituent.

  Specific examples of the substituent include a halogen atom, an alkoxy group (for example, each group such as methoxy, ethoxy, and epoxyethyloxy) or an acyloxy group (for example, each group such as acryloyloxy and methacryloyloxy).

  The aryl group is preferably a phenyl group or a naphthyl group, and particularly preferably a phenyl group. The aryl group may have a substituent.

  Specific examples of the substituent include, for example, a halogen atom, hydroxyl, cyano, nitro, carboxyl, alkyl group, alkenyl group, aryl group, alkoxy group, alkenyloxy group, aryloxy group, acyloxy group, alkoxycarbonyl group, alkenyloxy Carbonyl group, aryloxycarbonyl group, sulfamoyl, alkyl-substituted sulfamoyl group, alkenyl-substituted sulfamoyl group, aryl-substituted sulfamoyl group, sulfonamido group, carbamoyl, alkyl-substituted carmoyl group, alkenyl-substituted carbamoyl group, aryl-substituted carbamoyl group, amide group, alkylthio Groups, alkenylthio groups, arylthio groups and acyl groups are included. The said alkyl group is synonymous with the alkyl group mentioned above.

  The alkyl group of the alkoxy group, acyloxy group, alkoxycarbonyl group, alkyl-substituted sulfamoyl group, sulfonamido group, alkyl-substituted carbamoyl group, amide group, alkylthio group and acyl group is also synonymous with the alkyl group described above.

  The said alkenyl group is synonymous with the alkenyl group mentioned above.

  The alkenyl part of the alkenyloxy group, acyloxy group, alkenyloxycarbonyl group, alkenyl-substituted sulfamoyl group, sulfonamido group, alkenyl-substituted carbamoyl group, amide group, alkenylthio group and acyl group is also synonymous with the alkenyl group described above.

  Specific examples of the aryl group include phenyl, α-naphthyl, β-naphthyl, 4-methoxyphenyl, 3,4-diethoxyphenyl, 4-octyloxyphenyl, and 4-dodecyloxyphenyl. Can be mentioned.

  Examples of the aryloxy group, acyloxy group, aryloxycarbonyl group, aryl-substituted sulfamoyl group, sulfonamido group, aryl-substituted carbamoyl group, amide group, arylthio group, and acyl group are the same as the above aryl group.

When X ¹ , X ² or X ³ is —NR—, —O— or —S—, the heterocyclic group preferably has aromaticity.

  The heterocyclic ring in the heterocyclic group having aromaticity is generally an unsaturated heterocyclic ring, preferably a heterocyclic ring having the largest number of double bonds. The heterocyclic ring is preferably a 5-membered ring, a 6-membered ring or a 7-membered ring, more preferably a 5-membered ring or a 6-membered ring, and most preferably a 6-membered ring.

  The hetero atom in the heterocyclic ring is preferably each atom such as N, S or O, and particularly preferably an N atom.

  As the heterocyclic ring having aromaticity, a pyridine ring (as the heterocyclic group, for example, each group such as 2-pyridyl or 4-pyridyl) is particularly preferable. The heterocyclic group may have a substituent. Examples of the substituent of the heterocyclic group are the same as the examples of the substituent of the aryl moiety.

When X ¹ , X ² or X ³ is a single bond, the heterocyclic group is preferably a heterocyclic group having a free valence on the nitrogen atom. The heterocyclic group having a free valence on the nitrogen atom is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring, and a 5-membered ring. Is most preferred. The heterocyclic group may have a plurality of nitrogen atoms.

  Moreover, the hetero atom in a heterocyclic group may have hetero atoms other than a nitrogen atom (for example, O atom, S atom). The heterocyclic group may have a substituent. Specific examples of the substituent of the heterocyclic group are the same as the specific examples of the substituent of the aryl moiety.

  Specific examples of the heterocyclic group having a free valence on the nitrogen atom are shown below.

  The molecular weight of the compound having a 1,3,5-triazine ring is preferably 300 to 2,000. The boiling point of the compound is preferably 260 ° C. or higher. The boiling point can be measured using a commercially available measuring device (for example, TG / DTA100, manufactured by Seiko Electronics Industry Co., Ltd.).

  Specific examples of the compound having a 1,3,5-triazine ring are shown below.

  In addition, several R shown below represents the same group.

(1) Butyl (2) 2-Methoxy-2-ethoxyethyl (3) 5-Undecenyl (4) Phenyl (5) 4-Ethoxycarbonylphenyl (6) 4-Butoxyphenyl (7) p-Biphenylyl (8) 4 -Pyridyl (9) 2-naphthyl (10) 2-methylphenyl (11) 3,4-dimethoxyphenyl (12) 2-furyl

(14) phenyl (15) 3-ethoxycarbonylphenyl (16) 3-butoxyphenyl (17) m-biphenylyl (18) 3-phenylthiophenyl (19) 3-chlorophenyl (20) 3-benzoylphenyl (21) 3 -Acetoxyphenyl (22) 3-benzoyloxyphenyl (23) 3-phenoxycarbonylphenyl (24) 3-methoxyphenyl (25) 3-anilinophenyl (26) 3-isobutyrylaminophenyl (27) 3-phenoxy Carbonylaminophenyl (28) 3- (3-ethylureido) phenyl (29) 3- (3,3-diethylureido) phenyl (30) 3-methylphenyl (31) 3-phenoxyphenyl (32) 3-hydroxyphenyl (33) 4-Ethoxycarbonylphenyl (34) 4-butoxyphenyl (35) p-biphenylyl (36) 4-phenylthiophenyl (37) 4-chlorophenyl (38) 4-benzoylphenyl (39) 4-acetoxyphenyl (40) 4-benzoyloxyphenyl ( 41) 4-phenoxycarbonylphenyl (42) 4-methoxyphenyl (43) 4-anilinophenyl (44) 4-isobutyrylaminophenyl (45) 4-phenoxycarbonylaminophenyl (46) 4- (3-ethyl (Ureido) phenyl (47) 4- (3,3-diethylureido) phenyl (48) 4-methylphenyl (49) 4-phenoxyphenyl (50) 4-hydroxyphenyl (51) 3,4-diethoxycarbonylphenyl ( 52) 3,4-dibutoxyphenyl (53) 3 -Diphenylphenyl (54) 3,4-diphenylthiophenyl (55) 3,4-dichlorophenyl (56) 3,4-dibenzoylphenyl (57) 3,4-diacetoxyphenyl (58) 3,4-dibenzoyl Oxyphenyl (59) 3,4-diphenoxycarbonylphenyl (60) 3,4-dimethoxyphenyl (61) 3,4-dianilinophenyl (62) 3,4-dimethylphenyl (63) 3,4-diphenoxy Phenyl (64) 3,4-dihydroxyphenyl (65) 2-naphthyl (66) 3,4,5-triethoxycarbonylphenyl (67) 3,4,5-tributoxyphenyl (68) 3,4,5- Triphenylphenyl (69) 3,4,5-triphenylthiophenyl (70) 3,4,5-trichlorophenyl (71) 3,4,5-tribenzoylphenyl (72) 3,4,5-triacetoxyphenyl (73) 3,4,5-tribenzoyloxyphenyl (74) 3,4,5-triphenoxycarbonylphenyl (75) 3,4,5-trimethoxyphenyl (76) 3,4,5-trianilinophenyl (77) 3,4,5-trimethylphenyl (78) 3,4,5-triphenoxyphenyl (79 ) 3,4,5-trihydroxyphenyl

(80) phenyl (81) 3-ethoxycarbonylphenyl (82) 3-butoxyphenyl (83) m-biphenylyl (84) 3-phenylthiophenyl (85) 3-chlorophenyl (86) 3-benzoylphenyl (87) 3 -Acetoxyphenyl (88) 3-benzoyloxyphenyl (89) 3-phenoxycarbonylphenyl (90) 3-methoxyphenyl (91) 3-anilinophenyl (92) 3-isobutyrylaminophenyl (93) 3-phenoxy Carbonylaminophenyl (94) 3- (3-ethylureido) phenyl (95) 3- (3,3-diethylureido) phenyl (96) 3-methylphenyl (97) 3-phenoxyphenyl (98) 3-hydroxyphenyl (99) 4-Ethoxycarbonylphenyl (100) 4-butoxyphenyl (101) p-biphenylyl (102) 4-phenylthiophenyl (103) 4-chlorophenyl (104) 4-benzoylphenyl (105) 4-acetoxyphenyl (106) 4-benzoyloxyphenyl ( 107) 4-phenoxycarbonylphenyl (108) 4-methoxyphenyl (109) 4-anilinophenyl (110) 4-isobutyrylaminophenyl (111) 4-phenoxycarbonylaminophenyl (112) 4- (3-ethyl (Ureido) phenyl (113) 4- (3,3-diethylureido) phenyl (114) 4-methylphenyl (115) 4-phenoxyphenyl (116) 4-hydroxyphenyl (117) 3,4-diethoxycarbonylphenyl ( 118) 3 , 4-dibutoxyphenyl (119) 3,4-diphenylphenyl (120) 3,4-diphenylthiophenyl (121) 3,4-dichlorophenyl (122) 3,4-dibenzoylphenyl (123) 3,4- Diacetoxyphenyl (124) 3,4-dibenzoyloxyphenyl (125) 3,4-diphenoxycarbonylphenyl (126) 3,4-dimethoxyphenyl (127) 3,4-dianilinophenyl (128) 3,4 -Dimethylphenyl (129) 3,4-diphenoxyphenyl (130) 3,4-dihydroxyphenyl (131) 2-naphthyl (132) 3,4,5-triethoxycarbonylphenyl (133) 3,4,5- Tributoxyphenyl (134) 3,4,5-triphenylphenyl (135) 3 4,5-triphenylthiophenyl (136) 3,4,5-trichlorophenyl (137) 3,4,5-tribenzoylphenyl (138) 3,4,5-triacetoxyphenyl (139) 3,4 5-tribenzoyloxyphenyl (140) 3,4,5-triphenoxycarbonylphenyl (141) 3,4,5-trimethoxyphenyl (142) 3,4,5-trianilinophenyl (143) 3,4 , 5-trimethylphenyl (144) 3,4,5-triphenoxyphenyl (145) 3,4,5-trihydroxyphenyl

(146) phenyl (147) 4-ethoxycarbonylphenyl (148) 4-butoxyphenyl (149) p-biphenylyl (150) 4-phenylthiophenyl (151) 4-chlorophenyl (152) 4-benzoylphenyl (153) 4 -Acetoxyphenyl (154) 4-benzoyloxyphenyl (155) 4-phenoxycarbonylphenyl (156) 4-methoxyphenyl (157) 4-anilinophenyl (158) 4-isobutyrylaminophenyl (159) 4-phenoxy Carbonylaminophenyl (160) 4- (3-ethylureido) phenyl (161) 4- (3,3-diethylureido) phenyl (162) 4-methylphenyl (163) 4-phenoxyphenyl (164) 4-hydroxyphenyl

(165) phenyl (166) 4-ethoxycarbonylphenyl (167) 4-butoxyphenyl (168) p-biphenylyl (169) 4-phenylthiophenyl (170) 4-chlorophenyl (171) 4-benzoylphenyl (172) 4 -Acetoxyphenyl (173) 4-benzoyloxyphenyl (174) 4-phenoxycarbonylphenyl (175) 4-methoxyphenyl (176) 4-anilinophenyl (177) 4-isobutyrylaminophenyl (178) 4-phenoxy Carbonylaminophenyl (179) 4- (3-ethylureido) phenyl (180) 4- (3,3-diethylureido) phenyl (181) 4-methylphenyl (182) 4-phenoxyphenyl (183) 4-hydroxyphenyl

(184) phenyl (185) 4-ethoxycarbonylphenyl (186) 4-butoxyphenyl (187) p-biphenylyl (188) 4-phenylthiophenyl (189) 4-chlorophenyl (190) 4-benzoylphenyl (191) 4 -Acetoxyphenyl (192) 4-benzoyloxyphenyl (193) 4-phenoxycarbonylphenyl (194) 4-methoxyphenyl (195) 4-anilinophenyl (196) 4-isobutyrylaminophenyl (197) 4-phenoxy Carbonylaminophenyl (198) 4- (3-ethylureido) phenyl (199) 4- (3,3-diethylureido) phenyl (200) 4-methylphenyl (201) 4-phenoxyphenyl (202) 4-hydroxyphenyl

(203) phenyl (204) 4-ethoxycarbonylphenyl (205) 4-butoxyphenyl (206) p-biphenylyl (207) 4-phenylthiophenyl (208) 4-chlorophenyl (209) 4-benzoylphenyl (210) 4 -Acetoxyphenyl (211) 4-benzoyloxyphenyl (212) 4-phenoxycarbonylphenyl (213) 4-methoxyphenyl (214) 4-anilinophenyl (215) 4-isobutyrylaminophenyl (216) 4-phenoxy Carbonylaminophenyl (217) 4- (3-ethylureido) phenyl (218) 4- (3,3-diethylureido) phenyl (219) 4-methylphenyl (220) 4-phenoxyphenyl (221) 4-hydroxyphenyl

(222) phenyl (223) 4-butylphenyl (224) 4- (2-methoxy-2-ethoxyethyl) phenyl (225) 4- (5-nonenyl) phenyl (226) p-biphenylyl (227) 4-ethoxy Carbonylphenyl (228) 4-butoxyphenyl (229) 4-methylphenyl (230) 4-chlorophenyl (231) 4-phenylthiophenyl (232) 4-benzoylphenyl (233) 4-acetoxyphenyl (234) 4-benzoyl Oxyphenyl (235) 4-phenoxycarbonylphenyl (236) 4-methoxyphenyl (237) 4-anilinophenyl (238) 4-isobutyrylaminophenyl (239) 4-phenoxycarbonylaminophenyl (240) 4- ( 3-ethylureido Phenyl (241) 4- (3,3-diethylureido) phenyl (242) 4-phenoxyphenyl (243) 4-hydroxyphenyl (244) 3-butylphenyl (245) 3- (2-methoxy-2-ethoxyethyl) ) Phenyl (246) 3- (5-nonenyl) phenyl (247) m-biphenylyl (248) 3-ethoxycarbonylphenyl (249) 3-butoxyphenyl (250) 3-methylphenyl (251) 3-chlorophenyl (252) 3-phenylthiophenyl (253) 3-benzoylphenyl (254) 3-acetoxyphenyl (255) 3-benzoyloxyphenyl (256) 3-phenoxycarbonylphenyl (257) 3-methoxyphenyl (258) 3-anilinophenyl (259) 3-I Butyrylaminophenyl (260) 3-phenoxycarbonylaminophenyl (261) 3- (3-ethylureido) phenyl (262) 3- (3,3-diethylureido) phenyl (263) 3-phenoxyphenyl (264) 3 -Hydroxyphenyl (265) 2-butylphenyl (266) 2- (2-methoxy-2-ethoxyethyl) phenyl (267) 2- (5-nonenyl) phenyl (268) o-biphenylyl (269) 2-ethoxycarbonyl Phenyl (270) 2-Butoxyphenyl (271) 2-Methylphenyl (272) 2-Chlorophenyl (273) 2-Phenylthiophenyl (274) 2-Benzoylphenyl (275) 2-Acetoxyphenyl (276) 2-Benzoyloxy Phenyl (277) 2 Phenoxycarbonylphenyl (278) 2-methoxyphenyl (279) 2-anilinophenyl (280) 2-isobutyrylaminophenyl (281) 2-phenoxycarbonylaminophenyl (282) 2- (3-ethylureido) phenyl ( 283) 2- (3,3-diethylureido) phenyl (284) 2-phenoxyphenyl (285) 2-hydroxyphenyl (286) 3,4-dibutylphenyl (287) 3,4-di (2-methoxy-2) -Ethoxyethyl) phenyl (288) 3,4-diphenylphenyl (289) 3,4-diethoxycarbonylphenyl (290) 3,4-didodecyloxyphenyl (291) 3,4-dimethylphenyl (292) 3, 4-dichlorophenyl (293) 3,4-dibenzoyl Enyl (294) 3,4-diacetoxyphenyl (295) 3,4-dimethoxyphenyl (296) 3,4-di-N-methylaminophenyl (297) 3,4-diisobutyrylaminophenyl (298) 3 , 4-diphenoxyphenyl (299) 3,4-dihydroxyphenyl (300) 3,5-dibutylphenyl (301) 3,5-di (2-methoxy-2-ethoxyethyl) phenyl (302) 3,5- Diphenylphenyl (303) 3,5-diethoxycarbonylphenyl (304) 3,5-didodecyloxyphenyl (305) 3,5-dimethylphenyl (306) 3,5-dichlorophenyl (307) 3,5-dibenzoyl Phenyl (308) 3,5-diacetoxyphenyl (309) 3,5-dimethoxyphenyl (3 0) 3,5-di-N-methylaminophenyl (311) 3,5-diisobutyrylaminophenyl (312) 3,5-diphenoxyphenyl (313) 3,5-dihydroxyphenyl (314) 2,4 -Dibutylphenyl (315) 2,4-di (2-methoxy-2-ethoxyethyl) phenyl (316) 2,4-diphenylphenyl (317) 2,4-diethoxycarbonylphenyl (318) 2,4-di Dodecyloxyphenyl (319) 2,4-dimethylphenyl (320) 2,4-dichlorophenyl (321) 2,4-dibenzoylphenyl (322) 2,4-diacetoxyphenyl (323) 2,4-dimethoxyphenyl ( 324) 2,4-di-N-methylaminophenyl (325) 2,4-diisobutyrylaminopheny (326) 2,4-diphenoxyphenyl (327) 2,4-dihydroxyphenyl (328) 2,3-dibutylphenyl (329) 2,3-di (2-methoxy-2-ethoxyethyl) phenyl (330) 2,3-diphenylphenyl (331) 2,3-diethoxycarbonylphenyl (332) 2,3-didodecyloxyphenyl (333) 2,3-dimethylphenyl (334) 2,3-dichlorophenyl (335) 2, 3-dibenzoylphenyl (336) 2,3-diacetoxyphenyl (337) 2,3-dimethoxyphenyl (338) 2,3-di-N-methylaminophenyl (339) 2,3-diisobutyrylaminophenyl (340) 2,3-diphenoxyphenyl (341) 2,3-dihydroxyphenyl (342 2,6-dibutylphenyl (343) 2,6-di (2-methoxy-2-ethoxyethyl) phenyl (344) 2,6-diphenylphenyl (345) 2,6-diethoxycarbonylphenyl (346) 2, 6-didodecyloxyphenyl (347) 2,6-dimethylphenyl (348) 2,6-dichlorophenyl (349) 2,6-dibenzoylphenyl (350) 2,6-diacetoxyphenyl (351) 2,6- Dimethoxyphenyl (352) 2,6-di-N-methylaminophenyl (353) 2,6-diisobutyrylaminophenyl (354) 2,6-diphenoxyphenyl (355) 2,6-dihydroxyphenyl (356) 3,4,5-tributylphenyl (357) 3,4,5-tri (2-methoxy-2-ethoxy) Til) phenyl (358) 3,4,5-triphenylphenyl (359) 3,4,5-triethoxycarbonylphenyl (360) 3,4,5-tridodecyloxyphenyl (361) 3,4,5- Trimethylphenyl (362) 3,4,5-trichlorophenyl (363) 3,4,5-tribenzoylphenyl (364) 3,4,5-triacetoxyphenyl (365) 3,4,5-trimethoxyphenyl ( 366) 3,4,5-tri-N-methylaminophenyl (367) 3,4,5-triisobutyrylaminophenyl (368) 3,4,5-triphenoxyphenyl (369) 3,4,5 -Trihydroxyphenyl (370) 2,4,6-tributylphenyl (371) 2,4,6-tri (2-methoxy-2-ethoxyethyl) ) Phenyl (372) 2,4,6-triphenylphenyl (373) 2,4,6-triethoxycarbonylphenyl (374) 2,4,6-tridodecyloxyphenyl (375) 2,4,6-trimethyl Phenyl (376) 2,4,6-trichlorophenyl (377) 2,4,6-tribenzoylphenyl (378) 2,4,6-triacetoxyphenyl (379) 2,4,6-trimethoxyphenyl (380 ) 2,4,6-tri-N-methylaminophenyl (381) 2,4,6-triisobutyrylaminophenyl (382) 2,4,6-triphenoxyphenyl (383) 2,4,6- Trihydroxyphenyl (384) Pentafluorophenyl (385) Pentachlorophenyl (386) Pentamethoxyphenyl (38 ) 6-N-methylsulfamoyl-8-methoxy-2-naphthyl (388) 5-N-methylsulfamoyl-2-naphthyl (389) 6-N-phenylsulfamoyl-2-naphthyl (390) 5-Ethoxy-7-N-methylsulfamoyl-2-naphthyl (391) 3-methoxy-2-naphthyl (392) 1-ethoxy-2-naphthyl (393) 6-N-phenylsulfamoyl-8- Methoxy-2-naphthyl (394) 5-methoxy-7-N-phenylsulfamoyl-2-naphthyl (395) 1- (4-methylphenyl) -2-naphthyl (396) 6,8-di-N- Methylsulfamoyl-2-naphthyl (397) 6-N-2-acetoxyethylsulfamoyl-8-methoxy-2-naphthyl (398) 5-acetoxy-7- N-phenylsulfamoyl-2-naphthyl (399) 3-benzoyloxy-2-naphthyl (400) 5-acetylamino-1-naphthyl (401) 2-methoxy-1-naphthyl (402) 4-phenoxy-1 -Naphtyl (403) 5-N-methylsulfamoyl-1-naphthyl (404) 3-N-methylcarbamoyl-4-hydroxy-1-naphthyl (405) 5-methoxy-6-N-ethylsulfamoyl- 1-naphthyl (406) 7-tetradecyloxy-1-naphthyl (407) 4- (4-methylphenoxy) -1-naphthyl (408) 6-N-methylsulfamoyl-1-naphthyl (409) 3- N, N-dimethylcarbamoyl-4-methoxy-1-naphthyl (410) 5-methoxy-6-N-benzylsulfamoyl 1-naphthyl (411) 3,6-di-N-phenylsulfamoyl-1-naphthyl (412) methyl (413) ethyl (414) butyl (415) octyl (416) dodecyl (417) 2-butoxy-2 -Ethoxyethyl (418) benzyl (419) 4-methoxybenzyl

(424) Methyl (425) Phenyl (426) Butyl

(430) methyl (431) ethyl (432) butyl (433) octyl (434) dodecyl (435) 2-butoxy-2-ethoxyethyl (436) benzyl (437) 4-methoxybenzyl

  In the present invention, a melamine polymer may be used as the compound having a 1,3,5-triazine ring. The melamine polymer is preferably synthesized by a polymerization reaction between a melamine compound represented by the following general formula (13) and a carbonyl compound.

In the above synthetic reaction scheme, R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group.

  The alkyl group, alkenyl group, aryl group, heterocyclic group and substituents thereof have the same meanings as the groups and substituents described in the general formula (12).

  The polymerization reaction between the melamine compound and the carbonyl compound is the same as the method for synthesizing a normal melamine resin (for example, melamine formaldehyde resin). Moreover, you may use a commercially available melamine polymer (melamine resin).

  The molecular weight of the melamine polymer is preferably 2,000 to 400,000. Specific examples of the repeating unit of the melamine polymer are shown below.

MP-1: R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ : CH ₂ OH
^{MP-2: R 13, R} 14, R 15, R 16: CH 2 OCH 3
^{MP-3: R 13, R} 14, R 15, R 16: CH 2 O-i-C 4 H 9
^{MP-4: R 13, R} 14, R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-5: R 13, R} 14, R 15, R 16: CH 2 NHCOCH = CH 2
^{MP-6: R 13, R} 14, R 15, R 16: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3
^{MP-7: R 13, R} 14, R 15: CH 2 OH; R 16: CH 2 OCH 3
^{MP-8: R 13, R} 14, R 16: CH 2 OH; R 15: CH 2 OCH 3
^{MP-9: R 13, R} 14: CH 2 OH; R 15, R 16: CH 2 OCH 3
^{MP-10: R 13, R} 16: CH 2 OH; R 14, R 15: CH 2 OCH 3
^{MP-11: R 13: CH} 2 OH; R 14, R 15, R 16: CH 2 OCH 3
^{MP-12: R 13, R} 14, R 16: CH 2 OCH 3; R 15: CH 2 OH
^{MP-13: R 13, R} 16: CH 2 OCH 3; R 14, R 15: CH 2 OH
^{MP-14: R 13, R} 14, R 15: CH 2 OH; R 16: CH 2 O-i-C 4 H 9
^{MP-15: R 13, R} 14, R 16: CH 2 OH; R 15: CH 2 O-i-C 4 H 9
^{MP-16: R 13, R} 14: CH 2 OH; R 15, R 16: CH 2 O-i-C 4 H 9
^{MP-17: R 13, R} 16: CH 2 OH; R 14, R 15: CH 2 O-i-C 4 H 9
^{MP-18: R 13: CH} 2 OH; R 14, R 15, R 16: CH 2 O-i-C 4 H 9
^{MP-19: R 13, R} 14, R 16: CH 2 O-i-C 4 H 9; R 15: CH 2 OH
^{MP-20: R 13, R} 16: CH 2 O-i-C 4 H 9; R 14, R 15: CH 2 OH
MP-21: R ¹³ , R ¹⁴ , R ¹⁵ : CH ₂ OH; R ¹⁶ : CH _{2 On} -C ₄ H ₉
^{MP-22: R 13, R} 14, R 16: CH 2 OH; R 15: CH 2 O-n-C 4 H 9
^{MP-23: R 13, R} 14: CH 2 OH; R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-24: R 13, R} 16: CH 2 OH; R 14, R 15: CH 2 O-n-C 4 H 9
^{MP-25: R 13: CH} 2 OH; R 14, R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-26: R 13, R} 14, R 16: CH 2 O-n-C 4 H 9; R 15: CH 2 OH
^{MP-27: R 13, R} 16: CH 2 O-n-C 4 H 9; R 14, R 15: CH 2 OH
^{MP-28: R 13, R} 14: CH 2 OH; R 15: CH 2 OCH 3; R 16: CH 2 O-n-C 4 H 9
^{MP-29: R 13, R} 14: CH 2 OH; R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 OCH 3
^{MP-30: R 13, R} 16: CH 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 O-n-C 4 H 9
^{MP-31: R 13: CH} 2 OH; R 14, R 15: CH 2 OCH 3; R 16: CH 2 O-n-C 4 H 9
^{MP-32: R 13: CH} 2 OH; R 14, R 16: CH 2 OCH 3; R 15: CH 2 O-n-C 4 H 9
^{MP-33: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-34: R 13: CH} 2 OH; R 14, R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 OCH 3
^{MP-35: R 13, R} 14: CH 2 OCH 3; R 15: CH 2 OH; R 16: CH 2 O-n-C 4 H 9
^{MP-36: R 13, R} 16: CH 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 O-n-C 4 H 9
^{MP-37: R 13: CH} 2 OCH 3; R 14, R 15: CH 2 OH; R 16: CH 2 O-n-C 4 H 9
^{MP-38: R 13, R} 16: CH 2 O-n-C 4 H 9; R 14: CH 2 OCH 3; R 15: CH 2 OH
^{MP-39: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 NHCOCH = CH 2
^{MP-40: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 O-n-C 4 H 9
^{MP-41: R 13: CH} 2 OH; R 14: CH 2 O-n-C 4 H 9; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 OCH 3
^{MP-42: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 NHCOCH = CH 2
^{MP-43: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 O-n-C 4 H 9
^{MP-44: R 13: CH} 2 O-n-C 4 H 9; R 14: CH 2 OCH 3; R 15: CH 2 OH; R 16: CH 2 NHCOCH = CH 2
^{MP-45: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 16: CH 2 NHCOCH = CH 2
^{MP-46: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3
^{MP-47: R 13: CH} 2 OH; R 14: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 OCH 3
^{MP-48: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 16: CH 2 NHCOCH = CH 2
^{MP-49: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3
^{MP-50: R 13: CH} 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 14: CH 2 OCH 3; R 15: CH 2 OH; R 16: CH 2 NHCOCH = CH 2

^{MP-51: R 13, R} 14, R 15, R 16: CH 2 OH
^{MP-52: R 13, R} 14, R 15, R 16: CH 2 OCH 3
^{MP-53: R 13, R} 14, R 15, R 16: CH 2 O-i-C 4 H 9
^{MP-54: R 13, R} 14, R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-55: R 13, R} 14, R 15, R 16: CH 2 NHCOCH = CH 2
^{MP-56: R 13, R} 14, R 15, R 16: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3
^{MP-57: R 13, R} 14, R 15: CH 2 OH; R 16: CH 2 OCH 3
^{MP-58: R 13, R} 14, R 16: CH 2 OH; R 15: CH 2 OCH 3
^{MP-59: R 13, R} 14: CH 2 OH; R 15, R 16: CH 2 OCH 3
^{MP-60: R 13, R} 16: CH 2 OH; R 14, R 15: CH 2 OCH 3
^{MP-61: R 13: CH} 2 OH; R 14, R 15, R 16: CH 2 OCH 3
^{MP-62: R 13, R} 14, R 16: CH 2 OCH 3; R 15: CH 2 OH
^{MP-63: R 13, R} 16: CH 2 OCH 3; R 14, R 15: CH 2 OH
^{MP-64: R 13, R} 14, R 15: CH 2 OH; R 16: CH 2 O-i-C 4 H 9
^{MP-65: R 13, R} 14, R 16: CH 2 OH; R 15: CH 2 O-i-C 4 H 9
^{MP-66: R 13, R} 14: CH 2 OH; R 15, R 16: CH 2 O-i-C 4 H 9
^{MP-67: R 13, R} 16: CH 2 OH; R 14, R 15: CH 2 O-i-C 4 H 9
^{MP-68: R 13: CH} 2 OH; R 14, R 15, R 16: CH 2 O-i-C 4 H 9
^{MP-69: R 13, R} 14, R 16: CH 2 O-i-C 4 H 9; R 15: CH 2 OH
^{MP-70: R 13, R} 16: CH 2 O-i-C 4 H 9; R 14, R 15: CH 2 OH
^{MP-71: R 13, R} 14, R 15: CH 2 OH; R 16: CH 2 O-n-C 4 H 9
^{MP-72: R 13, R} 14, R 16: CH 2 OH; R 15: CH 2 O-n-C 4 H 9
^{MP-73: R 13, R} 14: CH 2 OH; R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-74: R 13, R} 16: CH 2 OH; R 14, R 15: CH 2 O-n-C 4 H 9
^{MP-75: R 13: CH} 2 OH; R 14, R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-76: R 13, R} 14, R 16: CH 2 O-n-C 4 H 9; R 15: CH 2 OH
^{MP-77: R 13, R} 16: CH 2 O-n-C 4 H 9; R 14, R 15: CH 2 OH
^{MP-78: R 13, R} 14: CH 2 OH; R 15: CH 2 OCH 3; R 16: CH 2 O-n-C 4 H 9
^{MP-79: R 13, R} 14: CH 2 OH; R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 OCH 3
^{MP-80: R 13, R} 16: CH 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 O-n-C 4 H 9
^{MP-81: R 13: CH} 2 OH; R 14, R 15: CH 2 OCH 3; R 16: CH 2 O-n-C 4 H 9
^{MP-82: R 13: CH} 2 OH; R 14, R 16: CH 2 OCH 3; R 15: CH 2 O-n-C 4 H 9
^{MP-83: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-84: R 13: CH} 2 OH; R 14, R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 OCH 3
^{MP-85: R 13, R} 14: CH 2 OCH 3; R 15: CH 2 OH; R 16: CH 2 O-n-C 4 H 9
^{MP-86: R 13, R} 16: CH 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 O-n-C 4 H 9
^{MP-87: R 13: CH} 2 OCH 3; R 14, R 15: CH 2 OH; R 16: CH 2 O-n-C 4 H 9
^{MP-88: R 13, R} 16: CH 2 O-n-C 4 H 9; R 14: CH 2 OCH 3; R 15: CH 2 OH
^{MP-89: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 NHCOCH = CH 2
^{MP-90: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 O-n-C 4 H 9
^{MP-91: R 13: CH} 2 OH; R 14: CH 2 O-n-C 4 H 9; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 OCH 3
^{MP-92: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 NHCOCH = CH 2
^{MP-93: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 O-n-C 4 H 9
^{MP-94: R 13: CH} 2 O-n-C 4 H 9; R 14: CH 2 OCH 3; R 15: CH 2 OH; R 16: CH 2 NHCOCH = CH 2
^{MP-95: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 16: CH 2 NHCOCH = CH 2
^{MP-96: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3
^{MP-97: R 13: CH} 2 OH; R 14: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 OCH 3
^{MP-98: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 16: CH 2 NHCOCH = CH 2
^{MP-99: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3
^{MP-100: R 13: CH} 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 14: CH 2 OCH 3; R 15: CH 2 OH; R 16: CH 2 NHCOCH = CH 2

^{MP-101: R 13, R} 14, R 15, R 16: CH 2 OH
^{MP-102: R 13, R} 14, R 15, R 16: CH 2 OCH 3
^{MP-103: R 13, R} 14, R 15, R 16: CH 2 O-i-C 4 H 9
^{MP-104: R 13, R} 14, R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-105: R 13, R} 14, R 15, R 16: CH 2 NHCOCH = CH 2
^{MP-106: R 13, R} 14, R 15, R 16: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3
^{MP-107: R 13, R} 14, R 15: CH 2 OH; R 16: CH 2 OCH 3
^{MP-108: R 13, R} 14, R 16: CH 2 OH; R 15: CH 2 OCH 3
^{MP-109: R 13, R} 14: CH 2 OH; R 15, R 16: CH 2 OCH 3
^{MP-110: R 13, R} 16: CH 2 OH; R 14, R 15: CH 2 OCH 3
^{MP-111: R 13: CH} 2 OH; R 14, R 15, R 16: CH 2 OCH 3
^{MP-112: R 13, R} 14, R 16: CH 2 OCH 3; R 15: CH 2 OH
^{MP-113: R 13, R} 16: CH 2 OCH 3; R 14, R 15: CH 2 OH
^{MP-114: R 13, R} 14, R 15: CH 2 OH; R 16: CH 2 O-i-C 4 H 9
^{MP-115: R 13, R} 14, R 16: CH 2 OH; R 15: CH 2 O-i-C 4 H 9
^{MP-116: R 13, R} 14: CH 2 OH; R 15, R 16: CH 2 O-i-C 4 H 9
^{MP-117: R 13, R} 16: CH 2 OH; R 14, R 15: CH 2 O-i-C 4 H 9
^{MP-118: R 13: CH} 2 OH; R 14, R 15, R 16: CH 2 O-i-C 4 H 9
^{MP-119: R 13, R} 14, R 16: CH 2 O-i-C 4 H 9; R 15: CH 2 OH
^{MP-120: R 13, R} 16: CH 2 O-i-C 4 H 9; R 14, R 15: CH 2 OH
^{MP-121: R 13, R} 14, R 15: CH 2 OH; R 16: CH 2 O-n-C 4 H 9
^{MP-122: R 13, R} 14, R 16: CH 2 OH; R 15: CH 2 O-n-C 4 H 9
^{MP-123: R 13, R} 14: CH 2 OH; R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-124: R 13, R} 16: CH 2 OH; R 14, R 15: CH 2 O-n-C 4 H 9
^{MP-125: R 13: CH} 2 OH; R 14, R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-126: R 13, R} 14, R 16: CH 2 O-n-C 4 H 9; R 15: CH 2 OH
^{MP-127: R 13, R} 16: CH 2 O-n-C 4 H 9; R 14, R 15: CH 2 OH
^{MP-128: R 13, R} 14: CH 2 OH; R 15: CH 2 OCH 3; R 16: CH 2 O-n-C 4 H 9
^{MP-129: R 13, R} 14: CH 2 OH; R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 OCH 3
^{MP-130: R 13, R} 16: CH 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 O-n-C 4 H 9
^{MP-131: R 13: CH} 2 OH; R 14, R 15: CH 2 OCH 3; R 16: CH 2 O-n-C 4 H 9
^{MP-132: R 13: CH} 2 OH; R 14, R 16: CH 2 OCH 3; R 15: CH 2 O-n-C 4 H 9
^{MP-133: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-134: R 13: CH} 2 OH; R 14, R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 OCH 3
^{MP-135: R 13, R} 14: CH 2 OCH 3; R 15: CH 2 OH; R 16: CH 2 O-n-C 4 H 9
^{MP-136: R 13, R} 16: CH 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 O-n-C 4 H 9
^{MP-137: R 13: CH} 2 OCH 3; R 14, R 15: CH 2 OH; R 16: CH 2 O-n-C 4 H 9
^{MP-138: R 13, R} 16: CH 2 O-n-C 4 H 9; R 14: CH 2 OCH 3; R 15: CH 2 OH
^{MP-139: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 NHCOCH = CH 2
^{MP-140: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 O-n-C 4 H 9
^{MP-141: R 13: CH} 2 OH; R 14: CH 2 O-n-C 4 H 9; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 OCH 3
^{MP-142: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 NHCOCH = CH 2
^{MP-143: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 O-n-C 4 H 9
^{MP-144: R 13: CH} 2 O-n-C 4 H 9; R 14: CH 2 OCH 3; R 15: CH 2 OH; R 16: CH 2 NHCOCH = CH 2
^{MP-145: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 16: CH 2 NHCOCH = CH 2
^{MP-146: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3
^{MP-147: R 13: CH} 2 OH; R 14: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 OCH 3
^{MP-148: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 16: CH 2 NHCOCH = CH 2
^{MP-149: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3
^{MP-150: R 13: CH} 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 14: CH 2 OCH 3; R 15: CH 2 OH; R 16: CH 2 NHCOCH = CH 2

^{MP-151: R 13, R} 14, R 15, R 16: CH 2 OH
^{MP-152: R 13, R} 14, R 15, R 16: CH 2 OCH 3
^{MP-153: R 13, R} 14, R 15, R 16: CH 2 O-i-C 4 H 9
^{MP-154: R 13, R} 14, R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-155: R 13, R} 14, R 15, R 16: CH 2 NHCOCH = CH 2
^{MP-156: R 13, R} 14, R 15, R 16: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3
^{MP-157: R 13, R} 14, R 15: CH 2 OH; R 16: CH 2 OCH 3
^{MP-158: R 13, R} 14, R 16: CH 2 OH; R 15: CH 2 OCH 3
^{MP-159: R 13, R} 14: CH 2 OH; R 15, R 16: CH 2 OCH 3
^{MP-160: R 13, R} 16: CH 2 OH; R 14, R 15: CH 2 OCH 3
^{MP-161: R 13: CH} 2 OH; R 14, R 15, R 16: CH 2 OCH 3
^{MP-162: R 13, R} 14, R 16: CH 2 OCH 3; R 15: CH 2 OH
^{MP-163: R 13, R} 16: CH 2 OCH 3; R 14, R 15: CH 2 OH
^{MP-164: R 13, R} 14, R 15: CH 2 OH; R 16: CH 2 O-i-C 4 H 9
^{MP-165: R 13, R} 14, R 16: CH 2 OH; R 15: CH 2 O-i-C 4 H 9
^{MP-166: R 13, R} 14: CH 2 OH; R 15, R 16: CH 2 O-i-C 4 H 9
^{MP-167: R 13, R} 16: CH 2 OH; R 14, R 15: CH 2 O-i-C 4 H 9
^{MP-168: R 13: CH} 2 OH; R 14, R 15, R 16: CH 2 O-i-C 4 H 9
^{MP-169: R 13, R} 14, R 16: CH 2 O-i-C 4 H 9; R 15: CH 2 OH
^{MP-170: R 13, R} 16: CH 2 O-i-C 4 H 9; R 14, R 15: CH 2 OH
^{MP-171: R 13, R} 14, R 15: CH 2 OH; R 16: CH 2 O-n-C 4 H 9
^{MP-172: R 13, R} 14, R 16: CH 2 OH; R 15: CH 2 O-n-C 4 H 9
^{MP-173: R 13, R} 14: CH 2 OH; R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-174: R 13, R} 16: CH 2 OH; R 14, R 15: CH 2 O-n-C 4 H 9
^{MP-175: R 13: CH} 2 OH; R 14, R 15, R 16: CH 2 O-n-C 4 H 9
MP-176: R ¹³ , R ¹⁴ , R ¹⁶ : CH _{2 On} -C ₄ H ₉ ; R ¹⁵ : CH ₂ OH
^{MP-177: R 13, R} 16: CH 2 O-n-C 4 H 9; R 14, R 15: CH 2 OH
^{MP-178: R 13, R} 14: CH 2 OH; R 15: CH 2 OCH 3; R 16: CH 2 O-n-C 4 H 9
^{MP-179: R 13, R} 14: CH 2 OH; R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 OCH 3
^{MP-180: R 13, R} 16: CH 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 O-n-C 4 H 9
^{MP-181: R 13: CH} 2 OH; R 14, R 15: CH 2 OCH 3; R 16: CH 2 O-n-C 4 H 9
^{MP-182: R 13: CH} 2 OH; R 14, R 16: CH 2 OCH 3; R 15: CH 2 O-n-C 4 H 9
^{MP-183: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15, R 16: CH 2 O-n-C 4 H 9
^{MP-184: R 13: CH} 2 OH; R 14, R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 OCH 3
^{MP-185: R 13, R} 14: CH 2 OCH 3; R 15: CH 2 OH; R 16: CH 2 O-n-C 4 H 9
^{MP-186: R 13, R} 16: CH 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 O-n-C 4 H 9
^{MP-187: R 13: CH} 2 OCH 3; R 14, R 15: CH 2 OH; R 16: CH 2 O-n-C 4 H 9
^{MP-188: R 13, R} 16: CH 2 O-n-C 4 H 9; R 14: CH 2 OCH 3; R 15: CH 2 OH
^{MP-189: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 NHCOCH = CH 2
^{MP-190: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 O-n-C 4 H 9
^{MP-191: R 13: CH} 2 OH; R 14: CH 2 O-n-C 4 H 9; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 OCH 3
^{MP-192: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 O-n-C 4 H 9; R 16: CH 2 NHCOCH = CH 2
^{MP-193: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 O-n-C 4 H 9
^{MP-194: R 13: CH} 2 O-n-C 4 H 9; R 14: CH 2 OCH 3; R 15: CH 2 OH; R 16: CH 2 NHCOCH = CH 2
^{MP-195: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 16: CH 2 NHCOCH = CH 2
^{MP-196: R 13: CH} 2 OH; R 14: CH 2 OCH 3; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3
^{MP-197: R 13: CH} 2 OH; R 14: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 OCH 3
^{MP-198: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 16: CH 2 NHCOCH = CH 2
^{MP-199: R 13: CH} 2 OCH 3; R 14: CH 2 OH; R 15: CH 2 NHCOCH = CH 2; R 16: CH 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3
^{MP-200: R 13: CH} 2 NHCO (CH 2) 7 CH = CH (CH 2) 7 CH 3; R 14: CH 2 OCH 3; R 15: CH 2 OH; R 16: CH 2 NHCOCH = CH 2
In the present invention, a copolymer obtained by combining two or more of the above repeating units may be used. Two or more homopolymers or copolymers may be used in combination.

  Moreover, you may use together the compound which has a 2 or more types of 1,3,5- triazine ring. Two or more kinds of discotic compounds (for example, a compound having a 1,3,5-triazine ring and a compound having a porphyrin skeleton) may be used in combination.

  Additives such as the rod-like compound and the discotic compound are preferably contained in an amount of 0.2 to 30% by mass, particularly preferably 1 to 20% by mass with respect to the optical compensation film.

(Matting agent)
In the optical film of the present invention, fine particles such as a matting agent can be added in order to impart slipperiness or improve physical properties. Examples of the fine particles include fine particles of an inorganic compound or fine particles of an organic compound, and a spherical shape, a flat plate shape, a rod shape, a needle shape, a layer shape, an indefinite shape, or the like is used.

  Examples of the fine particles include metal oxides such as silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, kaolin, talc, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate, and calcium phosphate. Inorganic fine particles such as hydroxides, silicates, phosphates, carbonates, and crosslinked polymer fine particles. Among these, silicon dioxide is preferable because it can reduce the haze of the film. In many cases, fine particles such as silicon dioxide are surface-treated with an organic substance, but such particles are preferred because they can reduce the haze of the film.

  Preferred organic substances for the surface treatment include halosilanes, alkoxysilanes, silazane, siloxane and the like. The larger the average particle size of the fine particles, the greater the sliding effect, and the smaller the average particle size, the better the transparency. The average particle size of the fine particles is in the range of 0.005 to 1.0 μm. Even these primary particles may be secondary particles formed by aggregation. The average particle size of the primary particles of preferable fine particles is preferably 5 to 50 nm, more preferably 7 to 14 nm. These fine particles can generate irregularities of 0.01 to 1.0 μm on the film surface. The content of the fine particles in the cellulose resin is preferably 0.005 to 10% by mass, particularly preferably 0.05 to 5% by mass with respect to the cellulose resin.

  Examples of the fine particles of silicon dioxide include Aerosil 200, 200V, 300, R972, R972V, R974, R202, R812, OX50, TT600 manufactured by Nippon Aerosil Co., Ltd., preferably Aerosil 200V, R972. , R972V, R974, R202, R812. Two or more kinds of these fine particles may be used in combination. When using 2 or more types together, it can mix and use in arbitrary ratios. In this case, fine particles having different average particle sizes and materials, for example, Aerosil 200V and R972V can be used in a mass ratio of 0.1: 99.9 to 99.9: 0.1.

  The presence of fine particles in the film used as the matting agent can be used for another purpose to improve the strength of the film.

  These fine particles can be added by kneading with a resin, and can also be kneaded with a plasticizer, a hindered amine compound, a hindered phenol compound, an ultraviolet absorber, an acid scavenger and the like. Alternatively, fine particles dispersed in advance in a solvent such as methanol or ethanol may be sprayed onto the cellulose resin, mixed and dried, and the fine particles dispersed in the solvent are mainly composed of methylene chloride or methyl acetate. What was added and mixed with the cellulose resin solution and dried and solidified may be used as a raw material for melt casting. More preferably, the cellulose resin solution containing the fine particles further contains a part or all of a plasticizer, a hindered amine compound, a hindered phenol compound, an ultraviolet absorber, an acid scavenger and the like.

  A film having a surface layer containing fine particles is formed from a surface layer containing fine particles having an average particle diameter of 1.0 μm or less on at least one surface by forming the film by a co-extrusion method or a sequential extrusion method. I can do it. When fine particles are contained in the surface layer, the fine particles may also be contained in a layer constituting the inside of the film.

(Film formation)
The optical film of the present invention is formed by melt casting. The molding method by melt casting which is heated and melted without using the solvent (for example, methylene chloride, etc.) used in the solution casting method, more specifically, melt extrusion molding method, press molding method, inflation method, injection molding method , Blow molding method, stretch molding method and the like. Among these, in order to obtain a polarizing plate protective film having excellent mechanical strength and surface accuracy, the melt extrusion method is excellent. In view of the physical properties of the obtained optical film, the melting temperature is preferably in the range of 120 to 280 ° C, more preferably 200 to 250 ° C.

  That is, after the raw material cellulose resin formed into a powder or pellet form is dried with hot air or vacuum, it is heated and melted together with the film constituent material to express its fluidity, melt extruded, and sheeted from a T die. For example, it is made to adhere to a cooling drum or an endless belt by an electrostatic application method or the like, and is cooled and solidified to obtain an unstretched sheet. The temperature of the cooling drum is preferably maintained at 90 to 150 ° C.

  The film peeled from the cooling drum is preferably cooled after being heated once again in the longitudinal direction through one or more roll groups and / or a heating device such as an infrared heater, and then stretched in the longitudinal direction. At this time, when the glass transition temperature of the film of the present invention is defined as Tg, the film is heated in the range of (Tg-30) to (Tg + 100) ° C., more preferably (Tg-20) to (Tg + 80) ° C. Direction; MD) or transverse direction (TD). It is preferable to perform transverse stretching within the temperature range of (Tg-20) to (Tg + 20) ° C. and then heat-set. It is also preferable to perform relaxation treatment after the stretching step.

  The Tg of the optical film can be controlled by the material type constituting the film and the ratio of the constituting materials. In the application of the present invention, the Tg of the film is preferably 120 ° C. or higher, and more preferably 135 ° C. or higher. This is because when the optical film of the present invention is used in a liquid crystal display device, if the Tg of the film is lower than the above, the orientation state of molecules fixed inside the film due to the influence of the temperature of the use environment and the heat of the backlight. This increases the possibility that the retardation value and the dimensional stability and shape of the film will greatly change. Conversely, if the Tg of the film is too high, it becomes difficult to produce because it approaches the decomposition temperature of the film constituting material, and the presence of a volatile component or coloring may occur due to the decomposition of the material itself used when forming a film. Accordingly, it is preferably 200 ° C. or lower, more preferably 170 ° C. or lower. At this time, the Tg of the film can be determined by the method described in JIS K7121.

  In the case of transverse stretching (width direction: TD), it is preferable to perform transverse stretching while sequentially raising the temperature difference in the range of 1 to 50 ° C. in the stretching region divided into two or more, so that the distribution of physical properties in the width direction can be reduced. . Further, after the transverse stretching, it is preferable that the film is held at a temperature of Tg-40 ° C. or higher at a temperature equal to or lower than the final transverse stretching temperature for 0.01 to 5 minutes because the distribution of physical properties in the width direction can be further reduced.

  In the heat setting, heat setting is usually performed for 0.5 to 300 seconds at a temperature higher than the final transverse stretching temperature and within a temperature range of Tg-20 ° C or lower. At this time, it is preferable to heat-fix while sequentially raising the temperature difference in the range of 1 to 100 ° C. in the region divided into two or more.

  The heat-set film is usually cooled to Tg or less, and clip holding portions at both ends of the film are cut and wound. At this time, it is preferable to perform a relaxation treatment of 0.1 to 10% in the lateral direction and / or the longitudinal direction within a temperature range of not more than the final heat setting temperature and not less than Tg. In addition, it is preferable that the cooling is gradually performed from the final heat setting temperature to Tg at a cooling rate of 100 ° C. or less per second. Means for cooling and relaxation treatment are not particularly limited, and can be performed by a conventionally known means. In particular, it is preferable to carry out these treatments while sequentially cooling in a plurality of temperature ranges from the viewpoint of improving the dimensional stability of the film. The cooling rate is a value obtained by (T1-T2) / t, where T1 is the final heat setting temperature and t is the time until the film reaches T2 from the final heat setting temperature.

  The preferred stretching ratio of the optical film is that stretched by 1.01 to 2 times in both the longitudinal direction and the width direction. More preferably, it is stretched 1.01 to 1.5 times, and more preferably 1.01 to 1.3 times. Thereby, while being able to obtain the optical film excellent in optical isotropy preferably, the optical film with favorable flatness can be obtained. It is preferable to perform the width maintenance or the transverse stretching in the film forming process by a tenter, and it may be a pin tenter or a clip tenter.

  In the case of obtaining an optical compensation film, which will be described later, by changing the stretching ratio in the longitudinal direction and in the width direction, stretching is performed such that one of the stretching ratios is larger than the other stretching ratio. Can be obtained. In this case, the draw ratio between the width direction and the longitudinal direction is preferably 1.1 to 2.0, more preferably 1.2 to 1.5.

  In the present invention, an optical film having a laminated structure can be produced by co-extrusion of a composition containing a cellulose resin having different additive concentrations such as the aforementioned polymer, plasticizer, ultraviolet absorber, and fine particles. For example, an optical film having a structure of skin layer / core layer / skin layer can be produced. For example, the fine particles can be contained in the skin layer in a large amount or only in the skin layer. More polymer, plasticizer, and ultraviolet absorber can be contained in the core layer than in the skin layer, and may be contained only in the core layer. It is also possible to change the type of polymer, plasticizer and ultraviolet absorber between the core layer and the skin layer. For example, the skin layer contains a low-volatile polymer, plasticizer and / or ultraviolet absorber, and the core layer It is also possible to add a plasticizer excellent in plasticity or an ultraviolet absorber excellent in ultraviolet absorption. The Tg of the skin layer and the core layer may be different, and the Tg of the core layer is preferably lower than the Tg of the skin layer. Also, the viscosity of the melt containing the cellulose resin during melt casting may be different between the skin layer and the core layer, and the viscosity of the skin layer> the viscosity of the core layer or the viscosity of the core layer ≧ the viscosity of the skin layer may be used.

  The coextrusion method can distribute the concentration of additives such as plasticizers in the film thickness direction and reduce the content of the surface, but the single layer extrusion can produce a uniform film with a small distribution of additives in the film thickness direction. It can also be obtained and preferably used.

  When the optical film of the present invention is used as a protective film for polarizing plates, the thickness of the protective film is preferably 10 to 500 μm. 10-100 micrometers is especially preferable, 20-80 micrometers is preferable, Especially preferably, it is 30-60 micrometers.

  In the solution casting method, when the film thickness is increased, the drying load is remarkably increased. However, in the present invention, since a drying step is not required, a film having a large film thickness can be produced with high productivity. Therefore, there is an advantage that it is easier than ever to increase the thickness of the film in accordance with purposes such as imparting a necessary retardation or reducing moisture permeability. Moreover, even if it is a film with a thin film thickness, it has the effect that it can be produced with high productivity by extending | stretching such a thick film.

  The film thickness variation of the optical film support is preferably in the range of ± 3% in the longitudinal direction and the width direction, more preferably ± 1%, more preferably ± 0.1%.

  The width of the optical film of the present invention is preferably 1 to 4 m, and particularly preferably 1.4 to 4 m.

  The cellulose ester film using the polyhydric alcohol ester compound of the organic acid represented by the general formula (1) of the present invention as a plasticizer provides an optical film with excellent flatness. It can be applied. In particular, those having a width of 1.4 to 4 m are preferably used, and particularly preferably 1.4 to 2 m. If it exceeds 4 m, conveyance becomes difficult.

  The winding length is preferably 500 to 5000 m, more preferably 1000 to 5000 m. It is also preferable to wind up by providing a knurling with a height of 0 to 25% of the film thickness at both ends of the width.

(Volatile component removal)
In order to stably produce such a long film, it is important that volatile components are not mixed in the material to be cast. Film formation by the melt casting method differs significantly from the solution casting method in the temperature at the time of film formation, and if there are volatile components in the material to be cast, these additives volatilize and adhere to the film forming apparatus at the time of film formation. However, since it causes various failures, it is not preferable from the viewpoint of ensuring the flatness and transparency of the film for utilizing the function as a film or a polarizing plate protective film. In particular, when it adheres to the die, it may cause a streak on the film surface and induce flatness deterioration. Therefore, when a film constituent material is formed into a film, it is not preferable that a component that volatilizes exists in a region lower than the melting temperature for film formation from the viewpoint of avoiding generation of a volatile component during heating and melting.

  The volatile components include moisture absorbed in any of the film constituent materials, mixed gases such as oxygen and nitrogen, or solvents, catalysts, unreacted monomers mixed before the material is purchased or synthesized. And other by-products and impurities such as evaporation by heating, sublimation or volatilization by decomposition. The solvent here is different from the solvent for adjusting the resin as a solution as a solution casting, and is contained in a trace amount in the film constituting material. Therefore, selection of the film constituent material is important in avoiding the generation of volatile components.

  In the present invention, it is preferable that the film constituent material used for melt casting removes volatile components typified by the moisture, the solvent, or impurities before film formation or during heating. A method by drying can be applied to this removal method, and it can be performed by a method such as a heating method, a reduced pressure method, or a heated reduced pressure method. Drying may be performed in air or in an atmosphere in which an inert gas such as nitrogen or argon is selected as the inert gas. These inert gases preferably have a low content of water or oxygen, and preferably do not substantially contain them. When these known drying methods are performed, it is preferable in terms of film quality to be performed in a temperature range where the film constituting material does not decompose. In the case where the liquid film constituent material is liquid or heated, it is preferably made into a liquid state and water, solvent, impurities and the like mixed therein are preferably removed by bubbling dry nitrogen gas or the like.

  In particular, the moisture content of the cellulose ester resin is preferably less than 0.5% by mass. These characteristic values can be measured by ASTM-D817-96. The cellulose resin is preferably used as 0.1 to 1000 ppm by further reducing the moisture by heat treatment.

  The film constituent material can reduce the generation of volatile components by drying before film formation, and the resin alone, or at least one mixture or compatible material other than the resin among the resin and the film constituent material. It can be divided and dried. The preferable drying temperature is preferably 80 ° C. or higher and not higher than the Tg or melting point of the material to be dried. Including the viewpoint of avoiding fusion between materials, the drying temperature is more preferably 100 to (Tg-5) ° C, and still more preferably 110 to (Tg-20) ° C. A preferable drying time is 0.5 to 24 hours, more preferably 1 to 18 hours, and still more preferably 1.5 to 12 hours. Below these ranges, the removal rate of volatile components may be low, or drying may take too long, and when Tg is present in the material to be dried, heating to a drying temperature higher than Tg will cause the material to be removed. May be difficult to handle due to fusion. Drying is preferably performed at 1 atm or less, and particularly preferably performed while reducing the pressure from vacuum to 1/2 atm. Drying is preferably performed while appropriately stirring the material such as resin, and the fluidized bed method in which drying air or dry nitrogen is fed from the lower part in the drying container can perform necessary drying in a shorter time. It is preferable because it is possible.

  The drying process may be separated into two or more stages. For example, the material may be formed using a material that has been subjected to storage of the material in the preliminary drying process and drying immediately before film formation to immediately before a week. .

(Retardation value)
The in-plane retardation value (Ro) and the retardation value (Rt) in the thickness direction of the optical film according to the present invention are 0 ≦ Ro ≦ 300 nm and −150 nm ≦ Rt ≦ 150 nm when used as a polarizer protective film. Is preferred. More preferably, 0 ≦ Ro ≦ 200 nm and −50 nm ≦ Rt ≦ 50 nm, and more preferably 0 ≦ Ro ≦ 70 nm and −30 nm ≦ Rt ≦ 30 nm.

  Further, the variation of Rt and the width of the distribution are preferably less than ± 10 nm, preferably less than ± 8 nm, and preferably less than ± 5 nm. Further, it is preferably less than ± 3 nm, more preferably less than ± 1 nm. Most preferably, there is no variation in Rt.

  The retardation values Ro and Rt can be obtained by the following equations.

Formula (i) Ro = (nx−ny) × d
Formula (ii) Rt = ((nx + ny) / 2−nz) × d
Here, d is the thickness (nm) of the film, the refractive index nx (also referred to as the maximum refractive index in the plane of the film, the refractive index in the slow axis direction), ny (in the direction perpendicular to the slow axis in the film plane). ) (Refractive index of the film in the thickness direction).

  The retardation values (Ro) and (Rt) can be measured using an automatic birefringence meter. For example, it can be obtained at a wavelength of 590 nm using KOBRA-21ADH (Oji Scientific Instruments) under an environment of 23 ° C. and 55% RH.

  The slow axis is preferably in the width direction ± 1 ° or the longitudinal direction ± 1 ° of the long film. More preferably, it is ± 0.7 ° with respect to the width direction or the longitudinal direction, more preferably ± 0.5 ° with respect to the width direction or the longitudinal direction, and particularly preferably ± 0.1 °.

(Residual solvent, moisture content)
Since the optical film of the present invention does not substantially use a solvent in the film forming process, the amount of residual organic solvent contained in the optical film wound up after film formation is stably less than 0.1% by mass. Thus, it is possible to provide an optical film having more stable flatness and Rt than conventional. In particular, it is possible to provide an optical film having stable flatness and Rt even in a long roll of 100 m or more. The optical film is not particularly limited with respect to the winding length, and is preferably used even if it is 1500 m, 2500 m, or 5000 m.

  The amount of residual organic solvent can be measured by the headspace gas chromatography method. That is, a known amount of cellulose ester film is heated in a sealed container at 120 ° C. for 20 minutes, and the organic solvent contained in the gas phase in the sealed container is quantified by gas chromatography. From this result, the residual organic solvent amount (%) can be calculated.

  Moreover, when a film contains a water | moisture content, the moisture content (g) further contained in the cellulose-ester film is calculated | required by another method, and the mass of a water | moisture content from the mass difference (g) of the cellulose-ester film before and behind the said heat processing. The residual organic solvent content (%) can be obtained from the value obtained by subtracting (g).

  It is difficult to reduce the residual organic solvent amount (%) of the cellulose ester film produced by the solution casting method to 0.1% by mass or less, which requires a long drying step. Accordingly, a cellulose ester film having a very low residual organic solvent content can be obtained at a low cost, and a cellulose ester film having excellent characteristics as an optical film can be obtained.

  When the film constituting material is heated and melted, the decomposition reaction becomes remarkable, and this decomposition reaction may be accompanied by coloring or deterioration. Moreover, generation | occurrence | production of the unfavorable volatile component may be accompanied by a decomposition reaction.

  The film constituent material can be stored as one or more kinds of pellets for the purpose of avoiding material alteration and hygroscopicity, and a melt can be produced using this. Pelletization can improve the mixability or compatibility of the film constituent materials at the time of melting, and contributes to obtaining optical uniformity of the film. Mixing the constituent materials other than the cellulose resin uniformly with the resin before melting can contribute to providing uniform meltability when heated and melted.

(Polymer layer)
The optical compensation film of the present invention is characterized in that a polymer layer is provided on the optical film according to the present invention (hereinafter sometimes referred to as a molten cellulose ester film) and stretched together with the support. Details will be described below.

  The polymer layer according to the present invention can be provided by coating. The polymer layer forming step is not particularly limited as long as it is after the cellulose ester film composition as a support has been melt cast and formed as an optical film. For example, the polymer layer forming step may be continuously performed in the film forming step. . In addition, after film formation, the melted cellulose ester film that has been wound up is drawn out, and a polymer layer is applied and dried by a micro gravure coater or an extrusion coater, and then stretched and dried together with the support by a stretching process using a tenter. A method of performing processing may be used. From the viewpoint of freedom in production and quality assurance, a method in which the film forming step and the polymer layer forming step / stretching step are performed separately is preferable.

  As another method, a method of coating a polymer layer on another support and transferring it to the molten cellulose ester film according to the present invention via an adhesive or the like can also be used.

  The thickness of the polymer layer according to the present invention is preferably 1 to 20 μm, and if it is less than 1 μm, it is difficult to impart desired retardation characteristics, and if it exceeds 20 μm, the film becomes too thick, cracks, breaks, etc. Inferior to handleability. The thickness of the polymer layer is preferably 15 μm or less, more preferably 12 μm or less, and particularly preferably 2 to 10 μm from the viewpoint of thinning and imparting desired retardation characteristics.

  For the formation of the polymer layer, a solid polymer that can be applied by a coating method is preferable, and a solid with good heat resistance that can form a layer having a light transmittance of 75% or more, particularly 85% or more, and excellent in light transmittance. Polymers are preferred. In the present invention, polyether ketone, particularly polyaryl ether ketone, polyamide, polyester, polyimide, polyamide imide or polyester imide, or two or more kinds thereof from the viewpoint of coating layer forming property, retardation imparting by stretching, etc. A mixture or the like is preferably used.

  Specific examples of the above-described polyether ketone, particularly polyaryl ether ketone, include those having a repeating unit represented by the following general formula (14) (Japanese Patent Laid-Open No. 2001-49110).

In the general formula (14), X is a halogen, an alkyl group or an alkoxy group, and the number of bonds q of X to the benzene ring, that is, the p-tetrafluorobenzoylene group and the oxyalkylene group are not bonded, The value of the hydrogen atom substitution number q is an integer of 0 to 4. R ¹ is a compound (group) represented by the following general formula (15), and m is 0 or 1. Further, n represents the degree of polymerization, preferably 2 to 5000, particularly preferably 5 to 500.

  In addition, as a halogen as X in the said General formula (14), a fluorine atom, a bromine atom, a chlorine atom, an iodine atom etc. are mentioned, for example, A fluorine atom is preferable. Examples of the alkyl group include linear or branched alkyl groups having 1 to 6 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group. A halogenated alkyl group such as a group, an ethyl group or a trifluoromethyl group thereof is preferred.

  Furthermore, examples of the alkoxy group include linear or branched alkoxy groups having 1 to 6, especially 1 to 4, such as methoxy group, ethoxy group, propoxy group, isopropoxy group, and butoxy group. A halogenated alkoxy group such as a methoxy group, an ethoxy group, or a trifluoromethoxy group thereof is preferable. In the above, X is particularly preferably a fluorine atom.

  On the other hand, in the group represented by the general formula (15), X ′ is a halogen, an alkyl group or an alkoxy group, and the value of the number of bonds q ′ of X ′ to the benzene ring is an integer of 0 to 4. . Examples of the halogen, alkyl group or alkoxy group as X ′ are the same as those described above for X.

  Preferred X ′ is a fluorine atom, a methyl group or an ethyl group, a halogenated alkyl group such as a trifluoromethyl group thereof, a methoxy group or an ethoxy group, or a halogenated alkoxy group such as a trifluoromethoxy group thereof. Atoms are preferred.

  In the general formulas (14) and (15), X and X ′ may be the same or different. Further, in the general formulas (14) and (15), two or more X or X ′ present in the molecule based on q or q ′ being 2 or more may be the same or different from each other. It may be.

Particularly preferred R ¹ is a group represented by the following general formula (16).

In the general formulas (15) and (16), R ² is a divalent aromatic group, and P is 0 or 1. Examples of the divalent aromatic group include (o, m or p-) phenylene group, naphthalene group, biphenyl group, anthracene group, (o, m or p-) terphenyl group, phenanthrene group, dibenzofuran group, biphenyl. Examples thereof include an ether group, a biphenyl sulfone group, and a divalent aromatic group represented by the following formula. In the divalent aromatic group, hydrogen directly bonded to the aromatic ring may be substituted with the halogen, alkyl group or alkoxy group described above.

In the above, preferable divalent aromatic groups (R ² ) are those represented by the following formulae.

  The polyaryletherketone represented by the general formula (14) may be composed of the same repeating unit, or may have two or more different repeating units. In the latter case, each repeating unit may exist in a block form or may exist randomly.

  Based on the above, the preferable polyaryl ether ketone represented by the general formula (14) is represented by the following general formula (17).

  A preferable polyaryletherketone including a group at the molecular end is represented by the following general formula (18) corresponding to the general formula (14), and corresponds to the general formula (17). Is represented by the following general formula (19). In these, a fluorine atom is bonded to the p-tetrafluorobenzoylene group side in the molecule, and a hydrogen atom is bonded to the oxyalkylene group side.

  On the other hand, specific examples of the polyamide or polyester described above include those having a repeating unit represented by the following general formula (20).

  In the general formula (20), B is halogen, an alkyl group having 1 to 3 carbon atoms or a halide thereof, a phenyl group substituted with one or more of them, or an unsubstituted phenyl group. . z is an integer of 0-3.

E is a covalent bond, an alkenyl group having 2 carbon atoms or a halide thereof, CH ₂ group, C (CX ₃ ) ₂ group, CO group, O atom, S atom, SO ₂ group, Si (R) ₂ group, or NR group. X in the C (CX ₃ ) ₂ group is a hydrogen atom or halogen, and R in the Si (R) ₂ group and the NR group is an alkyl group having 1 to 3 carbon atoms or a halide thereof. E is in a meta position or a para position with respect to the carbonyl group or the Y group. Halogen is a fluorine atom, a chlorine atom, an iodine atom or a bromine atom (hereinafter the same in the general formula (20)).

  Y is an O atom or an NH group. A is a hydrogen atom, halogen, an alkyl group having 1 to 3 carbon atoms or a halide thereof, a nitro group, a cyano group, a thioalkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms or a halide thereof, aryl Group or a halide thereof, an alkyl ester group having 1 to 9 carbon atoms, an aryl ester group having 1 to 12 carbon atoms or a substituted derivative thereof, or an arylamide group having 1 to 12 carbon atoms or a substituted derivative thereof.

  N is an integer of 0 to 4, p is an integer of 0 to 3, q is an integer of 1 to 3, and r is an integer of 0 to 3. A preferred polyamide or polyester has a repeating unit represented by the following general formula (21), wherein r and q are 1, and at least one of the biphenyl rings is substituted at the 2-position and 2′-position. Is.

  In the general formula (21), m is an integer of 0 to 3, preferably 1 or 2, and x and y are 0 or 1, and are not 0 at the same time. The other symbols have the same meanings as in the general formula (20), but E is a covalent bond having a para orientation with respect to the carbonyl group or the Y group.

  In the general formulas (20) and (21), when a plurality of B, E, Y, or A are present in the molecule, they may be the same or different. Similarly, z, n, m, x, and y may be the same or different. In this case, B, E, Y, A, z, n, m, x, and y are determined independently.

  The polyamide or polyester represented by the general formula (20) may be composed of the same repeating unit, or may have two or more different repeating units. In the latter case, each repeating unit may exist in a block form or may exist randomly.

  On the other hand, specific examples of the polyimide described above include, for example, a condensation polymerization product of 9,9-bis (aminoaryl) fluorene and an aromatic tetracarboxylic dianhydride, and are represented by the following general formula (22). And those having one or more repeating units.

  In the general formula (22), R is a hydrogen atom, a halogen, a phenyl group, a phenyl group substituted with 1 to 4 halogens or an alkyl group having 1 to 10 carbon atoms, or 1 to 10 An alkyl group having a carbon atom. Four Rs can be determined independently and can be substituted in the range of 0 to 4. The substituents are preferably those described above, but some of them may be different. Halogen is a fluorine atom, a chlorine atom, an iodine atom or a bromine atom (hereinafter the same in general formula (22)).

  Z is a trisubstituted aromatic group having 6 to 20 carbon atoms. Preferred Z is a pyromellitic group, a polycyclic aromatic group such as a naphthylene group, a fluorenylene group, a benzofluorenylene group or an anthracenylene group or a substituted derivative thereof, or a group represented by the following general formula (23). is there. Examples of the substituent in the substituted derivative of the polycyclic aromatic group include halogen, an alkyl group having 1 to 10 carbon atoms, or a fluorinated product thereof.

In the general formula (23), D is a covalent bond, C (R ² ) ₂ group, CO group, O atom, S atom, SO ₂ group, Si (C ₂ H ₅ ) ₂ group, N (R ³ ₂ ) or a combination thereof, m is an integer of 1-10. R ² is independently a hydrogen atom or a C (R ⁴ ) ₃ group. R ³ is independently a hydrogen atom, an alkyl group having 1 to about 20 carbon atoms, or an aryl group having about 6 to about 20 carbon atoms. Each R ⁴ is independently a hydrogen atom, a fluorine atom or a chlorine atom.

  Moreover, what has a unit represented by the following general formula (24), (25) as a polyimide other than the above can be mentioned. Moreover, the polyimide which has a unit represented by General formula (26) is preferable.

  In the above general formulas (24), (25), and (26), T and L are halogen, an alkyl group having 1 to 3 carbon atoms or a halide thereof, phenyl substituted by one or more of them. Group or an unsubstituted phenyl group. The halogen is a fluorine atom, a chlorine atom, an iodine atom or a bromine atom (hereinafter the same in the general formulas (24), (25) and (26)). z is an integer of 0-3.

G and J are covalent bonds or bond bonds, CH ₂ groups, C (CX ₃ ) ₂ groups, CO groups, O atoms, S atoms, SO ₂ groups, Si (C ₂ H ₅ ) ₂ groups, or N ( CH ₃ ) group. X in the C (CX ₃ ) ₂ group is a hydrogen atom or halogen (hereinafter the same in general formulas (24), (25), and (26)).

  A is a hydrogen atom, a halogen, an alkyl group or a halide thereof, a nitro group, a cyano group, a thioalkyl group, an alkoxy group or a halide thereof, an aryl group or a halide thereof, or an alkyl ester group or a substituted derivative thereof.

  R is a hydrogen atom, a substituted phenyl group such as a halogen, a phenyl group or a halide thereof, or a substituted alkyl group such as an alkyl group or a halide thereof. n is an integer of 0 to 4, p is an integer of 0 to 3, and q is an integer of 1 to 3.

  In the general formulas (24), (25), and (26), when a plurality of T, A, R, or L are present in the molecule, they may be the same or different. May be. Similarly, z, n, and m may be the same or different. In this case, T, A, R, L, z, n, and m are determined independently.

  The polyimides represented by the general formulas (22), (24), (25), and (26) may be composed of the same repeating unit or have two or more different repeating units. It may be. The different repeating unit may be formed by copolymerizing one or more of acid dianhydrides and / or diamines other than those described above. As the diamine, an aromatic diamine is particularly preferable. When it has the latter different repeating unit, each repeating unit may exist in a block shape or may exist randomly.

  Examples of the acid dianhydride for forming the different repeating units include pyromelt acid dianhydride, 3,6-diphenylpyromelt acid dianhydride, and 3,6-bis (trifluoromethyl) pyromelt acid dianhydride. 3,6-dibromopyromelt acid dianhydride, 3,6-dichloropyromelt acid dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 2,3,3 ′ , 4′-benzophenone tetracarboxylic dianhydride, 2,2 ′, 3,3′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylcarboxylic dianhydride, bis (2 , 3-dicarbophenyl) methane dianhydride.

  Also, bis (2,5,6-trifluoro-3,4-dicarboxyphenyl) methane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3- Hexafluoropropane dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride (4,4′-oxydiphthalic anhydride), bis (3,4-dicarboxyphenyl) sulfone dianhydride (3,3 3 ', 4,4'-diphenylsulfonetetracarboxylic anhydride), 4,4'-[4,4'-isopropylidene-di (p-phenyleneoxy)] bis (phthalic anhydride) is An example of an anhydride is given.

  Furthermore, N, N- (3,4-dicarboxyphenyl) -N-methylamine dianhydride, bis (3,4-dicarboxyphenyl) diethylsilane dianhydride, 2,3,6,7-naphthalene-tetra Naphthalenetetracarboxylic acids such as carboxylic dianhydrides, 1,2,5,6-naphthalene-tetracarboxylic dianhydrides, 2,6-dichloro-naphthalene-1,4,5,8-tetracarboxylic dianhydrides Acid dianhydride, thiophene-2,3,4,5-tetracarboxylic dianhydride and pyrazine-2,3,5,6-tetracarboxylic dianhydride, pyridine-2,3,5,6-tetra Heterocyclic aromatic tetracarboxylic dianhydrides such as carboxylic dianhydrides are also examples of the acid dianhydrides.

  Preferably used acid dianhydrides are 2,2′-dibromo-4,4 ′, 5,5′-biphenyltetracarboxylic dianhydride and 2,2′-dichloro-4,4 ′, 5,5 ′. -Biphenyltetracarboxylic dianhydrides, 2,2'-substituted dianhydrides such as 2,2'-trihalo-substituted dianhydrides, especially 2,2-bis (trifluoromethyl) -4,4 ' , 5,5'-biphenyltetracarboxylic dianhydride is preferred.

  On the other hand, examples of the diamine for forming the different repeating units include (o, m or p-) phenylenediamine, 2,4-diaminotoluene, 1,4-diamino-2-methoxybenzene, 1,4- Benzenediamine such as diamino-2-phenylbenzene, 1,3-diamino-4-chlorobenzene, 4,4′-diaminobiphenyl, 4,4-diaminodiphenylmethane, 2,2-bis (4-aminophenyl) propane, 2 , 2-bis (4-aminophenyl) -1,1,1,1,3,3,3-hexafluoropropane, 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 1,3-bis ( 3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) ), And benzene.

  4,4′-bis (4-aminophenoxy) biphenyl, 4,4′-bis (3-aminophenoxy) biphenyl, 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 2,2 -Bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 4,4′-diaminodiphenylthioether, 4,4′-diaminodiphenylsulfone 2,2′-diaminobenzophenone, 3,3′-diaminobenzophenone, naphthalenediamine such as 1,8-diaminonaphthalene and 1,5-diaminonaphthalene, 2,6-diaminopyridine and 2,4-diaminopyridine, Heterocyclic aromatic diamines such as 1,4-diamino-S-triazine are also examples of the diamines described above.

  Examples of polyimides that can be preferably used include 2,2′-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride and 4,4′-bis (3,4-dicarboxyphenyl) -2,2-diphenyl. Heat-resistant and solvent-soluble polyimides prepared using aromatic dianhydrides such as propane dianhydride, naphthalenetetracarboxylic dianhydride and bis (3,4-dicarboxyphenyl) sulfone dianhydride It is.

  Examples of diamines include 4,4- (9-fluorenylidene) -dianiline, 2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl, and 3,3′-dichloro-4,4′-diamino. Diphenylmethane, 2,2′-dichloro-4,4′-diaminobiphenyl, 2,2 ′, 5,5′-tetrachlorobenzidine, 2,2-bis (4-aminophenoxyphenyl) propane, 2,2-bis (4-aminophenoxyphenyl) hexafluoropropane, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, etc. A heat-resistant and solvent-soluble polyimide prepared using an aromatic diamine can be preferably used.

  On the other hand, the above-mentioned polyamideimide or polyesterimide is not particularly limited, and one or more suitable types can be used. Of these, polyamide imides described in JP-A No. 61-162512 and polyester imides described in JP-A No. 64-38472 can be preferably used.

  The molecular weight of the solid polymer for forming the polymer layer is not particularly limited, but is preferably soluble in a solvent. Weight average molecular weight in terms of coating film thickness accuracy, surface accuracy or surface smoothness, film strength, prevention of cracking due to expansion and contraction and distortion when formed into a film, and solubility in solvents (preventing gelation) 10,000 to 1,000,000, preferably 20,000 to 500,000, particularly 50,000 to 200,000. The weight average molecular weight is a value measured by gel permeation chromatography (GPC) using polyethylene oxide as a standard sample and a dimethylformamide solvent.

  For the formation of the polymer layer, the above-mentioned polyaryletherketone, polyamide, polyester, polyimide, or other solid polymer may be used alone, or two or more of the same species may be mixed and used. Further, for example, a mixture of two or more polymers having different functional groups, such as a mixture of polyaryl ether ketone and polyamide, may be used.

  In addition, one of appropriate polymers such as polyethylene, polypropylene, polystyrene, polymethyl methacrylate, ABS resin and AS resin, polyacetate, polycarbonate, etc. other than those described above as long as the orientation of the solid polymer forming the polymer layer is not significantly reduced. Or you may use 2 or more types together. Thermosetting resins such as epoxy resins, phenol resins, and novolac resins are also examples of the combined polymer. The amount of the combined polymer used is not particularly limited as long as the orientation is not significantly lowered, but is usually 50% by mass or less, preferably 40% by mass or less, and particularly preferably 30% by mass or less.

  For liquefaction of the solid polymer forming the polymer layer, an appropriate method such as a method in which a thermoplastic polymer is heated and melted or a method in which a solid polymer is dissolved in a solvent to form a solution can be employed. Therefore, solidification of the spreading layer can be performed by cooling the spreading layer in the former melt and by drying after removing the solvent from the spreading layer in the latter solution. In forming the polymer layer, various additives including stabilizers, plasticizers, metals, and the like can be blended as necessary.

  Drying after the coating of the polymer layer can be performed by a natural drying (air drying) method or a heat drying method, generally hot air, infrared rays, a heating roll, microwaves, or the like. It is preferable to carry out with hot air in terms of simplicity. It is preferable that the drying temperature is gradually increased in the range of 40 to 150 ° C. by 3 to 5 stages of the zone drying method in consideration of the stretching temperature by the tenter which is the next step. It is more preferable to carry out in the range of ° C in order to improve physical properties such as scratch resistance and dimensional stability of the polymer layer.

  Examples of the solvent include chloroform and dichloromethane, carbon tetrachloride and dichloroethane, tetrachloroethane and trichloroethylene, halogenated hydrocarbons such as tetrachloroethylene, chlorobenzene, and orthodichlorobenzene, phenols such as phenol and parachlorophenol, benzene and toluene, Aromatic hydrocarbons such as xylene, methoxybenzene, 1,2-dimethoxybenzene, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, 2-pyrrolidone, ketones such as N-methyl-2-pyrrolidone, acetic acid Examples include esters such as ethyl and butyl acetate.

  Further, alcohols such as t-butyl alcohol and glycerin, ethylene glycol and triethylene glycol, ethylene glycol monomethyl ether and diethylene glycol dimethyl ether, propylene glycol and dipropylene glycol and 2-methyl-2,4-pentanediol, dimethylformamide and dimethyl Examples of the solvent include amides such as acetamide, nitriles such as acetonitrile and butyronitrile, ethers such as diethyl ether, dibutyl ether and tetrahydrofuran, methylene chloride, carbon disulfide, ethyl cellosolve and butyl cellosolve.

  A solvent can be used individually or in mixture of 2 or more types by an appropriate combination. From the viewpoint of coating viscosity and the like, the solution is preferably prepared by dissolving 2 to 100 parts by mass, preferably 5 to 50 parts by mass, particularly 10 to 40 parts by mass of the solid polymer with respect to 100 parts by mass of the solvent.

  For the development of the liquefied polymer on the molten cellulose ester film, for example, spin coating method, roll coating method, flow coating method, printing method, dip coating method, casting film forming method, bar coating method, gravure printing method, etc. An appropriate film forming method such as a casting method or an extrusion method can be employed. Among them, a solution film forming method such as a casting method can be preferably applied from the viewpoint of mass productivity of a film having little thickness unevenness and alignment strain unevenness.

  For the polymer layer, the polymer solution dissolved in a solvent and liquefied as described above is spread on a support and dried, and the support is subjected to stretching treatment described later. The stretching treatment is preferably performed by a tenter method. According to this method, the polymer layer can be processed in a state of being supported by the base material, and the manufacturing efficiency and processing accuracy are excellent, and continuous manufacturing is also possible.

(Stretching operation)
A preferred stretching operation for the optical compensation film of the present invention will be described.

  In the optical compensation film of the present invention, it is preferable to control the retardation by simultaneously stretching the polymer layer and the optical film by the following stretching operation after the polymer layer is provided on the melt-cast optical film. Moreover, the optical film alone melt-cast before providing the polymer layer may be similarly stretched.

  The stretching is preferably performed by stretching 1.0 to 2.0 times in one direction of the optical film, and the other is stretched by about 0.8 to 1.5 times.

  For example, the film can be stretched sequentially or simultaneously in the longitudinal direction of the film and in the direction perpendicular to the film plane, that is, the width direction, but at this time, it is sufficient if the stretching ratio in at least one direction is too small. If the phase difference cannot be obtained and is too large, stretching may be difficult and fracture may occur.

  For example, when the film is stretched in the direction of melting and casting, if the contraction in the width direction is too large, the refractive index in the thickness direction of the film becomes too large. In this case, the width shrinkage of the film can be suppressed or improved by stretching in the width direction. When stretching in the width direction, the refractive index may be distributed with a width. This is sometimes seen when the tenter method is used, but it is a phenomenon that occurs when the film is stretched in the width direction, causing contraction force at the center of the film and the ends being fixed. It is thought to be called a phenomenon. Even in this case, by stretching in the casting direction, the bowing phenomenon can be suppressed and the distribution of the width retardation can be reduced.

  Furthermore, the film thickness fluctuation | variation of the film obtained can be reduced by extending | stretching in the biaxial direction orthogonal to each other. When the film thickness variation of the optical compensation film is too large, the retardation becomes uneven, and unevenness such as coloring may be a problem when used in a liquid crystal display.

  The film thickness variation of the optical compensation film of the present invention is preferably in the range of ± 3%, and more preferably ± 1%. For the purposes as described above, a method of stretching in biaxial directions perpendicular to each other is effective.

  As the optical compensation film, in order to control retardation in the in-plane direction or the thickness direction, free end uniaxial stretching may be performed in the film forming direction, or unbalanced biaxial stretching in which the film is stretched in the width direction and contracted in the casting direction. The magnification in the shrinking direction is preferably 0.7 to 1.0.

  When a cellulose resin that obtains positive birefringence with respect to stress is used, the slow axis of the optical compensation film can be imparted in the width direction by stretching in the width direction. In this case, in the present invention, in order to improve display quality, the slow axis of the optical compensation film is preferably in the width direction, and satisfies (stretch ratio in the width direction)> (stretch ratio in the casting direction). It is preferable.

  Prior to stretching, the melt-cast optical film coated with the polymer layer is 50 to 180 ° C. or less, more preferably 60 to 160 ° C. or less, still more preferably 70 to 150 ° C. or less, 5 seconds or more and 3 minutes or less, More preferably, heat treatment (pre-heat treatment) is performed for 10 seconds or more and 2 minutes or less, and further preferably for 15 seconds or more and 90 seconds or less. This heat treatment is preferably performed from immediately before gripping the film with a tenter to immediately before stretching starts. Particularly preferably, it is carried out between the time when the film is held by a tenter and the time immediately before stretching starts.

  The stretching is preferably performed at 5 to 300% / min, more preferably 10 to 200% / min, and further preferably 15 to 150% / min. The stretching is preferably performed by gripping both ends of the film using a tenter.

  The stretching angle is preferably 2 ° to 10 °, more preferably 3 ° to 7 °, and most preferably 3 ° to 5 °. The stretching speed may be constant or may be changed.

  The stretching temperature is preferably controlled so that the stretching temperature B is represented by the following formula (I).

Formula (I) Melting temperature A-100 ° C. ≦ Extension temperature B ≦ Melting temperature A-40 ° C.
(However, the melting temperature A represents the temperature at the time of melt casting of the optical film)
When the stretching temperature B is a temperature lower than the melting temperature A-100 ° C., it is necessary to increase the stretching ratio in order to obtain a sufficient phase difference, and the film is broken or haze and coloring are increased. On the other hand, when the stretching temperature B is higher than the melting temperature A-40 ° C., the retardation control and reproducibility are poor and stretching unevenness is likely to occur. Also in this case, the coloration tends to increase over a long period of time.

  A more preferable stretching temperature B is to satisfy the relationship of melting temperature A−90 ° C. ≦ stretching temperature B ≦ melting temperature A−50 ° C.

The atmospheric temperature in the tenter process preferably has a small distribution, preferably within ± 5 ° C in the width direction, more preferably within ± 2 ° C, still more preferably within ± 1 ° C, and most preferably within ± 0.5 ° C. . In the tenter process, preferably subjected to heat treatment in the heat transfer coefficient ^{20J / m 2 hr~130 × 10 3} J / m 2 hr. More preferably, in the range of ^{40J / m 2 hr~130 × 10 3} J / m 2 hr, and most preferably in the range of ^{42J / m 2 hr~84 × 10 3} J / m 2 hr.

  The film transport tension in the film forming process such as in the tenter depends on the temperature, but is preferably 120 N / m to 200 N / m, and more preferably 140 N / m to 200 N / m. 140 N / m to 160 N / m is most preferable.

  In order to prevent unintended film elongation in the film forming process, it is preferable to provide a tension cut roll in front of or behind the tenter.

The optical compensation film according to the present invention is preferably subjected to a heat treatment after stretching to alleviate the remaining strain. The heat treatment is preferably performed at 110 to 150 ° C, preferably 100 to 180 ° C, more preferably 130 to 160 ° C. In this case, it is preferable to carry out the heat treatment in the heat transfer coefficient ^{20J / m 2 hr~130 × 10 3} J / m 2 hr. More preferably, in the range of ^{40J / m 2 hr~130 × 10 3} J / m 2 hr, and most preferably in the range of ^{42J / m 2 hr~84 × 10 3} J / m 2 hr. Thereby, the remaining strain is reduced, and the dimensional stability under high temperature conditions such as 90 ° C. or high temperature high humidity conditions such as 80 ° C. and 90% RH is improved.

  The stretched film is cooled to room temperature after stretching. The stretched film preferably starts to be cooled while being held in a width by a tenter, and the width held by the tenter during this period is 1 to 10%, more preferably 2 to 9%, relative to the film width after stretching. More preferably, it is reduced and relaxed by 2% or more and 8% or less. The cooling rate is preferably 10 to 300 ° C./min, more preferably 30 to 250 ° C./min, and still more preferably 50 to 200 ° C./min. Although it may be cooled to room temperature while being held by the tenter, it is preferable to stop the holding in the middle and switch to roll conveyance, and then it is wound into a roll.

  The optical compensation film of the present invention produced as described above has the following characteristics.

(optical properties)
The optical compensation film of the present invention is preferably such that the retardation value Ro defined by the above formula is 20 to 300 nm and the retardation value Rt is in the range of −600 to 600 nm in a state where the polymer layer is laminated on the optical film. . Further, a more preferable range is a range where the Ro value is 20 to 120 nm and an Rt value is -400 to 400 nm, and a particularly preferable range is a range where the Ro value is 40 to 100 nm and the Rt value is -300 to 300 nm.

  The optical compensation film of the present invention is particularly advantageously used as an optical compensation film for a VA liquid crystal display device having a VA mode liquid crystal cell. The optical compensation film used in the VA liquid crystal display device preferably has a Ro value of 20 to 150 nm and an Rt value of 70 to 400 nm. The Ro value is more preferably 30 to 100 nm. When two optical compensation films are used in the VA liquid crystal display device, the Rt value of the film is preferably 70 to 250 nm. When one optical compensation film is used for the VA liquid crystal display device, the Rt value of the film is preferably 150 to 400 nm.

  By making a retardation value into the said range, the optical performance as a retardation film for polarizing plates can be fully satisfied especially.

  Hereinafter, other physical properties of the optical film and the optical compensation film of the present invention will be described. The following physical properties are preferable physical properties of the optical film alone and an optical compensation film in which a polymer layer is coated and fixed on the optical film.

(Moisture permeability)
It optical film of the present invention, the moisture permeability of the optical compensation film is 25 ° C., preferably from 1~250g / m ² · 24 hours under 90% RH environment, 10~200g / m ² · 24 hours Is more preferable, and most preferably 20 to 180 g / m ² · 24 hours. The moisture permeability can be measured by the method described in JIS Z0208.

(Equilibrium moisture content)
The optical film and the optical compensation film preferably have an equilibrium water content of 0.1 to 3% at a temperature of 25 ° C. and a relative humidity of 60%, more preferably 0.3 to 2%, and more preferably 0.5 to Particularly preferred is 1.5%.

  Equilibrium water content is measured by a Karl Fischer method (Karl Fischer moisture measuring device CA-05, manufactured by Mitsubishi Chemical Corporation, moisture vaporizer: VA-05, internal liquid: Aquamicron CXμ, external liquid: Aquamicron AX, Nitrogen gas flow rate: 200 ml / min, heating temperature: 150 ° C.). Specifically, 0.6-1.0 g of a sample conditioned at 25 ° C. and 60% relative humidity for 24 hours or more is accurately weighed and measured with a measuring machine, and the equilibrium moisture content is obtained from the obtained water content. I can do it.

The water content of the optical film and optical compensation film of the present invention is preferably 0.3 to 15 g / m ² at 30 ° C. and 85% RH so as not to impair the adhesiveness with polyvinyl alcohol (polarizer). . More preferably, it is 0.5-10 g / m < ² >. If it is greater than 15 g / m ^{2, the} variation of retardation due to temperature change and humidity change tends to increase.

(Dimensional stability)
The optical film and the optical compensation film according to the present invention are also characterized by excellent dimensional stability. The dimensional stability is evaluated by measuring a dimensional change (shrinkage) rate as a change rate (%) with respect to the original length by the following measurement method. The dimensional change rate is preferably 0 to -0.06%.

<Measurement of dimensional change rate>
The film was conditioned for 24 hours in a room conditioned at a temperature of 23 ° C. and a relative humidity of 55%, and then marked with a cutter at intervals of about 10 cm in width and length, and the distance (L1) was measured. Next, the film was stored for 24 hours in a thermostatic chamber set to predetermined temperature and humidity conditions. The film was conditioned again in a room conditioned at a temperature of 23 ° C. and a relative humidity of 55% for 24 hours, and the distance (L2) between the marks was measured. The dimensional change rate was evaluated by the following formula.

Dimensional change rate (%) = {(L2-L1) / L1} × 100
(Polarizer)
The polarizing plate can be produced by a general method. The optical film of the present invention, the back side of the optical compensation film is subjected to alkali saponification treatment, and the treated optical film and the optical compensation film are immersed and stretched in an iodine solution. It is preferable to bond using an aqueous polyvinyl alcohol solution. Even if the optical film of the present invention is used on the other side, norbornene polymer or polycarbonate, polyether sulfone or polysulfone, polyolefin or acrylic polymer, polyarylate, polystyrene or polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, cellulose A polymer film such as an ester polymer may be used, or another polarizing plate protective film may be used. A commercially available cellulose ester film can be used for the polarizing plate protective film used on the other surface of the optical film and the optical compensation film of the present invention. For example, as a commercially available cellulose ester film, Konica Minoltac KC8UX, KC4UX, KC5UX, KC8UY, KC4UY, KC12UR, KC8UXW-H, KC8UYW-HA, KC8UX-RHA (manufactured by Konica Minolta Opto Co., Ltd. cellulose) A polarizing plate that is preferably used, has excellent flatness, and has a stable viewing angle widening effect can be obtained.

  The polarizing film, which is the main component of the polarizing plate, is an element that transmits only light having a polarization plane in a certain direction. A typical polarizing film known at present is a polyvinyl alcohol polarizing film, which is a polyvinyl alcohol film. There are one in which iodine is dyed on a system film and one in which dichroic dye is dyed. As the polarizing film, a polyvinyl alcohol aqueous solution is formed and dyed by uniaxially stretching or dyed, or uniaxially stretched after dyeing, and then preferably subjected to a durability treatment with a boron compound. On the surface of the polarizing film, one side of the optical compensation film of the present invention is bonded to form a polarizing plate. It is preferably bonded with an aqueous adhesive mainly composed of completely saponified polyvinyl alcohol or the like.

  Since the polarizing film is stretched in a uniaxial direction (usually the longitudinal direction), when the polarizing plate is placed in a high-temperature and high-humidity environment, the stretching direction (usually the longitudinal direction) shrinks, and the direction perpendicular to the stretching (usually the width direction) ) Will grow. As the thickness of the polarizing plate protective film becomes thinner, the expansion / contraction ratio of the polarizing plate increases, and in particular, the amount of contraction in the stretching direction of the polarizing film increases. Normally, the stretching direction of the polarizing film is bonded to the casting direction (MD direction) of the polarizing plate protective film. Therefore, when thinning the polarizing plate protective film, it is particularly important to suppress the stretch rate in the casting direction. It is. Since the optical compensation film of the present invention is extremely excellent in dimensional stability, it is suitably used as such a polarizing plate protective film. The thickness of the polarizing film is preferably 5 to 30 μm.

  That is, even when the durability test is performed at 60 ° C. and 90% RH, the wavy unevenness does not increase, and even if the polarizing plate has an optical compensation film on the back side, the viewing angle characteristics fluctuate after the durability test. Good visibility can be provided without doing so.

  The polarizing plate can be constituted by further bonding a protective film on one surface of the polarizing plate and a separate film on the other surface. The protective film and the separate film are used for the purpose of protecting the polarizing plate at the time of shipping the polarizing plate and at the time of product inspection. In this case, the protect film is bonded for the purpose of protecting the surface of the polarizing plate, and is used on the side opposite to the surface where the polarizing plate is bonded to the liquid crystal plate. Moreover, a separate film is used in order to cover the contact bonding layer bonded to a liquid crystal board, and is used for the surface side which bonds a polarizing plate to a liquid crystal cell.

(Liquid crystal display device)
By using the polarizing plate of the present invention as a liquid crystal display device bonded to at least one surface of a liquid crystal cell, the liquid crystal display device of the present invention having various visibility can be produced. The optical film and the optical compensation film of the present invention are various drive systems such as a reflective type, a transmissive type, a transflective type LCD, or a TN type, STN type, OCB type, HAN type, VA type (PVA type, MVA type), IPS type, etc. It is preferably used in LCDs. Moreover, the optical film and optical compensation film of the present invention are excellent in flatness and are preferably used for various display devices such as a plasma display, a field emission display, an organic EL display, an inorganic EL display, and electronic paper. In particular, a large-screen display device with a 30-inch screen or more has the effect that there is little unevenness in color and undulation, and eyes are not tired even during long-time viewing.

  For example, the preferred configuration of the liquid crystal display device is as follows, but is not limited thereto. The molten cellulose ester film refers to the optical film according to the present invention.

(Viewing side) Molten cellulose ester film / polarizer / melted cellulose ester film / liquid crystal cell / polymer layer / molten cellulose ester film / polarizer / molten cellulose ester film (backlight)
(Viewing side) Molten cellulose ester film / polarizer / molten cellulose ester film / polymer layer / liquid crystal cell / polymer layer / molten cellulose ester film / polarizer / protective film / (backlight)
In the present invention, by using an optical compensation film provided with a polymer layer and stretched together with the support, expression of sufficient retardation can be expected. Therefore, one optical compensation film provided with a polymer layer may be used. This is preferable from the viewpoint of the stability of retardation, which is the purpose.

  The molten cellulose ester film on the viewing side includes an antistatic layer, a transparent conductive layer, a hard coat layer, an antiglare hard coat layer, an antireflection layer, an antifouling layer, a slippery layer, an easy adhesion layer, and an antiglare layer. A known functional layer such as a gas barrier layer may be coated on the film.

  The backlight used in the liquid crystal display device of the present invention may be a sidelight type, a direct type, or a combination thereof, but is preferably a direct type backlight. A particularly preferred direct type backlight is an LED backlight for a color liquid crystal display device having a red (R) LED, a green (G) LED, and a blue (B) LED, for example, the peak of the red (R) LED. Preferably, the wavelength is 610 nm or more, the peak wavelength of the green (G) LED is in the range of 530 ± 10 nm, and the peak wavelength of the blue (B) LED is 480 nm or less. Examples of types of green (G) LEDs having a peak wavelength within the above range include DG1112H (manufactured by Stanley Electric Co., Ltd.), UG1112H (manufactured by Stanley Electric Co., Ltd.), and E1L51-3G (manufactured by Toyoda Gosei Co., Ltd.). E1L49-3G (manufactured by Toyoda Gosei Co., Ltd.), NSPG500S (manufactured by Nichia Chemical Co., Ltd.), and the like. The types of LEDs used as red (R) LEDs include, for example, FR1112H (manufactured by Stanley Electric Co., Ltd.), FR5366X (manufactured by Stanley Electric Co., Ltd.), NSTM515AS (manufactured by Nichia Corporation), GL3ZR2D1COS (Sharp) GM1JJ35200AE (manufactured by Sharp Corporation) and the like. As types of LEDs used as blue (B) LEDs, DB1112H (manufactured by Stanley Electric Co., Ltd.), DB5306X (manufactured by Stanley Electric Co., Ltd.), E1L51-3B (manufactured by Toyoda Gosei Co., Ltd.), E1L4E-SB1A (manufactured by Stanley Electric Co., Ltd.) Toyoda Gosei Co., Ltd.), NSPB630S (Nichia Chemical Co., Ltd.), NSPB310A (Nichia Chemical Co., Ltd.), and the like.

  A backlight can be formed by combining the above-described three-color LEDs. Alternatively, a white LED can be used.

  In addition, as a direct type backlight (or direct type), a direct type backlight described in JP-A No. 2001-281656, a direct type backlight using a point light source such as an LED described in JP-A No. 2001-305535, Examples include a direct type backlight described in JP-A-2002-311412, but are not limited thereto.

  According to the present invention, a change in visibility due to heat generated by an LED backlight or environmental changes is significantly reduced, and a liquid crystal display device excellent in color reproducibility can be manufactured.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Example 1
[Synthesis of Polymers 1-12]
<Polymer 1>
Methyl acrylate 10 parts by weight 2-hydroxyethyl acrylate 1 part by weight Azobisisobutyronitrile (AIBN) 1 part by weight Toluene 30 parts by weight Four-necked flask (input, thermometer, reflux condenser, nitrogen introduction) And the temperature is gradually raised to 80 ° C., and polymerization is performed for 5 hours while stirring. After the polymerization, the polymer solution is poured into a large amount of methanol to precipitate, and further washed with methanol. Purification and drying gave Polymer 1 having a weight average molecular weight of 5000 (measured by GPC).

<Polymer 2>
Methyl acrylate 10 parts by mass 2-hydroxyethyl acrylate 1 part by mass AIBN 2 parts by mass Toluene 30 parts by mass Polymerization, precipitation and purification were performed in the same manner as in Polymer 1 to obtain Polymer 2 having a weight average molecular weight of 2,000.

<Polymer 3>
Methyl acrylate 12 parts by mass Azobis (2-hydroxyethylbutyrate) 2.4 parts by mass Toluene 30 parts by mass Polymerization, precipitation and purification were performed in the same manner as in Polymer 1 to obtain Polymer 3 having a weight average molecular weight of 2000.

<Polymer 4>
Methyl methacrylate 10 parts by mass 2-hydroxyethyl methacrylate 1 part by mass AIBN 2 parts by mass Toluene 30 parts by mass Polymerization, precipitation and purification were performed in the same manner as in Polymer 1 to obtain a polymer 4 having a weight average molecular weight of 2000.

<Polymer 5>
Methyl acrylate 6 parts by mass Ethyl acrylate 5 parts by mass 2-hydroxyethyl acrylate 1 part by mass AIBN 2 parts by mass Toluene 30 parts by mass Polymerization, precipitation and purification were performed in the same manner as in Polymer 1 to obtain Polymer 5 having a weight average molecular weight of 2,000.

<Polymer 6>
Methyl methacrylate 6 parts by weight Ethyl methacrylate 5 parts by weight 2-hydroxyethyl methacrylate 1 part by weight AIBN 2 parts by weight Toluene 30 parts by weight Polymerization, precipitation and purification were performed in the same manner as in Polymer 1 to obtain a polymer 6 having a weight average molecular weight of 2,000. .

<Polymer 7>
Bulk polymerization was performed by the polymerization method described in JP-A No. 2000-344823. That is, the contents were heated to 70 ° C. while introducing the following methyl methacrylate and ruthenocene into a flask equipped with a stirrer, a nitrogen gas inlet tube, a thermometer, an inlet, and a reflux condenser. Next, half of the following β-mercaptopropionic acid which had been sufficiently purged with nitrogen gas was added to the flask under stirring. After the addition of β-mercaptopropionic acid, the contents in the stirring flask were maintained at 70 ° C. and polymerization was carried out for 2 hours. Further, after adding the other half of β-mercaptopropionic acid substituted with nitrogen gas, the temperature of the content being stirred was maintained at 70 ° C., and polymerization was carried out for 4 hours. The temperature of the reaction product was returned to room temperature, and 20 parts by mass of a 5% by mass benzoquinone tetrahydrofuran solution was added to the reaction product to stop the polymerization. While gradually heating the polymer to 80 ° C. under reduced pressure with an evaporator, tetrahydrofuran, residual monomer and residual thiol compound were removed to obtain polymer 7. The weight average molecular weight was 3400. The hydroxyl value (according to the measurement method described below) was 50.

Methyl methacrylate 100 parts by mass Ruthenocene (metal catalyst) 0.05 parts by mass β-mercaptopropionic acid 12 parts by mass (Method for measuring hydroxyl value)
This measurement conforms to JIS K 0070 (1992). This hydroxyl value is defined as the number of mg of potassium hydroxide required to neutralize acetic acid bonded to a hydroxyl group when 1 g of a sample is acetylated. Specifically, sample Xg (about 1 g) is precisely weighed in a flask, and 20 ml of an acetylating reagent (a solution obtained by adding pyridine to 20 ml of acetic anhydride to 400 ml) is accurately added thereto. An air cooling tube is attached to the mouth of the flask and heated in a glycerin bath at 95-100 ° C. After 1 hour and 30 minutes, the mixture is cooled, 1 ml of purified water is added from an air condenser, and acetic anhydride is decomposed into acetic acid. Next, titration is performed with a 0.5 mol / L potassium hydroxide ethanol solution using a potentiometric titrator, and the inflection point of the obtained titration curve is set as the end point. Further, as a blank test, titration is performed without a sample, and an inflection point of the titration curve is obtained. The hydroxyl value is calculated by the following formula.

Hydroxyl value = {(BC) × f × 28.05 / X} + D
In the formula, B is the amount (ml) of 0.5 mol / L potassium hydroxide ethanol solution used for the blank test, C is the amount (ml) of 0.5 mol / L potassium hydroxide ethanol solution used for titration, f is a factor of 0.5 mol / L potassium hydroxide ethanol solution, D is an acid value, and 28.05 is 1/2 of 1 mol amount of potassium hydroxide 56.11.

<Polymer 8>
Bulk polymerization was performed by the polymerization method described in JP-A No. 2000-128911. That is, the following methyl acrylate was introduced into a flask equipped with a stirrer, a nitrogen gas inlet tube, a thermometer, an inlet, and a reflux condenser, and the following thioglycerol, which was substituted with nitrogen gas by introducing nitrogen gas, was stirred. Added. After the addition of thioglycerol, polymerization was carried out for 4 hours while maintaining the temperature of the contents at 60 ° C., the contents were returned to room temperature, and 20 parts by mass of a 5% by mass benzoquinone tetrahydrofuran solution was added thereto to stop the polymerization. The contents were transferred to an evaporator, and tetrahydrofuran, residual monomer and residual thioglycerol were removed under reduced pressure at 80 ° C. to obtain polymer 8. The weight average molecular weight was 2100, and the hydroxyl value was 35.

Methyl acrylate 100 parts by mass Thioglycerol 5 parts by mass <Polymer 9>
Polymer 9 was polymerized using a ruthenocene and β-mercaptopropionic acid in the same manner as for polymer 7 using a mixed monomer of methyl acrylate and benzyl methacrylate. The weight average molecular weight was 1800, and the hydroxyl value was 35.

Methyl acrylate 70 parts by mass Benzyl methacrylate 30 parts by mass Ruthenocene 0.05 part by mass β-mercaptopropionic acid 12 parts by mass <Polymer 10>
Polymerization was performed in the same manner as for polymer 8 using a mixed monomer of methyl acrylate and cyclohexyl methacrylate and thioglycerol to obtain polymer 10. The weight average molecular weight was 2200, and the hydroxyl value was 40.

Methyl acrylate 65 parts by mass Cyclohexyl methacrylate 35 parts by mass Thioglycerol 5 parts by mass <Polymer 11>
Polymerization was carried out using vinyl acetate monomer and thioglycerol in the same manner as polymer 8 to obtain polymer 11. The weight average molecular weight was 1600, and the hydroxyl value was 35.

Vinyl acetate 100 parts by mass Thioglycerol 5 parts by mass <Polymer 12>
Polymer 12 was polymerized in the same manner as Polymer 8 using a mixed monomer of vinyl acetate monomer and vinyl benzoate and thioglycerol. The weight average molecular weight was 4000 and the hydroxyl value was 47.

70 parts by weight of vinyl acetate 30 parts by weight of vinyl benzoate 5 parts by weight of thioglycerol <Polymer 13>
A polymer 13 was obtained in the same manner as in the preparation of the polymer 1 except that 2.5 parts by mass of azobisisobutyronitrile (AIBN) was changed. The weight average molecular weight was 300.

<Polymer 14>
A polymer 14 was obtained in the same manner as in the preparation of the polymer 1 except that 2.0 parts by mass of azobisisobutyronitrile (AIBN) was changed. The weight average molecular weight was 500.

<Polymer 15>
A polymer 15 was obtained in the same manner as in the preparation of the polymer 1 except that 0.5 part by mass of azobisisobutyronitrile (AIBN) was changed. The weight average molecular weight was 10,000.

<Polymer 16>
A polymer 16 was obtained in the same manner as in the preparation of the polymer 1 except that azobisisobutyronitrile (AIBN) was changed to 0.25 part by mass. The weight average molecular weight was 15000.

<Polymer 17>
Polymer 17 was obtained in the same manner as in the preparation of polymer 1 except that 0.15 parts by mass of azobisisobutyronitrile (AIBN) was used. The weight average molecular weight was 30000.

<Polymer 18>
A polymer 18 was obtained in the same manner as in the preparation of the polymer 1 except that azobisisobutyronitrile (AIBN) was changed to 0.10 parts by mass. The weight average molecular weight was 40,000.

(Material)
<Cellulose resin: 90 parts by mass>
Cellulose ester 1: cellulose tripropionate having a substitution degree of propionyl group of 2.91, a number average molecular weight of 75,000 and a residual sulfuric acid content (as a sulfur element) of 16 ppm. Cellulose ester 2: substitution degree of acetyl group of 1.90, Cellulose acetate propionate having a substitution degree of propionyl group of 0.75, a number average molecular weight of 80,000, and a residual sulfuric acid content (as sulfur element) of 50 ppm. Cellulose ester 3: substitution degree of acetyl group is 2.0, Cellulose acetate propionate having a degree of substitution of 0.75, a number average molecular weight of 100,000, and a residual sulfuric acid content (as elemental sulfur) of 25 ppm Cellulose ester 4: The degree of substitution of acetyl group is 2.0, and the degree of substitution of propionyl group is 0.8, number average molecular weight 95,000, residual sulfuric acid contained Cellulose acetate propionate having 45 ppm (as elemental sulfur) Cellulose ester 5: Degree of substitution of acetyl group is 2.0, degree of substitution of butyryl group is 0.70, number average molecular weight 120,000, residual sulfuric acid content (elemental sulfur Cellulose acetate butyrate cellulose ester 6: acetyl group substitution degree 1.90, propionyl group substitution degree 0.75, number average molecular weight 80000, residual sulfuric acid content (as sulfur element) 75 ppm Cellulose acetate propionate cellulose ester 7: Degree of substitution of acetyl group is 2.0, degree of substitution of propionyl group is 0.75, number average molecular weight is 100,000, residual sulfuric acid content (as elemental sulfur) is 0.1 ppm Some cellulose acetate propionate (cellulose 3 Prepared to remove residual sulfuric acid is washed with water after washing with .01N sodium hydroxide solution)
(Residual sulfuric acid content measurement method)
The residual sulfuric acid content was measured by the following method.

<Preprocessing>
500 mg (M) of a sample is weighed into a polypropylene container, and 10 ml of ultrapure water is added.

  This is dispersed with an ultrasonic cleaner for 30 minutes and then filtered with an aqueous chromatodisc (0.45 μm). This is used as a sample.

(Quantification of SO ₄ )
<Apparatus> DX-120 made by ion chromatograph DIONEX
<Column> IonPac AG14 (4 mm) + IonPac AS14 (4 mm)
<Suppressor> ASRS-ULTRAII (4mm)
<Eluent> 3.5 mM-Na ₂ CO ₃ 1.0 mM-NaHCO ₃
<SRS current> 50 mA
<Flow rate> 1.0 ml / min
<Injection volume> 25 μl
<Conversion method>
Content (ppm) = Measured value (mg / l) / 1000 × 10 / M (mg) × 1000000
<Plasticizer>
Plasticizer 1: 10 parts by weight of triphenyl phosphate Plasticizer 2: 10 parts by weight of trimethylolpropane tribenzoate Plasticizer 3: Polyester plasticizer Sample No. 3 (Aromatic terminal ester sample)
10 parts by mass Plasticizer 4: citrate plasticizer Compound PL-11 described in JP-A-2002-62430 10 parts by mass Plasticizer 5: phthalate ester plasticizer The following compound-1 10 parts by mass

<Ultraviolet absorber>
UV-1: Tinuvin 109 (manufactured by Ciba Specialty Chemicals Co., Ltd., weight average molecular weight: 486, molar extinction coefficient at 380 nm = 6780) 2 parts by mass UV-2: polymer UV agent P-1 by the following synthesis 2 parts by mass ( Polymer UV Agent P-1 Synthesis Example)
2 (2′-Hydroxy-5′-t-butyl-phenyl) -5-carboxylic acid- (2-methacryloyloxy) ethyl ester-2H-benzotriazole (Exemplary Compound MUV-19) was prepared according to the method described below. Synthesized.

  20.0 g 3-nitro-4-amino-benzoic acid was dissolved in 160 ml water and 43 ml concentrated hydrochloric acid was added. After adding 8.0 g of sodium nitrite dissolved in 20 ml of water at 0 ° C., the mixture was stirred at 0 ° C. for 2 hours. To this solution, 17.3 g of 4-t-butylphenol was added dropwise at 0 ° C. in a solution of 50 ml of water and 100 ml of ethanol while keeping the liquidity alkaline with potassium carbonate. The solution was stirred for 1 hour while maintaining at 0 ° C., and further for 1 hour at room temperature. The reaction solution was acidified with hydrochloric acid, and the resulting precipitate was filtered and washed thoroughly with water.

  The filtered precipitate was dissolved in 500 ml of 1 mol / L NaOH aqueous solution, 35 g of zinc powder was added, and 110 g of 40% NaOH aqueous solution was added dropwise. After dropping, the mixture was stirred for about 2 hours, filtered, washed with water, and the filtrate was neutralized with hydrochloric acid to neutral. The deposited precipitate is filtered, washed with water, dried and then recrystallized with a mixed solvent of ethyl acetate and acetone to give 2 (2'-hydroxy-5'-t-butyl-phenyl) -5-carboxylic acid-2H. -Benzotriazole was obtained.

  Then 10.0 g of 2 (2′-hydroxy-5′-t-butyl-phenyl) -5-carboxylic acid-2H-benzotriazole and 0.1 g of hydroquinone, 4.6 g of 2-hydroxyethyl methacrylate, 0 .5 g of p-toluenesulfonic acid is added to 100 ml of toluene, and heated and perfused for 10 hours in a reaction vessel equipped with an ester tube. The reaction solution was poured into water, and the precipitated crystals were filtered, washed with water, dried, and recrystallized with ethyl acetate. ) -5-carboxylic acid- (2-methacryloyloxy) ethyl ester-2H-benzotriazole was obtained.

  Next, a copolymer of 2 (2'-hydroxy-5'-t-butyl-phenyl) -5-carboxylic acid- (2-methacryloyloxy) ethyl ester-2H-benzotriazole and methyl methacrylate (polymer UV Agent P-1) was synthesized according to the method described below.

To 80 ml of tetrahydrofuran, 4.0 g of 2 (2′-hydroxy-5′-t-butyl-phenyl) -5-carboxylic acid- (2-methacryloyloxy) ethyl ester-2H-benzotriazole synthesized in Synthesis Example 3 above. And 6.0 g of methyl methacrylate were added followed by 1.14 g of azoisobutyronitrile. The mixture was heated to reflux for 9 hours under a nitrogen atmosphere. Tetrahydrofuran was distilled off under reduced pressure, then redissolved in 20 ml of tetrahydrofuran and added dropwise to a large excess of methanol. The deposited precipitate was collected by filtration and dried in vacuo at 40 ° C. to obtain 9.1 g of a polymer UV agent P-1 which was a gray white powdery polymer. This copolymer was confirmed to have a weight average molecular weight of 9000 by GPC analysis based on standard polystyrene.
The molar extinction coefficient of the monomer component at 380 nm was 7320.

  From the NMR spectrum and UV spectrum, the copolymer was found to contain 2 (2'-hydroxy-5'-t-butyl-phenyl) -5-carboxylic acid- (2-methacryloyloxy) ethyl ester-2H-benzotriazole and methacrylic acid. It was confirmed that it was a copolymer of methyl acid. The composition of the polymer is approximately 2 (2′-hydroxy-5′-t-butyl-phenyl) -5-carboxylic acid- (2-methacryloyloxy) ethyl ester-2H-benzotriazole: methyl methacrylate = 40: 60.

  UV-3: RUVA-100 (manufactured by Otsuka Chemical Co., Ltd., weight average molecular weight is 494.5, molar extinction coefficient at 380 nm is 4340) 1 part by mass

  UV-4: LA-31 (Asahi Denka Kogyo Co., Ltd., weight average molecular weight 658.9, molar extinction coefficient at 380 nm is 8250) 1.6 parts by mass

UV-5: PUVA-30M (manufactured by Otsuka Chemical Co., Ltd., weight average molecular weight is 9000, molar absorption coefficient of monomer component at 380 nm is 600, 3- (2H-1,2,3-benzotriazol-2-yl) -4-hydroxyphenethyl = methacrylate and methyl = methacrylate copolymer composition ratio = 30: 70) 2 parts by mass However, when two kinds of ultraviolet absorbers are used in combination, the total addition amount is 2 parts by mass, and the combined ratio To 1: 1. (In the table, UV-2 / 3 indicates that two types of UV-2 and UV-3 are used in combination. The same applies to UV-2 / 5 and the like.)
<Additive>
Additive 1: IRGANOX 1010 (manufactured by Ciba Specialty Chemicals, Inc., antioxidant) 0.2 parts by mass Additive 2: Epoxidized tall oil (acid scavenger) 0.2 parts by mass Additive 3: HALS-1 (hindered amine) Light stabilizer) 0.2 parts by mass <Matting agent>
Aerosil 200V (0.016μm silica fine particles, manufactured by Nippon Aerosil Co., Ltd.)
Example 1
(Preparation of support by melt casting film forming method: optical films 1 to 32)
The above cellulose ester 1 was heat-treated at 120 ° C. for 1 hour in dry air and allowed to cool to room temperature in dry air. To 90 parts by weight of the dried cellulose resin, add the following parts by weight of a plasticizer and an ultraviolet absorber other than cellulose ester with the following constitution shown in Table 1. After mixing with a Henschel mixer, the mixture is heated using an extruder and pelletized. Was prepared and allowed to cool.

Cellulose ester 1: cellulose tripropionate having a substitution degree of propionyl group of 2.91, a number average molecular weight of 75,000 and a residual sulfuric acid content (as elemental sulfur) of 16 ppm 90 parts by mass plasticizer 1: 10 parts by mass of triphenyl phosphate UV −1: Tinuvin 109 (manufactured by Ciba Specialty Chemicals Co., Ltd., weight average molecular weight: 486, molar extinction coefficient at 380 nm = 6780) 2 parts by mass The obtained pellets were heated at 105 ° C. using a hot air dryer in which air was circulated. Water was removed by drying for 2 hours. Next, the pellets were extruded using a single-screw extruder having a coat hanger type T die with a lip width of 1.5 m (manufactured by Mitsubishi Heavy Industries, Ltd .: screw diameter 90 mm, T die lip material is tungsten carbide). From the opening of the additive hopper provided in the intermediate part of the machine, the matting agent was added by a continuous feeder so as to be 0.05% of the extrusion amount, and melt extrusion was performed to produce a cellulose ester film. Extrusion molding was performed in a clean room of class 10,000 or less under molding conditions of a melting temperature of 230 ° C. and a T die temperature of 240 ° C. The obtained film was stretched 1.02 times in the longitudinal direction, and then stretched 1.05 times in the width direction using a tenter device to provide retardation Ro5 nm in the in-plane direction, retardation Rt 38 nm in the thickness direction, and length 3000 m. A cellulose ester film having a thickness of 75 μm and a width of 1.4 m was obtained. Both ends of the film were subjected to a knurling process having a width of 1 cm and an average height of 8 μm to produce a wound optical film 1.

  Next, in the same manner as in the production of the optical film 1, the types 1 and 18 of the polymers 1 to 18, cellulose esters 1 to 7, the plasticizer, the ultraviolet absorber, and the additives prepared as described above with the configuration shown in Table 1 were used. Optical films 2-32 were produced. In addition, 10 mass parts of polymers 1-18 were used for 90 mass parts of cellulose resin.

(Evaluation)
Using the obtained optical films 1 to 32, the retardation value and the retardation fluctuation with respect to the humidity change were measured by the following method, assuming the long-term use, and the evaluation results are shown in Table 1.

(Retardation Ro, Rt)
Using a film that was allowed to stand for 24 hours in an environment of 23 ° C. and 55% RH, the retardation of the film at a wavelength of 590 nm was determined with an automatic birefringence meter KOBRA-21ADH (manufactured by Oji Scientific Instruments). It was. The average refractive index and film thickness d of the film constituting material measured with an Abbe refractometer were input, and values of in-plane retardation (Ro) and thickness direction retardation (Rt) were obtained.

Formula (i) Ro = (nx−ny) × d
Formula (ii) Rt = {(nx + ny) / 2−nz} × d
(Where nx is the refractive index in the slow axis direction in the film plane, ny is the refractive index in the fast axis direction in the film plane, nz is the refractive index in the thickness direction of the film, and d is Represents film thickness (nm).)
(Retardation value fluctuation with humidity change)
Using the retardation value measuring method, Rt (a) fluctuation due to humidity change was determined by the following method.

  After the film sample was conditioned at 23 ° C. and 20% RH for 24 hours, the Rt value measured in the same environment was defined as Rt (b), and the same film was continuously conditioned at 23 ° C. and 80% RH for 24 hours. Thereafter, the Rt value measured in the same environment was determined and this was set as Rt (c), and the Rt fluctuation Rt (a) due to humidity change was determined from the following equation.

Rt (a) = | Rt (b) −Rt (c) |
Furthermore, the humidity-controlled sample was measured again in an environment of 23 ° C. and 55% RH, and it was confirmed that this change was a reversible change.

  Table 1 shows the configuration of the optical film and the results obtained.

  The optical films 4 to 24, 26, and 28 to 31 of the present invention are suitable for development of retardation values as optical films for polarizing plate protective films with respect to the comparative optical films 1 to 3, 25, 27, and 32. In addition, it can be seen that the retardation value variation with respect to the humidity change is significantly reduced.

Moreover, it turns out that the effect of this invention has fallen somewhat for the optical film 4 which used the triphenyl phosphate as a phosphate ester plasticizer and used the low molecular weight ultraviolet absorber (UV-1).

  Moreover, it turns out that the optical film 10, 11, 14-24 which used the ultraviolet absorber preferable for this invention is excellent also in all the characteristics.

Example 2
Using the optical films 1 and 4 to 32 prepared in Example 1, a polymer layer was formed on each optical film by the following method, and then stretched to prepare optical compensation films 1 to 35 shown in Table 2.

  Weight average molecular weight of 59,000 synthesized from 2,2′-bis (3,4-dicarboxyphenyl) hexafluoropropane and 2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl A 15% by weight cyclohexanone solution of polyimide is applied on each optical film so as to have a dry film thickness of 5 μm, and then dried while supporting both ends with a tenter device, and subsequently 1 in the width direction at a predetermined temperature. The film was stretched 15 times to obtain an optical compensation film of Ro 70 nm and Rt 270 nm.

(Evaluation)
The following evaluation was performed using the obtained optical compensation films 1 to 35.

(transparency)
The transparency of the obtained optical compensation film was evaluated using a transparency measuring device (manufactured by KOTAKI Corporation).

○: No decrease in transparency is observed △: A slight decrease in transparency is observed ×: A decrease in transparency is observed (flatness; visual evaluation)
Cut each sample into a size of 90cm in width and 100cm in length, and arrange five 50W fluorescent lamps at a height of 1.5m so that the sample stage can be illuminated from a 45 ° angle. Each film sample was placed, and the unevenness that appeared to be reflected on the film surface was visually observed and judged as follows. By this method, it is possible to determine “tsun” and “wrinkle”.

◎: All five fluorescent lamps look straight ○: Some fluorescent lamps appear to be bent slightly △: Fluorescent lamps appear to be slightly bent overall ×: Fluorescent lamps appear to swell greatly (Retardation Ro, Rt variation) )
Retardation is measured at intervals of 1 cm in the width direction of the obtained film sample, and is expressed by a coefficient of variation (CV) of the obtained retardation. For measurement, an automatic birefringence meter KOBURA-21ADH (manufactured by Oji Scientific Instruments Co., Ltd.) is used and is three-dimensionally spaced at 1 cm intervals in the width direction of the sample at a wavelength of 590 nm in an environment of 23 ° C. and 55% RH. Birefringence measurement was performed. The obtained in-plane and thickness direction retardations were respectively determined as standard deviations by the (n-1) method. For the retardation distribution, the coefficient of variation (CV) shown below was obtained and used as an index. In actual measurement, n was set to 130.

Coefficient of variation (CV) = standard deviation / retardation average value ◎: variation (CV) is less than 1.5% ○: variation (CV) is 1.5% or more and less than 5% Δ: variation (CV) is 5% or more Less than 10% x: Evaluation results with a variation (CV) of 10% or more are shown in Table 2.

The optical compensation films 3 to 27, 29 and 31 to 34 of the present invention are coated with a polymer layer on the optical film of the present invention and stretched together with the support, so that the optical compensation film without the polymer layer of the comparative example is provided. 1. It can be seen that variations in transparency, flatness, and retardation are comprehensively superior to those of the optical compensation films 2, 28, 30, and 35 in which a polymer layer is provided on the optical film of Comparative Example.
Example 3
<Production of polarizing plate>
The following hard coat layer and antireflection layer were formed on the optical film 11 produced in Example 1 to produce an antireflection film.

<Hard coat layer>
The following hard coat layer composition was applied to a dry film thickness of 3.5 μm and dried at 80 ° C. for 1 minute. Next, it was cured under a condition of 150 mJ / cm ^{2 with} a high-pressure mercury lamp (80 W) to produce a hard coat film having a hard coat layer. The refractive index of the hard coat layer was 1.50.

<Hard coat layer composition (C-1)>
Dipentaerythritol hexaacrylate (contains about 20% of dimer or higher components)
108 parts by mass Irgacure 184 (manufactured by Ciba Specialty Chemicals) 2 parts by mass Propylene glycol monomethyl ether 180 parts by mass Ethyl acetate 120 parts by mass <Medium refractive index layer>
On the hard coat layer of the hard coat film, the following medium refractive index layer composition was applied by an extrusion coater and dried for 1 minute at 80 ° C. and 0.1 m / second. At this time, a non-contact floater was used until completion of touch drying (a state where the coated surface was touched with a finger and felt dry). As the non-contact floater, a horizontal floater type air tumbler manufactured by Belmatik was used. The static pressure in the floater was set to 9.8 kPa, and the floater was lifted uniformly in the width direction of about 2 mm and conveyed. After drying, ultraviolet rays were irradiated with 130 mJ / cm ² using a high pressure mercury lamp (80 W) and cured to produce a middle refractive index layer film having a middle refractive index layer. The medium refractive index layer had a thickness of 84 nm and a refractive index of 1.66.

<Medium refractive index layer composition>
20% ITO fine particle dispersion (average particle size 70 nm, isopropyl alcohol solution)
100g
Dipentaerythritol hexaacrylate 6.4g
Irgacure 184 (Ciba Specialty Chemicals Co., Ltd.) 1.6g
Tetrabutoxy titanium 4.0g
10% FZ-2207 (Nihon Unicar Co., Ltd., propylene glycol monomethyl ether solution) 3.0 g
Isopropyl alcohol 530g
90g of methyl ethyl ketone
265 g of propylene glycol monomethyl ether
<High refractive index layer>
On the medium refractive index layer, the following high refractive index layer composition was applied by an extrusion coater and dried for 1 minute at 80 ° C. and 0.1 m / second. At this time, a non-contact floater was used until completion of touch drying (a state where the coated surface was touched with a finger and felt dry). The non-contact floater was under the same conditions as the formation of the middle refractive index layer. After drying, a high-pressure mercury lamp (80 W) was used to cure by irradiating with ultraviolet rays of 130 mJ / cm ² to produce a high refractive index layer film having a high refractive index layer.

<High refractive index layer composition>
95 parts by mass of tetra (n) butoxytitanium dimethylpolysiloxane (KF-96-1000CS manufactured by Shin-Etsu Chemical Co., Ltd.) 1 part by mass of γ-methacryloxypropyltrimethoxysilane (KBM503 manufactured by Shin-Etsu Chemical Co., Ltd.)
5 parts by mass Propylene glycol monomethyl ether 1750 parts by mass Isopropyl alcohol 3450 parts by mass Methyl ethyl ketone 600 parts by mass The thickness of the high refractive index layer of this high refractive index layer film was 50 μm and the refractive index was 1.82.

<Low refractive index layer>
First, silica-based fine particles (cavity particles) were prepared.

(Preparation of silica-based fine particles P-1)
A mixture of 100 g of silica sol having an average particle diameter of 5 nm and a SiO ₂ concentration of 20% by mass and 1900 g of pure water was heated to 80 ° C. The pH of this reaction mother liquor was 10.5, and 9000 g of 0.98 mass% sodium silicate aqueous solution as SiO ₂ and 9000 g of 1.02 mass% sodium aluminate aqueous solution as Al ₂ O ₃ were simultaneously added to the mother liquor. did. Meanwhile, the temperature of the reaction solution was kept at 80 ° C. The pH of the reaction solution rose to 12.5 immediately after the addition, and hardly changed thereafter. After completion of the addition, the reaction solution was cooled to room temperature and washed with an ultrafiltration membrane to prepare a SiO ₂ .Al ₂ O ₃ core particle dispersion having a solid content concentration of 20% by mass. (Process (a))
1700 g of pure water is added to 500 g of this core particle dispersion and heated to 98 ° C., and while maintaining this temperature, a silicic acid solution (SiO ₂₎ obtained by dealkalizing a sodium silicate aqueous solution with a cation exchange resin. A dispersion of core particles in which 3000 g (concentration of 3.5% by mass) was added to form a first silica coating layer was obtained. (Process (b))
Next, 1125 g of pure water is added to 500 g of the core particle dispersion liquid that has been washed with an ultrafiltration membrane to form a first silica coating layer having a solid content concentration of 13% by mass, and concentrated hydrochloric acid (35.5%) is further added dropwise. The pH was adjusted to 1.0 and dealumination was performed. Next, the aluminum salt dissolved in the ultrafiltration membrane was separated while adding 10 L of hydrochloric acid aqueous solution of pH 3 and 5 L of pure water, and SiO ₂ · Al from which some of the constituent components of the core particles forming the first silica coating layer were removed. A dispersion of ₂ O ₃ porous particles was prepared (step (c)). A mixture of 1500 g of the above porous particle dispersion, 500 g of pure water, 1,750 g of ethanol, and 626 g of 28% ammonia water is heated to 35 ° C., and then 104 g of ethyl silicate (SiO ₂ 28 mass%) is added. The surface of the porous particles on which the first silica coating layer was formed was coated with a hydrolyzed polycondensate of ethyl silicate to form a second silica coating layer. Next, a dispersion of silica-based fine particles having a solid content concentration of 20% by mass was prepared by replacing the solvent with ethanol using an ultrafiltration membrane.

Table 2 shows the thickness, average particle diameter, MOx / SiO ₂ (molar ratio), and refractive index of the first silica coating layer of the silica-based fine particles. Here, the average particle diameter was measured by a dynamic light scattering method, and the refractive index was measured by the following method using Series A, AA made by CARGILL as a standard refractive liquid.

<Measuring method of particle refractive index>
(1) The particle dispersion is taken in an evaporator and the dispersion medium is evaporated.

  (2) This is dried at 120 ° C. to obtain a powder.

  (3) A standard refraction liquid having a known refractive index is dropped on a glass plate of a few drops, and the above powder is mixed therewith.

  (4) The operation of (3) is performed with various standard refractive liquids, and the refractive index of the standard refractive liquid when the mixed liquid becomes transparent is used as the refractive index of the colloidal particles.

<Formation of low refractive index layer>
Si (OC ₂ H _{5) 4} to _{95mol%, C 3 F 7 -} (OC 3 F 6) 24 -O- (CF 2) 2 -C 2 H 4 -O-CH 2 Si (OCH 3) 3 to 5mol A low-refractive-index coating agent obtained by adding 35% by mass of the above silica-based fine particles P-1 having an average particle diameter of 47 nm to a matrix mixed at 1%, 1.0N-HCl as a catalyst, and further diluting with a solvent. Produced. A coating solution is applied on the high refractive index layer at a film thickness of 100 nm using a die coater method, dried at 120 ° C. for 1 minute, and then irradiated with ultraviolet light to form a low refractive index layer having a refractive index of 1.37. Formed.

  An antireflection film was produced as described above.

(Preparation of polarizing plate)
<Preparation of viewing side polarizing plate>
Next, a 120 μm thick polyvinyl alcohol film was uniaxially stretched (temperature: 110 ° C., stretch ratio: 5 times). This was immersed in an aqueous solution composed of 0.075 g of iodine, 5 g of potassium iodide and 100 g of water for 60 seconds, and then immersed in an aqueous solution of 68 ° C. composed of 6 g of potassium iodide, 7.5 g of boric acid and 100 g of water. This was washed with water and dried to obtain a polarizing film.

  Next, the polarizing film was bonded to the antireflection film and the optical film 11 prepared in Example 1 according to the following steps 1 to 5 to prepare a polarizing plate.

  Step 1: It was immersed in a 2 mol / L sodium hydroxide solution at 60 ° C. for 90 seconds, then washed with water and dried to obtain an optical film 11 saponified on the side to be bonded to a polarizer, and an antireflection film.

  Step 2: The polarizing film was immersed in a polyvinyl alcohol adhesive tank having a solid content of 2% by mass for 1 to 2 seconds.

  Step 3: Excess adhesive adhered to the polarizing film in Step 2 was gently wiped off, and this was placed on the optical film 11 and antireflection film processed in Step 1 and laminated.

Step 4: The optical film 11, the polarizing film and the antireflection film laminated in Step 3 were bonded at a pressure of 20 to 30 N / cm ² and a conveyance speed of about 2 m / min.

  Step 5: A sample obtained by bonding the polarizing film prepared in Step 4 to the optical film 11 and the antireflection film in a dryer at 80 ° C. was dried for 2 minutes to prepare a viewing side polarizing plate.

<Preparation of backlight-side polarizing plate>
Using the produced polarizing film, the optical compensation films 1 to 35 produced in Example 2, and the optical film 11 produced in Example 1 on the back side, backlight-side polarizing plates 1 to 35 according to the above steps 1 to 5 were used. Produced. The optical compensation film was bonded to the polarizing film so that the polymer layer was on the outside.

<Production of liquid crystal display device>
A liquid crystal panel was produced as follows, and the characteristics as a liquid crystal display device were evaluated.

  The 30-inch Sharp Corporation liquid crystal cell backlight-side polarizing plate and the viewing-side polarizing plate of the liquid crystal cell of the Aquos liquid crystal display device are peeled off and aligned with the polarizing axis of the polarizing plate previously bonded. A liquid crystal cell of 35 inches is attached to the liquid crystal cell through an adhesive layer so that the optical compensation film side of the liquid crystal cell and the optical film 11 side of the polarizing plate on the viewing side are on the liquid crystal cell side. did. This device uses a direct backlight system.

(Evaluation)
<Visibility>
The manufactured liquid crystal display device was tested for durability for 1000 hours by turning on the direct backlight in an environment of 60 ° C. and 90% RH, and after 5 hours of turning on the backlight at room temperature, Displayed and visually observed to give the following ranks.

◎: Black appears dark, clear, and no color irregularities are observed. ○: Black appears dark and clear, but slight color irregularities are observed. △: Black margins are slightly not clear. Slightly low and uneven color is observed ×: no black spots, low sharpness and worrisome color unevenness The above evaluation results are shown in Table 2.

  From Table 2, the liquid crystal display devices 3 to 27, 29, 31 to 34 of the present invention are compared with Comparative Examples 1, 2, 28, 30, and 35 even after the direct type backlight is lit for a long time under high temperature and high humidity. It is clear that the visibility is excellent.

  The stretching temperature is within the range of the present invention, and the liquid crystal display device and the liquid crystal display device using the optical compensation film in combination with the preferred UV absorber for the present invention are comprehensive in transparency, flatness, retardation variation, and visibility. Is good.

Claims (9)

In the method for producing an optical film for melt casting a composition containing a cellulose resin and a plasticizer, the cellulose resin has a residual sulfuric acid content in the range of 0.1 to 50 ppm, and the composition is ethylenically unsaturated. method for producing an optical film having a weight average molecular weight obtained by polymerizing a monomer is characterized by containing the polymer over is 500 to 30,000. The method for producing an optical film according to claim 1, wherein the cellulose resin is a mixed fatty acid ester having a total acyl group substitution degree of 2.5 to 2.9 and a number average molecular weight (Mn) of 70000 to 200000. . The at least one plasticizer is selected from polyhydric alcohol ester plasticizers, polyester plasticizers, citrate ester plasticizers, and phthalate ester plasticizers. The manufacturing method of the optical film of description. The said residual sulfuric acid amount is the range of 0.1-45 ppm, The manufacturing method of the optical film of any one of Claims 1-3 characterized by the above-mentioned. The said composition contains a ultraviolet absorber, The weight average molecular weights of this ultraviolet absorber are the range of 490-50000, The manufacturing method of the optical film of any one of Claims 1-4 characterized by the above-mentioned. The said composition contains 0.01-5 mass% of hindered amine type | system | group or a hindered phenol type compound, The manufacturing method of the optical film of any one of Claims 1-5 characterized by the above-mentioned. An optical film is manufactured with the manufacturing method of any one of Claims 1-6, a polymer layer is provided on this optical film, and it extends | stretches, The manufacturing method of the optical compensation film characterized by the above-mentioned. The method for producing an optical compensation film according to claim 7, wherein the polymer layer is made of at least one selected from polyether ketone, polyamide, polyester, polyimide, polyamideimide, and polyesterimide. The method for producing an optical compensation film according to claim 7 or 8, wherein the stretching temperature B at the time of stretching is represented by the following formula (I).
  Formula (I) Melting temperature A-100 ° C. ≦ Extension temperature B ≦ Melting temperature A-40 ° C.
(However, the melting temperature A represents the temperature at the time of melt casting of the optical film)