JP6582440B2 - Cellulose ester resin modifier, cellulose ester resin composition, optical film and liquid crystal display device - Google Patents

Description

  The present invention relates to a modifier for cellulose ester resin from which an optical film excellent in moisture resistance can be obtained. Further, the present invention relates to a cellulose ester resin composition containing the modifier, an optical film obtained using the composition, and a liquid crystal display device having the optical film.

  The cellulose ester resin (CA) film is transparent, optically isotropic, and tough, and has an adhesive property with polyvinyl alcohol (hereinafter abbreviated as “PVA”), which is a material for a polarizer of a liquid crystal display device. Since it is favorable, it is used as an optical film such as a polarizing plate protective film constituting a polarizing plate of a liquid crystal display device such as a television or a notebook computer.

  In general, a polarizing plate of a liquid crystal display device has a structure in which a polarizing plate protective film made of a cellulose ester is pasted on both sides of a polarizing plate in which dichroic molecules are oriented on a PVA film. The polarizing plate protective film made of cellulose ester is easy to pass humidity (having poor moisture permeability resistance, that is, having high moisture permeability), and easily takes moisture from outside into the polarizing plate. A polarizing plate to which a polarizing plate protective film made of cellulose ester is attached due to this moisture has a drawback that the polarizer tends to deteriorate.

  In order to reduce the moisture permeability of the cellulose ester resin film, an optical film has been conventionally obtained using a cellulose ester resin composition to which a phosphoric ester compound such as triphenyl phosphate is added. However, in recent years, with the thinning of the liquid crystal display device, the thickness of the polarizing plate protective film has been reduced to 10 to 50 μm, which was conventionally 80 μm, and the phosphoric acid ester compound has moisture permeability resistance. It is becoming impossible to grant enough. When the amount of the phosphoric acid ester compound added to the cellulose ester resin is increased in order to improve the moisture resistance, problems such as a decrease in the heat resistance of the film and a bleeding of the phosphoric acid ester compound to the film surface (bleed) Will occur.

  A modifier that can lower the moisture permeability when compared with the same amount of addition, sufficient moisture permeability resistance corresponding to thinning without causing deterioration of the heat resistance of the film and bleeding problems Can be granted. Therefore, a modifier capable of lowering the moisture permeability with the same amount added is desired.

  As a modifier capable of imparting good moisture permeability resistance to the cellulose ester resin film, for example, a glycol having 2 to 5 carbon atoms and an aromatic (anhydrous) dicarboxylic acid having 8 to 12 carbon atoms or Cellulose ester resin modifier comprising an ester compound obtained by reacting the esterified product with an aromatic monocarboxylic acid having 5 to 11 carbon atoms and having a number average molecular weight of 300 to 5,000. Is disclosed (for example, see Patent Document 1). However, even with the modifier disclosed in Patent Document 1, it is difficult to develop a sufficiently low moisture permeability corresponding to the thinning of the film.

  In addition, in order to obtain an optical film in which fluctuations in retardation such as Re and Rth are small with respect to changes in humidity in the usage environment, some or all of the hydrogen atoms on the aromatic ring such as hydroxybenzoic acid are added to the cellulose ester resin. A technique for adding an aromatic carboxylic acid compound having a structure in which is substituted with a hydroxyl group is disclosed (for example, see Patent Document 2). However, the compound disclosed in Patent Document 2 cannot provide sufficient moisture permeation resistance corresponding to thinning.

  In addition, when obtaining a cellulose ester resin film, a cellulose ester resin, an aromatic carboxylic acid compound having a structure in which part or all of hydrogen atoms on an aromatic ring such as hydroxybenzoic acid are substituted with hydroxyl groups, and 2- The technique using the composition containing the plasticizer containing ester compounds with alcohol, such as ethylhexanol and isodecanol, is disclosed (for example, refer patent document 3). However, the technique described in Patent Document 3 discloses as an object to suppress the elution to the saponification solution during the saponification treatment of the polarizing plate protective film, and to reduce failures during the production of the polarizing plate due to the elution and foreign matters. It is not intended to impart moisture permeability resistance to the film. Even if the plasticizer disclosed in Patent Document 3 is used, sufficient moisture permeation resistance corresponding to thinning cannot be provided.

JP 2006-282987 A JP 2011-227508 A JP 2010-271620 A

  The problem to be solved by the present invention is to provide a modifier for cellulose ester resin from which an optical film excellent in moisture permeability resistance can be obtained. Moreover, it is providing the cellulose-ester resin composition containing the said modifier, the optical film which consists of this resin composition, and the liquid crystal display device using this optical film.

  As a result of diligent research, the inventors of the present invention obtained using a polyhydric alcohol having 2 to 10 carbon atoms and reacting with an aromatic monocarboxylic acid having a hydroxyl group on an aromatic ring as a monocarboxylic acid. The present inventors have found that an optical film having excellent moisture permeability can be obtained by using an ester compound as a modifier for cellulose ester resin, and the present invention has been completed.

  That is, the present invention provides the following formula (1):

（式中Ｇは、炭素原子数２〜１０の多価アルコールの残基である。Ａは芳香環上の水素原子の一部乃至全部が水酸基に置換された構造を有する芳香族モノカルボン酸残基である。ｎは２〜６の整数である。）
で表されることを特徴とするセルロースエステル樹脂用改質剤を提供するものである。

(In the formula, G is a residue of a polyhydric alcohol having 2 to 10 carbon atoms. A is an aromatic monocarboxylic acid residue having a structure in which part or all of the hydrogen atoms on the aromatic ring are substituted with hydroxyl groups. (N is an integer of 2 to 6.)
It provides the modifier for cellulose ester resins characterized by these.

  The present invention also provides a cellulose ester resin composition comprising the cellulose ester resin modifier and a cellulose ester resin.

  The present invention also provides an optical film containing the cellulose ester resin composition.

  Furthermore, the present invention provides a liquid crystal display device comprising the optical film.

  ADVANTAGE OF THE INVENTION According to this invention, the modifier for cellulose ester resins from which the optical film excellent in moisture permeability can be obtained can be provided. The optical film obtained by using the modifier for cellulose ester resin of the present invention can be suitably used as a polarizing plate protective film or a retardation film.

  In addition, the retardation film obtained using the modifier for cellulose ester resin of the present invention can be expected to have an effect of little change in the value of Rth (phase difference in the thickness direction) depending on the humidity of the environment. Therefore, by using the cellulose ester resin modifier of the present invention, it is possible to provide a liquid crystal display device in which the color and viewing angle are not easily affected by environmental humidity.

  The modifier for cellulose ester resin of the present invention has the following formula (1):

（式中Ｇは、炭素原子数２〜１０の多価アルコールの残基である。Ａは芳香環上の水素原子の一部乃至全部が水酸基に置換された構造を有する芳香族モノカルボン酸残基である。ｎは２〜６の整数である。）
で表されることを特徴とする。

(In the formula, G is a residue of a polyhydric alcohol having 2 to 10 carbon atoms. A is an aromatic monocarboxylic acid residue having a structure in which part or all of the hydrogen atoms on the aromatic ring are substituted with hydroxyl groups. (N is an integer of 2 to 6.)
It is represented by.

  The “residue of the polyhydric alcohol” represents an organic group excluding the hydroxyl group of the polyhydric alcohol. Further, the “aromatic monocarboxylic acid residue” represents an organic group excluding the carboxyl group possessed by the aromatic monocarboxylic acid. Further, “chain” described later means that no ring is included, and the chain includes a straight chain and a branched chain.

  G is a residue of a polyhydric alcohol having 2 to 10 carbon atoms. Examples of the residue of a polyhydric alcohol having 2 to 10 carbon atoms include, for example, a residue of an aliphatic polyhydric alcohol having 2 to 10 carbon atoms and a residue of an aromatic polyhydric alcohol having 2 to 10 carbon atoms. Etc.

  Examples of the residue of the aliphatic polyhydric alcohol having 2 to 10 carbon atoms include, for example, a residue of a chain aliphatic polyhydric alcohol having 2 to 10 carbon atoms and a cyclic aliphatic having 2 to 10 carbon atoms. A residue of an aromatic polyhydric alcohol. Examples of the residue of the chain aliphatic polyhydric alcohol having 2 to 10 carbon atoms include ethylene glycol residue, propylene glycol residue, 1,3-propanediol residue, 2-methyl- 1,3-propanediol residue, 1,2-butanediol residue, 1,3-butanediol residue, 1,4-butanediol residue, 2,3-butanediol residue, 1,5-pentanediol residue, 3-methyl-1,5-pentanediol residue, 1,6-hexanediol residue, 1,7-heptanediol residue, 1,8-octanediol Residue of 1,9-nonanediol, residue of divalent aliphatic alcohol such as residue of 1,10-decandiol; residue of glycerin, residue of 1,2,3-butanetriol 1,2,4-butanetri Residues, 1,2,3-heptatriol residues, 1,2,4-heptatriol residues, 1,2,5-heptatriol residues, 2,3,4-heptatriol Residues of trivalent fatty alcohols such as residues of trimethylolpropane; residues of tetravalent aliphatic alcohols such as residues of pentaerythritol, residues of erythritol; residues of xylitol, etc. Examples include residues of pentavalent aliphatic alcohols; residues of hexavalent aliphatic alcohols such as sorbitol residues.

  Examples of the residue of the cycloaliphatic polyhydric alcohol having 2 to 10 carbon atoms include, for example, a cyclopentanediol residue, a cyclopentanedimethanol residue, a cyclohexanediol residue, and a cyclohexanedimethanol residue. , Residues of cycloheptanediol, residues of cycloheptanedimethanol, and the like.

  In the present invention, the “residue of the aliphatic polyhydric alcohol” includes a structure having an ether group (—O—) in the aliphatic structure. In this case, the number of carbon atoms refers to the total number of carbon atoms of the aliphatic group present via the ether group. Examples of the residue containing a structure having an ether group (—O—) in the aliphatic structure include a diethylene glycol residue, a triethylene glycol residue, a dipropylene glycol residue, a tripropylene glycol residue, Examples include dipentaerythritol residues.

  Examples of the residue of the aromatic polyhydric alcohol having 2 to 10 carbon atoms include a residue of 1,2-benzenedimethanol, a residue of 1,3-benzenedimethanol, and 1,4-benzenedimethanol. And the like.

  Among the G, a chain aliphatic polyhydric alcohol residue having 2 to 8 carbon atoms is preferable because it can impart excellent moisture resistance and water resistance to the film, and is a straight chain having 2 to 6 carbon atoms. More preferred are aliphatic aliphatic polyhydric alcohol residues or branched aliphatic polyhydric alcohol residues having 2 to 6 carbon atoms, such as ethylene glycol residues, propylene glycol residues, and 1,3-propane. More preferred are diol residues, 2-methyl-1,3-propanediol residues or 3-methyl-1,5-pentanediol residues.

  Said n is an integer of 2-6. n is preferably an integer of 2 to 3 because excellent moisture permeability and water resistance can be imparted to the film. Here, n corresponds to the valence of a polyhydric alcohol having 2 to 10 carbon atoms, which will be described later.

  A is an aromatic monocarboxylic acid residue having a structure in which part or all of the hydrogen atoms on the aromatic ring are substituted with hydroxyl groups. Examples of the aromatic monocarboxylic acid residue having a structure in which some or all of the hydrogen atoms on the aromatic ring are substituted with hydroxyl groups include, for example, a monohydroxybenzoic acid residue, a dihydroxybenzoic acid residue, and a trihydroxybenzoic acid residue. Examples include acid residues, monohydroxynaphthalene carboxylic acid residues, and the like.

  Examples of the residue of monohydroxybenzoic acid include a residue of 2-hydroxybenzoic acid (salicylic acid), a residue of 3-hydroxybenzoic acid, a residue of 4-hydroxybenzoic acid (parahydroxybenzoic acid), 3 , 5-di-tert-butyl-4-hydroxybenzoic acid residues, and the like.

  Examples of the residue of the dihydroxybenzoic acid include a residue of 2,3-dihydroxybenzoic acid (2-pyrocatechuic acid), a residue of 2,4-dihydroxybenzoic acid (β-resorcinic acid), and 2,5- Residue of dihydroxybenzoic acid (gentisic acid), residue of 2,6-dihydroxybenzoic acid (γ-resorcinic acid), residue of 3,4-dihydroxybenzoic acid (protocatechuic acid), 3,5-dihydroxybenzoic acid Examples include residues of (α-resorcinic acid).

  Examples of the residue of trihydroxybenzoic acid include residues of trihydroxybenzoic acid such as residues of 3,4,5-trihydroxybenzoic acid, residues of 2,4,6-trihydroxybenzoic acid, and the like. Is mentioned.

  Examples of the monohydroxynaphthalenecarboxylic acid residue include 2-hydroxy-1-naphthoic acid residue, 1-hydroxy-2-naphthoic acid residue, 3-hydroxy-2-naphthoic acid residue, 6 -Residues of hydroxy-2-naphthoic acid and the like.

  Among the above-mentioned A, the moisture-resistant and water-resistant film has excellent aromatic monocarboxylic acid residues (monohydroxybenzoic acid residues) having a structure in which one of the hydrogen atoms on the aromatic ring is substituted with a hydroxyl group. The residue of 4-hydroxybenzoic acid (parahydroxybenzoic acid) is more preferable.

  In this invention, n in General formula (1) is an integer of 2-6. The number of “—OCO-A” in the general formula (1) varies depending on the integer represented by n. "-A" in "-OCO-A" which exists in plurality in the general formula (1) may be the same or different. In addition to the compound represented by the general formula (1), the modifier for cellulose ester resin of the present invention includes other compounds, specifically, the hydroxyl group of the polyhydric alcohol in the general formula (1). Compounds such as partially remaining compounds may be included as long as the effects of the present invention are not impaired.

  The modifier for cellulose ester resin of the present invention includes, for example, a polyhydric alcohol (g) having 2 to 6 carbon atoms having a valence of a hydroxyl group and a part or all of hydrogen atoms on an aromatic ring. It can be obtained by reacting with an aromatic monocarboxylic acid (a) having a structure substituted with a hydroxyl group.

  Examples of the polyhydric alcohol (g) include aliphatic polyhydric alcohols having 2 to 10 carbon atoms and aromatic polyhydric alcohols having 2 to 10 carbon atoms. Examples of the aliphatic polyhydric alcohol having 2 to 10 carbon atoms include a chain aliphatic polyhydric alcohol having 2 to 10 carbon atoms and a cyclic aliphatic polyhydric alcohol having 2 to 10 carbon atoms. Can be mentioned.

  Examples of the aliphatic polyhydric alcohol having 2 to 10 carbon atoms include a chain aliphatic polyhydric alcohol having 2 to 10 carbon atoms and a cyclic aliphatic polyhydric alcohol having 2 to 10 carbon atoms. . Examples of the chain aliphatic polyhydric alcohol having 2 to 10 carbon atoms include ethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, and 1,2-butane. Diol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1, Divalent aliphatic alcohols such as 7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol; glycerin, 1,2,3-butanetriol, 1,2,4 -Butanetriol, 1,2,3-heptatriol, 1,2,4-heptatriol, 1,2,5-heptatriol, 2,3,4-hept Examples include trivalent aliphatic alcohols such as triol and trimethylolpropane; tetravalent aliphatic alcohols such as pentaerythritol and erythritol; pentavalent aliphatic alcohols such as xylitol; hexavalent aliphatic alcohols such as sorbitol and the like. . The aliphatic polyhydric alcohol (g) may be used alone or in combination of two or more.

  Examples of the cycloaliphatic polyhydric alcohol having 2 to 10 carbon atoms include cyclopentanediol, cyclopentanedimethanol, cyclohexanediol, cyclohexanedimethanol, cycloheptanediol, and cycloheptanedimethanol.

  In the present invention, a polyhydric alcohol having an ether group (—O—) in the aliphatic structure can also be used as the aliphatic polyhydric alcohol (g). Examples of such alcohol include diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, and dipentaerythritol.

  Examples of the aromatic polyhydric alcohol having 2 to 10 carbon atoms include 1,2-benzenedimethanol, 1,3-benzenedimethanol, 1,4-benzenedimethanol, and the like.

  Among the polyhydric alcohols (g), a chain aliphatic polyhydric alcohol having 2 to 8 carbon atoms is preferable because it can impart excellent moisture resistance and water resistance to the film, and has 2 to 6 carbon atoms. A linear aliphatic polyhydric alcohol or a branched aliphatic polyhydric alcohol having 2 to 6 carbon atoms is more preferable, and ethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3- More preferred is propanediol or 3-methyl-1,5-pentanediol.

  Examples of the aromatic monocarboxylic acid (a) include 2-hydroxybenzoic acid (salicylic acid), 3-hydroxybenzoic acid, 4-hydroxybenzoic acid (parahydroxybenzoic acid), and 3,5-di-tert-butyl. Monohydroxybenzoic acid such as -4-hydroxybenzoic acid; 2,3-dihydroxybenzoic acid (2-pyrocatechuic acid), 2,4-dihydroxybenzoic acid (β-resorcinic acid), 2,5-dihydroxybenzoic acid (gentidine) Acid), 2,6-dihydroxybenzoic acid (γ-resorcinic acid), 3,4-dihydroxybenzoic acid (protocatechuic acid), 3,5-dihydroxybenzoic acid (α-resorcinic acid) and the like; 3, Trihydroxybenzoic acid such as 4,5-trihydroxybenzoic acid, 2,4,6-trihydroxybenzoic acid; 1-naphthoic acid, 1-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid and monohydroxy-naphthalene carboxylic acid such as 6-hydroxy-2-naphthoic acid.

  Among the aromatic monocarboxylic acids (a), an aromatic monocarboxylic acid (monohydroxybenzoic acid) having a structure in which one of the hydrogen atoms on the aromatic ring is substituted with a hydroxyl group is excellent in moisture permeability resistance to the film, From the viewpoint of providing water resistance, 4-hydroxybenzoic acid is more preferable.

  The modifier for cellulose ester resin of the present invention is, for example, the polyhydric alcohol (g) and the aromatic monocarboxylic acid (a) in the presence of an esterification catalyst as necessary, for example, 100 to 250. It can manufacture by making it esterify within the temperature range of 2 degreeC for 2 to 25 hours. In addition, conditions, such as temperature of esterification reaction and time, are not specifically limited, You may set suitably.

  Examples of the esterification catalyst include titanium catalysts such as tetraisopropyl titanate and tetrabutyl titanate; tin catalysts such as dibutyltin oxide; and organic sulfonic acid catalysts such as p-toluenesulfonic acid.

  Although the usage-amount of the said esterification catalyst should just be set suitably, it is preferable to use normally in 0.001-0.1 mass part with respect to 100 mass parts of whole quantity of a raw material.

  When obtaining the cellulose ester resin modifier of the present invention, a carboxylic acid other than the aromatic monocarboxylic acid (a) or an alcohol other than the polyhydric alcohol (g) is used within a range not impairing the effects of the present invention. You may do it.

  Examples of carboxylic acids other than the aromatic monocarboxylic acid (a) include aliphatic dicarboxylic acids, aliphatic monocarboxylic acids, aromatic dicarboxylic acids, and aromatic monocarboxylic acids having no hydroxyl group.

  Examples of the aliphatic dicarboxylic acid include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, cyclohexanedicarboxylic acid, dimer acid, and fumaric acid. Examples thereof include methyl esters of dicarboxylic acids and acid chlorides.

  Examples of the aliphatic monocarboxylic acid include acetic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, 2-ethylhexylic acid, and nonanoic acid, and methyl of these aliphatic monocarboxylic acids. Examples include esters, acid chlorides and acid anhydrides.

  Examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-biphenyldicarboxylic acid and methyl esters, acid chlorides and acid anhydrides of these aromatic dicarboxylic acids. Thing etc. are mentioned.

  Examples of the aromatic monocarboxylic acid having no hydroxyl group include benzoic acid, dimethylbenzoic acid, trimethylbenzoic acid, tetramethylbenzoic acid, ethylbenzoic acid, propylbenzoic acid, butylbenzoic acid, cumic acid, and paratertiary. Butyl benzoic acid, orthotoluic acid, metatoluic acid, paratoluic acid, ethoxybenzoic acid, propoxybenzoic acid, naphthoic acid, nicotinic acid, furoic acid, anisic acid, and methyl esters, acid chlorides and acids of these aromatic monocarboxylic acids An anhydride etc. are mentioned.

  Examples of alcohols other than the polyhydric alcohol (g) include methanol, ethanol, 1-butanol, 2-butanol, isobutanol, t-butanol, 1-pentanol, isopentyl alcohol, tert-pentyl alcohol, and cyclopentine. Monoalcohols such as butanol, 1-hexanol, cyclohexanol, 1-heptanol, 1-octanol, 2-ethyl-1-hexanol, isononyl alcohol, 1-nonyl alcohol, amyl alcohol, lauryl alcohol, methyl lactate, ethyl lactate; Hydrogenated bisphenol A, dimer diol, bisphenol A, ethylene oxide adduct of bisphenol A, propylene oxide adduct, polyethylene glycol, polypropylene glycol, polytetramethylene Diol call, and the like.

  The amount of the carboxylic acid other than the aromatic monocarboxylic acid (a) and the alcohol other than the polyhydric alcohol (g) is 0 in total in 100 parts by mass of the raw material for the cellulose ester resin modifier of the present invention. -50 mass parts is preferable, and 0-30 mass parts is more preferable.

  The number average molecular weight (Mn) of the modifier for cellulose ester resin of the present invention is preferably in the range of 200 to 1,000, more preferably in the range of 250 to 700, because the film has excellent moisture permeability and water resistance.

  Here, the number average molecular weight (Mn) is a value in terms of polystyrene based on gel permeation chromatography (GPC) measurement. The measurement conditions for GPC are as follows.

[GPC measurement conditions]
Measuring device: High-speed GPC device “HLC-8320GPC” manufactured by Tosoh Corporation
Column: "TSK GARDCOLUMN SuperHZ-L" manufactured by Tosoh Corporation + "TSK gel SuperHZM-M" manufactured by Tosoh Corporation + "TSK gel SuperHZM-M" manufactured by Tosoh Corporation + "TSK gel SuperHZ-2000" manufactured by Tosoh Corporation "TSK gel SuperHZ-2000" manufactured by Tosoh Corporation
Detector: RI (differential refractometer)
Data processing: “EcoSEC Data Analysis version 1.07” manufactured by Tosoh Corporation
Column temperature: 40 ° C
Developing solvent: Tetrahydrofuran Flow rate: 0.35 mL / min Sample for measurement: 15 mg of sample was dissolved in 10 ml of tetrahydrofuran, and the obtained solution was filtered through a microfilter to obtain a sample for measurement.
Sample injection volume: 20 μl
Standard sample: The following monodisperse polystyrene having a known molecular weight was used according to the measurement manual of “HLC-8320GPC”.

(Monodispersed polystyrene)
“A-300” manufactured by Tosoh Corporation
“A-500” manufactured by Tosoh Corporation
"A-1000" manufactured by Tosoh Corporation
"A-2500" manufactured by Tosoh Corporation
"A-5000" manufactured by Tosoh Corporation
“F-1” manufactured by Tosoh Corporation
"F-2" manufactured by Tosoh Corporation
“F-4” manufactured by Tosoh Corporation
“F-10” manufactured by Tosoh Corporation
“F-20” manufactured by Tosoh Corporation
“F-40” manufactured by Tosoh Corporation
“F-80” manufactured by Tosoh Corporation
“F-128” manufactured by Tosoh Corporation
“F-288” manufactured by Tosoh Corporation

  The properties of the modifier for cellulose ester resin of the present invention vary depending on the number average molecular weight (Mn), composition, and the like, but are usually liquid, solid, paste, etc. at room temperature.

  The cellulose ester resin composition of the present invention comprises the cellulose ester resin modifier of the present invention and a cellulose ester resin.

  The cellulose ester resin is obtained by esterifying a part or all of hydroxyl groups of cellulose obtained from cotton linter, wood pulp, kenaf and the like. Among these, a film obtained by using cellulose ester resin obtained by esterifying cellulose obtained from cotton linter is easy to peel off from the metal support constituting the film production apparatus, and improves the production efficiency of the film. It is preferable because it becomes possible.

  Specific examples of the cellulose ester resin include, for example, cellulose acetate such as triacetyl cellulose and diacetyl cellulose, cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate propionate butyrate, cellulose acetate phthalate, and cellulose nitrate. Can be mentioned. These cellulose ester resins can be used alone or in combination of two or more. When the film comprising the cellulose ester resin composition of the present invention is used as an optical film, particularly as a polarizing plate protective film, it is possible to obtain a film excellent in mechanical properties and transparency by using cellulose acetate. Therefore, it is preferable.

  As the cellulose acetate, when the average degree of acetylation (bound acetic acid amount) is in the range of 50.0 to 62.5% by mass, the resulting optical film made of the cellulose ester resin composition has mechanical properties and transparency. Since it becomes a film excellent in property, it is preferable.

  Moreover, in order to improve the moisture permeability resistance of an optical film, it is preferable that the average acetylation degree of a cellulose acetate is the range of 54-61.5 mass%. By using triacetyl cellulose having a higher average degree of acetylation, a cellulose ester resin film having excellent moisture resistance can be obtained. Moreover, in order to adjust an optical film to a high retardation value, it is preferable that the average acetylation degree of a cellulose acetate is the range of 50.0-58 mass%.

  In addition, an average acetylation degree is a mass ratio of the acetic acid produced | generated by saponifying this cellulose acetate on the basis of the mass of a cellulose acetate.

  The cellulose ester resin preferably has a number average molecular weight in the range of 30,000 to 300,000 because the mechanical properties of the film can be improved. Moreover, when higher mechanical properties are required, it is more preferable to use a material in the range of 50,000 to 200,000.

  As content of the modifier for cellulose ester resins in the cellulose ester resin composition of this invention, the range of 0.5-50 mass parts is preferable with respect to 100 mass parts of cellulose ester resins, 0.5-30 The range of parts by mass is more preferable, and the range of 5 to 15 parts by mass is more preferable. If the said cellulose ester resin modifier is used in this range, it will become the composition from which it is excellent in moisture permeability resistance, and is excellent in transparency, and can be used suitably for an optical use.

  The optical film of the present invention is a film containing the cellulose ester resin composition of the present invention. Although the film thickness of the cellulose ester film of the present invention varies depending on the application used, it is generally preferably in the range of 10 to 200 μm.

  The optical film of the present invention may have characteristics such as optical anisotropy or optical isotropy. However, when the optical film is used as a protective film for a polarizing plate, it does not inhibit light transmission. It is preferable to use an optically isotropic film.

  The optical film of the present invention can be used in various applications. As the most effective use, for example, there is a protective film for a polarizing plate that requires optical isotropy of a liquid crystal display device, but it is also used for a support for a protective film for a polarizing plate that requires an optical compensation function. Can do.

  The optical film of the present invention can be used for liquid crystal cells in various display modes. For example, IPS (In-Plane Switching), TN (Twisted Nematic), VA (Vertically Aligned), OCB (Optically Compensatory Bend) and the like can be exemplified.

  The optical film of the present invention can be produced by, for example, a melt extrusion method. Specifically, the cellulose ester resin composition containing the cellulose ester resin, the cellulose ester resin modifier, and other various additives as necessary is melt-kneaded with an extruder or the like, for example. It can be obtained by forming into a film using a T-die or the like.

  In addition to the molding method, the optical film of the present invention may be prepared by, for example, providing a resin solution obtained by dissolving the cellulose ester resin and the cellulose ester resin modifier in an organic solvent on a metal support. And then molding by a so-called solution casting method (solvent casting method) in which the organic solvent is distilled off and dried.

  According to the solution casting method, it is possible to obtain a film in which unevenness is hardly formed on the surface and the surface is excellent in smoothness. Therefore, the film obtained by the solution casting method can be preferably used for optical applications, and particularly preferably used for a protective film for polarizing plates.

  The solution casting method generally includes a first step in which the cellulose ester resin and the cellulose ester resin modifier are dissolved in an organic solvent, and the resulting resin solution is cast on a metal support; A second step of forming a film by distilling off the organic solvent contained in the cast resin solution, followed by peeling the film formed on the metal support from the metal support and drying by heating. It consists of a 3rd process.

  Examples of the metal support used in the first step include endless belt-shaped or drum-shaped metal supports, for example, stainless steel with a mirror-finished surface can be used. .

  When casting the resin solution on the metal support, it is preferable to use a resin solution filtered with a filter in order to prevent foreign matters from entering the film obtained.

  Although it does not specifically limit as the drying method of the said 2nd process, For example, it includes in the said resin solution cast | casted by applying the wind of the temperature range of 30-50 degreeC to the upper surface and / or lower surface of the said metal support body. The method of evaporating 50-80 mass% of the organic solvent to be formed, and forming a film on the said metal support body is mentioned.

  Next, the third step is a step in which the film formed in the second step is peeled off from the metal support and heat-dried under a temperature condition higher than that in the second step. As the heat drying method, for example, a method in which the temperature is raised stepwise under a temperature condition of 100 to 160 ° C. is preferable because good dimensional stability can be obtained. The organic solvent remaining in the film after the second step can be almost completely removed by heating and drying under the temperature condition.

  In the first to third steps, the organic solvent can be recovered and reused.

  The organic solvent that can be used when the cellulose ester resin and the cellulose ester resin modifier are mixed and dissolved in an organic solvent is not particularly limited as long as they can be dissolved. When using acetate, it is preferable to use organic halogen compounds such as methylene chloride and dioxolanes as good solvents.

  In addition, it is preferable to use a poor solvent such as methanol, ethanol, 2-propanol, n-butanol, cyclohexane, cyclohexanone or the like together with the good solvent in order to improve the production efficiency of the film.

  The mixing ratio of the good solvent and the poor solvent is preferably in the range of good solvent / poor solvent = 75/25 to 95/5 in mass ratio.

  10-50 mass% is preferable and, as for the density | concentration of the cellulose ester resin in the said resin solution, 15-35 mass% is more preferable.

  In the solution casting method, after obtaining the heat-dried film in the third step, a fourth step of further heating and stretching the film can be provided.

  In the fourth step, the film obtained is heated and stretched after film formation using the cellulose ester resin composition of the present invention in the first step to the third step. The stretching operation may be performed in multiple stages, or biaxial stretching may be performed in the casting direction and the width direction. Moreover, when performing biaxial stretching, simultaneous biaxial stretching may be performed and you may implement in steps. In this case, stepwise means that, for example, stretching in different stretching directions can be sequentially performed, stretching in the same direction is divided into multiple stages, and stretching in different directions is added to any one of the stages. Is also possible.

  Simultaneous biaxial stretching includes stretching in one direction and contracting the other direction by relaxing the tension. The preferred draw ratio of simultaneous biaxial stretching is, for example, x1.05 to 1.5 times in the width direction and x0.8 to x1.3 times in the longitudinal direction (casting direction), and particularly in the width direction. X1.1 to x2.5 times and x0.8 to x0.99 times in the longitudinal direction. Particularly preferably, it is x1.1 to x2.0 times in the width direction and x0.9 to x0.99 times in the longitudinal direction.

  Examples of other various additives that can be added as necessary include modifiers other than the cellulose ester resin modifier of the present invention, thermoplastic resins, ultraviolet absorbers, matting agents, dyes, and the like. Can be mentioned.

  Examples of other various additives that can be added as necessary include modifiers other than the modifier for cellulose ester resin of the present invention. Examples of the modifier other than the cellulose ester resin modifier of the present invention include phosphate esters such as triphenyl phosphate (TPP), tricresyl phosphate, and cresyl diphenyl phosphate; dimethyl phthalate, diethyl phthalate, and dibutyl phthalate. , Phthalic acid esters such as di-2-ethylhexyl phthalate, ethyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate; ester compounds of polyhydric alcohols such as trimethylolpropane tribenzoate, pentaerythritol tetraacetate, tributyl acetylcitrate A polyester compound whose end is sealed with an aliphatic monocarboxylic acid such as acetic acid, a polyester compound whose end is sealed with an aromatic monocarboxylic acid such as benzoic acid, a poly having a terminal hydroxyl group Polyester compounds such as steal polyol; sugar ester compounds having a furanose structure or pyranose structure such as sucrose octaacetate and sucrose benzoate; compounds having a barbituric acid structure; 5-membered aromatic heterocycles such as imidazole, triazole and pyrazole, and 6 And compounds having a structure in which a member aromatic hydrocarbon ring is linked.

  Examples of the thermoplastic resin include polyester resin, polyester ether resin, polyurethane resin, epoxy resin, toluenesulfonamide resin, and the like.

  The ultraviolet absorber is not particularly limited, and examples thereof include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, and the like. The ultraviolet absorber is preferably in the range of 0.01 to 2 parts by mass with respect to 100 parts by mass of the cellulose ester resin.

  Examples of the matting agent include silicon oxide, titanium oxide, aluminum oxide, calcium carbonate, calcium silicate, aluminum silicate, magnesium silicate, calcium phosphate, kaolin, and talc. The matting agent is preferably in the range of 0.1 to 0.3 parts by mass with respect to 100 parts by mass of the cellulose ester resin.

  The dye is not particularly limited in terms of type and blending amount as long as the object of the present invention is not impaired.

  The film thickness of the optical film of the present invention is preferably in the range of 5 to 120 μm, more preferably in the range of 8 to 100 μm, and particularly preferably in the range of 10 to 80 μm. When the optical film is used as a protective film for a polarizing plate, a film thickness in the range of 10 to 80 μm is suitable for reducing the thickness of the liquid crystal display device, and has sufficient film strength and Rth stability. Excellent performance such as moisture permeability resistance can be maintained.

  Since the optical film of the present invention has good moisture permeation resistance, such as a protective film for polarizing plate, a retardation film, a reflector, a viewing angle improving film, an antiglare film, an antireflective film, an antistatic film, a color filter, etc. It can be suitably used as a member of a liquid crystal display device.

  Hereinafter, the present invention will be described more specifically based on examples. Unless otherwise indicated, parts and% in the examples are based on mass.

Example 1 (Modifier for cellulose ester resin)
In a 1 liter four-necked flask equipped with a thermometer, a stirrer and a water separator, 138 g of p-hydroxybenzoic acid, 39 g of ethylene glycol, 200 g of xylene as a solvent, p-toluenesulfonic acid monohydrate 1 as a catalyst .9 g was added. In order to carry out the esterification reaction under azeotropic dehydration conditions with xylene, the temperature was raised to 140 ° C. over 1.5 hours, and the reaction was carried out at 140 ° C. for 3 hours. After the reaction, the reaction mixture was cooled to room temperature, and the precipitated contents were filtered to obtain a solid. 500 g of ion-exchanged water was added to the obtained solid, stirred for 30 minutes, filtered, and dried at 120 ° C. for 4 hours. 300 g of methanol was added to the resulting solid and stirred for 15 minutes, and then the undissolved part was filtered and dried at 120 ° C. for 1 hour to thereby modify the cellulose ester resin modifier (1) of the present invention. Obtained. The modifier (1) for cellulose ester resin was solid at room temperature. As a result of analysis by GPC, the number average molecular weight was 390 and the weight average molecular weight was 393.

Example 2 (same as above)
In a 1 liter four-necked flask equipped with a thermometer, stirrer and water separator, p-hydroxybenzoic acid 138 g, propylene glycol 47.9 g, solvent xylene 200 g, catalyst p-toluenesulfonic acid monohydrate 1.9 g of product was added. In order to carry out the esterification reaction under the conditions of azeotropic dehydration with xylene, the temperature was raised to 140 ° C. over 1 hour and reacted at 140 ° C. for 3 hours. After the reaction, the mixture was cooled to room temperature, 200 g of ethyl acetate was added, and the mixture was stirred for 30 minutes. After preparing a uniform solution, 100 g of a saturated aqueous sodium hydrogen carbonate solution was added, and the mixture was stirred at room temperature for 30 minutes and allowed to stand. The upper organic layer was transferred to a separatory funnel and washed twice with 50 g of saturated aqueous sodium hydrogen carbonate solution and twice with saturated brine. The obtained organic layer was adjusted to pH 7 by adding phosphoric acid. The organic layer was dried using 20 g of anhydrous sodium sulfate, and the solvent was removed by reducing the pressure at 40 ° C. to obtain the cellulose ester resin modifier (2) of the present invention. The modifier (2) for cellulose ester resin was a highly viscous liquid at room temperature. As a result of analysis by GPC, the number average molecular weight was 470 and the weight average molecular weight was 500.

Example 3 (same as above)
To a 0.5 liter four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser, 234.8 g of p-hydroxybenzoic acid, 71.1 g of propylene glycol, and 0.018 g of tetraisopropyl titanate as a catalyst were added. While stirring under a nitrogen stream, the temperature was raised stepwise until it reached 220 ° C. and reacted for a total of 20 hours. After the reaction, unreacted propylene glycol was removed under reduced pressure at 180 ° C. to obtain the cellulose ester resin modifier (3) of the present invention. The modifier (3) for cellulose ester resin was solid at room temperature. As a result of analysis by GPC, the number average molecular weight was 640, and the weight average molecular weight was 830.

Example 4 (same as above)
To a 0.5 liter four-necked flask equipped with a thermometer, a stirrer and a reflux condenser, 221.0 parts by mass of p-hydroxybenzoic acid and 48.7 parts by mass of 1,3-propanediol were added. While stirring under a nitrogen stream, the temperature was raised stepwise until it reached 220 ° C. and reacted for a total of 12 hours. After the reaction, unreacted 1,3-propanediol was removed under reduced pressure at 180 ° C. to obtain the cellulose ester resin modifier (4) of the present invention. The modifier (4) for cellulose ester resin was solid at room temperature. As a result of analysis by GPC, the number average molecular weight was 440, and the weight average molecular weight was 470.

Example 5 (same as above)
To a 0.5 liter four-necked flask equipped with a thermometer, a stirrer and a reflux condenser, 221.0 g of p-hydroxybenzoic acid and 46.7 g of 2-methyl-1,3-propanediol were added. While stirring under a nitrogen stream, the temperature was raised stepwise to 220 ° C., and the reaction was allowed to proceed for a total of 12.5 hours. After the reaction, unreacted 2-methyl-1,3-propanediol was removed under reduced pressure at 180 ° C. to obtain the cellulose ester resin modifier (5) of the present invention. The modifier (5) for cellulose ester resin was solid at room temperature. As a result of analysis by GPC, the number average molecular weight was 460, and the weight average molecular weight was 490.

Example 6 (same as above)
To a 0.5 liter four-necked flask equipped with a thermometer, a stirrer and a reflux condenser, 221 g of p-hydroxybenzoic acid and 93.4 g of 2-methyl-1,3-propanediol were added. While stirring under a nitrogen stream, the temperature was raised stepwise until reaching 220 ° C., and the reaction was carried out for a total of 9 hours. After the reaction, unreacted 2-methyl-1,3-propanediol was removed under reduced pressure at 180 ° C. to obtain the cellulose ester resin modifier (6) of the present invention. The modifier (6) for cellulose ester resin was a highly viscous liquid at room temperature. As a result of analysis by GPC, the number average molecular weight was 440, and the weight average molecular weight was 480.

Example 7 (same as above)
To a 0.5 liter four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser, 221 g of p-hydroxybenzoic acid and 75.6 g of 3-methyl-1,5-pentanediol were added. While stirring under a nitrogen stream, the temperature was raised stepwise to 220 ° C., and the reaction was allowed to proceed for a total of 12.5 hours. After the reaction, unreacted 3-methyl-1,5-pentanediol was removed under reduced pressure at 180 ° C. to obtain the cellulose ester resin modifier (7) of the present invention. The cellulose ester resin modifier (7) was a highly viscous liquid at room temperature. As a result of analysis by GPC, the number average molecular weight was 440, and the weight average molecular weight was 450.

Example 8 (same as above)
To a 0.3 liter four-necked flask equipped with a thermometer, a stirrer, and a water separator, 243 g of salicylic acid, 25 g of ethylene glycol, and 3.3 g of p-toluenesulfonic acid monohydrate as a catalyst were added. In order to carry out the esterification reaction, the temperature was raised to 140 ° C. over 1 hour and reacted at 140 ° C. for 3 hours. After the reaction, the reaction mixture was cooled to room temperature, 100 g of a saturated aqueous sodium hydrogen carbonate solution was added, and the precipitated light red solid was separated by filtration. To the obtained solid content, 100 g of methanol was added and dissolved, and 200 g of ion-exchanged water was added to precipitate a white solid content. 100 g of toluene was added to form a cloudy solution, and filtered to obtain a pale yellow toluene solution. The toluene solution was dried using 20 g of anhydrous sodium sulfate, depressurized at 40 ° C., and the toluene was removed to obtain the cellulose ester resin modifier (8) of the present invention. The modifier for cellulose ester resin (8) was solid at room temperature. As a result of analysis by GPC, the number average molecular weight was 286, and the weight average molecular weight was 288.

Example 9 (same as above)
In a 0.5 liter four-necked flask equipped with a thermometer, a stirrer and a reflux condenser, 236.0 parts by mass of p-hydroxybenzoic acid, 145.3 parts by mass of 2-methyl-1,3-propanediol, 31.9 parts by mass of succinic acid, 44.9 parts by mass of terephthalic acid, and 0.027 g of tetraisopropyl titanate as a catalyst were added. While stirring under a nitrogen stream, the temperature was raised stepwise until it reached 220 ° C. and reacted for a total of 17 hours. After the reaction, unreacted 2-methyl-1,3-propanediol was removed under reduced pressure at 200 ° C. to obtain the cellulose ester resin modifier (9) of the present invention. The modifier (9) for cellulose ester resin was solid at room temperature. As a result of analysis by GPC, the number average molecular weight was 610, and the weight average molecular weight was 810.

Example 10 (cellulose ester resin composition)
To 100 parts of triacetylcellulose (product name LT-35, degree of acetylation 61%, manufactured by Daicel Chemical Industries) and 10 parts of the modifier for cellulose ester resin (1), 810 parts of methylene chloride and 135 parts of methanol were added. It melt | dissolved and the dope liquid was obtained. The dope solution was cast on a glass plate to a thickness of about 0.8 mm, left at room temperature overnight, dried at 50 ° C. for 30 minutes and 120 ° C. for 30 minutes, and a cellulose ester film having a thickness of 60 μm (1 -1) was obtained.

  The obtained cellulose ester film (1-1) was evaluated for moisture permeability, retardation value in the thickness direction (Rth value), HAZE value, and water resistance according to the following methods. The evaluation results are shown in Table 1.

<Method for evaluating moisture permeability>
Measurement was performed according to the method described in JIS Z 0208. The measurement conditions were a temperature of 40 ° C. and a relative humidity of 90%. It represents that it is excellent in moisture permeability resistance, so that the value obtained is small.

<Rth value evaluation method>
The retardation value (Rth value) in the thickness direction of the film was measured by a parallel Nicol rotation method using a phase difference measuring device KOBRA-WR (manufactured by Oji Scientific Instruments). The film was left for 1 hour or longer at 23 ° C. and 55% RH and used for measurement.

<Measurement method of HAZE value>
The HAZE value was measured according to JIS K 7105 using a turbidimeter (“NDH 5000” manufactured by Nippon Denshoku Industries Co., Ltd.).

<Water resistance evaluation method>
The water resistance was evaluated by the ratio of the Rth value that varies depending on the humidity of the environment. After measuring Rth in the above <Rth value evaluation method>, the cellulose ester film (1-1) was immersed in ion-exchanged water at 23 ° C. for 12 hours or more. Immediately after removing from the ion-exchanged water, the water was wiped off and the Rth value was measured. The measurement was performed by the KOBRA-WR installed in an environment of 23 ° C. and 55% RH. The change rate of the Rth value was determined according to the following formula. It was judged that the closer this value was to 0%, the smaller the amount of change in Rth value due to humidity, and the better the water resistance.
Ratio of change in Rth value (%) = [(Rth value after immersion in ion exchange water−Rth value before immersion in ion exchange water) / Rth value before immersion in ion exchange water] × 100

Example 11 (same as above)
Example 10 except that 10 parts of the cellulose ester resin modifier (1) was used instead of 10 parts of the cellulose ester resin modifier (2) and 90 parts of methanol was used instead of 135 parts of methanol. Thus, a cellulose ester film (2-1) was obtained. Evaluation was performed in the same manner as in Example 10, and the results are shown in Table 1.

Example 12 (same as above)
Example 10 except that 10 parts of cellulose ester resin modifier (1) was used in place of 10 parts of cellulose ester resin modifier (1), and 90 parts of methanol was used in place of 135 parts of methanol. Thus, a cellulose ester film (3-1) was obtained. Evaluation was performed in the same manner as in Example 10, and the results are shown in Table 1.

Example 13 (same as above)
Example 10 except that 10 parts of cellulose ester resin modifier (1) was used in place of 10 parts of cellulose ester resin modifier (1), and 90 parts of methanol was used in place of 135 parts of methanol. Thus, a cellulose ester film (4-1) was obtained. Evaluation was performed in the same manner as in Example 10, and the results are shown in Table 1.

Example 14 (same as above)
Example 10 except that 10 parts of cellulose ester resin modifier (1) was used instead of 10 parts of cellulose ester resin modifier (1), and 90 parts of methanol was used instead of 135 parts of methanol. Thus, a cellulose ester film (5-1) was obtained. Evaluation was performed in the same manner as in Example 10, and the results are shown in Table 1.

Example 15 (same as above)
Example 10 except that 10 parts of cellulose ester resin modifier (1) was used instead of 10 parts of cellulose ester resin modifier (1), and 90 parts of methanol was used instead of 135 parts of methanol. Thus, a cellulose ester film (6-1) was obtained. Evaluation was performed in the same manner as in Example 10, and the results are shown in Table 1.

Example 16 (same as above)
Example 10 except that 10 parts of the cellulose ester resin modifier (1) was used instead of 10 parts of the cellulose ester resin modifier (7) and 90 parts of methanol was used instead of 135 parts of methanol. Thus, a cellulose ester film (7-1) was obtained. Evaluation was performed in the same manner as in Example 10, and the results are shown in Table 1.

Example 17 (same as above)
Example 10 except that 10 parts of the cellulose ester resin modifier (1) was used instead of 10 parts of the cellulose ester resin modifier (8) and 90 parts of methanol was used instead of 135 parts of methanol. Thus, a cellulose ester film (8-1) was obtained. Evaluation was performed in the same manner as in Example 10, and the results are shown in Table 1.

Example 18 (same as above)
Example 10 except that 10 parts of the cellulose ester resin modifier (1) was used instead of 10 parts of the cellulose ester resin modifier (1) and 90 parts of methanol was used instead of 135 parts of methanol. Thus, a cellulose ester film (9-1) was obtained. Evaluation was performed in the same manner as in Example 10, and the results are shown in Table 1.

Example 19 (same as above)
To 100 parts of diacetyl cellulose (product name L-50, degree of acetylation 55%, manufactured by Daicel Chemical Industries) and 10 parts of the modifier for cellulose ester resin (1), 810 parts of methylene chloride and 135 parts by weight of methanol were added. It melt | dissolved and the dope liquid was obtained. The dope solution was cast on a glass plate to a thickness of about 0.8 mm, left at room temperature overnight, dried at 50 ° C. for 30 minutes and 120 ° C. for 30 minutes, and a cellulose ester film having a thickness of 60 μm (1 -2) was obtained. Evaluation was carried out in the same manner as in Example 10, and the results are shown in Table 2.

Example 20 (same as above)
Example 10 except that 10 parts of the cellulose ester resin modifier (1) was used instead of 10 parts of the cellulose ester resin modifier (2) and 90 parts of methanol was used instead of 135 parts of methanol. Thus, a cellulose ester film (2-2) was obtained. Evaluation was carried out in the same manner as in Example 10, and the results are shown in Table 2.

Example 21 (same as above)
Example 10 except that 10 parts of the cellulose ester resin modifier (1) was used in place of 10 parts of the cellulose ester resin modifier (1) and 90 parts of methanol was used in place of 135 parts of methanol. Thus, a cellulose ester film (3-2) was obtained. Evaluation was carried out in the same manner as in Example 10, and the results are shown in Table 2.

Example 22 (same as above)
Example 10 except that 10 parts of cellulose ester resin modifier (1) was used in place of 10 parts of cellulose ester resin modifier (4), and 90 parts of methanol was used in place of 135 parts of methanol. Thus, a cellulose ester film (4-2) was obtained. Evaluation was carried out in the same manner as in Example 10, and the results are shown in Table 2.

Example 23 Same as above)
Example 10 except that 10 parts of the cellulose ester resin modifier (1) was used in place of 10 parts of the cellulose ester resin modifier (5) and 90 parts of methanol was used in place of 135 parts of methanol. Thus, a cellulose ester film (5-2) was obtained. Evaluation was carried out in the same manner as in Example 10, and the results are shown in Table 2.

Example 24 (same as above)
Example 10 except that 10 parts of the cellulose ester resin modifier (1) was used in place of 10 parts of the cellulose ester resin modifier (1) and 90 parts of methanol was used in place of 135 parts of methanol. Thus, a cellulose ester film (6-2) was obtained. Evaluation was carried out in the same manner as in Example 10, and the results are shown in Table 2.

Example 25 (same as above)
Example 10 except that 10 parts of the cellulose ester resin modifier (1) was used in place of 10 parts of the cellulose ester resin modifier (7) and 90 parts of methanol was used in place of 135 parts of methanol. Thus, a cellulose ester film (7-2) was obtained. Evaluation was carried out in the same manner as in Example 10, and the results are shown in Table 2.

Example 26 (same as above)
Example 10 except that 10 parts of the cellulose ester resin modifier (1) was used in place of 10 parts of the cellulose ester resin modifier (8), and 90 parts of methanol was used instead of 135 parts of methanol. Thus, a cellulose ester film (8-2) was obtained. Evaluation was carried out in the same manner as in Example 10, and the results are shown in Table 2.

Example 27 (same as above)
Example 10 except that 10 parts of cellulose ester resin modifier (1) was used in place of 10 parts of cellulose ester resin modifier (1), and 90 parts of methanol was used in place of 135 parts of methanol. Thus, a cellulose ester film (26-2) was obtained. Evaluation was carried out in the same manner as in Example 10, and the results are shown in Table 2.

Comparative Example 1 (Modifier for Comparative Control Cellulose Ester Resin)
Into a 3 liter four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was charged 463 g of dimethyl terephthalate, 410 g of propylene glycol, 648 g of benzoic acid, and 0.091 g of tetraisopropyl titanate as an esterification catalyst. While stirring under a nitrogen stream, the temperature was raised stepwise until reaching 220 ° C., and the condensation reaction was carried out for a total of 17 hours. After the reaction, unreacted propylene glycol was removed under reduced pressure at 200 ° C., and a modifier for cellulose ester resin for comparison (1 ′) (acid value 0.5, hydroxyl value 10, number average), which was a normal temperature high viscosity liquid A molecular weight of 450) was obtained.

Comparative Example 2 (same as above)
In a four-necked flask with an internal volume of 3 liters equipped with a thermometer, a stirrer, and a reflux condenser, 1709 parts by weight of benzoic acid, 639 parts by weight of 1,2-propylene glycol, and tetraisopropyl titanate as an esterification catalyst. 141 g was charged, and the temperature was raised stepwise to 220 ° C. while stirring under a nitrogen stream, and the condensation reaction was carried out for a total of 11 hours. After the reaction, unreacted propylene glycol is removed under reduced pressure at 200 ° C., and the modifier for cellulose ester resin for comparison (2 ′) (acid value 0.2, hydroxyl value 5, number average molecular weight 300, which is a liquid at room temperature. )

Comparative Example 3 (same as above)
Implemented except that 10 parts of the cellulose ester resin modifier (1) was used in place of 10 parts of the cellulose ester resin modifier (1), and 90 parts of methanol was used instead of 135 parts of methanol. In the same manner as in Example 10, a comparative cellulose ester film (1′-1) was obtained. Evaluation was performed in the same manner as in Example 10, and the results are shown in Table 3.

Comparative Example 4 (same as above)
Implemented except that 10 parts of the cellulose ester resin modifier (1) was used instead of 10 parts of the cellulose ester resin modifier (2 ') and 90 parts of methanol was used instead of 135 parts of methanol. In the same manner as in Example 10, a comparative cellulose ester film (2′-1) was obtained. Evaluation was performed in the same manner as in Example 10, and the results are shown in Table 3.

Comparative Example 5 (same as above)
Cellulose ester resin modifier (1) 10 parts of parahydroxybenzoic acid instead of 10 parts and 90 parts of methanol instead of 135 parts of methanol An ester film (3′-1) was obtained. Evaluation was performed in the same manner as in Example 10, and the results are shown in Table 3.

Comparative Example 6 (same as above)
Cellulose ester resin modifier (1) A comparative cellulose ester film as in Example 10, except that 10 parts of benzyl salicylate were used instead of 10 parts and 90 parts of methanol was used instead of 135 parts of methanol. (4′-1) was obtained. Evaluation was performed in the same manner as in Example 10, and the results are shown in Table 3.

Comparative Example 7 (same as above)
Example 1 except that 10 parts of sucrose benzoate (Monopet SB, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was used instead of 10 parts of the cellulose ester resin modifier (1), and 90 parts of methanol was used instead of 135 parts of methanol. In the same manner as in Example 10, a comparative cellulose ester film (5′-1) was obtained. Evaluation was performed in the same manner as in Example 10, and the results are shown in Table 3.

Comparative Example 8 (same as above)
135 parts of methanol using 10 parts of 2-ethylhexyl 4-hydroxybenzoate (6 ′) (2-Ethylhexyl 4-Hydroxybenzoate, manufactured by Tokyo Chemical Industry Co., Ltd.) instead of 10 parts of the cellulose ester resin modifier (1) A comparative cellulose ester film (6′-1) was obtained in the same manner as in Example 10 except that 90 parts of methanol was used instead of. Evaluation was performed in the same manner as in Example 10, and the results are shown in Table 3.

Comparative Example 9 (same as above)
To 100 parts by mass of triacetyl cellulose (product name LT-35, degree of acetylation 61%, manufactured by Daicel Chemical Industries), 810 parts by weight of methylene chloride and 90 parts by weight of methanol were added and dissolved to obtain a dope solution. A dope solution is cast on a glass plate to a thickness of about 0.8 mm, left at room temperature overnight, dried at 50 ° C. for 30 minutes and 120 ° C. for 30 minutes, and a cellulose ester for comparison having a thickness of 60 μm. A film (7'-1) was obtained. Evaluation was performed in the same manner as in Example 10, and the results are shown in Table 3.

Comparative Example 10 (same as above)
Implemented except that 10 parts of the cellulose ester resin modifier (1 ') was used in place of 10 parts of the cellulose ester resin modifier (1), and 90 parts of methanol was used instead of 135 parts of methanol. In the same manner as in Example 19, a comparative cellulose ester film (1′-2) was obtained. Evaluation was carried out in the same manner as in Example 10, and the results are shown in Table 4.

Comparative Example 11 (same as above)
Cellulose ester resin modifier (1) In the same manner as in Example 19, except that 10 parts of parahydroxybenzoic acid was used instead of 10 parts, and 90 parts of methanol was used instead of 135 parts of methanol. An ester film (2′-2) was obtained. Evaluation was carried out in the same manner as in Example 10, and the results are shown in Table 4.

Comparative Example 12 (same as above)
To 100 parts by mass of diacetylcellulose (product name L-50, degree of acetylation 55%, manufactured by Daicel Chemical Industries), 810 parts by weight of methylene chloride and 90 parts by weight of methanol were added and dissolved to obtain a dope solution. A dope solution is cast on a glass plate to a thickness of about 0.8 mm, left at room temperature overnight, dried at 50 ° C. for 30 minutes and 120 ° C. for 30 minutes, and a cellulose ester for comparison having a thickness of 60 μm. A film (3′-2) was obtained. Evaluation was carried out in the same manner as in Example 10, and the results are shown in Table 4.

Footnotes in Tables 3 and 4 POB: parahydroxybenzoic acid BnS: benzyl salicylate

Claims (8)

  A divalent aliphatic alcohol (g) having 2 to 10 carbon atoms, an aromatic monocarboxylic acid (a) having a structure in which some or all of the hydrogen atoms on the aromatic ring are substituted with hydroxyl groups, and an aliphatic group A water resistance and moisture permeation resistance modifier for cellulose ester resin, which is obtained by reacting dicarboxylic acid and / or aromatic dicarboxylic acid.   The water resistance for cellulose ester resin according to claim 1, wherein the divalent aliphatic alcohol (g) having 2 to 10 carbon atoms is a chain divalent aliphatic alcohol having 2 to 8 carbon atoms. Moisture permeability modifier.   The divalent aliphatic alcohol (g) having 2 to 10 carbon atoms is a straight chain divalent aliphatic alcohol having 2 to 6 carbon atoms or a branched divalent aliphatic alcohol having 2 to 6 carbon atoms. The water- and moisture-permeable modifier for cellulose ester resins according to claim 1, which is an aliphatic alcohol.   The divalent aliphatic alcohol (g) having 2 to 10 carbon atoms is selected from ethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, and 3-methyl-1,5. The water- and moisture-resistant modifier for cellulose ester resins according to claim 1, which is one or more alcohols selected from the group consisting of pentanediol.   The aromatic monocarboxylic acid (a) having a structure in which part or all of the hydrogen atoms on the aromatic ring are substituted with a hydroxyl group is an aromatic having a structure in which one of the hydrogen atoms on the aromatic ring is substituted with a hydroxyl group. The water- and moisture-permeable modifier for cellulose ester resins according to claim 1, which is a monocarboxylic acid.   The water resistance for cellulose ester resin according to claim 1, wherein the aromatic monocarboxylic acid (a) having a structure in which part or all of the hydrogen atoms on the aromatic ring are substituted with hydroxyl groups is parahydroxybenzoic acid. Moisture permeability modifier.   The aliphatic dicarboxylic acid is one or more selected from the group consisting of succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, cyclohexanedicarboxylic acid, dimer acid, and fumaric acid. The water- and moisture-resistant modifier for cellulose ester resins according to claim 1, which is an aliphatic dicarboxylic acid.   2. The aromatic dicarboxylic acid is one or more aromatic dicarboxylic acids selected from the group consisting of phthalic acid, isophthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, and 4,4′-biphenyldicarboxylic acid. The water-resistant and moisture-permeable modifier for cellulose ester resins as described.