KR20200018404A - Ester resin, semiplasticizer, cellulose ester resin composition, optical film, and liquid crystal display device - Google Patents

Abstract

The ester resin which is excellent in the balance of the intensity | strength, moisture permeability, and the optical characteristic at the time of processing into a film form especially, and can be conveniently used as a semiplasticizing agent with respect to optical resin, the resin composition containing this, and the said resin composition are used The optical film obtained by this and the liquid crystal display device using this are provided. Specifically, B- (GA) _n -GB [ _wherein B is a monocarboxylic acid residue, G is an alkylene glycol residue, an oxyalkylene glycol residue or an aryl glycol residue, A is a dicarboxylic acid residue, and the sum of A 20 mol% or more of the number of moles is an isophthalic acid residue, n is a repeating number, and G and A may be the same or different for every repetition, and a plurality of B and G may be the same or different]. Ester resin, the cellulose-ester resin composition containing this, the optical film containing this composition, and a liquid crystal display device.

Description

Ester resin, semiplasticizer, cellulose ester resin composition, optical film, and liquid crystal display device

This invention relates to the ester resin suitable as the semiplasticizer of resin for optical materials, the cellulose ester resin containing this, the optical film obtained using the said resin composition, and the liquid crystal display device using this.

In recent years, thinning of a liquid crystal display is progressing, and also thinning of a polarizing plate protective film is progressing from 60 micrometers to 25 micrometers from conventional 80 micrometers. The triacetyl cellulose resin (hereinafter, TAC) has been used conventionally for the protective film of a polarizing plate from a viewpoint of easily sticking with a polarizer.

However, since TAC is brittle, problems such as insufficient strength and breakage tends to occur when a film is formed. Moreover, since TAC has high moisture permeability and it is easy to produce the dimensional change by moisture absorption, it is necessary to suppress moisture absorption with an additive, and various additives have been provided (for example, refer patent document 1).

Usually, when an additive is added in order to suppress moisture permeation, plasticization of resin occurs at the same time, and therefore, it is difficult to make both the strength and moisture permeability resistance of the film obtained. Therefore, the development of the additive (= semi-plasticizer) which is compatible with both moisture suppression and improvement of an elastic modulus is calculated | required.

Japanese Patent Application Laid-Open No. 2013-151699

In view of the above circumstances, the problem to be solved by the present invention is particularly excellent in the balance of strength, moisture permeability and optical properties when processed into a film, and can be suitably used as a semiplasticizer for optical resins. It is providing the ester resin, the resin composition containing this, the optical film obtained using the said resin composition, and the liquid crystal display device using the same.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining, the present inventors discovered that the said subject could be solved by adjusting the use ratio of the raw material, especially dicarboxylic acid, in ester resin, and came to complete this invention.

That is, this invention is the following general formula (1)

B- (GA) _n- GB (1)

[In Formula (1), B is a monocarboxylic acid residue, G is an alkylene glycol residue, an oxyalkylene glycol residue, or an aryl glycol residue, A is a dicarboxylic acid residue, and 20 mol% or more of the total number of moles of A is iso Is a phthalic acid residue, n is a repetition number, and G and A may be the same or different for every repetition, and a plurality of B and G may be the same or different]

It is provided with the ester resin characterized by the above, the resin composition containing this, the optical film obtained using this composition, and the liquid crystal display device using the said optical film.

ADVANTAGE OF THE INVENTION According to this invention, the ester resin which is excellent in the balance of the intensity | strength, moisture permeability, and optical characteristics at the time of processing into a film form, and which can be used suitably as a semiplasticizer for optical resin can be provided. Moreover, by using the said specific ester resin, especially in the optical film containing a cellulose ester resin, both the improvement of an elasticity modulus, moisture permeation suppression, and the maintenance of an optical characteristic can be compatible, and it is an optical film used for a liquid crystal display device. It can be used suitably.

The ester resin of this invention is following General formula (1)

B- (GA) _n- GB (1)

[In Formula (1), B is a monocarboxylic acid residue, G is an alkylene glycol residue, an oxyalkylene glycol residue, or an aryl glycol residue, A is a dicarboxylic acid residue, and 20 mol% or more of the total number of moles of A is iso Is a phthalic acid residue, n is a repetition number, and G and A may be the same or different for every repetition, and a plurality of B and G may be the same or different]

Characterized in that is displayed.

B in the said General formula (1) is a monocarboxylic acid residue, Specifically, an aryl monocarboxylic acid residue or an aliphatic monocarboxylic acid residue is mentioned. Here, a "carboxylic acid residue" represents groups other than -OH in a carboxy group. As said aryl monocarboxylic acid residue, what is a C6-C12 aryl monocarboxylic acid residue is a thing of moisture permeability, elastic modulus, and optical characteristic, when mixing with the raw material availability, the ease of esterification reaction, and the cellulose ester resin mentioned later. It is preferable from a viewpoint of being easy to balance, For example, benzoic acid, dimethyl benzoic acid, trimethyl benzoic acid, tetramethyl benzoic acid, ethyl benzoic acid, propyl benzoic acid, butyl benzoic acid, cuminic acid, parabutyl benzoic acid, ortho toluic acid, metatoluic acid And paratoluic acid, ethoxybenzoic acid, propoxybenzoic acid, aniseic acid, naphthoic acid, and the like, and may be used alone or in combination of two or more thereof. In particular, it is preferable that it is a residue of benzoic acid, paratoluic acid, and dimethyl benzoic acid from a viewpoint which is easy to express the effect of this invention, and it is more preferable that it is a residue of benzoic acid. In addition, a carbon atom number shall not contain the carbon atom in a carboxy group here. Moreover, residues, such as nicotinic acid and furoic acid which have aromaticity, which may have a substituent may be sufficient.

As said aliphatic monocarboxylic acid residue, a C1-C8 aliphatic monocarboxylic acid residue is a balance of moisture permeability, elastic modulus, and optical properties when it is mixed with the raw material availability, the ease of esterification reaction, and the cellulose ester resin mentioned later. It is preferable from the viewpoint of making it easy to match, For example, residues, such as an acetic acid, a propionic acid, butanoic acid, a hexanoic acid, an octanoic acid, an octylic acid, are mentioned, may be individual or may use 2 or more types together, and especially is acetic acid It is preferable. In addition, a carbon atom number shall not contain the carbon atom in a carboxy group here.

G in the said General formula (1) is an alkylene glycol residue, an oxyalkylene glycol residue, or an aryl glycol residue. A glycol residue represents group after removing a hydrogen atom from a hydroxyl group.

As said alkylene glycol residue, it is preferable that it is a C2-C12 alkylene glycol residue from a viewpoint which expresses the effect of this invention more easily, For example, ethylene glycol, 1, 2- propylene glycol, 1 , 3-propanediol, 1,2-butanediol, 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-trimethyl1,3-pentanediol, 2-ethyl-1,3-hexane Residues such as diol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, and the like may be used alone or in combination of two or more thereof. You may do it. Among these, it is preferable that carbon number of atoms which do not contain the branch between OH groups is 3 or less from a viewpoint of being ester resin excellent in compatibility when mixed with the cellulose ester resin mentioned later, and especially ethylene glycol and 1,2- It is preferable that it is a residue of propylene glycol, 1, 3- propanediol, 1, 2- butanediol, and 2-methyl- 1, 3- propanediol, and it is more preferable that it is a residue of ethylene glycol and 1,2-propylene glycol.

As said oxyalkylene glycol residue, it is preferable that it is a C4-C12 oxyalkylene glycol residue from a viewpoint which is easy to express the effect of this invention, For example, diethylene glycol, triethylene glycol, tetra The residues, such as ethylene glycol, dipropylene glycol, and tripropylene glycol, are mentioned, You may be independent and may use 2 or more types together.

As said aryl glycol residue, it is preferable that it is a C6-C18 aryl glycol residue from a viewpoint which is easy to express the effect of this invention, For example, the alkylene oxide of hydroquinone, a resorcinol, bisphenol A, bisphenol A, Residues, such as an adduct, bisphenol F, the alkylene oxide adduct of bisphenol F, a biphenol, and the alkylene oxide adduct of biphenol, are mentioned, and may be individual and may use 2 or more types together.

In addition, A in said General formula (1) is a dicarboxylic acid residue, Specifically, an alkylenedicarboxylic acid residue (A1) or an aryldicarboxylic acid residue (A2) is mentioned, and the isophthalic acid residue in the total mole number of A is mentioned. It is essential that the number of moles is 20 mol% or more. Here, a dicarboxylic acid residue means group except -OH in a carboxy group.

In the ester resin represented by the said General formula (1), when mixed with the optical resin mentioned later by using a lot of isophthalic acid as a dicarboxylic acid of a raw material, it calcinates this about the said optical resin, especially cellulose ester resin. When processing into a film form without making it into a film, it improves an elasticity modulus and provides moisture permeability, and can use it suitably for the optical film use to which thinning advances, without impairing the optical characteristic which the said resin for optics originally has. .

From the viewpoint of showing the above-mentioned effect, it is essential that the number of moles of isophthalic acid residues in the dicarboxylic acid residues is 20 mol% or more, and in particular, the content of the isophthalic acid residues is 25 to 100 mol% from the viewpoint of showing the effect more. It is preferable that it is in the range of.

As said alkylenedicarboxylic acid residue (A1) which may be used together with an isophthalic acid residue, it is preferable that it is a C2-C12 alkylenedicarboxylic acid residue from a viewpoint of expressing the effect of this invention more easily, for example Residues such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, 1,2-dicarboxycyclohexane, 1,2-dicarboxycyclohexene, and may be used alone. You may use 2 or more types together. Among these, since the optical film which is more excellent in moisture permeability is obtained, it is preferable that it is a residue of succinic acid, adipic acid, and 1,2-dicarboxycyclohexane, and the residue of adipic acid is the most preferable.

As said aryldicarboxylic acid residue (A2) which may be used together with an isophthalic acid residue, For example, phthalic acid, terephthalic acid, 1, 4- naphthalenedicarboxylic acid, 2, 3- naphthalenedicarboxylic acid, 2, 6- naphthalenedicarboxylic acid And residues such as 2,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, and may be used alone or in combination of two or more. Among these, since a higher intensity optical film is obtained, it is preferable that it is a residue of phthalic acid and terephthalic acid, and the residue of phthalic acid is the most preferable.

In this invention, as ester resin represented by the said General formula (1), B, G, and A are the same thing, n, ie, the mixture of only another repeating number may be sufficient, or B in General formula (1) , G, A and n may each be a mixture of different compounds. In this invention, in the optical film obtained by mixing with resin for optical materials mentioned later, especially a cellulose ester resin, in order to combine the improvement of moisture permeability and elastic modulus, in the GPC measurement of ester resin shown in General formula (1) In the area ratio, the ratio of the area% of the component where n = 0 to 10% in the general formula (1) and n is 3 or more and the area% of the n = 0 component (n ≧ 3) / (n = It is more preferable that 0) is 3 or less.

By making such n = 0 component and a so-called diester compound into a specific content rate, it arrange | positions suitably between the gaps of resin for optical materials, especially a cellulose ester resin, As a result, the effect which suppresses moisture permeability is expressed, and n By making the content rate of these three or more components comparatively small, compatibility with resin for optical materials can be ensured, and transparency which can be used as an optical film can be maintained more effectively.

These effects are further expressed, and from the viewpoint of suppressing contamination of a production line or the like due to volatilization, or maintaining transparency of an optical film, etc., the general formula (1) is described in terms of the area ratio in the GPC measurement. It is preferable that n = 0 component in () is 20-50%, and ratio (n≥3) / (n = 0) of the area% of the component of which n is 3 and the area% of n = 0 component is 0.2- It is preferable that it is the range of 1.5.

In addition, GPC measurement in this invention is performed on condition of the following.

[GPC measurement conditions]

 Measuring device: High speed GPC device "HLC-8320GPC" manufactured by Tosoh Corp.

 Column: "TSK GELDCOLUMN SuperHZ-L" + "TSK gel SuperHZM-M" made by Tosoh Kawasaki Co., Ltd. "TSK gel SuperHZM-M" + made by Tosoh Kawasaki Co., Ltd. "TSK gel SuperHZ-2000" + Doso Chemical Co., Ltd. "TSK gel SuperHZ-2000"

 Detector: RI (Differential Refractometer)

 Data processing: EcoSEC Data Analysis version 1.07 (manufactured by Tosoh Corp.)

 Column temperature: 40 ℃

 Developing Solvent: Tetrahydrofuran

 Flow rate: 0.35 mL / min

 Measurement sample: 7.5 mg of the sample was dissolved in 10 ml of tetrahydrofuran, and the resulting solution was filtered with a micro filter to obtain a measurement sample.

 Sample injection volume: 20 μl

 Standard sample: Based on the said measurement manual of "HLC-8320GPC", the following monodisperse polystyrene whose molecular weight is known was used.

Monodisperse Polystyrene

 "A-300" made by Toso Corporation

 "A-500" made by Toso Corporation

 "A-1000" made by Toso Corporation

 "A-2500" made by Toso Corporation

 "A-5000" made by Toso Corporation

 "F-1" made by Toso Corporation

 "F-2" made by Toso Corporation

 "F-4" made by Toso Corporation

 "F-10" made by Toso Corporation

 "F-20" made by Toso Corporation

 `` F-40 '' made by Toso Corporation

 "F-80" made by Toso Corporation

 "F-128" made by Toso Corporation

 "F-288" made by Toso Corporation

(GPC analysis condition)

The area% of the n = 0 component and the component whose n is 3 or more in the ester resin of this invention can be computed as follows. The GPC measurement of ester resin was performed, the polystyrene conversion molecular weight of each component corresponding to the detected peak was calculated | required, and the content rate (area fraction) of each component corresponding to the detected peak was computed from the ratio of the detected peak area.

In view of further expressing the effect of the present invention, in the general formula (1), B is a benzoic acid, a residue of acetic acid, G is ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,2 -Butanediol, residues of 2-methyl-1,3-propanediol, A1 which may be used together, residues of succinic acid, adipic acid, 1,2-dicarboxycyclohexane, A2 is preferably phthalic acid, terephthalic acid In particular, it is most preferable that B is a residue of benzoic acid, G is a residue of ethylene glycol and 1,2-propylene glycol, and A1, which may be present, is an adipic acid residue, and A2 is a residue of phthalic acid.

Moreover, as ester resin of this invention, it is preferable that it is the range of 350-1200, and it is especially preferable that the weight average molecular weight is compatible from a viewpoint of making compatibility and film physical property compatible. In addition, as an average value of the repeating number n in the said General formula (1), it is preferable that it is the range of 0.2-3 from a viewpoint of making compatible and film physical properties compatible similarly. Moreover, this weight average molecular weight and the average value of n are also the value measured by the said GPC measurement.

Moreover, as an acid value of the ester resin of this invention, it is preferable that it is 5 or less from a viewpoint of more favorable compatibility with resin for optical materials, and 1 or less is more preferable. Moreover, it is preferable that it is 50 or less, and, as for the hydroxyl value of ester resin from a similar viewpoint, it is more preferable that it is 20 or less.

The ester resin of the present invention is, for example, by subjecting the above-described raw material to esterification in the presence of an esterification catalyst, if necessary, for example, within a temperature range of 180 to 250 ° C for 10 to 25 hours. It can manufacture. Moreover, conditions, such as temperature and time of esterification reaction, are not specifically limited, You may set suitably. About monocarboxylic acid and dicarboxylic acid, the acid itself may be used as a raw material, or the esterified substance, acid chloride, anhydride of dicarboxylic acid, etc. may be used as a raw material.

As said esterification catalyst, For example, titanium-type 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 may be suitably set, it is preferable to use normally in 0.001-0.1 mass part with respect to 100 mass parts of whole amounts of a raw material.

The properties of the ester resin of the present invention vary depending on factors such as the weight average molecular weight, the combination of the raw materials, and the like, but are usually liquid, solid, paste or the like at normal temperature.

As a manufacturing method of a more specific ester resin, the above-mentioned alkylene glycol, oxyalkylene glycol, or aryl glycol, the compound which has a hydroxyl group in the terminal obtained using dicarboxylic acid, and the method of making monocarboxylic acid react are mentioned. Here, the said alkylene glycol, oxyalkylene glycol, or aryl glycol, dicarboxylic acid, and monocarboxylic acid may be thrown into the reaction system collectively, and may be made to react, or alkylene glycol, oxyalkylene glycol, or aryl glycol, and dicarboxylic acid. After obtaining the compound which has a hydroxyl group at the terminal obtained by using, the sequential reaction which adds monocarboxylic acid to a reaction system may be sufficient.

As long as the content of the isophthalic acid residue prescribed | regulated by this invention is 20 mol% or more, the ester resin obtained above may be used as an ester resin of this invention as it is, or the composition for every repetition of n by said GPC measurement is mentioned. For example, the content of the n = 0 component and the content of the high molecular weight component may be adjusted by methods such as distillation by a thin film distillation apparatus, column adsorption, and solvent separation and extraction. In particular, after distilling off the content rate of n = 0 component to 8% or less by the area ratio by GPC measurement by a thin film distillation apparatus, the diester compound (II) prepared separately is added as n = 0 component, and GPC measurement In the area ratio in (n), the ratio (n ≧ 3) / (ratio between the area% of the n = 0 component in the general formula (1) is 10 to 50% and n is 3 or more and the area% of the n = 0 component. The method of making it into the ester resin which satisfy | fills n = 0) is 3 or less may be sufficient. The raw material used for the ester resin at this time, and the raw material of the diester compound prepared separately may be the same, and may differ from each other. At this time, it is necessary to adjust so that 20 mol% or more of the total number of moles of A in the ester resin formed by mixing may be an isophthalic acid residue.

When employ | adopting the said manufacturing method, it is preferable that diester compound (II) added after that is represented by following General formula (2).

  B2-G2-B2 (2)

(In formula, B2 is an aryl monocarboxylic acid residue or an aliphatic monocarboxylic acid residue, G2 is an alkylene glycol residue, an oxyalkylene glycol residue, or an aryl glycol residue, and two or more B2 may be same or different).

B2 in the said General formula (2) is an aryl monocarboxylic acid residue or an aliphatic monocarboxylic acid residue. Here, a "carboxylic acid residue" represents groups other than -OH in a carboxy group. As said aryl monocarboxylic acid residue, what is a C6-C12 aryl monocarboxylic acid residue is the balance of the moisture permeability and the improvement of an elastic modulus when mixed with the raw material availability, the ease of esterification reaction, and the cellulose ester resin mentioned later. It is preferable from a viewpoint which is easy to match, For example, benzoic acid, dimethyl benzoic acid, trimethyl benzoic acid, tetramethyl benzoic acid, ethyl benzoic acid, propyl benzoic acid, butyl benzoic acid, cuminic acid, parabutyl benzoic acid, ortho toluic acid, metatoluic acid, Paratoluic acid, ethoxy benzoic acid, propoxy benzoic acid, aniseic acid, naphthoic acid, etc. are mentioned, You may be independent or may use 2 or more types together. In particular, it is preferable that it is a residue of benzoic acid, paratoluic acid, and dimethyl benzoic acid from a viewpoint which is easy to express the effect of this invention, and it is more preferable that it is a residue of benzoic acid. In addition, a carbon atom number shall not contain the carbon atom in a carboxy group here. Moreover, residues, such as nicotinic acid and furoic acid which have aromaticity, which may have a substituent may be sufficient.

As said aliphatic monocarboxylic acid residue, what is a C1-C8 aliphatic monocarboxylic acid residue is a balance of the moisture permeability and the improvement of an elastic modulus when mixed with the raw material availability, the ease of esterification reaction, and the cellulose ester resin mentioned later. It is preferable from a viewpoint of being easy to match, For example, residues, such as an acetic acid, a propionic acid, butanoic acid, hexanoic acid, an octanoic acid, an octylic acid, are mentioned, may be individual or may use 2 or more types together, and especially the residue of acetic acid Is preferably. In addition, a carbon atom number shall not contain the carbon atom in a carboxy group here.

G in the said General formula (1) is an alkylene glycol residue, an oxyalkylene glycol residue, or an aryl glycol residue. A glycol residue represents group after removing a hydrogen atom from a hydroxyl group.

As said alkylene glycol residue, it is preferable that it is a C2-C12 alkylene glycol residue from a viewpoint which expresses the effect of this invention more easily, For example, ethylene glycol, 1, 2- propylene glycol, 1 , 3-propanediol, 1,2-butanediol, 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-trimethyl1,3-pentanediol, 2-ethyl-1,3-hexane Residues such as diol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, and the like may be used alone or in combination of two or more thereof. You may do it. Among them, from the viewpoint of improving the strength of the film, 1,2-propylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, 1 Preference is given to residues of, 5-pentanediol.

As said oxyalkylene glycol residue, it is preferable that it is a C4-C12 oxyalkylene glycol residue from a viewpoint which is easy to express the effect of this invention, For example, diethylene glycol, triethylene glycol, tetra The residues, such as ethylene glycol, dipropylene glycol, and tripropylene glycol, are mentioned, You may be independent and may use 2 or more types together.

As said aryl glycol residue, it is preferable that it is a C6-C18 aryl glycol residue from a viewpoint which is easy to express the effect of this invention, For example, the alkylene oxide of hydroquinone, a resorcinol, bisphenol A, bisphenol A, Residues, such as an adduct, bisphenol F, the alkylene oxide adduct of bisphenol F, a biphenol, and the alkylene oxide adduct of biphenol, are mentioned, and may be individual and may use 2 or more types together.

From the viewpoint that the effects of the present invention are further expressed, in general formula (2), B2 is benzoic acid, a residue of acetic acid, G is 1,2-propylene glycol, 1,3-propanediol, 1,2-butanediol, It is preferable that they are residues of 1,3-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, diethylene glycol and dipropylene glycol.

The said diester compound (II) may be synthesize | combined, and may be commercially available, and when synthesize | combining, it manufactures using the method similar to the above-mentioned esterification reaction, and in the said General formula (1) The component of n = 0 can be obtained by a well-known method, such as the method of isolating using operation, such as distillation and a column, and is not limited as the method. In addition, as a diester compound (II) as long as it can satisfy | fill the conditions prescribed | regulated by this invention in the mixture after mixing uniformly with ester resin (I), the subcomponent other than n = 0 component may be contained. You may use the some thing which consists of different raw materials.

The ester resin of this invention obtained by such a method etc. can make it excellent in the balance of the moisture permeability, elastic modulus, and optical characteristic of the film obtained by mix | blending this to resin for optical materials, and can be used as what is called a semiplasticizer. In particular, it can use suitably as an optical film.

The resin for the optical material is not particularly limited as long as it has high transparency and can be processed into a film, and for example, (meth) acrylic resin, cyclic olefin resin, polycarbonate resin, cellulose ester resin Etc. can be mentioned. It is preferable to use a cellulose ester resin from a viewpoint which especially the effect of this invention further shows.

What is necessary is just to determine the compounding quantity of the ester resin of this invention with respect to resin for optical materials according to the target performance (moisture permeability, elastic modulus, etc.), for example, 0.1-50 mass parts with respect to 100 mass parts of resin for optical materials. It is a range, It is preferable that it is the range of 1-30 mass parts, It is more preferable that it is the range of 5-20 mass parts especially.

Examples of the cellulose ester resins include those in which some or all of the hydroxyl groups of the cellulose obtained from cotton linter, wood pulp, kenaf, etc. are esterified, and among them, cellulose obtained from cotton linter Since the film obtained using the cellulose ester resin obtained by esterification is easy to peel from the metal support which comprises the manufacturing apparatus of the film mentioned later, since the productive efficiency of a film can be improved more, it is preferable.

As said cellulose ester resin, a cellulose acetate, a cellulose acetate propionate, a cellulose acetate butyrate, a cellulose acetate phthalate, cellulose nitrate etc. are mentioned, for example, When using as a protective film for polarizing plates, using Since it is possible to obtain a film excellent in mechanical properties and transparency, it is preferable. These cellulose ester resins may be individual or may use 2 or more types together.

As said cellulose acetate, it is preferable that it is the range of polymerization degree 250-400, Furthermore, it is preferable that it is the range of 54.0-62.5 mass%, and it is more preferable that it is the range of 58.0-62.5 mass%. When the degree of polymerization and acetonitrile of the cellulose acetate are within these ranges, a film having excellent mechanical properties can be obtained. In this invention, it is more preferable to use what is called cellulose triacetate. In addition, the degree of acetization referred to in the present invention is the mass ratio of acetic acid produced by saponifying the cellulose acetate to the total amount of cellulose acetate.

It is preferable that it is the range of 70,000-300,000, and, as for the number average molecular weight of the said cellulose acetate, it is more preferable that it is the range of 80,000-200,000. When the number average molecular weight of the cellulose acetate is in this range, a film having excellent mechanical properties can be easily obtained.

The optical film in this invention uses the cellulose ester resin composition containing the ester resin and cellulose ester resin of this invention, and may use the resin composition which contains other various additives etc. as needed.

In order to obtain the optical film of this invention, methods, such as extrusion molding and cast molding, are used, for example. Specifically, for example, an unstretched optical film can be extruded using an extruder equipped with a T die, a circular die, or the like. When obtaining the optical film of this invention by extrusion molding, the resin composition obtained by melt-kneading the said ester resin, a cellulose ester resin, other additives, etc. can also be used previously, and melt-kneading at the time of extrusion molding, It can also be extrusion molded as it is.

As said additive, For example, other modifiers other than the ester resin of this invention, a thermoplastic resin, a ultraviolet absorber, a mat agent, a deterioration inhibitor (for example, antioxidant, a peroxide decomposing agent, a radical inhibitor, a metal) Inactivating agents, acid trapping agents and the like), dyes and the like.

As said other modifier, ester resins other than the ester resin prescribed | regulated by this invention, phosphate esters, such as a triphenyl phosphate (TPP), a tricresyl phosphate, and a cresyl diphenyl phosphate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate Phthalic acid esters such as di-2-ethylhexyl phthalate, ethyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, trimethylol propane tribenzoate, pentaerythritol tetraacetate, acetyl citrate tributyl and the like It can be used in a range that does not impair the effect.

Although it does not specifically limit as said thermoplastic resin, For example, polyester resins other than the ester resin of this invention, polyester ether resin, a polyurethane resin, an epoxy resin, toluene sulfonamide resin, etc. are mentioned.

Although it does not specifically limit as said ultraviolet absorber, For example, an oxybenzophenone type compound, a benzotriazole type compound, a salicylic acid ester type compound, a benzophenone compound, a cyanoacrylate type compound, a nickel complex salt type compound, etc. are mentioned. . It is preferable to use the said ultraviolet absorber in 0.01-2 mass parts with respect to 100 mass parts of said cellulose ester resins.

Examples of the mat agent include silicon oxide, titanium oxide, aluminum oxide, calcium carbonate, calcium silicate, aluminum silicate, magnesium silicate, calcium phosphate, kaolin, and talc. It is preferable to use the said mat agent in 0.1-0.3 mass part with respect to 100 mass parts of said cellulose ester resins.

As said dye, if it is a range which does not impair the objective of this invention, a kind, compounding quantity, etc. will not be specifically limited.

Moreover, the said optical film casts the resin solution obtained by melt | dissolving the said cellulose-ester resin composition in the organic solvent other than the said shaping | molding method on a metal support body, and next, the said organic solvent It can also be obtained by shaping by a so-called solution casting method (solvent cast method) which is distilled off and dried.

According to the said solution casting | flow_spreading method, since the orientation of the said cellulose-ester resin in the film in the middle of shaping | molding can be suppressed, the film obtained can show optically isotropy substantially. The film which shows the said optical isotropy can be used, for example for optical materials, such as a liquid crystal display, and it is especially useful for the protective film for polarizing plates. Moreover, the film obtained by the said method is hard to form an unevenness | corrugation on the surface, and is excellent also in surface smoothness.

Generally, the solution casting method dissolves the cellulose ester resin composition in an organic solvent to distill off the first step of casting the obtained resin solution on a metal support, and the organic solvent contained in the cast resin solution. It consists of the 2nd process of drying and forming a film, and the 3rd process of peeling and heat-drying the film formed on the metal support from the metal support followed by it.

Examples of the metal support used in the first step include an endless belt-like or drum-like metal, and the like, for example, those made of stainless steel and whose surface is mirror-finished. Can be used

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

Although it does not specifically limit as a drying method of a said 2nd process, For example, of the organic solvent contained in the said flexible resin solution by matching 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% and forming a film on the said metal support body is mentioned.

Next, the said 3rd process is a process of peeling the film formed in the said 2nd process from the metal support body, and heat-drying on temperature conditions higher than the said 2nd process. As the heat-drying method, for example, a method of raising the temperature stepwise at a temperature condition of 100 to 160 ° C. is preferable because good dimensional stability can be obtained. By heating and drying at the said temperature conditions, the organic solvent which remain | survives in the film after the said 2nd process can be removed almost completely.

Moreover, in the said 1st process-the 3rd process, organic solvent can also be collect | recovered and reused.

The organic solvent which can be used when the resin composition is mixed with the organic solvent and dissolved therein is not particularly limited as long as it can dissolve them. For example, when using cellulose acetate as the cellulose ester, as a good solvent, For example, it is preferable to use organic halogen compounds, such as methylene chloride, and dioxolane.

In addition, the use of poor solvents such as methanol, ethanol, 2-propanol, n-butanol, cyclohexane, cyclohexanone, etc. together with the above good solvents improves the production efficiency of the film. desirable.

It is preferable that the mixing ratio of the said good solvent and a poor solvent is the range of a good solvent / poor solvent = 75 / 25-95 / 5 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 this invention, the optical film extended | stretched by transverse uniaxial stretching in the direction orthogonal to a mechanical flow direction or longitudinally uniaxial stretching in a mechanical flow direction as needed, for example is carried out by the optical film of the unstretched state obtained by the said method. You can get it. Moreover, the biaxially stretched stretched film can be obtained by extending | stretching by the sequential biaxial stretching method of roll extending | stretching and tenter stretching, the simultaneous biaxial stretching method by tenter stretching, the biaxial stretching method by tubular stretching, etc. It is preferable that a draw ratio is 0.1% or more and 1000% or less in at least one direction, It is more preferable that they are 0.2% or more and 600% or less, It is especially preferable that they are 0.3% or more and 300% or less. By designing in this range, the elongated optical film which is preferable from a birefringence, heat resistance, and an intensity point is obtained.

Since the optical film of this invention is excellent in moisture permeability, transparency, and excellent in an elasticity modulus, it can be used, for example for the optical film of a liquid crystal display device. As an optical film of the said liquid crystal display device, the protective film for polarizing plates, retardation film, a reflection film, a viewing angle improvement film, an anti-glare film, an antireflection film, an antistatic film, a color filter, etc. are mentioned, for example, a polarizing plate among them, It can use preferably as a protective film for resin.

It is preferable that the film thickness of the said optical film is 20-120 micrometers, It is more preferable that it is the range of 25-100 micrometers, It is especially preferable that it is the range of 25-80 micrometers. When using the said optical film as a protective film for polarizing plates, when the film thickness is 25-80 micrometers, it is suitable when thinning a liquid crystal display device, and it is excellent in sufficient film strength, Rth stability, moisture permeability, etc. Maintain performance.

The optical film of the present invention is characterized in that the elastic modulus is higher than that in which no ester resin is blended. Generally, about the cellulose-ester resin, although the polyester resin mix | blended for the purpose of improving the workability may be called a "plasticizer," the ester resin of this invention can improve intensity | strength to resin for optical materials rather than a plasticization effect. In terms of being used, it is different from the conventional one in that it is used as a semiplasticizer.

Moreover, since the said protective film for polarizing plates can also be adjusted to desired Rth, without generating bleed under high temperature and high humidity, it can be used for various liquid crystal display systems widely according to a use.

As the liquid crystal display system, for example, IPS (In-Plane Switching), TN (Twisted Nematic), VA (Vertically Aligned), OCB (Optical Compensation) Bend: Optically Compensatory Bend) etc. can be illustrated.

The optical film which concerns on this invention is a polarizing plate protective film used for displays, such as a liquid crystal display device, a plasma display, an organic electroluminescent display, a field emission display, a rear projection television, as an optical material, a 1/4 wavelength plate, 1/2 It can be used suitably for retardation films, such as a wavelength plate, a viewing angle control film, and a liquid crystal optical compensation film, a display front plate. In addition, the resin composition of the present invention can also be used for waveguides, lenses, optical fibers, optical fiber substrates, coating materials, LED lenses, lens covers, and the like in the fields of optical communication systems, optical exchange systems, and optical measurement systems. have.

(Example)

Hereinafter, the present invention will be described in more detail with reference to Examples. Parts and percentages in the examples are based on mass unless otherwise specified.

Example 1

412 g of isophthalic acid (hereinafter abbreviated as "IPA") as a glycol component to 412 g of 1,2-propylene glycol (hereinafter abbreviated as "PG") as a glycol component and a monocarboxylic acid component as a glycol component, benzoic acid ( Hereinafter, 611 g of "abbreviated as" BzA ") and 0.08 g of tetraisopropyl titanate (hereinafter abbreviated as" TIPT ") as a catalyst were charged, and the temperature was gradually raised to 230 ° C under a nitrogen stream from a nitrogen inlet tube. It condensed reaction at 230 degreeC for 8 hours, and it confirmed that the acid value became 1.0 or less. The ester resin (1) of this invention was obtained by removing excess glycol at 195 degreeC under reduced pressure. Obtained ester resin (1) was pale yellow liquid at normal temperature, the acid value was 0.12, the hydroxyl value was 10.0, and the weight average molecular weight was 590. As for n = 0 component in GPC measurement, 29 area% and (n≥3) / (n = 0) were 1.0.

Example 2

Ester resin by synthesizing in the same manner as in Example 1 using PG 412 g as the glycol component, 280 g of IPA as the dicarboxylic acid component, 82 g of adipic acid (hereinafter abbreviated as "AA"), and BzA 611 g and TIPT 0.08 g as the monocarboxylic acid component. (2) was obtained. Obtained ester resin (2) was pale yellow liquid at normal temperature, the acid value was 0.07, the hydroxyl group was 0.0, and the weight average molecular weight was 780. As for n = 0 component in GPC measurement, 24 area% and (n≥3) / (n = 0) were 1.1.

Example 3

The ester resin (3) was obtained by synthesizing in the same manner as in Example 1 using PG 412 g as the glycol component, IPA 187 g, AA 164 g as the dicarboxylic acid component, BzA 611 g and TIPT 0.08 g as the monocarboxylic acid component. Obtained ester resin (3) was pale yellow liquid at normal temperature, the acid value was 0.05, the hydroxyl group was 1.1, and the weight average molecular weight was 670. The n = 0 component in the GPC measurement was 25 area%, and (n ≧ 3) / (n = 0) was 1.1.

Example 4

An ester resin (4) was obtained by synthesizing in the same manner as in Example 1 using PG 412 g as the glycol component, IPA 94 g, AA 245 g as the dicarboxylic acid component, BzA 611 g and TIPT 0.08 g as the monocarboxylic acid component. Obtained ester resin (4) was pale yellow liquid at normal temperature, the acid value was 0.08, the hydroxyl value was 5.4, and the weight average molecular weight was 620. The n = 0 component in the GPC measurement was 31 area%, and (n ≧ 3) / (n = 0) was 0.7.

Example 5

Synthesis was carried out in the same manner as in Example 1 using 412 g of 1,3-propanediol (hereinafter abbreviated as "13PD") as the glycol component, IPA 280 g, AA 82 g as the dicarboxylic acid component, and BzA 611 g and TIPT 0.08 g as the monocarboxylic acid component. Thus, ester resin (5) was obtained. Obtained ester resin (5) was pale yellow liquid at normal temperature, the acid value was 0.11, the hydroxyl value was 8.9, and the weight average molecular weight was 640. As for the n = 0 component in GPC measurement, 29 area% and (n≥3) / (n = 0) were 0.8.

Example 6

Example 1 using 488 g of 2-methyl-1,3-propanediol (hereinafter abbreviated as "2MPD") as the glycol component, 280 g of IPA as the dicarboxylic acid component, 82 g of AA as the monocarboxylic acid component, and 611 g of BzA as the monocarboxylic acid component and 0.08 g of TIPT. The ester resin (6) was obtained by synthesizing in the same manner as in the above. The obtained ester resin (6) was pale yellow liquid at normal temperature, the acid value was 0.11, the hydroxyl value was 12.6, and the weight average molecular weight was 560. 40 area% and (n≥3) / (n = 0) of the n = 0 component in GPC measurement were 0.4.

Comparative Example 1

Into a two-liter three-necked flask, 437 g of PG as a glycol component, 180 g of phthalic acid (hereinafter abbreviated as "PA") as a dicarboxylic acid component, 178 g of AA, and 659 g of BzA as a monocarboxylic acid component and 0.09 g of TIPT are added to the flask. It heated up to 220 degreeC stepwise under nitrogen stream. It was confirmed that the acid value was 1.0 or less by condensation reaction at 220 ° C. for 13 hours. The ester resin (1 ') for a comparative control was obtained by removing excess glycol at 195 degreeC under reduced pressure. The obtained ester resin (1 ') was a pale yellow liquid at normal temperature, the acid value was 0.09, the hydroxyl group was 1.2, and the weight average molecular weight was 640.

Comparative Example 2

A polyester resin (2 ') for comparison was obtained by synthesizing in the same manner as in Comparative Example 1 using PG 313g, AA 262g, BzA 436g, and TIPT 0.10g as the glycol component. The obtained comparative polyester resin (2 ') was a pale yellow liquid at normal temperature, the acid value was 0.50, the hydroxyl value was 12.6, and the weight average molecular weight was 610.

Comparative Example 3

A polyester resin (3 ') for comparison was obtained by synthesizing in the same manner as in Comparative Example 1 using 460 g of PG, 466 g of dimethyl terephthalate, 586 g of BzA, and 0.09 g of TIPT. The obtained comparative polyester resin (3 ') was a pale yellow viscous liquid at normal temperature, the acid value was 0.24, the hydroxyl value was 5.4, and the weight average molecular weight was 650.

Examples 7-12, Comparative Examples 4-7

<Adjustment of a cellulose-ester optical film>

100 parts of triacetyl cellulose resins ("LT-35" by Daicel Co., Ltd.), ester resins (1)-(6), 10 parts of ester resins (1 ')-(3'), 810 parts of methylene chloride, and methanol 90 It melt | dissolved in addition to the mixed solvent which consists of parts, and prepared the dope liquid which is a cellulose-ester resin composition. In Comparative Example 7, only the triacetyl cellulose resin was dissolved in the mixed solvent without mixing the ester resin to obtain a dope solution. The dope liquid was cast so as to be 0.8 mm or 0.5 mm in thickness on a glass plate, and dried at room temperature for 16 hours, and then dried at 50 ° C. for 30 minutes and further at 120 ° C. for 30 minutes, thereby providing the optical film of the present invention (60 μm). Or 40 µm). About the obtained film, physical properties were measured as follows and the result was shown in Table 1.

<Measurement of Elastic Modulus of Optical Film>

 Device: Shimazu Seisakujo Co., Ltd. Autograph AG-IS

 Test piece: Strip type of 150 mm × 10 mm and 40 µm thick

 Between chuck: 100㎜

 Test speed: 10 mm / min

It shows that it is a hard film so that elasticity modulus is large.

<Retardation Rth Measurement of Optical Film>

The Rth value in wavelength 590nm was measured using the birefringence measuring apparatus (KOBRA-WR, Ojiisokuki Co., Ltd. product) in the environment whose relative humidity is 55% at 23 degreeC.

Measurement of moisture permeability of optical film

It measured according to the method of JISZ0220. Measurement conditions were performed at the temperature of 40 degreeC, and 90% of a relative humidity. The smaller the value obtained, the better the moisture permeability.

TABLE 1

Claims (11)

General formula (1)
B- (GA) _n- GB (1)
[In Formula (1), B is a monocarboxylic acid residue, G is an alkylene glycol residue, an oxyalkylene glycol residue, or an aryl glycol residue, A is a dicarboxylic acid residue, and 20 mol% or more of the total number of moles of A is iso Is a phthalic acid residue, n is a repeating number, and G and A may be the same or different for every repetition, and a plurality of B and G may be the same or different]
Ester resin, characterized in that represented by. The method of claim 1,
In the area ratio in the GPC measurement, the ratio of the area% of the component where n = 0 in the general formula (1) is 10 to 50% and n is 3 or more and the area% of the n = 0 component (n≥3) An ester resin whose / (n = 0) is 3 or less. The method according to claim 1 or 2,
B in said General formula (1) is a C6-C12 aryl monocarboxylic acid residue or a C1-C8 aliphatic monocarboxylic acid residue, G is a C2-C12 alkylene glycol residue, carbon Ester resin of the C4-C12 oxyalkylene glycol residue or the C6-C18 aryl glycol residue, and the average value of n is 0.2-3. The method according to any one of claims 1 to 3,
The ester resin whose weight average molecular weight of the said ester resin is the range of 350-1200. The method according to any one of claims 1 to 4,
B in the general formula (1) is at least one residue selected from the group consisting of acetic acid, benzoic acid, paratoluic acid and dimethyl benzoic acid, G is ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, One or more residues selected from the group consisting of 1,2-butanediol and 2-methylpentyl glycol, and A is one selected from the group consisting of succinic acid, adipic acid, dicarboxycyclohexane, phthalic acid, terephthalic acid and isophthalic acid. The ester resin of the above-mentioned residues, and 20 mol% or more of the total number of moles of A is isophthalic acid. The method according to any one of claims 1 to 5,
Ester resin whose 25-100 mol% of the total number-of-moles of A in the said General formula (1) is isophthalic acid. The method according to any one of claims 1 to 6,
Ester resin which is a semiplasticizer of resin for optical materials. The cellulose ester resin composition containing the ester resin and cellulose ester resin in any one of Claims 1-6. The cellulose-ester resin composition of Claim 8 is contained, The optical film characterized by the above-mentioned. The method of claim 9,
Optical film for polarizer protection. It has the optical film of Claim 9 or 10, The liquid crystal display device characterized by the above-mentioned.