CN101389659A - Modified cellulose acylate and molded body for optical use - Google Patents

Abstract

Disclosed is a modified cellulose acylate (for example, a modified cellulose acetate), which is excellent in optical isotropy and suitably used for optical films and the like. Specifically disclosed is a hydroxy acid-modified cellulose acylate having a cellulose acylate (such as cellulose acetate) and a graft chain formed by graft-polymerizing a hydroxy acid component (for example, a hydroxy acid such as lactic acid and a cyclic ester such as lactone and lactide) to a hydroxyl group of the cellulosed acylate. In this hydroxy acid-modified cellulose acylate, the substitution degree of acyl groups in the cellulose acylate is not less than 2.7, and the ratio of the graft-polymerized hydroxy acid component relative to 1 mole of the glucose unit of the cellulose acylate is 0.1-5 moles on average in terms of the hydroxy acid.

Description

Modified cellulose acylate and molded body for optical use

Technical field

The present invention relates to can be used as the alcohol acid modified cellulose acylate (for example, alcohol acid modified-cellulose acetic ester) of optical applications (for example, blooming etc.) etc., and by the formed molded body for optical use of this modified cellulose acylate (for example, blooming etc.).

Background technology

Cellulose ester (cellulose acylate) is because therefore its optical characteristics excellence is usually used in the support of sensitive photographic material, the molded body for optical use such as polaroid protective film, phase retardation film or colour filter of liquid crystal indicator.

In the cellulose ester; as the acyl group Mierocrystalline cellulose that can be used for blooming; (for example be extensive use of the big cellulose acylate of acyl substituted degree; cellulose ethanoate acylates such as cellulose ethanoate (cellulosic triacetate), cellulose acetate propionate, cellulose acetate butyrate); particularly; in order to give the optical isotropy, can use cellulosic triacetate.

This cellulosic triacetate is not suitable for thermoforming, and it can carry out the film moulding by the method for forming of using qualification solvents such as methylene dichloride.For example; open in the flat 11-5851 communique (patent documentation 1) the spy; a kind of film that contains cellulose ethanoate is disclosed; this cellulose ethanoate; its the 2nd, the 3rd and the 6th 's degree of substitution with acetyl group (for example adds up to more than 2.67; 2.77 more than), and its 2nd and the 3rd 's degree of substitution with acetyl group adds up to below 1.97.Put down in writing in the document, when stating cellulose ethanoate in the use, by the hot-cold lysis method; even use non-halogen solvent; also can prepare stable solution, and by casting method, it is little and be suitable as the film of polaroid protective film to obtain the length of delay of thickness direction.

On the other hand, the optical characteristics of this cellulose ester, the distortion that causes along with moisture absorption, peel off, variations in refractive index etc. and reducing.Therefore, when auto-navigation system etc. is exposed to inevitable requirement wet fastness (or humidity resistance) when hot and humid in car, even and the use in general family also requires so.But the water absorbability or the water-absorbent of cellulosic triacetate are big, and wet fastness is insufficient.In addition, compare with cellulosic triacetate, cellulose acetate propionate, cellulose acetate butyrate etc., though water-absorbent is low slightly, its hydrophobicity is still not enough, wet fastness is also not enough.

On the other hand, also reported the technology of passing through hydroxycarboxylic acid or cyclic ester (rac-Lactide, lactone etc.) modified cellulose acylate.For example, open in the clear 60-188401 communique (patent documentation 2) the spy, a kind of fatty acid cellulose ester analog thermoplastic formed material is disclosed, it can be by with respect to the fatty acid cellulose ester (cellulose ethanoate etc.) with free hydroxyl group, makes the cyclic ester (6-caprolactone etc.) of each anhydrous grape sugar unit addition 0.5～4.0mol and obtains.Also put down in writing in the document,, need not add the softening agent of volume, can carry out forming process by injection molding, extrusion moulding etc., and can be used for moulding product such as sheet, film by inner plasticization.In addition, put down in writing in the document, obtained degree of substitution with acetyl group in an embodiment and be up to 2.25 6-caprolactone addition cellulose ethanoate.But, the cellulose ethanoate that this degree of substitution with acetyl group is low, the wet fastness deficiency is even and aspect optical characteristics, also high than degree of substitution with acetyl group cellulose ethanoate is poor.In addition; in the method for the document; in the cyclic ester addition reaction; produced the hydrolysis of acyl group, and the acyl substituted degree of the cyclic ester addition fatty acid cellulose ester that is generated, be lower than acyl substituted degree as the fatty acid cellulose ester of raw material; and be difficult to obtain the cyclic ester affixture of desired acyl substituted degree; further, because the reduction of acyl substituted degree, and have the defective that above-mentioned optical characteristics reduces.

In addition, open in the flat 6-287279 communique (patent documentation 3), disclose a kind ofly in the presence of esterifying catalyst (C), make rac-Lactide (A) and cellulose ester or ether of cellulose (B) carry out the preparation method of the rac-Lactide quasi-graft copolymer of open loop graft copolymerization the spy.Put down in writing in the document, the rac-Lactide quasi-graft copolymer has the transparency, and has decomposability, thermoplasticity, can be used for preparing lamination, resin for printing ink, and can be used as film material, molding resin.

Can think that cellulose ester and cellulose ethanoate by hydroxycarboxylic acid or cyclic ester (rac-Lactide, lactone etc.) modification are equally applicable to optical applications such as blooming.For example, open in the 2001-281448 communique (patent documentation 4) the spy, the optical element (claim 1) that contains lactic acid and the lactic acid multipolymer that can (be total to) the polymerization multi-functional compounds is in addition disclosed, the polymerization multi-functional compounds that can (be total to) beyond the lactic acid is at least a optical element (claim 4) that is selected from lactic acid hydroxycarboxylic acid, cyclic ester, polycarboxylic acid, polybasic acid anhydride, polyvalent alcohol, polyose and the aminocarboxylic acid in addition, and polyose is at least a optical element (claim 9) that is selected from Mierocrystalline cellulose and the chemically-modified cellulose.In addition, only put down in writing in the document, but the multi-functional compounds's of polyoses such as Mierocrystalline cellulose conduct copolymerization a example, and do not put down in writing any detailed content about above-mentioned chemically-modified cellulose.

In addition, open in the 2005-300978 communique (patent documentation 5) the spy, disclose a kind of to cellulose ester resin sheet by the moulding of fusion curtain coating system embrane method, the cellulose ester membrane that obtains at the width stretch orientation is formed, thickness is 20～100 μ m, postponing (Ro) in the face is 20～100nm, and thickness direction retardation (Rt) is the phase retardation film of 90～200nm.In the document; as cellulose ester; the cellulose acylates such as cellulose ethanoate, cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate propionic acid butyric ester of having given an example, or have cellulose ethanoate of aliphatic polyester graft side chain (pendant graft polymer chains) etc.And; in the document; put down in writing (i) as cellulose ethanoate with aliphatic polyester graft side chain; can enumerate with lactic acid is the cellulose ethanoate with aliphatic polyester graft side chain of main repeating unit; it (ii) is the degree of substitution with acetyl group of the cellulose ethanoate with aliphatic polyester graft side chain of main repeating unit with lactic acid; be preferably every glucose unit 2.5～3.0, (iii) the molecular weight of aliphatic polyester graft side chain is preferably 1000～10000.Specifically; in embodiment 2; put down in writing and made the cellulose ethanoate (degree of substitution with acetyl group: 2.8 of 100 weight part vacuum-dryings after 24 hours under 60 ℃; number-average molecular weight 120000) and 400 weight part L-rac-Lactides reactions; finally obtain laminar resultant of reaction, will contain the compound particles granulation of this resultant of reaction and oxidation inhibitor, obtain resin sheet; stretch again, obtain the phase retardation film that thickness is 100 μ m.

But, in the cellulose ethanoate that the document is put down in writing,, therefore damaged the characteristic of the cellulose ethanoate of modification because the amount of the lactic acid (poly(lactic acid) or polylactide) that replaces in the cellulose ethanoate is too much with aliphatic polyester graft side chain.In addition, if the polymerization degree of lactic acid grafted chain or molecule quantitative change are big, then because grafted chain partly demonstrates crystallinity, therefore produce albefaction (or gonorrhoea) etc., and aspect transparent, produce defective.Further, the second-order transition temperature of cellulose ethanoate is low, the thermotolerance deficiency.Therefore, the cellulose ethanoate that this lactic acid grafting amount is many easily because of heat causes optical characteristics to change, and lacks practicality.

Patent documentation 1: the spy opens flat 11-5851 communique (claim, paragraph sequence number [0005])

Patent documentation 2: the spy opens clear 60-188401 communique (claim, hurdle, page 2 bottom right)

Patent documentation 3: the spy opens flat 6-287279 communique (claim, invention effect hurdle)

Patent documentation 4: the spy opens 2001-281448 communique (claim, paragraph sequence number [0033])

Patent documentation 5: the spy opens 2005-300978 communique (claim, paragraph sequence number [0023], [0029], [0030], [0074]～[0076])

Summary of the invention

The problem that invention will solve

Therefore, the object of the invention is to provide a kind of novel modified cellulose acylate of optical isotropy excellence.

Another object of the present invention is to provide a kind of modified cellulose acylate that can take into account optical isotropy and wet fastness with high level, and by the formed molded body for optical use of this modified cellulose acylate (for example, blooming).

Further purpose of the present invention is to provide a kind of hydroxyalkanoic acid component modification of promptly using; also can give excellent thermotolerance; and the modified cellulose acylate that can suitably be used for optical applications such as blooming (for example; modified cellulose acylate etc.); and by the formed molded body for optical use of this modified cellulose acylate (for example, blooming).

Other purpose of the present invention is to provide a kind of optical isotropy excellence; even and also can suitably used high practicability modified cellulose acylate in requiring stable on heating purposes; and by the formed molded body for optical use of this modified cellulose acylate (for example, blooming).

The scheme that is used to deal with problems

Present inventor etc.; in order to finish above-mentioned problem; carried out active research; found that and have the cellulose acylate of specific substitution value (especially; cellulose ethanoate) in, make hydroxyalkanoic acid component (for example, lactone, lactic acid, lactide etc.) carry out graft polymerization with specific ratio; can obtain to take into account the novel modified cellulose acylate of optical isotropy and high wet fastness, and finish the present invention thus.

That is to say; alcohol acid modified cellulose acylate of the present invention; comprise cellulose acylate and graft polymerization hydroxyalkanoic acid component and the grafted chain that forms on the hydroxyl of this cellulose acylate; the average substitution degree of its acyl group is more than 2.7; the ratio of the hydroxyalkanoic acid component of graft polymerization on cellulose acylate is; with respect to the glucose unit of 1mol formation cellulose acylate, being converted into alcohol acid is average 0.1～5mol.

Above-mentioned cellulose acylate for example also can be, the average substitution degree of acyl group is about 2.7～2.99 cellulose acylate (particularly cellulose ethanoate).Above-mentioned hydroxyalkanoic acid component can be to be selected from alcohol acid (for example, hydroxyl C such as lactic acid _2-10Alkanoic acid etc.), lactone (for example, C _4-10Lactone etc.) and lactide (for example, C such as rac-Lactide _4-10Lactide) at least a.

As typical above-mentioned modified cellulose acylate; comprise following modified cellulose acylate; this cellulose acylate is a cellulose ethanoate; the ratio of the average substitution degree of ethanoyl and the average substitution degree of grafted chain with the former/latter counts 90/10～99.5/0.5; the ratio of the hydroxyalkanoic acid component of graft polymerization on cellulose acylate; with respect to the glucose unit of 1mol formation cellulose acylate, being converted into alcohol acid is average 0.2～4mol.

In above-mentioned modification acylate, the mean polymerisation degree of grafted chain converts with alcohol acid, can be about 2～40.Particularly; in the above-mentioned modified cellulose acylate; above-mentioned cellulose acylate is that the average substitution degree of ethanoyl is 2.85～2.95 cellulose ethanoate; the ratio of the hydroxyalkanoic acid component of graft polymerization on cellulose acylate; constitute the glucose unit of cellulose acylate with respect to 1mol; being converted into alcohol acid is average 0.3～3mol, and the mean polymerisation degree of grafted chain to be converted into alcohol acid be 4～25 modified cellulose acylate.

Modified cellulose acylate of the present invention no matter whether graft polymerization has hydroxyalkanoic acid component, all has high second-order transition temperature, and for example, the second-order transition temperature of above-mentioned modified cellulose acylate can be for more than 80 ℃.In addition, compare with cellulosic triacetate etc., the excellent moisture resistance of above-mentioned modified cellulose acylate, for example, water-intake rate can be for below 3%.

Modified cellulose acylate of the present invention, the optical isotropy excellence that it is above-mentioned, and can suitably be used for optical applications.Therefore, in the present invention, also comprise by the formed molded body for optical use of above-mentioned modified cellulose acylate.This molded body for optical use can be blooming especially.This blooming, the optical isotropy excellence, for example, the length of delay Re in the face is 0～10nm, and the length of delay Rth of film thickness direction be-20nm～+ 20nm.

In addition; in this specification sheets; so-called " average substitution degree "; be meant in the 2nd, the 3rd of glucose unit and the 6th 's hydroxyl; the hydroxyl that carries out acidylate, grafting etc. (for example; acyl group, grafted chain) the mean value of substitution value (substitute proportion), and and cellulose ester etc. in " average substitution degree " equivalent in meaning.

In addition, in this specification sheets, so-called " hydroxyalkanoic acid component " is used for expression and not only is alcohol acid, also comprises lower alkyl esters (for example, the C of alcohol acid _1-2Alkyl ester), the cyclic ester of alcohol acid.

The invention effect

In the present invention; in with the modified cellulose acylate of hydroxyalkanoic acid component graft polymerization on cellulose acylate (particularly cellulose ethanoate); the specific graft ratio of specific acyl substituted degree and hydroxyalkanoic acid component is combined, therefore can obtain the novel modified cellulose acylate of optical isotropy excellence.In addition, modified cellulose acylate of the present invention is compared with cellulosic triacetate etc., and its wet fastness is improved, and can take into account optical isotropy and wet fastness with high level.Further, modified cellulose acylate of the present invention under with the situation of using the hydroxyalkanoic acid component modification, also can be given excellent thermotolerance, and can suitably be used for optical applications such as blooming.Therefore, the optical isotropy excellence can also suitably be used for the stable on heating purposes of requirement, and the practicality height.

Embodiment

[modified cellulose acylate]

Modified cellulose acylate of the present invention comprises cellulose acylate (cellulose acylate skeleton) with specific acyl substituted degree and the grafted chain that forms with specified proportion graft polymerization hydroxyalkanoic acid component on the hydroxyl of this cellulose acylate.

(cellulose acylate)

In cellulose acylate (acyl group Mierocrystalline cellulose), as acyl group, can enumerate, for example alkyl-carbonyl [for example, C such as ethanoyl, propionyl, butyryl radicals _2-10Alkyl-carbonyl (for example, C _2-8Alkyl-carbonyl, preferred C _2-6Alkyl-carbonyl, further preferred C _2-4Alkyl-carbonyl) etc. naphthene base carbonyl (for example, C such as cyclohexyl-carbonyl], _5-10Naphthene base carbonyl etc.), aryl carbonyl (for example, C such as benzoyl, carboxylbenzoyl _7-12Aryl carbonyl etc.) etc.Mode with independent or two or more combinations on cellulosic glucose unit connects acyl group.In these acyl groups, the preferred alkyl carbonyl.Particularly, in these acyl groups, preferably ethanoyl is connected on the glucose unit at least, for example can be only to connect ethanoyl, also can be ethanoyl and other acyl group (C _3-4Acyl group etc.) connect.

As typical cellulose acylate, can enumerate Mierocrystalline cellulose C such as cellulose ethanoate (cellulose acetate), cellulose propionate, cellulose butylate, cellulose acetate propionate, cellulose acetate butyrate _2-6Acylate, preferred cellulose C _2-4Acylate etc., and special preferred cellulose acetic ester (cellulosic triacetate).

In cellulose acylate, the average substitution degree of acyl group is as long as get final product in (for example, 2.72～2.999) more than 2.7; for example can be more than 2.75 (for example; 2.78～2.996), be preferably (for example, 2.83～2.995) more than 2.8; more preferably more than 2.84 (for example;～2.99), 2.85 particularly (for example, 2.88～2.96) more than 2.87; and for example be generally 2.7～2.99[, 2.85～2.95 (for example 2.87～2.93)] about.Among the present invention, by improving above-mentioned these acyl substituted degree, and will this high acyl substituted degree and specific graft ratio make up, can improve optical isotropy, and can improve characteristics such as wet fastness.

In addition; in cellulose acylate; the ratio of hydroxyl (remaining hydroxyl); be not particularly limited, with respect to the 1mol glucose unit, can for; for example average 0.001～0.22mol; be preferably 0.01～0.2mol, and 0.03～0.15mol (for example, about 0.05～0.12mol) more preferably.

The polymerization degree of cellulose acylate as long as can be used for desired purpose, just is not particularly limited, and needs only and the present industrial commodity same degree that gets, and just can suitably use.For example, the mean polymerisation degree of cellulose acylate (viscosity average polymerization degree) can be selected from more than 70 that (for example, 80～800) scope is generally 100～500, is preferably 110～400, and further preferred about 120～350.

In addition, can use commercially available cellulose acylate, also can be synthetic by conventional process.For example; cellulose acylate can be prepared as follows usually; that is, Mierocrystalline cellulose is carried out activation treatment, use sulfuric acid catalyst then by the pairing organic carboxyl acid of acyl group (acetate etc.); and (for example by acylating agent; acid anhydrides such as diacetyl oxide) preparation three acyl esters (particularly, cellulosic triacetate), excessive acylating agent is (particularly; acid anhydrides such as diacetyl oxide) inactivation, and adjust the acidylate degree by deacylation or saponification (hydrolysis or slaking) and prepare.As acylating agent, can be organic acyl halides such as Acetyl Chloride 98Min., and can use C such as diacetyl oxide, propionic anhydride, butyryl oxide usually _2-6Alkanoic acid acid anhydride etc.

In addition, for general cellulose acylate preparation method, can be with reference to " wood chemistry (on) " (right field etc., upright altogether (strain), nineteen sixty-eight distribution, the 180th page～the 190th page published).

Form grafted chain by graft polymerization on the hydroxyl of this cellulose acylate (or reaction) hydroxyalkanoic acid component.That is to say, in modified cellulose acylate,, come grafted chain in conjunction with acyl group and hydroxyalkanoic acid component by the hydroxyl of Mierocrystalline cellulose glucose unit.In addition, as described below, modified cellulose acylate also can have not acidylate or not grafting and remaining hydroxyl (unsubstituted hydroxyl).

(hydroxyalkanoic acid component)

As hydroxyalkanoic acid component, can enumerate alcohol acid, cyclic ester etc.These hydroxyalkanoic acid components may be used singly or in combination of two or more.Among the present invention, can suitably use cyclic ester.

As alcohol acid (hydroxycarboxylic acid), the aliphatic hydroxyl carboxylic acid of can giving an example, for example hydroxyl C such as oxyacetic acid, lactic acid (L-lactic acid, D-lactic acid or their mixture), hydroxy-propionic acid, Alpha-hydroxy butyric acid, 6 hydroxycaproic acid _2-10Alkanoic acid (preferred Alpha-hydroxy C _2-6Alkanoic acid, further preferred Alpha-hydroxy C _2-4Alkanoic acid) etc.In addition, alcohol acid can carry out lower alkyl esters (for example, C _1-2Alkyl ester) changes.In these alcohol acids, preferred especially alpha hydroxy acid [particularly, lactic acid (L-lactic acid, D-lactic acid or their mixture)].Alcohol acid may be used singly or in combination of two or more.

As cyclic ester; so long as intramolecularly has at least one ester group (COO-); and can the grafted compound for cellulose acylate; just be not particularly limited; for example; can enumerate lactone (or ring-type monoesters; for example; beta-propiolactone, beta-butyrolactone, gamma-butyrolactone, δ-Wu Neizhi, 6-caprolactone, lauryl lactone, oenantholacton, dodecalactone, stearolactone, Alpha-Methyl-6-caprolactone, Beta-methyl-6-caprolactone, γ-methyl-6-caprolactone, β; δ-dimethyl-6-caprolactone, 3; 3, C such as 5-trimethylammonium-6-caprolactone _3-20Lactone, preferred C _4-15Lactone, and further preferred C _4-10Lactone), lactide (for example, glycollide, rac-Lactide C such as (L-rac-Lactide, D-rac-Lactide or their mixtures) _4-15Lactide, preferred C _4-10Lactide etc.) etc.

In these cyclic esters,, can enumerate, for example C as preferred cyclic ester _4-10Lactone (for example, C such as beta-butyrolactone, δ-Wu Neizhi, 6-caprolactone _5-8Lactone), C _4-10Lactide [rac-Lactide (L-rac-Lactide, D-rac-Lactide or their mixture) etc.].As preferred cyclic ester, as long as can obtain easily, just be not particularly limited industrial, for example, can enumerate 6-caprolactone, rac-Lactide (L-rac-Lactide, D-rac-Lactide or their mixture) etc.

Cyclic ester may be used singly or in combination of two or more.When being used in combination, as preferred combination, for example, the combination of can give an example 6-caprolactone and rac-Lactide (L-rac-Lactide, D-rac-Lactide or their mixture) etc.

(grafted chain)

Among the present invention, by in the cellulose acylate of above-mentioned specific acyl substituted degree, the small proportion grafting hydroxyalkanoic acid component with specific can not damage the excellent specific property of cellulose acylate, and can give excellent optical isotropy.That is to say that the ratio of grafted hydroxyalkanoic acid component is big more on cellulose acylate, then can improve the optical isotropy of gained modified cellulose acylate, but on the other hand, greatly reduce the characteristic (transparency, thermotolerance etc.) of cellulose acylate.In addition; even reduce to be used for the ratio of the hydroxyalkanoic acid component of graft polymerization on cellulose acylate with respect to cellulose acylate; the ratio of the alcohol acid of grafting also is not easy to reduce in the general cellulose acylate; even and can reduce the graft ratio of hydroxyalkanoic acid component, also be difficult to improve optical isotropy.Therefore, in the present invention, have the cellulose acylate of specific high acyl substituted degree by use, the graft ratio with hydroxyalkanoic acid component is adjusted into above-mentioned specific small proportion simultaneously, can give excellent optical isotropy.

That is to say; in modified cellulose acylate of the present invention; the ratio of the hydroxyalkanoic acid component of graft polymerization on cellulose acylate; constitute the glucose unit of cellulose acylate with respect to 1mol; convert (for example, in rac-Lactide, converting) with alcohol acid with lactic acid, if for average 0.1～5mol (for example; 0.15～4.5mol) get final product; for example, be preferably 0.2～4mol (for example, 0.25～3.5mol); 0.3～3mol more preferably; usually can be for about 0.35～3.2mol, and be in particular following (for example, the 0.1～2.5mol of 3mol; be preferably 0.15～2mol; and more preferably 0.2～1.8mol), and can be following [for example, the 0.1～1.1mol of 1.2mol usually; be preferably 0.05～1mol (for example, about 0.1～0.9mol)].In addition; by making the graft ratio with respect to the hydroxyalkanoic acid component of cellulose acylate integral body is aforementioned proportion; can keep the thermotolerance of cellulose acylate (cellulose acylate etc.) and can not reduce terrifically, and can obtain the modified cellulose acylate of excellent heat resistance.In addition, no matter the polymerization degree of grafted chain equals 1 or greater than 1, and the ratio of above-mentioned hydroxyalkanoic acid component (mol) is meant at the glucose unit of the cellulose acylate average addition mole number of the hydroxyalkanoic acid component of institute's addition (grafted) on the whole.

The mean polymerisation degree of grafted chain (or the hydroxyalkanoic acid component that constitutes grafted chain is scaled the average addition mole number of alcohol acid), (for example convert with alcohol acid, in 6-caprolactone, convert with hydroxycaproic acid, in rac-Lactide with lactic acid conversion etc.), for example can be selected from, scope about 1～100 (for example, 1.5～70), and can be 1～60 (for example, 1.5～50), be preferably 2～40 (for example, 3～30), more preferably 4～25 (for example, 5～22), be in particular 7～20, and be generally about 3～18 (for example, 5～15).

In addition, the molecular-weight average of grafted chain (number-average molecular weight etc.) for example can be, 80～20000, be preferably 100～10000 (for example, 150～7000), and more preferably 500～5000, and be in particular 800～3000 (for example, 1000～2000).

In addition; if the polymerization degree or the molecule quantitative change of grafted chain (the particularly grafted chain of alpha hydroxy acid composition such as rac-Lactide) are big; then grafted chain partly has crystallinity; and in modified cellulose acylate; when carrying out the thermal history more than the second-order transition temperature, the deterioration that produces albefaction or mist degree because of crystallization easily.Therefore, can make the polymerization degree of grafted chain or molecular weight less.

In modified cellulose acylate; the average substitution degree of grafted chain (promptly; grafting hydroxyalkanoic acid component on the hydroxyl of cellulose acylate and the average substitution degree of the grafted chain that forms; carry out the average substitution degree of the hydroxyl of grafting replacement by hydroxyalkanoic acid component); for example can be; 0.001～0.25 (for example; 0.005～0.22); (for example be preferably 0.01～0.2; 0.015～0.18), 0.02～0.15 (for example, 0.025～0.12) more preferably; and be in particular about 0.03～0.1 (for example, 0.04～0.08).

In addition; (for example by the lactone composition; lactone) and the alpha hydroxy acid composition [for example; lactic acid, lactide (rac-Lactide) etc.] when constituting hydroxyalkanoic acid component; in modified cellulose acylate; graft polymerization is the alpha hydroxy acid components in proportions on cellulose acylate at lactone composition on the cellulose acylate and graft polymerization; convert with alcohol acid; can be the former/latter's (mol ratio)=99/1～1/99; (for example be preferably 95/5～5/95; 90/10～10/90), and more preferably about 80/20～20/80 (for example, 75/25～25/75).

In addition; in modified cellulose acylate; the ratio of the average substitution degree (or mole number) of average substitution degree of acyl group (or mole number) and grafted chain; can be the former/latter=90/10～99.9/0.1 (for example, 92/8～99.7/0.3), (for example be preferably 95/5～99.5/0.5; 96/4～99.2/0.8); more preferably 97/3～99/1 (for example, 98/2～98.8/1.2), and usually can be for about 90/10～99.5/0.5.

In addition; in modified cellulose acylate; the ratio of hydroxyl (remaining hydroxyl) (or with respect to the 1mol glucose unit, not acidylate or the not ratio of the remaining hydroxyl of grafting), with respect to the 1mol glucose unit; for example can be; average 0～0.25mol is preferably 0.01～0.2mol (for example, 0.015～0.15mol); be preferably 0.02～0.1mol, and more preferably about 0.03～0.08mol.

In addition, in modified cellulose acylate, the polymerization degree of the substitution value of acyl group or grafted chain, hydroxyl concentration, grafted chain (molecular weight) etc. can be used conventional process, for example NMR (Nuclear Magnetic Resonance) spectrum (NMR) ( ¹H-NMR, ¹³C-NMR etc.) etc. measure.

In addition, modified cellulose acylate can also have hydroxyl usually.This hydroxyl can be enumerated the hydroxyl of grafted chain end, remaining hydroxyl etc. in glucose unit.In order to suppress or protect the purposes such as water absorbability of modify and graft derivative, this hydroxyl can also be protected by protecting group as required.

As protecting group, so long as can protect the non-reacted group of hydroxyl, just be not particularly limited, can enumerate, for example [for example, methyl, ethyl, 2-cyclohexyl-2-propyl group, hexyl, chloromethyl etc. can have the C of substituting group (halogen atom etc.) to alkyl _1-12Alkyl (preferred C _1-6Alkyl) etc.], (for example, cyclohexyl etc. can have substituent C to cycloalkyl _5-8Cycloalkyl), aromatic hydrocarbyl (C such as phenyl _6-12Aralkyl such as aryl, benzyl etc.), bridge joint ring type alkyl alkyl such as (adamantyls etc.); Ether ring alkyl (for example, 5～8 Yuans ether ring alkyl); Alkoxyalkyl (for example, C _1-6Alkoxy-C _1-6Alkyl) acetals protecting group such as; Alkyl-carbonyl (C such as ethanoyl, propionyl _1-10Alkyl-carbonyl), acyl group such as naphthene base carbonyl, aryl carbonyl etc.

Protecting group may be used singly or in combination of two or more in the protection hydroxyl.

In the modified cellulose acylate that uses protecting group protection hydroxyl, the ratio of protecting group (or protection ratio of the hydroxyl of grafted chain) is with respect to the 1mol grafted chain; can be selected from the scope of 0.7～1mol; for example, can be 0.9～1mol, and be preferably about 0.95～0.999mol.

In addition, with regard to modified cellulose acylate, though only a little, also exist to have the situation of carboxyl.This carboxyl also can with above-mentioned hydroxyl similarly protected (or end-blocking).

Modified cellulose acylate of the present invention, no matter whether have the grafted chain that the grafting hydroxyalkanoic acid component forms, the graft ratio of hydroxyalkanoic acid component all is specific small proportion, therefore have than high glass transition, and the thermotolerance height.The second-order transition temperature of cellulose acylate of the present invention; can be selected from more than 70 ℃ () scope for example, about 75～240 ℃, for example; can be more than 80 ℃ [for example; about 80～220 ℃ (for example, 90～200 ℃)], (for example be preferably 100～190 ℃; 110～180 ℃); more preferably about 120～170 ℃, and be generally about 130～180 ℃ (for example, 140～170 ℃).In addition, the second-order transition temperature of modified cellulose acylate also can be adjusted by the polymerization degree of adjusting grafted chain, the kind (substituent kinds such as substitution value, acyl group etc.) of cellulose acylate etc.

In addition; modified cellulose acylate of the present invention; be (for example to come from the lactone composition particularly at grafted chain; lactone) grafted chain (for example; polycaprolactone chain etc.) time; compare with common cellulose acylate (for example, cellulose acetate propionate, cellulose acetate butyrate etc.) etc., have from the smaller characteristic of temperature dependency (variation of storage modulus) of vitreous state to the storage modulus of the so-called transition process of rubbery transition.Therefore, modified cellulose acylate of the present invention changes with respect to mold temperature, and its optical characteristics can not change sensitively, and can stably give characteristic [for example, optical characteristics (for example, desirable length of delay)] as desired.

For example; in the storage modulus of modified cellulose acylate of the present invention; be temperature with transverse axis (or X-axis); the longitudinal axis (Y-axis) is in the storage modulus curve of storage modulus (E ') of modified cellulose acylate; storage modulus shows the maximum slope (δ y/ δ x) of 10～100MPa scope, can be-12～0MPa ℃ ^-1(for example ,-12～-1MPa ℃ ^-1), be preferably-11～-1.5MPa ℃ ^-1, and more preferably-10～-2MPa ℃ ^-1In addition, in above-mentioned transition process, the storage modulus of modified cellulose acylate, situation about reducing along with the temperature rising is more.Therefore, above-mentioned maximum slope, the temperature when showing the 10MPa storage modulus be t1 (℃), the temperature when showing the 100MPa storage modulus be t2 (℃) time, can be approximated to be by 90 * (t2-t1) ^-1(MPa ℃ ^-1) value obtained.In addition, the form of used above-mentioned modified glucan derivative is not particularly limited when measuring storage modulus, for example, can use membranaceous formed body (particularly unstretching film) to measure.

In addition, modified cellulose acylate of the present invention, its wet fastness is also excellent.For example; the water-intake rate of modified cellulose acylate of the present invention can be selected from the scope of (for example, about 0～4.5%) below 5%; for example be below 4% (for example; 0.1 about～3.5%), be preferably (for example, about 0.2～2.7%) below 3%; more preferably below 2.5% (for example; 0.3 about～2.2%), and be in particular (for example, about 0.5～1.8%) below 2%.

(preparation method of modified cellulose acylate)

Modified cellulose acylate of the present invention can obtain by making cellulose acylate and hydroxyalkanoic acid component reaction (ring-opening polymerization or condensation reaction).That is to say, can prepare modified cellulose acylate by graft polymerization hydroxyalkanoic acid component in cellulose acylate.In addition, graft reaction (graft polymerization reaction), (for example using cyclic ester, during lactide such as lactone, lactide) as hydroxyalkanoic acid component, it is the ring-opening reaction (ring-opening polymerization, the reaction of open loop grafting) of following the cyclic ester open loop, when using alcohol acid (lactic acid, hydroxycaproic acid etc.), be condensation reaction (reaction of condensation grafting).In the present invention, can suitably utilize the open loop grafting reaction of using cyclic ester.

In addition; graft polymerization (particularly; the ring-opening polymerization of use cyclic ester) the moisture amount of employed cellulose acylate and hydroxyalkanoic acid component in; preferably the least possible, and separately with respect to generally, can be [about 0 (or limit of detection)～0.3 weight %] below the 0.5 weight %; it is following (for example to be preferably 0.1 weight %; 0.0001 about～0.05 weight %), and more preferably below the 0.01 weight % (for example, about 0.0003～0.005 weight %).In addition, the moisture amount can pass through conventional process, for example distillation, contacts with siccative (sal epsom etc.) etc. and reduces.

In reaction (graft polymerization); the ratio of hydroxyalkanoic acid component (usage ratio) is not particularly limited; with respect to 100 weight part cellulose acylates, for example, can for 1～300 weight part (for example; 5～250 weight parts); be preferably 10～200 weight parts, more preferably 15～150 weight parts (for example, 20～130 weight parts); and be generally below 120 weight parts (for example, 20～110 weight parts).

(or graft polymerization) is following carries out in reaction, can be (for example according to the kind of hydroxyalkanoic acid component, cyclic ester), under existing, habitual catalyzer [for example, organic acid, inorganic acids, metal (basic metal, magnesium, zinc, tin, aluminium etc.), metallic compound [tin compound (dibutyl tin laurate (ジ Block チ Le チ Application ラ ウ レ-ト), tin chloride), organic alkali metal compound, organo-aluminium compound, organic titanic compound (alkyl dioxide etc.), organic zirconate etc.] etc.] carries out.Catalyzer may be used singly or in combination of two or more.

Particularly, as catalyzer (graft polymerization catalyzer), be the compound that forms hydroxyalkanoic acid component graft polymerization (particularly, using the ring-opening polymerization of cyclic ester) catalyzer, and can use the not metal complex (or metallic compound) of independent initiated polymerization.By using this catalyzer (and specific solvent described later), can significantly suppress the generation of hydroxyalkanoic acid component homopolymer, and can obtain graftomer (modified cellulose acylate) efficiently.In addition; when using this catalyzer (and specific solvent described later); can not produce the reduction of the acyl substituted degree of being found in the method for above-mentioned patent documentation 2; and the resultant after graft polymerization (promptly; modified cellulose acylate) in; can reflect acyl substituted degree as the cellulose acylate of raw material, and can effectively obtain the having desirable acyl substituted degree modified cellulose acylate of (with the grafted chain substitution value).

Do not cause above-mentioned polymeric metal complex (metallic compound), comprise central metal and the part that is coordinated in this central metal, (or do not show the part of polymerization activity for hydroxyalkanoic acid component as the concrete part that constitutes above-mentioned metal complex, or be inactive part) for hydroxyalkanoic acid component, can enumerate, for example carbon monoxide, halogen atom (chlorine atom etc.), Sauerstoffatom, hydrocarbon [for example, alkane (C _1-20Alkane etc.), loop chain alkane, aromatic hydrocarbons (benzene, toluene etc.) etc.], beta-diketon (β-C such as methyl ethyl diketone _5-10Diketone etc.), carboxylic acid [for example, paraffinic acid (C such as acetate, valeric acid, caproic acid, 2 ethyl hexanoic acid _1-20Paraffinic acid) aliphatic chain alkanoic acid such as; Aromatic carboxylic acids such as M-nitro benzoic acid etc.], pairing part (for example, halogen, alkyl, acyl group pyruvic acid ester group (ァ シ Le ァ セ ト Na ト), acyl group) such as carbonic acid, boric acid etc.These parts can independent or two or more combinations be coordinated in central metal.

As the typical graft polymerizing catalyst, can enumerate do not have alkoxyl group (and hydroxyl) and/or amino (amino beyond uncle's amino) as the metal complex of part, for example, alkali metal compound (carbonic acid an alkali metal salt, carboxy acid alkali's metal-salts such as sodium acetate etc.), alkaline earth metal compound (for example, the carbonic acid alkaline earth salt, carboxy acid alkali's earth metal salt such as lime acetate), zn cpds (zinc acetate, acetopyruvic acid zinc etc.), aluminum compound (for example, trialkylaluminium), germanium compound (for example, germanium oxide etc.), tin compound [for example, carboxylic acid tin (for example, stannous octoate C such as (stannous octoates) _2-18Alkanoic acid tin, preferred C _4-14Alkanoic acid tin), (for example, dibutyltin diacetate, dibutyl tin laurate, three sad Monobutyltins etc. are single or two C for the alkanoic acid tin alkyl _1-12Tin alkyl C _2-18Chain alkyl carboxylic acid ester etc.) carboxylic acid tin class such as; Alkyl-tin oxide (for example, list such as monobutyltin oxide, dibutyl tin oxide or dialkyl tin oxide etc.); Tin halides; Halogenation acetyl acetone tin; Mineral acid tin (nitric acid tin, tin sulphate etc.) etc.], lead compound (lead acetate etc.), antimony compounds (ANTIMONY TRIOXIDE SB 203 99.8 PCT etc.), bismuth compound typical metallic compounds such as (bismuth acetates etc.) or typical metal complex; Rare earth compound (for example, carboxylic acid such as lanthanum acetate, acetate samarium rare earth metal salt), titanium compound (acetate titanium etc.), zirconium compounds (zirconium acetate, acetyl acetone zirconium etc.), niobium compound (acetate niobium etc.), iron cpd transistion metal compounds such as (ironic acetate, acetyl acetone iron etc.).

In these catalyzer, tin coordination compoundes (perhaps tin compound) such as special optimization acid's tin class.Catalyzer may be used singly or in combination of two or more.

In reaction (graft polymerization reaction), the ratio of above-mentioned catalyzer (usage ratio) with respect to the hydroxyl of the above-mentioned cellulose acylate of 1mol, for example, can be 10 ^-7～10 ^-1Mol is preferably 5 * 10 ^-7～5 * 10 ^-2Mol, and more preferably 10 ^-6～3 * 10 ^-2About mol.

In addition, reaction (graft polymerization reaction) can be carried out in solvent-free or in solvent, and can carry out in solvent usually.As solvent, for example, can use hydro carbons, ethers (tetrahydrofuran (THF), diox, dioxolane etc.), ester class (methyl acetate, ethyl acetate etc.), nitrogen-containing solvent (Nitromethane 99Min., acetonitrile, N-Methyl pyrrolidone, dimethyl formamide etc.), ketone (acetone, methylethylketone, mibk, cyclopentanone, pimelinketone etc.), sulfoxide class (dimethyl sulfoxide (DMSO) etc.) etc., and also the hydroxyalkanoic acid component (for example, lactone, lactide etc.) of surplus can be used for solvent.Solvent may be used singly or in combination of two or more.

In addition; in the ring-opening polymerization system of using cyclic ester; except above-mentioned specified catalyzer; can also further use the little designated solvent of solubleness in water; can do one's utmost to suppress the influence of the water in polymerization system or the reaction thus; therefore the generation of hydroxyalkanoic acid component homopolymer can be suppressed high-levelly, and modified cellulose acylate can be obtain.Specifically, the used solubleness of solvent in 20 ℃ of water in the graft polymerization reaction, can from below the 10 weight % [for example, 0 (or limit of detection)～8 weight %] scope in select, for example, can for below the 7 weight % (for example, 0.0001 about～6 weight %), be preferably 5 weight % following (for example, about 0.0005～4 weight %), more preferably 3 weight % are following (for example, 0.0008 about～2 weight %), and be preferably following (for example, 0.001～0.8 weight % of 1 weight % especially, preferred 0.002～0.5 weight % is further about preferred 0.003～0.3 weight %).

As the little solvent of the solubleness in water, specifically, can enumerate, for example aliphatic hydrocarbon [for example, alkane (for example, C such as heptane, octane, nonane, decane _7-20Alkane etc.), loop chain alkane (for example, C such as hexanaphthene _4-10Loop chain alkane) etc. aromatic hydrocarbon based (for example, C such as benzene,toluene,xylene (adjacent, or p-Xylol), ethylbenzene], _6-12Aromatic hydrocarbons, preferred C _6-10Aromatic hydrocarbons), aliphatics ketone [for example, dialkyl group ketone (for example, C such as metacetone, methyl n-propyl ketone, methyl isopropyl Ketone, methyl n-butyl ketone, di ketone, diisopropyl ketone, diisobutyl ketone _5-15Dialkyl ketone, preferred C _7-10Dialkyl ketone) etc. chain ethers [for example, dialkyl ether (C], _6-10Dialkyl ether etc.), alkyl aryl ether (methyl-phenoxide etc.) etc.] etc. non-halogen solvent, halogen solvent etc.As the halogen solvent, can enumerate, for example halogenated alkane (for example, halo C such as ethylene dichloride, trichloroethane, tetrachloroethane, propylene dichloride _1-10Alkane), halo loop chain alkane (halo C such as chlorocyclohexane _4-10Loop chain alkane), aromatic hydrocarbon based (the halo C such as chlorobenzene, dichlorobenzene, toluene(mono)chloride, chloromethylbenzene, chloroethyl benzene of halogen _6-12Aromatic hydrocarbons, preferred halo C _6-10Aromatic hydrocarbons etc.) halogenated hydrocarbons etc. such as.

The ratio of solvent; according to solvent types and different; with respect to 100 weight part cellulose acylates; it is above (for example to be selected from 50 weight parts; about 55～500 weight parts) scope; for example; 60～450 weight parts (for example, 65～400 weight parts) (for example are preferably 60～300 weight parts; 65～250 weight parts); 70～200 weight parts (for example, 75～190 weight parts) more preferably, and (for example be preferably 80～180 weight parts especially; 85～170 weight parts, preferred 90～150 weight parts) about.In addition; the ratio of solvent; total amount with respect to 100 weight part cellulose acylates and hydroxyalkanoic acid component; for example be 10～200 weight parts; be preferably 30～150 weight parts, more preferably 40～120 weight parts (for example, 50～100 weight parts); and usually can be for about 45～90 weight parts (for example, 50～80 weight parts).

Reaction (grafting reaction) can be carried out at normal temperatures, usually, in order more effectively to react, also can carry out under the condition of heating.In addition, if in the ring-opening polymerization boiling point of solvent be A (℃) time, temperature of reaction can be the temperature more than the solvent boiling point usually, for example, A～(A+30) (℃) [for example, A～(A+25) (℃)], be preferably A～(A+22) (℃), and more preferably (A+3)～(A+20) (℃) about.In addition, when solvent was mixed solvent, also the boiling point of solvent that can boiling point when the pure substance is minimum was as above-mentioned boiling point.When reacting at low temperatures, it is little to the effect of the influence of polymerization system (particularly ring-opening polymerization system) to suppress water, and can't suppress the generation of homopolymer fully, and when under the temperature more too high than solvent for use boiling point, carrying out polymerization, it is fierce that the backflow of solvent becomes, and be difficult to control.Concrete temperature of reaction according to solvent types, for example, can be 60～250 ℃, is preferably 80～220 ℃, more preferably 100～180 ℃ (for example, 105～170 ℃), and can be about 110～160 ℃ usually.

Reaction can be carried out in air or in the nonactive atmosphere (rare gas such as nitrogen, helium), and normally carries out under nonactive atmosphere.In addition, reaction can be under normal pressure or is carried out adding to depress.Further, grafting can under agitation carry out.

In addition, carry out, can effectively suppress the generation or the side reaction of the homopolymer of hydroxyalkanoic acid component thus owing to be reflected under the few state of moisture.For example; in reaction (particularly; ring-opening polymerization) in; total amount with respect to cellulose acylate, hydroxyalkanoic acid component and solvent; moisture content for example can be [about 0 (or limit of detection)～0.25 weight %] below the 0.3 weight %; it is following (for example to be preferably 0.2 weight %; 0.0001 about～0.18 weight %); more preferably 0.15 weight % is following (for example; 0.0005 about～0.12 weight %); and be preferably especially below the 0.1 weight % (for example, about 0.001～0.05 weight %).In addition, when carrying out grafting, can use the boiling point solvent higher, utilize methods such as azeotropic to remove the water that is generated, and react than water by condensation reaction.

In graft polymerization reaction, the reaction times is not particularly limited, and for example, can be 10 minutes～24 hours, is preferably 30 minutes～10 hours, and more preferably about 1～6 hour.

In addition, when protection hydroxyl and/or carboxyl, protection can followingly be implemented, can be by separating the resultant of gained in (and purifying) above-mentioned reaction (grafting), and make the grafting resultant of this separation (and purifying), with protective material [for example, hydroxy-protecting agent such as acylating agents such as carboxylic acid halides, acid anhydrides, alkene acylate (for example, methylvinyl acetate etc.) corresponding to above-mentioned protecting group; Carboxy protective agent such as carbonization imide compound etc.] reaction and carrying out, and can in the reaction system identical, carry out continuously with above-mentioned grafting.When in same reaction system, carrying out,, can add solvent as required, and can be in advance in grafting, use the hydroxyalkanoic acid component of volume or excess quantity, and the hydroxyalkanoic acid component that uses this excess quantity is as solvent in order to reduce the viscosity of reaction system.

The reaction mixture that reaction finishes back (after the graft polymerization, behind graft polymerization and the hydroxyl protection) can pass through customary way, for example filter, concentrate, separation methods such as distillation, extracting, neutralization, precipitation, or their combination separation method carries out separation and purification.

In addition; in aforesaid method; being A1 (mol) through the hydroxyalkanoic acid component of graft polymerization on cellulose acylate; with what constitute generation (be in detail; generate as by product) when the hydroxyalkanoic acid component of hydroxyalkanoic acid component homopolymer is A2 (mol); by the represented percentage of grafting of [A1/ (A1+A2)] * 100 (%) can for more than 20% (for example; about 40～100%), more than 70% (for example, 80～100%); (for example be preferably more than 85%; about 88～99.9%), more preferably (for example, about 93～99.8%) more than 90%; and further be preferably (for example, about 96～99.7%) more than 95%.In addition, percentage of grafting is high more, and expression can suppress the generation of the homopolymer of hydroxyalkanoic acid component more.

[formed body]

Modified cellulose acylate of the present invention can be used for forming various formed bodys (the three-dimensionally shaped body of two-dimentional formed body, bending or three-dimensional shapes such as film, sheet, film (or film) etc.).Particularly, because modified cellulose acylate of the present invention has excellent optical isotropy, therefore be suitable for forming molded body for optical use (particularly blooming).That is to say that formed body of the present invention [particularly, molded body for optical use such as blooming] forms (or formation) by above-mentioned modified cellulose acylate (for example, modified cellulose acylate).

Below, film (particularly blooming) and preparation method thereof is elaborated.

Film of the present invention (modified cellulose acylate film), according to kind of its substitution value or acyl group etc., can be by any preparation of fusion system embrane method (extrusion moulding etc.), solution film-forming method (casting method).The film that usually, can prepare the planarity excellence by solution film-forming method.

In solution film-forming method, can be by making rubber cement (or organic solvent solution) curtain coating on the separability support that contains modified cellulose acylate and organic solvent, and the film that generates peeled off from the separability support, dry and preparation film.The separability support can be metal support (stainless steel etc.) usually, and can be drum type or ring-band shape.Processing is polished on the surface of support usually, and level and smooth situation is more.

Being used to prepare the organic solvent of rubber cement, can be halogen organic solvent (particularly chlorine class organic solvent), also can be non-halogen organic solvent (being non-chlorine class organic solvent especially).Organic solvent may be used singly or in combination of two or more, and for example, chlorine class organic solvent and non-chlorine class organic solvent can be combined.As halogen organic solvent (particularly chlorine class organic solvent), can enumerate halogenated hydrocarbons such as methylene dichloride, chloroform (particularly chlorinated hydrocarbons) etc.As non-halogen organic solvent (being non-chlorine class organic solvent especially), can have for example, for example ester class (acetate esters such as methyl acetate, ethyl acetate, pentyl acetate, butylacetate), ketone (dialkyl group ketone, pimelinketone etc. such as acetone, methylethylketone, mibk), ethers (ring-type ethers such as chain ethers, diox, tetrahydrofuran (THF) such as diethyl ether etc.), alcohols (for example, C such as methyl alcohol, ethanol, Virahol, propyl carbinol _1-4Alkanols) etc.

In rubber cement, can add various additives, for example softening agent [phosphate plasticizer, carboxylic acid esters softening agent (phthalic ester, adipic acid ester, sebate, citrate etc.), vanay etc.], stablizer (oxidation inhibitor, UV light absorber, anti-bad dose etc.), lubricant (microgranular lubricant), fire retardant, releasing agent etc.In addition, in rubber cement, can also add and postpone rising agent (the delay rising agent that the spy opens in the 2001-139621 communique to be put down in writing etc.), stripper (stripper that the spy opens in the 2002-309009 communique to be put down in writing etc.) etc.

In addition, rubber cement can utilize conventional process, for example preparation such as high-temperature digestion method, hot-cold lysis method.Cellulose ester concentration in the rubber cement can be 10～35 weight %, and is preferably about 20～30 weight % (for example, 15～25 weight %).In addition, in order to obtain high quality film (liquid crystal indicator with film etc.), can further carry out filtration treatment to rubber cement.

Can utilize curtain coating mould etc. to make rubber cement curtain coating on support, and dry and preparation film.Usually, predrying by making rubber cement curtain coating on support, drying contains the predrying film of organic solvent and prepares film then.

In the fusion film-forming method, for example, can pass through to use the above-mentioned modified cellulose acylates of melting mixing (with other compositions such as softening agent as required) such as forcing machine, and, prepare film by cooling by mould (T shape mould, circular die etc.) extrusion moulding.Melt mix temperature for example can be selected from, the scope about 120～250 ℃.

Film thickness can be selected according to purposes, for example, can be 5～200 μ m, is preferably 10～150 μ m, and more preferably about 20～120 μ m.

In addition, film of the present invention, its cellulose acylate is modified by hydroxyalkanoic acid component, and in order to optimize stretchiness, also can implement stretch processing, and still, usually in order to give its optical isotropy, it is more film not to be carried out the situation of stretch processing.

Film of the present invention is to be formed by above-mentioned modified cellulose acylate, so the optical isotropy excellence.For example, in film of the present invention (unstretching film), the length of delay Re in the face for example can be 0～20nm, is preferably 0～10nm, 0～5nm more preferably, and be in particular 0～3nm (for example, about 0～2nm).In addition, in film of the present invention (unstretching film), the length of delay Rth of film thickness direction, for example can for-30nm～+ 30nm (for example ,-25nm～+ 25nm), be preferably-20nm～+ 20nm (for example,-15nm～+ 15nm), more preferably-10nm～+ 10nm, and be in particular-5nm～+ 5nm (for example ,-3nm～+ 3nm) about.

In addition, the length of delay of film (the length of delay Re in the face, the length of delay Rth of thickness direction) can be by measuring specific refractory power, the specific refractory power of quick shaft direction and the specific refractory power of thickness direction of slow-axis direction, and by these specific refractory poweres, and calculate respectively based on the defined formula of following formula.

Re＝(nx-ny)×d

Rth＝{(nx+ny)/2-nz}×d

(in the formula, nx represents the specific refractory power of the slow-axis direction in the face, and ny represents the specific refractory power of the quick shaft direction in the face, and nz represents the specific refractory power of film thickness direction, and d represents the thickness of film.)

In addition, above-mentioned length of delay can be the length of delay of the film of plasticizer-containing not usually.In addition, the length of delay Re in the face can be near the value of (or middle body) the film central authorities usually.

Industrial applicibility

Modified cellulose acylate of the present invention, its optical isotropy excellence, and wet fastness height.In addition,, also have high glass-transition temperature though have the grafted chain of hydroxyalkanoic acid component, and the thermotolerance height.Therefore, even require stable on heating purposes, optical characteristics such as optical isotropy can not reduce or change yet, and the practicality height.Therefore, modified cellulose acylate of the present invention can be used for forming the formed body (for example, display material or display element such as liquid crystal panel) of optical applications.The formed body of optical applications can be the formed body of above-mentioned three-dimensional configuration, and be particularly suitable for being membranaceous formed body.As film (blooming); can enumerate various bloomings; for example; the base material film of colour filter, sensitive photographic material, display unit with film optical compensation films such as (for example) liquid crystal display optical compensate films, phase retardation film, protective membrane (protective film for polarizing plate etc.), prevent the base material film of reflectance coating etc.

Embodiment

Below, the present invention will be described in more detail based on embodiment, but the present invention is not limited to these embodiment.In addition, among the embodiment, under situation about being not particularly limited, so-called " part " expression " weight part ".

In addition, among the embodiment, the following mensuration of various characteristics.

(second-order transition temperature)

Second-order transition temperature (Tg) uses highly sensitive type differential scanning calorimeter (SeikoInstruments (strain) makes, " DSC6200 "), and according to the method for JIS K7121, measures under the following conditions.

Example weight: 8.0mg

Nitrogen influx: 40ml/min

Rate of heating: 20 ℃/min

Speed of cooling: 20 ℃/min

Measure starting temperature: 20 ℃

Measure end temp: 210 ℃

In addition, second-order transition temperature carried out damping in 48 hours by sample is placed, and measures under equivalent environment in 23 ℃, the constant temperature of relative humidity 50%, humidity room.

(length of delay)

(prince's instrumentation machine (strain) is made to use automatic double refraction meter, " KOBRA-21ADH "), under 23 ℃, the environment of 50%RH, measure film (the film stretch before of 590nm wavelength to gained, film after the stretching) three-dimensional refractive index, obtain the refractive index n x of slow-axis direction, the refractive index n y of quick shaft direction and the refractive index n z of thickness direction, and by these values, and calculate the length of delay Re in the face and the length of delay Rth of thickness direction based on the defined formula of following formula.In addition, the length of delay Re in the face is near the value the film central authorities.

Re＝(nx-ny)×d

Rth＝{(nx+ny)/2-nz}×d

(in the formula, nx represents the specific refractory power of the slow-axis direction in the face, and ny represents the specific refractory power of the quick shaft direction in the face, and nz represents the specific refractory power of film thickness direction, and d represents the thickness of film.)

(specific refractory power)

With the film of gained in embodiment and the comparative example, in 23 ℃, the constant temperature of relative humidity 50%, humidity room, placed 48 hours, and under equivalent environment, use Abbe refractometer ((strain) atago makes, " 2T "), according to JIS K7142, measure specific refractory power.

(mist degree)

With the film of gained in embodiment and the comparative example, in 23 ℃, the constant temperature of relative humidity 50%, humidity room, placed 48 hours, and under equivalent environment, use turbidometer (Japanese electric look industry (strain), " NDH5000W "), according to JIS K7136, measure mist degree.

(total light transmittance)

With the film of gained in embodiment and the comparative example, in 23 ℃, the constant temperature of relative humidity 50%, humidity room, placed 48 hours, and use turbidometer (Japanese electric look industry (strain), " NDH5000W "), according to JIS K7361-1, measure total light transmittance.

(water-intake rate)

With the film of gained in embodiment and the comparative example, be cut into the square sample of 3cm * 3cm respectively, and this sample is kept 23 ℃ in 23 ℃, the distilled water of 500ml, flooded 48 hours.Behind the dipping, use Karl Fischer moisture meter (DIA INSTRUMENTS (strain), CA-100), (DIA INSTRUMENTS (strain) VA-100) measures water-intake rate to the moisture gasification installation.

Embodiment 1

(synthesizing of grafts)

In reactor with stirrer, anchor type paddle, add 70 parts of rhodias (daicel chemical industry (strain) make, LT-35, substitution value 2.90), and under 110 ℃, 4Torr drying under reduced pressure 4 hours.Then, use drying nitrogen to purify, reflux condensing tube is installed, and is added drying, distilled 30 parts of 6-caprolactones, 67 parts of pimelinketone (ANON) in advance, be heated to 160 ℃, stir, make the rhodia uniform dissolution.In this reaction solution, add 0.25 part of Monobutyltin three octanoate, and in 160 ℃ of following stirrings 2 hours, limit heating.Then, reaction solution is cooled to room temperature, termination reaction obtains reaction product.In addition, with respect to 90 parts of chloroforms, dissolve 10 parts of reaction product, then, slowly drip to 900 parts of excessive methyl alcohol, the throw out of filtering-depositing (grafts) is removed the homopolymer of 6-caprolactone thus.Further, at 60 ℃ of following heat dryings more than 5 hours, obtain 6-caprolactone and be grafted on grafts (cellulose acylate-caprolactone graft copolymer) on the cellulose acylate.

Then, by ¹H-NMR analyzes the primary structure of gained grafts.The result is, the average mol (MS) of grafted 6-caprolactone is 0.68 on every 1mol glucose unit, and the average substitution degree (DS) of grafted chain (grafted caprolactone) is 0.05, and the mean polymerisation degree of the 6-caprolactone of grafted chain (DPn) is 13.6.In addition, the second-order transition temperature of the grafts of gained is 154.4 ℃.Further, the water-intake rate of the grafts of gained is 1.3%.

(making of film)

Grafts, 78 weight part methylene dichloride and the 7 weight part methyl alcohol of 15 weight part gained are packed in the encloses container, slowly stir the mixture, through 24 hours with its dissolving.Behind this rubber cement of pressure filtration, left standstill again 24 hours, remove the bubble in the rubber cement.

Use the bar type spreader, under 30 ℃ temperature, make above-mentioned rubber cement curtain coating on sheet glass.The sheet glass of airtight curtain coating in order to make surface evenly (leveling), left standstill 2 minutes.After the homogenizing, use 40 ℃ warm wind drying machine to be dried 8 minutes, then stripping film from the sheet glass.Then, film is supported on the frame of stainless steel, uses 100 ℃ warm wind drying machine to make its dry 20 minutes, obtain the film that thickness is 100 μ m.The Re of gained film is 0nm, and Rth is-2nm.In addition, the total light transmittance of gained film is 93.4%, and specific refractory power is 1.48, and mist degree is 0.3%.

Embodiment 2

(synthesizing of grafts)

In reactor with stirrer, anchor type paddle, add 70 parts of rhodias (daicel chemical industry (strain) is made, LT-35, substitution value 2.90) and 30 parts of L-rac-Lactides ((strain), the wild chemical research manufacturing of Musashi), drying under reduced pressure is 12 hours and under 65 ℃, 4Torr.Then, use drying nitrogen to purify, reflux condensing tube is installed, and add dry in advance, distilled 67 parts of pimelinketone (ANON), be heated to 160 ℃, stir, make the rhodia uniform dissolution.In this reaction solution, add 0.25 part of Monobutyltin three octanoate, heated 2 hours down at 160 ℃, and stir.Then, reaction solution is cooled to room temperature, termination reaction obtains reaction product.In addition, with respect to 90 parts of chloroforms, dissolve 10 parts of reaction product, then, slowly drip to 900 parts of excessive methyl alcohol, the throw out of filtering-depositing (grafts) is removed the homopolymer of L-rac-Lactide thus.Further, at 60 ℃ of following heat dryings more than 5 hours, obtain the L-rac-Lactide and be grafted on grafts (cellulose acylate-rac-Lactide graft copolymer) on the cellulose acylate.

Then, by ¹H-NMR analyzes the primary structure of gained grafts.The result is, the average mol (MS) of grafted lactic acid units is 0.75 on a glucose ring, the average substitution degree (DS) of grafted chain (grafted L-rac-Lactide) is 0.06, and the mean polymerisation degree of the lactic acid units of grafted chain (DPn) is 12.5, and second-order transition temperature is 158 ℃.Further, the water-intake rate of the grafts of gained is 2.1%.

(making of film)

Use the grafts and the embodiment 1 of gained similarly to obtain the film that thickness is 100 μ m.The Re of gained film is 0nm, and Rth is 4nm.In addition, the total light transmittance of gained film is 93.4%, and specific refractory power is 1.47, and mist degree is 0.6%.

Comparative example 1

(synthesizing of grafts)

In reactor with stirrer, anchor type paddle, add 70 parts of rhodias (daicel chemical industry (strain) make, L-20, substitution value 2.41), and under 110 ℃, 4Torr drying under reduced pressure 4 hours.Then, use drying nitrogen to purify, reflux condensing tube is installed, and is added drying, distilled 30 parts of 6-caprolactones, 67 parts of pimelinketone (ANON) in advance, be heated to 160 ℃, stir, make the rhodia uniform dissolution.In this reaction solution, add 0.25 part of Monobutyltin three octanoate, and in 160 ℃ of following stirrings 2 hours, limit heating.Then, reaction solution is cooled to room temperature, termination reaction obtains reaction product.In addition, with respect to 90 parts of chloroforms, dissolve 10 parts of reaction product, then, slowly drip to 900 parts of excessive methyl alcohol, the throw out of filtering-depositing (grafts) is removed the homopolymer of 6-caprolactone thus.Further, at 60 ℃ of following heat dryings more than 5 hours, obtain 6-caprolactone and be grafted on grafts (cellulose acylate-caprolactone graft copolymer) on the cellulose acylate.

Then, by ¹H-NMR analyzes the primary structure of gained grafts.The result is, the average mol (MS) of grafted 6-caprolactone is 0.86 on every 1mol glucose unit, and the average substitution degree (DS) of grafted chain (grafted caprolactone) is 0.12, and the mean polymerisation degree of the 6-caprolactone of grafted chain (DPn) is 7.4.In addition, the second-order transition temperature of the grafts of gained is 125.4 ℃.Further, the water-intake rate of the grafts of gained is 4.7%.

(making of film)

Use the grafts and the embodiment 1 of gained similarly to obtain the film that thickness is 100 μ m.The Re of gained film (film before stretching) is 11nm, and Rth is 130nm.In addition, the total light transmittance of gained film is 93.4%, and specific refractory power is 1.48, and mist degree is 0.7%.

Comparative example 2

(synthesizing of grafts)

In reactor with stirrer, anchor type paddle, add 60 parts of rhodias (daicel chemical industry (strain) make, LM-80, substitution value 2.10), and under 110 ℃, 4Torr drying under reduced pressure 4 hours.Then, use drying nitrogen to purify, reflux condensing tube is installed, and is added drying, distilled 40 parts of 6-caprolactones, 67 parts of pimelinketone (ANON) in advance, be heated to 160 ℃, stir, make the rhodia uniform dissolution.In this reaction solution, add 0.25 part of Monobutyltin three octanoate, and in 160 ℃ of following stirrings 2 hours, limit heating.Then, reaction solution is cooled to room temperature, termination reaction obtains reaction product.In addition, with respect to 90 parts of chloroforms, dissolve 10 parts of reaction product, then, slowly drip to 900 parts of excessive methyl alcohol, the throw out of filtering-depositing (grafts) is removed the homopolymer of 6-caprolactone thus.Further, at 60 ℃ of following heat dryings more than 5 hours, obtain 6-caprolactone and be grafted on grafts (cellulose acylate-caprolactone graft copolymer) on the cellulose acylate.

Then, by ¹H-NMR analyzes the primary structure of gained grafts.The result is, the average mol (MS) of grafted 6-caprolactone is 1.29 on every 1mol glucose unit, and the average substitution degree (DS) of grafted chain (grafted caprolactone) is 0.34, and the mean polymerisation degree of the 6-caprolactone of grafted chain (DPn) is 3.9.In addition, the second-order transition temperature of the grafts of gained is 104.3 ℃.Further, the water-intake rate of the grafts of gained is 5.56%.

(making of film)

Use the grafts and the embodiment 1 of gained similarly to obtain the film that thickness is 100 μ m.The Re of gained film is 6nm, and Rth is 102nm.In addition, the total light transmittance of gained film is 93.4%, and specific refractory power is 1.48, and mist degree is 0.7%.

Comparative example 3

(synthesizing of grafts)

In reactor with stirrer, anchor type paddle, add 70 parts of rhodias (daicel chemical industry (strain) is made, L-20, substitution value 2.41) and 30 parts of L-rac-Lactides ((strain), the wild chemical research manufacturing of Musashi), drying under reduced pressure is 12 hours and under 65 ℃, 4Torr.Then, use drying nitrogen to purify, reflux condensing tube is installed, and add dry in advance, distilled 67 parts of pimelinketone (ANON), be heated to 160 ℃, stir, make the rhodia uniform dissolution.In this reaction solution, add 0.25 part of Monobutyltin three octanoate, and in 160 ℃ of following stirrings 2 hours, limit heating.Then, reaction solution is cooled to room temperature, termination reaction obtains reaction product.In addition, with respect to 90 parts of chloroforms, dissolve 10 parts of reaction product, then, slowly drip to 900 parts of excessive methyl alcohol, the throw out of filtering-depositing (grafts) is removed the homopolymer of L-rac-Lactide thus.Further, at 60 ℃ of following heat dryings more than 5 hours, obtain the L-rac-Lactide and be grafted on grafts (cellulose acylate-rac-Lactide graft copolymer) on the cellulose acylate.

Then, by ¹H-NMR analyzes the primary structure of gained grafts.The result is, the average mol (MS) of grafted lactic acid units is 0.85 on every 1mol glucose unit, and the average substitution degree (DS) of grafted chain (grafted L-rac-Lactide) is 0.22, and the mean polymerisation degree of the lactic acid units of grafted chain (DPn) is 3.9.In addition, the second-order transition temperature of the grafts of gained is 155.9 ℃.Further, the water-intake rate of the grafts of gained is 4.5%.

(making of film)

Grafts, 78 weight part methylene dichloride and the 7 weight part methyl alcohol of 15 weight part gained are packed in the encloses container, slowly stir the mixture, through 24 hours with its dissolving.Behind this rubber cement of pressure filtration, left standstill again 24 hours, remove the bubble in the rubber cement.

Use the bar type spreader, under 30 ℃ temperature, make above-mentioned rubber cement curtain coating on sheet glass.The sheet glass of airtight curtain coating in order to make surface evenly (leveling), left standstill 2 minutes.After the homogenizing, use 40 ℃ warm wind drying machine to make its dry 8 minutes, then stripping film from the sheet glass.Then, film is supported on the frame of stainless steel, uses 100 ℃ warm wind drying machine to make its dry 20 minutes, obtain the film that thickness is 100 μ m.The Re of gained film is 4nm, and Rth is 173nm.In addition, the total light transmittance of gained film is 93.5%, and specific refractory power is 1.47, and mist degree is 0.5%.

Comparative example 4

(synthesizing of grafts)

In reactor with stirrer, anchor type paddle, add 20 parts of rhodias (daicel chemical industry (strain) is made, NAC, substitution value 2.74) and 80 parts of L-rac-Lactides ((strain), the wild chemical research manufacturing of Musashi), drying under reduced pressure is 24 hours and under 65 ℃, 4Torr.Then, use drying nitrogen to purify, reflux condensing tube is installed, be heated to 140 ℃, stir, make the rhodia uniform dissolution.In this reaction solution, add 0.10 part of stannous octoate, and in 140 ℃ of following stirrings 1 hour, limit heating.Then, reaction solution is cooled to room temperature, termination reaction obtains reaction product.In addition, with respect to 90 parts of chloroforms, dissolve 10 parts of reaction product, then, slowly drip to 900 parts of excessive methyl alcohol, the throw out of filtering-depositing (grafts) is removed the homopolymer of L-rac-Lactide thus.Further, at 60 ℃ of following heat dryings more than 5 hours, obtain the L-rac-Lactide and be grafted on grafts (cellulose acylate-rac-Lactide graft copolymer) on the cellulose acylate.

Then, by ¹H-NMR analyzes the primary structure of gained grafts.The result is, the average mol (MS) of grafted lactic acid units is 14.1 on every 1mol glucose unit, and the average substitution degree (DS) of grafted chain (grafted L-rac-Lactide) is 0.23, and the mean polymerisation degree of the lactic acid units of grafted chain (DPn) is 60.5.In addition, the second-order transition temperature of the grafts of gained is 65.0 ℃.Further, the water-intake rate of the grafts of gained is 0.9%.

(making of film)

Grafts, 78 weight part methylene dichloride and the 7 weight part methyl alcohol of 15 weight part gained are packed in the encloses container, slowly stir the mixture, through 24 hours with its dissolving.Behind this rubber cement of pressure filtration, left standstill again 24 hours, remove the bubble in the rubber cement.

Use the bar type spreader, under 30 ℃ temperature, make above-mentioned rubber cement curtain coating on sheet glass.The sheet glass of airtight curtain coating in order to make surface evenly (leveling), left standstill 2 minutes.After the homogenizing, use 40 ℃ warm wind drying machine to make its dry 8 minutes, then stripping film from the sheet glass.Then, film is supported on the frame of stainless steel, uses 45 ℃ warm wind drying machine to make its dry 120 minutes, obtain the film that thickness is 100 μ m.The Re of gained film is 1nm, and Rth is 4nm.In addition, the total light transmittance of gained film is 93.3%, and specific refractory power is 1.49, and mist degree is 1.5%.

Comparative example 5

(making of film)

Except use rhodia (daicel chemical industry (strain) is made, LT-35, substitution value 2.90,194.1 ℃ of second-order transition temperatures, water-intake rate 5.2%) to replace outside the grafts and embodiment 1 similarly, obtain the film that thickness is 100 μ m.The Re of gained film is 4nm, and Rth is 80nm.In addition, the total light transmittance of gained film is 93.5%, and specific refractory power is 1.47, and mist degree is 0.6%.

Comparative example 6

(making of film)

(Northeast chemistry (strain) is made except using cellulose acetate butyrate; catalog No.40425-1A; degree of substitution with acetyl group 1.06; butyryl radicals substitution value 1.66; 139.0 ℃ of second-order transition temperatures; water-intake rate 3.2%) replace outside the grafts and embodiment 1 similarly, obtain the film that thickness is 100 μ m.The Re of gained film is 8nm, and Rth is 127nm.In addition, the total light transmittance of gained film is 93.4%, and specific refractory power is 1.47, and mist degree is 0.8%.

Gained the results are shown in table 1.In addition, in table 1, " CA " represents rhodia, and " CL " represents 6-caprolactone, " LA " expression L-rac-Lactide, and " Tg " represents second-order transition temperature.

Claims (10)

1, a kind of alcohol acid modified cellulose acylate; described alcohol acid modified cellulose acylate comprises cellulose acylate and graft polymerization hydroxyalkanoic acid component and the grafted chain that forms on the hydroxyl of this cellulose acylate; wherein; the average substitution degree of described acyl group is more than 2.7; the ratio of the hydroxyalkanoic acid component of graft polymerization on cellulose acylate is; with respect to the glucose unit of 1mol formation cellulose acylate, being converted into alcohol acid is average 0.1～5mol.

2, the described alcohol acid modified cellulose acylate of claim 1, wherein, cellulose acylate is that the average substitution degree of acyl group is 2.7～2.99 cellulose ethanoate.

3, the described alcohol acid modified cellulose acylate of claim 1, wherein, hydroxyalkanoic acid component is to be selected from hydroxyl C _2-10Alkanoic acid, C _4-10Lactone and C _4-10At least a in the lactide.

4, the described alcohol acid modified cellulose acylate of claim 1; wherein; cellulose acylate is a cellulose ethanoate; the ratio of the average substitution degree of ethanoyl and the average substitution degree of grafted chain with the former/latter counts 90/10～99.5/0.5; the ratio of the hydroxyalkanoic acid component of graft polymerization on cellulose acylate; with respect to the glucose unit of 1mol formation cellulose acylate, being converted into alcohol acid is average 0.2～4mol.

5, the described alcohol acid modified cellulose acylate of claim 1, wherein, the mean polymerisation degree of grafted chain, being converted into alcohol acid is 2～40.

6, the described alcohol acid modified cellulose acylate of claim 1; wherein; cellulose acylate is that the average substitution degree of ethanoyl is 2.85～2.95 cellulose ethanoate; the ratio of the hydroxyalkanoic acid component of graft polymerization on cellulose acylate; constitute the glucose unit of cellulose acylate with respect to 1mol; being converted into alcohol acid is average 0.3～3mol, and the mean polymerisation degree of grafted chain to be converted into alcohol acid be 4～25.

7, the described alcohol acid modified cellulose acylate of claim 1, wherein, second-order transition temperature is more than 80 ℃, and water-intake rate is below 3%.

8, a kind of molded body for optical use, wherein, described molded body for optical use is formed by the described alcohol acid modified cellulose acylate of claim 1.

9, the described molded body for optical use of claim 8, wherein, described molded body for optical use is a blooming.

10, the described molded body for optical use of claim 9, wherein, the length of delay Re in the face of described molded body for optical use is 0～10nm, and the length of delay Rth of film thickness direction be-20nm～+ 20nm.