TW201226461A - Cellulose film - Google Patents

Abstract

A cellulose film is provided. The cellulose film includes triacetyl cellulose and a plasticizer. The plasticizer contains a polyol ester compound. The polyol ester compound is prepared by synthesizing one or more kinds of monocarboxylic acids with an aliphatic polyol. The content of the plasticizer is between 5%-20% and the content of the polyol ester compound is more than 0 and less than 3% or 3%-20% when the thickness of the cellulose film is 65 um-200 um based on the total weight of the cellulose film. The cellulose film in the invention has good size stability, low moisture transmittance and high hardness.

Description

201226461

33029twf.d〇c/I VI. Description of the Invention: [Technical Field] The present invention relates to a cellulose ester film, and in particular to a film having low water vapor permeability, low heat shrinkage rate and high hardness Cellulose vinegar film. [Prior Art]

With the advancement of display technology, people can make life more convenient by the aid of the display. In order to make the display light and thin, the flat panel display (FPD) has become the mainstream. Among many flat panel displays, liquid crystal displays (LCDs) have superior characteristics such as space utilization efficiency, low power consumption, no radiation, and low electromagnetic interference. Therefore, liquid crystal displays are popular among consumers. In a general liquid crystal display, a polarizing plate (p〇larizati〇n) is usually disposed on the upper surface and the lower surface of the liquid crystal display panel to achieve a remarkable effect. The polarizing plate is usually attached by a ship fiber film. Manufactured on a transparent substrate. As the use time of the liquid crystal display increases, the heat resistance characteristics of the film (such as heat shrinkage _ also touch (four) rate) 2 characteristics (such as water vapor transmission rate) will deteriorate with time. Therefore, it affects the imaging quality of the liquid crystal display. The Guwei film has low water vapor transmission rate and low heat shrinkage rate, and can be achieved by the method of filming in the film. According to the disclosure of the patent. Content, Wei Lai's additives are often used in fiber 3 201226461

33029twf.doc/I in the film of the vitamin ester. The addition of 3% to 30% of the polyol ester compound in the cellulose ester film having a thickness of 10 um to 65 um in accordance with the contents disclosed in the Republic of China Patent No. 593493 helps to reduce the water vapor transmission rate. Therefore, how to produce a cellulose ester film having a low water vapor permeability, a low heat shrinkage rate and a high hardness has become an important subject in the industry. [Summary of the Invention]

The present invention provides a cellulose ester film which has characteristics such as low water vapor permeability, low heat shrinkage ratio and high hardness. The present invention provides a cellulose ester film comprising cellulose triacetate and a plasticizer. The plasticizer contains a polyol ester compound which is synthesized from one or more monocarboxylic acids and an aliphatic polyol. The content of the polyol ester compound is greater than 〇 and less than 3% based on the total weight of the cellulose ester film, or the content of the polyol ester compound when the thickness of the cellulose ester film is between 65 um and 2 〇〇 um Between 3% and 2%. According to the cellulose g film according to the embodiment of the present invention, the above aliphatic polyol is represented by the formula (1):

Ri-(〇H)n The formula (1) has an η-valent organic group and is an integer of not less than 2. According to the cellulose granule film of the embodiment of the present invention, the molecular structure of the above-mentioned mono-wei has, for example, an aromatic ring or a ring-burning ring. The above-mentioned multi-acetate-molecular structure towel according to an embodiment of the present invention has, for example, a dough or a Wei-based ring. Cellulose brewing film according to an embodiment of the present invention, the above polyol 4 201226461

33029twf.doc/I The molecular structure of the vinegar compound has, for example, an aromatic ring. According to the fibrous phase film of the present invention, the above plasticizer may further contain at least one compound and the compound is not a polyol vinegar compound. According to the cellulose lysate according to the embodiment of the present invention, the above enzyme-based compound is, for example, a vinegar-based compound. According to the cellulose vinegar film according to the embodiment of the present invention, the above-mentioned dish vinegar compound is represented by the formula (2) or the formula (3), for example, 2 ο 3 R-ο.

Re 0 r7 ο R5« Ό ο .R9, \0, 0

Re 'or Formula (3) wherein R 2 , R 3 , R 4 , R 5 , r 6 , R 7 , and r 8 are each independently an alkyl group, an aryl group or a aryl group ' Rs gt; is a linking gr〇up; rn is An integer from 1 to 10. The cellulose ester film according to an embodiment of the present invention may further contain an ultraviolet light absorber. The cellulose ester film according to the embodiment of the present invention is thinner than cellulose g 201226461

33029twf.doc/I Membrane, </ RTI> </ RTI> Between 0.001% and 5% of the above ultraviolet light absorber. ^ The cellulose vine film according to the embodiment of the present invention has a cellulose vinegar thinness of &lt;$°, and the content of the plasticizer is, for example, between 5% and 20%. - The cellulose transition according to the embodiment of the present invention, wherein the thickness of the above-mentioned cellulose ester film is, for example, between 1 〇 [1111 to 2 〇〇 111 111. In the above, since the plasticizer in the cellulose vinegar film of the present invention contains only a small amount of 4 berger expensive polyols, the purpose of the second is. Further, the plasticizer in the cellulose (tetra) film of the present invention contains a price, and the cheap Wei-compound is more effective in the heat-preserving property and moisture-proof property of the cellulose vinegar film. The above features and advantages of the present invention will be more apparent from the following description. [Embodiment] The transfer has a low water vapor permeability and a low heat shrinkage rate. This Ukih-type cellulose _ membrane cellulose and plastic #1. The thickness of the fiber __ film is between 200 μιη. The μϊη cellulose triacetate is the main component of the cellulose-based film, and the main structure of the cellulose-containing thief, such as cellulose acetate, is as follows: —睹 6 201226461

33029twf.doc/I

0- The amount of the 'acetamidine substitution rate (the ratio of the OH group substituted by an ethyl fluorenyl group) in the above structure affects the properties of cellulose triacetate. The substitution rate of acetamidine is preferably between 2.5 and 3.0. The plasticizer contains a polyol ester compound. The polyol ester compound is synthesized from a variety of mononuclear and aliphatic polyols. The total weight S of the film of the aging (4) film is between 5% and genus, while the content of the polyol is greater than 〇 and less than 3%, or when the cellulose _ film = When between 65 um and um, the polyol § compound is between 3% and 20%. The illusion is an aliphatic single _. Alternatively, the mono-acidic acid or the σ structure may have an aromatic ring or a carboxylic acid 2 aromatic monocarboxylic acid. The alicyclic monocarboxylic acid and the lan monocarboxylic acid have: ί Improved steam transfer rate and retention. Wei (7) in water: the acid is, for example, an example having i to 32 hydrazines including saturated fatty acids (such as acetic acid, propionic acid, early decanoic acid, heptanoic acid, citric acid, citric acid, 2 71 · pentacene, Lost 2-ethyl·hexyl acid, eleven bright, month

•»S 7 201226461

33029twf.docA laurel, dodecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, heptadecanoic acid, hard citric acid, nonadecanoic acid, arachidic acid, behenic acid, tetracosanoic acid , hexadecanoic acid, heptacosanoic acid, octadecanoic acid, triacontanic acid, lacquer wax, etc.) and unsaturated fatty acids (such as undecylenic acid, oleic acid, sorbic acid, sub-acid ). Particularly, in improving the compatibility with the cellulose ester film, the aliphatic monocarboxylic acid is preferably acetic acid, and more preferably a mixture of acetic acid and other monocarboxylic acids. However, the present invention does not specifically limit the monocarboxylic acid. Examples of the alicyclic monobasic acid include cyclopropanecarboxylic acid, cyclohexanecarboxylic acid, cyclooctylamine, and its derivatives. Examples of the aromatic mono-acids include benzoic acid, alkyl-substituted benzoic acid, naphthalenecarboxylic acid, rhubarb tetracarboxylic acid, and derivatives thereof. The above aliphatic polyol is represented, for example, by the formula (1): RH〇H)n Formula (1) wherein R1 is an 11-valent organic group and is an integer of not less than 2. ! The valence organic group is, for example, an alkylene group (such as a decyl group, an ethyl group, a trimethyl group, a tetramethyl group, etc.), an alkenyl group (such as a vinyl group), and an alkynyl group (such as an ethynyl group). And the like, a cycloalkyl group (such as anthracene, 4_cyclohexanediyl, etc.) or an alkanetriyl group (such as 1,2,3-propanetriyl, etc.). η is preferably an integer of 2 to 2 Å, more preferably an integer of 2 to 15, and most preferably an integer of 3 to 1 Å. Examples of the aliphatic polyhydric alcohol include adonitol, arabitol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propylene glycol, dipropylene glycol, and three Propylene glycol, hydrazine, 2-butanediol, decanediol, butanediol, dibutylene glycol, 1,3,4-butanetriol, pentanediol, 1,6-hexanediol, hexanetriol, Galactitol, mannitol, hong methyl pentane 1,3,5 triol, pinacol, sorbitol, trimethylolpropane, top three 201226461

33029 twf.doc/I Ethyl alcohol, xylitol, etc., among which triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, sorbitol, trimethylol xylenol are preferred.

The molecular weight of the polyvalent compound synthesized from the one or more kinds of mono (tetra) and the aliphatic polyhydric alcohol is not particularly limited in the present invention, and is more than between 300 and 1,500, more preferably between 35 and 75 Torr. . The polyol ester compound having a high molecular weight of = 2 is advantageous in terms of retention and = having a lower molecular weight _ element - the compound is advantageous in terms of water vapor transfer rate and compatibility of the zeolitic vinegar film. In the molecular structure of the poly(alcoholic) compound, for example, having a scale or a cycloalkyl group, in the present invention, in the preparation of the polyol vinegar compound, all or part of the mono-individual polyol Secrets can be reinstated to retain free hydroxyl groups. The multicomponent _ compound ^ is exemplified by an aromatic ring, three or more weimeng rings and a cycloalkyl ring. Polyol (4) Three or more fragrances (1).

201226461 33029twf.doc/I

(2) Ο

R13o

, an example of which is (DINCH)

(3)

Ίο

201226461 33029twf.doc/I

(7)

Ο——ch2ch2ch

s 11 201226461

33029twf.doc/I

C-O-CH〇CH-O II I o ch3 c-II o

(11)

K CHsGH'a;—G -G'ifi—0-0

II ◎ crn^o-c —II 0 12 &lt;3 201226461

33029twf.doc/I (12)

ο

C HjC Hi —CH?—〇 -C u 0 CHi-O-C—CH3 II 0

CH3CW2—C—CHa—O ~C—CHS I 〇 CHs —c ·ΌΗ3 H 〇 (14) o

H2C o-c-ch3 0 In particular, since the above polyol is relatively expensive from the target compound, the cellulose ester film of the present invention may contain only a small amount of a polyol ester compound (content less than 3%). ), thus the cellulose ester film of the present invention

S 13 201226461 33029twf.doc/I has a lower production cost than a general cellulose ester film. Further, when the thickness of the cellulose ester film of the present invention is between 65 um and 2 um, the content of the polyol ester compound is between 2% and 2%, which is in the form of shrinkage, hardness, and water vapor permeation. The penetration rate can also reach the level of the commercial material. Further, in order to further reduce the heat shrinkage rate and the hardness of the cellulose ester film, the above plasticizer may contain other compounds. For example, the above plasticizer may contain at least one ester compound of a non-polyol ester compound. The ester compound is, for example, a phosphate compound, which may be represented by the formula (2) or the formula (3).

Wherein the rulers 2, 113, 114, 115, the ruler 6, the ruler 7, and the ruler 8 are each independently an alkyl group, an aryl group or an aryl group; R9 is a linking group; m is an integer of 1 to 10. The phosphate compound may be biphenyl diphenylphosphate (BDP), triphenyl phosphate (TPP), tricresyl phosphate (TCP), 201226461

33029twf.doc/I decyl phenyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate, and the like. The phosphate compounds are as follows: OR23 R25〇-P-OR24 Ο , examples of which are:

15 201226461

33029twf.doc/I

H2 h2 h2 h2 o Further, an additive may be added to the cellulose ester film of the present invention according to actual needs. The additive is, for example, an ultraviolet light absorber or a nano powder. The above additives may be used singly or in combination. The ultraviolet light absorber is preferably contained in an amount of from 0.001% to 5%, more preferably from 〇1 to 1%, based on the total weight of the cellulose ester film. The ultraviolet light absorber may be a salicylate absorbent, a diphenylketone absorbent, a benzotriazole absorbent, a benzoate absorbent, a cyanoacrylate 10-ester absorbent or a nickel complex. The salt-based absorbent is preferably a diphenylketone-based absorbent, a benzotriazine-based absorbent, or a salicylic acid-based absorbent, and more preferably a benzotriene-based absorbent. Examples of the diphenylketone-based absorbent include 2,4-dihydroxydiphenyl ketone, 2-pyridyl-4-ethenyloxydiphenyl-I, 2-pyridyl-4-methoxydiphenyl Ketone, 2,2'-di-trans--4-methoxydiphenyl ketone, 2,2'-di-diyl-4,4'-nonyloxydiphenyl-, 2-carbyl-4 - n-octyloxydiphenyl ketone, 2_transbasic dodecyloxy 16 201226461 33029twf.doc/I bisdiphenyl ketone, 2-hydroxy-4-(2-hydroxy-3-mercapto propyleneoxy) Propoxydiphenylphosphonium. Examples of the benzotriazole-based absorbent include 2-(2'-hydroxy-3,-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'- Base_5,-t-butylphenyl)benzotriazole, 2-(2,-hydroxy-3,5'-di-p-pentylphenyl)benzotriene. Sit, 2-(2'. thiol_3',5'-di-t-butylphenyl)-5-gas benzotriazole, 2-(2,-hydroxy-5'-trioctylbenzene Benzotriazole. Examples of the salicylic acid-based absorbent include phenyl salicylate, p-octylbenzene sulphate, and p-tert-butylphenyl sulphate. Among the above ultraviolet light absorbers, 2-glycosyl-4-ethenyloxydiphenyl ketone and 2,2'-di-diyl-4,4'-nonyloxydiphenyl ketone are preferred. 2-(2,-hydroxy-3'-t-butyl-5'-methylphenyl)-5-gas benzotriazole, 2-(2'-hydroxy-5,-tert-butylphenyl Benzotriazole, 2-(2,-radio- 3',5'-di-third-pentylphenyl)benzotriazole, 2-(2,-radio-3,5,-di The third butylphenyl)-5-gas benzotriene sits three times. The above ultraviolet light absorbers may be used singly or in combination. The ultraviolet light absorber is mainly used to absorb ultraviolet light having a wavelength of 400 nm or less to prevent the component covered by the cellulose ester film from being damaged by ultraviolet light. It is preferred to use a plurality of ultraviolet light absorbers having different absorption wavelengths in combination to absorb ultraviolet light in a wide wavelength range. The content of the nanopowder is, for example, between 0.001% and 2% based on the total weight of the cellulose ester film. The material of the nano powder is, for example, cerium oxide, which may be Aerosil 200, 200V, 300, R972, R972V, R972CF, R974, R202, R805, R812, OX50, TT600, etc., preferably Aerosil 17 201226461

33029twf.doc/I 200, 200V, R972, R972V R974, R202, R805, R812. The above nano powders may be used singly or in combination. [Manufacturing method and test of cellulose ester thinner] Cellulose triacetate (145.5 kg) and plasticizer (components as shown in Table 1) were added to the solvent (dichloromethane: 730 kg, decyl alcohol: 11 kg) And mixing, followed by defoaming, filtration, solvent casting to form a cellulose ester film.

The formed cellulose ester film was subjected to the following tests: Heat shrinkage test The cellulose ester film to be tested was cut into 3 pieces each having a size of 1 〇 cn X 15 cm in the film transport direction (MD direction). The length of the case is 15 cm, and when the long shoulder in the direction perpendicular to the film transport direction (TD direction) is 10 cm for the heat shrinkage test, the temperature of the supply tank is as follows. ^. Using the second-element instrument to measure the MD direction and the TD direction

Then, the fiber surface films were placed in an oven, and placed in a small ^ = post-measurement in the MD direction and the τ inch bath shrinkage value B using a two-dimensional instrument. By the formula (A_B) / a, the material dependence rate. The lower the rate of change, the lower the temperature of the cellulose _ membrane, the lower the hot water vapor penetration test = the diameter of the 7 round cellulose 黯 film release box (50% RH, 23 〇 5 5 hours. ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

A solution of 33029 twf.doc/I (saturated ammonium dihydrogen phosphate) was added to the glass jar. Next, the cellulose ester film was placed tightly and fixed on the top of the bottle cap to allow only water vapor to pass through the cellulose ester film. Following this, the glass jar was placed in a constant temperature and humidity chamber for 4 days, and it was taken out every day to weigh the record. By subtracting the weight of the cellulose vinegar film from the weight of the bottle obtained from the reset, the weight lost per day (in g/m2.day) can be obtained. Test at least two more at a time.

Ship pen hardness test Sample preparation:

L is based on the airside and bekside of the film, and the length in the MD direction is 2 cm in the TD direction. 2. Make a test note on the surface of the film as follows: , lcm 0.5 cm

^ IIL ------- Remove the dust on the surface of the sample with a sticky dust wheel. 3. Machine operation, recognition, speed 30r/min 'put into the sample, both sides of the sentence clamped) pen (W The side is considered as long: 3.2 Balance is completed, put the weight of 500 §. 'Start the test, press ',, stop the test 35 Rotate the pencil to the other side, repeat the above steps. Grinding - the wrong pen can measure three data, remember Every grinding is wrong (5) 201226461 33029twf.doc/I Balance action is required. 3.6 Each sample needs to be tested at the same pencil level, 5 of which will be upgraded by one level, otherwise it will be lowered by one level. 3.7 Pencil grade classification: 2B&lt B&lt;HB &lt;F&lt;H&lt;2H&lt;3H. Table 1 shows the results obtained by heat shrinking, pencil hardness test and water vapor penetration test of the cellulose ester film.

Sample Plasticizer Plasticizer Content (%) Water Vapor Transmission Rate Thermal Shrinkage Pencil Hardness 1 TMPTB 10% 137.4 -0.27 B 2 TPP 10% 164 -0.156 B 3 BDP 10% 161.4 -0.149 B 4 EPEG 10% 135.3 -0.156 &lt;;B 5 DINCH 10% 157.7 -0.213 &lt;B 6 SR368 10% 157.7 -0.316 &lt;B 7 DPHA 10% 154.7 -0.212 &lt;B 8 TPP + BDP 10% 135.3 -0.16 F 9 TMPTB + EPEG 10% 123 - 0.203 HB 10 TMPTB (2.5%) + TPP 10% 118.6 -0.136 F 11 TMPTB (2.5%) + TPP + BDP 10% 110.8 -0.11 F 12 TMPTB (0.5%) + TPP + BDP 10% 114.5 -0.13 F

In Samples 1, 4, 5, 6, and 7, the plasticizer contained only one polyol ester compound; in Samples 2 and 3, the plasticizer contained only one phosphate compound; in Sample 8, the plasticizer contained two phosphate esters. Compound; in sample 9, 20 201226461

33029twf.doc/I The plasticizer contains two kinds of multi-plasticizers and contains I 5 substances; in the samples ig, 11, 12, 'alcoholized people's people's wide-ranging compounds (four) _ the compound, and the multiple = the object 3 In 3%, the cellulose vinegar which belongs to the present invention is known from Table 1 - when the content of the plasticizer in the same day is 1%, and the content of the polyol hearing compound is 2 , compound and vinegar compound: only 3 of them have a small amount of polyol vinegar compound (content less than 3), so it has lower manufacturing cost than other samples. Table 2 shows the comparison between the formulation of the present invention and the commercial materials of various manufacturers when the thickness of the cellulose ester film is 8 〇 ^^. Please refer to Table 2. Table 2 Sample thickness 13 80 um Commercial material 14 80 um Commercial material 15 SO um Commercial material 16 80 um Commercial material 17 80 um ΤΒ-1 18 80 um ΤΒ-2 Plasticizer addition amount unknown unknown unknown unknown unknown unknown unknown ΤΜΡΤΒ ( 5%)+ ΤΡΡ 10% ΤΜΡΤΒ (5%) + TPP + BDP 10%

Water Vapor Transmission Rate Thermal Shrinkage Pencil Hardness 106 -0.12 F 115 -0.156 ΗΒ 120 0.21 ΗΒ 125 -0.256 Β 106 -0.136 F 107 -0.11 F Samples 13-16 are currently available from various manufacturers. Samples 17, 18 are -.g- 21 201226461

33029twf.doc/I 80 Secrets = It can be seen that the thickness of the cellulose ester film is two, 1 &amp; 'When the content of the polyol ester compound is between 3% and 20% - n cellulose s The thin-grain size, hardness and water penetration rate have reached the level of commercial materials. The cellulose vinegar film of the present invention can be applied to the liquid crystal according to the user rate = and the two parts. For example, the cellulose granulated film having a low water vapor permeability value can be applied to the liquid crystal. A polarizer in the display or other optical film. In the cellulose ester film of the present invention, since the #axis of the present invention contains only ruthenium, (4) xiangyuan compound = weight, the content is less than 3), so that the use amount of the second: bet 70 alcohol ester compound can be reduced to achieve a decrease. The production cost is 'when the thickness of the cellulose vinegar film of the present invention is between 65 um and 斗 == the content of the polyol vinegar compound is between 3% and 20%. And the money penetration rate can also reach the outside of the product. 'When the plasticizer in the cellulose ester film of the present invention contains the compound, it can effectively improve the resistance of the cellulose ester film, and has a moisture-proof property. In order to increase the service life of the cellulose ester film. The application value of the cellulose-based film of the present day and the month is applied to the liquid-day display. The cellulose ester film has low water vapor transmission rate and low contribution rate. · 'Therefore, the life of the polarizing plate can be increased, so that the liquid helium display can have better image quality. Although the invention has been disclosed above by way of example, it is not intended to limit 22 201226461

33029 twf.doc/I The present invention, any one of ordinary skill in the art, may make some modifications and refinements without departing from the spirit and scope of the present invention. The scope defined by the patent scope shall prevail. [Simple description of the diagram]

[Main component symbol description] None

twenty three

Claims (1)

201226461 33029twf.doc/I VII. Patent application scope: 1. A cellulose ester film comprising: cellulose diacetate; and a promising hydrazine, a polyhydric alcohol ester compound, the polyol ester compound is one or more Single-synthesis with an aliphatic polyol, wherein the content of the multi-component compound is greater than 〇 and less than 3 〇 / 〇 ', or when the thickness of the cellulosic film is between &amp; When the content is between 2 and 2, the content of the polyol S is between 3% and 20%. The fibrous fine film according to Item 1, wherein Ri-(OH)n is a formula (1) wherein R1 is an 11-valent organic group and is an integer of not less than 2. 3. For example, the molecular structure of the acid of the first application of the scope of the patent range is "Woxiang". "In the case of the patent application, the 兀 兀 % 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 5. For example, the patent scope of the first formula or the cycloalkyl ring. The molecular structure of the alcoholic vinegar compound _ 'where the polycyclic ring. 〃 香 香 香 环 环 环 环 6 6 6 6 6 6 6 6 6 6 6 6 6 The plasticizer further comprises a cellulose ester film of at least one ester compound, wherein the polyol vinegar compound, and the compound is not 7. The product of the sixth compound of the claim 5, the ester compound includes a monophosphate cellulose ester film, wherein 24 201226461 33029twf.doc/I 阙^ secret, where Ο r2 , 0, N Ο r6 〇 (2) 0 r5. 0 , 〇 η \0- ο o' -Re Formula (3) wherein mu'n or aryl pit group; divalent linking group; aryl-based material of the first material, s§ film, and (4) cellulose according to item 9 of the patent scope (4) Membrane, wherein the ultraviolet light absorption amount is between 0.001% and 5%, based on the total weight of the film of &quot;0^01./^. 1) The cellulose vinegar film according to the patent scope of claim ,i, which is between 50/❶ and 20%, based on the total weight of the film of the cellulose g, such as 12 ψ Ή 范 范 1 a cellulose ester film, wherein the cellulose (tetra) film has a thickness of between 10 μm and a sum of μm. 25 .5^201226461 33029twf.doc/I 3%-20% when the thickness of the cellulose film is 65 um- 200 um based on the total weight of the cellulose film. The cellulose film in the invention has good size stability, low moisture transmittance and high hardness. IV. Designated representative map: (1) Designated representative figure of the case: None (2) A brief description of the symbol of the representative figure: 5. If there is a chemical formula in this case, please disclose the chemical formula that best shows the characteristics of the invention: