TW201343791A - Resin composition containing ladder-like silsesquioxane polymer for optical film - Google Patents

Abstract

The present invention relates to a resin composition for an optical film containing a silsesquioxane polymer with excellent solubility to a cellulose-based resin and a ladder-like structure, thereby having excellent heat resistance, UV light blocking effect, water tolerance and plasticizing effect. The solution of this invention is to provide a resin composition for an optical film, comprising: 1) a ladder-like silsesquioxane polymer with a weight average molecular weight of 1,000 to 1,000,000; and 2) a cellulose-based resin.

Description

Resin composition for optical film containing ladder-like sesquioxanes (SILSESQUIOXANE) polymer Field of invention

The present invention relates to a resin composition for an optical film containing a ladder-like silsesquioxane polymer, and more particularly to a resin composition, an optical film using the same, and an optical In the apparatus, the resin composition is excellent in heat resistance, ultraviolet shielding effect, water resistance, plasticity effect, etc., because it contains a sesquisestamer polymer which exhibits a high compatibility with a cellulose resin and has a ladder structure. Usefully used in the manufacture of optical films such as protective films for polarizing plates and compensation films.

Background of the invention

In general, since the cellulose-based film is excellent in transparency and can easily produce a film having a small anisotropy of refractive index, it is widely used for optical applications such as a protective film for a polarizing plate. In particular, although the contrast (C/R) of the display can be greatly improved, the development of techniques such as phase difference adjustment has a high degree of usability as an expensive compensation film.

However, because of the complex technical factors required to impart a wide variety of functionalities and the need to diversify the film manufacturing steps, this point is immediately associated with an increase in price and is pointed out to be practical in a wide variety of applications. obstacle. As a representative example, the advanced view of the advanced-cellulosic compensation film, although having excellent performance, is difficult to apply to a general display such as a personal computer because of its complicated steps and high price. When a normal cellulose-based protective film which simply protects a polyvinyl alcohol (PVA) layer of a polarizing plate is used instead of this, there is a problem that it is not expected to improve the image quality of the display.

As described above, the performance improvement of the cellulose-based film is roughly divided into two types of fields, and the molecular unit operation such as a plasticizer or an optical additive is performed once, and then the secondary step condition adjustment such as stretching and bonding is required to achieve the desired Physical characteristics. In particular, the adjustment of optical physical properties by the operation of molecular units is arguably the core technical factor for all of the companies in which it is studied. The necessary conditions for the additives that can be applied at this stage are as follows:

1. It is excellent in compatibility with a cellulose resin and has no hazy phenomenon.

2. No separation and no reactivity under high temperature and alkaline conditions.

3. Minimize the degradation of properties of basic cellulose-based resins such as transparency, hardness, and optical isotropy.

However, since the organic-monomer-added components currently used in many fields cannot fully satisfy the above conditions, the performance improvement limit cannot be clearly predicted.

Therefore, in order to overcome the limitation of such performance, the Republic of Korea Patent Application No. 10-2009-0043088 seeks to use a metal-based nano dispersion. In order to improve the physical properties, the Republic of Korea Patent Application No. 10-2009-0132560 uses a new form of aminobenzothiazole as an additive component to improve the phase difference of the film. However, despite such a series of efforts, it is only possible to locally improve the limit of compatibility and the peeling of the added components of the molecular unit, but it cannot be completely overcome.

Prior technical literature Patent literature

Patent Document 1: Republic of Korea Patent Application No. 10-2009-0043088

Patent Document 2: Republic of Korea Patent Application No. 10-2009-0132560

Summary of invention

In order to solve the problems as described above, the object of the present invention is to provide a resin composition for an optical film which contains a sesquisilane polymer which is excellent in compatibility with a cellulose resin and has a ladder structure. Excellent heat resistance, UV shielding effect, water resistance and plastic effect.

Another object of the present invention is to provide an optical film and an optical device comprising the same, wherein the optical film is produced from the resin composition, and maintains excellent optical transmittance of the cellulose-based film while improving physical properties.

In order to achieve the above object, the present invention provides a resin composition for an optical film comprising: 1) a weight average molecular weight of 1,000 to 1,000,000 ladders of silsesquioxane polymer; and 2) cellulose resin.

Further, the present invention provides an optical film made of a resin composition for an optical film and an optical device comprising the same.

The resin composition for an optical film containing a ladder-like sesquiacetyl polymer and a cellulose resin of the present invention contains a ladder-like 显示 which exhibits high compatibility even if it does not cause another chemical reaction with the cellulose resin. The semi-oxygenated polymer is excellent in heat resistance, ultraviolet shielding effect, water resistance, and plasticizing effect, and is advantageous for maintaining excellent light transmittance of the cellulose-based film, and manufacturing a protective film for a polarizing plate and a compensation film having improved physical properties. A cellulose-based optical film.

Fig. 1 is a result of comparing the compatibility of the cellulose solution of Synthesis Example 1 with the mixed resin compositions of Examples 1 to 5 of the present invention (the content of the cellulose resin in the cellulose solution was 10% by weight).

Fig. 2 shows the results of comparing the compatibility of the phenyl hydrazine of the sesquioxane polymer with the cellulose resin according to the transmittance.

Fig. 3 shows the results of measuring the IR of the cellulose-germantane mixed film of the present invention using an FT-IR spectroscope.

Fig. 4 shows the results of measuring the thermal decomposition stability of the cellulose-germantane mixed film of the present invention using a TGA (thermal gravimetric analyzer).

Figure 5 is a graph showing the cellulose-germanium sesquioxane mixture of the present invention using DSC. The result of the thermal stability of the film.

Form for implementing the invention

The resin composition for an optical film of the present invention comprises: 1) a ladder-like mercaptopropane polymer having a weight average molecular weight of 1,000 to 1,000,000; and 2) a cellulose resin.

Hereinafter, each component will be described.

1) 矽 sesquioxane polymer

The silsesquioxane polymer ladder polymer used in the present invention has a weight average molecular weight of 1,000 to 1,000,000, preferably 10,000 to 100,000.

It is preferred that the ladder-like sesquioxanes polymer has the structure of the following chemical formula 1:

In the above Chemical Formula 1, R ¹ to R ⁴ are each independently a hydrogen or a cyclic or acyclic aliphatic organofunctional group which is bonded by C ₁ to C ₂₀ , an alkyl group, an alkyl halide, an aryl group or an amine. a (meth)acrylic group, a vinyl group, an epoxy group or a thiol group, in which case R ¹ to R ⁴ may be substituted by all the same or all different organic functional groups; R ⁵ to R ⁸ are each independently And is a group selected from the group consisting of an alkyl group of C _{1-5 ,} a cycloalkyl group of C _3-10 , an aryl group of C _6-12 , an alcohol, an alkoxy group, and the like; n is from 1 to 100,000.

In the above, the alcohol or alkoxy group is preferably -OCR' or -CR'=N-OH, and in this case, R' is a _C1-6 alkyl group.

The ladder-like sesquioxalic acid polymer used in the present invention can be produced by a known method, or can be used commercially, and the sesquisesquioxane polymer system of the above Chemical Formula 1 is preferred. The trifunctional decane obtained by introducing an organic functional group can be produced by continuously hydrolyzing a compound of the following chemical formula 2: [Chemical Formula 2] R ⁹ _4-m -Q _p -Si-(OR ¹⁰ ) _m

In the above Chemical Formula 2, R ^{9 is} , for example, hydrogen, a cyclic or acyclic aliphatic organofunctional group bonded by C ₁ to C ₂₀ , an alkyl group, an alkyl halide group, an aryl group, an amine group, or a (meth) group. An organic functional group such as an acryl group, a vinyl group, an epoxy group or a thiol group; R ¹⁰ is selected from the group consisting of an alkyl group of C _{1-5 ,} a cycloalkyl group of C _3-10 , an aryl group of C _6-12 , alcohols, and combinations of such alkoxy group constituted, Q-based C _1-6 alkylene or C _1-6 alkoxy extending, m is an integer of 0 to 4 lines, p is 0 or 1 based Integer.

In the above, the alcohol or alkoxy group is preferably -OCR' or -CR'=N-OH. In this case, R' is a _C1-6 alkyl group.

Further, in the above Chemical Formula 2, R ⁹ or R ¹⁰ may be an aromatic organic functional group such as a phenyl group, but since R ¹ to R ^{4 of a} side chain group in the ladder-like sesquisquioxane polymer of the present invention When the content of the aromatic organic functional group is too large, the transmittance tends to be low, and it is preferred that the content of the phenyl group in 100% of the total of the side chain groups R ¹ to R ⁴ is adjusted to be less than 80 m. % is better. This is because the excessive addition of the aromatic organic functional group may cause a difference in polarity with the cellulose-based film.

The reaction conditions in the case of producing the above-described ladder-like sesquisilated polymer of the present invention can be carried out by a method generally used in the field, and for example, the method described in Korean Patent Laid-Open No. 10-2010-0131904 can be used. carry out.

Further, the degree of condensation of the above-mentioned sesquisesquioxane polymer can be adjusted to 1 to 99.9%, and the content of -OH of the polymer terminal of the sesquisesquioxane can be changed according to the polarity of the cellulose-based resin to be used in combination. In the case where the content of -OH of the terminal of the sesquisquioxane polymer is 0.01 to 50% in the terminal group, it is preferable to produce a resin composition excellent in storage stability.

Further, when the compound of the above Chemical Formula 1 is produced, when a generally known ultraviolet absorber is introduced into R ¹ to R ⁸ , an additive for imparting ultraviolet shielding properties can be used in the production of an optical film. As a specific example, a compound which is an ultraviolet absorber can be used, and (2-(5-chloro-2H-benzotriazol-2-yl)-6-(1,1-dimethylethyl) can be used. -4-methyl-phenol (2-(5-chloro-2H-benzotriazole-2-yl)-6(1,1-dimethylethyl)-4-methyl-phenol), octyl-3-[3- Tributyl-4-hydroxy-5-(5-chloro-2H-benzotriazol-2-yl)phenyl]propionate (Octyl-3-[3-tert-butyl-4-hydroxy-5- (5-chloro-2H-benzotriazol-2-yl)phenyl]propionate) and other ultraviolet absorbers containing a halogen element; and 2-(2H-benzotriazol-2-yl)-4,6-bistriphenyl 2-(2H-benzotriazol-2-yl)-4,6-ditertylphenol, 2-(2H-benzotriazol-2-yl)-4,6-bis ( 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, 2-(2H-benzotriene) 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl) Phenol), 2-(2H-benzotriazol-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl) Phenol(2-(2H-benzotriazol-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol 2-[4-[(2-hydroxy-3-(2'-ethyl)hexyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)- 1,3,5-three (2-[4-[(2-Hydroxy-3-(2'-ethyl)hexyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine , 2-[4-[(2-hydroxy-3-dodecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl) -1,3,5-three (2-[4-[(2-Hydroxy-3-dodecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine) Elemental UV absorber.

2) Cellulose resin

The resin composition for an optical film of the present invention contains a cellulose resin. As the cellulose-based resin, a cellulose-based resin such as cellulose triacetate, cellulose acetate butyrate or cellulose acetate propionate can be used singly or in combination of two or more kinds, and it is preferable to use it. Cellulose triacetate. In this case, the compatibility with the ladder-like sesquioxane polymer is particularly preferable, and optical and physical properties such as transmittance, heat resistance, and water resistance can be simultaneously satisfied.

The resin composition for an optical film of the present invention preferably contains 0.1 to less than 20 parts by weight, preferably less than 15 parts by weight, based on 1 part by weight of the cellulose resin. At this time, it is possible to simultaneously satisfy heat resistance characteristics, ultraviolet shielding effect, water resistance, and plastic effect. When the content of the sesquisesquioxane polymer is 20 parts by weight or more based on 1 part by weight of the cellulose-based resin, the difference in polarity between the two substances is excessively generated, and the degree of commercialization is lowered and a turbid effect is caused.

Although the resin composition for an optical film of the present invention can be used in various forms as long as the composition itself, it can also be used in order to be produced by a usual method such as solvent casting which has been commercialized. The type of the solvent is such that as long as the two kinds of the mixture are not separated, the use of any substance can have the same effect.

In this case, the content of the solvent may include the remaining amount of the resin obtained by removing the ladder-like mercaptopropane polymer and the cellulose resin, and is preferably the ladder-like sesquioxane polymer and cellulose. It is preferred to use a solvent such that the total solid content of the resin is from 1 to 50% by weight, preferably from 10 to 40% by weight. When the content of the solid content is within the above range, the flatness, workability, and the like of the film can be favorably maintained.

In addition, the resin composition for an optical film of the present invention can be added with a plasticizer, an ultraviolet shielding agent, or a functional additive which can be usually contained in the resin composition for an optical film, in a usual range.

Moreover, the present invention provides an optical film produced from the resin composition for an optical film described above and an optical device including the optical film.

The optical film of the present invention is used in addition to the optical film described above. Other than the resin composition, it can be produced by a method generally used in the field, for example, by applying a thickness of 0.1 to 5,000 μm on a suitable substrate by a spray method, a roll coating method, a spin coating method, or the like, at 30~. The temperature range of 150 ° C is produced by drying with hot air, and the resin composition excellent in heat resistance, ultraviolet shielding effect, water resistance, and plasticity effect is used to produce excellent light transmittance while maintaining the cellulose film. A cellulose-based optical film such as a protective film for a polarizing plate or a compensation film which is improved in characteristics is also useful.

In the following, the preferred embodiments are set forth to understand the present invention, but the following examples are merely illustrative of the present invention, and the scope of the present invention is not limited by the following examples.

Synthesis Example 1: Production of Cellulose Solution

1 part by weight of cellulose triacetate (Sigma-Aldrich, Fluka) was added dropwise to 9 parts by weight of a mixed solvent obtained by mixing dichloromethane and methanol at a ratio of 9:1 (by weight), and mixed for 1 day or more, followed by production. Cellulose solution.

Synthesis Example 2: Production of a fluorenyl sesquioxane polymer

In a dried flask equipped with a cooling tube and a stirrer, 15% by weight of distilled water, 4% by weight of methanol (purity: 99.86%), and 1% by weight of tetramethylammonium hydroxide (25% in water) were mixed to prepare a catalyst-free medium. After mixing the reaction solvent, 80% by weight of decane monomer was added to the prepared mixed reaction solvent. At this time, the mixing ratio of the decane monomer was adjusted to trimethoxyphenyl decane (DOW CORNING, trade name DOW CORNING (R) Z-6124 SILANE) 10 mol% and γ-methyl propylene oxime The propyl trimethoxy decane (DOW CORNING, trade name DOW CORNING (R) Z-6030 SILANE) was added in an amount of 90 mol%.

Thereafter, after stirring slowly for 8 hours in a nitrogen atmosphere, the reaction solution was stopped and allowed to stand at room temperature for 24 hours, and then the reaction solution containing the precipitate was vacuum-filtered to separate the precipitate. After the separated precipitate was washed with a mixture of distilled water and methanol several times and filtered to remove impurities, and finally washed with methanol, and then dried under vacuum at room temperature for 20 hours, 1 part by weight of the obtained product was obtained. To the mixed solvent of 9:1 (weight ratio) of dichloromethane and methanol, 9 parts by weight of the mixed solvent was dropped to prepare a target polyaliphatic aromatic sesquioxane polymer resin. The obtained polyaliphatic aromatic sesquioxane polymer had a weight average molecular weight of 40,000. In this case, the weight average molecular weight is a polystyrene-converted average molecular weight measured by gel permeation chromatography.

Synthesis Examples 3 to 9: Production of a fluorenyl sesquioxane polymer

Except that 15% by weight of distilled water, 4% by weight of methanol (purity: 99.86%), and 1% by weight of tetramethylammonium hydroxide (25% in water), 80% by weight of decane monomer was dropped at a molar ratio as shown in Table 1 below. A polymer sesquisile resin was produced in the same manner as in the above Synthesis Example 2 except for the above.

Examples 1 to 5: Production of a mixed solution of a cellulose/hydrazine sesquioxane resin composition and film production by a solution casting method

The sesquisesquioxane polymer produced in the above Synthesis Example 2 was mixed with 1 part by weight of the cellulose solution produced in the above Synthesis Example 1 at 0.2, 0.4, 0.6, 0.8, and 1 part by weight, respectively. A resin composition produced by solution casting. The produced composition was cast on a glass plate at a rate of 20 cm/sec and dried by hot air to form a film.

Examples 6 to 12

In addition to the respective resin compositions prepared by mixing 1 part by weight of the sesquisesquioxane polymer produced in the above Synthesis Examples 3 to 9 with 1 part by weight of the cellulose solution produced in the above Synthesis Example 1, A film was produced in the same manner as in the above Example 1.

Comparative example 1

The cellulose solution produced in the above Synthesis Example 1 was cast on a glass plate at a rate of 20 cm/sec as in Example 1 and dried by hot air to obtain a film.

Comparative example 2

A resin composition was prepared in the same manner as in Example 1 except that 1 part by weight of the cellulose sulfonate polymer produced in Synthesis Example 2 was mixed in an amount of 2 parts by weight in the cellulose solution produced in Synthesis Example 1. Matter and film.

Comparative example 3

A resin composition was produced in the same manner as in Examples 6 to 12, except that trimethoxyphenyl nonane was used alone as a decane monomer in an amount of 80% by weight, and a resin was produced in the same manner as in the above-mentioned Synthesis Example 2. film.

Test example 1

The compatibility of the fluorenylsesquioxane/cellulose resin composition of the above Examples 1 to 5 and the resin compositions of Comparative Examples 1 and 2, the turbidity, and the transmittance were confirmed. Specifically, in order to test the compatibility, a lattice (lattice area=5 mm ² ) was produced by a method of transversely cutting a 10×10 grid used for testing the substrate adhesion force, and the turbidity difference of 100 grids was 5 with respect to the center lattice. When the number of the grids of % or more is less than 10, the compatibility is judged to be excellent, and when it is less than 20, it is judged to be excellent, and when it is less than 30, it is judged to be normal, and when it is 50 or more, it is judged that it is difficult to commercialize and it is arranged. Further, in order to accurately measure the turbidity, the turbidity of the corner portion and the central portion of all the film samples produced was measured three times or more, and the average value thereof was described. Further, the transmittance of the produced film was measured by using the same method as the turbidity and using an angle and a central portion measurement method to average the light absorption spectrum of the visible light, and measuring the light transmittance at 400 nm. The results are shown in Table 2 below and Figure 1.

As shown in the above-mentioned Table 2 and FIG. 1, it is considered that the composition of Examples 1 to 5 of the present invention shows that the transmittance of the base film produced in Comparative Example 1 is 92%. Further, as the compatibility is large, the turbidity effect is also less than 1%, which is very excellent.

On the other hand, in the composition produced in the above Comparative Example 2, as shown in the following table, it was observed that the compatibility between the two resins was drastically reduced. It is known that such a result has a proportional effect on the transmission characteristics of the manufactured film.

Test example 2

The compatibility and transmittance of the resin compositions produced in Examples 6 to 12 and the resin composition of Comparative Example 3 were confirmed, and the results are shown in Table 3 below and FIG.

As shown in the above Table 3 and Figure 2, it can be observed that the haze is increased when the content of the aromatic organic functional group in the organic side chain functional group in the sesquisquioxane polymer increases above a certain level. I am eager to participate. Therefore, in order to suppress such a result, it was confirmed that the content of the aromatic functional group used for the purpose of improving physical properties must be adjusted to a certain level.

Test Example 3

IR was measured for the cellulose-germantilsquioxane mixed film produced in the above Example 1 using an FT-IR spectroscope (ATR mode of Perkin-Elmer system Spectrum-GX), and the results are shown in Fig. 3 .

As shown in Figure 3, the optical film of the present invention exhibits a broad bimodal (continuous double shape) absorption peak at 960 to 1,200 cm-1, which is derived from the vertical in the sesquioxane chain. Stretching Vibration of the (-Si-O-Si-R) and the level (-Si-O-Si-) direction of the decane bond. Further, even when it was mixed with the cellulose-based solution, it was confirmed that the sesquioxanes were clearly present in the structure and did not exhibit turbidity characteristics.

Test Example 4

The thermal stability of the cellulose-germantilsquioxane mixed film produced in the above Example 1 was confirmed using a TGA (thermal gravimetric analyzer) and DSC, and the results are shown in Figs. 4 and 5, respectively. At this time, the TGA system was measured at a scanning speed of 10 ° C / min under a nitrogen gas at a temperature range of 50 to 600 ° C.

As shown in Fig. 4 and Fig. 5, it was confirmed that the cellulose-germantium sesquioxane mixed film-based cellulose of the present invention has no thermal characteristics and the thermal characteristics are increased by adding a sesquisquioxane polymer.

Test Example 5

In order to observe the change in moisture permeability (unit: g/m ² .day) of the cellulose-germane sesquioxane polymer mixed film produced in the above Example 1 and the cellulose film of Comparative Example 1, Mocon 3/33 was used. The pattern was carried out at 25 ° C in a 100% environment, and the results are shown in Table 4 below.

As shown in the above Table 4, the film of the ladder-containing sesquiacetyl polymer according to the present invention showed a drastic reduction to a moisture permeability of about 1/14 as compared with the cellulose resin film itself.

Therefore, the film produced in accordance with the present invention can be effectively made The iodine-reducing function of the cellulose-based film used for the protective material of the polarizing film is further increased.

Claims (16)

A resin composition for an optical film comprising: 1) a ladder-like mercaptopropane polymer having a weight average molecular weight of 1,000 to 1,000,000; and 2) a cellulose resin. The resin composition for an optical film according to the first aspect of the invention, wherein the ladder-like sesquisilated polymer is contained in an amount of 0.1 to less than 20 parts by weight based on 1 part by weight of the cellulose resin. The resin composition for an optical film according to the first aspect of the invention, wherein the ladder-like sesquiacetylene polymer has a structure of the following chemical formula 1: In the above Chemical Formula 1, R ¹ to R ⁴ are each independently a hydrogen or a cyclic or acyclic aliphatic organofunctional group which is bonded by C ₁ to C ₂₀ , an alkyl group, an alkyl halide, an aryl group or an amine. a (meth)acrylic group, a vinyl group, an epoxy group or a thiol group, in which case R ¹ to R ⁴ may be substituted by all the same or all different organic functional groups; R ⁵ to R ⁸ are each independently And is a group selected from the group consisting of an alkyl group of C _{1-5 ,} a cycloalkyl group of C _3-10 , an aryl group of C _6-12 , an alcohol, an alkoxy group, and the like; n is from 1 to 100,000. The resin composition for an optical film according to the third aspect of the invention, wherein the sesquisesquioxane polymer of the above Chemical Formula 1 is produced by continuously hydrolyzing a compound of the following Chemical Formula 2, followed by condensation reaction: R ⁹ _4-m -Q _p -Si-(OR ¹⁰ ) _m In the above formula, R ⁹ is hydrogen and a cyclic or acyclic aliphatic organofunctional group which is bonded by C ₁ to C ₂₀ , alkyl, halogenated alkyl, aryl, amine, (meth)acrylic, vinyl, epoxy or thiol; R ¹⁰ is selected from C _1-5 alkyl, C _3-10 a group consisting of a cycloalkyl group, an aryl group of C _6-12 , an alcohol, an alkoxy group, and combinations thereof; a Q system of a C _1-6 alkylene group or a C _1-6 alkoxy group; An integer from 0 to 4; p is an integer of 0 or 1. The resin composition for an optical film according to claim 3, wherein the alcohol or alkoxy group is -OCR' or -CR'=N-OH, and in this case, R' is a _C1-6 alkyl group. . The resin composition for an optical film according to claim 3, wherein the content of the aromatic organic functional group in 100% of the total of the above Chemical Formula 1, R ¹ to R ⁴ is less than 80%. The resin composition for an optical film according to claim 3, wherein the above-mentioned Chemical Formula 1 has an end-OH content of 0.01 to 50% in the terminal group. The resin composition for an optical film according to claim 3, wherein at least one of the above R ¹ to R ⁸ further contains an ultraviolet absorber component. The cellulose-based resin composition for an optical film according to the first aspect of the invention, wherein the cellulose-based resin is selected from the group consisting of deuterated cellulose and triethyl One or more groups of the group consisting of acid cellulose, cellulose acetate butyrate, and cellulose acetate propionate. The cellulose-based resin composition for an optical film according to the first aspect of the invention, wherein the cellulose-based resin is cellulose triacetate. The cellulose resin composition for an optical film according to the first aspect of the invention, wherein the resin composition further contains a plasticizer, a functional additive or an ultraviolet shielding agent. An optical film produced by applying a resin composition for an optical film according to the first aspect of the invention to a substrate, and then drying the resin composition. The optical film of claim 12, wherein the optical film has a transmittance of at least 80%. The optical film of claim 12, wherein the optical film has a moisture permeability change of 50 g/m ² .day or less at 25 ° C. The optical film of claim 12, wherein the optical film is a compensation film of a display or a protective film of a polarizing plate. An optical or display machine comprising an optical film as in claim 12 of the patent application.