JP6189413B2 - Resin composition for optical film containing ladder-like silsesquioxane polymer - Google Patents

Description

  The present invention relates to a resin composition for an optical film including a ladder-like silsesquioxane polymer, and more particularly, a silsesquioxane having a ladder-like structure having high compatibility with a cellulose resin. By including molecules, the resin composition is excellent in heat resistance, ultraviolet blocking effect, water resistance, plastic effect, etc., and can be usefully used in the production of optical films such as protective films for polarizing plates and compensation films, and the like. The present invention relates to an optical film and an optical apparatus.

  In general, a cellulose-based film is widely used for optical applications such as a protective film for a polarizing plate because a film having excellent transparency and a small refractive index anisotropy can be easily produced. In particular, while the contrast ratio (C / R) of the display is greatly improved, it is also highly utilized as an expensive compensation film (Compensation film) by technical development such as phase difference adjustment.

  However, in order to provide various functions, complex technical elements are necessary, and diversification of the film manufacturing process is necessary. It is pointed out as an obstacle in application fields. As a representative example, 'Wide view (WV, Nippon Fuji Film)', which is a high-grade cellulose-based compensation film, has a complicated process and a very expensive price despite its excellent performance. It is difficult to apply to general displays such as, and in the case of using a general cellulosic protective film that simply protects the polyvinyl alcohol (PVA) layer of the polarizing plate in order to replace this, an improvement in display image quality is expected. The problem that you can not do.

The performance improvement of the cellulose-based film as described above is roughly divided into two types of fields, and after secondary molecular unit operations such as plasticizer and optical additive are first preceded, secondary such as stretching and coalescence. Desired physical properties are achieved through process condition adjustment. In particular, the adjustment of optophysical properties through molecular unit manipulation can be said to be the core technical element of all companies studying this, and the additive requirements applicable to such a stage are as follows:
1. The compatibility with the cellulosic resin is excellent and there is no haze phenomenon.
2. No desorption and reactivity at high temperatures and alkaline conditions.
3. Minimize degradation of basic cellulosic resin properties such as transparency, hardness and optical isotropy.

  However, since the organic-monomer additive component currently used in many fields does not satisfy the above-mentioned conditions perfectly, the limit of performance improvement is clearly predicted.

  Therefore, in order to overcome such performance limitations, Korean Patent Application No. 10-2009-0043088 uses a metal-based nanodispersion to improve physical properties, and Korean Patent Application No. 10-2009-0132560 A new form of aminobenzothiazole was used as an additive to improve the retardation of the film. However, in spite of such a series of efforts, the compatibility limit and the delamination phenomenon of the molecular unit addition component have only been locally improved and have not been completely overcome.

Korean Patent Application No. 10-2009-0043088 Korean Patent Application No. 10-2009-0132560

  In order to solve the above-mentioned problems, the present invention includes a silsesquioxane polymer having a ladder-like structure excellent in compatibility with a cellulosic resin, and has heat resistance, ultraviolet blocking effect, water resistance. Another object of the present invention is to provide a resin composition for an optical film that is excellent in plastic effect and the like.

  Another object of the present invention is to provide an optical film manufactured from the resin composition and having improved physical properties while maintaining excellent light transmittance of the cellulose-based film, and an optical apparatus including the same. .

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

  Moreover, this invention provides the optical film manufactured from the resin composition for optical films, and an optical apparatus containing the same.

  A resin composition for an optical film comprising a ladder-like silsesquioxane polymer and a cellulose resin according to the present invention comprises a ladder-like silsesquioxane polymer exhibiting high compatibility without a separate chemical reaction with the cellulose resin. Cellulose such as a protective film for a polarizing plate and a compensation film, which have excellent heat resistance, UV blocking effect, water resistance, plasticity effect, etc. It is useful for the production of optical system films.

It is the result of having compared the compatibility of the cellulose solution of Synthesis Example 1 and the mixed resin compositions of Examples 1 to 5 according to the present invention by transmittance (the content of the cellulose resin in the cellulose solution is 10% by weight). It is the result which compared the compatibility with the cellulose resin by the increase in the phenyl group of a silsesquioxane polymer | macromolecule by the transmittance | permeability. It is the result of having measured IR using the FT-IR spectrometer with respect to the cellulose-silsesquioxane mixed film by this invention. It is the result of having measured thermal decomposition stability of the cellulose-silsesquioxane mixed film by this invention using TGA (thermal gravimetric analyzer). It is the result of having measured the thermal stability of the cellulose-silsesquioxane mixed film by this invention using DSC.

  The resin composition for an optical film of the present invention comprises 1) a ladder-like silsesquioxane 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) Silsesquioxane Polymer The silsesquioxane polymer used in the present invention is a ladder-like silsesquioxane polymer having a weight average molecular weight of 1,000 to 1,000. 1,000, preferably 10,000 to 100,000.

Preferably, the ladder-like silsesquioxane polymer has a structure of the following chemical formula 1:
[Chemical Formula 1]

In the above chemical formula 1,
R ^{1 to} R ⁴ are each independently hydrogen, a cyclic or acyclic aliphatic organic functional group linked by C _{1 to} C ₂₀ , an alkyl group, an alkyl halogen, an aryl group, an amino group, a (meth) acryl group, vinyl A group, an epoxy group or a thiol group, wherein R ^{1 to} R ⁴ are all substituted with the same or different organic functional groups;
R ^{5 to} R ⁸ are each independently selected from the group consisting of a C _1-5 alkyl group, a C _3-10 cycloalkyl group, a C _6-12 aryl group, an alcohol, an alkoxy group, and combinations thereof;
n is 1 to 100,000.

In the above, the alcohol or alkoxy group is preferably —OCR ′ or —CR′═N—OH, wherein R ′ is a C _1-6 alkyl group.

The ladder-like silsesquioxane polymer used in the present invention may be produced by a known method or may be a commercially available one. Preferably, the silsesquioxane polymer of Formula 1 is used. Is a trifunctional silane having an organic functional group introduced therein, and can be produced by hydrolyzing a compound of the following chemical formula 2 and then continuously subjecting it to a condensation reaction:
[Chemical formula 2]
R ⁹ _4-m -Q _p -Si- (OR ¹⁰ ) _m
In Formula 2,
R ⁹ is hydrogen, a cyclic or acyclic aliphatic organic functional group linked by C _{1 to} C ₂₀ , an alkyl group, an alkyl halogen, an aryl group, an amino group, a (meth) acryl group, a vinyl group, an epoxy group, or a thiol group. An organic functional group such as
R ¹⁰ is selected from the group consisting of a C _1-5 alkyl group, a C _3-10 cycloalkyl group, a C _6-12 aryl group, an alcohol, an alkoxy group, and combinations thereof;
Q is a C _1-6 alkylene group or a C _1-6 alkyleneoxy group,
m is an integer from 0 to 4,
p is an integer of 0 or 1.

In the above, the alcohol or alkoxy group is preferably —OCR ′ or —CR′═N—OH, wherein R ′ is a C _1-6 alkyl group.

In the chemical formula 2, R ⁹ or R ¹⁰ may be an aromatic organic functional group such as a phenyl group, but R ^{1 to} R ⁴ which are side chain groups in the ladder-like silsesquioxane polymer of the present invention. When the content of the aromatic organic functional group in is excessively large, the transmittance tends to be low. Therefore, the content of phenyl in the total 100% of the side chain groups R ^{1 to} R ⁴ is preferably less than 80 mol% It is good to adjust to. This is because an excessive increase in the aromatic organic functional group may cause a difference in polarity from the cellulose film.

  The reaction conditions during the production of the ladder-like silsesquioxane polymer of the present invention can be achieved by a method usually used in the art, for example, a method described in Korean Patent Publication No. 10-2010-0131904. .

  In addition, the degree of condensation of the silsesquioxane polymer can be adjusted to 1 to 99.9%, and the content of —OH at the end of the silsesquioxane polymer depends on the polarity change of the cellulose resin used in the mixture. Resin having excellent storage stability when the content of —OH at the terminal of the silsesquioxane polymer is 0.01 to 50% of the terminal group, can be applied by adjusting variously and arbitrarily. A composition can be produced.

In addition, when an ultraviolet absorber generally known at the time of producing the compound of the chemical formula 1 is introduced into R ^{1 to} R ⁸ , it can be used as an additive for imparting an ultraviolet blocking property at the time of producing an optical film. As a specific example, a compound that can be used as an ultraviolet absorber is (2- (5-chloro-2H-benzotriazol-2-yl) -6- (1,1-dimethylethyl) -4-methyl- Phenol (2- (5-chloro-2H-benzotriazole-2-yl) -6 (1,1-dimethylethyl) -4-methyl-phenol), octyl-3- [3-tert-butyl-4-hydroxy-5 -(5-Chloro-2H-benzotriazol-2-yl) phenyl] propionate (Octyl-3- [3-tert-4-butyl-4-hydroxy-5- (5-chloro-2H-benzotriazol-2-yl) phenyl) ] An ultraviolet absorber containing a halogen element such as -(2H-benzotriazol-2-yl) -4,6-ditertylphenol (2- (2H-benzotriazol-2-yl) -4,6-ditertylphenol), 2- (2H-benzotriazol-2-yl) ) -4,6-bis (1-methyl-1-phenylethyl) phenol (2- (2H-benzotriazol-2-yl) -4,6-bis (1-methyl-1-phenylethyl) phenol), 2- (2H-benzotriazol-2-yl) -4 (1,1,3,3-tetramethylbutyl) phenol (2- (2H-benzotriazol-2-yl) -4- (1,1,3,3- tetramethylbutyl) phenol), 2- (2H-benzotriazol-2-yl) -6- (1- Tyl-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-triazine (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-dodecyloxy) (Lopyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine (2- [4-[(2-Hydroxy-3-dodeoxypropyl) oxy]] An ultraviolet absorber containing no halogen element such as 2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine) can be used.

2) Cellulosic resin The resin composition for an optical film of the present invention contains a cellulose resin. Preferably, as the cellulose resin, cellulose acylate resins such as cellulose acylate, cellulose triacetate, cellulose acetate butyrate, and cellulose acetate propionate can be used alone or in admixture of two or more, most preferably Cellulose triacetate can be used. In this case, the compatibility with the ladder-like silsesquioxane polymer is particularly good, and optical and physical properties such as transmittance, heat resistance and water resistance can be satisfied at the same time.

  In the resin composition for an optical film of the present invention, the ladder-like silsesquioxane polymer may be contained in an amount of less than 0.1 to 20 parts by weight, preferably less than 15 parts by weight with respect to 1 part by weight of the cellulose resin. In this case, the heat resistance, the ultraviolet blocking effect, the water resistance and the plastic effect can be satisfied at the same time. When the content of the silsesquioxane polymer is 20 parts by weight or more with respect to 1 part by weight of the cellulosic resin, the polarity difference between the two substances may occur excessively, the degree of commercialization is reduced, and the clouding effect is reduced. May occur.

  The resin composition for an optical film of the present invention can be used in various ways only by the composition itself, but a solvent can be used for production by a usual method such as commercialized solvent casting. The same effect can be expected regardless of the type used so long as the two mixtures are not separated.

  At this time, the content of the solvent is included in the remaining amount of the resin excluding the ladder-like silsesquioxane polymer and the cellulose resin, preferably the total solid content of the ladder-like silsesquioxane polymer and the cellulose resin. The solvent may be used so that the content is 1 to 50% by weight, preferably 10 to 40% by weight. When the solid content is within the above range, the flatness and workability of the film can be maintained well.

  Moreover, the resin composition for optical films of this invention can contain the functional additive which can be normally contained in the plasticizer, the ultraviolet blocker, or the resin composition for optical films as needed within the normal range.

  Moreover, this invention provides the optical film manufactured from the said resin composition for optical films, and an optical apparatus containing the same.

  The optical film according to the present invention can be produced by a method commonly used in the art except that the resin composition for an optical film is used. For example, the optical film is suitable for a spray method, a roll coater method, a spin coating method, etc. It can be manufactured by applying hot air drying in a temperature range of 30 to 150 ° C. after coating on a substrate with a thickness of 0.1 to 5,000 μm, and has heat resistance, UV blocking effect, water resistance and plastic effect. It is useful for the production of cellulose optical films such as protective films for polarizing plates and compensation films that have improved physical properties while maintaining the excellent light transmission properties of cellulose films. It is.

  Hereinafter, preferred examples will be presented for the understanding of the present invention. However, the following examples are merely illustrative of the present invention, and the scope of the present invention is not limited to the following examples.

Synthesis Example 1 Production of Cellulose Solution 1 part by weight of triacetyl cellulose (Sigma Aldrich, Fluka) was dropped into 9 parts by weight of a mixed solvent in which methylene chloride and methanol were mixed at 9: 1 (weight ratio) and mixed for 1 day or more. After that, a cellulose solution was produced.

Synthesis Example 2 Production of Silsesquioxane Polymer A dried flask equipped with a condenser and a stirrer was charged with 15% by weight of distilled water, 4% by weight of methanol (purity 99.86%) and tetramethylammonium hydroxide ( 25% in water) 1% by weight was mixed to prepare a mixed reaction solvent containing the catalyst in advance, and then 80% by weight of the silane monomer was added to the prepared mixed reaction solvent. At this time, the mixing ratio of the silane monomer was 10% by mole of trimethoxyphenylsilane (Dow Corning, trade name DOW CORNING (R) Z-6124 SILANE) and gamma-methacryloxypropyltrimethoxysilane (Dow Corning, Trade name DOW CORNING (R) Z-6030 SILANE) was adjusted to 90 mol%.

  Thereafter, after gradually stirring in a nitrogen atmosphere for 8 hours, stirring of the reaction solution was stopped and the reaction solution was allowed to stand at room temperature for 24 hours, and then the reaction solution containing the precipitate was vacuum filtered to separate the precipitate. The separated precipitate was washed several times with a mixed solution of distilled water and methanol and filtered to remove impurities, finally washed with methanol, and then vacuum-dried at room temperature for 20 hours to obtain 1 part by weight of the obtained product. 9 parts by weight of a mixed solvent in which methylene chloride and methanol were mixed at 9: 1 (weight ratio) was added dropwise to produce the desired polyaliphatic aromatic silsesquioxane polymer resin. The resulting polyaliphatic aromatic silsesquioxane polymer had a weight average molecular weight of 40,000. At this time, a weight average molecular weight is a polystyrene conversion average molecular weight measured using gel permeation chromatography.

Synthesis Examples 3 to 9 : Production of silsesquioxane polymer 15% by weight of distilled water, 4% by weight of methanol (purity 99.86%), 1% by weight of silane and 1% by weight of tetramethylammonium hydroxide (25% in water) A polymer silsesquioxane resin was produced in the same manner as in Synthesis Example 2 except that 80% by weight of the product was dropped into a molar ratio as shown in Table 1 below.

Examples 1 to 5 : Production of mixed solution of cellulose / silsesquioxane resin composition and film production using solution casting method The silsesquioxane polymer produced in Synthesis Example 2 was produced in Synthesis Example 1. The cellulose composition was mixed with 1 part by weight of the cellulose solution at 0.2, 0.4, 0.6, 0.8 and 1 part by weight, respectively, to prepare a resin composition for solution casting production. The prepared composition was cast on a glass plate at a speed of 20 cm / second, dried in hot air, and then manufactured into a film.

Examples 6 to 12
Except that 1 part by weight of each of the silsesquioxane polymers prepared in Synthesis Examples 3 to 9 was mixed with 1 part by weight of the cellulose solution prepared in Synthesis Example 1 to prepare each resin composition. Produced a film in the same manner as in Example 1.

Comparative Example 1
The cellulose solution prepared in Synthesis Example 1 was cast on a glass plate at a rate of 20 cm / second as in Example 1, dried with hot air, and then manufactured into a film.

Comparative Example 2
Resin composition in the same manner as in Example 1 except that 1 part by weight of the cellulose solution produced in Synthesis Example 1 was mixed with 2 parts by weight of the silsesquioxane polymer produced in Synthesis Example 2. And produced a film.

Comparative Example 3
A resin composition was produced in the same manner as in Examples 6 to 12 after the resin was produced in the same manner as in Synthesis Example 2 except that trimethoxyphenylsilane was used as a single silane monomer at 80% by weight. And made into film.

Test example 1
The compatibility, haze and transmittance of the silsesquioxane / cellulose resin compositions of Examples 1 to 5 and the resin compositions of Comparative Examples 1 and 2 were confirmed. Specifically, a 10 × 10 cell used for the substrate adhesion test for the compatibility test is manufactured by a cross-cut method (cell area = 5 mm ² ), and the difference in haze of 100 cells is relative to the central cell. If the number of cells that are 5% or more is less than 10, the compatibility is judged to be very good. If it is less than 20, the compatibility is excellent, if it is less than 30, it is normal, and if it is 50 or more, it is commercialized. Judged that it was difficult. In addition, in order to accurately measure the haze, the cloudiness of the corner portion and the center portion of all the produced film samples was measured three times or more, and the average value was described. Further, the transmittance of the manufactured film was described by averaging the light absorption spectrum (spectrum) of visible light by the method of measuring the angle and the central part in the same manner as the haze, and measuring the light transmittance at 400 nm. The results are shown in Table 2 below and FIG.

  As shown in Table 2 and FIG. 1, considering that the transmittance of the base material film manufactured in Comparative Example 1 is 92%, the compositions of Examples 1 to 5 according to the present invention are in phase. The solubility was shown to be very good. It was also shown that the haze effect was very good at less than 1% due to the increased compatibility.

  On the other hand, in the case of the composition produced in Comparative Example 2, it was observed as shown in the following table that the compatibility between the two resins rapidly decreased. Such results have been found to have a proportional effect on the transmission properties of the manufactured film.

Test example 2
The compatibility and transmittance of the resin compositions prepared in Examples 6 to 12 and the resin composition of Comparative Example 3 were confirmed, and the results are shown in Table 3 and FIG.

  As shown in Table 3 and FIG. 2, if the content of the aromatic organic functional group in the organic side chain functional group increases within a certain level in the silsesquioxane polymer, the haze is increased. Can be observed to increase rapidly. Therefore, based on these results, it was confirmed that the content of aromatic functional groups used for improving physical properties had to be adjusted to a certain level.

Test example 3
IR of the cellulose-silsesquioxane mixed film produced in Example 1 was measured using an FT-IR spectrometer (Perkin-Elmer system Spectrum-GX ATR mode), and the results are shown in FIG. Indicated.

As shown in FIG. 3, the optical film according to the present invention exhibits a broad bimodal (continuous double shape) absorption peak at 960 to 1,200 cm ⁻¹ , which is within the silsesquioxane chain. This is derived from stretching vibration of siloxane bonds in the vertical (-Si-O-Si-R) and horizontal (-Si-O-Si-) directions. In addition, the silsesquioxane was structurally clearly present even when mixed with the cellulose-based solution, and the haze characteristics were not shown.

Test example 4
The thermal stability of the cellulose-silsesquioxane mixed film prepared in Example 1 was confirmed using TGA (thermal gravimetric analyzer) and DSC, and the results are shown in FIGS. 4 and 5, respectively. At this time, TGA was measured at a scan rate of 10 ° C./min in a temperature range of 50 to 600 ° C. under nitrogen.

  As shown in FIGS. 4 and 5, in the cellulose-silsesquioxane mixed film according to the present invention, the thermal properties are increased by the addition of the silsesquioxane polymer without decreasing the thermal properties of the cellulose. I was able to confirm.

Test Example 5
In order to observe the change in moisture permeability (unit: g / m ² .day) of the cellulose-silsesquioxane polymer mixed film produced in Example 1 and the cellulose film of Comparative Example 1, Mocon 3/33 model was used. The results are shown in Table 4 below.

  As shown in Table 4, the film containing the ladder-like silsesquioxane polymer according to the present invention showed a moisture permeability that was greatly reduced to about 1/14 compared to the cellulose resin film itself.

Accordingly, the film produced according to the present invention can further effectively increase the iodine sublimation preventing function of the cellulose-based film used as a protective agent for the polarizing film.

Claims (14)

1) ladder silsesquioxane polymer having a weight average molecular weight of 1,000 to 1,000,000; and 2) look containing a cellulose resin,
The ladder-like silsesquioxane polymer has a structure of Formula 1 below:
[Chemical Formula 1]
In the above chemical formula 1,
R ^{1 to} R ⁴ are each independently hydrogen, a cyclic or acyclic aliphatic organic functional group linked by C _{1 to} C ₂₀ , an alkyl group, an alkyl halogen, an aryl group, an amino group, a (meth) acryl group, vinyl A group, an epoxy group or a thiol group, wherein R ^{1 to} R ⁴ are all substituted with the same or different organic functional groups;
R ^{5 to} R ⁸ are each independently selected from the group consisting of a C _1-5 alkyl group, a C _3-10 cycloalkyl group, a C _6-12 aryl group, hydrogen, an alkoxy group, and combinations thereof;
n is 1 to 100,000,
The resin composition for an optical film, wherein the content of the aromatic organic functional group in the total 100% of R ^{1 to} R ^{4 in} the chemical formula 1 is less than 80% .   The resin composition for an optical film according to claim 1, wherein the ladder-like silsesquioxane polymer is contained in an amount of less than 0.1 to 20 parts by weight with respect to 1 part by weight of the cellulose resin. object. 2. The optical film according to claim 1 , wherein the silsesquioxane polymer of Formula 1 is manufactured by hydrolyzing a compound of Formula 2 below and then continuously performing a condensation reaction. Resin composition:
[Chemical formula 2]
R ⁹ _4-m -Q _p -Si- (OR ¹⁰ ) _m
Where
R ⁹ is hydrogen, a cyclic or acyclic aliphatic organic functional group linked by C _{1 to} C ₂₀ , an alkyl group, an alkyl halogen, an aryl group, an amino group, a (meth) acryl group, a vinyl group, an epoxy group, or a thiol group. Is;
R ¹⁰ is selected from the group consisting of a C _1-5 alkyl group, a C _3-10 cycloalkyl group, a C _6-12 aryl group, an alcohol, an alkoxy group, and combinations thereof;
Q is a C _1-6 alkylene group or a C _1-6 alkyleneoxy group,
m is an integer from 0 to 4,
p is an integer of 0 or 1. Said alcohol or alkoxy groups are -OCR 'or -CR' = N-OH, this time, characterized in that R 'is an alkyl group of _{C 1-6,} optical of claim 1 or 3 Resin composition for film. In Formula 1, wherein the content of end of -OH is 0.01 to 50% of the inside of the terminal groups, an optical film resin composition according to claim 1. The resin composition for an optical film according to claim 1 , wherein at least one of R ^{1 to} R ⁸ further includes an ultraviolet absorber component.   The cellulose-based optical film according to claim 1, wherein the cellulose-based resin is selected from the group consisting of cellulose acylate, cellulose triacetate, cellulose acetate butyrate, and cellulose acetate propionate. Resin composition.   The cellulose resin composition for an optical film according to claim 1, wherein the cellulose resin is cellulose triacetate.   The cellulose resin composition for an optical film according to claim 1, wherein the resin composition additionally contains a plasticizer, a functional additive, or an ultraviolet blocking agent.   An optical film produced by applying the resin composition for an optical film according to claim 1 to a substrate and then drying it. The optical film according to claim 10 , wherein the transmittance of the optical film is at least 80%. The moisture permeability change of the optical film is 50 g / m ² at 25 ° C. The optical film according to claim 10 , wherein the optical film is less than a day. The optical film according to claim 10 , wherein the optical film is a compensation film for a display or a protective film for a polarizing plate. An optical or display device comprising an optical film according to claim 10 .