KR20170112555A - Resin composition - Google Patents

Abstract

The present invention relates to a resin composition, an optical film containing the same, and a polarizing plate comprising the same, and is a resin composition having excellent ultraviolet ray absorbing performance, heat resistance at a high temperature and preventing coloring and contamination problems, .

Description

Resin composition {RESIN COMPOSITION}

The present invention relates to a resin composition, an optical film comprising the same, and a polarizing plate comprising the same.

Various optical films such as a polarizing film, a polarizer protective film, a retardation film, a light guide plate and the like are used for the display device. For example, in the case of a polarizing plate, a protective film is required to protect the polarizing plate from external impact, friction and contamination, from the manufacturing process of the polarizing plate to the process of making the LCD module. In order to prevent the liquid crystal or the polarizer from deterioration due to ultraviolet rays, a technique of imparting ultraviolet ray absorption capability to such an optical film is provided. However, when an optical film is conventionally produced by adding an ultraviolet absorber, there is a problem that the absorbent decomposes at high temperature processing to lower the ultraviolet absorptivity and also tint the film to yellow. In addition, in the above case, the glass transition temperature of the resin is greatly lowered to decrease the heat resistance, or the ultraviolet ray absorbing ability may be lowered when exposed to ultraviolet rays for a long period of time, and the optical property of the optical film itself changes.

The present invention provides a resin composition which is excellent in ultraviolet ray absorption performance, has heat resistance at a high temperature and can prevent coloring and contamination problems, and an optical film containing the same.

The present application relates to a resin composition. The resin composition may be a composition for an optical film. The optical film may be used as a polarizing film, a polarizer protective film, a retardation film, a light guide plate, and the like, which are applied to a display device.

Exemplary resin compositions may include polymers comprising as polymerized units a compound of formula

[Chemical Formula 1]

Wherein R ₁ is hydrogen or an alkyl group, R ₂ is a single bond, an alkylene group, an alkylidene group or an arylene group, R ₃ is a benzotriazole group, a benzophenone group, a triazine group, a benzoate group, Group, an oxanilide group or a pyrene group.

As used herein, the term " single bond " means a single bond connecting atoms and atoms without separate atoms. For example, when R ₂ in the formula (1) is a single bond, the oxygen of formula (1) may be directly connected to R ₃ .

Conventionally, when an ultraviolet absorber is added, the additive can be decomposed at the time of high-temperature processing, and the additive may be colored in yellow. Accordingly, when the additive is used, the optical properties of the optical film itself are significantly lowered. However, the present application can provide an optical film in which the resin composition contains a polymer having a compound of the formula (1) as a polymerization unit, thereby exhibiting excellent ultraviolet ray absorbing performance, excellent heat resistance, and preventing coloring and contamination problems.

The term "alkyl group" as used herein means an alkyl group having 1 to 30 carbon atoms, 1 to 25 carbon atoms, 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms or 1 to 4 carbon atoms ≪ / RTI > The alkyl group may have a linear, branched or cyclic structure and may optionally be substituted with one or more substituents.

Unless otherwise specified, the term "alkylene group" or "alkylidene group" as used herein may mean an alkylene group or an alkylidene group having 1 to 12 carbon atoms, 4 to 10 carbon atoms, or 6 to 9 carbon atoms . The alkylene group or alkylidene group may be linear, branched or cyclic. Also, the alkylene group or alkylidene group may be optionally substituted with one or more substituents.

The term " arylene group " as used herein, unless otherwise specified, includes monovalent or divalent moieties derived from a compound containing benzene or a compound containing a structure in which two or more benzenes are condensed or bonded, It can mean. The aryl group may be, for example, an aryl group having 6 to 22 carbon atoms, preferably 6 to 16 carbon atoms, and more preferably 6 to 13 carbon atoms, and examples thereof include a phenyl group, a phenylethyl group, a phenylpropyl group, , A tolyl group, a xylyl group or a naphthyl group.

In embodiments of the present application, the polymer may comprise comonomers as polymerized units. The comonomer may be, for example, a (meth) acrylate ester-based monomer, an amide group-containing monomer, an unsaturated nitrile monomer, a vinyl ester monomer, a vinyl ether monomer, a halogen-containing?,? -Unsaturated monomer or an?,? But are not limited to, monomers.

In one example of the present application, the polymer of the pressure-sensitive adhesive layer may contain a (meth) acrylic acid ester-based monomer as a polymerization unit. In one example, the polymer may comprise alkyl (meth) acrylates having linear, branched or cyclic alkyl groups as polymerized units. The alkyl (meth) acrylate may be an alkyl (meth) acrylate having an alkyl group having 1 to 14 carbon atoms in consideration of physical properties such as cohesion, glass transition temperature and tackiness. Examples of such alkyl (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (Meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, Acrylate, lauryl (meth) acrylate, and tetradecyl (meth) acrylate. One or more of these may be contained in a polymerized form in the resin.

In addition, the polymer may further comprise, as polymerized units, a compound comprising at least one reactive functional group. That is, when a compound containing a reactive functional group is contained as polymerized units, the compound may provide a reactive functional group capable of reacting with the polyfunctional crosslinking agent in the polymer. Examples of such a compound containing a reactive functional group include a hydroxy group-containing compound or a carboxyl group-containing compound. In the production of polymers, various copolymerizable monomers capable of providing such reactive functional groups to acrylic polymers are known. In the present invention, such monomers may be used without limitation. Examples of the compound having a hydroxy group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl Hydroxypropyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 2-hydroxyethyleneglycol (meth) acrylate or 2-hydroxypropyleneglycol (Meth) acryloyloxybutyric acid, acrylic acid dimer, itaconic acid, itaconic acid, and the like may be used alone or in combination of two or more selected from the group consisting of (meth) acrylic acid, 2- (meth) acryloyloxyacetic acid, 3- , Maleic acid, maleic anhydride, and the like can be used, but the present invention is not limited thereto. On the other hand, the compound containing a reactive functional group is, for example, 0.1 to 30 parts by weight, 3 to 30 parts by weight, 5 to 30 parts by weight, 8 to 30 parts by weight, 10 to 30 parts by weight 13 to 30 parts by weight, By weight or 15 to 30 parts by weight.

In the present application, the polymer may comprise 30 to 95 parts by weight of the comonomer and 1 to 20 parts by weight of the compound of the formula (1) as polymerized units. In the present invention, the unit " parts by weight " means the weight ratio. By adjusting the weight ratio between the monomers as described above, properties such as ultraviolet barrier property, durability and optical properties can be maintained excellent.

Such polymers in the present application may be prepared by conventional polymerization methods in this field, such as solution polymerization, photo polymerization, bulk polymerization, suspension polymerization or emulsion polymerization Emulsion polymerization, and the like, preferably by a solution polymerization method. In the above, the polymer may be present in the pressure-sensitive adhesive layer in a crosslinked state or in a non-crosslinked state.

In the present application, the polymer may be crosslinked by a multifunctional crosslinking agent. Such a crosslinking agent improves the cohesion of the resin cured product (pressure-sensitive adhesive) through the reaction with the polar functional group contained in the acrylic polymer, imparts a crosslinking structure, and controls the adhesive property.

In one example, the polymer in the pressure-sensitive adhesive layer may be crosslinked by at least one polyfunctional crosslinking agent selected from the group consisting of an isocyanate crosslinking agent, an epoxy crosslinking agent, an aziridine crosslinking agent and a metal chelate crosslinking agent, In consideration of the kind, one or more kinds of crosslinking agents can be appropriately selected.

Examples of the isocyanate crosslinking agent include tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, tetramethylxylene diisocyanate, and naphthalene diisocyanate, Addition reaction product of an isocyanate compound and a polyol may be used. As the polyol, trimethylolpropane or the like may be used. Examples of the epoxy crosslinking agent include ethylene glycol diglycidyl ether, triglycidyl ether, trimethylol propane triglycidyl ether, N, N, N ', N'-tetraglycidylethylenediamine or glycerin diglycidyl Ether and the like can be used. As the aziridine crosslinking agent, N, N'-toluene-2,4-bis (1-aziridine carboxamide), N, N'-diphenylmethane- , 4'-bis (1-aziridine carboxamide), triethylene melamine, bisisopropanoyl-1- (2-methylaziridine) or tri-1-aziridinylphosphine oxide But is not limited thereto. Examples of the metal chelate crosslinking agent include compounds in which a polyvalent metal such as aluminum, iron, zinc, tin, titanium, antimony, magnesium and / or vanadium is coordinated to acetylacetone or ethyl acetate or the like. But is not limited to. The multifunctional crosslinking agent may be contained in an amount of 0.01 to 10 parts by weight, 0.1 to 9 parts by weight, or 0.2 to 8 parts by weight based on 100 parts by weight of the polymer.

In one example, the polymer may have a weight average molecular weight in the range of from 50,000 to 500,000, from 100,000 to 450,000, or from 150,000 to 400,000. The present application can effectively control the stretching and extruding process of the optical film using the resin composition in this range.

In one example, the compound of Formula 1 may be included in an amount of 1 to 20 parts by weight, 3 to 18 parts by weight, or 4 to 16 parts by weight based on 100 parts by weight of the polymer. Within the above-mentioned range, the present application can provide an optical film excellent in ultraviolet ray absorption performance, excellent in heat resistance, and prevented from coloring and contamination problems.

Further, in the embodiments of the present application, the resin composition may have a glass transition temperature in the range of 0 占 폚 to 150 占 폚 or 50 占 폚 to 100 占 폚. The glass transition temperature may be measured after the resin composition is cured. By controlling the glass transition temperature of the composition within the above range, the present application can achieve the desired properties as an ultraviolet shielding film in the present application.

In the resin composition of the present application, in addition to the above-mentioned components, a silane coupling agent; Tackifiers; Epoxy resin; Ultraviolet stabilizer; Antioxidants; Coloring agent; Reinforcing agents; Filler; Defoamer; A surfactant, a plasticizer, and the like may be further included.

The present application also relates to optical films. The optical film may be an ultraviolet shielding film.

In the embodiment of the present application, the optical film may include the above-mentioned resin composition. The optical film can be produced using a resin pellet containing the above-mentioned resin composition. In the case of the resin pellet, the average particle diameter of the resin particles may be in the range of 10 to 500 mu m, 50 to 450 mu m, or 100 to 400 mu m. In the present application, extrusion kneadability can be excellently realized by controlling the average particle diameter of the resin particles within the above range. The difference between the maximum particle diameter and the minimum particle diameter of the resin particles may be 5 mm or less, or 3 mm or less. By controlling the difference between the maximum particle diameter and the minimum particle diameter of the resin particles as described above, it is possible to prevent the pressure instability due to the uneven discharge amount during the melt processing process and to prevent the film thickness and appearance defect.

Further, in the embodiments of the present application, the optical film of the present application can be produced through a stretching process. The stretching process may be performed in a longitudinal direction and in a transverse direction, respectively, or may be performed together. When the longitudinal direction stretching and the transverse direction stretching are performed together, either one of them may be stretched in the other direction, or both directions may be stretched at the same time. The stretching may be performed in one step or may be performed in multiple steps. In the case of longitudinal stretching, stretching by the speed difference between rolls can be performed, and in the case of transverse stretching, tenter can be used. The railing angle of the tenter is usually set to 10 degrees or less so that the bowing phenomenon occurring in the transverse direction drawing can be suppressed and the angle of the optical axis can be regularly controlled. Even when the transverse stretching is performed in multiple stages, the effect of suppressing the bowing can be obtained.

Further, in the embodiments of the present application, the optical film may have a low haze value. Specifically, the optical film may have a haze value of 3% or less or 2% or less, and the lower limit is not particularly limited, but may be 0% or 0.1%. In the present specification, haze may be measured according to JIS K7105 standard test method using a haze meter.

In addition, the optical film may have high light transmittance in the visible light region. An exemplary optical film may have a light transmittance of at least 85% or at least 90% at a wavelength of 550 nm. The light transmittance may be measured by converting the thickness of the optical film into 60 mu m. In the present specification, the light transmittance can be measured using a UV-Vis spectrometer.

Further, in the embodiments of the present application, the optical film may have a light transmittance of 10% or less or 8% or less at a wavelength of 380 nm. Also, the light transmittance at a wavelength of 290 nm may be 5% or less or 3% or less. By controlling the light transmittance of the optical film in the above-described range at a wavelength of 380 nm or 290 nm, the present invention can prevent ultraviolet ray blocking effect and change in color tone.

The present application also relates to a polarizing plate. Exemplary polarizing plates may comprise the optical film described above. In one example, the polarizing plate may include at least one polarizer and the optical film formed on one or both sides of the polarizer. In one example, the optical film may be directly attached to the polarizer and further include a protective film present on the optical film. As the material constituting the protective film, materials known in the art can be used, for example, TAC, COP or acrylic resin can be exemplified.

The polarizing plate may further include a low reflective layer or an anti-glare layer on the protective film. The material constituting the low reflection layer or the anti-glare layer may be any material known in the art and is not particularly limited.

The present invention provides a resin composition which is excellent in ultraviolet ray absorption performance, has heat resistance at a high temperature and can prevent coloring and contamination problems, and an optical film containing the same.

Hereinafter, the present invention will be described in more detail with reference to the following examples and comparative examples, but the scope of the present invention is not limited by the following examples.

Example  One

(RUVA-93, Otsuka Chemical Co., Ltd.) of 50 parts by weight and a pyrene-based compound (wherein R ₁ is hydrogen and R ₂ is an arylene group And R < ₃ > is pyrene). Subsequently, 8 parts by weight of a 5 wt% polyvinyl alcohol solution (POVAL PVA217) and 0.1 part by weight of boric acid were mixed with 2000 parts by weight of distilled water and mixed with 5 parts by weight of 2,2'-azobisisobutyronitrile. While stirring at 2000 rpm, To prepare a suspension.

Next, the suspension was heated to 70 DEG C and polymerization was carried out for 5 hours. Thereafter, the suspension was cooled to 30 DEG C, washed with distilled water, dehydrated and dried to obtain a resin composition.

The resin composition was supplied to a biaxial compressor (Leistritz, L / D = 36) and melted at 260 DEG C to obtain pellets.

The pellets thus obtained were hot-air dried at 80 DEG C for 6 hours, melted at 265 DEG C by an extruder, passed through a coat hanger type T-die, passed through a casting roll and a drying roll , And an optical film was prepared by stretching 100% longitudinally and transversely at a rate of 200 mm / min at 135 ° C using an experimental film stretching machine, respectively.

Example  2

Except that methyl methacrylate (MMA), a benzotriazole-based ultraviolet ray absorbing agent (RUVA-93, Otsuka), and a pyrene-based ultraviolet absorbing agent were added at a weight ratio of 950: 40: 10, respectively. Optical films were prepared in the same manner.

Example  3

Except that methyl methacrylate (MMA), a benzotriazole-based ultraviolet ray absorbing agent (RUVA-93, Otsuka), and a pyrene-based ultraviolet absorbing agent were added at a weight ratio of 850: 100: 50, respectively. Optical films were prepared in the same manner.

Comparative Example  One

An optical film was prepared using IH830B (LGMMA), polymethylmethacrylate (PMMA).

Comparative Example  One

An optical film was prepared in the same manner as in Comparative Example 1, except that 90 parts by weight of IH830B as a PMMA was added with 10 parts by weight of a benzotriazole-based additive Tinuvin (BASF).

Each physical property in this example was evaluated in the following manner.

1. Film appearance

After observing the optical films prepared in Examples and Comparative Examples with naked eyes, the film having a problem in the appearance of the film was further observed with an optical microscope (LV100P, Nikon) to determine the shape of bubbles or precipitated additives The appearance was measured by the method of discrimination.

2. Light transmittance  Measure

Optical films prepared in Examples and Comparative Examples were measured for light transmittance at 550 nm, 380 nm, and 290 nm using a UV-Vis Spectrometer (SHIMADZU UV-3600) in terms of film thickness of 60 μm.

division Example Comparative Example One 2 3 One 2 Film appearance Good Good Good Good Precipitation occurrence Light transmittance (550 nm) 93 93 93 93 87 Light transmittance (380 nm) 3.1 5.5 1.0 93 5.7 Light transmittance (290 nm) 0.0 0.1 0.0 88 0.9

Claims (12)

1. A resin composition comprising a polymer comprising, as polymerized units, a compound represented by the following formula
[Chemical Formula 1]

Wherein R ₁ is hydrogen or an alkyl group, R ₂ is a single bond, an alkylene group, an alkylidene group or an arylene group, R ₃ is a benzotriazole group, a benzophenone group, a triazine group, a benzoate group, Group, an oxanilide group or a pyrene group. The resin composition according to claim 1, wherein the polymer comprises a comonomer as a polymerization unit. 3. The composition of claim 2, wherein the comonomer is selected from the group consisting of a (meth) acrylic ester monomer, an amide group-containing monomer, an unsaturated nitrile monomer, a vinyl ester monomer, a vinyl ether monomer, A resin composition comprising an unsaturated aromatic monomer. The resin composition according to claim 1, wherein the polymer has a weight average molecular weight in the range of 50,000 to 500,000. The resin composition according to claim 1, wherein the compound of formula (1) is contained in an amount of 1 part by weight to 20 parts by weight based on 100 parts by weight of the polymer. The resin composition according to claim 1, wherein the glass transition temperature is in a range of 0 占 폚 to 150 占 폚. An optical film comprising the resin composition of claim 1. The optical film according to claim 7, having a haze value of 3% or less. The optical film according to claim 7, wherein the light transmittance at a wavelength of 550 nm is 85% or more. The optical film according to claim 7, wherein the light transmittance at a wavelength of 380 nm is 10% or less. The optical film according to claim 7, wherein the light transmittance at a wavelength of 290 nm is 5% or less. A polarizer comprising a polarizer and the optical film of claim 7 formed on one or both sides of the polarizer.