WO2022149752A1

WO2022149752A1 - Optical laminate, and optical display device including same

Info

Publication number: WO2022149752A1
Application number: PCT/KR2021/019185
Authority: WO
Inventors: 최종규; 신광호; 박진영; 이길재
Original assignee: 삼성에스디아이 주식회사
Priority date: 2021-01-11
Filing date: 2021-12-16
Publication date: 2022-07-14
Also published as: KR20220101517A

Abstract

Provided are an optical laminate and an optical display device including same, the optical laminate comprising: a polarizer; and a laminate which is laminated on the lower surface of the polarizer, wherein the polarizer has a thickness of about 10 µm or less, the laminate includes at least one among a bonding layer, a retardation layer, and an adhesive layer, and the laminate includes a thiosulfate anion (S2O3 2-)-containing salt or a hydrate thereof.

Description

Optical laminate and optical display including same

The present invention relates to an optical laminate and an optical display device including the same. More particularly, the present invention relates to an optical laminate having a thin polarizer having a thickness of 10 μm or less, having a high degree of polarization and minimizing iodine elution after long-term storage at high temperature and high humidity, and an optical display device including the same.

As a method of driving the liquid crystal panel, there is a capacitive method. The capacitive method is a method of forming a transparent electrode on one or both surfaces of a substrate that drives the touch screen sensor and recognizing and detecting a current applied from the outside. However, the capacitive method may cause serious problems when static electricity is generated from the outside. In order to solve this problem, a method of forming an antistatic layer on the surface of the panel is used.

On the other hand, as the thickness is reduced in recent years, the demand for a polarizing plate having a high degree of polarization is increasing. In particular, in order to realize a high degree of polarization for a polarizer having a thickness of 10 μm or less, it is necessary to increase the concentration of a dichroic material, for example, iodine when manufacturing the polarizer. A polarizer having a thickness of 10 μm or less and a high degree of polarization has a thickness of 10 μm or less, a low degree of polarization, or a polarizer having a thickness of greater than 10 μm and inevitably contains a relatively high concentration of iodine compared to a polarizer having a high degree of polarization.

However, among iodine impregnated in the polarizer with a high content, iodine I ₂ , which has a weak binding force to a polyvinyl alcohol-based film and a high degree of freedom, is eluted from the polarizer when left for a long time under high temperature and high humidity, and the eluted iodine resists by contaminating the antistatic layer The inventors have confirmed that it can increase the value or corrode the transparent electrode.

Therefore, there is a need to provide an optical laminate that includes a thin polarizer having a thickness of 10 μm or less, has a high degree of polarization, and minimizes iodine elution after being left for a long time at high temperature and high humidity.

Background art of the present invention is disclosed in Japanese Patent Application Laid-Open No. 2017-210049 and the like.

It is an object of the present invention to provide an optical laminate that includes a polarizer having a thin thickness and a high degree of polarization and exhibits remarkably low iodine elution after being left for a long time at high temperature and high humidity.

Another object of the present invention is to provide an optical laminate that includes a polarizer that provides a thin thickness and a high degree of polarization and blocks iodine contamination in an antistatic layer and/or a touch panel when left for a long time at high temperature and high humidity.

One aspect of the present invention is an optical laminate.

1. The optical laminate includes a polarizer and a laminate laminated on the lower surface of the polarizer, the polarizer has a thickness of about 10 μm or less, and the laminate includes at least one of an adhesive layer, a retardation layer, and an adhesive layer and a thiosulfate anion (S ₂ O ₃ ^2- ) containing salt or a hydrate thereof.

In 2.1, the optical laminate may have a polarization degree of about 99% or more.

In 3.1-2, the thiosulfate anion-containing salt may include sodium thiosulfate (Na ₂ S ₂ O ₃ ).

In 4.1-3, the thiosulfate anion (S ₂ O ₃ ^2- ) containing salt or a hydrate thereof may be included in an amount of about 0.1 wt% to about 5.0 wt% in the laminate.

In 5.1-4, the laminate may have a thickness of about 60 μm or less.

In 6.1-5, the laminate includes the adhesive layer, the retardation layer and the adhesive layer sequentially stacked from the polarizer, and the adhesive layer is the thiosulfate anion (S ₂ O ₃ ^2- ) containing salt or a hydrate thereof. may include

In 7.6, the adhesive layer may be formed of a photocurable adhesive.

In 8.6-7, the retardation layer may include a liquid crystal coating layer or a liquid crystal film.

In 9.1-8, the laminate may further include an ester-based plasticizer.

In 10.9, the ester plasticizer may be included in an amount of about 0.1 wt% to about 15.0 wt% of the laminate.

In 11.6-10, a protective layer may be further laminated between the polarizer and the adhesive layer.

In 12.11, the protective layer may include a film made of a cellulose ester-based resin or a polyester-based resin.

Another aspect of the present invention is an optical display device.

An optical display device includes the optical laminate of the present invention.

The present invention provides an optical laminate that includes a polarizer having a thin thickness and a high degree of polarization and exhibits remarkably low iodine elution after being left for a long time at high temperature and high humidity.

The present invention provides an optical laminate that includes a polarizer having a thin thickness and a high degree of polarization and blocks iodine contamination of a touch panel when left for a long time at high temperature and high humidity.

1 is a cross-sectional view of an optical laminate according to an embodiment of the present invention.

2 is a cross-sectional view of an optical laminate according to another embodiment of the present invention.

Hereinafter, embodiments of the present application will be described in more detail with reference to the accompanying drawings. However, the technology disclosed in the present application is not limited to the embodiments described herein and may be embodied in other forms. However, the embodiments introduced herein are provided so that the disclosed content may be thorough and complete, and the spirit of the present application may be sufficiently conveyed to those skilled in the art.

In order to clearly express the components of each device in the drawings, the size of the width or thickness of the component is slightly enlarged, and the size of the width or thickness of the component in the present invention is limited to the scope of the present invention. it's not going to be In a plurality of drawings, the same reference numerals refer to elements that are substantially the same as each other.

In this specification, "upper" and "lower" are defined based on the drawings, and depending on the perspective of the city, "upper" may be changed to "lower" and "lower" to "upper", and "on" or What is referred to as “on” may include cases in which other structures are interposed in the middle as well as immediately above. On the other hand, reference to "directly on" or "immediately on" or "directly formed" refers to no intervening other structures such as intermediates.

When describing a numerical range in the present specification, "X to Y" means X or more and Y or less (X≤ and ≤Y).

In the present specification, "polarization" may be a value measured at a wavelength of 300 nm to 800 nm, for example, 550 nm.

As used herein, “(meth)acryl” means acrylic and/or methacrylic.

The optical laminate includes a polarizer and a laminate laminated on the lower surface of the polarizer, the polarizer has a thickness of about 10 μm or less, and the laminate includes at least one of an adhesive layer, a retardation layer, and an adhesive layer, The laminate includes a thiosulfate anion (S ₂ O ₃ ^2- ) containing salt or a hydrate thereof.

The optical laminate includes a polarizer having a thickness of about 10 μm or less and has a polarization degree of about 99% or more, thereby providing a thickness reduction effect and a high polarization degree effect. In general, when the optical laminate implementing the above-described thickness and polarization degree is adhered to the touch panel in the optical display device, iodine (I ₂ ) is eluted after being left for a long time at high temperature and high humidity, thereby causing contamination of the touch panel by iodine. The touch panel includes a layer of indium tin oxide (ITO) patterned, and if it is contaminated with iodine, it may cause problems such as malfunction, reduced touch sensitivity, and corrosion of the touch panel. However, the inventor of the present invention includes a laminate on the lower surface of the polarizer, and the laminate contains a thiosulfate anion (S ₂ O ₃ ^2- ) containing salt or a hydrate thereof, so that iodine is eluted after being left for a long time at high temperature and high humidity It was confirmed that reliability was provided by minimizing the contamination by iodine of the touch panel due to the remarkably low iodine.

Hereinafter, an optical laminate according to an embodiment of the present invention will be described with reference to FIG. 1 .

Referring to FIG. 1 , the optical laminate includes a polarizer 10 , a laminate 20 laminated on a lower surface of the polarizer 10 , and a first protective layer 30 laminated on an upper surface of the polarizer 10 . can do.

편광자polarizer

The polarizer 10 linearly polarizes external light to transmit it, and linearly polarizes the reflected internal light to emit it, thereby providing an antireflection effect.

The polarizer 10 has a thickness of about 10 μm or less. Within the above range, it is possible to provide a thinning effect of the optical laminate. Specifically, the polarizer may have a thickness of greater than about 0 μm and less than or equal to about 10 μm. For example, a polarizer has a thickness of about 0.0001, 0.0005, 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, It can be 9 or 10 μm.

The polarizer 10 may increase the degree of polarization of the optical laminate so that the optical laminate performs an antireflection function. The degree of polarization of the optical laminate is substantially determined by the degree of polarization of the polarizer. The degree of polarization of the optical laminate may be about 99% or more, specifically, about 99.95% to about 100%. Within the above range, it is possible to provide an antireflection effect and provide an antireflection effect even after long-term use. For example, the polarization degree of the optical laminate is about 99.0, 99.1, 99.2, 99.3, 99.4, 99.5, 99.6, 99.7, 99.8, 99.9, 99.91, 99.92, 99.93, 99.94, 99.95, 99.96, 99.97, 99.98, 99.99 or 100%. can be

The polarizer 10 may include a polarizer manufactured by dyeing and stretching a dichroic material or a polarizer produced by orientation of a polyene-based structure. Among them, a polarizer manufactured by dyeing and stretching a dichroic material needs to be dyed with a relatively high content of the dichroic material in order to realize a polarization degree of about 99% or less while having a thickness of about 10 μm or less. This is because the degree of polarization comes from the dichroic material oriented by stretching.

A method of manufacturing a polarizer that has a thickness of about 10 μm or less and can realize a polarization degree of about 99% or more will first be described.

The polarizer 10 may be manufactured by treating the polyvinyl alcohol-based film in the order of a dyeing process, a stretching process, and a crosslinking process.

The polyvinyl alcohol-based film may include a conventional polyvinyl alcohol-based film known to those skilled in the art. In one embodiment, the polyvinyl alcohol-based film may include a film having only hydrophilic functional groups or containing hydrophilic functional groups and hydrophobic functional groups. The hydrophobic functional group may be present in addition to the hydroxyl group (OH group), which is a hydrophilic functional group present in the polyvinyl alcohol-based film.

The hydrophobic functional group is present in at least one of the main chain and the side chain of the polyvinyl alcohol-based resin constituting the polyvinyl alcohol-based film. The "main chain" refers to a portion forming the main skeleton of the polyvinyl alcohol-based resin, and the "side chain" refers to a skeleton connected to the main chain.

The polyvinyl alcohol-based resin into which the hydrophilic functional group and the hydrophobic functional group are introduced is one or more vinyl esters such as vinyl acetate, vinyl formate, vinyl propionate, vinyl butyrate, vinyl pivalate, and isopropenyl acetate, and a hydrophobic functional group. It can be prepared by polymerizing a monomer that provides Preferably, the vinyl ester monomer may include vinyl acetate. The monomer providing the hydrophobic functional group may include a monomer providing a hydrocarbon repeating unit including ethylene, propylene, and the like.

The dyeing process includes treating the polyvinyl alcohol-based film in a dyeing tank containing a dichroic material. In the dyeing process, the polyvinyl alcohol-based film is immersed in a dyeing tank containing a dichroic material. The dichroic substance-containing dyeing tank contains an aqueous solution containing a dichroic substance and boric acid. The dyeing tank dyes the polyvinyl alcohol-based film by including the dichroic material and the boron compound together, and even if the polyvinyl alcohol-based film is stretched under the stretching conditions described in detail below, there may be no breakage of the polyvinyl alcohol-based film.

The dichroic material may include one or more of potassium iodide, hydrogen iodide, lithium iodide, sodium iodide, zinc iodide, lithium iodide, aluminum iodide, lead iodide, and copper iodide as iodine. The dichroic material may be included in the dyeing tank preferably in an amount of about 0.5 mol/ml to about 10 mol/ml, preferably about 0.5 mol/ml to about 5 mol/ml in the dyeing solution. Within the above range, there may be an effect that uniform dyeing is possible. For example, the dichroic material may be included in the dyeing tank preferably in an amount of about 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 mol/ml in the dyeing solution. can

The boron compound may help prevent melt fracture of the polyvinyl alcohol-based film during stretching of the polyvinyl alcohol-based film. The boron compound may help prevent melting and breakage of the film even when the polyvinyl alcohol-based film is stretched at a high temperature and a high draw ratio in the stretching process performed after the dyeing process.

The boron compound may include at least one of boric acid and borax. The boron compound may be included in an amount of about 0.1 wt% to about 5 wt%, preferably about 0.3 wt% to about 3 wt%, in the dyeing bath, preferably, in an aqueous dyeing solution. Within the above range, there may be no melting and no fracture in the stretching process, and there may be an effect of achieving high reliability. For example, the boron compound is about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5 or It may be included in 5% by weight.

The temperature of the dyeing solution may be preferably from about 20 °C to about 50 °C, specifically, from about 25 °C to about 40 °C. In the dyeing process, the polyvinyl alcohol-based film may be immersed in a dyeing tank for about 30 seconds to about 120 seconds, specifically, about 40 seconds to about 80 seconds.

In the stretching process, the dyed polyvinyl alcohol-based film is stretched at a stretching ratio of about 5.7 times or more, for example, about 5.7 times to about 7 times, preferably about 5.8 times to about 7 times, at a stretching temperature of about 58°C or more, for example about 58 and stretching at about 65° C. to about 65° C. When the conventional polyvinyl alcohol-based film is stretched at the above-described stretching ratio and stretching temperature, the polyvinyl alcohol-based film may melt and/or break, and thus a polarizer cannot be manufactured.

For example, in the stretching process, the dyed polyvinyl alcohol-based film is subjected to a stretching ratio of about 5.7, 5.8, 5.9, 6, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9 or 7 times, and a stretching temperature of about 58 , 59, 60, 61, 62, 63, 64 or 65°C.

The stretching process is performed in either wet stretching or dry stretching. Preferably, the stretching process includes wet stretching in order to apply the boron compound in the stretching process. Wet stretching includes uniaxial stretching of a polyvinyl alcohol-based film in a mechanical direction in an aqueous solution containing a boron compound.

The boron compound may include at least one of boric acid and borax, preferably boric acid. The boron compound may be included in an amount of about 0.5 wt% to about 10 wt%, preferably about 1 wt% to about 5 wt%, in the stretching bath, preferably, in the stretching aqueous solution. Within the above range, there may be no melting and no fracture in the stretching process, and there may be an effect of achieving high reliability. For example, the boron compound may be about 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5 or 10% by weight.

The crosslinking process is performed in order to strengthen the adsorption of the dichroic material in the polyvinyl alcohol-based film subjected to the stretching process. The crosslinking solution used in the crosslinking process contains a boron compound. The boron compound may help improve reliability even if the polarizer is left under high temperature or thermal shock while strongly adsorbing the above-described dichroic material.

The boron compound may include at least one of boric acid and borax. The boron compound may be included in an amount of about 0.5 wt% to about 10 wt%, preferably about 1 wt% to about 5 wt%, in the crosslinking bath, preferably, in an aqueous crosslinking solution. Within the above range, there may be no melting and no fracture in the stretching process, and there may be an effect of achieving high reliability. For example, the boron compound is preferably about 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5 or 10% by weight.

Before the dyeing process treatment, the polyvinyl alcohol-based film may further include at least one of a water washing process and a swelling process.

In the water washing process, the polyvinyl alcohol-based film is washed with water, and foreign substances attached to the polyvinyl alcohol-based film are removed.

In the swelling process, dyeing and stretching of the dichroic material can be made easier by immersing the polyvinyl alcohol-based film in a swelling tank of a predetermined temperature range. The swelling process may include treating at about 15° C. to about 35° C., preferably at about 20° C. to about 30° C., for about 30 seconds to about 50 seconds. For example, the swelling process is about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34 or 35 °C. in about 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 seconds. can do.

After the crosslinking process treatment, the polyvinyl alcohol-based film may be further treated with a complementary color process. Complementary color treatment can improve the durability of the polyvinyl alcohol-based film. The complementary hue may comprise greater than about 0 wt% and up to about 10 wt% potassium iodide, preferably from about 1 wt% to about 5 wt% potassium iodide. For example, the complementary hue is about 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5 potassium iodide. , 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5 or 10% by weight.

적층체laminate

The laminate 20 includes a thiosulfate anion (S ₂ O ₃ ^2- ) containing salt or a hydrate thereof (not shown in FIG. 1 ). The thiosulfate anion-containing salt or hydrate thereof can significantly lower the elution of iodine (I ₂ ) from the optical laminate when the optical laminate is left at high temperature and high humidity for a long period of time. In particular, when the optical laminate is adhered to the touch panel in the optical display device, the optical laminate can minimize contamination of the touch panel by iodine after being left for a long time at high temperature and high humidity. Iodine (I ₂ ) is a dichroic material, ie, iodine, is essentially generated when the polyvinyl alcohol-based film is dyed. Among iodine contained in the polarizer, the degree of freedom is high and does not contribute to the expression of optical properties, that is, the degree of polarization.

For example, the optical laminate may have an iodine elution amount of about 10 mg/kg or less measured by the method described in Experimental Examples below, and the reliability of the optical laminate and the optical display device may be excellent in the above range. For example, in the optical laminate, the iodine elution amount is about 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8 , 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3 , 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8 , 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 9.0, 9.1, 9.2, 9.3 , 9.4, 9.5, 9.6, 9.7, 9.8, 9.9 or 10 mg/kg.

The thiosulfate anion-containing salt or hydrate thereof may include an alkali metal salt or alkaline earth metal salt or a hydrate thereof, containing a thiosulfate anion. Preferably, the thiosulfate anion-containing salt may include an alkali metal salt containing a thiosulfate anion, and the alkali metal salt containing a thiosulfate anion may further enhance the effects of the present invention. Specifically, sodium thiosulfate (Na ₂ S ₂ O ₃ ) or a hydrate thereof may be included.

The thiosulfate anion-containing salt or hydrate thereof may be included in an amount of about 0.1 wt% to about 5.0 wt%, specifically, about 0.5 wt% to about 3.0 wt% of the laminate. In the above range, the polarization degree and light transmittance of the optical laminate may not be affected even after long-term storage at high temperature and high humidity at the same time as lowering the elution of iodine. For example, the thiosulfate anion-containing salt or hydrate thereof is about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7 in the laminate. , 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2 , 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9 or 5.0% by weight.

The thiosulfate anion-containing salt or hydrate thereof may be included at any position in the laminate. Preferably, the thiosulfate anion-containing salt or hydrate thereof is included in a position adjacent to the polarizer in the laminate to lower the amount of iodine elution and block contamination of iodine in other parts of the laminate.

The laminate 20 may have a thickness of greater than about 0 μm and less than or equal to about 60 μm, specifically, about 5 μm to about 60 μm, and about 5 μm to about 50 μm. In the above range, when a thiosulfate anion-containing salt or a hydrate thereof is included, it helps to lower the iodine elution amount to about 10 mg/kg or less, and a thinning effect of the optical laminate can be obtained. For example, the laminate 20 has a thickness of about 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60 μm.

The laminate 20 may include a first adhesive layer 21 , a first retardation layer 22 , and an adhesive layer 23 sequentially stacked from the polarizer 10 . Preferably, when the thiosulfate anion-containing salt or hydrate thereof is a solid material, it may be included in the first adhesive layer 21 in order to suppress iodine elution amount and block iodine contamination in any layer of the laminate. Since the thiosulfate anion-containing salt or hydrate thereof is included in the first adhesive layer 21 , contamination of the first retardation layer 22 and the adhesive layer 23 by the eluted iodine can be minimized. However, the thiosulfate anion-containing salt or hydrate thereof may be included in at least one of the first adhesive layer, the first retardation layer, and the adhesive layer.

Hereinafter, a case in which a thiosulfate anion-containing salt or a hydrate thereof is included in the first adhesive layer will be described.

The first adhesive layer 21 may be laminated between the polarizer 10 and the first retardation layer 22 to adhere the polarizer and the first retardation layer to each other.

The first adhesive layer 21 may be formed of a water-based adhesive or a photo-curable adhesive. Preferably, the first adhesive layer may be formed of a photocurable adhesive. When the first adhesive layer is formed of a photocurable adhesive and the first retardation layer is a liquid crystal coating layer or a liquid crystal film, the amount of iodine elution may be further reduced.

The photocurable adhesive includes at least one of an epoxy-based compound and a (meth)acrylate-based compound; And it may include one or more of a photo-acid generator and a photosensitizer.

The epoxy-based compound may include at least one of an alicyclic epoxy-based compound, an aromatic epoxy-based compound, and an aliphatic epoxy-based compound. The detailed kind of each of the alicyclic epoxy-based compound, the aromatic epoxy-based compound, and the aliphatic epoxy-based compound may be appropriately selected as it is well known in the field of photocurable adhesives.

Preferably, the epoxy-based compound may include an alicyclic epoxy-based compound. The cycloaliphatic epoxy-based compound may provide adhesion of the adhesive layer even if it contains a thiosulfate anion-containing salt or a hydrate thereof. The alicyclic epoxy compound is 2-(3,4-epoxy)cyclohexyl-5,5-spiro-(3,4-epoxy)cyclohexane-m-dioxane, (3,4-epoxycyclohexane)methyl-3 ,4-epoxycyclohexylcarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxylate, vinylcyclohexanedioxide, bis(3,4- Epoxycyclohexylmethyl)adipate, bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate, exo-exobis(2,3-epoxycyclopentyl)ether, endo-exobis(2,3- Epoxycyclopentyl)ether, 2,2-bis[4-(2,3-epoxypropoxy)cyclohexyl]propane, 2,6-bis(2,3-epoxypropoxycyclohexyl-p-dioxane), 2 ,6-bis(2,3-epoxypropoxy)norbornene, limonene dioxide, 2,2-bis(3,4-epoxycyclohexyl)propane, dicyclopentadienedioxide, 1,2-epoxy- 6-(2,3-epoxypropoxy)hexahydro-4,7-methanoindane, p-(2,3-epoxy)cyclopentylphenyl-2,3-epoxypropyl ether, 1-(2,3- Epoxypropoxy)phenyl-5,6-epoxyhexahydro-4,7-methanoindane, o-(2,3-epoxy)cyclopentylphenyl-2,3-epoxypropylether), 1,2-bis[ 5-(1,2-epoxy)-4,7 hexahydromethanoindanoxyl]ethanecyclopentenylphenylglycidyl ether, methylenebis(3,4-epoxycyclohexane)ethyleneglycoldi(3,4-epoxy) Cyclohexylmethyl) ether, ethylenebis(3,4-epoxycyclohexanecarboxylate), etc. are mentioned. Among them, it may be preferable to use 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate from the viewpoint of reactivity.

The (meth)acrylate-based compound may include at least one of (meth)acrylate containing a hydrophilic group including at least one hydroxyl group, and (meth)acrylate without a hydrophilic group. Detailed types of hydrophilic (meth)acrylate and (meth)acrylate without a hydrophilic group may be appropriately selected as well known in the field of photocurable adhesives.

Preferably, by including a hydrophilic (meth)acrylate having one or more hydroxyl groups as a (meth)acrylate-based compound, even if a thiosulfate anion-containing salt or a hydrate thereof is included, the adhesive layer provides adhesion and provides a thiosulfate anion-containing salt or It is possible to provide an effect of inhibiting the elution of iodine by its hydrate. When the thiosulfate anion-containing salt or hydrate thereof is a solid substance, it cannot but remain in the solid state even in the adhesive layer, so the components constituting the adhesive layer are important.

In one embodiment, (meth)acrylate having one or more hydroxyl groups is 2-hydroxyethyl (meth)acrylate, 2 or 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylic and monofunctional (meth)acrylates such as 2-hydroxy-3-phenoxypropyl (meth)acrylate. Preferably, the (meth)acrylate having one or more hydroxyl groups may further improve the iodine elution inhibiting effect of the present invention or help improve adhesion by having an aromatic group.

The photoacid generator may use an onium salt containing a cation and an anion as a photocationic initiator. The photosensitizer may be one or more of phosphorus, triazine, acetophenone, benzophenone, benzoin, and oxime.

The photocurable adhesive includes about 40 parts by weight to about 90 parts by weight of the epoxy-based compound, about 10 parts by weight to about 60 parts by weight of the (meth)acrylate-based compound, and 100 parts by weight of the total of the epoxy-based compound and the (meth)acrylate-based compound It may include about 0.1 parts by weight to about 10 parts by weight of at least one of a photoacid generator and a photosensitizer. In the above range, adhesion between the polarizer and the first retardation layer may be excellent.

For example, the photocurable adhesive contains about 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89 or 90 parts by weight may be included.

For example, the photocurable adhesive contains about 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60 parts by weight.

For example, the photo-curable adhesive contains about 0.1, 0.2, 0.3, 0.4, 0.5, at least one of the photo-acid generator and the photosensitizer, based on 100 parts by weight of the total of the epoxy-based compound and the (meth)acrylate-based compound. 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 parts by weight may be included.

The first adhesive layer 21 may contain a thiosulfate anion-containing salt or a hydrate thereof in an amount of about 0.1 wt% to about 3.0 wt%. In the above range, it is possible to provide an effect of inhibiting iodine elution and adhesion. Preferably, it may contain from about 0.5% by weight to about 1.5% by weight and the iodine elution inhibitory effect can be further improved in the above range. For example, the first adhesive layer 21 may contain a thiosulfate anion-containing salt or a hydrate thereof of about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9 or 3.0 wt%.

The first adhesive layer 21 may have a thickness of greater than about 0 μm and less than or equal to about 50 μm, specifically, from about 1 μm to about 50 μm, and from about 1 μm to about 30 μm. Within the above range, the effect of reducing the thickness of the optical laminate can be obtained. For example, the first adhesive layer 21 has a thickness of about 0.01, 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 , 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 , 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 μm.

The first retardation layer 22 prevents reflection of external light by circularly polarizing linearly polarized light emitted after external light passes through the polarizer, thereby improving screen quality.

In one embodiment, the first retardation layer may have an in-plane retardation (Re) of about 100 nm to about 220 nm, specifically, about 100 nm to about 180 nm, for example, a λ/4 retardation at a wavelength of 550 nm. In the above range, it is possible to obtain an effect of improving screen quality by lowering the reflectance for external light. For example, the first retardation layer has an in-plane retardation (Re) of about 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219 or 220 nm.

In another embodiment, the first retardation layer may have an in-plane retardation (Re) of about 225 nm to about 350 nm, specifically about 225 nm to about 300 nm, for example, a λ/2 retardation at a wavelength of 550 nm. In the above range, it is possible to obtain an effect of improving screen quality by lowering the reflectance for external light. For example, the first retardation layer has an in-plane retardation (Re) of about 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, at a wavelength of 550 nm. 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259, 260, 261, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279, 280, 281, 282, 283, 284, 285, 286, 287, 288, 289, 290, 291, 292, 293, 294, 295, 296, 297, 298, 299, 300, 301, 302, 303, 304, 305, 306, 307, 308, 309, 310, 311, 312, 313, 314, 315, 316, 317, 318, 319, 320, 321, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334, 335, 336, 337, 338, 339, 340, 341, 342, 343, 344, 345, 346, 347, 348, 349 or 350 nm.

In the present specification, the 'in-plane retardation (Re)' is Re = (nx - ny) x d (nx, ny is the slow axis direction and the fast axis direction of the retardation layer, respectively, the refractive index in the direction, d is the retardation layer can be calculated as the thickness of (unit: nm)).

The first retardation layer 22 may have a thickness of about 0.1 μm to about 30 μm, for example, about 1 μm to about 10 μm. Within the above range, the optical laminate may be thinned and a target retardation may be realized. For example, the first retardation layer 22 has a thickness of about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or 30 μm.

The first retardation layer 22 may be a film or a coating layer. For the thinning effect of the optical laminate, the first retardation layer 22 may be a coating layer.

The first retardation layer in the form of a film may be prepared from a resin commonly known to those skilled in the art. For example, the first retardation layer is a cellulose ester-based resin containing triacetyl cellulose (TAC), etc., a cyclic polyolefin (COP)-based resin containing amorphous cyclic polyolefin, etc., a polycarbonate-based resin, polyethylene terephthalate (PET) ) and the like, including polyester-based resins, polyethersulfone-based resins, polysulfone-based resins, polyamide-based resins, polyimide-based resins, acyclic-polyolefin-based resins, polyacrylics including polymethyl methacrylate resins It may include at least one of a rate-based resin, a polyvinyl alcohol-based resin, a polyvinyl chloride-based resin, and a polyvinylidene chloride-based resin. Alternatively, the first retardation layer may be a liquid crystal film formed of a liquid crystal composition.

The first retardation layer in the form of a coating layer may include a coating layer formed of a liquid crystal composition or a coating layer formed of a heat-curable or active energy ray-curable composition with non-liquid crystallinity.

Preferably, the first retardation layer is a coating layer or liquid crystal film formed of a liquid crystal composition, thereby obtaining the effect of reducing the thickness of the polarizing plate, ease of manufacture, and further suppressing the elution of iodine.

In one embodiment, the first retardation layer is formed by coating and curing a composition containing a liquid crystal compound, and the liquid crystal compound is aligned to implement the above-described in-plane retardation. The liquid crystal compound may be a polymer, oligomer, or monomer comprising a unit composed of an aromatic ring capable of imparting liquid crystallinity and a polymerizable functional group. The polymerizable functional group may be a (meth)acryloyl group, an epoxy group, or a vinyl ether group, and may be cured by heat or light to increase the strength of the first retardation layer. The composition may further include additives such as a leveling agent, a polymerization initiator, an orientation aid, a heat stabilizer, a lubricant, a plasticizer, an antistatic agent, and the like, and these detailed types refer to those known to those skilled in the art.

1 illustrates a case in which the first retardation layer is a single-layer film or coating layer. However, the first retardation layer may be a laminate in which two or more films or coating layers are laminated. This is described in more detail below.

The adhesive layer 23 can adhere the laminate to an adherend, for example, a display panel, a touch panel, or the like.

The adhesive layer 23 may have a thickness of greater than about 0 μm and less than or equal to about 50 μm, specifically, about 1 μm to about 50 μm. Within the above range, it can be used in an optical laminate. For example, the adhesive layer 23 has a thickness of about 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50 μm.

The adhesive layer 23 may be formed of a composition for an adhesive layer including an adhesive resin such as (meth)acrylic, epoxy, silicone, or urethane. Preferably, the pressure-sensitive adhesive layer is formed of a (meth)acrylic pressure-sensitive adhesive, thereby helping to reduce the amount of iodine elution.

The laminate 20 may further include an ester-based plasticizer in addition to the thiosulfate anion (S ₂ O ₃ ^2- )-containing salt or hydrate thereof.

The ester plasticizer can further increase the reliability of the optical laminate by lowering the elution amount of iodine. Therefore, the ester plasticizer lowers the amount of iodine elution with the same content, and the amount of the thiosulfate anion (S ₂ O ₃ ^2- )-containing salt or hydrate thereof can be reduced.

The ester plasticizer may be included in an amount of about 0.1 wt% to about 15.0 wt%, specifically about 3.0 wt% to about 10.0 wt% of the laminate. In the above range, it is possible to obtain an effect of reducing the amount of iodine elution and improving the durability of high temperature and high humidity. For example, the ester plasticizer is about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15% by weight.

The ester plasticizer may be included in the same position or at a different position in the laminate compared to the thiosulfate anion (S ₂ O ₃ ^2- ) containing salt or hydrate thereof, but by being included in the same position, the effect of reducing the amount of iodine elution can be increased. The ester-based plasticizer may be included in one or more of the first adhesive layer, the first retardation layer, and the adhesive layer, and preferably included in the first adhesive layer.

The ester plasticizer is an ester of a monobasic acid or polybasic acid having 6 to 18 carbon atoms and a branched alcohol having 3 to 18 carbon atoms, an ester of an unsaturated fatty acid or branched acid having 14 to 18 carbon atoms and a tetravalent alcohol or less, and an alcohol having tetravalent or less carbon atoms. and esters of 6 to 10 monobasic acids or polybasic acids and polyalkylene glycol.

The ester plasticizer may have an ester group represented by the following Chemical Formula 1:

[Formula 1]

*-OC(=O)-X-CH(CH ₃ ) ₂

(In Formula 1,

* is the linking site of the element, X is a single bond or a divalent organic group).

In one embodiment, X is a straight alkylene group having 6 to 18 carbon atoms.

For example, ester plasticizers include trimethyl fentanyl diisobutyrate, isopropyl myristate, isopropyl palmitate, isotridecyl isononanoate, 1,2-cyclohexane dicarboxylic acid diisononyl ester, isostearyl palmi tate, isostearyl laurate, diisostearyl adipate, and diisocetyl sebacate, but is not limited thereto.

The ester plasticizer may be included in an amount of about 0.1 wt% to about 15.0 wt%, specifically about 3.0 wt% to about 10.0 wt% of the adhesive layer. In the above range, it is possible to obtain an effect of reducing the amount of iodine elution and improving the durability of high temperature and high humidity. For example, the ester plasticizer is about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15% by weight.

제1보호층first protective layer

The first protective layer 30 may be laminated on the upper surface of the polarizer to protect the polarizer, increase mechanical strength of the optical laminate, or provide an additional function to the optical laminate.

The first protective layer 30 may include an optically transparent protective film or protective coating layer.

The protective film may include a film formed by a process of melting and extruding an optically transparent resin. If necessary, the process may further include a stretching process. The resin includes a cellulose ester-based resin including triacetyl cellulose, a cyclic polyolefin-based resin including an amorphous cyclic polyolefin (cyclic olefin polymer, COP), a polycarbonate-based resin, polyethylene terephthalate (PET), etc. Polyacrylate-based resins including polyester-based resins, polyethersulfone-based resins, polysulfone-based resins, polyamide-based resins, polyimide-based resins, acyclic-polyolefin-based resins, polymethylmethacrylate resins, and the like; It may include at least one of a polyvinyl alcohol-based resin, a polyvinyl chloride-based resin, and a polyvinylidene chloride-based resin.

The protective coating layer may include a coating layer formed of an active energy ray-curable or heat-curable composition. For example, the protective coating layer may include at least one of a (meth)acrylate-based compound and an epoxy-based compound, and at least one of a photoacid generator and a photosensitizer.

The thickness of the first protective layer 30 may be about 5 μm to about 200 μm, specifically, about 20 μm to about 40 μm. Within the above range, it can be used for a polarizing plate. For example, the first protective layer 30 has a thickness of about 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195 or 200 μm .

The first protective layer 30 may be laminated on the polarizer by an adhesive layer. A functional coating layer, for example, a hard coating layer, an anti-fingerprint layer, an antireflection layer, a low reflection layer, and the like may be further formed on the upper surface of the first protective layer 30 .

The laminate 20 may further include at least one of a second retardation layer and a second adhesive layer between the first adhesive layer 21 and the first retardation layer 22 . In this case, the thiosulfate anion-containing salt or hydrate thereof may be included in one or more of the first adhesive layer 21 , the first retardation layer 22 , the second retardation layer, the second adhesive layer, and the adhesive layer 23 .

In one embodiment, the laminate may have a structure in which a first adhesive layer, a first retardation layer, a second adhesive layer, a second retardation layer, and an adhesive layer are stacked in this order. In another embodiment, the laminate may have a structure in which a first adhesive layer, a first retardation layer, a second retardation layer, and an adhesive layer are stacked in this order.

The second retardation layer may prevent reflection of external light by circularly polarizing linearly polarized light emitted after external light passes through the polarizer to improve screen quality.

In one embodiment, the second retardation layer may have an in-plane retardation (Re) of about 100 nm to about 220 nm, specifically, about 100 nm to about 180 nm, for example, a λ/4 retardation at a wavelength of 550 nm. In the above range, it is possible to obtain an effect of improving screen quality by lowering the reflectance for external light. For example, the second retardation layer has an in-plane retardation (Re) of about 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, at a wavelength of 550 nm. 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219 or 220 nm.

In another embodiment, the second retardation layer may have an in-plane retardation (Re) of 225 nm to 350 nm, specifically 225 nm to 300 nm, for example, a λ/2 retardation at a wavelength of 550 nm. In the above range, it is possible to obtain an effect of improving screen quality by lowering the reflectance for external light. For example, the second retardation layer has an in-plane retardation (Re) of about 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240 at a wavelength of 550 nm. 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259, 260, 261, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279, 280, 281, 282, 283, 284, 285, 286, 287, 288, 289, 290, 291, 292, 293, 294, 295, 296, 297, 298, 299, 300, 301, 302, 303, 304, 305, 306, 307, 308, 309, 310, 311, 312, 313, 314, 315, 316, 317, 318, 319, 320, 321, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334, 335, 336, 337, 338, 339, 340, 341, 342, 343, 344, 345, 346, 347, 348, 349 or 350 nm.

The second retardation layer may have the same or different thickness than the first retardation layer, and may have a thickness of about 0.1 μm to about 30 μm, for example, about 1 μm to about 10 μm. Within the above range, the optical laminate may be thinned and a target retardation may be realized. For example, the second retardation layer has a thickness of about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or 30 μm.

The second retardation layer may be a film or a coating layer. For the thinning effect of the optical laminate, the second retardation layer may be a coating layer.

The second retardation layer in the form of a film may include at least one of the above-described resins in the first retardation layer. The first retardation layer in the form of a coating layer may include a coating layer formed of a liquid crystal composition or a coating layer formed of a non-liquid crystal thermosetting or active energy ray-curable composition as described above in the first retardation layer.

The second adhesive layer may adhere the first retardation layer and the second retardation layer to each other.

The second adhesive layer may be formed of a water-based adhesive or a photocurable adhesive. Preferably, the second adhesive layer may be formed of a photocurable adhesive. When the second adhesive layer is formed of a photocurable adhesive and the second retardation layer is a liquid crystal coating layer or a liquid crystal film, the amount of iodine elution may be further reduced.

The photocurable adhesive includes at least one of an epoxy-based compound and a (meth)acrylate-based compound; And it may include one or more of a photo-acid generator and a photosensitizer. An epoxy-based compound, a (meth)acrylate-based compound, a photoacid generator, and a photosensitizer may be used by selecting one or more of the types described above.

The second adhesive layer may have the same or different thickness than the first adhesive layer, and may have a thickness greater than about 0 μm and less than or equal to about 50 μm, specifically, from about 1 μm to about 50 μm, and from about 1 μm to about 30 μm. Within the above range, the effect of reducing the thickness of the optical laminate can be obtained. For example, the second adhesive layer has a thickness of about 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9 , 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34 , 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 μm.

Referring to FIG. 2, an optical laminate according to another embodiment of the present invention will be described.

Referring to FIG. 2 , the optical laminate includes a polarizer 10 , a laminate 20 laminated on a lower surface of the polarizer 10 , and a first protective layer 30 laminated on an upper surface of the polarizer 10 . and a second protective layer 40 between the polarizer 10 and the laminate 20 may be further included.

The optical laminate shown in FIG. 2 is substantially the same as the optical laminate of FIG. 1 except that a second protective layer 40 is further included between the polarizer 10 and the laminate 20 . Accordingly, the contents described in relation to the optical laminate of FIG. 1 , such as the polarizer, the laminate, and the first protective layer, are substantially identically applied to FIG. 2 . Accordingly, only the second protective layer 40 will be described below.

The optical laminate of FIG. 2 further including the second protective layer 40 may significantly reduce the amount of iodine elution compared to the optical laminate of FIG. 1 .

The second protective layer 40 may be laminated on the lower surface of the polarizer 10 to protect the polarizer, increase mechanical strength of the optical laminate, or provide an additional function to the optical laminate.

The second protective layer 40 may include an optically transparent protective film or protective coating layer.

The protective film may include a film formed by a process of melting and extruding an optically transparent resin. If necessary, the process may further include a stretching process. The resin includes a cellulose ester-based resin including triacetyl cellulose, a cyclic polyolefin-based resin including an amorphous cyclic polyolefin (cyclic olefin polymer, COP), a polycarbonate-based resin, polyethylene terephthalate (PET), etc. Polyacrylate-based resins including polyester-based resins, polyethersulfone-based resins, polysulfone-based resins, polyamide-based resins, polyimide-based resins, acyclic-polyolefin-based resins, polymethylmethacrylate resins, and the like; It may include at least one of a polyvinyl alcohol-based resin, a polyvinyl chloride-based resin, and a polyvinylidene chloride-based resin. Preferably, the effect of the present invention can be further enhanced by including a cellulose ester-based resin including triacetyl cellulose or a polyester-based resin including polyethylene terephthalate, more preferably a cellulose ester-based resin.

The thickness of the second protective layer 40 is greater than the thickness of the polarizer 10 , and may be, for example, greater than about 10 μm and less than or equal to about 200 μm, specifically, from about 20 μm to about 40 μm. In the above range, it can be used in a polarizing plate and the effect of inhibiting iodine elution can be further improved. For example, the thickness of the second protective layer 40 is about 10.01, 10.05, 10.1, 10.5, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195 or 200 μm.

The second protective layer 40 may be laminated on the polarizer by an adhesive layer. The adhesive layer may be formed of the above-described photocurable adhesive or water-based adhesive, and preferably may be formed of a photocurable adhesive. The photocurable adhesive may include at least one of the above-mentioned epoxy-based compounds and (meth)acrylate-based compounds; And it may include one or more of a photo-acid generator and a photosensitizer. In this case, the photocurable adhesive may or may not include a thiosulfate-containing salt or a hydrate thereof.

2 illustrates a case in which a thiosulfate-containing salt or a hydrate thereof is included in the first adhesive layer of the laminate 20 . However, the thiosulfate-containing salt or hydrate thereof may be included in at least one of the above-mentioned adhesive layer, second protective layer, and laminate.

Hereinafter, an optical display device according to an embodiment of the present invention will be described.

The optical display device of the present invention includes the optical laminate of the present invention. The optical display device may include at least one of a liquid crystal display device and a light emitting display device. A light emitting display device is a light emitting device, and includes an organic or organic-inorganic light emitting device, and includes a light emitting material such as a light emitting diode (LED), an organic light emitting diode (OLED), a quantum dot light emitting diode (QLED), and a phosphor. It may mean a small In one embodiment, the optical laminate may be laminated on one surface of the touch panel.

Hereinafter, the configuration and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, these are presented as preferred examples of the present invention and cannot be construed as limiting the present invention in any sense.

실시예 1Example 1

(1)편광자의 제조(1) Preparation of polarizer

A polyvinyl alcohol-based film (VF-TS#2000, Kuraray, thickness: 20 μm) washed with water at 25° C. was subjected to swelling treatment in a water swelling tank at 30° C. The film passed through the swelling bath was treated for 65 seconds in a dyeing bath at 30° C. containing an aqueous solution containing 1 mol/ml of potassium iodide and 1% by weight of boric acid. The film passed through the dyeing tank was stretched at a draw ratio of 5.9 times in a wet drawing tank, which is a 60°C aqueous solution containing 3 wt% of boric acid. The film passed through the stretching bath was treated in a crosslinking bath containing an aqueous solution at 25° C. containing 3% by weight of boric acid for 65 seconds. The film passed through the crosslinking bath was treated for 10 seconds in a complementary color bath containing a complementary color solution, which is an aqueous solution at 30 °C containing 4.5 wt% of potassium iodide. The film passed through the complementary color tone was washed with water and dried to prepare a polarizer (thickness: 7 μm).

(2)소듐 티오설페이트(sodium thiosulfate) 함유 접착층용 조성물의 제조(2) Preparation of a composition for an adhesive layer containing sodium thiosulfate

A composition for a UV-curable adhesive layer containing sodium thiosulfate was prepared. 0.8 parts by weight of sodium thiosulfate (solid), Celloxide 2021P (Daicel, alicyclic epoxy compound) as an epoxy compound 67 parts by weight, DA-141 (2-hydroxy-3-phenoxy) as a (meth)acrylate compound Cypropyl acrylate, Nagase Chemtex Co.) 29.2 parts by weight, diphenyl 4-(phenylthio)phenyl sulfonium hexafluorophosphate (CPI-100P, San-apro Co.) 3.0 parts by weight as a photoacid generator to mix solvent-free UV A composition for a curable adhesive layer was prepared. Sodium thiosulfate in the composition is included in 0.8% by weight.

(2)편광판의 제조(2) Manufacture of polarizing plate

A cycloolefin polymer film (COP25CM-HC, Konica Minolta, thickness: 28 μm) was adhered to the upper surface of the prepared polarizer as an upper protective layer with a photocurable adhesive. A triacetyl cellulose film (KC2CT1W, Konica Minolta, thickness: 20 μm) was attached to the lower surface of the polarizer as a lower protective layer with a photocurable adhesive. The composition for an adhesive layer containing sodium thiosulfate is applied to the lower surface of the lower protective layer to a predetermined thickness, and a liquid crystal retardation film laminate (QLAA-388 and QLAB-318 laminated body, Fuji film, thickness : 7㎛), the adhesive layer (acrylic adhesive layer, thickness: 15㎛) are sequentially laminated, the upper protective layer - the polarizer - the lower protective layer - the adhesive layer - the laminate of the liquid crystal retardation film - the optical laminated in the order of the adhesive layer A laminate was prepared.

실시예 2 Example 2

In the same manner as in Example 1, except that the lower protective layer was not included in Example 1, an optical laminate laminated in the order of an upper protective layer - a polarizer - an adhesive layer - a liquid crystal retardation film laminate - an adhesive layer was manufactured did.

실시예 3 Example 3

In the same manner as in Example 1, except that the thickness of the polarizer was changed by changing the stretch ratio in Example 1, the upper protective layer - the polarizer - the lower protective layer - the adhesive layer - the laminate of the liquid crystal retardation film - the adhesive layer in the order A laminated optical laminate was prepared.

실시예 4Example 4

A composition for a UV-curable adhesive layer containing sodium thiosulfate and an ester-based crosslinking agent was prepared. Specifically, 0.8 parts by weight of sodium thiosulfate (solid phase), 6.5 parts by weight of an ester plasticizer (TXIB, Eastman Chemical, trimethyl fentanyl diisobutyrate), Celloxide 2021P as an epoxy compound (Daicel, alicyclic epoxy compound) 64 25.7 parts by weight of DA-141 (2-hydroxy-3-phenoxypropyl acrylate, Nagase Chemtex) as a (meth)acrylate-based compound, 25.7 parts by weight as a photoacid generator, 4-(phenylthio)phenyl sulfonium hexa A composition for a solvent-free UV-curable adhesive layer was prepared by mixing 3.0 parts by weight of fluorophosphate (CPI-100P, San-apro). In the composition, sodium thiosulfate is included in an amount of 0.8% by weight, and an ester-based crosslinking agent is included in an amount of 6.5% by weight.

비교예 1Comparative Example 1

Celloxide 2021P (Daicel, alicyclic epoxy compound) 67 parts by weight as an epoxy compound, DA-141 (2-hydroxy-3-phenoxypropyl acrylate, Nagase Chemtex) 30 as a (meth)acrylate compound A composition for a solvent-free UV-curable adhesive layer that does not contain sodium thiosulfate by mixing 3.0 parts by weight of diphenyl 4-(phenylthio)phenyl sulfonium hexafluorophosphate (CPI-100P, San-apro) as a photoacid generator was prepared. In Example 1 using the prepared composition, an optical laminate was prepared in the same manner as in Example 1, except that the upper protective layer - the polarizer - the adhesive layer - the laminate of the liquid crystal retardation film - the adhesive layer was laminated in the order. .

비교예 2Comparative Example 2

In the same manner as in Comparative Example 1, a composition for a non-solvent type UV-curable adhesive layer containing no sodium thiosulfate was prepared. Optical lamination in the same manner as in Example 1, except that in Example 1 using the prepared composition, the upper protective layer - the polarizer - the lower protective layer - the adhesive layer - the laminate of the liquid crystal retardation film - the adhesive layer were laminated in the order sieve was prepared.

비교예 3Comparative Example 3

In the same manner as in Comparative Example 1, a composition for a non-solvent type UV-curable adhesive layer containing no sodium thiosulfate was prepared. A polarizer having a thickness of 12 μm was manufactured with reference to the manufacturing method of the polarizer in Example 1. In Example 1, using the prepared polarizer and the prepared adhesive layer composition, the upper protective layer - the polarizer - the lower protective layer - the adhesive layer - the laminate of the liquid crystal retardation film - the adhesive layer was laminated in the order of Example An optical laminate was manufactured in the same manner as in 1.

The following physical properties were evaluated for the polarizing plates prepared in Examples and Comparative Examples, and the results are shown in Table 1 below. In Table 1 below, "-" means that the corresponding component or the corresponding layer is not included.

(1) Polarization degree (unit: %): With respect to the polarizing plate, the polarization degree was measured using a polarization meter V7100 (JASCO Corporation).

(2) Iodine elution amount (unit: mg/kg): A polarizing plate is cut to a size of length x width 50mm x 50mm, and a triacetylcellulose film of the same size (KC2CT1W, Konica Minolta, thickness: 20 μm) to prepare a specimen. The prepared specimen was left at 60° C. and 95% relative humidity for 500 hours. Through this, iodine moves from the lower surface of the polarizer to the triacetyl cellulose film, and the moved iodine is absorbed by the triacetyl cellulose film. Take a triacetyl cellulose film from the specimen and measure its weight to a level of 0.1 mg. The taken triacetylcellulose film was diluted to about 100 times the film weight in N-methyl-2-pyrrolidone (NMP) at 25° C. to completely dissolve the film, and then analyzed using an inductively coupled plasma mass spectrometer ICP-MS DRC II (PerkinElmer). The total amount of iodine was analyzed by analysis.

As shown in Table 1, the polarizing plate of the present invention contains a thiosulfate anion-containing salt to control the iodine elution amount to 10 mg/kg or less despite including a polarizer having a thickness of 10 μm or less and a high degree of polarization. In particular, Examples 1 and 3 having a protective layer between the polarizer and the adhesive layer were remarkably excellent in the effect of suppressing the amount of iodine elution compared to Example 2.

On the other hand, Comparative Examples 1 and 2 containing a polarizer having a thickness of 10 μm or less and a high degree of polarization without including a thiosulfate anion-containing salt significantly exceeded the iodine elution amount of 10 mg/kg. Comparative Example 3 having a high degree of polarization but having a polarizer having a thickness of more than 10 μm confirmed that the iodine elution amount was 10 mg/kg or less even without including a thiosulfate anion-containing salt. This means that iodine elution amount is a problem in a polarizing plate including a polarizer having a thickness of 10 μm or less and a high degree of polarization.

Simple modifications or changes of the present invention can be easily carried out by those of ordinary skill in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.

Claims

A polarizer and a laminate laminated on the lower surface of the polarizer,

The polarizer has a thickness of about 10 μm or less,

The laminate includes at least one of an adhesive layer, a retardation layer, and an adhesive layer,

The laminate is a thiosulfate anion (S 2 O 3 2- ) containing a salt or a hydrate thereof, the optical laminate.
The optical laminate of claim 1 , wherein the optical laminate has a polarization degree of about 99% or more.
The optical laminate of claim 1 , wherein the thiosulfate anion-containing salt comprises sodium thiosulfate (Na 2 S 2 O 3 ).
The optical laminate according to claim 1, wherein the thiosulfate anion (S 2 O 3 2- ) containing salt or hydrate thereof is included in an amount of about 0.1% to about 5.0% by weight of the laminate.
The optical laminate of claim 1 , wherein the laminate has a thickness of about 60 μm or less.
According to claim 1, wherein the laminate comprises the adhesive layer, the retardation layer and the adhesive layer sequentially laminated from the polarizer,

The adhesive layer includes the thiosulfate anion (S 2 O 3 2- ) containing salt or a hydrate thereof, the optical laminate.
The optical laminate according to claim 6, wherein the adhesive layer is formed of a photocurable adhesive.
The optical laminate according to claim 6, wherein the retardation layer comprises a liquid crystal coating layer or a liquid crystal film.
The optical laminate according to claim 1, wherein the laminate further comprises an ester-based plasticizer.
The optical laminate according to claim 9, wherein the ester-based plasticizer is included in an amount of about 0.1% to about 15.0% by weight of the laminate.
The optical laminate according to claim 6, wherein a protective layer is further laminated between the polarizer and the adhesive layer.
The optical laminate according to claim 11, wherein the protective layer comprises a film made of a cellulose ester-based resin or a polyester-based resin.
The optical display device comprising the optical laminate of any one of claims 1 to 12.