KR20120100175A - A polarizing plate and liquid crystal display comprising the same - Google Patents

Abstract

The present invention relates to a polarizing plate and a liquid crystal display including the same, and more particularly to a polarizer; An adhesive layer laminated on one or both surfaces of the polarizer and containing 0.0 to 60 parts by weight of an aldonic acid compound based on 100 parts by weight of the adhesive composition; And a polarizer protective film laminated on the adhesive layer, using a polarizer manufactured in a continuous process in an aqueous solution, a polarizing plate having excellent polarization characteristics and preventing degradation after being placed under dry heat, and having excellent color durability and a liquid crystal including the same. It relates to a display device.

Description

Polarizing plate and liquid crystal display including the same {A POLARIZING PLATE AND LIQUID CRYSTAL DISPLAY COMPRISING THE SAME}

The present invention relates to a polarizing plate having excellent optical properties and preventing degradation even after being left in dry heat and having excellent color durability using a polarizer manufactured by performing a continuous process in an aqueous solution, and a liquid crystal display including the same.

The polarizing plate usually has a structure in which a transparent protective film is laminated on both surfaces or one side of a polarizer made of a polyvinyl alcohol-based resin in which a dichroic dye is adsorbed and oriented.

The polarizer using iodine as a dichroic dye is an iodine type polarizer, and the polarizer using a dichroic dye is called a dye type polarizer. Dual iodine polarizers have high transmittance and high polarization (high contrast) compared to dye polarizers and are widely used.

However, iodine polarizers have superior optical characteristics than dye-based polarizers, but have low optical durability. For example, when the iodine polarizer or the polarizing plate including the polarizer is left under dry heat, there is a problem that the transmittance is reduced or discolored.

Moreover, in recent years, as the field of use of the liquid crystal display device is expanded and the peripheral technology is advanced, the demand for the performance of the polarizing plate is becoming more stringent. Specifically, a polarizer having high contrast (high transmittance and high polarization) and excellent optical durability such as heat resistance and moisture heat resistance is required.

On the contrary, Korean Patent Laid-Open Publication No. 2005-63692 attempts to improve problems such as decrease in transmittance and discoloration under dry heat by using an aldonic acid compound during the manufacturing process of an iodine polarizer.

However, in the above method, the polyvinyl alcohol film is stretched in the air, and then the subsequent processes such as dyeing, dipping and washing with water are carried out in an aqueous solution. This is because the manufacturing environment is performed in a different two-step process, and the continuity of the process is low, and a portion in which the in-plane elongation ratio is not uniform due to the change in the manufacturing environment may deteriorate the quality of the liquid crystal display device.

In addition, when the aldonate compound is used in the entire process of stretching, dyeing, dipping, washing with water, or the like, a problem may occur in that the polyvinyl alcohol film is cut or the optical properties of the polarizer produced are lowered.

The present invention is to provide a polarizing plate that is excellent in polarization characteristics and prevented deterioration after being left under dry heat using a polarizer prepared in a continuous process in an aqueous solution and excellent in color durability.

In addition, the present invention is to provide a liquid crystal display device including the polarizing plate.

The present inventors use a polarizer manufactured in a continuous process in an aqueous solution having high process efficiency and capable of maintaining the same optical properties (polarization and transmittance) as in the prior art, and an adhesive composition for implementing degradation prevention and color durability even after being left under dry heat. The polarizing plate was comprised including the adhesive bond layer in which the fixed amount of the aldonic-acid compound was mixed.

Thus, the present invention provides a polarizer; An adhesive layer laminated on one or both surfaces of the polarizer and containing 0.0 to 60 parts by weight of an aldonic acid compound based on 100 parts by weight of the adhesive composition; And it provides a polarizing plate comprising a polarizer protective film laminated on the adhesive layer.

The aldonic acid-based compound may be contained in the range of 0.1 to 20 parts by weight based on 100 parts by weight of the adhesive composition.

The aldonic acid-based compound may be gluconic acid or zinc gluconate.

The adhesive layer may be prepared by using an adhesive composition and an aldonic acid-based compound in the form of a one-part or two-part type.

The polarizer uniaxially stretch the polyvinyl alcohol-based film in an aqueous solution; Dyeing with a dichroic dye to adsorb; Treating with an aqueous boric acid solution; And washing with water and drying.

The dichroic dye may be iodine.

The polarizer protective film may be acrylic, cellulose, polyolefin-based or polyester-based.

In addition, the present invention provides a liquid crystal display device including the polarizing plate.

The present invention may be applied to a polarizer prepared in a continuous process in an aqueous solution to produce a polarizing plate in an excellent process and excellent polarization characteristics.

In addition, the polarizing plate according to the present invention is prevented from deterioration after being left under dry heat and excellent in color durability, and thus is useful for a liquid crystal display device that may be exposed to high temperatures such as for cellular phones or in vehicles.

In addition, the present invention is environmentally friendly and economical because it is possible to implement the anti-deterioration and color durability in a significantly lower amount than the amount of the aldonic acid compound used in the manufacture of the polarizer.

The present invention relates to a polarizing plate having excellent optical properties and preventing degradation even after being left in dry heat and having excellent color durability using a polarizer manufactured by performing a continuous process in an aqueous solution, and a liquid crystal display including the same.

Hereinafter, the present invention will be described in detail.

Polarizing plate of the present invention is a polarizer; An adhesive layer laminated on one or both surfaces of the polarizer and containing 0.0 to 60 parts by weight of an aldonic acid compound based on 100 parts by weight of the adhesive composition; And a polarizer protective film laminated on the adhesive layer.

The polarizer is a dichroic dye adsorbed on the stretched polyvinyl alcohol-based film.

The polyvinyl alcohol-based resin constituting the polarizer can be obtained by saponifying a polyvinyl acetate-based resin. As polyvinyl acetate type resin, the copolymer etc. of vinyl acetate and the other monomer copolymerizable with this besides the polyvinyl acetate which is a homopolymer of vinyl acetate are mentioned. As another monomer copolymerizable with vinyl acetate, an unsaturated carboxylic acid type, an unsaturated sulfonic acid type, an olefin type, a vinyl ether type, an acrylamide type monomer which has an ammonium group, etc. are mentioned. The polyvinyl alcohol-based resin may be modified, for example, polyvinyl formal or polyvinyl acetal modified with aldehydes may be used. Saponification degree of polyvinyl alcohol-type resin is 85-100 mol% normally, Preferably it is 98 mol% or more. In addition, the degree of polymerization of the polyvinyl alcohol-based resin is usually 1,000 to 10,000, preferably 1,500 to 5,000.

What formed such a polyvinyl alcohol-type resin into a film is used as a raw film of a polarizer. The film formation method of polyvinyl alcohol-type resin is not specifically limited, A well-known method can be used. The film thickness of the raw film is not particularly limited, and may be, for example, 10 to 150 µm.

The polarizer of this invention is manufactured through the process of uniaxially stretching a polyvinyl alcohol-type film in aqueous solution, the process of dyeing and adsorb | sucking with a dichroic dye, the process of treating with an aqueous solution of boric acid, and the process of washing with water and drying.

In some cases, a polyvinyl alcohol-based film is uniaxially stretched in the air, and then a post-process such as dyeing, dipping, and washing in an aqueous solution may be performed. In this case, the process is performed in a two-step process having different environmental conditions, and thus, the continuity of the process is low, and inconsistencies in the in-plane elongation ratio may occur due to changes in the manufacturing environment, thereby degrading the quality of the liquid crystal display device. have.

In addition, when the entire process, such as stretching, dyeing, dipping, washing with water, using the aldonic acid compound may cause a problem that the polyvinyl alcohol film is cut or the optical properties of the polarizer produced is lowered.

The process of uniaxially stretching the polyvinyl alcohol-based film may be performed before dyeing, may be simultaneously performed with dyeing, or may be performed after dyeing. When the uniaxial stretching is performed after dyeing, it may be performed before boric acid treatment, or may be performed during boric acid treatment. Of course, it is also possible to perform uniaxial stretching in these multiple steps. For uniaxial stretching, rolls or heat rolls with different circumferential speeds can be used. In addition, uniaxial stretching may be dry stretching extending | stretching in air | atmosphere, and wet extending | stretching extending | stretching in the state swollen with a solvent may be sufficient as it. The draw ratio is usually 4 to 8 times.

As a process of dyeing a stretched polyvinyl alcohol-type film with a dichroic dye, the method of immersing a polyvinyl alcohol-type film in the aqueous solution containing a dichroic dye can be used, for example. As a dichroic dye, iodine or a dichroic dye is used. In addition, the polyvinyl alcohol-based film is preferably swelled by dipping in water before dyeing.

When using iodine as a dichroic dye, the method of immersing and dyeing a polyvinyl alcohol-type film in the dyeing aqueous solution containing iodine and potassium iodide can be used normally. Usually, the content of iodine in the aqueous solution for dyeing is 0.01 to 1 part by weight based on 100 parts by weight of water (distilled water), and the content of potassium iodide is 0.5 to 20 parts by weight based on 100 parts by weight of water. The temperature of the aqueous solution for dyeing is usually 20 to 40 ° C., and the immersion time (dyeing time) is usually 20 to 1,800 seconds.

Boric acid treatment of the dyed polyvinyl alcohol-based film can be carried out by immersing in a boric acid-containing aqueous solution. Usually, the content of boric acid in the aqueous solution containing boric acid is 2 to 15 parts by weight, preferably 5 to 12 parts by weight, based on 100 parts by weight of water. When iodine is used as the dichroic dye, the boric acid-containing aqueous solution preferably contains potassium iodide, and the content thereof is usually 0.1 to 15 parts by weight, preferably 5 to 12 parts by weight with respect to 100 parts by weight of water. The temperature of the boric acid-containing aqueous solution is usually 50 ° C or higher, preferably 50 to 85 ° C, more preferably 60 to 80 ° C, and the immersion time is usually 60 to 1,200 seconds, preferably 150 to 600 seconds, more preferably. Preferably it is 200 to 400 seconds.

After the boric acid treatment, the polyvinyl alcohol-based film is usually washed with water and dried. Washing treatment can be performed by immersing the boric acid-treated polyvinyl alcohol-based film in water. The temperature of the water of a washing | cleaning process is 5-40 degreeC normally, and immersion time is 1-120 second normally. A polarizer can be obtained by drying after washing with water. The drying treatment can usually be carried out using a hot air dryer or a far infrared heater. The drying treatment temperature is usually 30 to 100 ° C, preferably 50 to 80 ° C, and the drying time is usually 60 to 600 seconds, preferably 120 to 600 seconds.

The thickness of the polarizer produced as described above is 5 to 40㎛.

The adhesive layer contains an aldonic acid compound in an adhesive composition capable of bonding the polarizer and the polarizer protective film.

The adhesive composition is generally used in the art and is not particularly limited, and specifically, at least one selected from the group consisting of isocyanate, polyvinyl alcohol, gelatin, vinyl polymer, latex and water-soluble polyesters Can be.

The aldonic acid-based compound may specifically include an aldonic acid or a salt thereof. Aldonic acid is a polyhydroxycarboxylic acid obtained by oxidizing an aldehyde group of aldose, and is represented by the chemical formula of HOCH ₂ (CHOH) _n COOH (where n is an integer of 1 or more).

Aldonic acid is generally used in the art and is not particularly limited, but specifically, gluconic acid, galactonic acid, mannonic acid, talonic acid, and gulonic acid ), Idon acid (idonic acid), allonic acid (allonic acid) and selected from the group consisting of altronic acid (altronic acid), can be used alone or in combination of two or more. Of these, it is preferable to use gluconic acid which is commercially available.

Specifically, the salt of the aldonic acid may be selected from the group consisting of sodium salts, potassium salts, calcium salts, and zinc salts, and it is preferable to use zinc salts having a high effect of suppressing discoloration under dry heat of the dual polarizer.

In the aqueous aldonic acid solution, aldonic acid and aldonoractone have an equilibrium relationship, and their abundance varies with the pH of the aqueous solution. The stronger the alkalinity of the aqueous solution, the greater the proportion of aldonic acid. On the contrary, the stronger the acidity of the aqueous solution, the greater the proportion of aldonoractone.

In addition, aldonolactone is obtained by concentrating the aqueous aldonic acid solution to form a solid. Therefore, the aldon acid in the present invention may include aldonolactone, which is a lactone thereof, in addition to the aldonic acid itself. Aldonoractones that are in equilibrium with aldonic acid include, for example, gluconolactone for gluconic acid, galactonolactone for galactonic acid, and the like.

Aldonic acid is usually produced by fermentation of glucose and sold in form.

The present invention can obtain an effect of suppressing problems such as discoloration under dry heat of a polarizing plate including the aldonic acid-based compound in the adhesive composition. In addition, additives, such as a stabilizer and a preservative, can also be further contained in the range which does not inhibit the effect by the said aldon acid type compound.

In the adhesive layer of the present invention, the adhesive composition and the aldonic acid-based compound may be used in the form of one-part or two-part type. Specifically, a mixture (one-component) in which the adhesive composition and the aldonic acid-based compound are mixed is sprayed using one nozzle, or the adhesive composition and the aldonic acid-based compound are sprayed at each nozzle (two-component) to form a spray-type adhesive layer. Can be used in a way. In the two-component type, the spraying order of each nozzle is not particularly limited as long as the mixing ratio of the adhesive composition and the aldonic acid compound in the adhesive layer can be maintained within the scope of the present invention.

The aldonic acid compound of the present invention is preferably 0.02 to 60 parts by weight, preferably 0.05 to 30 parts by weight, and more preferably 0.1 to 20 parts by weight based on 100 parts by weight of the adhesive composition. If the aldonic acid-based compound is less than 0.02 parts by weight, the effect of suppressing problems such as discoloration under dry heat of the polarizing plate is not sufficiently exhibited. If the aldon acid compound is more than 60 parts by weight, the adhesion between the iodine-based polarizer and the polarizer protective film is not sufficiently exhibited. Peeling may occur at the iodine in the polarizer may cause sublimation or decolorization or shrinkage of the polyvinyl alcohol resin film.

The polarizer protective film is not particularly proposed to be excellent in transparency, mechanical strength, thermal stability, moisture shielding, isotropy, and the like, and specifically, acrylic, cellulose, polyolefin, or polyester may be used.

For example, Acrylic resin, such as polymethyl (meth) acrylate and polyethyl (meth) acrylate; Polyester resins such as polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, and polybutylene terephthalate; Cellulose resins such as diacetyl cellulose and triacetyl cellulose; Polyolefin resins such as polyethylene, polypropylene, cyclo-based or norbornene-structured polyolefin-based and ethylene-propylene copolymers; A protective film containing these etc. can be mentioned.

The thickness of the polarizer protective film is 10 to 200㎛, preferably 10 to 150㎛. In addition, when the polarizer protective film is laminated on both sides of the polarizer may maintain the same or different thickness.

The bonding easy process can be performed to the surface joined with the polarizer of a protective film. Examples of the easy treatment for bonding include dry treatment such as plasma treatment, corona treatment, chemical treatment such as alkali treatment (soap treatment), and coating treatment for forming an easy adhesive layer.

The thickness of the adhesive layer is usually about 0.01 to 10 µm, preferably 0.05 to 5 µm, and most preferably 0.1 to 1 µm. The surface which is not bonded to the polarizer of the protective film may be subjected to a treatment for the purpose of hard coat treatment, antireflection treatment, sticking prevention, diffusion or antiglare.

The bonding method may be a conventional method in the art, for example, using a casting method, a meyer bar coating method, a gravure coating method, a die coating method, a dip coating method, a spray coating method, or the like on the bonding surface of the polarizer or the protective film. After apply | coating an adhesive composition, the method of joining these is mentioned. The casting method is a method in which the adhesive composition is applied to the bonding surface while the polarizer or the protective film is generally moved in the vertical direction, the horizontal direction or the inclined direction between the two. After the adhesive composition is applied, the polarizer or the protective film is sandwiched by nip roll or the like.

After bonding the polarizer and the protective film may be a drying treatment. The drying treatment is carried out, for example, by spraying hot air, and the drying temperature is appropriately selected in the range of 40 to 100 ° C, preferably 60 to 100 ° C. Drying time may be about 20 to 1,200 seconds. After drying, curing is preferably performed at room temperature or slightly higher, for example, at a temperature of 20 to 50 ° C. for about 12 to 600 hours. The thickness of an adhesive bond layer after drying is 0.001-5 micrometers normally, Preferably it is 0.01 micrometer-2 micrometers, More preferably, it is 0.01-1 micrometer or less. When the thickness of an adhesive bond layer exceeds 5 micrometers, it will be easy to produce the external appearance problem of a polarizing plate.

Surface treatment layers such as a hard coating layer, an antireflection layer, an antiglare layer, an antistatic layer and the like may be further laminated on the other side of the polarizer having the polarizer protective film bonded to one surface thereof. In addition, the optical functional film may be further laminated by the pressure-sensitive adhesive layer. As the optical functional film, for example, an optical compensation film in which a liquid crystalline compound or a polymer compound thereof is oriented on the surface of a substrate, reflective polarization that transmits polarized light of any kind and reflects polarized light having a property opposite thereto. Separation film, retardation film containing polycarbonate resin, retardation film containing cyclic polyolefin-based resin, anti-glare function film having an uneven shape on the surface, an additional film subjected to the surface anti-reflection treatment, a reflection film having a reflection function on the surface, The semi-transmissive reflective film etc. which have a reflection function and a transmission function together are mentioned.

In addition, the present invention may include a polarizing plate to form a liquid crystal display device.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention. Such variations and modifications are intended to be within the scope of the appended claims.

Example 1

The polyvinyl alcohol resin film having a thickness of 75 µm and an average polymerization degree of about 2,400 and a saponification degree of 99.9 mol% or more were stretched about 1.5 times while immersing in 30 ° C pure water for 2 minutes. Thereafter, the film was stretched about 2.0 times while immersing in a dye bath at 30 ° C. for 3 minutes containing an aqueous solution having a weight ratio of 0.01 / 1.0 / 100 of iodine / potassium iodide / water. Thereafter, the film was stretched about 2.0 times while immersing for 1 minute at 53 ° C. in an aqueous solution in which potassium iodide / boric acid / water was mixed at a weight ratio of 10/5/100. Thereafter, the resultant was washed with pure water at 15 ° C. for 1.5 seconds and then dried at 50 ° C. for 5 minutes to prepare a polarizer having iodine adsorbed on polyvinyl alcohol.

The modified adhesive composition was prepared by mixing modified polyvinyl alcohol (Gosepima Z200, Nippon Synthetic Chemical Co., Ltd.), 10% by weight aqueous solution of sodium glyoxylate (SPM-01, Nippon Synthetic Chemical Co., Ltd.) and water in 3/3/100 parts by weight. After the preparation, 10 parts by weight of a 50% by weight aqueous solution of gluconic acid (Aldrich) was mixed with respect to 100 parts by weight of the adhesive composition to prepare a one-component gluconic acid mixed adhesive composition.

A triacetylcellulose resin film having a thickness of 80 μm and 40 μm was respectively bonded to both surfaces of the polarizer having the iodine adsorption-oriented polarizer with the one-component gluconic acid mixed adhesive composition and dried at 80 ° C. for 5 minutes to prepare a polarizing plate.

Example 2

In the same manner as in Example 1, the polarizing plate was prepared using the adhesive composition and 50% by weight aqueous solution of gluconic acid (Aldrich) in the form of a two-part type each sprayed from a separate nozzle.

Example 3

In the same manner as in Example 1, a polarizing plate was prepared using 5 parts by weight of zinc gluconate (wakosa, 100% by weight of solid content) instead of 100 parts by weight of the adhesive composition in place of the 50% aqueous solution of gluconic acid.

Example 4

In the same manner as in Example 1, a polarizing plate was prepared by bonding a triacetyl cellulose resin film having a thickness of 40 μm to both surfaces of the polarizer, respectively.

Example 5

In the same manner as in Example 1, using 5 parts by weight of zinc gluconate (wakosa, 100% by weight of solid content) to 100 parts by weight of the adhesive composition in place of the 50% aqueous solution of gluconic acid, the thickness of each side of the polarizer The triacetyl cellulose resin film of 40 micrometers was bonded together, and the polarizing plate was produced.

Example 6

A polarizing plate was prepared in the same manner as in Example 1, using 0.05 parts by weight of 50% aqueous solution of gluconic acid based on 100 parts by weight of the adhesive composition.

Example 7

A polarizing plate was prepared in the same manner as in Example 1, using 55 parts by weight of the 50% aqueous solution of gluconic acid based on 100 parts by weight of the adhesive composition.

Comparative Example 1

An average polymerization degree of about 2,400 and saponification degree of 99.9 mol% or more were stretched by about 1.5 times while immersing the polyvinyl alcohol resin film having a thickness of 75 μm in pure water at 30 ° C. for 2 minutes. Thereafter, the film was stretched about 2.0 times while immersing in a dye bath at 30 ° C. for 3 minutes containing an aqueous solution having a weight ratio of 0.01 / 1.0 / 100 of iodine / potassium iodide / water. Thereafter, the film was stretched by about 2.0 times while immersing in a 50% aqueous solution of gluconic acid / potassium iodide / boric acid / water in a weight ratio of 10/10/5/100 while immersing at 53 ° C for 1 minute. Thereafter, the resultant was washed with pure water at 15 ° C. for 1.5 seconds and then dried at 50 ° C. for 5 minutes to prepare a polarizer having iodine adsorbed on polyvinyl alcohol.

The modified adhesive composition was prepared by mixing modified polyvinyl alcohol (Gosepima Z200, Nippon Synthetic Chemical Co., Ltd.), 10% by weight aqueous solution of sodium glyoxylate (SPM-01, Nippon Synthetic Chemical Co., Ltd.) and water in 3/3/100 parts by weight. Prepared.

A triacetylcellulose resin film having a thickness of 80 μm and 40 μm was respectively bonded to both surfaces of the polarizer having the iodine adsorption-oriented polarizer with the adhesive composition and dried at 80 ° C. for 5 minutes to prepare a polarizing plate.

Comparative Example 2

The same procedure as in Comparative Example 1, except that 50% aqueous solution of gluconic acid / potassium iodide / boric acid / water was stretched about 1.5 times while immersing for 1 minute at 53 ℃ in an aqueous solution of 10/10/5/100 by weight ratio polarizing plate Was prepared.

Comparative Example 3

In the same manner as in Comparative Example 1, a polarizing plate was prepared using 5 weight ratios of zinc gluconate (wakosa, 100 wt% solids) instead of 50% aqueous gluconic acid solution.

Comparative Example 4

A polarizer was prepared in the same manner as in Example 1, using only the adhesive composition without the aqueous 50% by weight aqueous solution of gluconic acid.

Comparative Example 5

A polarizer was prepared in the same manner as in Example 1, using 0.01 parts by weight of the 50% aqueous solution of gluconic acid based on 100 parts by weight of the adhesive composition.

Comparative Example 6

A polarizing plate was prepared in the same manner as in Example 1, using 65 parts by weight of the 50% aqueous solution of gluconic acid based on 100 parts by weight of the adhesive composition.

Experimental Example

The physical properties of the polarizing plates prepared in Examples and Comparative Examples were measured by the following method, and the results are shown in Table 1 below.

1. Evaluation of durability

The spectral transmittance (tau) ((lambda)) of the polarizing plate was measured using the spectrophotometer (V7100 of Nippon Corp., Ltd.). The orthogonal spectral transmission spectrum was calculated | required from the measured spectral transmittance (tau) ((lambda)), and orthogonal color L *, a *, and b * were calculated | required from the spectral transmission spectrum.

Subsequently, the polarizing plate was left to stand in a dry atmosphere at 105 ° C. for 30 minutes (durability test), and then the spectral transmittance τ (λ) was measured again, and the orthogonal spectral transmission spectrum was obtained from the measured spectral transmittance τ (λ), and the spectral transmission Orthogonal colors L *, a * and b * were obtained from the spectra.

Equations 1 to 3 are ΔL *, Δa *, and Δb * of orthogonal colors L *, a *, and b *, respectively, before and after the durability test, and Equation 4 below represents the total color difference ΔE *. At this time, it is determined that the larger the value of Δb * and ΔE *, the greater the degree of discoloration under dry heat.

In Equations 1 to 3, before is a value before the durability test, and after is a value after the durability test.

2. Polarization degree and transmittance

The polarization degree (Py) of the prepared polarizing plate was measured by using an ultraviolet visible spectrophotometer (V-7100 / VAP-7070, manufactured by Nippon Bunco Co., Ltd.) to measure the parallel transmittance (H ₀ ) and the orthogonal transmittance (H ₉₀ ) of the polarizing plate. After that, it was calculated based on Equation 5 below and evaluated based on the following criteria. The transmittance | permeability is the Y value which corrected visibility by the 2 degree field of view (C light source) prescribed | regulated to JISZ 8701 (1982 edition).

3. Peeling of Polarizing Plate

After leaving the prepared polarizing plate in a dry atmosphere at 105 ° C. for 30 minutes, the polarizer and the presence or absence of the triacetylcellulose resin film peeling were visually observed.

division Color Durability Rating (Ortho) Transmittance
(%) Polarization degree
(%) With / without peeling Before durability test After durability test Δb * △ E * L * a * b * L * a * b * Example 1 0.05 0.13 0.02 0.17 0.74 0.25 0.23 0.67 43.02 99.99 radish Example 2 0.05 0.14 0.03 0.18 0.77 0.27 0.24 0.69 42.98 99.99 radish Example 3 0.06 0.13 0.03 0.18 0.79 0.26 0.23 0.71 42.91 99.98 radish Example 4 0.05 0.15 0.03 0.15 0.69 0.21 0.19 0.58 43.25 99.99 radish Example 5 0.06 0.14 0.03 0.14 0.54 0.17 0.15 0.43 43.25 99.98 radish Example 6 0.05 0.13 0.03 0.22 1.05 0.34 0.31 0.99 42.97 99.98 radish Example 7 0.06 0.14 0.02 0.13 0.5 0.15 0.13 0.39 42.95 99.98 radish Comparative Example 1 Unable to manufacture polarizer by cutting film Comparative Example 2 Durability test not performed due to insufficient initial performance 39.78 98.15 radish Comparative Example 3 Unable to manufacture polarizer by cutting film Comparative Example 4 0.11 0.39 0.12 0.51 2.60 0.82 0.70 2.35 43.06 99.98 radish Comparative Example 5 0.10 0.35 0.11 0.48 2.39 0.76 0.65 2.17 43.05 99.98 radish Comparative Example 6 0.05 0.13 0.02 0.18 0.51 0.13 0.11 0.42 42.95 99.98 U

Claims (8)

Polarizer;
An adhesive layer laminated on one or both surfaces of the polarizer and containing 0.0 to 60 parts by weight of an aldonic acid compound based on 100 parts by weight of the adhesive composition; And
Polarizing plate comprising a polarizer protective film laminated on the adhesive layer.
The polarizing plate of claim 1, wherein the aldonic acid-based compound is contained in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the adhesive composition.
The polarizing plate of claim 1, wherein the aldonic acid compound is gluconic acid or zinc gluconate.
The polarizing plate of claim 1, wherein the adhesive layer is prepared by using an adhesive composition and an aldonic acid-based compound in the form of a one-part or two-part type.
The method of claim 1, wherein the polarizer is a step of uniaxially stretching the polyvinyl alcohol-based film in an aqueous solution; Dyeing with a dichroic dye to adsorb; Treating with an aqueous boric acid solution; And a polarizing plate prepared by performing a process of washing with water and drying.
The polarizing plate of claim 5, wherein the dichroic dye is iodine.
The polarizing plate of claim 1, wherein the polarizer protective film is acrylic, cellulose, polyolefin, or polyester.
Liquid crystal display device comprising the polarizing plate of any one of claims 1 to 7.