KR20130038514A - Method for preparing polarizer - Google Patents

Abstract

PURPOSE: A manufacturing method of a polarized light device is provided to prevent the deterioration after leaving under the sun, to have excellent color endurance, to prevent the leakage of the iodine complex, and to have an excellent optical property such as the transmittance and polarization. CONSTITUTION: A manufacturing method of a polarized light device comprises a swelling step of a polyvinyl alcohol film, a staining step, a cross-linking step, and an elongation step. And after the staining step, a step in which dipping the polyvinyl alcohol film into an aqueous solution containing the acetylacetonate metal salt or the hydrate is added. Considering the convenience of the process, the step is able to be performed with the cross-linking step at the same time by containing the polyvinyl alcohol film with the acetylacetonate metal salt or the hydrate in the cross linkage aqueous.

Description

[0001] METHOD FOR PREPARING POLARIZER [0002]

The present invention relates to a method for producing a polarizer having excellent optical characteristics and preventing deterioration even after being left under dry heat and excellent in color durability.

The polarizing plate has a structure in which a transparent protective film is laminated on both sides or one side of a polarizer made of a polyvinyl alcohol-based resin in which 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 polarizing plate having high contrast (high transmittance and high polarization) and excellent optical durability such as heat resistance is required.

On the contrary, Japanese Patent Application Laid-Open No. 2007-122050 adds a step of impregnating zinc after dyeing, stretching and boric acid treatment to improve the problem of lowering of transmittance and discoloration under dry heat. However, the method requires a separate additional process, which complicates the process and thus has a disadvantage in that handleability and productivity are reduced.

In addition, Japanese Patent Application Laid-Open No. 2000-035512 discloses a method of adding zinc ions to a boric acid crosslinking bath. However, in the above method, a chemical reaction occurs between the dye solution and zinc ions, and a precipitate is generated by the chemical reaction, resulting in poor appearance, foreign matter, and fracture.

The present invention is to provide a method of manufacturing a polarizer which is prevented from deterioration and excellent in color durability after being left under dry heat.

In addition, the present invention is to provide a method of manufacturing a polarizer having excellent optical properties such as transmittance and polarization degree by preventing the leakage of the iodine complex.

In addition, the present invention is to provide a polarizing plate comprising the polarizer.

The inventors of the present invention immersed in an aqueous solution containing acetylacetonate metal salt or its hydrate after the dyeing step during the manufacturing process of the polarizer, while maintaining the optical properties such as transmittance and polarization degree, while preventing the deterioration after standing in dry heat and color durability It was found that this excellent polarizer can be manufactured and completed the present invention.

Accordingly, the present invention is a method for producing a polarizer comprising a swelling step, a dyeing step, a crosslinking step and an stretching step of a polyvinyl alcohol-based film, after the dyeing step, the polyvinyl alcohol-based film acetylacetonate metal salt or It provides a method of manufacturing a polarizer comprising the step of immersing in an aqueous solution containing a hydrate thereof.

Immersion in the aqueous solution may be performed before or after the crosslinking step.

When performing the crosslinking step, a polyvinyl alcohol-based film may be immersed in an acetylacetonate metal salt or a crosslinking aqueous solution containing a hydrate, a boron compound, and an iodide thereof.

The acetylacetonate metal salt may be represented by Formula 1 below.

Wherein M is Li, Na, K, Rb, Cs, Ag, Mg, Ca, Sr, Ba, Cu, Zn, Fe, Co, Ni, Ru, Rh, Pd, Zr, Pt, Al, Ga, In , Ti, La, Ce, Eu, Gd, Y, Nd, Sm, Ir, Pr, Tm, Er, Sn, V, Cr, Mo or Mn, n is an integer of 1-4.

The acetylacetonate metal salt or a hydrate thereof may be contained in an amount of 1 to 5 wt% based on 100 wt% of the crosslinking aqueous solution.

The boron compound may be contained in an amount of 1 to 10% by weight based on 100% by weight of the crosslinking aqueous solution.

The iodide may be contained in an amount of 0.05 to 15 wt% based on 100 wt% of the crosslinking aqueous solution.

In addition, the present invention provides a polarizing plate in which a protective film is laminated on at least one surface of a polarizer produced by the above production method.

The polarizer according to the present invention is prevented from deterioration after being left under dry heat and excellent in color durability, which is useful for a liquid crystal display device which is likely to be exposed to high temperatures such as for cellular phones or in-vehicle vehicles.

In addition, the polarizer according to the present invention is excellent in optical properties such as transmittance and polarization degree by preventing the leakage of the iodine complex.

The present invention relates to a method for producing a polarizer having excellent optical characteristics and preventing deterioration even after being left under dry heat and excellent in color durability.

It will be described below in detail.

The method of manufacturing a polarizer of the present invention includes a method of manufacturing a polarizer including a swelling step, a dyeing step, a crosslinking step and an stretching step of a polyvinyl alcohol-based film, after the dyeing step, the acetylacetonate of the polyvinyl alcohol-based film Immersing in an aqueous solution containing a metal salt or a hydrate thereof.

In the present invention, the polarizer means a conventional iodine-based polarizer in which iodine is adsorbed and oriented on the polymer film.

The polymer film for preparing the polarizer is not particularly limited as long as it is a dichroic material, that is, a film that can be dyed by iodine, and specifically, a polyvinyl alcohol film, a partially gumified polyvinyl alcohol film; Hydrophilic polymer films such as polyethylene terephthalate film, ethylene-vinyl acetate copolymer film, ethylene-vinyl alcohol copolymer film, cellulose film, partially gumified film thereof and the like; Or a dehydrated polyvinyl alcohol film, a dehydrochloric acid-treated polyvinyl alcohol film, and the like. Among them, polyvinyl alcohol-based films are preferred in that they are excellent in effect of enhancing uniformity in polarization degree and excellent in dyeing affinity for iodine.

Usually, the method of manufacturing a polarizer includes a swelling step, a dyeing step, a crosslinking step, an stretching step, a washing step and a drying step, and are mainly classified by the stretching method. For example, a dry drawing method, a wet drawing method, or the hybrid drawing method which mixed the said two types of drawing methods, etc. are mentioned. Hereinafter, the manufacturing method of the polarizer of the present invention will be described using the wet stretching method as an example, but is not limited thereto.

The remaining steps except the drying step are performed in a state in which the polyvinyl alcohol film is immersed in a constant temperature bath filled with one or more kinds of solutions selected from various kinds of solutions.

In addition, the order and the number of repetition of each step are not particularly limited, and each step may be performed simultaneously or sequentially, and some steps may be omitted. For example, the stretching step may be performed before the dyeing step or after the dyeing step, and may be performed simultaneously with the swelling step or the dyeing step.

The swelling step is immersed in a swelling tank filled with an swelling aqueous solution before dyeing the unstretched polyvinyl alcohol-based film, to remove impurities such as dust and antiblocking agent deposited on the surface of the polyvinyl alcohol-based film and to remove polyvinyl alcohol It is a step for improving the physical properties of the polarizer by swelling the system film to improve the stretching efficiency and to prevent dyeing unevenness.

Water (pure water, deionized water) can usually be used as a swelling aqueous solution, and when a small amount of glycerin or potassium iodide is added thereto, the swelling of the polymer film and the processability can be improved. It is preferable that content of glycerin is 5 weight% or less with respect to 100 weight% of aqueous solutions for swelling, and content of potassium iodide is 10 weight% or less.

The swelling bath temperature is preferably 20 to 45 캜, more preferably 25 to 40 캜.

The execution time (swelling tank immersion time) of the swelling step is preferably 180 seconds or less, more preferably 90 seconds or less. When the immersion time is within the above range, it is possible to prevent the swelling from becoming excessive and saturation, to prevent breakage due to softening of the polyvinyl alcohol film and to improve the polarization degree by uniformly adsorbing iodine in the dyeing step have.

The stretching step may be carried out together with the swelling step, wherein the stretching ratio is preferably about 1.1 to 3.5 times.

The swelling step may be omitted and swelling may be performed simultaneously in the staining step.

The dyeing step is a step of adsorbing iodine to the polyvinyl alcohol-based film by immersing the polyvinyl alcohol-based film in a dye bath filled with a dichroic material, for example, an aqueous solution for dyeing containing iodine.

The dyeing aqueous solution may comprise water, a water-soluble organic solvent or a mixed solvent thereof and iodine. The content of iodine is preferably 0.4 to 400 mmol / L, more preferably 0.8 to 275 mmol / L, and most preferably 1 to 200 mmol / L with respect to 100 wt% of the aqueous solution for dyeing. In order to further improve dyeing efficiency, iodide may be further included as a dissolution aid. As the iodide, potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide and titanium iodide may be used alone or in combination of two or more. Of these, potassium iodide is preferable in view of high solubility in water. The content of iodide is preferably 0.010 to 10% by weight, more preferably 0.100 to 5% by weight, based on 100% by weight of the dyeing aqueous solution.

The temperature of the dye bath is preferably 5 to 42 ° C, more preferably 10 to 35 ° C. The immersion time of the polyvinyl alcohol film in the dyeing bath is not particularly limited, and is preferably 1 to 20 minutes, and more preferably 2 to 10 minutes.

The dyeing step and the stretching step may be carried out. In this case, the cumulative stretching ratio is preferably 1.1 to 4.0 times. In this specification, "cumulative draw ratio" represents the value of the product of draw ratios in each step.

The present invention includes the step of immersing the polyvinyl alcohol-based film in an aqueous solution containing an acetylacetonate metal salt or a hydrate thereof after the dyeing step to improve the optical durability and color durability of the polarizer. Specifically, the step of immersing in the aqueous solution may be carried out before or after the crosslinking step, in consideration of the convenience of the process, the crosslinking step by containing a polyvinyl alcohol-based film acetylacetonate metal salt or a hydrate thereof in the crosslinking aqueous solution It is preferable to carry out at the same time. In addition, when carried out before or after the crosslinking step, the degree of crosslinking may be relatively improved. Therefore, it is good to select suitably in consideration of the effect made into the objective.

The crosslinking step is a step of fixing the adsorbed iodine molecules by immersing the dyed polyvinyl alcohol-based film in an aqueous solution for crosslinking so that the dyeability by physically adsorbed iodine molecules is not lowered by the external environment. Dichroic dyes are not often eluted in a humid environment, but iodine is often dissolved or sublimed depending on the environment when the crosslinking reaction is unstable, and sufficient crosslinking reaction is required. In addition, in order to orient all polyvinyl alcohol molecules and iodine molecules located between the molecules to improve optical properties, the crosslinking step is important because it generally has to be drawn at the largest draw ratio in the crosslinking step.

When the polyvinyl alcohol film subjected to the dyeing step is immersed in an aqueous solution containing the acetylacetonate metal salt or a hydrate thereof, a chelate structure is generated between the metal salt and polyvinyl alcohol, thereby improving the degree of crosslinking. If the degree of crosslinking is improved, deterioration (redding phenomenon) is prevented even after being left under dry heat, and appearance defects are reduced, and leakage of iodine complex (combination of polyvinyl alcohol and polyvalent iodine ion) is prevented, so that a polarizer and a polarizing plate having excellent durability can be manufactured. have.

At this time, the acetylacetonate metal salt or a hydrate thereof may be added an appropriate amount of acid to the aqueous solution in order to improve solubility. The acid is preferably such that the pH is 4 or less. In particular, when used in addition to the aqueous solution for crosslinking, solubility improvement may act as an important factor.

The present invention describes a method of performing a crosslinking step using an aqueous solution for crosslinking containing an acetylacetonate metal salt or a hydrate thereof as follows, but is not limited thereto. As described above, when a separate step of immersion in an aqueous solution containing acetylacetonate metal salt or a hydrate thereof is performed before or after the crosslinking step, a crosslinking step which is usually performed in the art is performed.

The acetylacetonate metal salt is preferably in the following formula (1).

 [Formula 1]

Wherein M is Li, Na, K, Rb, Cs, Ag, Mg, Ca, Sr, Ba, Cu, Zn, Fe, Co, Ni, Ru, Rh, Pd, Zr, Pt, Al, Ga, In , Ti, La, Ce, Eu, Gd, Y, Nd, Sm, Ir, Pr, Tm, Er, Sn, V, Cr, Mo or Mn, n is an integer of 1-4.

In consideration of optical properties and economics, M is preferably Zn, Cu, Al or Zr.

In addition, the number of water molecules bonded to one molecule of the acetylacetonate metal salt is different in the hydrate of the acetylacetonate metal salt according to the type of the metal. The number of water molecules changes depending on the valence of the ions when the metal atoms form ions.

The crosslinked aqueous solution may include water as a solvent, a boron compound such as boric acid and sodium borate, an iodide, and the acetylacetonate metal salt or a hydrate thereof, and may further include an organic solvent that is mutually soluble with water.

The boron compound imparts short crosslinking and rigidity to suppress wrinkling during processing, thereby improving handling properties and forming iodine alignment.

It is preferable that content of a boron compound is 1 to 10 weight% with respect to 100 weight% of crosslinking aqueous solution, More preferably, it is 2 to 6 weight%. If the content is less than 1% by weight, the crosslinking effect of the boron compound is reduced, and thus it is difficult to impart rigidity. If the content is more than 10% by weight, the crosslinking reaction of the inorganic crosslinking agent is excessively activated, so that the crosslinking reaction of the organic crosslinking agent is difficult to proceed effectively.

Iodide is used to prevent the uniformity of the degree of polarization in the plane of polarizers and the desorption of dyed iodine. The iodide may be the same as that used in the dyeing step, the content may be 0.05 to 15% by weight relative to 100% by weight of the crosslinking aqueous solution, preferably 0.5 to 11% by weight. If the content is less than 0.05% by weight, the iodine ions in the film is released and the transmittance is increased, if the content exceeds 15% by weight iodine ions in the aqueous solution is penetrated into the film there is a problem that the transmittance is reduced.

Acetyl acetonate metal salt or a hydrate thereof may be added and used as appropriate within the range that can achieve the effects of the present invention, preferably 0.1 to 5% by weight, more preferably 0.2 to 1% by weight, acetylaceto Small amounts of acid can be added to improve the solubility of the nate metal salt. When the content of the acetylacetonate is less than 0.1% by weight, the amount is too small to achieve the effect of the present invention and when the content exceeds 5% by weight, durability and optical properties may be realized but acid may be added to improve solubility. In this case, it is preferable to maintain the above range because the amount of acid is increased to increase the risk.

The temperature of the crosslinking bath is 20 to 70 캜, and the immersion time of the polyvinyl alcohol film in the crosslinking bath may be 1 second to 15 minutes, preferably 5 seconds to 10 minutes.

The stretching step may be performed together with the crosslinking step, in which case it is preferable that the stretching is performed such that the total cumulative stretching ratio is 3.0 to 8.0 times.

As described above, the stretching step may be carried out with the swelling step, the dyeing step, the crosslinking step, and may be carried out as an independent stretching step using a separate stretching tank filled with the running aqueous solution after the crosslinking step.

The washing step is a step of removing the unnecessary residue such as boric acid attached to the polyvinyl alcohol-based film in the previous steps by immersing the polyvinyl alcohol-based film cross-linked and stretched in a washing tank filled with aqueous solution for washing.

The aqueous solution for washing may be water, and further iodide may be added thereto.

It is preferable that the temperature of a water washing tank is 10-60 degreeC, More preferably, it is 15-40 degreeC.

The washing step may be omitted and may be performed whenever previous steps such as dyeing step, crosslinking step or stretching step are completed. In addition, it may be repeated one or more times, and the number of repetitions is not particularly limited.

The drying step is a step of obtaining a polarizer having excellent optical properties by drying the washed polyvinyl alcohol-based film and further improving the orientation of the iodine molecules dyed by neck-in by drying.

As the drying method, natural drying, air drying, heating and drying, far infrared ray drying, microwave drying, hot air drying and the like can be used. Recently, microwave drying in which only water in the film is activated and dried is newly used, Drying is mainly used. For example, it may be hot air dried at 20 to 90 DEG C for 1 to 10 minutes. The drying temperature is preferably low in order to prevent deterioration of the polarizer, more preferably 80 ° C or lower, and most preferably 60 ° C or lower.

In addition, the present invention provides a polarizing plate in which a protective film is laminated on at least one surface of the polarizer manufactured by the manufacturing method.

The protective film is not particularly limited as long as it is a film excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, and the like. Specifically, polyester resins such as polyethylene terephthalate, polyethylene isophthalate and polybutylene terephthalate; Cellulose-based resins such as diacetylcellulose and triacetylcellulose; Polycarbonate resin; Acrylic resins such as polymethyl (meth) acrylate and polyethyl (meth) acrylate; Styrene resins such as polystyrene and acrylonitrile-styrene copolymer; Polyolefin resins such as polyethylene, polypropylene, cyclo- or norbornene-structured polyolefins, and ethylene propylene copolymers; Vinyl chloride resin; Polyamide resins such as nylon and aromatic polyamide; Imide resin; Polyether sulfone type resin; Sulfone resins; Polyether ketone resins: sulfide polyphenylene resins; Vinyl alcohol-based resins; Vinylidene chloride resins; Vinyl butyral resin; Allylate series resin; Polyoxymethylene type resin; Epoxy resin, and the like, and a film composed of the blend of the thermoplastic resin may also be used. Moreover, you may use the film which consists of thermosetting resins or ultraviolet curable resins, such as (meth) acrylic-type, urethane type, epoxy type, and silicone type. Among them, a cellulose-based film having a surface saponified (saponified) by alkali or the like is preferable in consideration of polarization characteristics or durability. In addition, the protective film may have a function of the following optical layer.

In the present invention, the structure of the polarizing plate is not particularly limited, and various kinds of optical layers capable of satisfying required optical properties may be laminated on the polarizer. For example, a structure in which a protective film for protecting the polarizer is laminated on at least one surface of the polarizer; A structure in which a surface treatment layer such as a hard coating layer, an antireflection layer, an anti-sticking layer, a diffusion preventing layer, an anti-glare layer, or the like is laminated on at least one surface or a protective film of the polarizer; It may have a structure in which an alignment liquid crystal layer or another functional film for compensating a viewing angle is laminated on at least one surface or a protective film of the polarizer. In addition, a phase difference including a wavelength plate (including a λ plate) such as an optical film, a reflector, a semi-transmissive plate, a 1/2 wave plate, or a quarter wave plate, such as a polarization conversion device used to form various image display devices At least one of the plate, the viewing angle compensation film, and the brightness enhancement film may be laminated with an optical layer. In more detail, a polarizing plate having a structure in which a protective film is laminated on one surface of a polarizer, the polarizing plate having a reflector or a transflective reflector laminated on a laminated protective film; An oval or circular polarizing plate in which retardation plates are stacked; A wide viewing angle polarizer on which a viewing angle compensation layer or a viewing angle compensation layer is stacked; Or the polarizing plate in which the brightness improving film was laminated | stacked is preferable.

Such a polarizing plate can be applied to various image display devices such as electroluminescent display devices, plasma display devices, and field emission display devices as well as ordinary liquid crystal display devices.

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

A transparent unstretched polyvinyl alcohol film (VF-PS, KURARAY) having a degree of saponification of 99.9% or more was swelled by immersion in water (deionized water) at 30 ° C. for 2 minutes, and then 3.5 mmol / L of iodine and 2 wt% of potassium iodide It was dyed by immersion for 4 minutes in an aqueous solution for dyeing at 30 ℃ containing. At this time, the stretching ratio was 1.3 times and 1.4 times in the swelling and dyeing step, respectively. Subsequently, it was crosslinked by dipping for 2 minutes in an aqueous solution for crosslinking at 50 ° C. containing 10% by weight of potassium iodide, 3.7% by weight of boric acid, and 1% by weight of zinc acetylacetonate hydrate. At this time, the crosslinking step was a total cumulative stretching ratio of 5.8 times and the pH was maintained below 4 by adding sulfuric acid. After the crosslinking was completed, the polyvinyl alcohol film was dried in an oven at 70 DEG C for 4 minutes to prepare a polarizer.

A triacetylcellulose (TAC) film was laminated on both sides of the prepared polarizer to prepare a polarizing plate.

Example 2

The polarizer was prepared in the same manner as in Example 1, using an aqueous solution for crosslinking containing 5% by weight of zinc acetylacetonate hydrate.

Example 3

The polarizer was prepared in the same manner as in Example 1, using an aqueous solution for crosslinking containing 1% by weight of copper acetylacetonate.

Example 4

The polarizer was prepared in the same manner as in Example 1, using a crosslinking aqueous solution containing 1% by weight of aluminum acetylacetonate.

Example 5

The polarizer was prepared in the same manner as in Example 1, using an aqueous solution for crosslinking containing 1% by weight of zirconium acetylacetonate.

Comparative Example 1

The polarizer was prepared in the same manner as in Example 1, using an aqueous solution for crosslinking containing 10 wt% of potassium iodide and 3.7 wt% of boric acid.

Comparative Example 2

The polarizer was prepared in the same manner as in Example 1, using a crosslinking aqueous solution containing 10% by weight of potassium iodide, 3.7% by weight of boric acid, and 0.5% by weight of zinc chloride.

Test Example

The physical properties of the polarizers prepared in the above Examples and Comparative Examples were measured by the following methods, and the results are shown in Table 1 below.

1. Optical characteristics (polarization, transmittance)

After cutting the prepared polarizer into 4 cm x 4 cm size, the transmittance was measured using an ultraviolet visible light spectrometer (V-7100, manufactured by JASCO). At this time, the polarization degree is defined by the following equation (1).

(Wherein T ₁ is the parallel transmittance obtained when the pair of polarizers are arranged in parallel with the absorption axis, and T ₂ is the orthogonal transmittance obtained when the pair of polarizers are arranged in the state where the absorption axes are orthogonal) .

Thereafter, the polarizer was allowed to stand in a dry atmosphere at 105 캜 for 30 minutes (durability test), and optical characteristics were again measured to confirm the amount of change.

2. Color Evaluation

The spectral transmission spectrum of the polarizer was obtained using a spectrophotometer (V7100 of Nippon Spectrophotometer Co., Ltd.), and the orthogonal color b was obtained therefrom.

Thereafter, the polarizer was left to stand in a dry atmosphere at 105 ° C. for 30 minutes (durability test), and the orthogonal color b was measured again to confirm the amount of change.

The variation in the optical characteristics and color evaluation is considered to be better as the value is smaller.

division Initial Characteristics Durability Transmittance
(%) Polarization degree
(%) Ortho b △ Transmittance △ Polarization degree △ Ortho b Example 1 41.7 99.994 -0.01 0.05 0.0011 0.14 Example 2 41.6 99.993 -0.02 0.03 0.0011 0.12 Example 3 41.5 99.993 -0.02 0.06 0.0012 0.14 Example 4 41.6 99.994 -0.01 0.07 0.0013 0.13 Example 5 41.7 99.994 -0.03 0.07 0.0010 0.14 Comparative Example 1 41.7 99.994 -0.03 0.17 0.0025 0.21 Comparative Example 2 41.6 99.993 -0.03 0.15 0.0018 0.2

As shown in Table 1, Examples 1 to 5 according to the present invention was confirmed that the change amount is significantly low compared to Comparative Examples 1 to 2, it is excellent in durability characteristics.

Claims (8)

In the method for producing a polarizer comprising a polyvinyl alcohol-based film swelling step, dyeing step, crosslinking step and stretching step,
After the dyeing step, a method of manufacturing a polarizer comprising the step of immersing the polyvinyl alcohol-based film in an aqueous solution containing acetylacetonate metal salt or a hydrate thereof.
The method of claim 1, wherein the immersion in the aqueous solution is performed before or after the crosslinking step.
The method of claim 1, wherein the polyvinyl alcohol-based film is immersed in an aqueous crosslinking solution containing an acetylacetonate metal salt or a hydrate thereof, a boron compound, and an iodide when the crosslinking step is performed.
The method according to claim 1, wherein the acetylacetonate metal salt is a polarizer manufacturing method of the formula
[Formula 1]

Wherein M is Li, Na, K, Rb, Cs, Ag, Mg, Ca, Sr, Ba, Cu, Zn, Fe, Co, Ni, Ru, Rh, Pd, Zr, Pt, Al, Ga, In , Ti, La, Ce, Eu, Gd, Y, Nd, Sm, Ir, Pr, Tm, Er, Sn, V, Cr, Mo or Mn, n is an integer of 1-4.
The method of claim 3, wherein the acetylacetonate metal salt or a hydrate thereof is contained in an amount of 1 to 5 wt% based on 100 wt% of the crosslinked aqueous solution.
The method of claim 3, wherein the boron compound is contained in an amount of 1 to 10 wt% based on 100 wt% of the crosslinked aqueous solution.
The method of claim 3, wherein the iodide is contained in an amount of 0.05 to 15 wt% based on 100 wt% of the crosslinked aqueous solution.
A polarizing plate in which a protective film is laminated on at least one side of the polarizer manufactured by the manufacturing method of any one of claims 1 to 7.