KR100932070B1 - Adhesive for Polarizer - Google Patents

Abstract

As a condition of the polarizing plate having good optical properties, the transmittance should be lowered except that the light generated from the light source vibrates in the same direction as the polarization axis in the visible light field. In general, the polarizing plate is a boron compound to control the light leakage of the long wavelength, the light leakage control of the short wavelength is by the aqueous solution of iodine and potassium iodine. In this case, in order to solve the difficulty in realizing a polarizing plate having good optical properties due to the increase in light transmittance due to the difference in light leakage control between the boron compound and iodine, the boron compound is used by using a metal oxide having excellent UV blocking effect in the adhesive. By introducing the iodine as well as the metal oxide as the short wavelength light leakage control means, the short wavelength light leakage control effect was further enhanced. Therefore, the use of iodine can be lowered in the manufacturing process of the polarizer, nevertheless, it is possible to realize a higher short wavelength light leakage control effect by the metal oxide, and as a result, the difference in the light leakage control process between the iodine and the boron compound Since the action phenomenon can be lowered, it is possible to implement a polarizing plate having good optical characteristics in the visible light propagation band.

Polarizer, polarizer, metal oxide, adhesive, dispersant

Description

Adhesive for Polarizing Plate {ADHESIVE FOR POLARIZING PLATE}

The present invention relates to an adhesive for use in a polarizing plate for an image display device. More specifically, the present invention relates to a polarizing plate adhesive including a metal oxide in order to implement a polarizing plate having excellent optical characteristics and a method of manufacturing the same.

LCD products sometimes make the screen look mottled because the brightness varies between locations when black or gray is placed on the entire screen. This is commonly referred to as "light leakage phenomenon" or "sun rise phenomenon" (hereinafter referred to as "light leakage phenomenon").

 In order to solve the light leakage phenomenon, the primary problem is to completely block the light generated in the entire frequency range of visible light except the polarization axis in the polarizer. Polarizers that meet these requirements are often referred to as "good optical properties."

In order to manufacture a polarizing plate with good optical properties, in general, boron compounds are used in the manufacturing process of the polarizing plate to suppress light leakage of a long wavelength band (600 nm to 700 nm), and potassium iodine, which is used for aqueous solution of iodine and color correction, is short wavelength band (400 nm to 500 nm) light leakage is suppressed.

However, the long- and short-wavelength light leakage control phenomena caused by the addition of boron compounds and potassium iodine have opposite results. That is, the addition of the boron compound is easy to control the long wavelength light leakage, but not easy to control the short wavelength light leakage, and the addition of potassium iodine is not easy to control the short wavelength light leakage.

Due to the difference in light leakage control between the boron compound and iodine, the light transmittance is increased, and thus, it is difficult to manufacture a polarizing plate having excellent optical characteristics, that is, a polarizing plate having easy light leakage control in the visible photoelectric region (380 nm to 780 nm).

In the present invention, in order to solve this problem, a metal oxide having excellent UV blocking effect is introduced into the adhesive used in the polarizer manufacturing process.

Polarizing plate according to the present invention is a polarizing plate comprising a polarizer, two or more polarizer protective films provided on both sides of the polarizer, the polarizing plate is provided with an adhesive layer on at least one side.

The adhesive layer uses a polarizing plate adhesive obtained by dissolving an adhesive composition containing a transparent polymer resin, a water-soluble crosslinking agent, and a metal oxide in a dispersant.

(1) transparent polymer resin

The transparent polymer resin used in the present invention is suitable as an adhesive for use in the polarizing plate of the liquid crystal display device as well as providing cohesive force, adhesive force and weakness, as well as being excellent in transparency, weather resistance and heat resistance.

In particular, in the present invention, the cohesive force of the transparent polymer used as the adhesive is an important factor in order to ensure the desired light blocking function by mixing with the metal oxide.

When the cohesive force of the transparent polymer is low, pressing marks remain due to foreign matter between the polarizing plates, or pressing marks are generated on the adhesive layer due to the weight of the polarizing plate itself, thereby acting as a fatal defect when driving the liquid crystal display. In addition, when the polarizing plate is cut to a certain size, the lack of a property that the adhesive located on one side of the polarizing plate is neatly cut. If this lacking characteristic does not reach the desired level, the glass is contaminated in the process of attaching the polarizing plate to the glass substrate of the liquid crystal display.

Transparent polymer resins for satisfying the cohesion and lacking properties of the adhesives mentioned above use adhesives composed of general PVA compounds, polyurethane compounds, polyester compounds, polyacrylic compounds, polyepoxy compounds, and polycyanoacrylate compounds. It is desirable to. Here, the PVA-based compound, the polyurethane-based compound, the polyester compound, the polyacrylic compound, the polyepoxy compound, the polycyanoacrylate-based compound and the like are each a PVA-based adhesive, a polyurethane-based adhesive, a polyester-based adhesive, a polyacrylic adhesive, a poly It is a main component of an epoxy adhesive and a polycyanoacrylate adhesive.

In the adhesive used in the present invention, the PVA-based adhesive is mainly used in consideration of aspects such as polarizer and bonding properties and post-bonding properties, and the remaining compounds are preferably used alone or in combination. In addition, the PVA-based adhesive is a PVA-based adhesive comprising PVA-based adhesive composed of monomers of PVA-based compound alone, PVA-based adhesive composed of two or more monomers of PVA-based compound, and PVA-based compound composed of monomers containing functional groups in PVA-based. It is possible to use a system adhesive.

 You may mix | blend another additive, catalyst, such as an acid as needed. Moreover, when apply | coating the said adhesive agent, you may mix | blend another additive, a catalyst, such as an acid, with the said adhesive composition, for example.

It is preferable that the transparent polymer resin in 100 weight% of adhesive compositions is 50 to 95 weight%, More preferably, it is 60 to 85 weight%. Even more preferably 65% to 75% by weight. When the content of the transparent polymer resin in the adhesive composition is 95% by weight or more, there is a disadvantage in that optical anisotropy appears in the polarizer protective layer and optical interference pattern due to birefringence occurs.

(2) water-soluble crosslinking agent

It is preferable to further contain a water-soluble crosslinking agent of PVA-based polymers, such as glutaraldehyde, melamine, oxalic acid, in that the adhesive layer is not easily peeled off due to humidity, heat or the like, and can form a polarizing plate excellent in light transmittance and polarization degree. Do.

In addition, in order to improve the durability of these transparent polymer resins, water-soluble crosslinking agents that crosslink vinyl alcohol polymers such as boric acid, borax, glutaraldehyde, melamine, oxalic acid, chitin, chitosan, alcohol solvents, and the like may be added. In particular, a crosslinking agent is preferable in promoting adhesion | attachment of a polarizer with the polyvinyl alcohol film.

In 100 weight% of adhesive compositions, it is preferable that a water-soluble crosslinking agent is 0.01 to 0.5 weight%. When the water-soluble crosslinking agent is less than 0.01% by weight, it is difficult to expect the adhesion promoting effect due to the addition of the water-soluble crosslinking agent, and when the water-soluble crosslinking agent is 0.5% by weight or more, the crosslinking density is significantly increased, making it difficult to easily process the adhesive composition. Moreover, when there is too much compounding quantity of a crosslinking agent, reaction of a crosslinking agent will advance easily in a short time, and there exists a tendency for an adhesive agent to gelatinize. As a result, the usable time (pot life) as an adhesive may be shortened.

(3) dispersant

Dispersant in the present invention serves to evenly disperse the transparent polymer resin and the metal oxide. In the present invention, by using an appropriate dispersant in the adhesive for polarizing plate to ensure an even distribution of the metal oxide to maintain the colloidal state of the metal oxide, to prevent the coagulation (Coagulation) to meet the molecular size of the oxide to the purpose of the present invention Adjustment should be made to ensure that the final product is colored and the desired clarity is achieved. At the same time, it is important to select in consideration of the solubility with the transparent polymer resin, the polarizer 10 and the coating property, the adhesion of the polarizer protective layer 20 and the like.

In the present invention, it is preferable to use an organic solvent in which the dispersant may be evenly dispersed in the transparent polymer resin and the metal oxide.

The organic solvent used as the dispersant in the present invention is used in consideration of the polarizer 10 and the coating property, the adhesion between the polarizer protective layer 20 and the like.

The organic solvent used in the present invention is a C1-8 saturated hydrocarbon alcohol such as methanol, isopropanol, butanol, t-butanol, isobutanol and the like, acetone, methyl ethyl ketone, methyl isobutyl ketone and the like of ketones. Saturated hydrocarbon-based diketones having 1 to 8 carbon atoms, such as saturated hydrocarbon-based ketones and acetyl acetones, saturated hydrocarbon-based esters having 1 to 8 carbon atoms, such as ethyl acetate and butyl acetate, and ether alcohols. Solves, methyl cellosolves, butyl cellosolves, 1-methoxy-2-propanol, and N-methyl pyrrolidone, ethyl cellosolve acetate, diacetone alcohol, and the like are used alone or in combination. Moreover, benzene, toluene, xylene, ethylbenzene, etc. corresponding to an aromatic hydrocarbon can also be used individually or in mixture.

The organic solvent is preferably used in an amount of 20 parts by weight to 110 parts by weight with respect to 100 parts by weight of the adhesive composition, and more preferably 30 parts by weight to 80 parts by weight. When the content of the organic solvent is less than 20 parts by weight with respect to 100 parts by weight of the adhesive composition, the viscosity is low, resulting in poor applicability and adhesion to the polarizer protective layer. Profitability is inferior by using

(4) metal oxides

The material having transparency in the visible region and having a UV blocking effect is not particularly limited, but a material having a high refractive index having a refractive index of visible light of 1.6 or more, preferably 1.8 or more, and more preferably 2.0 or more is used.

Usable as the metal oxide included in the adhesive composition is indium (In), titanium (Ti), zirconium (Zr), bismuth (Bi), tin (Sn), zinc (Zn), antimony (Sb), tantalum (Ta) ), Oxides such as cerium (Ce), neodium (Nd), lanthanum (La), triumium (Th), magnesium (Mg), gallium (Ga), or these oxides with manganese (Mn) or iron (Fe) And mixtures thereof.

The content of the metal oxide is about 0.1 to 20% by weight, preferably about 1 to 10% by weight, more preferably about 3 to 8% by weight, especially about 4 to 7% by weight, such as 4 to 100% by weight of the adhesive composition. It is preferred to be present at 6%, in particular about 5%.

If the metal oxide content is less than 0.1% by weight with respect to 100% by weight of the adhesive composition, it is difficult to expect a short wavelength light leakage control effect. In addition, when the metal oxide content is more than 20% by weight, it is impossible to satisfy a predetermined clarity required for the polarizing film, and it is difficult to expect good adhesion. When the content of the metal oxide is more than 0.1% by weight, a constant short wavelength light leakage control effect occurs. When the content of the metal oxide is less than 20% by weight, it is possible to maintain excellent adhesion and at the same time obtain satisfactory transparency.

The metal oxide form is dispersed in the adhesive and the average primary particle size of the particles is generally in the range of about 1 nm to 200 nm, in the range of about 1 nm to 150 nm, and is most preferably present at about 1 nm to 100 nm, especially 50 nm.

The particle size is preferable as a range in which the light leakage control effect can be secured within the above range and the clarity of the final product, that is, the color can be avoided. However, the thickness of the adhesive layer is preferably larger than the particle size of the metal oxide.

If the particles are substantially spherical, the particle size can be considered to represent a diameter. However, the present invention also encompasses particles that are non-spherical and in this case the particle size means the largest dimension.

Hereinafter, a method of manufacturing a polarizing plate using the adhesive using the metal oxide will be described in detail.

The manufacturing method of the polarizing plate consists of a polarizer manufacturing process, an adhesive coating process, and an adhesive process for bonding the polarizer and the polarizer protective layer.

(1) Polarizer manufacturing process

The polarizer is treated with polyvinyl alcohol (hereinafter referred to as 'PVA') with iodine or dichroic dye solution and then stretched so that the iodine or dye molecules are arranged side by side in the stretching direction. Says floor.

In the present invention, the polarizer uses PVA having a degree of polymerization of 1,700 to 2,800 and a degree of reduction of 80% to 99.9%. It is preferable that PVA thickness is 40 micrometers-80 micrometers. The PVA film is washed with water at 10 ° C to 35 ° C.

When the degree of polymerization of PVA is less than 1,700, the optical properties may be degraded as a polarizer, and when the degree of polymerization is greater than 2,800, the mechanical performance for processing the polarizer may be out of range. In addition, the saponification degree is preferably maintained in a range of saponification degree for the reliability and durability of the polarizer after the processing, the lamination of the polarizer and the polarizer protective layer.

If the PVA thickness is smaller than 40 μm, it is difficult to obtain the desired thickness in the present invention after PVA stretching, and if the PVA thickness is larger than 80 μm, the stretching should be more than normal, and the PVA may be uneven overall. If the temperature of the water for cleaning the PVA film is too high or too low, it may not maintain the state after stretching and the PVA film may shrink or be affected by physical properties.

The washed PVA is swollen in water in which 8% by weight or less of boric acid or borax is dissolved. When swelling, the water temperature is preferably 15 ° C. to 40 ° C., and the swelling time is preferably 30 seconds to 5 minutes.

If the content of boric acid or borax is greater than 8% by weight, the PVA is not excessively swollen and the dyeing of the dichroic material is not good, which may adversely affect the optical and appearance properties of the polarizer.

In addition, when the temperature of the water when the swelling is lower than 15 ℃ the reaction with boric acid or borax and the PVA film swelling reaction by water is not active, if higher than 40 ℃ the swelling is excessively vigorously difficult to control. If the swelling time is too short, the desired degree of swelling state cannot be obtained. If the swelling time is too long, the physical properties of the PVA can be changed.

The swollen PVA film is dissolved in water in a ratio of 1: 2 to 1: 150 of iodine and potassium iodide or ammonium iodide to dye a concentration of 0.0001% to 0.1% by weight. The time of dyeing proceeds for 7 seconds to 10 minutes. In addition, when the dyeing exaggeration temperature is carried out in the range of 25 ℃ to 45 ℃ (deposition process).

The ratio of iodine and potassium iodide or ammonium iodide is mixed in order to obtain a proper level of dyeing, and when it is out of the range of 1: 2 to 1: 150, the amount of iodine ions that are salted is insufficient or excessively high, resulting in uniform optical properties and color values. Hard to get If the concentration of iodine and potassium iodide or ammonium iodide is less than 0.0001% by weight, even if dyeing occurs, the amount of dyeing is extremely small, so that the optical properties to be obtained are difficult to be obtained. It becomes a polarizing film.

It is preferable that the dyeing time under the mixing ratio and concentration conditions proceeds in the above-described range.

After dyeing, crosslinking is performed using boric acid or borax of 8% or less, and the PVA film is stretched 3 to 7 times in water at 40 ° C to 60 ° C. The stretched PVA film is dried in a dryer at a temperature of 40 ° C. to 85 ° C. for 1 to 10 minutes.

If the boric acid or borax concentration is less than 0.1%, the crosslinking reaction is not active, and if it is greater than 8%, the crosslinking reaction may occur excessively. The range that can be stretched while satisfying the durability and optical properties of the PVA film is 3 to 7 times.

After the swelling process and the crosslinking process as in the present invention, the stretching process may be performed, or after the stretching process, the crosslinking process may be performed again.

The polarizing plate of the present invention is prepared by adhering the transparent protective film and the polarizer using the adhesive.

(2) Adhesive manufacturing and coating process

It is preferable that the adhesive agent in this invention manages the temperature from preparation to application | coating by mixing of a transparent polymer resin and a crosslinking agent. By controlling the temperature of the adhesive, the water resistance and the stability of the metal oxide can be further improved. It is preferable to make management temperature of an adhesive agent into the range of 20-50 degreeC. More preferably, it is 25-45 degreeC, More preferably, it is 30-40 degreeC. If it is less than 20 degreeC, it becomes difficult to use it as an adhesive because it is likely to gelatinize immediately after mixing a crosslinking agent, and when it exceeds 50 degreeC, peeling between a protective film and a polarizer will occur easily, and it will become difficult to use as an adhesive agent.

In the present invention, the adhesive coating process includes a method of applying an adhesive in advance to bond the polarizer and the polarizer protective layer, and a method of dropping the adhesive when the polarizer and the polarizer protective layer are laminated.

In the case of the method of apply | coating an adhesive agent previously in this invention, an adhesive agent may be apply | coated to either a transparent protective film or a polarizer, or may apply to both. After adhesion | attachment, a drying process is performed and the adhesive layer which consists of an application dry layer is formed.

In the present invention, the coating method is not particularly limited, and various means such as a roll method, a spray method, and a dipping method can be adopted.

Although the thickness of an adhesive bond layer is not specifically limited, The thickness after drying is 1 nm-500 nm, for example, Preferably it is 10 nm-300 nm, More preferably, it is 20 nm-100 nm.

(3) Polarizer protective layer adhesion process

In the present invention, in the method of adhering the polarizer protective layer to the polarizer, the device-dried polarizer is precipitated in a PVA solution to apply an adhesive, and then the polarizer protective layer is adhered to both sides of the polarizer.

When the polarizer protective layer is bonded to both sides of the polarizer, a polarizer and a polarizer protective layer are injected through a roller, and the polarizer plate in which the polarizer and the polarizer protective layer are combined is completed through product drying. The polarizer and the polarizer protective layer adhere to each other according to a roll-to-roll method, and the roll-to-roll method used in the present invention is a down-top method and a top-down method. It adopts either method or horizontal lamination method.

The present invention enhances the short wavelength light leakage control effect by introducing a metal oxide as well as iodine as the short wavelength light leakage control means while maintaining the long wavelength light leakage control effect by the boron compound.

Therefore, the use of iodine can be lowered in the manufacturing process of the polarizer, nevertheless, it is possible to realize a higher short wavelength light leakage control effect by the metal oxide, and as a result, the difference generated in the light leakage control process between the iodine and the boron compound Since the action phenomenon can be lowered, it is possible to implement a polarizing plate having good optical characteristics in the visible light propagation band.

Using a polarizing plate manufactured from the examples, the single transmittance (Ts), parallel transmittance (TP), orthogonal transmittance (Tc), and polarization degree (PE) were measured. In the comparative example, the experiment was carried out using an adhesive for PVA which is generally used for the adhesion of the polarizer 10 and the polarizer protective layer 20 to which no metal oxide was added.

Example 1

(a) Preparation of Polarizer 10

The polyvinyl alcohol film having a thickness of 75 μm was moved by using a guide roll, and immersed and dyed in a dye solution of iodine and potassium iodine, and then stretched about 3 to 5 times. The film was introduced into a bath of boric acid and potassium iodide, crosslinked, and dried at 80 ° C. for 5 to 8 minutes to obtain a polarizing film.

(b) Preparation of Adhesives Containing Metal Oxides

Polyvinyl alcohol (average degree of polymerization 2000, 99.9%) was dissolved in methanol to prepare a solution of 3.0%. To the polyvinyl alcohol solution prepared above, the metal compound TiO ₂ was added at 1% by weight per 100% by weight of the adhesive composition, and glutaraldehyde was added at 0.3% by weight per 100% by weight of the adhesive composition to the prepared polyvinyl alcohol solution. Add and mix with stirring.

(c) Preparation of Polarizing Plate 40

Using the adhesive prepared above, a saponified TAC film having a thickness of 80 μm as the polarizer protective layer 20 while applying the adhesive layer 30 to both surfaces of the polarizer 10 at a thickness of 50 μm and maintaining 35 ° C. After adhering, laminating and drying, a polarizing plate 40 was prepared.

Example 2

3 wt% of the metal oxide TiO ₂ was added in the process of preparing the adhesive composition to prepare the same conditions as in Example 1.

Example 3

5 wt% of the metal oxide TiO ₂ was added in the process of preparing the adhesive composition to prepare the same conditions as in Example 1.

Comparative Example 1

Except not adding a metal oxide TiO ₂ in the process of preparing the adhesive composition was prepared under the same conditions as in Example 1.

Remarks Comparative example Example 1 Example 2 Example 3 Metal Oxide Concentration Jungnang% 0 One 3 5 Ts (group transmittance) % 43.15 43.07 43.12 43.17 TP (parallel transmission rate) % 37.28 37.16 37.19 37.32 Tc (Orthogonal Transmittance) % 0.019 0.015 0.008 0.007 PE (polarization degree) % 99.949 99.960 99.979 99.981 450nm (Tc) % 0.0151 0.0112 0.0083 0.0068 550nm (Tc) % 0.0149 0.0105 0.0079 0.0060 650nm (Tc) % 0.0205 0.0198 0.0201 0.0197

The transmittance | permeability was calculated | required using the following formula.

Transmittance = 100 × I _out / I _in (%)

Where I _in : incident light and I _out : transmitted light

Single transmittance (Ts): Total light transmittance of one polarizing plate. (%)

Parallel transmittance (TP): Total light transmittance when two polarizing plates are overlapped in parallel with each other. (%)

Orthogonal Transmittance (Tc): Total light transmittance when the polarizing axes of two polarizing plates are orthogonal and overlapped. (%)

Polarization degree was calculated | required using the following formula.

Polarization degree (PE) = [(TP-Tc) / (TP + Tc)] ^1/2 * 100 (%)

As shown in Table 1, it can be verified that as the addition concentration of the metal oxide increases, the orthogonal transmittance decreases and the polarization increases at the same level of transmittance and parallel transmittance. In addition, as the addition concentration of the metal oxide increased, the light emission control ability of the medium wavelength (550 nm) and the short wavelength (450 nm) was improved, but the light wavelength control ability of the long wavelength band (650 nm) was the same level.

As a result, by applying a metal oxide to the adhesive, it is possible to produce a polarizing plate having excellent optical characteristics in the visible light propagation band by exhibiting the light leakage control effect in the short wavelength band while maintaining the long wavelength light leakage control effect by the boron compound.

In the above, this invention was demonstrated in detail with reference to an Example and a comparative example centering on a structure. However, the scope of the present invention is not limited to the above embodiments, but may be embodied in various forms of embodiments within the scope of the appended claims. Without departing from the gist of the invention as claimed in the claims, any person of ordinary skill in the art is deemed to be within the scope of the claims underlying the present invention to the extent possible for various modifications.

1 is a polarizing plate bonded to the upper and lower sides of the polarizer protective layer according to the present invention.

<Explanation of symbols for the main parts of the drawings>

10: polarizer

20: polarizer protective layer

30: adhesive layer containing metal oxide

40: polarizer

Claims (10)

In the adhesive for polarizing plates containing an adhesive composition and a dispersing agent containing a transparent polymer resin, a water-soluble crosslinking agent, and a metal oxide, In 100% by weight of the adhesive composition, Iii) 50% by weight to 95% by weight of the transparent polymer resin Ii) 0.01 wt% to 0.5 wt% of the water-soluble crosslinking agent Iii) 0.1 wt% to 5 wt% of the metal oxide having a size of 1 nm to 200 nm, The dispersing agent adhesive for a polarizing plate, characterized in that 20 to 110 parts by weight based on 100 parts by weight of the adhesive composition. The method of claim 1, The transparent polymer resin is at least one of a polyvinyl alcohol compound, a polyurethane compound, a polyester compound, a polyacrylic compound, a polyepoxy compound or a polycyanoacrylate compound. The method of claim 1, The water-soluble crosslinking agent is a polarizing plate adhesive comprising a polyethylene terephthalate polarizer protective layer, characterized in that at least one of boric acid, borax, glutaraldehyde, melamine, oxalic acid, chitin, chitosan or alcohol solvents. The method of claim 1, The dispersant may be a saturated hydrocarbon alcohol having 1 to 8 carbon atoms, a saturated hydrocarbon ketone having 1 to 8 carbon atoms, a saturated hydrocarbon diketone having 1 to 8 carbon atoms, a saturated hydrocarbon ester having 1 to 8 carbon atoms, or an ethyl alcohol of an ether alcohol. Solv, methyl cellosolve, butyl cellosolve, 1-methoxy-2-propanol, N-methyl pyrrolidone, ethyl cellosolve acetate and diacetone alcohol, characterized in that the organic solvent used alone or in combination Adhesive for polarizing plate to do. The method of claim 4, wherein Said saturated hydrocarbon alcohol is methanol, isopropanol, butanol, t-butanol or isobutanol singly or mixed, The adhesive for polarizing plates characterized by the above-mentioned. The method of claim 4, wherein Said saturated hydrocarbon ketone is acetone, methyl ethyl ketone, or methyl isobutyl ketone. The method of claim 4, wherein The saturated hydrocarbon diketone is acetyl acetone adhesive for polarizing plate, characterized in that. The method of claim 4, wherein The saturated hydrocarbon-based ester is an adhesive for a polarizing plate, characterized in that the ethyl acetate, butyl acetate alone or mixed. The method of claim 1, The metal oxide is indium (In), titanium (Ti), zirconium (Zr), bismuth (Bi), tin (Sn), zinc (Zn), antimony (Sb), tantalum (Ta), cerium (Ce), neo Adhesive for polarizing plates comprising at least one of oxides, manganese (Mn) and iron (Fe) for sodium (Nd), lanthanum (La), triumium (Th), magnesium (Mg) or gallium (Ga) . delete

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