Method for peptizing UV polaroid

Abstract

The invention discloses a peptizing method of a UV polaroid, a PVA protective layer of the polaroid is at least one of a polymethyl methacrylate material or a cellulose triacetate material, glue between the PVA protective layer and a PVA layer is UV glue, and the peptizing method comprises the following steps: S1, cutting a sample to be detected and stripping a release film and a protective film to obtain a sample sheet A; s2, the sample sheet A is placed in a mixed solution of ethyl alcohol and water to be soaked for 10 s to 30 s, the soaking temperature is 20 DEG C to 30 DEG C, and a sample sheet B is obtained after the sample sheet A is taken out; and S3, putting the sample sheet B in a peptizing solution at the temperature of 20-40 DEG C for peptizing for 10-65 minutes, taking out the sample sheet B after peptizing, and stripping and removing the PVA protection layer at the temperature of 20-40 DEG C to obtain the PVA layer. The method overcomes the defects in the prior art, and can better separate the upper and lower PVA protection layers and the PVA layer of the polaroid.

Description

Technical Field

[0001] The invention relates to the technical field of polarizers, and in particular to a method for peptizing a UV polarizer. Background Art

[0002] The basic structure of polarizer mainly includes: protective film (PET), PVA layer, UV light curing adhesive layer, upper and lower PVA protective layers, PSA (pressure sensitive adhesive) layer, release film, such as Figure 1 In the production process of polarizers, UV light-curing glue is usually used to laminate the upper and lower PVA protective layers with the PVA layer. This is a high-efficiency, energy-saving, and environmentally friendly high-tech curing technology. When the colloid is irradiated with high-energy ultraviolet light as the curing energy source, the photoinitiator in the system absorbs the ultraviolet light to generate free radicals, which trigger a chain polymerization reaction between the photosensitive resin (prepolymer) and the reactive diluent molecules. The liquid phase system is polymerized, cross-linked, and cured instantly. This is an extremely important step in the production process of polarizers.

[0003] In the actual production process, the production line is relatively complex, and the cleanliness of some areas does not meet high standards, which leads to foreign matter being easily entrained and wrapped in the polarizer during the production process. Due to the high adhesion, high temperature resistance, high hardness and toughness of UV light-curing adhesive, the upper and lower PVA protective layers are firmly bonded to the PVA layer, making it difficult to peel them off under normal circumstances. This greatly increases the difficulty of detecting foreign matter sandwiched between the upper and lower PVA protective layers and the PVA during the production process, making it impossible to promptly discover and analyze the composition of the foreign matter, thereby affecting the yield of the polarizer.

[0004] Since the UV light-curing adhesives used in polarizers are mainly divided into cationic curing UV adhesives and free radical / cationic mixed UV adhesives, the reactions are mainly divided into cationic curing reactions and free radical curing reactions. The cationic curing reaction is based on cationic light-curing epoxy resins. The photoinitiators mainly composed of sulfonium salts and iodonium salts are activated to an excited state after absorbing ultraviolet light energy. The molecules undergo a series of decomposition reactions, and eventually produce super strong proton acids or Lewis acids as active species, which trigger cationic polymerization reactions of glycidyl or alicyclic epoxy groups, vinyl ethers, etc., and then cure into a cross-linked network. The free radical curing reaction is that the free radical photoinitiator obtains an excited state after absorbing ultraviolet light, and then generates highly active free radicals through chemical bond cleavage or molecular hydrogen abstraction, which triggers the polymerization of acrylate double bonds on the resin and monomer, and then cures into a cross-linked network. This makes it difficult to separate the upper and lower PVA protective layers from the PVA layer in polarizers. Existing technology relies solely on marking samples using an optical microscope. This method cannot promptly analyze the composition of foreign matter during production and implement appropriate remedial measures, which can easily lead to a decline in product quality and yield over a large area. Therefore, there is an urgent need to develop a UV polarizer gelation method to further improve foreign matter detection capabilities and thereby increase the yield of polarizers. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for peptization of UV polarizers, which overcomes the shortcomings of the prior art.

[0006] In order to solve the above problems, the technical solutions adopted by the present invention are as follows:

[0007] A method for gelling a UV polarizer, wherein the PVA protective layer of the polarizer is made of at least one of polymethyl methacrylate and triacetyl cellulose, and the glue between the PVA protective layer and the PVA layer is UV glue, comprising the following steps:

[0008] S1, cutting the sample to be tested and peeling off the release film and protective film to obtain sample A;

[0009] S2, soaking sample A in a mixed solution of ethanol and water for 10s-30s at a temperature of 20°C-30°C, and taking it out to obtain sample B;

[0010] S3, placing sample B in a peptization solution at a temperature of 20°C-40°C for peptization for 10 min-65 min, taking it out after peptization, and peeling off the PVA protective layer at 20°C-40°C to obtain a PVA layer.

[0011] The size of the sample after cutting shall not exceed 60mm*60mm.

[0012] The peptization solution includes oxalic acid with a volume concentration of 10%-30%, ethanol with a volume concentration of 5%-15%, and water; the PVA protective layer is made of polymethyl methacrylate, the peptization temperature is 30°C-40°C, and the time is 20min-30min.

[0013] The peptization solution in step S3 includes butanone with a volume concentration of 10-50%, acetic acid with a volume concentration of 15%-40%, ethanol with a volume concentration of 30%-45%, tetramethylammonium chloride with a mass concentration of 5%-20%, and water; wherein the PVA protective layer is made of cellulose triacetate, the peptization temperature is 20°C-30°C, and the time is 25min-35min.

[0014] The peptization solution in step S3 comprises butanone with a volume concentration of 10-20%, acetic acid with a volume concentration of 15%-25%, ethanol with a volume concentration of 30%-40%, tetramethylammonium chloride with a mass concentration of 5%-10%, and water.

[0015] The peptization solution in step S3 comprises butanone with a volume concentration of 20-50%, acetic acid with a volume concentration of 25%-40%, ethanol with a volume concentration of 30%-45%, tetramethylammonium chloride with a mass concentration of 10%-20%, and water.

[0016] The PVA protective layers on both sides of the PVA layer of the polarizer are made of polymethyl methacrylate and triacetyl cellulose respectively, and the peptization solution in step S3 uses solution A and solution B;

[0017] Wherein, solution A comprises oxalic acid with a volume concentration of 10%-30%, ethanol with a volume concentration of 5%-15%, and water; solution B comprises butanone with a volume concentration of 10-50%, acetic acid with a volume concentration of 15%-40%, ethanol with a volume concentration of 30%-45%, tetramethylammonium chloride with a mass concentration of 5%-20%, and water;

[0018] Solution A was used to peptize the PVA protective layer made of polymethyl methacrylate at a peptization temperature of 30°C-40°C for 20 min-30 min. Solution B was used to peptize the PVA protective layer made of cellulose triacetate at a peptization temperature of 20°C-30°C for 25 min-35 min.

[0019] Compared with the prior art, the implementation effects of the present invention are as follows: the method of the present invention can better separate the upper and lower PVA protective layers and the PVA layer of the polarizer, solving the problem that foreign matter could only be observed using an optical microscope and its composition could not be detected, thereby failing to promptly issue solutions, thereby significantly improving the yield of the polarizer. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a structural diagram of the UV polarizer of the present invention;

[0021] Figure 2 Schematic diagram of the PMMA protective layer peeling principle;

[0022] Figure 3 Schematic diagram of the TAC protective layer peeling principle. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] Example 1

[0025] The polarizer to be peptized has a PVA protective layer made of polymethyl methacrylate (PMMA). The sample to be tested is cut into a size of 60mm*60mm, preferably between 30mm*30mm and 60mm*60mm. The specific cutting size can be adjusted according to actual conditions, and it is best not to exceed 60mm*60mm. The cut polarizer is then peeled off the release film and protective film to obtain sample A. Sample A is then immersed in a mixed solution of ethanol and water (ethanol by volume is 60%) for 30 seconds at a temperature of 30°C. After immersion, sample B is removed and peptized for 30 minutes in a peptization solution at a temperature of 30°C. The peptization solution comprises 30% by volume oxalic acid, 15% by volume ethanol, and the remainder is water. After peptization, the PVA protective layer and the PVA layer are peeled off at 20°C to obtain.

[0026] like Figure 2 As shown: Acetic acid acts on the UV curing agent, destroying the polar groups on the curing agent, partially breaking the polar covalent bonds between the original UV curing adhesive and the upper PVA protective layer. This weakens the polar groups in the UV curing adhesive's adsorption to the PMMA material and dissolves some of the UV curing adhesive, reducing the viscosity between the two, thereby achieving a peeling effect. Furthermore, by increasing the temperature, the reaction process is accelerated, while preventing the PVA from curling, making it easier to peel.

[0027] Example 2

[0028] The polarizer to be peptized, with a polymethyl methacrylate (PMMA) PVA protective layer, was cut into 60mm x 60mm dimensions. The release film and protective film were then peeled off to obtain Sample A. Sample A was then immersed in a mixture of ethanol and water (70% ethanol by volume) at 25°C for 20 seconds. Sample B was then removed and peptized for 25 minutes in a peptization solution at 35°C containing 20% oxalic acid, 10% ethanol, and the balance water. After peptization, the PVA protective layer and PVA layer were peeled off at 30°C to obtain the remaining PVA layer.

[0029] Example 3

[0030] The polarizer to be peptized, whose PVA protective layer is made of polymethyl methacrylate, was cut into 60mm x 60mm dimensions. The release film and protective film were then peeled off to obtain Sample A. Sample A was then immersed in a mixture of ethanol and water (80% ethanol by volume) at 20°C for 20 seconds. After removal, Sample B was obtained. Sample B was peptized for 20 minutes in a peptization solution at 40°C containing 10% oxalic acid, 5% ethanol, and the balance water. After peptization, the PVA protective layer and PVA layer were peeled off at 40°C to obtain the remaining PVA layer.

[0031] Example 4

[0032] The polarizer to be peptized, whose PVA protective layer is made of triacetyl cellulose (TAC), was cut into 60mm x 60mm dimensions. The release film and protective film were then peeled off to obtain Sample A. Sample A was then immersed in a mixture of ethanol and water (70% ethanol by volume) for 20 seconds at 25°C. After removal, Sample B was obtained. Sample B was peptized for 35 minutes in a peptization solution at 30°C containing 10% by volume butanone, 15% by volume acetic acid, 30% by volume ethanol, 5% by weight tetramethylammonium chloride, and the balance water. After peptization, the PVA protective layer and PVA layer were peeled off at 20°C to obtain the PVA protective layer and PVA layer.

[0033] like Figure 3As shown in the figure: (1) The UV light-curing glue is dissolved by butanone and an acylation reaction occurs, resulting in the appearance of acyl groups, which are then fused with hydroxyl groups, thereby separating the PVA protective layer from the PVA; (2) Butanone acts as a diluent to reduce the viscosity of the glue, thereby achieving separation between the PVA protective layer and the PVA; (3) Acetic acid acts on the UV light-curing agent, destroying the polar groups on the light-curing agent, so that the polar covalent bonds between the original UV light-curing glue and the lower PVA protective layer are partially destroyed, weakening the adsorption of the polar groups in the UV light-curing glue on the TAC material, and dissolving part of the UV light-curing glue. (4) Tetramethylammonium chloride acts as a catalyst to promote the acylation reaction during the gelation process, thereby increasing the reaction rate.

[0034] Example 5

[0035] The polarizer to be peptized, whose PVA protective layer is made of triacetyl cellulose, was cut into 60mm x 60mm dimensions. The release film and protective film were then peeled off to obtain Sample A. Sample A was then immersed in a mixture of ethanol and water (70% ethanol by volume) for 10-30 seconds at a temperature of 20°C to 30°C. After removal, Sample B was obtained. Sample B was peptized for 25 minutes in a peptization solution at 20°C containing 20% by volume butanone, 25% by volume acetic acid, 40% by volume ethanol, 10% by weight tetramethylammonium chloride, and the balance water. After peptization, the PVA protective layer and PVA layer were peeled off at 30°C to obtain the remaining PVA layer.

[0036] Example 6

[0037] The polarizer to be peptized, with a PVA protective layer made of triacetyl cellulose, was cut into 60mm x 60mm dimensions. The release film and protective film were then peeled off to obtain Sample A. Sample A was then immersed in a mixture of ethanol and water (70% ethanol by volume) for 20 seconds at 25°C. After removal, Sample B was obtained. Sample B was peptized for 30 minutes in a peptization solution at 25°C containing 15% by volume butanone, 20% by volume acetic acid, 35% by volume ethanol, 8% by weight tetramethylammonium chloride, and the balance water. After peptization, the PVA protective layer and PVA layer were peeled off at 40°C to obtain the PVA protective layer and PVA layer.

[0038] Example 7

[0039] The PVA protective layers on both sides of the PVA layer of the polarizer to be gelled are made of polymethyl methacrylate and triacetyl cellulose respectively. The sample to be tested is cut into a size of 60mm*60mm, and then the release film and the protective film are peeled off to obtain sample A; then A is placed in a mixed solution of ethanol and water (the volume fraction of ethanol is 70%) and immersed for 20s at a temperature of 25°C. After being taken out, sample B is obtained; sample B is placed in a solution A comprising 30% by volume oxalic acid, 5% by volume ethanol and the balance being water to gelate the PVA protective layer made of polymethyl methacrylate, and the gelation temperature is 3 0℃, time 20min; after peptization, take out and peel off the PVA protective layer made of polymethyl methacrylate at 20℃, and then wash with water at 20℃ for 40s; then, peptize the PVA protective layer made of triacetyl cellulose on the other side in solution B including 10% by volume butanone, 40% by volume acetic acid, 45% by volume ethanol, 20% by mass tetramethylammonium chloride and the balance water, at a peptization temperature of 20℃ and a time of 35min; after peptization, peel off the PVA protective layer made of triacetyl cellulose at 20℃ to obtain a PVA protective layer and a PVA layer.

[0040] Example 8

[0041] The PVA protective layers on both sides of the PVA layer of the polarizer to be peptized are made of polymethyl methacrylate and triacetyl cellulose, respectively. The sample to be tested is cut into a size of 60mm*60mm, and then the release film and the protective film are peeled off to obtain sample A; then A is placed in a mixed solution of ethanol and water (the volume fraction of ethanol is 70%) and immersed for 20s at a temperature of 25°C. After being taken out, sample B is obtained; sample B is placed in a solution A comprising oxalic acid with a volume concentration of 20%, ethanol with a volume concentration of 10% and the balance being water to peptize the PVA protective layer made of polymethyl methacrylate. The peptization temperature is 25°C. The temperature is 35°C for 25 minutes; after the peptization, the PVA protective layer made of polymethyl methacrylate is taken out and peeled off at 25°C, and then washed with water at a temperature of 30°C for 20 seconds; then, the PVA protective layer made of triacetyl cellulose on the other side is peptized in a solution B including 15% by volume of butanone, 20% by volume of acetic acid, 35% by volume of ethanol, 8% by mass of tetramethylammonium chloride and the balance of water, at a peptization temperature of 25°C for 30 minutes; after the peptization, the PVA protective layer made of triacetyl cellulose is peeled off at 30°C to obtain a PVA protective layer and a PVA layer.

[0042] Example 9

[0043] The PVA protective layers on both sides of the PVA layer of the polarizer to be peptized are made of polymethyl methacrylate and triacetyl cellulose, respectively. The sample to be tested is cut into a size of 60mm*60mm, and then the release film and the protective film are peeled off to obtain sample A; then A is placed in a mixed solution of ethanol and water (the volume fraction of ethanol is 70%) and immersed for 20s at a temperature of 25°C. After being taken out, sample B is obtained; sample B is placed in a solution A comprising 10% by volume oxalic acid, 15% by volume ethanol and the balance being water to peptize the PVA protective layer made of polymethyl methacrylate. The peptization temperature is 40°C, time 30 min; after peptization, take out and peel off the PVA protective layer made of polymethyl methacrylate at 30°C, and then wash with water at a temperature of 40°C for 10s; then, peptize the PVA protective layer made of triacetyl cellulose on the other side in solution B including 50% by volume of butanone, 15% by volume of acetic acid, 30% by volume of ethanol, 5% by mass of tetramethylammonium chloride and the balance of water, at a peptization temperature of 30°C and a time of 25 min; after peptization, peel off the PVA protective layer made of triacetyl cellulose at 40°C to obtain a PVA protective layer and a PVA layer.

[0044] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for peptization of a UV polarizer, characterized in that: The following steps are involved: S1, cutting the sample to be tested and peeling off the release film and protective film to obtain sample A; S2, soaking sample A in a mixed solution of ethanol and water for 10s-30s at a temperature of 20°C-30°C, and taking it out to obtain sample B; S3, placing sample B in a peptization solution at a temperature of 20°C-40°C for peptization for 10 minutes-65 minutes; taking out after peptization, peeling off the PVA protective layer at 20°C-40°C to obtain a PVA layer.

2. The method for peptization of a UV polarizer according to claim 1, wherein: The size of the sample after cutting shall not exceed 60mm*60mm.

3. The method for peptization of a UV polarizer according to claim 1, wherein: The peptization solution includes oxalic acid with a volume concentration of 10%-30%, ethanol with a volume concentration of 5%-15%, and water; wherein the PVA protective layer is made of polymethyl methacrylate, the peptization temperature is 30°C-40°C, and the time is 20min-30min.

4. The method for peptization of a UV polarizer according to claim 1, wherein: The peptization solution in step S3 includes butanone with a volume concentration of 10-50%, acetic acid with a volume concentration of 15%-40%, ethanol with a volume concentration of 30%-45%, tetramethylammonium chloride with a mass concentration of 5%-20%, and water; wherein the PVA protective layer is made of cellulose triacetate, the peptization temperature is 20°C-30°C, and the time is 25min-35min.

5. The method for peptization of a UV polarizer according to claim 4, wherein: The peptization solution in step S3 includes butanone with a volume concentration of 10-20%, acetic acid with a volume concentration of 15%-25%, ethanol with a volume concentration of 30%-40%, tetramethylammonium chloride with a mass concentration of 5%-10%, and water.

6. The method for peptization of a UV polarizer according to claim 4, wherein: The peptization solution in step S3 includes butanone with a volume concentration of 20-50%, acetic acid with a volume concentration of 25%-40%, ethanol with a volume concentration of 30%-45%, tetramethylammonium chloride with a mass concentration of 10%-20%, and water.

7. The method for peptization of a UV polarizer according to claim 1, wherein: The PVA protective layers on both sides of the PVA layer of the polarizer are made of polymethyl methacrylate and triacetyl cellulose respectively, and the peptization solution in step S3 uses solution A and solution B; Wherein, solution A comprises oxalic acid with a volume concentration of 10%-30%, ethanol with a volume concentration of 5%-15%, and water; solution B comprises butanone with a volume concentration of 10-50%, acetic acid with a volume concentration of 15%-40%, ethanol with a volume concentration of 30%-45%, tetramethylammonium chloride with a mass concentration of 5%-20%, and water; Solution A was used to peptize the PVA protective layer made of polymethyl methacrylate at a peptization temperature of 30°C-40°C for 20 min-30 min. Solution B was used to peptize the PVA protective layer made of cellulose triacetate at a peptization temperature of 20°C-30°C for 25 min-35 min.

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