Preparation method of high-temperature-resistant and wet-resistant vehicle-mounted polaroid

Abstract

The invention discloses a preparation method of a high-temperature-resistant and wet-resistant vehicle-mounted polaroid, and belongs to the technical field of polaroid production, and the preparation method is characterized by comprising the following steps: removing free iodine on a film surface of a dyed and stretched PVA film, curing and complementing color, drying, and attaching a protective layer to obtain the polaroid, the polaroid has the advantages that the polarizing film can keep good performance in the aspect of high temperature and humidity resistance, especially under the condition that the relative humidity is 85% at 85 DEG C, the polarization losing phenomenon cannot be generated, and the polaroid has better high temperature and humidity resistance and can be suitable for severe environments.

Description

Technical Field

[0001] The present application relates to the technical field of polarizer production, and more specifically, it relates to a preparation method of a high-temperature and high-humidity resistant polarizer for vehicle use. Background Art

[0002] Vehicle polarizers need to adapt to the complex environmental conditions inside the vehicle. For example, the temperature inside the vehicle can vary greatly in different seasons and regions. In hot summers, the temperature inside the vehicle can be very high, and the polarizer should be able to maintain stable performance in high-temperature environments without problems such as deformation and discoloration. In cold winters, the low-temperature environment should not affect its polarization function and mechanical properties, etc. At the same time, the humidity inside the vehicle also fluctuates greatly, and the polarizer should have good moisture resistance to prevent problems such as delamination and performance degradation after being exposed to moisture. This is because during the use of the vehicle, it will experience various climatic conditions, and the polarizer must be reliable and durable to ensure long-term normal operation.

[0003] The main existing method for producing polarizers is that after PVA is dyed and stretched, it is mainly cross-linked and cured with boric acid. During the preparation process, free iodine exists in the coating material, which will reduce the weather resistance of the optical film. Because free iodine will decompose under environmental conditions such as light, high temperature, and humidity, it will damage the structure of the film material and reduce the weather resistance of the film material. Therefore, the polarizing film prepared by this method has poor high-temperature and high-humidity resistance performance, especially poor durability under the conditions of 85°C and 85% relative humidity, and is prone to polarization loss. For the above reasons, it is of great significance to study a preparation method of a polarizer with high-temperature and high-humidity resistance, especially with high durability under the conditions of 85°C and 85% relative humidity. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a preparation method of a high-temperature and high-humidity resistant polarizer for vehicle use. The advantage of this preparation method is that it can effectively make the polarizing film maintain good performance in terms of high-temperature and high-humidity resistance, especially under the conditions of 85°C and 85% relative humidity, without polarization loss.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A preparation method of a high-temperature and high-humidity resistant polarizer for vehicle use, comprising the following steps:

[0006] (1) Washing and swelling of the PVA film: After the PVA film is unrolled, it is immersed in pure water at 15°C - 35°C for 15s - 180s;

[0007] (2) Dyeing of the PVA film: The swollen PVA film is put into a dyeing tank for dyeing. The dyeing solution in the dyeing tank contains 0.01% - 0.3% iodine, 0.1% - 5% potassium iodide, and 0.1% - 3% boric acid;

[0008] (3) Washing of PVA film: Put the dyed PVA film into a washing tank to wash away the dyeing solution;

[0009] (4) Stretching of PVA film: Stretch the washed PVA film by 4 - 7 times;

[0010] (5) Cleaning of free iodine in PVA optical film: Immerse the stretched PVA film in a cleaning tank, where the concentration of free iodine remover in the cleaning tank is 0.1% - 4%, boric acid is 1% - 4%, the temperature is 5°C - 30°C, and the time is 2s - 20s;

[0011] (6) Curing and color compensation: Put the cleaned PVA optical film into a curing and color compensation tank, where the concentration of potassium iodide is 1% - 10%, the concentration of boric acid is 1% - 4%, the temperature is 5°C - 45°C, and the time is 3s - 60s;

[0012] (7) Drying and lamination: After drying the PVA film, laminate and protect the upper and lower surfaces with TAC film to obtain a polarizer.

[0013] Further preferably in the present invention: In step (4), the stretched PVA film is immersed in a solution containing a free iodine remover, the concentration of the free iodine remover is 0.1% - 10%, the concentration of boric acid in the free iodine remover solution is 1% - 4%, the temperature of the free iodine remover solution is 5°C - 30°C, and the residence time of the PVA film in the solution containing the free iodine remover is 2s - 20s.

[0014] Further preferably in the present invention: The free iodine remover includes any one or a combination of several of sodium bicarbonate, potassium bicarbonate, sodium bisulfite, potassium bisulfite, disodium hydrogen phosphate, or dipotassium hydrogen phosphate.

[0015] Further preferably in the present invention: A cross - linker is added to the curing and color compensation tank in step (4), and the concentration of the cross - linker is 0.5% - 3.5%.

[0016] Further preferably in the present invention: The cross - linker in the curing and color compensation solution includes any one or a combination of several of calcium chloride, calcium nitrate, zirconium chloride, zirconium sulfate, or zirconium nitrate.

[0017] In summary, the present invention has the following advantages:

[0018] Through the preparation method designed by the present invention, after the PVA optical film is dyed and stretched, it is immersed in a solution containing a free iodine remover, and then after curing and color compensation with the addition of a cross - linker, the high - temperature and high - humidity resistance of the polarizer is significantly improved. It can effectively enable the polarizing film to maintain good performance in terms of high - temperature and high - humidity resistance, especially under the conditions of 85°C and 85% relative humidity, without generating polarization loss. The polarizer has better high - temperature and high - humidity resistance and can be applied to harsh environments. Specific embodiments

[0019] The following further elaborates on the preferred embodiments of the present invention. These embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific operation processes are given.

[0020] Example 1

[0021] The polarizer in this Example 1 is prepared according to the following steps:

[0022] 1. After the PVA film is washed and swollen in pure water at 25°C for 100 s, it is dyed in a dyeing solution with an iodine concentration of 0.1%, a potassium iodide concentration of 3%, and a boric acid concentration of 1.5%. Then, after washing, it is stretched 6 times in a stretching solution.

[0023] 2. The optical film stretched in Step 1 is immersed in a cleaning tank with a free iodine remover concentration of 1%, boric acid of 4%, a temperature of 15°C, and a time of 5 s.

[0024] 3. The optical film after removing free iodine in Step 2 is immersed in a curing and color compensation solution with a crosslinking agent concentration of 1%, a potassium iodide concentration of 5%, a boric acid concentration of 3.5%, and a temperature of 7°C for 10 s.

[0025] 4. The polarizer after curing and color compensation in Step 3 is placed in a hot air oven for drying, and finally, it is conventionally laminated with the treated TAC to obtain a polarizer sample. The optical performance change of the polarizer sample under the conditions of 85°C and 85% relative humidity for 500 h is tested.

[0026] Example 2

[0027] The polarizer in this Example 2 is prepared according to the following steps:

[0028] 1. After the PVA film is washed and swollen in pure water at 25°C for 100 s, it is dyed in a dyeing solution with an iodine concentration of 0.1%, a potassium iodide concentration of 3%, and a boric acid concentration of 1.5%. Then, after washing, it is stretched 6 times in a stretching solution.

[0029] 2. The optical film stretched in Step 1 is immersed in a cleaning tank with a free iodine remover concentration of 1%, boric acid of 4%, a temperature of 15°C, and a time of 5 s.

[0030] 3. The optical film after removing free iodine in Step 2 is immersed in a curing and color compensation solution with a crosslinking agent concentration of 3%, a potassium iodide concentration of 5%, a boric acid concentration of 3.5%, and a temperature of 7°C for 10 s.

[0031] 4. The polarizer after curing and color compensation in Step 3 is placed in a hot air oven for drying, and finally, it is conventionally laminated with the treated TAC to obtain a polarizer sample. The optical performance change of the polarizer sample under the conditions of 85°C and 85% relative humidity for 500 h is tested.

[0032] Example 3

[0033] The polarizer in this Example 3 is prepared according to the following steps:

[0034] 1. After the PVA film is washed and swollen in pure water at 25°C for 100 s, it is dyed in a dyeing solution with an iodine concentration of 0.1%, a potassium iodide concentration of 3%, and a boric acid concentration of 1.5%. After washing, it is stretched 6 times in a stretching solution.

[0035] 2. The optical film stretched in step 1 is immersed in a cleaning tank with a free iodine remover concentration of 4%, boric acid of 4%, a temperature of 15°C, and a time of 5 s.

[0036] 3. The optical film after removing free iodine in step 2 is immersed in a curing and color compensating solution with a crosslinking agent concentration of 1%, a potassium iodide concentration of 5%, a boric acid concentration of 3.5%, and a temperature of 7°C for 10 s.

[0037] 4. The polarizer after curing and color compensating in step 3 is dried in a hot air oven, and finally conventionally laminated with the treated TAC to obtain a polarizer sample, and the 500H optical performance change of the polarizer sample under the conditions of 85°C and 85% relative humidity is tested.

[0038] Example 4

[0039] The polarizer in this Example 4 is prepared according to the following steps:

[0040] 1. After the PVA film is washed and swollen in pure water at 25°C for 100 s, it is dyed in a dyeing solution with an iodine concentration of 0.1%, a potassium iodide concentration of 3%, and a boric acid concentration of 1.5%. After washing, it is stretched 6 times in a stretching solution.

[0041] 2. The optical film stretched in step 1 is immersed in a cleaning tank with a free iodine remover concentration of 4%, boric acid of 4%, a temperature of 15°C, and a time of 5 s.

[0042] 3. The optical film after removing free iodine in step 2 is immersed in a curing and color compensating solution with a crosslinking agent concentration of 3%, a potassium iodide concentration of 5%, a boric acid concentration of 3.5%, and a temperature of 7°C for 10 s.

[0043] 4. The polarizer after curing and color compensating in step 3 is dried in a hot air oven, and finally conventionally laminated with the treated TAC to obtain a polarizer sample, and the 500H optical performance change of the polarizer sample under the conditions of 85°C and 85% relative humidity is tested.

[0044] Example 5

[0045] The polarizer in this Example 5 is prepared according to the following steps:

[0046] 1. After swelling the PVA film in pure water at 25°C for 100 s, it is dyed in a dyeing solution with an iodine concentration of 0.1%, a potassium iodide concentration of 3%, and a boric acid concentration of 1.5%. Then, after washing, it is stretched 6 times in a stretching solution.

[0047] 2. The optical film stretched in step 1 is immersed in a cleaning tank with a free iodine remover concentration of 1%, boric acid of 4%, a temperature of 15°C, and a time of 5 s.

[0048] 3. The optical film after removing free iodine in step 2 is immersed in a curing and color - compensating solution with a potassium iodide concentration of 5%, a boric acid concentration of 3.5%, and a temperature of 7°C for 10 s.

[0049] 4. The polarizer after color - compensation in step 3 is dried in a hot - air oven and finally conventionally laminated with the treated TAC to obtain a polarizer sample, and the 500H optical property change of the polarizer sample is tested under the conditions of 85°C and 85% relative humidity.

[0050] Example 6

[0051] The polarizer in this Example 6 is prepared according to the following steps:

[0052] 1. After swelling the PVA film in pure water at 25°C for 100 s, it is dyed in a dyeing solution with an iodine concentration of 0.1%, a potassium iodide concentration of 3%, and a boric acid concentration of 1.5%. Then, after washing, it is stretched 6 times in a stretching solution.

[0053] 2. The optical film stretched in step 1 is immersed in a cleaning tank with boric acid of 4%, a temperature of 15°C, and a time of 5 s.

[0054] 3. The optical film after cleaning in step 2 is immersed in a curing and color - compensating solution with a cross - linker concentration of 1%, a potassium iodide concentration of 5%, a boric acid concentration of 3.5%, and a temperature of 7°C for 10 s.

[0055] 4. The polarizer after curing and color - compensation in step 3 is dried in a hot - air oven and finally conventionally laminated with the treated TAC to obtain a polarizer sample, and the 500H optical property change of the polarizer sample is tested under the conditions of 85°C and 85% relative humidity.

[0056] Comparative Example 1

[0057] The polarizer in this Comparative Example 1 is prepared according to the following steps:

[0058] 1. After swelling the PVA film in pure water at 25°C for 100 s, it is dyed in a dyeing solution with an iodine concentration of 0.1%, a potassium iodide concentration of 3%, and a boric acid concentration of 1.5%. Then, after washing, it is stretched 6 times in a stretching solution.

[0059] 2. Immerse the optical film stretched in Step 1 in a cleaning tank with 4% boric acid, at a temperature of 15°C for 5 s.

[0060] 3. Immerse the optical film cleaned in Step 2 in a curing and color compensation solution with a potassium iodide concentration of 5%, a boric acid concentration of 3.5%, and a temperature of 7°C for 10 s.

[0061] 4. Place the polarizer after color compensation in Step 3 in a hot air oven for drying, and finally perform conventional lamination with the treated TAC to obtain a polarizer sample. Test the change in the optical properties of the polarizer sample under the conditions of 85°C and 85% relative humidity for 500 h.

[0062] Detect the examples and comparative examples under high-temperature and high-humidity conditions, and the results are shown in Table 1.

[0063] Table 1 Comparison table of the detection results of the optical properties of examples and comparative examples under high-temperature and high-humidity conditions

[0064]

[0065] The beneficial effects of the present invention are as follows:

[0066] As can be seen from Table 1, compared with the polarizers of the comparative examples, the polarizers of Examples 5 and 6 prepared by the present invention also have a significant improvement in optical properties under the high-temperature and high-humidity conditions of 85°C and 85% relative humidity when adding a free iodine remover or a crosslinking agent alone; when the free iodine remover and the crosslinking agent act together, the high-temperature and high-humidity resistance performance is better, and with the increase of the concentrations of the free iodine remover and the crosslinking agent, the high-temperature and high-humidity resistance performance is even better. As described above, the polarizer prepared according to the present invention has better high-temperature and high-humidity resistance performance than the conventional polarizer and can be applied to harsh environments.

[0067] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the design concept of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a high temperature and humidity resistant vehicle-mounted polarizer, characterized in that The steps include: (1) PVA film washing and swelling: After unwinding, the PVA film is soaked in 15℃-35℃ pure water for 15s-180s; (2) PVA film dyeing: The swollen PVA film is placed in a dyeing tank for dyeing. The dyeing solution in the dyeing tank contains 0.01%-0.3% iodine, 0.1%-5% potassium iodide, and 0.1%-3% boric acid; (3) PVA film cleaning: Place the dyed PVA film in a cleaning tank to clean the dye solution; (4) PVA film stretching: The washed PVA film is stretched 4-7 times; (5) PVA optical film free iodine cleaning: The stretched PVA film is immersed in a cleaning tank, the concentration of free iodine remover in the cleaning tank is 0.1%-4%, boric acid is 1%-4%, the temperature is 5°C-30°C, and the time is 2s-20s; (6) Curing and color correction: Place the cleaned PVA optical film into a curing and color correction tank, with a potassium iodide concentration of 1%-10%, a boric acid concentration of 1%-4%, a temperature of 5°C-45°C, and a time of 3s-60s; (7) Drying and laminating: After the PVA film is dried, the upper and lower surfaces are laminated with TAC films for protection to obtain a polarizer.

2. The method for preparing a high temperature and humidity resistant vehicle-mounted polarizer according to claim 1, characterized in that: The PVA film after stretching in step (4) is immersed in a solution containing a free iodine remover, wherein the concentration of the free iodine remover is 0.1% to 10%, the concentration of boric acid in the free iodine remover solution is 1% to 4%, the temperature of the free iodine remover solution is 5° C. to 30° C., and the residence time of the PVA film in the solution containing the free iodine remover is 2s to 20s.

3. The method for preparing a high temperature and humidity resistant vehicle-mounted polarizer according to claim 2, characterized in that: The free iodine remover includes any one or a combination of sodium bicarbonate, potassium bicarbonate, sodium bisulfite, potassium bisulfite, disodium hydrogen phosphate or dipotassium hydrogen phosphate.

4. The method for preparing a high temperature and humidity resistant vehicle-mounted polarizer according to claim 1, characterized in that: A cross-linking agent is added to the curing color-correcting tank in step (4), and the concentration of the cross-linking agent is 0.5%-3.5%.

5. The method for preparing a high temperature and humidity resistant vehicle-mounted polarizer according to claim 4, characterized in that: The cross-linking agent in the solidified color-replenishing solution comprises any one or a combination of calcium chloride, calcium nitrate, zirconium chloride, zirconium sulfate and zirconium nitrate.

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