High-temperature-resistant and high-humidity-resistant polaroid and preparation method thereof

Abstract

The embodiment of the invention relates to the field of polaroids, and provides a high-temperature-resistant and high-humidity-resistant polaroid and a preparation method thereof.The method comprises the steps that 1, a cleaned polyvinyl alcohol film is soaked in a tridecyl borate solution and preliminarily stretched, and a first polyvinyl alcohol film is obtained; step 2, soaking and dyeing the first polyvinyl alcohol film in a mixed dyeing solution to obtain a second polyvinyl alcohol film; step 3, infiltrating and stretching the second polyvinyl alcohol film in a stretching bath solution; 4, TAC films are attached to the two sides of the stretched second polyvinyl alcohol film, drying treatment is carried out, the polaroid is obtained, and the high temperature resistance and the moisture resistance of the polaroid are improved.

Description

Technical Field

[0001] The present application relates to the technical field of polarizers, and in particular to a polarizer resistant to high temperature and high humidity and a preparation method thereof. Background Art

[0002] Polarizer is one of the important raw materials for display, and its performance has a direct impact on the display effect. When making polarizers, polyvinyl alcohol film is usually used as the base material. In the specific production, after the polyvinyl alcohol film is dyed and stretched, since the polyvinyl alcohol film itself is sensitive to moisture, and the polarizing film after stretching and alignment has a certain retraction stress, the polarizer will shrink in a high temperature and high humidity environment. Specifically, since the colorant iodine is easy to sublimate under high temperature conditions, the polyvinyl alcohol film is sensitive to moisture and is hygroscopic. Therefore, under high temperature and high humidity conditions, the complexed and oriented polyiodide ions in the polyvinyl alcohol iodine polarizing film are easily destroyed, resulting in reduced stability of the polarizer. For example, a polarizer (display) used under high temperature conditions will cause the polarization performance of the display screen to be reduced, resulting in reduced overall performance. Summary of the invention

[0003] The embodiment of the present application provides a polarizer resistant to high temperature and high humidity and a preparation method thereof, which can perform preliminary stretching on a polyvinyl alcohol film in a tridecyl borate solution and stretch it again after dyeing. The double stretching method can use a tridecyl borate solution of dioctadecyl dimethyl ammonium chloride and sodium metaphosphate to perform secondary stretching on the polyvinyl alcohol film after dyeing. Since dioctadecyl dimethyl ammonium chloride can further improve the ductility of the polyvinyl alcohol film and also promote the shaping of molecules, the high temperature and high humidity resistance of the prepared polarizer is improved.

[0004] A first aspect of an embodiment of the present application provides a method for preparing a polarizer resistant to high temperature and high humidity, the method comprising: Step 1, soaking the cleaned polyvinyl alcohol film in a tridecyl borate solution and performing preliminary stretching to obtain a first polyvinyl alcohol film, wherein the concentration of the tridecyl borate is 1.2% to 1.6%, and the stretching ratio of the preliminary stretching is 0.5 to 0.7; Step 2, soaking and dyeing the first polyvinyl alcohol film in a mixed dyeing solution to obtain a second polyvinyl alcohol film, wherein the mixed dyeing solution contains tridecyl borate, and the concentration of tridecyl borate in the mixed dyeing solution is 3.0% to 4.5%; Step 3, soaking and stretching the second polyvinyl alcohol film in a stretching bath with a stretching ratio of 3.0 to 4.5 times to obtain a stretched second polyvinyl alcohol film, wherein the stretching bath is a tridecyl borate solution containing dioctadecyl dimethyl ammonium chloride and sodium metaphosphate, wherein the concentration of tridecyl borate is 7% to 10%, the concentration of dioctadecyl dimethyl ammonium chloride is 0.51% to 0.61%, and the concentration of sodium metaphosphate is between 0.10% and 0.15%; Step 4, adhering TAC films to both sides of the stretched second polyvinyl alcohol film and drying the film to obtain a polarizer.

[0005] Preferably, in a possible implementation, in the step 1, the degree of polymerization of the polyvinyl alcohol film is greater than 2500.

[0006] Preferably, in a possible implementation, the mixed dyeing solution includes a mixed dye with a concentration of 1.8% to 1.9% and an iodine with a concentration of 0.4% to 0.45%.

[0007] Preferably, in a possible implementation, in step 3, the stretching rate is set by the current temperature value of the stretching bath, including: The current temperature value of the stretching bath solution is detected and obtained; and the stretching rate is determined according to the current temperature value and the concentration of tridecyl borate.

[0008] Preferably, in a possible implementation, in step 3, in the stretching bath, the concentration of dioctadecyl dimethyl ammonium chloride is between 0.55% and 0.61%, and the concentration of sodium metaphosphate is between 1.2% and 0.14%.

[0009] Preferably, in a possible implementation, in step 4, during the drying process, the second polyvinyl alcohol film after film pasting is first dried at a temperature of 55°C to 70°C for 20 to 25 minutes, and then dried at a temperature of 80°C to 90°C for 20 to 25 minutes.

[0010] Preferably, in a possible implementation, in step 3, the stretching rate is 0.45 m / min to 0.55 m / min.

[0011] Preferably, in a possible implementation, in step 3, the drying temperature during the drying process is 60° C. to 70° C.

[0012] Preferably, in a possible implementation, in step 3, the concentration of tridecyl borate is 10%, the concentration of dioctadecyl dimethyl ammonium chloride is 0.61%, and the concentration of sodium metaphosphate is 0.15%.

[0013] The second aspect of the embodiment of the present application provides a polarizer resistant to high temperature and high humidity. The polarizer resistant to high temperature and high humidity is prepared by the method described in any one of the first aspects.

[0014] The solution provided in the above application is to initially stretch the polyvinyl alcohol film in a tridecyl borate solution and stretch it again after dyeing. The two-stretching method can use a tridecyl borate solution of dioctadecyl dimethyl ammonium chloride and sodium metaphosphate to stretch the polyvinyl alcohol film for the second time after dyeing. Since dioctadecyl dimethyl ammonium chloride can further improve the ductility of the polyvinyl alcohol film, it can also promote the shaping of molecules, thereby improving the high temperature and high humidity resistance of the prepared polarizer. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 A schematic flow chart of a method for preparing a polarizer resistant to high temperature and high humidity is provided for an embodiment of the present application. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0018] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0019] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0020] In order to better understand the method for preparing a polarizer resistant to high temperature and high humidity provided in the embodiment of the present application, the method for preparing a polarizer resistant to high temperature and high humidity in the existing scheme is briefly introduced below. In the existing scheme, when preparing a polarizer resistant to high temperature and high humidity, when the dyed polyvinyl alcohol film is stretched, hexadecyltrimethylammonium chloride and sodium tripolyphosphate are added to the stretching bath to increase the toughness of the polyvinyl alcohol film modified with boric acid. However, when using boric acid for modification, due to the limitations of its concentration of boric acid and the processes such as immersion and stretching, the polarizer obtained is not good in terms of moisture resistance, and there is still a lot of room for improvement.

[0021] In order to solve the above technical problems, the embodiment of the present application provides a method for preparing a polarizer resistant to high temperature and high humidity, which can perform preliminary stretching on a polyvinyl alcohol film in a tridecyl borate solution and stretch it again after dyeing. The double stretching method can use a tridecyl borate solution of dioctadecyl dimethyl ammonium chloride and sodium metaphosphate to perform secondary stretching on the polyvinyl alcohol film after dyeing. Since dioctadecyl dimethyl ammonium chloride can further improve the ductility of the polyvinyl alcohol film, it can also promote the shaping of molecules, thereby improving the high temperature and high humidity resistance of the prepared polarizer.

[0022] In a specific embodiment, see Figure 1 , Figure 1 A schematic flow chart of a method for preparing a polarizer resistant to high temperature and high humidity is provided for the embodiment of the present application. Figure 1 As shown, the method comprises the following steps: Step 1, soaking the cleaned polyvinyl alcohol film in a tridecyl borate solution and performing preliminary stretching to obtain a first polyvinyl alcohol film, wherein the concentration of the tridecyl borate is 1.2% to 1.6%, and the stretching ratio of the preliminary stretching is 0.5 to 0.7; Step 2, soaking and dyeing the first polyvinyl alcohol film in a mixed dyeing solution to obtain a second polyvinyl alcohol film, wherein the mixed dyeing solution contains tridecyl borate, and the concentration of tridecyl borate in the mixed dyeing solution is 3.0% to 4.5%; Step 3, soaking and stretching the second polyvinyl alcohol film in a stretching bath with a stretching ratio of 3.0 to 4.5 times to obtain a stretched second polyvinyl alcohol film, wherein the stretching bath adopts a tridecyl borate solution containing dioctadecyl dimethyl ammonium chloride and sodium metaphosphate, wherein the concentration of tridecyl borate is 7% to 10%, the concentration of dioctadecyl dimethyl ammonium chloride is 0.51% to 0.61%, and the concentration of sodium metaphosphate is between 0.10% and 0.15%; Step 4, adhering TAC films to both sides of the stretched second polyvinyl alcohol film and drying the film to obtain a polarizer.

[0023] In the above preparation method, in step 1, the clear polyvinyl alcohol film is immersed in a tridecyl borate solution and preliminarily stretched, wherein the concentration of tridecyl borate is 1.2%~1.6%, and the stretching ratio of the preliminary stretching is 0.5-0.7. Then, the polyvinyl alcohol film can be preliminarily stretched at a low ratio at a lower tridecyl borate concentration, so that the stretched polyvinyl alcohol film has preliminary molecular shaping, which is convenient for the dyeing effect during the infiltration dyeing in step 2, and specifically can improve the dyeing levelness and dyeing rate during dyeing.

[0024] In step 2, since the first polyvinyl alcohol film preliminarily stretched after infiltration in step 1 has good molecular shaping, tridecyl borate at a concentration of 3.0% to 4.5% is added to the mixed dyeing solution during dyeing. Since tridecyl borate has good stability and can improve the strength of the second polyvinyl alcohol film through cross-linking, the heat resistance and weather resistance of the second polyvinyl alcohol film can also be improved.

[0025] In step 3, since a certain concentration of dioctadecyl dimethyl ammonium chloride and sodium metaphosphate are added to the stretching bath, dioctadecyl dimethyl ammonium chloride can further improve the ductility of the polyvinyl alcohol film, and can also promote the shaping of molecules, improve the leveling and dyeing rate of the polarizer during dyeing, and also improve the high temperature and moisture resistance. In step 4, a general film lamination and drying treatment method can be used for processing, and subsequent cutting and other treatments can be performed to obtain a polarizer.

[0026] In a possible implementation, in the step S1, the degree of polymerization of the polyvinyl alcohol film is greater than 2500.

[0027] In a possible implementation, the mixed dyeing solution includes 1.8% to 1.9% of a mixed dye and 0.4% to 0.45% of iodine.

[0028] In a possible implementation, in step 3, the stretching rate is set by the current temperature value of the stretching bath, including: The current temperature value of the stretching bath solution is detected and obtained; and the stretching rate is determined according to the current temperature value and the concentration of tridecyl borate.

[0029] Due to the difference in temperature, the speed of the movement and collision of molecules will also be different. The temperature velocity curve of the movement speed of the tridecyl borate ester molecule in the dye can be extracted through relevant experimental data, and the temperature velocity curve that changes with the temperature change, and because the molecular motion is irregular, the temperature velocity curve here only represents the curve between the temperature value and the velocity value, to reflect the influence of temperature on the tridecyl borate ester molecule when moving. Thus, the current temperature of the stretching bath can be monitored in real time, and the corresponding molecular motion speed can be determined according to the temperature velocity curve. Due to the difference in molecular motion speed, when stretching, the corresponding stretching rate can also be maintained, so as to achieve more accurate stretching treatment, reduce the energy consumption when stretching, and also enable molecules to better reach a balance, so as to quickly stabilize. Avoid the stretching rate too fast to cause the uniformity and dyeing rate to decrease, and the time increase of stretching caused by too slow, increase system consumption. Different concentrations of tridecyl borate result in different numbers of molecules per unit volume in the stretching bath, which in turn result in different abilities of the molecules to bind to each other during movement. Therefore, the stretching rate can be determined based on the current temperature value and the concentration of tridecyl borate to improve the reliability and stability of the stretching system.

[0030] Of course, the stretching rate can also be set to a fixed stretching rate range, for example, 0.45 m / min~0.55 m / min.

[0031] In a possible implementation, in step 3, in the stretching bath solution, the concentration of dioctadecyl dimethyl ammonium chloride is 0.55%-0.61%, and the concentration of sodium metaphosphate is 1.2%-0.14%.

[0032] In a possible implementation, in step 4, during the drying process, the second polyvinyl alcohol film after lamination is first dried at a temperature of 55° C. to 70° C. for 20 to 25 minutes, and then dried at a temperature of 80° C. to 90° C. for 20 to 25 minutes.

[0033] In a possible implementation, in step 3, the stretching rate is 0.45 m / min to 0.55 m / min.

[0034] In a possible implementation, in step 3, the drying temperature during the drying process is 60° C. to 70° C.

[0035] In a possible implementation, in step 3, the concentration of tridecyl borate is 10%, the concentration of dioctadecyl dimethyl ammonium chloride is 0.61%, and the concentration of sodium metaphosphate is 0.15%.

[0036] In another specific embodiment, specifically Embodiment 1: Step 1, soaking the cleaned polyvinyl alcohol film in a tridecyl borate solution and performing preliminary stretching to obtain a first polyvinyl alcohol film, wherein the concentration of the tridecyl borate is 1.2%, and the stretching ratio of the preliminary stretching is 0.5; Step 2, immersing the first polyvinyl alcohol film in a mixed dyeing solution for dyeing to obtain a second polyvinyl alcohol film, wherein the mixed dyeing solution contains tridecyl borate, and the concentration of tridecyl borate in the mixed dyeing solution is 3.0%; Step 3, soaking and stretching the second polyvinyl alcohol film in a stretching bath solution at a stretching ratio of 3.0 times to obtain a stretched second polyvinyl alcohol film, wherein the stretching bath solution is a tridecyl borate solution containing dioctadecyl dimethyl ammonium chloride and sodium metaphosphate, wherein the concentration of tridecyl borate is 7%, the concentration of dioctadecyl dimethyl ammonium chloride is 0.51%, and the concentration of sodium metaphosphate is 0.10%; Step 4, adhering TAC films to both sides of the stretched second polyvinyl alcohol film and drying the film to obtain a polarizer.

[0037] Among them, the current temperature value of the stretching bath is 50 degrees Celsius, and the stretching rate is 0.46 m / min.

[0038] In another specific embodiment, specifically Embodiment 2: Step 1, soaking the cleaned polyvinyl alcohol film in a tridecyl borate solution and performing preliminary stretching to obtain a first polyvinyl alcohol film, wherein the concentration of the tridecyl borate is 0.13%, and the stretching ratio of the preliminary stretching is 0.6; Step 2, immersing the first polyvinyl alcohol film in a mixed dyeing solution for dyeing to obtain a second polyvinyl alcohol film, wherein the mixed dyeing solution contains tridecyl borate, and the concentration of tridecyl borate in the mixed dyeing solution is 3.5%; Step 3, soaking and stretching the second polyvinyl alcohol film in a stretching bath solution at a stretching ratio of 3.0 to 4.5 times to obtain a stretched second polyvinyl alcohol film, wherein the stretching bath solution is a tridecyl borate solution containing dioctadecyl dimethyl ammonium chloride and sodium metaphosphate, wherein the concentration of tridecyl borate is 8%, the concentration of dioctadecyl dimethyl ammonium chloride is 0.55%, and the concentration of sodium metaphosphate is 0.13%; Step 4, adhering TAC films to both sides of the stretched second polyvinyl alcohol film and drying the film to obtain a polarizer.

[0039] Among them, the current temperature value of the stretching bath is 53 degrees Celsius, and the stretching rate is 0.50 m / min.

[0040] In another specific embodiment, specifically Embodiment 3: Step 1, soaking the cleaned polyvinyl alcohol film in a tridecyl borate solution and performing preliminary stretching to obtain a first polyvinyl alcohol film, wherein the concentration of the tridecyl borate is 1.6%, and the stretching ratio of the preliminary stretching is 0.7; Step 2, immersing the first polyvinyl alcohol film in a mixed dyeing solution for dyeing to obtain a second polyvinyl alcohol film, wherein the mixed dyeing solution contains tridecyl borate, and the concentration of tridecyl borate in the mixed dyeing solution is 4.5%; Step 3, soaking and stretching the second polyvinyl alcohol film in a stretching bath solution at a stretching ratio of 4.5 times to obtain a stretched second polyvinyl alcohol film, wherein the stretching bath solution is a tridecyl borate solution containing dioctadecyl dimethyl ammonium chloride and sodium metaphosphate, wherein the concentration of tridecyl borate is 10%, the concentration of dioctadecyl dimethyl ammonium chloride is 0.61%, and the concentration of sodium metaphosphate is 0.15%; Step 4, adhering TAC films to both sides of the stretched second polyvinyl alcohol film and drying the film to obtain a polarizer.

[0041] Among them, the current temperature value of the stretching bath is 56 degrees Celsius, and the stretching rate is 0.54 m / min.

[0042] The polarizers prepared in Examples 1-3 were subjected to performance tests to test their initial transmittance and polarization degree, as well as the transmittance and polarization degree of the polarizers after aging at 95 degrees Celsius and 90% humidity for 1100 hours.

[0043] Table 1, test results of Examples 1-3 It can be seen from Table 1 that the initial transmittance and polarization degree of the polarizers of Examples 1-3 of the present application are at a relatively high level. The transmittance of many polarizers in the industry after being manufactured is about 41.5, and the polarization degree is about 99.50. After aging, the difference in polarization degree before and after aging in Examples 1-3 of the present application is maintained at about 7.1%, and the transmittance is maintained at about 1.6%, which is at a relatively high industry level. It can be seen that the polarizers prepared in the embodiments of the present application have relatively high resistance to high temperature and high humidity.

[0044] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0045] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0046] The embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for general technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A method for preparing a polarizer resistant to high temperature and high humidity, characterized in that: The method comprises: Step 1, soaking the cleaned polyvinyl alcohol film in a tridecyl borate solution and performing preliminary stretching to obtain a first polyvinyl alcohol film, wherein the concentration of the tridecyl borate is 1.2% to 1.6%, and the stretching ratio of the preliminary stretching is 0.5 to 0.7; Step 2, soaking and dyeing the first polyvinyl alcohol film in a mixed dyeing solution to obtain a second polyvinyl alcohol film, wherein the mixed dyeing solution contains tridecyl borate, and the concentration of tridecyl borate in the mixed dyeing solution is 3.0% to 4.5%; Step 3, soaking and stretching the second polyvinyl alcohol film in a stretching bath with a stretching ratio of 3.0 to 4.5 times to obtain a stretched second polyvinyl alcohol film, wherein the stretching bath is a tridecyl borate solution containing dioctadecyl dimethyl ammonium chloride and sodium metaphosphate, wherein the concentration of tridecyl borate is 7% to 10%, the concentration of dioctadecyl dimethyl ammonium chloride is 0.51% to 0.61%, and the concentration of sodium metaphosphate is between 0.10% and 0.15%; Step 4, adhering TAC films to both sides of the stretched second polyvinyl alcohol film and drying the film to obtain a polarizer.

2. The method for preparing a high temperature and high humidity resistant polarizer according to claim 1, characterized in that: In the step 1, the degree of polymerization of the polyvinyl alcohol film is greater than 2500.

3. The method for preparing a high temperature and high humidity resistant polarizer according to claim 1, characterized in that: The mixed staining solution includes a mixed dye with a concentration of 1.8% to 1.9% and an iodine with a concentration of 0.4% to 0.45%.

4. The method for preparing a high temperature and high humidity resistant polarizer according to claim 1, characterized in that: In step 3, the stretching rate is set by the current temperature value of the stretching bath, including: The current temperature value of the stretching bath solution is detected and obtained; and the stretching rate is determined according to the current temperature value and the concentration of tridecyl borate.

5. The method for preparing a high temperature and high humidity resistant polarizer according to any one of claims 1 to 4, characterized in that: In step 3, in the stretching bath solution, the concentration of dioctadecyl dimethyl ammonium chloride is between 0.55% and 0.61%, and the concentration of sodium metaphosphate is between 1.2% and 0.14%.

6. The method for preparing a high temperature and high humidity resistant polarizer according to claim 5, characterized in that: In step 4, during the drying process, the second polyvinyl alcohol film after film pasting is first dried at a temperature of 55° C. to 70° C. for 20 to 25 minutes, and then dried at a temperature of 80° C. to 90° C. for 20 to 25 minutes.

7. The method for preparing a high temperature and high humidity resistant polarizer according to claim 6, characterized in that: In step 3, the stretching rate is 0.45 m / min to 0.55 m / min.

8. The method for preparing a high temperature and high humidity resistant polarizer according to claim 5, characterized in that: In step 3, the drying temperature during the drying process is 60°C to 70°C.

9. The method for preparing a high temperature and high humidity resistant polarizer according to claim 4, characterized in that: In step 3, the concentration of tridecyl borate is 10%, the concentration of dioctadecyl dimethyl ammonium chloride is 0.61%, and the concentration of sodium metaphosphate is 0.15%.

10. A polarizer resistant to high temperature and humidity, characterized in that: The high temperature and high humidity resistant polarizer is prepared by the method according to any one of claims 1 to 9.

Images