Preparation process of antistatic semi-reflective and semi-transmissive polarizing plate

Abstract

The application belongs to the technical field of polarizing plates, and particularly relates to a preparation process of an antistatic semi-reflective and semi-transmissive polarizing plate. The process comprises the following steps: ester exchange synthesis of PCThB type polycarbonate; preparation of photonic microcrystalline particles; preparation of antistatic pressure-sensitive adhesive and semi-transmissive film, and compounding of the polarizing plate. The PCThB copolymer is prepared by melt ester exchange, 2,5-dihydroxymethyl tetrahydrofuran is added to reduce the agglomeration of the PCThB copolymer, reduce the melting point, improve the uniformity of the particle size distribution of the microcrystalline particles and the crystalline arrangement, thereby improving the reflection capacity, bisphenol fluorene is added for copolymerization to introduce a symmetrical structure, which can better form the microcrystalline particles subsequently, improve the reflection effect of the subsequent semi-transmissive film, reduce the birefringence effect, improve the brightness and visual angle of the polarizing plate, reduce the amount of the microcrystalline particles, improve the effect of the polarizing plate, ensure the product quality, and meet the application in various scenes.

Description

Technical Field

[0001] The invention belongs to the technical field of polarizers, and in particular relates to a preparation process of an antistatic semi-reflective and semi-transmissive polarizer. Background Art

[0002] As one of the core components of liquid crystal displays (LCDs), polarizers enhance display contrast and color reproduction by selectively transmitting light with a specific polarization direction. As display technology develops toward high brightness, wide viewing angles, and energy efficiency, transflective polarizers, due to their ability to dynamically balance ambient light reflection and backlight transmission, can improve the display quality of LCD screens, ensuring clear visibility even in strong light environments, making them an important choice for high-end display devices.

[0003] Traditional semi-reflective and semi-transmissive polarizers are mainly composed of two types of semi-permeable membranes: pearlescent powder semi-permeable membrane and BEF membrane. Among them, pearlescent powder semi-permeable membrane is mostly made of natural pearlescent powder as raw material. Natural pearlescent powder contains a lot of impurities and easily forms black spots on the polarizer. Even if the natural pearlescent powder is removed, its stability in the semi-permeable membrane is poor, and it is easy to form defects, and the product quality stability is poor. The core of BEF film is to improve the utilization rate of backlight. It directs scattered light in the vertical direction through the prism structure, focusing on reflection rather than transmission. Its transmittance is often low, and it cannot be selectively adjusted in scenes that need to balance ambient light reflection and backlight transmission, and its usage scenarios are limited. Summary of the Invention

[0004] In order to solve the above-mentioned technical defects, the present invention has developed a preparation process for an anti-static semi-reflective and semi-transparent polarizer. By preparing microcrystalline particles with high reflective ability and high compatibility, it is possible to reduce the amount of particles used in the semi-transparent membrane while ensuring the reflection effect of the product, thereby enhancing the stability of the polarizer, and conveniently adjusting the proportion of microcrystalline particles to adjust the light transmittance and reflectance ratio of the semi-transparent membrane, thereby expanding the applicable scenarios of the semi-reflective and semi-transparent polarizer.

[0005] A preparation process of an antistatic semi-reflective and semi-transmissive polarizer comprises the following steps:

[0006] S1 Synthesis of PCThB-type polycarbonate by transesterification: Bisphenol fluorene, 2,5-dihydroxymethyltetrahydrofuran, and dimethyl carbonate were stirred uniformly at a molar ratio of 1:(1-1.5):(5-6.5), tetrabutyl titanate was added, and PCThB copolymer was prepared by melt transesterification reaction and precipitation purification;

[0007] Preparation of S2 photonic microcrystal particles: PCThB copolymer, acrylic acid, PEG-4000 and titanium dioxide are ultrasonically dispersed in tetrahydrofuran, and then added to a PVA aqueous solution for high-speed dispersion. After concentration, a pre-assembled solution is obtained. A quartz slide is subjected to surface hydrophilic treatment and assembled into a capillary assembly plate. After inserting the pre-assembled solution, it is air-dried and subjected to high-temperature treatment while being vibrated at high speed to obtain microcrystal particles.

[0008] Preparation of S3 anti-static pressure-sensitive adhesive and semipermeable membrane and composite of polarizer: butyl acrylate, 2-methoxyethyl 2-acrylate, cycloethyl methacrylate, 2-hydroxyethyl acrylate, dibenzoyl peroxide and 1-butyl-3-methylimidazole bis(trifluoromethylsulfonyl)imide are refluxed and then lithium dioxalatoborate is added and stirred evenly to obtain an anti-static pressure-sensitive adhesive; 4-biphenylmethanol acrylate, microcrystalline particles, dispersant, leveling agent, defoaming agent and light curing agent are mixed into a semipermeable colloid, which is then coated on the surface of a PET film and cured to obtain a semipermeable membrane; a PVA film, a TAC film, a semipermeable membrane, a release film and the anti-static pressure-sensitive adhesive are composited to obtain an antistatic semi-reflective and semi-transmissive polarizer.

[0009] Furthermore, step S1, the transesterification synthesis of PCThB type polycarbonate, comprises the following steps:

[0010] S1.1: Add bisphenol fluorene, 2,5-dihydroxymethyltetrahydrofuran, and dimethyl carbonate to a container at a molar ratio of 1:(1-1.5):(5-6.5). Purge the air from the container with nitrogen. Then, add tetrabutyl titanate (0.2-0.3% by mole of 2,5-dihydroxymethyltetrahydrofuran) and stir evenly. Raise the temperature to 170-175°C. Once the reactants in the container are completely melted, stir at 120-150 rpm for 20-25 minutes. Raise the temperature to 195-200°C and continue stirring for 1-1.5 hours. Raise the temperature to 215-220°C and continue stirring for 15-20 minutes. Distill off all by-products to obtain the oligomerization product.

[0011] S1.2: The temperature in the container is increased and the pressure is reduced at a heating rate of 0.25-0.3°C / min. When the temperature in the container is 230-235°C, the pressure is reduced to 10-15kPa. When the temperature is increased to 240-242°C, the pressure is reduced to 5-6kPa. Finally, the temperature is increased to 245-250°C and the pressure is reduced to 30-40Pa. The pressure is maintained for 40-60 minutes. The product is dissolved in 3-4 times the mass of dichloromethane and then purified by precipitation using 12-15 times the mass of ethanol. The purified copolymer is dried at 45-50°C for 20-24 hours to obtain a PCThB copolymer.

[0012] Furthermore, step S2 of preparing the photonic microcrystal particles comprises the following steps:

[0013] S2.1: 3-4 parts by weight of PCThB copolymer, 0.2-0.3 parts by weight of acrylic acid, 0.4-0.5 parts by weight of PEG-4000 and 0.6-0.8 parts by weight of titanium dioxide are placed in a container, 15-20 parts by weight of tetrahydrofuran is added, ultrasonic is performed at a frequency of 25-30 kHz for 15-20 minutes to obtain a mixed solution, the mixed solution is slowly added to 45-50 parts by weight of a PVA aqueous solution with a mass fraction of 1-1.5% under the condition of a rotation speed of 800-1000 rpm, magnetic stirring is performed at 80-85°C and a rotation speed of 3000-3500 rpm, and concentration is performed to 25-30% of the original volume to obtain a pre-assembly solution;

[0014] S2.2: A glass slide is placed in deionized water for ultrasonic cleaning, then immersed in a hydrogen peroxide-concentrated sulfuric acid treatment solution for 7-8 hours, the surface is washed clean with deionized water, and dried, then treated with oxygen plasma for 3-4 minutes to obtain a hydrophilic substrate, a 15-30 μm tin foil is clamped between two hydrophilic substrates for 4-5 hours, and then fixed after the distance is stable, the tin foil is taken out to obtain a capillary force assembly plate;

[0015] S2.3: The capillary force assembly plate is inserted into the pre-assembly solution, and when the pre-assembly solution fills the capillary force assembly plate, it is placed in a fume hood for air drying for 24-25 hours, then placed in an oven at 60-65°C for drying for 30-35 minutes, then heated to 120-150°C, and kept for 4-4.5 hours, then cooled and vibrated with a vibration rod at high speed for 2-3 minutes, and the capillary force assembly plate is opened to collect the microcrystalline particles therebetween.

[0016] Further, the preparation of the antistatic pressure-sensitive adhesive and the semi-permeable membrane and the compounding of the polarizing sheet of step S3 include the following steps:

[0017] S3.1: Butyl acrylate, 2-methoxyethyl 2-acrylate, cycloethyl methacrylate, 2-hydroxyethyl acrylate and dibenzoyl peroxide are mixed and stirred in a mass ratio of (40-45): (25-30): (25-30): (10-12): (0.4-0.5) to obtain a mixed monomer. 65-70 parts by weight of ethyl acetate are added to the reaction vessel based on the volume percentage of the reaction vessel. The mixture is stirred and heated to 75-80°C. The mixture is kept at reflux for 30-35 minutes, and then 45-50 parts by weight of the mixed monomer are added. The monomers are mixed, and the mixture is refluxed for 1-1.5 hours in a water bath at 75-80° C., kept warm, and 45-50 parts by weight of the mixed monomers and 4-6 parts by weight of 1-butyl-3-methylimidazole bis(trifluoromethylsulfonyl)imide are slowly added dropwise over 1-2 hours, and the reflux reaction is continued for 1.5-2 hours. Finally, 65-70 parts by weight of ethyl acetate are added, and the mixture is heated in a water bath to 84-85° C., and the reflux reaction is continued for 4-5 hours. After adding 4-6 wt % of lithium bis(oxalatoborate), the mixture is stirred at a uniform speed, and naturally cooled to room temperature to obtain an anti-static pressure-sensitive adhesive.

[0018] S3.2: 80-85 parts by weight of 4-biphenylmethanol acrylate, 8-10 parts by weight of microcrystalline particles, 0.2-0.5 parts by weight of dispersant BYK-111, 0.2-0.5 parts by weight of leveling agent BYK-333, 0.1-0.3 parts by weight of degassing agent BYK-052, and 3-5 parts by weight of light curing agent are mixed uniformly in a light-proof environment to obtain a semipermeable colloid, and the semipermeable colloid is uniformly coated on the surface of a PET film with a thickness of 60-80 μm to a coating thickness of 20-25 μm, and heated in an oven at 60-65°C for 3-5 minutes, and then placed in a UV curing machine for curing to obtain a semipermeable membrane;

[0019] S3.3: Evenly apply anti-static pressure-sensitive adhesive on the front and back surfaces of the PVA film, then adhere the composite TAC film on the front and back surfaces to obtain a polarizing layer, evenly apply anti-static pressure-sensitive adhesive on the front and back surfaces of the polarizing layer, adhere the composite semi-permeable film on the front surface, and adhere the composite release film on the back surface to obtain an anti-static semi-reflective and semi-transmissive polarizer.

[0020] Furthermore, in step S2.1, the mixed solution is added to the PVA aqueous solution within 25-30 minutes.

[0021] Furthermore, in the hydrogen peroxide-concentrated sulfuric acid treatment solution of step S2.2, the mass ratio of hydrogen peroxide to concentrated sulfuric acid is 1:(0.8-1).

[0022] Furthermore, the frequency of the high-speed vibration in step S2.3 is 1500-2000 times / minute.

[0023] Furthermore, the photocuring agent in step S3.2 is ethyl 2,4,6-trimethylbenzoylphenylphosphonate.

[0024] Furthermore, the curing conditions in step S3.2 are 380nm ultraviolet wavelength, 100-105mW / cm 2 Cure for 1-1.5 minutes under the light intensity of 500 nm.

[0025] Furthermore, in step S3.3, the thickness of the PVA film is 25-30 μm, the thickness of the adhesive layer formed by the anti-static pressure-sensitive adhesive is 12-18 μm, the thickness of the TAC film is 55-60 μm, and the thickness of the release film is 30-35 μm.

[0026] The beneficial effects are as follows: 1. The present invention obtains a PCThB copolymer by melt ester exchange of bisphenol fluorene, 2,5-dihydroxymethyltetrahydrofuran and dimethyl carbonate in a molar ratio of 1: (1-1.5): (5-6.5), wherein the ether bond of 2,5-dihydroxymethyltetrahydrofuran can improve the hydrophilicity of PCThB, so that it can be better dispersed in the subsequent pre-assembly solution, reduce agglomeration, and lower the melting point of PCThB, which not only enables better pre-assembly of the capillary assembly plate, but also can melt into a film at a lower temperature during high-temperature treatment, thereby improving the uniformity of the particle size distribution and crystalline arrangement of the microcrystalline particles, thereby improving their reflectivity, and the copolymerization of bisphenol fluorene can introduce a symmetrical structure, inhibit the close stacking between the copolymer molecular chains, and better form microcrystalline particles in the subsequent process, thereby improving the reflective effect of the subsequent semi-transparent membrane and reducing the birefringence effect. While improving the brightness and viewing angle of the polarizer, the amount of microcrystalline particles can be reduced, improving the effect of the polarizer while ensuring product quality, and can well meet its application in various scenarios.

[0027] 2. The present invention prepares a pre-assembled solution by ultrasonically dispersing PCThB copolymer, acrylic acid, PEG-4000 and titanium dioxide in tetrahydrofuran, and then mixing it with a PVA aqueous solution at high speed. Under the capillary force of the highly hydrophilic capillary assembly plate, the pre-assembled solution fills the gaps between the assembly plates. During the air-drying process, the PCThB copolymer and titanium dioxide spontaneously assemble into a crystalline photonic structure with high reflectivity and high compatibility. In addition, through high-speed vibration, the thin film formed by high-temperature treatment is fully broken, and the size distribution of the microcrystalline particles is improved. The semi-permeable membrane solidified by the microcrystalline particles and 4-biphenylmethanol acrylate has better reflective effect and stability, and can be conveniently adjusted to the applicable scenario by adjusting the ratio. When compounded in a polarizer, the brightness and product quality of the polarizer can be further improved.

[0028] 3、The application can endow the pressure-sensitive adhesive with good antistatic ability, improve the compatibility of the matrix and lithium bis(oxalato)borate, prevent the precipitation of lithium bis(oxalato)borate, and improve the antistatic stability of the pressure-sensitive adhesive by adding 1-butyl-3-methylimidazolium di(trifluoromethylsulfonyl) imide into the preparation process of polyacrylate from butyl acrylate, 2-methoxyethyl acrylate, cycloethyl methacrylate, 2-hydroxyethyl acrylate and dibenzoyl peroxide, and then adding lithium bis(oxalato)borate. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 A preparation process flow chart of the antistatic semi-reflective and semi-transmissive polarizing plate is used for the embodiments of the application. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the application.

[0031] Embodiment 1

[0032] A preparation process of an antistatic semi-reflective and semi-transmissive polarizing plate, as shown in Figure 1 , includes the following steps:

[0033] S1.1: Bisphenol fluorene, 2,5-dihydroxymethyl tetrahydrofuran and dimethyl carbonate are added into a container in a molar ratio of 1:1:5, nitrogen is introduced to exhaust the air in the container, then 0.2% of the molar amount of 2,5-dihydroxymethyl tetrahydrofuran is added in the form of tetrabutyl titanate and stirred uniformly, the temperature is raised to 170℃, then the reaction in the container is completely melted, and then stirred at a stirring speed of 120 rpm for 20 minutes, the temperature is raised to 195℃, and then stirred for 1 hour, the temperature is raised to 215℃, and then stirred for 15 minutes, and all by-products are evaporated to obtain an oligomer product;

[0034] S1.2: The container is subjected to temperature rising and pressure reduction, the temperature is raised at a temperature rising rate of 0.25℃ / min, when the temperature in the container is 230℃, the pressure is reduced to 10kPa, when the temperature is raised to 240℃, the pressure is reduced to 5kPa, and finally the temperature is raised to 245℃ and the pressure is reduced to 30Pa, and the temperature is maintained for 40 minutes, the product is dissolved in 3 times the mass of dichloromethane, and then precipitated and purified by using 12 times the mass of ethanol, and the copolymer obtained by purification is dried at 45℃ for 20 hours to obtain a PCThB copolymer.

[0035] S2: Preparation of photonic microcrystalline particles

[0036] S2.1: 3 parts by weight of PCThB copolymer, 0.2 parts by weight of acrylic acid, 0.4 parts by weight of PEG-4000, and 0.6 parts by weight of titanium dioxide are placed in a container, 15 parts by weight of tetrahydrofuran are added, and the mixture is ultrasonically treated at a frequency of 25 kHz for 15 minutes to obtain a mixed solution. The mixed solution is slowly added to 45 parts by weight of a 1% PVA aqueous solution at a rotation speed of 800 rpm over 25 minutes. The mixture is magnetically stirred at 80°C and 3000 rpm, and concentrated to 25% of the original volume to obtain a pre-assembly solution.

[0037] S2.2: Place a quartz glass slide in deionized water for ultrasonic cleaning, then soak it in a hydrogen peroxide-concentrated sulfuric acid treatment solution with a mass ratio of hydrogen peroxide to concentrated sulfuric acid of 1:0.8 for 7 hours. Rinse the surface with deionized water, dry it, and treat it with oxygen plasma for 3 minutes to obtain a hydrophilic substrate. Take 15μm tinfoil and clamp it between two hydrophilic substrates for 4 hours. After the distance between them stabilizes, fix it and remove the tinfoil to obtain a capillary assembly board.

[0038] S2.3: Insert the capillary force assembly plate into the pre-assembly solution. When the pre-assembly solution fills the space between the capillary force assembly plates, place it in a fume hood to air-dry for 24 hours, then place it in a 60°C oven to dry for 30 minutes, then heat it to 120°C and keep it warm for 4 hours. After cooling, use a vibrating rod to vibrate the capillary force assembly plate at high speed for 2 minutes. The frequency of the high-speed vibration is 1500 times / minute, and then open the capillary force assembly plate to collect the microcrystalline particles in between.

[0039] S3: Preparation of anti-static pressure-sensitive adhesive and semi-permeable membrane and composite of polarizer

[0040] S3.1: Butyl acrylate, 2-methoxyethyl 2-acrylate, cycloethyl methacrylate, 2-hydroxyethyl acrylate and dibenzoyl peroxide are mixed and stirred in a mass ratio of 40:25:25:10:0.4 to obtain a mixed monomer. 65 parts by weight of ethyl acetate are added to the reaction vessel based on the volume percentage of the reaction vessel. The mixture is stirred and heated to 75°C. The mixture is kept refluxed for 30 minutes. Then, 45 parts by weight of the mixed monomer are added. The mixture is refluxed in a water bath at 75°C for 1 hour. The mixture is kept warm and 45 parts by weight of the mixed monomer and 4 parts by weight of 1-butyl-3-methylimidazole bis(trifluoromethylsulfonyl)imide are slowly added dropwise within 1 hour. The reflux reaction is continued for 1.5 hours. Finally, 65 parts by weight of ethyl acetate are added. The mixture is heated to 84°C in a water bath. The reflux reaction is continued for 4 hours. 4 wt% of lithium dioxalatoborate is added and the mixture is stirred at a uniform rate. The mixture is naturally cooled to room temperature to obtain an anti-static pressure-sensitive adhesive.

[0041] S3.2: 80 parts by weight of 4-biphenylmethanol acrylate, 8 parts by weight of microcrystalline particles, 0.2 parts by weight of dispersant BYK-111, 0.2 parts by weight of leveling agent BYK-333, 0.1 parts by weight of degassing agent BYK-052 and 3 parts by weight of ethyl 2,4,6-trimethylbenzoylphenylphosphonate were mixed in a dark environment to obtain a semipermeable colloid, and the semipermeable colloid was evenly coated on the surface of a PET film with a thickness of 60 μm to a coating thickness of 20 μm. The film was heated in an oven at 60°C for 3 minutes, and then placed in a UV curing machine under an ultraviolet wavelength of 380 nm and a light intensity of 100 mW / cm 2 Curing under light intensity of 1 minute to obtain a semipermeable membrane;

[0042] S3.3: Evenly apply anti-static pressure-sensitive adhesive on the front and back surfaces of the PVA film, then adhere the composite TAC film on the front and back surfaces to obtain a polarizing layer, evenly apply anti-static pressure-sensitive adhesive on the front and back surfaces of the polarizing layer, adhere the composite semi-permeable film on the front, and adhere the composite release film on the back to obtain an anti-static semi-reflective and semi-transmissive polarizer.

[0043] Example 2

[0044] A preparation process of an antistatic semi-reflective and semi-transmissive polarizer, such as Figure 1 As shown, the following steps are included:

[0045] S1.1: Add bisphenol fluorene, 2,5-dihydroxymethyltetrahydrofuran, and dimethyl carbonate to a container at a molar ratio of 1:1.5:6.5. Purge the air in the container with nitrogen. Then, add tetrabutyl titanate (0.3% by molar ratio of 2,5-dihydroxymethyltetrahydrofuran) and stir evenly. Raise the temperature to 170°C. After the reactants in the container are completely melted, stir at 120 rpm for 20 minutes. Raise the temperature to 195°C and continue stirring for 1 hour. Then, raise the temperature to 215°C and continue stirring for 15 minutes. Distill off all by-products to obtain the oligomerization product.

[0046] S1.2: The temperature in the container is increased and the pressure is reduced at a heating rate of 0.25°C / min. When the temperature in the container is 230°C, the pressure is reduced to 10 kPa. When the temperature is increased to 240°C, the pressure is reduced to 5 kPa. Finally, the temperature is increased to 245°C and the pressure is reduced to 30 Pa. The pressure is maintained for 40 minutes. The product is dissolved in 3 times the mass of dichloromethane and then purified by precipitation using 12 times the mass of ethanol. The purified copolymer is dried at 45°C for 20 hours to obtain PCThB copolymer.

[0047] S2: Preparation of photonic microcrystal particles

[0048] S2.1: 4 parts by weight of PCThB copolymer, 0.3 parts by weight of acrylic acid, 0.5 parts by weight of PEG-4000, and 0.8 parts by weight of titanium dioxide are placed in a container, 20 parts by weight of tetrahydrofuran are added, and the mixture is ultrasonically treated at a frequency of 25 kHz for 15 minutes to obtain a mixed solution. The mixed solution is slowly added to 45 parts by weight of a 1.5% PVA aqueous solution at a rotation speed of 800 rpm over 25 minutes. The mixture is magnetically stirred at 80°C and 3000 rpm, and concentrated to 25% of the original volume to obtain a pre-assembly solution.

[0049] S2.2: Place a quartz glass slide in deionized water for ultrasonic cleaning, then soak it in a hydrogen peroxide-concentrated sulfuric acid treatment solution with a mass ratio of hydrogen peroxide to concentrated sulfuric acid of 1:0.8 for 7 hours. Rinse the surface with deionized water, dry it, and treat it with oxygen plasma for 3 minutes to obtain a hydrophilic substrate. Take 15μm tinfoil and clamp it between two hydrophilic substrates for 4 hours. After the distance between them stabilizes, fix it and remove the tinfoil to obtain a capillary assembly board.

[0050] S2.3: Insert the capillary force assembly plate into the pre-assembly solution. When the pre-assembly solution fills the space between the capillary force assembly plates, place it in a fume hood to air-dry for 24 hours, then place it in a 60°C oven to dry for 30 minutes, then heat it to 120°C and keep it warm for 4 hours. After cooling, use a vibrating rod to vibrate the capillary force assembly plate at high speed for 2 minutes. The frequency of the high-speed vibration is 1500 times / minute, and then open the capillary force assembly plate to collect the microcrystalline particles in between.

[0051] S3: Preparation of anti-static pressure-sensitive adhesive and semi-permeable membrane and composite of polarizer

[0052] S3.1: Butyl acrylate, 2-methoxyethyl 2-acrylate, cycloethyl methacrylate, 2-hydroxyethyl acrylate and dibenzoyl peroxide are mixed and stirred in a mass ratio of 45:30:30:12:0.5 to obtain a mixed monomer. 70 parts by weight of ethyl acetate are added to the reaction vessel based on the volume percentage of the reaction vessel. The mixture is stirred and heated to 75°C. The mixture is kept refluxed for 30 minutes. Then, 50 parts by weight of the mixed monomer are added. The mixture is refluxed in a water bath at 75°C for 1 hour. The mixture is kept warm and 50 parts by weight of the mixed monomer and 6 parts by weight of 1-butyl-3-methylimidazole bis(trifluoromethylsulfonyl)imide are slowly added dropwise within 1 hour. The reflux reaction is continued for 1.5 hours. Finally, 70 parts by weight of ethyl acetate are added. The mixture is heated in a water bath to 84°C. The reflux reaction is continued for 4 hours. After 6 wt% of lithium dioxalatoborate is added, the mixture is stirred at a uniform rate and naturally cooled to room temperature to obtain an anti-static pressure-sensitive adhesive.

[0053] S3.2: 85 parts by weight of 4-biphenylmethanol acrylate, 10 parts by weight of microcrystalline particles, 0.5 parts by weight of dispersant BYK-111, 0.5 parts by weight of leveling agent BYK-333, 0.3 parts by weight of degassing agent BYK-052 and 5 parts by weight of ethyl 2,4,6-trimethylbenzoylphenylphosphonate were mixed in a dark environment to obtain a semipermeable colloid, and the semipermeable colloid was evenly coated on the surface of a PET film with a thickness of 60 μm to a coating thickness of 20 μm. The film was heated in an oven at 60°C for 3 minutes, and then placed in a UV curing machine under an ultraviolet wavelength of 380 nm and a temperature of 100 mW / cm 2 Curing under light intensity of 1 minute to obtain a semipermeable membrane;

[0054] S3.3: Evenly apply anti-static pressure-sensitive adhesive on the front and back surfaces of the PVA film, then adhere the composite TAC film on the front and back surfaces to obtain a polarizing layer, evenly apply anti-static pressure-sensitive adhesive on the front and back surfaces of the polarizing layer, adhere the composite semi-permeable film on the front, and adhere the composite release film on the back to obtain an anti-static semi-reflective and semi-transmissive polarizer.

[0055] Example 3

[0056] A preparation process of an antistatic semi-reflective and semi-transmissive polarizer, such as Figure 1 As shown, the following steps are included:

[0057] S1.1: Bisphenol fluorene, 2,5-dihydroxymethyltetrahydrofuran, and dimethyl carbonate are added to a container at a molar ratio of 1:1:5. Nitrogen is introduced to expel air from the container. Tetrabutyl titanate (0.2% by molar weight of 2,5-dihydroxymethyltetrahydrofuran) is then added and stirred evenly. The temperature is raised to 175°C. After the reactants in the container are completely melted, the mixture is stirred at 150 rpm for 25 minutes. The temperature is then raised to 200°C and stirring is continued for 1.5 hours. The temperature is then raised to 220°C and stirring is continued for 20 minutes. All by-products are evaporated to obtain an oligomerization product.

[0058] S1.2: The temperature in the container is increased and the pressure is reduced at a heating rate of 0.3°C / min. When the temperature in the container is 235°C, the pressure is reduced to 15 kPa. When the temperature is increased to 242°C, the pressure is reduced to 6 kPa. Finally, the temperature is increased to 250°C and the pressure is reduced to 40 Pa. The pressure is maintained for 60 minutes. The product is dissolved in 4 times the mass of dichloromethane and then purified by precipitation using 15 times the mass of ethanol. The purified copolymer is dried at 50°C for 24 hours to obtain PCThB copolymer.

[0059] S2: Preparation of photonic microcrystal particles

[0060] S2.1: 3 parts by weight of PCThB copolymer, 0.2 parts by weight of acrylic acid, 0.4 parts by weight of PEG-4000, and 0.6 parts by weight of titanium dioxide are placed in a container, 15 parts by weight of tetrahydrofuran are added, and the mixture is ultrasonically treated at a frequency of 30 kHz for 20 minutes to obtain a mixed solution. The mixed solution is slowly added to 45 parts by weight of a 1% PVA aqueous solution at a rotation speed of 1000 rpm over 30 minutes. The mixture is magnetically stirred at 85°C and 3500 rpm, and concentrated to 30% of the original volume to obtain a pre-assembly solution.

[0061] S2.2: Place a quartz glass slide in deionized water for ultrasonic cleaning, then soak it in a hydrogen peroxide-concentrated sulfuric acid treatment solution with a mass ratio of hydrogen peroxide to concentrated sulfuric acid of 1:1 for 8 hours. Rinse the surface with deionized water, dry it, and treat it with oxygen plasma for 4 minutes to obtain a hydrophilic substrate. 30μm tinfoil is clamped between two hydrophilic substrates for 5 hours. After the spacing stabilizes, fix it and remove the tinfoil to obtain a capillary assembly board.

[0062] S2.3: Insert the capillary force assembly plate into the pre-assembly solution. When the pre-assembly solution fills the space between the capillary force assembly plates, place it in a fume hood to air-dry for 25 hours, then place it in a 65°C oven to dry for 35 minutes, then heat it to 150°C and keep it warm for 4.5 hours. After cooling, use a vibrating rod to vibrate the capillary force assembly plate at high speed for 3 minutes. The frequency of the high-speed vibration is 2000 times / minute, and then open the capillary force assembly plate to collect the microcrystalline particles in between.

[0063] S3: Preparation of anti-static pressure-sensitive adhesive and semi-permeable membrane and composite of polarizer

[0064] S3.1: Butyl acrylate, 2-methoxyethyl 2-acrylate, cycloethyl methacrylate, 2-hydroxyethyl acrylate and dibenzoyl peroxide are mixed and stirred in a mass ratio of 40:25:25:10:0.4 to obtain a mixed monomer. 65 parts by weight of ethyl acetate are added to the reaction vessel based on the volume percentage of the reaction vessel. The mixture is stirred and heated to 80°C. The mixture is kept at reflux for 35 minutes. Then, 45 parts by weight of the mixed monomer are added. The mixture is refluxed in an 80°C water bath for 1.5 hours. The mixture is kept at reflux and 45 parts by weight of the mixed monomer and 4 parts by weight of 1-butyl-3-methylimidazole bis(trifluoromethylsulfonyl)imide are slowly added dropwise within 2 hours. The reflux reaction is continued for 2 hours. Finally, 65 parts by weight of ethyl acetate are added. The mixture is heated to 85°C in a water bath and the reflux reaction is continued for 5 hours. 4 wt% of lithium dioxalatoborate is added and the mixture is stirred at a uniform rate. The mixture is naturally cooled to room temperature to obtain an anti-static pressure-sensitive adhesive.

[0065] S3.2: 80 parts by weight of 4-biphenylmethanol acrylate, 8 parts by weight of microcrystalline particles, 0.2 parts by weight of dispersant BYK-111, 0.2 parts by weight of leveling agent BYK-333, 0.1 parts by weight of degassing agent BYK-052 and 3 parts by weight of ethyl 2,4,6-trimethylbenzoylphenylphosphonate were mixed in a dark environment to obtain a semipermeable colloid, and the semipermeable colloid was evenly coated on the surface of a PET film with a thickness of 80 μm to a coating thickness of 25 μm. The film was heated in an oven at 60°C for 3 minutes, and then placed in a UV curing machine under an ultraviolet wavelength of 380 nm and an ultraviolet radiation of 105 mW / cm 2 Curing under light intensity of 1.5 minutes to obtain a semipermeable membrane;

[0066] S3.3: Evenly apply anti-static pressure-sensitive adhesive on the front and back surfaces of the PVA film, then adhere the composite TAC film on the front and back surfaces to obtain a polarizing layer, evenly apply anti-static pressure-sensitive adhesive on the front and back surfaces of the polarizing layer, adhere the composite semi-permeable film on the front, and adhere the composite release film on the back to obtain an anti-static semi-reflective and semi-transmissive polarizer.

[0067] Comparative Example 1: A preparation process for an antistatic semi-reflective and semi-transmissive polarizer. Compared with Example 1, the difference is that Comparative Example 1 removes step S1 and step S2, and replaces the microcrystalline particles in step S3.2 with natural pearl powder of equal mass. The remaining steps are the same as those in Example 1.

[0068] Comparative Example 2: A preparation process for an antistatic semi-reflective and semi-transmissive polarizer. Compared with Example 1, the difference is that, in Comparative Example 2, the capillary force assembly plate is vibrated at high speed using a vibrating rod after not cooling, and the microcrystalline particles between the capillary force assembly plates are directly scraped off and collected. The remaining steps are the same as those in Example 1.

[0069] Comparative Example 3: A preparation process for an antistatic semi-reflective and semi-transmissive polarizer. Compared with Example 1, the difference is that Comparative Example 3 does not add 1-butyl-3-methylimidazole bis(trifluoromethylsulfonyl)imide in step S3.1, and the remaining steps are the same as Example 1.

[0070] Tensile strength test: Three samples of the antistatic semi-reflective and semi-transmissive polarizers prepared in Examples 1-3 and Comparative Examples 1-3 were taken as samples, and the tensile strength was tested with reference to the standard of GB13022-91. The test results are shown in Table 1.

[0071] Table 1: Tensile strength of antistatic semi-reflective and semi-transmissive polarizers

[0072] Tensile strength / MPa The first Second copy The third Example 1 403.5 405.1 404.4 Example 2 408.3 407.6 408.8 Example 3 398.5 397.6 398.1 Comparative Example 1 394.4 394.7 394.5 Comparative Example 2 397.3 396.8 397.4 Comparative Example 3 343.8 345.1 344.5

[0073] It can be seen from the data of Examples 1-3 and Comparative Examples 1-3 in Table 1 that the mechanical properties of the antistatic semi-reflective and semi-transmissive polarizers prepared in the examples are higher than those in Comparative Examples 1-3, proving that the antistatic semi-reflective and semi-transmissive polarizers prepared in this example have high mechanical properties, and it can be seen from Comparative Example 1 that when the microcrystalline particles are replaced with natural pearl powder to prepare the semipermeable membrane, the mechanical properties of the polarizer are reduced, proving that the microcrystalline particles have better compatibility with the semipermeable membrane, and the data from Comparative Example 2 show that high-speed vibration after high-temperature treatment for the preparation of microcrystalline particles can improve the size distribution of the microcrystalline particles and can slightly improve the mechanical properties of the polarizer, and the data from Comparative Example 3 show that the addition of 1-butyl-3-methylimidazole bis(trifluoromethylsulfonyl)imide can greatly improve the mechanical properties of the polarizer, proving that it can improve the binding force of its various components during the preparation of the antistatic pressure-sensitive adhesive.

[0074] Reflectivity test: Three samples each of Examples 1-3, Comparative Examples 1-2, and a blank group (neither microcrystalline particles nor natural pearl powder were added in step S3.2) were taken as samples, and the reflectivity was measured using a Trixon NR4510 reflectivity meter. The test results are shown in Table 2.

[0075] Table 2: Transmittance of antistatic semi-reflective and semi-transmissive polarizers

[0076] Reflectivity / % The first Second copy The third Blank group 1.2 1.5 1.3 Example 1 50.4 50.8 50.3 Example 2 53.9 53.5 54.2 Example 3 48.8 49.1 48.6 Comparative Example 1 37.7 37.3 38.2 Comparative Example 2 43.9 43.5 43.8

[0077] It can be seen from the data of Examples 1-3 and the blank group in Table 2 that after adding 8% of microcrystalline particles, the reflectivity of the polarizer in Examples 1-3 is greatly improved, which proves that the prepared semi-permeable membrane has good reflective performance, while the average reflectivity of Comparative Example 1 after adding 8% natural pearl powder is only 37.7%, which is quite different from the examples, proving that more demanding anti-static semi-reflective and semi-transmissive polarizers can be prepared with fewer microcrystalline particles, which can reduce the content of impurities in the semi-permeable membrane and ensure product quality. It can be seen from Comparative Example 2 that high-speed vibration after high-temperature treatment of the microcrystalline particles can improve the size distribution of the microcrystalline particles and enhance their reflective effect.

[0078] Antistatic performance test: Three samples of the antistatic semi-reflective and semi-transmissive polarizers prepared in Examples 1-3 and Comparative Example 3 were taken as samples. After removing the release film, the surface resistivity of the antistatic pressure-sensitive adhesive layer was measured using a Mitsubishi Chemical Corporation MCP-HT800 high resistivity meter at an ambient temperature of 23±2°C, in accordance with GB / T1410-2006. The average value was taken.

[0079] Six pieces of the antistatic semi-transmissive and semi-reflective polarizing plate prepared in Example 1-3 and Comparative Example 3 were taken as samples, and three pieces of each were placed in a blast drying oven at 80°C for 7 days, and three pieces were placed in a programmable constant temperature and humidity test chamber at 60°C / 90% RH for 7 days. The release film was removed, and the surface of the release film was observed for residue by irradiation with a three-wavelength lamp. The test results are shown in Table 3.

[0080] Table 3: Surface resistivity and residue residue

[0081] Average resistivity (Ω / sq) Residue in 80℃ blast drying oven Residual conditions at 60℃ / 90%RH Example 1 5.22×1010 No residue No residue Example 2 5.08×1010 No residue No residue Example 3 5.31×1010 No residue No residue Comparative Example 3 7.23×1010 There are residues There are residues

[0082] As can be seen from Table 3, the antistatic semi-transmissive and semi-reflective polarizing plate prepared in Examples 1-3 has a low surface resistivity, proving that it has good antistatic ability. As can be seen from Comparative Example 3, the addition of 1-butyl-3-methylimidazolium di(trifluoromethylsulfonyl) imide in the preparation of polyacrylate can reduce the resistivity and increase the stability of the antistatic pressure-sensitive adhesive, preventing the precipitation of lithium bis(oxalato)borate.

[0083] The above examples are only illustrative of the principles and effects of the present application, and are not intended to limit the present application. Any person skilled in the art can modify or change the above examples without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical thought disclosed in the present application should be covered by the claims of the present application.

Claims

1. A process for preparing an antistatic semi-reflective and semi-transmissive polarizer, characterized in that: The following steps are involved: S1 Synthesis of PCThB-type polycarbonate by transesterification: Bisphenol fluorene, 2,5-dihydroxymethyltetrahydrofuran, and dimethyl carbonate were stirred uniformly at a molar ratio of 1:(1-1.5):(5-6.5), tetrabutyl titanate was added, and PCThB copolymer was prepared by melt transesterification reaction and precipitation purification; Preparation of S2 photonic microcrystal particles: PCThB copolymer, acrylic acid, PEG-4000 and titanium dioxide are ultrasonically dispersed in tetrahydrofuran, and then added to a PVA aqueous solution for high-speed dispersion. After concentration, a pre-assembled solution is obtained. A quartz slide is subjected to surface hydrophilic treatment and assembled into a capillary force assembly plate. The pre-assembled solution is inserted and air-dried. After drying at 60-65°C, the plate is heated to 120-150°C for high-temperature treatment, and then vibrated at a high-speed frequency of 1500-2000 times / minute to obtain microcrystal particles. Preparation of S3 anti-static pressure-sensitive adhesive and semipermeable membrane and composite of polarizer: butyl acrylate, 2-methoxyethyl 2-acrylate, cycloethyl methacrylate, 2-hydroxyethyl acrylate, dibenzoyl peroxide and 1-butyl-3-methylimidazole bis(trifluoromethylsulfonyl)imide are refluxed and then lithium dioxalatoborate is added and stirred evenly to obtain an anti-static pressure-sensitive adhesive; 4-biphenylmethanol acrylate, microcrystalline particles, dispersant, leveling agent, defoaming agent and light curing agent are mixed into a semipermeable colloid, which is then coated on the surface of a PET film and cured to obtain a semipermeable membrane; a PVA film, a TAC film, a semipermeable membrane, a release film and the anti-static pressure-sensitive adhesive are composited to obtain an antistatic semi-reflective and semi-transmissive polarizer.

2. The process for preparing an antistatic semi-reflective and semi-transmissive polarizer according to claim 1, wherein: Step S1: Transesterification to synthesize PCThB type polycarbonate, comprising the following steps: S1.1: Add bisphenol fluorene, 2,5-dihydroxymethyltetrahydrofuran, and dimethyl carbonate to a container at a molar ratio of 1:(1-1.5):(5-6.5). Purge the air from the container with nitrogen. Then, add tetrabutyl titanate (0.2-0.3% by mole of 2,5-dihydroxymethyltetrahydrofuran) and stir evenly. Raise the temperature to 170-175°C. Once the reactants in the container are completely melted, stir at 120-150 rpm for 20-25 minutes. Raise the temperature to 195-200°C and continue stirring for 1-1.5 hours. Raise the temperature to 215-220°C and continue stirring for 15-20 minutes. Distill off all by-products to obtain the oligomerization product. S1.2: The temperature in the container is increased and the pressure is reduced at a heating rate of 0.25-0.3°C / min. When the temperature in the container is 230-235°C, the pressure is reduced to 10-15kPa. When the temperature is increased to 240-242°C, the pressure is reduced to 5-6kPa. Finally, the temperature is increased to 245-250°C and the pressure is reduced to 30-40Pa. The pressure is maintained for 40-60 minutes. The product is dissolved in 3-4 times the mass of dichloromethane and then purified by precipitation using 12-15 times the mass of ethanol. The purified copolymer is dried at 45-50°C for 20-24 hours to obtain a PCThB copolymer.

3. The process for preparing an antistatic semi-reflective and semi-transmissive polarizer according to claim 2, wherein: Step S2: Preparation of photonic microcrystal particles, including the following steps: S2.1: 3-4 parts by weight of PCThB copolymer, 0.2-0.3 parts by weight of acrylic acid, 0.4-0.5 parts by weight of PEG-4000, and 0.6-0.8 parts by weight of titanium dioxide are placed in a container, 15-20 parts by weight of tetrahydrofuran are added, and ultrasonication is performed at an ultrasonic frequency of 25-30 kHz for 15-20 minutes to obtain a mixed solution. The mixed solution is slowly added to 45-50 parts by weight of a 1-1.5% PVA aqueous solution at a rotation speed of 800-1000 rpm, and magnetic stirring is performed at 80-85°C and 3000-3500 rpm. The mixture is concentrated to 25-30% of the original volume to obtain a pre-assembly solution; S2.2: Place a quartz glass slide in deionized water for ultrasonic cleaning, then soak it in a hydrogen peroxide-concentrated sulfuric acid treatment solution for 7-8 hours. Rinse the surface with deionized water, dry it, and treat it with oxygen plasma for 3-4 minutes to obtain a hydrophilic substrate. Take 15-30 μm tinfoil and clamp it between two hydrophilic substrates for 4-5 hours. After the distance between them stabilizes, fix it and remove the tinfoil to obtain a capillary assembly board. S2.3: Insert the capillary force assembly plate into the pre-assembly solution. When the pre-assembly solution fills the space between the capillary force assembly plates, place it in a fume hood to air-dry for 24-25 hours, then place it in an oven at 60-65°C to dry for 30-35 minutes, then heat it to 120-150°C and keep it warm for 4-4.5 hours. After cooling, use a vibrating rod to vibrate the capillary force assembly plate at high speed for 2-3 minutes, open the capillary force assembly plate to collect the microcrystalline particles in between.

4. The process for preparing an antistatic semi-reflective and semi-transmissive polarizer according to claim 3, wherein: Step S3, preparation of the anti-static pressure-sensitive adhesive and the semi-permeable membrane and compounding of the polarizer, comprises the following steps: S3.1: Butyl acrylate, 2-methoxyethyl 2-acrylate, cycloethyl methacrylate, 2-hydroxyethyl acrylate and dibenzoyl peroxide are mixed and stirred in a mass ratio of (40-45): (25-30): (25-30): (10-12): (0.4-0.5) to obtain a mixed monomer. 65-70 parts by weight of ethyl acetate are added to the reaction vessel based on the volume percentage of the reaction vessel. The mixture is stirred and heated to 75-80°C. The mixture is kept at reflux for 30-35 minutes, and then 45-50 parts by weight of the mixed monomer are added. The monomers are mixed, and the mixture is refluxed for 1-1.5 hours in a water bath at 75-80° C., kept warm, and 45-50 parts by weight of the mixed monomers and 4-6 parts by weight of 1-butyl-3-methylimidazole bis(trifluoromethylsulfonyl)imide are slowly added dropwise over 1-2 hours, and the reflux reaction is continued for 1.5-2 hours. Finally, 65-70 parts by weight of ethyl acetate are added, and the mixture is heated in a water bath to 84-85° C., and the reflux reaction is continued for 4-5 hours. After adding 4-6 wt % of lithium bis(oxalatoborate), the mixture is stirred at a uniform speed, and naturally cooled to room temperature to obtain an anti-static pressure-sensitive adhesive. S3.2: 80-85 parts by weight of 4-biphenylmethanol acrylate, 8-10 parts by weight of microcrystalline particles, 0.2-0.5 parts by weight of dispersant BYK-111, 0.2-0.5 parts by weight of leveling agent BYK-333, 0.1-0.3 parts by weight of degassing agent BYK-052, and 3-5 parts by weight of light curing agent are mixed uniformly in a light-proof environment to obtain a semipermeable colloid, and the semipermeable colloid is uniformly coated on the surface of a PET film with a thickness of 60-80 μm to a coating thickness of 20-25 μm, and heated in an oven at 60-65°C for 3-5 minutes, and then placed in a UV curing machine for curing to obtain a semipermeable membrane; S3.3: Evenly apply anti-static pressure-sensitive adhesive on the front and back surfaces of the PVA film, then adhere the composite TAC film on the front and back surfaces to obtain a polarizing layer, evenly apply anti-static pressure-sensitive adhesive on the front and back surfaces of the polarizing layer, adhere the composite semi-permeable film on the front surface, and adhere the composite release film on the back surface to obtain an anti-static semi-reflective and semi-transmissive polarizer.

5. The process for preparing an antistatic semi-reflective and semi-transmissive polarizer according to claim 3, wherein: The mixed solution in step S2.1 is added to the PVA aqueous solution within 25-30 minutes.

6. The process for preparing an antistatic semi-reflective and semi-transmissive polarizer according to claim 3, wherein: In the hydrogen peroxide-concentrated sulfuric acid treatment solution of step S2.2, the mass ratio of hydrogen peroxide to concentrated sulfuric acid is 1:(0.8-1).

7. The process for preparing an antistatic semi-reflective and semi-transmissive polarizer according to claim 4, wherein: The photocuring agent in step S3.2 is ethyl 2,4,6-trimethylbenzoylphenylphosphonate.

8. The process for preparing an antistatic semi-reflective and semi-transmissive polarizer according to claim 4, wherein: The curing conditions in step S3.2 are 380nm UV wavelength, 100-105mW / cm 2 Cure for 1-1.5 minutes under the light intensity of 500 nm.

9. The process for preparing an antistatic semi-reflective and semi-transmissive polarizer according to claim 4, wherein: In step S3.3, the thickness of the PVA film is 25-30 μm, the thickness of the adhesive layer formed by the anti-static pressure-sensitive adhesive is 12-18 μm, the thickness of the TAC film is 55-60 μm, and the thickness of the release film is 30-35 μm.

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