CN114690302B

CN114690302B - Polarization component for improving dark state bluish color, preparation method and polarizer

Info

Publication number: CN114690302B
Application number: CN202011639317.1A
Authority: CN
Inventors: 季露露; 严兵华; 张良宝
Original assignee: Hengmei Optoelectronics Co ltd
Current assignee: Hengmei Optoelectronics Co ltd
Priority date: 2020-12-31
Filing date: 2020-12-31
Publication date: 2024-04-09
Anticipated expiration: 2040-12-31
Also published as: CN114690302A

Abstract

The invention relates to a polarized light, a preparation method and a polarizer for improving dark state bluish color, wherein the polarized light is dyed by immersing a polyvinyl alcohol film into an aqueous solution containing iodine and potassium iodide, iodine molecules or polyiodide ions are fixed in a PVA film by a boric acid solution in a bridging groove, and then the iodine molecules or polyiodide ions are arranged in a specific direction through an extension groove. The prepared partial photon is immersed into a black phosphorus quantum dot dispersion liquid, and is obtained through high-temperature drying at 60-70 ℃; and bonding the prepared polarons with upper and lower polaron protective films, performing bonding, then performing high-temperature oven at 80-100 ℃ to obtain an original reflection, and performing original reflection coating on the pressure-sensitive adhesive to obtain the polaroid. The invention can realize the following polarizer improvement: the black phosphorus quantum dots are uniformly attached to the surface of the polarizer, so that light of a blue light area wave band can be absorbed, and the orthogonal transmittance of the polarizer in the blue light area is reduced. The high-temperature and high-humidity optical resistance of the polaroid is improved, and the polarization degree reduction in the high-temperature and high-humidity reliability test of the polaroid is reduced.

Description

Polarization component for improving dark state bluish color, preparation method and polarizer

Technical Field

The present invention relates to a polarizer, and more particularly, to a polarizer for improving blue light in dark state, a method for preparing the polarizer, and a polarizer prepared from the polarizer.

Background

Polarizing plates are mainly used for liquid crystal and organic EL displays, and are indispensable elements for displaying images. In the main conventional production process, a PVA (polyvinyl alcohol) film dyed with iodine is uniaxially stretched as a polarizer, and in order to improve the strength, water resistance, moisture resistance, etc., a highly transparent film material such as TAC (triacetyl cellulose film), PMMA (acryl film), COP (cyclopentene film), PET (polyethylene terephthalate film) and the like having optical transparency is generally selected as a polarizer protective layer. With the high-speed development of artificial intelligence, the application range of the liquid crystal display is wider and wider, and the requirements of the market on the optical performance of the polaroid are stricter due to the diversification of the use environment and the requirements, so that the problems of dark state bluing and unbiasing of the polaroid are always the difficult problems in the field of research of the polaroid. At present, the polarizer generally has high orthogonal transmittance in a blue light region, and the reason is that the iodine-based polarizer is difficult to absorb blue light with stronger energy completely due to iodine-based dye, and part of blue light can leak in an orthogonal state, so that the dark state blue bias phenomenon of the polarizer is caused. In addition, the polarization degree of the existing polaroid is reduced more at 168hr under the conditions of high temperature and high humidity of 60-100 ℃/70-90%.

Disclosure of Invention

The invention provides a polarization element for improving dark state bluish and depolarization problems of a polarizer, a preparation method and the polarizer, wherein the polarization element prepared by the preparation method and the polarizer containing the polarization element can absorb light of a blue light area wave band, reduce the orthogonal transmittance of the polarizer in the blue light area, inhibit depolarization of the polarization degree caused by iodine loss under high-temperature high-humidity conditions, and improve the durability of the polarizer.

The technical scheme adopted by the invention is as follows: a preparation method of a polarized light element for improving dark state bluish color comprises the following steps

S01 swelling: cleaning and soaking the polyvinyl alcohol film to clean and swell the surface of the polyvinyl alcohol film;

s02 dyeing: placing the cleaned and swelled polyvinyl alcohol film into a dyeing tank for dyeing, wherein the dyeing tank is internally provided with mixed liquid of iodine liquid, boric acid and iodide ions, and iodine simple substance and iodide ions are used as dichroism mediums, so that the polyvinyl alcohol film can absorb specific light rays;

s03 bridging: placing the dyed polyvinyl alcohol film in a bridging groove for crosslinking, wherein boric acid is arranged in the bridging groove and is bonded with hydroxyl groups on the polyvinyl alcohol film, and fixing iodine simple substance and iodine ions on the polyvinyl alcohol film;

s04 extends: placing the bridged polyvinyl alcohol film into an extension groove for extension;

s05, adjusting: placing the stretched polyvinyl alcohol film in a color fixing groove for color fixing and adjusting of the hue of the polaroid, wherein a color fixing liquid is arranged in the color fixing groove, and the color fixing liquid contains an iodide ion solution;

s06 adsorption: immersing the regulated polyvinyl alcohol film into the black phosphorus quantum dot dispersion liquid, and adsorbing the black phosphorus quantum dots by the polyvinyl alcohol film;

s07, drying: and drying the polyvinyl alcohol film after the black phosphorus quantum dots are adsorbed.

Further, the concentration of the black phosphorus quantum dots in the adsorption step is 0.1-10 ppm.

Further, the polyvinyl alcohol film is a copolymer of vinyl acetate and a monomer, and the monomer is unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

Further, the mass concentration of the elemental iodine in the dyeing tank is 0.2-1.0%, the boric acid concentration is 4%, the dyeing time is 20-100 seconds, and the temperature is 20-60 ℃.

Further, the polyvinyl alcohol film is stretched for 2-8 times, the temperature of the stretching section is 50-70 ℃, KI and boric acid solution are arranged in the stretching groove, the KI concentration is 4%, the boric acid concentration is 0.1-5%, and the stretching time can be 80-200 seconds.

Further, the color fixing liquid contains KI, the concentration of KI is 0.1-5%, the color fixing time is 20-100 seconds, and the color fixing temperature is 20-60 ℃.

Further, in the adsorption step, the concentration of the black phosphorus quantum dot dispersion liquid is 0.1-10 ppm, and the adsorption temperature is 20-40 ℃; the adsorption time is 100-200 seconds.

Further, in the drying step, the polyvinyl alcohol film passes through a polarizer oven, the polarizer oven is a 3-section sectional oven with the same length, the oven temperature is 60-70 ℃, and the total residence time of the polyvinyl alcohol film in the oven is 80-150 seconds.

The invention also relates to a polarized light element prepared by the preparation method for improving the polarized light element of dark state bluish.

In addition, the polaroid comprises the polaroid for improving dark state bluing, and the polaroid consists of a protective film, an upper polaroid protective film, a UV adhesive bonding layer, a polaroid, a UV adhesive bonding layer, a lower polaroid protective film, a PSA adhesive layer and a release film.

Further, the preparation method of the polaroid comprises the following steps: attaching the two surfaces of the polarizer with the improved dark state bluish color and the upper and lower polarizer protective films through a UV adhesive, and drying in a sectional manner to obtain the original reflection of the polarizer; connecting the lower polarizer protective layer of the original reverse polarizer with the release film layer through a pressure sensitive adhesive; the laminating tension is 1000-1500N, the temperature of the oven after lamination is 80-100 ℃ and the total residence time of the film after the oven is 200-400 s, so that the UV glue can be further solidified to improve the cohesiveness and the stability of iodine molecules or polyiodide ions and black scale quantum dots on the PVA film can be improved.

Further, the upper polarizer protective film is made of a thermoplastic resin such as cellulose triacetate; an acrylic film; a cyclic polyolefin resin; a polycarbonate resin; (meth) acrylic resins;

further, the lower polarizer protective film employs a hydrophobic cyclopentene film, such as a modified cyclopentene film developed by Konikoku Meida Co., ltd; also included are thermoplastic resins such as cellulose triacetate; an acrylic film; a cyclic polyolefin resin; a polycarbonate resin; (meth) acrylic resins.

Further, the pressure sensitive adhesive adopts butyl acrylate, ethyl acrylate, isooctyl acrylate, n-butyl acrylate, n-ethyl acrylate, methacrylic acid, hydroxyethyl methacrylate, hydroxypropyl acrylate and methacrylamide.

Further, the UV adhesive is a UV hardening adhesive, and the UV photoinitiator is a free radical photoinitiator or a cationic photoinitiator; the UV adhesive layer is hardened by ultraviolet rays, the UV irradiation wavelength is 220 nm-440 nm, and the thickness is 0.02 mu m-4 mu m.

The beneficial effects of the invention include: according to the invention, the unique chair-type hexagonal net structure of the black phosphorus quantum dots is uniformly attached to the surface of the polarizer and combined with the polyvinyl alcohol, so that light of a blue light area wave band can be absorbed, and the orthogonal transmittance of the polarizer in the blue light area is reduced. The temperature of the oven of the polaroid and the temperature of the oven after lamination are improved, so that iodine molecules or polyiodide ions and black phosphorus quantum dots attached to the polaroid are more firmly adsorbed between polyvinyl alcohol macromolecules, the reduction (depolarization) of the polarization degree caused by iodine loss under the conditions of high temperature and high humidity is inhibited, and the durability of the polaroid is improved.

Drawings

FIG. 1 is a schematic diagram of a polarizer for suppressing bluish and unbiased dark states according to the present invention;

FIG. 2 is a preparation flow of the present invention;

FIG. 3 is a diagram of a black phosphorus quantum dot structure;

fig. 4 is a graph of orthogonal spectra of different mass ratios of black phosphorus quantum dot dispersion experiments of the present invention.

Detailed Description

The invention will be explained in further detail below with reference to the drawings and the specific embodiments, but it should be understood that the scope of protection of the invention is not limited to the specific embodiments.

Example 1

The polarizer is prepared as shown in FIG. 2, and comprises swelling, dyeing, stretching, adjusting and adsorbing, in particular

The prepared PVA film (polyvinyl alcohol film) was immersed in pure water at 20 ℃ for 40 seconds, and the PVA film was washed and swelled. Then, the resultant was immersed in an aqueous solution having a mass concentration of 0.02% of iodine, 0.3% of potassium iodide and 0.5% of boric acid at 30℃for 70 seconds to dye, and immersed in an aqueous solution having a mass concentration of 2% of potassium iodide and 4% of boric acid for 70 seconds to crosslink, and uniaxially stretched 2 times. Then, the sheet was stretched at 60℃in an aqueous solution of 4% potassium iodide and 4% boric acid at a mass concentration, and the cumulative stretching ratio was 6 times. Then, the hue was adjusted in an aqueous solution of 5% by mass of potassium iodide at a temperature of 30 ℃. Then, the black phosphorus quantum dots were immersed in a dispersion of black phosphorus quantum dots having a mass concentration of 0.2 ppm at a temperature of 30℃for 60 seconds to adsorb the black phosphorus quantum dots, and an ultrasonic device was mounted at an ultrasonic frequency of 100KHz. After the adsorption is completed, the polarized light is obtained by drying in an oven with the temperature of 60 ℃, 65 ℃ and 70 ℃ and the temperature of 3 sections respectively, and the total drying time is 100 seconds.

With the polarizer prepared as described above, as shown in fig. 1, the upper polarizer protective film and the lower polarizer protective film are attached to the front and back sides of the PVA film through UV adhesive bonding layers, after fitting into a 10-section oven-drying for 200 seconds, oven temperatures were 80 ℃, 90 ℃, 100 ℃ and 100 ℃, respectively. And a release film is attached to the lower polarizer protective film by utilizing the PSA adhesive layer, and a PET protective film is attached to the upper polarizer protective film to obtain the polaroid for inhibiting dark state bluing, and the surface state of the polaroid is visually observed, so that the polaroid shows that the color phase is gray and not bluing. The polarizer was visually observed in a dark room in a nicol cross (Nicole cross) state, and almost no blue light was leaked. The transmittance at 405nm of blue light absorption wavelength at 0 hours, the value of the hue b of the orthogonal color, the degree of polarization, and the degree of polarization at 85 ℃/85% under high temperature and high humidity conditions for 168 hours were measured by a spectroluminance meter with an integrating sphere.

As shown in fig. 2, the black phosphorus quantum dot (orthorhombic structure P allotrope) is a unique chair-type hexagonal net structure, and the structure and the polyvinyl alcohol are combined to have stronger absorption on a blue light region in an orthorhombic state, so that the performance of inhibiting dark state blue bias is provided for the PVA film; the orthogonal transmittance of the polarized light in the blue light area can be reduced, and the polarized light has stable optical characteristics.

Examples 2 to 4

Examples 2 to 4 and example 1 were repeated in the same manner except that black phosphorus quantum dot dispersions of different concentrations were used instead to prepare polarizers having suppressed bluish and unbiased dark states, and the black phosphorus quantum dot dispersions of examples 2 to 4 were 0.4ppm, 0.6ppm, 0.8ppm in concentration, and the polarizers thus prepared were observed in a dark room in a nicol orthometric state with little blue light leakage. The value of the orthogonal transmittance at 405nm of the blue light absorption wavelength and the value of the orthogonal hue b were measured by a spectroluminance meter with an integrating sphere.

Comparative example 1

The comparative example was repeated in the same manner as in example 1 except that the concentration of the black phosphorus quantum dot in the black phosphorus quantum dot dispersion was 0.05 ppm to prepare a polarizer having suppressed bluish and unbiased dark states, and the polarizer thus prepared was also reduced in the content of the black phosphorus quantum dot adsorbed on the PVA film due to the lower concentration of the black phosphorus quantum dot dispersion than in example 1, and bluish gray on the surface of the polarizer was observed visually, and some blue light leakage of the polarizer was observed in a darkroom in a nicol orthorhombic state. The value of the orthogonal transmittance at 405nm of the blue light absorption wavelength and the value of the orthogonal hue b were measured by a spectroluminance meter with an integrating sphere.

Comparative example 2

The comparative example was repeated in the same manner as in example 1 except for the black phosphorus quantum dot adsorption step and the carried ultrasonic device to prepare a polarizer having suppressed bluish and unbiased dark states, that is, a general iodine-based polarizer was prepared in a conventional manner, and the polarizer thus prepared was visually observed to have a bluish surface and more blue light leakage in a dark room in a nicol orthometric state. The value of the orthogonal transmittance and the orthogonal hue b at a blue light absorption wavelength of 405nm at 0 hour were measured by a spectroluminance meter with an integrating sphere.

TABLE 1 orthogonal optical manifestation of blue regions of different concentrations of black phosphorus quantum dots

In table 1, the comparison between 1 and 2 is that the phosphor quantum dot dispersion liquid with low content and the black phosphor quantum dot dispersion liquid without absorption are respectively absorbed, the orthogonal rate of the blue light area is larger, the orthogonal b is more negative, the whole polarizer leaks blue light in a dark state, and in the embodiment 1 to 4, the transmittance of the blue light area is gradually reduced and the value of the orthogonal phase b of the blue hue is also gradually increased along with the increase of the concentration of the black phosphor quantum dots by adding the black phosphor quantum dot dispersion liquid with different mass ratios.

As shown in fig. 4, except for adding black phosphorus quantum dots with different mass percentages, orthogonal spectra of photons with the same polarization and attached upper and lower protective films are obtained, and the spectra represent the transmittance at different wavelengths of 380 nm-700 nm, and the transmittance at 405nm is the Tc405 value. Tc405 represents the dark blue light leakage value, and represents less blue light leakage when the orthogonal transmittance is lower, and represents more blue light leakage when the orthogonal transmittance is higher. As shown in fig. 4, the higher the black phosphorus quantum dot mass concentration, the lower the value of Tc405, indicating that the amount of dark blue light leakage is smaller. The black phosphorus quantum dots have the effect of inhibiting the dark state bluish of the polaroid, and the higher the concentration is, the better the inhibition effect is.

Comparative example 3

The comparative example was repeated in the same manner as in example 1 except that the ultrasonic device was not mounted to prepare a polarizer having suppressed bluish dark state, and the polarizer thus prepared had uneven distribution of black phosphorus quantum dots adsorbed on the PVA film due to agglomeration of black phosphorus quantum dots, visually observable fine particulate attachments, and observed that more blue light leaked out of the polarizer in a dark room in a nicol orthometric state, and the agglomerated black phosphorus quantum dots could not have the effect of suppressing bluish dark state of the polarizer. The transmittance at 405nm of blue light absorption wavelength and the value of the hue b of the orthogonal color were measured by a spectroluminance meter with an integrating sphere and are shown in Table 2.

TABLE 2 orthogonal optical manifestations of black phosphorus quantum dots with and without sonication

Comparative example 1 and comparative example 3: except that the black phosphorus quantum dots are not subjected to ultrasonic treatment, the conditions of the black phosphorus quantum dots are the same as those of the embodiment 1, the cross-over rate of the blue light region of the polaroid prepared in the embodiment 3 is high, the cross-over b is negative, and the whole polaroid leaks blue light in a dark state, so that the black phosphorus quantum dots which are not subjected to ultrasonic treatment do not have the effect of inhibiting the dark state of the polaroid from being bluish.

Comparative example 4

Comparative example 4 was repeated in the same manner as in example 1 except that the temperatures of the polarizer oven and the oven after lamination were different to prepare a polarizer having suppressed bluish and unbiased dark states, and thus prepared polarizer had reduced stability due to adsorption of iodine molecules or polyiodide ions and black phosphorus quantum dots between polyvinyl alcohol polymers because of low temperatures of the polarizer oven and the oven after lamination. The polarization degree was measured with a spectroluminance meter with an integrating sphere for 0 hour and the polarization degree was 85℃for 168 hours under high temperature and high humidity conditions of 85%.

TABLE 3 high temperature and high humidity depolarization behavior at different oven temperatures (0 hr for 0hr polarization degree, 168hr for 85 ℃/85% polarization degree under high temperature and high humidity conditions for 168 hours, Δ168hr for 85 ℃/85% polarization degree difference between 168 hours polarization degree under high temperature and high humidity conditions and 0 hour)

Comparative example 1 and comparative example 4: comparative example 4 the polarizer prepared in the case of low temperature of the polarizer oven and the oven after lamination was large in the degree of polarization drop of 168 hours under the conditions of high temperature and high humidity of 85 ℃ and 85%, which indicates that the polarizer prepared under the conditions was easy to depolarize under high temperature and high humidity, and the durability was poor.

The foregoing has outlined rather broadly the basic principles, features, and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the foregoing embodiments, and that the foregoing embodiments and description are merely illustrative of the principles of this invention, and various changes and modifications may be made without departing from the spirit and scope of the invention, which is defined in the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A preparation method of a polarized light element for improving dark state bluish is characterized by comprising the following steps: comprises the following steps

s02 dyeing: placing the cleaned and swelled polyvinyl alcohol film into a dyeing tank for dyeing, wherein the dyeing tank is internally provided with a mixed solution of elemental iodine, boric acid and iodide ions;

s03 bridging: placing the dyed polyvinyl alcohol film in a bridging groove for crosslinking, wherein boric acid is arranged in the bridging groove and bonded with hydroxyl groups on the polyvinyl alcohol film;

s07, drying: drying the polyvinyl alcohol film after adsorbing the black phosphorus quantum dots;

the concentration of the black phosphorus quantum dots in the adsorption step is 0.1-10 ppm;

the color fixing liquid contains a KI solution, the concentration of the KI solution is 0.1-5%, the color fixing time is 20-100 seconds, and the color fixing temperature is 20-60 ℃;

the adsorption temperature in the adsorption step is 20-40 ℃; the adsorption time is 100-200 seconds;

in the drying step, the polyvinyl alcohol film is subjected to sectional drying through 3-5 sections of ovens at 60-70 ℃, and the total residence time of the polyvinyl alcohol film in the ovens is 80-150 seconds.

2. The method for preparing the polarized light component for improving the dark state bluish color according to claim 1, wherein the method comprises the following steps: the polyvinyl alcohol film is a copolymer of vinyl acetate and a monomer, and the monomer is unsaturated carboxylic acid, olefin, vinyl ether, unsaturated sulfonic acid or acrylamide with ammonium groups.

3. The method for preparing the polarized light component for improving the dark state bluish color according to claim 1, wherein the method comprises the following steps: the concentration of elemental iodine in the dyeing tank is 0.2-1.0%, the concentration of boric acid is 4%, the dyeing time is 20-100 seconds, and the temperature is 20-60 ℃.

4. The method for preparing the polarized light component for improving the dark state bluish color according to claim 1, wherein the method comprises the following steps: the polyvinyl alcohol film is stretched for 2-8 times, the temperature of the stretching section is 50-70 ℃, KI and boric acid solution are arranged in the stretching groove, the KI concentration is 4%, the boric acid concentration is 0.1-5%, and the stretching time is 80-200 seconds.

5. A polarized light element produced by the method for producing a polarized light element for improving a dark state bluish color according to any one of claims 1 to 4.

6. A polarizer, characterized in that: comprising the bias light of claim 5.