RGB (red, green and blue) resin coating, preparation method thereof and polaroid

Abstract

The invention discloses an RGB resin coating and a preparation method thereof and a polaroid in the technical field of polaroids, and the RGB resin coating is prepared from the following raw materials in parts by mass: 45-96 parts of a resin mixture, 2-35 parts of a coloring agent, 1-10 parts of an initiator, 0.01-5 parts of a flatting agent and 0.01-5 parts of other auxiliaries. Wherein the resin mixture is composed of 50-99 parts by mass of an acrylic ester and 1-50 parts by mass of a polymerizable compound, and the polymerizable compound is a compound capable of being polymerized by means of an active radical and / or an acid generated by a polymerization initiator. According to the RGB resin coating prepared by the preparation method of the RGB resin coating provided by the invention, a polaroid prepared from the RGB resin coating has relatively high transmittance, and meanwhile, the light resistance and durability of the polaroid can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of polarizers, and in particular to an RGB resin coating and a preparation method thereof, and a polarizer. Background Art

[0002] Polarizers are made by laminating multiple films. Typically, PVA film is dyed with a dichroic pigment in a solution at a certain temperature and simultaneously stretched and aligned. With the help of UV adhesive, the upper and lower PVA protective layers are laminated to the PVA film. A layer of PSA glue is then applied to the surface of the lower protective layer, followed by a release film.

[0003] There are two main types of dichroic pigments: iodine and dyes. The corresponding PVA film dyeing processes are called iodine dyeing and dye dyeing, respectively. The iodine dyeing method uses iodine and potassium iodide as dichroic media. Its advantages include excellent optical properties, easily achieving high polarization (over 99.9%) and transmittance (over 42%). However, its disadvantage is that the molecular structure of iodine is easily destroyed in high temperature and humidity. This results in poor light resistance, moisture resistance, and heat resistance of the produced polarizer, which limits its application range. Summary of the Invention

[0004] The object of the present invention is to overcome the deficiencies in the prior art and provide an RGB resin coating, a preparation method thereof, and a polarizer. The RGB resin coating has a glass transition temperature of ≥84°C, so that the polarizer prepared therefrom has a high transmittance and can effectively improve the light resistance and durability of the polarizer.

[0005] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0006] In a first aspect, the present invention provides an RGB resin coating, comprising the following raw materials in parts by mass: 45 to 96 parts of a resin mixture, 2 to 35 parts of a colorant, 1 to 10 parts of an initiator, 0.01 to 5 parts of a leveling agent, and 0.01 to 5 parts of an auxiliary agent;

[0007] The resin mixture is composed of 50 to 99 parts by mass of an acrylate and 1 to 50 parts by mass of a polymerizable compound, wherein the polymerizable compound is a compound that can be polymerized using active free radicals and / or acids generated by a photoinitiator;

[0008] The auxiliary agent includes one or more of a cross-linking agent, a dispersant, a color fixing agent, a solvent and a dyeing auxiliary agent.

[0009] Furthermore, the colorant consists of 5 to 70 parts by mass of RGB dye and 30 to 95 parts by mass of solvent.

[0010] Furthermore, the acrylate includes (meth)acrylate, and the (meth)acrylate is selected from one or more of (meth)acrylate containing a hydroxyl group, (meth)acrylate containing a carboxyl group, and (meth)acrylic acid adducts of epoxy acrylate.

[0011] Further, the (meth)acrylate containing a hydroxyl group is selected from pentaerythritol triacrylate (PETA), dipentaerythritol hexaacrylate (DPHA) and 2-phenoxyethyl acrylate (PHEA);

[0012] The carboxyl group-containing (meth)acrylate is selected from one or more of 2-acryloxypropyltetrahydrophthalic acid, 2-acryloxypropylhexahydrophthalic acid, methacryloyloxyethylsuccinic acid, methacryloyloxyethylphthalic acid, methacryloyloxyethyltetrahydrophthalic acid, methacryloyloxyethylhexahydrophthalic acid, 2-acryloyloxypropyloxyphthalic acid, 2-methacryloyloxypropyltetrahydrophthalic acid and 2-methacryloyloxypropylhexahydrophthalic acid;

[0013] The (meth)acrylic acid adduct of epoxy acrylate is selected from one or more of 3-methyl-3-(meth)acryloyloxymethyloxetane / (meth)acrylic acid / styrene copolymer, benzyl (meth)acrylate / (meth)acrylic acid copolymer and styrene / (meth)acrylic acid copolymer.

[0014] Furthermore, the polymerizable functional groups in the polymerizable compound are separated by oxygen-containing structures having 1 to 20 carbon atoms, and the polymerizable functional groups are selected from one or more of alkyl groups, alkenyl groups, alicyclic groups and unsaturated alicyclic groups.

[0015] Furthermore, the polymerizable compound is a (meth)acrylate compound, selected from one or more of a (meth)acrylate monomer or a composition thereof, an ethylene oxide-containing monomer or a composition thereof, a propylene oxide-containing monomer or a composition thereof, an isocyanate-containing monomer or a composition thereof, a polyacrylamide-containing monomer or a composition thereof, an alkoxy-containing monomer or a composition thereof, a phenyl-containing monomer or a composition thereof, and a silane-containing monomer or a composition thereof.

[0016] Furthermore, the initiator is a photoinitiator, and the photoinitiator is a free radical initiator or a cationic initiator;

[0017] And / or, the leveling agent is selected from one or more of acrylic leveling agents, silicone leveling agents, and fluorocarbon leveling agents.

[0018] In a second aspect, the present invention provides a method for preparing the RGB resin coating, comprising the following steps:

[0019] Add the colorant and solvent to the reaction vessel and stir until well mixed;

[0020] Add the resin mixture to the reaction vessel and stir until well mixed;

[0021] Add the initiator to the reaction vessel and stir for 20-40 minutes until the mixture is uniform;

[0022] Add the leveling agent and other additives into the reaction container, stir until the mixture is evenly mixed, and then filter to obtain the RGB resin coating.

[0023] In a third aspect, the present invention provides a polarizer comprising a polyvinyl alcohol (PVA) layer and a PVA protective layer, wherein the PVA layer and the PVA protective layer are pasted together by curing an RGB resin coating, wherein the RGB resin coating is the RGB resin coating according to any one of claims 1 to 7, or is prepared by the preparation method of the RGB resin coating according to claim 8.

[0024] Furthermore, the PVA protective layer is a hydrophobic material, selected from any one of PMMA acrylic, PET polyethylene terephthalate, cycloolefin polymer COP, COP derivatives and COP modified products.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The RGB resin coating provided by the present invention is composed of the following raw materials in parts by weight: 45-96 parts of a resin mixture, 2-35 parts of a colorant, 1-10 parts of an initiator, 0.01-5 parts of a leveling agent, and 0.01-5 parts of other additives. The resin mixture is composed of 50-99 parts by weight of an acrylate and 1-50 parts by weight of a polymerizable compound. By controlling the appropriate ratio, the acrylate with a higher glass transition temperature is mixed with a comonomer with a lower glass transition temperature, so that the final RGB resin coating has a glass transition temperature of 84°C or higher. Compared with the iodine dyeing method, the present invention combines the dyeing step with the UV adhesive coating step in the method for preparing a polarizer, simplifying the PVA raw material preparation process, resulting in a polarizer with higher transmittance and polarization degree. It can also effectively improve the adhesion of the RGB resin coating for bonding the PVA layer and the PVA protective layer, making the polarizer more durable. DETAILED DESCRIPTION

[0027] The present invention will be further described below. The following examples are only used to more clearly illustrate the technical solution of the present invention and are not intended to limit the scope of protection of the present invention.

[0028] In the embodiment of the present invention, the UV lamp spectrum is preferably UVV ≥ 1300 mJ / cm 2 The irradiation distance between the UV lamp and the product is preferably 3 to 15 inches, the number of UV curing times is preferably 1 to 3 times, and the UV curing temperature is preferably 20 to 90°C. The specific situation can be selected according to needs.

[0029] Example 1

[0030] This embodiment provides an RGB resin coating and a preparation method thereof, as well as a polarizer and a preparation method thereof. The UV adhesive layer in the polarizer is prepared by coating and curing the RGB resin coating provided by this embodiment.

[0031] The preparation method of the RGB resin coating comprises:

[0032] 1) Dissolve 60 g of CI Direct Blue 40 and 40 g of ethyl acetate in a beaker and mix well to obtain a colorant;

[0033] 2) Add 28.5g of alkyl (meth)acrylate monomer, 12g of isocyanate-containing monomer, and 8.25g of silyl-containing monomer into a mixing bucket, stirring for 40 minutes. Then, add 15g of polycyclohexyl methacrylate, 12.25g of dipentaerythritol penta(meth)acrylate, 3g of toluene diisocyanate, and 3g of 2-hydroxy-2-methyl-1-phenylpropane-1-one in this order, and continue stirring for 20 minutes.

[0034] 3) 15 g of a colorant, 2 g of a silicone leveling agent, and 1 g of an antistatic agent were added to a mixing bucket, stirred for 30 min, and filtered to prepare an RGB resin coating. The stirring speed was 1000 rpm.

[0035] In this embodiment, the organic silicon leveling agent is polyether-modified silicone oil, and the antistatic agent is a polyacrylate-based antistatic agent.

[0036] The preparation method of the polarizer comprises:

[0037] The RGB resin coating was applied to both surfaces of the PVA film, and a PVA protective layer was attached to each surface. The film was then irradiated with a gallium lamp for double-sided curing to form a three-layer original and reverse structure. The energy density of the gallium lamp was 1300 mJ / cm 2 ; In this embodiment, a COP derivative is selected as the PVA protective layer, which is from SANUQI of Konica.

[0038] A pressure-sensitive adhesive is transferred onto one surface of the original reverse structure through a release film, and a PE protective film is attached to the other surface to obtain a polarizer.

[0039] Example 2

[0040] This embodiment provides an RGB resin coating and a preparation method thereof, as well as a polarizer and a preparation method thereof. The UV adhesive layer in the polarizer is prepared by coating and curing the RGB resin coating provided by this embodiment.

[0041] The preparation method of the RGB resin coating comprises:

[0042] 1) Dissolve 60 g of CI Direct Blue 40 and 40 g of ethyl acetate in a beaker and mix well to obtain a colorant;

[0043] 2) Add 25.7g of alkyl (meth)acrylate monomer, 10.8g of isocyanate-containing monomer, and 8.25g of silyl-containing monomer into a mixing bucket, stirring for 40 minutes. Then, add 17g of polycyclohexyl acrylate, 12.25g of dipentaerythritol penta(meth)acrylate, 3g of toluene diisocyanate, and 3g of 2-hydroxy-2-methyl-1-phenylpropane-1-one in this order, and continue stirring for 20 minutes.

[0044] 3) Place 17 g of colorant, 2 g of silicone leveling agent, and 1 g of antistatic agent in a mixing bucket, stir for 30 minutes, and filter to produce an RGB resin coating. The mixer speed is 1000 rpm.

[0045] The preparation method of the polarizer is the same as that of Example 1.

[0046] Example 3

[0047] This embodiment provides an RGB resin coating and a preparation method thereof, as well as a polarizer and a preparation method thereof. The UV adhesive layer in the polarizer is prepared by coating and curing the RGB resin coating provided by this embodiment.

[0048] The preparation method of the RGB resin coating comprises:

[0049] 1) Dissolve 60g of CI Direct Blue 40 and 40g of ethyl acetate in a beaker and mix well to obtain a colorant.

[0050] 2) Add 27.3g of alkyl (meth)acrylate monomer, 11.2g of isocyanate-containing monomer, and 8.25g of silyl-containing monomer into a stirring bucket, stirring for 40 minutes. Then, add 17g of polycyclohexyl acrylate, 12.25g of dipentaerythritol penta(meth)acrylate, 3g of toluene diisocyanate, and 3g of 2-hydroxy-2-methyl-1-phenylpropane-1-one in this order, and continue stirring for 20 minutes.

[0051] 3) 15 g of a colorant, 2 g of a silicone leveling agent, and 1 g of an antistatic agent were added to a mixing bucket, stirred for 30 min, and filtered to prepare an RGB resin coating. The stirring speed was 1000 rpm.

[0052] The preparation method of the polarizer is the same as that of Example 1.

[0053] Comparative Example 1

[0054] This comparative example provides an RGB resin coating and a preparation method thereof, as well as a polarizer and a preparation method thereof. The UV adhesive layer in the polarizer is prepared by coating and curing the RGB resin coating provided in this comparative example.

[0055] The preparation method of the comparative example coating comprises:

[0056] 1) Dissolve 60g of CI Direct Blue 40 and 40g of ethyl acetate in a beaker and mix well to obtain a colorant.

[0057] 2) Add 20 g of alkyl (meth)acrylate monomer and 26.75 g of isocyanate-containing monomer into a stirring bucket, stirring for 40 min. Then add 15 g of polycyclohexyl acrylate, 12.25 g of dipentaerythritol penta(meth)acrylate, 2 g of tris{4-[(4-acetylphenyl)sulfonyl]phenyl}ammonium sulfonate hexafluorophosphate, 3 g of toluene diisocyanate, and 3 g of 2-hydroxy-2-methyl-1-phenylpropane-1-one in this order, stirring for another 20 min.

[0058] 3) 15 g of a colorant, 2 g of a silicone leveling agent, and 1 g of an antistatic agent were added to a mixing bucket, stirred for 30 min, and filtered to prepare an RGB resin coating. The stirring speed was 1000 rpm.

[0059] The preparation method of the polarizer is the same as that of Example 1.

[0060] Comparative Example 2

[0061] This comparative example provides a coating and a preparation method thereof, as well as a polarizer and a preparation method thereof. The UV adhesive layer in the polarizer is prepared by coating and curing the coating provided in this comparative example.

[0062] The preparation method of the coating provided in this comparative example includes:

[0063] 1) Add 30.96g of alkyl (meth)acrylate monomer, 13.01g of isocyanate-containing monomer, and 9.94g of silyl-containing monomer into a stirring bucket, stirring for 40 minutes. Then, add 20.48g of polycyclohexyl acrylate, 14.76g of dipentaerythritol penta(meth)acrylate, 3.61g of toluene diisocyanate, and 3.61g of 2-hydroxy-2-methyl-1-phenylpropane-1-one in this order, and continue stirring for 20 minutes.

[0064] 2) 2.41 g of an organosilicon leveling agent and 1.2 g of an antistatic agent were added to a stirring bucket, stirred for 30 min, and filtered to prepare an RGB resin coating, wherein the stirring speed was 1000 rpm.

[0065] The preparation method of the polarizer provided in this comparative example includes:

[0066] The RGB resin coating (dye-free version) was applied to both surfaces of the iodine-dyed PVA film, and PVA protective layers were attached to both surfaces. The film was then irradiated with a gallium lamp for double-sided curing to form a three-layer original-reverse structure. The energy density of the gallium lamp was 1300 mJ / cm 2 ; In this embodiment, a COP derivative is selected as the PVA protective layer, which is from SANUQI of Konica.

[0067] A pressure-sensitive adhesive is transferred onto one surface of the original reverse structure through a release film, and a PE protective film is attached to the other surface to obtain a polarizer.

[0068] The glass transition temperature (Tg) test was performed on the RGB resin coatings provided in Examples 1-3 and Comparative Examples 1 and 2, and then the adhesion test and optical test were performed on the polarizers provided in Examples 1-3 and Comparative Examples 1 and 2, respectively. The test methods are as follows:

[0069] A. Glass transition temperature (Tg) test

[0070] The RGB resin coating is coated on the release film, and then the RGB resin coating is coated on the release film with a UVV of ≥ 1300 mJ / cm 2 After the energy was UV-cured twice, a UV adhesive was obtained, and the obtained UV adhesive was tested by differential scanning calorimetry (DSC).

[0071] B. Adhesion Test

[0072] Cut the resulting polarizer into 15 mm x 150 mm pieces. Separate the PVA and PVA protective layers with a knife tip. Secure the separated sections to a material tensile testing machine (Instron 3665) using 31B tape, with the tape attached for a length of ≥ 3 cm. Then, pull the polarizer apart at a speed of 1000 mm / min, applying a force perpendicular to the polarizer at a 90° angle. Record the resulting adhesion strength.

[0073] C. Optical testing

[0074] The resulting polarizer was cut into 30 mm x 40 mm pieces and attached to optical glass. The transmittance and polarization degree of the polarizer were measured using a spectrocolorimeter (Jasco V-7100) according to JIS Z 8701.

[0075] The results of the glass transition temperature (Tg) test are shown in Table 1.

[0076] Table 1 Glass transition temperature (Tg) test

[0077] Project / No. Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Tg About 95℃ About 84℃ About 83℃ About 70℃ About 81℃

[0078] The results of the adhesion test are shown in Table 2.

[0079] Table 2 Adhesion test results (unit: gf / 15mm)

[0080] Project / No. Sample 1 Sample 2 Sample 3 average value Example 1 187 190 187 188 Example 2 230 235 226 230 Example 3 257 261 255 258 Comparative Example 1 260 266 270 265 Comparative Example 2 220 215 230 222

[0081] The results of the optical test are shown in Table 3 and Table 4, wherein Table 3 is the test result of the single transmittance, and Table 4 is the test result of the polarization degree.

[0082] Table 3 Optical test results - single-unit transmittance (%)

[0083] Project / No. Sample 1 Sample 2 Sample 3 average value Example 1 43.53 43.60 43.62 43.58 Example 2 43.82 44.10 43.86 43.93 Example 3 43.68 43.71 43.75 43.71 Comparative Example 1 43.55 43.62 43.68 43.62 Comparative Example 2 43.05 42.98 43.22 43.08

[0084] Table 4 Optical test results - polarization degree (%)

[0085] Project / No. Sample 1 Sample 2 Sample 3 average value Example 1 99.998 99.998 99.998 99.998 Example 2 99.999 99.989 99.988 99.992 Example 3 99.998 99.997 99.999 99.998 Comparative Example 1 99.998 99.989 99.990 99.992 Comparative Example 2 99.998 99.898 99.990 99.962

[0086] As can be seen from Table 1, the glass transition temperatures of the RGB resin coatings provided in Examples 1-3 of the present invention are all ≥83°C, while the glass transition temperature of the RGB resin coating provided in Comparative Example 1 is only 70°C. It can be seen from the test data that the glass transition temperature of Comparative Example 2 using the iodine dyeing method is relatively low. At the same time, it can be seen from Tables 2-4 that, under the premise of increasing the glass transition temperature, the RGB resin coatings provided by the present invention still maintain good transmittance, polarization degree and adhesion. The transmittance of the polarizer monomer prepared in Examples 1-3 can reach more than 43%, and the polarization degree can reach more than 99.99%. The performance of the polarizer is not poor due to changing the dyeing method, and the glass transition temperature can be controlled by adjusting the ratio of the resin mixture.

[0087] The dyeing mechanism of azo-type direct dyes for polyvinyl alcohol film is that the dye molecules react with the hydroxyl groups of the polyvinyl alcohol and can also bind and adsorb through hydrogen bonds and van der Waals forces. As a result, the moisture resistance of the dyed polyvinyl alcohol film is significantly improved. Gray polarizing films formed by stretching and aligning RGB resin coatings on polyvinyl alcohol films have relatively average transmittance and polarization across the visible wavelength range, and their hue is similar to that of iodine-based polarizers.

[0088] In summary, the present invention, by mixing a dye with a resin to obtain a resin coating, simplifies the production process of the polarizer while also achieving good performance. Furthermore, by adjusting the formulation components of the resin mixture, the glass transition temperature (Tg) of the RGB resin coating can be controlled, resulting in a polarizer with both excellent optical properties and excellent adhesion.

[0089] The embodiments of the present invention are described above, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which are all protected by the present invention.

Claims

1. An RGB resin coating, characterized in that: The composition comprises the following raw materials in parts by mass: 45-96 parts of a resin mixture, 2-35 parts of a colorant, 1-10 parts of an initiator, 0.01-5 parts of a leveling agent, and 0.01-5 parts of an auxiliary agent; The resin mixture is composed of 50 to 99 parts by mass of an acrylate and 1 to 50 parts by mass of a polymerizable compound, wherein the polymerizable compound is a compound that can be polymerized using active free radicals and / or acids generated by a photoinitiator; The auxiliary agent includes one or more of a cross-linking agent, a dispersant, a color fixing agent, a solvent and a dyeing auxiliary agent.

2. The RGB resin coating according to claim 1, characterized in that: The colorant consists of 5 to 70 parts by mass of RGB dye and 30 to 95 parts by mass of solvent.

3. The RGB resin coating according to claim 1, characterized in that: The acrylate includes (meth)acrylate, and the (meth)acrylate is selected from one or more of (meth)acrylate containing a hydroxyl group, (meth)acrylate containing a carboxyl group, and (meth)acrylic acid adducts of epoxy acrylate.

4. The RGB resin coating according to claim 3, characterized in that: The (meth)acrylate containing a hydroxyl group is selected from pentaerythritol triacrylate, dipentaerythritol hexaacrylate and 2-phenoxyethyl acrylate; The carboxyl group-containing (meth)acrylate is selected from one or more of 2-acryloxypropyltetrahydrophthalic acid, 2-acryloxypropylhexahydrophthalic acid, methacryloyloxyethylsuccinic acid, methacryloyloxyethylphthalic acid, methacryloyloxyethyltetrahydrophthalic acid, methacryloyloxyethylhexahydrophthalic acid, 2-acryloyloxypropyloxyphthalic acid, 2-methacryloyloxypropyltetrahydrophthalic acid and 2-methacryloyloxypropylhexahydrophthalic acid; The (meth)acrylic acid adduct of epoxy acrylate is selected from one or more of 3-methyl-3-(meth)acryloyloxymethyloxetane / (meth)acrylic acid / styrene copolymer, benzyl (meth)acrylate / (meth)acrylic acid copolymer and styrene / (meth)acrylic acid copolymer.

5. The RGB resin coating according to claim 1, characterized in that: The polymerizable functional groups in the polymerizable compound are sandwiched by oxygen-containing structures having 1 to 20 carbon atoms, and the polymerizable functional groups are selected from one or more of alkyl groups, alkenyl groups, alicyclic groups and unsaturated alicyclic groups.

6. The RGB resin coating according to claim 1, characterized in that: The polymerizable compound is a (meth)acrylate compound, selected from one or more of a (meth)acrylate alkyl monomer or a composition thereof, an ethylene oxide-containing monomer or a composition thereof, a propylene oxide-containing monomer or a composition thereof, an isocyanate-containing monomer or a composition thereof, a polyacrylamide-containing monomer or a composition thereof, an alkoxy-containing monomer or a composition thereof, a phenyl-containing monomer or a composition thereof, and a silane-containing monomer or a composition thereof.

7. The RGB resin coating according to claim 1, characterized in that: The initiator is a photoinitiator, and the photoinitiator is a free radical initiator or a cationic initiator; And / or, the leveling agent is selected from one or more of acrylic leveling agents, silicone leveling agents, and fluorocarbon leveling agents.

8. A method for preparing the RGB resin coating according to any one of claims 1 to 7, characterized in that: The steps include: Add the colorant and solvent to the reaction vessel and stir until well mixed; Add the resin mixture to the reaction vessel and stir until well mixed; Add the initiator to the reaction vessel and stir for 20-40 minutes until the mixture is uniform; Add the leveling agent and other additives into the reaction container, stir until the mixture is evenly mixed, and then filter to obtain the RGB resin coating.

9. A polarizer, characterized in that: It comprises a polyvinyl alcohol (PVA) layer and a PVA protective layer, wherein the PVA layer and the PVA protective layer are pasted together by an RGB resin coating after curing. The RGB resin coating is the RGB resin coating according to any one of claims 1 to 7, or is prepared by the preparation method of the RGB resin coating according to claim 8.

10. The polarizer according to claim 9, wherein: The PVA protective layer is a hydrophobic material, and is selected from any one of PMMA acrylic, PET polyethylene terephthalate, cycloolefin polymer COP, COP derivatives and COP modified products.