Adhesive for polarizer and preparation method thereof

Abstract

The invention discloses an adhesive for polarizer and a preparation method thereof, relates to the technical field of adhesives, and is prepared from the following components by weight: 25-35 parts of hyperbranched perfluoropolyether polyurethane acrylate oligomer, 3-5 parts of vinyl ethylene carbonate, 2-4 parts of isocyanoethyl methacrylate, 2-4 parts of N-vinyl carbazole, 1-3 parts of styrene, 3-5 parts of dicyclopentene methacrylate, 3-5 parts of 3,9-divinyl-2,4,8,10-tetraoxaspiro[5.5]undecane, 1-2 parts of tetrahydroxymethyl glycoluril, 15-25 parts of diluent, 0.5-4 parts of photoinitiator, 0.2-0.6 parts of catalyst, and 2-5 parts of auxiliary agent. The adhesive for polarizer has good bonding performance, good water resistance and weather resistance, sufficient light transmittance, excellent high temperature and humidity resistance and water vapor barrier performance.

Description

Technical Field

[0001] The present invention relates to the technical field of adhesives, and in particular to an adhesive for polarizers and a preparation method thereof. Background Art

[0002] Polaroid is the full name of polarizing film, which is an important component of liquid crystal display. Its function is to change the properties of light, converting natural light into polarized light to increase the clarity of the display. Polaroid is generally a multi-layer film structure, and there is adhesive between the film layers. Adhesive is one of the important raw materials of polaroid. In addition to having a certain bonding force, the adhesive used for polaroid must also have the property of not affecting the optical performance.

[0003] The existing adhesives for polarizers have limited bonding performance, water resistance and weather resistance, and the high temperature and high humidity resistance and water vapor barrier performance need to be further improved, and the light transmittance needs to be further improved. In order to solve the above problems, the Chinese invention patent with the authorization publication number CN107586521B provides a method for preparing an adhesive for polarizers and a method for preparing polarizers. The method for preparing the adhesive for polarizers includes the following steps: swelling polyvinyl alcohol in water to obtain an aqueous solution containing swollen polyvinyl alcohol; under continuous stirring, heating the aqueous solution containing swollen polyvinyl alcohol to 90-100°C, adding a modifier, and keeping it at 90-100°C for 40-60 minutes, and then cooling it to below 40°C to obtain a pre-prepared liquid; under continuous stirring, adjusting the pH value of the pre-prepared liquid to 1.5-2, and then adding dialdehydes, additives, cross-linking agents and alcohols to carry out a cross-linking reaction at room temperature to obtain an adhesive. The polarizer adhesive prepared by the preparation method of the polarizer adhesive has good bonding performance and can also improve the high temperature yellowing resistance of the polarizer. However, its weather resistance, water vapor barrier performance and high temperature and high humidity resistance need to be further improved.

[0004] It can be seen that the art still needs an adhesive for polarizers having good bonding properties, good water resistance and weather resistance, sufficient light transmittance, excellent high temperature and high humidity resistance and water vapor barrier properties, and a preparation method thereof. Summary of the invention

[0005] The main purpose of the present invention is to provide an adhesive for polarizers having good bonding properties, good water resistance and weather resistance, sufficient light transmittance, excellent high temperature and high humidity resistance and water vapor barrier properties, and a preparation method thereof.

[0006] To achieve the above purpose, the present invention provides an adhesive for polarizer, which is made of the following components in parts by weight: 25-35 parts of hyperbranched perfluoropolyether polyurethane acrylate polymer, 3-5 parts of vinyl ethylene carbonate, 2-4 parts of isocyanoethyl methacrylate, 2-4 parts of N-vinyl carbazole, 1-3 parts of styrene, 3-5 parts of dicyclopentene methacrylate, 3-5 parts of 3,9-divinyl-2,4,8,10-tetraoxaspiro[5.5]undecane, 1-2 parts of tetrakishydroxymethyl glycoluril, 15-25 parts of diluent, 0.5-4 parts of photoinitiator, 0.2-0.6 parts of catalyst and 2-5 parts of auxiliary agent.

[0007] Preferably, the auxiliary agent includes a defoamer, and the defoamer is one or more of tributyl phosphate, defoamer Deqian 3100, and defoamer BYK088.

[0008] Preferably, the catalyst is dibutyltin dilaurate.

[0009] Preferably, the photoinitiator is at least one of photoinitiator Irgacure 184, photoinitiator Darocure 1173, photoinitiator Irgacure 907, and photoinitiator TPO.

[0010] Preferably, the diluent is a mixture of butyl acrylate, hydroxyethyl acrylate and 2-methoxyethyl acrylate in a mass ratio of (1-3):2:(3-5).

[0011] Preferably, there is no special requirement for the source of the hyperbranched perfluoropolyether polyurethane acrylate oligomer. In one embodiment of the present invention, the hyperbranched perfluoropolyether polyurethane acrylate oligomer is prepared according to the method of Example 1 of the Chinese invention patent with authorization publication number CN105482680B.

[0012] Another object of the present invention is to provide a method for preparing the adhesive for polarizer, comprising the following steps: mixing the components uniformly by weight to obtain a finished product of the adhesive for polarizer.

[0013] Due to the application of the above technical solution, the present invention has the following beneficial effects:

[0014] (1) The method for preparing the adhesive for polarizer disclosed in the present invention has simple process, convenient operation and use, low dependence on equipment, high preparation efficiency and finished product qualification rate, is suitable for industrial continuous production, and has high promotion and application value.

[0015] (2) The polarizer adhesive disclosed in the present invention is made of the following components by weight: 25-35 parts of hyperbranched perfluoropolyether polyurethane acrylate oligomer, 3-5 parts of vinyl ethylene carbonate, 2-4 parts of isocyanoethyl methacrylate, 2-4 parts of N-vinyl carbazole, 1-3 parts of styrene, 3-5 parts of dicyclopentene methacrylate, 3-5 parts of 3,9-divinyl-2,4,8,10-tetraoxaspiro[5.5]undecane, 1-2 parts of tetrahydroxymethyl glycoluril, 15-25 parts of diluent, 0.5-4 parts of photoinitiator, 0.2-0.6 parts of catalyst, and 2-5 parts of auxiliary agent. Through the mutual cooperation between the components, the prepared polarizer adhesive has good bonding performance, good water resistance and weather resistance, sufficient light transmittance, excellent high temperature and high humidity resistance and water vapor barrier performance.

[0016] (3) The adhesive for polarizer disclosed in the present invention, the components containing unsaturated olefinic bonds such as hyperbranched perfluoropolyether polyurethane acrylate polymer, vinyl ethylene carbonate, isocyanoethyl methacrylate, N-vinyl carbazole, styrene, dicyclopentene methacrylate and diluent can undergo UV curing reaction under the action of photoinitiator, and the hydroxyl groups on tetramethylol glycoluril can also react chemically with isocyanoethyl methacrylate under the action of catalyst to form a multiple interpenetrating network structure, which effectively improves the weather resistance, high temperature and high humidity resistance and water vapor barrier performance of the adhesive, making it more durable and longer in service life. Through the above reaction, fluorine-containing hyperbranched polyurethane, carbonate, carbazole, phenyl, dicyclopentene, glycoluril structures are simultaneously introduced into the molecular structure of the adhesive. Under the multiple effects of electronic effect, steric effect and conjugation effect, these structures make the prepared adhesive have good bonding performance, good water resistance and weather resistance, sufficient light transmittance, high temperature and high humidity resistance and excellent water vapor barrier performance. DETAILED DESCRIPTION

[0017] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations. Example 1

[0018] The invention discloses an adhesive for polarizers, which is prepared from the following components in parts by weight: 25 parts of hyperbranched perfluoropolyether polyurethane acrylate oligomer, 3 parts of vinyl ethylene carbonate, 2 parts of isocyanoethyl methacrylate, 2 parts of N-vinyl carbazole, 1 part of styrene, 3 parts of dicyclopentene methacrylate, 3 parts of 3,9-divinyl-2,4,8,10-tetraoxaspiro[5.5]undecane, 1 part of tetrakishydroxymethyl glycoluril, 15 parts of diluent, 0.5 parts of photoinitiator, 0.2 parts of catalyst and 2 parts of auxiliary agent.

[0019] The auxiliary agent includes a defoamer, which is tributyl phosphate; the catalyst is dibutyltin dilaurate; the photoinitiator is photoinitiator Irgacure184; the diluent is a mixture of butyl acrylate, hydroxyethyl acrylate, and 2-methoxyethyl acrylate in a mass ratio of 1:2:3; the hyperbranched perfluoropolyether polyurethane acrylate polymer is prepared according to the method of Example 1 of the Chinese invention patent with authorization publication number CN105482680B.

[0020] A method for preparing the adhesive for polarizer includes the following steps: uniformly mixing the components according to weight to obtain a finished product of the adhesive for polarizer. Example 2

[0021] An adhesive for polarizers is prepared from the following components in parts by weight: 28 parts of hyperbranched perfluoropolyether polyurethane acrylate oligomer, 3.5 parts of vinyl ethylene carbonate, 2.5 parts of isocyanoethyl methacrylate, 2.5 parts of N-vinyl carbazole, 1.5 parts of styrene, 3.5 parts of dicyclopentene methacrylate, 3.5 parts of 3,9-divinyl-2,4,8,10-tetraoxaspiro[5.5]undecane, 1.2 parts of tetrakishydroxymethyl glycoluril, 18 parts of diluent, 1 part of photoinitiator, 0.3 parts of catalyst and 3 parts of auxiliary agent.

[0022] The auxiliary agent includes a defoamer, which is Deqian 3100; the catalyst is dibutyltin dioctanoate; the photoinitiator is Darocure 1173; the diluent is a mixture of butyl acrylate, hydroxyethyl acrylate, and 2-methoxyethyl acrylate in a mass ratio of 1.5:2:3.5; the hyperbranched perfluoropolyether polyurethane acrylate polymer is prepared according to the method of Example 1 of the Chinese invention patent with authorization publication number CN105482680B.

[0023] A method for preparing the adhesive for polarizer includes the following steps: uniformly mixing the components according to weight to obtain a finished product of the adhesive for polarizer. Example 3

[0024] An adhesive for polarizers is prepared from the following components in parts by weight: 30 parts of hyperbranched perfluoropolyether polyurethane acrylate oligomer, 4 parts of vinyl ethylene carbonate, 3 parts of isocyanoethyl methacrylate, 3 parts of N-vinyl carbazole, 2 parts of styrene, 4 parts of dicyclopentene methacrylate, 4 parts of 3,9-divinyl-2,4,8,10-tetraoxaspiro[5.5]undecane, 1.5 parts of tetrahydroxymethyl glycoluril, 20 parts of diluent, 2.5 parts of photoinitiator, 0.4 parts of catalyst and 3.5 parts of auxiliary agent.

[0025] The auxiliary agent includes a defoamer, which is one or more of tributyl phosphate, defoamer Deqian 3100, and defoamer BYK088; the catalyst is dibutyltin dilaurate; the photoinitiator is photoinitiator Irgacure907; the diluent is a mixture of butyl acrylate, hydroxyethyl acrylate, and 2-methoxyethyl acrylate in a mass ratio of 2:2:4; the hyperbranched perfluoropolyether polyurethane acrylate polymer is prepared according to the method of Example 1 of the Chinese invention patent with authorization publication number CN105482680B.

[0026] A method for preparing the adhesive for polarizer includes the following steps: uniformly mixing the components according to weight to obtain a finished product of the adhesive for polarizer. Example 4

[0027] An adhesive for polarizers is prepared from the following components in parts by weight: 33 parts of hyperbranched perfluoropolyether polyurethane acrylate oligomer, 4.5 parts of vinyl ethylene carbonate, 3.5 parts of isocyanoethyl methacrylate, 3.5 parts of N-vinyl carbazole, 2.5 parts of styrene, 4.5 parts of dicyclopentene methacrylate, 4.5 parts of 3,9-divinyl-2,4,8,10-tetraoxaspiro[5.5]undecane, 1.8 parts of tetrakishydroxymethyl glycoluril, 23 parts of diluent, 3.5 parts of photoinitiator, 0.5 parts of catalyst and 4.5 parts of auxiliary agent.

[0028] The auxiliary agent includes a defoamer, which is a mixture of tributyl phosphate, defoamer Deqian 3100, and defoamer BYK088 in a mass ratio of 1:2:3; the catalyst is dibutyltin dilaurate; the photoinitiator is a mixture of photoinitiator Irgacure 184, photoinitiator Darocure 1173, photoinitiator Irgacure 907, and photoinitiator TPO in a mass ratio of 1:1:3:5; the diluent is a mixture of butyl acrylate, hydroxyethyl acrylate, and 2-methoxyethyl acrylate in a mass ratio of 2.5:2:4.5; the hyperbranched perfluoropolyether polyurethane acrylate polymer is prepared according to the method of Example 1 of the Chinese invention patent with authorization publication number CN105482680B.

[0029] A method for preparing the adhesive for polarizer includes the following steps: uniformly mixing the components according to weight to obtain a finished product of the adhesive for polarizer. Example 5

[0030] The invention discloses an adhesive for polarizers, which is prepared from the following components in parts by weight: 35 parts of hyperbranched perfluoropolyether polyurethane acrylate oligomer, 5 parts of vinyl ethylene carbonate, 4 parts of isocyanoethyl methacrylate, 4 parts of N-vinyl carbazole, 3 parts of styrene, 5 parts of dicyclopentene methacrylate, 5 parts of 3,9-divinyl-2,4,8,10-tetraoxaspiro[5.5]undecane, 2 parts of tetrakishydroxymethyl glycoluril, 25 parts of diluent, 4 parts of photoinitiator, 0.6 parts of catalyst and 5 parts of auxiliary agent.

[0031] The auxiliary agent includes a defoamer, which is defoamer BYK088; the catalyst is dibutyltin dilaurate; the photoinitiator is photoinitiator TPO; the diluent is a mixture of butyl acrylate, hydroxyethyl acrylate, and 2-methoxyethyl acrylate in a mass ratio of 3:2:5; the hyperbranched perfluoropolyether polyurethane acrylate polymer is prepared according to the method of Example 1 of the Chinese invention patent with authorization publication number CN105482680B.

[0032] A method for preparing the adhesive for polarizer includes the following steps: uniformly mixing the components according to weight to obtain a finished product of the adhesive for polarizer.

[0033] Comparative Example 1

[0034] An adhesive for polarizers is substantially the same as that of Example 1, except that 3,9-divinyl-2,4,8,10-tetraoxaspiro[5.5]undecane and isocyanoethyl methacrylate are not added.

[0035] Comparative Example 2

[0036] An adhesive for polarizers is substantially the same as that of Example 1, except that dicyclopentene methacrylate and tetramethylol glycoluril are not added.

[0037] In order to further illustrate the beneficial technical effects of the polarizer adhesives prepared in various embodiments of the present invention, relevant performance tests were conducted on the polarizer adhesives prepared in Examples 1-5 and Comparative Examples 1-2. The test results are shown in Table 1. The test method is as follows:

[0038] (1) Tensile shear strength: GB / T 7124-2008 was used to measure the tensile shear strength at room temperature of 20°C. Curing was performed using an 80W / cm high-pressure mercury lamp, irradiated at room temperature for 12 seconds, and then heat treated at 80°C for 5 minutes. The thickness of the adhesive layer was 0.2 mm.

[0039] (2) Moisture and heat resistance: The cured adhesive samples of each example were placed in an environment of 80°C and 90% relative humidity for 100 hours. After cooling to room temperature, the tensile shear strength was tested again according to the method in (1), and the retention rate of the tensile shear strength was calculated. The larger the value, the better the moisture and heat resistance.

[0040] (3) Water vapor transmission rate: The obtained adhesive was evenly coated on the TAC film material with a scraper to a coating thickness of 15 μm, and then cured to obtain a sample to be tested; the curing was performed using an 80W / cm high pressure mercury lamp, irradiated at room temperature for 12 seconds, and then heat treated at 80°C for 5 minutes. The sample to be tested was fixed in the sample chamber of the water vapor transmission rate tester, and the water vapor transmission rate of each sample to be tested was tested. Three samples were tested for each embodiment and comparative example, and the average value was used for representation. For specific operation methods, reference can be made to the national standard GB / T30412-2013.

[0041] (4) Light transmittance: The obtained adhesive was evenly coated on the TAC film with a scraper to a coating thickness of 15 μm, and then cured to obtain the sample to be tested; the curing was performed using an 80W / cm high-pressure mercury lamp, irradiated at room temperature for 12 seconds, and then heat treated at 80°C for 5 minutes. The light transmittance test was then performed with reference to the national standard GB / T2410-2008.

[0042] As can be seen from Table 1, the adhesive for polarizer disclosed in the embodiment of the present invention has good light transmittance. Compared with the comparative example product, it has more excellent bonding performance, water vapor barrier performance and moisture and heat resistance. The introduction of 3,9-divinyl-2,4,8,10-tetraoxaspiro[5.5]undecane, isocyanoethyl methacrylate, dicyclopentene methacrylate and tetrakishydroxymethyl glycoluril is beneficial to improving the above properties.

[0043] Table 1

[0044] project Tensile shear strength Heat and humidity resistance Water vapor transmission rate Light transmittance unit MPa % <![CDATA[g / m 2 ·24h]]> % Example 1 4.4 98.9 75.35 91.88 Example 2 4.6 99.3 74.96 91.94 Example 3 4.8 99.5 74.12 92.11 Example 4 5.1 99.8 73.77 92.30 Example 5 5.2 99.9 73.04 92.35 Comparative Example 1 3.3 97.0 123.6 91.90 Comparative Example 2 3.5 96.4 120.2 91.97

[0045] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. An adhesive for polarizer, characterized in that: The invention is prepared from the following components in parts by weight: 25-35 parts of hyperbranched perfluoropolyether polyurethane acrylate oligomer, 3-5 parts of vinyl ethylene carbonate, 2-4 parts of isocyanoethyl methacrylate, 2-4 parts of N-vinyl carbazole, 1-3 parts of styrene, 3-5 parts of dicyclopentene methacrylate, 3-5 parts of 3,9-divinyl-2,4,8,10-tetraoxaspiro[5.5]undecane, 1-2 parts of tetrahydroxymethyl glycoluril, 15-25 parts of diluent, 0.5-4 parts of photoinitiator, 0.2-0.6 parts of catalyst and 2-5 parts of auxiliary agent; the diluent is a mixture of butyl acrylate, hydroxyethyl acrylate and 2-methoxyethyl acrylate in a mass ratio of (1-3):2:(3-5).

2. The adhesive for polarizer according to claim 1, characterized in that: The auxiliary agent includes a defoamer, and the defoamer is one or more of tributyl phosphate, defoamer Deqian 3100, and defoamer BYK088.

3. The adhesive for polarizer according to claim 1, characterized in that: The catalyst is dibutyltin dilaurate.

4. The adhesive for polarizer according to claim 1, characterized in that: The photoinitiator is at least one of photoinitiator Irgacure 184, photoinitiator Darocure 1173, photoinitiator Irgacure 907 and photoinitiator TPO.

5. A method for preparing the adhesive for polarizer according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: uniformly mixing the components according to weight to obtain a finished adhesive for polarizer.