An acid-free polarizer pressure-sensitive adhesive and its preparation method

Abstract

The present invention discloses an acid-free polarizer pressure-sensitive adhesive and a preparation method thereof, which relates to the technical field of adhesives. By weight, it includes the following components: 30-40 parts of acrylate copolymer, 2-4 parts of hydroxyl-terminated vinyl hyperbranched poly(urethane-amine), 3-5 parts of terpene resin, 2-4 parts of 3,3'-diamino-4,4'-difluorodiphenyl sulfone, 0.8-1.5 parts of polythiophene with an alcoholamine group in the side chain, 0.8-1.2 parts of initiator, and 30-50 parts of solvent. The acid-free polarizer pressure-sensitive adhesive provided by the present invention has excellent bonding performance, water resistance and weather resistance, good high-temperature and high-humidity resistance and light transmittance performance, and a long service life.

Description

Technical Field

[0001] The present invention relates to the technical field of adhesives, and in particular to an acid-free polarizer pressure-sensitive adhesive and a preparation method thereof. Background Art

[0002] With the increasing popularity of various electronic display devices, mankind has entered a brand-new "screen era". Liquid crystal display screens have been widely used in fields such as mobile phones, computers, liquid crystal TVs, automotive electronics, medical devices, and instruments. A polarizer is an important component in a liquid crystal display, and the imaging of a liquid crystal display must rely on a polarizer. During use, a polarizer needs to be attached to the glass substrate of a liquid crystal display through a pressure-sensitive adhesive, and the performance of the polarizer pressure-sensitive adhesive directly affects the use effect and service life of the polarizer. Therefore, it is particularly important to develop a polarizer pressure-sensitive adhesive with excellent comprehensive performance and performance stability.

[0003] Common polarizer pressure-sensitive adhesives are acrylic pressure-sensitive adhesives. Since these pressure-sensitive adhesives contain acidic substances in their components, they have a certain corrosive effect on polarizers, affecting the use effect and service life of polarizers. Other types of polarizer pressure-sensitive adhesives on the market also have more or less defects such as limited bonding performance, water resistance, and weather resistance, and the need to further improve the high-temperature and high-humidity resistance and light transmittance performance.

[0004] For example, Chinese invention patent document CN102010672B discloses a UV-curable pressure-sensitive adhesive for an LCD polarizer and a preparation method thereof; it consists of at least three substances in the following mass fractions: a. 30-60 parts of an acrylate copolymer with a weight-average molecular weight of 100,000-1,000,000 and a dispersity M w / M n of 3-10; b. 40-70 parts of a UV-curable component, and the sum of a and b is 100 parts; c. a photoinitiator system, which is 0.5-6.5 parts compared to the sum of a and b of 100 parts. This invention avoids the use of a thermal crosslinking agent and adopts UV crosslinking. The crosslinking process is fast, the production efficiency is high, and the crosslinking process is easier to control. The curing time only needs 0.5-3 min, avoiding the long thermal crosslinking process of traditional processes. The prepared pressure-sensitive adhesive can meet the actual use requirements in terms of performance (initial adhesion, peel strength). The initial adhesion can be greater than a No. 14 ball, and the peel strength can be greater than 9.81 N / 25 mm. However, it contains the acidic monomer acrylic acid, which has a certain corrosive effect on polarizers and liquid crystal displays.

[0005] Therefore, developing an acid-free polarizer pressure-sensitive adhesive with good bonding performance, water resistance, and weather resistance, good high-temperature and high-humidity resistance and light transmittance performance, and a long service life, as well as a preparation method thereof, meets the market demand, has broad market value and application prospects, and is of great significance for promoting the development of the polarizer pressure-sensitive adhesive field. Summary of the Invention

[0006] The main object of the present invention is to provide a non-acid polarizing film pressure-sensitive adhesive with excellent bonding performance, water resistance and weather resistance, good high-temperature and high-humidity resistance and light-transmitting performance, and a long service life, and a preparation method thereof.

[0007] To achieve the above object, the present invention provides a non-acid polarizing film pressure-sensitive adhesive, which comprises the following components by weight: 30-40 parts of acrylate copolymer, 2-4 parts of hydroxyl-terminated vinyl hyperbranched poly(urethane-amine), 3-5 parts of terpene resin, 2-4 parts of 3,3'-diamino-4,4'-difluorodiphenyl sulfone, 0.8-1.5 parts of polythiophene with an alcoholamine group in the side chain, 0.8-1.2 parts of initiator, and 30-50 parts of solvent.

[0008] Preferably, the acrylate copolymer is made from the following raw materials by weight: 18-32 parts of soft monomer, 8-10 parts of hard monomer, 1-3 parts of 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, 3-5 parts of bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 0.2-0.5 parts of azobisisobutyronitrile, and 20-30 parts of solvent.

[0009] Preferably, the solvent is one or more of methyl ethyl ketone, toluene, ethyl acetate, and N,N-dimethylformamide.

[0010] Preferably, the soft monomer is one or more of butyl acrylate, lauryl acrylate, n-octyl acrylate, ethyl acrylate, and isooctyl acrylate.

[0011] Preferably, the hard monomer is one or more of acrylonitrile, styrene, methyl methacrylate, isobornyl methacrylate, tert-butyl acrylate, ethyl methacrylate, and n-butyl methacrylate.

[0012] Preferably, the preparation method of the acrylate copolymer comprises the following steps: after mixing the raw materials evenly by weight, stirring and reacting at 60-75°C for 4-6 hours in an inert gas atmosphere, and cooling and discharging after the reaction to obtain the acrylate copolymer.

[0013] Preferably, the inert gas is any one of nitrogen, helium, neon, and argon.

[0014] Preferably, there are no special requirements for the source of the hydroxyl-terminated vinyl hyperbranched poly(urethane-amine). In one embodiment of the present invention, the hydroxyl-terminated vinyl hyperbranched poly(urethane-amine) is a hyperbranched poly(urethane-amine) with hydroxyl groups at the end and vinyl groups in the internal branching units, which is prepared according to the method in Example 1 of Chinese Patent No. CN106519158B.

[0015] Preferably, the terpene resin is terpene resin T80.

[0016] Preferably, there are no special requirements for the source of the polythiophene with an alcoholamine group in the side chain. In one embodiment of the present invention, the polythiophene with an alcoholamine group in the side chain is prepared according to the method in Example 2 of Chinese Patent Document No. CN201610225149.9.

[0017] Preferably, the initiator is one or more of azobisisobutyronitrile, benzoyl peroxide, and azodiisooctanenitrile.

[0018] Another object of the present invention is to provide a method for preparing the acid-free polarizer pressure-sensitive adhesive, which includes the following steps: mixing the components of the acid-free polarizer pressure-sensitive adhesive evenly by weight, standing for defoaming to obtain a pressure-sensitive adhesive coating solution, then evenly coating the pressure-sensitive adhesive coating solution on the surface of the polarizer, drying and laminating a release film, and then performing a curing process to obtain the acid-free polarizer pressure-sensitive adhesive.

[0019] Preferably, the drying temperature is 100 - 115 °C and the time is 2 - 4 min; the curing process temperature is 30 - 40 °C and the time is 1 - 2 days.

[0020] Due to the application of the above technical solutions, the present invention has the following beneficial effects:

[0021] (1) The preparation method of the acid-free polarizer pressure-sensitive adhesive disclosed in the present invention only needs to mix the raw materials evenly, coat, dry and cure them, without the need for special equipment or modification of the existing production line. It has low capital investment, low energy consumption, high preparation efficiency and high product qualification rate, is suitable for continuous large-scale production, and has high popularization and application value.

[0022] (2) The acid-free polarizer pressure-sensitive adhesive disclosed in the present invention, by weight, includes the following components: 30 - 40 parts of acrylate copolymer, 2 - 4 parts of hydroxyl-terminated vinyl hyperbranched poly(urethane-amine), 3 - 5 parts of terpene resin, 2 - 4 parts of 3,3'-diamino-4,4'-difluorodiphenyl sulfone, 0.8 - 1.5 parts of polythiophene with an alcoholamine group in the side chain, 0.8 - 1.2 parts of initiator, and 30 - 50 parts of solvent. Through the mutual cooperation of each component, the prepared pressure-sensitive adhesive has good bonding performance, water resistance and weather resistance, good high-temperature and high-humidity resistance and light transmittance performance, and a long service life.

[0023] (3)The acid-free polarizing film pressure-sensitive adhesive disclosed by the present invention, wherein the acrylate copolymer is prepared from the following raw materials by weight: 18-32 parts of soft monomer, 8-10 parts of hard monomer, 1-3 parts of 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, 3-5 parts of bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 0.2-0.5 parts of azobisisobutyronitrile, and 20-30 parts of solvent. Through the reasonable selection of the preparation raw material formula, the formed copolymer can better synergize with other components, improve the bonding performance, water resistance and weather resistance of the pressure-sensitive adhesive, enhance the high temperature and high humidity resistance performance and light transmittance, and extend its service life.

[0024] (4)The acid-free polarizing film pressure-sensitive adhesive disclosed by the present invention, adding polythiophene with an alcoholamine group in the side chain, can endow the pressure-sensitive adhesive with good antistatic performance, and due to the existence of its alcoholamine group, it has good compatibility with other components, thereby improving the performance stability of the pressure-sensitive adhesive and extending its service life.

[0025] (5)The acid-free polarizing film pressure-sensitive adhesive disclosed by the present invention, through the reasonable selection of components and raw materials, simultaneously introduces hyperbranched poly(urethane-amine), zwitterionic salt, triazinone, ester group, terpene resin, difluorodiphenyl sulfone, alcoholamine group and polythiophene structures into the pressure-sensitive adhesive structure. Under the multiple actions of electronic effect, steric effect and conjugate effect, etc., the comprehensive physical properties and performance stability of the pressure-sensitive adhesive are further improved, making the product have good bonding performance, water resistance and weather resistance, good high temperature and high humidity resistance performance and light transmittance performance, and a long service life. Detailed implementation mode

[0026] 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 in the following description are only examples, and those skilled in the art can think of other obvious variations. Example 1

[0027] An acid-free polarizing film pressure-sensitive adhesive, by weight, comprises the following components: 30 parts of acrylate copolymer, 2 parts of terminal hydroxy vinyl hyperbranched poly(urethane-amine), 3 parts of terpene resin, 2 parts of 3,3'-diamino-4,4'-difluorodiphenyl sulfone, 0.8 part of polythiophene with an alcoholamine group in the side chain, 0.8 part of initiator, and 30 parts of solvent.

[0028] The acrylate copolymer is prepared from the following raw materials in parts by weight: 18 parts of soft monomer, 8 parts of hard monomer, 1 part of 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, 3 parts of bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 0.2 part of azobisisobutyronitrile, and 20 parts of solvent; the solvent is methyl ethyl ketone; the soft monomer is butyl acrylate; the hard monomer is acrylonitrile.

[0029] The preparation method of the acrylate copolymer comprises the following steps: After mixing the raw materials evenly in parts by weight, stirring and reacting at 60 °C for 4 hours in an inert gas atmosphere, and after the reaction is completed, cooling and discharging to obtain the acrylate copolymer; the inert gas is nitrogen.

[0030] The hydroxyl-terminated vinyl hyperbranched poly(urethane-amine) is a hyperbranched poly(urethane-amine) with hydroxyl groups at the ends and vinyl groups in the internal branching units, and is prepared by the method of Example 1 in Chinese Invention Patent CN106519158B; the terpene resin is terpene resin T80; the polythiophene with an alcoholamine group in the side chain is prepared by the method of Example 2 in Chinese Invention Patent Document CN201610225149.9; the initiator is azobisisobutyronitrile.

[0031] A preparation method of the acid-free polarizing film pressure-sensitive adhesive comprises the following steps: After mixing the components of the acid-free polarizing film pressure-sensitive adhesive evenly in parts by weight, standing to defoam to obtain a pressure-sensitive adhesive coating solution, then uniformly coating the pressure-sensitive adhesive coating solution on the surface of the polarizing film, drying and laminating a release film, and then performing a curing process to obtain the acid-free polarizing film pressure-sensitive adhesive; the drying temperature is 100 °C and the time is 2 min; the temperature of the curing process is 30 °C and the time is 1 day. Example 2

[0032] An acid-free polarizing film pressure-sensitive adhesive, by weight, comprises the following components: 33 parts of acrylate copolymer, 2.5 parts of hydroxyl-terminated vinyl hyperbranched poly(urethane-amine), 3.5 parts of terpene resin, 2.5 parts of 3,3'-diamino-4,4'-difluorodiphenyl sulfone, 1 part of polythiophene with an alcoholamine group in the side chain, 0.9 part of initiator, and 35 parts of solvent.

[0033] The acrylate copolymer is prepared from the following raw materials in parts by weight: 22 parts of soft monomer, 8.5 parts of hard monomer, 1.5 parts of 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, 3.5 parts of bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 0.3 part of azobisisobutyronitrile, and 23 parts of solvent; the solvent is toluene; the soft monomer is lauryl acrylate; the hard monomer is styrene.

[0034] The preparation method of the acrylate copolymer comprises the following steps: after mixing the raw materials evenly in parts by weight, stirring and reacting at 65 °C for 4.5 hours in an inert gas atmosphere, and after the reaction is completed, cooling and discharging to obtain the acrylate copolymer; the inert gas is helium.

[0035] The hydroxyl-terminated vinyl hyperbranched poly(urethane-amine) is a hyperbranched poly(urethane-amine) with hydroxyl groups at the ends and vinyl groups in the internal branching units, and is prepared by the method of Example 1 in Chinese Invention Patent CN106519158B; the terpene resin is terpene resin T80; the polythiophene with an alcoholamine group in the side chain is prepared by the method of Example 2 in Chinese Invention Patent Document CN201610225149.9; the initiator is benzoyl peroxide.

[0036] A preparation method of the acid-free polarizing film pressure-sensitive adhesive comprises the following steps: after mixing the components of the acid-free polarizing film pressure-sensitive adhesive evenly in parts by weight, standing for defoaming to obtain a pressure-sensitive adhesive coating solution, then uniformly coating the pressure-sensitive adhesive coating solution on the surface of the polarizing film, drying and laminating with a release film, and then performing a curing process to obtain the acid-free polarizing film pressure-sensitive adhesive; the drying temperature is 105 °C and the time is 2.5 min; the temperature of the curing process is 32 °C and the time is 1.2 days. Example 3

[0037] An acid-free polarizing film pressure-sensitive adhesive, by weight, comprises the following components: 35 parts of acrylate copolymer, 3 parts of hydroxyl-terminated vinyl hyperbranched poly(urethane-amine), 4 parts of terpene resin, 3 parts of 3,3'-diamino-4,4'-difluorodiphenyl sulfone, 1.2 parts of polythiophene with an alcoholamine group in the side chain, 1 part of initiator, and 40 parts of solvent.

[0038] The acrylate copolymer is prepared from the following raw materials in parts by weight: 25 parts of soft monomer, 9 parts of hard monomer, 2 parts of 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, 4 parts of bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 0.35 part of azobisisobutyronitrile, and 25 parts of solvent; the solvent is ethyl acetate; the soft monomer is n-octyl acrylate; the hard monomer is methyl methacrylate.

[0039] The preparation method of the acrylate copolymer comprises the following steps: after mixing the raw materials evenly in parts by weight, carrying out stirring reaction at 68 °C for 5 hours in an inert gas atmosphere, and cooling and discharging after the reaction is completed to obtain the acrylate copolymer; the inert gas is neon.

[0040] The hydroxyl-terminated vinyl hyperbranched poly(urethane-amine) is a hyperbranched poly(urethane-amine) with hydroxyl groups at the ends and vinyl groups in the internal branching units, and is prepared by the method in Example 1 of Chinese invention patent CN106519158B; the terpene resin is terpene resin T80; the polythiophene with an alcoholamine group in the side chain is prepared by the method in Example 2 of Chinese invention patent document CN201610225149.9; the initiator is azobisisoheptonitrile.

[0041] A preparation method of the acid-free polarizing film pressure-sensitive adhesive comprises the following steps: mixing the components of the acid-free polarizing film pressure-sensitive adhesive evenly in parts by weight, standing for defoaming to obtain a pressure-sensitive adhesive coating solution, then uniformly coating the pressure-sensitive adhesive coating solution on the surface of the polarizing film, drying and laminating a release film, and then carrying out a curing process to obtain the acid-free polarizing film pressure-sensitive adhesive; the drying temperature is 110 °C and the time is 3 min; the temperature of the curing process is 35 °C and the time is 1.5 days. Example 4

[0042] An acid-free polarizing film pressure-sensitive adhesive, by weight, comprises the following components: 38 parts of acrylate copolymer, 3.5 parts of hydroxyl-terminated vinyl hyperbranched poly(urethane-amine), 4.5 parts of terpene resin, 3.5 parts of 3,3'-diamino-4,4'-difluorodiphenyl sulfone, 1.3 parts of polythiophene with an alcoholamine group in the side chain, 1.1 part of initiator, and 45 parts of solvent.

[0043] The acrylate copolymer is prepared from the following raw materials in parts by weight: 30 parts of soft monomer, 9.5 parts of hard monomer, 2.5 parts of 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, 4.5 parts of bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 0.45 part of azobisisobutyronitrile, and 28 parts of solvent; the solvent is N,N-dimethylformamide; the soft monomer is a mixture formed by mixing butyl acrylate, lauryl acrylate, n-octyl acrylate, ethyl acrylate, and isooctyl acrylate in a mass ratio of 1:2:1:3:2; the hard monomer is a mixture formed by mixing acrylonitrile, styrene, methyl methacrylate, isobornyl methacrylate, tert-butyl acrylate, ethyl methacrylate, and n-butyl methacrylate in a mass ratio of 1:3:1:2:1:1:3.

[0044] The preparation method of the acrylate copolymer comprises the following steps: After mixing the raw materials evenly in parts by weight, stirring and reacting at 73 °C for 5.5 hours in an inert gas atmosphere, and after the reaction is completed, cooling and discharging to obtain the acrylate copolymer; the inert gas is argon.

[0045] The hydroxyl-terminated vinyl hyperbranched poly(urethane-amine) is a hyperbranched poly(urethane-amine) with hydroxyl groups at the ends and vinyl groups in the internal branching units, and is prepared by the method of Example 1 in Chinese Patent CN106519158B; the terpene resin is terpene resin T80; the polythiophene with an alcoholamine group in the side chain is prepared by the method of Example 2 in Chinese Patent Document CN201610225149.9; the initiator is a mixture formed by mixing azobisisobutyronitrile, benzoyl peroxide, and azodiisobutyronitrile in a mass ratio of 1:3:2.

[0046] A preparation method of the acid-free polarizing film pressure-sensitive adhesive comprises the following steps: After mixing the components of the acid-free polarizing film pressure-sensitive adhesive evenly in parts by weight, standing for defoaming to obtain a pressure-sensitive adhesive coating solution, then uniformly coating the pressure-sensitive adhesive coating solution on the surface of the polarizing film, drying and laminating a release film, and then performing a curing process to obtain the acid-free polarizing film pressure-sensitive adhesive; the drying temperature is 113 °C and the time is 3.5 min; the curing process temperature is 38 °C and the time is 1.8 days. Example 5

[0047] An acid-free polarizing film pressure-sensitive adhesive, by weight, comprises the following components: 40 parts of acrylate copolymer, 4 parts of hydroxyl-terminated vinyl hyperbranched poly(urethane-amine), 5 parts of terpene resin, 4 parts of 3,3'-diamino-4,4'-difluorodiphenyl sulfone, 1.5 parts of polythiophene with an alcoholamine group in the side chain, 1.2 parts of initiator, and 50 parts of solvent.

[0048] The acrylate copolymer is prepared from the following raw materials in parts by weight: 32 parts of soft monomer, 10 parts of hard monomer, 3 parts of 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, 5 parts of bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 0.5 part of azobisisobutyronitrile, and 30 parts of solvent; the solvent is methyl ethyl ketone; the soft monomer is isooctyl acrylate; the hard monomer is isobornyl methacrylate.

[0049] The preparation method of the acrylate copolymer comprises the following steps: After mixing the raw materials evenly in parts by weight, stirring and reacting at 75°C for 6 hours in an inert gas atmosphere, and after the reaction is completed, cooling and discharging to obtain the acrylate copolymer; the inert gas is nitrogen.

[0050] The hydroxyl-terminated vinyl hyperbranched poly(urethane-amine) is a hyperbranched poly(urethane-amine) with hydroxyl groups at the ends and vinyl groups in the internal branching units, and is prepared by the method of Example 1 in Chinese Invention Patent CN106519158B; the terpene resin is terpene resin T80; the polythiophene with an alcoholamine group in the side chain is prepared by the method of Example 2 in Chinese Invention Patent Document CN201610225149.9; the initiator is azobisisobutyronitrile.

[0051] A preparation method of the acid-free polarizing film pressure-sensitive adhesive comprises the following steps: After mixing the components of the acid-free polarizing film pressure-sensitive adhesive evenly in parts by weight, standing for defoaming to obtain a pressure-sensitive adhesive coating solution, then evenly coating the pressure-sensitive adhesive coating solution on the surface of the polarizing film, drying and laminating a release film, and then performing a curing process to obtain the acid-free polarizing film pressure-sensitive adhesive; the drying temperature is 115°C and the time is 4 min; the curing process temperature is 40°C and the time is 2 days.

[0052] Comparative Example 1

[0053] The present invention provides an acid-free polarizing film pressure-sensitive adhesive, the formula and preparation method of which are similar to those of Example 1, except that 3,3'-diamino-4,4'-difluorodiphenyl sulfone and 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt are not added.

[0054] Comparative Example 2

[0055] The present invention provides an acid-free polarizing film pressure-sensitive adhesive, whose formulation and preparation method are similar to those of Example 1, except that terminal hydroxyl vinyl hyperbranched poly(urethane-amine) and bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione are not added.

[0056] In order to further illustrate the unexpected beneficial technical effects of the acid-free polarizing film pressure-sensitive adhesive involved in the embodiments of the present application, relevant performance tests were carried out on the acid-free polarizing film pressure-sensitive adhesives prepared in each group of Examples 1-5 and Comparative Examples 1-2. The test results are shown in Table 1. During the preparation of the test samples, the dry adhesive thickness of each pressure-sensitive adhesive was controlled to be 10 μm. The test methods are as follows:

[0057] (1) Peel strength test: Cut the pressure-sensitive adhesive into a size of 300×25 mm, tear off the release film, attach the pressure-sensitive adhesive to the glass surface, and use an electronic universal testing machine (model: AGS-X) to perform a peel test under the conditions of an angle of 180 。 and a tensile speed of 300 mm / min.

[0058] (2) Adhesive layer resistance test: Cut the pressure-sensitive adhesive into a size of 12×12 mm, tear off the release film, and test the surface resistance of the adhesive on a high-resistance meter (model: SME-8310).

[0059] (3) High-temperature and high-humidity test: Cut the pressure-sensitive adhesive into a size of 6×10 mm, tear off the release film, attach the pressure-sensitive adhesive to the glass surface, and put it into a programmable constant temperature and humidity test chamber. After 85°C, 90% RH×500 h, observe whether there are wrinkles, detachment, and bubbles on the glass surface of the pressure-sensitive adhesive. If not, it is judged as OK; if so, it is judged as NG.

[0060] (4) High-temperature and high-humidity residual performance: Cut the pressure-sensitive adhesive into a sample with a size of 6 cm×10 cm, tear off the release film, attach it to the glass surface, ensure that there are no bubbles in the attachment, put it into a programmable constant temperature and humidity test chamber (model: WHTH-150L-40-880) at a temperature of 60°C and a humidity of 90% RH for 7 d, and finally tear off the pressure-sensitive adhesive and observe whether there are residues on the glass surface under a three-wavelength lamp; among them, ○ means no residue; △ means slight residue; × means obvious residue.

[0061]

[0062] As can be seen from Table 1, the acid-free polarizer pressure-sensitive adhesive prepared in the embodiments of the present invention has better bonding performance, high-temperature and high-humidity resistance performance, and antistatic performance, and there is no residual glue under high-temperature and high-humidity conditions. The addition of 3,3'-diamino-4,4'-difluorodiphenyl sulfone, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, hydroxyl-terminated vinyl hyperbranched poly(urethane-amine), and bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione is beneficial to improving the above-mentioned properties.

[0063] 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 by the above embodiments, and what is described in the above embodiments and the specification is only the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A non-acidic polarizer pressure-sensitive adhesive, characterized in that, By weight parts, it includes the following components: 30-40 parts of acrylate copolymer, 2-4 parts of hydroxyl-terminated vinyl hyperbranched poly(urethane-amine), 3-5 parts of terpene resin, 2-4 parts of 3,3'-diamino-4,4'-difluorodiphenyl sulfone, 0.8-1.5 parts of polythiophene with an alcoholamine group in the side chain, 0.8-1.2 parts of initiator, and 30-50 parts of solvent; the acrylate copolymer is made from the following raw materials by weight parts: 18-32 parts of soft monomer, 8-10 parts of hard monomer, 1-3 parts of 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, 3-5 parts of bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 0.2-0.5 parts of azobisisobutyronitrile, and 20-30 parts of solvent.

2. The acid-free polarizer pressure-sensitive adhesive according to claim 1, wherein The solvent is one or more of methyl ethyl ketone, toluene, ethyl acetate, and N,N-dimethylformamide.

3. The pressure-sensitive adhesive for acid-free polarizing film according to claim 1, wherein The soft monomer is one or more of butyl acrylate, lauryl acrylate, n-octyl acrylate, ethyl acrylate, and isooctyl acrylate.

4. The pressure-sensitive adhesive for acid-free polarizing film according to claim 1, characterized in that, The hard monomer is one or more of acrylonitrile, styrene, methyl methacrylate, isobornyl methacrylate, tert-butyl acrylate, ethyl methacrylate, and n-butyl methacrylate.

5. The acid-free polarizer pressure-sensitive adhesive according to claim 1, wherein The preparation method of the acrylate copolymer includes the following steps: After mixing each raw material evenly by weight parts, under an inert gas atmosphere, stir and react at 60-75 °C for 4-6 hours, and after the reaction ends, cool and discharge to obtain the acrylate copolymer.

6. The acid-free polarizer pressure-sensitive adhesive according to claim 5, wherein The inert gas is any one of nitrogen, helium, neon, and argon.

7. The pressure-sensitive adhesive for acid-free polarizing film according to claim 1, wherein The terpene resin is terpene resin T80; the initiator is one or more of azobisisobutyronitrile, benzoyl peroxide, and azodiisooctanenitrile.

8. A method for preparing an acid-free polarizer pressure-sensitive adhesive according to any one of claims 1-7, characterized in that, It includes the following steps: After mixing each component of the acid-free polarizer pressure-sensitive adhesive evenly by weight parts, stand still to defoam to obtain a pressure-sensitive adhesive coating solution, then evenly coat the pressure-sensitive adhesive coating solution on the surface of the polarizer, dry and laminate with a release film, and then carry out a curing process to obtain the acid-free polarizer pressure-sensitive adhesive.

9. The preparation method of the acid-free polarizer pressure-sensitive adhesive according to claim 8, wherein The drying temperature is 100-115 °C and the time is 2-4 min; the curing process temperature is 30-40 °C and the time is 1-2 days.

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