Acrylic resin for optical polaroid and preparation method thereof

Abstract

The invention relates to acrylic resin for an optical polarizer and a preparation method of the acrylic resin. Comprising the following components in parts by weight: 15-36 parts of polyurethane, 8-16 parts of modified epoxy resin, 25-66 parts of modified acrylic resin, 0.1-1.2 parts of succinic anhydride, 0.3-1.5 parts of triethylamine, 1-3 parts of an initiator, 0.5-3.5 parts of an antioxidant and 12-35 parts of a curing agent. The prepared acrylic resin for the optical polaroid has good optical transparency, heat resistance, tensile strength and light resistance.

Description

Technical Field

[0001] The invention relates to the technical field of anti-blue light materials, and more specifically, to an acrylic resin for an optical polarizer and a preparation method thereof. Background Art

[0002] Polarizer is an indispensable and important component material in flat panel displays. In recent years, the price of flat panel displays has fallen, forcing more manufacturers to seek more ways to reduce the production cost of the product in order to ensure their sales profits. Compounding the polarizer's polyvinyl alcohol (PVA) support substrate, phase difference plate and other functional optical films to reduce the amount of materials used has gradually become a major trend.

[0003] Polymethyl methacrylate (PMMA) has very high light transmittance, high mechanical strength and good chemical stability, and is the most ideal optical film material for polarizers. However, the glass transition temperature of PMMA resin is less than 110°C, its high temperature resistance is poor, its water absorption rate is as high as 0.3%-0.4%, and the side chains of the molecular chain contain polar groups and have negative birefringence, which will undoubtedly severely limit its scope of use in polarizer optical films. A methacrylic resin with a new structure designed in an existing document contains a grafted copolymer obtained by grafting and polymerizing vinyl polymerizable monomers to form a core-shell structure. Although it can make it have high heat resistance, excellent mechanical properties and high light transmittance, it still fails to solve the problem of negative birefringence of the optical film produced therefrom, and it still cannot be widely used in the diversified needs of the polarizer field.

[0004] Existing acrylic resins for optical polarizers have poor adhesion, poor heat resistance, poor foaming resistance and poor light resistance, and cannot meet people's needs. Summary of the invention

[0005] The invention provides an acrylic resin for an optical polarizer and a preparation method thereof. The prepared acrylic resin for an optical polarizer has good optical transparency, good heat resistance, tensile strength and light resistance.

[0006] In a first aspect, the present invention provides an acrylic resin for an optical polarizer, comprising the following parts by weight: 15-36 parts of polyurethane, 8-16 parts of modified epoxy resin, 25-66 parts of modified acrylic resin, 0.1-1.2 parts of succinic anhydride, 0.3-1.5 parts of triethylamine, 1-3 parts of initiator, 0.5-3.5 parts of antioxidant, and 12-35 parts of curing agent.

[0007] Preferably, it comprises the following parts by weight: 18-32 parts of polyurethane, 10-16 parts of modified epoxy resin, 32-60 parts of modified acrylic resin, 0.5-1.2 parts of succinic anhydride, 0.8-1.2 parts of triethylamine, 1-3 parts of initiator, 1.5-3.5 parts of antioxidant, and 15-30 parts of curing agent.

[0008] Preferably, it comprises the following parts by weight: 22-30 parts of polyurethane, 12-16 parts of modified epoxy resin, 40-55 parts of modified acrylic resin, 0.6-1.0 parts of succinic anhydride, 0.5-1.0 parts of triethylamine, 2-3 parts of initiator, 2.5-3.5 parts of antioxidant, and 15-30 parts of curing agent.

[0009] Preferably, it includes the following parts by weight: 30 parts of polyurethane, 15 parts of modified epoxy resin, 60 parts of modified acrylic resin, 1.0 parts of succinic anhydride, 0.8 parts of triethylamine, 2 parts of initiator, 2.5 parts of antioxidant, and 22 parts of curing agent.

[0010] Preferably, the modified epoxy resin comprises methyl hexahydrophthalic anhydride, phenolic hydroxyl polysiloxane, N,N-dimethylbenzylamine and special bisphenol A epoxy resin, and the mass ratio of the methyl hexahydrophthalic anhydride, phenolic hydroxyl polysiloxane, N,N-dimethylbenzylamine and special bisphenol A epoxy resin is 1-3:2-5:1-3:5-9.

[0011] Preferably, the preparation method of the modified epoxy resin comprises the following steps: mixing methyl hexahydrophthalic anhydride, phenolic hydroxyl polysiloxane, N,N-dimethylbenzylamine and special bisphenol A epoxy resin according to a mass ratio, stirring at a temperature of 100-150° C. and a stirring time of 1-3 hours.

[0012] Preferably, the modified acrylic resin is prepared by mixing chloroether resin, methyl methacrylate and butyl acrylate and then adopting a solution polymerization method.

[0013] Preferably, the mass ratio of the chloroether resin, methyl methacrylate and butyl acrylate is 1:2-3:0.8-1.5.

[0014] Preferably, the initiator is one or more of benzoyl peroxide, tert-butyl perbenzoate, and (2,4,6-trimethylbenzoyl)diphenylphosphine oxide.

[0015] Preferably, the antioxidant is one of tris(4-methyl-2-tert-butylphenyl)phosphite, tris(biphenyl)phosphite and tris(4-cinnamylphenyl)phosphite.

[0016] In a second aspect, the present invention provides a method for preparing an acrylic resin for an optical polarizer, comprising the following steps: (1) Mixing polyurethane, modified epoxy resin, modified acrylic resin, succinic anhydride and triethylamine, and subjecting them to a thermal reaction at a temperature of 200-350° C. to obtain a composite; (2) adding an initiator and an antioxidant to the composite, mixing and stirring, and obtaining a precursor; (3) Add a curing agent to the precursor, stir, and let stand for 0.5-1 hour to obtain an acrylic resin for an optical polarizer.

[0017] Preferably, in step (2), the stirring temperature is 55-80°C.

[0018] In a second aspect, the present invention provides an optical polarizer, which is prepared by compounding the optical polarizer according to claim 1 with acrylic resin, polyvinyl alcohol material and other functional films.

[0019] In summary, the present invention has the following beneficial effects: The specific mechanism of the modified epoxy resin and the modified polypropylene resin after mixed modification in the present invention mainly involves a crosslinking reaction to form an interpenetrating network structure. The acrylic resin contains a carboxyl group, which can react with the epoxy group in the epoxy resin to form a stable chemical bond, thereby realizing crosslinking modification; the acrylate block copolymer can also be used as a toughening modifier, synthesized by atom transfer radical polymerization, and used to modify the epoxy resin. This method enhances the toughness of the epoxy resin by introducing flexible chains and rigid chains, thereby improving its dynamic mechanical behavior.

[0020] 2. In the present invention, the introduction of polysiloxane into the epoxy resin potting material can improve its brittleness and thermal stress. Since polysiloxane has excellent UV resistance, heat resistance, low surface energy and good chemical stability, and contains a flexible Si-O-Si skeleton, polysiloxane with reactive groups (such as hydroxyl, amino, epoxy and anhydride groups, etc.) can be used to improve its compatibility through chemical bond connection, so that the modified epoxy resin has better thermal stability, thermal properties and mechanical properties.

[0021] 3. The process of the chloroether-acrylate aqueous dispersion in the present invention follows the free radical polymerization mechanism and is composed of elementary reactions such as chain initiation, chain growth, chain transfer and chain termination. The initiator decomposes under heat to produce primary free radicals, which initiate the acrylate monomers to form monomer free radicals; the monomer free radicals quickly open the π bonds of other monomer molecules, and continuously add to make the polymer chain grow, and the active center is always at the end of the active chain. The chlorine atoms on the main chain skeleton of the chloroether resin are relatively active and are easily captured by chain free radicals, resulting in a chain transfer process, which causes the tertiary carbon atoms on the vinyl chloride chain segments to carry single electrons, further initiating monomer polymerization, growing side chains, and forming a graft copolymer of the chloroether resin and the acrylic resin, so that the modified acrylic resin has better dispersibility and makes it easier to combine during the polymer formation process.

[0022] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not intended to limit the scope of protection of the present invention. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with the examples. It is particularly noted that if no specific conditions are specified in the following examples, the reactions are carried out according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following examples can be obtained from common commercial sources. Preparation Example

[0024] Preparation Example 1 A method for preparing a modified epoxy resin comprises the following steps: mixing methyl hexahydrophthalic anhydride, phenolic hydroxyl polysiloxane, N,N-dimethylbenzylamine and special bisphenol A epoxy resin in a mass ratio of 1:2:1:5, with a stirring temperature of 100 DEG C and a stirring time of 1 hour.

[0025] Preparation Example 2 A method for preparing a modified epoxy resin comprises the following steps: mixing methyl hexahydrophthalic anhydride, phenolic hydroxyl polysiloxane, N,N-dimethylbenzylamine and special bisphenol A epoxy resin in a mass ratio of 3:2:1:7, stirring at a stirring temperature of 120°C and a stirring time of 1 hour.

[0026] Preparation Example 3 A method for preparing a modified epoxy resin comprises the following steps: mixing methyl hexahydrophthalic anhydride, phenolic hydroxyl polysiloxane, N,N-dimethylbenzylamine and special bisphenol A epoxy resin in a mass ratio of 3:3:1:5, with a stirring temperature of 150 DEG C and a stirring time of 1 hour.

[0027] Preparation Example 4 A method for preparing a modified acrylic resin comprises the following steps: mixing chloroether resin, methyl methacrylate and butyl acrylate in a mass ratio of 1:2:0.8, reacting at 90°C for 5 hours, and using propylene glycol butyl ether and ethylene glycol butyl ether as solvents.

[0028] Preparation Example 5 A method for preparing a modified acrylic resin comprises the following steps: mixing chloroether resin, methyl methacrylate and butyl acrylate in a mass ratio of 1:3:1.1, reacting at a temperature of 100°C for a reaction time of 5 hours, and using propylene glycol butyl ether and ethylene glycol butyl ether as solvents.

[0029] Preparation Example 6 A preparation method of modified acrylic resin comprises the following steps: mixing chloroether resin, methyl methacrylate and butyl acrylate in a mass ratio of 1:3:1.5, reacting at 90°C for 5 hours, and using propylene glycol butyl ether and ethylene glycol butyl ether as solvents. Example

[0030] Example 1

[0031] An acrylic resin for an optical polarizer comprises the following parts by weight: 15 parts of polyurethane, 8 parts of modified epoxy resin, 25 parts of modified acrylic resin, 0.1 parts of succinic anhydride, 0.3 parts of triethylamine, 1 part of initiator, 0.5 parts of antioxidant and 12 parts of curing agent.

[0032] Among them, the modified epoxy resin is prepared in Preparation Example 1; the modified acrylic resin is prepared in Preparation Example 4; the initiator is a mixture of benzoyl peroxide and tert-butyl perbenzoate in a ratio of 1:1; the antioxidant is tris (4-methyl-2-tert-butylphenyl) phosphite; A method for preparing acrylic resin for optical polarizers comprises the following steps: (1) polyurethane, modified epoxy resin, modified acrylic resin, succinic anhydride and triethylamine are mixed and subjected to a thermal reaction at a temperature of 300° C. to obtain a composite; (2) adding an initiator and an antioxidant to the composite, mixing and stirring at a stirring temperature of 55° C. to obtain a precursor; (3) Add a curing agent to the precursor, stir, and let stand for 0.5 h to obtain an acrylic resin for an optical polarizer.

[0033] Example 2

[0034] An acrylic resin for an optical polarizer comprises the following parts by weight: 22 parts of polyurethane, 12 parts of modified epoxy resin, 39 parts of modified acrylic resin, 0.8 parts of succinic anhydride, 1.2 parts of triethylamine, 2 parts of initiator, 3 parts of antioxidant and 25 parts of curing agent.

[0035] Among them, the modified epoxy resin is prepared in Preparation Example 2; the modified acrylic resin is prepared in Preparation Example 5; the initiator is a mixture of benzoyl peroxide and tert-butyl perbenzoate in a mass ratio of 1:2; the antioxidant is tris (4-methyl-2-tert-butylphenyl) phosphite; A method for preparing acrylic resin for optical polarizers comprises the following steps: (1) polyurethane, modified epoxy resin, modified acrylic resin, succinic anhydride and triethylamine are mixed and subjected to a thermal reaction at a temperature of 280° C. to obtain a composite; (2) adding an initiator and an antioxidant to the composite, mixing and stirring at a stirring temperature of 60° C. to obtain a precursor; (3) Add a curing agent to the precursor, stir, and let stand for 1 hour to obtain an acrylic resin for an optical polarizer.

[0036] Example 3

[0037] An acrylic resin for an optical polarizer comprises the following parts by weight: 18 parts of polyurethane, 10 parts of modified epoxy resin, 30 parts of modified acrylic resin, 0.3 parts of succinic anhydride, 0.8 parts of triethylamine, 1.5 parts of initiator, 2.6 parts of antioxidant and 15 parts of curing agent.

[0038] Among them, the modified epoxy resin is prepared in Preparation Example 3; the modified acrylic resin is prepared in Preparation Example 6; the initiator is a mixture of benzoyl peroxide and tert-butyl perbenzoate in a ratio of 1:1; the antioxidant is tris (4-methyl-2-tert-butylphenyl) phosphite; A method for preparing acrylic resin for optical polarizers comprises the following steps: (1) polyurethane, modified epoxy resin, modified acrylic resin, succinic anhydride and triethylamine are mixed and subjected to thermal reaction at a temperature of 350° C. to obtain a composite; (2) adding an initiator and an antioxidant to the composite, mixing and stirring at a stirring temperature of 80° C. to obtain a precursor; (3) Add a curing agent to the precursor, stir, and let stand for 0.5 h to obtain an acrylic resin for an optical polarizer.

[0039] Example 4

[0040] An acrylic resin for an optical polarizer comprises the following parts by weight: 32 parts of polyurethane, 15 parts of modified epoxy resin, 52 parts of modified acrylic resin, 1.1 parts of succinic anhydride, 0.8 parts of triethylamine, 1 part of initiator, 2 parts of antioxidant and 15 parts of curing agent.

[0041] Among them, the modified epoxy resin is prepared in Preparation Example 1; the modified acrylic resin is prepared in Preparation Example 4; the initiator is a mixture of benzoyl peroxide and tert-butyl perbenzoate in a mass ratio of 1:2; the antioxidant is tris (4-methyl-2-tert-butylphenyl) phosphite; A method for preparing acrylic resin for optical polarizers comprises the following steps: (1) polyurethane, modified epoxy resin, modified acrylic resin, succinic anhydride and triethylamine are mixed and subjected to a thermal reaction at a temperature of 200° C. to obtain a composite; (2) adding an initiator and an antioxidant to the composite, mixing and stirring at a stirring temperature of 65° C. to obtain a precursor; (3) Add a curing agent to the precursor, stir, and let stand for 0.5 h to obtain an acrylic resin for an optical polarizer.

[0042] Example 5

[0043] An acrylic resin for an optical polarizer comprises the following parts by weight: 28 parts of polyurethane, 16 parts of modified epoxy resin, 60 parts of modified acrylic resin, 1.2 parts of succinic anhydride, 0.9 parts of triethylamine, 1 part of initiator, 1.5 parts of antioxidant and 18 parts of curing agent.

[0044] Among them, the modified epoxy resin is prepared in Preparation Example 1; the modified acrylic resin is prepared in Preparation Example 4; the initiator is a mixture of benzoyl peroxide and tert-butyl perbenzoate in a mass ratio of 1:3; the antioxidant is tris (4-methyl-2-tert-butylphenyl) phosphite; A method for preparing acrylic resin for optical polarizers comprises the following steps: (1) polyurethane, modified epoxy resin, modified acrylic resin, succinic anhydride and triethylamine are mixed and subjected to a thermal reaction at a temperature of 300° C. to obtain a composite; (2) adding an initiator and an antioxidant to the composite, mixing and stirring at a stirring temperature of 80° C. to obtain a precursor; (3) Add a curing agent to the precursor, stir, and let stand for 0.5 h to obtain an acrylic resin for an optical polarizer. Comparative Example

[0045] Comparative Example 1 The acrylic resin for optical polarizer was prepared according to the method of Example 2, except that no modified epoxy resin was added.

[0046] Comparative Example 2 An acrylic resin for an optical polarizer is prepared according to the method of Example 2, except that the modified acrylic resin is replaced by acrylic resin.

[0047] Comparative Example 3 An acrylic resin for an optical polarizer was prepared according to the method of Example 2, except that no polyurethane was added.

[0048] Comparative Example 4 The acrylic resin for optical polarizer was prepared according to the method of Example 2, except that the modified epoxy resin was replaced by epoxy resin.

[0049] Performance Testing The following performance tests were performed on the materials obtained in the above Examples 1-5 and Comparative Examples 1-4, and the test methods were as follows: Density is tested according to ISO 1183 test standard; Water absorption is tested according to ISO 62 test standard; The surface hardness is tested according to the test standard of GB / T 6739-86; The flexural modulus is tested according to the test standard of ISO 178; The tensile strength is tested according to the test standard of ISO 527; The glass transition temperature is tested according to the DSC test method. The specific test method is: 2 Under protection, the temperature was raised from room temperature to 230°C at a rate of 10°C / min, kept at 230°C for 3min to eliminate the thermal history, then cooled to 30°C at a rate of 10°C / min, stayed at 30°C for 3min, and then raised to 230°C at a rate of 10°C / min; The refractive index is tested according to the test standard of ISO 489; The light transmittance is tested according to the test method of ISO 13468.

[0050] Table 1 Performance test results

[0051] From the above performance test results, it can be seen that Examples 1-5 have better thermal stability, thermal properties and mechanical properties, especially Example 2, the comprehensive performance of bending modulus, tensile strength, glass transition temperature and light transmittance is the most outstanding. This is mainly because the graft copolymer of chloroether resin and acrylic resin is formed, which makes the modified acrylic resin have better dispersion properties and makes it easier to combine during the polymer formation process.

[0052] However, since the necessary technical solutions were not adopted in the comparative examples, the corresponding performance tests were significantly worse than those of Examples 1-5. In Comparative Example 1, no modified epoxy resin was added, and it can be seen that the tensile strength decreased, proving that the addition of modified epoxy resin has an important influence on the mechanical properties. In Comparative Example 2, the acrylic resin was not modified, and it can be seen from the results that the graft copolymer of the chloroether resin and the acrylic resin was affected, further resulting in a decrease in the refractive index. The above experimental results further prove the importance of the technical solution defined in the present invention for its technical effect.

[0053] The above is only an exemplary embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An acrylic resin for optical polarizer, characterized in that: The invention comprises the following parts by weight: 15-36 parts of polyurethane, 8-16 parts of modified epoxy resin, 25-66 parts of modified acrylic resin, 0.1-1.2 parts of succinic anhydride, 0.3-1.5 parts of triethylamine, 1-3 parts of initiator, 0.5-3.5 parts of antioxidant and 12-35 parts of curing agent.

2. The acrylic resin for optical polarizer according to claim 1, characterized in that: The modified epoxy resin comprises methyl hexahydrophthalic anhydride, phenolic hydroxyl polysiloxane, N,N-dimethylbenzylamine and special bisphenol A epoxy resin, and the mass ratio of the methyl hexahydrophthalic anhydride, phenolic hydroxyl polysiloxane, N,N-dimethylbenzylamine and special bisphenol A epoxy resin is 1-3:2-5:1-3:5-9.

3. The acrylic resin for optical polarizer according to claim 1, characterized in that: The preparation method of the modified epoxy resin comprises the following steps: mixing methyl hexahydrophthalic anhydride, phenolic hydroxyl polysiloxane, N,N-dimethylbenzylamine and special bisphenol A epoxy resin according to a mass ratio, stirring at a temperature of 100-150° C. and for a time of 1-3 hours.

4. The acrylic resin for optical polarizer according to claim 1, characterized in that: The modified acrylic resin is prepared by mixing chloroether resin, methyl methacrylate and butyl acrylate and adopting a solution polymerization method.

5. The acrylic resin for optical polarizer according to claim 4, characterized in that: The mass ratio of the chloroether resin, methyl methacrylate and butyl acrylate is 1:2-3:0.8-1.

5.

6. The acrylic resin for optical polarizer according to claim 1, characterized in that: The initiator is one or more of benzoyl peroxide, tert-butyl perbenzoate, and (2,4,6-trimethylbenzoyl)diphenylphosphine oxide.

7. The acrylic resin for optical polarizer according to claim 1, characterized in that: The antioxidant is one of tris(4-methyl-2-tert-butylphenyl)phosphite, tris(biphenyl)phosphite and tris(4-cinnamylphenyl)phosphite.

8. The method for preparing the acrylic resin for optical polarizer according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) Mixing polyurethane, modified epoxy resin, modified acrylic resin, succinic anhydride and triethylamine, and subjecting them to a thermal reaction at a temperature of 200-350° C. to obtain a composite; (2) adding an initiator and an antioxidant to the composite, mixing and stirring, and obtaining a precursor; (3) Add a curing agent to the precursor, stir, and let stand for 0.5-1 hour to obtain an acrylic resin for an optical polarizer.

9. The method for preparing acrylic resin for optical polarizer according to claim 8, characterized in that: In step (2), the stirring temperature is 55-80°C.

10. An optical polarizer, characterized in that: The polarizer is prepared by compounding the optical polarizer as claimed in claim 1 with acrylic resin, polyvinyl alcohol material and other functional films.

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