Yellowing-resistant grafted acrylate adhesive and preparation method thereof

Abstract

The invention discloses an anti-yellowing grafted acrylate adhesive and a preparation method thereof, and relates to the technical field of adhesives. The adhesive is prepared from the following raw materials in parts by weight: 30-40 parts of an acrylamido-grafted modified fluorosilicone thermoplastic polyurethane elastomer, 100 parts of an acrylate monomer, 5-8 parts of isocyano ethyl methacrylate, 3-5 parts of 4-acryloyloxybenzophenone, 1-3 parts of melamine, 1-3 parts of 4, 4 '-difluoro-1, 3, 4-trimethyl-1, 3-pentanediol monoisobutyrate, 1-3 parts of an initiator, 1-3 parts of an initiator, 1-3 parts of an initiator, 1-3 parts of an initiator, 1-3 parts of an initiator and The preparation method comprises the following steps: preparing the following components in parts by weight: 1-2 parts of 2, 6-hydroxy-2-cyanobenzothiazole, 1-3 parts of glycerol triabietate, 0.8-1.2 parts of a catalyst and 1-2 parts of an initiator. The adhesive is high in bonding strength and excellent in yellowing resistance and low temperature resistance.

Description

Technical Field

[0001] The invention relates to the technical field of adhesives, and in particular to a yellowing-resistant grafted acrylate adhesive and a preparation method thereof. Background Art

[0002] Adhesives, also known as adhesives, are natural or synthetic, organic or inorganic substances that can connect two or more parts or materials together through interfacial adhesion and cohesion. They are usually referred to as glue. As one of the five major polymer materials, adhesives have become an indispensable new material in the development of high-tech with the development of the national economy and science and technology. They have been widely used in various sectors of the national economy and related fields of daily life, such as packaging, construction, automobiles, electronics, footwear, textiles, plastics, wood, optics, medical care, aerospace, and marine transportation. However, with the improvement of material performance requirements, the yellowing problem of adhesives has become increasingly serious. Yellowing adhesives not only affect the appearance, but also cause the deterioration of bonding performance.

[0003] Acrylic adhesives are one of the most common adhesives. They are easy to use, fast curing at room temperature, and have high bonding strength. They can produce strong adhesion to polar materials such as rubber, metal, plastic, ceramic, glass, and biological tissue. Therefore, they have broad application prospects in many fields in my country. However, unmodified acrylic adhesives still have more or less technical problems such as insufficient low temperature resistance and yellowing resistance that need to be further improved.

[0004] In order to solve the above problems, the Chinese invention patent with the authorization announcement number CN113185938B discloses an environmentally friendly low-humidity resistant acrylic adhesive and its preparation method, which includes the following components and their mass fractions: 100 parts of acrylic adhesive, 5-15 parts of a mixture of tackifying resin and solvent, 0.3-1.0 parts of curing agent and 5-20 parts of modified silane coupling agent. The invention adds a modified silane coupling agent to the acrylic adhesive, the main chain of which is a long-chain alkane, which has good compatibility with acrylic adhesives, and the side chain contains a sulfonic acid group, which can promote the hydrolysis of siloxane groups and absorb water vapor in the air, thereby wetting the interface, and finally making the modified acrylic adhesive have high adhesion to the carton in a low temperature environment. However, its yellowing resistance still needs to be further improved.

[0005] It can be seen that it is particularly important to develop an acrylic adhesive with high bonding strength, excellent yellowing resistance and low temperature resistance. Summary of the invention

[0006] The main purpose of the present invention is to provide a yellowing-resistant grafted acrylic adhesive with high bonding strength, excellent yellowing resistance and low-temperature resistance and a preparation method thereof.

[0007] To achieve the above purpose, the present invention provides a yellowing-resistant grafted acrylic adhesive, which is made of the following raw materials in parts by weight: 30-40 parts of acrylamide-based grafted fluorosilicone-type thermoplastic polyurethane elastomer, 100 parts of acrylic ester monomers, 5-8 parts of isocyanoethyl methacrylate, 3-5 parts of 4-acryloxybenzophenone, 1-3 parts of melamine, 1-2 parts of 4,6-hydroxy-2-cyanobenzothiazole, 1-3 parts of trirosin acid glycerol, 0.8-1.2 parts of catalyst, and 1-2 parts of initiator.

[0008] Preferably, the preparation method of the acrylamide-grafted modified fluorosilicone thermoplastic polyurethane elastomer comprises the following steps: uniformly mixing a fluorosilicone thermoplastic polyurethane elastomer containing a benzene ring, 2-acrylamide-2-methylpropanesulfonic acid, phosphorus pentoxide, polyphosphoric acid, and a polymerization inhibitor to obtain a mixture, then adding the mixture to a high boiling point solvent, uniformly mixing, stirring and reacting at 170-180° C. for 3-6 hours, cooling to room temperature, precipitating in a saturated solution of sodium carbonate, and washing the precipitated polymer with water and ethanol in turn, and drying to obtain the acrylamide-grafted modified fluorosilicone thermoplastic polyurethane elastomer.

[0009] Preferably, there is no special requirement for the source of the fluorosilicone thermoplastic polyurethane elastomer containing benzene rings. In one embodiment of the present invention, the fluorosilicone thermoplastic polyurethane elastomer containing benzene rings is made according to the method of Example 3 of the Chinese invention patent in the authorization announcement number CN111154064B.

[0010] Preferably, the mass ratio of the fluorosilicone thermoplastic polyurethane elastomer containing benzene rings, 2-acrylamide-2-methylpropanesulfonic acid, phosphorus pentoxide, polyphosphoric acid, inhibitor, and high boiling point solvent is (4-6):1:(0.8-1.2):0.5:(0.08-0.12):(15-25).

[0011] Preferably, the polymerization inhibitor is methylhydroquinone; and the high boiling point solvent is dimethyl sulfoxide.

[0012] Preferably, the acrylic ester monomer is a mixture of isooctyl acrylate, methyl methacrylate and methacrylamide in a mass ratio of (1-3):3:(0.8-1.2).

[0013] Preferably, the catalyst is at least one of an organic bismuth catalyst DY-20 and dibutyltin dilaurate DY-12.

[0014] Preferably, the initiator is azobisisobutyronitrile.

[0015] Another object of the present invention is to provide a method for preparing the yellowing-resistant grafted acrylic adhesive, comprising the following steps: mixing the raw materials uniformly by weight, vacuuming and degassing to obtain the yellowing-resistant grafted acrylic adhesive.

[0016] Due to the application of the above technical solution, the present invention has the following beneficial effects: (1) The method for preparing the yellowing-resistant grafted acrylic adhesive disclosed in the present invention has simple process, convenient operation and control, low labor intensity, small impact on the environment, high preparation efficiency and finished product qualification rate, and is suitable for industrial production.

[0017] (2) The yellowing-resistant grafted acrylic adhesive disclosed in the present invention is made of the following raw materials in parts by weight: 30-40 parts of acrylamide-based grafted fluorosilicone-type thermoplastic polyurethane elastomer, 100 parts of acrylic ester monomers, 5-8 parts of isocyanoethyl methacrylate, 3-5 parts of 4-acryloxybenzophenone, 1-3 parts of melamine, 1-2 parts of 4,6-hydroxy-2-cyanobenzothiazole, 1-3 parts of trirosin acid glycerol, 0.8-1.2 parts of catalyst, and 1-2 parts of initiator. Through the mutual cooperation between the raw materials, the manufactured adhesive product has high bonding strength, excellent yellowing resistance and low temperature resistance; fluorosilicone polyurethane, ester group, benzophenone, triazine, cyanobenzothiazole and rosin acid glycerol ester structures are simultaneously introduced into the adhesive film formed after the adhesive is cured. These structures, under the multiple effects of electronic effect, steric effect and conjugation effect, make the product have higher bonding strength, better yellowing resistance and low temperature resistance, and longer service life.

[0018] (3) The yellowing-resistant grafted acrylic adhesive disclosed in the present invention introduces cross-linkable sites on the elastomer material by grafting acrylamide-modified fluorosilicone thermoplastic polyurethane elastomer, which can improve the comprehensive performance and performance stability of the formed film and avoid the impact on the performance and stability of the film caused by compatibility problems; the monomer containing unsaturated olefinic bonds can undergo a cross-linking and curing reaction under the action of an initiator; at the same time, the raw materials containing an isocyanate structure can react chemically with the components containing hydroxyl and amino groups, thereby forming multiple interpenetrating network structures in the film. These interpenetrating network structures exist at the same time and cooperate with each other, so that the prepared adhesive product has higher bonding strength, better yellowing resistance and low temperature resistance, and longer service life. DETAILED DESCRIPTION

[0019] 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

[0020] A yellowing-resistant grafted acrylic adhesive is prepared from the following raw materials in parts by weight: 30 parts of acrylamide-based grafted modified fluorosilicone thermoplastic polyurethane elastomer, 100 parts of acrylic ester monomers, 5 parts of isocyanoethyl methacrylate, 3 parts of 4-acryloxybenzophenone, 1 part of melamine, 1 part of 4,6-hydroxy-2-cyanobenzothiazole, 1 part of trirosin acid glycerol, 0.8 parts of a catalyst, and 1 part of an initiator.

[0021] The preparation method of the acrylamide-grafted modified fluorosilicone thermoplastic polyurethane elastomer comprises the following steps: uniformly mixing a fluorosilicone thermoplastic polyurethane elastomer containing a benzene ring, 2-acrylamide-2-methylpropanesulfonic acid, phosphorus pentoxide, polyphosphoric acid and a polymerization inhibitor to obtain a mixed material, then adding the mixed material into a high boiling point solvent, uniformly mixing, stirring and reacting at 170° C. for 3 hours, cooling to room temperature, precipitating in a saturated solution of sodium carbonate, and washing the precipitated polymer with water and ethanol in sequence, and drying to obtain the acrylamide-grafted modified fluorosilicone thermoplastic polyurethane elastomer; The fluorosilicone thermoplastic polyurethane elastomer containing benzene rings is prepared according to the method of Example 3 of the Chinese invention patent with authorization announcement number CN111154064B; the mass ratio of the fluorosilicone thermoplastic polyurethane elastomer containing benzene rings, 2-acrylamide-2-methylpropane sulfonic acid, phosphorus pentoxide, polyphosphoric acid, inhibitor, and high boiling point solvent is 6:1:0.8:0.5:0.08:15; the inhibitor is methyl hydroquinone; the high boiling point solvent is dimethyl sulfoxide; calculated by weight change and elemental analysis, the graft modification rate of 2-acrylamide-2-methylpropane sulfonic acid is 9.2%.

[0022] The acrylic ester monomer is a mixture of isooctyl acrylate, methyl methacrylate and methacrylamide in a mass ratio of 1:3:0.8; the catalyst is an organic bismuth catalyst DY-20; and the initiator is azobisisobutyronitrile.

[0023] A method for preparing the yellowing-resistant grafted acrylic adhesive comprises the following steps: mixing the raw materials uniformly according to weight, vacuuming and degassing to obtain the yellowing-resistant grafted acrylic adhesive. Example 2

[0024] A yellowing-resistant grafted acrylic adhesive is prepared from the following raw materials in parts by weight: 33 parts of acrylamide-based grafted modified fluorosilicone thermoplastic polyurethane elastomer, 100 parts of acrylic ester monomers, 6 parts of isocyanoethyl methacrylate, 3.5 parts of 4-acryloxybenzophenone, 1.5 parts of melamine, 1.2 parts of 4,6-hydroxy-2-cyanobenzothiazole, 1.5 parts of trirosin acid glycerol, 0.9 parts of a catalyst, and 1.2 parts of an initiator.

[0025] The preparation method of the acrylamide-grafted modified fluorosilicone thermoplastic polyurethane elastomer comprises the following steps: uniformly mixing a fluorosilicone thermoplastic polyurethane elastomer containing a benzene ring, 2-acrylamide-2-methylpropanesulfonic acid, phosphorus pentoxide, polyphosphoric acid and a polymerization inhibitor to obtain a mixed material, then adding the mixed material into a high boiling point solvent, uniformly mixing, stirring and reacting at 173°C for 4 hours, cooling to room temperature, precipitating in a saturated solution of sodium carbonate, and washing the precipitated polymer with water and ethanol in sequence, and drying to obtain an acrylamide-grafted modified fluorosilicone thermoplastic polyurethane elastomer; Amine-grafted modified fluorosilicone thermoplastic polyurethane elastomer; the fluorosilicone thermoplastic polyurethane elastomer containing benzene rings is made according to the method of Example 3 of the Chinese invention patent with authorization announcement number CN111154064B; the mass ratio of the fluorosilicone thermoplastic polyurethane elastomer containing benzene rings, 2-acrylamide-2-methylpropanesulfonic acid, phosphorus pentoxide, polyphosphoric acid, inhibitor, and high boiling point solvent is 5.5:1:0.9:0.5:0.09:17; the inhibitor is methylhydroquinone; and the high boiling point solvent is dimethyl sulfoxide.

[0026] The acrylic ester monomer is a mixture of isooctyl acrylate, methyl methacrylate and methacrylamide in a mass ratio of 1.5:3:0.9; the catalyst is dibutyltin dilaurate DY-12; and the initiator is azobisisobutyronitrile.

[0027] A method for preparing the yellowing-resistant grafted acrylic adhesive comprises the following steps: mixing the raw materials uniformly according to weight, vacuuming and degassing to obtain the yellowing-resistant grafted acrylic adhesive. Example 3

[0028] A yellowing-resistant grafted acrylic adhesive is prepared from the following raw materials in parts by weight: 35 parts of acrylamide-based grafted modified fluorosilicone thermoplastic polyurethane elastomer, 100 parts of acrylic ester monomers, 6.5 parts of isocyanoethyl methacrylate, 4 parts of 4-acryloxybenzophenone, 2 parts of melamine, 1.5 parts of 4,6-hydroxy-2-cyanobenzothiazole, 2 parts of trirosin acid glyceryl, 1 part of catalyst, and 1.5 parts of initiator.

[0029] The preparation method of the acrylamide-grafted modified fluorosilicone thermoplastic polyurethane elastomer comprises the following steps: uniformly mixing a fluorosilicone thermoplastic polyurethane elastomer containing a benzene ring, 2-acrylamide-2-methylpropanesulfonic acid, phosphorus pentoxide, polyphosphoric acid and a polymerization inhibitor to obtain a mixed material, then adding the mixed material into a high boiling point solvent, uniformly mixing, stirring and reacting at 175°C for 4.5 hours, cooling to room temperature, precipitating in a saturated solution of sodium carbonate, and washing the precipitated polymer with water and ethanol in sequence, and drying to obtain a acrylamide-grafted modified fluorosilicone thermoplastic polyurethane elastomer; the fluorosilicone thermoplastic polyurethane elastomer containing benzene rings is made according to the method of Example 3 of the Chinese invention patent with authorization announcement number CN111154064B; the mass ratio of the fluorosilicone thermoplastic polyurethane elastomer containing benzene rings, 2-acrylamide-2-methylpropanesulfonic acid, phosphorus pentoxide, polyphosphoric acid, inhibitor, and high boiling point solvent is 5:1:1:0.5:0.1:20; the inhibitor is methylhydroquinone; and the high boiling point solvent is dimethyl sulfoxide.

[0030] The acrylic ester monomer is a mixture of isooctyl acrylate, methyl methacrylate and methacrylamide in a mass ratio of 2:3:1; the catalyst is an organic bismuth catalyst DY-20; and the initiator is azobisisobutyronitrile.

[0031] A method for preparing the yellowing-resistant grafted acrylic adhesive comprises the following steps: mixing the raw materials uniformly according to weight, vacuuming and degassing to obtain the yellowing-resistant grafted acrylic adhesive. Example 4

[0032] A yellowing-resistant grafted acrylic adhesive is prepared from the following raw materials in parts by weight: 38 parts of acrylamide-based grafted modified fluorosilicone thermoplastic polyurethane elastomer, 100 parts of acrylic monomers, 7.5 parts of isocyanoethyl methacrylate, 4.5 parts of 4-acryloxybenzophenone, 2.5 parts of melamine, 1.8 parts of 4,6-hydroxy-2-cyanobenzothiazole, 2.5 parts of trirosin acid glyceryl, 1.1 parts of a catalyst, and 1.8 parts of an initiator.

[0033] The preparation method of the acrylamide-grafted modified fluorosilicone thermoplastic polyurethane elastomer comprises the following steps: uniformly mixing a fluorosilicone thermoplastic polyurethane elastomer containing a benzene ring, 2-acrylamide-2-methylpropanesulfonic acid, phosphorus pentoxide, polyphosphoric acid and a polymerization inhibitor to obtain a mixed material, then adding the mixed material into a high boiling point solvent, uniformly mixing, stirring and reacting at 178°C for 5.5 hours, cooling to room temperature, precipitating in a saturated solution of sodium carbonate, and washing the precipitated polymer with water and ethanol in sequence, and drying to obtain an acrylamide-grafted modified fluorosilicone thermoplastic polyurethane elastomer; Amide-grafted modified fluorosilicone thermoplastic polyurethane elastomer; the fluorosilicone thermoplastic polyurethane elastomer containing benzene rings is made according to the method of Example 3 of the Chinese invention patent with authorization announcement number CN111154064B; the mass ratio of the fluorosilicone thermoplastic polyurethane elastomer containing benzene rings, 2-acrylamide-2-methylpropanesulfonic acid, phosphorus pentoxide, polyphosphoric acid, inhibitor, and high boiling point solvent is 4.5:1:1.1:0.5:0.11:24; the inhibitor is methylhydroquinone; and the high boiling point solvent is dimethyl sulfoxide.

[0034] The acrylic ester monomer is a mixture of isooctyl acrylate, methyl methacrylate and methacrylamide in a mass ratio of 2.5:3:1.1; the catalyst is an organic bismuth catalyst DY-20 and dibutyltin dilaurate DY-12 in a mass ratio of bismuth 3:5; and the initiator is azobisisobutyronitrile.

[0035] A method for preparing the yellowing-resistant grafted acrylic adhesive comprises the following steps: mixing the raw materials uniformly according to weight, vacuuming and degassing to obtain the yellowing-resistant grafted acrylic adhesive. Example 5

[0036] A yellowing-resistant grafted acrylic adhesive is prepared from the following raw materials in parts by weight: 40 parts of acrylamide-based grafted modified fluorosilicone thermoplastic polyurethane elastomer, 100 parts of acrylic ester monomers, 8 parts of isocyanoethyl methacrylate, 5 parts of 4-acryloxybenzophenone, 3 parts of melamine, 2 parts of 4,6-hydroxy-2-cyanobenzothiazole, 3 parts of trirosin acid glyceryl, 1.2 parts of a catalyst, and 2 parts of an initiator.

[0037] The preparation method of the acrylamide-grafted modified fluorosilicone thermoplastic polyurethane elastomer comprises the following steps: uniformly mixing a fluorosilicone thermoplastic polyurethane elastomer containing a benzene ring, 2-acrylamide-2-methylpropanesulfonic acid, phosphorus pentoxide, polyphosphoric acid and a polymerization inhibitor to obtain a mixed material, then adding the mixed material into a high boiling point solvent, uniformly mixing, stirring and reacting at 180°C for 6 hours, cooling to room temperature, precipitating in a saturated solution of sodium carbonate, and washing the precipitated polymer with water and ethanol in sequence, and drying to obtain an acrylamide-grafted modified fluorosilicone thermoplastic polyurethane elastomer; Amide-grafted modified fluorosilicone thermoplastic polyurethane elastomer; the fluorosilicone thermoplastic polyurethane elastomer containing benzene rings is made according to the method of Example 3 of the Chinese invention patent with authorization announcement number CN111154064B; the mass ratio of the fluorosilicone thermoplastic polyurethane elastomer containing benzene rings, 2-acrylamide-2-methylpropanesulfonic acid, phosphorus pentoxide, polyphosphoric acid, inhibitor, and high boiling point solvent is 4:1:1.2:0.5:0.12:25; the inhibitor is methylhydroquinone; and the high boiling point solvent is dimethyl sulfoxide.

[0038] The acrylic ester monomer is a mixture of isooctyl acrylate, methyl methacrylate and methacrylamide in a mass ratio of 3:3:1.2; the catalyst is dibutyltin dilaurate DY-12; and the initiator is azobisisobutyronitrile.

[0039] A method for preparing the yellowing-resistant grafted acrylic adhesive comprises the following steps: mixing the raw materials uniformly according to weight, vacuuming and degassing to obtain the yellowing-resistant grafted acrylic adhesive.

[0040] Comparative Example 1 A method for preparing a yellowing-resistant grafted acrylic adhesive is basically the same as that of Example 1, except that an equal amount of a phenyl-containing fluorosilicone thermoplastic polyurethane elastomer is used to replace the acrylamide-based graft-modified fluorosilicone thermoplastic polyurethane elastomer.

[0041] Comparative Example 2 A method for preparing a yellowing-resistant grafted acrylic adhesive is substantially the same as that of Example 1, except that melamine and 4,6-hydroxy-2-cyanobenzothiazole are not added.

[0042] In order to further illustrate the beneficial technical effects of the yellowing-resistant grafted acrylate adhesives involved in the embodiments of the present invention, relevant performance tests were conducted on the yellowing-resistant grafted acrylate adhesives involved in Examples 1-5 and Comparative Examples 1-2. The test results are shown in Table 1. The test method is as follows: (1) Tensile shear strength: GB / T 7124-2008 was used to measure the tensile shear strength at room temperature of 20°C. The curing was divided into two stages: curing at 80°C for 1 hour and then drying at 120°C for 1 hour. The thickness of the adhesive layer was 0.2 mm.

[0043] (2) Low temperature resistance: The cured adhesive samples of each example were placed in an environment of -30°C for 200 hours. After returning 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 low temperature resistance.

[0044] (3) Yellowing resistance: Refer to the naked eye observation method in GB / T 39294-2020 for yellowing resistance test, and use the gray sample card to assess the discoloration level.

[0045] Table 1 project Tensile shear strength Low temperature resistance Yellowing resistance unit MPa % class Example 1 37.5 99.80 5 Example 2 38.0 99.86 5 Example 3 38.3 99.90 5 Example 4 39.9 99.93 5 Example 5 39.3 99.98 5 Comparative Example 1 30.3 97.31 4 Comparative Example 2 32.8 96.43 4-5 It can be seen from Table 1 that the yellowing-resistant grafted acrylic adhesives disclosed in the embodiments of the present invention have better bonding performance, low temperature resistance and yellowing resistance than the comparative example products; the addition of acrylamide-based grafted modified fluorosilicone thermoplastic polyurethane elastomer, melamine and 4,6-hydroxy-2-cyanobenzothiazole is beneficial to improving the above properties.

[0046] 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. A yellowing-resistant grafted acrylic adhesive, characterized in that: The invention is prepared from the following raw materials in parts by weight: 30-40 parts of acrylamide-grafted modified fluorosilicone thermoplastic polyurethane elastomer, 100 parts of acrylate monomers, 5-8 parts of isocyanoethyl methacrylate, 3-5 parts of 4-acryloxybenzophenone, 1-3 parts of melamine, 1-2 parts of 4,6-hydroxy-2-cyanobenzothiazole, 1-3 parts of trirosin acid glyceryl ester, 0.8-1.2 parts of catalyst and 1-2 parts of initiator.

2. The yellowing-resistant grafted acrylic adhesive according to claim 1, characterized in that: The preparation method of the acrylamide-grafted modified fluorosilicone thermoplastic polyurethane elastomer comprises the following steps: uniformly mixing a fluorosilicone thermoplastic polyurethane elastomer containing a benzene ring, 2-acrylamide-2-methylpropanesulfonic acid, phosphorus pentoxide, polyphosphoric acid and a polymerization inhibitor to obtain a mixed material, then adding the mixed material into a high boiling point solvent, uniformly mixing, stirring and reacting at 170-180° C. for 3-6 hours, cooling to room temperature, precipitating in a saturated solution of sodium carbonate, and washing the precipitated polymer with water and ethanol in turn, and drying to obtain the acrylamide-grafted modified fluorosilicone thermoplastic polyurethane elastomer.

3. The yellowing-resistant grafted acrylic adhesive according to claim 2, characterized in that: The mass ratio of the fluorosilicone thermoplastic polyurethane elastomer containing benzene rings, 2-acrylamide-2-methylpropanesulfonic acid, phosphorus pentoxide, polyphosphoric acid, inhibitor, and high boiling point solvent is (4-6):1:(0.8-1.2):0.5:(0.08-0.12):(15-25).

4. The yellowing-resistant grafted acrylic adhesive according to claim 2, characterized in that: The polymerization inhibitor is methylhydroquinone; and the high boiling point solvent is dimethyl sulfoxide.

5. The yellowing-resistant grafted acrylic adhesive according to claim 1, characterized in that: The acrylic acid ester monomer is prepared by mixing isooctyl acrylate, methyl methacrylate and methacrylamide in a mass ratio of (1-3):3:(0.8-1.2).

6. The yellowing-resistant grafted acrylic adhesive according to claim 1, characterized in that: The catalyst is at least one of an organic bismuth catalyst DY-20 and dibutyltin dilaurate DY-12.

7. The yellowing-resistant grafted acrylic adhesive according to claim 1, characterized in that: The initiator is azobisisobutyronitrile.

8. A method for preparing the yellowing-resistant grafted acrylic adhesive according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: mixing the raw materials uniformly according to weight, vacuuming and degassing to obtain a yellowing-resistant grafted acrylic adhesive.