Anti-warping adhesive and preparation method thereof

Abstract

The invention discloses an anti-warping adhesive and a preparation method thereof, and relates to the technical field of adhesives, the anti-warping adhesive comprises the following components by weight: 50-70 parts of matrix resin, 10-20 parts of a modifier, 8-12 parts of a filler, 5-8 parts of a curing agent, 1.5-4 parts of an auxiliary agent, 4-6 parts of other monomers, and 45-55 parts of a diluent; the matrix resin is prepared by mixing hyperbranched abietinol polyurethane acrylate resin and Atlac 430 epoxy bisphenol A vinyl resin according to a mass ratio of (3 to 5): 1; the modifier is a nano montmorillonite / nano silicon dioxide compound modified by amino-terminated hyperbranched polysiloxane (HPSi-NH2). The adhesive is sufficient in bonding performance, good in high-temperature and high-humidity resistance, excellent in anti-warping performance and long in service life.

Description

Technical Field

[0001] The present invention relates to the technical field of adhesives, and particularly to an anti-warping adhesive and a preparation method thereof. Background Art

[0002] An adhesive is a substance with excellent bonding properties. It connects objects by surface adhesion through adhesive force and cohesive force, and has very wide applications in many fields such as electronic device manufacturing, furniture production, and packaging industry. With the diversified development of materials, the market demand for adhesives is increasing, and the performance requirements for them are also getting higher and higher.

[0003] Existing adhesives are prone to warping due to the difference in thermal expansion coefficients between the substrate and the adhesive layer or curing shrinkage in high-temperature and high-humidity environments, resulting in bonding failure. To improve the anti-warping performance of adhesives, it is currently usually achieved by adding toughening agents (such as rubber particles) or reducing the curing shrinkage rate (such as inorganic fillers). However, toughening agents are likely to reduce the bonding strength, and excessive inorganic fillers will lead to uneven dispersion and decreased fluidity. Other types of anti-warping adhesives on the market also more or less have technical defects such as insufficient bonding performance, poor high-temperature and high-humidity resistance, limited anti-warping performance, and short service life.

[0004] In order to solve the above problems, a Chinese invention patent with the application publication number CN119307203A discloses an anti-warping water-based optical adhesive for an optical diffusion film, a preparation method and applications thereof, including the following steps: mixing mesitylene and ethylene glycol monobutyl ether to obtain a mixed solvent; adding acrylic monomers and initiators to the mixed solvent and carrying out a heating reaction to obtain a reaction product; adding a neutralizing agent to the reaction product for a neutralization reaction, and then adding water and stirring to obtain an anti-warping water-based optical adhesive for an optical diffusion film. This water-based optical adhesive can replace traditional optical adhesives and be applied to an optical diffusion film. It is coated on the surface of a PET film and cured to form a water-based optical adhesive film. The water-based optical adhesive film and the PET film form an optical diffusion film and are then applied to a display screen. The stress generated during the curing process of the water-based optical adhesive is small, which can prevent the PET film from warping, thereby improving the performance of the optical diffusion film. However, the high-temperature and high-humidity resistance and anti-warping performance of this adhesive still need to be further improved.

[0005] Therefore, developing an anti-warping adhesive with sufficient bonding performance, excellent high-temperature and high-humidity resistance, excellent anti-warping performance, and long service life and its preparation method meets the market demand, has broad market value and application prospects, and is of great significance for promoting the development of the anti-warping adhesive field. Summary of the Invention

[0006] The main purpose of the present invention is to provide an anti-warping adhesive with sufficient bonding performance, excellent high-temperature and high-humidity resistance, excellent anti-warping performance, and long service life and a preparation method thereof.

[0007] To achieve the above object, the present invention provides an anti-warping adhesive, which comprises the following components by weight: 50-70 parts of matrix resin, 10-20 parts of modifier, 8-12 parts of filler, 5-8 parts of curing agent, 1.5-4 parts of auxiliary agent, 4-6 parts of other monomers, and 45-55 parts of diluent; the matrix resin is composed of hyperbranched rosin alcohol polyurethane acrylate resin and Atlac 430 epoxy bisphenol A vinyl resin mixed in a mass ratio of (3-5):1; the modifier is an amino-terminated hyperbranched polysiloxane HPSi-NH2 modified nano-montmorillonite / nano-silica composite.

[0008] Preferably, there is no special requirement for the source of the hyperbranched rosin alcohol polyurethane acrylate resin. In an embodiment of the present invention, the hyperbranched rosin alcohol polyurethane acrylate resin is prepared by the method of Example 1 of the Chinese invention patent with the application publication number CN110078893A.

[0009] Preferably, the preparation method of the modifier comprises the following steps: mixing nano-montmorillonite and nano-silica, uniformly dispersing them in an organic solvent, adding silane coupling agent KH560, stirring and reacting at 60-80 °C for 4-6 h, then adding amino-terminated hyperbranched polysiloxane HPSi-NH2 thereto, and continuously stirring and reacting at 75-85 °C for 3-6 h, and rotary evaporating to remove the solvent to obtain the modifier.

[0010] Preferably, the mass ratio of the nano-montmorillonite, nano-silica, organic solvent, silane coupling agent KH560, and amino-terminated hyperbranched polysiloxane HPSi-NH2 is (1-3):1:(10-20):(0.2-0.4):(0.3-0.5).

[0011] Preferably, the particle size of the nano-montmorillonite is 10-80 nm.

[0012] Preferably, the particle size of the nano-silica is 20-90 nm.

[0013] Preferably, the organic solvent is N,N-dimethylformamide.

[0014] Preferably, there is no special requirement for the source of the amino-terminated hyperbranched polysiloxane HPSi-NH2. In an embodiment of the present invention, the amino-terminated hyperbranched polysiloxane HPSi-NH2 is prepared by the method of Example 1 of the Chinese invention patent with the authorization announcement number CN110156948B.

[0015] Preferably, the filler is composed of mica powder, nano-boron fiber, and attapulgite mixed in a mass ratio of (1-3):0.3:(0.3-0.5).

[0016] Preferably, the mica powder has an aspect ratio of ≥70 and is selected from at least one of mica powders of grades A-41S, SYA-21RS, B-82, and A-21S.

[0017] Preferably, the average diameter of the nano-boron fiber is 300-500 nm, and the aspect ratio is (15-25):1.

[0018] Preferably, the particle size of the attapulgite is 800-1200 mesh.

[0019] Preferably, the curing agent is a mixture of a photoinitiator, (3,6-diaminoacridine-9-yl)boric acid, 3,3'-diamino-4,4'-difluorodiphenyl sulfone and methyl hexahydrophthalic anhydride in a mass ratio of 1:(0.8-1.2):(1-3):(0.8-1.2).

[0020] Preferably, the photoinitiator is benzoin ethyl ether.

[0021] Preferably, the auxiliary agent is a coupling agent and a defoaming agent mixed in a mass ratio of (3-5):1.

[0022] Preferably, the coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570; the defoaming agent is one or more of tributyl phosphate, defoaming agent Deqian 3100, and defoaming agent BYK088.

[0023] Preferably, the other monomers are 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione and 2,4,6-trivinyl cycloboroxine mixed in a mass ratio of (3-5):1.

[0024] Preferably, the diluent is a mixture of isooctyl acrylate and methyl methacrylate in a mass ratio of (3-5):1.

[0025] Another object of the present invention is to provide a method for preparing the anti-warping adhesive, comprising the following steps: mixing the components uniformly by weight, vacuuming and degassing for 1-2 hours, and finally standing and degassing before storing to obtain the anti-warping adhesive.

[0026] Due to the application of the above technical solution, the present invention has the following beneficial effects: (1) The preparation method of the anti-warping adhesive disclosed in the present invention is simple and easy to operate, easy to control, mild in conditions, can be widely used, is suitable for large-scale industrial production, and has very good practical value.

[0027] (2) The anti-warping adhesive disclosed in the present invention comprises the following components by weight: 50-70 parts of base resin, 10-20 parts of modifier, 8-12 parts of filler, 5-8 parts of curing agent, 1.5-4 parts of auxiliary agent, 4-6 parts of other monomers, and 45-55 parts of diluent; the base resin is a mixture of hyperbranched rosin alcohol polyurethane acrylate resin and Atlac 430 epoxy bisphenol A vinyl resin in a mass ratio of (3-5):1; the modifier is a terminal amino hyperbranched polysiloxane HPSi-NH2 modified nano-montmorillonite / nano-silica composite. Through the mutual cooperation between the components, the anti-warping adhesive has sufficient bonding performance, good high temperature and high humidity resistance, excellent anti-warping performance, and long service life. The matrix resin is a mixture of hyperbranched rosin alcohol polyurethane acrylate resin and Atlac 430 epoxy bisphenol A vinyl resin in a mass ratio of (3-5):1. It is combined with a curing agent and other monomers to introduce multiple groups into the film molecular structure. These groups can reduce the volume shrinkage during the curing process and the risk of warping due to uneven shrinkage under the multiple effects of electronic effect, steric effect and conjugation effect. It can also improve the bonding performance. In terms of proportion, the content of the matrix resin is precisely adjusted to achieve the best synergistic effect with other components on the basis of ensuring the bonding strength, thereby enhancing the resistance to warping stress. (3) The anti-warping adhesive disclosed in the present invention, the modifier is a terminal amino hyperbranched polysiloxane HPSi-NH2 modified nano-montmorillonite / nano-silica composite; the nano-montmorillonite improves the interface toughness through the intercalation effect, and can produce a synergistic anti-warping effect after compounding with nano-silica; after the surface terminal amino hyperbranched polysiloxane HPSi-NH2 is modified, its compatibility with the adhesive system is further improved, and it is more evenly dispersed in the adhesive to form a more stable physical cross-linking network, effectively enhancing the internal structural stability of the adhesive and resisting warping deformation. The filler is a mixture of mica powder, nano-boron fiber, and attapulgite in a mass ratio of (1-3):0.3:(0.3-0.5); it can play a role similar to a "skeleton" in the adhesive, preventing the material from deforming due to stress, and further improving the anti-warping performance.

[0028] (4) The anti-warping adhesive disclosed in the present invention introduces hyperbranched structures into both the base resin and the modifier, which improves flexibility without significantly reducing the strength of the adhesive, and can absorb energy through its own elastic deformation when resisting warping stress, thereby reducing the occurrence of warping. By reasonably selecting the amount of these hyperbranched structures introduced, the adhesive can be given good flexibility to relieve the warping stress without excessively affecting the rigidity of the adhesive, ensuring that the adhesive can maintain good anti-warping performance under various working conditions.

[0029] (5) The anti-warping adhesive disclosed in the present invention has components containing unsaturated olefinic bonds that can undergo photocuring reactions, and components containing epoxy groups that can undergo curing reactions with other curing agent components other than photoinitiators; by introducing two cross-linkable polymer networks into the adhesive system, they penetrate and entangle each other during the curing process to form an interpenetrating network structure (IPN). This interpenetrating network structure can combine the performance advantages of multiple polymers, enhance the overall mechanical properties of the adhesive, and improve its ability to resist warping stress. This is because the interaction between different networks can disperse stress and avoid the warping phenomenon caused by stress concentration. DETAILED DESCRIPTION

[0030] 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

[0031] An anti-warping adhesive comprises the following components by weight: 50 parts of a base resin, 10 parts of a modifier, 8 parts of a filler, 5 parts of a curing agent, 1.5 parts of an auxiliary agent, 4 parts of other monomers, and 45 parts of a diluent; the base resin is prepared by mixing a hyperbranched rosin alcohol polyurethane acrylate resin and an Atlac 430 epoxy bisphenol A vinyl resin in a mass ratio of 3:1; the modifier is an amino-terminated hyperbranched polysiloxane HPSi-NH2 modified nano-montmorillonite / nano-silicon dioxide composite; the hyperbranched rosin alcohol polyurethane acrylate resin is prepared by a method according to Example 1 of the Chinese invention patent application publication number CN110078893A.

[0032] The preparation method of the modifier comprises the following steps: mixing nano-montmorillonite and nano-silica, uniformly dispersing the mixture in an organic solvent, adding a silane coupling agent KH560, stirring and reacting the mixture at 60°C for 4 hours, then adding an amino-terminated hyperbranched polysiloxane HPSi-NH2, stirring and reacting the mixture at 75°C for 3 hours, and removing the solvent by rotary evaporation to obtain the modifier; the mass ratio of the nano-montmorillonite, nano-silica, organic solvent, silane coupling agent KH560, and amino-terminated hyperbranched polysiloxane HPSi-NH2 is 1:1:10:0.2:0.3; the particle size of the nano-montmorillonite is 10 nm; the particle size of the nano-silica is 20 nm; the organic solvent is N,N-dimethylformamide; and the amino-terminated hyperbranched polysiloxane HPSi-NH2 is prepared according to the method of Example 1 of the Chinese invention patent with the authorization announcement number CN110156948B.

[0033] The filler is a mixture of mica powder, nano-boron fiber and attapulgite in a mass ratio of 1:0.3:0.3; the mica powder has a diameter-to-thickness ratio of 80 and a grade of A-41S; the nano-boron fiber has an average diameter of 300 nm and an aspect ratio of 15:1; and the attapulgite has a particle size of 800 meshes.

[0034] The curing agent is a mixture of a photoinitiator, (3,6-diaminoacridine-9-yl)boric acid, 3,3'-diamino-4,4'-difluorodiphenyl sulfone and methyl hexahydrophthalic anhydride in a mass ratio of 1:0.8:1:0.8; the photoinitiator is benzoin ethyl ether; the auxiliary agent is a coupling agent and a defoaming agent in a mass ratio of 3:1; the coupling agent is a silane coupling agent KH550; the defoaming agent is tributyl phosphate; the other monomers are a mixture of 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione and 2,4,6-trivinyl cycloboroxine in a mass ratio of 3:1; the diluent is a mixture of isooctyl acrylate and methyl methacrylate in a mass ratio of 3:1.

[0035] A preparation method of the anti-warping adhesive comprises the following steps: mixing the components uniformly according to weight, vacuuming and degassing for 1 hour, and finally standing and degassing before storing to obtain the anti-warping adhesive. Example 2

[0036] An anti-warping adhesive comprises the following components by weight: 55 parts of a base resin, 13 parts of a modifier, 9 parts of a filler, 6 parts of a curing agent, 2 parts of an auxiliary agent, 4.5 parts of other monomers, and 48 parts of a diluent; the base resin is prepared by mixing a hyperbranched rosin alcohol polyurethane acrylate resin and an Atlac 430 epoxy bisphenol A vinyl resin in a mass ratio of 3.5:1; the modifier is an amino-terminated hyperbranched polysiloxane HPSi-NH2 modified nano-montmorillonite / nano-silicon dioxide composite; the hyperbranched rosin alcohol polyurethane acrylate resin is prepared by a method according to Example 1 of the Chinese invention patent with application publication number CN110078893A.

[0037] The preparation method of the modifier comprises the following steps: mixing nano-montmorillonite and nano-silica, uniformly dispersing the mixture in an organic solvent, adding a silane coupling agent KH560, stirring the mixture at 65°C for reaction for 4.5 hours, then adding an amino-terminated hyperbranched polysiloxane HPSi-NH2, stirring the mixture at 78°C for reaction for 4 hours, and removing the solvent by rotary evaporation to obtain the modifier; the mass ratio of the nano-montmorillonite, nano-silica, organic solvent, silane coupling agent KH560, and amino-terminated hyperbranched polysiloxane HPSi-NH2 is 1.5:1:13:0.25:0.35; the particle size of the nano-montmorillonite is 30 nm; the particle size of the nano-silica is 40 nm; the organic solvent is N,N-dimethylformamide; and the amino-terminated hyperbranched polysiloxane HPSi-NH2 is prepared according to the method of Example 1 of the Chinese invention patent with the authorization announcement number CN110156948B.

[0038] The filler is a mixture of mica powder, nano-boron fiber, and attapulgite in a mass ratio of 1.5:0.3:0.35; the mica powder has a diameter-to-thickness ratio of 90 and a brand name of SYA-21RS; the nano-boron fiber has an average diameter of 350nm and an aspect ratio of 18:1; the attapulgite has a particle size of 900 meshes; the curing agent is a mixture of a photoinitiator, (3,6-diaminoacridine-9-yl)boric acid, 3,3'-diamino-4,4'-difluorodiphenyl sulfone, and methylhexahydrophthalic anhydride in a mass ratio of 1:0.9:1.5:0.9; the photoinitiator The agent is benzoin ethyl ether; the auxiliary agent is a coupling agent and a defoaming agent mixed in a mass ratio of 3.5:1; the coupling agent is a silane coupling agent KH560; the defoaming agent is a defoaming agent Deqian 3100; the other monomers are 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione and 2,4,6-trivinyl cycloboroxine mixed in a mass ratio of 3.5:1; the diluent is a mixture of isooctyl acrylate and methyl methacrylate in a mass ratio of 3.5:1.

[0039] A preparation method of the anti-warping adhesive comprises the following steps: mixing the components uniformly according to weight, vacuuming and degassing for 1.2 hours, and finally standing and degassing before storing to obtain the anti-warping adhesive. Example 3

[0040] An anti-warping adhesive comprises the following components by weight: 60 parts of a base resin, 15 parts of a modifier, 10 parts of a filler, 6.5 parts of a curing agent, 3 parts of an auxiliary agent, 5 parts of other monomers, and 50 parts of a diluent; the base resin is prepared by mixing a hyperbranched rosin alcohol polyurethane acrylate resin and an Atlac 430 epoxy bisphenol A vinyl resin in a mass ratio of 4:1; the modifier is an amino-terminated hyperbranched polysiloxane HPSi-NH2 modified nano-montmorillonite / nano-silicon dioxide composite; the hyperbranched rosin alcohol polyurethane acrylate resin is prepared by a method according to Example 1 of the Chinese invention patent application publication number CN110078893A.

[0041] The preparation method of the modifier comprises the following steps: mixing nano-montmorillonite and nano-silica, uniformly dispersing the mixture in an organic solvent, adding a silane coupling agent KH560, stirring and reacting the mixture at 70°C for 5 hours, then adding an amino-terminated hyperbranched polysiloxane HPSi-NH2, stirring and reacting the mixture at 80°C for 4.5 hours, and removing the solvent by rotary evaporation to obtain the modifier; the mass ratio of the nano-montmorillonite, nano-silica, organic solvent, silane coupling agent KH560, and amino-terminated hyperbranched polysiloxane HPSi-NH2 is 2:1:15:0.3:0.4; the particle size of the nano-montmorillonite is 50 nm; the particle size of the nano-silica is 60 nm; the organic solvent is N,N-dimethylformamide; and the amino-terminated hyperbranched polysiloxane HPSi-NH2 is prepared according to the method of Example 1 of the Chinese invention patent with the authorization announcement number CN110156948B.

[0042] The filler is a mixture of mica powder, nano-boron fiber and attapulgite in a mass ratio of 2:0.3:0.4; the mica powder has a diameter-to-thickness ratio of 100 and a grade of B-82; the nano-boron fiber has an average diameter of 400 nm and an aspect ratio of 20:1; the attapulgite has a particle size of 1000 mesh; the curing agent is a mixture of a photoinitiator, (3,6-diaminoacridine-9-yl)boric acid, 3,3'-diamino-4,4'-difluorodiphenyl sulfone and methyl hexahydrophthalic anhydride in a mass ratio of 1:1:2:1; the photoinitiator is Benzoin ethyl ether; the auxiliary agent is a coupling agent and a defoaming agent mixed in a mass ratio of 4:1; the coupling agent is a silane coupling agent KH570; the defoaming agent is a defoaming agent BYK088; the other monomers are 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione and 2,4,6-trivinylcycloboroxine mixed in a mass ratio of 4:1; the diluent is a mixture of isooctyl acrylate and methyl methacrylate mixed in a mass ratio of 4:1.

[0043] A preparation method of the anti-warping adhesive comprises the following steps: mixing the components uniformly according to weight, vacuuming and degassing for 1.5 hours, and finally standing and degassing before storing to obtain the anti-warping adhesive. Example 4

[0044] An anti-warping adhesive comprises the following components by weight: 65 parts of a base resin, 18 parts of a modifier, 11 parts of a filler, 7.5 parts of a curing agent, 3.5 parts of an auxiliary agent, 5.5 parts of other monomers, and 53 parts of a diluent; the base resin is prepared by mixing a hyperbranched rosin alcohol polyurethane acrylate resin and an Atlac 430 epoxy bisphenol A vinyl resin in a mass ratio of 4.5:1; the modifier is an amino-terminated hyperbranched polysiloxane HPSi-NH2 modified nano-montmorillonite / nano-silicon dioxide composite; the hyperbranched rosin alcohol polyurethane acrylate resin is prepared by a method according to Example 1 of the Chinese invention patent application publication number CN110078893A.

[0045] The preparation method of the modifier comprises the following steps: mixing nano-montmorillonite and nano-silica, uniformly dispersing the mixture in an organic solvent, adding a silane coupling agent KH560, stirring the mixture at 75°C for reaction for 5.5 hours, then adding an amino-terminated hyperbranched polysiloxane HPSi-NH2, stirring the mixture at 83°C for reaction for 5.5 hours, and removing the solvent by rotary evaporation to obtain the modifier; the mass ratio of the nano-montmorillonite, nano-silica, organic solvent, silane coupling agent KH560, and amino-terminated hyperbranched polysiloxane HPSi-NH2 is 2.5:1:18:0.35:0.45; the particle size of the nano-montmorillonite is 70 nm; the particle size of the nano-silica is 80 nm; the organic solvent is N,N-dimethylformamide; and the amino-terminated hyperbranched polysiloxane HPSi-NH2 is prepared according to the method of Example 1 of the Chinese invention patent with the authorization announcement number CN110156948B.

[0046] The filler is a mixture of mica powder, nano-boron fiber and attapulgite in a mass ratio of 2.5:0.3:0.45; the mica powder has a diameter-to-thickness ratio of ≥70, and is a mixture of mica powders of grades A-41S, SYA-21RS, B-82 and A-21S in a mass ratio of 1:2:1:1; the average diameter of the nano-boron fiber is 450nm, and the aspect ratio is 23:1; the particle size of the attapulgite is 1100 mesh; the curing agent is a mixture of a photoinitiator, (3,6-diaminoacridine-9-yl)boric acid, 3,3'-diamino-4,4'-difluorodiphenyl sulfone and methyl hexahydrophthalic anhydride in a mass ratio of 1:1.1:2.5:1.1; the photoinitiator is benzoin ethyl ether; the auxiliary agent The coupling agent and the defoaming agent are mixed in a mass ratio of 4.5:1; the coupling agent is a mixture of silane coupling agent KH550, silane coupling agent KH560 and silane coupling agent KH570 in a mass ratio of 1:2:3; the defoaming agent is a mixture of tributyl phosphate, defoaming agent Deqian 3100 and defoaming agent BYK088 in a mass ratio of 1:3:5; the other monomers are a mixture of 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione and 2,4,6-trivinyl cycloboroxine in a mass ratio of 4.5:1; the diluent is a mixture of isooctyl acrylate and methyl methacrylate in a mass ratio of 4.5:1.

[0047] A preparation method of the anti-warping adhesive comprises the following steps: mixing the components uniformly according to weight, vacuuming and degassing for 1-2 hours, and finally standing and degassing before storing to obtain the anti-warping adhesive. Example 5

[0048] An anti-warping adhesive comprises the following components by weight: 70 parts of a base resin, 20 parts of a modifier, 12 parts of a filler, 8 parts of a curing agent, 4 parts of an auxiliary agent, 6 parts of other monomers, and 55 parts of a diluent; the base resin is prepared by mixing a hyperbranched rosin alcohol polyurethane acrylate resin and an Atlac 430 epoxy bisphenol A vinyl resin in a mass ratio of 5:1; the modifier is an amino-terminated hyperbranched polysiloxane HPSi-NH2 modified nano-montmorillonite / nano-silicon dioxide composite; the hyperbranched rosin alcohol polyurethane acrylate resin is prepared by a method according to Example 1 of the Chinese invention patent application publication number CN110078893A.

[0049] The preparation method of the modifier comprises the following steps: mixing nano-montmorillonite and nano-silicon dioxide, uniformly dispersing the mixture in an organic solvent, adding a silane coupling agent KH560, stirring the mixture for reaction at 80°C for 6 hours, then adding an amino-terminated hyperbranched polysiloxane HPSi-NH2, stirring the mixture for reaction at 85°C for 6 hours, and removing the solvent by rotary evaporation to obtain the modifier; the mass ratio of the nano-montmorillonite, nano-silicon dioxide, organic solvent, silane coupling agent KH560, and amino-terminated hyperbranched polysiloxane HPSi-NH2 is 3:1:20:0.4:0.5; the particle size of the nano-montmorillonite is 80 nm; the particle size of the nano-silicon dioxide is 90 nm; the organic solvent is N,N-dimethylformamide; and the amino-terminated hyperbranched polysiloxane HPSi-NH2 is prepared according to the method of Example 1 of the Chinese invention patent with the authorization announcement number CN110156948B.

[0050] The filler is a mixture of mica powder, nano-boron fiber and attapulgite in a mass ratio of 3:0.3:0.5; the mica powder has a diameter-to-thickness ratio of 100 and a brand of B-82; the nano-boron fiber has an average diameter of 500 nm and an aspect ratio of 25:1; the attapulgite has a particle size of 1200 meshes; the curing agent is a mixture of a photoinitiator, (3,6-diaminoacridine-9-yl)boric acid, 3,3'-diamino-4,4'-difluorodiphenyl sulfone and methyl hexahydrophthalic anhydride in a mass ratio of 1:1.2:3:1.2; the photoinitiator The agent is benzoin ethyl ether; the auxiliary agent is a coupling agent and a defoaming agent mixed in a mass ratio of 5:1; the coupling agent is a silane coupling agent KH550; the defoaming agent is a defoaming agent Deqian 3100; the other monomers are 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione and 2,4,6-trivinyl cycloboroxine mixed in a mass ratio of 5:1; the diluent is a mixture of isooctyl acrylate and methyl methacrylate in a mass ratio of 5:1.

[0051] A preparation method of the anti-warping adhesive comprises the following steps: mixing the components uniformly according to weight, vacuuming and degassing for 2 hours, and finally standing and degassing before storing to obtain the anti-warping adhesive.

[0052] Comparative Example 1 An anti-warping adhesive and a preparation method thereof are basically the same as those in Example 1, except that an equal amount of nano-silicon dioxide is used instead of nano-montmorillonite; and an equal amount of hyperbranched rosin alcohol polyurethane acrylate resin is used instead of Atlac 430 epoxy bisphenol A vinyl resin.

[0053] Comparative Example 2 An anti-warping adhesive and its preparation method are basically the same as those in Example 1, except that (3,6-diaminoacridin-9-yl)boronic acid and 2,4,6-trivinylcyclotriboroxane are not added.

[0054] To further illustrate the beneficial technical effects of the anti-warping adhesives involved in the embodiments of the present invention, relevant performance tests were carried out on the anti-warping adhesives involved in Examples 1-5 and Comparative Examples 1-2. The test results are shown in Table 1, and the test methods are as follows: 1. Warpage rate test: Aluminum alloy plates and plexiglass plates with dimensions of 100mm×50mm×2mm were selected and bonded with the adhesives of Examples 1-5 and Comparative Examples 1-2 respectively. A high-pressure mercury lamp with 110W / cm was used for irradiation at room temperature for 30 seconds, and then heat treatment was carried out at 85°C for 10 minutes, with the adhesive film thickness of 0.2mm. Then the bonded samples were placed in a temperature cycle test chamber. The test chamber cooled from room temperature (25°C) to -20°C at a rate of 2°C per minute. After reaching -20°C, the samples were kept at this temperature for 15 minutes. Then the test chamber heated from -20°C to 80°C at a rate of 2°C per minute. After heating to 80°C, the samples were kept at this temperature for 25 minutes. Subsequently, the test chamber cooled from 80°C to room temperature at a rate of 2°C per minute again. After cooling to room temperature, the samples were kept for 15 minutes again. The above process was one cycle. After 5 consecutive cycles, a laser displacement sensor was used to measure the warpage height of the samples, and the warpage rate was calculated. Warpage rate = (Warpage height ÷ Sample length) × 100%.

[0055] 2. Tensile shear strength: According to the standard of GB / T 7124-2008 "Determination of Tensile Shear Strength of Adhesives (Rigid Material to Rigid Material)", a universal material testing machine was used to test the bonding strength of the adhesives of Examples 1-5 and Comparative Examples 1-2. Curing conditions: A high-pressure mercury lamp with 110W / cm was used for irradiation at room temperature for 30 seconds, and then heat treatment was carried out at 85°C for 10 minutes; the adhesive film thickness was 0.2mm.

[0056] 3. High temperature and high humidity resistance performance: The cured adhesive samples of each example were placed in an environment of 85°C and 85% relative humidity for 1000 hours. Then, the tensile shear strength was detected again according to the method in 2, and the retention rate of the tensile shear strength was statistically calculated. The larger the value, the better the heat aging performance; Curing conditions: A high-pressure mercury lamp with 110W / cm was used for irradiation at room temperature for 30 seconds, and then heat treatment was carried out at 85°C for 10 minutes; the adhesive film thickness was 0.2mm; Bonding strength retention rate = (Bonding strength after treatment under high temperature and high humidity conditions ÷ Initial bonding strength) × 100%.

[0057] As can be seen from Table 1, the anti-warping adhesive disclosed in the embodiments of the present invention has higher tensile shear strength, better high temperature and high humidity resistance, and more excellent anti-warping performance than the products of the comparative examples; the combined use of nano-silica, nano-montmorillonite, hyperbranched rosin alcohol polyurethane acrylate resin, Atlac 430 epoxy bisphenol A vinyl resin, (3,6-diaminoacridin-9-yl)boric acid and 2,4,6-trivinylcyclotriboroxane is beneficial to improving the above-mentioned properties.

[0058] Table 1 Test results of the performance of the anti-warping adhesive Project Tensile shear strength High temperature and high humidity resistance Warpage rate Unit MPa % % Example 1 25.2 99.15 0.52 Example 2 25.7 99.33 0.45 Example 3 26.0 99.58 0.40 Example 4 26.6 99.73 0.30 Example 5 26.8 99.93 0.26 Comparative Example 1 23.6 96.87 2.63 Comparative Example 2 22.3 94.69 1.45 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. An anti-warping adhesive, characterized in that: The invention comprises the following components in parts by weight: 50-70 parts of base resin, 10-20 parts of modifier, 8-12 parts of filler, 5-8 parts of curing agent, 1.5-4 parts of auxiliary agent, 4-6 parts of other monomers and 45-55 parts of diluent; the base resin is prepared by mixing hyperbranched rosin alcohol polyurethane acrylate resin and Atlac 430 epoxy bisphenol A vinyl resin in a mass ratio of (3-5):1; the modifier is a terminal amino hyperbranched polysiloxane HPSi-NH2 modified nano-montmorillonite / nano-silica composite.

2. The anti-warping adhesive according to claim 1, characterized in that: The preparation method of the modifier comprises the following steps: mixing nano-montmorillonite and nano-silicon dioxide, uniformly dispersing the mixture in an organic solvent, adding a silane coupling agent KH560, stirring and reacting the mixture at 60-80°C for 4-6h, then adding amino-terminated hyperbranched polysiloxane HPSi-NH2, stirring and reacting the mixture at 75-85°C for 3-6h, and removing the solvent by rotary evaporation to obtain the modifier.

3. The anti-warping adhesive according to claim 2, characterized in that: The mass ratio of the nano-montmorillonite, nano-silica, organic solvent, silane coupling agent KH560, and amino-terminated hyperbranched polysiloxane HPSi-NH2 is (1-3):1:(10-20):(0.2-0.4):(0.3-0.5).

4. The anti-warping adhesive according to claim 2, characterized in that: The particle size of the nano-montmorillonite is 10-80nm; the particle size of the nano-silicon dioxide is 20-90nm; and the organic solvent is N,N-dimethylformamide.

5. The anti-warping adhesive according to claim 1, characterized in that: The filler is a mixture of mica powder, nano boron fiber and attapulgite in a mass ratio of (1-3):0.3:(0.3-0.5).

6. The anti-warping adhesive according to claim 5, characterized in that: The mica powder has a diameter-to-thickness ratio of ≥70 and is selected from at least one of mica powders with grades A-41S, SYA-21RS, B-82, and A-21S; the average diameter of the nano-boron fiber is 300-500nm, and the aspect ratio is (15-25):1; the particle size of the attapulgite is 800-1200 mesh.

7. The anti-warping adhesive according to claim 1, characterized in that: The curing agent is a mixture of a photoinitiator, (3,6-diaminoacridine-9-yl)boric acid, 3,3'-diamino-4,4'-difluorodiphenyl sulfone and methyl hexahydrophthalic anhydride in a mass ratio of 1:(0.8-1.2):(1-3):(0.8-1.2); the photoinitiator is benzoin ethyl ether.

8. The anti-warping adhesive according to claim 1, characterized in that: The auxiliary agent is a coupling agent and a defoaming agent mixed in a mass ratio of (3-5):1; the coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570; the defoaming agent is one or more of tributyl phosphate, defoaming agent Deqian 3100, and defoaming agent BYK088.

9. The anti-warping adhesive according to claim 1, characterized in that: The other monomers are 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione and 2,4,6-trivinyl cycloboroxine mixed in a mass ratio of (3-5):1; the diluent is isooctyl acrylate and methyl methacrylate mixed in a mass ratio of (3-5):

1.

10. A method for preparing the anti-warping adhesive according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: uniformly mixing the components according to weight, vacuuming and degassing for 1-2 hours, and finally standing and degassing before storing to obtain the anti-warping adhesive.