Adhesive for inhibiting metal paint from falling off as well as preparation method and construction method of adhesive

Abstract

The invention belongs to the technical field of adhesive materials, and particularly relates to an adhesive for inhibiting metal paint from falling off as well as a preparation method and a construction method thereof. Acrylic acid molecules are used as polymeric monomers, terpyridyl ruthenium chloride is used as a photocatalyst, 3-((2-(methacryloyloxy) ethyl) dimethyl ammonium) propane-1-sulfonate is used as a cross-linking agent, water-based inorganic nano hybrid particles are matched, preparation of the adhesive is completed under the illumination condition, and due to the enhancement effect of the water-based inorganic nano hybrid particles, the water-based inorganic nano hybrid particles can be used for preparing the adhesive. Strong cohesive force and interface adhesive force are formed in cooperation with hydrogen-bond interaction, physical winding effect, electrostatic interaction and the like among the components in the adhesive, so that the adhesive and a metal base material show super-strong adhesive performance; and meanwhile, the adhesive and a photocureable coating can be synchronously cured, so that good combination of the adhesive and a coating layer is realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of adhesive materials, and particularly relates to an adhesive for inhibiting metal coating from falling off and a preparation method and a construction method thereof. BACKGROUND

[0002] With the rapid development of science and technology, metal materials are used more and more widely. In different fields, the performance requirements for metals are also higher and higher; the microstructure, atoms and electrons of metals determine the use characteristics of the metals. In order to obtain metal materials with excellent performance, the metal needs to be surface treated to form a protective coating. With the continuous development of society and industry, more and more types of metal high-temperature-resistant coatings have been developed. The high-temperature-resistant coating is generally composed of resin, filler, additive and solvent. At present, the high-temperature-resistant coating is developed towards high performance and functionalization. By modifying the coating at the molecular level and introducing corresponding atoms or groups, the high-temperature-resistant coating can protect the internal combustible substrate when a fire occurs. The metal surface and the coating may fall off due to poor combination, which specifically includes the following reasons: (1) insufficient adhesion, the coating cannot form a firm chemical or mechanical combination with the metal surface; (2) oxidation and rusting of the metal substrate (especially steel), the rust layer can lift the coating, resulting in falling off; (3) osmotic pressure foaming, water vapor penetrates into the coating and metal interface, and gathers to form bubbles at defects, thereby destroying the adhesion; (4) the stress generated by volume shrinkage or thermal expansion and contraction during coating curing is greater than the adhesion; (5) metal surface pollution, oil stains, dust, moisture and other pollutants hinder the direct contact of the coating.

[0003] An adhesive is a material that can form a chemical bond or physical action between the same or two or more materials to connect the adjacent surfaces together, and has a certain strength after curing. The adhesive can be an organic material or an inorganic material, and the adhesive can also be called a bonding agent or an adhesive. The wide application range and important position of the adhesive in production make its development more and more rapid, and the exploration and research of the bonding technology are also deepened. In the early stage, people usually use some inorganic materials to complete some basic bonding. With the advent of phenolic resin adhesive, people realize the great significance of polymers to bonding.

[0004] In the extreme high-temperature, high-impact and strong corrosion environment of a space launch site, the surface of a flow guide, a flow guide groove and a steel structure often needs to be coated with a metal or ceramic-based protective coating that is resistant to high temperature and ablation. However, these coatings are prone to falling off under complex working conditions such as thermal shock, high-speed gas scouring and mechanical vibration, which seriously affects the structural safety and service life. The introduction of an adhesive between the metal substrate and the protective coating layer can significantly improve the bonding strength between the two, effectively inhibit the coating from falling off, and thus ensure that key facilities such as the flow guide, the flow guide groove and the steel structure of the launch site can be long-lasting and resistant to extreme environmental corrosion.

[0005] In the prior art, the surface of a metal material is first pretreated by rust removal and polishing, and then paint is directly coated on the surface of the metal substrate, but the combination between the paint and the metal substrate is poor, so that the paint layer is prone to large-area falling during use, which seriously affects the actual application.

[0006] Therefore, there is an urgent need for an adhesive with good thermal stability and mechanical properties, which realizes good combination between the metal substrate and the paint layer by component design and introduction of functional particles, effectively improves the peeling strength with the metal substrate, and obtains the effect of inhibiting the falling of metal paint. SUMMARY

[0007] The purpose of the present application is to provide an adhesive for inhibiting the falling of metal paint and a preparation method and construction method thereof. The present application first uses silane coupling agent KH-570 as an inorganic-organic bridge, zirconium alkoxide as a zirconium source, and tetraethyl silicate as a silicon source to prepare water-based inorganic nano hybrid particles through hydrolysis-condensation reaction, then uses 2-chloroquinoline and benzyl alcohol as raw materials to obtain a polymerization initiator through temperature rising reaction, and combines with acrylic acid, a complex acidic monomer, a crosslinking agent, a photocatalyst, etc. to obtain the adhesive. The adhesive not only has excellent thermal stability and tensile strength, but also has good combination with the metal substrate and photocurable paint, and can effectively inhibit the falling of metal paint.

[0008] In order to achieve the above purpose, the present application provides the following technical solutions: The present application provides an adhesive for inhibiting the falling of metal paint, The adhesive comprises the following components in parts by weight: 30-34 parts of acrylic acid, 0.8-1.2 parts of a polymerization initiator, 3.2-3.6 parts of an acidic monomer, 6-10 parts of water-based inorganic nano hybrid particles, 1.4-1.8 parts of a crosslinking agent, 0.02-0.04 parts of a photocatalyst, and 60-64 parts of deionized water.

[0009] As a preferred scheme, the weight fraction of the acrylic acid in the present application can be 30 parts, 31 parts, 32 parts, 33 parts, or 34 parts, etc.

[0010] As a preferred scheme, the weight fraction of the polymerization initiator in the present application can be 0.8 parts, 0.9 parts, 1.0 parts, 1.1 parts, or 1.2 parts, etc.

[0011] As a preferred scheme, the weight fraction of the acidic monomer in the present application can be 3.2 parts, 3.3 parts, 3.4 parts, 3.5 parts, or 3.6 parts, etc.

[0012] As a preferred scheme, the weight fraction of the water-based inorganic nano hybrid particles in the present application can be 6 parts, 7 parts, 8 parts, 9 parts, or 10 parts, etc.

[0013] As a preferred scheme, the weight fraction of the crosslinking agent in the application can be 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts or 1.8 parts, etc.

[0014] As a preferred scheme, the weight fraction of the photocatalyst in the application can be 0.02 parts, 0.03 parts or 0.04 parts, etc.

[0015] As a preferred scheme, the preparation method of the aqueous inorganic nano hybrid particles comprises: stirring and reacting silane coupling agent, alkoxyl zirconate and tetraethyl silicate as raw materials to obtain aqueous inorganic nano hybrid particles.

[0016] The application uses silane coupling agent KH-570 as an inorganic-organic bridge, alkoxyl zirconate as a zirconium source, and tetraethyl silicate as a silicon source, and through acetic acid to control the pH catalytic hydrolysis-condensation reaction, to promote the covalent connection of the silane coupling agent after hydrolysis and the inorganic phase through the silicon-oxygen bond, thereby obtaining aqueous inorganic nano hybrid particles.

[0017] As a preferred scheme, the step of stirring and reacting is: mixing 80-85 parts of anhydrous ethanol and 15-20 parts of deionized water uniformly, then adding 4-6 parts of silane coupling agent, 10-14 parts of alkoxyl zirconate and 2-4 parts of tetraethyl silicate and stirring for 30-40 min, using acetic acid to adjust the pH to 5.2-5.6, and stirring and reacting at 40-50℃ for 100-140 min to obtain aqueous inorganic nano hybrid particles.

[0018] As a preferred scheme, the silane coupling agent is silane coupling agent KH-570.

[0019] The application selects KH-570 as a silane coupling agent, and the chemical name of KH-570 is gamma-methacryloxypropyl trimethoxysilane. Its inorganic reaction end contains three methoxyl groups which can be hydrolyzed into silicon hydroxyl groups and firmly anchored on the skeleton of inorganic nanoparticles through reaction; and the organic functional end contains a carbon-carbon double bond with high reactivity, which can occur free radical copolymerization reaction with acrylic monomers.

[0020] As a preferred scheme, the alkoxyl zirconate is ZCA-N38 of Nanjing Nengde New Material, with a density of 1.13g / cm 3 , and a viscosity of 300cps at 25℃.

[0021] The alkoxyl zirconate of the present application selects ZCA-N38 of Nanjing Nengde New Material, the inorganic end of which can be hydrolyzed to generate zirconium hydroxyl in the aqueous system, cooperate with the hydrolysis product of tetraethyl silicate, and condense with the silane coupling agent to build a high-density inorganic network; the organic end provides an allyl double bond, which can occur free radical copolymerization with the double bond of the subsequent organic matrix to form a strong chemical bond connection of inorganic particles-organic matrix.

[0022] As a preferred scheme, the preparation method of the polymerization initiator comprises: preparing the polymerization initiator by temperature reaction with 2-chloroquinoline and benzyl alcohol as raw materials.

[0023] As a preferred scheme, the step of the temperature reaction is: adding 3.2-3.6 parts of sodium hydride into 540-560 parts of N,N-dimethylformamide, uniformly mixing, then adding 10-12 parts of benzyl alcohol dropwise, stirring for 20-40 min, then adding 10-12 parts of 2-chloroquinoline, heating to 80-90 DEG C for 20-22 h, after the reaction is completed, extracting and collecting the organic phase, removing the solvent by reduced pressure distillation, purifying to obtain the polymerization initiator.

[0024] In the present application, benzyl alcohol is first added to sodium hydride, the hydrogen anion of sodium hydride as a strong base will take the active hydrogen on the hydroxyl group of benzyl alcohol to generate sodium benzyl alcohol; then 2-chloroquinoline (an electron-deficient aromatic heterocycle) is added, the chlorine atoms at positions 2 and 4 of 2-chloroquinoline are very active due to the electron-withdrawing effect of the nitrogen atom on the ring, and are prone to nucleophilic aromatic substitution reaction; the alkoxide anion in sodium benzyl alcohol acts as a nucleophile to attack the carbon atom at position 2 in 2-chloroquinoline connected to the chlorine atom to occur aromatic nucleophilic substitution, replace the chlorine atom and generate the polymerization initiator.

[0025] As a preferred scheme, the acidic monomer is ascorbic acid and gallic acid.

[0026] As a preferred scheme, the mass ratio of ascorbic acid and gallic acid in the acidic monomer is (1-2):1.

[0027] The acidic monomer of the present application is compounded by ascorbic acid and gallic acid, ascorbic acid as a reducing agent in the photocatalytic cycle can reduce the excited state of the photoinitiator, help the photocatalyst enter the next cycle; gallic acid can inhibit oxygen inhibition and free radical side reaction, by reacting with peroxide radicals, thereby reducing the influence on the polymerization of acrylic acid; ascorbic acid and gallic acid are compounded in the system to form a synergistic effect of promoting initiation-preventing inhibition, which can not only enhance the photoinitiation efficiency, but also avoid oxygen inhibition and side reactions, ensuring the smooth preparation of the adhesive.

[0028] As a preferred scheme, the crosslinking agent is 3-((2-(methacryloyloxy)ethyl)dimethylammonio)propane-1-sulfonate.

[0029] As a preferred scheme, the photocatalyst is trispyridine ruthenium chloride.

[0030] The second aspect of the present application provides a preparation method of the adhesion agent for inhibiting metal coating from falling off according to the first aspect, comprising the following steps: In parts by weight, 30-34 parts of acrylic acid, 0.8-1.2 parts of a polymerization initiator, 3.2-3.6 parts of an acidic monomer, 1.4-1.8 parts of a crosslinking agent and 0.02-0.04 parts of a photocatalyst are added into 60-64 parts of deionized water and uniformly mixed, then 6-10 parts of water-based inorganic nano hybrid particles are added and stirred for 10-20 min, and pre-polymerization is performed under light for 2-4 min, to obtain the adhesion agent for inhibiting metal coating from falling off.

[0031] The third aspect of the present application provides a construction method of the adhesion agent according to the first aspect, comprising the following steps: The surface of the metal substrate is rusted and polished, the adhesion agent according to the first aspect is brushed, and then the adhesion agent is compounded with the coating and solidified under light to firmly combine the metal substrate with the coating.

[0032] As a preferred scheme, the coating is a light-cured coating.

[0033] The fourth aspect of the present application provides an application of the adhesion agent according to the first aspect in launch site fairing, fairing groove and steel structure.

[0034] Compared with the prior art, the present application has the following advantages and beneficial effects: 1、The present application uses acrylic acid molecules as polymer monomers, trispyridine ruthenium chloride as a photocatalyst, 3-((2-(methacryloyloxy)ethyl)dimethylammonio)propane-1-sulfonate as a crosslinking agent, and water-based inorganic nano hybrid particles, to complete the preparation of the adhesion agent under light conditions. Due to the enhancement of the water-based inorganic nano hybrid particles, the hydrogen bond interaction, physical entanglement and electrostatic interaction between the components in the adhesion agent, a strong cohesive force and interfacial adhesion force are formed, so that the adhesion agent exhibits super strong adhesion performance with the metal substrate; at the same time, the adhesion agent can be simultaneously solidified with the light-cured coating, to realize good combination of the adhesion agent and the coating layer. The present application introduces the adhesion agent between the metal substrate and the protective coating layer, which can significantly improve the bonding strength between the two, effectively inhibit the coating from falling off, and can be applied in related fields such as launch site fairing, fairing groove and steel structure.

[0035] 2、The polymerization initiator of the present application is an important component of the adhesive photoinitiating system. The protonated polymerization initiator is reduced by trispyridyl ruthenium chloride, which leads to the cleavage of the C-O bond connecting the benzyl and quinolinyl oxygen groups in the molecule, releasing a benzyl radical and a quinolinyl oxygen radical. Both of these highly active radicals can attack the carbon-carbon double bond of the acrylic monomer, thereby initiating the free radical polymerization chain reaction, thus achieving the preparation of the adhesive.

[0036] 3、The water-based inorganic nano-hybrid particles of the present application use KH-570 as a silane coupling agent. One end of the molecule is a hydrolysable trimethoxysilyl group, which can covalently connect with the inorganic phase. The other end contains a carbon-carbon double bond, which, together with the double bond introduced by the alkoxy zirconate ZCA-N38, participates in the free radical polymerization of acrylic acid, thereby grafting the water-based inorganic nano-hybrid particles to the molecular chain of the adhesive during polymerization. The silicon-zirconium inorganic framework in the water-based inorganic nano-hybrid particles can effectively block the transfer of heat and the diffusion of small molecule gases produced by the thermal decomposition of the polymer, thereby delaying the thermal degradation process of the adhesive and improving the thermal stability of the material. At the same time, the uniformly dispersed rigid nanoparticles are embedded in the soft polymer chains. When the material is subjected to tensile stress, the rigid particles can effectively share and transfer the load, thereby improving the tensile strength. In addition, the silicon-zirconium inorganic phase in the hybrid particles can act as an anchor point, penetrating deeply into the micropores of the metal substrate and tightly bonding with the substrate through its inorganic part, thereby improving the peel strength between the adhesive and the metal. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 Schematic diagram for the preparation of the polymerization initiator in Example 1. DETAILED DESCRIPTION

[0038] The technical solutions in the examples of the present application will be described below in a clear and complete manner. Obviously, the described examples are only a part of the examples of the present application, not all examples. Based on the examples in the present application, all other examples obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0039] Some components in the examples and comparative examples are as follows: Alkoxy zirconate, item number ZCA-N38, density 1.13 g / cm 3 , viscosity 300 cps at 25°C, purchased from Nanjing Nengde New Material Co., Ltd.; 3-((2-(methacryloyloxy)ethyl)dimethylammonio)propane-1-sulfonate, CAS number 3637-26-1, purchased from Shanghai Lingfu Pharmaceutical Research Co., Ltd.; Trispyridyl ruthenium chloride, item number T113540, purchased from Shanghai Aldrin Biochemical Technology Co., Ltd.; Photocuring coating, product number 5640, available from Nanxiong Ketian Chemical Co., Ltd.

[0040] Example 1 The adhesive for inhibiting metal coating from falling off comprises the following components by weight: 34 parts of acrylic acid, 1.2 parts of polymerization initiator, 3.6 parts of acidic monomer (2.4 parts of ascorbic acid and 1.2 parts of gallic acid), 10 parts of aqueous inorganic nano hybrid particles, 1.8 parts of crosslinking agent 3-((2-(methacryloyloxy)ethyl)dimethylammonio)propane-1-sulfonate, 0.04 parts of photocatalyst trispyridine ruthenium chloride and 64 parts of deionized water.

[0041] Preparation of the aqueous inorganic nano hybrid particles: 85 parts of anhydrous ethanol and 15 parts of deionized water are uniformly mixed, then 6 parts of silane coupling agent KH-570, 14 parts of alkoxy zirconate (ZCA-N38 of Nanjing Nengde New Material) and 4 parts of tetraethyl silicate are stirred for 40 min, the pH is adjusted to 5.6 using acetic acid, and the reaction is stirred at 50°C for 100 min to obtain the aqueous inorganic nano hybrid particles.

[0042] Preparation of the polymerization initiator: 3.6 parts of sodium hydride is added to 560 parts of N,N-dimethylformamide and uniformly mixed, then 12 parts of benzyl alcohol is added dropwise and stirred for 40 min, 12 parts of 2-chloroquinoline is added, the temperature is raised to 90°C, and the reaction is carried out for 20 h. After the reaction is completed, the organic phase is collected by extraction, the solvent is removed by reduced pressure distillation, and the product is purified to obtain the polymerization initiator.

[0043] Example 2 The adhesive for inhibiting metal coating from falling off comprises the following components by weight: 30 parts of acrylic acid, 0.8 parts of polymerization initiator, 3.2 parts of acidic monomer (1.6 parts of ascorbic acid and 1.6 parts of gallic acid), 6 parts of aqueous inorganic nano hybrid particles, 1.4 parts of crosslinking agent 3-((2-(methacryloyloxy)ethyl)dimethylammonio)propane-1-sulfonate, 0.02 parts of photocatalyst trispyridine ruthenium chloride and 60 parts of deionized water.

[0044] Preparation of the aqueous inorganic nano hybrid particles: 80 parts of anhydrous ethanol and 20 parts of deionized water are uniformly mixed, then 4 parts of silane coupling agent KH-570, 10 parts of alkoxy zirconate (ZCA-N38 of Nanjing Nengde New Material) and 2 parts of tetraethyl silicate are stirred for 30 min, the pH is adjusted to 5.2 using acetic acid, and the reaction is stirred at 40°C for 140 min to obtain the aqueous inorganic nano hybrid particles.

[0045] Preparation of polymerization initiator: 3.2 parts of sodium hydride was added into 540 parts of N,N-dimethylformamide, mixed uniformly, then 10 parts of benzyl alcohol was added dropwise, stirred for 20 min, then 10 parts of 2-chloroquinoline was added, the temperature was raised to 80℃ and reacted for 22 h. After the reaction was completed, the organic phase was collected by extraction, the solvent was removed by reduced pressure distillation, and the product was purified to obtain the polymerization initiator.

[0046] Example 3 This example provides an adhesive for inhibiting the peeling of metal paint, which comprises the following components by weight: 32 parts of acrylic acid, 0.9 parts of polymerization initiator, 3.4 parts of acidic monomer (2.2 parts of ascorbic acid and 1.2 parts of gallic acid), 8 parts of aqueous inorganic nano-hybrid particles, 1.6 parts of crosslinking agent 3-((2-(methacryloyloxy)ethyl)dimethylammonio)propane-1-sulfonate, 0.03 parts of photocatalyst trispyridine ruthenium chloride, and 62 parts of deionized water.

[0047] Preparation of the aqueous inorganic nano-hybrid particles: 82 parts of anhydrous ethanol and 18 parts of deionized water were mixed uniformly, then 5 parts of silane coupling agent KH-570, 12 parts of alkoxy zirconate (ZCA-N38 from Nanjing Nengden New Material) and 3 parts of tetraethyl silicate were added and stirred for 35 min, the pH was adjusted to 5.4 using acetic acid, and the reaction was stirred at 45℃ for 120 min to obtain the aqueous inorganic nano-hybrid particles.

[0048] Preparation of polymerization initiator: 3.4 parts of sodium hydride was added into 550 parts of N,N-dimethylformamide, mixed uniformly, then 11 parts of benzyl alcohol was added dropwise, stirred for 30 min, then 11 parts of 2-chloroquinoline was added, the temperature was raised to 85℃ and reacted for 21 h. After the reaction was completed, the organic phase was collected by extraction, the solvent was removed by reduced pressure distillation, and the product was purified to obtain the polymerization initiator.

[0049] Comparative Example 1 The difference between this comparative example and Example 1 is that 1.2 parts of polymerization initiator is not added in the adhesive.

[0050] Comparative Example 2 The difference between this comparative example and Example 1 is that 10 parts of aqueous inorganic nano-hybrid particles is not added in the adhesive.

[0051] Comparative Example 3 The difference between this comparative example and Example 1 is that 3.6 parts of acidic monomer is replaced by 3.2 parts of ascorbic acid and 0.4 parts of gallic acid in the adhesive.

[0052] Comparative Example 4 The difference between this comparative example and Example 1 is that 3.6 parts of acidic monomer is replaced by 0.4 parts of ascorbic acid and 3.2 parts of gallic acid in the adhesive.

[0053] Comparative Example 5 The difference between this comparative example and Example 1 is that the amount of silane coupling agent KH-570 used in the preparation of the aqueous inorganic nano-hybrid particles is changed to 16 parts.

[0054] Comparative Example 6 The difference between this comparative example and Example 1 is that the amount of alkoxy zirconate used in the preparation of the aqueous inorganic nano-hybrid particles is changed to 4 parts.

[0055] Comparative Example 7 The difference between this comparative example and Example 1 is that the amount of tetraethyl silicate used in the preparation of the aqueous inorganic nano-hybrid particles is changed to 14 parts.

[0056] Comparative Example 8 The difference between this comparative example and Example 1 is that the ammonium persulfate initiator is used instead of the polymerization initiator.

[0057] Performance Test Thermogravimetric analysis test: the adhesives of the examples and comparative examples were tested using a thermogravimetric analyzer (STA 449 F5, Netzsch, Germany), with a temperature range of 30-600°C, a heating rate of 20°C / min, and nitrogen as the protective gas, to obtain the temperature Td corresponding to a 5% mass loss. Tensile strength test: the tensile strength of the adhesives of the examples and comparative examples was tested using an electronic universal testing machine, with the test sample cut into dumbbell shape, a gauge length of 50 mm, and a tensile speed of 20 mm / min.

[0058] Peeling strength test: the surface of the metal substrate was first cleaned, then the adhesives of the examples and comparative examples were applied to the cleaned surface of the metal substrate, cured, and then subjected to a peeling test (T-peel) at a speed of 100 mm / min at room temperature, and the adhesion of the adhesive to the metal substrate was evaluated by the peeling strength.

[0059] Table 1 Performance Test Results

[0060] From the above performance test results, it can be seen that the comprehensive performance of Examples 1-3 is the best, which is mainly because the silane coupling agent KH-570 is used as the inorganic-organic bridge, the alkoxy zirconate is used as the zirconium source, and the tetraethyl silicate is used as the silicon source, and the aqueous inorganic nano-hybrid particles are prepared by hydrolysis-condensation reaction, then the 2-chloroquinoline and benzyl alcohol are used as raw materials for temperature rising reaction to obtain the polymerization initiator, and the adhesive is obtained by combining acrylic acid, complex acidic monomer, crosslinking agent, and photocatalyst, which not only has excellent thermal stability and tensile strength, but also combines well with the metal substrate and photocurable coating.

[0061] Compared with Example 1, no 1.2 parts of polymerization initiator was added in the adhesive of Comparative Example 1, and the adhesive could not be effectively shaped; compared with Example 1, no 10 parts of water-based inorganic nano hybrid particles was added in the adhesive of Comparative Example 2, and the effect of the inorganic skeleton was lacking, so that the thermal stability of the adhesive was poor, the tensile strength was reduced, and the peel strength was small; compared with Example 1, 3.6 parts of acid monomer was replaced by 3.2 parts of ascorbic acid and 0.4 parts of gallic acid in the adhesive of Comparative Example 3, and too much ascorbic acid led to poor compounding effect, so that the thermal stability of the adhesive was poor, the tensile strength was reduced, and the peel strength was small; compared with Example 1, 3.6 parts of acid monomer was replaced by 0.4 parts of ascorbic acid and 3.2 parts of gallic acid in the adhesive of Comparative Example 4, and too much gallic acid led to poor compounding effect, so that the thermal stability of the adhesive was poor, the tensile strength was reduced, and the peel strength was small; compared with Example 1, the amount of silane coupling agent KH-570 was changed to 16 parts in the preparation process of the water-based inorganic nano hybrid particles of Comparative Example 5, and the preparation effect of the hybrid particles was poor, so that the thermal stability of the adhesive was poor, the tensile strength was reduced, and the peel strength was small; compared with Example 1, the amount of alkoxyl zirconate was changed to 4 parts in the preparation process of the water-based inorganic nano hybrid particles of Comparative Example 6, and the preparation effect of the hybrid particles was poor, so that the thermal stability of the adhesive was poor, the tensile strength was reduced, and the peel strength was small; compared with Example 1, the amount of tetraethyl silicate was changed to 14 parts in the preparation process of the water-based inorganic nano hybrid particles of Comparative Example 7, and the preparation effect of the hybrid particles was poor, so that the thermal stability of the adhesive was poor, the tensile strength was reduced, and the peel strength was small; compared with Example 1, ammonium persulfate initiator was used instead of polymerization initiator in the adhesive of Comparative Example 8, and the effect was poor due to no temperature initiation, so that the thermal stability of the adhesive was poor, the tensile strength was reduced, and the peel strength was small.

Claims

1. A kind of adhesive for inhibiting metal paint to fall off, characterized by, It includes the following components by weight: 30~34 parts of acrylic acid, 0.8~1.2 parts of polymerization initiator, 3.2~3.6 parts of acidic monomer, 6~10 parts of aqueous inorganic nano hybrid particles, 1.4~1.8 parts of crosslinking agent, 0.02~0.04 parts of photocatalyst and 60~64 parts of deionized water; The preparation method of the aqueous inorganic nano hybrid particles comprises: stirring reaction with silane coupling agent, alkoxyl zirconate and tetraethyl silicate as raw materials to obtain aqueous inorganic nano hybrid particles. 2.The adhesive for inhibiting metal paint to fall off according to claim 1, characterized by, The preparation method of the polymerization initiator comprises: temperature rising reaction with 2-chloroquinoline and benzyl alcohol as raw materials to obtain polymerization initiator. 3.The adhesive for inhibiting metal paint to fall off according to claim 2, characterized by, The temperature rising reaction comprises the following steps: by weight, 3.2~3.6 parts of sodium hydride is added into 540~560 parts of N,N-dimethylformamide and mixed uniformly, then 10~12 parts of benzyl alcohol is added dropwise and stirred for 20~40 min, 10~12 parts of 2-chloroquinoline is added, the temperature is raised to 80~90 ℃ and reacted for 20~22 h, after the reaction is completed, the organic phase is collected by extraction, the solvent is removed by reduced pressure distillation, and the polymerization initiator is obtained by purification. 4.The adhesive for inhibiting metal paint to fall off according to claim 1, characterized by, The acidic monomer is ascorbic acid and gallic acid; The mass ratio of ascorbic acid to gallic acid in the acidic monomer is (1~2) :

1. 5.The adhesive for inhibiting metal paint to fall off according to claim 1, characterized by, The stirring reaction comprises the following steps: by weight, 80~85 parts of anhydrous ethanol and 15~20 parts of deionized water are mixed uniformly, then 4~6 parts of silane coupling agent, 10~14 parts of alkoxyl zirconate and 2~4 parts of tetraethyl silicate are added and stirred for 30~40 min, the pH is adjusted to 5.2~5.6 using acetic acid, and the aqueous inorganic nano hybrid particles are obtained by stirring reaction at 40~50 ℃ for 100~140 min. 6.The adhesive for inhibiting metal paint to fall off according to claim 5, characterized by, The silane coupling agent is silane coupling agent KH-570. 7.The adhesive for inhibiting metal paint to fall off according to claim 5, characterized by, The alkoxyl zirconate is ZCA-N38 from Nanjing Nengxin Material, with a density of 1.13 g / cm 3 and a viscosity of 300 cps at 25°C. 8.The adhesive for inhibiting metal paint to fall off according to claim 1, characterized by, The crosslinking agent is 3-((2-(methacryloyloxy)ethyl)dimethylammonio)propane-1-sulfonate, and the photocatalyst is trispyridyl ruthenium chloride. 9.A preparation method of an adhesive for inhibiting metal paint to fall off, characterized by, It comprises the following steps: By weight parts, 30~34 parts of acrylic acid, 0.8~1.2 parts of polymerization initiator, 3.2~3.6 parts of acid monomer, 1.4~1.8 parts of crosslinking agent and 0.02~0.04 parts of photocatalyst are added into 60~64 parts of deionized water to mix uniformly, then 6~10 parts of water-based inorganic nano hybrid particles are stirred for 10~20 min, and pre-polymerization is performed under light for 2~4 min to obtain an adhesive for inhibiting metal paint from falling off.

10. A construction method of an adhesive for inhibiting metal paint from falling off, characterized in that, comprising the following steps: The surface of the metal substrate is rusted and polished, the adhesive of any one of claims 1~8 is brushed, and then the paint is compounded and cured under light to firmly combine the metal substrate with the paint.

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