Silicon-containing monomer and photocurable adhesive

Abstract

The application discloses a kind of silicon-containing monomer and photocuring adhesive, belong to functional material technical field.The silicon-containing monomer provided in the application has the structural formula as shown in the following formula (I): In the silicon-containing monomer of the application, siloxane bond can give system good flexibility, adhesion, water resistance, transparency and other properties, and in humid environment, siloxane bond can hydrolysis crosslinking with water, improve crosslinking density while also can strengthen adhesion;Urea bond and carbamate bond can improve the hydrogen bond concentration of system, thereby improving adhesion;Acrylate double bond is conducive to the rapid curing of monomer, improve preparation efficiency.Using the silicon-containing monomer of the application, few bubble, strong adhesion, high transparency, good durability photocuring adhesive can be prepared, realize the firm bonding between various materials.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of functional materials, and particularly relates to a silicon-containing monomer and a photocuring adhesive. BACKGROUND

[0002] The photocuring adhesive is a kind of material capable of being rapidly cured under the irradiation of ultraviolet light (UV) or visible light, and has the advantages of fast curing speed, low energy consumption, environmental friendliness, and low energy consumption. The principle thereof mainly utilizes the irradiation of ultraviolet light or visible light. The photoinitiator therein absorbs light of a specific wavelength and decomposes to generate active free radicals or cations. These active substances then initiate the polymerization reaction of monomers and prepolymers, form a crosslinked network structure, and thus rapidly cure the liquid.

[0003] The traditional photocuring adhesive on the market is usually composed of various modified acrylate resins, and different additives are added according to different requirements to meet the bonding requirements of different materials. Although the progress and development of the photocuring adhesive greatly improve the efficiency of bonding and sealing in chemical production and daily life, there are still some technical challenges. For example, it is difficult to avoid the generation of bubbles in the production process, and an additional defoaming agent needs to be added, which affects the performance of the adhesive. For another example, the permeability of the adhesive is poor, which reduces the effect of the adhesive due to insufficient internal resin crosslinking degree. SUMMARY

[0004] In order to overcome at least one problem existing in the prior art, one of the purposes of the present application is to provide a silicon-containing monomer which has good flexibility, adhesion, and water resistance, and can be used to prepare a photocuring adhesive with good performance.

[0005] The second purpose of the present application is to provide a preparation method of the above-mentioned silicon-containing monomer.

[0006] The third purpose of the present application is to provide a photocuring adhesive.

[0007] In order to achieve the above-mentioned purposes, the technical scheme adopted by the present application is as follows:

[0008] The first aspect of the present application provides a silicon-containing monomer, and the structure of the silicon-containing monomer is shown in the following formula (I):

[0009]

[0010] In formula (I), R1 represents C1-C30 alkyl or C6-C30 aromatic group; R2 represents C1-C30 alkyl, and is optionally interrupted by one or more O atoms, and / or interrupted by one or more -C(=O)O-; R3 represents C1-C30 alkyl; R4-R6 each independently represents C1-C20 alkyl.

[0011] Preferably, R1 represents C3-C20 branched or straight-chain alkyl, C3-C20 cycloalkyl which is substituted or unsubstituted by C1-C5 alkyl, C6-C20 aryl which is substituted or unsubstituted by C1-C5 alkyl; further preferably, R1 represents

[0012]

[0013] It should be noted that "*" in the present application represents the connecting site of the group in formula (I).

[0014] Preferably, R2 represents C3-C20 alkyl, and is optionally interrupted by 1-10 O atoms, and / or interrupted by 1-10 -C(=O)O-; further preferably, R2 represents

[0015]

[0016] Preferably, R3 represents C1-C20 alkyl; further preferably, R3 represents C3-C12 alkyl.

[0017] Preferably, R4-R6 each independently represents C1-C10 alkyl; further preferably, R4-R6 each independently represents methyl or ethyl.

[0018] In some specific embodiments of the present application, the silicon-containing monomer contains a longer segment, which can increase the flexibility of the adhesive to a certain extent, and due to the urea bond contained in the silicon-containing monomer, the hydrogen bond concentration can be increased, thereby enhancing the adhesion of the adhesive.

[0019] Preferably, the silicon-containing monomer comprises:

[0020]

[0021]

[0022] The second aspect of the present application provides a preparation method of the silicon-containing monomer as described in the first aspect of the present application, comprising the following steps:

[0023] S1, mixing a diisocyanate containing R1 with a polymerization inhibitor, adding an acrylate containing R2 and a catalyst, and performing a first polymerization reaction to obtain an intermediate;

[0024] S2, mixing the intermediate obtained in step S1 with a silane coupling agent containing R3-R6, and performing a second polymerization reaction to obtain the silicon-containing monomer.

[0025] Preferably, the diisocyanate containing R1 comprises toluene diisocyanate isophorone diisocyanate diphenylmethane diisocyanate dicyclohexylmethane diisocyanate or hexamethylene diisocyanate at least one of.

[0026] The present application adopts diisocyanate as one of the reaction raw materials, which needs to graft the acrylic double bond at one end so that it can participate in curing, and introduces siloxane bond at the other end, which is beneficial to improve the performance of the adhesive.

[0027] Preferably, the acrylate containing R2 includes 2-(acryloyloxy)ethyl-6-hydroxyhexanoate caprolactone-2-(acryloyloxy)ethyl ester or 20-hydroxy-3,6,9,12,15,18-hexaoxaeicosan-1-yl acrylate at least one of.

[0028] Preferably, the silane coupling agent containing R3-R6 includes 3-aminopropyl triethoxysilane 3-aminopropyl trimethoxysilane 4-aminobutyl triethoxysilane aminomethyl triethoxysilane or 11-aminoundecyl triethoxysilane at least one of.

[0029] Preferably, the polymerization inhibitor includes at least one of hydroquinone, imidazoline, catechol or hydroquinone; further preferably, the polymerization inhibitor includes at least one of hydroquinone, imidazoline or catechol.

[0030] Preferably, the catalyst includes at least one of bisdimethylaminoethyl ether, pentamethyldiethylenetriamine, dimethylcyclohexylamine, dibutyl tin dilaurate, organobismuth or triazine type trimerization catalyst; further preferably, the catalyst includes dibutyl tin dilaurate, organobismuth or a combination thereof.

[0031] Preferably, the molar ratio of the diisocyanate containing R1 to the acrylate containing R2 is 1:(1-1.1); further preferably, it is 1:(1.02-1.05).

[0032] Preferably, the molar ratio of the intermediate to the silane coupling agent containing R3-R6 is 1:(1-1.1); further preferably, it is 1:(1-1.05).

[0033] Preferably, the amount of the polymerization inhibitor is 600-1000 ppm, based on the total mass of the diisocyanate containing R1 and the acrylate containing R2.

[0034] Preferably, the amount of the catalyst is 1000-2000 ppm, based on the total mass of the diisocyanate containing R1 and the acrylate containing R2.

[0035] Preferably, the reaction temperature of the first polymerization reaction is 40-55°C; further preferably, 42-50°C.

[0036] Preferably, the reaction time of the first polymerization reaction is 1-4 h; further preferably, 1.5-3 h.

[0037] Preferably, the reaction temperature of the second polymerization reaction is 50-80°C; further preferably, 55-70°C.

[0038] Preferably, the reaction time of the second polymerization reaction is 1-4 h; further preferably, 1.5-3 h.

[0039] Preferably, the step S1 and the step S2 are carried out in an atmosphere of a protective gas; further preferably, the protective gas comprises at least one of nitrogen, argon or helium; more preferably, the protective gas comprises nitrogen, argon or a combination thereof.

[0040] Preferably, the step S1 further comprises a step of measuring the NCO group content of the reaction product, and when the measured NCO group content is 45-55% of the NCO group content of the diisocyanate containing R1, the first polymerization reaction is stopped to obtain an intermediate.

[0041] Preferably, the step S2 further comprises a step of measuring the NCO group content of the reaction product, and when the measured NCO group content is less than 0.1%, the second polymerization reaction is stopped to obtain the silicon-containing monomer. In some embodiments of the present application, the method for measuring the NCO group content can be selected from infrared spectroscopy, and when the infrared detection finds that the characteristic peak at 2260 cm -1 disappears, the second polymerization reaction is stopped to obtain the silicon-containing monomer.

[0042] The third aspect of the present application provides a photocurable adhesive comprising the following raw materials: a base resin, a photoinitiator and the silicon-containing monomer of the first aspect of the present application.

[0043] Preferably, the photocurable adhesive comprises the following raw materials by mass fraction: 30-60 parts of a base resin, 3-8 parts of a photoinitiator and 20-50 parts of a silicon-containing monomer.

[0044] Preferably, the base resin comprises at least one of a polyurethane acrylic resin, an epoxy resin or an epoxy acrylate; further preferably, the base resin is selected from a polyurethane acrylic resin.

[0045] The silicon-containing monomer of the present application can be compounded with polyurethane acrylate resin, epoxy resin, epoxy acrylate and other matrix resins to obtain a photocuring adhesive with good bonding performance; wherein the polyurethane acrylate resin has a more similar structure with the silicon-containing monomer of the present application, and the compatibility between the two is good, and the polyurethane acrylate resin can also provide urethane bonds to further increase the hydrogen bond concentration of the system, thereby improving the bonding force of the adhesive.

[0046] Preferably, the photoinitiator comprises at least one of 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide or benzophenone.

[0047] Preferably, the raw materials for preparing the photocuring adhesive further comprise an acrylate monomer, a defoaming agent or a combination thereof; further preferably, the raw materials for preparing the photocuring adhesive further comprise an acrylate monomer, or an acrylate monomer and a defoaming agent.

[0048] Preferably, the raw materials for preparing the photocuring adhesive do not comprise a defoaming agent.

[0049] Preferably, the photocuring adhesive comprises the following mass fractions of raw materials: 30-60 parts of matrix resin, 3-8 parts of photoinitiator, 20-50 parts of silicon-containing monomer, 10-30 parts of acrylate monomer, 0-2 parts of defoaming agent; further preferably, the photocuring adhesive comprises the following mass fractions of raw materials: 30-60 parts of matrix resin, 3-8 parts of photoinitiator, 20-50 parts of silicon-containing monomer, 10-30 parts of acrylate monomer; and does not comprise a defoaming agent.

[0050] Preferably, the acrylate monomer comprises at least one of acryloyl morpholine, methyl acrylate, ethyl acrylate, 2-methyl methyl acrylate or 2-methyl ethyl acrylate; further preferably, the acrylate monomer is selected from acryloyl morpholine.

[0051] The addition of the acrylate monomer in the present application can adjust the viscosity of the adhesive and adjust the bonding performance.

[0052] The beneficial effects of the present application are: in the silicon-containing monomer of the present application, the siloxane bond can give the system good flexibility, adhesion, water resistance, transparency and other properties, and in a humid environment, the siloxane bond can hydrolyze and crosslink with water, increasing the crosslinking density while also strengthening the adhesion; the urea bond and the urethane bond can increase the hydrogen bond concentration of the system, thereby improving the adhesion; the acrylate double bond is conducive to rapid curing of the monomer, improving the preparation efficiency. Using the silicon-containing monomer of the present application, a photocuring adhesive with few bubbles, strong adhesion, high transparency and good durability can be prepared, achieving firm bonding between various materials.

[0053] Specifically, compared with the prior art, the present application has the following advantages:

[0054] 1. In the preparation method of the silicon-containing monomer of the present application, the isocyanate is first reacted with the hydrogen bond to introduce the required acrylate double bond for curing, and then the amino group is reacted with the isocyanate group to form a substituted urea. The reaction is rapid and can ignore the reaction steric hindrance brought by the previous step, so that the preparation process of the monomer is relatively convenient. In addition, the acrylate raw material adopted in the present application contains a long chain segment and a reactive double bond, which not only imparts flexibility to the adhesive, but also can participate in curing.

[0055] 2. The photocuring adhesive of the present application has siloxane bond, urea bond, urethane bond and acrylate double bond, etc. due to the introduction of the silicon-containing monomer, which can obtain good flexibility and adhesion, reduce the influence of environmental moisture on the product, enhance the practicality and durability, reduce the system viscosity, reduce the generation of internal bubbles, thereby increase the transparency and durability of the adhesive, and obtain good adhesion; the silicon-containing monomer combined with the base resin (such as polyurethane acrylate resin, etc.) can further enhance the hydrogen bond concentration of the system, thereby improving the adhesion of the adhesive.

[0056] 3. The photocuring adhesive of the present application can be cured and crosslinked under ultraviolet light, which is more convenient than the traditional liquid adhesive. The adhesive has low surface energy and good defoaming performance, so that it can ensure less bubble generation without adding defoaming agent, and obtain a product with good transparency and durability, which is also conducive to simplifying the raw material formula and reducing the preparation cost. In addition, the adhesive has good flexibility, heat resistance and durability, and can be widely used in the bonding between various materials. BRIEF DESCRIPTION OF DRAWINGS

[0057] Figure 1 The test process schematic diagram of the photocuring adhesive of the adhesive examples 1-5 and the adhesive comparative example 1 is shown in the following figure.

[0058] Figure 2 The water contact angle picture of the adhesive examples 1-5 and the adhesive comparative example 1 is shown in the following figure. DETAILED DESCRIPTION

[0059] The application will be further described in detail by specific examples. It should also be understood that the following examples are only used to further illustrate the application and cannot be understood as limiting the scope of the application. Some non-essential improvements and adjustments made by those skilled in the art according to the principles set forth in the application are within the scope of the application. The following examples specifically show the process parameters, which are only one example in the appropriate range, i.e. those skilled in the art can make appropriate selection within the range according to the description herein, and are not limited to the specific data in the following examples. The raw materials, reagents or devices used in the following examples and comparative examples can be obtained from conventional commercial channels or can be obtained by known methods, unless otherwise specified.

[0060] Silicon-containing monomer Example 1

[0061] This example provides a silicon-containing monomer M1, and the specific preparation process is as follows:

[0062] S1. Isophorone diisocyanate (44.44 g, 0.20 mol) and (0.14 g, 1500 ppm) catechol as a polymerization inhibitor were sequentially added to a 250 ml four-necked flask, a stirring device and nitrogen inlet were installed, and 2-(acryloyloxy)ethyl-6-hydroxyhexanoate (46.51 g, 0.202 mol) was slowly added by using a feeding device, the flow addition time was controlled between 0.5-1 hour, the reaction temperature was controlled between 40℃-50℃ during the period, and after uniform stirring until the system was no longer exothermic, (0.07 g, 800 ppm) dibutyltin dilaurate was added after 0.5 h of incubation, and the reaction was incubated at 45℃±2℃ for 2 hours after the reaction was no longer exothermic. The NCO value was titrated until the conversion rate was 50%, the reaction was stopped, and a semi-capped acrylic polyurethane was obtained.

[0063] S2. The temperature of the above mixture was controlled at 45℃±2℃, and nitrogen was passed, and (36.57 g, 0.204 mol) 3-aminopropyltrimethoxysilane was slowly added dropwise, the flow addition time was controlled between 0.5-1 hour, and after uniform stirring until the system was no longer exothermic, the incubation was carried out at 60℃±2℃ for 2 hours, and the NCO value was titrated until the blank, and a silicon-containing photocurable monomer M1 was obtained.

[0064] The specific structural formula of the silicon-containing photocurable monomer M1 is:

[0065]

[0066] The monomer M1 can be subjected to nuclear magnetic hydrogen spectrum analysis after being dissolved in deuterated chloroform as a solvent, and TMS is used as an internal standard. 1H NMR (300 MHz): δ (t, 1H, -CH=CH2) = 6.12 ppm; δ (s, 3H, -Si-O-CH3) = 3.56 ppm; δ (s, 3H, -CH3 on the aliphatic ring) = 0.88 ppm.

[0067] Silicon-containing monomer example 2

[0068] This example provides a silicon-containing monomer M2, the specific preparation process is as follows:

[0069] S1. (34.83 g, 0.20 mol) of toluene diisocyanate and (0.12 g, 1500 ppm) of hydroquinone as a polymerization inhibitor were sequentially added into a 250 ml four-necked flask, a stirring device and nitrogen inlet were installed, and (46.51 g, 0.202 mol) of 2-(acryloyloxy)ethyl-6-hydroxyhexanoate was slowly added by using a feeding device, the feeding time was controlled between 0.5-1 hour, the reaction temperature was controlled between 40-50°C during the period, after uniform stirring until the system was no longer exothermic, (0.06 g, 800 ppm) of dibutyltin dilaurate was added after 0.5 h of incubation, the reaction was incubated to 45°C ± 2°C after the reaction was no longer exothermic, and the incubation reaction was carried out for 2 hours, the NCO value was titrated until the conversion rate was 50%, the reaction was stopped, and a semi-capped acrylic polyurethane was obtained;

[0070] S2. The temperature of the above mixture was controlled at 45°C ± 2°C, and (36.57 g, 0.204 mol) of 3-aminopropyltrimethoxysilane was slowly added by dripping, the feeding time was controlled between 0.5-1 hour, after uniform stirring until the system was no longer exothermic, the incubation reaction was carried out for 2 hours at 60°C ± 2°C, and the NCO value was titrated until the blank, and a silicon-containing photocurable monomer M2 was obtained.

[0071] The specific structural formula of the silicon-containing photocurable monomer M2 is:

[0072]

[0073] After the monomer M2 is dissolved by using deuterated chloroform as a solvent, nuclear magnetic hydrogen spectrum analysis can be carried out, and TMS is used as an internal standard. 1 H NMR (300 MHz): δ (t, 1H, -CH=CH2) = 6.12 ppm; δ (s, 3H, -Si-O-CH3) = 3.56 ppm; δ (s, 3H, -CH3 on the aliphatic ring) = 0.88 ppm.

[0074] Silicon-containing monomer example 3

[0075] This example provides a silicon-containing monomer M3, the specific preparation process is as follows:

[0076] S1. Isophorone diisocyanate (44.44 g, 0.20 mol) was added into a 250 ml four-necked flask with a stirrer and nitrogen inlet, and a polymerization inhibitor, hydroquinone (0.14 g, 1600 ppm), was added. Then, 2-(acryloyloxy)ethyl-6-hydroxyhexanoate (46.51 g, 0.202 mol) was slowly added into the flask using a dropping funnel. The reaction temperature was controlled at 40-50°C, and the reaction was stirred for 0.5-1 hour. After the reaction was no longer exothermic, bismuth (0.08 g, 900 ppm) was added, and the reaction was stirred for 2 hours at 45°C±2°C. The NCO value was titrated until the conversion rate was 50%. The reaction was stopped, and a semi-capped acrylic polyurethane was obtained.

[0077] S2. The temperature of the mixture was controlled at 45°C±2°C, and nitrogen was introduced. Then, 4-aminobutyltriethoxysilane (48.02 g, 0.204 mol) was slowly added dropwise. The reaction was stirred for 0.5-1 hour. After the reaction was no longer exothermic, the reaction was stirred for 2 hours at 60°C±2°C. The NCO value was titrated until the blank was obtained. A silicon-containing photocuring monomer M3 was obtained.

[0078] The specific structural formula of the silicon-containing photocuring monomer M3 is as follows:

[0079]

[0080] The monomer M3 can be subjected to nuclear magnetic hydrogen spectrum analysis after being dissolved in deuterated chloroform as a solvent, and TMS is used as an internal standard. 1 H NMR (300 MHz): δ (t, 1H, -CH=CH2) = 6.15 ppm; δ (dd, 2H, -Si-O-CH2-CH3) = 3.84 ppm; δ (s, 3H, -CH3 on the aliphatic ring) = 0.94 ppm.

[0081] Silicon-containing monomer example 4

[0082] This example provides a silicon-containing monomer M4, and the specific preparation process is as follows:

[0083] S1. Into a 250ml four-necked flask, (34.83g, 0.20mol) of toluene diisocyanate and (0.16g, 1500ppm) of imidazoline polymerization inhibitor were added successively, a stirring device and nitrogen inlet were installed, (70.26g, 0.204mol) of caprolactone-2-(acryloyloxy)ethyl ester was slowly added by using a feeding device, the feeding time was controlled between 0.5-1 hour, the reaction temperature was controlled between 40-50°C during the feeding, after the system was uniformly stirred and no more heat was released, (0.10g, 1000ppm) of organic bismuth was added after 0.5h of incubation, the reaction was incubated at 45°C±2°C for 2 hours after the reaction was no longer exothermic, the NCO value was titrated until the conversion rate was 50%, the reaction was stopped, and a semi-capped acrylic polyurethane was obtained;

[0084] S2. The temperature of the above mixture was controlled at 45°C±2°C, nitrogen was introduced, (48.02g, 0.204mol) of 4-aminobutyl triethoxysilane was slowly added dropwise, the feeding time was controlled between 0.5-1 hour, the system was uniformly stirred until no more heat was released, and the incubation was carried out at 60°C±2°C for 2 hours, the NCO value was titrated until the blank, and a silicon-containing photocuring monomer M4 was obtained.

[0085] The specific structural formula of the silicon-containing photocuring monomer M4 is as follows:

[0086]

[0087] The monomer M4 can be subjected to nuclear magnetic hydrogen spectrum analysis after being dissolved in deuterated chloroform as a solvent, and TMS is used as an internal standard. 1 H NMR (300MHz): δ (t, 1H, -CH=CH2) = 6.13ppm; δ (dd, 2H, -Si-O-CH2-CH3) = 3.82ppm; δ (s, 3H, -CH3 on the benzene ring) = 2.18ppm.

[0088] Silicon-containing monomer example 5

[0089] This example provides a silicon-containing monomer M5, and the specific preparation process is as follows:

[0090] S1. Isophorone diisocyanate (44.44 g, 0.20 mol) and (0.18 g, 1600 ppm) catechol polymerization inhibitor were sequentially added into a 250 ml four-necked flask, a stirring device and nitrogen inlet were installed, and ((70.26 g, 0.204 mol) dihexyl lactone-2-(acryloxy)ethyl ester was slowly added by using a feeding device, the feeding time was controlled between 0.5-1 hour, the reaction temperature was controlled between 40℃-50℃ during the feeding, after the system was uniformly stirred and no longer exothermic, (0.10 g, 900 ppm) dibutyl tin dilaurate was added after 0.5 h of incubation, the reaction was incubated at 45℃±2℃ for 2 hours after the reaction was no longer exothermic, and the NCO value was titrated until the conversion rate was 50%, the reaction was stopped, and a semi-capped acrylic polyurethane was obtained;

[0091] S2. The temperature of the above mixture was controlled at 45℃±2℃, nitrogen was introduced, and (39.44 g, 0.204 mol) aminomethyl triethoxysilane was slowly added dropwise, the feeding time was controlled between 0.5-1 hour, the system was uniformly stirred until no longer exothermic, and incubated at 60℃±2℃ for 2 hours, and the NCO value was titrated until the blank, and a silicon-containing photocuring monomer M5 was obtained.

[0092] The specific structural formula of the silicon-containing photocuring monomer M5 is:

[0093]

[0094] The monomer M5 can be subjected to nuclear magnetic hydrogen spectrum analysis after being dissolved by using deuterated chloroform as a solvent, and TMS is used as an internal standard. 1 H NMR (300 MHz): δ (t, 1H, -CH=CH2) = 6.15 ppm; δ (dd, 2H, -Si-O-CH2-CH3) = 3.85 ppm; δ (s, 3H, -CH3 on the aliphatic ring) = 0.88 ppm.

[0095] Adhesive example 1

[0096] This example provides a photocuring adhesive, and the specific preparation process is as follows:

[0097] A polyurethane acrylic resin was purchased from the market, 4.5 g of polyurethane acrylic resin, 3.5 g of silicon-containing monomer M1 prepared by the silicon-containing monomer example 1, 2 g of acryloyl morpholine and 0.3 g of photoinitiator 1173 were mixed, and stirred uniformly in a 65℃ water bath, and a photocuring adhesive was obtained.

[0098] Adhesive examples 2-5

[0099] Adhesive Examples 2-5 each provide a photocurable adhesive, which differs from the adhesive of Adhesive Example 1 in that the silicon-containing monomer M1 in Adhesive Example 1 is replaced by the silicon-containing monomers M2-M5 prepared in Silicon-Containing Monomer Examples 2-5, respectively, to obtain the photocurable adhesive of Adhesive Examples 2-5.

[0100] Adhesive Comparative Example 1

[0101] This example provides a photocurable adhesive, which is prepared according to the following specific process:

[0102] 8 g of polyurethane acrylic resin, 2 g of acryloyl morpholine, and 0.3 g of photoinitiator 1173 are mixed and stirred uniformly in a 65°C water bath, to obtain the photocurable adhesive.

[0103] Performance Test

[0104] (1) The photocurable adhesives obtained in Adhesive Examples 1-5 and Adhesive Comparative Example 1 are subjected to bonding performance testing, with the specific standard referring to GB / T 33333-2016, and the testing process being as follows: each test sample is poured into a customized mold, and after standing for 5 minutes, is subjected to radiation curing for 10 s using a mercury lamp, with the radiation intensity being 250 mJ·cm -2 . The finished product is cut into a shape of 25 mm x 10 mm, placed between iron sheets, and subjected to extrusion under a force of 5 MPa for 2 min, to obtain the bonding sample. The bonding performance of the sample is tested using a Shenzhen Sanechips UTM4202 electronic universal testing machine, the bonding sample is separated in a direction parallel to the bonding surface, and the testing process is schematically shown in Figure 1 . The tensile shear strength of the sample is tested and recorded, so as to determine the strength of the bonding performance.

[0105] (2) In order to observe the change in the bonding performance of the sample with the extension of the storage time, durability testing is performed, with the specific standard referring to GB / T 33333-2016, and the testing process being as follows: the bonding sample is prepared according to the steps in Performance Test (1), and after being stored for seven days, the bonding performance of the sample is tested using the electronic universal testing machine, so as to determine the change in the bonding performance.

[0106] (3) Hydrophobic performance testing is performed, with the specific standard referring to GB / T 30693-2014, and the testing process being as follows: the bonding sample is prepared according to the steps in Performance Test (1), and the water contact angle of the surface of the sample is tested using a Shanghai Zhongchen JC2000C1 contact angle measuring instrument.

[0107] (4) Thermal stability test was carried out, and the specific standard referred to GB / T 27761-2011, and the test process was as follows: the adhesive sample was prepared according to the steps in performance test (1), and the thermal stability test of the sample was carried out by using the thermal gravimetric analyzer of Germany Nanjing under the condition of N2 atmosphere and at the temperature rising speed of 10 ℃ / min in the range of 35 ℃ to 750 ℃, the N2 flow was 20 mL / min, the thermal decomposition temperature and the carbon residue rate of the sample were obtained, and the carbon residue rate was calculated according to the undecomposed mass and the original mass.

[0108] The test results are shown in Table 1.

[0109] Table 1: Performance test results of the photocurable adhesives obtained from adhesive examples 1-5 and adhesive comparative example 1

[0110]

[0111]

[0112] As shown in Table 1, no silicon-containing monomer is added in adhesive comparative example 1, and the bonding performance, durability, thermal stability and hydrophobicity obtained are all worse than those in adhesive examples 1-5. The water contact angle pictures of adhesive examples 1-5 and adhesive comparative example 1 are shown in Figure 2 , wherein (a) is adhesive example 1, (b) is adhesive example 2, (c) is adhesive example 3, (d) is adhesive example 4, (e) is adhesive example 5, and (f) is adhesive comparative example 1. As shown in Figure 2 , compared with adhesive comparative example 1, adhesive examples 1-5 of the present application have better hydrophobic effect.

[0113] As shown in the above examples, in the preparation method of the silicon-containing monomer of the present application, the acrylate double bond required for curing is first introduced by using hydrogen bond and isocyanate reaction, and then the substituted urea is generated by using amino and isocyanate group reaction, the reaction is rapid, and the reaction steric hindrance brought by the previous step reaction can be ignored, so that the preparation process of the monomer is relatively convenient. In addition, the acrylate raw material adopted in the present application contains a long chain segment and a active double bond, which not only gives the adhesive flexibility, but also can participate in curing.

[0114] The light-curing adhesive of the embodiment of the present application has siloxane bond, urea bond, urethane bond and acrylic ester double bond active groups due to the introduction of the silicon-containing monomer, can obtain good flexibility and adhesion, and also reduces the influence of environmental water vapor on the product, enhances practicality and durability, and can reduce the viscosity of the system, reduces the generation of internal bubbles, thereby increasing the transparency and durability of the adhesive, and obtaining good adhesion; the silicon-containing monomer combined with the base resin (such as polyurethane acrylate resin) can further enhance the hydrogen bond concentration of the system, thereby improving the adhesion of the adhesive. Moreover, the light-curing adhesive in the embodiment of the present application can be cured and cross-linked under ultraviolet light, is more convenient to use than traditional liquid adhesives; and the adhesive has low surface energy and good defoaming performance, thereby ensuring less bubble generation without adding a defoaming agent, obtaining a product with good transparency and durability, which is also conducive to simplifying the raw material formula and reducing the preparation cost; in addition, the adhesive has good flexibility, heat resistance and durability, and can be widely applied to the adhesion between various materials.

[0115] In summary, in the silicon-containing monomer of the present application, the siloxane bond can impart the system with good flexibility, adhesion, water resistance, transparency and other properties, and in a humid environment, the siloxane bond can hydrolyze and cross-link with water, improving the cross-linking density while also strengthening the adhesion; the urea bond and urethane bond can improve the hydrogen bond concentration of the system, thereby improving the adhesion; the acrylic ester double bond is conducive to the rapid curing of the monomer, improving the preparation efficiency. Using the silicon-containing monomer of the present application, a light-curing adhesive with less bubbles, strong adhesion, high transparency and good durability can be prepared, realizing the firm adhesion between various materials.

Claims

1. A silicon-containing monomer, characterized in that, The structural formula of the silicon-containing monomer is shown in the following formula (I): Formula (I); In equation (I), R1 represents , , , or R2 indicates or R3 represents C1~C20 alkylene; R4~R6 each independently represent C1~C10 alkyl.

2. The silicon-containing monomer according to claim 1, characterized in that, R3 indicates a C3~C12 alkylene group; And / or, R4~R6 each independently represent methyl or ethyl.

3. The silicon-containing monomer according to claim 1, characterized in that, The silicon-containing monomer includes: 、 、 、 or 。 4. A method for preparing a silicon-containing monomer as described in any one of claims 1 to 3, characterized in that, Includes the following steps: S1. Mix the diisocyanate containing R1 with the polymerization inhibitor, add the acrylate containing R2 and the catalyst, and carry out the first polymerization reaction to obtain the intermediate. S2. The intermediate obtained in step S1 is mixed with a silane coupling agent containing R3 to R6 to carry out a second polymerization reaction to obtain the silicon-containing monomer.

5. The preparation method according to claim 4, characterized in that, The diisocyanate containing R1 is at least one of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, or hexamethylene diisocyanate. And / or, the acrylate containing R2 is at least one of 2-(acryloyloxy)ethyl-6-hydroxyhexanoate and dicaprolactone-2-(acryloyloxy)ethyl ester; And / or, the silane coupling agent containing R3 to R6 is at least one of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 4-aminobutyltriethoxysilane, aminomethyltriethoxysilane or 11-aminoundecyltriethoxysilane. And / or, the polymerization inhibitor is at least one of hydroquinone, imidazoline, catechol or hydroquinone; And / or, the catalyst is at least one of bis(dimethylaminoethyl) ether, pentamethyldiethylenetriamine, dimethylcyclohexylamine, dibutyltin dilaurate, organobismuth or triazine trimerizing catalyst; And / or, the molar ratio of the diisocyanate containing R1 to the acrylate containing R2 is 1:(1~1.1). And / or, the molar ratio of the intermediate to the silane coupling agent containing R3 to R6 is 1:(1 to 1.1). And / or, based on the total mass of the diisocyanate containing R1 and the acrylate containing R2, the amount of the polymerization inhibitor is 600~1000 ppm; And / or, the amount of catalyst used is 1000~2000 ppm, based on the total mass of the diisocyanate containing R1 and the acrylate containing R2.

6. The preparation method according to claim 4, characterized in that, The reaction temperature of the first polymerization reaction is 40~55℃; And / or, the reaction time of the first polymerization reaction is 1 to 4 hours; And / or, the reaction temperature of the second polymerization reaction is 50~80℃; And / or, the reaction time of the second polymerization reaction is 1 to 4 hours; And / or, steps S1 and S2 are performed in a protective gas atmosphere.

7. A light-curing adhesive, characterized in that, The preparation materials include the following: matrix resin, photoinitiator, and silicon-containing monomer as described in any one of claims 1 to 3.

8. The light-curing adhesive according to claim 7, characterized in that, The photocurable adhesive comprises the following raw materials in parts by weight: 30-60 parts matrix resin, 3-8 parts photoinitiator, and 20-50 parts silicon-containing monomer; And / or, the matrix resin is at least one of polyurethane acrylic resin, epoxy resin or epoxy acrylate; And / or, the photoinitiator is at least one of 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxycyclohexylphenyl ketone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, or benzophenone.

9. The photocurable adhesive according to claim 7, characterized in that, The raw materials for preparing the light-curing adhesive also include acrylate monomers, defoamers, or combinations thereof; the acrylate monomers are at least one of acrylomorpholine, methyl acrylate, ethyl acrylate, methyl 2-methacrylate, or ethyl 2-methacrylate.

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