Organosilicon modified polyurethane acrylate UV viscosity-reducing adhesive containing triple dynamic bonds and preparation method thereof

Abstract

The invention belongs to the technical field of preparation of stimuli-responsive materials, and particularly relates to an organosilicone modified polyurethane acrylate UV viscosity-reducing adhesive containing triple dynamic bonds and a preparation method of the organosilicone modified polyurethane acrylate UV viscosity-reducing adhesive. The preparation method comprises the following steps: preparing a siloxane-urethane prepolymer from hydroxyl-terminated polydimethylsiloxane and diisocyanate, then adding diaminoglyoxal oxime, carrying out a reaction to obtain a polysiloxane urethane prepolymer containing an oxime-carbamate bond, a dynamic urea bond and a hydrogen bond, and finally, carrying out terminating with hydroxyethyl acrylate to obtain the high-temperature-resistant polyurethane elastomer. And uniformly mixing with a photoinitiator and a reactive diluent to obtain the UV viscosity-reducing glue. The viscosity-reducing adhesive combines the characteristics of siloxane, polyurethane and acrylate, has good adhesive force to metal, plastic, glass and other base materials, and can form firm adhesion. A large number of dynamic covalent bonds maintain the stable mechanical performance of the adhesive, and also have the characteristic of rapid decrosslinking, and when the adhesive needs to be disassembled, the adhesive can lose the binding force after being heated to 120 DEG C for 3 minutes, so that the adhesive has a very high application prospect in the field of electronic equipment maintenance.

Description

Technical Field

[0001] The present invention belongs to the technical field of the preparation of stimulus-responsive materials, and particularly relates to an organosilicon-modified polyurethane acrylate UV tackifier containing triple dynamic bonds and a preparation method thereof. Background Art

[0002] In most of the electronic and energy fields, sealing and encapsulation are achieved through adhesives, which play roles such as waterproofing and moisture-proofing, protecting circuits, and antistatic shielding. During the production process of electronic devices, component sticking errors may occur, and the adhesive needs to have a certain degree of detachability to enable the readjustment and replacement of components, reducing material waste.

[0003] Existing tackifiers such as CN112126036A, a bio-based degradable cross-linked self-healing polyurethane based on disulfide bonds and a preparation method thereof. Using castor oil as a bio-based material as one of the polyols to prepare a degradable cross-linked polyurethane prepolymer, and then introducing disulfide and dimethylglyoxime as chain extenders into the polyurethane system to prepare a self-healing degradable cross-linked polyurethane. CN117844428A, a biodegradable polyurethane pressure-sensitive adhesive and a preparation method thereof. The pressure-sensitive adhesive uses biodegradable polycaprolactone polyol, polybutylene succinate polyol, polytrimethylene ether glycol, and a small amount of polypropylene glycol as the soft segment; uses diisocyanate as the hard segment; and uses dimethylglyoxime as a functional chain extender to obtain a polyurethane pressure-sensitive adhesive through reaction. CN117903742A, a detachable polyurethane structural adhesive containing dynamic covalent bonds, a preparation method and application thereof, obtaining a polyurethane structural adhesive by reacting polyether triol, modified castor oil, dimethylglyoxime, polyether diol, and diisocyanate.

[0004] The above several solutions all utilize the thermoreversibility of the oxime bond itself to reduce viscosity and dissociate the structure through thermal degradation, and the temperature at which the oxime-carbamate bond completely dissociates is about 150-160°C. Summary of the Invention

[0005] In order to overcome the deficiencies of existing polyurethane tackifiers, the present invention provides an organosilicon-modified polyurethane acrylate UV tackifier containing triple dynamic bonds and a preparation method thereof. First, a siloxane-urethane prepolymer is prepared by hydroxyl-terminated polydimethylsiloxane and diisocyanate, then diaminoglyoxime is added thereto, and after reaction, a polysiloxane urethane prepolymer containing oxime-carbamate bonds, dynamic urea bonds, and hydrogen bonds is obtained. Finally, it is capped with hydroxyethyl acrylate to obtain an organosilicon-modified polyurethane acrylate containing triple dynamic bonds, and then it is mixed and stirred evenly with a photoinitiator and an active diluent to obtain a UV tackifier.

[0006] Among them, the preparation method of the organosilicon-modified polyurethane acrylate containing triple dynamic bonds is specifically as follows:

[0007] (1) Under a nitrogen atmosphere, the hydroxyl-terminated polydimethylsiloxane, diisocyanate, organotin catalyst, and solvent that have been dehydrated under vacuum are added to a three-necked flask. After repeated evacuation and nitrogen purging, the mixture is stirred to ensure thorough mixing of the raw materials. The mixture is heated to 70 °C and reacted for 2 - 3 h to obtain an isocyanate-terminated prepolymer polysiloxane urethane;

[0008] Among them, the molecular weight of the hydroxyl-terminated polydimethylsiloxane is 500;

[0009] The solvent is selected from one of the following: tetrahydrofuran, ethyl acetate, toluene, and xylene;

[0010] The diisocyanate is selected from one of the following: toluene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and hexamethylene diisocyanate;

[0011] The organotin catalyst is dibutyltin dilaurate, and its dosage is 0.3% - 0.5% of the total mass of the reaction system.

[0012] (2) Add diaminoglyoxime oxime to the isocyanate-terminated prepolymer polysiloxane urethane and react at 70 °C for 2 - 3 h to obtain a polysiloxane urethane containing oxime-carbamate bonds, dynamic urea bonds, and hydrogen bonds;

[0013] (3) Continue to add hydroxyethyl acrylate and react at 70 °C for 3 - 4 h to obtain a silane-modified polyurethane acrylate containing triple dynamic bonds; after the reaction is completed, the temperature is lowered to 50 °C, and low-molecular substances and solvents are removed by vacuum distillation. Then, it is placed in a vacuum oven at 50 °C to remove the solvent to obtain a pale yellow viscous liquid organosilicon-modified polyurethane acrylate.

[0014] The chemical reaction equation for obtaining the organosilicon-modified polyurethane acrylate is as follows:

[0015]

[0016] R1:

[0017] R2:

[0018] The organosilicon-modified polyurethane acrylate containing triple dynamic bonds is composed of the following in parts by mass: 50 - 60 parts by mass of hydroxyl-terminated polydimethylsiloxane, 50 - 100 parts by mass of diisocyanate, 6 - 10 parts by mass of diaminoglyoxime oxime, and 15 - 20 parts by mass of hydroxyethyl acrylate.

[0019] The present invention also provides a preparation method of a silicone-modified polyurethane acrylate UV tackifier containing triple dynamic bonds: The prepared silicone-modified polyurethane acrylate containing triple dynamic bonds, hydroxyethyl acrylate, and a photoinitiator are mixed evenly under high-speed stirring, and then placed in a vacuum oven for defoaming in the dark for 30 min to obtain a detachable adhesive.

[0020] The reactive diluent is hydroxyethyl acrylate, and its dosage is 20% of the mass of the silicone-modified polyurethane acrylate containing triple dynamic bonds. The photoinitiator is 2-hydroxy-2-methylpropiophenone, and its dosage is 4% of the mass of the silicone-modified polyurethane acrylate containing triple dynamic bonds.

[0021] Beneficial effects:

[0022] Through the molecular structure of diaminoglyoxime with chemically coupled four-arm dynamic sites, the present invention synthesizes a triple dynamic bond polymer network containing both oxime-carbamate bonds and dynamic urea bonds, as well as a large number of hydrogen bonds. It combines the characteristics of siloxane, polyurethane, and acrylate, has good spreading properties, and has good adhesion to various substrates such as metals, plastics, glass, and ceramics, and can form a firm bond. Among them, a large number of dynamic covalent bonds not only maintain the stable mechanical properties of the adhesive but also have the characteristics of rapid de-crosslinking. In the thermal degradation experiment, the purpose of complete de-crosslinking can be achieved by heating to 110-120 °C. Description of the drawings

[0023] Figure 1 The figure shows the infrared spectrum of the tackifier of the product in Example 1. Detailed implementation manners

[0024] The following further explains the technical solutions of the present invention in combination with examples, and clearly and completely describes the technical solutions in the examples of the present invention.

[0025] Example 1

[0026] Under a nitrogen atmosphere, 50 g of hydroxyl-terminated polydimethylsiloxane and 70 g of toluene diisocyanate after vacuum dehydration were added to a three-necked flask equipped with a mechanical stirring device and a condenser tube. Then, 0.9 g of dibutyltin dilaurate and 120 g of tetrahydrofuran were added. After mixing evenly, it was stirred vigorously for 1 h. The mixture was heated to 70 °C and reacted for 3 h to obtain an isocyanate-terminated polysiloxane-urethane prepolymer. Then, 6 g of diaminoglyoxime was added thereto, and the temperature was maintained at 70 °C and reacted for 3 h to obtain a polysiloxane urethane prepolymer containing both oxime-carbamate bonds and dynamic urea bonds and a large number of hydrogen bonds. Then, 17 g of 2-hydroxyethyl acrylate was added for capping, and the reaction continued at 70 °C for 3 h to obtain a silane-modified polyurethane acrylate containing triple dynamic covalent bonds. After the reaction was completed, the temperature was lowered to 50 °C, and vacuum distillation was carried out to remove low-molecular substances and solvents. Then, it was placed in a vacuum oven at 50 °C to remove trace solvents to obtain a light yellow viscous liquid of silane-modified polyurethane acrylate containing triple dynamic covalent bonds.

[0027] The prepared silane-modified polyurethane acrylate containing triple dynamic covalent bonds was mixed evenly with 29.4 g of 2-hydroxyethyl acrylate and 7.6 g of photoinitiator 2-hydroxy-2-methylpropiophenone under high-speed stirring. Then, it was placed in a vacuum oven for defoaming in the dark for 30 min to obtain a detachable adhesive.

[0028] The infrared spectrum of the prepared pressure-sensitive adhesive is shown in Figure 1 , at 800 cm -1 -1200 cm -1 corresponding to the bending vibration of (Si-O-Si) in the polysiloxane chain segment, at 1600 cm -1 -1700 cm -1 corresponding to the stretching vibration of (C=N) in the oxime bond, at 1680 cm -1 -1780 cm -1 corresponding to the stretching vibration of (C=O) in the carbamate bond, and at 1600 - 1680 cm -1 corresponding to the stretching vibration of (C=C) in the acrylate group. Moreover, it can be observed that the stretching vibration peak of the hydroxyl group at 3600 cm -1 basically disappears. The above results can indicate the successful synthesis of the pressure-sensitive adhesive.

[0029] Example 2

[0030] Under a nitrogen atmosphere, 50 g of hydroxyl-terminated polydimethylsiloxane and 90 g of isophorone diisocyanate that had been vacuum dehydrated were added to a three-necked flask equipped with a mechanical stirring device and a condenser. Then, 1.0 g of dibutyltin dilaurate and 130 g of ethyl acetate were added. After mixing evenly, the mixture was stirred thoroughly for 1 h. The mixture was heated to 70 °C and reacted for 3 h to obtain an isocyanate-terminated polysiloxane-urethane prepolymer. Then, 8 g of diaminoglyoxime was added thereto, and the temperature was maintained at 70 °C and reacted for 3 h to obtain a polysiloxane urethane prepolymer containing both oxime-carbamate bonds and dynamic urea bonds as well as a large number of hydrogen bonds. Then, 18 g of hydroxyethyl acrylate was added for capping, and the reaction was continued at 70 °C for 3 h to obtain a silane-modified polyurethane acrylate containing triple dynamic covalent bonds. After the reaction was completed, the temperature was lowered to 50 °C, and low molecular substances and solvents were removed by vacuum distillation. Then, it was placed in a vacuum oven at 50 °C to remove trace solvents, and a light yellow viscous liquid of silane-modified polyurethane acrylate containing triple dynamic covalent bonds was obtained.

[0031] The prepared prepolymer was mixed evenly with 34 g of hydroxyethyl acrylate and 7.8 g of photoinitiator 2-hydroxy-2-methylpropiophenone under high-speed stirring, and then placed in a vacuum oven for defoaming in the dark for 30 min to obtain a removable adhesive.

[0032] Example 3

[0033] Under a nitrogen atmosphere, 60 g of hydroxyl-terminated polydimethylsiloxane and 100 g of dicyclohexylmethane diisocyanate that had been vacuum dehydrated were added to a three-necked flask equipped with a mechanical stirring device and a condenser. Then, 1.2 g of dibutyltin dilaurate and 140 g of toluene were added. After mixing evenly, the mixture was stirred thoroughly for 1 h. The mixture was heated to 70 °C and reacted for 3 h to obtain an isocyanate-terminated polysiloxane-urethane prepolymer. Then, 10 g of diaminoglyoxime was added thereto, and the temperature was maintained at 70 °C and reacted for 3 h to obtain a polysiloxane urethane prepolymer containing both oxime-carbamate bonds and dynamic urea bonds as well as a large number of hydrogen bonds. Then, 20 g of hydroxyethyl acrylate was added for capping, and the reaction was continued at 70 °C for 3 h to obtain a silane-modified polyurethane acrylate containing triple dynamic covalent bonds. After the reaction was completed, the temperature was lowered to 50 °C, and low molecular substances and solvents were removed by vacuum distillation. Then, it was placed in a vacuum oven at 50 °C to remove trace solvents to obtain a light yellow viscous liquid of silane-modified polyurethane acrylate containing triple dynamic covalent bonds.

[0034] The prepared silane-modified polyurethane acrylate containing triple dynamic covalent bonds was mixed evenly with 38 g of hydroxyethyl acrylate and 8.9 g of photoinitiator 2-hydroxy-2-methylpropiophenone under high-speed stirring, and then placed in a vacuum oven for defoaming in the dark for 30 min to obtain a removable adhesive.

[0035] Example 4

[0036] Under a nitrogen atmosphere, 55 g of hydroxyl-terminated polydimethylsiloxane and 75 g of hexamethylene diisocyanate that had been dehydrated by vacuum pumping were added to a three-necked flask equipped with a mechanical stirring device and a condenser. Then, 0.8 g of dibutyltin dilaurate and 120 g of xylene were added. After mixing evenly, the mixture was stirred thoroughly for 1 h. The mixture was heated to 70 °C and reacted for 3 h to obtain an isocyanate-terminated polysiloxane-urethane prepolymer. Then, 8 g of diaminoglyoxime was added thereto, and the temperature was maintained at 70 °C and reacted for 3 h to obtain a polysiloxane urethane prepolymer containing both oxime-carbamate bonds and dynamic urea bonds and a large number of hydrogen bonds. Then, 18 g of 2-hydroxyethyl acrylate was added for capping, and the reaction was continued at 70 °C for 3 h to obtain a silane-modified polyurethane acrylate containing oxime bonds. After the reaction was completed, the temperature was lowered to 50 °C, and low-molecular substances and solvents were removed by vacuum distillation. Then, it was placed in a vacuum oven at 50 °C to remove trace solvents to obtain a pale yellow viscous liquid of silane-modified polyurethane acrylate containing triple dynamic covalent bonds.

[0037] The prepared silane-modified polyurethane acrylate containing triple dynamic covalent bonds was mixed evenly with 32 g of 2-hydroxyethyl acrylate and 6.8 g of photoinitiator 2-hydroxy-2-methylpropiophenone under high-speed stirring. Then, it was placed in a vacuum oven to degas in the dark for 30 min to obtain a detachable adhesive.

[0038] Example 5

[0039] Under a nitrogen atmosphere, 60 g of hydroxyl-terminated polydimethylsiloxane and 100 g of dicyclohexylmethane diisocyanate that had been dehydrated by vacuum pumping were added to a three-necked flask equipped with a mechanical stirring device and a condenser. Then, 1.2 g of dibutyltin dilaurate and 140 g of toluene were added. After mixing evenly, the mixture was stirred thoroughly for 1 h. The mixture was heated to 70 °C and reacted for 3 h to obtain an isocyanate-terminated polysiloxane-urethane prepolymer. Then, 7 g of diaminoglyoxime was added thereto, and the temperature was maintained at 70 °C and reacted for 3 h to obtain a polysiloxane urethane prepolymer containing both oxime-carbamate bonds and dynamic urea bonds and a large number of hydrogen bonds. Then, 20 g of 2-hydroxyethyl acrylate was added for capping, and the reaction was continued at 70 °C for 3 h to obtain a silane-modified polyurethane acrylate containing triple dynamic covalent bonds. After the reaction was completed, the temperature was lowered to 50 °C, and low-molecular substances and solvents were removed by vacuum distillation. Then, it was placed in a vacuum oven at 50 °C to remove trace solvents to obtain a pale yellow viscous liquid of silane-modified polyurethane acrylate containing triple dynamic covalent bonds.

[0040] The preparation method of the detachable adhesive was the same as that in Example 1.

[0041] Example 6

[0042] Under a nitrogen atmosphere, 60 g of hydroxyl-terminated polydimethylsiloxane after vacuum dehydration and 100 g of dicyclohexylmethane diisocyanate were added to a three-necked flask equipped with a mechanical stirring device and a condenser. Then, 1.2 g of dibutyltin dilaurate and 140 g of toluene were added. After mixing evenly, the mixture was stirred thoroughly for 1 h. The mixture was heated to 70 °C and reacted for 3 h to obtain an isocyanate-terminated polysiloxane-urethane prepolymer. Then, 8 g of diaminoglyoxime was added thereto, and the temperature was maintained at 70 °C and reacted for 3 h to obtain a polysiloxane urethane prepolymer containing both oxime-carbamate bonds and dynamic urea bonds and a large number of hydrogen bonds. Then, 20 g of 2-hydroxyethyl acrylate was added for capping, and the reaction was continued at 70 °C for 3 h to obtain a silane-modified polyurethane acrylate containing triple dynamic covalent bonds. After the reaction was completed, the temperature was lowered to 50 °C, and low-molecular substances and solvents were removed by vacuum distillation. Then, it was placed in a vacuum oven at 50 °C to remove trace solvents to obtain a pale yellow viscous liquid of silane-modified polyurethane acrylate containing triple dynamic covalent bonds.

[0043] The preparation method of the detachable adhesive is the same as that in Example 1.

[0044] Example 7

[0045] Under a nitrogen atmosphere, 60 g of hydroxyl-terminated polydimethylsiloxane after vacuum dehydration and 100 g of dicyclohexylmethane diisocyanate were added to a three-necked flask equipped with a mechanical stirring device and a condenser. Then, 1.2 g of dibutyltin dilaurate and 140 g of toluene were added. After mixing evenly, the mixture was stirred thoroughly for 1 h. The mixture was heated to 70 °C and reacted for 3 h to obtain an isocyanate-terminated polysiloxane-urethane prepolymer. Then, 9 g of diaminoglyoxime was added thereto, and the temperature was maintained at 70 °C and reacted for 3 h to obtain a polysiloxane urethane prepolymer containing both oxime-carbamate bonds and dynamic urea bonds and a large number of hydrogen bonds. Then, 20 g of 2-hydroxyethyl acrylate was added for capping, and the reaction was continued at 70 °C for 3 h to obtain a silane-modified polyurethane acrylate containing triple dynamic covalent bonds. After the reaction was completed, the temperature was lowered to 50 °C, and low-molecular substances and solvents were removed by vacuum distillation. Then, it was placed in a vacuum oven at 50 °C to remove trace solvents to obtain a pale yellow viscous liquid of silane-modified polyurethane acrylate containing triple dynamic covalent bonds.

[0046] The preparation method of the detachable adhesive is the same as that in Example 1.

[0047] Example 8

[0048] Under a nitrogen atmosphere, 60 g of hydroxyl-terminated polydimethylsiloxane and 100 g of dicyclohexylmethane diisocyanate after vacuum dehydration were added to a three-necked flask equipped with a mechanical stirring device and a condenser tube. Then, 1.2 g of dibutyltin dilaurate and 140 g of toluene were added. After mixing evenly, the mixture was stirred vigorously for 1 h. The mixture was heated to 70 °C and reacted for 3 h to obtain an isocyanate-terminated polysiloxane-urethane prepolymer. Then, 10 g of diaminoglyoxime was added thereto, and the temperature was maintained at 70 °C and reacted for 3 h to obtain a polysiloxane urethane prepolymer containing both oxime-carbamate bonds and dynamic urea bonds and a large number of hydrogen bonds. Then, 20 g of 2-hydroxyethyl acrylate was added thereto for end-capping, and the reaction was continued at 70 °C for 3 h to obtain a silane-modified polyurethane acrylate containing triple dynamic covalent bonds. After the reaction was completed, the temperature was lowered to 50 °C, and low-molecular substances and solvents were removed by vacuum distillation. Then, it was placed in a vacuum oven at 50 °C to remove trace solvents to obtain a pale yellow viscous liquid of silane-modified polyurethane acrylate containing triple dynamic covalent bonds.

[0049] The preparation method of the detachable adhesive is the same as that in Example 1.

[0050] Example 9

[0051] The preparation process of the silane-modified polyurethane acrylate containing triple dynamic covalent bonds is the same as that in Example 7.

[0052] The silane-modified polyurethane acrylate containing triple dynamic covalent bonds prepared in Example 7 was mixed evenly with 20 g of 2-hydroxyethyl acrylate and 7.6 g of photoinitiator 2-hydroxy-2-methylpropiophenone under high-speed stirring, and then placed in a vacuum oven for defoaming in the dark for 30 min to obtain a detachable adhesive.

[0053] Example 10

[0054] The preparation process of the silane-modified polyurethane acrylate containing triple dynamic covalent bonds is the same as that in Example 7.

[0055] The silane-modified polyurethane acrylate containing triple dynamic covalent bonds prepared in Example 7 was mixed evenly with 40 g of 2-hydroxyethyl acrylate and 7.6 g of photoinitiator 2-hydroxy-2-methylpropiophenone under high-speed stirring, and then placed in a vacuum oven for defoaming in the dark for 30 min to obtain a detachable adhesive.

[0056] Example 11

[0057] The preparation process of the silane-modified polyurethane acrylate containing triple dynamic covalent bonds is the same as that in Example 7.

[0058] The silane-modified polyurethane acrylate containing triple dynamic covalent bonds prepared in Example 7 was uniformly mixed with 29.4 g of hydroxyethyl acrylate and 5 g of photoinitiator 2-hydroxy-2-methylpropiophenone under high-speed stirring, and then placed in a vacuum oven to degas for 30 minutes in the dark to obtain a detachable adhesive.

[0059] Example 12

[0060] The preparation process of silane-modified polyurethane acrylate containing triple dynamic covalent bonds is the same as that in Example 7.

[0061] The silane-modified polyurethane acrylate containing triple dynamic covalent bonds prepared in Example 7 was uniformly mixed with 29.4 g of hydroxyethyl acrylate and 10 g of photoinitiator 2-hydroxy-2-methylpropiophenone under high-speed stirring, and then placed in a vacuum oven to degas for 30 minutes in the dark to obtain a detachable adhesive.

[0062] Comparative Example 1

[0063] Under a nitrogen atmosphere, 50 g of hydroxyl-terminated polydimethylsiloxane and 70 g of toluene diisocyanate after vacuum removal of water were added to a three-necked flask equipped with a mechanical stirring device and a condenser, and then 0.9 g of dibutyltin dilaurate and 120 g of tetrahydrofuran were added, mixed evenly and stirred for 1 hour; the mixture was heated to 70°C for reaction for 3 hours to obtain an isocyanate-terminated polysiloxane-urethane prepolymer, and then 9 g of dimethylglyoxime was added thereto, and the temperature was kept at 70°C for reaction for 3 hours to obtain a polysiloxane urethane prepolymer, and then 17 g of hydroxyethyl acrylate was added thereto for end-capping, and the reaction was continued at 70°C for 3 hours to obtain silane-modified polyurethane acrylate. After the reaction was completed, the temperature was lowered to 50°C, and the low molecular weight substances and solvents were removed by vacuum distillation, and then the mixture was placed in a 50°C vacuum oven to remove trace amounts of solvent to obtain a light yellow viscous liquid.

[0064] The prepared light yellow viscous liquid was mixed evenly with 29.4 g of hydroxyethyl acrylate and 7.6 g of a photoinitiator 2-hydroxy-2-methylpropiophenone under high-speed stirring, and then placed in a vacuum oven to degas for 30 minutes in the dark to obtain a detachable adhesive.

[0065] test

[0066] (1) Curing efficiency of adhesives: In order to investigate the effect of the amount of photoinitiator added on the curing efficiency of adhesives, each group of adhesives was irradiated with a UV light source for 5 min, and then the conversion rate of double bonds in the adhesives was investigated by real-time infrared spectroscopy, expressed as a percentage.

[0067] (2) Tensile shear strength of adhesive: In order to explore the effect of the addition amount of hydroxyethyl acrylate on the tensile shear strength of the adhesive, the tensile shear strength of the adhesive was tested according to GB7124-1986 standard.

[0068] (3) Thermal detachable performance test of the adhesive: Fix one end of two glass substrates bonded by the adhesive, place a 1 kg weight at the other end, and then perform heat treatment on the bonded area at 120 °C using a hot air gun, and record the time when the weight drops.

[0069] Table 1 Test data of each example

[0070] Curing efficiency Tensile shear strength Heating disassembly time Example 1 92.6％ 3.56MPa 178s Example 2 92.1％ 3.48MPa 185s Example 3 92.8％ 3.52MPa 188s Example 4 92.5％ 3.58MPa 175s Example 5 92.5％ 3.59MPa 178s Example 6 92.3％ 3.54MPa 172s Example 7 92.5％ 3.54MPa 170s Example 8 92.4％ 3.53MPa 179s Example 9 92.6％ 1.96MPa 205s Example 10 91.8％ 1.39MPa 214s Example 11 65.6％ 3.45MPa 202s Example 12 72.3％ 3.42MPa 225s Comparative Example 1 91.0％ 2.87MPa 230s

[0071] Inspired by the ideal embodiments of the present invention described above, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A silicone-modified polyurethane acrylate containing triple dynamic bonds, characterized in that, The organosilicon-modified polyurethane acrylate is composed of the following components in parts by mass: 50-60 parts by mass of hydroxyl-terminated polydimethylsiloxane, 50-100 parts by mass of diisocyanate, 6-10 parts by mass of diaminoglyoxime, and 15-20 parts by mass of hydroxyethyl acrylate.

2. The organosilicon-modified polyurethane acrylate containing triple dynamic bonds according to claim 1, wherein, The structural formula of the organosilicon-modified polyurethane acrylate containing triple dynamic bonds is as follows:

3. The organosilicon-modified polyurethane acrylate containing triple dynamic bonds according to claim 1, wherein The preparation method of the organosilicon-modified polyurethane acrylate containing triple dynamic bonds comprises the following steps: (1) Under a nitrogen atmosphere, the hydroxyl-terminated polydimethylsiloxane, diisocyanate, organotin catalyst and solvent that have been dehydrated by vacuum are added to a three-necked flask, evacuated, filled with nitrogen, and stirred to fully mix the raw materials; the mixture is heated to 70 °C and reacted for 2-3 h to obtain a prepolymer polysiloxane urethane; (2) Add diaminoglyoxime to the prepolymer polysiloxane urethane and react at 70 °C for 2-3 h to obtain a polysiloxane urethane containing oxime-carbamate bonds, dynamic urea bonds and hydrogen bonds; (3) Continuously add hydroxyethyl acrylate and react at 70 °C for 3-4 h to obtain a silane-modified polyurethane acrylate containing triple dynamic bonds; after the reaction is completed, the temperature is lowered to 50 °C, and vacuum distillation is carried out to remove low-molecular substances and solvents, and then it is placed in a vacuum oven at 50 °C to remove the solvent to obtain a pale yellow viscous liquid organosilicon-modified polyurethane acrylate.

4. The organosilicon-modified polyurethane acrylate containing triple dynamic bonds according to claim 3, characterized in that, In step (1), the hydroxyl-terminated polydimethylsiloxane has a molecular weight of 500; the solvent is selected from one of tetrahydrofuran, ethyl acetate, toluene, and xylene.

5. The organosilicon-modified polyurethane acrylate containing triple dynamic bonds according to claim 3, characterized in that, In step (1), the diisocyanate is selected from one of toluene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and hexamethylene diisocyanate.

6. The organosilicon-modified polyurethane acrylate containing triple dynamic bonds according to claim 3, wherein In step (1), the organotin catalyst is dibutyltin dilaurate, and its dosage is 0.3%-0.5% of the total mass of the reaction system.

7. A silicone-modified polyurethane acrylate UV tackifier containing triple dynamic bonds, characterized in that, The pressure-sensitive adhesive is composed of the organosilicon-modified polyurethane acrylate containing triple dynamic bonds as described in claim 1, an active diluent and a photoinitiator.

8. The silicone-modified polyurethane acrylate UV tackifier containing triple dynamic bonds according to claim 7, wherein, The active diluent is hydroxyethyl acrylate, and its dosage is 20% of the mass of the organosilicon-modified polyurethane acrylate.

9. The silicone-modified polyurethane acrylate UV tack-reducing adhesive containing triple dynamic bonds according to claim 7, wherein, The photoinitiator is 2-hydroxy-2-methylpropiophenone, and its dosage is 4% of the mass of the organosilicon-modified polyurethane acrylate.

10. A preparation method of the silicone-modified polyurethane acrylate UV pressure-sensitive adhesive containing triple dynamic bonds according to claim 7, characterized in that, The preparation method is: uniformly mix the organosilicon-modified polyurethane acrylate, the active diluent and the photoinitiator under high-speed stirring, and then place it in a vacuum oven to remove bubbles in the dark for 30 min to obtain a detachable adhesive.

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