Organic silicon adhesion promoter, organic silicon pressure-sensitive adhesive and adhesive tape

Abstract

The invention discloses an organic silicon adhesion promoter, an organic silicon pressure-sensitive adhesive and an adhesive tape. The organic silicon adhesion promoter disclosed by the invention is prepared by carrying out hydrosilylation reaction on hydrogen-containing polysiloxane and an epoxy compound containing a carbon-carbon double bond. The organic silicon pressure-sensitive adhesive disclosed by the invention is prepared by performing a sulfydryl-epoxy ring-opening reaction and a sulfydryl-vinyl click chemical reaction on an organic silicon bonding accelerant, sulfydryl silicone oil, vinyl silicone oil and methyl MQ silicon resin. The photo-thermal curing organic silicon pressure-sensitive adhesive disclosed by the invention can be used for carrying out photo-curing cross-linking reaction, has high bonding strength on adhered objects such as glass, steel plates and the like, and is simple in preparation method, wide in raw material source, low in production cost, high in production efficiency and suitable for large-scale industrial production and application.

Description

Technical Field

[0001] The present invention relates to the technical field of silicone adhesives, and specifically relates to a silicone adhesion promoter, a silicone pressure-sensitive adhesive and a tape. Background Art

[0002] A pressure-sensitive adhesive is a special adhesive that can quickly form a good adhesive force with the adherend only by applying a slight pressure, and its application range is very wide. The silicone pressure-sensitive adhesive is composed of a flexible Si-O-Si main chain and non-polar side groups, has a low surface energy, good wettability with various adherends, and can exhibit excellent stability in both high and low temperature environments, having broad application prospects. However, most of the existing silicone pressure-sensitive adhesives lack reactive groups, and the overall presents a weak polar or non-polar state, with a low bonding strength to adherends such as plastics and metals, and is not suitable for applications in some scenarios that require high adhesive force.

[0003] The main cross-linking methods of silicone materials can be divided into the following two types: 1) using the condensation reaction between silanols; 2) using a platinum catalyst or a peroxide initiator to carry out a hydrosilylation reaction or a free radical polymerization cross-linking reaction at high temperature. CN 108424746A discloses a preparation method of a silicone pressure-sensitive adhesive by polycondensation reaction between a hydroxyl-containing silicone rubber and a fluorophenyl silicone resin, but the hydrolysis polycondensation process used therein has cumbersome and unstable process steps and low production efficiency; CN116218456A discloses a method for preparing a silicone pressure-sensitive adhesive with medium to high adhesive force by adding a hydroxyl- and alkoxy-containing cage-like polyhedral oligomeric silsesquioxane functional additive, vinyl silicone rubber and MQ silicone resin, but the platinum catalyst used therein is easily poisoned by elements such as nitrogen / phosphorus / sulfur in the system and loses its catalytic ability, and the relatively high reaction temperature limits its application in fields such as heat-sensitive electronic components. UV curing has the advantages of high production efficiency, energy saving, environmental friendliness, etc., and is widely used in fields such as aerospace, automotive manufacturing, architectural decoration and electronic appliances. However, the conventional free radical polymerization method represented by acrylate groups has the problem that the reaction is easily quenched by a large amount of oxygen in the environment, and the shrinkage stress after curing is large, which severely limits its popularization and application in large-scale industrial production.

[0004] Therefore, it is of great significance to develop a silicone pressure-sensitive adhesive that can be cured by light and heat and has a high bonding strength. Summary of the Invention

[0005] The purpose of the present invention is to provide a silicone adhesion promoter, a silicone pressure-sensitive adhesive and a tape.

[0006] The technical solution adopted by the present invention is:

[0007] An organosilicon adhesion promoter is prepared by hydrosilylation reaction of a hydrogen-containing polysiloxane with an epoxy compound containing a carbon-carbon double bond; the hydrogen-containing polysiloxane is at least one of a hydrogen-containing silicone oil and a hydrogen-containing silicone resin; the epoxy compound containing a carbon-carbon double bond is at least one of allyl glycidyl ether, glycidyl methacrylate, epoxybutene, 1,2-epoxy-5-hexene, 3,4-epoxy-1-cyclohexene, 1,2-epoxy-4-vinylcyclohexane.

[0008] Preferably, the molar ratio of the Si-H group in the hydrogen-containing polysiloxane to the C═C group in the epoxy compound containing a carbon-carbon double bond is 1.0 to 1.5:1.

[0009] Preferably, the hydrogen content of the hydrogen-containing polysiloxane is 0.1 wt% to 1.2 wt%.

[0010] Preferably, the number average molecular weight of the organosilicon adhesion promoter is 1000 to 20000, and the epoxy value is 100 mmol / 100 g to 1200 mmol / 100 g.

[0011] A preparation method of the organosilicon adhesion promoter as described above includes the following steps:

[0012] 1) Disperse the hydrogen-containing polysiloxane and the epoxy compound containing a carbon-carbon double bond in an organic solvent, then add a platinum catalyst and react to obtain a polyorganosiloxane containing epoxy groups;

[0013] 2) Add activated carbon to the polyorganosiloxane containing epoxy groups for adsorption, filter, and take the filtrate for vacuum distillation to obtain the organosilicon adhesion promoter.

[0014] Preferably, the organic solvent in step 1) is at least one of toluene, xylene, tetrahydrofuran, methanol, ethanol, isopropanol, acetonitrile, cyclohexane, acetone, 1,4-dioxane.

[0015] Preferably, the platinum catalyst in step 1) is at least one of chloroplatinic acid and Karstedt platinum catalyst.

[0016] More preferably, the platinum catalyst in step 1) is at least one of an isopropanol solution of chloroplatinic acid, a tetrahydrofuran solution of chloroplatinic acid, and Karstedt platinum catalyst, and the platinum concentration is 1000 ppm to 4000 ppm.

[0017] Preferably, the addition amount of the platinum catalyst in step 1) is 1 ppm to 20 ppm.

[0018] Preferably, the reaction in step 1) is carried out at a temperature of 50 °C to 100 °C, and the reaction time is 1 h to 6 h.

[0019] Preferably, the adsorption time in step 2) is 2 h to 10 h.

[0020] Preferably, the vacuum distillation in step 2) is carried out under the condition that the temperature is 40°C to 150°C.

[0021] An organosilicon pressure-sensitive adhesive is prepared by subjecting the above-mentioned organosilicon adhesion promoter, mercapto silicone oil, vinyl silicone oil and methyl MQ silicone resin to thiol-epoxy ring-opening reaction and thiol-vinyl click chemical reaction.

[0022] Preferably, the molar ratio of the epoxy group in the organosilicon adhesion promoter to the SH group in the mercapto silicone oil is 1:1 to 5.

[0023] Preferably, the molar ratio of the C═C group in the vinyl silicone oil to the SH group in the mercapto silicone oil is 1:1 to 12.

[0024] Preferably, the number-average molecular weight of the mercapto silicone oil is 3000 to 50000, and the mercapto content is 1 mmol / 100 g to 1000 mmol / 100 g.

[0025] Preferably, the number-average molecular weight of the vinyl silicone oil is 5000 to 800000, and the vinyl content is 0.01 wt% to 5.00 wt%.

[0026] Preferably, the M / Q ratio of the methyl MQ silicone resin is 0.5 to 1.2, and the molar mass is 1000 g / mol to 5000 g / mol.

[0027] Preferably, the dosage of the methyl MQ silicone resin is 0 wt% to 600 wt% of the mass of the vinyl silicone oil.

[0028] A preparation method of the organosilicon pressure-sensitive adhesive as described above includes the following steps: dissolving the vinyl silicone oil and the methyl MQ silicone resin in an organic solvent, adding the organosilicon adhesion promoter, mercapto silicone oil, photoinitiator and thermal initiator, mixing evenly, then carrying out defoaming, then carrying out thiol-epoxy ring-opening reaction, and then carrying out thiol-vinyl click chemical reaction to obtain the organosilicon pressure-sensitive adhesive.

[0029] Preferably, the organic solvent is at least one of toluene, xylene, tetrahydrofuran, methanol, ethanol, isopropanol, acetonitrile, cyclohexane, acetone, 1,4-dioxane.

[0030] Preferably, the photoinitiator is at least one of benzophenone, benzoin dimethyl ether, 2-hydroxy-2-methyl-1-phenyl-1-propanone, hydroxycyclohexanone phenyl ketone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoyl phenylphosphonate.

[0031] Preferably, the mass ratio of the vinyl silicone oil to the photoinitiator is 1:0.001 - 0.05.

[0032] Preferably, the thermal initiator is at least one of 2,4,6-tris(dimethylaminomethyl)phenol, benzyldimethylamine, and 1,8-diazabicyclo[5.4.0]undec-7-ene.

[0033] Preferably, the ratio of the molar amount of the epoxy group in the organosilicon adhesion promoter to the molar amount of the thermal initiator is 1:0.05 - 0.5.

[0034] Preferably, the thiol-epoxy ring-opening reaction is carried out at a temperature of 30°C to 150°C for a reaction time of 0.5 h to 5 h.

[0035] Preferably, the thiol-vinyl click chemical reaction is carried out under the conditions of a UV light irradiation dose of 50 mJ / cm 2 ~2000 mJ / cm 2 and a maximum light intensity of 5 mW / cm 2 ~300 mW / cm 2 for a reaction time of 1 s to 600 s.

[0036] A tape, the composition of which includes a PET substrate and an adhesive layer attached to one side / both sides of the PET substrate; the adhesive layer contains the above-mentioned organosilicon pressure-sensitive adhesive.

[0037] The beneficial effects of the present invention are as follows: The organosilicon pressure-sensitive adhesive of the present invention can undergo photocuring crosslinking reaction, has high adhesive strength to adherends such as glass and steel plates, and its preparation method is simple, the raw materials are widely available, the production cost is low, and the production efficiency is high, which is suitable for large-scale industrial production and application.

[0038] Specifically:

[0039] 1) The organosilicon pressure-sensitive adhesive of the present invention can be crosslinked by thiol-vinyl click reaction after being initiated by UV light, is insensitive to oxygen and moisture, and does not require protection by inert gases such as nitrogen.

[0040] 2) The organosilicon pressure-sensitive adhesive of the present invention can undergo ring-opening reaction under heating conditions, and the generated polar hydroxyl groups can form strong hydrogen bonds and van der Waals forces with the adherend, significantly improving the adhesive strength between the organosilicon pressure-sensitive adhesive and adherends such as glass and steel plates, and can be widely applied in the fields of transportation, consumer electronics, and biomedicine.

[0041] 3) The preparation method of the organosilicon pressure-sensitive adhesive of the present invention is simple, the raw materials are widely available, the production cost is low, and the production efficiency is high, which is suitable for large-scale industrial production and application. Description of the Drawings

[0042] Figure 1 It is the Fourier infrared spectrum diagram of hydrogen-containing silicone oil, 1,2-epoxy-4-vinylcyclohexane and the silicone adhesive promoter in Example 1. Specific Embodiments

[0043] The present invention will be further explained and described below in conjunction with specific embodiments.

[0044] Example 1:

[0045] A silicone adhesive promoter, and its preparation method is as follows:

[0046] 1) At 25 °C, add 4.2 g of hydrogen-containing silicone oil with a hydrogen content of 0.75 wt% (containing 0.031 mol of Si-H), 3.1 g of 1,2-epoxy-4-vinylcyclohexane (containing 0.025 mol of C=C), 0.008 g of Karstedt platinum catalyst with a platinum concentration of 2000 ppm, and 10 g of isopropanol into a reaction kettle with a volume of 100 mL, stir for 30 min, then raise the temperature to 80 °C and react for 5 h to obtain a polyorganosiloxane containing epoxy groups;

[0047] 2) Add an appropriate amount of activated carbon to the polyorganosiloxane containing epoxy groups for adsorption for 5 h, filter, and take the filtrate for vacuum distillation at 80 °C to obtain the silicone adhesive promoter.

[0048] The Fourier infrared spectrum diagrams of the hydrogen-containing silicone oil, 1,2-epoxy-4-vinylcyclohexane, and the silicone adhesive promoter in this example are as Figure 1 shown (testing method: using ATR attenuated total reflection spectroscopy, directly drop the liquid sample on the ZnSe crystal, use infrared interference light to pass through the sample and collect the interference signal of the sample, the wave number range is 4000 cm -1 ~650 cm -1 , the accuracy is 4 cm -1 , and the number of scans is 16 times).

[0049] It can be seen from Figure 1 that:

[0050] a) The characteristic peak of the hydrogen-containing silicone oil appearing at 2965 cm -1 belongs to the antisymmetric stretching vibration peak of C-H in -Si-CH 3 , the characteristic peak at 2160 cm -1 belongs to the stretching vibration peak of -Si-H, the characteristic peak at 1260 cm -1 belongs to the characteristic absorption peak of -Si-CH 3 , and 1092 cm -1 and 1035 cm -1The characteristic peak at [specific location] belongs to the symmetric stretching absorption peak of -Si-O-Si;

[0051] b) The characteristic peaks that appear at 2931 cm -1 and 2855 cm -1 belong to the C-H stretching vibration peak in -CH 2 , the characteristic peak at 1640 cm -1 belongs to the stretching vibration peak of C=C, and the characteristic peak at 911 cm -1 belongs to the stretching vibration peak of the epoxy group;

[0052] c) In addition to the above characteristic peaks, the characteristic peak at 1640 cm -1 belonging to the stretching vibration peak of C=C disappears for the organosilicon adhesion promoter. However, since the amount of silicon-hydrogen bond is greater than that of carbon-carbon double bond, there is still a certain intensity of the stretching vibration peak of -Si-H;

[0053] In summary, it can be seen that the organosilicon adhesion promoter with the expected structure is indeed synthesized in this example.

[0054] An organosilicon pressure-sensitive adhesive, and its preparation method is as follows:

[0055] Dissolve 100 parts by mass of vinyl silicone oil (number-average molecular weight is 800000, vinyl content is 0.01 wt%) and 100 parts by mass of methyl MQ silicone resin (M / Q ratio is 0.8, molar mass is 3000 g / mol) in toluene, and then add 1 part by mass of the above organosilicon adhesion promoter, 5.6 parts by mass of mercapto silicone oil (number-average molecular weight is 20000, mercapto content is 180 mmol / 100 g), 2 parts by mass of 2-hydroxy-2-methyl-1-phenyl-1-propanone, and 1,8-diazabicyclo[5.4.0]undec-7-ene accounting for 35 mol% of the molar amount of the epoxy group in the organosilicon adhesion promoter. Stir evenly at 25°C, then defoam for 10 min under the condition of a vacuum degree of 0.01 MPa. Then coat the obtained mixture on the surface of the PET film, then place it in an oven and bake at 80°C for 3 h, and then place it in a UV curing machine for irradiation crosslinking for 60 s, controlling the irradiation dose to be 1000 mJ / cm 2 and the maximum light intensity to be 80 mW / cm 2 , thus obtaining the organosilicon pressure-sensitive adhesive.

[0056] Example 2:

[0057] An organosilicon adhesion promoter, and its preparation method is as follows:

[0058] 1) At 10 °C, 7.6 g of hydrogen-containing silicone oil with a hydrogen content of 0.1 wt% (containing 0.0075 mol of Si-H), 0.7 g of allyl glycidyl ether (containing 0.006 mol of C=C), 0.017 g of Karstedt platinum catalyst with a platinum concentration of 1000 ppm, and 10 g of toluene were added to a reaction kettle with a volume of 100 mL, stirred for 30 min, and then heated to 50 °C and reacted for 1 h to obtain a polyorganosiloxane containing epoxy groups;

[0059] 2) An appropriate amount of activated carbon was added to the polyorganosiloxane containing epoxy groups for adsorption for 2 h, filtered, and the filtrate was subjected to vacuum distillation at 40 °C to obtain an organosilicon adhesion promoter.

[0060] A method for preparing an organosilicon pressure-sensitive adhesive is as follows:

[0061] 100 parts by mass of vinyl silicone oil (number-average molecular weight of 200,000 and vinyl content of 0.02 wt%) and 10 parts by mass of methyl MQ silicone resin (M / Q ratio of 0.5 and molar mass of 1000 g / mol) were dissolved in toluene, and then 0.1 part by mass of the above-mentioned organosilicon adhesion promoter, 88.3 parts by mass of mercapto silicone oil (number-average molecular weight of 40,000 and mercapto content of 15 mmol / 100 g), 0.1 part by mass of benzophenone, and 2,4,6-tris(dimethylaminomethyl)phenol accounting for 5 mol% of the molar amount of epoxy groups in the organosilicon adhesion promoter were added. After stirring evenly at 25 °C, defoaming was carried out for 10 min under a vacuum of 0.01 MPa. Then, the obtained mixture was coated on the surface of a PET film, placed in an oven at 30 °C and baked for 0.5 h, and then irradiated and crosslinked in a UV curing machine for 10 s, controlling the irradiation dose to be 50 mJ / cm 2 and the maximum light intensity to be 5 mW / cm 2 , thus obtaining the organosilicon pressure-sensitive adhesive.

[0062] Example 3:

[0063] A method for preparing an organosilicon adhesion promoter is as follows:

[0064] 1) At 40 °C, 5.3 g of hydrogen-containing silicone oil with a hydrogen content of 1.2 wt% (containing 0.0625 mol of Si-H), 7.1 g of glycidyl methacrylate (containing 0.05 mol of C=C), 0.13 g of Karstedt platinum catalyst with a platinum concentration of 4000 ppm, and 15 g of toluene were added to a reaction kettle with a volume of 100 mL, stirred for 30 min, and then heated to 100 °C and reacted for 6 h to obtain a polyorganosiloxane containing epoxy groups;

[0065] 2) Add an appropriate amount of activated carbon to the epoxy group-containing polysiloxane for adsorption for 10 h, filter, and take the filtrate for vacuum distillation at 150 °C to obtain the silicone adhesion promoter.

[0066] A silicone pressure-sensitive adhesive, and its preparation method is as follows:

[0067] Dissolve 100 parts by mass of vinyl silicone oil (number-average molecular weight is 8000, vinyl content is 0.8 wt%) and 230 parts by mass of methyl MQ silicone resin (M / Q ratio is 1.2, molar mass is 1000 g / mol) in toluene, and then add 5 parts by mass of the above-mentioned silicone adhesion promoter, 19.6 parts by mass of mercapto silicone oil (number-average molecular weight is 3000, mercapto content is 1000 mmol / 100 g), 5 parts by mass of benzoin dimethyl ether, and 50 mol% of the molar amount of the epoxy group in the silicone adhesion promoter of benzyl dimethylamine, stir evenly at 25 °C, then defoam for 10 min under the condition of a vacuum degree of 0.01 MPa, then apply the obtained mixture on the surface of the PET film, then place it in an oven at 150 °C for baking for 5 h, and then place it in a UV curing machine for irradiation crosslinking for 600 s, controlling the irradiation dose to be 2000 mJ / cm 2 and the maximum light intensity is 300 mW / cm 2 to obtain the silicone pressure-sensitive adhesive.

[0068] Example 4:

[0069] A silicone adhesion promoter, and its preparation method is as follows:

[0070] 1) At 30 °C, add 18.9 g of hydrogen-containing silicone oil with a hydrogen content of 0.8 wt% (containing 0.15 mol of Si-H), 9.6 g of 3,4-epoxy-1-cyclohexene (containing 0.1 mol of C=C), 0.19 g of chloroplatinic acid platinum catalyst with a platinum concentration of 3000 ppm, and 30 g of toluene to a reaction kettle with a volume of 100 mL, stir for 30 min, and then raise the temperature to 90 °C for reaction for 5 h to obtain the epoxy group-containing polysiloxane;

[0071] 2) Add an appropriate amount of activated carbon to the epoxy group-containing polysiloxane for adsorption for 8 h, filter, and take the filtrate for vacuum distillation at 100 °C to obtain the silicone adhesion promoter.

[0072] A silicone pressure-sensitive adhesive, and its preparation method is as follows:

[0073] Dissolve 100 parts by mass of vinyl silicone oil (number-average molecular weight is 10,000, vinyl content is 0.6 wt%) and 100 parts by mass of methyl MQ silicone resin (M / Q ratio is 1.0, molar mass is 4,000 g / mol) in toluene, then add 3 parts by mass of the above silicone adhesive promoter, 28 parts by mass of mercapto silicone oil (number-average molecular weight is 30,000, mercapto content is 500 mmol / 100 g), 3 parts by mass of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 30 mol% of benzyl dimethylamine based on the molar amount of epoxy groups in the silicone adhesive promoter, stir evenly at 25°C, then defoam for 10 min under the condition of a vacuum degree of 0.01 MPa, then coat the obtained mixture on the surface of the PET film, then place it in an oven and bake at 100°C for 4 h, and then place it in a UV curing machine for irradiation crosslinking for 450 s, controlling the irradiation dose to be 1500 mJ / cm 2 , and the maximum light intensity is 150 mW / cm 2 , thus obtaining the silicone pressure-sensitive adhesive.

[0074] Example 5:

[0075] A silicone adhesive promoter, and its preparation method is as follows:

[0076] 1) Add 10.1 g of hydrogen-containing silicone oil with a hydrogen content of 1.0 wt% (containing 0.1 mol of Si-H), 9.6 g of 3,4-epoxy-1-cyclohexene (containing 0.1 mol of C=C), 0.21 g of Karstedt platinum catalyst with a platinum concentration of 2000 ppm and 20 g of ethanol into a reaction kettle with a volume of 100 mL at 40°C, stir for 30 min, then raise the temperature to 60°C and react for 2 h to obtain a polyorganosiloxane containing epoxy groups;

[0077] 2) Add an appropriate amount of activated carbon to the polyorganosiloxane containing epoxy groups for adsorption for 3 h, filter, and take the filtrate for vacuum distillation at 50°C to obtain the silicone adhesive promoter.

[0078] A silicone pressure-sensitive adhesive, and its preparation method is as follows:

[0079] Dissolve 100 parts by mass of vinyl silicone oil (number-average molecular weight is 12,000, vinyl content is 0.5 wt%) and 150 parts by mass of methyl MQ silicone resin (M / Q ratio is 0.9, molar mass is 1500 g / mol) in toluene, then add 4 parts by mass of the above silicone adhesive promoter, 39.3 parts by mass of mercapto silicone oil (number-average molecular weight is 15,000, mercapto content is 300 mmol / 100 g), 2 parts by mass of ethyl 2,4,6-trimethylbenzoyl phenylphosphinate and 2,4,6-tris(dimethylaminomethyl)phenol accounting for 10 mol% of the molar amount of epoxy groups in the silicone adhesive promoter, stir evenly at 25 °C, then defoam for 10 min under the condition of a vacuum degree of 0.01 MPa, then coat the obtained mixture on the surface of the PET film, then place it in an oven and bake at 80 °C for 5 h, and then place it in a UV curing machine for irradiation crosslinking for 200 s, controlling the irradiation dose to be 800 mJ / cm 2 , and the maximum light intensity is 100 mW / cm 2 , thus obtaining the silicone pressure-sensitive adhesive.

[0080] Example 6:

[0081] A silicone adhesive promoter, and its preparation method is as follows:

[0082] 1) At 20 °C, add 20.1 g of hydrogen-containing silicone oil with a hydrogen content of 0.6 wt% (containing 0.12 mol of Si-H), 11.4 g of allyl glycidyl ether (containing 0.1 mol of C=C), 0.48 g of Karstedt platinum catalyst with a platinum concentration of 2000 ppm and 40 g of tetrahydrofuran into a reaction kettle with a volume of 100 mL, stir for 30 min, and then raise the temperature to 50 °C and react for 5 h to obtain a polyorganosiloxane containing epoxy groups;

[0083] 2) Add an appropriate amount of activated carbon to the polyorganosiloxane containing epoxy groups for adsorption for 5 h, filter, and take the filtrate for vacuum distillation at 80 °C to obtain the silicone adhesive promoter.

[0084] A silicone pressure-sensitive adhesive, and its preparation method is as follows:

[0085] Dissolve 100 parts by mass of vinyl silicone oil (number-average molecular weight is 18,000, vinyl content is 0.3 wt%) and 100 parts by mass of methyl MQ silicone resin (M / Q ratio is 0.6, molar mass is 1200 g / mol) in toluene, then add 1 part by mass of the above silicone adhesive promoter, 73.6 parts by mass of mercapto silicone oil (number-average molecular weight is 30,000, mercapto content is 100 mmol / 100 g), 1 part by mass of ethyl 2,4,6-trimethylbenzoyl phenylphosphinate and 2,4,6-tris(dimethylaminomethyl)phenol accounting for 20 mol% of the molar amount of epoxy groups in the silicone adhesive promoter, stir evenly at 25 °C, then defoam for 10 min under the condition of a vacuum degree of 0.01 MPa, then coat the obtained mixture on the surface of the PET film, then place it in an oven and bake at 50 °C for 5 h, and then place it in a UV curing machine for irradiation crosslinking for 300 s, controlling the irradiation dose to be 1000 mJ / cm 2 ², and the maximum light intensity is 100 mW / cm 2 , thus obtaining the silicone pressure-sensitive adhesive.

[0086] Example 7:

[0087] A silicone adhesive promoter, and its preparation method is as follows:

[0088] 1) At 25 °C, add 26.2 g of hydrogen-containing silicone oil with a hydrogen content of 0.5 wt% (containing 0.13 mol of Si-H), 11.4 g of allyl glycidyl ether (containing 0.1 mol of C═C), 0.38 g of Karstedt platinum catalyst with a platinum concentration of 2000 ppm and 40 g of acetonitrile into a reaction kettle with a volume of 100 mL, stir for 30 min, and then raise the temperature to 50 °C and react for 6 h to obtain a polyorganosiloxane containing epoxy groups;

[0089] 2) Add an appropriate amount of activated carbon to the polyorganosiloxane containing epoxy groups for adsorption for 10 h, filter, and take the filtrate for vacuum distillation at 80 °C to obtain the silicone adhesive promoter.

[0090] A silicone pressure-sensitive adhesive, and its preparation method is as follows:

[0091] Dissolve 100 parts by mass of vinyl silicone oil (number-average molecular weight is 20,000, vinyl content is 0.2 wt%) and 66 parts by mass of methyl MQ silicone resin (M / Q ratio is 0.7, molar mass is 1900 g / mol) in toluene, then add 3 parts by mass of the above silicone adhesive promoter, 103 parts by mass of mercapto silicone oil (number-average molecular weight is 40,000, mercapto content is 50 mmol / 100 g), 3 parts by mass of benzoin dimethyl ether and 20 mol% of benzyl dimethylamine based on the molar amount of epoxy groups in the silicone adhesive promoter. Stir evenly at 25 °C, then defoam for 10 min under the condition of a vacuum degree of 0.01 MPa. Then coat the obtained mixture on the surface of the PET film, place it in an oven and bake at 70 °C for 2 h, and then place it in a UV curing machine for irradiation crosslinking for 200 s, controlling the irradiation dose to be 500 mJ / cm 2 , and the maximum light intensity is 50 mW / cm 2 , thus obtaining the silicone pressure-sensitive adhesive.

[0092] Example 8:

[0093] A silicone adhesive promoter, and its preparation method is as follows:

[0094] 1) At 40 °C, add 36.9 g of hydrogen-containing silicone oil with a hydrogen content of 0.3 wt% (containing 0.11 mol of Si-H), 14.2 g of glycidyl methacrylate (containing 0.1 mol of C=C), 1.03 g of Karstedt platinum catalyst with a platinum concentration of 1000 ppm and 50 g of 1,4-dioxane into a reaction kettle with a volume of 100 mL, stir for 30 min, and then raise the temperature to 80 °C and react for 2 h to obtain a polyorganosiloxane containing epoxy groups;

[0095] 2) Add an appropriate amount of activated carbon to the polyorganosiloxane containing epoxy groups for adsorption for 10 h, filter, and take the filtrate for vacuum distillation at 100 °C to obtain the silicone adhesive promoter.

[0096] A silicone pressure-sensitive adhesive, and its preparation method is as follows:

[0097] Dissolve 100 parts by mass of vinyl silicone oil (number-average molecular weight is 30,000, vinyl content is 0.1 wt%) and 230 parts by mass of methyl MQ silicone resin (M / Q ratio is 0.8, molar mass is 2000 g / mol) in toluene, then add 1 part by mass of the above silicone adhesive promoter, 6 parts by mass of mercapto silicone oil (number-average molecular weight is 10,000, mercapto content is 500 mmol / 100 g), 2 parts by mass of dimethoxybenzyl ether, and 10 mol% of benzyldimethylamine based on the molar amount of epoxy groups in the silicone adhesive promoter. Stir evenly at 25°C, then defoam for 10 min under the condition of a vacuum degree of 0.01 MPa. Then coat the obtained mixture on the surface of the PET film, place it in an oven and bake at 60°C for 1 h, and then place it in a UV curing machine for irradiation crosslinking for 500 s, controlling the irradiation dose to be 2000 mJ / cm 2 , and the maximum light intensity is 50 mW / cm 2 , thus obtaining the silicone pressure-sensitive adhesive.

[0098] Comparative Example 1:

[0099] A silicone pressure-sensitive adhesive, and its preparation method is as follows:

[0100] Dissolve 100 parts by mass of vinyl silicone oil (number-average molecular weight is 33,000, vinyl content is 0.09 wt%) and 100 parts by mass of methyl MQ silicone resin (M / Q ratio is 0.8, molar mass is 2100 g / mol) in toluene, then add 0.76 parts by mass of hydrogen-containing silicone oil (hydrogen content is 0.75 wt%) and 5.26 parts by mass of Karstedt platinum catalyst with a platinum concentration of 2000 ppm. Stir evenly at 25°C, then defoam for 10 min under the condition of a vacuum degree of 0.01 MPa. Then coat the obtained mixture on the surface of the PET film, place it in an oven and bake at 80°C for 2 h, thus obtaining the silicone pressure-sensitive adhesive.

[0101] Comparative Example 2:

[0102] A silicone pressure-sensitive adhesive, and its preparation method is as follows:

[0103] Dissolve 100 parts by mass of vinyl silicone oil (number-average molecular weight is 33000, vinyl content is 0.09 wt%), 4 parts by mass of vinyl silicone oil (vinyl content is 3.13 wt%) and 100 parts by mass of methyl MQ silicone resin (M / Q ratio is 0.8, molar mass is 2500 g / mol) in toluene, then add 26.5 parts by mass of mercapto silicone oil (number-average molecular weight is 20000, mercapto content is 55 mmol / 100 g) and 2 parts by mass of 2-hydroxy-2-methyl-1-phenyl-1-propanone, stir evenly at 25 °C, then defoam for 10 min under the condition of a vacuum degree of 0.01 MPa, then coat the obtained mixture on the surface of a PET film, and then place it in a UV curing machine for irradiation crosslinking for 100 s, controlling the irradiation dose to be 1000 mJ / cm 2 and the maximum light intensity is 70 mW / cm 2 , thus obtaining the silicone pressure-sensitive adhesive.

[0104] Performance test:

[0105] The test results of the adhesion performance of the silicone pressure-sensitive adhesives in Examples 1 to 8 and Comparative Examples 1 to 2 are shown in the following table:

[0106] Table 1 Test results of the adhesion performance of silicone pressure-sensitive adhesives

[0107]

[0108]

[0109] Note:

[0110] Adhesion performance (180° peel strength): Test according to "GB / T 2792-2014 Test method for peel strength of adhesive tapes", the width of the pressure-sensitive adhesive is 25 mm ± 1 mm, the thickness is 50 μm ± 10 μm, the length is about 200 mm, the adherend substrate is PET, and the adherend is glass.

[0111] Adhesion performance (initial tack of rolling ball): Test according to "GB / T 4852-2002 Test method for initial tack of pressure-sensitive adhesive tapes", the width of the pressure-sensitive adhesive is 25 mm ± 1 mm, the thickness is 50 μm ± 10 μm, and the length is about 100 mm.

[0112] Adhesion performance (holding power): Test according to "GB / T 4851-2014 Test method for holding power of adhesive tapes", the width of the pressure-sensitive adhesive is 25 mm ± 1 mm, the thickness is 50 μm ± 10 μm, the adherend is a stainless steel test plate wiped with ethanol and toluene, and the bonding area size is 25 mm × 10 mm.

[0113] As can be seen from Table 1, the bonding performance of the silicone pressure-sensitive adhesives without the silicone bonding promoter (Comparative Example 1 and Comparative Example 2) is poor. However, the silicone pressure-sensitive adhesives in Examples 1 to 8 have excellent bonding strength with the glass adherend, and maintain a high initial tack and holding tack. That is, the silicone bonding promoter of the present invention can significantly improve the bonding performance of the silicone pressure-sensitive adhesive with the adherend, and the bonding strength is better than that of the existing silicone pressure-sensitive adhesives (for example, the 180° peel force of the silicone pressure-sensitive adhesive in Example 1 on the glass adherend is as high as 12.5 N / 25 mm, which is 124 times higher than that of the silicone pressure-sensitive adhesive in Comparative Example 2). The reason is that the epoxy compound containing a carbon-carbon double bond is successfully grafted onto the hydrogen-containing polysiloxane through a hydrosilylation reaction to obtain a polar epoxy group-containing silicone bonding promoter. The epoxy group-containing silicone bonding promoter and the silicone matrix both contain a Si-O-Si main chain, so they have good compatibility. Moreover, the epoxy group will undergo a ring-opening reaction with the mercapto silicone oil in the system under heating conditions, and the generated hydroxyl groups can form strong hydrogen bond interactions and van der Waals forces with the adherend, so it has the effect of increasing the adhesive force.

[0114] The above embodiments are the preferred embodiments of the present invention. However, the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A silicone adhesion promoter, characterized in that: The invention is prepared by a hydrosilylation reaction between a hydrogen-containing polysiloxane and an epoxy compound containing a carbon-carbon double bond; the hydrogen-containing polysiloxane is at least one of hydrogen-containing silicone oil and hydrogen-containing silicone resin; the epoxy compound containing a carbon-carbon double bond is at least one of allyl glycidyl ether, glycidyl methacrylate, epoxybutene, 1,2-epoxy-5-hexene, 3,4-epoxy-1-cyclohexene and 1,2-epoxy-4-vinylcyclohexane.

2. The organic silicon adhesion promoter according to claim 1, characterized in that: The molar ratio of the Si-H group in the hydrogen-containing polysiloxane to the C=C group in the epoxy compound containing a carbon-carbon double bond is 1.0-1.5:

1.

3. The organic silicon adhesion promoter according to claim 1 or 2, characterized in that: The hydrogen content of the hydrogen-containing polysiloxane is 0.1 wt % to 1.2 wt %.

4. The organic silicon adhesion promoter according to claim 1 or 2, characterized in that: The number average molecular weight of the organic silicon adhesion promoter is 1000 to 20000, and the epoxy value is 100 mmol / 100 g to 1200 mmol / 100 g.

5. A silicone pressure-sensitive adhesive, characterized in that: The adhesive is prepared by subjecting the organic silicon adhesion promoter according to any one of claims 1 to 4, mercapto silicone oil, vinyl silicone oil and methyl MQ silicone resin to mercapto-epoxy ring-opening reaction and mercapto-vinyl click chemical reaction.

6. The organic silicone pressure-sensitive adhesive according to claim 5, characterized in that: The molar ratio of the epoxy group in the organic silicon adhesion promoter to the SH group in the mercapto silicone oil is 1:1-5.

7. The organic silicone pressure-sensitive adhesive according to claim 5 or 6, characterized in that: The molar ratio of the C=C group in the vinyl silicone oil to the SH group in the mercapto silicone oil is 1:1-12.

8. The organic silicone pressure-sensitive adhesive according to claim 5 or 6, characterized in that: The number average molecular weight of the mercapto silicone oil is 3000-50000, and the mercapto content is 1mmol / 100g-1000mmol / 100g; the number average molecular weight of the vinyl silicone oil is 5000-800000, and the vinyl content is 0.01wt%-5.00wt%; the M / Q ratio of the methyl MQ silicone resin is 0.5-1.2, and the molar mass is 1000g / mol-5000g / mol.

9. A method for preparing an organosilicon pressure-sensitive adhesive as claimed in any one of claims 5 to 8, characterized in that: The following steps are involved: Vinyl silicone oil and methyl MQ silicone resin are dissolved in an organic solvent, and then silicone adhesion promoter, mercapto silicone oil, photoinitiator and thermal initiator are added and mixed, and then defoaming is performed, and then mercapto-epoxy ring-opening reaction is performed, and then mercapto-vinyl click chemical reaction is performed to obtain silicone pressure-sensitive adhesive.

10. An adhesive tape, characterized in that: The composition includes a PET substrate and an adhesive layer attached to one side or both sides of the PET substrate; The adhesive layer comprises the organic silicone pressure-sensitive adhesive according to any one of claims 5 to 8.

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