Preparation method and application of high-temperature-resistant pressure-sensitive adhesive tape

Abstract

The invention discloses a preparation method and application of a high-temperature-resistant pressure-sensitive adhesive tape, belongs to the technical field of pressure-sensitive adhesive tape processing, and aims to solve the technical problem that the high-temperature resistance and the adhesion property of a polyacrylate pressure-sensitive adhesive tape need to be further improved in the prior art. The preparation method comprises the following steps: adding composite polypropylene and N, N-dimethylformamide into a flask, stirring until a system is dissolved, and screening with a 500-mesh screen to obtain a composite polypropylene solution; putting the composite polypropylene solution into a three-neck flask under the protection of nitrogen, stirring, and adding isocyanatopropyltriethoxysilane into the three-neck flask in batches; the cross-linked composite polypropylene with relatively uniform molecular weight and the tackifier are prepared, and the isocyanatopropyltriethoxysilane and the activation liquid are added to cooperate with each other, so that the high temperature resistance of the pressure-sensitive adhesive tape is effectively improved, the initial adhesion strength, the peel strength and the holding power of the pressure-sensitive adhesive tape are improved, and the pressure-sensitive adhesive tape has good adhesion performance.

Description

Technical Field

[0001] The invention relates to the technical field of pressure-sensitive adhesive tape processing, and in particular to a preparation method and application of a high-temperature resistant pressure-sensitive adhesive tape. Background Art

[0002] Pressure-sensitive adhesive is a type of adhesive that is sensitive to pressure. The pressure-sensitive adhesive and the surface of the adherend are mainly bonded by van der Waals force. Based on the main components of the pressure-sensitive adhesive, it can be divided into polyacrylate pressure-sensitive adhesive, rubber-type pressure-sensitive adhesive, thermoplastic elastomer pressure-sensitive adhesive and polyurethane pressure-sensitive adhesive, etc. Due to its characteristic of not being easy to dry, it is also commonly known as self-adhesive.

[0003] Acrylic pressure-sensitive adhesives in the prior art are usually prepared by inducing a free radical polymerization reaction of acrylic monomers under the initiation of a free radical initiator to obtain polyacrylates, and in the preparation process, different acrylate monomer compositions are selected to improve the adhesion performance of the pressure-sensitive adhesive. However, the free radical polymerization process is a process that ignores copolymerization, which leads to uneven distribution of molecular chain lengths of acrylic monomer copolymers obtained by free radical polymerization, and it is difficult to maintain stability in a high temperature environment. Although this situation can be improved by adding alkyl mercaptan as a molecular weight regulator during the reaction process, the addition of alkyl mercaptan will destroy the cohesive force of the pressure-sensitive adhesive layer. In addition, traditional polyacrylate pressure-sensitive tapes are easily separated from the tape base cloth in a high temperature environment to form residual adhesive on the surface of the bonding sample, resulting in the high temperature resistance and adhesion performance of the pressure-sensitive tape to be further improved.

[0004] In view of the technical defects in this aspect, a solution is now proposed. Summary of the invention

[0005] The purpose of the present invention is to provide a preparation method and application of a high temperature resistant pressure-sensitive adhesive tape, so as to solve the technical problem in the prior art that the high temperature resistance and adhesion performance of polyacrylate pressure-sensitive adhesive tape need to be further improved.

[0006] The purpose of the present invention can be achieved by the following technical solution: A method for preparing a high temperature resistant pressure-sensitive adhesive tape, comprising the following steps:

[0007] S1. Add composite polypropylene and N,N-dimethylformamide into a flask, stir until the system is dissolved, and pass through a 500-mesh sieve to obtain a composite polypropylene solution;

[0008] S2, placing the composite polypropylene solution in a three-necked flask protected by nitrogen and stirring, adding isocyanatepropyl triethoxysilane to the three-necked flask in batches, stirring at room temperature for 40-60 minutes, adding a tackifier to the three-necked flask, stirring at room temperature for 20-30 minutes, to obtain a pre-coating solution;

[0009] The synthetic reaction mechanism of the coating liquid is:

[0010] The isocyanate group on the isocyanatepropyl triethoxysilane undergoes a condensation reaction with the active groups such as the amino group on the composite polypropylene solution molecules to form triethoxysilane modifications on the composite polypropylene molecules to form pre-coating liquid molecules.

[0011] S3, adding the pre-coating liquid and the activation liquid into a beaker and stirring for 40-50 minutes to obtain a coating liquid, and then evenly coating the coating liquid on the surface of the PET film on one side after the corona treatment to form a coating layer with a thickness of 60-80 μm on the surface of the PET film, and then drying and forming it to form an adhesive layer on the surface of the PET film;

[0012] S4, attaching a release paper on the top of the adhesive layer and rolling it with a rubber roller to obtain a primary pressure-sensitive tape;

[0013] S5, cutting the primary pressure-sensitive adhesive tape, winding and packaging it, and obtaining the pressure-sensitive adhesive tape.

[0014] Furthermore, in step S1, the usage ratio of the composite polypropylene and N,N-dimethylformamide is 1 g:2 mL.

[0015] Furthermore, in step S2, the polyacrylic acid solution, isocyanatepropyltriethoxysilane and the tackifier are used in a ratio of 50 mL:4 g:8-10 g, and the tackifier is composed of terpene phenolic resin and N,N-dimethylformamide in a ratio of 1 g:3 mL.

[0016] Furthermore, in step S3, the volume ratio of the pre-coating liquid to the activation liquid is 10:1, the activation liquid is a 0.6-0.8 mol / L sodium hydroxide solution, the drying and molding temperature is 100-120° C., and the drying time is 6-8 min.

[0017] Further, the composite polypropylene is processed by the following steps:

[0018] A1. Add butyl acrylate, isooctyl acrylate, 2-methoxyethyl acrylate, N-(methoxymethyl)-2-acrylamide and ethyl acetate into a beaker and mix well to obtain a monomer mixture;

[0019] A2. Add polysiloxane and ethyl acetate into a three-necked flask protected by nitrogen, and ultrasonically disperse for 30-50 minutes. Transfer the three-necked flask to a water bath with mechanical stirring, and add the monomer mixture and xylene into the three-necked flask. Set the water bath temperature to 80-85°C, keep the three-necked flask at reflux, and drop the initiator solution into the three-necked flask. After the dropwise addition is completed, keep the solution warm for 4-6 hours, and post-treat to obtain composite polypropylene.

[0020] The synthetic reaction formula of composite polypropylene is:

[0021]

[0022] The synthetic reaction mechanism of composite polypropylene is:

[0023] Under the action of an initiator and with polysiloxane as a crosslinking agent, the olefin double bonds of the monomer molecules in the monomer mixture react with the olefin double bonds on the polysiloxane molecules to undergo free radical polymerization to prepare a composite polypropylene with a long carbon chain structure modified with multiple branches.

[0024] Furthermore, in step A1, the usage ratio of butyl acrylate, isooctyl acrylate, 2-methoxyethyl 2-acrylate, N-(methoxymethyl)-2-acrylamide and ethyl acetate is 7-8 g:4-5 g:3-4 g:2-3 g:16-20 mL.

[0025] Furthermore, in step A2, the dosage ratio of the polysiloxane, ethyl acetate, monomer mixture, xylene and initiator solution is 1g:10mL:10mL:3mL:1g, the initiator solution is composed of benzoyl peroxide and ethyl acetate in a dosage ratio of 1g:5mL, and the post-treatment includes: after the reaction is completed, evaporating the solvent under reduced pressure to obtain composite polypropylene.

[0026] Furthermore, the preparation method of polysiloxane is: octamethylcyclotetrasiloxane, 5-hexenyltrimethoxysilane, 3-aminopropyltriethoxysilane and emulsion are added to a three-necked flask and stirred, the temperature of the three-necked flask is increased to 70-80° C., alkali solution is added to the three-necked flask, and the mixture is stirred for 80-100 minutes under heat preservation, and polysiloxane is obtained by post-treatment.

[0027] The synthetic reaction formula of polysiloxane is:

[0028]

[0029] In the formula

[0030] for

[0031] The synthetic reaction mechanism of polysiloxane is:

[0032] During the reaction process, octamethylcyclotetrasiloxane, 5-hexenyltrimethoxysilane and 3-aminopropyltriethoxysilane molecules are uniformly dispersed in an emulsion, and under the catalytic action of an alkaline solution, the siloxane bonds on the molecules are broken and then copolymerized to form siloxane-silicon bonds, thereby preparing a polysiloxane with a high degree of crosslinking and olefin double bonds and amino modifications.

[0033] Furthermore, the amount ratio of octamethylcyclotetrasiloxane, 5-hexenyltrimethoxysilane, 3-aminopropyltriethoxysilane, emulsion and alkali solution is 10g:2g:1g:70mL:5g, the alkali solution is 0.5-0.8mol / L sodium hydroxide solution, the emulsion is composed of sodium dodecyl sulfate, OP-10, Tween-80, anhydrous ethanol and deionized water in an amount ratio of 3g:1g:1g:80mL:10mL, and the post-treatment includes: after the reaction is completed, the temperature of the three-necked flask is lowered to room temperature, centrifuged, the bottom sediment is separated, washed with deionized water to neutrality, washed with anhydrous ethanol 3 times and then dried, and then transferred to a drying oven at a temperature of 85-95°C, and vacuum dried to constant weight to obtain polysiloxane.

[0034] The invention discloses an application of a high temperature resistant pressure sensitive adhesive tape, and applies the pressure sensitive adhesive tape to high temperature working conditions in automobile manufacturing, electronic and electrical appliance manufacturing, aerospace manufacturing, etc.

[0035] The present invention has the following beneficial effects:

[0036] 1. The high temperature resistant pressure-sensitive adhesive tape of the present invention uses polysiloxane as a crosslinking agent to promote the free radical polymerization reaction of acrylic monomers to form highly crosslinked composite polypropylene. The flexibility of the molecular chain of polysiloxane enables the molecular chain of polysiloxane to more easily adapt to the slight unevenness of the surface of the adherend, and then closely combines with the surface of the adherend through physical adsorption such as van der Waals force and hydrogen bond, so that the physical adsorption is tighter and firmer, thereby enhancing the adhesion of the composite polypropylene. When preparing the composite polypropylene, xylene is added to the solution, and the strong chain transfer ability of xylene cooperates with ethyl acetate to regulate the molecular weight of the acrylic ester copolymer. The molecular chain of the composite polypropylene is prevented from being too long and the molecular weight is kept evenly distributed, so that the molecular chain of the composite polypropylene is more uniform, and the cohesive failure of the pressure-sensitive adhesive layer caused by alkyl mercaptan as a molecular weight regulator is eliminated, so that the composite polypropylene maintains structural stability at high temperatures, reduces the unstable adhesion of the pressure-sensitive adhesive layer and the brittleness at high temperatures caused by the molecular chain being too long or too short, reduces the risk of its breakage at high temperatures, maintains good adhesion properties of the pressure-sensitive adhesive tape, introduces polysiloxane chain segments into the composite polypropylene to cooperate with the polypropylene chain segments, makes the pressure-sensitive adhesive tape more stable in a high temperature environment, and further improves the high temperature resistance and adhesion properties of the material.

[0037] 2. The high temperature resistant pressure-sensitive adhesive tape of the present invention uses butyl acrylate and isooctyl acrylate as adhesive monomers, and 2-methoxyethyl 2-acrylate as an internal monomer. The ester group on the molecule makes the polymer have a certain polarity, and the methoxy group gives the polymer a certain flexibility and chemical resistance. The multiple unsaturated olefin double bonds modified by the polysiloxane molecule serve as reactive active sites. By using xylene as a chain transfer agent, the crosslinking degree of the composite polypropylene molecules is adjusted, so that the pressure-sensitive adhesive tape can maintain sufficient adhesion while reducing the problem of adhesion reduction caused by excessive crosslinking. The terpene phenolic resin as a tackifier can form a stronger interaction force with the surface of the adherend, and the polar functional groups on the composite polypropylene molecular chain can reduce the polarity difference between it and the terpene phenolic resin, so that the composite polypropylene and the terpene phenolic resin can be evenly fused, thereby improving the initial adhesion strength of the pressure-sensitive adhesive tape. The terpene phenolic resin itself has a certain heat resistance and can still maintain a good adhesion effect under high temperature environment. In the pressure-sensitive adhesive tape, it can increase the interaction force between polymer molecular chains and improve the overall heat resistance of the pressure-sensitive adhesive tape.

[0038] 3. The high temperature resistant pressure-sensitive adhesive tape of the present invention activates the pre-coating liquid by using sodium hydroxide solution as an activating liquid, and the siloxane bonds on the composite polysiloxane molecular chain are hydrolyzed to form silanol groups, which promotes the cross-linking and bonding between the molecules in the pre-coating liquid and the active groups on the PET film layer, so that the adhesive layer can be tightly adhered to the PET film, while further improving the adhesion strength and high temperature resistance of the pressure-sensitive adhesive tape. DETAILED DESCRIPTION

[0039] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] Example 1

[0041] This embodiment provides a method for preparing a high temperature resistant pressure-sensitive adhesive tape, comprising the following steps:

[0042] S1. Preparation of polysiloxane

[0043] Sodium dodecyl sulfate, OP-10, Tween-80, anhydrous ethanol and deionized water were mixed uniformly in a dosage ratio of 3g:1g:1g:80mL:10mL to obtain an emulsion;

[0044] Weigh: 50 g of octamethylcyclotetrasiloxane, 10 g of 5-hexenyltrimethoxysilane, 5 g of 3-aminopropyltriethoxysilane and 350 mL of emulsion, add them into a three-necked flask and stir, raise the temperature of the three-necked flask to 70° C., add 25 g of 0.5 mol / L sodium hydroxide solution into the three-necked flask, keep warm and stir for 80 min, lower the temperature of the three-necked flask to room temperature, centrifuge, separate the bottom sediment, wash it with deionized water to neutrality, wash it with anhydrous ethanol 3 times and then drain it, then transfer it to a drying oven at a temperature of 85° C., and vacuum dry it to constant weight to obtain polysiloxane.

[0045] S2. Preparation of composite polypropylene

[0046] Weigh: 35 g of butyl acrylate, 20 g of isooctyl acrylate, 15 g of 2-methoxyethyl 2-acrylate, 10 g of N-(methoxymethyl)-2-acrylamide and 80 mL of ethyl acetate, add into a beaker and mix well to obtain a monomer mixture;

[0047] Benzoyl peroxide and ethyl acetate were mixed evenly at a ratio of 1 g:5 mL to obtain an initiator solution;

[0048] Weigh: 20 g of polysiloxane and 200 mL of ethyl acetate are added to a three-necked flask protected by nitrogen, and ultrasonically dispersed for 30 minutes. The three-necked flask is transferred to a water bath with mechanical stirring and stirred. 200 mL of monomer mixture and 60 mL of xylene are added to the three-necked flask. The water bath temperature is set to 80°C, and the three-necked flask is kept at reflux. 20 g of initiator solution is added dropwise to the three-necked flask. After the addition is completed, the reaction is kept warm for 4 hours, and the solvent is evaporated under reduced pressure to obtain composite polypropylene.

[0049] S3. Preparation of pre-coating solution

[0050] Add composite polypropylene and N,N-dimethylformamide into a flask at a ratio of 1 g:2 mL, stir until the system is dissolved, and pass through a 500-mesh sieve to obtain a composite polypropylene solution;

[0051] Terpene phenolic resin and N,N-dimethylformamide were added into a flask at a ratio of 1 g:3 mL and stirred. The temperature of the flask was raised to 70° C. and stirred until the system was dissolved and clear. The temperature was naturally lowered to room temperature to obtain a tackifier.

[0052] Weigh: 250 mL of polyacrylic acid solution was placed in a three-necked flask protected by nitrogen and stirred, 20 g of isocyanatepropyltriethoxysilane was added to the three-necked flask in batches, and stirred at room temperature for 40 min, 40 g of viscosity enhancer was added to the three-necked flask, and stirred at room temperature for 20 min to obtain a pre-coating liquid.

[0053] S4, coating molding

[0054] The pre-coating liquid and 0.6 mol / L sodium hydroxide solution were added into a beaker in a volume ratio of 10:1 and stirred for 40 minutes to obtain a coating liquid. The coating liquid was then evenly coated on the surface of the PET film on one side that had been corona treated to form a coating layer with a thickness of 60-80 μm on the surface of the PET film. The film was then transferred to a dryer at a temperature of 100°C and dried for 6 minutes to form an adhesive layer on the surface of the PET film.

[0055] S5. Preparation of pressure-sensitive adhesive tape

[0056] A release paper was attached to the top of the adhesive layer, and a 2 kg rubber roller was used to reciprocate and roll the adhesive layer 3 times to obtain a preliminary pressure-sensitive tape. The preliminary pressure-sensitive tape was cut and then wound and packaged to obtain a pressure-sensitive tape.

[0057] Example 2

[0058] This embodiment provides a method for preparing a high temperature resistant pressure-sensitive adhesive tape, comprising the following steps:

[0059] S1. Preparation of polysiloxane

[0060] Sodium dodecyl sulfate, OP-10, Tween-80, anhydrous ethanol and deionized water were mixed uniformly in a dosage ratio of 3g:1g:1g:80mL:10mL to obtain an emulsion;

[0061] Weigh: 50 g of octamethylcyclotetrasiloxane, 10 g of 5-hexenyltrimethoxysilane, 5 g of 3-aminopropyltriethoxysilane and 350 mL of emulsion, add them into a three-necked flask and stir, raise the temperature of the three-necked flask to 75° C., add 25 g of 0.7 mol / L sodium hydroxide solution into the three-necked flask, keep warm and stir for 90 minutes, lower the temperature of the three-necked flask to room temperature, centrifuge, separate the bottom sediment, wash it with deionized water to neutrality, wash it with anhydrous ethanol 3 times and then drain it, then transfer it to a drying oven at a temperature of 90° C., and vacuum dry it to constant weight to obtain polysiloxane.

[0062] S2. Preparation of composite polypropylene

[0063] Weigh: 37 g of butyl acrylate, 23 g of isooctyl acrylate, 17 g of 2-methoxyethyl 2-acrylate, 13 g of N-(methoxymethyl)-2-acrylamide and 90 mL of ethyl acetate, add into a beaker and mix well to obtain a monomer mixture;

[0064] Benzoyl peroxide and ethyl acetate were mixed evenly at a ratio of 1 g:5 mL to obtain an initiator solution;

[0065] Weigh: 20 g of polysiloxane and 200 mL of ethyl acetate are added to a three-necked flask protected by nitrogen, and ultrasonically dispersed for 40 minutes. The three-necked flask is transferred to a water bath with mechanical stirring and stirred. 200 mL of monomer mixture and 60 mL of xylene are added to the three-necked flask. The water bath temperature is set to 83°C, and the three-necked flask is kept at reflux. 20 g of initiator solution is added dropwise to the three-necked flask. After the addition is completed, the reaction is kept warm for 5 hours, and the solvent is evaporated under reduced pressure to obtain composite polypropylene.

[0066] S3. Preparation of pre-coating solution

[0067] Add composite polypropylene and N,N-dimethylformamide into a flask at a ratio of 1 g:2 mL, stir until the system is dissolved, and pass through a 500-mesh sieve to obtain a composite polypropylene solution;

[0068] Terpene phenolic resin and N,N-dimethylformamide were added into a flask at a ratio of 1 g:3 mL and stirred. The temperature of the flask was raised to 75° C. and stirred until the system was dissolved and clear. The temperature was naturally lowered to room temperature to obtain a tackifier.

[0069] Weigh: 250 mL of polyacrylic acid solution was placed in a three-necked flask protected by nitrogen and stirred, 20 g of isocyanatepropyltriethoxysilane was added to the three-necked flask in batches, and stirred at room temperature for 50 min, 45 g of viscosity enhancer was added to the three-necked flask, and stirred at room temperature for 25 min to obtain a pre-coating liquid.

[0070] S4, coating molding

[0071] The pre-coating liquid and 0.7 mol / L sodium hydroxide solution were added into a beaker in a volume ratio of 10:1 and stirred for 45 minutes to obtain a coating liquid. The coating liquid was then evenly coated on the surface of the PET film on one side that had been corona treated to form a coating layer with a thickness of 60-80 μm on the surface of the PET film. The film was then transferred to a dryer at a temperature of 110°C and dried for 7 minutes to form an adhesive layer on the surface of the PET film.

[0072] S5. Preparation of pressure-sensitive adhesive tape

[0073] A release paper was attached to the top of the adhesive layer, and a 2 kg rubber roller was used to reciprocate and roll the adhesive layer 4 times to obtain a preliminary pressure-sensitive tape. The preliminary pressure-sensitive tape was cut and then wound and packaged to obtain a pressure-sensitive tape.

[0074] Example 3

[0075] This embodiment provides a method for preparing a high temperature resistant pressure-sensitive adhesive tape, comprising the following steps:

[0076] S1. Preparation of polysiloxane

[0077] Sodium dodecyl sulfate, OP-10, Tween-80, anhydrous ethanol and deionized water were mixed uniformly in a dosage ratio of 3g:1g:1g:80mL:10mL to obtain an emulsion;

[0078] Weigh: 50 g of octamethylcyclotetrasiloxane, 10 g of 5-hexenyltrimethoxysilane, 5 g of 3-aminopropyltriethoxysilane and 350 mL of emulsion, add them into a three-necked flask and stir, raise the temperature of the three-necked flask to 80° C., add 25 g of 0.8 mol / L sodium hydroxide solution into the three-necked flask, keep warm and stir for 100 min, lower the temperature of the three-necked flask to room temperature, centrifuge, separate the bottom sediment, wash it with deionized water to neutrality, wash it with anhydrous ethanol 3 times and then drain it, then transfer it to a drying oven at a temperature of 95° C., and vacuum dry it to constant weight to obtain polysiloxane.

[0079] S2. Preparation of composite polypropylene

[0080] Weigh: 40 g of butyl acrylate, 25 g of isooctyl acrylate, 20 g of 2-methoxyethyl 2-acrylate, 15 g of N-(methoxymethyl)-2-acrylamide and 100 mL of ethyl acetate, add into a beaker and mix well to obtain a monomer mixture;

[0081] Benzoyl peroxide and ethyl acetate were mixed evenly at a ratio of 1 g:5 mL to obtain an initiator solution;

[0082] Weigh: 20 g of polysiloxane and 200 mL of ethyl acetate are added to a three-necked flask protected by nitrogen, and ultrasonically dispersed for 50 minutes. The three-necked flask is transferred to a water bath with mechanical stirring and stirred. 200 mL of monomer mixture and 60 mL of xylene are added to the three-necked flask. The water bath temperature is set to 85°C, and the three-necked flask is kept at reflux. 20 g of initiator solution is added dropwise to the three-necked flask. After the addition is completed, the reaction is kept warm for 6 hours, and the solvent is evaporated under reduced pressure to obtain composite polypropylene.

[0083] S3. Preparation of pre-coating solution

[0084] Add composite polypropylene and N,N-dimethylformamide into a flask at a ratio of 1 g:2 mL, stir until the system is dissolved, and pass through a 500-mesh sieve to obtain a composite polypropylene solution;

[0085] Terpene phenolic resin and N,N-dimethylformamide were added into a flask at a ratio of 1 g:3 mL and stirred, the temperature of the flask was raised to 80° C., stirred until the system was dissolved, and cooled naturally to room temperature to obtain a tackifier;

[0086] Weigh: 250 mL of polyacrylic acid solution was placed in a three-necked flask protected by nitrogen and stirred, 20 g of isocyanatepropyltriethoxysilane was added to the three-necked flask in batches, and stirred at room temperature for 60 min, 50 g of viscosity enhancer was added to the three-necked flask, and stirred at room temperature for 30 min to obtain a pre-coating liquid.

[0087] S4, coating molding

[0088] The pre-coating liquid and 0.8 mol / L sodium hydroxide solution were added into a beaker in a volume ratio of 10:1 and stirred for 50 minutes to obtain a coating liquid. The coating liquid was then evenly coated on the corona-treated surface of the PET film to form a coating layer with a thickness of 60-80 μm on the surface of the PET film. The film was then transferred to a dryer at a temperature of 120°C and dried for 8 minutes to form an adhesive layer on the surface of the PET film.

[0089] S5. Preparation of pressure-sensitive adhesive tape

[0090] A release paper was attached to the top of the adhesive layer, and a 2 kg rubber roller was used to reciprocate and roll the adhesive layer 4 times to obtain a preliminary pressure-sensitive tape. The preliminary pressure-sensitive tape was cut and then wound and packaged to obtain a pressure-sensitive tape.

[0091] Comparative Example 1

[0092] The difference between this comparative example and Example 3 is that in step S1, 3-aminopropyltriethoxysilane is not added, and the amount of 5-hexenyltrimethoxysilane is reduced to 3 g.

[0093] Comparative Example 2

[0094] The difference between this comparative example and Example 3 is that in the process of preparing composite polypropylene in step S2, xylene is not added.

[0095] Comparative Example 3

[0096] The difference between this comparative example and Example 3 is that in the process of preparing the pre-coating liquid in step S3, no isocyanatepropyltriethoxysilane is added.

[0097] Comparative Example 4

[0098] The difference between this comparative example and Example 3 is that, in the process of preparing the pre-coating liquid in step S3, no viscosity enhancer is added.

[0099] Performance Test:

[0100] The pressure-sensitive tape samples prepared in Examples 1-3 and Comparative Examples 1-4 were measured on an inclined plate of an initial adhesion meter at an angle of 30° to the horizontal plane according to the inclined rolling ball method, and the initial adhesion strength was tested according to the standard GB / T 4852-2002 "Test method for initial adhesion of pressure-sensitive adhesive tapes (rolling ball method)";

[0101] The 180° peel strength of the pressure-sensitive adhesive tape samples prepared in Examples 1-3 and Comparative Examples 1-4 was measured with reference to the standard GB / T 2792-2014 “Test method for peel strength of adhesive tape”;

[0102] The adhesion time of the pressure-sensitive adhesive tape samples prepared in Examples 1-3 and Comparative Examples 1-4 to a 1 kg weight was measured with reference to the standard GB / T 4851-2014 "Test method for adhesive tape persistence", which was recorded as persistence;

[0103] The highest temperature at which the pressure-sensitive tape samples prepared in Examples 1-3 and Comparative Examples 1-4 can be peeled off without residual adhesive at different temperatures was measured with reference to the standard GB / T 2792-2014 "Test method for peel strength of adhesive tapes", which is recorded as the high temperature resistance temperature. The specific test results are shown in Table 1 below.

[0104] Table 1-Performance test data of the sample

[0105]

[0106] Data Analysis:

[0107] A comparative analysis of the data in Table 1 above shows that the initial adhesion strength of the pressure-sensitive tape prepared by the present invention reaches 20# steel ball, the 180° peel strength reaches 26.8N / cm, the adhesion time for a 1kg weight reaches 1890min, and the high temperature resistance temperature reaches 200°C. All performance parameters are better than those of the comparative example. The present invention prepares a cross-linked composite polypropylene with relatively uniform molecular weight and a tackifier, adds isocyanatepropyltriethoxysilane and an activation liquid to cooperate with each other, which not only effectively improves the high temperature resistance of the pressure-sensitive tape, but also improves its initial adhesion strength, peel strength and sustained adhesion, and has good adhesion performance.

[0108] The above contents are merely examples and explanations of the structure of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing a high temperature resistant pressure-sensitive adhesive tape, characterized in that: The following steps are involved: S1. Add composite polypropylene and N,N-dimethylformamide into a flask, stir until the system is dissolved, and pass through a 500-mesh sieve to obtain a composite polypropylene solution; S2, placing the composite polypropylene solution in a three-necked flask protected by nitrogen and stirring, adding isocyanatepropyl triethoxysilane to the three-necked flask in batches, stirring at room temperature for 40-60 minutes, adding a tackifier to the three-necked flask, stirring at room temperature for 20-30 minutes, to obtain a pre-coating solution; S3, adding the pre-coating liquid and the activation liquid into a beaker and stirring for 40-50 minutes to obtain a coating liquid, and then evenly coating the coating liquid on the surface of the PET film on one side after the corona treatment to form a coating layer with a thickness of 60-80 μm on the surface of the PET film, and then drying and forming it to form an adhesive layer on the surface of the PET film; S4, attaching a release paper on the top of the adhesive layer and rolling it with a rubber roller to obtain a primary pressure-sensitive tape; S5, cutting the primary pressure-sensitive adhesive tape, winding and packaging it, and obtaining the pressure-sensitive adhesive tape.

2. The method for preparing a high temperature resistant pressure sensitive adhesive tape according to claim 1, characterized in that: In step S1, the usage ratio of the composite polypropylene and N,N-dimethylformamide is 1 g:2 mL.

3. The method for preparing a high temperature resistant pressure sensitive adhesive tape according to claim 1, characterized in that: In step S2, the polyacrylic acid solution, isocyanatepropyltriethoxysilane and tackifier are used in a ratio of 50 mL:4 g:8-10 g, and the tackifier is composed of terpene phenolic resin and N,N-dimethylformamide in a ratio of 1 g:3 mL.

4. The method for preparing a high temperature resistant pressure sensitive adhesive tape according to claim 1, characterized in that: In step S3, the volume ratio of the pre-coating liquid to the activation liquid is 10:1, the activation liquid is a 0.6-0.8 mol / L sodium hydroxide solution, the drying and molding temperature is 100-120° C., and the drying time is 6-8 min.

5. The method for preparing a high temperature resistant pressure sensitive adhesive tape according to claim 1, characterized in that: Composite polypropylene is processed by the following steps: A1. Add butyl acrylate, isooctyl acrylate, 2-methoxyethyl acrylate, N-(methoxymethyl)-2-acrylamide and ethyl acetate into a beaker and mix well to obtain a monomer mixture; A2. Add polysiloxane and ethyl acetate into a three-necked flask protected by nitrogen, and ultrasonically disperse for 30-50 minutes. Transfer the three-necked flask to a water bath with mechanical stirring, and add the monomer mixture and xylene into the three-necked flask. Set the water bath temperature to 80-85°C, keep the three-necked flask at reflux, and drop the initiator solution into the three-necked flask. After the dropwise addition is completed, keep the solution warm for 4-6 hours, and post-treat to obtain composite polypropylene.

6. The method for preparing a high temperature resistant pressure sensitive adhesive tape according to claim 5, characterized in that: In step A1, the usage ratio of butyl acrylate, isooctyl acrylate, 2-methoxyethyl 2-acrylate, N-(methoxymethyl)-2-acrylamide and ethyl acetate is 7-8 g: 4-5 g: 3-4 g: 2-3 g: 16-20 mL.

7. The method for preparing a high temperature resistant pressure sensitive adhesive tape according to claim 5, characterized in that: In step A2, the amount ratio of the polysiloxane, ethyl acetate, monomer mixture, xylene and initiator solution is 1g:10mL:10mL:3mL:1g, and the initiator solution is composed of benzoyl peroxide and ethyl acetate in a ratio of 1g:5mL.

8. The method for preparing a high temperature resistant pressure sensitive adhesive tape according to claim 1, characterized in that: The preparation method of polysiloxane is as follows: octamethylcyclotetrasiloxane, 5-hexenyltrimethoxysilane, 3-aminopropyltriethoxysilane and emulsion are added into a three-necked flask and stirred, the temperature of the three-necked flask is increased to 70-80° C., alkali solution is added into the three-necked flask, the flask is stirred for 80-100 minutes under heat preservation, and polysiloxane is obtained by post-treatment.

9. The method for preparing a high temperature resistant pressure sensitive adhesive tape according to claim 8, characterized in that: The dosage ratio of octamethylcyclotetrasiloxane, 5-hexenyltrimethoxysilane, 3-aminopropyltriethoxysilane, emulsion and alkali solution is 10g:2g:1g:70mL:5g, the alkali solution is 0.5-0.8mol / L sodium hydroxide solution, and the emulsion is composed of sodium dodecyl sulfate, OP-10, Tween-80, anhydrous ethanol and deionized water in a dosage ratio of 3g:1g:1g:80mL:10mL.

10. An application of a high temperature resistant pressure sensitive adhesive tape, characterized in that: The pressure-sensitive adhesive tape prepared by the method for preparing a high-temperature resistant pressure-sensitive adhesive tape as described in any one of claims 1 to 9 is applied to high-temperature working conditions in automobile manufacturing, electronic and electrical manufacturing, aerospace manufacturing, etc.

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