An easily peelable hot deactivating pressure sensitive adhesive tape and its production process

Abstract

This invention discloses an easy-to-peel heat-resistant pressure-sensitive tape and its manufacturing process, belonging to the field of pressure-sensitive tape technology. First, fluorinated thermally expandable microspheres are prepared, then grafted with KH550 via amidation, followed by hydrolysis and condensation with tridecafluorooctyltrimethoxysilane to obtain low surface energy thermally expandable microspheres. Next, catechol, formaldehyde, and N-methylethanolamine are used to synthesize catechol methacrylate monomers via the Mannich reaction and methacryloyl chloride esterification. These monomers are then copolymerized with isooctyl acrylate and acrylic acid free radicals to obtain catechol-modified polyacrylate. Finally, the catechol-modified polyacrylate is mixed with tetrahydrofuran methacrylate, trimethylolpropane trimethacrylate, photoinitiator TPO, leveling agent BYK307, ethyl acetate, and the low surface energy thermally expandable microspheres to prepare a heat-resistant adhesive. Through a step-by-step double-sided coating process, an easy-to-peel heat-resistant pressure-sensitive tape is obtained. This effectively solves the problems of premature tack reduction and residual adhesive in traditional heat-resistant tapes during high-temperature processes.

Description

Technical Field

[0001] This invention belongs to the field of pressure-sensitive adhesive tape technology, specifically relating to an easy-to-peel heat-resistant pressure-sensitive adhesive tape and its manufacturing process. Background Technology

[0002] Pressure-sensitive adhesive tape is a special adhesive material that maintains its adhesion at room temperature, bonds with light pressure, and requires no solvents or heat to cure. It is widely used in the manufacturing process of FPC flexible circuit boards and the processing of precision electronic components, mainly serving functions such as temporary fixation of boards, process protection, and precision positioning. However, traditional pressure-sensitive tape has significant drawbacks. Its adhesion remains constant after bonding. After processes such as high-temperature reflow soldering, lamination, chip bonding, and board demolding of FPCs, it is extremely easy to tear the thin FPC substrate and damage the fine circuitry during peeling, leaving adhesive residue. This not only increases rework and cleaning costs but also reduces product yield, failing to meet the production requirements of non-destructive demolding and reworkability in precision FPC manufacturing processes.

[0003] Based on the above problems, a heat-sensitive pressure-sensitive tape with reduced adhesion was designed. This tape combines the basic characteristics of ordinary pressure-sensitive tape with heat-sensitive reduced adhesion performance. It has stable adhesion at room temperature and can firmly adhere to the workpiece, playing a role in fixing and protection. After being triggered by heating at a specific temperature, the adhesive layer structure changes, the adhesive force is greatly reduced or even completely disappeared, and it can be easily peeled off. It achieves strong adhesion in the process and easy peeling after completion, taking into account the requirements of production stability and non-destructive disassembly, and is suitable for precision machining scenarios.

[0004] Chinese invention patent application CN119286424A discloses a heat-resistant pressure-sensitive adhesive tape and its preparation method. The tape has a structure of a release layer / heat-resistant layer / substrate layer (such as a PET film). The heat-resistant adhesive formulation (parts by weight) contains 90-120 parts of acrylate copolymer resin, 5-15 parts of modified resin, 0.01-1 part of curing agent, 2-10 parts of modified thermally expandable microspheres, and a solvent. The modified microspheres are prepared by spraying 0.5-1.3 parts of tridecafluorooctyltrimethoxysilane onto 100 parts of thermoplastic polyacrylate microspheres, followed by kneading, sealing and heating, alkaline treatment, acid washing, and drying. In tape preparation, the adhesive is coated onto the substrate, pre-baked, and then baked to form the heat-resistant layer. After laminating with a release film, the tape is cured to obtain the final product.

[0005] In the above scheme, under the high temperature of 260℃ reflow soldering and the catalysis of trace amounts of moisture, the siloxane bonds on the surface of the microspheres are easily hydrolyzed and broken, resulting in microcracks and local detachment of the coating layer. This leads to premature migration of fluorine segments, uncontrolled expansion of the microspheres, and ultimately causes the tape to unexpectedly lose tack during reflow soldering or leave residue when finally peeled off, reducing the yield of the FPC process. Summary of the Invention

[0006] The purpose of this invention is to provide an easy-to-peel heat-resistant pressure-sensitive tape and its manufacturing process, which solves the problem that the fluorinated polysiloxane coating layer on the surface of microspheres is prone to hydrolysis and cracking under the high temperature of 260°C reflow soldering and trace moisture, resulting in premature migration of fluorine segments, uncontrolled expansion of microspheres, and unexpected tape detack reduction or residue.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] A manufacturing process for an easy-to-peel heat-resistant pressure-sensitive adhesive tape includes the following steps:

[0009] Step 1: Fluorinated thermally expandable microspheres are prepared by suspension polymerization, then grafted with KH550 and hydrolyzed and condensed with tridecafluorooctyltrimethoxysilane to obtain low surface energy thermally expandable microspheres.

[0010] Step 2: Using catechol, formaldehyde and N-methylethanolamine, catechol methacrylate monomer is synthesized by Mannich reaction and methacryloyl chloride esterification, and then copolymerized with isooctyl acrylate and acrylic acid free radical to obtain catechol modified polyacrylate.

[0011] Step 3: The catechol-modified polyacrylate is mixed with tetrahydrofuran methacrylate, trimethylolpropane trimethacrylate, photoinitiator TPO, leveling agent BYK307, ethyl acetate and low surface energy thermal expansion microspheres to prepare a heat-resistant adhesive. The adhesive is then applied in a stepwise double-sided coating process to obtain an easy-to-peel heat-resistant pressure-sensitive tape.

[0012] Furthermore, the mass ratio of catechol-modified polyacrylate, tetrahydrofuran methacrylate, trimethylolpropane trimethacrylate, photoinitiator TPO, leveling agent BYK307, ethyl acetate, and low surface energy thermal expansion microspheres is 40-46:55-60:5-8:3-4:0.25-0.32:20-24:3-5.

[0013] Furthermore, the specific preparation method of low surface energy thermal expansion microspheres is as follows:

[0014] Modified fluorinated thermal expansion microspheres were added to an alkaline ethanol aqueous solution and stirred for 10-15 min. Then, tridecafluorooctyltrimethoxysilane was added and stirred for 2-3 h. The mixture was then filtered, washed, and vacuum dried to constant weight to obtain low surface energy thermal expansion microspheres.

[0015] Furthermore, the alkaline ethanol aqueous solution is obtained by adjusting the pH value to 10 with sodium hydroxide from anhydrous ethanol and deionized water in a volume ratio of 18-20:2-3.

[0016] Furthermore, the ratio of modified fluorinated thermal expansion microspheres, alkaline ethanol aqueous solution, and tridecafluorooctyltrimethoxysilane is 5-8g: 1000-1150mL: 0.5-0.8g.

[0017] Furthermore, the specific preparation method of the modified fluorinated thermal expansion microspheres is as follows:

[0018] Fluorinated thermally expandable microspheres were added to anhydrous ethanol and stirred for 10-15 min. Then, N,N-diisopropylethylamine, tetramethylurea hexafluorophosphate, and silane coupling agent KH550 were added and stirred for 3-4 h. The mixture was then filtered, washed, and vacuum dried to constant weight to obtain modified fluorinated thermally expandable microspheres.

[0019] Furthermore, the ratio of fluorinated thermal expansion microspheres, anhydrous ethanol, N,N-diisopropylethylamine, tetramethylurea hexafluorophosphate, and silane coupling agent KH550 is 5-8g: 1000-1200mL: 0.5-0.8mL: 1-1.4g: 2-2.4g.

[0020] Furthermore, the specific preparation method of fluorinated thermal expansion microspheres is as follows:

[0021] The oil phase was added to the aqueous phase at 8000-9000 rpm and emulsified for 3-5 min. The mixture was then transferred to a pressure reactor and sealed. Nitrogen gas was applied to pressurize the reactor to 0.4-0.6 MPa, and the mixture was stirred and polymerized at 60-70℃ and 300-400 rpm for 24-26 h. The temperature was then raised to 70-75℃ and matured for 30-40 min. The mixture was cooled and discharged, and the product was collected. The pH of the product was adjusted to 2 with dilute hydrochloric acid. The product was washed, filtered, and vacuum dried to constant weight to obtain fluorinated thermally expanded microspheres.

[0022] Furthermore, the volume ratio of the oil phase to the water phase is 36-45:140-200.

[0023] Furthermore, the oil phase is obtained by mixing acrylonitrile, dodecafluoroheptyl methacrylate, vinyl acetate, acrylic acid, ethylene glycol dimethacrylate, azobisisobutyronitrile and isopentane in a mass ratio of 18-22:8.1-9.4:2.7-3.6:1.2-1.8:0.075-0.12:0.3-0.5:6-8.

[0024] Furthermore, the aqueous phase is obtained by mixing sodium chloride, sodium hydroxide, magnesium chloride hexahydrate, sodium dodecyl sulfate, sodium nitrite, polyvinylpyrrolidone K30, and deionized water in a ratio of 25-30g: 3.7-4.2g: 11.3-15.6g: 1.5-1.8g: 0.03-0.05g: 0.3-0.6g: 100-150mL.

[0025] Furthermore, the specific preparation method of catechol methacrylate monomer is as follows:

[0026] Add catechol, 37wt% formaldehyde aqueous solution and N-methylethanolamine to deionized water, stir at 40-50℃ for 4-5h, adjust the pH to 2 with dilute hydrochloric acid, extract with diethyl ether 2-4 times, discard the diethyl ether phase, adjust the pH to 8 with NaOH, extract with ethyl acetate 3-5 times, combine the organic phases, add anhydrous magnesium sulfate to dry, filter, rotary evaporate, add acetonitrile, heat to dissolve, cool and recrystallize to obtain hydroxyethylaminomethyl catechol;

[0027] Hydroxyethylaminomethylcatechol was dissolved in tetrahydrofuran, triethylamine was added, and methacryloyl chloride was added dropwise under ice bath. After the addition was complete, the mixture was stirred at room temperature for 2-3 hours, filtered, and the filtrate was collected. The filtrate was concentrated by rotary evaporation and separated by column chromatography to obtain the catechol methacrylate monomer.

[0028] Furthermore, the ratio of catechol, 37wt% formaldehyde aqueous solution, N-methylethanolamine, deionized water, diethyl ether, ethyl acetate, anhydrous magnesium sulfate, and acetonitrile is 22-28g: 16.2-21.4g: 15-18g: 100-150mL: 200-300mL: 600-700mL: 10-12g: 100-120mL.

[0029] Furthermore, the ratio of hydroxyethylaminomethylcatechol, tetrahydrofuran, triethylamine, and methacrylamide chloride is 14-16g: 350-400mL: 28-32g: 14.7-16.8g.

[0030] Furthermore, column chromatography was prepared by mixing ethyl acetate and petroleum ether in a volume ratio of 1:4.

[0031] Furthermore, the specific preparation method of catechol-modified polyacrylate is as follows:

[0032] Isooctyl acrylate, catechol methacrylate monomer, acrylic acid, azobisisobutyronitrile and ethyl acetate were added to a three-necked flask, and nitrogen gas was bubbled for 30-40 min. The oil bath temperature was raised to 65-70℃, and the mixture was stirred for 8-9 h under nitrogen protection. Most of the solvent was removed by rotary evaporation. The viscous liquid was slowly poured into n-hexane to precipitate. The precipitate was filtered, collected, and vacuum dried to constant weight to obtain catechol modified polyacrylate.

[0033] Furthermore, the ratio of isooctyl acrylate, catechol methacrylate monomer, acrylic acid, azobisisobutyronitrile and ethyl acetate is 40-46g: 2-4g: 2.5-3.2g: 0.6-0.8g: 200-300mL.

[0034] Furthermore, the specific operating steps of the step-by-step double-sided coating process are as follows:

[0035] The heat-reducing adhesive is coated onto one side of a brown PI film and dried for 5-8 minutes to obtain a heat-reducing functional layer. A 50μm transparent silicone release film is then bonded to the layer. The film is then passed through a 405nm LED conveyor belt UV curing machine at a speed of 0.5m / min under a nitrogen atmosphere. The film is then flipped over, and the heat-reducing adhesive is coated onto the other side of the PI film in the same manner. After drying, a second release film is bonded to the other side, and the film is cured to obtain an easily peelable heat-reducing pressure-sensitive tape.

[0036] Furthermore, the specific conditions for the LED tracked UV curing machine are a light intensity of 350-450 mW / cm². 2 The lightbox is approximately 1.2m long and the illumination time is approximately 2.4min.

[0037] The beneficial effects of this invention are:

[0038] 1. This invention effectively solves the problems of premature tape reduction under high reflow soldering temperatures, residual adhesive after tape reduction, insufficient holding power, and performance degradation under humid and hot environments by using microsphere shell fluorination and crosslinking design, surface covalent grafting and fluorinated polysiloxane coating, and catechol-functionalized polyacrylate adhesive. It provides a highly reliable, easy-peel heat-reducing pressure-sensitive tape suitable for precision electronic manufacturing processes and its industrial production method.

[0039] 2. The low surface energy thermal expansion microspheres of this invention first introduce acrylic acid during the suspension polymerization stage to uniformly distribute carboxyl groups on the surface of the microsphere shell, providing necessary active anchors for subsequent covalent modification. Then, using an amidation reaction, silane coupling agent KH550 is covalently grafted onto the carboxyl groups to construct a stable siloxane intermediate layer on the surface of the microsphere, introducing active silanol groups. Finally, under alkaline conditions, tridecafluorooctyltrimethoxysilane is hydrolyzed and condensed to grow a dense fluorinated polysiloxane network in situ using the covalently anchored silanol groups as nucleation sites. This not only endows the microspheres with a large number of low surface energy CF segments, but its dense hydrophobic structure can also effectively block moisture under reflow soldering conditions at 260°C. This provides a structural basis for the normal expansion of the microspheres and the active migration of fluorinated segments to the interface to reduce adhesion when the temperature is above 280°C, thereby achieving excellent performance with extremely low peel strength and no adhesive residue.

[0040] 3. The catechol-modified polyacrylate in this invention is prepared through a three-step synergistic process of Mannich reaction, esterification, and free radical copolymerization. Its side-chain catechol groups provide multiple interfacial bonding capabilities, such as hydrogen bonding and π-π stacking. The synergistic effect of polar adsorption of carboxyl groups and improved compatibility of long alkyl chains gives the adhesive layer high peel strength and high holding power at room temperature. At the same time, the reasonable cross-linking structure ensures that interfacial peeling occurs preferentially during high-temperature detack reduction. Combined with microsphere expansion and fluorine chain migration, clean interfacial peeling is achieved, thus realizing the core functions of strong adhesion at room temperature, easy peeling at high temperature, and no adhesive residue. Detailed Implementation

[0041] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments in the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0042] Example 1: A manufacturing process for an easy-to-peel heat-resistant pressure-sensitive adhesive tape, comprising the following steps:

[0043] S1: Mix 18g acrylonitrile, 8.1g dodecafluoroheptyl methacrylate, 2.7g vinyl acetate, 1.2g acrylic acid, 0.075g ethylene glycol dimethacrylate, 0.3g azobisisobutyronitrile and 6g isopentane to form an oil phase;

[0044] Add 25g sodium chloride, 3.7g sodium hydroxide, 11.3g magnesium chloride hexahydrate, 1.5g sodium dodecyl sulfate, 0.03g sodium nitrite and 0.3g polyvinylpyrrolidone K30 to 100mL of deionized water and mix to form an aqueous phase;

[0045] Add 36 mL of oil phase to 140 mL of aqueous phase at 8000 rpm, emulsify for 3 min, transfer to a pressure reactor and seal, pressurize with nitrogen to 0.4-0.6 MPa, stir and polymerize at 60℃ and 300 rpm for 24 h, then heat to 70℃ for 30 min, cool and discharge, collect the product, adjust the pH of the product to 2 with dilute hydrochloric acid, wash three times with deionized water, filter, and vacuum dry at 50℃ for 24 h to obtain fluorinated thermal expansion microspheres.

[0046] By using suspension polymerization, polymerizable monomers in the oil phase are polymerized into a polymer shell in a dispersed aqueous phase under pressure, while low-boiling-point alkanes (isopentane) are encapsulated inside, forming fluorinated thermally expandable microspheres with a "polymer shell-alkane core" structure.

[0047] S2: Add 5g of fluorinated thermal expansion microspheres to 1000mL of anhydrous ethanol and stir at 600rpm for 10min. Add 0.5mL of N,N-diisopropylethylamine, 1g of tetramethylurea hexafluorophosphate and 2g of silane coupling agent KH550 and stir at 300rpm for 3h. Filter, wash with anhydrous ethanol and vacuum dry at 60℃ for 24h to obtain modified fluorinated thermal expansion microspheres.

[0048] By amidation, silane coupling agent KH550 is covalently grafted onto the surface of fluorinated thermally expandable microspheres, introducing active siloxane groups and providing reaction sites for subsequent fluorinated polysiloxane coating.

[0049] S3: Mix 900 mL of anhydrous ethanol and 100 mL of deionized water evenly, adjust the pH to 10 with sodium hydroxide to obtain an alkaline ethanol aqueous solution; add 5 g of modified fluorinated thermal expansion microspheres to 1000 mL of alkaline ethanol aqueous solution, stir at 600 rpm for 10 min, add 0.5 g of tridecafluorooctyltrimethoxysilane, stir for 2 h, filter, wash 3 times with anhydrous ethanol, and vacuum dry at 50 °C for 24 h to obtain low surface energy thermal expansion microspheres.

[0050] Under alkaline conditions, tridecafluorooctyltrimethoxysilane undergoes hydrolysis to generate silanol. Using the KH550 siloxane groups grafted onto the surface of the microspheres as active sites, a fluorinated polysiloxane coating layer is formed on the surface of the microspheres through a condensation reaction, thereby endowing the microspheres with low surface energy and hydrophobic and oleophobic properties of CF bonds.

[0051] S4: Add 22g of catechol, 16.2g of 37wt% formaldehyde aqueous solution and 15g of N-methylethanolamine to 100mL of deionized water, stir at 40℃ for 4h, adjust the pH to 2 with 1mol / L dilute hydrochloric acid, extract twice with 200mL of diethyl ether, discard the diethyl ether phase, adjust the pH to 8 with 1mol / L NaOH, extract three times with 600mL of ethyl acetate, combine the organic phases, add 10g of anhydrous magnesium sulfate to dry, filter, rotary evaporate, add 100mL of acetonitrile, heat to dissolve, cool and recrystallize to obtain hydroxyethylaminomethylcatechol;

[0052] Dissolve 14g of hydroxyethylaminomethylcatechol in 350mL of tetrahydrofuran, add 28g of triethylamine, and add 14.7g of methacryloyl chloride dropwise under ice bath. After the addition is complete, stir at room temperature for 2h, filter, collect the filtrate, concentrate the filtrate by rotary evaporation, and separate by column chromatography (ethyl acetate: petroleum ether = 1:4) to obtain the catechol methacrylate monomer.

[0053] Catechol, formaldehyde, and N-methylethanolamine undergo a Mannich reaction in an aqueous phase to produce hydroxyethylaminomethylcatechol. After purification by pH-controlled extraction and recrystallization, it is esterified with methacryloyl chloride in the presence of triethylamine to obtain a polymerizable catechol methacrylate monomer.

[0054] S5: Add 40g isooctyl acrylate, 2g catechol methacrylate monomer, 2.5g acrylic acid, 0.6g azobisisobutyronitrile, and 200mL ethyl acetate to a three-necked flask, purge with nitrogen for 30min, heat to 65℃ in an oil bath, stir for 8h under nitrogen protection, and take a sample for infrared detection. If 1640cm... -1 and 810cm -1The double bond peak still existed, so 0.1 g of azobisisobutyronitrile was added, and the reaction continued until the double bond characteristic peak disappeared. Most of the solvent was removed by rotary evaporation, and the viscous liquid was slowly poured into 900 mL of n-hexane to precipitate. The precipitate was filtered, collected, and dried under vacuum at 40 °C for 24 h to obtain catechol-modified polyacrylate.

[0055] Using azobisisobutyronitrile as an initiator, under nitrogen protection, isooctyl acrylate, catechol methacrylate monomer and acrylic acid were subjected to free radical copolymerization in ethyl acetate to generate a copolymer with catechol groups in the side chain. After precipitation and drying, catechol-modified polyacrylate was obtained.

[0056] S6: Mix 55g tetrahydrofuran methacrylate, 5g trimethylolpropane trimethacrylate, 3g photoinitiator TPO and 0.25g leveling agent BYK307, stir for 5min, add 40g catechol-modified polyacrylate and 20g ethyl acetate, stir at 70℃ for 4h, cool to 40℃, add 3g low surface energy thermal expansion microspheres, stir at 300rpm for 15min to obtain heat-resistant adhesive;

[0057] The heat-resistant adhesive was applied to one side of a 50μm brown PI film using an 80μm line coater and dried at 60℃ for 5 minutes to obtain a heat-resistant functional layer with a dry film thickness of approximately 50μm. A 50μm transparent silicone release film was then laminated onto the layer. The semi-finished roll was then passed through a 405nm LED conveyor belt UV curing machine at a speed of 0.5m / min under a nitrogen atmosphere. The roll was then rewound (flipped over). The heat-resistant adhesive was applied to the other side of the PI film in the same manner, dried, laminated with a second release film, and cured to obtain an easily peelable heat-resistant pressure-sensitive adhesive tape with a total adhesive layer thickness of approximately 100μm.

[0058] Among them, the LED tracked UV curing machine has a light intensity of 350mW / cm². 2 The lightbox is approximately 1.2m long and the illumination time is approximately 2.4min.

[0059] Example 2: A manufacturing process for an easy-to-peel heat-resistant pressure-sensitive adhesive tape, comprising the following steps:

[0060] S1: Mix 20g acrylonitrile, 8.75g dodecafluoroheptyl methacrylate, 3.15g vinyl acetate, 1.5g acrylic acid, 0.0975g ethylene glycol dimethacrylate, 0.4g azobisisobutyronitrile and 7g isopentane to form an oil phase;

[0061] Add 27.5g sodium chloride, 3.95g sodium hydroxide, 13.45g magnesium chloride hexahydrate, 1.65g sodium dodecyl sulfate, 0.04g sodium nitrite and 0.45g polyvinylpyrrolidone K30 to 125mL of deionized water and mix to form an aqueous phase;

[0062] Add 40.5 mL of oil phase to 170 mL of aqueous phase at 8500 rpm, emulsify for 4 min, transfer to a pressure reactor and seal, pressurize with nitrogen to 0.4-0.6 MPa, stir and polymerize at 65℃ and 350 rpm for 25 h, then heat to 72.5℃ for 35 min, cool and discharge, collect the product, adjust the pH of the product to 2 with dilute hydrochloric acid, wash 4 times with deionized water, filter, and vacuum dry at 55℃ for 25 h to obtain fluorinated thermal expansion microspheres.

[0063] S2: 6.5g of fluorinated thermal expansion microspheres were added to 1100mL of anhydrous ethanol and stirred at 650rpm for 12.5min. Then, 0.65mL of N,N-diisopropylethylamine, 1.2g of tetramethylurea hexafluorophosphate and 2.2g of silane coupling agent KH550 were added and stirred at 350rpm for 3.5h. The mixture was then filtered, washed with anhydrous ethanol, and vacuum dried at 65℃ for 25h to obtain modified fluorinated thermal expansion microspheres.

[0064] S3: Mix 950 mL of anhydrous ethanol and 125 mL of deionized water evenly, adjust the pH to 10 with sodium hydroxide to obtain an alkaline ethanol aqueous solution; add 6.5 g of modified fluorinated thermal expansion microspheres to 1075 mL of alkaline ethanol aqueous solution, stir at 650 rpm for 12.5 min, add 0.65 g of tridecafluorooctyltrimethoxysilane, stir for 2.5 h, filter, wash 4 times with anhydrous ethanol, and vacuum dry at 55 °C for 25 h to obtain low surface energy thermal expansion microspheres.

[0065] S4: Add 25g of catechol, 18.8g of 37wt% formaldehyde aqueous solution and 16.5g of N-methylethanolamine to 125mL of deionized water, stir at 45℃ for 4.5h, adjust the pH to 2 with 1mol / L dilute hydrochloric acid, extract three times with 250mL of diethyl ether, discard the ether phase, adjust the pH to 8 with 1mol / L NaOH, extract four times with 650mL of ethyl acetate, combine the organic phases, add 11g of anhydrous magnesium sulfate to dry, filter, rotary evaporate, add 110mL of acetonitrile, heat to dissolve, cool and recrystallize to obtain hydroxyethylaminomethyl catechol;

[0066] Dissolve 15g of hydroxyethylaminomethylcatechol in 375mL of tetrahydrofuran, add 30g of triethylamine, and add 15.75g of methacryloyl chloride dropwise under ice bath. After the addition is complete, stir at room temperature for 2.5h, filter, collect the filtrate, concentrate the filtrate by rotary evaporation, and separate by column chromatography (ethyl acetate: petroleum ether = 1:4) to obtain the catechol methacrylate monomer.

[0067] S5: Add 43g isooctyl acrylate, 3g catechol methacrylate monomer, 2.85g acrylic acid, 0.7g azobisisobutyronitrile, and 250mL ethyl acetate to a three-necked flask, purge with nitrogen for 35min, heat to 67.5℃ in an oil bath, stir under nitrogen protection for 8.5h, and take a sample for infrared detection. If 1640cm... -1 and 810cm -1 The double bond peak still existed, so 0.12 g of azobisisobutyronitrile was added, and the reaction continued until the double bond characteristic peak disappeared. Most of the solvent was removed by rotary evaporation, and the viscous liquid was slowly poured into 950 mL of n-hexane to precipitate. The precipitate was filtered, collected, and dried under vacuum at 45 °C for 25 h to obtain catechol-modified polyacrylate.

[0068] S6: Mix 57.5g tetrahydrofuran methacrylate, 6.5g trimethylolpropane trimethacrylate, 3.5g photoinitiator TPO and 0.285g leveling agent BYK307, stir for 6.5min, add 43g catechol-modified polyacrylate and 22g ethyl acetate, stir at 75℃ for 4.5h, cool to 42.5℃, add 4g low surface energy thermal expansion microspheres, stir at 400rpm for 20min to obtain heat-reducing adhesive;

[0069] The heat-resistant adhesive was applied to one side of a 50μm brown PI film using an 80μm line coater and dried at 65℃ for 6.5 min to obtain a heat-resistant functional layer with a dry film thickness of approximately 55μm. A 50μm transparent silicone release film was then laminated onto the layer. The semi-finished roll was then passed through a 405nm LED conveyor belt UV curing machine at a speed of 0.5m / min under a nitrogen atmosphere. The roll was then rewound (flipped over). The heat-resistant adhesive was applied to the other side of the PI film in the same manner, dried, laminated with a second release film, and cured to obtain an easily peelable heat-resistant pressure-sensitive adhesive tape with a total adhesive layer thickness of approximately 110μm.

[0070] Among them, the LED tracked UV curing machine has a light intensity of 400mW / cm². 2 The lightbox is approximately 1.2m long and the illumination time is approximately 2.4min.

[0071] Example 3: A manufacturing process for an easy-to-peel heat-resistant pressure-sensitive adhesive tape, comprising the following steps:

[0072] S1: Mix 22g acrylonitrile, 9.4g dodecafluoroheptyl methacrylate, 3.6g vinyl acetate, 1.8g acrylic acid, 0.12g ethylene glycol dimethacrylate, 0.5g azobisisobutyronitrile and 8g isopentane to form an oil phase;

[0073] Add 30g sodium chloride, 4.2g sodium hydroxide, 15.6g magnesium chloride hexahydrate, 1.8g sodium dodecyl sulfate, 0.05g sodium nitrite and 0.6g polyvinylpyrrolidone K30 to 150mL of deionized water and mix to form an aqueous phase;

[0074] Add 45 mL of oil phase to 200 mL of aqueous phase at 9000 rpm, emulsify for 5 min, transfer to a pressure reactor and seal, pressurize with nitrogen to 0.4-0.6 MPa, stir and polymerize at 70℃ and 400 rpm for 26 h, then heat to 75℃ for 40 min, cool and discharge, collect the product, adjust the pH of the product to 2 with dilute hydrochloric acid, wash 5 times with deionized water, filter, and vacuum dry at 60℃ for 26 h to obtain fluorinated thermal expansion microspheres.

[0075] S2: Add 8g of fluorinated thermal expansion microspheres to 1200mL of anhydrous ethanol and stir at 700rpm for 15min. Add 0.8mL of N,N-diisopropylethylamine, 1.4g of tetramethylurea hexafluorophosphate and 2.4g of silane coupling agent KH550, stir at 400rpm for 4h, filter, wash with anhydrous ethanol, and vacuum dry at 70℃ for 26h to obtain modified fluorinated thermal expansion microspheres.

[0076] S3: Mix 1000 mL of anhydrous ethanol and 150 mL of deionized water evenly, adjust the pH to 10 with sodium hydroxide to obtain an alkaline ethanol aqueous solution; add 8 g of modified fluorinated thermal expansion microspheres to 1150 mL of alkaline ethanol aqueous solution, stir at 700 rpm for 15 min, add 0.8 g of tridecafluorooctyltrimethoxysilane, stir for 3 h, filter, wash 5 times with anhydrous ethanol, and vacuum dry at 60 °C for 26 h to obtain low surface energy thermal expansion microspheres.

[0077] S4: Add 28g of catechol, 21.4g of 37wt% formaldehyde aqueous solution and 18g of N-methylethanolamine to 150mL of deionized water, stir at 50℃ for 5h, adjust the pH to 2 with 1mol / L dilute hydrochloric acid, extract with 300mL of diethyl ether 4 times, discard the diethyl ether phase, adjust the pH to 8 with 1mol / L NaOH, extract with 700mL of ethyl acetate 5 times, combine the organic phases, add 12g of anhydrous magnesium sulfate to dry, filter, rotary evaporate, add 120mL of acetonitrile, heat to dissolve, cool and recrystallize to obtain hydroxyethylaminomethyl catechol;

[0078] Dissolve 16g of hydroxyethylaminomethylcatechol in 400mL of tetrahydrofuran, add 32g of triethylamine, and add 16.8g of methacryloyl chloride dropwise under ice bath. After the addition is complete, stir at room temperature for 3h, filter, collect the filtrate, concentrate the filtrate by rotary evaporation, and separate by column chromatography (ethyl acetate: petroleum ether = 1:4) to obtain the catechol methacrylate monomer.

[0079] S5: Add 46g isooctyl acrylate, 4g catechol methacrylate monomer, 3.2g acrylic acid, 0.8g azobisisobutyronitrile, and 300mL ethyl acetate to a three-necked flask, purge with nitrogen for 40min, heat to 70℃ in an oil bath, stir for 9h under nitrogen protection, and take a sample for infrared detection. If 1640cm... -1 and 810cm -1 The double bond peak still existed, so 0.14 g of azobisisobutyronitrile was added, and the reaction continued until the double bond characteristic peak disappeared. Most of the solvent was removed by rotary evaporation, and the viscous liquid was slowly poured into 1000 mL of n-hexane to precipitate. The precipitate was filtered, collected, and dried under vacuum at 50 °C for 26 h to obtain catechol-modified polyacrylate.

[0080] S6: Mix 60g tetrahydrofuran methacrylate, 8g trimethylolpropane trimethacrylate, 4g photoinitiator TPO and 0.32g leveling agent BYK307, stir for 8 min, add 46g catechol-modified polyacrylate and 24g ethyl acetate, stir at 80℃ for 5 h, cool to 45℃, add 5g low surface energy thermal expansion microspheres, stir at 500 rpm for 25 min to obtain heat-resistant adhesive;

[0081] The heat-resistant adhesive was applied to one side of a 50μm brown PI film using an 80μm line coater and dried at 70℃ for 8 minutes to obtain a heat-resistant functional layer with a dry film thickness of approximately 60μm. A 50μm transparent silicone release film was then laminated onto the layer. The semi-finished roll was then passed through a 405nm LED conveyor belt UV curing machine at a speed of 0.5m / min under a nitrogen atmosphere. The roll was then rewound (flipped over). The heat-resistant adhesive was applied to the other side of the PI film in the same manner, dried, laminated with a second release film, and cured to obtain an easily peelable heat-resistant pressure-sensitive adhesive tape with a total adhesive layer thickness of approximately 120μm.

[0082] Among them, the LED tracked UV curing machine has a light intensity of 450mW / cm². 2 The lightbox is approximately 1.2m long and the illumination time is approximately 2.4min.

[0083] In Examples 1-3, acrylonitrile was selected from Jinan Huifengda Chemical Co., Ltd., CAS No. 107-13-1; dodecafluoroheptyl methacrylate was selected from Wuhan Lanabai Pharmaceutical Chemical Co., Ltd., CAS No. 2261-99-6; vinyl acetate was selected from Jinan Hengcheng New Materials Co., Ltd., CAS No. 108-05-4; acrylic acid was selected from Shandong Mengqi Chemical Co., Ltd., CAS No. 79-10-7; ethylene glycol dimethacrylate was selected from Jinan Yuanyang Chemical Co., Ltd., CAS No. 97-90-5; azobisisobutyronitrile was selected from Jinan Zhixuan Chemical Co., Ltd., CAS No. 78-67-1; isopentane was selected from Zibo Yujin Trading Co., Ltd., CAS No. 78-78-4; and sodium chloride was selected from Jinan Jumeihui Chemical Co., Ltd., CAS No. 7647-14-5.

[0084] Magnesium chloride hexahydrate was selected from Jinan Hesun Chemical Co., Ltd., CAS No. 7791-18-6; sodium dodecyl sulfate was selected from Jinan Xinyuchengtai Chemical Technology Co., Ltd., CAS No. 151-21-3; sodium nitrite was selected from Jinan Jinhao Chemical Co., Ltd., CAS No. 7632-00-0; polyvinylpyrrolidone K30 was selected from Zhejiang Yicun Biotechnology Co., Ltd., CAS No. 9003-39-8; N,N-diisopropylethylamine was selected from Shanghai Bangcheng Chemical Co., Ltd., CAS No. 7087-68-5; tetramethylurea hexafluorophosphate was selected from Wuhan Kemic Biotechnology Co., Ltd. The following products were selected: Pharmaceutical Technology Co., Ltd. (CAS No. 148893-10-1); Silane coupling agent KH550 (CAS No. 3179-76-8); Tridecafluorooctyltrimethoxysilane (CAS No. 85857-16-5); Catechol (CAS No. 120-80-9); N-methylethanolamine (CAS No. 109-83-1); Anhydrous magnesium sulfate (CAS No. 748) from Langfang Qianyao Technology Co., Ltd. 7-88-9; Acetonitrile was selected from Shandong Mengqi Chemical Co., Ltd., CAS No. 75-05-8; Tetrahydrofuran was selected from Shandong Qiyun Chemical Technology Co., Ltd., CAS No. 109-99-9; Triethylamine was selected from Jinan Xinchen Chemical Co., Ltd., CAS No. 121-44-8; Methacryl chloride was selected from Hubei Langbowan Biopharmaceutical Co., Ltd., CAS No. 920-46-7; Isooctyl acrylate was selected from Jinan Anqi Chemical Co., Ltd., CAS No. 103-11-7; n-Hexane was selected from Jinan Mingxin Chemical Co., Ltd., CAS No. 110-54-3; Tetrahydrofuran... The methyl methacrylate was selected from Wuhan Kanos Technology Co., Ltd., model number KNX20241127; the trimethylolpropane trimethacrylate was selected from Jinan Kaichuang Chemical Co., Ltd., CAS number 3290-92-4; the photoinitiator TPO was selected from Hubei Jianchu Biomedical Co., Ltd., CAS number 75980-60-8; the leveling agent BYK307 was selected from Shanghai Dielin Chemical Co., Ltd.; the brown PI film was selected from Changzhou Diansheng Chemical Co., Ltd.; the transparent silicone oil release film was selected from Heshuo New Material Technology (Dongguan) Co., Ltd., item number HS-41; the remaining raw materials were all commercially available products.

[0085] Comparative Example 1: The difference from Example 1 is that acrylic acid is not added in step S1 to obtain fluorinated thermal expansion microspheres without carboxyl groups on the surface. The fluorinated thermal expansion microspheres in step S2 are replaced with fluorinated thermal expansion microspheres without carboxyl groups on the surface. The remaining steps remain unchanged to prepare an easy-to-peel heat-resistant pressure-sensitive adhesive tape.

[0086] Comparative Example 2: The difference from Example 1 is that step S2 is omitted, and the modified fluorinated thermal expansion microspheres in step S3 are replaced with fluorinated thermal expansion microspheres. The remaining steps remain unchanged, and an easy-to-peel heat-resistant pressure-sensitive adhesive tape is prepared.

[0087] Comparative Example 3: The difference from Example 1 is that step S3 is omitted, and the low surface energy thermal expansion microspheres in step S6 are replaced with modified fluorinated thermal expansion microspheres. The remaining steps remain unchanged, and an easy-to-peel heat-resistant pressure-sensitive adhesive tape is prepared.

[0088] Comparative Example 4: The difference from Example 1 is that step S4 is omitted, and the catechol methacrylate monomer in step S5 is replaced with an equal mass of commercially available methyl methacrylate. The remaining steps remain unchanged, and an easy-to-peel heat-resistant pressure-sensitive adhesive tape is prepared.

[0089] Comparative Example 5: The difference from Example 1 is that steps S4 and S5 are omitted, and the catechol-modified polyacrylate in step S6 is replaced with an equal mass of a common commercially available solvent-based acrylate pressure-sensitive adhesive (such as PS-8281). The remaining steps remain unchanged, and an easy-to-peel heat-resistant pressure-sensitive tape is prepared.

[0090] The following performance tests were performed on the easy-peel heat-resistant pressure-sensitive adhesive tapes prepared in Examples 1-3 and Comparative Examples 1-5:

[0091] Peel strength at 180°C at room temperature: The test was conducted according to GB / T 2792-2014 "Test method for peel strength of adhesive tape". A universal tensile testing machine was used. The heat-reducing pressure-sensitive tape was cut into samples 25mm wide and 200mm long and attached to a clean stainless steel plate. It was rolled twice with a 2kg roller at a speed of 300mm / min. After being placed in an environment of 23±2℃ and 50±5%RH for 20min, it was peeled at 180° at a speed of 300mm / min. The peel strength (N / 25mm) was recorded. The higher the value, the higher the adhesive strength at room temperature.

[0092] Peel force after reflow soldering at 260℃: Referring to GB / T 2792-2014 and simulating the reflow soldering process, the stainless steel plate with the bonded sample was placed in a 260℃ oven and heated for 5 minutes (simulating the peak temperature of lead-free reflow soldering). After being removed and cooled to room temperature, it was peeled at 180° at a speed of 300mm / min. The peel force (N / 25mm) was recorded. The value should not be less than 80% of the peel force at room temperature, proving that the tape was not de-tacky in advance during the reflow soldering process.

[0093] Peel strength and residual adhesive after heat-induced tack reduction: The bonded stainless steel plate was placed in a 280℃ oven and heated for 3 minutes. After cooling to room temperature, it was peeled off at a speed of 300 mm / min at a 180° angle. The peel strength (N / 25 mm) was recorded, and the residual adhesive on the surface of the stainless steel plate was observed under a standard light source. The residual adhesive area was classified into several grades: no residue, small amount, relatively large amount, large amount, and large amount. Under the same peel strength, the less residual adhesive and the lower the grade, the better the tack reduction performance.

[0094] Holding power test: The test was conducted in accordance with GB / T 4851-2014 "Test method for holding power of adhesive tape". A holding power tester was used. The tape was cut into samples 25mm wide and 150mm long and bonded to a clean stainless steel plate with a bonding area of ​​25mm×25mm. The tape was rolled twice with a 2kg roller and a 1kg weight was suspended in a 70℃ oven. The time (h) when the tape fell off the steel plate was recorded. The longer the time, the higher the high temperature cohesive strength.

[0095] Tests for reduced tack and residual adhesive after damp heat aging: The test was conducted according to GB / T 1740-2007 "Test Method for Resistance of Coating Film to Damp Heat". The stainless steel plate with the tape attached was placed in a constant temperature and humidity chamber at 85℃ and 85%RH for 72 hours. After removal, the tape was peeled off at 280℃ according to the above-mentioned "Test Method for Peel Strength and Residual Adhesive after Heat Reduction". The area of ​​residual adhesive was observed. The smaller the value, the better the long-term reliability of the tape in a damp heat environment.

[0096] The results are shown in Table 1:

[0097] Table 1 Performance test results of easily peelable heat-resistant pressure-sensitive adhesive tape

[0098] project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 180° peel force (N / 25mm) 12.3 13.5 14.2 9.8 10.5 12.8 7.6 10.2 Peel force (N / 25mm) after simulated reflow soldering at 260℃ 11.1 11.9 12.4 3.2 5.8 10.9 6.5 8.5 Peel force after heat-induced tack reduction (N / 25mm) 0.3 0.2 0.1 2.8 3.5 4.2 0.9 / Residual adhesive area after heat reduction No residue No residue No residue large amount many More small amount large amount Holding power (70℃, 1kg, h) 188 196 205 96.5 120.3 144.2 52.8 8.2 Reduced tack peel strength after damp heat aging (N / 25mm) 0.4 0.3 0.2 5.6 6.2 7.8 1.3 / Residual adhesive area after damp heat aging No residue No residue No residue large amount many many More large amount

[0099] As can be seen from Table 1, Examples 1-3 are superior to Comparative Examples 1-5 in terms of peel force at 180°C at room temperature, peel force after simulated reflow soldering at 260°C, holding power, peel force after heat de-tackification, residual adhesive, and de-tackification performance after damp heat aging.

[0100] In Comparative Example 1, no acrylic acid was added in step S1, and the microspheres lacked carboxyl groups on their surface. Consequently, their room-temperature peel strength, post-reflow soldering peel strength, and holding power all decreased. Residual adhesive increased after thermal de-tackification, and performance further deteriorated after humid heat aging. This may be because the absence of carboxyl groups makes it difficult for KH550 to be covalently grafted via amidation in S2, resulting in a lack of siloxane active sites on the microsphere surface. Furthermore, the hydrolytic condensation of tridecafluorooctyltrimethoxysilane in S3 cannot effectively anchor the coating, leading to insufficient coating strength. This makes the coating layer prone to damage during processing or in high-temperature environments, reducing the controllability of expansion behavior, hindering the full utilization of the low surface energy migration effect of fluorine segments, and weakening interfacial bonding strength.

[0101] In Comparative Example 2, which did not undergo step S2, the microspheres, although containing carboxyl groups, lacked KH550 grafting. Its performance was slightly better than Comparative Example 1 but still significantly lower than the examples, mainly manifested as decreased peel strength after reflow soldering, more residual adhesive, and performance degradation after humid heat aging. This may be because the silanols produced by the hydrolysis of tridecafluorooctyltrimethoxysilane can only adhere to the microsphere surface through physical adsorption or weak hydrogen bonding, resulting in poor coating integrity. This coating is prone to cracking and detachment during tape coating and in humid environments, potentially causing premature partial expansion of the microspheres and restricting the migration of fluorine segments during de-adhesion.

[0102] In Comparative Example 3, without step S3, the microspheres were only grafted with KH550 without fluorinated polysiloxane coating. The peel strength after reflow soldering did not decrease significantly, but the peel strength remained high and residual adhesive was minimal after thermal de-adhesion. Residual adhesive increased after humid heat aging. This may be because, without the fluorinated layer, although the microspheres can expand normally at higher temperatures, the lack of low surface energy CF segments on the surface prevents them from actively reducing interfacial adhesion during expansion, resulting in insufficient de-adhesion. Simultaneously, the silanol groups of KH550 are easily hydrolyzed under humid heat, weakening the interfacial bonding between the microspheres and the colloid.

[0103] In Comparative Example 4, without step S4, the catechol methacrylate monomer was replaced with methyl methacrylate. The resulting copolymer lacked catechol groups, and its peel strength and holding power at room temperature decreased significantly. Although the peel strength was still low after heat reduction, a small amount of adhesive residue remained. The adhesive residue increased after humid heat aging. This may be because the absence of catechol groups weakens the hydrogen bonds and π-π interactions that may exist between the adhesive and the silanol groups on the microsphere surface and the PI substrate, resulting in insufficient interfacial adhesion. At the same time, the polarity of the copolymer changes, leading to poorer compatibility with the microspheres and a decrease in the overall cohesive strength of the adhesive layer. Under humid heat, moisture penetration further weakens the interfacial bonding.

[0104] In Comparative Example 5, steps S4 and S5 were omitted, and a commercially available solvent-based acrylic pressure-sensitive adhesive was used directly to replace the catechol-modified polyacrylate. This resulted in lower peel strength and poorer holding power at room temperature. After heat reduction, cohesive failure easily occurred, leaving significant residue. Cohesive failure also occurred after hygrothermal aging. This may be because the crosslinking density and molecular weight distribution of the ordinary acrylic pressure-sensitive adhesive were not optimized for this system. At high temperatures, the cohesive strength decreased significantly, and the adhesive layer easily fractured from the inside rather than peeling off at the interface when the microspheres expanded. Simultaneously, the adhesive lacked strong interaction with the microspheres and PI film, resulting in weak interfacial bonding, which failed to meet the requirements of high holding power and zero residue in precision manufacturing processes.

[0105] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A manufacturing process for an easily peelable heat-resistant pressure-sensitive adhesive tape, characterized in that, Includes the following steps: Step 1: Fluorinated thermally expandable microspheres were prepared by suspension polymerization, and then grafted with KH550 and hydrolyzed and polycondensed with tridecafluorooctyltrimethoxysilane to obtain low surface energy thermally expandable microspheres. Step 2: Using catechol, formaldehyde and N-methylethanolamine, catechol methacrylate monomer is synthesized by Mannich reaction and methacryloyl chloride esterification, and then copolymerized with isooctyl acrylate and acrylic acid free radical to obtain catechol modified polyacrylate. Step 3: The catechol-modified polyacrylate is mixed with tetrahydrofuran methacrylate, trimethylolpropane trimethacrylate, photoinitiator TPO, leveling agent BYK307, ethyl acetate and low surface energy thermal expansion microspheres to prepare a heat-resistant adhesive. The adhesive is then applied in a stepwise double-sided coating process to obtain an easy-to-peel heat-resistant pressure-sensitive tape. The mass ratio of the catechol-modified polyacrylate, tetrahydrofuran methacrylate, trimethylolpropane trimethacrylate, photoinitiator TPO, leveling agent BYK307, ethyl acetate, and low surface energy thermal expansion microspheres is 40-46:55-60:5-8:3-4:0.25-0.32:20-24:3-5.

2. The production process of an easily peelable heat-resistant pressure-sensitive adhesive tape according to claim 1, characterized in that, The specific preparation method of the low surface energy thermal expansion microspheres is as follows: Modified fluorinated thermal expansion microspheres were added to an alkaline ethanol aqueous solution and stirred for 10-15 min. Then, tridecafluorooctyltrimethoxysilane was added and stirred for 2-3 h. The mixture was then filtered, washed, and vacuum dried to constant weight to obtain low surface energy thermal expansion microspheres. The alkaline ethanol aqueous solution is obtained by mixing anhydrous ethanol and deionized water in a volume ratio of 18-20:2-3, and adjusting the pH value to 10 with sodium hydroxide. The ratio of the modified fluorinated thermal expansion microspheres, alkaline ethanol aqueous solution, and tridecafluorooctyltrimethoxysilane is 5-8g: 1000-1150mL: 0.5-0.8g.

3. The production process of an easily peelable heat-resistant pressure-sensitive adhesive tape according to claim 2, characterized in that, The specific preparation method of the modified fluorinated thermal expansion microspheres is as follows: Fluorinated thermal expansion microspheres were added to anhydrous ethanol and stirred for 10-15 min. N,N-diisopropylethylamine, tetramethylurea hexafluorophosphate and silane coupling agent KH550 were added and stirred for 3-4 h. The mixture was then filtered, washed and vacuum dried to constant weight to obtain modified fluorinated thermal expansion microspheres. The ratio of the fluorinated thermal expansion microspheres, anhydrous ethanol, N,N-diisopropylethylamine, tetramethylurea hexafluorophosphate, and silane coupling agent KH550 is 5-8g: 1000-1200mL: 0.5-0.8mL: 1-1.4g: 2-2.4g.

4. The production process of an easily peelable heat-resistant pressure-sensitive adhesive tape according to claim 3, characterized in that, The specific preparation method of the fluorinated thermal expansion microspheres is as follows: The oil phase was added to the aqueous phase at 8000-9000 rpm and emulsified for 3-5 min. The mixture was then transferred to a pressure reactor and sealed. Nitrogen gas was applied to pressurize the reactor to 0.4-0.6 MPa, and the mixture was stirred and polymerized at 60-70℃ and 300-400 rpm for 24-26 h. The temperature was then raised to 70-75℃ and matured for 30-40 min. The mixture was cooled and discharged, and the product was collected. The pH of the product was adjusted to 2 with dilute hydrochloric acid. The product was washed, filtered, and vacuum dried to constant weight to obtain fluorinated thermally expanded microspheres. The volume ratio of the oil phase to the water phase is 36-45:140-200.

5. The production process of an easily peelable heat-resistant pressure-sensitive adhesive tape according to claim 4, characterized in that, The oil phase is composed of acrylonitrile, dodecafluoroheptyl methacrylate, vinyl acetate, acrylic acid, ethylene glycol dimethacrylate, azobisisobutyronitrile, and isopentane in an order of 18-22: The mixture was obtained by mixing ingredients in a mass ratio of 8.1-9.4: 2.7-3.6: 1.2-1.8: 0.075-0.12: 0.3-0.5: 6-8. The aqueous phase is obtained by mixing sodium chloride, sodium hydroxide, magnesium chloride hexahydrate, sodium dodecyl sulfate, sodium nitrite, polyvinylpyrrolidone K30, and deionized water in a ratio of 25-30g: 3.7-4.2g: 11.3-15.6g: 1.5-1.8g: 0.03-0.05g: 0.3-0.6g: 100-150mL.

6. The production process of an easily peelable heat-resistant pressure-sensitive adhesive tape according to claim 1, characterized in that, The specific preparation method of the catechol methacrylate monomer is as follows: Add catechol, 37wt% formaldehyde aqueous solution and N-methylethanolamine to deionized water, stir at 40-50℃ for 4-5h, adjust the pH to 2 with dilute hydrochloric acid, extract with diethyl ether 2-4 times, discard the diethyl ether phase, adjust the pH to 8 with NaOH, extract with ethyl acetate 3-5 times, combine the organic phases, add anhydrous magnesium sulfate to dry, filter, rotary evaporate, add acetonitrile, heat to dissolve, cool and recrystallize to obtain hydroxyethylaminomethyl catechol; Hydroxyethylaminomethylcatechol was dissolved in tetrahydrofuran, triethylamine was added, and methacryloyl chloride was added dropwise under ice bath. After the addition was complete, the mixture was stirred at room temperature for 2-3 hours, filtered, and the filtrate was collected. The filtrate was concentrated by rotary evaporation and separated by column chromatography to obtain the catechol methacrylate monomer.

7. The production process of an easily peelable heat-resistant pressure-sensitive adhesive tape according to claim 6, characterized in that, The ratio of catechol, 37wt% formaldehyde aqueous solution, N-methylethanolamine, deionized water, diethyl ether, ethyl acetate, anhydrous magnesium sulfate and acetonitrile is 22-28g: 16.2-21.4g: 15-18g: 100-150mL: 200-300mL: 600-700mL: 10-12g: 100-120mL; The ratio of hydroxyethylaminomethylcatechol, tetrahydrofuran, triethylamine, and methacrylamide chloride is 14-16g: 350-400mL: 28-32g: 14.7-16.8g; The column chromatography was prepared by mixing ethyl acetate and petroleum ether in a volume ratio of 1:

4.

8. The production process of an easily peelable heat-resistant pressure-sensitive adhesive tape according to claim 1, characterized in that, The specific preparation method of the catechol-modified polyacrylate is as follows: Isooctyl acrylate, catechol methacrylate monomer, acrylic acid, azobisisobutyronitrile and ethyl acetate were added to a three-necked flask, and nitrogen gas was bubbled for 30-40 min. The oil bath temperature was raised to 65-70℃, and the mixture was stirred for 8-9 h under nitrogen protection. Most of the solvent was removed by rotary evaporation. The viscous liquid was slowly poured into n-hexane to precipitate. The precipitate was filtered, collected, and vacuum dried to constant weight to obtain catechol modified polyacrylate. The ratio of isooctyl acrylate, catechol methacrylate monomer, acrylic acid, azobisisobutyronitrile and ethyl acetate is 40-46g: 2-4g: 2.5-3.2g: 0.6-0.8g: 200-300mL.

9. The manufacturing process of an easily peelable heat-resistant pressure-sensitive adhesive tape according to claim 1, characterized in that, The specific operation steps of the step-by-step double-sided coating process are as follows: The heat-reducing adhesive is coated on one side of a brown PI film and dried for 5-8 minutes to obtain a heat-reducing functional layer. A 50μm transparent silicone release film is then bonded to it. The film is then passed through a 405nm LED conveyor belt UV curing machine at a speed of 0.5m / min under a nitrogen atmosphere. The film is then flipped over, and the heat-reducing adhesive is coated on the other side of the PI film in the same way. After drying, a second release film is bonded to it and the film is cured to obtain an easy-to-peel heat-reducing pressure-sensitive tape. The specific conditions for the LED tracked UV curing machine are a light intensity of 350-450 mW / cm². 2 The lightbox is approximately 1.2m long and the illumination time is approximately 2.4min.

10. An easy-to-peel heat-resistant pressure-sensitive adhesive tape, characterized in that, It is prepared by the production process of the easily peelable heat-resistant pressure-sensitive adhesive tape according to any one of claims 1-9.