Easy-to-disassemble adhesive tape, preparation method and application of easy-to-disassemble adhesive tape in die cutting part

Abstract

The invention discloses an easy-to-detach adhesive tape, a preparation method and application of the easy-to-detach adhesive tape in a die cutting part, glue is designed to be strip-shaped, a gap between a bottom roller and an adhesive groove is blocked by an adhesive sheet to form a strip-shaped pattern in a blade coating mode, and the non-adhesive part is blocked by the adhesive sheet and uniformly coated on the surface layer of a material to be used for wrapping a battery; when the battery needs to be taken out, alcohol is dropwise added at the channel, and the alcohol and the glue are dissolved, so that the aim of weakening the viscosity of the back glue is fulfilled, and the battery is easily taken out.

Description

Technical Field

[0001] The invention relates to the technical field of adhesives, and in particular to an easily removable adhesive strip, a preparation method and application thereof in die-cut parts. Background Art

[0002] In the processing of digital products such as mobile phones, laptops, and tablet computers, double-sided adhesive die-cut parts are often used to fix the internal parts of mobile phones and laptops. For example, the bonding of batteries to the body / motherboard, the fixing of camera modules, the bonding of cables, etc. Its thinness can provide reliable bonding without increasing the thickness of the mobile phone, and can adapt to the complex structure and narrow space inside the mobile phone / laptop / tablet computer.

[0003] CN112300718A discloses an adhesive tape and its application, and a processing method for an adhesive tape bonding assembly. The adhesive tape of the invention includes a substrate, and adhesive layers are provided on both sides of the substrate. The substrate itself is a stratifiable material, or contains a separable material layer that can be stratified by a solvent. When it is used for battery bonding, it is easy to disassemble. When the battery is disassembled, the solvent penetrates into the substrate to cause the detachable material layer to be stratified and damaged, thereby reducing the strength of the substrate, and the battery can be easily disassembled without stretching. The shape of the tape die-cut parts is changeable, and there is no need to heat the tape, which will not affect the battery, thereby avoiding the risk of battery explosion due to heating. However, its design is complex and the design and processing costs are high. Summary of the invention

[0004] In view of the above-mentioned defects of the prior art, the present invention provides an easy-to-remove adhesive strip and a preparation method thereof, which can provide reliable bonding performance in the die-cut parts. The easy-to-remove adhesive strip can be directly dissolved by alcohol, so that the easy-to-remove adhesive strip loses its stickiness, and the battery can be easily removed.

[0005] The specific technical solutions are as follows:

[0006] A method for preparing an easily removable adhesive strip: by weight, 80-90 parts of methacrylamide, 8-12 parts of a viscosity modifier, 10-15 parts of isopropyl alcohol, and 2-5 parts of a photoinitiator are taken and stirred to obtain an adhesive solution, which is applied into strips by a scraper coating method, and cured under ultraviolet light to obtain an easily removable adhesive strip.

[0007] A method for preparing an easily removable adhesive strip comprises taking 1-5 parts of amylose, 75-85 parts of methacrylamide, 8-12 parts of a viscosity modifier, 10-15 parts of isopropyl alcohol and 2-5 parts of a photoinitiator, stirring and mixing them evenly to obtain an adhesive solution, applying the solution into strips by a scraper coating method, and curing the strips under ultraviolet light to obtain an easily removable adhesive strip.

[0008] A method for preparing an easily removable adhesive strip comprises taking 1-5 parts of modified amylose, 75-85 parts of methacrylamide, 8-12 parts of a viscosity modifier, 10-15 parts of isopropanol and 2-5 parts of a photoinitiator, stirring and mixing them evenly to obtain an adhesive solution; applying the adhesive solution into strips by a scraper coating method, and curing the strips under ultraviolet light to obtain an easily removable adhesive strip.

[0009] A method for preparing an easily removable adhesive strip comprises taking 1-5 parts of amylopectin, 75-85 parts of methacrylamide, 8-12 parts of a viscosity modifier, 10-15 parts of isopropanol and 2-5 parts of a photoinitiator, stirring and mixing them evenly to obtain an adhesive solution, applying the solution into strips by a scraper coating method, and curing the strips under ultraviolet light to obtain an easily removable adhesive strip.

[0010] Methacrylamide, as a polymerizable monomer, is cured and formed under the action of a photoinitiator and ultraviolet light, and can provide good bonding properties for the adhesive strip. The molecular structure of the adhesive strip based on methacrylamide has a certain polarity and is sensitive to alcohol.

[0011] Alcohol and ethanol molecules can reduce the interaction force between the molecules of the adhesive strip, causing the adhesive to dissolve, thereby achieving the subsequent disassembly operation between the adhesive strip and the die-cut part.

[0012] Branched-chain starch has excellent adhesive ability and can be used as the basic component of adhesive strips; methacrylamide can undergo polymerization reaction, and when photoinitiator is added, it will gradually transform the adhesive strip from its original sticky state to a solidified state with a certain hardness, and the curing effect is improved.

[0013] In the present invention, amylose, as an added component, interacts with other components such as methacrylamide and hydroxyethyl cellulose to increase the overall viscosity of the adhesive, thereby improving the peel strength of the adhesive strip. During the UV curing process, amylose may interact with the photoinitiator to improve the curing effect and make the performance of the adhesive strip more stable.

[0014] Modified amylose, the present invention uses reagents such as 4-chlorophenyl isocyanate and 3-trifluoromethylphenyl isocyanate to modify amylose. It has a stronger interaction with methacrylamide. Its functional group may change the electron cloud distribution of amylose molecules, and can react chemically with methacrylamide molecules to form chemical bonds, thereby enhancing the binding force between molecules; the functional group may also increase the physical interaction with methacrylamide molecules by changing the spatial structure and polarity of the molecules, forming a more stable network structure in the rubber strip, restricting the movement of molecules, and improving the mechanical properties and stability of the rubber strip.

[0015] Preferably, the viscosity modifier is any one of hydroxyethyl cellulose, hydroxypropyl methyl cellulose, carboxymethyl cellulose and polyvinyl acetate. Most preferably, the viscosity modifier is hydroxyethyl cellulose.

[0016] Preferably, the photoinitiator is any one of 2-hydroxy-2-methylpropiophenone, benzophenone, trimethylbenzoylphenylphosphine oxide, and 1-hydroxycyclohexylbenzophenone. Most preferably, the photoinitiator is 2-hydroxy-2-methylpropiophenone.

[0017] Preferably, the UV curing molding is to cure under a 365nm UV lamp for 3-8 minutes. Most preferably, the curing time is 5 minutes.

[0018] Furthermore, the modified amylose starch is modified by using 4-chlorophenyl isocyanate and / or 3-(trifluoromethyl)phenyl isocyanate.

[0019] Furthermore, the modified amylose is 4-chlorophenyl isocyanate modified amylose and / or 3-(trifluoromethyl)phenyl isocyanate modified amylose. Optimally, the modified amylose is 4-chlorophenyl isocyanate modified amylose and 3-(trifluoromethyl)phenyl isocyanate modified amylose in a mass ratio of 1:0.8-1.2.

[0020] Preferably, the preparation method of the 4-chlorophenyl isocyanate modified amylose is as follows: take 8-12g of amylose and vacuum dry it at 110-130°C for 3-5h, cool it to 102-108°C, stir and reflux it in 25-75mL N,N-dimethylacetamide for 10-15h, cool it to 20-30°C, add 0.2-0.5g of lithium chloride, heat it to 70-90°C after 2h-6h, add 20-80mL of pyridine, add 30-80g of 4-chlorophenyl isocyanate after 3-5h, cool it to room temperature after 10-20h, centrifuge it, wash it and dry it.

[0021] Preferably, the preparation method of 3-(trifluoromethyl)phenyl isocyanate modified amylose is as follows: take 8-12g amylose and vacuum dry it at 110-130°C for 3-5h, cool it to 102-108°C, stir and reflux it in 25-75mL N,N-dimethylacetamide for 10-15h, cool it to 20-30°C, add 0.2-0.5g lithium chloride, heat it to 70-90°C after 2-6h, add 20-80mL pyridine and 30-80g 3-(trifluoromethyl)phenyl isocyanate and mix them, cool it to room temperature after 10-20h, centrifuge it by sedimentation, wash it and dry it.

[0022] N,N-dimethylacetamide is used as a reaction solvent to provide a suitable reaction environment for amylose to fully contact with other reagents. Lithium chloride is used as a catalyst to affect the change of the molecular structure of amylose, which helps to promote the subsequent reaction. Pyridine is used as a reaction solvent and N,N-dimethylacetamide together provide a suitable environment for the reaction. The 4-chlorophenyl isocyanate and 3-(trifluoromethyl)phenyl isocyanate selected by the present invention as modification reagents react chemically with the hydroxyl group (-OH) on the amylose, and introduce the corresponding isocyanate group (-N=C=O) on the amylose molecule, thereby changing the chemical structure and properties of the amylose.

[0023] The present invention also discloses the application of the above-mentioned easy-to-detach adhesive strip in die-cut parts, which is as follows:

[0024] Through the scraper coating method, the gap between the bottom roller and the glue groove is blocked with film to form a strip pattern, and the part without glue is evenly coated on the surface of the material with film; after 6 sections of 150℃ oven, die-cut according to the required shape, the un-glued area can allow alcohol to quickly penetrate into it, and the alcohol will dissolve the back glue, so that the glue loses its viscosity and the battery can be easily removed.

[0025] Beneficial effects of the present invention:

[0026] 1. Compared with the prior art, the easy-to-remove adhesive strip of the present invention can provide reliable bonding performance and can be used to stick components such as batteries in die-cut parts. When the battery needs to be removed, alcohol can be dripped into the channel, and the alcohol and glue will dissolve, so that the adhesive strip loses its stickiness and the battery can be easily removed, solving the problem that some adhesive strips in the prior art are difficult to disassemble.

[0027] 2. The present invention selects methacrylamide and hydroxyethyl cellulose, which are cured and formed under the action of a photoinitiator and ultraviolet light, and can provide the adhesive strip with good bonding performance; its viscosity is not significantly affected during the aging process, and it is sensitive to alcohol, which facilitates subsequent disassembly work.

[0028] 3. The present invention uses the addition of amylopectin, amylose or modified amylose to improve the adhesive strip formula, thereby increasing the stability of the adhesive strip, affecting the bonding performance with the bonded material, reducing bonding defects and increasing peel strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is an application diagram of the easy-to-remove adhesive strip of the present invention in a die-cut part. The yellow part is a battery, the blue part is an easy-to-remove adhesive strip (die-cut part), and the gap is a channel that can be used for the injection of alcohol. DETAILED DESCRIPTION

[0030] The parameters and sources of specific chemical substances used are as follows:

[0031] Hydroxyethyl cellulose: viscosity (mPa·s) 2%, aqueous solution at 20°C 60000, sourced from Shandong Gomez Chemical Co., Ltd.

[0032] 3-(Trifluoromethyl)phenyl isocyanate: CAS number: 329-01-1.

[0033] 4-Chlorophenyl isocyanate, CAS number: 104-12-1.

[0034] Example 1

[0035] A method for preparing an easily removable adhesive strip is as follows: 85 g of methacrylamide, 10 g of hydroxyethyl cellulose, 12 mL of isopropanol, and 0.3 g of 2-hydroxy-2-methylpropiophenone are stirred at 100 r / min for 1 min at room temperature (25°C) to obtain an adhesive solution, which is then applied into strips by a scraper coating method, with an application amount of 0.1 g / m 2 , and cure under 365nm ultraviolet light for 5 minutes to obtain an easily removable adhesive strip.

[0036] Example 2

[0037] A method for preparing an easily removable adhesive strip comprises: stirring 5 g of amylopectin and 80 g of methacrylamide at 100 r / min for 10 min under nitrogen conditions; then adding 10 g of hydroxyethyl cellulose, 12 mL of isopropanol, and 0.3 g of 2-hydroxy-2-methylpropiophenone, stirring at 100 r / min for 1 min at room temperature of 25°C to obtain an adhesive solution, and applying the adhesive solution into strips by a scraper coating method, with an application amount of 0.1 g / m 2 , and cure under 365nm ultraviolet light for 5 minutes to obtain an easily removable adhesive strip.

[0038] Example 3

[0039] A method for preparing an easily removable adhesive strip comprises: stirring 5 g of modified amylopectin and 80 g of methacrylamide at 100 r / min for 10 min under nitrogen conditions; then adding 10 g of hydroxyethyl cellulose, 12 mL of isopropanol, and 0.3 g of 2-hydroxy-2-methylpropiophenone, stirring at 100 r / min for 1 min at room temperature of 25°C to obtain an adhesive solution, and applying the adhesive solution into strips by a scraper coating method, with an application amount of 0.1 g / m 2 , and cure under 365nm ultraviolet light for 5 minutes to obtain an easily removable adhesive strip.

[0040] The synthesis method of the modified amylopectin is as follows: 10 g of amylopectin is vacuum dried at 120° C. for 4 h, cooled to 105° C., stirred and refluxed at 100 r / min in 50 mL of N,N-dimethylacetamide for 12 h, cooled to 25° C., 0.3 g of lithium chloride is added, heated to 80° C. after 4 h, 50 mL of pyridine and 60 g of 3-(trifluoromethyl)phenyl isocyanate are added and mixed, cooled to room temperature after 16 h, 100 mL of methanol is added for sedimentation and centrifugation, washed 3 times with 100 mL of methanol, and vacuum dried at 60° C. for 8 h.

[0041] Example 4

[0042] A method for preparing an easily removable adhesive strip comprises: stirring 5 g of amylose and 80 g of methacrylamide at 100 r / min for 10 min under nitrogen conditions; then adding 10 g of hydroxyethyl cellulose, 12 mL of isopropanol, and 0.3 g of 2-hydroxy-2-methylpropiophenone, stirring at 100 r / min for 1 min at room temperature of 25°C to obtain an adhesive solution, and applying the adhesive solution into strips by a scraper coating method, with an application amount of 0.1 g / m 2 , and cure under 365nm ultraviolet light for 5 minutes to obtain an easily removable adhesive strip.

[0043] Example 5

[0044] A method for preparing an easily removable adhesive strip comprises: stirring 5 g of modified amylose A and 80 g of methacrylamide at 100 r / min for 10 min under nitrogen conditions; then adding 10 g of hydroxyethyl cellulose, 12 mL of isopropanol, and 0.3 g of 2-hydroxy-2-methylpropiophenone, stirring at 100 r / min for 1 min at room temperature of 25°C to obtain an adhesive solution, and applying the adhesive solution into strips by a scraper coating method, with an application amount of 0.1 g / m 2 , and cure under 365nm ultraviolet light for 5 minutes to obtain an easily removable adhesive strip.

[0045] The synthesis method of the modified amylose A is as follows: 10 g of amylose is vacuum dried at 120° C. for 4 h, cooled to 105° C., stirred and refluxed at 100 r / min in 50 mL of N,N-dimethylacetamide for 12 h, cooled to 25° C., 0.3 g of lithium chloride is added, heated to 80° C. after 4 h, 50 mL of pyridine is added, 50 g of 4-chlorophenyl isocyanate is added after 4 h, cooled to room temperature after 16 h, 100 mL of methanol is added for sedimentation and centrifugation, washed three times with 50 mL of methanol, and vacuum dried at 60° C. for 8 h.

[0046] Example 6

[0047] A method for preparing an easily removable adhesive strip comprises: stirring 5 g of modified amylose B and 80 g of methacrylamide at 100 r / min for 10 min under nitrogen conditions; then adding 10 g of hydroxyethyl cellulose, 12 mL of isopropanol, and 0.3 g of 2-hydroxy-2-methylpropiophenone, stirring at 100 r / min for 1 min at room temperature of 25°C to obtain an adhesive solution, and applying the adhesive solution into strips by a scraper coating method, with an application amount of 0.1 g / m 2 , and cure under 365nm ultraviolet light for 5 minutes to obtain an easily removable adhesive strip.

[0048] The synthesis method of the modified amylose B is as follows: 10 g of amylose is taken and vacuum dried at 120° C. for 4 h, cooled to 105° C., stirred and refluxed at 100 r / min in 50 mL of N,N-dimethylacetamide for 12 h, cooled to 25° C., 0.3 g of lithium chloride is added, heated to 80° C. after 4 h, 50 mL of pyridine and 50 g of 3-(trifluoromethyl)phenyl isocyanate are added and mixed, cooled to room temperature after 16 h, 100 mL of methanol is added for sedimentation and centrifugation, washed three times with 50 mL of methanol, and vacuum dried at 60° C. for 8 h.

[0049] Example 7

[0050] A method for preparing an easily removable adhesive strip comprises: stirring 2.5 g of modified amylose A and 2.5 g of modified amylose B with 80 g of methacrylamide at 100 r / min for 10 min under nitrogen conditions; then adding 10 g of hydroxyethyl cellulose, 12 mL of isopropanol, and 0.3 g of 2-hydroxy-2-methylpropiophenone, stirring at 100 r / min for 1 min at room temperature of 25°C to obtain an adhesive solution, and applying the adhesive solution into strips by a scraper coating method, with an application amount of 0.1 g / m 2 , and cure under 365nm ultraviolet light for 5 minutes to obtain an easily removable adhesive strip.

[0051] The preparation method of the modified amylose A is the same as that in Example 5 and will not be described again here.

[0052] The preparation method of the modified amylose B is the same as that in Example 6 and will not be described again here.

[0053] Application Examples

[0054] The application of the easily removable adhesive strips of Examples 1-7 in die-cut parts is as follows:

[0055] By scraper coating, the coating amount is 0.1g / m 2 , use film to block the gap between the bottom roller and the glue groove into a strip pattern, and use film to cover the part that is not glued and evenly apply it on the surface of the material; after 6 sections of 150℃ oven. Die-cut according to the required shape, the un-glued area can allow alcohol to quickly penetrate into it, dissolve the back glue through alcohol, so that the glue loses its viscosity and the battery can be easily removed.

[0056] Test Example 1

[0057] Peel test

[0058] Refer to GB / T 2792-2014 test method for peel strength of adhesive tape for sample preparation and testing, as follows:

[0059] Pour the adhesive strips prepared in Examples 1-7 onto a sample of 25 mm × 200 mm, tear off the release film and stick it on a standard steel plate wiped clean with alcohol and specially used for tape testing. The sticking position should ensure that the effective peeling length is about 100 mm; then place it on a non-woven fabric and roll it back and forth 3 times with a 2 kg pressure roller, and place it in the test room for a specified time for testing.

[0060] During the test: the HB-B01-D computer tensile testing machine produced by Meister Industrial Systems (China) Co., Ltd. was used to test the 180° peel strength of the glass and film interface of the adhesive strips prepared in Examples 1-5 at a tensile rate of 100 mm / min, and the average value of 3 tests was taken. The results are shown in Table 1.

[0061] Accelerated aging test: The adhesive tapes prepared in Examples 1-5 are placed in an environment of 66°C and 80% relative humidity for 96 hours, and then placed under standard laboratory conditions for a certain period of time to restore them to the standard environment. The adhesive tapes can then be tested as planned using the above method.

[0062] Table 1 Aging resistance test results

[0063]

[0064]

[0065] The surfaces of the tapes of Examples 1-7 are smooth after aging, without cracks, bubbles, discoloration, etc., and have no obvious difference from before aging, indicating that the viscosity is not significantly affected during the aging process, further indicating that the easily removable adhesive strips of the present invention have good stability.

[0066] It can be seen from the above table that the adhesive properties and heat aging resistance of the easy-to-detach adhesive strips of Examples 2-7 are significantly better than those of the easy-to-detach adhesive strips of Example 1. Compared with the easy-to-detach colloid of Example 2, which adds branched starch, and the easy-to-detach adhesive strip of Example 4, which adds amylose, the glucose units of amylose are linear macromolecules connected by α-1,4-glycosidic bonds, and the presence of branched chains makes the distance between molecular chains relatively large, and the hydrogen bond interaction between molecular chains is relatively weak, and the corresponding connection points are relatively few and unevenly distributed. When subjected to peeling force, the connection points are easily destroyed one by one, resulting in the peeling strength of Example 2 before and after aging being inferior to that of Example 4.

[0067] Compared with the amylopectin modified with 3-(trifluoromethyl)phenyl isocyanate added in Example 3, the amylopectin added in Example 2 may have many hydroxyl groups on the amylopectin molecules, which react with the isocyanate groups to undergo nucleophilic addition reactions, increase the interaction with the bonded object, and thus affect the bonding strength of the adhesive strip. There are a large number of short side chains in the amylopectin molecules, and the molecular chains are not tightly entangled and highly cross-linked like linear polymers. Excessive 3-(trifluoromethyl)phenyl isocyanate is required to modify it. The residual modification agent may interfere with the performance of the modified amylopectin, and cause pollution or harm to the environment. When applied to detachable adhesive strips for battery bonding, the force between it and the bonded surface is relatively weak. After UV curing, the adhesive strips of Example 3 may cause the adhesive strips to be harder and lose certain easy-to-disassemble properties.

[0068] Furthermore, modified amylose is added to the easily disassembled colloids of Examples 5-7. Amylose or modified amylose can interact with other ingredients such as methacrylamide and hydroxyethyl cellulose to increase the overall viscosity of the adhesive, thereby improving the peel strength. Moreover, during the UV curing process, amylose or modified amylose may interact with the photoinitiator to improve the curing effect and make the performance of the adhesive strip more stable.

[0069] In comparison, the effect of adding modified amylose is better than that of adding amylose. The reasons are: first, compared with amylose, the isocyanate groups in the molecular structure of 4-chlorophenyl isocyanate and 3-(trifluoromethyl)phenyl isocyanate in modified amylose have higher reactivity and react chemically with the hydroxyl groups in the amylose molecules; second, there is a stronger interaction between modified amylose and methacrylamide, forming a more stable network structure in the rubber strip, which can prevent the breakage and cross-linking of the molecular chain, thereby improving the adhesive performance and heat aging resistance of the rubber strip.

[0070] The modified amylose used in Example 5 has 4-chlorophenyl isocyanate added compared to 3-(trifluoromethyl)phenyl isocyanate in the modified amylose used in Example 6. The former has smaller steric hindrance and is more likely to interact with methacrylamide, so that when the adhesive strip is subjected to external force, it can better transfer stress, thereby improving the adhesive performance and aging resistance of the adhesive strip.

[0071] The present invention enhances the internal synergistic effect of the adhesive strip by introducing modified starch containing isocyanate groups. The isocyanate groups react with the hydroxyl groups in the amylose molecules to form a stable cross-linked network structure, and the bonding strength and heat aging resistance are improved under the hydrogen bonding of the hydroxyl groups of hydroxyethyl cellulose. At the same time, the unique molecular characteristics of 4-chlorophenyl isocyanate and 3-(trifluoromethyl)phenyl isocyanate play a complementary role: the small steric hindrance and moderate polarity of the former are conducive to the formation of a tightly cross-linked network and improve the bonding strength; the strong electron attraction effect of the latter enhances aging resistance and chemical stability. The combination of the two significantly improves the mechanical properties and stability of the adhesive strip.

Claims

1. A method for preparing an easily removable adhesive strip, characterized in that: The method comprises the following steps: taking 1-5 parts of starch, 75-85 parts of methacrylamide, 8-12 parts of viscosity modifier, 10-15 parts of isopropanol and 2-5 parts of photoinitiator by weight, stirring and mixing evenly to obtain glue solution; applying into strips by scraper coating, and curing and forming under ultraviolet light.

2. The method for preparing the easily removable adhesive strip according to claim 1, characterized in that: The following steps are involved: The starch is at least one of amylopectin, amylose, modified amylopectin and modified amylose.

3. The method for preparing the easily removable adhesive strip according to claim 2, characterized in that: The viscosity modifier is any one of hydroxyethyl cellulose, hydroxypropyl methyl cellulose, carboxymethyl cellulose and polyvinyl acetate.

4. The method for preparing the easily removable adhesive strip according to claim 2, characterized in that: The photoinitiator is any one of 2-hydroxy-2-methylpropiophenone, benzophenone, trimethylbenzoylphenylphosphine oxide and 1-hydroxycyclohexylbenzophenone.

5. The method for preparing the easily removable adhesive strip according to claim 2, characterized in that: UV curing molding is to cure under a 365nm UV lamp for 3-8 minutes.

6. The method for preparing the easily removable adhesive strip according to claim 2, characterized in that: The modified amylose is 4-chlorophenyl isocyanate modified amylose and / or 3-(trifluoromethyl)phenyl isocyanate modified amylose.

7. The method for preparing the easily removable adhesive strip according to claim 6, characterized in that: The preparation method of the 4-chlorophenyl isocyanate modified amylose comprises the following steps: taking 8-12 g amylose and vacuum drying it at 110-130° C. for 3-5 h, cooling it to 102-108° C., stirring and reflux it in 25-75 mL N,N-dimethylacetamide for 10-15 h, cooling it to 20-30° C., adding 0.2-0.5 g lithium chloride, heating it to 70-90° C. after 2 h-6 h, adding 20-80 mL pyridine, adding 30-80 g 4-chlorophenyl isocyanate after 3-5 h, cooling it to room temperature after 10-20 h, centrifuging it by sedimentation, washing it, and drying it. The preparation method of the 3-trifluoromethylphenylisocyanate modified amylose comprises the following steps: taking 8-12 g amylose and vacuum drying at 110-130° C. for 3-5 h, cooling to 102-108° C., stirring and reflux in 25-75 mL N,N-dimethylacetamide for 10-15 h, cooling to 20-30° C., adding 0.2-0.5 g lithium chloride, heating to 70-90° C. after 2-6 h, adding 20-80 mL pyridine, adding 30-80 g 3-trifluoromethylphenylisocyanate after 3-5 h, mixing, cooling to room temperature after 10-20 h, centrifuging by sedimentation, washing, and drying.

8. An easily removable adhesive strip, characterized in that: Prepared by the method according to any one of claims 1 to 7.

9. Use of the easily dismantled adhesive strip as claimed in claim 8 in die-cut parts.

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