Modified PET composite adhesive tape and preparation method thereof

Abstract

The invention discloses a modified PET composite adhesive tape and a preparation method thereof, and belongs to the technical field of adhesive tape preparation. The preparation method of the modified PET composite adhesive tape comprises the following steps: step 1, mixing PET resin, a modifier and a dispersant, then carrying out melt blending extrusion to obtain modified master batches, then carrying out melt extrusion on the modified master batches to form a thick sheet, and carrying out stretching, shaping and surface treatment to obtain a modified PET film; and 2, uniformly coating the modified adhesive on the surface of the modified PET film, drying and curing to obtain the modified PET composite adhesive tape. The composite adhesive tape prepared by the method has excellent mechanical property, ultraviolet resistance and adhesive property.

Description

Technical Field

[0001] The invention belongs to the technical field of adhesive tape preparation, and in particular relates to a modified PET composite adhesive tape and a preparation method thereof. Background Art

[0002] In application scenarios such as outdoor equipment, building curtain walls, photovoltaic modules and automotive exteriors, traditional PET tapes have long restricted the reliability and service life of materials in complex environments due to their dual shortcomings in UV resistance and adhesion performance. As a typical aromatic polyester, PET material has good mechanical strength and chemical stability due to the ester group and benzene ring structure in its molecular chain, but it also leads to its high UV absorption coefficient and strong sensitivity to photodegradation. Under the action of ultraviolet radiation, the PET molecular chain is prone to photoinduced bond breaking and free radical chain reactions, causing yellowing, embrittlement and surface energy attenuation of the substrate, which directly leads to a drop in peel strength of more than 60% after 6 months of outdoor exposure, and even powdering and shedding. At the same time, the crystalline orientation structure and non-polar characteristics of PET make it poorly wettable with most adhesive systems, and the lack of interface compatibility leads to low initial bonding strength. Under the synergistic effect of outdoor temperature and humidity cycles and ultraviolet rays, the bonding interface is prone to stress concentration and delamination failure, which has become the core bottleneck restricting its use as a long-term outdoor bonding solution.

[0003] Patent CN109135598A discloses a copolymer-modified PET tape, including a tape substrate and an adhesive. The copolymer-modified PET tape prepared by the invention can adapt to more complex environments, and the added carbamide peroxide-modified guar gum can be repeatedly peeled and stuck without leaving any traces of residual glue. However, the UV resistance, stability and bonding strength of the composite tape prepared by this method still have room for improvement. Summary of the invention

[0004] The object of the present invention is to provide a modified PET composite tape and a preparation method thereof, so as to solve the technical problems of poor UV resistance, stability and bonding strength of the composite tape in the prior art.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a method for preparing a modified PET composite tape, comprising the following steps:

[0007] Step 1: PET resin, modifier and dispersant are mixed, and then melt-blended and extruded to obtain modified masterbatch, and then the modified masterbatch is melt-extruded into a thick sheet, stretched, shaped, and surface treated to obtain a modified PET film;

[0008] Step 2: Uniformly coat the modified adhesive on the surface of the modified PET film, dry and cure it to obtain a modified PET composite tape.

[0009] Preferably, in Step 1, the dosage ratio of PET resin, modifier and dispersant is (70 - 85) g : (2 - 7) g : (0.5 - 1.6) g. The temperature of the extruder: the feeding section is 236 - 242 °C, the melting section is 258 - 263 °C, the die head section is 268 - 272 °C, and the rotation speed is 200 - 300 rpm. During the stretching process, longitudinal stretching and transverse stretching are carried out. The longitudinal stretching temperature is 80 - 100 °C, the transverse stretching temperature is 100 - 120 °C, the shaping temperature is 200 - 220 °C, and the time is 5 - 10 s. In the surface treatment, corona treatment is used, with a power of 3 - 5 kW and a treatment speed of 20 m / min. In Step 2, microgravure coating is adopted, and the coating speed is 30 - 50 m / min.

[0010] Preferably, the preparation method of the modifier includes the following steps:

[0011] S1: Add 2,4 - dihydroxyacetophenone, anhydrous potassium carbonate and anhydrous acetone into a container, heat and stir the reaction in an oil bath, then dropwise add chloromethyl methyl ether and stir the reaction. After the reaction is completed, cool, filter, wash with acetone, collect the filtrate, dry the filtrate with anhydrous sodium sulfate, filter, rotary evaporate the filtrate, and purify and separate it by column chromatography with a volume ratio of 10:1 petroleum ether and ethyl acetate to obtain Product 1;

[0012] S2: Under nitrogen protection, add Product 1 and 1 - naphthaldehyde into a container, then dropwise add a mixed solution of anhydrous ethanol and potassium hydroxide. After the addition is completed, continue to stir the reaction at room temperature. After the reaction is completed, perform suction filtration, washing, and recrystallization to obtain Product 2;

[0013] S3: Add Product 2 into a container containing methanol, dissolve it by refluxing, then dropwise add hydrochloric acid and continue the reflux reaction. After the reaction is completed, cool, perform suction filtration, recrystallize, and vacuum dry to obtain Product 3;

[0014] S4: Add Product 3, potassium hydroxide and deionized water into a container, stir and dissolve, add a phase transfer catalyst, continue to stir, then mix terephthaloyl chloride and isophthaloyl chloride and add them into the container, stir the reaction. After the reaction is completed, wash, filter, and dry to obtain the modifier.

[0015] In the above process, the synthesis reaction formula of the modifier is as follows:

[0016]

[0017] The results of mass spectrometry analysis of Product 1 are: m / z: 196.07 (100.0%), 197.08 (11.1%), 198.08 (1.4%); the results of mass spectrometry analysis of Product 2 are: m / z: 334.12 (100.0%), 335.12 (22.9%), 336.13 (2.5%); the results of mass spectrometry analysis of Product 3 are: m / z: 290.09 (100.0%), 291.10 (20.8%), 292.10 (2.7%).

[0018] Preferably, in S1, the dosage ratio of 2,4-dihydroxyacetophenone, anhydrous potassium carbonate, anhydrous acetone and chloromethyl methyl ether is (0.85 - 1.13) g : (3.12 - 4.63) g : (55 - 65) mL : (1.14 - 1.46) mL, the temperature of oil bath heating and stirring is 50 - 52 °C, and the stirring time is 1 - 2 h; in S2, the dosage ratio of Product 1, 1-naphthaldehyde, absolute ethanol and potassium hydroxide is (0.92 - 1.15) g : (0.92 - 1.27) g : (48 - 52) mL : (6.5 - 7.1) g, and the continuous stirring reaction time is 12 - 18 h.

[0019] Preferably, in S3, the dosage ratio of Product 2, methanol and hydrochloric acid is (1.12 - 1.35) g : (55 - 65) mL : (8 - 12) mL, and the concentration of hydrochloric acid is 5 mol / L.

[0020] Preferably, in S4, the dosage ratio of Product 3, potassium hydroxide, deionized water, phase transfer catalyst, terephthaloyl chloride and isophthaloyl chloride is (0.43 - 0.58) g : (0.12 - 0.25) g : (20 - 25) mL : (0.05 - 0.08) g : (0.05 - 0.11) g : (0.21 - 0.28) g.

[0021] Preferably, the preparation method of the modified adhesive includes the following steps:

[0022] Q1: Under a nitrogen atmosphere, add 1,5-naphthalene diisocyanate, (3-isocyanatopropyl)triethoxysilane and dibutyltin dilaurate to a container containing tetrahydrofuran, then dropwise add tetrahydrofuran solution of polytetramethylene ether glycol. After the dropping is completed, heat and react to obtain intermediate A;

[0023] Q2: Add intermediate A to N,N-dimethylformamide, slowly add diethanolamine in an ice bath environment, stir and react. After the reaction is completed, add the reaction solution to ethyl acetate, and solids will precipitate. Separate the product, wash it, and dry it under vacuum to obtain the modified adhesive.

[0024] In the above process, the synthesis reaction formula of the modified adhesive is as follows:

[0025]

[0026] Preferably, in the Q1, the dosage ratio of 1,5-naphthalene diisocyanate, (3-isocyanatopropyl)triethoxysilane, dibutyltin dilaurate, and polytetramethylene ether glycol is (2.12 - 3.14) g : (3.01 - 3.23) g : (0.07 - 0.11) g : (20 - 28) g, the heating reaction temperature is 80 - 84 °C, and the reaction time is 2 - 3 h.

[0027] Preferably, in the Q2, the dosage ratio of intermediate A, N,N-dimethylformamide, and diethanolamine is (10.12 - 14.25) g : (50 - 75) mL : (10.82 - 12.16) g.

[0028] The modified PET composite tape prepared by using the preparation method of the modified PET composite tape described above.

[0029] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows:

[0030] 1. The present invention applies the prepared modifier to the modified PET composite tape, which can effectively improve its mechanical properties, heat resistance, and ultraviolet resistance. The presence of the polycyclic aromatic hydrocarbon structure and cross-linked network in the modifier can effectively enhance the mechanical properties. The aromatic ring conjugate system contained can absorb heat energy and disperse it, delaying the thermal movement of molecular chains, and the cross-linked structure can also limit the movement of chain segments, thereby increasing the glass transition temperature and thermal decomposition temperature. At the same time, the benzene ring, carbonyl, and conjugated double bond structures contained in the modifier can absorb ultraviolet rays and release the light energy as heat energy through intramolecular energy transfer, thus improving the ultraviolet resistance of the composite tape.

[0031] 2. The present invention applies the prepared modified adhesive to the modified PET composite tape, which can effectively improve its bonding performance, mechanical strength, and ultraviolet resistance. The active groups contained can construct a high-strength cross-linked network, enhance the cohesion of the modified adhesive, and improve the bonding performance. The introduction of polytetramethylene ether glycol can endow the modified adhesive with flexibility and elasticity, enabling the composite tape to maintain the bonding performance under dynamic load or deformation conditions and reducing the interfacial stress concentration. The naphthalene ring and siloxane bond contained can protect the main chain of the modified adhesive from photooxidative damage and improve the ultraviolet resistance. The naphthalene ring and hydrogen bond contained in the modified adhesive can enhance the molecular chain rigidity and improve the mechanical properties. Specific Embodiments

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0033] Embodiment 1: This embodiment discloses a preparation method of a modifier, including the following steps:

[0034] S1: Add 0.98 g of 2,4-dihydroxyacetophenone, 3.92 g of anhydrous potassium carbonate, and 60 mL of anhydrous acetone into a container, heat and stir the reaction in an oil bath at 50 °C for 2 h, then dropwise add 1.3 mL of chloromethyl methyl ether, stir the reaction, after the reaction ends, cool, filter, wash with acetone, collect the filtrate, dry the filtrate with anhydrous sodium sulfate, filter, rotary evaporate the filtrate, and purify and separate by column chromatography with petroleum ether and ethyl acetate with a volume ratio of 10:1 to obtain Product 1;

[0035] S2: Under nitrogen protection, add 1.03 g of Product 1 and 1.09 g of 1-naphthaldehyde into a container, then dropwise add a mixed solution of 50 mL of anhydrous ethanol and 6.8 g of potassium hydroxide. After the addition is completed, continue to stir the reaction at room temperature for 16 h. After the reaction ends, carry out suction filtration, washing, and recrystallization to obtain Product 2;

[0036] S3: Add 1.23 g of Product 2 into a container containing 60 mL of methanol, dissolve by refluxing, then dropwise add 10 mL of hydrochloric acid with a concentration of 5 mol / L, continue the reflux reaction. After the reaction ends, cool, carry out suction filtration, recrystallize, and dry in vacuum to obtain Product 3;

[0037] S4: Add 0.46 g of Product 3, 0.18 g of potassium hydroxide, and 22.5 mL of deionized water into a container, stir to dissolve, add 0.06 g of a phase transfer catalyst, continue to stir, then mix 0.08 g of terephthaloyl chloride and 0.24 g of isophthaloyl chloride, add them into the container, stir the reaction. After the reaction ends, wash, filter, and dry to obtain the modifier.

[0038] This embodiment discloses a preparation method of a modified adhesive, including the following steps:

[0039] Q1: Under a nitrogen environment, add 2.63 g of 1,5-naphthalene diisocyanate, 3.12 g of (3-isocyanatopropyl)triethoxysilane, and 0.09 g of dibutyltin dilaurate into a container containing 25 mL of tetrahydrofuran, then dropwise add 125 mL of tetrahydrofuran dissolving 24 g of polytetramethylene ether glycol. After the addition ends, heat and react at 80 °C for 3 h to obtain Intermediate A;

[0040] Q2: Add 12.17 g of intermediate A to 62.5 mL of N,N-dimethylformamide. Slowly add 11.48 g of diethylene glycolamine in an ice bath environment. Stir and react. After the reaction is completed, add the reaction solution to ethyl acetate. Solids will precipitate. Separate the product, wash it, and dry it under vacuum to obtain the modified adhesive.

[0041] This example discloses a preparation method of a modified PET composite tape, including the following steps:

[0042] Step 1: Mix 77.5 g of PET resin, 4.5 g of modifier, and 1.05 g of polyethylene glycol, and then perform melt blending and extrusion. The temperature of the extruder: the feeding section is 240 °C, the melting section is 260 °C, the die head section is 270 °C, and the rotation speed is 250 rpm to obtain a modified masterbatch. Subsequently, melt extrude the modified masterbatch into a thick sheet and stretch it. During the stretching process, perform longitudinal stretching and transverse stretching. The longitudinal stretching temperature is 100 °C, the transverse stretching temperature is 120 °C, and it is shaped at 220 °C for 10 s. Use corona treatment with a power of 5 kW and a treatment speed of 20 m / min to obtain a modified PET film;

[0043] Step 2: Microgravure coat the modified adhesive onto the surface of the modified PET film at a coating speed of 30 - 50 m / min, dry it, and cure it to obtain the modified PET composite tape.

[0044] Example 2: This example discloses a preparation method of a modifier, including the following steps:

[0045] S1: Add 0.85 g of 2,4-dihydroxyacetophenone, 3.12 g of anhydrous potassium carbonate, and 65 mL of anhydrous acetone to a container. Heat and stir the reaction in an oil bath at 50 °C for 2 h. Subsequently, dropwise add 1.14 mL of chloromethyl methyl ether and stir the reaction. After the reaction is completed, cool it, filter it, wash it with acetone, collect the filtrate, dry the filtrate with anhydrous sodium sulfate, filter it, rotary evaporate the filtrate, and perform purification and separation by column chromatography with a volume ratio of 10:1 of petroleum ether and ethyl acetate to obtain product 1;

[0046] S2: Under nitrogen protection, add 0.92 g of product 1 and 0.92 g of 1-naphthaldehyde to a container. Subsequently, dropwise add a mixed solution of 48 mL of anhydrous ethanol and 6.5 g of potassium hydroxide. After the addition is completed, continue to stir the reaction at room temperature for 16 h. After the reaction is completed, perform suction filtration, washing, and recrystallization to obtain product 2;

[0047] S3: Add 1.12 g of product 2 to a container containing 65 mL of methanol. After refluxing and dissolving, dropwise add 12 mL of hydrochloric acid with a concentration of 5 mol / L, and continue refluxing the reaction. After the reaction is completed, cool it, perform suction filtration, recrystallize it, and dry it under vacuum to obtain product 3;

[0048] S4: Add 0.43 g of product 3, 0.12 g of potassium hydroxide, and 25 mL of deionized water into a container. After stirring and dissolving, add 0.05 g of a phase transfer catalyst. After continuous stirring, mix 0.05 g of terephthaloyl chloride and 0.21 g of isophthaloyl chloride, then add them into the container, stir and react. After the reaction ends, wash, filter, and dry to obtain a modifier.

[0049] This example discloses a preparation method of a modified adhesive, including the following steps:

[0050] Q1: Under a nitrogen atmosphere, add 2.12 g of 1,5-naphthalene diisocyanate, 3.01 g of (3-isocyanatopropyl)triethoxysilane, and 0.07 g of dibutyltin dilaurate into a container containing 25 mL of tetrahydrofuran. Then, dropwise add 125 mL of tetrahydrofuran dissolved with 20 g of polytetramethylene ether glycol. After the dropping ends, heat and react at 80 °C for 3 h to obtain intermediate A;

[0051] Q2: Add 10.12 g of intermediate A into 50 mL of N,N-dimethylformamide. Slowly add 10.82 g of diethanolamine in an ice bath environment, stir and react. After the reaction ends, add the reaction solution into ethyl acetate, and a solid precipitates. Separate the product, wash, and dry in vacuum to obtain a modified adhesive.

[0052] This example discloses a preparation method of a modified PET composite tape, including the following steps:

[0053] Step 1: Mix 70 g of PET resin, 7 g of modifier, and 0.5 g of polyethylene glycol, then melt and blend and extrude. The temperature of the extruder: the feeding section is 240 °C, the melting section is 260 °C, the die head section is 270 °C, and the rotation speed is 250 rpm to obtain a modified masterbatch. Subsequently, melt and extrude the modified masterbatch into a thick sheet and stretch. During the stretching process, perform longitudinal stretching and transverse stretching. The longitudinal stretching temperature is 100 °C, the transverse stretching temperature is 120 °C, and shape at 220 °C for 10 s. Use corona treatment with a power of 5 kW and a treatment speed of 20 m / min to obtain a modified PET film;

[0054] Step 2: Microgravure coat the modified adhesive onto the surface of the modified PET film at a coating speed of 30 - 50 m / min, dry, and cure to obtain a modified PET composite tape.

[0055] Example 3: This example discloses a preparation method of a modifier, including the following steps:

[0056] S1: Add 1.13 g of 2,4-dihydroxyacetophenone, 4.63 g of anhydrous potassium carbonate, and 55 mL of anhydrous acetone into a container. Heat and stir the reaction in an oil bath at 50 °C for 2 h. Then, dropwise add 1.46 mL of chloromethyl methyl ether and stir the reaction. After the reaction is completed, cool, filter, wash with acetone, collect the filtrate, dry the filtrate with anhydrous sodium sulfate, filter, rotary evaporate the filtrate, and purify and separate it by column chromatography with petroleum ether and ethyl acetate in a volume ratio of 10:1 to obtain Product 1;

[0057] S2: Under nitrogen protection, add 1.15 g of Product 1 and 1.27 g of 1-naphthaldehyde into a container. Then, dropwise add a mixed solution of 52 mL of anhydrous ethanol and 7.1 g of potassium hydroxide. After the addition is completed, continue to stir the reaction at room temperature for 16 h. After the reaction is completed, perform suction filtration, washing, and recrystallization to obtain Product 2;

[0058] S3: Add 1.35 g of Product 2 into a container containing 55 mL of methanol. After refluxing and dissolving, dropwise add 8 mL of hydrochloric acid with a concentration of 5 mol / L, and continue the reflux reaction. After the reaction is completed, cool, perform suction filtration, recrystallize, and dry in vacuo to obtain Product 3;

[0059] S4: Add 0.58 g of Product 3, 0.25 g of potassium hydroxide, and 20 mL of deionized water into a container. After stirring and dissolving, add 0.08 g of a phase transfer catalyst. After continuous stirring, mix 0.11 g of terephthaloyl chloride and 0.28 g of isophthaloyl chloride, and then add them into the container and stir the reaction. After the reaction is completed, wash, filter, and dry to obtain the modifier.

[0060] This example discloses a preparation method of a modified adhesive, including the following steps:

[0061] Q1: Under a nitrogen environment, add 3.14 g of 1,5-naphthalene diisocyanate, 3.23 g of (3-isocyanatopropyl)triethoxysilane, and 0.11 g of dibutyltin dilaurate into a container containing 25 mL of tetrahydrofuran. Then, dropwise add 125 mL of tetrahydrofuran solution containing 28 g of polytetramethylene ether glycol. After the addition is completed, heat and react at 80 °C for 3 h to obtain Intermediate A;

[0062] Q2: Add 14.25 g of Intermediate A into 75 mL of N,N-dimethylformamide. Slowly add 12.16 g of diethanolamine in an ice bath environment and stir the reaction. After the reaction is completed, add the reaction solution into ethyl acetate, and a solid precipitates. Separate the product, wash, and dry in vacuo to obtain the modified adhesive.

[0063] This example discloses a preparation method of a modified PET composite tape, including the following steps:

[0064] Step 1: Mix 85 g of PET resin, 2 g of modifier, and 1.6 g of polyethylene glycol, then perform melt blending and extrusion. The temperature of the extruder: the feeding section is 240 °C, the melting section is 260 °C, the die head section is 270 °C, and the rotation speed is 250 rpm to obtain a modified masterbatch. Subsequently, melt-extrude the modified masterbatch into a thick sheet and stretch it. During the stretching process, perform longitudinal stretching and transverse stretching. The longitudinal stretching temperature is 100 °C, the transverse stretching temperature is 120 °C, and it is shaped at 220 °C for 10 s. Use corona treatment with a power of 5 kW and a treatment speed of 20 m / min to obtain a modified PET film;

[0065] Step 2: Microgravure coat the modified adhesive onto the surface of the modified PET film at a coating speed of 30 - 50 m / min, dry it, and cure it to obtain a modified PET composite tape.

[0066] Example 4: This example discloses a preparation method of a modifier, including the following steps:

[0067] S1: Add 0.89 g of 2,4-dihydroxyacetophenone, 3.51 g of anhydrous potassium carbonate, and 62 mL of anhydrous acetone to a container, heat and stir the reaction in an oil bath at 50 °C for 2 h. Subsequently, dropwise add 1.22 mL of chloromethyl methyl ether, stir the reaction. After the reaction ends, cool it, filter it, wash it with acetone, collect the filtrate, dry the filtrate with anhydrous sodium sulfate, filter it, rotary evaporate the filtrate, and perform purification and separation by column chromatography with petroleum ether and ethyl acetate in a volume ratio of 10:1 to obtain Product 1;

[0068] S2: Under nitrogen protection, add 0.98 g of Product 1 and 0.98 g of 1-naphthaldehyde to a container. Subsequently, dropwise add a mixed solution of 49 mL of anhydrous ethanol and 6.6 g of potassium hydroxide. After the addition is complete, continue to stir the reaction at room temperature for 16 h. After the reaction ends, perform suction filtration, washing, and recrystallization to obtain Product 2;

[0069] S3: Add 1.18 g of Product 2 to a container containing 58 mL of methanol. After refluxing and dissolving, dropwise add 9 mL of hydrochloric acid with a concentration of 5 mol / L, and continue the reflux reaction. After the reaction ends, cool it, perform suction filtration, recrystallize it, and dry it under vacuum to obtain Product 3;

[0070] S4: Add 0.44 g of Product 3, 0.16 g of potassium hydroxide, and 21 mL of deionized water to a container. After stirring and dissolving, add 0.05 g of a phase transfer catalyst. After continuous stirring, mix 0.06 g of terephthaloyl chloride and 0.22 g of isophthaloyl chloride, and then add them to the container. Stir the reaction. After the reaction ends, wash it, filter it, and dry it to obtain the modifier.

[0071] This example discloses a preparation method of a modified adhesive, including the following steps:

[0072] Q1: Under a nitrogen atmosphere, 2.38 g of 1,5-naphthalene diisocyanate, 3.06 g of (3-isocyanatopropyl)triethoxysilane, and 0.08 g of dibutyltin dilaurate were added to a container containing 25 mL of tetrahydrofuran. Then, 125 mL of tetrahydrofuran solution containing 22 g of polytetramethylene ether glycol was added dropwise. After the addition, the mixture was heated and reacted at 80 °C for 3 h to obtain intermediate A;

[0073] Q2: 11.08 g of intermediate A was added to 55 mL of N,N-dimethylformamide. 11.03 g of diethanolamine was slowly added in an ice bath environment, and the mixture was stirred and reacted. After the reaction, the reaction solution was added to ethyl acetate, and a solid precipitated. The product was separated, washed, and dried under vacuum to obtain a modified adhesive.

[0074] This example discloses a preparation method of a modified PET composite tape, including the following steps:

[0075] Step 1: 72 g of PET resin, 3 g of modifier, and 0.8 g of polyethylene glycol were mixed, and then melt-blended and extruded. The temperature of the extruder: the feeding section was 240 °C, the melting section was 260 °C, the die head section was 270 °C, and the rotation speed was 250 rpm to obtain a modified masterbatch. Subsequently, the modified masterbatch was melt-extruded into a thick sheet and stretched. During the stretching process, longitudinal stretching and transverse stretching were performed. The longitudinal stretching temperature was 100 °C, the transverse stretching temperature was 120 °C, and it was shaped at 220 °C for 10 s. Corona treatment was used with a power of 5 kW and a treatment speed of 20 m / min to obtain a modified PET film;

[0076] Step 2: The modified adhesive was microgravure-coated on the surface of the modified PET film at a coating speed of 30 - 50 m / min, dried, and cured to obtain a modified PET composite tape.

[0077] Example 5: This example discloses a preparation method of a modifier, including the following steps:

[0078] S1: 1.02 g of 2,4-dihydroxyacetophenone, 4.32 g of anhydrous potassium carbonate, and 58 mL of anhydrous acetone were added to a container. The mixture was heated and stirred in an oil bath at 50 °C for 2 h. Subsequently, 1.38 mL of chloromethyl methyl ether was added dropwise and stirred. After the reaction, it was cooled, filtered, washed with acetone, the filtrate was collected, the filtrate was dried with anhydrous sodium sulfate, filtered, the filtrate was rotary-evaporated, and purified and separated by column chromatography with a volume ratio of 10:1 of petroleum ether and ethyl acetate to obtain product 1;

[0079] S2: Under nitrogen protection, 1.12 g of product 1 and 1.17 g of 1-naphthaldehyde were added to a container. Subsequently, a mixed solution of 51 mL of anhydrous ethanol and 7 g of potassium hydroxide was added dropwise. After the addition, the mixture was continuously stirred and reacted at room temperature for 16 h. After the reaction, it was suction-filtered, washed, and recrystallized to obtain product 2;

[0080] S3: Add 1.31 g of Product 2 into a container filled with 62 mL of methanol. After refluxing and dissolving, add dropwise 11 mL of hydrochloric acid with a concentration of 5 mol / L, continue the reflux reaction. After the reaction ends, cool, filter by suction, recrystallize, and dry under vacuum to obtain Product 3;

[0081] S4: Add 0.52 g of Product 3, 0.22 g of potassium hydroxide, and 24 mL of deionized water into a container. After stirring and dissolving, add 0.06 g of a phase transfer catalyst. After continuous stirring, mix 0.09 g of terephthaloyl chloride and 0.26 g of isophthaloyl chloride, then add them into the container and stir for reaction. After the reaction ends, wash, filter, and dry to obtain the modifier.

[0082] This example discloses a preparation method of a modified adhesive, which includes the following steps:

[0083] Q1: Under a nitrogen atmosphere, add 2.91 g of 1,5-naphthalene diisocyanate, 3.18 g of (3-isocyanatopropyl)triethoxysilane, and 0.1 g of dibutyltin dilaurate into a container filled with 25 mL of tetrahydrofuran. Then add dropwise 125 mL of tetrahydrofuran solution containing 26 g of polytetramethylene ether glycol. After the addition is completed, heat and react at 80 °C for 3 h to obtain Intermediate A;

[0084] Q2: Add 13.21 g of Intermediate A into 70 mL of N,N-dimethylformamide. Slowly add 11.94 g of diethanolamine in an ice bath environment and stir for reaction. After the reaction ends, add the reaction solution into ethyl acetate, and a solid precipitates. Separate the product, wash, and dry under vacuum to obtain the modified adhesive.

[0085] This example discloses a preparation method of a modified PET composite tape, which includes the following steps:

[0086] Step 1: Mix 80 g of PET resin, 6 g of the modifier, and 1.2 g of polyethylene glycol, then melt and blend and extrude. The temperature of the extruder: the feeding section is 240 °C, the melting section is 260 °C, the die head section is 270 °C, and the rotation speed is 250 rpm to obtain a modified masterbatch. Subsequently, melt and extrude the modified masterbatch into a thick sheet and stretch. During the stretching process, perform longitudinal stretching and transverse stretching. The longitudinal stretching temperature is 100 °C, the transverse stretching temperature is 120 °C, and shape at 220 °C for 10 s. Use corona treatment with a power of 5 kW and a treatment speed of 20 m / min to obtain a modified PET film;

[0087] Step 2: Microgravure coat the modified adhesive onto the surface of the modified PET film at a coating speed of 30 - 50 m / min, dry, and cure to obtain the modified PET composite tape.

[0088] Comparative Example 1: Compared with Example 1, in the process of preparing the modified PET composite tape in Comparative Example 1, no modifier was added, and other conditions remained unchanged.

[0089] Comparative Example 2: Compared with Example 1, in the process of preparing the modified PET composite tape in Comparative Example 2, natural rubber was used to replace the modified adhesive, and other conditions remained unchanged.

[0090] Experimental Example: The performance of the modified PET composite tapes prepared in Examples 1-5 and Comparative Examples 1-2 was tested. The tensile properties of the samples were tested according to GB / T 1040.1-2018, the ultraviolet resistance of the samples was tested according to GB / T 16422.2-2022, the peel strength of the samples was tested according to GB / T 2792-2014, and the high-temperature resistance of the samples was tested according to GB / T 32368-2015. The test results are shown in Table 1:

[0091]

[0092] It can be seen from the test results in Table 1 that the modified PET composite tapes prepared in Examples 1-5 of the present invention have excellent tensile strength, ultraviolet resistance, bonding strength and heat resistance. By comparing Comparative Example 1 with Examples 1-5, it can be seen that the use of the modifier can effectively improve the tensile strength, heat resistance and ultraviolet resistance of the modified PET composite tape; by comparing Comparative Example 2 with Examples 1-5, it can be seen that the use of the modified adhesive can improve the bonding performance, tensile strength and ultraviolet resistance of the modified PET composite tape.

[0093] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

[0094] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the present invention to only the specific embodiments. Obviously, many modifications and changes can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principle and practical application of the present invention, so that those skilled in the art in the relevant technical field can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A preparation method of a modified PET composite tape, characterized in that, It includes the following steps: Step 1: Mix PET resin, modifier and dispersant, then carry out melt blending and extrusion to obtain a modified masterbatch. Subsequently, melt extrude the modified masterbatch into a thick sheet, stretch it, shape it, and perform surface treatment to obtain a modified PET film; Step 2: Uniformly coat the modified adhesive on the surface of the modified PET film, dry it, and cure it to obtain a modified PET composite tape; Among them, the preparation method of the modifier includes the following steps: S1: Add 2,4-dihydroxyacetophenone, anhydrous potassium carbonate and anhydrous acetone into a container, heat and stir the reaction in an oil bath, then dropwise add chloromethyl methyl ether, stir the reaction. After the reaction is completed, cool, filter, wash, collect the filtrate, dry, filter, rotary evaporate, and purify and separate to obtain Product 1; S2: Under nitrogen protection, add Product 1 and 1-naphthaldehyde into a container, then dropwise add a mixed solution of anhydrous ethanol and potassium hydroxide. After the addition is completed, continue to stir the reaction at room temperature. After the reaction is completed, carry out suction filtration, washing, and recrystallization to obtain Product 2; S3: Add Product 2 into a container containing methanol, dissolve it by refluxing, then dropwise add hydrochloric acid, and continue the reflux reaction. After the reaction is completed, cool, carry out suction filtration, recrystallize, and vacuum dry to obtain Product 3; S4: Add Product 3, potassium hydroxide and deionized water into a container, stir and dissolve, add a phase transfer catalyst, continue to stir, then mix terephthaloyl chloride and isophthaloyl chloride and add them into the container, stir the reaction. After the reaction is completed, wash, filter, and dry to obtain the modifier.

2. The preparation method of a modified PET composite tape according to claim 1, characterized in that, In the said Step 1, the dosage ratio of PET resin, modifier and dispersant is (70 - 85) g : (2 - 7) g : (0.5 - 1.6) g. The temperature of the extruder: the feeding section is 236 - 242 °C, the melting section is 258 - 263 °C, the die head section is 268 - 272 °C, the rotation speed is 200 - 300 rpm. During the stretching process, longitudinal stretching and transverse stretching are carried out. The longitudinal stretching temperature is 80 - 100 °C, the transverse stretching temperature is 100 - 120 °C, the shaping temperature is 200 - 220 °C, and the time is 5 - 10 s. In the surface treatment, corona treatment is used, the power is 3 - 5 kW, and the treatment speed is 20 m / min; in the said Step 2, microgravure coating is adopted, and the coating speed is 30 - 50 m / min.

3. The preparation method of a modified PET composite tape according to claim 1, characterized in that, In the said S1, the dosage ratio of 2,4-dihydroxyacetophenone, anhydrous potassium carbonate, anhydrous acetone and chloromethyl methyl ether is (0.85 - 1.13) g : (3.12 - 4.63) g : (55 - 65) mL : (1.14 - 1.46) mL, the oil bath heating and stirring temperature is 50 - 52 °C, and the stirring time is 1 - 2 h; in the said S2, the dosage ratio of Product 1, 1-naphthaldehyde, anhydrous ethanol and potassium hydroxide is (0.92 - 1.15) g : (0.92 - 1.27) g : (48 - 52) mL : (6.5 - 7.1) g, and the time for continuing the stirring reaction is 12 - 18 h.

4. The preparation method of a modified PET composite tape according to claim 1, characterized in that, In S3, the dosage ratio of product 2, methanol and hydrochloric acid is (1.12 - 1.35) g : (55 - 65) mL : (8 - 12) mL, and the concentration of hydrochloric acid is 5 mol / L.

5. The preparation method of a modified PET composite tape according to claim 1, characterized in that, In S4, the dosage ratio of product 3, potassium hydroxide, deionized water, phase transfer catalyst, terephthaloyl chloride and isophthaloyl chloride is (0.43 - 0.58) g : (0.12 - 0.25) g : (20 - 25) mL : (0.05 - 0.08) g : (0.05 - 0.11) g : (0.21 - 0.28) g.

6. The preparation method of a modified PET composite tape according to claim 1, characterized in that, The preparation method of the modified adhesive comprises the following steps: Q1: Under a nitrogen atmosphere, add 1,5-naphthalene diisocyanate, (3-isocyanatopropyl)triethoxysilane and dibutyltin dilaurate into a container filled with tetrahydrofuran, then dropwise add tetrahydrofuran solution containing polytetramethylene ether glycol. After the dropping is completed, heat and react to obtain intermediate A; Q2: Add intermediate A into N,N-dimethylformamide, slowly add diethanolamine in an ice bath environment, stir and react. After the reaction is completed, add the reaction solution into ethyl acetate, solids precipitate out, separate the product, wash, and vacuum dry to obtain the modified adhesive.

7. The preparation method of a modified PET composite tape according to claim 6, wherein, In Q1, the dosage ratio of 1,5-naphthalene diisocyanate, (3-isocyanatopropyl)triethoxysilane, dibutyltin dilaurate and polytetramethylene ether glycol is (2.12 - 3.14) g : (3.01 - 3.23) g : (0.07 - 0.11) g : (20 - 28) g, the heating reaction temperature is 80 - 84 °C, and the reaction time is 2 - 3 h.

8. The preparation method of a modified PET composite tape according to claim 6, characterized in that, In Q2, the dosage ratio of intermediate A, N,N-dimethylformamide and diethanolamine is (10.12 - 14.25) g : (50 - 75) mL : (10.82 - 12.16) g.

9. The modified PET composite tape prepared by using the preparation method of the modified PET composite tape according to any one of claims 1 - 8.

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