A modified PET composite tape and preparation method thereof

Abstract

The present invention discloses a modified PET composite tape and a preparation method thereof, belonging to the technical field of tape preparation. The preparation method comprises the following steps: Step 1: Mixing a PET resin, a modifier, and a dispersant, followed by melt blending and extrusion to obtain a modified masterbatch; then melt-extruding the modified masterbatch into a thick sheet, stretching, shaping, and surface treating the sheet to obtain a modified PET film; and Step 2: Uniformly coating a modified adhesive onto the surface of the modified PET film, drying, and curing the sheet to obtain the modified PET composite tape. The composite tape prepared by this method exhibits excellent mechanical properties, UV resistance, and bonding properties.

Description

Technical Field

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

[0002] In applications such as outdoor equipment, building curtain walls, photovoltaic panels, and automotive exteriors, traditional PET tapes suffer from dual shortcomings in UV resistance and adhesion, which have long restricted their reliability and service life in complex environments. As a typical aromatic polyester, PET's ester and benzene ring structures in the molecular chain impart excellent mechanical strength and chemical stability, but this also results in a high UV absorption coefficient and strong sensitivity to photodegradation. Under the influence of ultraviolet radiation, PET molecular chains are prone to photoinduced bond scission and free radical chain reactions, causing yellowing, embrittlement, and surface energy degradation of the substrate. This directly leads to a drop in peel strength of over 60% after six months of outdoor exposure, and even powdering and shedding. Furthermore, PET's crystalline orientation and non-polar characteristics result in poor wettability with most adhesive systems. This lack of interfacial compatibility results in low initial bond strength. Under the combined effects of outdoor temperature and humidity cycles and ultraviolet light, stress concentration and delamination failure easily occur at the bonding interface, becoming a core bottleneck restricting its use as a long-term outdoor bonding solution.

[0003] Patent CN109135598A discloses a copolymer-modified PET tape, including a tape base material and an adhesive. The copolymer-modified PET tape prepared by this invention can adapt to more complex environments. The added carbonamide peroxide-modified guar gum can be repeatedly peeled and stuck without leaving any residual adhesive marks. However, the UV resistance, stability and bonding strength of the composite tape prepared by this method still need to be improved. 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, which is then melt-extruded into thick sheets, stretched, shaped, and surface treated to obtain modified PET film;

[0008] Step 2: evenly apply the modified adhesive to the surface of the modified PET film, dry it, and solidify it to obtain a modified PET composite tape.

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

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

[0011] S1: Add 2,4-dihydroxyacetophenone, anhydrous potassium carbonate, and anhydrous acetone to a container, heat in an oil bath and stir to react, then dropwise add chloromethyl methyl ether and stir to react. 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 using petroleum ether and ethyl acetate in a volume ratio of 10:1 to obtain product 1;

[0012] S2: Under nitrogen protection, product 1 and 1-naphthaldehyde are added to a container, and then a mixed solution of anhydrous ethanol and potassium hydroxide is added dropwise. After the addition is complete, stirring is continued at room temperature. After the reaction is completed, the product is filtered, washed, and recrystallized to obtain product 2;

[0013] S3: Add product 2 to a container filled with methanol, reflux to dissolve, then add hydrochloric acid dropwise and continue reflux reaction. After the reaction is completed, cool, filter, recrystallize, and vacuum dry to obtain product 3;

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

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

[0016]

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

[0018] Preferably, in S1, the amount 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 S2, the amount 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 stirring reaction time is continued for 12-18 h.

[0019] Preferably, in S3, the usage ratio of the 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 usage 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 comprises the following steps:

[0022] Q1: Under nitrogen atmosphere, 1,5-naphthalene diisocyanate, (3-isocyanopropyl)triethoxysilane, and dibutyltin dilaurate are added to a container containing tetrahydrofuran, and then tetrahydrofuran containing polytetramethylene ether glycol is added dropwise. After the addition is complete, the mixture is heated to react to obtain intermediate A.

[0023] Q2: Add intermediate A to N,N-dimethylformamide, slowly add diglycolamine in an ice bath, and stir to react. After the reaction is completed, add the reaction solution to ethyl acetate. Solid precipitates, separate the product, wash, and vacuum dry to obtain a modified adhesive.

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

[0025]

[0026] Preferably, in Q1, the amount ratio of 1,5-naphthalene diisocyanate, (3-isocyanopropyl)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 Q2, the usage ratio of the intermediate A, N,N-dimethylformamide and diglycolamine is (10.12-14.25) g: (50-75) mL: (10.82-12.16) g.

[0028] The modified PET composite tape is prepared by the preparation method of the modified PET composite tape.

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

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

[0031] 2. The present invention applies the prepared modified adhesive to a modified PET composite tape, which can effectively improve its bonding performance, mechanical strength and UV resistance. The active groups contained in the modified adhesive can build 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 give the modified adhesive flexibility and elasticity, so that the composite tape can still maintain bonding performance under dynamic load or deformation conditions and reduce interfacial stress concentration. The naphthalene rings and siloxane bonds contained in the modified adhesive can protect the modified adhesive main chain from photooxidation damage and improve UV resistance. The naphthalene rings and hydrogen bonds contained in the modified adhesive can enhance molecular chain rigidity and improve mechanical properties. DETAILED DESCRIPTION

[0032] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0033] Example 1: This example discloses a method for preparing a modifier, comprising the following steps:

[0034] S1: 0.98 g of 2,4-dihydroxyacetophenone, 3.92 g of anhydrous potassium carbonate, and 60 mL of anhydrous acetone were added to a container, heated in an oil bath at 50°C with stirring for 2 h, and then 1.3 mL of chloromethyl methyl ether was added dropwise and stirred for reaction. After the reaction was completed, the mixture was cooled, filtered, washed with acetone, and the filtrate was collected. The filtrate was dried over anhydrous sodium sulfate, filtered, and the filtrate was rotary evaporated. The product 1 was purified and separated by column chromatography using petroleum ether and ethyl acetate in a volume ratio of 10:1 to obtain product 1;

[0035] S2: Under nitrogen protection, 1.03 g of product 1 and 1.09 g of 1-naphthaldehyde were added to a container, and then a mixed solution of 50 mL of anhydrous ethanol and 6.8 g of potassium hydroxide was added dropwise. After the addition was complete, stirring was continued at room temperature for 16 h. After the reaction was completed, the product was filtered, washed, and recrystallized to obtain product 2;

[0036] S3: Add 1.23 g of product 2 to a container filled with 60 mL of methanol, reflux to dissolve, then add 10 mL of 5 mol / L hydrochloric acid dropwise, and continue the reflux reaction. After the reaction is complete, cool, filter, recrystallize, and vacuum dry 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 to a container, stir to dissolve, add 0.06 g of phase transfer catalyst, continue stirring, mix 0.08 g of terephthaloyl chloride and 0.24 g of isophthaloyl chloride, add to the container, stir to react, and after the reaction is completed, wash, filter, and dry to obtain a modifier.

[0038] This embodiment discloses a method for preparing a modified adhesive, comprising the following steps:

[0039] Q1: Under nitrogen, 2.63 g of 1,5-naphthalene diisocyanate, 3.12 g of (3-isocyanopropyl)triethoxysilane, and 0.09 g of dibutyltin dilaurate were added to a container containing 25 mL of tetrahydrofuran. 24 g of polytetramethylene ether glycol dissolved in 125 mL of tetrahydrofuran was then added dropwise. After the addition was complete, the mixture was heated 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 diglycolamine in an ice bath, and stir to react. After the reaction is completed, add the reaction solution to ethyl acetate. Solid precipitates, separate the product, wash, and vacuum dry to obtain a modified adhesive.

[0041] This embodiment discloses a method for preparing a modified PET composite tape, comprising the following steps:

[0042] Step 1: 77.5g of PET resin, 4.5g of modifier and 1.05g of polyethylene glycol were mixed, and then melt-blended and extruded. The temperature of the extruder was: 240°C in the feed section, 260°C in the melting section, 270°C in the die section, and the rotation speed was 250rpm to obtain a modified masterbatch. The modified masterbatch was then 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 the shaping was performed at 220°C for 10s. Corona treatment was used with a power of 5kW and a processing speed of 20m / min to obtain a modified PET film.

[0043] Step 2: Apply the modified adhesive to the surface of the modified PET film using a micro-concave coating method at a coating speed of 30-50 m / min, dry, and solidify to obtain a modified PET composite tape.

[0044] Example 2: This example discloses a method for preparing a modifier, comprising the following steps:

[0045] S1: 0.85 g of 2,4-dihydroxyacetophenone, 3.12 g of anhydrous potassium carbonate, and 65 mL of anhydrous acetone were added to a container, heated in an oil bath at 50°C with stirring for 2 h, and then 1.14 mL of chloromethyl methyl ether was added dropwise and stirred for reaction. After the reaction was completed, the mixture was cooled, filtered, washed with acetone, and the filtrate was collected. The filtrate was dried over anhydrous sodium sulfate, filtered, and the filtrate was rotary evaporated. The product 1 was purified and separated by column chromatography using petroleum ether and ethyl acetate in a volume ratio of 10:1 to obtain product 1;

[0046] S2: Under nitrogen protection, 0.92 g of product 1 and 0.92 g of 1-naphthaldehyde were added to a container, and then a mixed solution of 48 mL of anhydrous ethanol and 6.5 g of potassium hydroxide was added dropwise. After the addition was complete, stirring was continued at room temperature for 16 h. After the reaction was completed, the product was filtered, washed, and recrystallized to obtain product 2;

[0047] S3: Add 1.12 g of product 2 to a container filled with 65 mL of methanol, reflux to dissolve, then add 12 mL of 5 mol / L hydrochloric acid dropwise, and continue the reflux reaction. After the reaction is complete, cool, filter, recrystallize, and vacuum dry 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 to a container, stir to dissolve, add 0.05 g of a phase transfer catalyst, continue stirring, mix 0.05 g of terephthaloyl chloride and 0.21 g of isophthaloyl chloride, add the mixture to the container, stir to react, and after the reaction is completed, wash, filter, and dry to obtain a modifier.

[0049] This embodiment discloses a method for preparing a modified adhesive, comprising the following steps:

[0050] Q1: Under nitrogen, 2.12 g of 1,5-naphthalene diisocyanate, 3.01 g of (3-isocyanopropyl)triethoxysilane, and 0.07 g of dibutyltin dilaurate were added to a container containing 25 mL of tetrahydrofuran. 20 g of polytetramethylene ether glycol dissolved in 125 mL of tetrahydrofuran was then added dropwise. After the addition was complete, the mixture was heated at 80°C for 3 h to obtain intermediate A.

[0051] Q2: Add 10.12 g of intermediate A to 50 mL of N,N-dimethylformamide, slowly add 10.82 g of diglycolamine in an ice bath, and stir to react. After the reaction is completed, add the reaction solution to ethyl acetate. Solid precipitates, separate the product, wash, and vacuum dry to obtain a modified adhesive.

[0052] This embodiment discloses a method for preparing a modified PET composite tape, comprising the following steps:

[0053] Step 1: 70g PET resin, 7g modifier and 0.5g polyethylene glycol are mixed, and then melt-blended and extruded. The temperature of the extruder is: 240°C in the feed section, 260°C in the melting section, 270°C in the die section, and the rotation speed is 250rpm to obtain a modified masterbatch. The modified masterbatch is then melt-extruded into a thick sheet and stretched. During the stretching process, longitudinal stretching and transverse stretching are performed. The longitudinal stretching temperature is 100°C, the transverse stretching temperature is 120°C, and the shaping is performed at 220°C for 10s. Corona treatment is used with a power of 5kW and a processing speed of 20m / min to obtain a modified PET film.

[0054] Step 2: Apply the modified adhesive to the surface of the modified PET film using a micro-concave coating method at a coating speed of 30-50 m / min, dry, and solidify to obtain a modified PET composite tape.

[0055] Example 3: This example discloses a method for preparing a modifier, comprising the following steps:

[0056] S1: 1.13 g of 2,4-dihydroxyacetophenone, 4.63 g of anhydrous potassium carbonate, and 55 mL of anhydrous acetone were added to a container, heated in an oil bath at 50°C with stirring for 2 h, and then 1.46 mL of chloromethyl methyl ether was added dropwise and stirred for reaction. After the reaction was completed, the mixture was cooled, filtered, washed with acetone, and the filtrate was collected. The filtrate was dried over anhydrous sodium sulfate, filtered, and the filtrate was rotary evaporated. The product 1 was purified and separated by column chromatography using petroleum ether and ethyl acetate in a volume ratio of 10:1 to obtain product 1;

[0057] S2: Under nitrogen protection, 1.15 g of product 1 and 1.27 g of 1-naphthaldehyde were added to a container, and then a mixed solution of 52 mL of anhydrous ethanol and 7.1 g of potassium hydroxide was added dropwise. After the addition was complete, stirring was continued at room temperature for 16 h. After the reaction was completed, the product was filtered, washed, and recrystallized to obtain product 2;

[0058] S3: Add 1.35 g of product 2 to a container filled with 55 mL of methanol, reflux to dissolve, then add 8 mL of 5 mol / L hydrochloric acid dropwise, and continue the reflux reaction. After the reaction is complete, cool, filter, recrystallize, and vacuum dry 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 to a container, stir to dissolve, add 0.08 g of a phase transfer catalyst, continue stirring, mix 0.11 g of terephthaloyl chloride and 0.28 g of isophthaloyl chloride, add the mixture to the container, stir to react, and after the reaction is completed, wash, filter, and dry to obtain a modifier.

[0060] This embodiment discloses a method for preparing a modified adhesive, comprising the following steps:

[0061] Q1: Under nitrogen, 3.14 g of 1,5-naphthalene diisocyanate, 3.23 g of (3-isocyanopropyl)triethoxysilane, and 0.11 g of dibutyltin dilaurate were added to a container containing 25 mL of tetrahydrofuran. 28 g of polytetramethylene ether glycol dissolved in 125 mL of tetrahydrofuran was then added dropwise. After the addition was complete, the mixture was heated at 80°C for 3 h to obtain intermediate A.

[0062] Q2: 14.25 g of intermediate A was added to 75 mL of N,N-dimethylformamide, and 12.16 g of diglycolamine was slowly added in an ice bath environment. The mixture was stirred for reaction. After the reaction was completed, the reaction solution was added to ethyl acetate. Solids precipitated. The product was separated, washed, and vacuum-dried to obtain a modified adhesive.

[0063] This embodiment discloses a method for preparing a modified PET composite tape, comprising the following steps:

[0064] Step 1: 85g PET resin, 2g modifier and 1.6g polyethylene glycol are mixed, and then melt-blended and extruded. The temperature of the extruder is: 240°C in the feed section, 260°C in the melting section, 270°C in the die section, and the speed is 250rpm to obtain a modified masterbatch. The modified masterbatch is then melt-extruded into a thick sheet and stretched. During the stretching process, longitudinal stretching and transverse stretching are performed. The longitudinal stretching temperature is 100°C, the transverse stretching temperature is 120°C, and the shaping is performed at 220°C for 10s. Corona treatment is used with a power of 5kW and a processing speed of 20m / min to obtain a modified PET film.

[0065] Step 2: Apply the modified adhesive to the surface of the modified PET film using a micro-concave coating method at a coating speed of 30-50 m / min, dry, and solidify to obtain a modified PET composite tape.

[0066] Example 4: This example discloses a method for preparing a modifier, comprising the following steps:

[0067] S1: 0.89 g of 2,4-dihydroxyacetophenone, 3.51 g of anhydrous potassium carbonate, and 62 mL of anhydrous acetone were added to a container, heated in an oil bath at 50°C with stirring for 2 h, and then 1.22 mL of chloromethyl methyl ether was added dropwise and stirred for reaction. After the reaction was completed, the mixture was cooled, filtered, washed with acetone, and the filtrate was collected. The filtrate was dried over anhydrous sodium sulfate, filtered, and the filtrate was rotary evaporated. The product 1 was purified and separated by column chromatography using petroleum ether and ethyl acetate in a volume ratio of 10:1 to obtain product 1;

[0068] S2: Under nitrogen protection, 0.98 g of product 1 and 0.98 g of 1-naphthaldehyde were added to a container, and then a mixed solution of 49 mL of anhydrous ethanol and 6.6 g of potassium hydroxide was added dropwise. After the addition was complete, stirring was continued at room temperature for 16 h. After the reaction was completed, the product was filtered, washed, and recrystallized to obtain product 2;

[0069] S3: Add 1.18 g of product 2 to a container filled with 58 mL of methanol, reflux to dissolve, then add 9 mL of 5 mol / L hydrochloric acid dropwise, and continue the reflux reaction. After the reaction is complete, cool, filter, recrystallize, and vacuum dry 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, stir to dissolve, add 0.05 g of a phase transfer catalyst, continue stirring, mix 0.06 g of terephthaloyl chloride and 0.22 g of isophthaloyl chloride, add the mixture to the container, stir to react, and after the reaction is completed, wash, filter, and dry to obtain a modifier.

[0071] This embodiment discloses a method for preparing a modified adhesive, comprising the following steps:

[0072] Q1: Under nitrogen, 2.38 g of 1,5-naphthalene diisocyanate, 3.06 g of (3-isocyanopropyl)triethoxysilane, and 0.08 g of dibutyltin dilaurate were added to a container containing 25 mL of tetrahydrofuran. 22 g of polytetramethylene ether glycol dissolved in 125 mL of tetrahydrofuran was then added dropwise. After the addition was complete, the mixture was heated 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, and 11.03 g of diglycolamine was slowly added in an ice bath environment. The mixture was stirred for reaction. After the reaction was completed, the reaction solution was added to ethyl acetate. Solids precipitated. The product was separated, washed, and vacuum-dried to obtain a modified adhesive.

[0074] This embodiment discloses a method for preparing a modified PET composite tape, comprising the following steps:

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

[0076] Step 2: Apply the modified adhesive to the surface of the modified PET film using a micro-concave coating method at a coating speed of 30-50 m / min, dry, and solidify to obtain a modified PET composite tape.

[0077] Example 5: This example discloses a method for preparing a modifier, comprising 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, heated in an oil bath at 50°C with stirring for 2 h, and then 1.38 mL of chloromethyl methyl ether was added dropwise and stirred for reaction. After the reaction was completed, the mixture was cooled, filtered, washed with acetone, and the filtrate was collected. The filtrate was dried over anhydrous sodium sulfate, filtered, and the filtrate was rotary evaporated. The product 1 was purified and separated by column chromatography using petroleum ether and ethyl acetate in a volume ratio of 10:1 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, and then a mixed solution of 51 mL of anhydrous ethanol and 7 g of potassium hydroxide was added dropwise. After the addition was complete, stirring was continued at room temperature for 16 h. After the reaction was completed, the product was filtered, washed, and recrystallized to obtain product 2;

[0080] S3: Add 1.31 g of product 2 to a container filled with 62 mL of methanol, reflux to dissolve, then add 11 mL of 5 mol / L hydrochloric acid dropwise, and continue the reflux reaction. After the reaction is complete, cool, filter, recrystallize, and dry in vacuo 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 to a container, stir to dissolve, add 0.06 g of phase transfer catalyst, continue stirring, mix 0.09 g of terephthaloyl chloride and 0.26 g of isophthaloyl chloride, add to the container, stir to react, and after the reaction is completed, wash, filter, and dry to obtain a modifier.

[0082] This embodiment discloses a method for preparing a modified adhesive, comprising the following steps:

[0083] Q1: Under nitrogen, 2.91 g of 1,5-naphthalene diisocyanate, 3.18 g of (3-isocyanopropyl)triethoxysilane, and 0.1 g of dibutyltin dilaurate were added to a container containing 25 mL of tetrahydrofuran. 26 g of polytetramethylene ether glycol dissolved in 125 mL of tetrahydrofuran was then added dropwise. After the addition was complete, the mixture was heated at 80°C for 3 h to obtain intermediate A.

[0084] Q2: Add 13.21 g of intermediate A to 70 mL of N,N-dimethylformamide, slowly add 11.94 g of diglycolamine in an ice bath, and stir to react. After the reaction is completed, add the reaction solution to ethyl acetate. Solid precipitates, separate the product, wash, and vacuum dry to obtain a modified adhesive.

[0085] This embodiment discloses a method for preparing a modified PET composite tape, comprising the following steps:

[0086] Step 1: 80g PET resin, 6g modifier and 1.2g polyethylene glycol are mixed, and then melt-blended and extruded. The temperature of the extruder is: 240°C in the feed section, 260°C in the melting section, 270°C in the die section, and the rotation speed is 250rpm to obtain a modified masterbatch. The modified masterbatch is then melt-extruded into a thick sheet and stretched. During the stretching process, longitudinal stretching and transverse stretching are performed. The longitudinal stretching temperature is 100°C, the transverse stretching temperature is 120°C, and the shaping is performed at 220°C for 10s. Corona treatment is used with a power of 5kW and a processing speed of 20m / min to obtain a modified PET film.

[0087] Step 2: Apply the modified adhesive to the surface of the modified PET film using a micro-concave coating method at a coating speed of 30-50 m / min, dry, and solidify to obtain a 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 is used instead of the modified adhesive, and other conditions remain unchanged.

[0090] Experimental Example: The modified PET composite tapes prepared in Examples 1-5 and Comparative Examples 1-2 were subjected to performance tests. The tensile properties of the samples were tested according to GB / T 1040.1-2018, the UV 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] The test results in Table 1 indicate that the modified PET composite tapes prepared in Examples 1-5 of the present invention exhibit excellent tensile strength, UV resistance, bonding strength, and heat resistance. A comparison of Comparative Example 1 with Examples 1-5 demonstrates that the use of a modifier effectively improves the tensile strength, heat resistance, and UV resistance of the modified PET composite tapes. A comparison of Comparative Example 2 with Examples 1-5 demonstrates that the use of a modified adhesive improves the bonding performance, tensile strength, and UV resistance of the modified PET composite tapes.

[0093] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

[0094] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to specific embodiments. Obviously, many modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing a modified PET composite tape, characterized in that: The following steps are involved: Step 1: PET resin, modifier and dispersant are mixed, and then melt-blended and extruded to obtain modified masterbatch, which is then melt-extruded into thick sheets, stretched, shaped, and surface treated to obtain modified PET film; Step 2: evenly coating the modified adhesive on the surface of the modified PET film, drying, and curing to obtain a modified PET composite tape; The preparation method of the modifier comprises the following steps: S1: Add 2,4-dihydroxyacetophenone, anhydrous potassium carbonate, and anhydrous acetone to a container, heat in an oil bath and stir to react, then dropwise add chloromethyl methyl ether and stir to react. 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, product 1 and 1-naphthaldehyde are added to a container, and then a mixed solution of anhydrous ethanol and potassium hydroxide is added dropwise. After the addition is complete, stirring is continued at room temperature. After the reaction is completed, the product is filtered, washed, and recrystallized to obtain product 2; S3: Add product 2 to a container filled with methanol, reflux to dissolve, then add hydrochloric acid dropwise and continue reflux reaction. After the reaction is completed, cool, filter, recrystallize, and vacuum dry to obtain product 3; S4: adding product 3, potassium hydroxide, and deionized water to a container, stirring to dissolve, adding a phase transfer catalyst, continuing to stir, mixing terephthaloyl chloride and isophthaloyl chloride, adding the mixture to the container, stirring to react, washing, filtering, and drying after the reaction is completed to obtain a modifier; The preparation method of the modified adhesive comprises the following steps: Q1: Under nitrogen atmosphere, 1,5-naphthalene diisocyanate, (3-isocyanopropyl)triethoxysilane, and dibutyltin dilaurate are added to a container containing tetrahydrofuran, and then tetrahydrofuran containing polytetramethylene ether glycol is added dropwise. After the addition is complete, the mixture is heated to react to obtain intermediate A. Q2: Add intermediate A to N,N-dimethylformamide, slowly add diglycolamine in an ice bath, and stir to react. After the reaction is completed, add the reaction solution to ethyl acetate. Solid precipitates, separate the product, wash, and vacuum dry to obtain a modified adhesive.

2. The method for preparing a modified PET composite tape according to claim 1, wherein In the step 1, the amount ratio of the PET resin, the modifier, and the dispersant is (70-85) g: (2-7) g: (0.5-1.6) g. The temperature of the extruder is: 236-242° C. in the feed section, 258-263° C. in the melting section, 268-272° C. in the die section, and the rotation speed is 200-300 rpm. During the stretching process, longitudinal stretching and transverse stretching are performed. The longitudinal stretching temperature is 80-100° C., the transverse stretching temperature is 100-120° C., the setting temperature is 200-220° C., and the time is 5-10 s. During the surface treatment, corona treatment is used with a power of 3-5 kW and a processing speed of 20 m / min. In the step 2, micro-dimpled coating is adopted, and the coating speed is 30-50 m / min.

3. The method for preparing a modified PET composite tape according to claim 1, wherein 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 oil bath heating and stirring temperature is 50-52° C., and the stirring time is 1-2 h. In 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 stirring reaction time is continued for 12-18 h.

4. The method for preparing a modified PET composite tape according to claim 1, wherein In the S3, the usage ratio of the 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 method for preparing a modified PET composite tape according to claim 1, wherein: In the S4, the usage ratio of the 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 method for preparing a modified PET composite tape according to claim 1, wherein: In Q1, the usage ratio of 1,5-naphthalene diisocyanate, (3-isocyanopropyl)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.

7. The method for preparing a modified PET composite tape according to claim 1, wherein: In the above-mentioned Q2, the usage ratio of the intermediate A, N,N-dimethylformamide and diglycolamine is (10.12-14.25) g: (50-75) mL: (10.82-12.16) g.

8. A modified PET composite tape prepared by the method for preparing a modified PET composite tape according to any one of claims 1 to 7.

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