Tpe composition for a protective film adhesive layer and a method for preparing the same

Abstract

The application discloses a TPE composition for a protective film adhesive layer and a preparation method thereof, and relates to the technical field of polymer materials. The application comprises the following steps: mixing and internally mixing styrene-ethylene-butylene-styrene block copolymer and liquid paraffin, then adding modified elastomer, synergistic powder, modified nanoparticles, piperazine pyrophosphate, aluminum hypophosphite, L-arginine and a compatilizer and mixing, adding a crosslinking aid and mixing after cooling, pouring into a mold after discharging and pre-pressing under a nitrogen atmosphere, then gradient crosslinking, cooling, demolding and obtaining the TPE composition for the protective film adhesive layer. The addition of specific proportions of piperazine pyrophosphate, aluminum hypophosphite and L-arginine effectively improves the flame retardant capacity and ultraviolet resistance of the TPE composition; the introduction of the synergistic powder and other components further improves the interfacial adhesion, flame retardant capacity and ultraviolet resistance. Therefore, the application has a wider application prospect.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a TPE composition for a protective film adhesive layer and its preparation method. Background Technology

[0002] TPE (Thermoplastic Elastomer) is a thermoplastic elastomer material characterized by high strength, high resilience, and injection molding capability. It has a wide range of applications, is environmentally friendly, non-toxic, and safe, and possesses excellent colorability. Among them, styrene-ethylene-butene-styrene block copolymer (SEBS), due to the saturation of double bonds in the butadiene segments, exhibits excellent resistance to ultraviolet radiation, ozone, and oxidation. It is not prone to aging, yellowing, or cracking even after long-term outdoor use, maintaining good performance and appearance. It also possesses good elasticity, flexibility, processability, compatibility, and solubility, and is non-toxic and odorless. Therefore, styrene-ethylene-butene-styrene block copolymers are widely used in numerous fields, including the automotive industry, wire and cable, medical devices, construction, packaging, electronics, and daily necessities.

[0003] In summary, applying styrene-ethylene-butene-styrene block copolymers to the adhesive layer of automotive protective films also has significant advantages, but its weather resistance, flame retardancy, UV resistance, and interfacial adhesion all require further optimization. To improve these properties, relevant research literature has proposed several solutions, such as a method for preparing flame-retardant modified SEBS proposed in patent document CN118931095A. This invention uses DOPO, methylvinyldichlorosilane, cyclade, and 3-buten-1-ol as raw materials, undergoing addition and substitution reactions to obtain a flame-retardant modifier, which is then grafted onto SEBS to obtain DOPO-based SEBS. SEBS, DOPO-based SEBS, and other compounds are added to a mixer, stirred until homogeneous, extruded and granulated, dried, hot-pressed, and sampled to obtain flame-retardant modified SEBS. This invention utilizes the flame-retardant elements of the flame-retardant modifier to introduce them into SEBS, increasing the flame-retardant effect of SEBS. Furthermore, the triene structure contained in the flame-retardant modifier is used to graft with SEBS, forming a larger cross-linked network structure, which increases the mechanical properties of SEBS. However, the flame retardancy, UV resistance, and interfacial adhesion of TPE compositions prepared by these existing methods still need improvement. Summary of the Invention

[0004] The purpose of this invention is to provide a TPE composition for a protective film adhesive layer and its preparation method, thereby solving the following technical problems:

[0005] Existing TPE compositions have problems with flame retardancy, UV resistance, and interfacial adhesion.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A method for preparing a TPE composition for a protective film adhesive layer includes the following steps:

[0008] Styrene-ethylene-butene-styrene block copolymer is mixed with liquid paraffin and kneaded. Then, modified elastomer, synergistic powder, modified nanoparticles, piperazine pyrophosphate, aluminum hypophosphite, L-arginine, and compatibilizer are added and kneaded. After cooling to 100-110°C, crosslinking aids are added and kneaded again. After discharge, the mixture is poured into a mold and pre-pressed under a nitrogen atmosphere, followed by gradient crosslinking. After cooling and demolding, a TPE composition for protective film adhesive layer is obtained.

[0009] Preferably, the ratio of the styrene-ethylene-butene-styrene block copolymer, liquid paraffin, modified elastomer, synergistic powder, modified nanoparticles, piperazine pyrophosphate, aluminum hypophosphite, L-arginine, compatibilizer, and crosslinking aid is 100g:30-40g:15-20g:3-5g:1-2g:15-18g:5-6g:3-5g:1-2g:2-4g;

[0010] The pre-compression temperature is 125-130℃, the pressure is 10MPa, and the duration is 5min;

[0011] The gradient crosslinking process involves first performing crosslinking at 160-170℃ for 8-10 minutes, and then performing crosslinking at 185-190℃ for 13-15 minutes.

[0012] Preferably, the modified elastomer is prepared by the following method:

[0013] Step A1: Mix the styrene-ethylene-butene-styrene block copolymer with liquid paraffin and preheat it at 60°C with 500-600 r / min for 10-12 min. Then add maleic anhydride and dicumyl peroxide and stir at 48-52°C for 5-6 min to obtain the premixed elastomer.

[0014] Step A2: Under a nitrogen atmosphere, the premixed elastomer is extruded, water-cooled and pelletized, then extracted with acetone under reflux for 24-25 hours, and vacuum dried to obtain the modified elastomer.

[0015] Preferably, the ratio of styrene-ethylene-butene-styrene block copolymer, liquid paraffin, maleic anhydride, and dicumyl peroxide in step A1 is 100g: 5g: 6-8g: 0.3-0.5g;

[0016] In step A2, the ratio of premixed elastomer to acetone is 80-100g: 1600-2000mL;

[0017] In step A2, the screw speed during extrusion is 200 r / min, the material residence time is 3.5 min, the feed zone temperature is 120℃, the melting zone temperature is 160℃, the reaction zone temperature is 180℃, the devolatilization zone temperature is 170℃, and the vacuum degree is -0.095 MPa.

[0018] Preferably, the method for preparing the synergistic powder is as follows:

[0019] Nano-titanium dioxide was added to anhydrous ethanol and ultrasonically treated. Then carbon quantum dots were added and the mixture was stirred at 58-60℃ for 3-4 hours. After centrifugation and drying, the enhanced powder was obtained.

[0020] The ratio of anhydrous ethanol, nano-titanium dioxide, and carbon quantum dots is 100-150mL: 5-10g: 0.25-0.5g.

[0021] Preferably, the modified nanoparticles are prepared as follows:

[0022] Step B1: Add nano-titanium dioxide to anhydrous ethanol and sonicate it. Then add tetraethyl orthosilicate and adjust the pH to 9 with ammonia. Stir for 5-6 hours, then centrifuge to separate the precipitate. Wash the precipitate with anhydrous ethanol 3-5 times and vacuum dry to obtain composite nanoparticles.

[0023] Step B2: Dissolve tris(hydroxymethyl)aminomethane in deionized water, then adjust the pH to 8.5 with hydrochloric acid, and then add the composite nanoparticles and dopamine hydrochloride in sequence. Stir in the dark for 24-25 hours, centrifuge, wash the precipitate with deionized water 5-7 times, and then vacuum dry to obtain the modified nanoparticles.

[0024] Preferably, the ratio of anhydrous ethanol, nano titanium dioxide, and tetraethyl orthosilicate in step B1 is 100mL: 2.5-5g: 5-10mL;

[0025] The ratio of tris(hydroxymethyl)aminomethane, deionized water, composite nanoparticles, and dopamine hydrochloride in step B2 is 12.1-24.2g: 800mL: 1-2g: 0.2-0.4g.

[0026] Preferably, the compatibilizer is prepared by the following method:

[0027] Step C1: Add graphene oxide to deionized water and sonicate it. Then adjust the pH to 6.0-6.5 with ammonia to obtain a graphene oxide dispersion.

[0028] Step C2: Add chitosan to glacial acetic acid solution and stir for 4-5 hours. After filtration, add graphene oxide dispersion to the filtrate while stirring and perform ultrasonic blending. Then freeze-dry, grind, and sieve to obtain compatibilizer.

[0029] Preferably, the ratio of deionized water to graphene oxide in step C1 is 100 mL: 1-2 g;

[0030] The ratio of glacial acetic acid solution, chitosan, and graphene oxide dispersion in step C2 is 200 mL: 1.9-4.2 g: 100 mL;

[0031] The mass fraction of the glacial acetic acid solution in step C2 is 1%.

[0032] Preferably, the crosslinking aid is prepared by the following method:

[0033] Polymethylhydrosiloxane and allyl glycidyl ether were mixed, and then chloroplatinic acid hexahydrate was added. The mixture was reacted at 80°C for 2-3 hours to obtain a crosslinking aid.

[0034] The ratio of polymethylhydrosiloxane, allyl glycidyl ether, and chloroplatinic acid hexahydrate is 8.5-25.5g: 4.6-13.7g: 0.013-0.039g.

[0035] As a further aspect of the present invention.

[0036] The beneficial effects of this invention are:

[0037] This invention provides a TPE composition for protective film adhesive layers and its preparation method. The present invention effectively improves the interfacial adhesion, flame retardancy, UV resistance and weather resistance of the TPE composition for protective film adhesive layers through the following method.

[0038] (1) The modified elastomer prepared by the present invention through the triple action of polarization, crosslinking and purification can effectively improve the interfacial compatibility of SEBS with polar fillers such as nano-titanium dioxide and carbon quantum dots, reduce phase separation, and the network structure formed by its slight crosslinking can also enhance the mechanical properties, shape stability, elastic modulus, flexibility and weather resistance of TPE composition. The polar groups of the modified elastomer can also form stronger physical adsorption or chemical bonds with the adhesive layer substrate (such as metal and plastic), and synergistically enhance the interfacial adhesion and flame retardancy with flame retardant components such as piperazine pyrophosphate.

[0039] (2) The nano-titanium dioxide in the synergistic powder of this invention has a high specific surface area and surface hydroxyl groups, which can form physical anchoring with the styrene segments in SEBS through hydrogen bonding or chemical adsorption, thereby enhancing interfacial compatibility; the carbon quantum dots contain polar groups such as carboxyl and hydroxyl groups on their surface, which can form a synergistic effect with the hydroxyl groups on the surface of nano-titanium dioxide and polar additives such as chitosan in the TPE composition, further improving the interfacial bonding strength. At high temperatures, nano-titanium dioxide can promote the formation of a dense carbon layer in the TPE matrix, inhibit heat transfer and the release of combustible gases, and synergistically enhance the flame retardant ability with flame retardant components such as piperazine pyrophosphate; at the same time, the carbon quantum dots themselves are also rich in carbon elements, which can act as carbonization centers at high temperatures, accelerating the formation of the carbon layer and further enhancing the flame retardant effect. Nano-titanium dioxide exhibits strong UV absorption, effectively blocking UV penetration. Carbon quantum dots can inhibit the photo-oxidation reaction of double bonds in TPE compositions through energy transfer or free radical quenching mechanisms, delaying yellowing and embrittlement. Simultaneously, under UV light, carbon quantum dots can excite functional groups such as hydroxyl groups on their surface to dynamically bind with TPE segments, repairing microcracks. The antioxidant properties of carbon quantum dots also inhibit the oxidative degradation of TPE compositions at high temperatures. Combined with the light-shielding effect of nano-titanium dioxide, this enhances the stability of the material under high temperature and light exposure. The hydroxyl groups on the surface of nano-titanium dioxide and the polar groups of carbon quantum dots may reduce moisture penetration through physical adsorption, lowering the risk of hydrolytic aging.

[0040] (3) In the modified nanoparticles of this invention, the surface of nano-titanium dioxide is coated with silica to form a core-shell structure and modified with polydopamine. Among them, the hydroxyl groups of silica can combine with the polar groups in the TPE matrix through hydrogen bonds or chemical bonds, which significantly improves the compatibility between nanoparticles and the matrix, reduces interface defects, and thus enhances the interfacial adhesion. The polar functional groups of polydopamine can also form stronger physical or chemical adsorption with the polar components in the TPE matrix, further improving the interfacial adhesion. Nano-titanium dioxide can inhibit combustion by capturing free radicals and promoting the formation of char layer. The silica layer can also form a dense char layer during combustion, blocking heat and oxygen transfer and delaying material decomposition. The nitrogen-containing structure of polydopamine releases inert gases such as nitrogen during combustion, and its carbon skeleton can also participate in the construction of char layer, synergistically enhancing the flame retardant effect. In addition, the modified nanoparticles will also have a synergistic effect with flame retardant components such as piperazine pyrophosphate in the TPE composition, improving the overall flame retardant ability. The silica layer can improve the dispersion uniformity of nano-titanium dioxide in the matrix, further enhancing the ultraviolet shielding effect; polydopamine itself has a certain ultraviolet absorption capacity, and its antioxidant properties can slow down the free radical chain reaction in the matrix, extending the material's UV aging resistance life. The strong interfacial bonding between the modified nanoparticles and the matrix can inhibit stress concentration and delay structural damage to the material under long-term thermo-oxidative, ultraviolet, or mechanical stress.

[0041] (4) The amino and hydroxyl groups on the chitosan molecular chain in the compatibilizer of this invention can form hydrogen bonds or electrostatic interactions with the polar groups in the TPE composition, enhancing the interfacial bonding between the elastomer phase and the filler; the two-dimensional sheet structure of graphene oxide has a high specific surface area, which can be anchored in the TPE matrix through physical adsorption and mechanical interlocking effects, reducing phase separation, thereby effectively improving the overall mechanical strength and interfacial adhesion of the TPE composition; the composite structure formed by chitosan encapsulating graphene oxide can further optimize interfacial compatibility, making the filler more uniformly dispersed in the matrix and reducing stress concentration. Graphene oxide can form a continuous carbon layer at high temperature, blocking heat and oxygen transfer. It can also form a "carbon layer-phosphorus-nitrogen system" synergistic flame retardant system with flame retardant components such as piperazine pyrophosphate, significantly improving the flame retardant ability; when chitosan is thermally decomposed, it releases nitrogen-containing gas, and its carbonized residue can enhance the density of the carbon layer. Graphene oxide possesses strong absorption capabilities, effectively blocking ultraviolet light from penetrating materials. It also forms a multi-layered light barrier with carbon quantum dots, significantly improving resistance to UV aging. The conjugated structure in chitosan molecules further absorbs some ultraviolet light, while its film-forming properties protect the matrix from light radiation. Graphene oxide inhibits free radical-induced oxidation reactions, while the hydrophilicity of chitosan reduces water penetration and lowers the risk of hydrolytic aging. The porous structure formed by freeze-drying buffers environmental stress, further enhancing the weather resistance of TPE compositions.

[0042] (5) The epoxy groups in the crosslinking aid of this invention react with the polar groups in the TPE matrix or the active sites on the filler surface to form chemical bonds such as ether bonds and ester bonds. The dynamic crosslinking network structure formed by the reaction of the crosslinking aid enhances the intermolecular forces and reduces interfacial slippage, thereby improving the bonding strength between the material and the substrate. Polymethylhydrosiloxane decomposes at high temperature to generate a silica layer, which blocks the transfer of heat and oxygen and inhibits combustion. The dynamic crosslinking network also undergoes reversible fracture-reorganization under thermal and mechanical stress, avoiding the propagation of microcracks caused by stress concentration. The crosslinking aid also synergistically enhances the flame retardant components such as aluminum hypophosphite to form a "carbon layer + phosphorus flame retardant" composite flame retardant system to further improve the flame retardant ability. Crosslinking aids synergistically enhance the light shielding effect with carbon quantum dots; the siloxane structure has a strong absorption capacity for ultraviolet rays, which can convert light energy into heat energy and reduce damage to the polymer backbone; the crosslinked network formed also restricts molecular chain movement, reduces the sensitivity to photo-oxidative degradation, reduces high-temperature softening and creep, and delays the yellowing, embrittlement and mechanical property decline of materials under long-term ultraviolet irradiation.

[0043] (6) The amino and guanidin groups of L-arginine in the specific proportions of L-arginine, piperazine pyrophosphate, and aluminum hypophosphite added in this invention will form hydrogen bonds or chemical adsorption with the hydroxyl groups on the substrate surface, significantly enhancing the interfacial adhesion. At the same time, its polar groups can also improve the compatibility between TPE and fillers and reduce interfacial defects. At high temperatures, the phosphoric acid produced by the decomposition of piperazine pyrophosphate will promote carbonization, and the decomposition of aluminum hypophosphite will generate alumina and phosphorus pentoxide; the combination of the two can significantly improve the flame retardancy. The nitrogen-containing group of L-arginine will decompose to produce inert gases such as ammonia and nitrogen, and at the same time form a "phosphorus-nitrogen synergistic effect" with the two phosphorus-based flame retardants, further improving the flame retardancy efficiency. The guanidin group of L-arginine can capture free radicals induced by ultraviolet rays and inhibit photo-oxidative degradation. Its amino group can react with the double bonds in the AHP composition to reduce photo-crosslinking or breakage. L-arginine will also combine with the synergistic powder to form a "physical shielding + chemical quenching" dual protection, further improving the UV resistance. The amino group of L-arginine can form additional crosslinking points with crosslinking aids, improving the stability of the material network structure and further delaying the thermo-oxidative aging and ultraviolet degradation of TPE compositions.

[0044] Therefore, the TPE composition for protective film adhesive layer prepared by this invention has superior interfacial adhesion, flame retardancy, UV resistance, weather resistance, and broad application prospects. Detailed Implementation

[0045] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] The properties and sources of some of the raw materials used in this invention are as follows:

[0047] Styrene-ethylene-butene-styrene block copolymer (Kraton G1652) was purchased from Dongguan Zhangmutou Hongji Plastic Chemical Trading Company; liquid paraffin was purchased from Shenyang Chemical Reagent Factory, CAS: 3063-62-5; nano titanium dioxide (particle size 25nm) was purchased from (Kramar) Shanghai Puzhen Biotechnology Co., Ltd., CAS: 13463-67-7, item number 1227164000; carbon quantum dots were purchased from Beijing Bio-Tech Biotechnology Co., Ltd., item number: ABW-21-1.

[0048] Example 1: A method for preparing a TPE composition for a protective film adhesive layer is as follows:

[0049] S1: Mix 100g of styrene-ethylene-butene-styrene block copolymer with 5g of liquid paraffin and preheat at 60℃ with 500r / min for 10min. Then add 6g of maleic anhydride and 0.3g of dicumyl peroxide and stir at 48℃ with 700r / min for 5min to obtain a premixed elastomer.

[0050] S2: Under a nitrogen atmosphere, 80g of premixed elastomer was added to a twin-screw reactive extruder and extruded at a screw speed of 200r / min, a material residence time of 3.5min, a feed zone temperature of 120℃, a melt zone temperature of 160℃, a reaction zone temperature of 180℃, a devolatilization zone temperature of 170℃, and a vacuum degree of -0.095MPa. The extruded strip was water-cooled and pelletized, then refluxed with 1600mL of acetone for 24h, and finally vacuum-dried at 60℃ for 12h to obtain the modified elastomer.

[0051] S3: Add 5g of nano-titanium dioxide to 100mL of anhydrous ethanol and sonicate for 30min. Then add 0.25g of carbon quantum dots and stir at 58℃ for 3h. After centrifugation and drying, the enhanced powder is obtained.

[0052] S4: Add 2.5g of nano-titanium dioxide to 100mL of anhydrous ethanol and sonicate for 30min. Then add 5mL of tetraethyl orthosilicate and adjust the pH to 9 with 25% ammonia water. Stir for 5h, centrifuge first, then wash the precipitate 3 times with anhydrous ethanol, and finally vacuum dry at 58℃ for 6h to obtain composite nanoparticles.

[0053] S5: Dissolve 12.1g of tris(hydroxymethyl)aminomethane in 800mL of deionized water, then adjust the pH to 8.5 with concentrated hydrochloric acid, then add 1g of composite nanoparticles and 0.2g of dopamine hydrochloride in sequence, stir in the dark for 24h, centrifuge and wash the precipitate 5 times with deionized water, and finally vacuum dry at 58℃ for 6h to obtain modified nanoparticles.

[0054] S6: Add 1g of graphene oxide to 100mL of deionized water and sonicate at 300W and 30kHz for 30min. Then adjust the pH to 6.0 with 25% ammonia water to obtain graphene oxide dispersion.

[0055] S7: Add 1.9g of chitosan to 200mL of 1% glacial acetic acid solution and stir for 4h. Then filter with a filter membrane with a pore size of 0.45μm. Add 100mL of graphene oxide dispersion to the filtrate while stirring and perform ultrasonic blending treatment for 20min with a power of 400W and a pulse mode of 3s working and 2s pausing. Finally, pre-freeze at -80℃ for 24h and then dry under vacuum of 8Pa and cold trap temperature of -60℃ for 48h. After grinding and passing through a 100-mesh sieve, the compatibilizer is obtained.

[0056] S8: Mix 8.5g of polymethylhydrosiloxane and 4.6g of allyl glycidyl ether, then add 0.013g of chloroplatinic acid hexahydrate, and react at 80℃ for 2h to obtain a crosslinking aid;

[0057] S9: Mix 100g of styrene-ethylene-butene-styrene block copolymer with 30g of liquid paraffin and knead at 120℃ for 10min at 50r / min. Then add 15g of modified elastomer, 3g of synergistic powder, 1g of modified nanoparticles, 15g of piperazine pyrophosphate, 5g of aluminum hypophosphite, 3g of L-arginine, and 1g of compatibilizer. Knead at 135℃ for 8min at 70r / min. Cool to 100℃ and add 2g of crosslinking aid. Knead at 70r / min for 5min. After discharge, pour into a mold and pre-press at 125℃ and 10MPa for 5min under a nitrogen atmosphere. Then crosslink at 160℃ for 8min and finally crosslink at 185℃ for 13min. After cooling and demolding, obtain the TPE composition for the protective film adhesive layer.

[0058] Example 2: A method for preparing a TPE composition for a protective film adhesive layer is as follows:

[0059] S1: Mix 100g of styrene-ethylene-butene-styrene block copolymer with 5g of liquid paraffin and preheat at 60°C and 550r / min for 11min. Then add 7g of maleic anhydride and 0.4g of dicumyl peroxide and stir at 50°C and 750r / min for 5.5min to obtain a premixed elastomer.

[0060] S2: Under a nitrogen atmosphere, 90g of premixed elastomer was added to a twin-screw reactive extruder and extruded at a screw speed of 200r / min, a material residence time of 3.5min, a feed zone temperature of 120℃, a melt zone temperature of 160℃, a reaction zone temperature of 180℃, a devolatilization zone temperature of 170℃, and a vacuum degree of -0.095MPa. The extruded strip was water-cooled and pelletized, then refluxed with 1800mL of acetone for 24.5h, and finally vacuum dried at 60℃ for 14h to obtain the modified elastomer.

[0061] S3: Add 7.5g of nano-titanium dioxide to 125mL of anhydrous ethanol and sonicate for 35min. Then add 0.375g of carbon quantum dots and stir at 59℃ for 3.5h. After centrifugation and drying, the enhanced powder is obtained.

[0062] S4: Add 3.75g of nano-titanium dioxide to 100mL of anhydrous ethanol and sonicate for 35min. Then add 7.5mL of tetraethyl orthosilicate and adjust the pH to 9 with 25% ammonia water. Stir for 5.5h, centrifuge first, then wash the precipitate 4 times with anhydrous ethanol, and finally vacuum dry at 59℃ for 7h to obtain composite nanoparticles.

[0063] S5: Dissolve 18.15g of tris(hydroxymethyl)aminomethane in 800mL of deionized water, then adjust the pH to 8.5 with concentrated hydrochloric acid, then add 1.5g of composite nanoparticles and 0.3g of dopamine hydrochloride in sequence, stir in the dark for 24.5h, centrifuge, wash the precipitate 6 times with deionized water, and finally vacuum dry at 59℃ for 6.5h to obtain modified nanoparticles;

[0064] S6: Add 1.5g of graphene oxide to 100mL of deionized water and sonicate at 350W and 35kHz for 35min. Then adjust the pH to 6.3 with 25% ammonia water to obtain graphene oxide dispersion.

[0065] S7: Add 3.05g of chitosan to 200mL of 1% glacial acetic acid solution and stir for 4.5h. Then filter with a 0.45μm filter membrane. Add 100mL of graphene oxide dispersion to the filtrate while stirring and perform ultrasonic blending treatment for 25min with a power of 450W and a pulse mode of 3s working and 2s pausing. Finally, pre-freeze at -80℃ for 24.5h and then dry under vacuum of 9Pa and cold trap temperature of -55℃ for 49h. After grinding and passing through a 100-mesh sieve, the compatibilizer is obtained.

[0066] S8: Mix 17g of polymethylhydrosiloxane and 9.15g of allyl glycidyl ether, then add 0.026g of chloroplatinic acid hexahydrate, and react at 80℃ for 2.5h to obtain a crosslinking aid;

[0067] S9: Mix 100g of styrene-ethylene-butene-styrene block copolymer with 35g of liquid paraffin and knead at 120℃ for 10min at 50r / min. Then add 17.5g of modified elastomer, 4g of synergistic powder, 1.5g of modified nanoparticles, 16.5g of piperazine pyrophosphate, 5.5g of aluminum hypophosphite, 5g of L-arginine, and 1.5g of compatibilizer and knead at 138℃ for 9min at 75r / min. Cool to 105℃ and add 3g of crosslinking aid and knead at 75r / min for 5.5min. After discharge, pour into a mold and pre-press at 128℃ and 10MPa for 5min under a nitrogen atmosphere. Then crosslink at 165℃ for 9min and finally crosslink at 188℃ for 14min. After cooling and demolding, obtain the TPE composition for the protective film adhesive layer.

[0068] Example 3: A method for preparing a TPE composition for a protective film adhesive layer is as follows:

[0069] S1: Mix 100g of styrene-ethylene-butene-styrene block copolymer with 5g of liquid paraffin and preheat at 600r / min for 12min at 60℃. Then add 8g of maleic anhydride and 0.5g of dicumyl peroxide and stir at 800r / min for 6min at 52℃ to obtain a premixed elastomer.

[0070] S2: Under a nitrogen atmosphere, 100g of premixed elastomer was added to a twin-screw reactive extruder and extruded at a screw speed of 200r / min, a material residence time of 3.5min, a feed zone temperature of 120℃, a melt zone temperature of 160℃, a reaction zone temperature of 180℃, a devolatilization zone temperature of 170℃, and a vacuum degree of -0.095MPa. The extruded strip was water-cooled and pelletized, then refluxed with 2000mL of acetone for 25h, and finally vacuum-dried at 60℃ for 15h to obtain the modified elastomer.

[0071] S3: Add 10g of nano titanium dioxide to 150mL of anhydrous ethanol and sonicate for 40min. Then add 0.5g of carbon quantum dots and stir at 60℃ for 4h. After centrifugation and drying, the enhanced powder is obtained.

[0072] S4: Add 5g of nano-titanium dioxide to 100mL of anhydrous ethanol and sonicate for 40min. Then add 10mL of tetraethyl orthosilicate and adjust the pH to 9 with 25% ammonia water. Stir for 6h, centrifuge first, then wash the precipitate 5 times with anhydrous ethanol, and finally vacuum dry at 60℃ for 8h to obtain composite nanoparticles.

[0073] S5: Dissolve 24.2g of tris(hydroxymethyl)aminomethane in 800mL of deionized water, then adjust the pH to 8.5 with concentrated hydrochloric acid, then add 2g of composite nanoparticles and 0.4g of dopamine hydrochloride in sequence, stir in the dark for 25h, centrifuge and wash the precipitate 7 times with deionized water, and finally vacuum dry at 60℃ for 7h to obtain modified nanoparticles.

[0074] S6: Add 2g of graphene oxide to 100mL of deionized water and sonicate at 400W and 40kHz for 40min. Then adjust the pH to 6.5 with 25% ammonia water to obtain graphene oxide dispersion.

[0075] S7: Add 4.2g of chitosan to 200mL of 1% glacial acetic acid solution and stir for 5h. Then filter with a 0.45μm filter membrane. Add 100mL of graphene oxide dispersion to the filtrate while stirring and perform ultrasonic blending treatment for 30min with a power of 500W and a pulse mode of 3s working and 2s pausing. Finally, pre-freeze at -80℃ for 25h and then dry under vacuum of 10Pa and cold trap temperature of -50℃ for 50h. After grinding and passing through a 100-mesh sieve, the compatibilizer is obtained.

[0076] S8: Mix 25.5g of polymethylhydrosiloxane and 13.7g of allyl glycidyl ether, then add 0.039g of chloroplatinic acid hexahydrate, and react at 80℃ for 3h to obtain a crosslinking aid;

[0077] S9: Mix 100g of styrene-ethylene-butene-styrene block copolymer with 40g of liquid paraffin and knead at 120℃ for 10min at 50r / min. Then add 20g of modified elastomer, 5g of synergistic powder, 2g of modified nanoparticles, 18g of piperazine pyrophosphate, 6g of aluminum hypophosphite, 5g of L-arginine, and 2g of compatibilizer and knead at 140℃ for 10min at 80r / min. After cooling to 110℃, add 4g of crosslinking aid and knead at 80r / min for 6min. After discharge, pour into a mold and pre-press at 130℃ and 10MPa for 5min under a nitrogen atmosphere. Then crosslink at 170℃ for 10min and finally crosslink at 190℃ for 15min. After cooling and demolding, obtain the TPE composition for the protective film adhesive layer.

[0078] Comparative Example 1:

[0079] Compared with Example 1, this comparative example only replaces the step of "adding 5g of nano-titanium dioxide to 100mL of anhydrous ethanol and sonicating for 30min, then adding 0.25g of carbon quantum dots and stirring at 58°C for 3h, followed by centrifugation and drying to obtain the enhanced powder" with "adding 5.2g of nano-titanium dioxide to 100mL of anhydrous ethanol and sonicating for 30min, then adding 0.05g of carbon quantum dots and stirring at 58°C for 3h, followed by centrifugation and drying to obtain the enhanced powder". All other steps and parameters are the same, and will not be repeated in this comparative example. The final TPE composition for the protective film adhesive layer is obtained.

[0080] Comparative Example 2:

[0081] Compared with Example 1, this comparative example only replaces the "15g modified elastomer" added during the preparation of the protective film adhesive layer of S9 with "15g styrene-ethylene-butene-styrene block copolymer". All other steps and parameters are the same, and will not be repeated in this comparative example. Finally, the TPE composition for the protective film adhesive layer is obtained.

[0082] Comparative Example 3:

[0083] Compared with Example 1, this comparative example only replaces the following ingredients in the preparation process of the protective film adhesive layer using the TPE composition: "15g modified elastomer, 3g synergistic powder, 1g modified nanoparticles, 15g piperazine pyrophosphate, 5g aluminum hypophosphite, 3g L-arginine, 1g compatibilizer" with "15g modified elastomer, 1g modified nanoparticles, 15g piperazine pyrophosphate, 5g aluminum hypophosphite, 3g L-arginine, 1g compatibilizer". All other steps and parameters are the same, and will not be repeated in this comparative example. The final TPE composition for the protective film adhesive layer is obtained.

[0084] Comparative Example 4:

[0085] Compared with Example 1, this comparative example only replaces the "15g modified elastomer, 3g synergistic powder, 1g modified nanoparticles, 15g piperazine pyrophosphate, 5g aluminum hypophosphite, 3g L-arginine, 1g compatibilizer" added during the preparation of the protective film adhesive layer of S9 with "15g modified elastomer, 3g synergistic powder, 15g piperazine pyrophosphate, 5g aluminum hypophosphite, 3g L-arginine, 1g compatibilizer". All other steps and parameters are the same, and will not be repeated in this comparative example. The final TPE composition for the protective film adhesive layer is obtained.

[0086] Comparative Example 5:

[0087] Compared with Example 1, this comparative example only replaces the following ingredients in the preparation process of the protective film adhesive layer using the TPE composition: "15g modified elastomer, 3g synergistic powder, 1g modified nanoparticles, 15g piperazine pyrophosphate, 5g aluminum hypophosphite, 3g L-arginine, 1g compatibilizer" with "15g modified elastomer, 3g synergistic powder, 1g modified nanoparticles, 5g piperazine pyrophosphate, 15g aluminum hypophosphite, 3g L-arginine, 1g compatibilizer". All other steps and parameters are the same, and will not be repeated in this comparative example. The final TPE composition for the protective film adhesive layer is obtained.

[0088] Comparative Example 6:

[0089] Compared with Example 1, this comparative example only replaces the following ingredients in the preparation process of the protective film adhesive layer using the TPE composition in S9: "15g modified elastomer, 3g synergistic powder, 1g modified nanoparticles, 15g piperazine pyrophosphate, 5g aluminum hypophosphite, 3g L-arginine, 1g compatibilizer" with "15g modified elastomer, 3g synergistic powder, 1g modified nanoparticles, 15g piperazine pyrophosphate, 5g aluminum hypophosphite, 1g compatibilizer". All other steps and parameters are the same, and will not be repeated in this comparative example. The final TPE composition for the protective film adhesive layer is obtained.

[0090] Comparative Example 7:

[0091] Compared with Example 1, this comparative example only replaces the following ingredients in the preparation process of the protective film adhesive layer using the TPE composition in S9: "15g modified elastomer, 3g synergistic powder, 1g modified nanoparticles, 15g piperazine pyrophosphate, 5g aluminum hypophosphite, 3g L-arginine, 1g compatibilizer" with "15g modified elastomer, 3g synergistic powder, 1g modified nanoparticles, 15g piperazine pyrophosphate, 5g aluminum hypophosphite, 3g L-arginine". All other steps and parameters are the same, and will not be repeated in this comparative example. The final TPE composition for the protective film adhesive layer is obtained.

[0092] Comparative Example 8:

[0093] Compared with Example 1, this comparative example only replaces the "2g crosslinking aid" added during the preparation of the protective film adhesive layer of S9 with "0.013g chloroplatinic acid hexahydrate". All other steps and parameters are the same, and will not be repeated in this comparative example. Finally, the TPE composition for the protective film adhesive layer is obtained.

[0094] Performance testing:

[0095] Determination of peel strength (PS):

[0096] Referring to GB / T 2792-2014 "Test Method for Peel Strength of Adhesive Tapes", the peel strength (N / cm) of the TPE compositions for protective film adhesive layers prepared in Examples 1-3 and Comparative Examples 1-8 at 180° with stainless steel plates was determined. The test results are shown in Table 1.

[0097] Determination of Limiting Oxygen Index (LOI):

[0098] The limiting oxygen index (%) of the TPE compositions used to prepare the protective film adhesive layers in Examples 1-3 and Comparative Examples 1-8 was tested, and the test results are shown in Table 1.

[0099] Determination of UV protection ability:

[0100] Referring to ISO 4892-3:2016 standard, using a UVB-340 lamp, the TPE compositions used for the protective film adhesive layers prepared in Examples 1-3 and Comparative Examples 1-8 were tested at 0.76 W / m². 2 The yellowing index (ΔYI) and peel strength retention rate (%) after 1000h of cyclic UV aging at 340nm are shown in Table 1.

[0101] Stability determination:

[0102] The TPE composition was first stored at -40°C for 24 hours, and then at 85°C for 24 hours. The two temperatures were cycled 5 times. The peel strength retention rate (%) and deformation rate (%) of the protective film adhesive layer prepared by Examples 1-3 and Comparative Examples 1-8 were measured after 5 cycles. The duration (h) at 950°C for the cable material to remain intact was recorded. The test results are shown in Table 1.

[0103] Table 1: Performance test results of Examples 1-3 and Comparative Examples 1-8

[0104]

[0105] Data Analysis:

[0106] As can be seen from Table 1, the TPE composition for the protective film adhesive layer prepared in the embodiments of the present invention has better interfacial adhesion, flame retardancy, UV resistance and weather resistance.

[0107] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A method for preparing a TPE composition for a protective film adhesive layer, characterized in that, Includes the following steps: Styrene-ethylene-butene-styrene block copolymer is mixed with liquid paraffin and kneaded. Then, modified elastomer, synergistic powder, modified nanoparticles, piperazine pyrophosphate, aluminum hypophosphite, L-arginine, and compatibilizer are added and kneaded. After cooling to 100-110℃, crosslinking aid is added and kneaded again. After discharge, the mixture is poured into a mold and pre-pressed under a nitrogen atmosphere. Then, it is crosslinked in a gradient manner. After cooling and demolding, a TPE composition for protective film adhesive layer is obtained. The ratio of the styrene-ethylene-butene-styrene block copolymer, liquid paraffin, modified elastomer, synergistic powder, modified nanoparticles, piperazine pyrophosphate, aluminum hypophosphite, L-arginine, compatibilizer, and crosslinking aid is 100g:30-40g:15-20g:3-5g:1-2g:15-18g:5-6g:3-5g:1-2g:2-4g; The pre-compression temperature is 125-130℃, the pressure is 10MPa, and the duration is 5min; The gradient crosslinking process involves first performing crosslinking at 160-170℃ for 8-10 min, and then performing crosslinking at 185-190℃ for 13-15 min. The modified elastomer is prepared as follows: Step A1: Mix the styrene-ethylene-butene-styrene block copolymer with liquid paraffin and preheat it at 60°C with 500-600 r / min for 10-12 min. Then add maleic anhydride and dicumyl peroxide and stir at 48-52°C for 5-6 min to obtain the premixed elastomer. Step A2: Under a nitrogen atmosphere, the premixed elastomer is extruded, water-cooled and pelletized, then extracted with acetone under reflux for 24-25 hours, and vacuum dried to obtain the modified elastomer. The preparation method of the synergistic powder is as follows: Nano-titanium dioxide was added to anhydrous ethanol and ultrasonically treated. Then carbon quantum dots were added and the mixture was stirred at 58-60℃ for 3-4 hours. After centrifugation and drying, the enhanced powder was obtained. The ratio of anhydrous ethanol, nano-titanium dioxide, and carbon quantum dots is 100-150mL: 5-10g: 0.25-0.5g; The modified nanoparticles are prepared as follows: Step B1: Add nano-titanium dioxide to anhydrous ethanol and sonicate it. Then add tetraethyl orthosilicate and adjust the pH to 9 with ammonia. Stir for 5-6 hours, then centrifuge to separate the precipitate. Wash the precipitate with anhydrous ethanol 3-5 times and vacuum dry to obtain composite nanoparticles. Step B2: Dissolve tris(hydroxymethyl)aminomethane in deionized water, then adjust the pH to 8.5 with hydrochloric acid, then add the composite nanoparticles and dopamine hydrochloride in sequence, stir in the dark for 24-25 hours, centrifuge, wash the precipitate with deionized water 5-7 times, and vacuum dry to obtain the modified nanoparticles. The crosslinking aid is prepared as follows: Polymethylhydrosiloxane and allyl glycidyl ether were mixed, and then chloroplatinic acid hexahydrate was added. The mixture was reacted at 80°C for 2-3 hours to obtain a crosslinking aid. The ratio of polymethylhydrosiloxane, allyl glycidyl ether, and chloroplatinic acid hexahydrate is 8.5-25.5g: 4.6-13.7g: 0.013-0.039g; The compatibilizer is prepared as follows: Step C1: Add graphene oxide to deionized water and sonicate it. Then adjust the pH to 6.0-6.5 with ammonia to obtain a graphene oxide dispersion. Step C2: Add chitosan to glacial acetic acid solution and stir for 4-5 hours. After filtration, add graphene oxide dispersion to the filtrate while stirring and perform ultrasonic blending. Then freeze-dry, grind, and sieve to obtain compatibilizer.

2. The method for preparing the TPE composition for the protective film adhesive layer according to claim 1, characterized in that, The ratio of styrene-ethylene-butene-styrene block copolymer, liquid paraffin, maleic anhydride, and dicumyl peroxide used in step A1 is 100g: 5g: 6-8g: 0.3-0.5g; In step A2, the ratio of premixed elastomer to acetone is 80-100g: 1600-2000mL.

3. The method for preparing the TPE composition for the protective film adhesive layer according to claim 1, characterized in that, The ratio of anhydrous ethanol, nano titanium dioxide, and tetraethyl orthosilicate used in step B1 is 100mL: 2.5-5g: 5-10mL; The ratio of tris(hydroxymethyl)aminomethane, deionized water, composite nanoparticles, and dopamine hydrochloride in step B2 is 12.1-24.2g: 800mL: 1-2g: 0.2-0.4g.

4. The method for preparing the TPE composition for the protective film adhesive layer according to claim 1, characterized in that, The ratio of deionized water to graphene oxide used in step C1 is 100 mL: 1-2 g; The ratio of glacial acetic acid solution, chitosan, and graphene oxide dispersion in step C2 is 200 mL: 1.9-4.2 g: 100 mL; The mass fraction of the glacial acetic acid solution in step C2 is 1%.

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