TPE (thermoplastic elastomer) composition for protective film adhesive layer and preparation method of TPE composition

Abstract

The invention discloses a TPE composition for a protective film bonding layer and a preparation method of the TPE composition, and relates to the technical field of high polymer materials. The preparation method comprises the following steps: mixing and banburying a styrene-ethylene-butylene-styrene block copolymer and liquid paraffin, then adding a modified elastomer, synergistic powder, modified nanoparticles, piperazine pyrophosphate, aluminum hypophosphite, L-arginine and a compatilizer, mixing, cooling, then adding a cross-linking auxiliary agent, and mixing, and discharging, pouring into a mold, pre-pressing in a nitrogen atmosphere, carrying out gradient crosslinking, cooling, and demolding to obtain the TPE composition for the protective film adhesive layer. Piperazine pyrophosphate, aluminum hypophosphite and L-arginine are added according to a specific proportion, so that the flame retardance and ultraviolet resistance of the TPE composition are effectively improved; due to the introduction of the synergistic powder and other components, the interface bonding force, flame retardance and ultraviolet resistance are further improved. Therefore, the method has a wider application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a TPE composition for a protective film adhesive layer and a preparation method thereof. Background Art

[0002] TPE (Thermoplastic Elastomer) is a thermoplastic elastomer material characterized by high strength, high resilience, and injection molding processability. It has a wide range of applications, is environmentally friendly, non-toxic, safe, and has excellent colorability. Among them, styrene-ethylene-butylene-styrene block copolymer (SEBS), due to the saturation of double bonds in the butadiene segment, has excellent resistance to UV rays, ozone, and oxidation. It is not susceptible to aging, yellowing, or cracking in long-term outdoor use, and can maintain good performance and appearance. It also has excellent elasticity, flexibility, processability, compatibility, solubility, and is non-toxic and odorless. Therefore, styrene-ethylene-butylene-styrene block copolymer has a wide range of applications in the automotive industry, wire and cable, medical devices, construction, packaging, electronics, daily necessities, and many other fields.

[0003] In summary, the application of styrene-ethylene-butylene-styrene block copolymers in the adhesive layer of automotive protective films also offers significant advantages, but their weather resistance, flame retardancy, UV resistance, and interfacial adhesion require further optimization. To improve these properties, relevant research literature has proposed various solutions, such as patent document CN118931095A, which proposes a method for preparing flame-retardant modified SEBS. This invention uses DOPO, methylvinyldichlorosilane, cytidine, and 3-butene-1-ol as raw materials, undergoing addition and substitution reactions to obtain a flame-retardant modifier, which is then grafted onto SEBS to produce DOPO-based SEBS. SEBS, DOPO-based SEBS, and other materials are added to a blender, stirred and mixed, extruded into pellets, dried, hot-pressed, and sampled to produce flame-retardant modified SEBS. This invention utilizes the flame-retardant elements of the flame-retardant modifier to introduce them into SEBS, enhancing its flame retardancy. The triene structure in the flame-retardant modifier is then grafted onto SEBS to form a larger cross-linked network, enhancing the mechanical properties of SEBS. However, the flame retardancy, UV resistance, and interfacial adhesion of TPE compositions prepared using these existing methods still need to be improved. Summary of the Invention

[0004] The purpose of the present invention is to provide a TPE composition for a protective film adhesive layer and a preparation method thereof to solve the following technical problems:

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

[0006] The purpose of the present invention can be achieved through the following technical solutions:

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

[0008] Styrene-ethylene-butylene-styrene block copolymer and liquid paraffin are mixed and kneaded, and then a modified elastomer, a synergistic powder, modified nanoparticles, piperazine pyrophosphate, aluminum hypophosphite, L-arginine, and a compatibilizer are added and kneaded. After cooling to 100-110°C, a cross-linking aid is added and kneaded again. After discharging, the material is poured into a mold and pre-pressed under a nitrogen atmosphere, and then gradient cross-linked. After cooling and demolding, a TPE composition for a protective film adhesive layer is obtained.

[0009] Preferably, the usage ratio of the styrene-ethylene-butylene-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-pressing temperature is 125-130°C, the pressure is 10 MPa, and the duration is 5 minutes;

[0011] The gradient crosslinking is firstly carried out at 160-170° C. for 8-10 minutes, and then at 185-190° C. for 13-15 minutes.

[0012] Preferably, the preparation method of the modified elastomer is as follows:

[0013] Step A1: mixing styrene-ethylene-butylene-styrene block copolymer with liquid paraffin and preheating at 60° C. and 500-600 rpm for 10-12 minutes, then adding maleic anhydride and dicumyl peroxide and stirring at 48-52° C. for 5-6 minutes to obtain a premixed elastomer;

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

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

[0016] In step A2, the premixed elastomer and acetone are used in a ratio of 80-100 g: 1600-2000 mL;

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

[0018] Preferably, the preparation method of the synergistic powder is as follows:

[0019] Nano-titanium dioxide is added to anhydrous ethanol and ultrasonically treated, followed by adding carbon quantum dots and stirring at 58-60° C. for 3-4 hours, followed by centrifugal separation and drying to obtain a synergistic powder;

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

[0021] Preferably, the preparation method of the modified nanoparticles is as follows:

[0022] Step B1: Add nano-titanium dioxide to anhydrous ethanol and ultrasonicate, then add ethyl orthosilicate and adjust the pH to 9 with ammonia water. Stir for 5-6 hours, then centrifuge and 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, then add composite nanoparticles and dopamine hydrochloride in sequence, stir in the dark for 24-25 hours, centrifuge and wash the precipitate with deionized water 5-7 times, and vacuum dry to obtain modified nanoparticles.

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

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

[0026] Preferably, the preparation method of the compatibilizer is as follows:

[0027] Step C1: adding graphene oxide to deionized water and performing ultrasonic treatment, and then adjusting the pH to 6.0-6.5 with ammonia water to obtain a graphene oxide dispersion;

[0028] Step C2: chitosan is added to the glacial acetic acid solution and stirred for 4-5 hours. After filtering, the graphene oxide dispersion is added to the filtrate while stirring and ultrasonic blending is performed. Then, the mixture is freeze-dried, ground, and sieved to obtain a compatibilizer.

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

[0030] The usage ratio of the 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] The power of the ultrasonic blending treatment in step C2 is 400-500W, the pulse mode is working for 3s-pausing for 2s, and the power is 20-30min.

[0033] Preferably, the preparation method of the cross-linking auxiliary agent is as follows:

[0034] Mix polymethylhydrogensiloxane and allyl glycidyl ether, then add chloroplatinic acid hexahydrate, and react at 80°C for 2-3 hours to obtain a crosslinking aid;

[0035] The usage ratio of the polymethyl hydrogen siloxane, allyl glycidyl ether and chloroplatinic acid hexahydrate is 8.5-25.5 g: 4.6-13.7 g: 0.013-0.039 g.

[0036] As a further embodiment of the present invention.

[0037] Beneficial effects of the present invention:

[0038] The present invention provides a TPE composition for a protective film adhesive layer and a preparation method thereof. The present invention effectively improves the interfacial adhesion, flame retardancy, UV resistance and weather resistance of the TPE composition for a protective film adhesive layer through the following method.

[0039] (1) The modified elastomer prepared by the present invention through the triple effects 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 light crosslinking can also enhance the mechanical properties, shape stability, elastic modulus, flexibility, and weather resistance of the TPE composition. The polar groups of the modified elastomer also form stronger physical adsorption or chemical bonds with the adhesive layer substrate (such as metal or plastic), and synergize with flame retardant ingredients such as piperazine pyrophosphate to further enhance interfacial adhesion and flame retardancy.

[0040] (2) The nano-titanium dioxide in the synergistic powder of the present invention has a high specific surface area and surface hydroxyl groups, which can form a physical anchor with the styrene segment 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 the surface of the nano-titanium dioxide and polar additives such as chitosan in the TPE composition, thereby further improving the interfacial bonding strength. Nano-titanium dioxide can promote the formation of a dense carbon layer in the TPE matrix at high temperatures, inhibiting heat transfer and the release of combustible gases, and synergistically enhance the flame retardant ability with flame retardant ingredients such as piperazine pyrophosphate; at the same time, the carbon quantum dots themselves are rich in carbon elements and 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 has a strong absorption capacity for ultraviolet rays and can effectively block ultraviolet penetration; carbon quantum dots can inhibit the photooxidation reaction of double bonds in the TPE composition through energy transfer or free radical quenching mechanisms, delaying the yellowing and embrittlement of the material. At the same time, carbon quantum dots can excite functional groups such as hydroxyl groups on the surface to dynamically bind with TPE segments under ultraviolet light, thereby repairing microcracks. The antioxidant properties of carbon quantum dots can also inhibit oxidative degradation of TPE compositions at high temperatures. Combined with the light-shielding properties of nano-titanium dioxide, this improves the material's stability in high-temperature, light-exposed environments. The hydroxyl groups on the surface of nano-titanium dioxide and the polar groups of carbon quantum dots may physically adsorb to reduce water penetration, mitigating the risk of hydrolytic aging.

[0041] (3) The surface of the nano-titanium dioxide in the modified nanoparticles of the present invention is coated with silicon dioxide to form a core-shell structure and modified by polydopamine. Among them, the hydroxyl groups of silicon dioxide can be combined with the polar groups in the TPE matrix through hydrogen bonds or chemical bonds, significantly improving the compatibility of the nanoparticles and the matrix, reducing interface defects, and thus enhancing the interface 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 interface adhesion. Nano-titanium dioxide can inhibit combustion by capturing free radicals and promoting the formation of a carbon layer; the silicon dioxide layer can also form a dense carbon layer during the combustion process, blocking the transfer of heat and oxygen, and delaying the decomposition of the material; 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 the carbon layer, synergistically enhancing the flame retardant effect; and the modified nanoparticles can also produce a synergistic effect with flame retardant components such as piperazine pyrophosphate in the TPE composition, improving the overall flame retardant ability. The silica layer improves the uniformity of the nano-titanium dioxide dispersion within the matrix, further enhancing its UV shielding effectiveness. Polydopamine itself has a certain UV absorption capacity, and its antioxidant properties can slow the free radical chain reaction in the matrix, extending the material's UV-resistant lifespan. The strong interfacial bonding between the modified nanoparticles and the matrix suppresses stress concentration, delaying structural damage to the material under long-term thermal, oxidative, UV, or mechanical stress.

[0042] (4) The amino and hydroxyl groups on the chitosan molecular chain in the compatibilizer of the present invention can form hydrogen bonds or electrostatic interactions with the polar groups in the TPE composition, thereby enhancing the interfacial bonding between the elastomer phase and the filler. The two-dimensional lamellar structure of graphene oxide has a high specific surface area and 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 evenly dispersed in the matrix and reducing stress concentration. Graphene oxide can form a continuous carbon layer at high temperatures to block heat and oxygen transfer. It can also form a "carbon layer-phosphorus system-nitrogen system" synergistic flame retardant system with flame retardant ingredients such as piperazine pyrophosphate, significantly improving flame retardancy. Chitosan releases nitrogen-containing gas during thermal decomposition, and its carbonized residue can enhance the density of the carbon layer. Graphene oxide has a strong absorption capacity, effectively blocking UV rays from penetrating the material. It also forms a "multi-layer light barrier" with carbon quantum dots, effectively improving resistance to UV aging. The conjugated structure in the chitosan molecule further absorbs some UV rays, while its film-forming properties protect the substrate from light radiation. Graphene oxide inhibits free radical-induced oxidation reactions, while chitosan's hydrophilicity reduces water penetration and mitigates the risk of hydrolytic aging. The porous structure formed by freeze-drying buffers environmental stress, further enhancing the weather resistance of the TPE composition.

[0043] (5) The epoxy groups in the crosslinking aid of the present invention react with the polar groups in the TPE matrix or the active sites on the surface of the filler to form chemical bonds such as ether bonds and ester bonds. The dynamic crosslinking network structure formed by the crosslinking aid reaction will enhance the intermolecular force and reduce interfacial slip, thereby improving the bonding strength within the material and between the material and the substrate. Polymethylhydrogensiloxane decomposes at high temperatures to form a silicon dioxide layer, which blocks heat and oxygen transfer and inhibits combustion. The dynamic crosslinking network will also undergo reversible fracture and recombination under thermal stress and mechanical stress, avoiding the propagation of microcracks caused by stress concentration. The crosslinking aid will also synergize with flame retardant ingredients such as aluminum hypophosphite to form a "carbon layer + phosphorus flame retardant" composite flame retardant system to further improve the flame retardant ability. The cross-linking aid will synergize with the carbon quantum dots to enhance the light shielding effect; the siloxane structure has a strong ability to absorb ultraviolet rays, which can convert light energy into heat energy and reduce damage to the polymer main chain; the formed cross-linked network will also limit the movement of molecular chains, reduce the sensitivity to photooxidative degradation, reduce high-temperature softening and creep, and delay the yellowing, embrittlement and mechanical property degradation of the material under long-term ultraviolet irradiation.

[0044] (6) The amino and guanidine groups of L-arginine in the specific proportions of L-arginine, piperazine pyrophosphate, and aluminum hypophosphite added in the present 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 of 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 produce aluminum oxide and phosphorus pentoxide; the combination of the two can significantly improve flame retardancy; the nitrogen-containing groups 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 flame retardancy. The guanidine group of L-arginine can capture free radicals triggered by ultraviolet rays and inhibit photooxidative degradation, and its amino group can react with double bonds in the AHP composition to reduce photocrosslinking or breakage; L-arginine can also combine with the synergistic powder to form a "physical shielding + chemical quenching" dual protection, further improving the anti-ultraviolet performance. The amino group of L-arginine can form additional cross-linking points with the cross-linking aid, thereby improving the stability of the material network structure and further delaying the thermal oxidative aging and ultraviolet degradation of the TPE composition.

[0045] Therefore, the TPE composition for the protective film adhesive layer prepared by the present invention has more excellent interfacial adhesion, flame retardancy, UV resistance, weather resistance, and broad application prospects. DETAILED DESCRIPTION

[0046] 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 some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0047] The properties and sources of some raw materials in the present invention are as follows:

[0048] Styrene-ethylene-butylene-styrene block copolymer (Kraton G1652) was purchased from Hongji Plastic Trading Company in Zhangmutou, Dongguan City; liquid paraffin was purchased from Shenyang Chemical Reagent Factory, CAS: 3063-62-5; nano-titanium dioxide (particle size 25 nm) was purchased from Shanghai Puzhen Biotechnology Co., Ltd. (Kramar), CAS: 13463-67-7, item number 1227164000; carbon quantum dots were purchased from Beijing Biotai Biotechnology Co., Ltd., item number: ABW-21-1.

[0049] Example 1: A method for preparing a TPE composition for a protective film adhesive layer is as follows:

[0050] S1: 100 g of styrene-ethylene-butylene-styrene block copolymer was mixed with 5 g of liquid paraffin and preheated at 60°C and 500 rpm for 10 min. Then, 6 g of maleic anhydride and 0.3 g of dicumyl peroxide were added and stirred at 48°C and 700 rpm for 5 min to obtain a premixed elastomer;

[0051] S2: Under a nitrogen atmosphere, 80 g of the premixed elastomer was added to a twin-screw reaction extruder and extruded at a screw speed of 200 r / min, a material residence time of 3.5 min, a feed zone temperature of 120°C, a melting zone temperature of 160°C, a reaction zone temperature of 180°C, a devolatilization zone temperature of 170°C, and a vacuum degree of -0.095 MPa. The extruded strips were water-cooled and pelletized, and then reflux-extracted with 1600 mL of acetone for 24 h. Finally, the modified elastomer was dried under vacuum at 60°C for 12 h.

[0052] S3: Add 5 g of nano-titanium dioxide to 100 mL of anhydrous ethanol and ultrasonicate for 30 min. Then add 0.25 g of carbon quantum dots and stir at 58 °C for 3 h. Then, centrifuge and dry to obtain a synergistic powder.

[0053] S4: 2.5 g of nano-titanium dioxide was added to 100 mL of anhydrous ethanol and ultrasonicated for 30 min. Then, 5 mL of ethyl orthosilicate was added and the pH was adjusted to 9 with 25% ammonia water. After stirring for 5 h, the mixture was centrifuged and the precipitate was washed three times with anhydrous ethanol. Finally, the mixture was vacuum dried at 58 °C for 6 h to obtain composite nanoparticles.

[0054] S5: Dissolve 12.1 g of tris(hydroxymethyl)aminomethane in 800 mL of deionized water, adjust the pH to 8.5 with concentrated hydrochloric acid, then add 1 g of composite nanoparticles and 0.2 g of dopamine hydrochloride in sequence. Stir in the dark for 24 h, centrifuge, and wash the precipitate with deionized water five times. Finally, vacuum dry at 58°C for 6 h to obtain modified nanoparticles.

[0055] S6: 1 g of graphene oxide was added to 100 mL of deionized water and subjected to ultrasonic treatment at a power of 300 W and a frequency of 30 kHz for 30 min. The pH was then adjusted to 6.0 with 25% ammonia water to obtain a graphene oxide dispersion.

[0056] S7: 1.9 g of chitosan was added to 200 mL of 1% glacial acetic acid solution and stirred for 4 h. The mixture was then filtered through a filter membrane with a pore size of 0.45 μm. 100 mL of graphene oxide dispersion was added to the filtrate while stirring and ultrasonic blending was performed for 20 min at a power of 400 W and a pulse mode of working for 3 s and resting for 2 s. The mixture was then pre-frozen at -80°C for 24 h, dried at a vacuum degree of 8 Pa and a cold trap temperature of -60°C for 48 h, ground, and passed through a 100-mesh sieve to obtain a compatibilizer.

[0057] S8: 8.5 g of polymethylhydrogensiloxane and 4.6 g of allyl glycidyl ether were mixed, and then 0.013 g of chloroplatinic acid hexahydrate was added, and the mixture was reacted at 80° C. for 2 h to obtain a crosslinking aid;

[0058] S9: 100g of styrene-ethylene-butylene-styrene block copolymer was mixed with 30g of liquid paraffin and kneaded at 50r / min for 10min at 120°C. Then, 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 were added and kneaded at 70r / min for 8min at 135°C. After cooling to 100°C, 2g of cross-linking aid was added and kneaded at 70r / min for 5min. After discharging, the material was poured into a mold and pre-pressed at 125°C and 10MPa for 5min under a nitrogen atmosphere, then cross-linked at 160°C for 8min, and finally cross-linked at 185°C for 13min. After cooling and demolding, a TPE composition for a protective film adhesive layer was obtained.

[0059] Example 2: A method for preparing a TPE composition for a protective film adhesive layer is as follows:

[0060] S1: 100 g of styrene-ethylene-butylene-styrene block copolymer was mixed with 5 g of liquid paraffin and preheated at 60°C and 550 rpm for 11 min. Then, 7 g of maleic anhydride and 0.4 g of dicumyl peroxide were added and stirred at 50°C and 750 rpm for 5.5 min to obtain a premixed elastomer;

[0061] S2: Under a nitrogen atmosphere, 90 g of the premixed elastomer was added to a twin-screw reaction extruder and extruded at a screw speed of 200 r / min, a material residence time of 3.5 min, a feed zone temperature of 120°C, a melting zone temperature of 160°C, a reaction zone temperature of 180°C, a devolatilization zone temperature of 170°C, and a vacuum degree of -0.095 MPa. The extruded strips were water-cooled and pelletized, and then reflux-extracted with 1800 mL of acetone for 24.5 h. Finally, the strips were vacuum-dried at 60°C for 14 h to obtain a modified elastomer.

[0062] S3: Add 7.5 g of nano-titanium dioxide to 125 mL of anhydrous ethanol and ultrasonicate for 35 min. Then add 0.375 g of carbon quantum dots and stir at 59 °C for 3.5 h. Then, centrifuge and dry to obtain a synergistic powder.

[0063] S4: 3.75 g of nano-titanium dioxide was added to 100 mL of anhydrous ethanol and ultrasonicated for 35 min. Then, 7.5 mL of ethyl orthosilicate was added and the pH was adjusted to 9 with 25% ammonia water. After stirring for 5.5 h, the mixture was centrifuged and the precipitate was washed four times with anhydrous ethanol. Finally, the mixture was vacuum dried at 59°C for 7 h to obtain composite nanoparticles.

[0064] S5: 18.15 g of tris(hydroxymethyl)aminomethane was dissolved in 800 mL of deionized water, and the pH was adjusted to 8.5 with concentrated hydrochloric acid. 1.5 g of composite nanoparticles and 0.3 g of dopamine hydrochloride were added in sequence. The mixture was stirred in the dark for 24.5 h. After centrifugation, the precipitate was washed with deionized water six times and finally dried in vacuum at 59°C for 6.5 h to obtain modified nanoparticles.

[0065] S6: 1.5 g of graphene oxide was added to 100 mL of deionized water and subjected to ultrasonic treatment at a power of 350 W and a frequency of 35 kHz for 35 min. The pH was then adjusted to 6.3 with 25% by mass ammonia water to obtain a graphene oxide dispersion.

[0066] S7: 3.05 g of chitosan was added to 200 mL of 1% glacial acetic acid solution and stirred for 4.5 h. The mixture was then filtered through a filter membrane with a pore size of 0.45 μm. 100 mL of graphene oxide dispersion was added to the filtrate while stirring and ultrasonic blending was performed for 25 min at a power of 450 W and a pulse mode of working for 3 s and resting for 2 s. The mixture was then pre-frozen at -80°C for 24.5 h, and then dried at a vacuum degree of 9 Pa and a cold trap temperature of -55°C for 49 h. The compatibilizer was then ground and passed through a 100-mesh sieve.

[0067] S8: 17 g of polymethylhydrogensiloxane and 9.15 g of allyl glycidyl ether were mixed, followed by the addition of 0.026 g of chloroplatinic acid hexahydrate, and the mixture was reacted at 80° C. for 2.5 h to obtain a crosslinking aid;

[0068] S9: 100g of styrene-ethylene-butylene-styrene block copolymer was mixed with 35g of liquid paraffin and kneaded at 50r / min for 10min at 120°C. Then, 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 were added and kneaded at 75r / min for 9min at 138°C. After cooling to 105°C, 3g of cross-linking aid was added and kneaded at 75r / min for 5.5min. After discharging, the material was poured into a mold and pre-pressed at 128°C and 10MPa for 5min under a nitrogen atmosphere, then cross-linked at 165°C for 9min, and finally cross-linked at 188°C for 14min. After cooling and demolding, a TPE composition for a protective film adhesive layer was obtained.

[0069] Example 3: A method for preparing a TPE composition for a protective film adhesive layer is as follows:

[0070] S1: 100 g of styrene-ethylene-butylene-styrene block copolymer and 5 g of liquid paraffin were mixed and preheated at 60°C and 600 rpm for 12 min. Then, 8 g of maleic anhydride and 0.5 g of dicumyl peroxide were added and stirred at 52°C and 800 rpm for 6 min to obtain a premixed elastomer;

[0071] S2: Under a nitrogen atmosphere, 100 g of the premixed elastomer was added to a twin-screw reaction extruder and extruded at a screw speed of 200 r / min, a material residence time of 3.5 min, a feed zone temperature of 120°C, a melting zone temperature of 160°C, a reaction zone temperature of 180°C, a devolatilization zone temperature of 170°C, and a vacuum degree of -0.095 MPa. The extruded strips were water-cooled and pelletized, and then reflux-extracted with 2000 mL of acetone for 25 h. Finally, the extruded strips were vacuum-dried at 60°C for 15 h to obtain a modified elastomer.

[0072] S3: Add 10 g of nano-titanium dioxide to 150 mL of anhydrous ethanol and ultrasonicate for 40 min. Then add 0.5 g of carbon quantum dots and stir at 60 °C for 4 h. Then, centrifuge and dry to obtain a synergistic powder.

[0073] S4: 5 g of nano-titanium dioxide was added to 100 mL of anhydrous ethanol and ultrasonicated for 40 min. Then, 10 mL of ethyl orthosilicate was added and the pH was adjusted to 9 with 25% ammonia water. After stirring for 6 h, the mixture was centrifuged and then washed with anhydrous ethanol for 5 times. Finally, the mixture was vacuum dried at 60°C for 8 h to obtain composite nanoparticles.

[0074] S5: 24.2 g of tris(hydroxymethyl)aminomethane was dissolved in 800 mL of deionized water, and the pH was adjusted to 8.5 with concentrated hydrochloric acid. 2 g of composite nanoparticles and 0.4 g of dopamine hydrochloride were added in sequence. The mixture was stirred in the dark for 25 h. After centrifugation, the precipitate was washed seven times with deionized water and finally dried in vacuum at 60°C for 7 h to obtain modified nanoparticles.

[0075] S6: 2 g of graphene oxide was added to 100 mL of deionized water and subjected to ultrasonic treatment at a power of 400 W and a frequency of 40 kHz for 40 min. The pH was then adjusted to 6.5 with 25% by mass ammonia water to obtain a graphene oxide dispersion.

[0076] S7: 4.2 g of chitosan was added to 200 mL of 1% glacial acetic acid solution and stirred for 5 h. The mixture was then filtered through a filter membrane with a pore size of 0.45 μm. 100 mL of graphene oxide dispersion was added to the filtrate while stirring. Ultrasonic blending was performed for 30 min at a power of 500 W and a pulse mode of working for 3 s and resting for 2 s. The mixture was pre-frozen at -80°C for 25 h, and then dried at a vacuum degree of 10 Pa and a cold trap temperature of -50°C for 50 h. The compatibilizer was then ground and passed through a 100-mesh sieve.

[0077] S8: 25.5 g of polymethylhydrogensiloxane and 13.7 g of allyl glycidyl ether were mixed, followed by the addition of 0.039 g of chloroplatinic acid hexahydrate, and the mixture was reacted at 80° C. for 3 h to obtain a crosslinking aid;

[0078] S9: 100g of styrene-ethylene-butylene-styrene block copolymer was mixed with 40g of liquid paraffin and kneaded at 50r / min for 10min at 120°C. Then, 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 were added and kneaded at 80r / min for 10min at 140°C. After cooling to 110°C, 4g of cross-linking aid was added and kneaded at 80r / min for 6min. After discharging, the material was poured into a mold and pre-pressed at 130°C and 10MPa for 5min under a nitrogen atmosphere, then cross-linked at 170°C for 10min, and finally cross-linked at 190°C for 15min. After cooling and demolding, a TPE composition for a protective film adhesive layer was obtained.

[0079] Comparative Example 1:

[0080] Compared with Example 1, this comparative example only replaces the process of preparing the synergistic powder with "adding 5 g of nano-titanium dioxide to 100 mL of anhydrous ethanol and ultrasonically treating it for 30 minutes, then adding 0.25 g of carbon quantum dots and stirring and reacting at 58°C for 3 hours, and then centrifuging and drying to obtain a synergistic powder" with "adding 5.2 g of nano-titanium dioxide to 100 mL of anhydrous ethanol and ultrasonically treating it for 30 minutes, then adding 0.05 g of carbon quantum dots and stirring and reacting at 58°C for 3 hours, and then centrifuging and drying to obtain a synergistic powder". The remaining steps and parameters are the same and will not be repeated in this comparative example. Finally, a TPE composition for a protective film adhesive layer is obtained.

[0081] Comparative Example 2:

[0082] Compared with Example 1, this comparative example only replaces the "15g modified elastomer" added during the preparation of the TPE composition for the protective film adhesive layer of S9 with "15g styrene-ethylene-butylene-styrene block copolymer". The remaining 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.

[0083] Comparative Example 3:

[0084] 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, and 1g compatibilizer" added during the preparation of the TPE composition for the protective film adhesive layer of S9 with "15g modified elastomer, 1g modified nanoparticles, 15g piperazine pyrophosphate, 5g aluminum hypophosphite, 3g L-arginine, and 1g compatibilizer". The remaining steps and parameters are the same and will not be repeated in this comparative example. Finally, a TPE composition for the protective film adhesive layer is obtained.

[0085] Comparative Example 4:

[0086] 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, and 1g compatibilizer" added during the preparation of the TPE composition for the protective film adhesive layer of S9 with "15g modified elastomer, 3g synergistic powder, 15g piperazine pyrophosphate, 5g aluminum hypophosphite, 3g L-arginine, and 1g compatibilizer". The remaining steps and parameters are the same and will not be repeated in this comparative example. Finally, a TPE composition for the protective film adhesive layer is obtained.

[0087] Comparative Example 5:

[0088] 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, and 1g compatibilizer" added during the preparation of the TPE composition for the protective film adhesive layer of S9 with "15g modified elastomer, 3g synergistic powder, 1g modified nanoparticles, 5g piperazine pyrophosphate, 15g aluminum hypophosphite, 3g L-arginine, and 1g compatibilizer". The remaining steps and parameters are the same and will not be repeated in this comparative example. Finally, a TPE composition for the protective film adhesive layer is obtained.

[0089] Comparative Example 6:

[0090] 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, and 1g compatibilizer" added during the preparation of the TPE composition for the protective film adhesive layer of S9 with "15g modified elastomer, 3g synergistic powder, 1g modified nanoparticles, 15g piperazine pyrophosphate, 5g aluminum hypophosphite, and 1g compatibilizer". The remaining steps and parameters are the same and will not be repeated in this comparative example. Finally, a TPE composition for the protective film adhesive layer is obtained.

[0091] Comparative Example 7:

[0092] 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, and 1g compatibilizer" added during the preparation of the TPE composition for the protective film adhesive layer of S9 with "15g modified elastomer, 3g synergistic powder, 1g modified nanoparticles, 15g piperazine pyrophosphate, 5g aluminum hypophosphite, and 3g L-arginine". The remaining steps and parameters are the same and will not be repeated in this comparative example. Finally, a TPE composition for the protective film adhesive layer is obtained.

[0093] Comparative Example 8:

[0094] Compared with Example 1, this comparative example only replaced the "2 g cross-linking aid" added during the preparation of the TPE composition for the protective film adhesive layer of S9 with "0.013 g chloroplatinic acid hexahydrate". The remaining steps and parameters were the same and will not be repeated in this comparative example. Finally, a TPE composition for the protective film adhesive layer was obtained.

[0095] Performance testing:

[0096] Determination of peel strength (PS):

[0097] With reference to GB / T 2792-2014 "Test Method for Peel Strength of Adhesive Tapes", the peel strength (N / cm) at 180° between the TPE compositions for the adhesive layer of protective films prepared in Examples 1 to 3 and Comparative Examples 1 to 8 and the stainless steel plate was measured. The test results are shown in Table 1.

[0098] Determination of Limiting Oxygen Index (LOI):

[0099] The limiting oxygen index (%) test was performed on the TPE compositions for the adhesive layers of the protective films prepared in Examples 1 to 3 and Comparative Examples 1 to 8. The test results are shown in Table 1.

[0100] Determination of UV resistance:

[0101] With reference to ISO 4892-3:2016, the UVB-340 lamp was used to measure the TPE compositions for the adhesive layers of the protective films prepared in Examples 1 to 3 and Comparative Examples 1 to 8 at 0.76 W / m 2 The yellowing index (ΔY I) and peel strength retention rate (%) after 1000 hours of cyclic UV aging at 340 nm are shown in Table 1.

[0102] Determination of stability:

[0103] The TPE composition was first stored at -40°C for 24 hours and then at 85°C for 24 hours, and cycled 5 times at the two temperatures. The peel strength retention rate (%) and deformation rate (%) of the TPE composition for the protective film adhesive layer prepared in Examples 1 to 3 and Comparative Examples 1 to 8 after 5 cycles were measured, and the time (h) that the cable material remained intact at 950°C was recorded. The test results are shown in Table 1.

[0104] Table 1: Performance test results of Examples 1-3 and Comparative Examples 1-8

[0105]

[0106] Data Analysis:

[0107] As can be seen from Table 1, the TPE composition for the adhesive layer of the protective film prepared in the embodiment of the present invention has more excellent interfacial adhesion, flame retardancy, UV resistance and weather resistance.

[0108] The above is a detailed description of an embodiment of the present invention. However, the content described is only a preferred embodiment of the present invention and should not be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A method for preparing a TPE composition for a protective film adhesive layer, characterized in that: The following steps are involved: Styrene-ethylene-butylene-styrene block copolymer and liquid paraffin are mixed and kneaded, and then a modified elastomer, a synergistic powder, modified nanoparticles, piperazine pyrophosphate, aluminum hypophosphite, L-arginine, and a compatibilizer are added and kneaded. After cooling to 100-110°C, a cross-linking aid is added and kneaded again. After discharging, the material is poured into a mold and pre-pressed under a nitrogen atmosphere, and then gradient cross-linked. After cooling and demolding, a TPE composition for a protective film adhesive layer is obtained.

2. The method for preparing the TPE composition for the protective film adhesive layer according to claim 1, characterized in that: The usage ratio of the styrene-ethylene-butylene-styrene block copolymer, liquid paraffin, modified elastomer, synergistic powder, modified nanoparticles, piperazine pyrophosphate, aluminum hypophosphite, L-arginine, compatibilizer, and cross-linking aid is 100g: 30-40g: 15-20g: 3-5g: 1-2g: 15-18g: 5-6g: 3-5g: 1-2g: 2-4g; The pre-pressing temperature is 125-130°C, the pressure is 10 MPa, and the duration is 5 minutes; The gradient cross-linking is firstly carried out at 160-170° C. for 8-10 minutes, and then at 185-190° C. for 13-15 minutes.

3. The method for preparing the TPE composition for the protective film adhesive layer according to claim 1, characterized in that: The preparation method of the modified elastomer is as follows: Step A1: mixing styrene-ethylene-butylene-styrene block copolymer with liquid paraffin and preheating at 60° C. and 500-600 rpm for 10-12 minutes, then adding maleic anhydride and dicumyl peroxide and stirring at 48-52° C. for 5-6 minutes to obtain a premixed elastomer; Step A2: Under a nitrogen atmosphere, the premixed elastomer is extruded, water-cooled and pelletized, and then reflux-extracted with acetone for 24-25 hours, and vacuum-dried to obtain a modified elastomer.

4. The method for preparing the TPE composition for the protective film adhesive layer according to claim 3, characterized in that: The usage ratio of the styrene-ethylene-butylene-styrene block copolymer, liquid paraffin, maleic anhydride, and dicumyl peroxide in step A1 is 100 g: 5 g: 6-8 g: 0.3-0.5 g; In step A2, the ratio of the pre-mixed elastomer to acetone is 80-100 g: 1600-2000 mL.

5. The method for preparing the TPE composition for the protective film adhesive layer according to claim 1, characterized in that: The preparation method of the synergistic powder is as follows: Nano-titanium dioxide is added to anhydrous ethanol and ultrasonically treated, followed by adding carbon quantum dots and stirring at 58-60° C. for 3-4 hours, followed by centrifugal separation and drying to obtain a synergistic powder; The usage ratio of the anhydrous ethanol, nano-titanium dioxide and carbon quantum dots is 100-150 mL: 5-10 g: 0.25-0.5 g.

6. The method for preparing the TPE composition for the protective film adhesive layer according to claim 1, characterized in that: The preparation method of the modified nanoparticles is as follows: Step B1: Add nano-titanium dioxide to anhydrous ethanol and ultrasonicate, then add ethyl orthosilicate and adjust the pH to 9 with ammonia water. Stir for 5-6 hours, then centrifuge and 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 composite nanoparticles and dopamine hydrochloride in sequence, stir in the dark for 24-25 hours, centrifuge and wash the precipitate with deionized water 5-7 times, and vacuum dry to obtain modified nanoparticles.

7. The method for preparing the TPE composition for the protective film adhesive layer according to claim 6, characterized in that: The usage ratio of anhydrous ethanol, nano-titanium dioxide, and ethyl orthosilicate in step B1 is 100 mL: 2.5-5 g: 5-10 mL; The usage ratio of tris(hydroxymethyl)aminomethane, deionized water, composite nanoparticles, and dopamine hydrochloride in step B2 is 12.1-24.2 g:800 mL:1-2 g:0.2-0.4 g.

8. The method for preparing the TPE composition for the protective film adhesive layer according to claim 1, characterized in that: The preparation method of the compatibilizer is as follows: Step C1: adding graphene oxide to deionized water and performing ultrasonic treatment, and then adjusting the pH to 6.0-6.5 with ammonia water to obtain a graphene oxide dispersion; Step C2: chitosan is added to the glacial acetic acid solution and stirred for 4-5 hours. After filtering, the graphene oxide dispersion is added to the filtrate while stirring and ultrasonic blending is performed. Then, the mixture is freeze-dried, ground, and sieved to obtain a compatibilizer.

9. The method for preparing the TPE composition for the protective film adhesive layer according to claim 8, characterized in that: The ratio of deionized water to graphene oxide in step C1 is 100 mL: 1-2 g; The usage ratio of the 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%; The power of the ultrasonic blending treatment in step C2 is 400-500W, the pulse mode is working for 3s-pausing for 2s, and the power is 20-30min.

10. The method for preparing the TPE composition for the protective film adhesive layer according to claim 1, characterized in that: The preparation method of the cross-linking auxiliary agent is as follows: Mix polymethylhydrogensiloxane and allyl glycidyl ether, then add chloroplatinic acid hexahydrate, and react at 80°C for 2-3 hours to obtain a crosslinking aid; The usage ratio of the polymethyl hydrogen siloxane, allyl glycidyl ether and chloroplatinic acid hexahydrate is 8.5-25.5 g: 4.6-13.7 g: 0.013-0.039 g.

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