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US-12617979-B2 - Flame-retardant degradable adhesive tape and preparation method thereof

US12617979B2US 12617979 B2US12617979 B2US 12617979B2US-12617979-B2

Abstract

The present disclosure provides a preparation method of a flame-retardant degradable adhesive tape, including: preparing a degradable adhesive tape base layer and a flame-retardant degradable adhesive tape bonding layer separately, and then conducting coating, curing, and aging of the flame-retardant degradable adhesive tape bonding layer on a surface of the degradable adhesive tape base layer to obtain the flame-retardant degradable adhesive tape; where the degradable adhesive tape base layer is prepared by subjecting bis(2-hydroxybutyl) terephthalate (BHBT) and bis(2-hydroxybutyl) adipate (BHAT) to transesterification and polycondensation to obtain a degradable poly(butylene adipate-co-terephthalate) (PBAT) polymer polymer, and then conducting blow molding on the degradable PBAT polymer; the flame-retardant degradable adhesive tape bonding layer is prepared by subjecting the BHBT, the BHAT, and a pressure-sensitive adhesive (PSA) additive to transesterification and polycondensation to obtain a colloidal flame-retardant degradable PBAT polymer, and conducting curing on the colloidal flame-retardant degradable PBAT polymer.

Inventors

  • ZHENLIN JIANG
  • Yun Zhang
  • Keyu Zhu
  • Chenxue XU
  • Min Zhu
  • Xin Fan
  • Jiamin XU
  • Wanting REN

Assignees

  • SHANGHAI UNIVERSITY OF ENGINEERING SCIENCE

Dates

Publication Date
20260505
Application Date
20220323
Priority Date
20220318

Claims (20)

  1. 1 . A preparation method of a flame-retardant degradable adhesive tape, comprising: preparing a degradable adhesive tape base layer and a flame-retardant degradable adhesive tape bonding layer separately, and then conducting coating, curing, and aging of the flame-retardant degradable adhesive tape bonding layer on a surface of the degradable adhesive tape base layer to obtain the flame-retardant degradable adhesive tape; wherein the degradable adhesive tape base layer is prepared by subjecting bis(2-hydroxybutyl) terephthalate (BHBT) and bis(2-hydroxybutyl) adipate (BHAT) to transesterification and polycondensation to obtain a degradable poly(butylene adipate-co-terephthalate) (PBAT) polymer, and then conducting blow molding on the degradable PBAT polymer; the flame-retardant degradable adhesive tape bonding layer is prepared by subjecting the BHBT, the BHAT, and a pressure-sensitive adhesive (PSA) additive to transesterification and polycondensation to obtain a colloidal flame-retardant degradable PBAT polymer, and conducting curing on the colloidal flame-retardant degradable PBAT polymer; and the PSA additive is prepared by conducting esterification on 2-carboxyethylphenylphosphinic acid (CEPPA), 1,4-butanediol, and pentaerythritol.
  2. 2 . The preparation method of a flame-retardant degradable adhesive tape according to claim 1 , wherein a process of conducting the coating, the curing, and the aging of the flame-retardant degradable adhesive tape bonding layer on the surface of the degradable adhesive tape base layer to obtain the flame-retardant degradable adhesive tape specifically comprises: coating the flame-retardant degradable adhesive tape bonding layer on the surface of the degradable adhesive tape base layer, conducting the curing by baking at 85° C. to 95° C. for 2 min to 4 min, laying a release film on a surface of the flame-retardant degradable adhesive tape bonding layer, and conducting the aging in a warm room at 45° C. to 55° C. for 23 h to 25 h to obtain the flame-retardant degradable adhesive tape; wherein the release film is an organic silicone oil material; the release film has a thickness of 0.1 μm to 8 μm; the degradable adhesive tape base layer has a thickness of 10 μm to 60 μm; and the flame-retardant degradable adhesive tape bonding layer has a thickness of 3 μm to 50 μm.
  3. 3 . The preparation method of a flame-retardant degradable adhesive tape according to claim 1 , wherein the BHBT is regenerated BHBT prepared by conducting alcoholysis and filtration on a waste polybutylece terephthalate (PBT) material as a raw material; the alcoholysis is conducted with sodium phytate or potassium phytate as a complexant; and the regenerated BHBT has a residual metal ion content of less than 30 ppm.
  4. 4 . The preparation method of a flame-retardant degradable adhesive tape according to claim 3 , wherein the waste PBT material has polyurethane (PU) with a mass fraction of less than 5% and polyethylene terephthalate (PET) with a mass fraction of less than 10%.
  5. 5 . The preparation method of a flame-retardant degradable adhesive tape according to claim 3 , wherein the alcoholysis comprises: under nitrogen protection, dissolving the waste PBT material, the 1,4-butanediol, a catalyst, an anti-aging agent, and an ether inhibitor in a reactor at 180° C. to 210° C. to obtain a system; after the system is clarified, gradually heating to 200° C. to 240° C. to allow a reaction for 1.5 h to 2.5 h; recording a water output, and conducting vacuumizing at a vacuum degree of 200 Pa to 1,000 Pa for 20 min to 60 min when the water output reaches 90% of a theoretical value; and adding the complexant to allow a reaction for 15 min to 30 min, and conducting filtration to obtain the regenerated BHBT; wherein the waste PBT material and the 1,4-butanediol are at a mass ratio of 1:0.30 to 1:0.50; the catalyst is selected from the group consisting of zinc acetate, aluminum acetate, and calcium acetate; the catalyst has a mass 0.025 wt % to 0.15 wt % that of the waste PBT material; the anti-aging agent is selected from the group consisting of triphenyl phosphate, trimethyl phosphite, and triethyl phosphite; the anti-aging agent has a mass 0.075 wt % to 0.25 wt % that of the waste PBT material; the ether inhibitor is selected from the group consisting of sodium acetate and magnesium acetate; the ether inhibitor has a mass 0.1 wt % to 0.25 wt % that of the waste PBT material; and the complexant has a mass 0.02 wt % to 0.05 wt % that of the waste PBT material.
  6. 6 . The preparation method of a flame-retardant degradable adhesive tape according to claim 5 , wherein the waste PBT material is further subjected to a pretreatment before the alcoholysis; and the pretreatment comprises: processing the waste PBT material to obtain a PBT powder with a particle size of less than 2 mm, sieving, and drying a resulting sieved PBT powder in a vacuum oven at 100° C. to 130° C. for 8 h to 12 h.
  7. 7 . The preparation method of a flame-retardant degradable adhesive tape according to claim 1 , wherein a preparation process of the BHAT comprises: under nitrogen protection, allowing adipic acid and the 1,4-butanediol with a molar ratio of 1:1.05 to 1:1.45 to have esterification in a reactor at 180° C. to 200° C. for 2 h to 4 h; recording a water output, and detecting an acid value when the water output reaches 90% of a theoretical value; and terminating the esterification when the acid value reaches 20 KOH mg/g to 40 KOH mg/g to obtain the BHAT.
  8. 8 . The preparation method of a flame-retardant degradable adhesive tape according to claim 1 , wherein a preparation process of the PSA additive comprises: under nitrogen protection, conducting alcoholysis on the CEPPA, the 1,4-butanediol, a catalyst, an anti-aging agent, and an ether inhibitor in a reactor at 140° C. to 160° C.; after a resulting system is clarified, adding pentaerythritol to allow a reaction for 2 h to 4 h; gradually heating to 170° C. to 230° C. and recording a water output; and conducting vacuumizing at a vacuum degree of 300 Pa to 900 Pa for 30 min to 60 min when the water output reaches 90% of a theoretical value to obtain the PSA additive; wherein the CEPPA and the 1,4-butanediol are at a molar ratio of 1:1.10 to 1:1.40; the 1,4-butanediol and the pentaerythritol are at a molar ratio of 1:1.2 to 1:1.3; the catalyst is selected from the group consisting of zinc acetate, aluminum acetate, and calcium acetate; the catalyst has a mass 0.025 wt % to 0.15 wt % that of the CEPPa; the anti-aging agent is selected from the group consisting of triphenyl phosphate, trimethyl phosphite, and triethyl phosphite; the anti-aging agent has a mass 0.075 wt % to 0.25 wt % that of the CEPPA; the ether inhibitor is selected from the group consisting of sodium acetate and magnesium acetate; and the ether inhibitor has a mass 0.1 wt % to 0.25 wt % that of the CEPPA.
  9. 9 . The preparation method of a flame-retardant degradable adhesive tape according to claim 1 , wherein a preparation process of the degradable adhesive tape base layer comprises: (1) under nitrogen protection, dissolving the BHBT, the BHAT, and a condensation catalyst according a specified proportion in a reactor at 200° C. to 210° C. for 15 min, and gradually heating to 225° C. to 235° C. to allow a reaction for 1 h to 1.5 h; recording a water output, and heating to 250° C. to 265° C. to allow high-temperature polycondensation at a vacuum degree of 50 Pa to 1,000 Pa for 3.5 h to 5.5 h when the water output reaches 90% of a theoretical value, to obtain the degradable PBAT polymer; wherein the BHBT and the BHAT are at a molar ratio of 40:60 to 50:50; the condensation catalyst is a composite catalyst of poly(antimony ethylene glycoxide) and tetrabutyl titanate, and the poly(antimony ethylene glycoxide) and the tetrabutyl titanate are at a mass ratio of 1:0.25 to 1:0.85; and the condensation catalyst is added at 0.01 wt % to 0.06 wt % of the BHAT; and (2) subjecting the degradable PBAT polymer to blow molding at 160° C. to 180° C. and a blow-up ratio of (3-6):1 in a film blowing machine with a die gap of 10 μm to 50 μm, to obtain a regenerated PBAT polymer film as the degradable adhesive tape base layer.
  10. 10 . The preparation method of a flame-retardant degradable adhesive tape according to claim 1 , wherein a preparation process of the flame-retardant degradable adhesive tape bonding layer comprises: (1) under nitrogen protection, dissolving the BHBT, the BHAT, the PSA additive, and a condensation catalyst according a specified proportion in a reactor at 190° C. to 210° C. for 20 min, and gradually heating to 220° C. to 240° C. to allow a reaction for 1 h to 2 h; recording a water output, and heating to 245° C. to 250° C. to allow high-temperature polycondensation at a vacuum degree of 200 Pa to 600 Pa for 2.5 h to 4.5 h when the water output reaches 90% of a theoretical value, to obtain the colloidal flame-retardant degradable PBAT polymer; wherein the BHBT, the BHAT, and the PSA additive are at a molar ratio of 35:50:15 to 20:50:30; the condensation catalyst is a composite catalyst of poly(antimony ethylene glycoxide) and tetrabutyl titanate, and the poly(antimony ethylene glycoxide) and the tetrabutyl titanate are at a mass ratio of 1:0.25 to 1:0.85; and the condensation catalyst is added at 0.01 wt % to 0.06 wt % of the BHAT; and (2) aging the colloidal flame-retardant degradable PBAT polymer at 40° C. to 60° C., and allowing to stand for 1 h to 1.5 h to obtain the flame-retardant degradable adhesive tape bonding layer.
  11. 11 . A flame-retardant degradable adhesive tape prepared by the preparation method according to claim 1 , comprising a degradable adhesive tape base layer and a flame-retardant degradable adhesive tape bonding layer; wherein the degradable adhesive tape base layer has a tensile strength of greater than or equal to 20 MPa; the flame-retardant degradable adhesive tape bonding layer has a number-average molecular weight of 6,000 to 12,000, a glass-transition temperature (GTT) of −25° C. to 0° C., a viscoelastic range of −25° C. to 72° C., a complex viscosity η* of 14 Pa·s to 30 Pa·s, an initial adhesion of greater than or equal to 20 #, a permanent adhesion of greater than or equal to 30 h, and a 180° peel strength of greater than or equal to 5 N/cm under normal conditions; and the flame-retardant degradable adhesive tape has a limiting oxygen index of 28% to 45%, a flame-retardant grade of UL94 VTM-0, and a 90-day biodegradation rate of 50% to 90%.
  12. 12 . The flame-retardant degradable adhesive tape according to claim 11 , wherein a process of conducting the coating, the curing, and the aging of the flame-retardant degradable adhesive tape bonding layer on the surface of the degradable adhesive tape base layer to obtain the flame-retardant degradable adhesive tape specifically comprises: coating the flame-retardant degradable adhesive tape bonding layer on the surface of the degradable adhesive tape base layer, conducting the curing by baking at 85° C. to 95° C. for 2 min to 4 min, laying a release film on a surface of the flame-retardant degradable adhesive tape bonding layer, and conducting the aging in a warm room at 45° C. to 55° C. for 23 h to 25 h to obtain the flame-retardant degradable adhesive tape; wherein the release film is an organic silicone oil material; the release film has a thickness of 0.1 μm to 8 μm; the degradable adhesive tape base layer has a thickness of 10 μm to 60 μm; and the flame-retardant degradable adhesive tape bonding layer has a thickness of 3 μm to 50 μm.
  13. 13 . The flame-retardant degradable adhesive tape according to claim 11 , wherein the BHBT is regenerated BHBT prepared by conducting alcoholysis and filtration on a waste polybutylece terephthalate (PBT) material as a raw material; the alcoholysis is conducted with sodium phytate or potassium phytate as a complexant; and the regenerated BHBT has a residual metal ion content of less than 30 ppm.
  14. 14 . The flame-retardant degradable adhesive tape according to claim 13 , wherein the waste PBT material has polyurethane (PU) with a mass fraction of less than 5% and polyethylene terephthalate (PET) with a mass fraction of less than 10%.
  15. 15 . The flame-retardant degradable adhesive tape according to claim 13 , wherein the alcoholysis comprises: under nitrogen protection, dissolving the waste PBT material, the 1,4-butanediol, a catalyst, an anti-aging agent, and an ether inhibitor in a reactor at 180° C. to 210° C. to obtain a system; after the system is clarified, gradually heating to 200° C. to 240° C. to allow a reaction for 1.5 h to 2.5 h; recording a water output, and conducting vacuumizing at a vacuum degree of 200 Pa to 1,000 Pa for 20 min to 60 min when the water output reaches 90% of a theoretical value; and adding the complexant to allow a reaction for 15 min to 30 min, and conducting filtration to obtain the regenerated BHBT; wherein the waste PBT material and the 1,4-butanediol are at a mass ratio of 1:0.30 to 1:0.50; the catalyst is selected from the group consisting of zinc acetate, aluminum acetate, and calcium acetate; the catalyst has a mass 0.025 wt % to 0.15 wt % that of the waste PBT material; the anti-aging agent is selected from the group consisting of triphenyl phosphate, trimethyl phosphite, and triethyl phosphite; the anti-aging agent has a mass 0.075 wt % to 0.25 wt % that of the waste PBT material; the ether inhibitor is selected from the group consisting of sodium acetate and magnesium acetate; the ether inhibitor has a mass 0.1 wt % to 0.25 wt % that of the waste PBT material; and the complexant has a mass 0.02 wt % to 0.05 wt % that of the waste PBT material.
  16. 16 . The flame-retardant degradable adhesive tape according to claim 15 , wherein the waste PBT material is further subjected to a pretreatment before the alcoholysis; and the pretreatment comprises: processing the waste PBT material to obtain a PBT powder with a particle size of less than 2 mm, sieving, and drying a resulting sieved PBT powder in a vacuum oven at 100° C. to 130° C. for 8 h to 12 h.
  17. 17 . The flame-retardant degradable adhesive tape according to claim 11 , wherein a preparation process of the BHAT comprises: under nitrogen protection, allowing adipic acid and the 1,4-butanediol with a molar ratio of 1:1.05 to 1:1.45 to have esterification in a reactor at 180° C. to 200° C. for 2 h to 4 h; recording a water output, and detecting an acid value when the water output reaches 90% of a theoretical value; and terminating the esterification when the acid value reaches 20 KOH mg/g to 40 KOH mg/g to obtain the BHAT.
  18. 18 . The flame-retardant degradable adhesive tape according to claim 11 , wherein a preparation process of the PSA additive comprises: under nitrogen protection, conducting alcoholysis on the CEPPA, the 1,4-butanediol, a catalyst, an anti-aging agent, and an ether inhibitor in a reactor at 140° C. to 160° C.; after a resulting system is clarified, adding pentaerythritol to allow a reaction for 2 h to 4 h; gradually heating to 170° C. to 230° C. and recording a water output; and conducting vacuumizing at a vacuum degree of 300 Pa to 900 Pa for 30 min to 60 min when the water output reaches 90% of a theoretical value to obtain the PSA additive; wherein the CEPPA and the 1,4-butanediol are at a molar ratio of 1:1.10 to 1:1.40; the 1,4-butanediol and the pentaerythritol are at a molar ratio of 1:1.2 to 1:1.3; the catalyst is selected from the group consisting of zinc acetate, aluminum acetate, and calcium acetate; the catalyst has a mass 0.025 wt % to 0.15 wt % that of the CEPPa; the anti-aging agent is selected from the group consisting of triphenyl phosphate, trimethyl phosphite, and triethyl phosphite; the anti-aging agent has a mass 0.075 wt % to 0.25 wt % that of the CEPPA; the ether inhibitor is selected from the group consisting of sodium acetate and magnesium acetate; and the ether inhibitor has a mass 0.1 wt % to 0.25 wt % that of the CEPPA.
  19. 19 . The flame-retardant degradable adhesive tape according to claim 11 , wherein a preparation process of the degradable adhesive tape base layer comprises: (1) under nitrogen protection, dissolving the BHBT, the BHAT, and a condensation catalyst according a specified proportion in a reactor at 200° C. to 210° C. for 15 min, and gradually heating to 225° C. to 235° C. to allow a reaction for 1 h to 1.5 h; recording a water output, and heating to 250° C. to 265° C. to allow high-temperature polycondensation at a vacuum degree of 50 Pa to 1,000 Pa for 3.5 h to 5.5 h when the water output reaches 90% of a theoretical value, to obtain the degradable PBAT polymer; wherein the BHBT and the BHAT are at a molar ratio of 40:60 to 50:50; the condensation catalyst is a composite catalyst of poly(antimony ethylene glycoxide) and tetrabutyl titanate, and the poly(antimony ethylene glycoxide) and the tetrabutyl titanate are at a mass ratio of 1:0.25 to 1:0.85; and the condensation catalyst is added at 0.01 wt % to 0.06 wt % of the BHAT; and (2) subjecting the degradable PBAT polymer to blow molding at 160° C. to 180° C. and a blow-up ratio of (3-6):1 in a film blowing machine with a die gap of 10 μm to 50 μm, to obtain a regenerated PBAT polymer film as the degradable adhesive tape base layer.
  20. 20 . The flame-retardant degradable adhesive tape according to claim 11 , wherein a preparation process of the flame-retardant degradable adhesive tape bonding layer comprises: (1) under nitrogen protection, dissolving the BHBT, the BHAT, the PSA additive, and a condensation catalyst according a specified proportion in a reactor at 190° C. to 210° C. for 20 min, and gradually heating to 220° C. to 240° C. to allow a reaction for 1 h to 2 h; recording a water output, and heating to 245° C. to 250° C. to allow high-temperature polycondensation at a vacuum degree of 200 Pa to 600 Pa for 2.5 h to 4.5 h when the water output reaches 90% of a theoretical value, to obtain the colloidal flame-retardant degradable PBAT polymer; wherein the BHBT, the BHAT, and the PSA additive are at a molar ratio of 35:50:15 to 20:50:30; the condensation catalyst is a composite catalyst of poly(antimony ethylene glycoxide) and tetrabutyl titanate, and the poly(antimony ethylene glycoxide) and the tetrabutyl titanate are at a mass ratio of 1:0.25 to 1:0.85; and the condensation catalyst is added at 0.01 wt % to 0.06 wt % of the BHAT; and (2) aging the colloidal flame-retardant degradable PBAT polymer at 40° C. to 60° C., and allowing to stand for 1 h to 1.5 h to obtain the flame-retardant degradable adhesive tape bonding layer.

Description

The present application is a national stage application of International Patent Application No. PCT/CN2022/082481, filed on Mar. 23, 2022, which claims the benefit and priority to the Chinese Patent Application No. 202210271623.7, filed with the China National Intellectual Property Administration (CNIPA) on Mar. 18, 2022, and entitled “FLAME-RETARDANT DEGRADABLE ADHESIVE TAPE AND PREPARATION METHOD THEREOF”, which is incorporated herein by reference in its entirety. TECHNICAL FIELD The present disclosure belongs to the technical field of adhesive tapes, and relates to a flame-retardant degradable adhesive tape and a preparation method thereof. BACKGROUND With the rapid development of express delivery industry, a sharp increase in the consumption of packaging products has brought a huge burden to the society and environment. For example, the express business volume in China in 2018 reached 50.71 billion pieces, and a total of about 43 billion meters of packaging tape was consumed, which could circle the earth 1.077 times. At this stage, most of the adhesive tapes used in the industry are traditional biaxially-oriented polypropylene (BOPP) tapes. The raw materials of these tapes come from petroleum resources, which are non-renewable and are increasingly depleted with the increase in consumption. Moreover, this type of tape cannot be degraded within a short time after use. After completing the packaging mission, the materials used are directly turned into packaging waste. This not only exacerbates white pollution, but also increases a cost of recycling due to the separation of cartons and plastic tapes after packaging. Therefore, to achieve green and sustainable development of the express delivery industry, measures need to start from the source. The green development of packaging has received extensive attention, and degradable properties of the adhesive tapes also need further in-depth research. The biodegradable adhesive tape is still in an initial research stage, and there is still a certain distance from the commercialization of products based on same. The degradable adhesive tapes cannot completely replace the traditional BOPP tapes in terms of application performance, and also show a production cost much higher than that of the ordinary tapes, thus limiting promotion and application of the degradable adhesive tapes. An adhesive tape is mainly composed of two parts: a base layer and a bonding layer. The bonding layer is mainly prepare from polymers, and the polymers may be melted or decomposed into unstable flammable substances when being heated. Once encountering a spark, the adhesive tape burns and causes a fire. As a result, flame-retardant adhesive tapes have broad market application prospects. Various inorganic flame retardants such as aluminum hydroxide and zinc borate are cheap, non-volatile, desirable in thermal stability, and less harmful, and have an excellent smoke-suppression effect. However, these inorganic flame retardants are added in a large amount when being used to seriously affect a processing performance of the materials, and show extremely low flame retardancy. Halogenated flame retardants have a desirable flame retardant effect, and cause little influence on the performance of materials due to low volume of addition. However, this type of flame retardant is easy to release corrosive hydrogen halide gas and has a large amount of smoke during use. Phosphorus-based flame retardants have a low volume of addition, and produce phosphoric anhydride or phosphoric acid that is less harmful to the environment during combustion. In addition, the phosphorus-based flame retardants also show low toxicity, smoke generation, and halogen content, as well as high flame retardancy. Organic phosphorus-based flame retardants are suitable for polymerization reactions, and inorganic phosphorus-based flame retardants are generally used for blending. Flame retardant 2-carboxyethylphenylphosphinic acid (CEPPA) is an environmental-friendly reactive (copolymerization-typed) phosphorus-based flame retardant, which is suitable for permanent flame-retardant modification of polyesters. Moreover, the CEPPA is also a main-chain-type flame retardant, and has a phosphonate structure that can greatly reduce its glass-transition temperature (GTT) and improve its viscoelasticity. In this way, excellent pressure-sensitive properties are imparted to the polymers by CEPPA. As for conventional polyester pressure-sensitive adhesives (PSAs), their melting point and GTT are lowered by introducing a highly flexible polyether or long-chain polyol structure, thereby improving pressure-sensitive properties. Patent CN108003818A disclosed a heat-conducting and low-halogen flame-retardant PSA and a preparation method thereof. An acrylic monomer, an acrylate monomer, and an organic peroxide initiator are mixed to allow polymerization by heating to obtain a polyacrylate adhesive. The polyacrylate adhesive is mixed with a heat-conducting