Method for nano-depth surface activation of ptfe-based membrane

Patent metadata

Field	Value
Publication number	US-2023257635-A1
Application number	US-202017785074-A
Country	US
Kind code	A1
Filing date	Dec 15, 2020
Priority date	Nov 5, 2020
Publication date	Aug 17, 2023
Grant date	—

Abstract

A method for nano-depth surface activation of a PTFE-based membrane and relates to the technical field of polymer composites is disclosed. The method comprises the following steps: covering a functional surface of a PTFE-based nano functional composite membrane, performing surface activation treatment on a single surface of the membrane to which a bonding adhesive is applied, and migrating and complexing a high-toughness cold bonding adhesive tape on the membrane surface, with an activated structure layer, of the PTFE-based nano functional composite membrane through a mechanical adhesive applying device to form an adhesive-membrane complex. An extremely strong affinity and a high-strength bonding performance are generated between the membrane and the adhesive, and the adhesive-membrane complex is formed. Integration of membrane/adhesive bonding complexing, membrane/membrane bonding complexing and membrane/adhesive layer bonding is realized.

First claim

1 . A method for nano-depth surface activation of a PTFE-based membrane, comprising the following steps:
covering a functional surface of a PTFE-based nano functional composite membrane with a nano-scale and micron-scale concave-convex geometrical ultra-micro-structure morphology, performing surface activation treatment in a vacuum environment and a nitrogen-hydrogen mixed medium atmosphere below 40° C. at a speed of 1.5-3 m/min on a single surface of the membrane to which a bonding adhesive is applied, and enabling the adhesive-applied surface of the membrane to generate a nano-depth activated structure layer; and migrating and complexing a high-toughness cold bonding adhesive tape on the membrane surface, with the activated structure layer, of the PTFE-based nano functional composite membrane through a mechanical adhesive applying device, and enabling a functional group of the adhesive and the activated structural layer of the membrane to be chemically bonded to form an adhesive-membrane complex; wherein, the high-toughness cold bonding adhesive tape is prepared by the following steps: adding 0.2 kg of PVA-1788, 18 kg of butyl acrylate, 0.5 kg of acrylic acid, 1.0 kg of vinyl acetate, 1.0 kg of methyl methacrylate, 1.5 kg of an organosilicone monomer, 0.01 kg of TO-7, 0.01 kg of sodium dodecylbenzenesulfonate, 0.05 kg of benzoyl peroxide and 80 kg of water into a preparation tank for preparation at a temperature of 85° C. for 5 h, vacuuming and removing water, obtaining a pressure-sensitive tape with a solid content of 18.7%, complexing the pressure-sensitive tape on a release paper and rolling the release paper on a PVC tube core.

2 . The method for nano-depth surface activation of a PTFE-based membrane according to claim 1 , wherein the PTFE-based nano functional composite membrane is covered by a PE membrane.

3 . The method for nano-depth surface activation of a PTFE-based membrane according to claim 1 , the PTFE-based nano functional composite membrane with a nano-scale and micron-scale concave-convex geometrical ultra-micro-structure morphology is prepared by the following steps:
(1) preparing a PTFE-based nano functional composite membrane by monomer fusion polymerization and micro-polymerization, wherein,
1) preparing a rod material by blending, pre-pressing and pushing
infiltrating a PTFE resin with silicone oil capable of softening PTFE, blending the infiltrated PTFE resin, and conducting hot pre-pressing and hot pushing at a temperature of 60-90° C., a speed of 20-30 m/min and a pressure of 5-8 MPa to obtain a monomer polymerized PTFE rod material with a surface lubricity;
2) preparing a membrane by fusion polymerization under hot calendaring
conducting fusion polymerization of the prepared PTFE rod material under hot calendering at a temperature of 60-90° C. and a speed of 20-30 m/min, extruding the silicone oil with a monomer polymerization effect blended in the PTFE resin out of a hot calender under a temperature action to obtain a PTFE-based nano functional composite membrane with micron-scale pores, and rolling into a roll; wherein under the actions of temperature and stretching of the hot calendering, the cracked membrane presents a fibrous structure after a laminar exfoliation; and a PTFE-based membrane with a micro-pored nano-scale and micron-scale concave-convex geometrical ultra-micro-structure morphology is formed, and has a thickness of 100-120 μm and a milky white color; and
3) preparing a homogeneous membrane by micro-polymerization
micro-polymerizing the PTFE-based nano functional composite membrane with a micron-scale micro-concave-convex surface structure in an oil-removing oven by the action of temperature at a temperature of 180-200° C., polymerizing and consolidating the silicone oil infiltrating the PTFE resin for the monomer polymerization and not squeezed completely by the hot calender under the action of temperature to obtain a PTFE-based homogenous membrane, and rolling the roll-shaped PTFE-based membrane in the oil-removing oven at a speed of 6-8 m/min; and (2) preparing a PTFE-based nano functional composite membrane by a high-temperature high-linear-pressure micro-eutectic method, wherein setting a temperature in a high-temperature high-linear-pressure micro-eutectic cavity at 70-420° C., putting the PTFE-based nano functional composite membrane forwards at a speed of 6-8 m/min, enabling membrane molecular chains to shrink and generate eutectic phases by the high temperature in the cavity and micro-pores to be nano-scale and ultra-micron-scale, controlling a linear pressure of a surface of the PTFE-based membrane to be 50-80 N/m, enabling the color of the membrane to change from milky white to transparent with uniform transparency, and maintaining an original nano-scale and micron-scale concave-convex geometrical ultra-micro-structure morphology of the PTFE-based nano functional composite membrane.

4 . The method for nano-depth surface activation of a PTFE-based membrane according to claim 3 , wherein the vinyl silicone oil and the PTFE resin are blended at a mass ratio of (2˜3):100.

5 . The method for nano-depth surface activation of a PTFE-based membrane according to claim 4 , the PTFE-based nano functional composite membrane with a nano-scale and micron-scale concave-convex geometrical ultra-micro-structure morphology is prepared by the following steps:
(1) preparing a PTFE-based nano functional composite membrane by monomer fusion polymerization and micro-polymerization, wherein,
1) preparing a rod material by blending, pre-pressing and pushing
infiltrating a PTFE resin with silicone oil capable of softening PTFE with a mass ratio of the vinyl silicone oil and the PTFE resin at 2.5:100, blending the infiltrated PTFE resin, and conducting hot pre-pressing and hot pushing at a temperature of 60° C., a speed of 25 m/min and a pressure of 8 MPa to obtain a monomer polymerized PTFE rod material with a diameter of 17 mm and a surface lubricity;
2) preparing a membrane by fusion polymerization under hot calendaring
conducting fusion polymerization of the prepared PTFE rod material under hot calendering at a temperature of 60° C. and a speed of 25 m/min, extruding the silicone oil with a monomer polymerization effect blended in the PTFE resin out of a hot calender under a temperature action to obtain a PTFE-based nano functional composite membrane with micron-scale pores, and rolling into a roll; wherein under the actions of temperature and stretching of the hot calendering, the cracked membrane presents a fibrous structure after a laminar exfoliation; and a PTFE-based membrane with a micro-pored nano-scale and micron-scale concave-convex geometrical ultra-micro-structure morphology is formed, and has a thickness of 100 μm and a milky white color; and
3) preparing a homogeneous membrane by micro-polymerization
micro-polymerizing the PTFE-based nano functional composite membrane with a micron-scale micro-concave-convex surface structure in an oil-removing oven by the action of temperature at a temperature of 200° C., polymerizing and consolidating the silicone oil infiltrating the PTFE resin for the monomer polymerization and not squeezed completely by the hot calender under the action of temperature to obtain a PTFE-based homogenous membrane, and rolling the roll-shaped PTFE-based membrane in the oil-removing oven at a speed of 6 m/min; and (2) preparing a PTFE-based nano functional composite membrane by a high-temperature high-linear-pressure micro-eutectic method, wherein, setting a temperature in a high-temperature high-linear-pressure micro-eutectic cavity at 380° C., putting the PTFE-based nano functional composite membrane forwards at a speed of 6 m/min, enabling membrane molecular chains to shrink and generate eutectic phases by the high temperature in the cavit

Assignees

• China Three Gorges Corp
• China Three Gorges Renewables Group Co Ltd
• Nanjing Haohui Hi Tech Co Ltd

Inventors

• Liu Jianping
• Xiang Xin
• Wu Jianhua
• Zhu Yawei
• Zhao Jingxin
• Li Wenwei
• Shuai Zhengfeng
• Wu Hong
• Wu Jianping
• Zhao Fangliang

Classifications

• B29C43/24 Primary

  Calendering · CPC title

• B29C59/005

  characterised by the choice of material · CPC title

• B29C69/02

  of moulding techniques only · CPC title

• C09J7/24 Primary

  based on macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds · CPC title

• C09J7/385

  Acrylic polymers · CPC title