CN109054625B - Composite polyimide film for air bearing and preparation method thereof - Google Patents
Composite polyimide film for air bearing and preparation method thereof Download PDFInfo
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- CN109054625B CN109054625B CN201810801050.8A CN201810801050A CN109054625B CN 109054625 B CN109054625 B CN 109054625B CN 201810801050 A CN201810801050 A CN 201810801050A CN 109054625 B CN109054625 B CN 109054625B
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D179/00—Coating compositions based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen, with or without oxygen, or carbon only, not provided for in groups C09D161/00 - C09D177/00
- C09D179/04—Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors
- C09D179/08—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
- C09D5/08—Anti-corrosive paints
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
- C09D7/20—Diluents or solvents
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/18—Oxygen-containing compounds, e.g. metal carbonyls
- C08K3/20—Oxides; Hydroxides
- C08K3/22—Oxides; Hydroxides of metals
- C08K2003/2234—Oxides; Hydroxides of metals of lead
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/18—Oxygen-containing compounds, e.g. metal carbonyls
- C08K3/20—Oxides; Hydroxides
- C08K3/22—Oxides; Hydroxides of metals
- C08K2003/2244—Oxides; Hydroxides of metals of zirconium
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/38—Boron-containing compounds
- C08K2003/382—Boron-containing compounds and nitrogen
- C08K2003/385—Binary compounds of nitrogen with boron
Abstract
The invention discloses a composite polyimide film for an air bearing, which consists of a component A and a mixed organic solvent; the component A comprises, by weight, 40-65 parts of polyamide acid resin, 25-35 parts of polytetrafluoroethylene, 1-3 parts of rare earth fluoride, 0.5-2 parts of lead oxide, 0.5-1 part of boron nitride, 0.5-1 part of zirconium oxide and 0.01-1 part of surfactant; the addition amount of the mixed organic solvent is 1-1.5 times of the weight of the component A. The invention also discloses a preparation method of the film. The film disclosed by the invention has the performances of high hardness, low friction coefficient, long wear-resisting life and the like.
Description
Technical Field
The invention belongs to the technical field of materials, and relates to a composite polyimide film for an air bearing and a preparation method thereof.
Background
The polyimide is basically characterized by high temperature resistance, corrosion resistance, radiation resistance, water resistance and the like, and has good environmental resistance. Research shows that the polyimide material has high mechanical strength and chemical stability, and can meet the requirements on material performance in various harsh environments. In recent years, the mechanical theory, the preparation technology, the structural analysis means and the like of the polyimide and the composite material thereof are gradually improved and advanced, and the polyimide and the composite material thereof are widely applied. Wherein the thermosetting polyimide has important application in the fields of aviation, ships and warships and other heavy industries. Thermoplastic polyimide has more outstanding impact resistance, fatigue resistance and aging resistance, and more attention is paid to the thermoplastic polyimide.
A gas bearing is a sliding bearing that uses gas as a lubricant. Also known as hydrostatic air bearings. It is a new technology developed along with the development of new scientific technologies such as atomic energy, aerospace technology, microelectronics, information technology and bioengineering. Compared with the traditional rolling bearing or oil film lubrication bearing, the gas lubrication technology is gradually accepted by the majority of people as a high-efficiency and energy-saving lubrication scheme by virtue of the superiorities of high rotating speed, no pollution, no temperature use limit and the like. At present, a static pressure air bearing usually adopts a straddle type combined support technology to meet application requirements, but the support technology has a series of inherent problems such as complex air supply adjustment, non-compact structure and the like, and the use effect of the support technology is restricted. In precision machines, certain rotor components require extremely high speeds of movement and require frequent speed changes, which require precise fit between the stator and rotor. These factors determine that certain lubrication measures are required for the matching surfaces of the rotor, and film lubrication, mixed lubrication, jet lubrication and the like are preferred at present.
Disclosure of Invention
The invention aims to provide a composite polyimide film for an air bearing and a preparation method thereof.
The composite polyimide film for the air bearing can well solve the problem of friction and collision between a shaft and a shaft neck caused by airflow instability of the air bearing. When the bearing runs, the existence of the composite polyimide film enables a transfer film with uniform and better adhesive force to be formed on the mating surface in the friction process, thereby playing the roles of antifriction and wear resistance and achieving the role of protecting the friction and collision between the shaft and the journal of the air bearing.
The film consists of a binder, a solid lubricant, an anticorrosive additive, a wear-resistant additive, a surfactant and a dispersion medium; the binder is polyamide acid resin; the solid lubricant is polytetrafluoroethylene; rare earth fluoride is used as an anticorrosive additive; lead oxide, boron nitride and zirconium oxide are wear-resistant additives; one or more of cetyl trimethyl ammonium bromide and fluorocarbon surfactant are surfactants; the dispersion medium is selected from mixed organic solvents.
A composite polyimide film for an air bearing is characterized in that the film consists of a component A and a mixed organic solvent; the component A comprises, by weight, 40-65 parts of polyamide acid resin, 25-35 parts of polytetrafluoroethylene, 1-3 parts of rare earth fluoride, 0.5-2 parts of lead oxide, 0.5-1 part of boron nitride, 0.5-1 part of zirconium oxide and 0.01-1 part of surfactant; the addition amount of the mixed organic solvent is 1-1.5 times of the weight of the component A.
The structural formula of the polyamic acid resin is as follows:
wherein R represents a methylene group, and n is an integer of 20 to 30.
The purity of the polytetrafluoroethylene is more than 98%, and the particle size is less than 5 microns.
The rare earth fluoride is one or more of lanthanum fluoride and cerium fluoride, and the particle size is less than 5 microns.
The particle sizes of the lead oxide, the boron nitride and the zirconium oxide are all less than 5 microns.
The surfactant is one or two of cetyl trimethyl ammonium bromide and fluorocarbon surfactant.
The mixed organic solvent is one or more of N, N-dimethylformamide, N-dimethylacetamide and xylene.
The thickness of the film is 20-50 microns.
The preparation method of the composite polyimide film for the air bearing is characterized by comprising the following specific steps:
1) grinding the polyamide acid resin, polytetrafluoroethylene and the mixed organic solvent, adding rare earth fluoride, lead oxide, boron nitride, zirconium oxide, a surfactant and the mixed organic solvent, uniformly mixing, and performing ball milling to obtain the coating;
2) spraying the prepared coating on the surface of the part subjected to surface treatment under the condition of compressed air (oil-free and water-free) or compressed nitrogen by using a spray gun at the pressure of 0.1-0.3 Mpa; placing the sprayed part in clean air at room temperature for 5-30 minutes, and then placing the part in an oven for curing; the curing conditions are as follows: keeping the temperature of 100 +/-30 ℃ for 30-90 minutes, keeping the temperature of 200 +/-30 ℃ for 30-90 minutes, keeping the temperature of 300 +/-30 ℃ for 150-200 minutes, and cooling to room temperature along with the furnace; the temperature of the parts is 50-70 ℃ during spraying.
The surface of the part needs to be subjected to surface treatment such as sand blasting, oil removal, rust removal, phosphorization and the like in advance.
The binder selected by the invention is high-temperature resistant polyamic acid resin, so that the wear resistance and the temperature resistance are fully ensured; the selected lubricant is polytetrafluoroethylene, and the polytetrafluoroethylene has better matching property with a resin matrix and stability to irradiation, so that the wear resistance and the friction reduction performance of the coating are improved; the selected anti-corrosion additive is rare earth fluoride, can perform chemical reaction and physical reaction with the surface of the part, improves the binding force between the coating and the surface of the part, and is adsorbed on the surface of the lubricant to improve the anti-corrosion performance of the coating; the mixed organic solvent can make the polyamic acid resin fully dissolved in the solvent.
The main performance indexes of the polyimide film of the invention are as follows.
The film disclosed by the invention has the performances of high hardness, low friction coefficient, long wear-resisting life and the like.
Detailed Description
Example 1:
weighing 100g of polyamide acid resin and 27g of polytetrafluoroethylene, adding 100g of mixed organic solvent, grinding and dispersing by a conical mill, pouring into a ball milling tank, adding 1.5g of cerium fluoride, 0.9g of lead oxide, 0.8g of boron nitride, 0.5g of zirconium oxide, 0.6g of fluorocarbon surfactant and 80g of mixed organic solvent, and carrying out ball milling for 24 hours to obtain uniformly dispersed mixed paint [ mixed organic solvent: 30% of N, N-dimethylformamide and 70% of N, N-dimethylacetamide (volume percentage). Placing the workpiece to be subjected to film spraying at 60 ℃ for 30min, spraying the prepared coating on the surface of the workpiece by using a spray gun under the gas pressure of 0.2MPa, and placing the sprayed workpiece at room temperature for 15 min. Then putting the mixture into an oven for curing, wherein the curing conditions are as follows: keeping the temperature at 100 ℃ for 60 minutes, keeping the temperature at 200 ℃ for 60 minutes, keeping the temperature at 300 ℃ for 180 minutes, and naturally cooling the workpiece in an oven to room temperature.
Example 2:
weighing 100g of polyamide acid resin and 26g of polytetrafluoroethylene, adding 100g of mixed organic solvent, grinding and dispersing by a conical mill, pouring into a ball milling tank, adding 1.4g of lanthanum fluoride, 0.8g of lead oxide, 0.8g of boron nitride, 0.5g of zirconium oxide and 0.6g of fluorocarbon surfactant, adding 80g of mixed organic solvent, and carrying out ball milling for 24 hours to obtain uniformly dispersed mixed paint [ mixed organic solvent: 40% of N, N-dimethylformamide and 60% of N, N-dimethylacetamide (volume percentage). Placing the workpiece to be subjected to film spraying at 60 ℃ for 30min, spraying the prepared coating on the surface of the workpiece by using a spray gun under the gas pressure of 0.2MPa, and placing the sprayed workpiece at room temperature for 15 min. Then putting the mixture into an oven for curing, wherein the curing conditions are as follows: keeping the temperature at 100 ℃ for 60 minutes, keeping the temperature at 200 ℃ for 60 minutes, keeping the temperature at 300 ℃ for 180 minutes, and naturally cooling the workpiece in an oven to room temperature.
Example 3:
weighing 100g of polyamide acid resin and 26g of polytetrafluoroethylene, adding 100g of mixed organic solvent, grinding and dispersing by a conical mill, pouring into a ball milling tank, adding 0.8g of cerium fluoride, 0.7g of lanthanum fluoride, 0.8g of lead oxide, 0.7g of boron nitride, 0.5g of zirconium oxide, 0.4g of fluorocarbon surfactant and 0.3g of hexadecyl trimethyl ammonium bromide, and carrying out ball milling for 24 hours to obtain uniformly dispersed mixed paint [ mixed organic solvent: 20% of N, N-dimethylformamide, 60% of N, N-dimethylacetamide and 20% of xylene (volume percentage composition). Placing the workpiece to be subjected to film spraying at 60 ℃ for 30min, spraying the prepared coating on the surface of the workpiece by using a spray gun under the gas pressure of 0.2MPa, and placing the sprayed workpiece at room temperature for 15 min. Then putting the mixture into an oven for curing, wherein the curing conditions are as follows: keeping the temperature at 100 ℃ for 60 minutes, keeping the temperature at 200 ℃ for 60 minutes, keeping the temperature at 300 ℃ for 180 minutes, and naturally cooling the workpiece in an oven to room temperature.
Claims (7)
1. A composite polyimide film for an air bearing is characterized in that the film consists of a component A and a mixed organic solvent; the component A comprises, by weight, 40-65 parts of polyamide acid resin, 25-35 parts of polytetrafluoroethylene, 1-3 parts of rare earth fluoride, 0.5-2 parts of lead oxide, 0.5-1 part of boron nitride, 0.5-1 part of zirconium oxide and 0.01-1 part of surfactant; the adding amount of the mixed organic solvent is 1-1.5 times of the weight of the component A; the structural formula of the polyamic acid resin is as follows:
the preparation method comprises the following steps:
1) grinding the polyamide acid resin, polytetrafluoroethylene and the mixed organic solvent, adding rare earth fluoride, lead oxide, boron nitride, zirconium oxide, a surfactant and the mixed organic solvent, uniformly mixing, and performing ball milling to obtain the coating;
2) spraying the prepared coating on the surface of the part subjected to surface treatment under the condition of compressed air or compressed nitrogen by using a spray gun at the pressure of 0.1-0.3 MPa; placing the sprayed part in clean air at room temperature for 5-30 minutes, and then placing the part in an oven for curing; the curing conditions are as follows: keeping the temperature of 100 +/-30 ℃ for 30-90 minutes, keeping the temperature of 200 +/-30 ℃ for 30-90 minutes, keeping the temperature of 300 +/-30 ℃ for 150-200 minutes, and cooling to room temperature along with the furnace; the temperature of the parts is 50-70 ℃ during spraying.
2. The film of claim 1 wherein said polytetrafluoroethylene has a purity greater than 98% and a particle size of less than 5 microns; the particle sizes of the lead oxide, the boron nitride and the zirconium oxide are all less than 5 microns.
3. The film of claim 1, wherein the rare earth fluoride is one or more of lanthanum fluoride and cerium fluoride, and the particle size is less than 5 μm.
4. The film of claim 1, wherein the surfactant is one or both of cetyltrimethylammonium bromide, a fluorocarbon surfactant.
5. The film according to claim 1, wherein the mixed organic solvent is one or more of N, N-dimethylformamide, N-dimethylacetamide and xylene.
6. The film of claim 1, wherein said film has a thickness of 20 to 50 microns.
7. The membrane of claim 1 wherein said compressed air is oil-free and water-free.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN201810801050.8A CN109054625B (en) | 2018-07-20 | 2018-07-20 | Composite polyimide film for air bearing and preparation method thereof |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201810801050.8A CN109054625B (en) | 2018-07-20 | 2018-07-20 | Composite polyimide film for air bearing and preparation method thereof |
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| CN109054625A CN109054625A (en) | 2018-12-21 |
| CN109054625B true CN109054625B (en) | 2020-09-08 |
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Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN110894856A (en) * | 2019-09-29 | 2020-03-20 | 浙江中达精密部件股份有限公司 | Sliding bearing with polyimide sliding layer |
| CN112058611A (en) * | 2020-09-08 | 2020-12-11 | 中国科学院兰州化学物理研究所 | Method for processing engine shaft sleeve by adopting laser texturing |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1421501A (en) * | 2002-12-19 | 2003-06-04 | 中国科学院兰州化学物理研究所 | Antiwear lubricating paint for engine piston ring |
| CN1422902A (en) * | 2002-12-20 | 2003-06-11 | 鞍山市金钢碳纤维复合材料有限公司 | Polymer high-temperature unlubricated bearing material |
| CN1772812A (en) * | 2005-11-17 | 2006-05-17 | 复旦大学 | Reinforced toughened antiwear composite polyimide material |
| CN102250544A (en) * | 2010-05-18 | 2011-11-23 | 中国科学院兰州化学物理研究所 | Lubricating coating with low friction and long service life |
| CN102947088A (en) * | 2010-06-23 | 2013-02-27 | Asml控股股份有限公司 | Pneumatic bearing with bonded polymer film wear surface and production method thereof |
| EP2592290A1 (en) * | 2011-11-09 | 2013-05-15 | MAHLE International GmbH | Multi-layer sliding bearing |
| CN105684560A (en) * | 2014-09-30 | 2016-06-15 | 株式会社Lg化学 | Ductile metal laminate and method of manufacturing same |
| CN106957503A (en) * | 2017-03-20 | 2017-07-18 | 燕山大学 | Polytetrafluoroethylene (PTFE)/Polyimide/Nano silica self-lubricating material and preparation method thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20120097194A1 (en) * | 2002-09-09 | 2012-04-26 | Reactive Surfaces, Ltd. | Polymeric Coatings Incorporating Bioactive Enzymes for Catalytic Function |
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- 2018-07-20 CN CN201810801050.8A patent/CN109054625B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1421501A (en) * | 2002-12-19 | 2003-06-04 | 中国科学院兰州化学物理研究所 | Antiwear lubricating paint for engine piston ring |
| CN1422902A (en) * | 2002-12-20 | 2003-06-11 | 鞍山市金钢碳纤维复合材料有限公司 | Polymer high-temperature unlubricated bearing material |
| CN1772812A (en) * | 2005-11-17 | 2006-05-17 | 复旦大学 | Reinforced toughened antiwear composite polyimide material |
| CN102250544A (en) * | 2010-05-18 | 2011-11-23 | 中国科学院兰州化学物理研究所 | Lubricating coating with low friction and long service life |
| CN102947088A (en) * | 2010-06-23 | 2013-02-27 | Asml控股股份有限公司 | Pneumatic bearing with bonded polymer film wear surface and production method thereof |
| EP2592290A1 (en) * | 2011-11-09 | 2013-05-15 | MAHLE International GmbH | Multi-layer sliding bearing |
| CN105684560A (en) * | 2014-09-30 | 2016-06-15 | 株式会社Lg化学 | Ductile metal laminate and method of manufacturing same |
| CN106957503A (en) * | 2017-03-20 | 2017-07-18 | 燕山大学 | Polytetrafluoroethylene (PTFE)/Polyimide/Nano silica self-lubricating material and preparation method thereof |
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