WO2017166917A1

WO2017166917A1 - Self-lubricating coating for joint bearing and preparation method thereof

Info

Publication number: WO2017166917A1
Application number: PCT/CN2017/072325
Authority: WO
Inventors: 戴李宗; 吴顺伟; 曾碧榕; 朱继红; 李忠裕; 陈国荣
Original assignee: 厦门大学
Priority date: 2016-04-01
Filing date: 2017-01-24
Publication date: 2017-10-05
Also published as: CN105733408A; CN105733408B

Abstract

A self-lubricating coating for a joint bearing and a preparation method thereof. The coating comprises, in parts by mass: 40-60 parts of epoxy resin, 10-20 parts of a fluorine-containing epoxy resin, 30-50 parts of phenolic resin, 5-20 parts of a fluorine-containing dendritic macromolecule, 30-50 parts of a solvent, 1-3 parts of a silane coupling agent, 5-15 parts of a filler, 0.1-0.3 parts of an epoxy-resin curing-promoting agent, and 1-3 parts of a surfactant. The fluorine-containing dendritic macromolecule has a three-dimensional ordered structure with a large quantity of elemental fluorine introduced to the dendritic ends thereof. During friction, the three-dimensional ordered dendritic structure of the present invention functions as a micro-bearing, enabling self-lubrication of the coating.

Description

Self-lubricating coating for joint bearing and preparation method thereof

Technical field

The invention belongs to the technical field of coatings, and relates to a self-lubricating coating for joint bearings and a preparation thereof, in particular to a dendritic polymer self-lubricating coating and a preparation method thereof.

Background technique

Fabric-lined self-lubricating joint bearings are joint bearings that contain self-lubricating materials in the form of fabric liners between the inner and outer rings. They are widely used in aerospace, aerospace, electric power, transportation and textile equipment. The self-lubricating gasket between the inner and outer rings is bonded to the bearing metal ring by the adhesive. The wear phenomenon caused by the gasket during the use process will cause the inner and outer ring gaps to be too large, thus losing the normal lubricating ability. When the relevant mechanism is bite and stuck, the improvement of the wear resistance of the self-lubricating liner working surface is a hot research topic of the current self-lubricating gasket.

Dendrimers are a new type of polymer with three-dimensional structure and high order which has been developed in the past ten years. Among them, polyamide-amine dendrimer (PAMAM) is a mature research in dendrimer chemistry. Classes, with its simple synthesis, stable quality, unique structural properties, etc., have shown broad application prospects in many fields. In addition, PAMAM has a large number of cavities inside, which can encapsulate small molecular compounds and can be used under certain conditions. They are released again.

In the field of self-lubricating coatings, Ye Chunhui et al. (a heat-resistant and wear-resistant self-lubricating coating, Chinese patent, patent publication number CN103992726A) mixes epoxy resin and polyester resin, and adds a small amount of graphite, PTFE powder, Nano-materials such as quartz powder are prepared to obtain a self-lubricating coating, which can quickly remove the heat generated by friction and reduce the friction loss. However, the compatibility of the PTFE powder with the epoxy resin is poor, and the mechanical properties of the material are lowered. Zhang Qiu Ming et al (a self-lubricating epoxy resin material and its preparation method, Chinese patent, patent publication number CN101348600A), a lubricating oil capsule, an epoxy resin and a curing agent are uniformly mixed and molded to obtain a self-lubricating epoxy resin. material. This material can reduce the friction coefficient to a certain extent, but the lubricating oil capsule is unstable, the durability is poor, and the material can only be used now, and can not be stored for a long time, and the application is limited.

In the field of dendrimer curing agent, Su Jiangxun et al. (Preparation and properties of epoxy POSS/PAMAM hybrid materials, Fine Chemicals, 2011, Vol. 28, No. 8) with 3-glycidyloxypropyltrimethoxy Based on silane (EPTMS), octafunctional glycidyl ether-polyhedral oligomeric silsesquioxane (POSS-EP) was synthesized, and 4 generations of tree-terminated aminoamido-amine (PAMAM) was used as POSS-EP. A curing agent for an epoxy resin blend to prepare an epoxy POSS/PAMAM hybrid material having Excellent thermal and mechanical properties, but the curing temperature of the material is above 200 ° C, the curing time is long, the production cost is high, which is not conducive to industrial production, and the material does not have hydrophobic properties.

At present, the related work of preparing a self-lubricating epoxy phenolic coating using a fluorine-containing dendrimer has not been reported.

The invention provides a self-lubricating coating for a joint bearing and a preparation method thereof, the main feature is that a fluorine-containing dendrimer is added to the epoxy phenolic resin coating. The three-dimensional ordered structure of the fluorine-containing dendrimer can play the role of "micro-bearing" in the friction process, and improve the self-lubricating property of the material; in addition, the fluorine element is easy to migrate and the dendritic polymer is easy to form a film. The surface of the layer is easy to form a film, and the surface friction coefficient of the coating layer is lowered. In addition, the inorganic filler can be uniformly dispersed in the resin under the action of the silane coupling agent and the surfactant, and the disadvantage of the poor impact resistance of the conventional epoxy resin coating is solved.

Summary of the invention

The present invention aims to provide a coating material and a preparation method thereof for use in the field of self-lubricating joint bearings.

The main features of the preparation of the self-lubricating coating for joint bearings include:

(1) First, 30 to 50 parts of phenolic resin is dissolved in 30 to 50 parts of an organic solvent, and stirred for 0.5 to 1 hour to obtain a transparent solution; secondly, 40 to 60 parts of epoxy resin and 10 to 20 parts of fluorine-containing ring are added to the solution. Oxygen resin, after stirring for 0.5 to 1 hour, sequentially adding 5 to 20 parts of a fluorine-containing dendrimer, 1 to 3 parts of a silane coupling agent, 5 to 15 parts of an inorganic filler, 0.1 to 0.3 parts of an epoxy resin curing accelerator, and 1 to 3 parts of surfactant, stir for 2 to 3 hours, to obtain the required fluorine-containing self-lubricating coating compound.

(2) The fluorine-containing self-lubricating coating compound is scraped on the liner, and then the liner is pre-baked in a blast oven at 80-110 ° C for 0.5 to 1 h, and then bonded to the treated metal plate. Curing, curing conditions are 0.5 ~ 1MPa, 120 ~ 130 ° C for 0.5 ~ 1h pre-curing, and then heated to 160 ~ 180 ° C, heat for 1 ~ 3h.

The formulation of the self-lubricating coating is as follows: 40-60 parts of epoxy resin, 10-20 parts of fluorine-containing epoxy resin, 30-50 parts of phenolic resin, 5-20 parts of fluorine-containing dendrimer, solvent 30-50 The silane coupling agent is 1 to 3 parts, the filler is 5 to 15 parts, the epoxy resin curing accelerator is 0.1 to 0.3 parts, and the surfactant is 1 to 3 parts.

Preparation of the fluorine-containing dendrimer: 3.0-5.0 parts of PAMAM dendrimer is taken into a reaction vessel, and another fluorine-containing acrylate monomer is dissolved in methanol (molar ratio, PAMAM: fluorine-containing acrylate) Monomer = 1: (1 ~ 64)), then the fluoroacrylate monomer methanol solution is added dropwise to the reaction vessel, the temperature is controlled at 30 ~ 60 ° C, stirred under nitrogen for 20 ~ 30h, after reduction Pressure distillation to remove A The alcohol gives a fluorine-containing dendrimer.

The dendrimer is a polyamide-amine dendrimer.

The fluorine-containing monomer is a fluorine-containing acrylate monomer having a structural formula of CH ₂ =CRCO(CH ₂ ) _m C _n F _2n H (R is H or CH ₃ , m≥1, n≥1) ), such as hexafluorobutyl acrylate, dodecafluoroheptyl methacrylate, and the like.

The fluorine-containing epoxy resin structure is:

Wherein R ₁ and R ₂ are both CF ₃ or CF ₂ CF ₃ .

The epoxy resin is a commercial epoxy resin, that is, a compound containing two or more epoxy groups in the molecule, such as glycidyl ether, glycidylamine, glycidyl ester, etc.; wherein the glycidyl ether has a bisphenol A type , bisphenol F type, and bisphenol S type; glycidylamine has aniline glycidylamine, diaminodiphenylmethane tetraglycidylamine, etc.; glycidyl ester has diglycidyl pair (o) phthalate, etc. .

The silane coupling agent is a silane coupling agent of the formula Y(CH ₂ ) _n SiX ₃ wherein n=0 to 3; X is a chloro group, an acetoxy group or the like, and Y is an amino group or an epoxy group. .

The phenol resin is a thermosetting type and a thermoplastic phenol resin, and the phenol resin may be used singly or in combination.

The solvent is a solvent having a low boiling point, and includes ethyl acetate, ethanol, and acetone, and they may be used singly or in combination of two or more.

The filler is talc, kaolin, aluminum hydroxide, clay, silica, or the like, and the fillers may be used singly or in combination.

The epoxy resin accelerator is an amine accelerator such as benzyldimethylamine, triethylamine, triethanolamine, dimethylethanolamine or the like, and the accelerator may be used singly or in combination.

The surfactant has the structural formula R ₄ N ⁺ X ^- , wherein R may be the same or different hydrocarbon group, and X is mostly a halogen atom, or an acid group.

Compared with the prior art, the present invention has the following advantages:

1) The fluorine-containing dendrimer has a three-dimensional ordered structure, similar to a "sphere", which acts as a "micro-bearing" during the friction process to enhance the self-lubricating properties of the material;

2) The fluorine-containing dendrimer is easy to form a film, which increases the toughness of the coating and reduces the surface of the coating. Friction coefficient, enhance the wear resistance of the coating;

3) Fluorinated dendrimers use PAMAM's good compatibility to solve the problem of poor compatibility of fluorine elements, and the introduction of fluorine can reduce the friction coefficient of materials and enhance the heat resistance and weather resistance of materials.

4) The fluorine-containing dendrimer structure has an amino group which can react with the epoxy group to increase the crosslinking density of the material and improve the mechanical properties of the material.

DRAWINGS

Figure 1 is a diagram showing the action mechanism of a fluorine-containing dendrimer in a self-lubricating coating of a joint bearing.

detailed description

The present invention is further described below in conjunction with the accompanying drawings and embodiments:

Example 1:

(1) Preparation of fluorine-containing dendrimer: 10 parts of 5.0G PAMAM dendrimer was taken into a three-necked flask, and 15 parts of fluorine-containing acrylate monomer was dissolved in 20 parts of methanol, and then fluorine was added. The methanol solution of the acrylate monomer was dropwise added to a three-necked flask, the temperature was controlled at 35 ° C, and the reaction was stirred for 24 hours under nitrogen atmosphere, and then the methanol was removed under reduced pressure to obtain a fluorine-containing dendrimer.

(2) Preparation of self-lubricating coating:

1. Dissolve 40 parts of p-tert-butyl phenolic resin in 30 parts of ethyl acetate, stir for 0.5 h to obtain a transparent solution, then add 50 parts of epoxy resin and 8 parts of fluorine-containing epoxy resin to the solution, stir for 0.5 h. Then, 1 part of KH-560, 5 parts of talc, 1 part of kaolin, 0.1 part of triethanolamine, 1 part of cetyltrimethylammonium bromide and 5 parts of fluorine-containing dendrimer were added in order, and then rapidly stirred for 2 hours. Fluorine-containing self-lubricating coating compound required

2. The fluorine-containing self-lubricating coating compound is smeared on the liner, and then the liner is baked in a blast oven at 110 ° C for 0.5 to 1 h, and then bonded to the treated metal plate for curing. It was pre-cured at 0.5 MPa for 0.5 h at 130 ° C, then heated to 170 ° C and kept for 1.5 h. The friction and wear properties of the coating were tested by reciprocating oscillating friction and wear. The conditions were: normal temperature, the angle of oscillation was ±10°, the contact stress was 52 Mpa, the oscillation frequency was 2 Hz, and the number of consecutive oscillations per experiment was 2.5×104 times. The measured friction coefficient was 0.032, and the specific wear rate was 4.7 ± 1.3 (×10 ^-6 mm ³ /Nm).

Example 2:

(1) Preparation of fluorine-containing dendrimer: 8 parts of 5.0G PAMAM dendrimer to three-necked flask, 12 parts of fluorine-containing acrylate monomer dissolved in 20 parts of methanol, and then fluorine-containing Acrylate The monomeric methanol solution was added dropwise to a three-necked flask, the temperature was controlled at 40 ° C, and the reaction was stirred for 25 hours under nitrogen atmosphere, and then the methanol was removed under reduced pressure to obtain a fluorine-containing dendrimer.

(2) Preparation of self-lubricating coating:

1. Dissolve 30 parts of p-tert-butyl phenolic resin in 40 parts of ethyl acetate, stir for 1 hour to obtain a transparent solution, then add 50 parts of epoxy resin and 10 parts of fluorine-containing epoxy resin to the solution, and then stir for 1 hour. Add 1 part of KH-560, 4 parts of talc, 3 parts of kaolin, 0.1 part of triethanolamine, 1 part of cetyltrimethylammonium bromide and 10 parts of fluorine-containing dendrimer, and stir for 2 hours to obtain the required Fluorine-containing self-lubricating coating compound

2. The fluorine-containing self-lubricating coating compound is smeared on the liner, and then the liner is baked in a blast oven at 110 ° C for 1 h, and then bonded to the treated metal plate for curing, and the curing condition is 1 MPa. Under the preheating at 130 ° C for 0.5 h, then the temperature was raised to 170 ° C, and kept for 2 h. The friction and wear properties of the coating were tested by reciprocating oscillating friction and wear. The conditions were: normal temperature, the angle of oscillation was ±10°, the contact stress was 52 Mpa, the oscillation frequency was 2 Hz, and the number of consecutive oscillations per experiment was 2.5×104 times. The measured friction coefficient was 0.025, and the specific wear rate was 3.9 ± 1.5 (×10 ^-6 mm ³ /Nm).

Example 3:

(1) Preparation of fluorine-containing dendrimer: 13 parts of 3.0G PAMAM dendrimer to a three-necked flask, 18 parts of fluorine-containing acrylate monomer dissolved in 20 parts of methanol, and then fluorine-containing The methanol solution of the acrylate monomer was dropwise added to a three-necked flask, the temperature was controlled at 35 ° C, and the reaction was stirred for 24 hours under nitrogen atmosphere, and then the methanol was removed under reduced pressure to obtain a fluorine-containing dendrimer.

(2) Preparation of self-lubricating coating:

1. Dissolve 40 parts of p-tert-butyl phenolic resin in 30 parts of ethyl acetate, stir for 0.5 h to obtain a transparent solution, then add 60 parts of epoxy resin and 8 parts of fluorine-containing epoxy resin to the solution, and stir for 0.5 h. Then, 1 part of KH-560, 4 parts of talc, 5 parts of kaolin, 0.2 parts of triethanolamine, 1 part of cetyltrimethylammonium bromide and 5 parts of fluorine-containing dendrimer were added in sequence, and then rapidly stirred for 2 hours. Fluorine-containing self-lubricating coating compound required

2. The fluorine-containing self-lubricating coating compound is scraped on the liner, and then the liner is baked in a blast oven at 100 ° C for 0.5 h, and then bonded to the treated metal plate for curing. The curing condition is Pre-curing at 0.5 MPa for 0.5 h at 120 ° C, then heating to 175 ° C, and keeping warm for 1.5 h. The friction and wear properties of the coating were tested by reciprocating oscillating friction and wear. The conditions were: normal temperature, the angle of oscillation was ±10°, the contact stress was 52 Mpa, the oscillation frequency was 2 Hz, and the number of consecutive oscillations per experiment was 2.5×104 times. The measured friction coefficient was 0.030, and the specific wear rate was 4.8 ± 1.6 (×10 ^-6 mm ³ /Nm).

Example 4:

(1) Preparation of fluorine-containing dendrimer: 14 parts of 3.0G PAMAM dendrimer was taken into a three-necked flask, and another 15 parts of fluorine-containing acrylate monomer was dissolved in 30 parts of methanol, and then fluorine was added. The methanol solution of the acrylate monomer was added dropwise to a three-necked flask, the temperature was controlled at 40 ° C, and the reaction was stirred for 25 hours under nitrogen atmosphere, and then the methanol was removed under reduced pressure to obtain a fluorine-containing dendrimer.

(2) Preparation of self-lubricating coating:

1. Dissolve 40 parts of p-tert-butyl phenolic resin in 30 parts of ethyl acetate, stir for 1 hour to obtain a transparent solution, then add 60 parts of epoxy resin and 10 parts of fluorine-containing epoxy resin to the solution, and then stir for 1 hour. Add 1 part of KH-560, 8 parts of talc, 3 parts of kaolin, 0.2 parts of triethanolamine, 1 part of cetyltrimethylammonium bromide and 5 parts of fluorine-containing dendrimer, and stir for 2 hours to obtain the required Fluorine-containing self-lubricating coating compound

2. The fluorine-containing self-lubricating coating compound is scraped on the liner, and then the liner is baked in a blast oven at 100 ° C for 0.5 h, and then bonded to the treated metal plate for curing. The curing condition is Pre-curing at 0.5 MPa for 0.5 h at 120 ° C, then heating to 175 ° C, and keeping warm for 1.5 h. The friction and wear properties of the coating were tested by reciprocating oscillating friction and wear. The conditions were: normal temperature, the angle of oscillation was ±10°, the contact stress was 52 Mpa, the oscillation frequency was 2 Hz, and the number of consecutive oscillations per experiment was 2.5×104 times. The measured friction coefficient was 0.027, and the specific wear rate was 5.0 ± 1.5 (×10 ^-6 mm ³ /Nm).

Claims

A self-lubricating coating for a joint bearing, characterized in that the mass ratio is as follows: epoxy resin 40-60, fluorine-containing epoxy resin 10-20, phenolic resin 30-50, high fluorine-containing dendritic Molecules 5 to 20, solvents 30 to 50, silane coupling agents 1 to 3, fillers 5 to 15, epoxy resin curing accelerators 0.1 to 0.3, and surfactants 1 to 3.
A self-lubricating coating for a joint bearing according to claim 1, wherein said epoxy resin is a compound containing at least two epoxy groups in the molecule, and said epoxy resin may be selected from glycidol. One of an ether, a glycidylamine, and a glycidyl ester; the glycidyl ether may be one of bisphenol A glycidyl ether, bisphenol F glycidyl ether, and bisphenol S glycidyl ether; The glycidylamine may be selected from one of aniline glycidylamine and diaminodiphenylmethanetetraglycidylamine; the glycidyl ester may be diglycidyl (o) phthalate.
A self-lubricating coating for a joint bearing according to claim 1, wherein said fluorine-containing epoxy resin has the structural formula:

Wherein R 1 and R 2 are both CF 3 or CF 2 CF 3 .
A self-lubricating coating for a joint bearing according to claim 1, wherein said phenol resin is a thermosetting phenol resin or a thermoplastic phenol resin, and said phenol resin is selected from the group consisting of p-tert-butyl phenol resin. At least one of p-phenylphenol resin.
A self-lubricating coating for a joint bearing according to claim 1, wherein said fluorine-containing dendrimer is prepared by the following method:

Take 3 to 5 parts of PAMAM dendrimer to the reaction vessel, and further dissolve the fluorine-containing acrylate monomer in methanol, and then add the methanol solution of the fluorine-containing acrylate monomer to the container to control the temperature. After stirring at 30 to 60 ° C for 20 to 30 hours under nitrogen atmosphere, methanol is distilled off under reduced pressure to obtain a fluorine-containing dendrimer; molar ratio, PAMAM: fluorine-containing acrylate monomer = 1: (1 to 64); The dendrimer may be a polyamide-amine dendrimer;

The fluorine-containing acrylate monomer has a structural formula of CH 2 =CRCO(CH 2 ) m C n F 2n H, wherein R is H or CH 3 , m≥1, n≥1, the fluorine-containing acrylic acid The ester monomer may be selected from one of hexafluorobutyl acrylate and dodecafluoroheptyl methacrylate.
A self-lubricating coating for a joint bearing according to claim 1, wherein said solvent is a low boiling point solvent, and said solvent may be at least one selected from the group consisting of ethyl acetate, ethanol, and acetone.
A self-lubricating coating for a joint bearing according to claim 1, wherein said silane coupling agent employs a silane coupling agent of the formula Y(CH 2 ) n SiX 3 wherein n = 0 ～3; X is a chloro group or an acetoxy group, and Y is an amino group or an epoxy group;

The filler may be selected from at least one of talc, kaolin, aluminum hydroxide, clay, and silica.
A self-lubricating coating for a joint bearing according to claim 1, wherein said epoxy resin accelerator employs an amine accelerator, and said epoxy resin accelerator may be selected from benzyldimethylamine. At least one of triethylamine, triethanolamine, and dimethylethanolamine;

The surfactant has the structural formula R 4 N + X - , wherein R may be the same or different hydrocarbon group, and X is mostly a halogen atom, or an acid group.
A method of preparing a self-lubricating coating for a joint bearing according to claim 1, comprising the steps of:

1) Dissolving the phenolic resin in an organic solvent, stirring to obtain a transparent solution, adding an epoxy resin and a fluorine-containing epoxy resin to the transparent solution, and sequentially adding a fluorine-containing dendrimer, a silane coupling agent, and an inorganic filler after stirring. The epoxy resin curing accelerator and the surfactant are obtained, and the fluorine-containing self-lubricating coating compound is obtained after stirring;

2) The fluorine-containing self-lubricating coating compound obtained in the step 1) is scraped on the liner, and then the liner is dried and then bonded to the treated metal plate for curing, that is, used for the joint bearing. Self-lubricating coating.
A method for preparing a self-lubricating coating for a joint bearing according to claim 9, wherein in the step 2), the drying condition is that the liner is baked in a blast oven at 80 to 110 ° C. ~1h; the curing conditions can be pre-cured at 0.5 ~ 1MPa, 120 ~ 130 ° C for 0.5 ~ 1h, then raised to 160 ~ 180 ° C, and kept for 1-3h.