阅读说明：本技术 一种特氟龙涂料及其制备工艺和应用 (Teflon coating and preparation process and application thereof ) 是由 秦景芳 于 2021-02-22 设计创作，主要内容包括：本发明属于涂料技术领域,尤其涉及一种特氟龙涂料及其制备工艺和应用。所述特氟龙涂料的制备原料至少包括聚四氟乙烯、聚酰胺酰亚胺、填料；具体来说,按重量份计,至少包括聚四氟乙烯50～60份、聚酰胺酰亚胺30～40份、填料1～10份、分散剂1～2份、流平剂1～3份、有机溶剂80～120份。(The invention belongs to the technical field of coatings, and particularly relates to a Teflon coating and a preparation process and application thereof. The raw materials for preparing the Teflon coating at least comprise polytetrafluoroethylene, polyamide-imide and a filler; specifically, the coating at least comprises 50-60 parts by weight of polytetrafluoroethylene, 30-40 parts by weight of polyamide-imide, 1-10 parts by weight of filler, 1-2 parts by weight of dispersant, 1-3 parts by weight of flatting agent and 80-120 parts by weight of organic solvent.)

1. A Teflon coating is characterized in that: the preparation raw materials at least comprise polytetrafluoroethylene, polyamide-imide and filler.

2. A teflon coating according to claim 1, characterized in that: the preparation raw materials also comprise a dispersing agent and a flatting agent.

3. A teflon coating according to claim 2, characterized in that: the Teflon coating at least comprises, by weight, 50-60 parts of polytetrafluoroethylene, 30-40 parts of polyamide imide, 1-10 parts of a filler, 1-2 parts of a dispersing agent, 1-3 parts of a flatting agent and 80-120 parts of an organic solvent.

4. A teflon coating according to claim 3, characterized in that: the polytetrafluoroethylene comprises a mixture of polytetrafluoroethylene micro powder and polytetrafluoroethylene emulsion, and the weight ratio of the polytetrafluoroethylene micro powder to the polytetrafluoroethylene emulsion is (2-4) to 1.

5. A teflon coating according to claim 3, characterized in that: the filler comprises at least one of carbon black, graphite, graphene oxide, carbon nanotubes and molybdenum disulfide.

6. A Teflon coating according to claim 5, wherein: the filler is carbon black, and the average particle size of the carbon black is 5-20 nm.

7. A teflon coating according to claim 3, characterized in that: the polyamide imide is at least one selected from Torlon AI-10PAI powder and BLPF25PAI powder.

8. A Teflon coating according to claim 7, wherein: the weight ratio of the polytetrafluoroethylene to the polyamide imide is (1.3-1.7): 1.

9. A process for preparing a Teflon coating according to any one of claims 1 to 8, wherein the process comprises at least the following steps: adding the preparation raw materials into a reactor according to the formula, shearing, stirring and dispersing uniformly, and filtering by using filter cloth to obtain the Teflon coating.

10. The application of the Teflon coating is characterized in that: the Teflon coating of any one of claims 1 to 8 is used for brake calipers and brake pad guide rail clips.

Technical Field

The invention belongs to the technical field of coatings, and particularly relates to a Teflon coating and a preparation process and application thereof.

Background

The Teflon coating has the characteristics of small surface tension, oil stain resistance, corrosion resistance, wide use temperature range, outstanding non-adhesiveness, good thermal stability, excellent aging resistance and radiation resistance and the like, and is widely applied to various industries.

The long-term placement of the driver or environmental factors causes the corrosion of the combined parts and the generation of noise during sliding after the fixation phenomenon. In addition, some components of the actuator increase sliding resistance due to wear after a long time use, thereby affecting normal functions and decreasing useful life.

Disclosure of Invention

In order to solve the problems, the invention provides a Teflon coating, and the preparation raw materials at least comprise polytetrafluoroethylene, polyamide-imide and a filler.

As a preferable technical scheme, the preparation raw material also comprises a dispersing agent and a leveling agent.

As a preferred technical scheme, the Teflon coating at least comprises 50-60 parts by weight of polytetrafluoroethylene, 30-40 parts by weight of polyamide-imide, 1-10 parts by weight of filler, 1-2 parts by weight of dispersant, 1-3 parts by weight of leveling agent and 80-120 parts by weight of organic solvent.

As a preferable technical scheme, the polytetrafluoroethylene comprises a mixture of polytetrafluoroethylene micro powder and polytetrafluoroethylene emulsion, and the weight ratio is (2-4): 1.

As a preferred technical solution, the filler includes at least one of carbon black, graphite, graphene oxide, carbon nanotubes, and molybdenum disulfide.

As a preferable technical scheme, the filler is carbon black, and the average particle size of the carbon black is 5-20 nm.

As a preferred technical scheme, the polyamide imide is selected from at least one of Torlon AI-10PAI powder and BLPF25PAI powder.

As a preferable technical scheme, the weight ratio of the polytetrafluoroethylene to the polyamide imide is (1.3-1.7): 1.

The second aspect of the invention provides a preparation process of a teflon coating, which at least comprises the following steps: adding the preparation raw materials into a reactor according to the formula, shearing, stirring and dispersing uniformly, and filtering by using filter cloth to obtain the Teflon coating.

The third aspect of the invention provides application of a Teflon coating for brake calipers and brake pad guide rail shrapnel.

Has the advantages that:

according to the Teflon coating provided by the invention, the smoothness, high temperature resistance, acid and alkali resistance of the Teflon coating are further improved by mixing the specific polytetrafluoroethylene and the polyamide imide. In addition, carbon black with the average particle size of 5-20 nm and other auxiliary agents are combined, under the action of oxygen-containing groups in the polyamide imide, the wettability of the carbon black in the coating is improved, the viscosity is reduced by improving the wettability, and the viscosity is improved by oil absorption, so that the viscosity of the coating is improved, the coating is better combined with a sprayed object, and the performance after spraying is further improved. The brake block guide rail elastic sheet sprayed by the Teflon coating has very good lubricity, wear resistance and corrosion resistance.

Drawings

FIG. 1 is a 1000 hour salt fog test photograph of a brake shoe guide rail spring made of Teflon coating prepared in example 1;

figure 2 is a photograph of a 600 hour salt fog test of a brake shoe rail clip without teflon paint.

Detailed Description

The invention will be further understood by reference to the following detailed description of preferred embodiments of the invention and the examples included therein. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. To the extent that a definition of a particular term disclosed in the prior art is inconsistent with any definition provided in the present disclosure, the definition of the term provided in the present disclosure controls.

As used herein, a feature that does not define a singular or plural form is also intended to include a plural form of the feature unless the context clearly indicates otherwise. It will be further understood that the term "prepared from …," as used herein, is synonymous with "comprising," including, "comprising," "having," "including," and/or "containing," when used in this specification means that the recited composition, step, method, article, or device is present, but does not preclude the presence or addition of one or more other compositions, steps, methods, articles, or devices. Furthermore, the use of "preferred," "preferably," "more preferred," etc., when describing embodiments of the present invention, is meant to refer to embodiments of the invention that may provide certain benefits, under certain circumstances. However, other embodiments may be preferred, under the same or other circumstances. In addition, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of the invention.

In order to solve the problems, the invention provides a teflon coating in a first aspect, and the preparation raw materials at least comprise polytetrafluoroethylene, polyamide-imide and a filler.

Polytetrafluoroethylene (PTFE) is a high molecular weight polymer made by polymerization of tetrafluoroethylene as a monomer. Has the characteristics of resisting acid, resisting alkali and various organic solvents, and is almost insoluble in all solvents. Meanwhile, the polytetrafluoroethylene has the characteristics of high temperature resistance and high lubrication, and the friction coefficient of the polytetrafluoroethylene is extremely low.

Polyamideimide (PAI) is a polyimide containing amide bonds in the molecular chain, and is a modified species developed by amomo corporation, usa, for improving the processability of polyimide. The polyamide-imide has the characteristics of high temperature resistance, impact resistance, solvent resistance, irradiation resistance, good creep resistance and the like. In particular, the product has excellent wear resistance and easy processing formability. In addition, the polyamideimide contains both an amide bond and an imide bond. The amido bond endows the polyamide-imide coating with good flexibility, and the imide ring endows the polyamide-imide coating with good heat resistance.

In order to further improve the smoothness, high temperature resistance, acid and alkali resistance of the Teflon coating, the Teflon coating is prepared by mixing polytetrafluoroethylene and polyamide-imide.

In some preferred embodiments, the raw materials for preparing the teflon coating also comprise a dispersing agent and a leveling agent.

In some preferred embodiments, the raw materials for preparing the teflon coating at least comprise, by weight, 50-60 parts of polytetrafluoroethylene, 30-40 parts of polyamide-imide, 1-10 parts of filler, 1-2 parts of dispersant, 1-3 parts of leveling agent and 80-120 parts of organic solvent.

In some preferred embodiments, the polytetrafluoroethylene comprises at least one of polytetrafluoroethylene resin, polytetrafluoroethylene micropowder, and polytetrafluoroethylene emulsion.

In some preferred embodiments, the polytetrafluoroethylene comprises a mixture of polytetrafluoroethylene micropowder and polytetrafluoroethylene emulsion in a weight ratio of (1-3): 1.

In some preferred embodiments, the polytetrafluoroethylene micropowder has an average particle size of less than 15 μm.

In some preferred embodiments, the polytetrafluoroethylene emulsion has a solids content of 50-70%.

In some preferred embodiments, the filler comprises at least one of carbon black, graphite, graphene oxide, carbon nanotubes, molybdenum disulfide.

In order to improve the glossiness of the coating, in some preferred embodiments, the filler is carbon black, and in order to improve the viscosity of the coating and enable the coating to be more easily combined with a sprayed object, the average particle size of the carbon black is 5-20 nm. The applicant has found that, surprisingly, when the average particle size of the carbon black is too small, the oil absorption of the carbon black is increased, which increases the viscosity of the coating, is not beneficial to leveling property, and is easy to generate larger internal stress after curing, easy to crack and poor in adhesion. However, if the particle size of the carbon black is too large, uniform dispersion of the carbon black in the coating system is not facilitated. When the average particle size of the carbon black is 5-20 nm, the carbon black has good dispersibility and better viscosity. The applicant speculates that the carbon black has an average particle size of 5-20 nm, and the wettability of the carbon black in the coating is improved under the action of an oxygen-containing group in the polyamide imide, the viscosity is reduced by the wettability improvement, and the viscosity is improved by the oil absorption, so that the viscosity of the coating is improved, the coating is better combined with a sprayed object, and the performance after spraying is further improved. In addition, the particle size of the carbon black affects the light reflection and thus the hue of the coating. A too small particle size gives a bluish hue, while a too large particle size gives a brown hue. More preferably, the carbon black has an average particle diameter of 8 to 15 nm.

In some preferred embodiments, the polyamideimide includes at least one of a polyamideimide resin, a polyamideimide powder, and a polyamideimide dispersion.

In some preferred embodiments, the polyamideimide is selected from at least one of Torlon AI-10PAI powder and BLPF25PAI powder.

In some preferred embodiments, the weight ratio of polytetrafluoroethylene to polyamideimide is (1.3-1.7): 1.

In some preferred embodiments, the dispersant comprises at least one of TEGODispers 656, 670, 685 and 688.

In some preferred embodiments, the leveling agent includes at least one of an organic silicon type leveling agent, an acrylic type leveling agent, and a fluorine type leveling agent. More preferably a fluorine-based leveling agent, such as a molar energy chemical grade 1154 leveling agent.

In some preferred embodiments, the organic solvent comprises at least one of ethanol, propanol, n-butanol, xylene, trimethylbenzene, methyl isobutyl ketone.

In some preferred embodiments, the organic solvent comprises a mixture of n-butanol and xylene in a weight ratio of (2-4): 1.

The second aspect of the invention provides a preparation process of a teflon coating, which at least comprises the following steps:

adding polytetrafluoroethylene, polyamide-imide, a filler, a dispersant and a part of organic solvent into a reactor according to a formula, and shearing and dispersing at a high speed of 1000-1200 r/min for 10-15 min; grinding until no residue is left after the teflon coating passes through a 400-mesh filter screen, adding a leveling agent, stirring and dispersing uniformly, and then passing through a 400-mesh filter screen to obtain the teflon coating.

The third aspect of the invention provides application of a Teflon coating for brake calipers and brake pad guide rail shrapnel.

The present invention will be specifically described below by way of examples. It should be noted that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention, and that the insubstantial modifications and adaptations of the present invention by those skilled in the art based on the above disclosure are still within the scope of the present invention.

In addition, the starting materials used are all commercially available, unless otherwise specified.

Examples

The technical solution of the present invention is described in detail by the following examples, but the scope of the present invention is not limited to the examples.

Example 1

Embodiment 1 provides a teflon coating, which comprises, by weight, 55 parts of polytetrafluoroethylene, 35 parts of polyamideimide, 5 parts of a filler, 2 parts of a dispersant, 3 parts of a leveling agent, and 100 parts of an organic solvent.

The polytetrafluoroethylene comprises a mixture of polytetrafluoroethylene micro powder and polytetrafluoroethylene emulsion, and the weight ratio is 3: 1; the average particle size of the polytetrafluoroethylene micro powder is 8-17.6 mu m, and the polytetrafluoroethylene micro powder is purchased from Tianyuxiang micro powder material factories in Shenyang and is of a type of polytetrafluoroethylene micro powder-B; the solid content of the polytetrafluoroethylene emulsion is 58-62%, and the polytetrafluoroethylene emulsion is purchased from Guangzhou conifer chemical Co.

The polyamideimide was Torlon AI-10PAI powder available from Suwei, USA.

The filler is carbon black with the average particle size of 10-14 nm, is purchased from Anhui Heiyu pigment New Material Co, Ltd, and has the model number of

The dispersant was a TEGODISPERS 656 dispersant from Windy height.

The leveling agent is an 1154 leveling agent purchased from molecularization.

The organic solvent is a mixture of n-butanol and xylene, and the weight ratio is 3: 1.

A second aspect of example 1 provides a process for preparing a teflon coating, comprising the steps of:

adding polytetrafluoroethylene, polyamide-imide, a filler, a dispersant and a part of organic solvent into a reactor according to a formula, and shearing and dispersing at a high speed of 1000r/min for 15 min; grinding until no residue is left after the teflon coating passes through a 400-mesh filter screen, adding a leveling agent, stirring and dispersing uniformly, and then passing through a 400-mesh filter screen to obtain the teflon coating.

A third aspect of example 1 provides the use of a teflon paint prepared by spraying the teflon paint onto a brake pad rail clip.

Example 2

Embodiment 2 provides a teflon coating, which comprises, by weight, 55 parts of polytetrafluoroethylene, 35 parts of polyamideimide, 5 parts of a filler, 2 parts of a dispersant, 3 parts of a leveling agent, and 100 parts of an organic solvent.

The polytetrafluoroethylene comprises a mixture of polytetrafluoroethylene micro powder and polytetrafluoroethylene emulsion, and the weight ratio is 2: 1; the average particle size of the polytetrafluoroethylene micro powder is 8-17.6 mu m, and the polytetrafluoroethylene micro powder is purchased from Tianyuxiang micro powder material factories in Shenyang and is of a type of polytetrafluoroethylene micro powder-B; the solid content of the polytetrafluoroethylene emulsion is 58-62%, and the polytetrafluoroethylene emulsion is purchased from Guangzhou conifer chemical Co.

The polyamideimide was Torlon AI-10PAI powder available from Suwei, USA.

The filler is carbon black with the average particle size of 10-14 nm, is purchased from Anhui Heiyu pigment New Material Co, Ltd, and has the model number of

The dispersant was a TEGODISPERS 656 dispersant from Windy height.

The leveling agent is an 1154 leveling agent purchased from molecularization.

The organic solvent is a mixture of n-butanol and xylene, and the weight ratio is 3: 1.

A second aspect of example 2 provides a process for preparing a teflon coating, comprising the steps of:

adding polytetrafluoroethylene, polyamide-imide, a filler, a dispersant and a part of organic solvent into a reactor according to a formula, and shearing and dispersing at a high speed of 1000r/min for 15 min; grinding until no residue is left after the teflon coating passes through a 400-mesh filter screen, adding a leveling agent, stirring and dispersing uniformly, and then passing through a 400-mesh filter screen to obtain the teflon coating.

A third aspect of example 2 provides the use of a teflon paint prepared by spraying the teflon paint onto a brake pad rail clip.

Example 3

Embodiment 3 provides a teflon coating, which comprises, by weight, 50 parts of polytetrafluoroethylene, 35 parts of polyamideimide, 5 parts of a filler, 2 parts of a dispersant, 3 parts of a leveling agent, and 100 parts of an organic solvent.

The polytetrafluoroethylene comprises a mixture of polytetrafluoroethylene micro powder and polytetrafluoroethylene emulsion, and the weight ratio is 3: 1; the average particle size of the polytetrafluoroethylene micro powder is 8-17.6 mu m, and the polytetrafluoroethylene micro powder is purchased from Tianyuxiang micro powder material factories in Shenyang and is of a type of polytetrafluoroethylene micro powder-B; the solid content of the polytetrafluoroethylene emulsion is 58-62%, and the polytetrafluoroethylene emulsion is purchased from Guangzhou conifer chemical Co.

The polyamideimide was Torlon AI-10PAI powder available from Suwei, USA.

The filler is carbon black with the average particle size of 10-14 nm, is purchased from Anhui Heiyu pigment New Material Co, Ltd, and has the model number of

The dispersant was a TEGODISPERS 656 dispersant from Windy height.

The leveling agent is an 1154 leveling agent purchased from molecularization.

The organic solvent is a mixture of n-butanol and xylene, and the weight ratio is 3: 1.

A second aspect of example 3 provides a process for preparing a teflon coating, comprising the steps of:

adding polytetrafluoroethylene, polyamide-imide, a filler, a dispersant and a part of organic solvent into a reactor according to a formula, and shearing and dispersing at a high speed of 1000r/min for 15 min; grinding until no residue is left after the teflon coating passes through a 400-mesh filter screen, adding a leveling agent, stirring and dispersing uniformly, and then passing through a 400-mesh filter screen to obtain the teflon coating.

A third aspect of example 3 provides the use of a teflon paint prepared by spraying the teflon paint onto a brake pad rail clip.

Example 4

Embodiment 4 provides a teflon coating, which comprises, by weight, 55 parts of polytetrafluoroethylene, 40 parts of polyamideimide, 5 parts of a filler, 2 parts of a dispersant, 3 parts of a leveling agent, and 100 parts of an organic solvent.

The polytetrafluoroethylene comprises a mixture of polytetrafluoroethylene micro powder and polytetrafluoroethylene emulsion, and the weight ratio is 3: 1; the average particle size of the polytetrafluoroethylene micro powder is 8-17.6 mu m, and the polytetrafluoroethylene micro powder is purchased from Tianyuxiang micro powder material factories in Shenyang and is of a type of polytetrafluoroethylene micro powder-B; the solid content of the polytetrafluoroethylene emulsion is 58-62%, and the polytetrafluoroethylene emulsion is purchased from Guangzhou conifer chemical Co.

The polyamideimide was Torlon AI-10PAI powder available from Suwei, USA.

The filler is carbon black with the average particle size of 10-14 nm, is purchased from Anhui Heiyu pigment New Material Co, Ltd, and has the model number of

The dispersant was a TEGODISPERS 656 dispersant from Windy height.

The leveling agent is an 1154 leveling agent purchased from molecularization.

The organic solvent is a mixture of n-butanol and xylene, and the weight ratio is 3: 1.

A second aspect of example 4 provides a process for preparing a teflon coating, comprising the steps of:

adding polytetrafluoroethylene, polyamide-imide, a filler, a dispersant and a part of organic solvent into a reactor according to a formula, and shearing and dispersing at a high speed of 1000r/min for 15 min; grinding until no residue is left after the teflon coating passes through a 400-mesh filter screen, adding a leveling agent, stirring and dispersing uniformly, and then passing through a 400-mesh filter screen to obtain the teflon coating.

A third aspect of example 4 provides the use of a teflon paint prepared by spraying the teflon paint onto a brake pad rail clip.

Example 5

Embodiment 5 provides a teflon coating, which comprises, by weight, 55 parts of polytetrafluoroethylene, 35 parts of polyamideimide, 4 parts of a filler, 2 parts of a dispersant, 3 parts of a leveling agent, and 100 parts of an organic solvent.

The polytetrafluoroethylene comprises a mixture of polytetrafluoroethylene micro powder and polytetrafluoroethylene emulsion, and the weight ratio is 3: 1; the average particle size of the polytetrafluoroethylene micro powder is 8-17.6 mu m, and the polytetrafluoroethylene micro powder is purchased from Tianyuxiang micro powder material factories in Shenyang and is of a type of polytetrafluoroethylene micro powder-B; the solid content of the polytetrafluoroethylene emulsion is 58-62%, and the polytetrafluoroethylene emulsion is purchased from Guangzhou conifer chemical Co.

The polyamideimide was Torlon AI-10PAI powder available from Suwei, USA.

The filler is carbon black with the average particle size of 10-14 nm, is purchased from Anhui Heiyu pigment New Material Co, Ltd, and has the model number of

The dispersant was a TEGODISPERS 656 dispersant from Windy height.

The leveling agent is an 1154 leveling agent purchased from molecularization.

The organic solvent is a mixture of n-butanol and xylene, and the weight ratio is 3: 1.

A second aspect of example 5 provides a process for preparing a teflon coating, comprising the steps of:

adding polytetrafluoroethylene, polyamide-imide, a filler, a dispersant and a part of organic solvent into a reactor according to a formula, and shearing and dispersing at a high speed of 1000r/min for 15 min; grinding until no residue is left after the teflon coating passes through a 400-mesh filter screen, adding a leveling agent, stirring and dispersing uniformly, and then passing through a 400-mesh filter screen to obtain the teflon coating.

A third aspect of example 5 provides the use of a teflon paint prepared by spraying the teflon paint onto a brake pad rail clip.

Comparative example 1

Comparative example 1 provides a teflon coating, and the preparation raw materials comprise, by weight, 55 parts of polytetrafluoroethylene, 35 parts of polyamideimide, 5 parts of filler, 2 parts of dispersant, 3 parts of leveling agent and 100 parts of organic solvent.

The polytetrafluoroethylene is polytetrafluoroethylene micro powder which is purchased from Tianyuxiang micro powder material factories in Shenyang and is of the type of polytetrafluoroethylene micro powder-B.

The polyamideimide was Torlon AI-10PAI powder available from Suwei, USA.

The filler is carbon black with the average particle size of 10-14 nm, is purchased from Anhui Heiyu pigment New Material Co, Ltd, and has the model number of

The dispersant was a TEGODISPERS 656 dispersant from Windy height.

The leveling agent is an 1154 leveling agent purchased from molecularization.

The organic solvent is a mixture of n-butanol and xylene, and the weight ratio is 3: 1.

A second aspect of comparative example 1 provides a process for preparing a teflon coating, comprising the steps of:

adding polytetrafluoroethylene, polyamide-imide, a filler, a dispersant and a part of organic solvent into a reactor according to a formula, and shearing and dispersing at a high speed of 1000r/min for 15 min; grinding until no residue is left after the teflon coating passes through a 400-mesh filter screen, adding a leveling agent, stirring and dispersing uniformly, and then passing through a 400-mesh filter screen to obtain the teflon coating.

The third aspect of comparative example 1 provides the use of a teflon paint prepared by spraying the teflon paint on the brake pad rail clip.

Comparative example 2

Comparative example 2 provides a teflon coating, and the preparation raw materials comprise, by weight, 55 parts of polytetrafluoroethylene, 35 parts of polyamideimide, 5 parts of filler, 2 parts of dispersant, 3 parts of leveling agent and 100 parts of organic solvent.

The polytetrafluoroethylene comprises a mixture of polytetrafluoroethylene micro powder and polytetrafluoroethylene emulsion, and the weight ratio is 3: 1; the average particle size of the polytetrafluoroethylene micro powder is 8-17.6 mu m, and the polytetrafluoroethylene micro powder is purchased from Tianyuxiang micro powder material factories in Shenyang and is of a type of polytetrafluoroethylene micro powder-B; the solid content of the polytetrafluoroethylene emulsion is 58-62%, and the polytetrafluoroethylene emulsion is purchased from Guangzhou conifer chemical Co.

The polyamideimide was Torlon AI-10PAI powder available from Suwei, USA.

The filler is carbon black with the average particle size of 22-26 nm, is purchased from Anhui Heiyu pigment New Material Co, Ltd, and has the model number of

The dispersant was a TEGODISPERS 656 dispersant from Windy height.

The leveling agent is an 1154 leveling agent purchased from molecularization.

The organic solvent is a mixture of n-butanol and xylene, and the weight ratio is 3: 1.

A second aspect of comparative example 2 provides a process for preparing a teflon coating, comprising the steps of:

adding polytetrafluoroethylene, polyamide-imide, a filler, a dispersant and a part of organic solvent into a reactor according to a formula, and shearing and dispersing at a high speed of 1000r/min for 15 min; grinding until no residue is left after the teflon coating passes through a 400-mesh filter screen, adding a leveling agent, stirring and dispersing uniformly, and then passing through a 400-mesh filter screen to obtain the teflon coating.

The third aspect of comparative example 2 provides the use of a teflon paint prepared by spraying the teflon paint on the brake pad rail clip.

Comparative example 3

Comparative example 3 provides a teflon coating, and the preparation raw materials comprise, by weight, 55 parts of polytetrafluoroethylene, 35 parts of polyamide-imide, 5 parts of a filler, 2 parts of a dispersant, and 100 parts of an organic solvent.

The polytetrafluoroethylene comprises a mixture of polytetrafluoroethylene micro powder and polytetrafluoroethylene emulsion, and the weight ratio is 3: 1; the average particle size of the polytetrafluoroethylene micro powder is 8-17.6 mu m, and the polytetrafluoroethylene micro powder is purchased from Tianyuxiang micro powder material factories in Shenyang and is of a type of polytetrafluoroethylene micro powder-B; the solid content of the polytetrafluoroethylene emulsion is 58-62%, and the polytetrafluoroethylene emulsion is purchased from Guangzhou conifer chemical Co.

The polyamideimide was Torlon AI-10PAI powder available from Suwei, USA.

The filler is carbon black with the average particle size of 10-14 nm, is purchased from Anhui Heiyu pigment New Material Co, Ltd, and has the model number of

The dispersant was a TEGODISPERS 656 dispersant from Windy height.

The organic solvent is a mixture of n-butanol and xylene, and the weight ratio is 3: 1.

A second aspect of comparative example 3 provides a process for preparing a teflon coating, comprising the steps of:

adding polytetrafluoroethylene, polyamide-imide, a filler, a dispersant and a part of organic solvent into a reactor according to a formula, and shearing and dispersing at a high speed of 1000r/min for 15 min; and (4) sieving the mixture by a sieve of 400 meshes to obtain the Teflon coating.

The third aspect of comparative example 3 provides the use of a teflon paint prepared by spraying the teflon paint on the brake pad rail clip.

Evaluation of Performance

1. Sliding resistance test

The sliding resistance test is carried out on the brake block guide rail elastic sheet sprayed with the teflon coating prepared in the above examples and comparative examples; the brake shoe rail clips without teflon paint were used as a control and the results are shown in table 1.

2. Abrasion resistance test

a. Fixing the brake block guide rail elastic sheet sprayed with Teflon coating on an abrasion tester, applying downward force of 1.5 kilograms at the frequency of 33 times/min, and moving the brake block guide rail elastic sheet back and forth by the distance of 100mm by adopting the snake gourd cloth (3M7447C) with the length of 70mm +/-5 mm and the width of 30mm +/-5 mm;

b. starting the testing machine, replacing the scouring pad once every 500 times and observing with a magnifying lens of 10 times, and stopping the test if the non-stick surface has a grinding mark with the width of the exposed substrate surface exceeding 1mm or 10 linear grinding marks with the length of more than 2mm and the substrate is exposed;

c. the number of cycles N is recorded, based on the total number of cycles before the termination of the test.

If N is more than 10000 times, the test result is recorded in the table 1.

3. Salt spray test

Carrying out a sliding resistance test on the brake block guide rail elastic sheet sprayed with the Teflon coating prepared in the embodiment; brake shoe rail clips that were not coated with teflon paint served as controls. The experimental results are shown in fig. 1 and fig. 2, wherein fig. 1 is a 1000-hour salt spray test photograph of the teflon-coated brake block rail spring prepared in example 1, fig. 2 is a 600-hour salt spray test photograph of the brake block rail spring without the teflon coating, and it can be seen that a lot of rust stains appear in the 600-hour salt spray test of the brake block rail spring without the teflon coating, and the 1000-hour salt spray test photograph of the brake block rail spring with the teflon coating has higher surface quality than that of the brake block rail spring in fig. 2.

TABLE 1

According to the embodiments and the comparative examples, the Teflon coating and the preparation method and the application thereof are provided, and the brake block guide rail elastic sheet sprayed with the Teflon coating prepared by the invention has good lubricity, wear resistance and corrosion resistance.

Finally, it should be understood that the above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.