Preparation method for self-lubricating polyamide-imide enamelled wire insulated paint synthesized by grafting polymerization

Abstract

The invention relates to a preparation method for a self-lubricating polyamide-imide enamelled wire insulated paint synthesized by grafting polymerization. The method comprises the steps of preparing an aliphatic acid or alcohol with a long chain alkyl into a solution with a concentration of 10% by using N-methyl pyrrolidone as a solvent; adding the solution to hexamethylene diisocyanate with a spraying method; stirring rapidly and heating to a temperature of 100-150 DEG C gradually to obtain an intermediate A; adding the intermediate A and diphenylmethane diisocyanate together into trimellitic anhydride with a molar ratio of free -NCO in the intermediate A to that in diphenylmethane diisocyanate being 1 : 1-1 : 5; controlling the molar ratio of -NCO to two functional groups in trimellitic anhydride being 1 : 1-1 : 1.05; stirring for 2.5 hours slowly at a kettle temperature of 70 DEG C; heating to a temperature of 120 DEG C; fast stirring for 3.5 hours; and adding dimethylbenzene to make the self-lubricating polyamide-imide enamelled wire insulated paint. The self-lubricating polyamide-imide enamelled wire insulated paint has long quality guarantee period, and does not appear layering. The static friction coefficient can be lower than 0.06. Risks that the enamelled wire is scratched during the processes of winding coils, embedding wires and shaping can be decreased.

Description

Technical field [0001] The invention relates to a preparation method for synthesizing self-lubricating polyamide-imide enameled wire insulating varnish by graft polymerization, belonging to the field of chemistry. Background technique [0002] The composite enameled wire made of polyesterimide composite polyamideimide has a thermal class of 200 and has excellent comprehensive performance. It has been widely used in sealed motors, electric tools, and other high heat-resistant motors and electrical appliances. [0003] With the widespread use of automatic high-speed winding and automatic wire embedding and shaping, the production efficiency has been greatly improved, and at the same time, higher requirements have been put forward for the performance of enameled wire, especially the surface lubricity. The enameled wire with poor surface lubricity has large resistance during high-speed winding, unstable winding tension, easy to break, and the wound wire package is large or i...

AI Technical Summary

Problems solved by technology

Since lubricants must be dissolved in hydrocarbon solvents (concentration is roughly 0.5 to 2%), these solvents will naturally volatilize into the air after coating, causing serious waste of resources and causing environmental pollution; and due to paraffin lubricants and new Refrigerants are not compatible, so they cannot be used in refrigerator compressors, and polyester or oil-based lubricants do not lubricate well;

[0006] (2) Coating aliphatic nylon on the surface of the enameled wire to improve the surface lubricity of the enameled wire, but this type of nylon paint layer has poor lubricity, poor heat resistance, and cannot be used to seal the motor;

The disadvantage is that the lubricity is not good, especially for the high-speed enamelling machine baked at high temperature, the paraffin is evaporated and the lubricity is lost

Essentially indistinguishable from externally applied paraffin

And due to the incompatibility of paraffin and paint, the storage period of enameled wire paint is short, generally 3 months