Powder for an electrically insulating coating
The invention relates to the use of a powder comprising at least one polyamide and at least one epoxy resin for producing an electrically insulating coating on a surface. The invention also relates to an electricity transmitting component at least partially covered with a coating that can be obtained by melting such a powder.
1 . An electricity transmitting component at least partially covered with a coating that can be obtained by melting a powder comprising at least one polyamide and at least one epoxy resin,
wherein the epoxy resin is selected from the group consisting of sulfonamide epoxy resins, bisphenol A diglycidyl ethers, bisphenol F diglycidyl esters, novolac resin glycidyl ethers, novolac cresol epoxy resins, novolac phenolic epoxy resins, novolac alkylphenolic epoxy resins, hydrogenated bisphenol A diglycidyl ethers, hydrogenated bisphenol AD diglycidyl ethers, diglycidyl ethers of a polyol, epoxy resins obtained by reaction of an aliphatic or aromatic carboxylic acid with epichlorohydrin, epoxy resins obtained by reaction of an aliphatic or aromatic amine with epichlorohydrin, heterocyclic epoxy resins, and epoxy resins containing a spiro nucleus,
wherein the powder comprises from 50 to 99.5% by weight of the at least one polyamide and from 0.5 to 50% by weight of the at least one epoxy resin.
2 . The electricity transmitting component as claimed in claim 1 , which is a busbar.
3 . The electricity transmitting component as claimed in claim 1 , wherein the powder comprises from 75 to 98% by weight of the at least one polyamide and from 2 to 20% by weight of the at least one epoxy resin.
4 . The electricity transmitting component as claimed in claim 1 , wherein the coating is a film with a thickness of from 50 to 500 μm.
5 . A process for coating the surface of the electricity transmitting component according to claim 1 , comprising the following steps:
optionally applying a mask to the surface;
bringing the surface into contact with the powder comprising at least one polyamide and at least one epoxy resin;
melting the powder.
6 . The process as claimed in claim 5 , wherein the step of bringing the surface into contact with the powder comprises the steps of:
electrically charging the powder;
spraying the electrically charged powder onto the surface;
heating the powder-coated surface to a temperature above the melting point of the polyamide and above the melting point of the epoxy resin.
7 . The electricity transmitting component as claimed in claim 1 , wherein the epoxy resin is a sulfonamide epoxy resin.
8 . The electricity transmitting component as claimed in claim 1 , wherein the polyamide is a homopolyamide, a copolyamide and/or a copolymer with polyamide blocks and with polyether blocks.
9 . The electricity transmitting component as claimed in claim 1 , wherein the polyamide is chosen from the group consisting of polyamide 11, polyamide 12, polyamide 6, polyamide 10, polyamide 6.10, polyamide 6.12, polyamide 6.14, polyamide 6.18, polyamide 10.10, polyamide 10.12, polyamide 10.14, PA 10.X/Y, wherein X is 10 or 12 and Y is 11, 12 or 14, and combinations thereof.
10 . The electricity transmitting component as claimed in claim 1 , wherein the powder comprises polyamide particles having a volume median diameter Dv50 of from 10 to 200 μm.
11 . The electricity transmitting component as claimed in claim 1 , wherein the powder comprises epoxy resin particles having a volume median diameter Dv50 of from 1 to 20 μm.
12 . The electricity transmitting component as claimed in claim 1 , wherein the powder also comprises one or more additives chosen from the group consisting of pigments or dyes, anti-crater agents or spreading agents, reducing agents, antioxidants, reinforcing fillers, UV stabilizers, fluidizing agents and corrosion inhibitors.
13 . The electricity transmitting component as claimed in claim 1 , wherein the surface is a metal surface.
14 . An electricity transmitting component at least partially covered with a coating that can be obtained by melting a powder comprising a polyamide and a sulfonamide epoxy resin.
15 . The electricity transmitting component as claimed in claim 14 , which is a busbar.
16 . The electricity transmitting component as claimed in claim 14 , wherein the coating is a film with a thickness of from 50 to 500 μm.