Surface treatment of metal substrates

Patent metadata

Field	Value
Publication number	US-10196744-B2
Application number	US-201515514809-A
Country	US
Kind code	B2
Filing date	Sep 25, 2015
Priority date	Sep 26, 2014
Publication date	Feb 5, 2019
Grant date	Feb 5, 2019

Abstract

A process for surface treatment of metal substrates, including the steps of: providing a metal substrate including hydroxyl groups at its surface; bringing the metal substrate into contact with a solution of at least one organophosphorus compound to enable the reaction of the hydroxyl groups at the surface of the metal substrate with the organophosphorus compound to form a monomolecular layer over the surface and a second layer of physisorbed organophosphorus molecules at least preponderantly crystallized, the obtained treated substrate being coated with the organophosphorus compound in the form of a first monomolecular layer coating at least 15% of the surface of the substrate and in the form of a physisorbed second layer at least preponderantly crystallized. A treated metal substrate which may be obtained by the process thereof, corresponding solution and its use for treating metallic substrates to improve their tribological properties during their shaping, in particular their stamping.

First claim

The invention claimed is:

1. A metal substrate, the surface of which being coated with (i) at least an organophosphorus compound in the form of a first monomolecular layer coating at least 15% of the surface of the substrate and (ii) a second layer in the form of a physisorbed second layer of organophosphorus molecules at least preponderantly crystallized, said second layer being physisorbed on said first monomolecular layer.

2. Metal substrate according to claim 1 , wherein the at least one organophosphorus compound is of formula (I) below

wherein
A represents a hydrocarbon chain, saturated or unsaturated, straight or branched, comprising 4 to 28 atoms of carbon, the chain may be substituted with one or several group(s) selected from the group consisting of hydroxy, amino, cyano, halogen, sulfonic acid, and organophosphonic acid and/or interrupted by one or several atom(s) or group(s) selected from the group consisting of O, HN, and SH;
Z represents one or several terminal functional group(s) selected from the group consisting of alcohol, aldehyde, carboxylic acid, organophosphonic acid, thiol, amine, halogen, cyano, and silane, or is absent; and
R 1 and R 2 are, independently of each other, a hydrogen or a saturated alkyl, straight or branched, comprising 1 to 18 atoms of carbon.

3. Metal substrate according to claim 2 in which A represents a saturated alkyl group and/or a straight alkyl group.

4. Metal substrate according to claims 1 , wherein the substrate is made of aluminum, copper, chromium, titanium, zinc, gold, silver, ruthenium, rhodium, or any of their alloys.

5. Metal substrate according to claim 1 , wherein it consists of a flat product.

6. Process for the preparation of a metal substrate according to claim 1 , comprising the following steps:
(i) providing a metal substrate including hydroxyl groups at its surface;
(ii) bringing the metal substrate into contact with a solution of at least one organophosphorus compound;
said substrate being not rinsed after treatment according to step (ii).

7. The process according to claim 6 , wherein a solvent used for preparing the solution of organophosphorus compound comprises an alcohol, and/or water.

8. The process according to claim 7 , wherein the alcohol is an alcohol selected from the group consisting of methanol, ethanol, propanol, isopropanol, and butanol.

9. The process according to claim 6 , wherein the solution has a concentration in organophosphorus compound of more than 1 mM/l.

10. The process according to claim 9 , wherein the solution of the organophosphorus compound is supersaturated.

11. Metal substrate according to claim 2 in which A represents a hydrocarbon chain, saturated or unsaturated, straight or branched, comprising 16 carbon atoms, the chain may be substituted with one or several group(s) selected from the group consisting of hydroxy, amino, cyano, halogen, sulfonic acid, and organophosphonic acid and/or interrupted by one or several atom(s) or group(s) selected from the group consisting of O, HN, and SH.

Assignees

• Aperam
• Univ Franche Comte

Inventors

• Lallemand Fabrice
• Roizard Xavier
• Melot Jean-Marie
• Buteri Aurélien
• Borgeot Mélanie
• Evrard Romain

Classifications

• C10N2040/24

  without essential removal of material {, e.g. forming, gorging, drawing, pressing, stamping, rolling or extruding}; Punching metal · CPC title

• C10N2050/023

  Multi-layer lubricant coatings · CPC title

• C10N2040/246

  Iron or steel · CPC title

• C10N2040/247

  Stainless steel · CPC title

• C10N2040/244

  of specific metals · CPC title