Ceramic coating with scratch resistance and thermal conduction properties

Patent metadata

Field	Value
Publication number	US-9725809-B2
Application number	US-201314067033-A
Country	US
Kind code	B2
Filing date	Oct 30, 2013
Priority date	Oct 31, 2012
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

Provided is a ceramic coating intended to be applied on a metal support and having the form of at least a continuous film having a thickness between 2 and 100 μm, this coating comprising a matrix including at least a metal polyalkoxide and wherein are dispersed particles whereof the diameter ranges between 0.01 and 50 μm, said particles being from a material having a thermal conductivity equal to or higher than 10 W·m −1 ·K −1 and a bulk density of at the most 3.9 g/cm 3 . Also provided is an article, for example culinary, comprising such a coating and its method of manufacture.

First claim

The invention claimed is:

1. A ceramic coating, intended to be applied on a metal support and being in the form of a continuous film having a thickness between 2 and 100 μm, said coating comprising a matrix including at least a metal polyalkoxide and wherein are dispersed particles whereof the diameter ranges between 0.01 and 50 μm, said particles being from a material having a thermal conductivity equal to or higher than 10 W·m −1 ·K −1 and a bulk density of at the most 3.9 g/cm 3 ,
wherein the matrix further comprises at least a reactive silicone oil selected from among chlorinated oils, amino oils, (meth)acrylated oils, hydroxylated oils, and anhydride, hydride vinyl-terminated oils.

2. The coating according to claim 1 , wherein said particles have a hardness Mohs equal to or higher than 9.

3. The coating according to claim 1 , wherein the metal polyalkoxylate is selected from among the polyalkoxysilanes, aluminates, titanates, zirconates, vanadates, borates and their combinations, said metal polyalkoxylate further comprises at least a non-functionalized alkyl group.

4. The coating according to claim 1 , wherein the continuous film has a thickness ranging between 5 and 70 μm.

5. The coating according to claim 1 , wherein the diameter of said particles ranges between 0.05 and 20 μm.

6. The coating according to claim 1 , wherein the particles dispersed in the matrix are selected from among diamond particles, cubic boron nitride particles, diamond like carbon particles, silicon carbide particles, boron carbide particles, aluminum nitride particles, silicon nitride particles and their combinations.

7. The coating according to claim 1 , wherein the dispersed particles represent 0.5 to 8% in weight of said coating.

8. The coating according to claim 1 , wherein the silicone oil represents 0.01 to 2% in weight of said coating.

9. The coating according to claim 1 , wherein the silicone oil has a dynamic viscosity at 20° C. of 0.02 to 0.05 Pa·s.

10. The coating according to claim 1 , wherein the matrix further comprises at least a structuring filler and/or at least a pigment.

11. The coating according to claim 10 , wherein the pigment is selected from among coated or uncoated mica, titanium dioxide, mixed oxides of copper-chromium-manganese, copper-chromium, chromium-antimony-titanium, tin-zinc-titanium, spinels, aluminosilicates, iron oxides, carbon black, perylene red, flakes, interference pigments, thermochromic pigments, magnetic or magnetizable pigments, cobalt salts, nickel titanate and their combinations.

12. The coating according to claim 10 , wherein the structuring filler is selected from among:
(i) metal oxides,
(ii) silica,
(iii) zirconia,
(iv) mica,
(v) clays,
(vi) zinc oxide,
(vii) quartz, and
(viii) zirconium phosphate,
these fillers being in the form of a powder or colloidal suspensions.

13. The coating according to claim 12 , wherein the structuring filler is a powder of alumina or a colloidal suspension of alumina or a powder of silica or colloidal suspension of silica.

14. An article comprising at least a layer of coating according to claim 1 .

15. The article according to claim 14 , comprising at least two layers of coating, wherein the total thickness of said layers ranging between 10 and 120 μm.

16. The article according to claim 14 , which is a culinary article, or an iron soleplate, or hair smoothing iron plates or a lid of a household appliance.

17. The article according to claim 16 , which is a culinary article comprising a metal support having an inner side able to receive food and an outer side intended to be arranged towards the source of heat, and wherein said coating is applied on one at least of said inner and outer sides.

18. The article according to claim 14 , wherein the support is:
a monolayer structure being of anodized aluminum, non anodized aluminum, polished aluminum, brushed aluminum, microbeaded aluminum, sanded aluminum, chemically treated aluminum, cast aluminum, polished stainless steel, brushed stainless steel, microbeaded stainless steel, cast iron, beaten copper, or polished copper; or
a multilayer structure, in part or in totality, comprising from the outside to the inside the following layers stainless steel/aluminum/stainless steel, or stainless steel/aluminum/copper/aluminum/stainless steel, or a cast aluminum bowl, of aluminum or aluminum alloys doubled with an outside bottom being of stainless steel.

19. A method for manufacturing the coating according to claim 1 on at least a surface of a metal article, said method comprising the following steps:
i) optionally, a surface treatment of said surface in order to improve the adhesion of the sol-gel layer applied at step iv);
ii) preparation of a sol-gel composition with:
at least a sol-gel precursor selected from among the metal alkoxides,
at least particles having a diameter ranging between 0.01 and 50 μm and being made of a material having a thermal conductivity equal to or higher than 10 W·m −1 ·K −1 and a bulk density of at the most 3.9 g/cm 3 , and
(a) at least a reactive silicone oil selected from among chlorinated oils, amino oils, (meth)acrylated oils, hydroxylated oils, and anhydride, hydride vinyl-terminated oils and optionally (b) at least a structuring filler and/or optionally (c) at least a pigment,

iii) hydrolysis of said sol-gel precursor by introducing water and a catalyst, acid or base, followed by a partial condensation reaction for obtaining a sol-gel composition SG;
iv) application on said surface of at least a layer of said sol-gel composition SG obtained following step iii);
v) optionally drying of said layer at a temperature ranging between 40 and 90° C.; and
vi) curing said article coated following step iv) or v) at a temperature ranging between 150° C. and 400° C.

20. The method according to claim 19 , wherein said catalyst is an acid selected from among acetic acid, formic acid and hydrochloric acid.

21. The method according to claim 19 , wherein the filler is a powder or a colloidal suspension of alumina or silica.

22. The method according to claim 19 , wherein the application iv) of at least a layer of sol-gel composition SG resulting from step (iii) on a metal article is carried out by spraying after an optional degreasing and/or dusting of said metal article.

23. The method according to claim 19 , wherein the layer of sol-gel composition SG applied at step iv) has a thickness in the wet state of between 4 and 200 μm, and/or wherein step (iv) is repeated until obtention of a succession of layers whereof the total thickness in the wet state is of 20 to 240 μm.

24. The method according to claim 19 , which further comprises a step of applying a continuous or discontinuous layer of decoration, between the step iv) of applying the sol-gel composition, or if need be, of drying v) and the step vi) of curing the article, this application of a layer of decoration can be followed with a step of drying at a temperature less than 90° C. preceding the final curing vi) of the article.

Assignees

• Seb Sa

Inventors

• Perillon Jean-Luc
• Dubanchet Aurelien
• Caillier Laurent

Classifications

• C23C18/1254 Primary

  Sol or sol-gel processing · CPC title

• C09D5/26

  Thermosensitive paints · CPC title

• C23C2/04

  characterised by the coating material · CPC title

• A47J36/025

  Vessels with non-stick features, e.g. coatings · CPC title

• Y10T428/131

  Glass, ceramic, or sintered, fused, fired, or calcined metal oxide or metal carbide containing [e.g., porcelain, brick, cement, etc.] · CPC title