Process for preparing a coating

Patent metadata

Field	Value
Publication number	US-10377917-B2
Application number	US-201615221130-A
Country	US
Kind code	B2
Filing date	Jul 27, 2016
Priority date	Jul 27, 2015
Publication date	Aug 13, 2019
Grant date	Aug 13, 2019

Abstract

A process for preparing a coating on at least part of a tribological surface of a first machine component which, during machine operation, is adapted to be in sliding contact with a tribological surface of a second machine component is provided. The process provides the steps of: (a) applying a polymer formulation onto at least part of the tribological surface of the first machine component to form a coating. The polymer formulation provides an isocyanate that contains two or more isocyanate groups per molecule and an idocyanate-reactive polyol to form polyurethanes; and (b) subjecting at least part of the coating as obtained in step (a) to a curing treatment during which polyurethanes are formed in the coating on the at least part of the tribological surface of the first machine component.

First claim

The invention claimed is:

1. A process for preparing a coating on at least part of a tribological surface of a first machine component composed of nitrile butadiene rubber, styrene butadiene rubber or fluorocarbon rubber which, during machine operation, is adapted to be in sliding contact with a tribological surface of a second machine component, the process comprises:
(a) applying an aqueous polymer formulation onto at least part of the tribological surface of the first machine component to form a coating, the aqueous polymer formulation comprising a polyisocyanate and an acrylic polyol to form polyurethanes; and
(b) subjecting at least part of the coating as obtained in step (a) to a curing treatment during which the polyurethanes are formed in the coating on the at least part of the tribological surface of the first machine component;
wherein the acrylic polyol is the only polyol in the aqueous polymer formulation;
the acrylic polyol has a weight average molecular weight of 500-3000 Daltons and is obtained by copolymerizing an acrylic monomer with a hydroxylated acrylic monomer;
the acrylic monomer is selected from the group consisting of ethyl acrylates (EA), butyl acrylates (BA), acrylic acid (AA), methyl methacrylate (MMA) and styrene (ST); and
the hydroxylated acrylic monomer is selected from the group consisting of 2-hydroxyethyl acrylates (HEA) and 4-hydroxybutyl acrylates (HBA).

2. The process according to claim 1 , wherein the polymer formulation further comprises a hydroxy polydimethylsiloxane dispersion.

3. The process according to claim 1 , wherein the aqueous polymer formulation further comprises particles of a filler material which particles have an average particle size of less than 100 nm.

4. The process according to claim 1 , wherein the curing treatment in step (b) is a thermal treatment carried out at a temperature in the range of from 50-250° C.

5. A machine component on which a coating is formed using a process for preparing a coating on at least part of a tribological surface of a first machine component composed of nitrile butadiene rubber, styrene butadiene rubber or fluorocarbon rubber which, during machine operation, is adapted to be in sliding contact with a tribological surface of a second machine component, the process comprises:
(a) applying an aqueous polymer formulation onto at least part of the tribological surface of the first machine component to form a coating, the aqueous polymer formulation comprising a polyisocyanate and an acrylic polyol to form polyurethanes; and
(b) subjecting at least part of the coating as obtained in step (a) to a curing treatment during which the polyurethanes are formed in the coating on the at least part of the tribological surface of the first machine component;
wherein the acrylic polyol is the only polyol in the aqueous polymer formulation;
the acrylic polyol has a weight average molecular weight of 500-3000 Daltons and is obtained by copolymerizing an acrylic monomer with a hydroxylated acrylic monomer;
the acrylic monomer is selected from the group consisting of ethyl acrylates (EA), butyl acrylates (BA), acrylic acid (AA), methyl methacrylate (MMA) and styrene (ST); and
the hydroxylated acrylic monomer is selected from the group consisting of 2-hydroxyethyl acrylates (HEA) and 4-hydroxybutyl acrylates (HBA).

6. The process according to claim 1 , wherein the aqueous polymer dispersion contains water in an amount in the range of 0-60 wt % based on the total weight of the aqueous polymer formulation.

7. The process according to claim 6 , wherein the polyisocyanate is selected from the group consisting of isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, toluenediisocyanate and 4,4′-diphenylmethane diisocyanate.

8. The process according to claim 7 , wherein the aqueous polymer dispersion contains the polyisocyanate in an amount in the range of 20-40 wt % based on the total weight of the aqueous polymer formulation.

9. The process according to claim 8 , wherein the aqueous polymer formulation further comprises a polysiloxane.

10. The process according to claim 8 , wherein the aqueous polymer formulation further comprises a hydroxy polydimethylsiloxane dispersion.

11. The process according to claim 10 , wherein the aqueous polymer formulation further comprises silicon oxide particles having an average particle size of less than 100 nm.

12. The process according to claim 11 , wherein the aqueous polymer formulation further comprises a wetting agent in an amount in the range of 0.1-1 wt % based on the total weight of the aqueous polymer formulation.

13. The process according to claim 1 , wherein:
the aqueous polymer formulation consists of the polyisocyanate, the acrylic polyol and water.

14. The process according to claim 1 , wherein:
the aqueous polymer formulation consists of the polyisocyanate, the acrylic polyol, a hydroxy-functional polydimethyl siloxane, a wetting agent and water.

15. The process according to claim 1 , wherein:
the aqueous polymer formulation consists of the polyisocyanate, the acrylic polyol, a hydroxy-functional polydimethyl siloxane, a wetting agent, silicon oxide particles having an average particle size of less than 100 nm, acetone, an acetate and water.

16. The machine component according to claim 5 , wherein the aqueous polymer formulation consists of the polyisocyanate, the acrylic polyol and water.

17. The machine component according to claim 5 , wherein the aqueous polymer formulation consists of the polyisocyanate, the acrylic polyol, a hydroxy-functional polydimethyl siloxane, a wetting agent and water.

18. The machine component according to claim 5 , wherein the aqueous polymer formulation consists of the polyisocyanate, the acrylic polyol, a hydroxy-functional polydimethyl siloxane, a wetting agent, silicon oxide particles having an average particle size of less than 100 nm, acetone, an acetate and water.

19. The machine component according to claim 5 , wherein the aqueous polymer formulation further comprises:
a hydroxy polydimethylsiloxane dispersion; and
silicon oxide particles having an average particle size of less than 100 nm.

20. The machine component according to claim 19 , wherein the polyisocyanate is selected from the group consisting of isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, toluenediisocyanate and 4,4′-diphenylmethane diisocyanate.

Assignees

• Allen Warrick
• Nedelcu Ileana
• Skf Ab

Inventors

• Allen Warrick
• Nedelcu Ileana

Classifications

• F16J15/3284

  characterised by their structure; Selection of materials · CPC title

• F16J15/328

  Manufacturing methods specially adapted for elastic sealings (moulding B29C) · CPC title

• F16J15/3204

  with at least one lip · CPC title

• F16C33/7823

  of sealing lips · CPC title

• F16C33/208

  Methods of manufacture, e.g. shaping, applying coatings · CPC title