Process for modifying the surface polarity of rubber substrates

Patent metadata

Field	Value
Publication number	US-2022017652-A1
Application number	US-202117449283-A
Country	US
Kind code	A1
Filing date	Sep 29, 2021
Priority date	Mar 29, 2019
Publication date	Jan 20, 2022
Grant date	—

Abstract

The present invention relates to a process for modifying the surface polarity of elastomeric rubber substrates to facilitate their cold bonding to other rubber substrates or non-elastomeric substrates of a different material, preferably metal, by chlorinating the elastomeric rubber substrate surface by treatment with a chloride-containing composition and a peroxymonosulfate-containing composition. Further aspects relate to the thus-obtained surface-modified rubber substrates, processes of bonding them to other substrates by use of an adhesive, as well as the thus-obtained bonded substrates.

First claim

What is claimed is:

1 . A process of modifying a surface of an elastomeric rubber substrate, comprising steps of:
(a) applying a first composition and a second composition to an elastomeric rubber substrate surface, wherein the first composition is an aqueous composition comprising chloride (CO, and the second composition is an aqueous composition comprising peroxymonosulfate; (b) optionally applying a third composition comprising activated carbon; and (c) incubating the first and second compositions, and the third composition if present, on the elastomeric rubber substrate surface for a time period and under conditions producing chlorination of the elastomeric rubber substrate surface.

2 . The process according to claim 1 , wherein the first composition is an aqueous 1M to 6M sodium chloride solution.

3 . The process according to claim 2 , wherein the second composition is an aqueous 10M to 30M persulfate solution.

4 . The process according to claim 3 , wherein the first and second composition are applied in a weight ratio of about 3:1 to 1:3.

5 . The process according to claim 4 , wherein the first and/or second and/or third composition is applied to the elastomeric rubber substrate surface in an amount that ranges from 500 to 900 g/m 2 .

6 . The process according to claim 1 , wherein step (c) is carried out for 5 to 60 minutes.

7 . The process according to claim 1 , further comprising a step of cleaning the substrate surface after step (c).

8 . The process according to claim 1 , wherein the first composition further comprises a hydroxide.

9 . The process according to claim 8 , wherein the first composition contains the hydroxide in a concentration of 0.5 M to 3 M.

10 . The process according to claim 9 , wherein the hydroxide comprises sodium and/or potassium hydroxide.

11 . The process according to claim 1 , wherein the first composition is an aqueous solution of sodium chloride and the second composition is an aqueous solution of potassium monopersulfate.

12 . The process according to claim 11 , wherein the first composition is present in a concentration of 1M to 6M and the second composition is present in a concentration of 10M to 30M.

13 . An elastomeric rubber substrate having a surface modified by the process of claim 1 .

14 . A process of forming a bond between a first substrate and a second substrate, wherein the first substrate comprises an elastomeric rubber substrate having a chlorinated surface made according to the process of claim 1 and the second substrate is a rubber or metal substrate, wherein the process comprises:
(a) applying an adhesive composition to a to-be-bonded surface of the second substrate;
(b) contacting the chlorinated surface of the first substrate and the to-be-bonded surface of the second substrate with the applied adhesive under pressure thereby forming the bond.

15 . The process according to claim 14 , further comprising a step of cleaning the rubber and/or metal substrate surfaces prior to steps (a) and/or (b).

16 . The process according to claim 14 , wherein step (b) is carried out at a temperature of 15 to 30° C. and a relative humidity of 85% or less.

17 . The process according to claim 14 , wherein step (b) is carried out by rolling.

18 . The process according to claim 14 , wherein the adhesive composition is a 2K epoxy, polyurea, silicone or polyurethane adhesive comprising a resin formulation and a hardener formulation.

19 . A bonded product made according to the process of claim 14 .

Assignees

• Henkel Ag & Co Kgaa

Inventors

• Monesi Alessio
• Salmoiraghi Eleonora
• Signorile Marco
• Zaffaroni Giorgio

Classifications

• B32B7/12

  using interposed adhesives or interposed materials with bonding properties · CPC title

• B32B15/06

  of {natural rubber or synthetic} rubber · CPC title

• C08J5/124

  using adhesives based on a macromolecular component · CPC title

• C08J7/126 Primary

  Halogenation · CPC title

• C08K3/36

  Silica · CPC title