Surface treatment

• US 20040146660A1
• Filed: 02/26/2004
• Published: 07/29/2004
• Est. Priority Date: 06/06/2001
• Status: Abandoned Application

• Current Assignee: Dow, Inc.
• Original Assignee: Dow, Inc.
• Inventors: Badyal, Jas Pal Singh, Ward, Luke, Goodwin, Andrew James, Merlin, Patrick
• Application Number:
  US10/479,776
• Publication Number:
  US 20040146660A1
• Time in Patent Office: Days
• US Class Current: 427/535
• CPC Class Codes: A61L 27/34 Macromolecular materials
• CPC Class Codes: B05D 1/60 Deposition of organic layers from vapour phase vapour phase deposition in general C23C14/00, C23C16/00
• CPC Class Codes: B05D 2201/02 Polymeric substrate
• CPC Class Codes: B05D 3/145 After-treatment
• CPC Class Codes: C08G 77/00 Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
• CPC Class Codes: C08G 77/04 Polysiloxanes
• CPC Class Codes: C08J 2483/00 Characterised by the use of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen, or carbon only; Derivatives of such polymers
• CPC Class Codes: C08J 7/0427 with only one layer of a composition containing a polymer binder with more layers C08J7/042
• CPC Class Codes: C08J 7/056 Forming hydrophilic coatings
• CPC Class Codes: C08L 83/00 Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers
• CPC Class Codes: C09D 4/00 Coating compositions, e.g. paints, varnishes or lacquers, based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond ; Coating compositions, based on monomers of macromolecular compounds of groups C09D183/00 - C09D183/16

Abstract

A method of coating a surface of a low surface energy substrate by exposing the substrate to a silicon containing compound in liquid or gaseous form selected from a chlorine terminated polydimethylsiloxane, direct process residue, Z_xSiR⁵_4−x, Si_nY_2n+2 or a mixture thereof, where each Z is a chloro or alkoxy group and each R⁵ is an alkyl group or substituted alkyl group, x is 1 to 4, n is from 2 to 10 and each Y may be selected from a chloro, fluoro, alkoxy or alkyl group but at least two Y groups must be chloro, or alkoxy groups or a mixture thereof and forming a grafted coating layer on the substrate surface and subsequently post-treating the grafted coating layer by oxidation or, reduction, which is preferably utilising a plasma or corona treatment, in particular atmospheric pressure glow discharge or dielectric barrier discharge.

Claims

1. Method of coating a surface of a low surface energy substrate by the following steps:

(i) exposing the substrate to a silicon containing compound in liquid or gaseous form said silicon containing composition being selected from one or more of a chlorine terminated polydimethylsiloxane, direct process residue, Z_xSiR⁵<sub>4−

x</sub>, Si_nY_2n+2 or a mixture thereof, where each Z is chloro or an alkoxy group and each R⁵ is an alkyl group or a substituted alkyl group, x is 1,2,3 or 4, n is from 2 to 10 and each Y may be selected from a chloro, fluoro, alkoxy or alkyl group but at least two Y groups must be chloro or alkoxy groups or a mixture thereof to form a grafted coating layer on the substrate surface; and

(ii) post-treating the grafted coating layer prepared in step (i) by oxidation or, reduction.

2. A method in accordance with claim 1 wherein the silicon containing compound is direct process residue.

3. A method in accordance with any preceding claim wherein the grafted coating layer is subsequently oxidised or reduced by applying a plasma or corona treatment.

4. A method in accordance with claim 3 wherein subsequent to oxidation the grafted coating layer may be subjected to any one of the following:

i. further chemical grafting processes to produce an additional mono-layer or multilayer systems,

ii. coated with a plasma polymerised coating

iii. coated with a liquid by means of a traditional coating process, or

iv. laminated to another similarly prepared substrate.

5. A method in accordance with claim 3 or 4 wherein additional grafted coating layers may be applied onto the oxidised coating layer of claim 3 or 4 by applying a further grafted coating layer in accordance with the method of claim 1 and oxidising the resulting layer by applying a plasma or corona treatment.

6. A method in accordance with claim 5 wherein said further grafted coating layer comprises an oxidisable silicon containing compound selected from a chlorine terminated polydimethylsiloxane, direct process residue, Z_xSi R⁵₄₋

x, Si_nY_2n+2 or a mixture thereof.

7. A method in accordance with claim 6 wherein a top-coat comprising a silicon containing compound is applied to the outermost oxidised grafted coating layer.

8. A method in accordance with claim 3 or 4 wherein the plasma or corona treatment is either dielectric barrier discharge or atmospheric pressure glow discharge.

9. A method in accordance with any preceding claim wherein prior to exposing the low surface energy substrate to a chlorine terminated polydimethylsiloxane, or a silane of the formula, Z_xSiR⁵₄₋

x, separately or in combination with each other, the low energy substrate is subjected to a plasma pre-treatment.

10. A method in accordance with any preceding claim wherein prior to exposing the low surface energy substrate to an oxidisable silicon containing compound comprising a direct process residue, or a compound of the formula Si_nY_2n+2 said compound may be subjected to a plasma pre-treatment.

11. A method in accordance with either claim 9 or 10 wherein the plasma pre-treatment is by means of atmospheric pressure glow discharge or dielectric barrier discharge.

12. A method in accordance with any preceding claim wherein the substrate is a polyolefin or a polyester.

13. A method in accordance with any one of claims 1 to 10 wherein the substrate comprises a blend of an organic polymeric material and an organosilicon-containing additive which is substantially non-miscible with the organic polymeric material.

14. A method in accordance with any preceding claim wherein the substrate is a film, a natural fibre, a synthetic fibre, a woven fabric, a non-woven fabric, or a powder.

15. A coated substrate obtainable in accordance with any preceding claim.

16. Use of a coated substrate prepared in accordance with any one of claims 1 to 14 as a lamination adhesive, an oxygen and/or moisture barrier, a fuel or soil resistant coating, a hydrophilic or wettable coating, a release coating.