Process for hydrophilicization of hydrophobic polymers

• US 5,849,368 A
• Filed: 05/05/1997
• Issued: 12/15/1998
• Est. Priority Date: 02/01/1995
• Status: Expired due to Term

• Current Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Original Assignee: Schneider Electric SE
• Inventors: Helmus, Michael N., Ding, Ni, Hostettler, Fritz
• Primary Examiner(s): PADGETT, MARIANNE L
• Application Number:
  US08/851,052
• Time in Patent Office: 589 Days
• Field of Search: 427/536, 427/538, 427/539, 427/222, 427/255.4, 427/248.1, 427/488, 427/489, 427/491
• US Class Current: 427/536
• CPC Class Codes: C08J 2315/00 Characterised by the use of rubber derivatives C08J2311/00, C08J2313/00 takes precedence
• CPC Class Codes: C08J 2475/00 Characterised by the use of polyureas or polyurethanes; 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 7/043 Improving the adhesiveness of the coatings per se, e.g. forming primers adhesives in the form of films or foils characterised by the primer layers between the polymer carriers and the adhesives C09J7/50
• CPC Class Codes: C08J 7/046 Forming abrasion-resistant coatings; Forming surface-hardening coatings
• CPC Class Codes: C08J 7/056 Forming hydrophilic coatings
• CPC Class Codes: C08J 7/12 Chemical modification
• CPC Class Codes: C08J 7/123 Treatment by wave energy or particle radiation C08J7/18 takes precedence

Abstract

A process for rendering the surfaces of polymeric plastic or rubber materials, which are intrinsically non-polar or only slightly polar, and hydrophobic, polar or more polar, and hydrophilic, so that amine-containing functional groups, and ultimately, a durable tenaciously adhering, slippery polyurethane or polyurethane-urea hydrogel coating may subsequently be applied to the polymer surface, is disclosed. The process involves dual plasma-treatment of a polymeric plastic or rubber substrate material; the first treatment being with an oxygen-containing plasma gas, to affix hydroxyl, carboxyl and carbonyl groups to the substrate surface, thereby rendering the surface more polar and activated; and the second treatment being with a nitrogen-containing plasma gas, to affix amine and amino groups to the substrate surface to make it more hydrophilic and reactive toward terminal isocyanate groups of a polyurethane or polyurethane/urea prepolymer adduct intermediate tie-coat which is subsequently applied to the substrate surface and then converted to a tenaciously adhering, slippery hydrogel coating. The process is especially suited to the hydrophilicization of intrinsically non-polar and hydrophobic polymeric plastic materials, such as polyethylenes, nylons-11 and nylons-12.

Claims

1. A process for treating a material, the process comprising steps of:

(a) providing the material having an outer surface, the material comprising a polymer selected from the group consisting of polyethylene terephthalate, block copolymers comprising aliphatic polyethers and aromatic polyesters, block copolymers comprising aliphatic polyethers and polyamides, polyamides, polyimides, polyurethanes, polyethylenes, polypropylenes, natural rubbers, and synthetic rubbers;

(b) exposing the material to a first plasma stream containing O₂ gas and optionally NH₃ gas and/or Ar gas;

(c) exposing the material to a second plasma stream containing NH3 gas and/or an amine having the structure R₁ NH₂, R₁ NHR₂, or H₂ N--R₃ --NH₂, wherein R₁ and R₂ are hydrocarbons having from 1-8 carbon atoms and R₃ is a hydrocarbon having from 2-8 carbon atoms; and

(d) after the steps (a), (b) and (c), applying a hydrophilic prepolymer containing terminal isocyanate groups to at least part of the outer surface.

2. The process of claim 1 wherein both of steps (b) and (c) are performed at a radio frequency of about 13 MHz to about 14 MHz and a generating power of about 50-500 watts.

3. The process of claim 1 wherein the second plasma stream includes an amine.

4. The process of claim 2 wherein the second plasma stream includes an amine.

5. The process of claim 3 wherein the second plasma stream includes an amine selected from the group consisting of methylamine, dimethylamine, ethylamine, diethylamine, ethylmethylamine, n-propylamine, allylamine, isopropylamine, n-butylamine, n-butylmethylamine, n-amylamine, n-hexylamine, 2-ethylhexylamine, ethylenediamine, 1,4-butanediamine, 1,6-hexanediamine, cyclohexylamine, n-methylcyclohexylamine, ethyleneimine, and combinations thereof.

6. The process of claim 4 wherein the second plasma stream includes an amine selected from the group consisting of methylamine, dimethylamine, ethylamine, diethylamine, ethylmethylamine, n-propylamine, allylamine, isopropylamine, n-butylamine, n-butylmethylamine, n-amylamine, n-hexylamine, 2-ethylhexylamine, ethylenediamine, 1,4-butanediamine, 1,6-hexanediamine, cyclohexylamine, n-methylcyclohexylamine, ethyleneimine, and combinations thereof.

7. The process of claim 1 wherein the first plasma stream includes NH₃ gas.

8. The process of claim 1 wherein the first plasma stream includes Ar gas.

9. The process of claim 1 wherein the first plasma stream includes NH₃ gas and Ar gas.

10. The process of claim 1 wherein the second plasma stream includes NH₃ gas.

11. The process of claim 1 wherein the second plasma stream includes NH₃ gas and an amine.