Environmental wipe solvent processes

• US 6,248,403 B1
• Filed: 01/03/2000
• Issued: 06/19/2001
• Est. Priority Date: 08/24/1998
• Status: Expired due to Fees

• Current Assignee: Northrop Grumman Corporation
• Original Assignee: Northrop Grumman Corporation
• Inventors: McLaughlin, Joanne Swiderski, Weir, John Douglas
• Primary Examiner(s): Beck, Shrive
• Assistant Examiner(s): Crockford, Kirsten A.
• Application Number:
  US09/477,130
• Time in Patent Office: 533 Days
• Field of Search: 427/327, 427/397.7, 427/419.7, 427/410, 427/409, 156/329
• US Class Current: 427/327
• CPC Class Codes: B32B 15/04 comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material next to a bituminous or tarry layer B32B11/08; next to a water-setting substance layer B32B13/06; next to a glass layer B32B17/061; next to a cellulosic plastic layer B32B23/042
• CPC Class Codes: B32B 15/20 comprising aluminium or copper B32B15/016 and B32B15/017 take precedence
• CPC Class Codes: B32B 2255/06 on metal layer
• CPC Class Codes: B32B 2255/26 Polymeric coating
• CPC Class Codes: B32B 2307/714 Inert, i.e. inert to chemical degradation, corrosion
• CPC Class Codes: B32B 2307/752 Corrosion inhibitor
• CPC Class Codes: B32B 2311/24 Aluminium
• CPC Class Codes: B32B 2363/00 Epoxy resins
• CPC Class Codes: B32B 2375/00 Polyureas; Polyurethanes
• CPC Class Codes: B32B 5/00 Layered products characterised by the non- homogeneity or physical structure , i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: C11D 2111/16 Metals
• CPC Class Codes: C11D 7/5004 Organic solvents

Abstract

A non-chrome process for the pretreatment of substrate surfaces to simultaneously clean them and improve their bonding strength for organic coatings such as adhesives, protective primers, sealants, paints, composites and similar materials conventionally bonded to such substrates, including non-chromated or chromated curable organic resin protective coatings applied directly to bare aluminum substrates. The invention involves the use of novel wipe solvent compositions containing a major volume of an environmentally-safe volatile organic solvent which has a low composite vapor pressure or is otherwise exempt from federal, state or local regulations, and a minor volume of a polyfunctional coupling agent, preferably of the silane type.

Claims

1. A non-chrome process for the pre-treatment of a substrate surface comprising bare aluminum or bare aluminum alloy in order to clean the surface and simultaneously improve its bonding properties for a protective non-chromated organic resin paint primer coating which imparts oxidation- and corrosion-resistance to the substrate, which comprises the step of deoxidizing said substrate surface, wiping said substrate surface with a wipe solvent composition consisting essentially of 95 to 99.9% by volume of at least one environmentally-acceptable volatile organic solvent having a composite vapor pressure below about 45 mm Hg, and 0.1 to 5% by volume of 3-glycidoxypropyltrimethoxy silane polyfunctional coupling agent which hydrolyzes to form silanol groups having a bonding affinity for the substrate surface and for a paint primer coating to be applied thereto, and dry wiping the wipe solvent composition and evaporating the volatile organic solvent to deposit a receptive layer comprising the hydrolyzed coupling agent directly on the deoxidized substrate surface, and applying and curing a protective, nonchromated organic resin paint primer coating over said receptive layer to impart oxidation- and corrosion-resistance to the substrate.

2. Process according to claim 1 in which the organic resin comprises an epoxy resin and a curing agent.

3. Process according to claim 1 in which organic resin comprises a urethane resin.

4. Process according to claim 1 in which the organic resin contains a corrosion-resisting agent or inhibitor.

5. Process according to claim 1 in which a paint or top coat layer is applied over the cured primer layer.

6. Process according to claim 1 in which the curable organic resin composition is an adhesive bonding layer.

7. Process according to claim 6 which comprises bonding another substrate to said adhesive bonding layer to form a laminate.

8. Process according to claim 7 in which said another substrate is a graphite-epoxy composite substrate.

9. Process according to claim 6 in which said another substrate is a fiberglass-epoxy composite substrate.