Method of protecting surfaces from corrosion

Details Method of protecting surfaces from corrosion Method of protecting surfaces from corrosion

2002-11-14

2004-10-26

Thexton, Matthew A. (Department: 1714)

Synthetic resins or natural rubbers -- part of the class 520 ser

Synthetic resins

At least one aryl ring which is part of a fused or bridged...

C524S786000

Reexamination Certificate

active

06809150

ABSTRACT:

BACKGROUND
1. Technical Field
The present invention relates to a process for protecting surfaces prone to corrosion by applying a composition that has a relatively high content of unreacted polyisocyanates.
2. Prior Art
Traditionally, it has been problematic to paint directly over rust. Merely painting over rust generally traps moisture and oxygen under the paint, which chemicals continue to corrode the underlying steel surface. Ordinarily, rust must be mechanically or chemically removed before coating. Mechanical methods include sandblasting and applying steel wool. One chemical method is acid treatment.
Various claims have been made about “rust converters.” For example, phosphoric acid converts iron oxide to an iron phosphate complex. Latex compositions have been alleged to convert the rust to magnetite. Still other products claim to convert rust to iron stearate, iron rosinate and other iron compounds. These products have varying degrees of effectiveness. However, the products may not last long or require a topcoat, after which the coating still does not last very long.
Aluminum pigments are used widely in coatings as special-effect pigments. The term special-effect pigments is used to denote pigments which have a directed reflection at oriented, metallic or highly light-refractive particles of a predominantly flat configuration. They are always of plate-like or flake-like configuration and have very large particle diameters compared with dye pigments. Their optical properties are determined by reflection and interference. Depending on transparency, absorption, thickness, single-layer or multi-layer structure, the special-effect pigments exhibit a metallic shine, a pearl shine, interference or interference reflection. The main areas, of use are in the cosmetics and automobile sectors, in addition in coloring plastic materials, paints, leather coatings, in printing and ceramics.
What is needed is an easy-to-apply coating that simultaneously dehydrates the rust and seals the rust from future oxygen or water attack.
SUMMARY OF THE INVENTION
A method of protecting surfaces from corrosion is disclosed herein. In one embodiment, there is provided a method of protecting surfaces from corrosion, which provides a coating composition containing polyisocyanates with unreacted, active NCO groups. The coating composition is applied to a rust covered surface, whereby the active NCO groups in the coating composition react with the water within rust to dehydrate the rust and produce a strong coating with the underlying iron or steel which keeps out water and oxygen which corrode surfaces. In another embodiment, the active NCO content is about 3% to about 20%. In yet another embodiment, the active NCO content is about 5% to about 15%. In another embodiment, the active NCO content is about 5% to about 15%.
Also disclosed is a composition for coating an iron surface, the composition comprising polyisocyanates whose NCO content is between 5% and 20% and whose aluminum flakes are about 5% to about 50% by weight. In another embodiment, the NCO content is between about 7% and about 25%. In another embodiment, the NCO content is between about 10% and about 20%, between about 10% and 20%, or between about 12% and about 18%. The aluminum flake content is about 7% to about 40%, or preferably between about 10% and about 30%.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims.


REFERENCES:
patent: 4098844 (1978-07-01), Tsugukuni et al.
patent: 4279962 (1981-07-01), Meyer et al.
patent: 4383070 (1983-05-01), Markusch et al.
patent: 4484951 (1984-11-01), Uchimura et al.
patent: 4567230 (1986-01-01), Meyer et al.
patent: 4657953 (1987-04-01), Kojo et al.
patent: 4857623 (1989-08-01), Emmerling et al.
patent: 5081203 (1992-01-01), Pedain et al.
patent: 5179187 (1993-01-01), Pedain et al.
patent: 5372638 (1994-12-01), DePue et al.
patent: 5389139 (1995-02-01), Carpenter et al.
patent: 5391614 (1995-02-01), Chandalia et al.
patent: 5391686 (1995-02-01), Jadhav et al.
patent: 5452716 (1995-09-01), Clift
patent: 5494512 (1996-02-01), Yamamoto et al.
patent: 5494741 (1996-02-01), Fekete et al.
patent: 5587448 (1996-12-01), Engen
patent: 5589535 (1996-12-01), Schwab et al.
patent: 5596098 (1997-01-01), Nikles et al.
patent: 5686136 (1997-11-01), Nikles et al.
patent: 5695812 (1997-12-01), Pritchett
patent: 5817732 (1998-10-01), Asahina et al.
patent: 5931996 (1999-08-01), Reisser et al.
patent: 5944886 (1999-08-01), Hashizume
patent: 5964936 (1999-10-01), Reisser
patent: 5998532 (1999-12-01), Urs
patent: 6132504 (2000-10-01), Kuntz et al.
patent: 6277450 (2001-08-01), Katoot et al.
patent: RE37386 (2001-09-01), Melby et al.
patent: 6368669 (2002-04-01), Hughes et al.
patent: 6398861 (2002-06-01), Knox
patent: 6409814 (2002-06-01), Bosch et al.
patent: 6417252 (2002-07-01), Hiraoka et al.
patent: 2002/0006996 (2002-01-01), Lane et al.
L. Sung et al., “Effect of Aluminum Flake Orientation on Coating Appearance”,Proceedings of the 79thAnnual Meeting Technical Program of the FSCT, pp. 453-462, Nov. 2001.

Affiliated with

Also associated with

Rating

Method of protecting surfaces from corrosion does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method of protecting surfaces from corrosion, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of protecting surfaces from corrosion will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3269254