Coating processes – With post-treatment of coating or coating material – Heating or drying
Reexamination Certificate
2001-02-08
2002-09-17
Cameron, Erma (Department: 1762)
Coating processes
With post-treatment of coating or coating material
Heating or drying
Reexamination Certificate
active
06451382
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to use of silane based coating compositions for coating heat exchange systems, such as HVAC systems, whereby heating efficiencies and corrosion protection are both substantially improved. More particularly, the present invention is concerned with improving performance and useful lifetime of heat exchange systems wherein the heat exchange surfaces are coated with a very thin coating of glass-like silane based coating composition which penetrate into very small spaces at the interface between and in the heat exchange surfaces to provide a parallel path for heat transfer and prevent corrosion, thereby greatly improving short- and long-term efficiency.
2. Discussion of the Prior Art
Silane, silanol and siloxane compounds have been used for many years, as both solvent-based and aqueous-based, formulations, with or without modification with organic substituents, for such applications as coupling agents for glass or other inorganic substrates to organic compounds; non-permanent (limited life) water repellants for concrete and woven fabric materials; synthetic rubber like compounds for adhesives and sealers; adhesion modifiers for organic paints and inorganic coatings; and other property enhancing uses which take advantage of having the ability to form moderate to strong hydrogen bonds to organic and inorganic surfaces, more tenaciously than most classes of polymeric coatings.
U.S. Pat. Nos. 3,944,702, 3,976,497, 3,986,997 and 4,027,073 describe coating compositions which are acid dispersions of colloidal silica and hydroxylated silsequioxane in an alcohol-water medium.
U.S. Pat. No. 4,113,665 discloses chemically resistant ambient curable coatings based on a binder of which the major portion is prepared by reacting, in an acidic solution, trialkoxysilanes (e.g., methyltriethoxysilane) with aliphatic polyols, silicones or both. Barium fillers, such as barium metaborate, may be added to provide resistance to sulfur dioxide. Zinc oxide or metallic zinc may be included for further corrosion resistance. The compositions may be applied to, e.g., steel petroleum tanks, by spraying, concrete, vitreous surfaces.
U.S. Pat. No. 4,413,086 describes water reducible coating compositions containing organosilane-polyol which is a reaction product between certain hydrophilic organic polycarbinols and organosilicon material, e.g., organosilane, curing agent (e.g., aminoplast resin), organic solvent (optional), essentially unreacted polyol (optional), essentially unreacted hydrolyzed and condensed organosilane (optional), water (optional) and pigment (optional).
U.S. Pat. No. 4,648,904 describes an aqueous emulsion of (a) hydrolyzable silane, inclusive of methyltrimethoxysilane, (b) surfactant (e.g., Table I, col. 4) and (c) water. The coatings may be used for rendering masonry water repellant.
U.S. Pat. No. 5,275,645 is purported to provide an improvement to the acid-catalyzed organosilane coating compositions of the above-mentioned U.S. Pat. No. 4,113,665. According to this patent a protective coating is obtained at ambient temperature from a coating composition containing organosilanes having an Si—O bond, using an amine catalyst and an organometallic catalyst.
U.S. Pat. No. 5,879,437 describes a coating composition containing a tetraalkyl silicate or monomeric or oligomeric hydrolysis product thereof, present in a proportion of 40-90% by weight based on the non-volatile content of the composition and a hydrous oxide sol (Type A or Type B), in an amount such that the oxide constitutes 10-60% by weight of the non-volatiles. According to the patentees, this coating composition is suitable for the pretreatment of solid surfaces such as metals generally, including steel, titanium, copper, zinc and, particularly aluminum, to improve adhesion properties of the pretreated surface to subsequently applied coatings, such as paint, varnish, lacquer; or of adhesive, either in the presence or absence of a lubricant.
U.S. Pat. No. 5,882,543 describes methods and compositions for dehydrating, passivating and coating HVAC (heating, ventilating and air conditioning) systems. The compositions include an organometalloid and/or organometallic compound, which reacts with water in the system. The sealing function of these compositions is apparently obtained by introducing the composition to the fluid enclosure and upon exiting from an opening, the composition (i.e., organometallic) reacts with atmospheric moisture to seal the opening.
U.S. Pat. No. 5,954,869 discloses an antimicrobial coating from water-stabilized organosilanes obtained by mixing an organosilane having one or more hydrolyzable groups, with a polyol containing at least two hydroxyl groups. This patent includes a broad disclosure of potential applications and end uses, e.g., column 4, lines 35-53; columns 23-25.
U.S. Pat. No. 5,959,014 relates to organosilane coatings purported to have extended shelf life. Organosilane of formula R
n
SiX
4−n
(n=0-3; R=non-hydrolyzable group; X=hydrolyzable group) is reacted with a polyol containing at least three hydroxyl groups, wherein at least any two of the at least three hydroxyl groups are separated by at least three intervening atoms.
U.S. Pat. No. 5,929,159, to J. Schutt and A. Gedeon, and commonly assigned with the present application, describes an oligomeric coating composition in the form of an aqueous composition comprising a dispersion of divalent metal cations (especially, Ca, Mn, Cu and Zn divalent ions) in lower aliphatic alcohol-water solution of the partial condensate of at least one silanol (at least about 70 wt.% of which was methyltrimethoxy silane), and acid, in amount to provide a pH in the range of from about 2.5 to about 6.2, the amount of the divalent metal cations being from about 1.2 to about 2.4 millimoles, per molar equivalent of the partial condensate, calculated as methyl silane sesquioxide. It is also described to provide a coating composition as a two part formulation, the first part being an acidic aqueous dispersion of divalent metal cation, having a pH of from about 2.2 to about 2.8; and the second part a non-aqueous composition comprising at least one trialkoxy silane; with at least one of the first and second parts comprising a volatile organic solvent. The corrosion resistant coatings may be provided as aqueous-alcoholic dispersions of the partial condensate of monomethyl silanol (obtained by hydrolysis of monomethyl alkoxysilane) alone or in admixture with minor amounts of other silanol, e.g., phenyltrimethoxysilanol, gamma-glycidyloxy silanol, and the like, wherein the reaction is catalyzed by divalent metal ions, e.g., Ca
+2
, typically from alkaline earth metal oxides. When these coating are applied to, e.g., boat hulls, such as aluminum hulls, they are highly effective in preventing corrosion from salt water for extended periods.
Thus, this patent indicates that the patented coating compositions are suitable for application to various types of substrates, but especially, marine surfaces, such as aluminum boat hulls, to render the surface corrosion resistant in a salt water environment. Other representative potential applications and substrates for the patented silane based coating compositions mentioned in the Schutt and Gedeon patent include coatings for concrete/rock, wherein the coating can penetrate the porous materials, due to its low viscosity and active nature; metals/plastics, wherein the coating is preferably applied to very clean surfaces but will itself clean the pores in the metal or plastic and exhume the contamination which generally rises to the surface of the coating.
The compositions of the Schutt, et al patent are oligomeric coatings using a variety of siloxane bond forming monomers as described. Subsequent modifications of the compositions of the U.S. Pat. No. 5,929,159 patent have been developed by John Schutt and are described, for example, in copending provisional applications Ser. Nos. 60/185,367 and 60/185,354, both filed on Feb. 28, 2000, and Se
Gedeon Anthony A.
Schutt John B.
Stanich Jeffrey
Cameron Erma
Sherman & Shallway
LandOfFree
Method for improving heat efficiency using silane coatings... 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 for improving heat efficiency using silane coatings..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for improving heat efficiency using silane coatings... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2887104