Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...
Reexamination Certificate
2000-05-10
2002-02-19
Seidleck, James J. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
C525S101000, C524S832000, C524S494000, C524S507000, C524S601000, C524S779000, C106S287130, C428S423100, C428S425800
Reexamination Certificate
active
06348544
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to tintable coating compositions, and more particularly to a tintable coating compositions made from an admixture of a carboxylated urethane polymer mixture made from 1,6-hexanediol and 4,4-methylenebis(cyclohexylisocyanate); a hydroxylated methylmethacrylate acrylic polymer; an aziridine-based cross-linking agent; and an optional solvent.
2. Description of the Related Art
Increasingly stringent environmental regulations are gradually phasing out organic solvent-based paints, coatings, and adhesives in favor of those using more innocuous solvents, such as water. Water-based polymer coating components are becoming increasingly available to impart unique characteristics to metal surfaces, such as color, gloss, adhesive layers, corrosion protection, mar and wear resistance, and the like. However, such water-based polymer coatings have not performed as well as their organic solvent-based counterparts in terms of hardness, gloss, durability, and other characteristics that are demanded from the marketplace. Consequently, there is continuing development in the area of water-based polymer coatings that perform as well as organic solvent-based polymer coatings, yet are not damaging to the environment.
U.S. Pat. No. 5,118,752 discloses aqueous polymerization of vinyl monomers, including acrylates, in the presence of a polymeric surfactant containing urethane groups and silane groups.
U.S. Pat. No. 5,141,983 discloses an aqueous coating composition comprising an aqueous polyurethane resin and an aqueous dispersion of an acrylic copolymer, and an aqueous coating composition obtained by polymerizing radical-polymerizable acrylic monomers in the presence of an aqueous urethane resin.
U.S. Pat. No. 5,204,404 discloses a water-based coating composition containing an acrylic silane polymer and a polyurethane polymer. Similarly, U.S. Pat. No. 5,286,569 also discloses a water-based coating composition containing an acrylic silane polymer and a polyurethane polymer.
U.S. Pat. No. 5,739,194 discloses an aqueous dispersion of urethane and vinyl polymers that make up a water-based coating composition.
While these coating materials may be satisfactory for certain applications, there is still need for improved tintable coating compositions that have properties such as color or decoration, gloss, mar-, wear-, and moisture-resistance, strong adhesion to the substrate, the like, yet are water-based and safe for the environment. The present invention is believed to be an answer to that need.
SUMMARY OF THE INVENTION
In one aspect, the present invention is directed to a tintable coating composition, comprising an admixture of: (A) about 2 to about 80 wt % of a carboxylated urethane polymer dispersion mixture made from 1,6-hexanediol and 4,4-methylenebis(cyclohexylisocyanate); (B) about 5 to about 65 wt % of a hydroxylated methylmethacrylate acrylic polymer emulsion; (C) about 0.1 to about 3 wt % of a crosslinking agent, the crosslinking agent comprising an aziridine-based crosslinking compound; and (D) optionally, about 0.5 wt % to about 25 wt % of a solvent; all percentages based on the total weight of the coating composition.
In another aspect, the present invention is directed to a tintable coating composition, comprising an admixture of: (A) about 2 to about 80 wt % of a carboxylated urethane polymer mixture made from 1,6-hexanediol and 4,4-methylenebis(cyclohexylisocyanate), wherein the carboxylated urethane polymer mixture comprises a mixture of a about 2 to about 75 wt % of a first carboxylated urethane polymer made from 1,6-hexanediol and 4,4-methylenebis(cyclohexylisocyanate), and having an acid number of about 36, and about 5 to about 80 wt % of a second carboxylated urethane polymer made from 1,6-hexanediol and 4,4-methylenebis(cyclohexylisocyanate), and having an acid number of about 28; (B) about 5 to about 65 wt % of a hydroxylated methylmethacrylate acrylic polymer emulsion; (C) about 0.1 to about 3 wt % of a crosslinking agent, the crosslinking agent comprising an aziridine-based crosslinking compound; (D) about 5 to about 40 wt % a decorative component selected from the group consisting of dyes, metal flakes, metal powders, glass flakes, glass powders, and combinations thereof; (E) about 0.005 to about 2 wt % of one or more additives selected from the group consisting of surfactants, defoamers, and combinations thereof; and (F) optionally, about 0.5 wt % to about 25 wt % of a solvent selected from the group consisting of water, N-methylpyrrolidone, butylcarbitol, 2-butoxyethanol, isopropyl alcohol, and combinations thereof; all percentages based on the total weight of the coating composition.
In yet another aspect, the present invention is directed to substrates coated with the above tintable coating compositions.
These and other aspects will be more fully understood from the following detailed description of the invention.
DETAILED DESCRIPTION OF THE INVENTION
It has now been found, in accordance with the present invention, that an admixture of (1) about 2 to about 80 wt % of a carboxylated urethane polymer dispersion mixture made from 1,6-hexanediol and 4,4-methylenebis(cyclohexylisocyanate); (B) about 5 to about 65 wt % of a hydroxylated methylmethacrylate acrylic polymer emulsion; and (C) about 0.1 to about 3 wt % of a crosslinker comprising an aziridine-based crosslinking agent forms a water-based coating composition that possesses excellent hardness, durability, and wear-resistance. The coating composition of the invention has a low VOC (volatile organic content) and can be pigmented with many existing commercial pigments or other decorative additives to form “tinted”coatings. The composition has excellent adhesion to a variety of substrates such as aluminum, copper, stainless steel, cold rolled steel, phosphatized steel, steel coated with conventional primers such as electrodeposition primers and the like, plastic substrates such as polyester reinforced fiber glass, injection molded urethanes, polystyrenes, and polyimides. A clear coat can be applied to a layer of the tinted composition to provide a clear/color coat finish. The coating composition used for the clear coat can be the coating composition of this invention or another compatible aqueous or solvent based coating composition.
As used herein, the term “tintable” refers broadly to the presence of a decorative component in the composition of the present invention, such as a colorant, dye, pigment, metal flake or powder, or glass flake or powder, or other decorative component, to provide the coating composition with color or other decorative effect. The term “dispersion”, as used herein, refers generally to a two-phase system where one phase consists of finely divided particles distributed throughout a bulk substance (usually a solvent). The term “emulsion” refers to a stable mixture of two or more immiscible liquids held in suspension by small amounts of emulsifiers.
As mentioned above, the invention is a tintable coating composition, comprising an admixture containing primarily (A) a carboxylated urethane polymer dispersion mixture made from 1,6-hexanediol, and 4,4-methylenebis(cyclohexylisocyanate); (B) a hydroxylated methylmethacrylate acrylic polymer emulsion; (C) a crosslinking agent that comprises an aziridine-based crosslinking compound; and (D) optionally, a solvent. Each of these components is discussed in more detail below.
The carboxylated urethane polymer dispersion component of the present composition is a dispersion made from a combination of 1,6-hexanediol and 4,4-methylenebis(cyclohexylisocyanate). The solvent portion of the dispersion may be water, or a combination of water and water-miscible or water-immiscible organic solvents. A preferred material is sold under the trade name QW 18-1 (available commercially from SIA Polymers, Inc., Seabrook, NH) and has an acid number of about 36. When cured, this particular product, by itself, has a sword hardness of about 25. Another preferred material having a similar combination of ing
Bagwell Melanie D.
Garabedian Todd E.
Olin Corporation
Seidleck James J.
Wiggin & Dana LLP
LandOfFree
Tintable water-based coating composition does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Tintable water-based coating composition, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tintable water-based coating composition will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2959979