Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
2000-03-22
2003-02-11
Reddick, Judy M. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C524S077000, C524S104000, C524S140000, C524S270000, C524S271000, C524S272000, C524S276000, C524S277000, C524S284000, C524S292000, C524S296000, C524S297000, C524S317000, C524S369000, C524S377000, C524S457000, C524S458000, C524S475000, C524S487000, C524S514000, C524S538000, C525S179000, C525S180000, C525S181000, C525S182000, C525S183000, C525S184000
Reexamination Certificate
active
06518334
ABSTRACT:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
None.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is related to the preparation of aqueous dispersions of polymer blends. The polymer blends are composed of polycarboxypolyamide resins and alkali dispersible resins. The invention is further related to coatings, such as inks, floor finishes, paints, overprint varnishes, sizings, adhesives and the like employing the dispersions of the polymer blends.
2. Related Background Art
The preparation and use of alkali soluble resins are is closed in U.S. Pat. No. 5,183,847. These resins are carboxylated polyamide/acrylic resins and are synthesized in a two step fusion process. The polyamide is first condensed with a carboxylated rosin (e.g., maleated or fumarated rosin) at elevated temperatures in the range 200°-240° C. and this fusion product is further condensed with an acrylic or styrene/acrylic copolymer at 230° C. The resulting fusion resin can be dissolved or dispersed in water by neutralizing the acid groups with ammonia and/or amines.
In U.S. Pat. No. 5,180,782 compositions and methods of producing ammoniated water-soluble resins such as carboxylated polyamide-acrylic, carboxylated polyamide-styrene-acrylic or carboxylated polyamide-styrene-maleic resins are disclosed. The carboxylated polyamide is first prepared by the well-known procedure of heat fusion of a carboxylate rosin with a polyamide resin. The carboxylated polyamides resin must have an acid number of 65 or higher. The polyamide-acrylic resin is then prepared by blending, preferably at a temperature of 60 to 80° C., an aqueous solution of the carboxylated polyamide fusion product with an ammoniated aqueous solution of styrene-acrylic, styrene-maleic or all-acrylic resin until the two resins are compatible. Also described are resins synthesized with acid numbers in the range of 80-150 by a high temperature (180-250° C.) fusion reaction.
The use of anionic polyamide resin suspensoids in the preparation of paper products is disclosed in U.S. Pat. No. 2,926,117. The suspensoids employed are derived from polyamides prepared by reacting polymeric fatty acids with polyalkylene polyamines (e.g. diethylene triamine, triethylene tetraamine etc.). The polyamides are required to have high acid number of at least 50 and preferably 75-100. The polyamides are dispersed in an aqueous medium by reaction of the free carboxy groups with an aqueous alkali (e.g., inorganic and organic bases). The amount of alkali employed is only part of the quantity that would be required to completely neutralize the acid (usually, a quantity equivalent to an acid number of 25 to 50 is sufficient).
The dispersion process disclosed in U.S. Pat. No. 2,926,117 is carried out by mixing the resin with an aqueous alkali and heating the mixture. The resin disperses readily to form a stable suspensoid.
An example of a water dispersible polyamide blend is disclosed in U.S. Pat. No. 4,810,747. The polyamide blend is composed of two polyamide resins. The first resin comprises the reaction product of dibasic derivatives of fatty acids, monobasic acid and organic polyamides with an acid number of 20 to 50. The second resin comprises isophthalic acid, dibasic derivatives of fatty acids and organic polyamides with an acid number of 50 to 120. When the two resins are mixed the resulting polymer blend is water dispersible.
U.S. Pat. No. 4,973,617 disclose water-borne printing ink compositions based on acrylic resins and carboxylated rosin modified polyamides. The carboxylated rosin modified polyamides are prepared by a high temperature heat fusion process between a carboxylated rosin and polyamide polymer.
While many examples of aqueous resin blends containing polyamides modified by fusion reaction with a carboxylated resin are known, there remains a need for aqueous dispersions of polyamide resins that have relatively low acid number. Additionally, the polyamide resins should also be easily dispersed in basic aqueous solutions without large amounts of alcohol and have excellent storage stability.
SUMMARY OF THE INVENTION
This invention relates to polymer blends comprising a polycarboxypolyamide resin with an alkali dispersible resin. This invention also relates to the use of the polymer blends to prepare aqueous dispersions. The aqueous dispersions are generally comprised of 20 to 50 percent non-volatile material and 50 to 80 percent water. The aqueous dispersions are obtained by heating the polycarboxypolyamide resins with alkali dispersible resins in an aqueous medium. The dispersions have very fine particle size (i.e., less than 100 nm) and are useful as components of coatings (e.g., paints, varnishes, paper sizes, floor finishes, inks and adhesives, etc.).
In one preferred embodiment of the subject invention the polymer blend composition is useful in an aqueous dispersion and comprises: (a) a water insoluble polycarboxypolyamide resin in an amount from about 30 to about 90 percent by weight of the blend, having an acid number from about 25 to about 60; and (b) an alkali dispersible resin in an amount from about 10 to about 70 percent by weight of the blend. The polycarboxypolyamide resin has a number-average molecular weight of about 2,000 to about 20,000. Typically, the alkali dispersion resin has an acid number from about 75 to about 500 with a number-average molecular weight of about 500 to about 20,000.
The invention also relates to a blended polymer aqueous dispersion comprising:
(a) a water insouluble polycarboxypolyamide resin in an amount from about 30 to about 90 percent by weight of the total solids of the dispersion, having an acid number from about 25 to about 60;
(b) an alkali dispersible resin in an amount from about 10 to about 70 percent by weight of the total solids of the dispersion;
(c) at least one nonionic or anionic surfactant in an amount from about 0 to about 10 percent by weight of the total solids of the dispersion;
(d) a base in an amount from about 70 to about 150 percent of the amount required to neutralize acid functionality of the components (a) and (b); and
(e) water.
This invention also relates to methods for preparing aqueous dispersions of the disclosed polymer blends. Yet another embodiment of this invention is directed to coating compositions containing the aqueous dispersions disclosed in the subject application. These compositions include, for example, paper sizing agents, thermoset coatings, latexes and emulsion polymers, floor finishes, inks, adhesives and overprint varnishes. Another embodiment of this invention includes emulsion support resins prepared with the aqueous dispersions of this invention.
DETAILED DESCRIPTION OF THE INVENTION
This invention relates to polymer blends of water insoluble polycarboxypolyamide resins which are readily dispersed in aqueous media in the presence of alkali dispersible resins. Additionally, the polymer blends may be comprised of nonionic or anionic surfactants.
Preferably, the polycarboxypolyamide resin comprises about 30 to about 90 percent of the total solids of the polymer blend composition. More preferably, the polycarboxypolyamide resin comprises about 50 to 80 percent of the total solids of the polymer blend.
The term “polycarboxypolyamide resin” means polyamide resins containing carboxylic acid functionality. Typically, the polycarboxypolyamide resins are formed as the result of a high temperature fusion reaction between a polyamide resin and a carboxylic acid containing resin or as the result of a chemical condensation reaction between an excess of a carboxylic acid resin material (diacid) and an amine resin material (diamine).
The number-average molecular weight (Mn) of the polycarboxypolyamides generally range from about 2,000 to about 20,000. Preferably, the polycarboxypolyamides have acid numbers ranging from about 25 to about 60. More preferably, the polycarboxypolyamides have acid numbers ranging from about 35 to about 60. Most preferably, the polycarboxypolyamides have acid numbers ranging from about 45 to about 60.
The preparation of p
Calhoun Glenn C.
Sarkis Michael T.
Bovee Warren R.
Hamilton Neil E.
JohnsonDiversey, Inc.
Reddick Judy M.
Rymarz Renee J.
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