Abstract: Novel anionic polymeric hydrogels based on sulfonated amino aldehyde resins and a process for preparing such hydrogels are described. The hydrogels may include poly(N-vinyl 2-pyrrolidone) and other additives. Such hydrogels may be prepared by a four step process in which melamine and/or urea are reacted with formaldehyde, sulfonated, condensed to form a viscous gel and dried.

Abstract: A degradable agricultural mulch film as disclosed herein includes a plurality of layers for the controlled release of plant nutrients. The first layer is formed from a water-soluble synthetic resin, a releasable form of nitrogen and a releasable form of a plant nutrient in addition to nitrogen. A second layer includes a water-soluble synthetic resin having an average molecular weight which is greater than the average molecular weight of the water-soluble synthetic resin in the first layer and a releasable form of nitrogen admixed therein. The second layer also includes a thin film of water-resistant polymer to retard the degradation rate of the second layer and to slow the release of nitrogen in the second layer. And in the preferred embodiment of the invention a second film of water-resistant polymer which is relatively thin with respect to the first film separates the first and second layers.

Abstract: A drilling fluid includes a water soluble polymer such as a sulfonated amino-formaldehyde and/or methyl cellulose or polyvinyl alcohol in addition to water, bentonite and a weighting agent such as barite. And, these drilling fluids have improved heat stability and are useful for drilling a borehole into a subterranean formation using conventional drilling equipment.

Abstract: A highly stable melamine-formaldehyde condensate solution for use as superplasticizer additives for cement or the like is produced by condensing melamine and formaldehyde in an aqueous medium, sulfonating the melamine-formaldehyde condensate, further condensing and stabilizing the aqueous sulfonated melamine-formaldehyde condensate solution.

Abstract: Thermally stable water soluble resins are prepared in a multistep process by reacting the waste solids from the mother liquor waste stream of a melamine manufacturing plant with an aldehyde and a sulfonating agent under controlled conditions of pH and temperature. The resin compositions are useful, for example, as superplasticizing agents for concrete admixtures, as mud drilling additives, and in the paper and textile industry. The process not only provides useful resin compositions, but also recovers solid wastes which are considered to be a major contributor to the pollution problems of melamine manufacturing plants.

Abstract: The present invention relates to a method for improving the mechanical properties of soil. The method uses an aqueous solution of a sulfonated urea melamine formaldehyde resin and a water soluble polyvinyl alcohol having a molecular weight between 40,000 and 120,000. The aqueous solution is sprayed onto the surface of the soil.A number of water soluble compositions which include a sulfonated urea melamine formaldehyde resin and polyvinyl alcohol and methods for making the same are also disclosed.

Abstract: An agricultural mulch film is prepared by mixing conventional plant nutrients with a water-soluble polymer such as polyvinyl alcohol. The mixture is cast in the liquid form and allowed to dry to form a thin film. The dried film is then coated with a thin layer of a water-resistant resin such as polyvinyl acetate to form a composite mulch film. The release of the nutrients contained in the mulch film is controlled by the addition to the water-soluble polymer mixture of either (1) a nitrification inhibitor along with urea, or (2) a water-soluble urea-formaldehyde condensation product. The release of the nutrients is also controlled somewhat by the water-resistant resin coating. Other additives may be added to the mulch film to produce a multi-purpose product.

Abstract: Stable, water soluble, sulfonated melamine-formaldehyde and sulfonated melamine-urea-formaldehyde resin solutions are prepared in a four stage procedure, wherein (1) melamine or melamine and urea are condensed with formaldehyde in an aqueous medium at a relative low temperature and a pH of 10-13, followed by (2) the addition of a sulfonating agent, such as sodium metabisulfite, and continued reaction without pH adjustment, followed by (3) lowering the temperature of the reaction medium to 40.degree.-60.degree. C., adjusting the pH to 2.5-4 and continuing the reaction for about 5-150 minutes, and finally followed by (4) adjusting the pH to 6.5-9, heating the reaction medium to 70.degree.-100.degree. C. for 30-180 minutes, adjusting the final solids content to a predetermined value, such as 20%, and adjusting the pH to 8-11. The resulting aqueous solutions are suitable for use as superplasticizer additives to hydraulically settable cementitious materials.

Abstract: Thermally stable water soluble resins are prepared in a multistep process by reacting the waste solids from the mother liquor waste stream of a melamine manufacturing plant with an aldehyde and a sulfonating agent under controlled conditions of pH and temperature. The resin compositions are useful, for example, as superplasticizing agents for concrete mixtures, as mud drilling additives, and in the paper and textile industry. The process not only provides useful resin compositions, but also recovers solid wastes which are considered to be a major contributor to the pollution problems of melamine manufacturing plants.