Abstract: A curable silicone dental impression composition is presented, preferably comprising a polyorganohydrogensiloxane having at least one silicon-bonded hydrogen atom; a silicone polymer having at least alkenyl groups; a vinyl siloxane/platinum/palladium catalyst complex; and inorganic fillers and other additives known in the art. The catalyst in accordance with the present invention is a complex of 1,3-divinyltetramethyldisiloxane and hexachloroplatinic acid doped with palladium, and prevents outgassing of hydrogen. The final catalyst complex has a platinum content in the range from about 1.1%-1.2% platinum and 500-600 ppm palladium.

Abstract: A dental impression composition for use in the preparation of the oral tissue models comprising a dimethicone-based polysiloxane polyester polymer having terminal fluorinated alkoxy substituents such that the fluorine content of the polysiloxane polyester is in the range from about 5% to about 30% by weight, and having the general formula A--?--B--C--!.sub.x --A, wherein x is an integer greater than 1; A is a fluorinated alkoxy group having the formula F.sub.3 C(CF.sub.2).sub.n (CH.sub.2).sub.m O-- wherein n is an integer from 3 to 17 and m is an integer from 2 to 4; B is a diacid; and C is a dimethicone-based polysiloxane copolyol having the formula:Me.sub.3 Si--?--OSiMeR.sup.1 --!--?--OSiMeR.sup.1 --!.sub.o --?--OSiMeR--!.sub.q --OSiMe.sub.3wherein Me is methyl, R is methyl or phenyl, o is an integer in the range from 1 to 19, q is an integer in the range from 0 to 200, and R.sup.1 is a polyoxyalkylene substituent having the formula--(--CH.sub.2).sub.3 --(DO).sub.a (EO).sub.b (FO--).sub.

Abstract: Zirconium based granules are produced by the steps of forming an aqueous solution of a zirconium compound such as zirconium acetate, combining the aqueous solution with a phase stabilizer, and then heating the solution to evaporation thereby forming amorphous zirconium based granules.In an alternate embodiment, an alcohol solution of a zirconium compound such as zirconium propoxide in propanol is acidified and hydrolyzed with water. The partially or fully hydrolyzed zirconium complex is mixed with a phase stabilizer to form a homogeneous solution. The solution is then subjected to evaporation by heat to form amorphous zirconium based granules.Zirconia fibers are produced by making aqueous solutions of the amorphous zirconium based granules containing the phase stabilizer to the desired viscosity, fiberizing the solution, and finally converting the fibers under appropriate conditions.

Abstract: Zirconium based granules are produced by the steps of forming an aqueous solution of a zirconium compound such as zirconium acetate, combining the aqueous solution with a phase stabilizer, and then heating the solution to evaporation thereby forming amorphous zirconium based granules.In an alternate embodiment, an alcohol solution of a zirconium compound such as zirconium propoxide in propanol is acidified and hydrolyzed with water. The partially or fully hydrolyzed zirconium complex is mixed with a phase stabilizer to form a homogeneous solution. The solution is then subjected to evaporation by heat to form amorphous zirconium based granules.Zirconia fibers are produced by making aqueous solutions of the amorphous zirconium based granules containing the phase stabilizer to the desired viscosity, fiberizing the solution, and finally converting the fibers under appropriate conditions.

Abstract: Polymeric silicon alkoxide solutions are produced and then stabilized by the addition of calcium acetate. The calcium acetate serves to prevent the rapid evaporation of the polymerized silicon solution when applied as a coating to various substrates. Glass fiber substrates are preferred.

Abstract: A sol-gel coated substrate is additionally coated with certain disclosed aqueous quaternary ammonium hydroxide and/or alkanol amine compounds. Through this procedure, the drying time achieved to effect a crack-free coated substrate is greatly reduced. Also disclosed are coated substrates prepared by the process of the present invention.

Abstract: A process for the production of polymeric substances from metal alkoxides is provided comprising the steps of:(a) reacting at least a monofunctional carboxylic acid and at least a monofunctional hydroxylated organic compound in the presence of a suitable esterification catalyst to yield water in situ, and thereafter;(b) adding to the reaction mixture in (a) above at least a divalent metal alkoxide in an amount sufficient to form the desired polymeric network of at least partially hydrolyzed metal alkoxide.Also provided is a process for coating a substrate comprising applying the above disclosed polymeric substance to a substrate preferably by a dipping, spraying, or spinning technique. Articles coated with the polymeric substance provided by the process of the present invention are also disclosed.