Patents by Inventor Robert Purrmann
Robert Purrmann has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
-
Patent number: 4927866Abstract: A shapable material is disclosed which contains:(a) an aluminum fluorosilicate glass;(b) at least one polycarboxylic acid having an average molecular weight greater than 500;(c) a carbonate and/or hydrogen carbonate in an amount of at least 0.1% by weight, based on (a);(d) optionally a chelating agent; and(e) optionally water.Said material is especially suited as bone replacement material and can be shaped into porous articles.Type: GrantFiled: February 28, 1989Date of Patent: May 22, 1990Assignee: ESPE Stiftung & Co. Produktions- und Vertriebs KGInventors: Robert Purrmann, Rainer Guggenberger, Gunter Pieper
-
Patent number: 4544742Abstract: 1,2,6-Thiadiazine-3,5-dione-1,1-dioxides of the general formula ##STR1## wherein each R and R.sub.3 independently may be substituted or unsubstituted alkyl, alkenyl or substituted cycloalkyl are described. These compounds, as well as those wherein the R substituents additionally may be cycloalkyl or substituted or unsubstituted aryl, are useful as accelerators for the peroxidic polymerization of ethylenically unsaturated compounds, such as methacrylic acid compounds, and have particular utility in dental compositions.Type: GrantFiled: February 28, 1984Date of Patent: October 1, 1985Inventors: Werner Schmitt, Robert Purrmann, Peter Jochum, Heinz-Joachim Hubner, Bernd Burger
-
Patent number: 4493911Abstract: Impression materials based on cross-linked aziridino-polyester compounds which tend to adhere to the surface to be reproduced, are made nonadhesive by the addition of 1-15% by weight of oleic acid ethanolamide with respect to the aziridino-polyether component, and may thereafter be more easily and smoothly released from the object to be reproduced.Type: GrantFiled: December 9, 1983Date of Patent: January 15, 1985Assignee: Espe Fabrik pharmazeutischer Praparate, GmbHInventors: Werner Schmitt, Robert Purrmann, Peter Jochum
-
Patent number: 4443587Abstract: 1,2,6-Thiadiazine-3,5-dione-1,1-dioxides of the general formula ##STR1## wherein each R and R.sub.3 independently may be substituted or unsubstituted alkyl, alkenyl or substituted cycloalkyl are described. These compounds, as well as those wherein the R substituents additionally may be cycloalkyl or substituted or unsubstituted aryl, are useful as accelerators for the peroxidic polymerization of ethylenically unsaturated compounds, such as methacrylic acid compounds, and have particular utility in dental compositions.Type: GrantFiled: February 18, 1982Date of Patent: April 17, 1984Assignee: Abitz, Morf, GritschnederInventors: Werner Schmitt, Robert Purrmann, Peter Jochum, Heinz-Joachim Hubner, Bernd Burger
-
Patent number: 4389497Abstract: The invention relates to the use of agglomerates of silicic acid having an average agglomerate size of 0.5 to 50 .mu.m, containing primary particles of silicic acid having an average particle size of 1 to 100 nm and serving as filler in dental materials on the basis of ethylenically unsaturated polymerizable monomers. This reinforcing filler is practically colorless and can be blended in considerable quantity into the polymerizable monomer material especially mono-functional and di-functional as well as polyfunctional esters of the acrylic acid and the methacrylic acid and yields a satisfactorily processable plastically deformable paste. If necessary, the agglomerated silicic acid is used together with non-agglomerated micro-fine silicic acid of an average particle size of 1 to 100 nm.Type: GrantFiled: July 22, 1981Date of Patent: June 21, 1983Assignee: Espe Fabrik parmazeutischer Praparate GmbHInventors: Werner Schmitt, Robert Purrmann, Peter Jochum, Heinz-Joachim Hubner
-
Patent number: 4376835Abstract: A calcium aluminum fluorosilicate glass powder is disclosed which has average particle size of at least 0.5 microns, and is characterized in that the calcium in the surface of the powder's particles is depleted so that the quotient of the atomic ratio Si/Ca at the surface of the particles and the atomic ratio Si/Ca in the core region of the particles is at least 2.0, more preferably at least 3.0 and most preferably at least 4.0. The glass powder may be prepared by surface treating calcium aluminum fluorosilicate glass powder particles with an acid which forms calcium salts, washing the calcium salts off the treated particles and drying the washed particles.The glass powder has utility in self-hardening glass ionomer cements, such as dental or bone cements. Cements formed from the glass powder exhibit reduced periods of water sensitivity, while permitting sufficient time for processing.Type: GrantFiled: January 4, 1982Date of Patent: March 15, 1983Assignee: ESPE Fabrik Pharmazeutischer Praparate GmbHInventors: Werner Schmitt, Robert Purrmann, Peter Jochum, Oswald Gasser
-
Patent number: 4372836Abstract: An improved opaque, photopolymerizable dental filling material is provided comprised of acrylic acid ester compounds containing mono and/or polyfunctional acrylic or methacrylic ester compounds, photoinitiators, pigments and possibly activators and silicon dioxide or silicate fillers, the improvement comprising the presence of finely divided calcium fluoride as a white pigment in a quantity of from 1-20 percent by weight. The presence of the calcium fluoride enables an opaque effect to be achieved without reducing the permeability of the filling material to polymerization radiation.Type: GrantFiled: July 31, 1979Date of Patent: February 8, 1983Assignee: Espe Fabrik Parmazeutischer Praparate GmbHInventors: Werner Schmitt, Robert Purrmann, Peter Jochum, Heinz-Joachim Hubner
-
Patent number: 4360605Abstract: Dental glass ionomer cements are obtained by using as a mixing component for preparing the final cement mixture either a liquid mixing component comprising an aqueous solution of a certain maleic acid-acrylic acid-copolymer and optionally usual additives or a solid, powdery mixing component comprising a powder mixture of a glass ionomer cement powder and the maleic acid-acrylic acid-copolymer in solid form and optionally usual additives.Type: GrantFiled: August 5, 1980Date of Patent: November 23, 1982Assignee: Espe Fabrik pharmazeutischer Praparate GmbHInventors: Werner Schmitt, Robert Purrmann, Peter Jochum, Oswald Gasser
-
Patent number: 4189365Abstract: An improved photopolymerizable composition based on acrylic or methacrylic acid esters is disclosed. In addition to the mono- or polyfunctional acrylic or methacrylic acid ester compounds, an aliphatic, aromatic or mixed aliphatic-aromatic organic phosphite compound (in an amount of from about 0.1 to 20 percent by weight of the photopolymerizable ester compounds) and a monoketal of an aromatic 1,2-diketone compound (e.g., benzildimethylketal) are included as ultraviolet initiators to dramatically reduce the polymerization time of the composition without adversely affecting its stability.Type: GrantFiled: March 15, 1978Date of Patent: February 19, 1980Assignee: ESPE Fabrik Pharmazeutischer Praparate GmbHInventors: Werner Schmitt, Robert Purrmann, Peter Jochum
-
Patent number: 4131729Abstract: An improved dental composition having shortened hardening time and after hardening increased compressive strength and abrasion resistance, including a radical-inducing compound and a polymerizable acrylic or methacrylic acid ester or diester compound with at least 20 percent by weight of the polymerizable compound being the diacrylic or dimethacrylic acid ester of bishydroxymethyltricyclo [5.2.1.0.sup.2,6 ]-decane. Other monofunctional or difunctional acrylic or methacrylic acid esters as well as fillers, pigments and stabilizers can be included.Type: GrantFiled: April 21, 1978Date of Patent: December 26, 1978Assignee: ESPE Fabrik Pharmazeutischer Praparate GmbHInventors: Werner Schmitt, Robert Purrmann, Peter Jochum, Wolf-Dietrich Zahler
-
Patent number: 4116788Abstract: An improved process for the photopolymerization of compositions including photopolymerizable acrylic or methacrylic acid esters and an initiator (e.g., a benzoin compound) is disclosed. The addition of 0.1 to 20 weight percent (based on the amount of polymerizable material) of an organic phosphite substantially reduces the polymerization time of the resulting composition.Type: GrantFiled: November 19, 1976Date of Patent: September 26, 1978Assignee: ESPE Fabrik Pharmazeutischer Praparate GmbHInventors: Werner Schmitt, Robert Purrmann, Peter Jochum
-
Patent number: 4095018Abstract: An improvement in the redox polymerization of unsaturated compounds, e.g., acrylic or methacrylic acids or their ester derivatives, using novel accelerators is disclosed. The polymerization is performed utilizing as the accelerator N,N-bis-hydroxyalkyl-3,5-di-t-butyl anilines having the structural formula ##STR1## wherein R.sub.1 and R.sub.2 are the same or different and are H or a lower alkyl group having 1 to 4 carbon atoms. The resulting polymers are highly resistant to discoloration.Type: GrantFiled: December 17, 1976Date of Patent: June 13, 1978Assignee: ESPE Fabrik Pharmazeutischer Praparate GmbHInventors: Werner Schmitt, Robert Purrmann, Peter Jochum
-
Patent number: 4093555Abstract: Novel bromine-containing compounds of the formula ##STR1## in which R is an alkylidene radical having 1 to 6 carbon atoms, a cycloalkylidene radical or a SO.sub.2 radical, R' is an alkylene radical having 2 to 6 carbon atoms or a cycloalkylene radical and Y is an acyl radical of a carboxylic acid having 2 to 6 carbon atoms and optionally bearing an aromatic substituent, and x is 1 or 2 and y is 0, 1 or 2, which are particularly useful for the preparation of dental replacement parts and dental models when mixed with a substance that catalyzes the polymerization of the compounds.Type: GrantFiled: January 4, 1977Date of Patent: June 6, 1978Assignee: ESPE Fabrik Pharmazeutischer Praparate GmbHInventors: Werner Schmitt, Robert Purrmann, Peter Jochum, Wolf-Dietrich Zahler
-
Patent number: 4082722Abstract: Compositions, which may be mixed with water to prepare a dental silicate cement, consist essentially of a silicate glass powder and a solid polymeric material selected of polymers of unsaturated .alpha.,.beta.-dicarboxylic acids.Type: GrantFiled: September 8, 1976Date of Patent: April 4, 1978Inventors: Werner Schmitt, Robert Purrmann, Peter Jochum, Wolf-Dieter Zahler, Rainer Grimm-Lenz
-
Patent number: 4067853Abstract: Superior artificial teeth, dentures, other dental replacement parts and dental prosthetic articles and devices, which exhibit high abrasion resistance, stability to moisture and which do not undergo volume changes, are obtained by polymerization of a compound of the formula ##STR1## in which R is H or -CH.sub.3, X is an alkylidene or the -SO.sub.2 -group, Y is an oxyalkylene group having between 2 and 5 carbon atoms, or an alkylidene group having between 1 and 5 carbon atoms. In some instances, the polymerization is carried out in the presence of a filler.Type: GrantFiled: August 1, 1975Date of Patent: January 10, 1978Assignee: ESPE Fabrik pharmazeutischer Praparate GmbHInventors: Werner Schmitt, Robert Purrmann, Peter Jochum, Wolf Dieter Zahler
-
Patent number: 3986998Abstract: Dental cements are prepared by mixing a silicate powder with an aqueous solution of polymers of unsaturated alpha, beta-dicarboxylic acids.Type: GrantFiled: October 10, 1973Date of Patent: October 19, 1976Assignee: ESPE, Fabrik Pharmazeutischer Praparate GmbHInventors: Werner Schmitt, Robert Purrmann, Peter Jochum, Wolf-Dieter Zahler, Rainer Grimm-Lenz