Patent US3986998A successfully refreshed from Google Patents.
US3986998A
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US
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Mixing liquid for silicate cements
Assignee: SIH Stiftung and Co Industrie Holding KG
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Filing: 1973-10-10
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Granted: 1976-10-19
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Expires: 1993-10-10
Abstract
Abstract Dental cements are prepared by mixing a silicate powder with an aqueous solution of polymers of unsaturated alpha, beta-dicarboxylic acids.
Inventors
- 👤 Werner Schmitt
- 👤 Robert Purrmann
- 👤 Peter Jochum
- 👤 Wolf-Dieter Zahler
- 👤 Rainer Grimm-Lenz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:33
CPC Classifications
C; C08; C08K; C08K3/00; C08K3/34; A; A61; A61K; A61K6/00; A61K6/80; A61K6/849; A61K6/853; A61K6/884; A61K6/887; A61K6/889
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
120 words
The method of making a dental silicate cement comprising forming a paste by mixing an aluminum fluorosilicate glass powder with an aqueous solution of a solid polymeric material selected from the group consisting of a homopolymer of an ethylenically unsaturated alpha, beta-dicarboxylic acid of 4-5 carbon atoms, a copolymer of said acids with each other, and a copolymer of said acids with less than 10 mole percent of an ethylenically unsaturated monocarboxylic acid, methacrylic ester wherein the ester moiety is alkyl of 1-4 carbon atoms or methacrylic amide, said aqueous solution containing 20-65 weight percent polymer and having a viscosity of 0.5 to 3000 poise at 25° C. and subsequently permitting said paste to harden into a dental silicate cement.
Claim 2
Independent Claim
120 words
The method of making a dental silicate cement comprising forming a paste by mixing an aluminum fluorosilicate glass powder with an aqueous solution of a solid polymeric material selected from the group consisting of a homopolymer of an ethylenically unsaturated alpha, beta-dicarboxylic acid of 4-5 carbon atoms, a copolymer of said acids with each other, and a copolymer of said acids with less than 10 mole percent of an ethylenically unsaturated monocarboxylic acid, methacrylic ester wherein the ester moiety is alkyl of 1-4 carbon atoms or methacrylic amide, said aqueous solution containing 20-65 weight percent polymer and having a viscosity of 0.5 to 3000 poise at 25° C. and subsequently permitting said paste to harden into a dental silicate cement.
Claim 3
Dependent Claim
28 words
The method of claim 1, wherein the aqueous solution contains 35-65 weight percent polymer and the solution has a viscosity of 2 to 200 poise at 25° C.
Claim 4
Dependent Claim
28 words
The method of claim 1, wherein the aqueous solution contains 40-50 weight percent polymer and the solution has a viscosity of 5 to 100 poise at 25° C.
Claim 5
Dependent Claim
11 words
The method of claim 1, wherein the polymer is polymaleic acid.
Claim 6
Dependent Claim
24 words
The method of claim 1, wherein the aqueous solution additionally contains dissolved therein about 0.1-50% based on said polymeric material of solid polyacrylic acid.
Claim 7
Dependent Claim
20 words
The method of claim 1, wherein the weight ratio of the silicate powder to mixing liquid is 1.5:1 to 2.5:1.
Claim 8
Dependent Claim
12 words
The hardened dental silicate cement made by the method of claim 1.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-10-19 | 1980-04-19 | 1980-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-19 | 1984-04-19 | 1984-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-19 | 1988-04-19 | 1988-10-19 | $7700.00 | Window Closed / Lapsed |