US4182829A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Impression materials for dentistry
Assignee: Bayer AG
•
Filing: 1978-05-08
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Granted: 1980-01-08
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Expires: 1998-05-08
Abstract
Abstract The invention provides impression materials for use in dentistry comprising the reaction product of (a) a diisocyanate or triisocyanate, (b) a dihydroxy compound having a molecular weight of from 300 to 10,000 and (c) an unsaturated monohydroxy compound. The invention also includes processes for preparing said impression materials.
Inventors
- 👤 Michael Walkowiak
- 👤 Hans-Hermann Schulz
- 👤 Hans J. Rosenkranz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:29
CPC Classifications
C; C08; C08F; C08F299/00; C08F299/02; C08F299/06; A; A61; A61K; A61K6/00; A61K6/90; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/67; C08G18/671; C08G18/672
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
86 words
An impression material for use in dentistry comprising (I) the reaction product of (a) a diisocyanate or triisocyanate, (b) a dihydroxy compound selected from the group consisting of polyesters, polyethers, polythioethers, polyacetals, polycarbonates and polyester-amides having a molecular weight of from 300 to 10,000 and (c) a derivative of acrylic and/or methacrylic acid having a hydroxyl group wherein the molar ratio of compounds (a), (b) and (c) is 2:1:2, and (II) an inert dental carrier, said impression material having a hardening time of about 4-5 minutes.
Claim 2
Dependent Claim
86 words
An impression material for use in dentistry comprising (I) the reaction product of (a) a diisocyanate or triisocyanate, (b) a dihydroxy compound selected from the group consisting of polyesters, polyethers, polythioethers, polyacetals, polycarbonates and polyester-amides having a molecular weight of from 300 to 10,000 and (c) a derivative of acrylic and/or methacrylic acid having a hydroxyl group wherein the molar ratio of compounds (a), (b) and (c) is 2:1:2, and (II) an inert dental carrier, said impression material having a hardening time of about 4-5 minutes.
Claim 3
Dependent Claim
13 words
A material according to claim 1 wherein the isocyanate (a) is a diisocyanate.
Claim 4
Dependent Claim
16 words
A material according to claim 2 wherein the diisocyanate (a) is hexamethylene-diisocyanate, toluylene-diisocyanate, isophorone-diisocyanate or diphenylmethane-4,4'-diisocyanate.
Claim 5
Dependent Claim
20 words
A material according to claim 2 wherein the dihydroxy compound (b) has a molecular weight of from 1,000 to 8,000.
Claim 6
Dependent Claim
31 words
A process for preparing an impression material according to claim 1 which comprises mixing the dihydroxy compound (b) with the monohydroxy compound (c), then reacting the mixture with the diisocyanate (a).
Claim 7
Dependent Claim
29 words
A process for preparing an impression material according to claim 1 which comprises reacting equimolar amounts of compounds (a) and (c), then reacting the reaction product with compound (b).
Claim 8
Dependent Claim
16 words
A process according to claim 5 wherein a polymerization inhibitor is present to prevent premature gelling.
Claim 9
Dependent Claim
16 words
A process according to claim 6 wherein a polymerization inhibitor is present to prevent premature gelling.
Claim 10
Dependent Claim
12 words
An impression material according to claim 1 additionally containing a hardening catalyst.
Claim 11
Dependent Claim
20 words
A material according to claim 1 wherein the dihydroxy compound (b) has a molecular weight of from 2,000 to 4,000.
Claim 12
Dependent Claim
20 words
A material according to claim 2 wherein the dihydroxy compound (b) has a molecular weight of from 2,000 to 4,000.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-01-07 | 1983-07-09 | 1984-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-01-07 | 1987-07-09 | 1988-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-01-07 | 1991-07-09 | 1992-01-08 | $7700.00 | Window Closed / Lapsed |