US3998792A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyvinyl butyral polymer mixture for making intermediate sheeting for laminated glass
Assignee: Hoechst AG
•
Filing: 1975-11-11
•
Granted: 1976-12-21
•
Expires: 1995-11-11
Abstract
Abstract Mixtures of two distinct polyvinyl butyral grades, viz., one high viscosity and one low viscosity grade, both having a narrow molecular weight distribution exhibit good processing characteristics which nearly reach the performance of the high viscosity grades hitherto used.
Inventors
- 👤 Hans Dieter Hermann
- 👤 Joachim Ebigt
- 👤 Klaus Fabian
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 01:13
CPC Classifications
C; C08; C08L; C08L29/00; C08L29/14; B; B32; B32B; B32B17/00; B32B17/06; B32B17/10; B32B17/10005; B32B17/1055; B32B17/10559; B32B17/10577; B32B17/10761; B32B27/00; B32B27/18
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
131 words
A polymer mixture for making intermediate sheeting for laminated glass essentially consisting of polyvinyl butyral, the usual plasticizers and optionally stabilizers and auxiliaries to improve the adhesion wherein the polyvinyl butyral used is a mixture consisting of 70 to 97.5% by weight of a polyvinyl butyral having a viscosity in the range of from 60 to 120 cp in a 5% solution in ethanol at 23° C and from 30 to 2.5% by weight of a polyvinyl butyral having a viscosity in the range of from 2 to 30 cp in a 5% solution in ethanol at 23° C, the ratio M w /M n of the weight average to the numerical average of the molecular weight, determined by gel permeation chromatography, of the two polyvinyl butyrals being smaller than 5.
Claim 2
Dependent Claim
131 words
A polymer mixture for making intermediate sheeting for laminated glass essentially consisting of polyvinyl butyral, the usual plasticizers and optionally stabilizers and auxiliaries to improve the adhesion wherein the polyvinyl butyral used is a mixture consisting of 70 to 97.5% by weight of a polyvinyl butyral having a viscosity in the range of from 60 to 120 cp in a 5% solution in ethanol at 23° C and from 30 to 2.5% by weight of a polyvinyl butyral having a viscosity in the range of from 2 to 30 cp in a 5% solution in ethanol at 23° C, the ratio M w /M n of the weight average to the numerical average of the molecular weight, determined by gel permeation chromatography, of the two polyvinyl butyrals being smaller than 5.
Claim 3
Dependent Claim
21 words
A polymer mixture as claimed in claim 1, wherein the ratio M w to M n is from 1.5 to 3.
Claim 4
Dependent Claim
111 words
A process for the manufacture of polyvinyl butyral mixtures as claimed in claim 1, which comprises acetalizing with n-butyraldehyde in the presence of an acid catalyst a mixture of 70 to 97.5 parts by weight of a polyvinyl alcohol having a viscosity of from 25 to 40 cp in a 4% aqueous solution at 20° C and 30 to 2.5 parts by weight of a polyvinyl alcohol having a viscosity of 3 to 15 cp in a 4% aqueous solution at 20° C, the ratio M w /M n of the weight average to the numerical average of the molecular weight of the two polyvinyl alcohol components being smaller than 5.
Claim 5
Dependent Claim
20 words
A process as claimed in claim 3, wherein the ratio M w to M n is from 1.5 to 3.
References Cited (Backward Citations)
US2135075A
Cited
US2690410A
Cited
US2909507A
Cited
US3950305A
Cited
US3823113A
Cited
US3926918A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-12-21 | 1980-06-21 | 1980-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-12-21 | 1984-06-21 | 1984-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-12-21 | 1988-06-21 | 1988-12-21 | $7700.00 | Window Closed / Lapsed |