US4108806A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermoplastic expandable microsphere process and product
Assignee: Casco Adhesives AB
•
Filing: 1973-12-21
•
Granted: 1978-08-22
•
Expires: 1993-12-21
Abstract
Abstract Expandable synthetic resinous microspheres are expanded in a matrix by heating under pressure to at least a foaming temperature and permitting the microspheres to expand at a lower pressure.
Inventors
- 👤 William E. Cohrs
- 👤 Roland E. Gunderman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 01:34
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/32; B; B29; B29C; B29C70/00; B29C70/58; B29C70/66; B29K; B29K2105/00; B29K2105/06; B29K2105/16; B29K2105/165
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
138 words
A process for the incorporation of expandable thermoplastic synthetic resinous monocellular microspheres having a thermoplastic resinous shell, a volatile liquid foaming agent therein within a heat plastifiable matrix material which, at its heat plastification temperature does not act as a rapid solvent for the microspheres to cause the destruction thereof by solvent action or heat plastify at a temperature sufficiently high that the microspheres are destroyed by thermal degradation, the steps of the method comprising admixing the microspheres and matrix forming material, heat plastifying the matrix material and mechanically working the mixture to form a matrix about the microspheres without causing expansion thereof, subsequently passing the mixture into a zone of lower pressure wherein the microspheres expand to form a plurality of hollow, generally monocellular particles within the matrix, and cooling the mixture below the heat plastifying temperature.
Claim 2
Dependent Claim
138 words
A process for the incorporation of expandable thermoplastic synthetic resinous monocellular microspheres having a thermoplastic resinous shell, a volatile liquid foaming agent therein within a heat plastifiable matrix material which, at its heat plastification temperature does not act as a rapid solvent for the microspheres to cause the destruction thereof by solvent action or heat plastify at a temperature sufficiently high that the microspheres are destroyed by thermal degradation, the steps of the method comprising admixing the microspheres and matrix forming material, heat plastifying the matrix material and mechanically working the mixture to form a matrix about the microspheres without causing expansion thereof, subsequently passing the mixture into a zone of lower pressure wherein the microspheres expand to form a plurality of hollow, generally monocellular particles within the matrix, and cooling the mixture below the heat plastifying temperature.
Claim 3
Dependent Claim
17 words
The method of claim 1 wherein the unexpanded microspheres are heated under pressure in a screw extruder.
Claim 4
Dependent Claim
18 words
The method of claim 1 wherein the unexpanded microspheres are in admixture with a thermoplastic synthetic resinous binder.
Claim 5
Dependent Claim
20 words
The method of claim 3 wherein the thermoplastic binder is heated to a temperature sufficient to cause heat plastification thereof.
Claim 6
Dependent Claim
11 words
The method of claim 3 wherein the binder is a wax.
Claim 7
Independent Claim
79 words
A method of preparing a heat expandable product, the steps of the method comprising providing a mixture of heat expandable synthetic resinous microspheres capable of expanding on heating to form monocellular hollow gas-filled spheres within a thermoplastic synthetic resin, heating the mixture to a temperature sufficient to heat plastify the resin under pressure sufficient to prevent expansion of the microspheres, shaping the mixture to a desired configuration, and cooling the mixture below the heat plastifying temperature of the resin.
Claim 8
Independent Claim
79 words
A method of preparing a heat expandable product, the steps of the method comprising providing a mixture of heat expandable synthetic resinous microspheres capable of expanding on heating to form monocellular hollow gas-filled spheres within a thermoplastic synthetic resin, heating the mixture to a temperature sufficient to heat plastify the resin under pressure sufficient to prevent expansion of the microspheres, shaping the mixture to a desired configuration, and cooling the mixture below the heat plastifying temperature of the resin.
Claim 9
Dependent Claim
10 words
The method of claim 6 wherein the resin is polyethylene.
References Cited (Backward Citations)
US3353981A
Cited
US3219600A
Cited
US3515569A
Cited
US3466353A
Cited
US3673126A
Cited
US3615569A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-08-21 | 1982-02-20 | 1982-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-08-21 | 1986-02-20 | 1986-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-08-21 | 1990-02-20 | 1990-08-22 | $7700.00 | Window Closed / Lapsed |