US3627709A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of foam thermoplastics using a blowing agent and a viscosity increasing agent
Assignee: BASF SE
•
Filing: 1969-05-16
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Granted: 1971-12-14
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Expires: 1989-05-16
Abstract
Abstract Process for the production of expanded crystalline thermoplastics by emulsification under pressure of a polymer melt and a nonmiscible expanding agent of a comparable viscosity and releasing the pressure or cooling the unexpanded emulsion and heating it in a mold.
Inventors
- 👤 Karl-Friedrich Hansen
- 👤 Johann Zizlsperger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 01:55
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/12; C08J9/14; C08J9/142; C08J9/16
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
23 words
A process as claimed in claim 1 wherein said crystalline thermoplastic polymer is a polyolefin having a crystalline fraction of more than 20percent.
Claim 2
Dependent Claim
38 words
A prOcess as claimed in claim 1 wherein the viscosity of said liquid nonmiscible expanding agent is 0.1 to 1 times the viscosity of the thermoplastic polymer melt at the temperature at which the resultant emulsion is prepared.
Claim 3
Dependent Claim
51 words
A process as claimed in claim 1 in which the pressure on the resultant emulsion is released while the temperature is higher than the melting point of said thermoplastic polymer to a pressure below the vapor pressure of said liquid component of said nonmiscible expanding agent, thereby expanding said thermoplastic polymer.
Claim 4
Dependent Claim
19 words
A process as claimed in claim 1 in which the resultant emulsion is cooled without expanding said thermoplastic polymer.
Claim 5
Dependent Claim
28 words
A process as claimed in claim 1 in which said viscosity increasing agent is a polymer homogeneously miscible with said liquid component of said liquid nonmiscible expanding agent.
Claim 6
Dependent Claim
184 words
A process for the production of expanded thermoplastic polymers which comprises heating an emulsion of 3-40 parts by volume of a liquid nonmiscible expanding agent in 100 parts by volume of a crystalline thermoplastic polymer from the group consisting of polymers of olefinically unsaturated monomers from the group consisting of polyethylene, polypropylene, polyvinyl chloride, copolymers of ethylene with propylene, copolymers of ethylene and vinyl acetate, and copolymers of ethylene and acrylic esters of alcohols having two to eight carbon atoms, said liquid expanding agent not diffusing into the thermoplastic polymer and containing at least one liquid component from the group consisting of water and methanol and a sufficient amount of a viscosity increasing agent miscible with said liquid component but not diffusing into said polymer so that the ratio of the viscosity of said expanding agent to the viscosity of said thermoplastic polymer when said thermoplastic polymer is in the molten state is 0.01:1 to 10:1, to a temperature which is higher than the melting point of said thermoplastic polymer and above the vaporization temperature of said liquid component under the pressure conditions used.
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) | 1974-12-13 | 1975-06-14 | 1975-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-13 | 1979-06-14 | 1979-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-13 | 1983-06-14 | 1983-12-14 | $7700.00 | Window Closed / Lapsed |