§
Luxuse
Patent Intelligence
Sign In
← Back to Patent Explorer
US3977089A Expired / Lapsed US ⏱️ 0.0 years remaining

Microwave drying process for synthetic polymers

Assignee: ExxonMobil Technology and Engineering Co
•
Filing: 1971-11-18
•
Granted: 1976-08-31
•
Expires: 1991-11-18
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract Volatile polar vehicles such as water or organic solvents, are removed from nonpolar materials by passing said material through at least one pneumatic conveyor resonating cavity operating at a microwave frequency of about 600 to about 50,000 MHZ. For example, a polymer such as polyvinyl chloride may be dried by conveying the polymer through said pneumatic conveyor operating at a frequency of 915 MHZ for a time sufficient to reduce the volatiles content to about 5 wt. % and subsequently conveying the partially dried material through a second pneumatic conveyor resonating cavity operating at a microwave frequency of 2450 MHZ for a time sufficient to reduce the polar vehicle content to below 0.5 wt. %. The resonating cavities may constitute a single pneumatic conveyor having zones operating at different frequencies, said zones being isolated from one another by microwave suppressors such as "eggcrate" type suppressors. Alternately, several pneumatic conveyor systems, each operating at a different frequency, may be used.

Inventors

  • 👤 Eric O. Forster
  • 👤 Peter J. Creighton

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 18:38
CPC Classifications
F; F26; F26B; F26B3/00; F26B3/32; F26B3/34; F26B3/343

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 82 words
In a process for preparing an essentially nonpolar synthetic polymer utilizing a polar vehicle from which said polymer is separated, the improvement which comprises: a. transferring said polymer to a transfer line resonating cavity having introduced therein, at at least one point, microwave energy at a frequency of about 600 to 50,000 MHZ; and b. conveying said polymer through said transfer line for a period of time sufficient to reduce the polar vehicle content of said polymer to less than 5000 ppm.
Claim 2
Dependent Claim 82 words
In a process for preparing an essentially nonpolar synthetic polymer utilizing a polar vehicle from which said polymer is separated, the improvement which comprises: a. transferring said polymer to a transfer line resonating cavity having introduced therein, at at least one point, microwave energy at a frequency of about 600 to 50,000 MHZ; and b. conveying said polymer through said transfer line for a period of time sufficient to reduce the polar vehicle content of said polymer to less than 5000 ppm.
Claim 3
Dependent Claim 33 words
The process of claim 1 wherein the material is a synthetic polymer selected from the group consisting of GR-S rubber, halogenated butyl rubber, polyvinyl chloride, polypropylene, polyisobutylene, ethylene-propylene copolymers, EPDM, and mixtures thereof.
Claim 4
Dependent Claim 15 words
The process of claim 1 wherein the microwave frequency is about 900 to about 30,000.
Claim 5
Dependent Claim 61 words
A process for drying polyisobutylene polymer so that it is substantially free of occluded water which comprises passing particles of polyisobutylene having an initial moisture content of less than 5 wt. % through a transfer line resonating cavity operating at a frequency of 2450 MHZ for a period of time sufficient to reduce the moisture content to less than 1 ppm.
Claim 6
Dependent Claim 61 words
A process for drying polyisobutylene polymer so that it is substantially free of occluded water which comprises passing particles of polyisobutylene having an initial moisture content of less than 5 wt. % through a transfer line resonating cavity operating at a frequency of 2450 MHZ for a period of time sufficient to reduce the moisture content to less than 1 ppm.

References Cited (Backward Citations)

US3528179A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1979-08-31 1980-03-01 1980-08-31 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1983-08-31 1984-03-01 1984-08-31 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1987-08-31 1988-03-01 1988-08-31 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag