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US3753966A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for preparing polyvinyl chloride by suspension polymerization

Assignee: Shin-Etsu Chemical Co Ltd
•
Filing: 1970-12-16
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Granted: 1973-08-21
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Expires: 1990-12-16
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Abstract

Abstract THE POLYMERIZATION IS CONDUCTED IN THE PRESENCE OF A FFIRST CATALYST HAING THE FORMULA: (CH3-C(-R1)(-CH3)-CH2-C(-CN)(-CH3)-N=)2 WHEREIN R1 IS A RADICAL SELECTED FROM THE GROUP CONSISTNG OF ALKYL, ALKOXY AND ARYL RADICALS HAVING FROM 1 TO 6 CARBON ATOMS, AND A SECOND CATALYST SELECTED FROM THE GROUP CONSISTING OF AZONITRILES HAVING THE FORMULA: (R2-CH(-CH3)-CH2-C(-CN)(-R3)-N=)2 WHEREIN R2 AND R3 ARE EACH AN ALKYL RADICAL HAVING FROM 1 TO 4 CARBON ATOMS, AND OIL-SOLUBLE ORGANIC PEROXIDES WHICH ARE SOLUBLE IN VINYL CHLORIDE MONOMERS. A POLYVINYL CHLORIDE HAVING SUPERIOR THERMAL STABILITY AND A DESIRABLE PARTICLE SIZE DISTRIBUTION IS OBTANED QUICKLY AND AT A HIGH CONVERSION RATE. ADDITIONALLY, POLYMER SCALE DEPOSITION ON THE INSIDE WALL OF THE POLYMERIZATION VESSEL IS REDUCED.

Inventors

  • 👤 K Ogawa
  • 👤 K Taguchi
  • 👤 S Koyanagi
  • 👤 H Kitamura

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 18:18
CPC Classifications
C; C08; C08F; C08F14/00; C08F14/02; C08F14/04; C08F14/06; Y; Y10; Y10S; Y10S526/00; Y10S526/909

Claims Analysis

Total Claims: 0
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References Cited (Backward Citations)

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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) 1976-08-20 1977-02-19 1977-08-21 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-08-20 1981-02-19 1981-08-21 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-08-20 1985-02-19 1985-08-21 $7700.00 Window Closed / Lapsed

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