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US3673125A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of producing polyvinyl acetal porous articles

Assignee: Kanegafuchi Spinning Co Ltd
•
Filing: 1970-05-06
•
Granted: 1972-06-27
•
Expires: 1990-05-06
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Abstract

Abstract A mixed solution of polyvinyl alcohol and gelatinized starch for manufacturing polyvinyl acetal porous articles is prepared by introducing forcedly at a constant rate a dispersion formed by adding starch particles or a suspension of starch particles to an aqueous solution of polyvinyl alcohol having a relatively low temperature to one end of a cylindrical heater provided with an inner stirrer and a heating means in the outer periphery, heating the cylindrical heater at a sufficient temperature to gelatinize the starch in the dispersion by the time the continuously flowing dispersion reaches the other end of the cylindrical heater and withdrawing the gelatinized dispersion continuously from the cylindrical heater.

Inventors

  • 👤 Kenji Takahashi
  • 👤 Toshio Yamamura
  • 👤 Mitsuzo Ono
  • 👤 Korekiyo Eda

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 07:37
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/28; C08F; C08F8/00; C08F8/48; C08K; C08K13/00; C08L; C08L29/00; C08L29/02; C08L29/04; C08L3/00; D; D06; D06N; D06N3/00; D06N3/04; C08J2329/00; C08J2329/14

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 42 words
A method as claimed in claim 1, in which the reaction solution is flowed onto an endless belt to form a layer thereon and heating the layer on the endless belt to effect an acetalization reaction and to form a spongy sheet.
Claim 2
Dependent Claim 28 words
The method as claimed in claim 1, wherein after the gelatinized dispersion is withdrawn from the heater, the gelatinized dispersion is cooled in a separate continuous type cooler.
Claim 3
Dependent Claim 17 words
The method as claimed in claim 3, wherein said continuous type cooler is a vacuum defoaming cooler.
Claim 4
Dependent Claim 17 words
The method as claimed in claim 3, wherein said continuous type cooler is a cylindrical heat exchanger.

References Cited (Backward Citations)

US2609347A Cited
US3547837A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1975-06-27 1975-12-27 1976-06-27 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1979-06-27 1979-12-27 1980-06-27 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1983-06-27 1983-12-27 1984-06-27 $7700.00 Window Closed / Lapsed

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