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US2709694A Expired / Lapsed US ⏱️ 0.0 years remaining

Reaction of polyureas and formaldehyde and hydrolysis, and the products

Assignee: EIDP Inc
•
Filing: 1952-10-07
•
Granted: 1955-05-31
•
Expires: 1972-10-07
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Abstract

No abstract record available.

Inventors

  • 👤 Melvin A Dietrich
  • 👤 Henning W Jacobson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 12:31
CPC Classifications
D; D01; D01F; D01F6/00; D01F6/58; D01F6/72

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 166 words
A PROCESS FOR THE PREPARATION OF SHAPED OBJECTS HAVING AT LEAST ONE DIMENSION LARGE WITH RESPECT TO ANOTHER WHICH COMPRISES REACTING, IN SOLUTION IN A STRONG, OXYGEN-CONTAINING ACID OF IONIZATION CONSTANT OF AT LEAST 1X10-4, A HIGH MOLECULAR WEIGHT LINEAR POLYUREA HAVING AT LEAST 50% COMBINED INTRACHAIN -NHCONHUNITS, OF INHERENT VISCOSITY OF AT LEAST 0.7 IN 98% SULFURIC ACID AT A CONCENTRATION OF 0.5 GM. PER 100 CC. OF SOLUTION, AND FREE OF HYDROGEN ON AROMATIC CARBON ACTIVATED BY A STRONG ORTHO-, PARA-DIRECTING GROUP, WITH, AS ESSENTIALLY THE SOLE REACTANT FOR THE POLYUREA, FROM 0.2 TO 1.0 MOLE OF FORMALDEHYDE FOR EACH MOLE WEIGHT OF COMBINED -NHCONH- GROUP, FORMING THE REACTION MIXTURE THUS OBTAINED INTO THE DESIRED SHAPE, COAGULATING THE SAME, AND FINALLY HYDROLYZING THE THUS FORMED FORMALDEHYDE MODIFIED POLYMER BY BRINGING THE SAME IN CONTACT WITH DILUTE AQUEOUS MINERAL ACID UNTIL AT LEAST 80% OF THE COMBINED FORMALDEHYDE IS ELIMINATED BUT AT LEAST 0.15% OF THE UREA GROUPS REMAIN IN THE FORM OF URON GROUPS.
Claim 2
Dependent Claim 166 words
A PROCESS FOR THE PREPARATION OF SHAPED OBJECTS HAVING AT LEAST ONE DIMENSION LARGE WITH RESPECT TO ANOTHER WHICH COMPRISES REACTING, IN SOLUTION IN A STRONG, OXYGEN-CONTAINING ACID OF IONIZATION CONSTANT OF AT LEAST 1X10-4, A HIGH MOLECULAR WEIGHT LINEAR POLYUREA HAVING AT LEAST 50% COMBINED INTRACHAIN -NHCONHUNITS, OF INHERENT VISCOSITY OF AT LEAST 0.7 IN 98% SULFURIC ACID AT A CONCENTRATION OF 0.5 GM. PER 100 CC. OF SOLUTION, AND FREE OF HYDROGEN ON AROMATIC CARBON ACTIVATED BY A STRONG ORTHO-, PARA-DIRECTING GROUP, WITH, AS ESSENTIALLY THE SOLE REACTANT FOR THE POLYUREA, FROM 0.2 TO 1.0 MOLE OF FORMALDEHYDE FOR EACH MOLE WEIGHT OF COMBINED -NHCONH- GROUP, FORMING THE REACTION MIXTURE THUS OBTAINED INTO THE DESIRED SHAPE, COAGULATING THE SAME, AND FINALLY HYDROLYZING THE THUS FORMED FORMALDEHYDE MODIFIED POLYMER BY BRINGING THE SAME IN CONTACT WITH DILUTE AQUEOUS MINERAL ACID UNTIL AT LEAST 80% OF THE COMBINED FORMALDEHYDE IS ELIMINATED BUT AT LEAST 0.15% OF THE UREA GROUPS REMAIN IN THE FORM OF URON GROUPS.

References Cited (Backward Citations)

US2130948A Cited
GB574739A Cited
US2393972A Cited
GB582518A Cited
US2430860A Cited
US2441057A Cited
US2550767A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1958-05-30 1958-11-29 1959-05-31 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1962-05-30 1962-11-29 1963-05-31 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1966-05-30 1966-11-29 1967-05-31 $7700.00 Window Closed / Lapsed

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