← Back to Patent Explorer
US3193445A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of bleaching cellulosic materials with hydrogen peroxide

Assignee: PPG Industries Inc
•
Filing: 1962-07-16
•
Granted: 1965-07-06
•
Expires: 1982-07-16
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

No abstract record available.

Inventors

  • 👤 Walter F Parker
  • 👤 Garry L Burroway

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 01:33
CPC Classifications
D; D21; D21C; D21C9/00; D21C9/10; D21C9/1026; D21C9/1036; D06; D06L; D06L4/00; D06L4/10; D06L4/12

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 48 words
A METHOD OF BLEACHING CELLULOSIC MATERIAL WHICH COMPRISES CONTACTING SAID MATERIAL WITH AQUEOUS HYDROGEN PEROXIDE SOLUTION TO PROVIDE BLEACHED MATERIAL IN CONTACT WITH RESIDUAL HYDROGEN PEROXIDE AND THEREAFTER TREATING SUCH BLEACHED MATERIAL STILL IN CONTACT WITH RESIDUAL HYDROGEN PEROXIDE WITH ANHYDRIDE OF 2 TO 8 CARBON CARBOXYLIC ACID.
Claim 2
Independent Claim 48 words
A METHOD OF BLEACHING CELLULOSIC MATERIAL WHICH COMPRISES CONTACTING SAID MATERIAL WITH AQUEOUS HYDROGEN PEROXIDE SOLUTION TO PROVIDE BLEACHED MATERIAL IN CONTACT WITH RESIDUAL HYDROGEN PEROXIDE AND THEREAFTER TREATING SUCH BLEACHED MATERIAL STILL IN CONTACT WITH RESIDUAL HYDROGEN PEROXIDE WITH ANHYDRIDE OF 2 TO 8 CARBON CARBOXYLIC ACID.

References Cited (Backward Citations)

US2104120A Cited
US2112116A Cited
US2173474A Cited
US2287064A Cited
US2426142A Cited
US2822236A Cited
US2939813A Cited
US3085039A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1968-07-05 1969-01-04 1969-07-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1972-07-05 1973-01-04 1973-07-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1976-07-05 1977-01-04 1977-07-06 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag