The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 06, 2026
Filed:
Nov. 10, 2021
3m Innovative Properties Company, St. Paul, MN (US);
John C. Hulteen, Afton, MN (US);
S.M. Ibrahim Al-Rafia, Ontario, CA;
Rodrigo Marmol, Maplewood, MN (US);
Toheeb B. Alabi, Maplewood, MN (US);
Raul Pacheco De Moraes, Ontario, CA;
Kent E. Nielsen, Ontario, CA;
3M INNOVATIVE PROPERTIES COMPANY, St. Paul, MN (US);
Abstract
An intumescent article includes intumescent material including 50-92 wt-% graphite and 8-50 wt-% binder, and may have a free expansion ratio of 100× or greater and a free expansion aspect ratio of 1.0 or less. The intumescent article may be a sheet, and may be L-shaped, rectangle, triangle, or other shape. The intumescent article may have a 3D shape. The intumescent article may be an insert for an electrical box, having a surface area 75% or less of the surface area of the electrical box back wall. The intumescent sheet has a mass, and the ratio of the mass to the volume of the electrical box may be 3 g/100 cmor less. A method of making an intumescent article includes mixing from 50-92 wt-% graphite with 8-50 wt-% binder on a dry weight basis to form a mixture, pressing or molding the mixture into a shape and drying the shape.