公开(公告)号：US20240368371A1

公开(公告)日：2024-11-07

申请号：US18248269

申请日：2021-11-10

Applicant: 3M INNOVATIVE PROPERTIES COMPANY

Inventor： John C. Hulteen ,  S.M. Ibrahim Al-Rafia ,  Rodrigo Marmol ,  Toheeb B. Alabi ,  Raul Pacheco de Moraes ,  Kent E. Nielsen

IPC: C08K3/04 ,  C08J5/12 ,  C08J5/18 ,  H02G3/08

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 cm3 or 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.