Abstract: An intumescent putty or mastic is produced by admixing fine particles of solid intumescent material, polyvinyl butyral and a volatile solvent. The intumescent material can optionally be ground scrap intumescent door seals.

Abstract: An improvement in intumescent compositions is provided comprising, in part, melamine formaldehyde resin, a cross-linking agent, and a hydrophilic setting agent. The composition chemically absorbs water to yield an intumescent material with reduced cracking properties which decomposes into gas and a solid foam residue upon heating.

Abstract: The invention provides a composition for forming an intumescent material which upon heating decomposes into gas and a solid foam residue, comprising: a water-dispersible melamine formaldehyde resin which when cured is hydrophobic; a setting agent which hardens in the presence of water thereby to cause the composition to set; a cross-linking agent for curing the resin, the cross-linking agent being a polyamido compound; an ammonium phosphate; polyvinyl acetate; a solid polyhydroxy compound; and reinforcing fibrous material. To form the intumescent material, the composition is caused to set and the melamine resin is cured. The intumescent material has improved anti-cracking properties.

Abstract: A method of forming a conglomerated, bonded and preferably molded mass of particles of activated carbon bonded together by means of a polymer which is rendered adhesive by a solvent permeating a random and loose mass of the carbon particles and subsequently drained off.