# US 11,306,228 B2 · Hardening of bonding systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,306,228 B2 - Document ID: US11306228B2 - Status: Granted - Kind: B2 - Application number: 16/320,668 - Filed: 2017-07-26 - Published: 2019-05-23 - Granted: 2022-04-19 - Earliest claimed: 2016-07-27 - Assignees: Catalytic Systems C.E.D. LTD - Applicants: Catalytic Systems C.E.D. LTD - Inventors: Karolos Markesinis; Efthalia Markesini; Dimitrios Alexandropoulos; Panagiotis Nakos; Paschalis Tsirogiannis - Web page: https://patentgrep.com/patent/US11306228B2 ## CPC - C09J 161/06: of aldehydes with phenols - B27D 1/04: to produce plywood or articles made therefrom; Plywood sheets {(making a layered veneer cutting block B27L5/00)} - B27N 3/002: {characterised by the type of binder (compositions of macromolecular compounds C08L)} - B27N 3/06: Making particle boards or fibreboards, with preformed covering layers, the particles or fibres being compressed with the layers to a board in one single pressing operation - B32B 7/12: using interposed adhesives or interposed materials with bonding properties - B32B 21/02: {the layer being formed} of fibres, chips, or particles {, e.g. MDF, HDF, OSB, chipboard, particle board, hardboard} - B32B 21/13: all layers being exclusively wood - B32B 21/14: comprising wood board or veneer - C08G 8/10: with phenol - C08G 12/12: Ureas; Thioureas - C08G 18/022: {the polymeric products containing isocyanurate groups} - C08G 18/6492: {Lignin containing materials; Wood resins; Wood tars; Derivatives thereof} - C08G 18/7664: {containing alkylene polyphenyl groups} - C08L 97/02: Lignocellulosic material, e.g. wood, straw or bagasse {(manufacture of articles made from lignocellulosic material by dry processes B27N)} - C09J 161/12: with polyhydric phenols - C09J 161/24: with urea or thiourea - C09J 161/28: with melamine - C09J 175/04: Polyurethanes - B32B 2250/03: 3 layers - B32B 2260/026: Wood layer - B32B 2260/046: Synthetic resin - B32B 2307/54: Yield strength; Tensile strength - B32B 2307/72: Density - B32B 2307/732: Dimensional properties - C08G 2170/20: Compositions for hot melt adhesives - C09J: ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES (preparation of glue or gelatine C09H) - B27D: WORKING VENEER OR PLYWOOD (applying liquids or other fluent materials to surface in general B05; grinding, sanding, or polishing of wood B24; applying adhesives or glue to surfaces of wood B27G11/00; manufacture of veneer B27L5/00) - B27N: MANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUT ORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTING OF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL (containing cementitious material B28B; shaping of substances in a plastic state B29C; fibreboards made from fibrous suspensions D21J; drying F26B17/00) - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) ## Abstract The present invention provides bonding systems comprising a formaldehyde-based (urea-/melamine-/phenol-/resorcinol-formaldehyde or other combination) and/or a polymeric isocyanate resin system composition for bonding ligno-cellulosic materials to form panels and/or shaped products, which contain a resin hardener, also referred to as resin catalyst, characterised in that the hardener is activated by heat. ## Claims ### Claim 1 A composite structure comprising: a mat of ligno-cellulosic materials having at least: a first layer of the ligno-cellulosic materials combined with a first glue mix, the first glue mix of the first layer including a resin based on at least one of formaldehyde and polymeric isocyanate; a second layer of the ligno-cellulosic materials combined with a second glue mix, the second glue mix of the second layer also including the resin based on at least one of formaldehyde and polymeric isocyanate; and a third layer of the ligno-cellulosic materials combined with a third glue mix, the third glue mix of the third layer also including the resin based on at least one of formaldehyde and polymeric isocyanate; a resin hardener formed by a salt having an acid moiety and a base moiety; wherein one of the acid moiety and the base moiety of the resin hardener is a more volatile moiety, the more volatile moiety activating hardening of the resin in the first glue mix of the first layer upon vaporization; wherein the second and third layers are surface layers of the mat and the first layer is a core layer located therebetween; and wherein the resin hardener is not in the first glue mix of the first layer, the resin hardener being instead either: sprayed onto only outer surfaces of surface layers of the mat; or included in the second and third glue mixes of the second and third layer of the ligno-cellulosic materials, respectively. ### Claim 2 (depends on 1) The composite structure of claim 1, wherein the resin includes a urea-formaldehyde resin, a melamine-formaldehyde resin, a phenol-formaldehyde resin, a resorcinol-formaldehyde resin or a combination of the aforementioned resins. ### Claim 3 (depends on 1) The composite structure of claim 1, wherein the resin is derived from the reaction of diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI) or isophorone diisocyanate (IPDI) with poly-hydroxy functional compounds. ### Claim 4 (depends on 1) The composite structure of claim 1, wherein the composite structure is shaped to form a particleboard, a medium density fibreboard, a high density fibreboard, an oriented strand board or plywood. ### Claim 5 (depends on 1) The composite structure of claim 1, wherein the mat further includes a third layer, both the second and third layers being the surface layers with the first layer being a core layer located therebetween; and wherein the resin hardener is included in the second glue mix of the second layer and in a third glue mix of the third layer. ### Claim 6 (depends on 1) The composite structure of claim 1, wherein conventional curing catalysts are in at least the first glue mix.