# US 5,703,144 A · Solid furan binders for composite articles > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,703,144 A - Document ID: US5703144A - Status: Granted - Kind: A - Application number: 08/609,419 - Filed: 1996-03-01 - Granted: 1997-12-30 - Earliest claimed: 1994-08-16 - Assignees: QO Chemicals, Inc. - Inventors: Denis W. Akerberg - Web page: https://patentgrep.com/patent/US5703144A ## CPC - B22C 1/224: {Furan polymers (B22C1/2273 takes precedence)} - H05K 1/0326: {containing O} - B22C: FOUNDRY MOULDING (moulding refractory materials in general B28B) - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS ## Abstract Furfuryl alcohol-formaldehyde resins in solid form. ## Claims ### Claim 1 A solid dry resin composition heat curable to a rigid set condition comprising the reaction product of formaldehyde with furfuryl alcohol in a molar ratio of at least 2:1, the composition containing not more than 10% by weight of water insoluble material and not more than about 5% by weight of furfuryl alcohol. ### Claim 2 (depends on 1) A resin composition in accordance with claim 1 comprising the reaction product of formaldehyde with furfuryl alcohol in a molar ratio of about 2.75:1. ### Claim 3 (depends on 1) A resin composition in accordance with claim 1 comprising the reaction product of formaldehyde with furfuryl alcohol in a molar ratio of about 3.50:1. ### Claim 4 (depends on 1) A resin composition in accordance with claim 1 wherein the resin contains not more than about 5% by weight of water insoluble material. ### Claim 5 (depends on 1) A composition in accordance with claim 1 in particulate form. ### Claim 6 (depends on 1) A binder composition for composite articles comprising a particulate substrate material having admixed therewith a resin composition in accordance with claim 1. ### Claim 7 (depends on 6) A binder composition in accordance with claim 6 wherein the substrate material is sand. ### Claim 8 (depends on 6) A binder composition in accordance with claim 6 wherein the substrate material is fiberglass. ### Claim 9 (depends on 6) A binder composition in accordance with claim 6 wherein the substrate material is carbon. ### Claim 10 (depends on 1) A process for producing a bound composite article which comprises admixing with a particulate substrate material a resin in accordance with claim 1, curing the resin to a set condition, and recovering a bound composite article. ### Claim 11 (depends on 10) A process in accordance with claim 10 wherein the particulate substrate material is sand. ### Claim 12 (depends on 10) A process in accordance with claim 10 wherein the particulate substrate material is fiberglass. ### Claim 13 (depends on 10) A process in accordance with claim 10 wherein the particulate substrate material is carbon. ### Claim 14 A process for producing a bound composition article which comprises: a. impregnating a porous substrate material with a liquid resin comprising the reaction product of formaldehyde with furfuryl alcohol in a molar ratio of at least 2:1, the resin containing not more than 10% by weight of water insoluble material and not more than about 5% by weight of furfuryl alcohol, b. removing water from the impregnated material to obtain a solid dry resin, and c. curing the resin in the impregnated material to a set condition. ### Claim 15 A process for producing a solid dry resin composition heat curable to a set condition which comprises: a. reacting in the presence of a weak organic acid having a pKa of not less than about 4 at an elevated temperature formaldehyde with furfuryl alcohol in a molar ratio of at least about 2:1, b. recovering the liquid resin reaction product, the liquid resin reaction product containing not more than 10% by weight of water insoluble material, c. removing water from the liquid resin reaction product, and d. recovering the solid dry reaction product. ### Claim 16 (depends on 15) A process in accordance with claim 15 wherein the resin is the reaction product of formaldehyde with furfuryl alcohol in a molar ratio of about 2.75:1. ### Claim 17 (depends on 15) A process in accordance with claim 15 wherein the resin is the reaction product of formaldehyde with furfuryl alcohol in a molar ratio of about 3.50:1. ### Claim 18 (depends on 1) The composition of claim 1 containing not more than about 5% by weight of water insolubles. ### Claim 19 (depends on 1) The composition of claim 1 comprising the reaction product of furfuryl alcohol with formaldehyde in the presence of a weak organic acid having a pKa of not less than about 4. ### Claim 20 (depends on 1) The composition of claim 1 and which contains not more than about 0.5% by weight of formaldehyde. ### Claim 21 (depends on 20) The composition of claim 20 comprising the reaction product of furfuryl alcohol with formaldehyde in the presence of a weak organic acid having a pKa of not less than about 4. ### Claim 22 (depends on 1) The resin composition of claim 1 which is in a particulate, free-flowing form. ### Claim 23 (depends on 15) The process of claim 15 and which further includes the step, after recovering the solid product, of further processing the solid product to produce a particulate, free-flowing dry resin composition. ### Claim 24 (depends on 23) The process of claim 23 in which the further processing step comprises flaking, grinding or pulverizing the recovered solid reaction product to produce the particulate, free-flowing resin composition.