# US 9,039,927 B2 · Etherified melamine/formaldehyde condensates having a high solid content and low viscosity > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,039,927 B2 - Document ID: US9039927B2 - Status: Granted - Kind: B2 - Application number: 12/096,502 - Filed: 2006-12-07 - Published: 2009-05-14 - Granted: 2015-05-26 - Earliest claimed: 2005-12-09 - Assignees: BASF SE - Applicants: Andreas Eichfelder; Rainer Erhardt; Martin Reif; Eva Ruba; Günter Scherr; Jörg Schneider; Dieter Weilacher - Inventors: Andreas Eichfelder; Rainer Erhardt; Martin Reif; Eva Ruba; Günter Scherr; Jörg Schneider; Dieter Weilacher - Web page: https://patentgrep.com/patent/US9039927B2 ## CPC - C08G 12/427: {Melamine} - C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS ## Abstract Process for the preparation of etherified melamine/formaldehyde condensates, in which first a methylolation of melamine with a formaldehyde component in the molar ratio of from 1:6 to 1:15, preferably at a pH of >7, is carried out. This is followed by an etherification of the resulting hydroxymethylation intermediate in the presence of a C1-C20-alkyl, preferably of a C1-C6-alcohol, particularly preferably of a C1-C4-alcohol, at a pH of <4.5, and subsequently by at least one distillation step in order to remove in particular methanol from the system, the pH of >9.5 being established before, during and/or after the distillation. According to the invention, a plurality of hydroxymethylation, etherification and distillation steps follow in order to achieve an etherified melamine/formaldehyde condensate which is distinguished by a high degree of hydroxymethylation, a high solids content and a low viscosity. ## Claims ### Claim 1 A process for the preparation of etherified melamine/formaldehyde condensates, which consists of: (a) methylolating melamine with a formaldehyde component in the molar ratio of from 1:6 to 1:15 melamine:formaldehyde at a pH of >7 in a first reaction step at 40 to 100° C.; (b) etherifying a hydroxyl methylation intermediate formed in step (a) at 40 to 120° C. with methanol at a pH of <4.5 in a subsequent second reaction step; (c) in a third reaction step, adjusting the reaction mixture from step (b) to a pH of >10 by adding an inorganic base with the result that further hydroxymethylations take place and removing methanol by at least one distillation step the pH being maintained at more than 10; and (d) repeating the reaction steps (b) and (c) at least once whereupon further hydroxymethylation steps result owing to the excess of formaldehyde present. ### Claim 2 (depends on 1) The process for the preparation of etherified melamine/formaldehyde condensates according to claim 1, wherein methanol is removed in step (c) by a distillation step. ### Claim 3 (depends on 1) The process for the preparation of etherified melamine/formaldehyde condensates according to claim 1, wherein the at least one distillation step of reaction step (c) is carried out in a falling-film, thin-film or SAMBAY evaporator. ### Claim 4 (depends on 1) An etherified melamine/formaldehyde condensate, prepared by the process according to claim 1, wherein a proportion of mononuclear components having a degree of substitution of <6 is less than 10%, based on the total amount of melamine/formaldehyde condensate. ### Claim 5 (depends on 1) An etherified melamine/formaldehyde condensate, prepared by the process according to claim 1, wherein the solids content is more than 96%. ### Claim 6 (depends on 1) An etherified melamine/formaldehyde condensate, prepared by the process according to claim 1, wherein the viscosity is less than 3000 mPa·s. ### Claim 7 (depends on 1) A method of crosslinking a binder system containing hydroxyl groups wherein an etherified melamine/formaldehyde condensate prepared according to claim 1 is used as acid-curable crosslinking agent. ### Claim 8 (depends on 2) The process for the preparation of etherified melamine/formaldehyde condensates according to claim 2, wherein the at least one distillation step of reaction step (c) is carried out in a falling-film, thin-film or SAMBAY evaporator. ### Claim 9 (depends on 1) An etherified melamine/formaldehyde condensate, prepared by the process according to claim 1, wherein a proportion of mononuclear components having a degree of substitution of <6 is less than 10%, based on the total amount of melamine/formaldehyde condensate. ### Claim 10 (depends on 2) An etherified melamine/formaldehyde condensate, prepared by the process according to claim 2, wherein a proportion of mononuclear components having a degree of substitution of <6 is less than 10%, based on the total amount of melamine/formaldehyde condensate. ### Claim 11 (depends on 3) An etherified melamine/formaldehyde condensate, prepared by the process according to claim 3, wherein a proportion of mononuclear components having a degree of substitution of <6 is less than 10%, based on the total amount of melamine/formaldehyde condensate. ### Claim 12 (depends on 1) An etherified melamine/formaldehyde condensate, prepared by the process according to claim 1, wherein the solids content is more than 96%. ### Claim 13 (depends on 2) An etherified melamine/formaldehyde condensate, prepared by the process according to claim 2, wherein the solids content is more than 96%. ### Claim 14 (depends on 3) An etherified melamine/formaldehyde condensate, prepared by the process according to claim 3, wherein the solids content is more than 96%. ### Claim 15 (depends on 1) An etherified melamine/formaldehyde condensate, prepared by the process according to claim 1, wherein the viscosity is less than 3000 mPa·s. ### Claim 16 (depends on 2) An etherified melamine/formaldehyde condensate, prepared by the process according to claim 2, wherein the viscosity is less than 3000 mPa·s. ### Claim 17 (depends on 3) An etherified melamine/formaldehyde condensate, prepared by the process according to claim 3, wherein the viscosity is less than 3000 mPa·s. ### Claim 18 (depends on 1) The process according to claim 1, wherein the melamine and formaldehyde in step a are present in a molar ratio of from 1:7 to 1:10.