Method for preparing condensation resins and use thereof
AssigneeBASF SE
InventorsGabor Börzsönyi, Günter Scherr, Klaus Menzel, Stefan Meuer
Life of this patent
Estimating the term…
Abstract
The present invention relates to new condensation resins of urea, formaldehyde, and CH-acidic aldehydes, to methods for preparing them, and to their use.
Claims13
A method for reducing the viscosity of a condensation resin, which comprises reacting a substantially fully reacted condensation resin, synthesized from at least one, preferably precisely one, urea, formaldehyde, and at least one, preferably precisely one, CH-acidic aldehyde, with at least one monofunctional alcohol in the presence of at least one Brönsted acid.
The method according to any of the preceding claims, wherein the substantially fully reacted condensation resin is dissolved in at least one solvent selected from the group consisting of cyclohexane, methylcyclohexane, xylene, and toluene.
A method for preparing condensation resins with reduced viscosity from at least one, preferably precisely one, urea, formaldehyde, and at least one, preferably precisely one, CH-acidic aldehyde, by reaction of ureas of the general formula (I) and/or (II)
- in which R1 and R2 independently of one another are hydrogen or identical or different C1-C20 alkyl radicals, A is a C1-C20 alkylene radical, and X is oxygen or sulfur, with formaldehyde and a CH-acidic aldehyde of the general formula (III)
- in which the radicals R3 and R4 independently of one another are identical or different alkyl, cycloalkyl, aryl or alkylaryl radicals or R3 and R4 together may form a ring, in the temperature range between 60 and 150° C. in the presence of acids or bases, optionally in the presence of solvent and/or diluent, which comprises, after the end of the reaction, neutralizing the acids or bases, distillatively removing volatile constituents, and carrying out reactions subsequently with at least one alcohol in the presence of at least one acid.
The method according to any of the preceding claims, wherein the CH-acidic aldehyde is selected from the group consisting of isobutyraldehyde, 2-ethylhexanal, 2-methylpentanal, and isovaleraldehyde.
The method according to any of the preceding claims, wherein urea, formaldehyde, and CH-acidic aldehyde are reacted with one another in a molar ratio of 1:2 to 15:2 to 15.
The method according to any of the preceding claims, wherein the alcohol is an alkylene glycol monoalkyl ether or polyalkylene glycol monoalkyl ether having a molar weight of up to 300 g/mol.
The method according to any of the preceding claims, wherein the reaction takes place over a period of 1 to 10 hours at a temperature of 40 to 100° C.
A condensation resin obtainable according to any of the preceding methods.
Dependencies are inferred from the claim text.