摘要:
Continuous process for the manufacture of amino resin solutions, especially solutions of urea/formaldehyde resins, by contacting the reactants in a cascade of at least three stirred vessels with back-mixing of the solution whilst maintaining specific molar ratios of amino resin forming material to formaldehyde and specific pH ranges in the individual stirred vessels.
摘要:
A WATER-IN-OIL OR OIL-IN-WATER EMULSION CONTAINING A NACREOUS MATERIAL, A RESIN, AND ORGANIC SOLVENT, WATER, AND AN EMULSIFYING AGENT IS EMPLOYED IN ROLLER OR SCREEN PRINTING ON PAPER AND TEXTILE FABRICS.
摘要:
UREA FORMALDEHYDE CONDENSATION PRODUCTS, SUITABLE FOR USE AS LONG LASTING FERTILIZERS, ARE PRODUCED IN A TWO STAGE CONDENSATION PROCESS, THE FIRST STAGE BEING A PRECONDENSATION STAGE CARRIED OUT UNDER ALKALINE CONDITIONS, AND THE SECOND STAGE BEING A MAIN CONDENSATION, CARRIED OUT UNDER ACID CONDITIONS. INTERMEDIATE THE TWO STAGES, THE REACTION MEDIUM IS COOLED, AND THE PH IS ADJUSTED TO THAT DESIRED FOR THE SECOND STAGE. THE PRODUCT OF THE SECOND STAGE IS DRIED, FOR EXAMPLE IN SPRAY DRIER, RAPIDLY AND AT A LOW TEMPERATURE WHEREBY AN INCREASE IN INSOLUBLE NITROGEN IS AVOIDED.
摘要:
A process of preparing beads of urea-formaldehyde resin in which disperse particles of an aqueous urea-formaldehyde syrup are converted to hard polymer and azeotropically dehydrated. The aqueous syrup must have a solids content of at least 65% by weight and the mol ratio of formaldehyde to urea must be within the range of 1.9 - 2.3 to 1.
摘要:
WHEREIN R is selected from the group comprising hydrogen and an alkyl radical: R1 is selected from the group comprising hydrogen and a C1-C3 alkyl radical; R2 is selected from the group comprising hydrogen, methyl and ethyl radical; m is an integer from 0 to 1 and n is an integer from 0 to 1, and at least one nitrogen methylolated compound selected from the group comprising urea, its substituted derivatives and cyclic ureas.
A copolymer cross-linking agent comprises at least one unsaturated N-substituted amide of an Alpha , Beta -unsaturated carboxylic acid which cannot be methylolated the substituent of which is an aliphatic moiety containing a diol-1,2 or -1,3 group, the amide corresponding to the general formula:
摘要:
PRODUCTION OF COPOLYCONDENSATES OF 0.1 TO 1 MOLE OF A PHENOL, 0.3 TO 1 MOLE OF A UREA, O91 TO 1 MOLE OF A FURAN AND 2 TO 4 MOLES OF AN ALIPHATIC ALDEHYDE. THES POLYCONDENSATES ARE PREPARED BY STEP-WISE REACTION WHERE NO CATALYST IS USED IN THE FIRST STEP AND AND ALKALINE CATALYSTS ARE USED IN THE SECOND AND SUBSEQUENT STAGES. THE POLYCONDENSATE PRODUCT CAN BE CROSS-LINKED WITH A SUITABLE ACID CATALYST.
摘要:
POLYETHER UREA AND THIOUREAU CONDENSATION PRODUCTS PRODUCED BY THE ACTION OF HEMIFORMALS OF POLYVALENT ALCOHOLS, POSSIBLY IN MIXTURES WITH HEMIFORMALS OF MONOVALENT ALCOHOLS, WITH UREA AND/OR THIORUEA, AND IN THE PRESENCE OF ACID OR BASIC CATALYST.