Abstract:
NEW DI-N,N''-YAMINIPROPYL-DIHYDROURACILS, FOR EXAMPLE 1,3-DI-(Y-AMINOPROPYL)-5,5-DIMETHYL-5,6-DIHYDROURACIL, AND THEIR USE AS CURING AGENTS IN CURABLE MOULDING, COATING AND ADHESIVE COMPOSITIONS WHICH CONTAIN A POLYEPOXIDE COMPOUND, FOR EXAMPLE A LIQUID POLYGLYCIDYL ETHER OF BISPHENOL A. CURING CAN BE CARRIED OUT AT RELATIVLEY LOW TEMPERATURES, FOR EXAMPLE AT 40*C. THE NEW TYPE OF CURING AGENT BRIDGES, IN RESPECT OF ITS GRADATION OF REACTIVITY, A GAP BETWEEN ALIPHATIC POLYAMINES AND CYCLOALIPHATIC POLYAMINES. THE NEW CURING AGENTS FURTHERMORE HAVE THE ADVANTAGE RELATIVE TO THE AROMATIC POLYAMINES OF BEING NON-TOXIC.
Abstract:
NEW 1,3-DIGLYCIDYL-5,5-DIALKYL-5,6-DIHYDRO-URACILS (1,3DIGLYCIDYL-5,5-DIMETHYL-5,6-DIHYDRO-URACIL AND 1,3-DIGLYCIDYL-5,5-DIMETHYL-6-ISPOROPYL-5,6-DIHYDRO-URACIL) ARE PREPARED BY THE REACTION, KNOWN PER SE, OF 5,5-DIALKYL-5,6DIHYDRO-URACIL WITH EPICHLOROHYDRIN IN THE PRESENCE OF A TERTIARY AMINE OR OF A QUATERNARY AMMONIUM SALT, FOLLOWED BY DEHYDROHALOGENATION WITH ALKALI. (THE EASY ACCESS IS SURPRISING BEACUSE THE 5-UNSUBSTITUTED DIHYDROURACILS CAN BE CONVERTED ONLY INTO THE MONOGLYCIDYL DERIVATIVES EVEN WHEN A LARGE EXCESS OF EPICHLOROHYDRIN IS USED). AS A RULE, THE NEW DIEPOXIDES ARE LIQUID-VISCOUS AND CAN BE CURED WITH THE USUAL CURING AGENTS, SUCH AS DICARBOXYLIC ACID ANHYDRIDES OR POLYAMINES TO FORM SHAPED ARTICLES WITH GOOD MECHANICAL AND ELECTRICAL PROPERTIES.
Abstract:
NEW, SO-CALLED "ADVANCED" ADDUCTS CONTAINING EPOXIDE GROUPS, FROM POLYEPOXIDE COMPOUNDS CONTAINING ON AN AVERAGE MORE THAN ONE EPOXIDE GROUP IN THE MOLECULE AND MONONUCLEAR, FIVE- OR SIX-MEMBERED, UNSUBSTITUTED OR SUBSTITUTED N-HETEROCYLIC COMPOUND WHOSE MOLECULE CONTAINS TWO ENDOCYCLIC NH GROUPS, AND LESS THAN ONE EQUIVALENT NH GROUP FOR EVERY EPOXIDE GROUP EQUIPVALENT OF THE POLYEPOXIDE COMPOUND, OBTAINED BY REACTION OF FOR EXAMPLE 2 MOLS OF DIOMETHANEDIGLYCIDYL EHTER AND 1 MOL OF 5,5-DIMETHYLHYDANTOIN. THE EPOXIDE RESINS "ADVANCED" WITH THE AID OF SUCH NITROGEN COMPOUNDS HAVE A GOOD STORAGE STABLITY IN ADDITION TO EXCELLENT ELECTRICAL PROPERTIES.
Abstract:
HOT-CURABLE MOULDING, COATING AND ADHESIVE COMPOSITIONS WHICH ARE STORAGE-STABLE AT ROOM TEMPERATURE AND WHICH CONTAIN A POLYEPOXIDE COMPOUND, FOR EXAMPLE A LIQUID POLYGLYCIDYL ETHER OF BISPHENOL A AND, AS A LATENT CURING AGENT, A C2-C4-ACYLUREA, FOR EXAMPLE N-MONOACETYLUREA, N,N''-DIACETYLUREA OR N,N''-DIPROPIONYLUREA. AS A RULE 0.2-0.7 MOL OF ACETYLUREA ARE EMPLOYED PER EPOXIDE EQUIVALENT. IN ORDER TO OBTAIN PERFECT CASTINGS, THE CURE SHOULD BE CARRIED OUT STEPWISE BY GRADUAL WARMING, WITH THE MIXTURES BEING EXPOSED TO GRADUALLY RISING TEMPERATURES IN THE RANGE OF 100-180*C., AND THE TEMPERATURE MUST, ESPECIALLY IN THE RANGE OF 120-150*C., ONLY BE RAISED IN SMALL STEPS.
Abstract:
Curable molding, coating and adhesive compositions which contain a polyepoxide compound, for example a liquid polyglycidyl ether of bisphenol A, and, as the curing agent, an N,N'' -di-( gamma aminopropyl)-hydantoin, for example 1,3-di-( gamma -aminopropyl)5,5-dimethyl-hydantoin. Curing can be carried out at relatively low temperatures, for example at 40* C. The new type of curing agent bridges, in respect of its gradation of reactivity, a gap between aliphatic polyamines and cycloaliphatic polyamines. The new curing agents furthermore have the advantage relative to the aromatic polyamines of being nontoxic.