摘要:
Epoxy resins which are obtainable by a process in which, first of all(a) by reacting(A1) at least one substance selected from the substances of the formula (I) and of the formula (II): ##STR1## in which Alc is the radical of a diol which has been freed fromI ts hydroxyl groups and comprises 2 to 20 carbon atoms,Ac is the radical of a dicarboxylic acid which has been freed from its carboxyl groups and comprises 2 to 20 carbon atoms,[Ph] is the radical of a difunctional phenolic compound which has been freed from its phenolic hydroxyl groups and has 6 to 20 carbon atoms, andc is a number greater than 1 but not more than 2, with(A2) at least one liquid diglycidyl ether based on a first bisphenol compound in an amount chosen so that there are more than two equivalents of glycidyl groups of component (A2) for a total of one equivalent of carboxyl and phenolic hydroxyl groups of component (A1),a pre-advanced diglycidyl ether resin is formed in dispersion in the liquid diglycidyl ether of which there is at least one, and subsequently(b) the resin dispersion obtained in accordance with (a) is reacted with a phenol component comprising at least one bisphenol compound which is identical to or different from the first bisphenol compound, the amount of the phenol component being chosen so that in the mixture of the resin dispersion and the phenol component the glycidyl groups prior to the reaction are in a stoichiometric excess over the phenolic hydroxyl groups.
摘要:
An epoxy resin mixture is prepared by a) the reaction of (i) a diglycidyl compound, (ii) a bisphenol compound and (iii) at least one monophenol at temperatures of from 160 to 170° C. in the presence of an advancement catalyst that can be thermally deactivated, (b) upon completion of the reaction, the catalyst is deactivated by heating to a temperature of approximately 180° C. wherein (A1) one or more epoxy resins having an epoxy functionality of greater than two is added, and c) the resulting epoxy resin mixture is homogenized at that temperature.
摘要:
A powder coating composition comprising(A) a solid epoxy resin mixture that comprises at least one epoxy resin component (A1) and one epoxy resin component (A2) and(B) a free-carboxyl-group-containing polyester in an amount sufficient for the full cure of the composition,in which the epoxy resin component (A1) consists of one or more epoxy resins and has overall a mean epoxy functionality that is greater than 2,wherein the epoxy resin component (A2) consists of one or more advanced epoxy resins each of which has a mean epoxy functionality of at least 1.2 but less than 1.95 and is the product of a reaction in which (i) at least one diglycidyl compound is simultaneously reacted with (ii) at least one bisphenol compound and (iii) at least one monophenol as starting materials, and the difference between the mean epoxy functionality of the epoxy resin mixture (A) and the mean epoxy functionality of component (A2) of the mixture is at least 0.05 but less than 0.8.