摘要:
This invention relates to a crosslinking composition comprising and organic acid and a compound having the structure of Formula I: A′—NRA—RD where A′ is a moiety derived from the group consisting of triazines, linear or cyclic ureas, cyanuric acid, substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins, linear or cyclic carbamates and mixtures thereof, or a moiety comprising the structure: where RA is RD, hydrogen, an alkyl of 1 to 20 carbon atoms, or taken together with A′ forms a cyclic compound; RD is —CHRCORB, wherein RB is hydrogen, alkyl, aryl, aralkyl or an alkaryl having from 1 to about 24 carbon atoms and RC is an alkyl, halogenated alkyl, aryl, aralkyl, halogenated aralkyl, alkoxyalkyl or an alkaryl having from 1 to about 24 carbon atoms; A is a moiety derived from the group consisting of linear or cyclic ureas, cyanuric acid, substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins, linear or cyclic carbamates and mixtures thereof; B is a residue of a poly(alkylaldehyde) with n aldehyde groups; n is an integer of 2 to about 8; Ra is Rd, hydrogen, an alkyl of 1 to about 20 carbon atoms, or taken together with A forms a cyclic compound; where Rd is CHRcORb or where Rb is hydrogen, alkyl, aryl, aralkyl or an alkaryl having from 1 to about 24 carbon atoms and Rc is an alkyl, halogenated alkyl, aryl, aralkyl, halogenated aralkyl, alkoxyalkyl or an alkaryl having from 1 to about 24 carbon atoms; and where the alkyl or aryl groups in each radical may optionally have heteroatoms in their structure. This invention also relates to a process for producing the crosslinking composition by reacting an amino compound containing amino groups; a mono(alkylaldehyde) and/or a poly(alkylaldehyde), and an alcohol; and adding an organic compound where said amino compound is selected from the group consisting of: triazines, linear or cyclic ureas, cyanuric acid, substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins, linear or cyclic carbamates and mixtures thereof.
摘要:
Described is a process for preparing a dispersion of microcapsules by condensing a partially methylated melamine-formaldehyde resin having a molar ratio of melamine:formaldehyde:methanol of from 1:3.0:2.0 to 1:6.0:4.0 in water in which the essentially water-insoluble material forming the capsule core is present in dispersion in the presence of an alkali metal salt of a homopolymer or copolymer of 2-acrylamido-2-methylpropanesulfonic acid as protective colloid at a pH of from 3 to 6.5 by preforming the microcapsules at a temperature of from 20 to 50° C. and then curing the capsule wall of the preformed microcapsules at >50 to 100° C., which comprises adding from 5 to 100% by weight of melamine, based on the melamine-formaldehyde resin, in the course of curing. The microcapsule dispersions are formaldehyde-reduced and of low viscosity.
摘要:
Crosslinker compositions consisting essentially of 50 to 95 weight percent monomeric C1 to C8 alkoxymethyl melamine derivatives containing not more than about 0.20 wt. % of imino (>NnullH) groups. Such compositions further comprise 5 to 50 weight percent oligomeric C1 to C8 alkoxymethyl melamine derivatives and are useful for low temperature curing of functional resins, e.g. with active hydroxyl groups, for wood, automotive, appliance, coil and other coatings.
摘要:
A high solids polymer resin coating composition cross-linked with alkylated melamine resins possessing improved intercoat adhesion in multiple coating applications. A mixed methylated isobutylated melamine resin as a cross-linking agent for the high solids polymer resin coating composition surprisingly substantially eliminates intercoat adhesion failure without any negative effects on overall coating properties and performance. The backbone polymer of the composition may advantageously be acrylic resin, a polyester resin or mixtures thereof while the mixed methylated isobutylated melamine resin cross-linking agent is advantageously predominantly monomeric poly(methoxy isobutoxymethyl) melamine resin with an average methoxy content of 1-5 and an average isobutoxy content of 5-1, per triazine.
摘要:
Partially etherified melamine-formaldehyde resins having a melamine: formaldehyde molar ratio of 1:(1.25 to 1) can be prepared by a condensation reaction under neutral or weakly alkaline conditions if the condensation reaction is carried out in the presence of a glycol monoether of the general formula IR (OCH.sub.2 CH.sub.2).sub.n OH (I)wherein R denotes alkyl having 1 to 4 C atoms and n denotes a number from 1 to 5. The partially etherified melamine-formaldehyde resins are suitable for the production of compression moulding compositions having a high flow and minimal processing shrinkage and after-shrinkage.
摘要:
A water-reducible acrylic enamel coating composition capable of being substantially completely cured at a relatively low temperature, such as about 250.degree. F. and containing a water-miscible partially etherified melamine formaldehyde cross-linking agent and an acrylic copolymerization product of about 3% to about 8% of an unsaturated carboxylic acid, about 10% to 30% of a hydroxy functional monomer and about 62% to 87% of a nonfunctional monomer. The acrylic copolymer is further characterized as having a glass transition temperature of about -10.degree. C. to 45.degree. C. and a molecular weight of about 2,000 to about 100,000. The aminoplast resin preferably is only partially etherified and contains about 10% to about 30% by weight reactive methylol groups.
摘要:
Low-viscosity high-solids-content melamine-formaldehyde condensates having high reactivity, low content of free formaldehyde and good compatibility, are prepared by effecting condensation in an alcohol having up to 3 carbons, then concentrating the condensate and heating the concentrate in a higher alcohol having from 3 to 18 carbons and again concentrating. The final product cures on heating to a hard glossy film and can be added to other uncured resins to improve the hardness of their films.
摘要:
A PROCESS FOR THE MANUFACTURE OF ETHERIFIED MELAMINE RESINS BY REACTING ONE MOL OF MELAMINE AT AN ELEVATED TEMPERATURE WITH LESS THAN 3 MOLS OF FORMALDEHYDE POLYMER AND AT LEAST 4 MOLS OF A MONOHYDRIC ALIPHATIC WATERIMMISCIBLE ALCOHOL IN THE PRESENCE OF A CATALYTIC QUANTITY OF AN ACID AND CONTINUOUSLY REMOVING WATER BY DESTILLATION, COATINGS AND AN IMPREGNATED MATERIAL CONTAINING THE PRODUCTS OF THE PROCESS.
摘要:
AN ENCAPSULATION PROCESS IS PROVIDED WHEREIN THE SUBSTANCE TO BE ENCAPSULATED IS DISPERSED IN A LIQUID WITH WHICH IT IS SUBSTANTIALLY IMMISCIBLE IN THE PRESENCE OF A TENSIDE CAPABLE OF FORMING A COMPOUND THAT IS INSOLUBLE IN THE DISPERSING LIQUID AND THEREAFTER THE TENSIDE IN THE DISPERSION, WHICH IS IN ASSOCIATION WITH THE SUBSTANCE, IS CONVERTED INTO THE IRREVERSIBLY INSOLUBLE STATE TO ENCAPSULATE THE SUBSTANCE. PARTICULARLY SUITABLE A TENSIDES ARE THE SURFACE-ACTIVE, CROSS-LINKABLE AMINOPLASTS, PREFERABLY SURFACE-ACTIVE, ETHERIFIED METHYLOMELAMINES OR THE CORRESPONDING METHYLOLUREAS.