摘要:
The reaction of polymers containing carboxyl groups with organic nitrogen bases which have certain structural features leads to highly reactive products which are eminently suitable as binder components for powder lacquers which may be hardened with polyepoxides.
摘要:
Polyesters useful as a binder or a component of a binder for powder lacquers and which contain hydroxyls, carboxyls or both and which have an acid value of up to 50, a hydroxyl value of up to 200 and a sum of hydroxyl value and acid value of from 20 to 200 is produced by reacting:(a) an acid component selected from the group consisting of (a1) at least one poly-functional organic carboxylic acid, (a2) at least one ester-forming derivative of a poly-functional organic carboxylic acid, (a3) at least one organic hydroxycarboxylic acid, (a4) at least one lactone of an organic hydroxycarboxylic acid, and mixtures thereof, with the proviso that at least 50 mol-% of component (a) consists of aromatic species of components (a1), (a2), (a3), (a4), or mixtures thereof,with(b) a polyol component which is at least one polyhydric alcohol having a molecular weight in the range from 62 to 250,while maintaining an equivalent ratio of carboxyl groups to hydroxyl groups of form 0.65:1 to 1.5:1, with the proviso that component (b) is used in a quantity of at least 30% by weight, based on the weight of component (a), and the reaction is carried out in the presence of(c) at least 5% by weight, based on the weight of components (a) and (b), of a solvent containing amide groups, lactam groups, or both and said solvent is free from any nitrogenhydrogen bonds.
摘要:
Cyclic amidines which are modified by the incorporation of additional polar groups, may be used as catalysts for hardening heat-curable resin compositions comprising polyepoxides and optionally carboxyl group-containing polymers. Such amidine catalysts yield a high reactivity, an excellent storage stability and result in elastic coatings which show a high gloss and a good resistance to solvents.
摘要:
Cyclic amidines which are modified by the incorporation of additional polar groups, may be used as catalysts for hardening heat-curable resin compositions comprising polyepoxides and optionally carboxyl group-containing polymers. Such amidine catalysts yield a high reactivity, an excellent storage stability and result in elastic coatings which show a high gloss and a good resistance to solvents.
摘要:
Described is a process for producing segmented polyurethanes having improved processing characteristics in the melt state and an efficient spinning process based thereon to form highly elastic, fine linear density elastane yarn and filament having improved mechanical and thermal properties by using hydroxyalkyl-terminated polysiloxanes in combination with specific crosslinking-capable polyisocyanates in the reaction of long-chain high molecular weight polyhydroxy compounds with organic diisocyanates and low molecular weight diols and also optionally further auxiliary and additive substances in the melt.
摘要:
A process for modifying superabsorbent polymers is disclosed. The surface of a polymer containing hydrolyzed polyacrylonitrile in the form of particulates, is modified by crosslinking in a water/alcohol reaction mixture and in the presence of silica. The resulting product features improved absorbency under load and lesser degree of gel blocking.
摘要:
Super-absorbent polymer in the form of pre-formed spherical particles obtainable by alkaline hydrolysis of aqueous emulsions of crosslinked and/or un-crosslinked homopolymers and/or copolymers of acrylonitrile in water/alcohol mixtures and the use of the polymer in hygiene products, as a water-storing material in agriculture and for the sheathing of electrical cables.
摘要:
The present invention relates to a process for preparing polyisocyanates containing isocyanurate groups by trimerizing a portion of the isocyanate groups of an organic polyisocyanate component containing a) one or more diisocyanates corresponding to formula (1) ##STR1## wherein R represents a saturated, straight-chain, aliphatic hydrocarbon group having 8 to 15 carbon atoms and optionally b) up to 95 NCO equivalent-%, based on the total equivalents a) and b), of one or more organic polyisocyanates other than a), in the presence of trimerization catalysts and terminating the trimerization reaction at any desired degree of trimerization. The invention also relates to the polyisocyanates containing isocyanurate groups obtained by this process and to their use, optionally in excess starting polyisocyanates and optionally blocked with blocking agents for isocyanate groups, as an isocyanate component for preparing polyisocyanate addition products.
摘要:
The invention relates to new hexahydrotriazinetrione-containing high molecular weight polyarylene sulphides (PAS), preferably polyphenylene sulphides (PPS), and a process for their preparation.
摘要:
The invention relates to new, free-flowing polyamide molding compounds and blends, characterized in that they are prepared by mixing of polyamides known per se in the melt with low molecular weight, liquid-crystalline esters and/or ester amides corresponding to formula (I) and/or liquid-crystalline, oligomeric esters and/or ester amides corresponding to formula (II) and, optionally, other additives, at least one polymeric blending component being used as a further additive in the case of polyamide blends, and to the use of these liquid-crystalline (LC) additives I and/or II as flow promoters in polyamide molding compounds and blends and to a process for the production of the new polyamide molding compounds and blends. The invention also relates to the new oligomeric esters and/or ester amides corresponding to formula (II).