摘要:
Methods of producing vinyllactam copolymers which include: providing at least one water-soluble N-vinyllactam; providing at least one hydrophobic comonomer; and subjecting the at least one water-soluble N-vinyllactam and the at least one hydrophobic comonomer to free-radical polymerization in an organic solvent in the presence of an initiator, under a combination of process measures selected from the group consisting of A and B; wherein:(A) comprises (i) polymerization under reflux, and at least two of (ii), (iii), (iv), (v), (vi), and (vii), wherein (ii) comprises an addition of at least 5 mol % of N-vinyllactam to the polymerization mixture if at least 70 mol % of the total amount of hydrophobic monomer used have completely reacted, (iii) comprises return of condensate formed in the reflux from below to the polymerization mixture, (iv) comprises introduction of the initiator in the form of a solution in an organic solvent from below into the polymerization mixture, (v) comprises addition of N-vinyllactam to the reflux, (vi) comprises distilling off a portion of the organic solvent and continuing the polymerization following conversion of 70 to 99% by weight of the N-vinyllactam used, and (vii) comprises introduction of at least one monomer from below into the polymerization mixture; and wherein(B) comprises (viii) polymerization under a superatmospheric pressure such that vaporization of the polymerization components is avoided, and at least one of (i), (ii), (iii), (iv), (v), (vi), and (vii), with the proviso that a combination of (viii) with any of (i), (iii) or (v) is carried out sequentially.
摘要:
Method of producing vinyllactam copolymers by free-radical polymerization of at least one water-soluble N-vinyllactam and at least one hydrophobic comonomer in an organic solvent in the presence of an initiator under reflux conditions, where N-vinyllactam is added to the reflux.
摘要:
Method of producing vinyllactam copolymers by free-radical polymerization of at least one water-soluble N-vinyllactam and at least one hydrophobic comonomer in an organic solvent in the presence of an initiator under reflux conditions, where at least 10 mol % of the N-vinyllactam are added to the polymerization mixture when at least 90 mol % of the hydrophobic monomer have completely reacted.
摘要:
Method of producing copolymers by free-radical polymerization of at least one water-soluble N-vinyllactam and at least one hydrophobic comonomer in an organic solvent in the presence of an initiator, where the polymerization is carried out under a gauge pressure such that evaporation of the components is avoided.
摘要:
The invention relates to the aqueous preparation of a polymer. Said preparation contains a copolymer consisting of a) 30 to 79.5 wt. % N-vinylpyrrolidone, b) 20 to 69.5 wt. % vinylacetate, c) 0.5 to 25 wt % of a monovinyl ester of a C4 to C20 monocarboxylic acid and d) 0 to 40 wt. % of an additional, copolymerisable, ethylenically unsaturated compound.
摘要:
Condensates based on substituted ureas, their reaction products with di- and/or polyisocyanates, derivatives of di- and/or polycarboxylic acids or p-substituted phenols and/or their methylol derivatives, their preparation and their use. These condensates each contain two or more cyclic urea units and can be prepared either by reacting primary di- or polyamines with ureas and reacting the product with predominantly CH-acidic aldehydes or by reacting primary amines with isocyanates and reacting the product with predominantly CH-acidic aldehydes in the presence of an acidic catalyst. The said condensates and their reaction products are useful for the preparation of heat-curable coating materials and of binders for cathodic electrocoating.
摘要:
Binders for cathodic electrocoating which are based on polyadducts/polycondensates which carry basic nitrogen groups and are rendered water-dilutable by protonation with an acid, and one or more crosslinking agents for these polyadducts/polycondensates, their use and electrocoating baths prepared from them.These binders essentially consist of a mixture of(A) from 50 to 90% by weight of a polyadduct/polycondensate which carries basic nitrogen groups and is obtainable by reacting(a) an essentially epoxide-free adduct of a secondary amine and polyepoxide compound with(b) a condensate of a diamine/polyepoxide adduct which is prepared in the presence of excess diamine and separated off from excess diamine after complete conversion of the epoxide groups, with one or more mono- and/or dicarboxylic acids of not less than 6 carbon atoms.(B) from 10 to 50% by weight of a crosslinking agent which does not react with component (A) at room temperature but reacts with the latter at elevated temperatures with crosslinking.These binders are particularly useful for the cathodic electrocoating of electrically conductive substrates.
摘要:
Heat-curable surface-coating agents useful not only for application as solvent-containing finishes and for powder coating but also, in their protonated form, for cathodic electrocoating contain, as a binder, a mixture of (A) a polyadduct, polycondensate or other polymer having an average molecular weight M.sub.n of from 500 to 10,000 and, per molecule, on average two or more OH and/or primary and/or secondary amino groups and (B) a reaction product of (a) one or more polyisocyanates, (b) one or more secondary monoamines and, if appropriate, (c) one or more polyalcohols having two or more hydroxyl groups.
摘要:
Binders useful for cathodic electrocoating are water-dilutable on addition of acid and comprise a mixture of(A) a polyadduct which carries basic nitrogen groups and contains groups of the formula (I) and/or (II) ##STR1## where R.sup.1 and R.sup.2 are hydrogen or methyl and R.sup.3 and R.sup.4 are alkyl or hydroxyalkyl or together are a 5- or 6-membered ring, and(B) a reaction product of a polyisocyanate and an olefinically unsaturated amine which carries a secondary amino group and a methacrylamide or methacrylate group.
摘要:
The present invention relates to surface coating binders which are self-crosslinking when heated and are based on resin-like polyadducts, polycondensates or polymers. These binders have a mean molecular weight M.sub.n of from 500 to 10,000 and contain, on average per molecule, at least two groups of the general formula ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are identical or different and are each hydrogen or a methyl or ethyl radical, and additionally contain hydroxyl and/or primary and/or secondary amino groups and may or may not contain tertiary amino groups.They can be prepared by reacting appropriate resins containing primary amino groups with cyclic carbonates, and can be used, in solution in an organic solvent, as baking finishes, as well as for the preparation of cathodic electrocoating finishes.