摘要:
The present invention relates to a powder coating, in particular for internal coating of packaging containers, which is characterized in that it1.) comprises at least one epoxy resin having an epoxide equivalent weight of from 300 to 5500 and at least one hardener having more than one phenolic hydroxyl group per molecule and a hydroxyl equivalent weight, based on the phenolic OH groups, of from 100 to 500, and2.) has a particle size distribution such that at least 90 percent by weight of the powder coating particles have a particle size of between 1 and 60 .mu.m, the maximum particle size of the powder coating particles is .ltoreq.100 .mu.m, the mean particle size of the powder coating particles is between 5 and 20 .mu.m and the gradient of the particle distribution curve at the point of inflexion is .gtoreq.100.
摘要:
The invention relates to a cathodic electro-dipping process wherein the electro-dipping primer employed contains a crosslinking agent which can be obtained by reactinga) a diol and/or a triol or a mixture of diols and/or a mixture of triols,b) diphenylmethane 4,4'-diisocyanate the melting point of which has been depressed, by partial reaction with a monool and/or polyol or a mixture of monools and/or a mixture of polyols, so far that it is liquid at room temperature andc) a masking agent or a mixture of masking agentsto give a crosslinking agent which is free from isocyanate groups.
摘要:
The invention relates to a cathodic electro-dipcoating process, wherein the electro-dipcoating composition used contains a cationic, amine-modified epoxy resin, which is obtainable by reacting(A) a polyepoxide,(B) an amine and(C) an adduct, which is obtainable by . . . (sic)(c1) a polyether- or polyester-polyol,(c2) a polyisocyanate and(c3) a compound which contains at least one hydrogen atom which is reactive towards isocyanate groups and at least one ketimine group in the molecule, and/or(D) a hydrolysis product of (C)with one another in a relative proportion such that 20 to 90% of the epoxy groups of component (A) are reacted with component (B) and the remaining epoxy groups are reacted with component (C) and/or (D), and--if still necessary--at least partially protonating the reaction product thus obtained.
摘要:
The invention relates to an aqueous coating agent, obtained from an epoxy resin, ethylenically unsaturated monomers, some of which contain carboxyl groups, a peroxide initiator in a proportion of at least 2% by weight, relative to the total weight of the monomers, a crosslinking agent, a neutralizing agent, organic solvents, and, if appropriate, further conventional additives, such as plasticizers, stabilizers, wetting agents, dispersion auxiliaries, catalysts and pigments. The coating agent is based on a binder (a) which is obtainable from(A) 20 to 80% by weight of an epoxy resin having an average of more than one epoxy group per molecule and having an average molecular weight of at least 500,(B) 1 to 60% by weight of polyester polycarboxylic acids having an average molecular weight of 500 to 5,000 and having an acid number of 30 to 150, and(C) 10 to 50% by weight of ethylenically unsaturated monomers, 10 to 50% by weight of the monomers containing carboxyl groups,where the sum of (A), (B) and (C) is 100% by weight, the binder (a) has an acid number of 20 to 150, and the crosslinking agents (b) used are phenolic and/or amino resins, with the proviso that the coating agent contains(a) 30 to 70% by weight of the binder (a),(b) 2 to 30% by weight, preferably 5 to 16% by weight, of the crosslinking agent (b),(c) 1 to 7% by weight, preferably 2 to 5% by weight, of ammonia and/or amine as neutralizing agent, and(d) 20 to 60% by weight of organic solvents,where the sum of (a), (b), (c) and (d) is 100% by weight. The present invention also relates to a process for the preparation of the coating agents, and the use thereof for coating of cans.
摘要:
A process for the preparation of aqueous thermosetting electrical insulating varnishes, wherein polyester-imide precondensates are prepared by condensing aromatic tricarboxylic acid monoanhydrides, diamines, diols, triols containing an isocyanurate ring, and cyclic trimerization products of diisocyanates, whose free isocyanate groups are blocked, with or without aromatic dicarboxylic acids or their esterifiable derivatives, and are reacted, at from 50.degree. to 200.degree. C., with or without addition of from 1 to 10% by weight, based on polyester-imide, of a polar organic solvent, with ammonia or an organic amine, and then diluted with fully demineralized water, with or without addition of a water-soluble curing catalyst. The novel electrical insulating varnishes are used as wire enamels or impregnating varnishes.
摘要:
Thermosetting polycondensates containing amide and imide groups which are obtained by reacting 1,2,3,4-butanetetracarboxylic acid or its anhydride with one or more aliphatic, cycloaliphatic or aromatic diamines and one or more oxadicarboxylic acids or oxadicarboxylic acid esters of the general formulaROOC--CH.sub.2 --O--(CH.sub.2).sub.2 --O--.sub.n CH.sub.2 --COORwhere R is hydrogen or alkyl of 1 to 6 carbon atoms and n is 0 or an integer from 1 to 10, in a water-soluble organic solvent and/or water, at from 80.degree. to 200.degree. C. These polycondensates are useful as wire enamels, impregnating agents and adhesives.
摘要:
The invention relates to a cathodic electro-dipping process wherein the electro-dipping primer employed contains a crosslinking agent which can be obtained by(I) reacting, in a first stage,(a) diphenylmethane diisocyanate and(b) a monoalcohol or a mixture of monoalcohols to give an intermediate product (A) containing isocyanate groups, and(II) reacting this intermediate product (A) in a second stage with(c) a polyol or a mixture of polyols to give an intermediate product (B) containing hydroxyl groups which(III) is reacted in a third stage either with(d) a cycloaliphatic, aliphatic or araliphatic polyisocyanate or a mixture of such polyisocyanates and(e) a monofunctional masking agent or a mixture of such masking agents or with(f) a partially-masked polyisocyanate prepared from (d) and (e)to give a crosslinking agent which is free from isocyanate groups.
摘要:
The invention relates to a cathodic electro-dipping process wherein the electro-dipping primer employed contains a crosslinking agent which can be obtained by(I) reacting, in a first stage,(a) diphenylmethane diisocyanate and(b) a monoalcohol or a mixture of monoalcohols to give an intermediate product (A) containing isocyanate groups, and(II) reacting this intermediate product (A) in a second stage with(c) a polyol or a mixture of polyols to give an intermediate product (B) containing hydroxyl groups which(III) is reacted in a third stage either with(d) a cycloaliphatic, aliphatic or araliphatic polyisocyanate or a mixture of such polyisocyanates and(e) a monofunctional masking agent or a mixture of such masking agents or with(f) a partially-masked polyisocyanate prepared from (d) and (e)to give a crosslinking agent which is free from isocyanate groups.
摘要:
The invention relates to a process for a cathodic electrocoating process, wherein the electrocoating bath contains at least 7.5% by weight of a polyoxyalkylenepolyamine or a mixture consisting of several polyoxyalkylenepolyamines of different chemical structures, the percentage by weight referring to the total amount of binders contained in the electrocoating bath.
摘要:
The invention relates to water-dispersible binders for cationic electrocoating paints, a process for the preparation of these binders and a process for electrophoretic coating of an electrically conducting substrate, connected as cathode, from an aqueous bath based on this binder.The water-dispersible binders are reaction products of(A) epoxy resins containing low-molecular, preferably aromatic groups, having an epoxide equivalent weight below 750,(B) 10% to 60% by weight, prerferably 20% to 40% by weight, based on the total binder, of a prepolymer having a molecular weight (mass average) of 500 to 5000 and an average content per molecule of 0.1 to 1.9 hydroxyl groups and 0.1 to 1.0 carboxyl groups, the total of the hydroxyl and carboxyl groups being between 1 and 2, with an aromatic groups content of 10% to 45% by weight, calculated as phenylene groups contained in the resin solids in % by weight. In order to achieve water dispersibility, these reaction products are modified with(C) primary, secondary and/or tertiary amines and/or their salts or a sulfide/acid mixture or a phosphine/acid mixture.