摘要:
In order to increase the stone chip resistance of automobile finishes aqueous electrocoating paints are used which are produced by the use of a pigment paste which contains as grinding resin an at least partially protonated epoxide-amine adduct which is obtainable by reacting(A) a glycidyl ether of a polyphenol which contains on statistical average at least one epoxide group in the molecule, or a mixture of such glycidyl ethers,(B) a polyglycidyl ether of a polyol which contains on statistical average more than 1.0 epoxide groups in the molecule, or a mixture of such polyglycidyl ethers, and(C) a compound which contains a primary amino group in the molecule or a mixture of such compoundswith each other in such a stoichiometric ratio that an epoxide-amine adduct is obtained in which on statistical average at least 2.0 primary amino groups of the component (C) are incorporated in a chain-extending function with the formation of tertiary amino groups and the resultant epoxide-amine addict is at least partially protonated.
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 cathodic electrocoating process, which uses electrocoating baths which contain a cationc amine-modified epoxy resin otainable by reacting(A) a diepoxy compound of an epoxy equivalent weight below 2000B) a compound monofunctionally reactive toward the epoxide groups and containign an alcoholic OH group, a phenolic OH group or an SH group, and(C) an amine,the components (A) and (B) being used in molar ratio of 10:1 to 1:1, preferably 4:1 to 1.5:1 and the positive charges being introduced by protonization of the reaction product and/or by use of amine salts as the component (C). The electrocoating baths used are distinguished by containing at least 7.5% by weight of a polyoxyalkylenepolyamine, the percentage by weight referring to the total amount of binders contained in the electrocoating bath.
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 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 method of of coating electrically conductive substrates using cathodically depositable electrodip paints. The invention is notable in that the electrodip paints employed contain crosslinked polymer microparticles which can be prepared by reacting(A) a compound which contains on average more than 1.0 epoxide groups per molecule, or a mixture of such compounds, and(B) a compound which contains not only a group reactive toward epoxide groups but also at least one ketimine or aldimine group in the molecule, or a mixture of such compoundsto give a noncrosslinked intermediate product (C), which still contains on average at least one epoxide group per molecule, and dispersing this intermediate product in the presence of a Br onsted acid in an aqueous medium.
摘要:
The invention relates to a process for the preparation of aqueous dispersions to be further processed to electrocoating paints with baking temperatures below 160.degree. C. and baking times.ltoreq.30 minutes, which dispersions contain modified epoxide-amine adducts as binders and polyisocyanates blocked by hydroxyl groups as cross-linking agents.In this process polyepoxides and compounds containing one or more, preferably 2, hydroxyl groups per molecule are reacted at elevated temperatures in the presence of catalysts to furnish epoxide-containing intermediates.A solvent or a mixture of solvents is then added with external cooling ahd the solution is boiled under reflux, if necessary in vacuo, until the temperature of the solution drops to 95.degree. C. to 20.degree. C.Amines are then added onto the epoxide groups which are still present in a free state in the epoxy resin and a dispersion is prepared by adding a water/acid mixture after adding the crosslinking agent or the dispersion is first prepared and the crosslinking agent is added subsequently.
摘要:
The present invention relates to an aqueous binder dispersion for cathodic electrodeposition coatings obtained A) by reacting I. a precursor prepared at temperatures of from 120 to 180° C. from a) a diepoxide compound or a mixture of diepoxide compounds and b) an aromatic or aliphatic compound hydroxyl, carboxyl, phenol and/or thiol groups, or a mixture of such compounds with reaction of the phenolic hydroxyl groups with epoxide groups, II. with at least one organic amine or a mixture of organic amines at a temperature between 60 and about 130° C. to give an epoxide/amine adduct; B) subsequently or simultaneously reacting at least one secondary hydroxyl group of the precursor with an unreacted epoxide group of the epoxide/amine adduct prepared in step A) at a temperatures of from about 110 to about 150° C.; C) adding a crosslinking agent at a temperature of less than about 150° C.; D) neutralizing the resulting binder from step A to C at a temperature of from about 90 to about 110° C.; and E) dispersing the neutralized binder obtained in step A to D in water.
摘要:
The invention relates to aqueous electrodeposition coating materials comprising cathodically depositable synthetic resins and further comprising a reaction product (A) and a polymerization initiator (B) which forms free radicals, wherein the cathodically depositable synthetic resin is different from the reaction product (A), and the reaction product (A) is prepared by reacting (a) a polyisocyanate or a mixture of polyisocyanates with (b) an organic compound which contains both at least one ethylenically unsaturated double bond and at least one active hydrogen atom per molecule, or a mixture of such organic compounds, and (c) an organic compound which contains both at least one active hydrogen atom and at least one tertiary amino group and/or at least one ketimine and/or at least one aldimine group per molecule, or a mixture of such organic compounds, and if desired (d) an organic compound which is different from (b) and (c) and contains at least one active hydrogen atom per molecule, or a mixture of such organic compounds.