摘要:
Essentially phenol-free phenol resol ethers which are bonded via o,o'-methylene ether groups are prepared by a process in whichA. where the process is carried out beginning with the methylolation in an aqueous medium, the methylolation is carried out in the presence of 0.5-10% by weight, based on the phenol employed, of Me.sup.++ ions, the latter are then removed as a sparingly soluble salt, the water present as a solvent in the reaction mixture is removed at 30.degree.-80.degree. C. in the presence or absence of one or more monohydric, dihydric or trihydric alcohols and an entraining agent, and the water of reaction formed during the etherification is separated off at 45.degree.-120.degree. C., andB. where the process is carried out beginning with the methylolation in a non-polar organic solvent, the methylolation is carried out in the presence of 0.1-0.3% by weight, based on the phenol employed, of Me.sup.++ ions, the etherification is effected at 95.degree.-120.degree. C. in the presence of one or more monohydric, dihydric or trihydric alcohols, with or without recycling of the distillate which passes over, and finally residual phenol in the products prepared by A. or B. is removed by evaporation in a thin film evaporator until the phenol content is less than 1% by weight.The phenol resol ethers prepared according to the invention are useful for the preparation of coating systems and for adhesives.
摘要:
Novel anodes consist of a mixture of from 30 to 95% by weight of nagnetite, lead dioxide, magnetite/natural graphite mixture or lead dioxide/natural graphite mixture and from 70 to 5% by weight of a plastic. They may be used for the surface-coating of metallic substrates by cathodic electrocoating.
摘要:
Copolymers crosslinkable by a free radical method are prepared by polymer-analogous reaction ofA) a copolymer (A) which is composed ofa1) from 20 to 85 mol % of a monomer (a1) having the structural element of methacrylic acid anda2) from 15 to 80 mol % of another monomer (a2) which undergoes free radical polymerization,a3) from 5 to 50 mol % of the total amount of the monomers (a1) and (a2) being monomers (a3) which carry functional groups and whose functional groups are capable of undergoing a condensation or addition reaction,withB) an olefinically unsaturated monomer (B) which carries a functional group which is complementary to that of the monomers (a3),by a process in which the polymer-analogous reaction is carried out at from 90.degree. to 150.degree. C. in an average residence time of from 3 to 20 minutes in highly concentrated solution or in the absence of a solvent. Said copolymers are used as binders for powder coatings.
摘要:
A low-formaldehyde binder consists essentially of(A) from 5 to 80% by weight of a water-soluble condensation product of carbonyl number 0-200 which has been prepared by alkaline condensation from 0.1 to 0.4 mole of an aliphatic or cycloaliphatic condensable ketone and 1 mole of formaldehyde, and(B) from 20 to 95% by weight of 4,5-dihydroxyimidazolidin-2-one and/or an unetherified, partially etherified or completely etherified condensation product thereof with an aliphatic monoaldehyde or dialdehyde.
摘要:
Copolymers crosslinkable by a free radical method and having a number average molecular weight of from 1500 to 6000 and a molecular weight distribution corresponding to a polydispersity of from 1 to 4.0 are obtainable by polymer-analogous reaction ofA) a copolymer (A) which is composed ofa1) from 50 to 85 mol % of a monomer (a1) containing the structural element of methacrylic acid anda2) from 15 to 50 mol % of another monomer (a2) undergoing free radical polymerization,a3) from 5 to 50 mol % of the total amount of the monomers (a1) and (a2) being monomers (a3) which carry functional groups and whose functional groups are capable of undergoing a condensation or addition reaction,and is obtainable by free radical mass or solution polymerization at from 140.degree. to 210.degree. C. and with an average residence time of from 2 to 90 minuteswithB) an olefinically unsaturated monomer (B) which carries a functional group which is complementary to the functional groups of the monomers (a3).Said copolymers are used as binders for powder coatings.
摘要:
Phenol resins which are modified with compounds possessing amide and/or imide groups and are based on phenol resol ethers bonded via o,o'-methylene ether groups, and a process for their preparation.The novel modified phenol resol ethers are useful for the preparation of coating systems, in particular as crosslinking agents for cathodic electrocoating binders, and for the preparation of adhesives and rubber assistants.
摘要:
Pigment formulations and their use.The formulations contain pigments, organic solvents and from 10 to 80% by weight of a wetting agent consisting of a non-ionic organic compound which has a viscosity of from 500 to 10,000 mPa.s and has been produced by reacting an alkylated amide/formaldehyde reaction product and an epoxy resin, which may or may not be modified, in a weight ratio of from 9:1 to 1:9. They are used as additives in surface-coating binders, especially in cationic electrocoating finishes.
摘要:
Surface-coating binders for cathodic electrocoating which comprise a protonized heat-curable reaction product (A), substantially free from epoxide groups, of(a) one or more Mannich bases, prepared from(a.sub.1) one or more polyhydric condensed phenols which may or may not contain ether groups.(a.sub.2) one or more secondary amines which contain one or more hydroxyalkyl groups, with or without one or more secondary amines which do not contain such groups, and(a.sub.3) formaldehyde or a formaldehyde donor, with(b) one or more epoxy resins,Which binder also contains from 1 to 40% by weight, based on the total of (A) + (B), of a water-insoluble non-ionic resin (B), free from epoxide groups and containing urethane groups, which resin has been obtained by reacting a partially blocked diisocyanate or higher polyisocyanate with a reaction product of a polyepoxide and one or more low molecular weight compounds containing SH and/or OH groups.These surface-coating binders are especially used for the cathodic electrocoating of metal articles.
摘要:
Surface-coating binders based on a reaction product of Mannich bases, obtained from polyhydric phenols, secondary amines and formaldehyde, with epoxy resins. The Mannich bases and/or the epoxy resins carry hydroxyl groups, bonded to aliphatic structures, which have been converted to urethane groups by reaction with partially blocked polyisocyanates. When protonized and diluted with water, the surface-coating binders may be used as cationic electrocoatings.
摘要:
Aqueous nonwoven binders that give reduced formaldehyde emission on curing are based on condensation products of urea or derivatives thereof, formaldehyde and glyoxal in a molar ratio, based on the solid binder, of from 1.5 to 2.5 moles of formaldehyde and from 0.1 to 0.5 mole of glyoxal per mole of the total urea used.