摘要:
The present invention relates to binder mixtures for two-component polyurethane coating compositions which dry at room temperature and containa) a polyisocyanate component,b) a hydroxy-functional polyacrylate component based on a mixture of at least two hydroxyl group-containing poly(meth)acrylate resinsi) having a molecular weight (M.sub.n) of 1000 to 100,000,ii) having an at least bimodal molecular weight distribution,iii) prepared by radical copolymerization of olefinically unsaturated monomers in a solvent using monomer mixtures containing less than 50% by weight of monomers carrying hydroxyl groups andiv) wherein the hydroxyl group content of the component having the lowest molecular weight is at least 1.5 times the hydroxyl group content of the component having the highest molecular weight,c) optionally reactive diluents,wherein components a) and b) are present in an amount which corresponds to an NCO/OH equivalent ratio of 0.2:1 to 5:1.
摘要:
The present invention relates to a process for the production of polyhydroxyl compounds having a hydroxyl group content of 2 to 10% by weight and a viscosity at 23.degree. C. of 250 to 80,000 mPa.s by the radically initiated polymerization at a reaction temperature of 80.degree. to 220.degree. C. ofa) 100 parts by weight of a mixture of olefinically unsaturated monomers containing at least 1% by weight of monomers containing alcoholic hydroxyl groups in the presence ofb) 5 to 500 total parts by weight, which may be present at the beginning of the reaction or added during the reaction, of one or more cyclic compounds which, in the presence of initiator compounds containing alcoholic hydroxyl groups, are capable of a ring-opening polymerization reaction andc) 2 to 300 parts by weight, which may be present at the beginning of the reaction or added during the reaction, of one or more polyhydric alcohols having a molecular weight of 62 to 1000.The present invention also relates to the polyhydroxyl compounds obtained by this process and to their use in combination with suitable hardeners as binders for one-component or two-component coating compositions.
摘要:
The present invention relates to a process for recovering and recycling the organic binder components accumulating during the spraying of a solvent-containing, two-component polyurethane coating or a solvent-containing, moisture-curing one-component polyurethane coating byi) forming a coatings slurry containing the organic binder components, water and a coagulating agent,ii) mixing the coatings slurry, optionally after removing a portion of the water, with an organic solvent which is inert towards isocyanate groups,iii) reacting the free isocyanate groups present in the mixture obtained in step (ii) with a compound containing one isocyanate-reactive group which is more reactive with isocyanate groups than both water and the isocyanate-reactive component of the two-component polyurethane coating, if present, andiv) removing any remaining water and insoluble components from the organic phase accumulating in step (iii) and recovering the organic phase containing the organic binder components.
摘要:
The present invention relates to a binder composition containing a) 30 to 90 wt. % of an aqueous, hydroxy- and/or amino-functional resin dispersion and b) 10 to 70 wt. % of a curing agent containing alkoxysilyl groups and having a free isocyanate group content of 10 to 23 wt. % and a viscosity of 50 to 10000 mPa.multidot.s at 23.degree. C., wherein the molar ratio of the hydroxyl groups of component a) to the isocyanate groups of component b) is 0.5:1 to 2:1. The present invention also relates to the use of these binder compositions in coating and sealing compositions.
摘要:
The present invention relates to a process for the production of storage stable prepolymers containing free isocyanate groups by reactinga) an organic polyisocyanate component having (cyclo)aliphatically bound isocyanate groups and a maximum functionality of 4.5 withb) one or more hydroxy-functional polyacrylate resins having a content of alcoholic hydroxy groups of 0.05 to 7% by weight at an equivalent ratio of isocyanate groups of component a) to hydroxyl groups of component b) of 3:1 to 40:1, wherein components a) and b) are selected to provide a value B of at most 4 when calculated in accordance with the formula: ##EQU1## wherein F.sub.1 and F.sub.2 represent the NCO and OH functionalities of components a) and b), F.sub.1 representing the component with the lower functionality when the components differ in functionality andval.sub.A /val.sub.I represents the OH/NCO equivalent ratio of components a) and b). The invention also relates to the NCO prepolymers obtained by this process and to their use for the production of one-component, moisture-curing coating compositions.
摘要:
The present invention relates to a hydroxy-functional copolymer P, which is present as a dispersion and/or solution in water, and is obtained by successively carrying out process steps A-D: A) initially introducing a hydrophobic polymer containing hydroxyl groups into a reaction vessel, B) introducing an initiator component into that vessel, C) subsequently polymerizing a hydrophobic monomer mixture containing hydroxyl groups in that vessel and D) subsequently polymerizing a hydrophilic monomer mixture containing hydroxyl and acid groups in that vessel. The present invention also relates to a process for the preparation of copolymers P following the procedure previously set forth and to coating compositions containing these copolymers P and one or more crosslinking agents.
摘要:
The present invention relates to an aqueous coating composition containing a) a urethane (meth)acrylate having (meth)acryloyl groups and optionally free isocyanate groups, b) optionally a further polyisocyanate, c) a UV initiator which initiates polymerization by a free radical mechanism, and d) one or more aqueous binders containing isocyanate-reactive groups. The present invention also relates to the use of the coating compositions for coating various substrates, especially metal substrates.
摘要:
The present invention relates to aqueous polyurethane-urea dispersions having a resin solids content of at least 35 wt. % and a pH of at least 7.5 which are prepared bya) forming an isocyanate-terminated prepolymer by reacting a difunctional polyol having a molecular weight of 500 to 6000, a low molecular weight alcohol, a diisocyanate and/or triisocyanate and an isocyanate-reactive compound which has an acid group,b) neutralizing 65% to 95% of the acid groups prior to dispersing the prepolymer in water,c) dispersing the neutralized prepolymer in water,d) chain extending the isocyanate groups with water to form a polyurethane-urea, ande) after completion of the chain extending reaction adding additional neutralizing agent to provide a total amount of neutralizing agent that is sufficient to neutralize at least 115% of the acid groups of component D),wherein the polyurethane-urea contains 1.0 to 4.0%, based on resin solids, of the isolated urea groups. The present invention also relates to a process for the preparation of these polyurethane-urea dispersions and to their use in coating compositions.
摘要:
The invention relates to a process for the preparation of carbonates having a six-membered ring, of the formula ##STR1## by transesterification of 1,3-propanediol compounds with carbonic acid esters and subsequent distillative depolymerization of the oligo- or polycarbonate initially formed, one or more catalysts from the group consisting of compounds of Sn, Ti or Zr being employed both for the transesterification and for the depolymerization and, if appropriate, the distillation residue is at least partly recycled into the transesterification. Such carbonates having a six-membered ring can furthermore be stabilized against undesirable polymerization by addition of small amounts of acids of sulfur or phosphorus or esters or salts thereof.
摘要:
This invention relates to aqueous, crosslinkable binder dispersions which have a low solvent content and contain hydroxy-functional polyethers, hydroxy-functional acrylate copolymers and hydroxy- and carboxy-functional acrylate copolymers, to a process for the production of these binders, to one and two-component binder compositions containing these binders and to the use of the binder compositions in coating compositions.