| 摘要 |
#CMT# #/CMT# Coating agent comprises: (a) 10-90 wt.% of aqueous hydroxy- and/or aminofunctional resin dispersion; (b) 10-90 wt.% of nanoparticle modified polyisocyanate; and (c) 0-60 wt.% of further auxiliary materials and additives conventionally used in coating technology, where the percentage is related to the solids in the total composition. #CMT#USE : #/CMT# The coating agent is useful in lacquer, coating and sealants preferably for anticorrosive applications. The coating agent (i.e. in the form of pigmented primer/primer/bonding agents, fillers, topcoats and clear coats) is useful in the fields of automotive refinishes, commercial vehicle- and industrial-coating. #CMT#ADVANTAGE : #/CMT# The aqueous two-component polyurethane coating provides improved corrosion protection with high application safety. #CMT#INORGANIC CHEMISTRY : #/CMT# Preferred Components: The component (c) includes inorganic oxide, mixed oxide, hydroxide, sulfate, carbonate, carbide, boride and nitride of the elements of groups II to IV main groups and/or elements of the groups I to VIII subgroups of the periodic table including the lanthanides. The component (c) includes surface modified particles. #CMT#POLYMERS : #/CMT# The component (a) comprises, relative to the solid resin, 0.5-7 wt.% of hydroxyl group and acid number of less than 50 mg potassium hydroxide/g. The component (b) is based on (cyclo)aliphatic, araliphatic and/or aromatic diisocyanate having an average isocyanate functionality of at least 2.1 and a content of isocyanate group (calculated as NCO, molecular weight of 42) of 2-24 wt.% and is obtained by reacting (a1) hydrophobic polyisocyanate component, (a2) hydrophilic modified polyisocyanate component with (b1) alkoxysilane compound of formula (Q-Z-Si-X-nY 1> 3 - n) (I), subsequently dispersing (c1) surface modified inorganic particle having an average particle size of less than 200 nm measured by a dynamic light scattering in particle number weight, and optionally adding (d) solvent. The component (a1) is polyisocyanate or polyisocyanate mixture with aliphatic and/or cycloaliphatic bound isocyanate groups. The component (a2) comprises at least one hydrophobic starting polyisocyanate and at least one ionic and/or non-ionic emulsifier, where the emulsifier is: a reaction product of polyisocyanate with hydrophilic polyether alcohol; a reaction product of monomeric diisocyanate or diisocyanate mixture with pure polyethylene glycol monomethyletheralcohol having average 5-50 (preferably 5-25) ethylene oxide unit; a reaction product obtained by mixing and reacting polyether urethane emulsifier with polyisocyanate in the presence of catalyst to form allophanate; a reaction product of polyisocyanate with 2-(cyclohexylamino)-ethanesulfonic acid and/or 3-(cyclohexylamino)-propane sulfonic acid; or tertiary amine neutralized alkylphenolpolyglycol ether phosphate, alkylphenolpolyglycol phosphonate, fatty alcohol polyglycol ether phosphate, fatty alcohol polyglycol ether phosphonate, alkylphenol polyglycol ether sulfate or fatty alcohol polyglycol ether sulfate. Q : reactive group against isocyanate (preferably urethane- or (thio)urea-forming reactive group); X : hydrolyzable group (preferably alkoxy- or hydroxy group); Y 1> : alkyl group (preferably 1-4C alkyl); Z : 1-12C alkylene group (preferably 1-4C alkylene); and n : 1-3. #CMT#EXAMPLE : #/CMT# Typical clear coat lacquer composition comprised of: component 1 comprising (in wt.%) Bayhydrol XP 2645(RTM: Water-reducible, hydroxyfunctional polyacrylate dispersion) (89), Surfynol 104BC(RTM: A non-ionic wetting agent and molecular defoamer) (2.3), Borchigel PW 25(RTM: Thickening agent) (0.3), Baysilone 3468(RTM: Modified polysiloxane (1.9)) as wetting agent, Tinuvin 292(RTM: Liquid hindered amine light stabilizer) (0.8), Tinuvin 1130(RTM: [3-[3-(2H-Benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropyl]-w-[3-[3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropoxy]poly(oxy-1,2-ethanediyl)) (1.6), and demineralized water (10.1); and component 2 comprising 80% of starting polyisocyanate (obtained by reacting 980 g of isocyanurate group containing 1,6-hexamethylene diisocyanate, 20 g of 3-(cyclohexylamino)-propane sulfonic acid, 11 g of dimethylcyclohexylamine to give colorless, clear polyisocyanate mixture) in 3-methoxy-n-butylacetate (38.7 wt.%). |
