Prepn. of storage-stable antirust compsn. - contg. zinc dust, organic montmorillonite deriv., poly:isocyanate prepolymer and solvent

摘要

An anti-rust coating compsn., which can be stored in closed containers and which hardens with atmos. moisture, is prepd. by (a) mixing 3-6 pts. wt. of dimethyldioctadecyl-ammonium-montmorillonite, or an organic deriv. of montmorillonite (I) prepd. from (I) by ion-exchange with alkyl-ammonium bases, 0.3-0.5 pts. wt. of a salt of a long-chain polyamineamide and a high-mol. acid ester, as wetting agent, 0.3-0.8 pts. wt. of a drier and stabiliser for 1-component polyurethane lacquers, and 3.5-4.5 pts. wt. of an aromatic solvent with boiling range 160-180 degrees C, (b) allowing the mixt. to stand for =48 hours, to form a chelate, (c) mixing the chelate with 6-10 pts. wt. of a moisture-hardening polyisocyanate prepolymer with 16% NCO, 0.01-0.03 pts. wt. of a deaerating agent, and 3.5-4.5 pts. wt. of the aromatic solvent, and (d) dispersing in the mixt. 4-7 pts. wt. of flaky pigment and 65-75 pts. wt. of fine Zn dust. The compsn. can be stored for =3 years in a closed container at between -40 degrees C and 50 degrees C. A firmly bonded coating, with a pore-free surface, is obtd. on substrates. The compsn. is esp. used in shipbuilding and in steel hydraulic constructions.