摘要:
The part is subjected to action of an acid aqueous bath in order to cause the surface of the part to be porous over a thickness which is a fraction of the thickness of the zinc which it includes, and the part is caused to adsorb at least one sealing material.
摘要:
Disclosed are the 1:2 chromium complex of the formula ##STR1## and the alkali metal salts thereof which are useful for the coloration of oxide layers produced on aluminum and alloys thereof and for dyeing natural and synthetic polyamides.
摘要:
A coating composition comprising an aqueous mixture containing inorganic particles, a catechol compound, and one or more fluoroacids. The preferred fluoroacids are selected from fluorotitanic acid, fluorozirconic acid, fluorosilicic acid, fluoroboric acid, fluorostannic acid, fluorogermanic acid, fluorohafnic acid, fluoroaluminic acid or salts of each thereof. The invention is also directed to a coating on a metal substrate. The coating comprises silica particles attached to the metal substrate through a metal-oxide matrix. The metal-oxide matrix comprises a metal selected from titanium, zirconium, silicon, hafnium, boron, aluminum, germanium, or tin, and a catechol compound.
摘要:
To provide a substrate of aluminum with a dark surface layer of high absorption/emission ratio for luminous energy, the degreased and pickled substrate is immersed in a hot chromating bath until an oxide coating of not more than 2.5.mu. thickness is formed thereon. This coating is then colored black in a hot, acidic dyeing solution (pH between about 0.5 and 5) of potassium permanganate and a nitrate of cobalt or copper.