摘要:
A composition and method for coating and touching up a metal surface is provided. The composition contains from about 0.5 to about 240 millimoles per kilograms of a fluorometallate ion, from about 0.5 grams/liters to about 10 grams/liter of phosphorous-containing inorganic oxy anions calculated at their stoichiometric equivalent as H3PO4; from about 0.05 g/l to about 3.5 g/l of hexavalent chromium and from about 0.10 g/l to about 2.20 g/l of trivalent chromium ions.
摘要:
The present invention provides a method for producing a highly corrosion resistant organic composite-plated steel sheet which is inhibited from liberation of chromium, which comprises forming a chromate film comprising a composition of the following (A) as a first layer at a coating amount of 5-150 mg/m.sup.2 as a solid film on the surface of a zinc or zinc alloy plated or zinc composite alloy plated steel sheet and then, coating on the first layer an organic solvent coating composition of the following (B) as a second layer at a thickness of 0.3-5 .mu.m as a solid film.(A) coating type chromate bath composition1 Cr.sup.6+ : 1-30 g/l,2 Cr.sup.3+ : 1-30 g/l,3 Cr.sup.6+ /Cr.sup.3+ weight ratio: 0.2-2.0,4 HF+H.sub.3 PO.sub.4 : 1-60 g/l,5 HF+H.sub.3 PO.sub.4 /Cr.sup.3+ weight ratio: 0.5-3.5, and6 silane coupling agent/Cr.sup.6+ molar ratio: 0.05-0.3(B) organic solvent coating composition(a) a bisphenol epoxy resin having a number-average molecular weight of 300-100,000 in an amount of 30% by weight or more based on the solid content of the coating composition;(b) at least one curing agent selected from the group consisting of polyisocyanate compounds and blocked polyisocyanate compounds at 1/10-20/10 in a weight ratio to solid content of the epoxy resin;(c) fumed silica of 0.1-100 m.mu. in an average particle size in an amount of 5-50% by weight based on the solid content of the coating composition;(d) a ketone type organic solvent in an amount of 40% by weight or more based on the weight of the coating composition; and the solid content of the coating composition being in the range of 10-50% by weight.
摘要:
A metal article is improved on its surface for the purpose of plating thereon by treatment with an additive of an anionic, cationic or amphoteric and water-soluble or water-self-dispersible organic polymer J, K or L. J is a polymer having an aromatic ring and OH group and a polar group. K is a polymer of hydroxystyrene having a polar group. L is a copolymer of hydroxystyrene having a polar group and a vinyl compound. The parted article is improved in corrosion resistance.
摘要:
A chromating liquid for forming a chromate film on a Zn or Zn-alloy plated steel sheet, is prepared by adding and mixing a silane coupling agent in a molar ratio of from 0.05 to 0.3 relative to Cr.sup.6+ contained in an aqueous chromating liquid which contains 1-30 g/l of Cr.sup.6+ and 1-30 g/l of Cr.sup.3+ at a weight ratio of Cr.sup.6+ /Cr.sup.3+ ranging from 0.1 to 2.0; and further contains 1-59 g/l of hydrofluoric acid and 1-59 g/l of phosphoric acid at total of hydrofluoric acid and phosphoric acid ranging from 2 to 60 g/l and at a weight ratio of (fluoride ions+phosphate ions)/Cr.sup.3+ ranging from 0.5 to 3.5. and, further said chromating liquid is applied on a surface of the zinc-based plated steel sheet and is then dried, thereby forming the chromate film having a coating amount of from 10 to 150 mg/m.sup.2 in terms of the chromium.
摘要:
A method of producing highly corrosion-resistant surface-treated steel plates where Cr elusion is small in spite of drying at low temperatures and corrosion resistance is excellent. In a process for producing surface treated steels where Zn type plated steels are treated through (i) chromate treatment, (ii) coating a resin composition and (iii) baking treatment, zirconium fluoride ion and Zn ion of appropriate amounts are added into the chromate bath, and Cr.sup.6+ /Cr.sup.3+ ratio in the bath is controlled to be low. Further the resin composition to be coated after the chromate treatment is rendered a solvent type resin composition obtained by adding silica and/or sparingly water soluble Cr compound to basic epoxy resin.
摘要:
A concentrated aqueous solution containing: (A) a component of dissolved phosphate ions; (B) a component of dissolved hexavalent chromium; (C) a component of dissolved anions selected from the group consisting of BF.sub.4.sup.-, AlF.sub.6.sup.-3, SiF.sub.6.sup.-2, TiF.sub.6.sup.-2, FeF.sub.6.sup.-3, SnF.sub.6.sup.-2, ZrF.sub.6.sup.-2, and HfF.sub.6.sup.-2 ; and (D) a component of free fluoride ions; and, optionally and preferably, (E) a component of dissolved trivalent chromium; and, optionally, one or more of: (F) a component of dissolved organic substances produced by reducing some hexavalent chromium initially added to trivalent chromium; (G) a component of dissolved, stably suspended, or both dissolved and stably suspended film forming polymer molecules; and (H) a component of dissolved, stably suspended, or both dissolved and stably suspended substances selected from the group consisting of silica and silicates is more resistant to development of precipitates during extended storage than similar compositions without the free fluoride component, and upon dilution makes at least equally satisfactory working compositions for forming a chromate conversion "passivating" coating on zinciferous surfaces.