Nippon Paint Compnay, Ltd.

Akio Tokuyama

Tamotsu Sobata

Koetsu Endo

Seiichiro Shirahata

Shoji Shiraishi

Yasutake Mino

Masahiro Jo

Takamasa Shimizu

Koichi Saito

Manabu Yoshioka

Nobuo Furuno

Kazuhiko Nishimoto

Kazuhiko Usuki

Eiichi Nakano

Masahiro Itai

Yoshio Ota

To treat an iron-based, zinc-based, and an aluminumbased surfaces etc. with zinc phosphate using the same solution, a treating solution is adjusted in concentrations so as to contain a simple fluoride in a range of 200.about.500 mg/l upon converting into a HF concentration and to contain a fluoride complex in a range shown in the following formula; ##EQU1## and also, it is adjusted in an active fluorine concentration so as to be 15.about.130 .mu.A at a value indicated by a silicon electrode meter. Instead of such adjusting, aluminum ions in the treating solution is precipitated in an outside of a treating bath to separate them from the treating solution and then, this treating solution may be returned in to the treating bath.

Method for phosphating metal surface with zinc phosphate

The invention relates to formation of a resin film excellent in adhesion with metal or other material and also excellent in alkaline resistance. The invention presents a water-based resin dispersion having an acid value of 0 to 15 obtained by emulsion polymerization of a monomer mixture comprising, in 100 parts by weight of .alpha.,.beta.-ethylenically unsaturated monomer, (1) 1 to 20 parts by weight of .alpha.,.beta.-ethylenically unsaturated monomer with a .beta.-ketoester group, (2) 0.05 to 5 parts by weight of crosslinking .alpha.,.beta.-ethylenically unsaturated monomer with two or more radically polymerizable groups, and (3) the rest of other .alpha.,.beta.-ethylenically unsaturated monomer than (1) and (2), by using a radically polymerizable emulsifier at a ratio of 0.2 to 10 parts by weight against the total of 100 pats by weight of the .alpha.,.beta.-ethylenically unsaturated monomer.

Water-based resin dispersion and resin composition for coating

The present inventin concerns a process for phosphating a metal surface comprising treating a metal surface with an acidic aqueous phosphate solution comprising zinc ion, phosphate ion, a phosphating accelerator and particular concentration of colloidal particles having an isoelectric point of 3 or less and an average particle diameter of 0.1.mu. or less, the metal surface being iron-based surface, zinc-based surface or combination thereof and the resulted phosphate coating being excellent in film adhesion, corrosion resistance and especially scab corrosion resistance.

Phosphate coatings for metal surfaces

A zinc phosphate film on a metal surface is used as a surface-protecting film and an under coating film for coating and so on. The zinc phosphate film is formed by treating a metal surface with an aqueous zinc phosphate solution. The aqueous zinc phosphate solution includes solutions containing a zinc ion in a concentration of more than 2 g/l to 20 g/l, a phosphate ion in a concentration of 5 g/l to 40 g/l, and at least one of silicotungstic acid and a silicotungstate in a concentration of 0.005 g/l to 20 g/l measured in terms of tungsten content.

Method for forming zinc phosphate film on metal surface

To treat an iron-based, zinc-based, and an aluminum-based surfaces etc. with zinc phosphate using the same solution, a treating solution is adjusted in concentrations so as to contain a simple fluoride in a range of 200.about.500 mg/l upon converting into a HF concentration and to contain a fluoride complex in a range shown in the following formula; ##EQU1## and also, it is adjusted in an active fluorine concentration so as to be 15.about.130 .mu.A at a value indicated by a silicon electrode meter. Instead of such adjusting aluminum ions in the treating solution is precipitated in an outside of a treating bath to separate them from the treating solution and then, this treating solution may be returned into the treating bath.

A process for phosphating the surfaces of iron-based metals, zinc-based metals or combination of such surfaces by treating the metal surfaces with an aqueous acidic zinc-phosphating solution comprising from about 0.1 to about 200 g/l of zinc ion, from about 5 to about 40 g/l of phosphate ion, from about 0.01 to 20.0 g/l as tungsten of soluble tungsten compound and a conversion coating accelerator. The metal surfaces thus phosphated with the solution are suitable for electrocoating.

Process for phosphating metal surfaces

Disclosed is a surface treating agent which improves the adhesive properties between a metal surface and a paint layer thereon. The surface treating agent is an acidic aqueous solution comprising zinc ions, nickel ions and phosphate ions, characterized by adding a cyclic metaphosphate thereto in the form of (MPO.sub.3).sub.n wherein M represents a metal atom and n is

Surface treating agent before coating

The present invention provides a method of controlling an electrocoating bath using an ion exchange resin. The ion exchange resin is maintained in a porous container in a suspended state in the electrocoating bath, and is used in a quantity of not more than the chemical equivalent of excess counter-ion to be removed from the bath. Bath control is easily achieved without any coagulation trouble as often observed in conventional column methods.

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Osaka, Japan

Akio Tokuyama