DE2022749A1 - Corrosion-inhibiting paints containing metal pigments - Google Patents

Description

Cologne, the 2 4, Λ. 70 Ke / Re

Company Lindgens & Sons GmbH & Co.KG. 5 Cologne-Mülheim, Deutz-Mülheimer Strasse

Corrosion-inhibiting, containing metal pigments

Paints

It has long been known to paint based on natural and synthetic binders, the metal phosphates contained as pigments, to be used for the production of protective coatings on surfaces made of iron or iron alloys. The effect of this phosphate-containing, paints containing zinc phosphate in particular are known to be based on the fact that by phosphating the iron-containing metallic base, anti-corrosive phosphate protective layers are formed under the paint by the interaction between iron and pigment (J. Oil Color Chemist's Assoc. April 1965 and FATIPEC Congress Book 1966 p. 359).

The most varied combinations of metal phosphates have already been used in such paints. For example, in "Deutsche Farben-Zeitschrift" 22 (1968), page J.45, combinations of the sparingly soluble affirmative barium phosphate are used for practical, usable white protective coatings. (BaHPO _1. ) _? · HpQ described with the somewhat more easily soluble zinc phosphate. According to

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BATH

"Farbe und Lack" 71 (1965), page 116, are also combinations of zinc phosphate and lead phosphate in practice used in white metal primers; continued to prove Combinations of zinc molybdate, calcium molybdate and zinc phosphate in the test as useful (paint and varnish, 70 (1964), page 536). These white pigment combinations however have disadvantages; because they are either expensive, especially when using molybdates, or but in their effect they are the best zinc chromate paints and especially inferior to red lead paints.

Surprisingly, it has now been found that the paints containing phosphate, borate and / or molybdate pigments have only a weak corrosion-inhibiting effect contain, which are more or less sparingly soluble in water, can be significantly improved, so that with zinc dust paints comparable paints can be achieved if these paints have a reducing effect Phosphoar salts mixed in. According to the invention are thus these non-oxidizing metal pigments and optionally containing fillers based on natural paints or synthetic binders characterized by an additional content of reducing agents Phosphorus salts in amounts of 1 to 50 wt .- #, based on the total amount of pigment and filler in the paint.

It has been found that such an addition of reducing active phosphorus salts are mainly used in paints based on natural or synthetic Tried and tested binders that contain more or less sparingly soluble phosphate, borate and / or molybdate pigments with weakly contain corrosion-inhibiting effect, such as secondary barium phosphate, zinc phosphate, antimony phosphate, '

Lead phosphate, chromium phosphate and manganese phosphate, calcium. 0 0 9 BA 8/1 80 5

and zinc molybdate and barium metaborate.

Phosphites and hypophosphites, in particular of divalent or trivalent metals, in particular phosphites of barium, magnesium and manganese and hypophosphites of calcium and iron, can be used individually or together as reducing phosphorus compounds. Preferred metal phosphites and hypophosphites are those which are soluble in water in at least amounts of about 0.05 to 5% by weight. The metal phosphites and / or hypophosphites are added to the paints in amounts of preferably 3 to 30% by weight , in particular 5 to 15% by weight, based on the total amount of pigment and filler content of the paint. The known pigments which improve adhesion, coloring pigments and also fillers can of course be added to the paints.

At the moment it cannot be overlooked what the effect of phosphites, namely to improve the corrosion-inhibiting properties of the non-oxidizing metal pigments, can be attributed to. Probably the result is the increased activity of the cathodic centers with the addition of reducing pigments, on the one hand poorly soluble cathodic protective layers and, on the other hand, at the same time improved anodic protective layers on the iron surface. In any case, the improvement is very clear; because, for example, a coating with 50% reactive pigments (10 % zinc phosphate, 10% secondary barium phosphate and 10 % barium phosphite) corresponds to that of a good chromate combination with 50 % zinc chromate.

Another advantage is that the paint, According to the invention, in addition to the metal phosphites and hypophosphites which are used, do not average the color

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any primer that can be colored Have their own color and thus practically do not affect the basic color at all, while the -corrosion-sheromenden Properties of the base color clearly improved will.

Some pigment combinations are listed below as examples, which can be tested in practice Have proven extremely successful, both in the salt spray test as well as in an industrial atmosphere;

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B e i s ρ i e 1 e

1. Zinc phosphate 10.0 Tel Barium phosphite 10.0 sek, bar iumpho spha t 10.0 Millicarb 10.0 RUtIl-TiO ₀ 20.0 Bauxite cream 4o.O. 2. Zinc molybdate 15.0 Tel Zinc phosphate 25.0 Barium phosphite 10.0 Bauxite cream 25.0 Siilitin N 15.0 Kaolin ASP 400 10.0

Ghrome phosphate violet) 25.8 parts chromium phosphate green)

Barium phosphite 22.8

Iron hypophosphite 8.6

Rutile TiO ₂ 11.4

Kaolin 8.6

Pias tor it.0OdO. '.. 8/22.

Chromium phosphate violet 10.0 parts

Calcium hypophosphite 10.0

Secondary barium phosphate 10.0

Millicarb 10.0

RUtIl-TiO ₂ 20.0

Plastorit 0000 40.0

Zinc phosphate 15.0 parts

Manganese phosphate 10.0

sec.Barium phosphate · 5 »0

Zinc oxide. 10.0

Millions 10.0 ·

Kaolin 15.0

Ai / mg silicate 35.0 009 «48 / '18QS

Claims (5)

Patent claims 1) Non-oxidizing metal pigments and optionally fillers containing paints based on natural or synthetic binders with improved corrosion-inhibiting properties, characterized by an additional content of reducing phosphorus salts in amounts of 1 to 50 wt .- ^, based on the Total amount of pigment and plastic in the paint. 2) paint according to claim 1, characterized by a Content of phosphites and / or hypophosphites 2- or 5-valent metals in amounts from 5 to 30 wt .- ^, based on the total amount of pigment and filler content of the Paint. ο "'■' ■ - 3) paint according to claim 1 or 2 ,. marked by a content of phosphites of barium, magnesium and / or manganese. 4) paint according to claim 1 to 3, characterized by a content of hypophosphites of calcium and / or Iron. 5) paints according to claim 1 to 4, characterized in that they are phosphates, borates and / or as metal pigments Contains molybdates of barium, calcium, zinc, lead, antimony, chromium and / or manganese. 6) Methods of improving the corrosion-inhibiting properties of natural-based paints containing metal pigments and optionally fillers or synthetic binders, characterized 0098A8 / 1 805 " that one additionally uses 1 to 50% by weight of " reducing phosphorus salts, based on the total amount of pigment and filler content" in the paint. ?) A method according to claim 6, characterized in that 3 to 30 wt -.%, In particular 5 to 15 wt -.% Phosphites and / or hypophosphites 2- or 3-valent metals, based on the total amount of pigment and Füllstoffantelies used. 8) Method according to claim 6 or 7, characterized in that phosphites of barium, magnesium and / or manganese are used. 9) Method according to claim 6 to 8, characterized in that that hypophosphites of calcium and / or iron are used, 10) Method according to claim 6 to 9, characterized in that that one uses such metal phosphites and / or hypophosphites which are at least in amounts of 0.05 to 5 wt .- ^ are soluble in water. 11) Method according to claim β to 10, characterized in that that the reducing phosphorus salts are used in paints which contain phosphates as metal pigments, Contain borates and / or molybdates of barium, calcium, zinc, lead, antimony, chromium and / or manganese. 009848/1805