DE1939303C3 - Corrosion protection compounds for metal surfaces - Google Patents

Description

35 is lower than in the case of the compounds containing only zinc.

A wide variety of anti-corrosion compositions have already been used.

Schulzmassen suggested for metal surfaces, th expediently 3 to 70, preferably 3 to 50 Ge

the particular protection against the cathodic weight percent binder, based on the total

Ensure anodic corrosion of metal parts, mass. A wide variety of binders are suitable

z. B. for underground pipes and storage containers 40 organic and inorganic materials. Fs hangs

ter, for hulls, for support structures for drilling from the respective requirements to the from the

systems at sea or dock systems. Mass-produced protective coatings, which spe-

The anti-corrosive compound forms the binding agent used according to the target. As a binder

one embodiment with the metal surface can be used with a wide variety of plastics, such as

Local clement, which is why they use metal particles 45 epoxies, chlorinated rubber, polystyrene, vinyl butyral

contains, which are electroncgativcr than the polymers to be protected, vinyl acetate polymers or silicones.

Metal surface. Mostly zinc is used as the filler, examples of suitable inorganic binders

dust used with an inorganic or silicate, such as alkali metal silicate, z. B. sodium silicate,

organic binder is mixed. as well as phosphates, hydrolyzed ethyl silicates and

But it was found that the metal flakes, 50 butyl titanals.

such as zinc dust or zinc powder, the cost of such The ferrous used as filler according to the invention

Greatly increase the masses. phosphorus is an iron phosphide compound that is found in

In addition, quite high levels, generally about 20 to 28 percent by weight, of phosphorus are often required

based on the total mass, e.g. B. 80 contains by weight and a mixture in the composition

percent and above, corresponds to this relatively expensive metal filler 55 made of Ie ₂ P and I eP. Those in ferrophosphorus

Use substances to remove the necessary corrosion - the main impurities that occur are silicon,

To achieve protective effect. Vanadium, chromium, nickel and manganese, as well as traces

The object of the invention is to find new corrosion other elements. The largest share of the

protection / .masscn available for metal surfaces impurities have silicon and manganese, their

to provide the at least equally protective over- 60 typical proportions each up to about 7 percent by weight

Delivering trains like the well-known, zinc-rich Korro-amounts. Ferrophosphorus is a technical one

sionsschulzmassen, but cheaper than these are. Phosphorus production through reduction of Mincral

The invention thus relates to anticorrosive phosphates occurring in electric furnaces

sen for metal surfaces, consisting of a binding product, whereby that contained in the mineral phosphates

medium and a mixture of zinc dust and particles 65 containing iron which forms ice phosphide compounds,

a heat-resistant iron alloy as filler, the ferrophosphorus expediently has a diameter

and optionally solvents and / or soft cut grain size from 1 to 10 μ, preferably from

makers and / or hardening agents, which are 1 to 5 μ.

Ϊ9 39 303

With regard to the corrosion treasure effect, better results are obtained by using the alloy cleans after crushing and / or grinding. The cleaning is expediently carried out by washing the \ milled ferrophosphorus with aqueous acids, preferably with hydrochloric acid. A 1 to 12% strength hydrochloric acid is preferably used and the Wash until an activated surface is created on the ferrophosphorus. Usually the alloy is washed for 1 to 4 hours. After washing you can add the ferrophosphorus Rinse with water and dry to remove residual acid.

It is assumed that the surface of the ferrophosphorus when grinding to the required grain size is somehow passivated. The aforementioned washing of the ground particles with acids is used thus to reactivate the surfaces of the particulate iron alloy.

The anti-corrosion compositions of the invention can be produced by adding the binder or Plastic components by any known mixing method in the aforementioned proportions mixed with the fillers. You can add the zinc dust and the crushed ferrophosphorus to the binder either incorporated separately or premixed and mixed in suitable proportions to form a filler mix this with the binding agent.

Depending on the binder used, the anti-corrosion compositions of the invention can also be used, for. B. contain suitable solvents, hardeners or plasticizers. Examples of solvents that can be used are xylene, toluene, iproin, methanol, ethanol, ßutanol, isopropanol, ethyl butyl ketone, methyl isobutyl ketone, Ethylene glycol monobutyl ether, ethylene glycol monoethyl ether, Ethylene glycol monoethyl ether acetate, ethyl acetate and butyl acetate.

Examples of suitable hardening agents are cobalt, Lead and manganese siccatives such as naphthenates, polyamines such as triethylenetetramine, polyamides such as the condensation products made from saturated aliphatic dicarboxylic acids with ethylenediamine, Phosphoric acid and oxalic acid.

Examples of suitable plasticizers are Dioelylsebacat, Dioctyl phthalate, dioctyl adipate, diethylene glycol dibenzoal. Castor Oil, Mcthylricionlcat, Polyester, Epoxidized Soybean Oil, Epoxycster, Tricresyl Phosphate, chlorinated biphenyls, chlorinated polyphenyls and chlorinated paraffinic hydrocarbons.

The preferred proportion of solvent in the anti-corrosion compositions of the invention is 5 to 60 percent by weight, while the proportions of hardeners and plasticizers are each up to 70 percent by weight based on the total mass.

The anti-corrosion compositions according to the invention can be applied to the metal surface to be protected by any method, e.g. B. apply by spraying, brushing, dipping or flooding. The compositions are preferably applied in such a way that a coating or a film with a thickness from about 0.013 to 0.13 mm. The filler content the mass is preferably 30 to 97 percent by weight. After applying the coating to the Metal surface to be protected is dried and / or the coating is cured. It was found that the The aforementioned coatings are used to protect a wide variety of metal surfaces, e.g. B. made of iron and Iron alloys and copper are suitable.

It should be mentioned here that the anti-corrosion compounds The coatings produced according to the invention exert their protective effect by acting as an anode works. It was also found that the anodic corrosion protection effect of the zinc particles Corrosion protection compositions of the invention by the presence of the crushed heat-resistant iron alloy, d. H. of ferropliosphorus, is improved. Although the exact mechanism by which this

ίο improvement is effected, is unknown, takes one suggests that the ferrophosphorus somehow causes the formation of a surface on which the simultaneously with the effect of the zinc particles as a sacrificial anode, the cathode effect can occur. From The coatings produced by the anti-corrosive compositions of the invention thus provide excellent results anodic corrosion protection.

The examples illustrate the invention. Parts and percentages relate to the weight, if

unless otherwise stated.

example 1

A corrosion protection compound is produced from the following components or proportions:

Components parts by weight

Zinc dust 371.6

Ferrophosphorus (23.4% P) 356.9

Magnesium montmorillonite

(Dicikmittel) 7.5

Methanol 4.0

50% solution *) of polybisphenol

A-epoxy (epoxy equivalent: 500) .. 63.6

Xylene 53.7

Butanol 45.5

Methyl isobutyl ketone 7.63

*) Composition of the solvent:

49.97% xylene

7.63% methyl isobutyl ketone

42.40% butanol

200 parts of this corrosion protection compound are mixed with 5.3 parts of the solution of a hardening agent, the 200 TdIe of a polyamide produced from a dicarboxylic acid with ethylenediamine (amine value: 230 to 246) and 84.9 parts of xylene.

Then test specimens made of steel with the dimensions 7.6 × 12.7 cm are made with the mass obtained coated and cured for a few days at room temperature and a relative humidity of 50%. Cross patterns are then scratched into the test specimens, and the test specimens are immersed in a 1% sodium chloride solution submerged. After 4 days of storage in this solution, the test specimens are undamaged and show no rust formation.

Comparative example

For comparison, a corrosion protection compound is made from the following components or proportions manufactured:

Components parts by weight

Zinc dust 372

Barium sulfate 220

Magnesium montmorillonite

(Thickener) 7.5

Methanol 4.0

Poly bisphenol A epoxy

(Epoxy equivalent: 450 to 525) 78.2

Xylene 86.6

Butanol 72.6

Methyl isobutyl ketone 13.0

100 parts of this mass are mixed with 7.1 parts of the hardener solution from Example 1.

Then test specimens made of steel with the dimensions 7.6-12.7 cm are made analogously to the procedure of Example 1 coated with the mass, cured and tested. After 4 days of immersion in a 1% Sodium chloride solution is applied along the entire surface of the film covering the test specimens Slight to medium rust formation observed. According to ASTM test standard D 714-56 (blistering) the result is a bubble density between the ratings "medium (M)" and "medium divht (MD)", as well as a bubble size no. 6.

Example 2

A corrosion protection compound is produced from the following components or proportions:

Components parts by weight

Zinc 112.5

Ferrophosphorus 37.5

Solution of hydrolyzed ethyl silicate in ethylene glycol monobutyl ether and “ ₀

Ethanol (38% solids) 385

The solution is sprayed onto test specimens made of steel in a similar manner to the method of Example 1. The received The coating is air-dried for about 15 hours and the coated test specimens are analogous to the example 1 tested after storage in a 5% sodium chloride solution. After 4 days of immersion they are Films on the test specimens are intact and show no rust formation.

40 Example 3

The procedure of Example 2 is repeated, but a corrosion protection composition from the following is obtained Components or proportions used:

Components

Parts by weight

45

Zinc 604

Ferrophosphorus 257

Dioctyl phthalate 2.97

High-boiling gasoline 35

Xylene 48

Turpentine 8

Chlorinated rubber (viscosity of the 20% solution in toluene:

20 cP / 25 C) 28.2

55 Chlorinated biphenyl (67 weight percent chlorine) 19.84

The test specimens are coated as in Example 2 and, after storage, in a 3% sodium chloride solution checked. Essentially the same results are obtained.

Example 4

The procedure of Example 2 is repeated, but the corrosion protection compound contains 186 parts of zinc, 186 parts of ferrophosphorus and 160 parts of the hydrolyzed ethyl silicate. The test specimens are analogous Example 2 coated and tested. Similar results are obtained.

Example 5

Two corrosion protection compounds (A and B) are made from the components or parts to be examined manufactured:

Components parts by weight

AWAY

Zinc dust 1123.4 730.7

Ferrophosphorus (26.2% P) .... - 313.0

Dispersant 2.1 2.0

46.2 ° _u solution *) of PoIybisphenol-A-epoxy (epoxy equivalent: 450 to 550) 141.2

Solvent *) 73.8

Hardener solution **) 49.4

*) Solvent: mixture of 50 percent by weight ethylene glycol monobutyl ether and 50 percent by weight Xylene.

**) Solution of 71.6% by weight of one produced from a dicarboxylic acid and ethylenediarnine Polyamide (amine value 230 to 246) in xylene.

Test specimens made of steel with the dimensions 7.6 x 12.7 cm are each with the masses A and B, respectively coated. The test specimens coated with the comparative mass A are exposed to air for 30 minutes and then Hardened for 30 min at 150 to 153 ° C. The one with the Test specimens coated with mass B according to the invention are exposed to air for 25 to 40 minutes and then 30 min hot at temperatures from 148 to 152'C hardened. The test specimens are then exposed to salt spray. The coated with the mass A. Test specimens show moderate to strong rust formation after 171 h 40 min exposure to salt mist, as well as according to ASTM test standard D 714-56 a bubble density between the ratings "medium" to "Medium density" and a bubble size of No. 6. The test specimens coated with compound B show on the other hand, no rust formation and although they have the same bubble density as the aforementioned test specimens, however the number 8 smaller bubble size

153.9
56.3
53.5

Claims (5)

are characterized in that they contain ferrophosphorus as a heat-resistant iron alloy. ^^ ^ ^?. Weight percent based on the 1. Corrosion protection compounds for metal surface filler. chen, consisting of a binder and a 5 Although the iron alloy ferrophosphorus as Mixture of zinc dust and particles of a heat equivalent to other iron alloys described Iron alloy as a filler, as well as has been, wasn’t -u expect it to be straight Solvents and / or soft in anti-corrosion compounds have a special effect ■ In, would thereby evoke and be particularly suitable as it is heat-resistant, it could replace the expensive zinc previously used. -, ₆ ~ ^, .._ ₆ ... _u .. _e L ... " _H ""iphor contained, where- The only rust inhibitors were paint its proportion of 10 to 75 percent by weight, based on linseed oil, is known, which is a powdered on the filler is an alloy made from the elements Si, Cr and Fc. 2. Corrosion protection compositions according to claim 1, but this alloy is not ferrophosphorus, and characterized in that the proportion of the binding agent is also not used in combination with zinc 3 to 70 percent by weight and the filler sets with the aim of at least partially the expensive zinc proportion of 30 to 97 percent by weight, each based to be replaced. to the mass. Coating compounds for high-temperature 3. Corrosion protection compositions according to claim 1 or temperature resistant protective coatings have been described, 2, characterized in that the average * ° a silica-containing sand and a metal grain size of the ferrous pigment contained in the filler, such as aluminum, stainless steel or steel phosphorus I to 10 μ, preferably 1 to 5 μ alloys, contain. For corrosion protection purposes and that the surface of the ferrophosphorus particles is also used zinc,
has been activated by washing with acids. Finally, coating compositions are known as 4. Corrosion protection compositions according to claim 1 to 25 contain an essential component ferrochrome, wherein 3, characterized by a solvent content it particularly affects the abrasion resistance of the protection of 5 to 60 percent by weight, based on the coatings compared to z. B. Sand and dust storms entire mass. matters, but not on corrosion protection 5. Use of the anti-corrosion compounds In the context of the invention, however, about-J according to claim 1 to 4 for the coating of metal 3 ° surprisingly shown that the new corrosion surfaces. Protective masses in some cases even a better one Provide protection than the usual zinc filler-only compositions when the Total filler content! (Zinc> ferrophosphorus)