DE2025648A1 - Anti-corrosion paint - Google Patents

Description

The invention relates to the barges of iron and steel Steel surfaces and especially a lacquer composition, and their use to protect iron and steel surfaces from corrosion.

Corrosion of metal surfaces "exposed to all kinds of weather conditions" poses a serious problem in terms of the durability of structures and structures made using iron and steel.

In recent years, various compounds and compositions have been developed which are intended to protect such iron-metal surfaces that are exposed to all possible weather conditions. One of the relatively successful «

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ORIGfNAt INSPECTED

The only methods that have been developed to date to protect iron and steel surfaces are the use of so-called "zinc-rich ¹ paints. E3 it has been estimated that the production of finc-rich paints exceeds 15.9 million liters per year. Under a" zinc-rich ¹¹ Paint is to be understood as one that contains a high proportion of metallic zinc pigment.

The success of the zinc-rich paints with regard to the shot of Iron and steel surfaces in corrosive environments, can be corrosive to the diversity, chemical action Materials related to zinc compared to iron are recycled. It is essential that that the zinc as it is closer in the tension series of the elements Among the base metals, iron * is preferred before the iron is attacked. The zinc surface becomes therefore preferentially resolved. The way through /.A rich lacquer assured contactor requires but giriert effective electrical contact between the zinc particles and also between the zinc and the Hisea or steel overlays *

The zinc particles must, together with a binding agent, the former cohesion should be applied. This binder has a double function in that it binds the zinc particles to one another as well as other coatings to the coatings imparts desirable properties. Such properties are, for example, adhesion, flexibility, abrasion resistance, Impact resistance and weather resistance »Furthermore, the binder must be able to withstand chemical attack through the lifting products that reacted as a result of zinc " to be able to withstand dust. Furthermore, to Purpose of achieving the necessary optimal electrical Contact properties and to create the desired mechanical Properties the amount of oil in miäii & ai will be.

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Another important factor in making the zinc rich Lacquer consists in the fact that you have a one-component lacquer as opposed to a multi-component lacquer, which is divided into two Containers must be kept and shipped, the Gives preference. The practical importance of the one-component paint and its lower costs cannot be overestimated will. However, when packing or storing the zinc-rich paint, you have to make sure that the binder is chemically is of such a nature that it does not react with the metallic zinc, which would produce gaseous hydrogen, what the container would burst and cause the paint to gel. "

Dipse reduce preconditions very considerably the number of types of resin that can be used as a binder in a zinc-containing paint. Vinyl chloride-vinyl acetate copolymers are known for their weak adhesion to steel. Hydroxy-modified vinyl chloride-vinyl acetate copolymers also only very poor adhesion to steel. On the other hand, the carboxy-modified copolymers have one good adhesion to steel, but adversely react with the pigment.

It has made further experiments with inorganic binders such examples as g game with silicates in aqueous solution. However, these binders have to be shipped separately from the pigment and, moreover, show only weak adhesion to steel.

Two-part epoxy resins have adequate properties as a binder for zinc-rich paints. However, such epoxy resins also disadvantageously require more or less one separate packing brvr. Storage. It is also known that Epoxy resins, once mixed, have only a limited lifespan or shelf life and that you can use them must also be used at temperatures above about 15 ° C in order to avoid the otherwise extremely long curing times.

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BATH ORIGINAL

It has also already tried to use chlorine-containing rubbers as a binder in paints sinkreichen. A very considerable disadvantage of these chlorine-containing rubbers, however, is their inherent brittleness or brittleness. In order to compensate for this disadvantage, a large amount of plasticizer has to be used necessary to keep the addition of additives and modifiers to a minimum. " This is also done in order to eliminate the problems which generally go hand in hand with the use of high percentages of additives and modifiers, such as, for example, wsiclmacher-Uanderungt leaching and seepage phenomena.

Another Hars5typ _s is often used in sinkreichen paints, are the phenolic resins ο ■ However, the flexibility and the reverse impact resistance of Phenoaqrharzfilme is very weak. " In addition, these types of lacquers are difficult to adhere to. Furthermore, expensive oxygen-containing solvents are necessary to dissolve the Hienoxyharze *

It could also be oil-modified binders with very low Acid number, such as certain epoacyeoters and alkyds » resins, are used as binders in zinc-rich one-component paints. The obvious disadvantage of these varnishes However, it consists in the fact that the film is sensitive to solvents due to its oil content «You could therefore, do not apply a chemically resistant outer lacquer coating on the zinc-rich lacquer, as the lacquer in the outer Strong solvents contained in coating paint, otherwise the zinc-rich ones Would remove paint.

In contrast, the present invention creates a lacquer composition for iron and steel surfaces different from the aforementioned and other disadvantages.

Surprisingly, it was found that the® © in leaps and bounds

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advanced anti-corrosion paint to protect iron and Steel surfaces, created by having a high proportion of a metallic zinc pigment of one particle size from about 1 to 25 microns and a relatively low proportionate amount of binder made up of a copolymer Vinyl chloride and an alkyl vinyl ether, the alkyl group Contains 1 to 8 carbon atoms. .

In particular, the paint composition according to the invention has about 80 to about 95 weight percent of a metallic "zinc pigment having a particle size of 1 to 25 microns and preferably of 4 to 7 microns, as well as about 5 to about 20 parts by weight of a binder for this pigment. The binder consists according to the invention from a copolymer of vinyl chloride and an alkyl vinyl ether in which the alkyl group is 1 to 8 carbon atoms possesses · A suitable solvent for the Binder can optionally be present. The solvent preferably consists of an aromatic hydrocarbon, an aliphatic hydrocarbon or mixtures thereof. The exact composition of the solvent system depends only of the drying properties desired in each case and on any other desired properties.

The essence of the present invention will now be based on exemplary embodiments further explained.

Example ii

A solution of a copolymer of 25 parts by weight of vinyl chloride and 25 parts by weight of isobutyl vinyl ether was prepared in a mixed solvent system. The solution contained 50 grams of the copolymer, 93 grams of toluene, 30. »75. Grams of a solvent consisting of 98% aromatic hydrocarbons and has a Destillationaberelch of 160 ⁰ C to 176.7 ° C, and 30.75 grams of crystalline © mainly aliphatic © © loiileawaaserstofi lationsbereichea of 121 ⁰ O "14J 0 ° contained «

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First 2.5 g of a pretreated bentonite, which was wetted with 0.8 g of propylene carbonate, and then 4-50 g of a zinc powder pigment, which consisted of 97% metallic zinc and were added to this resin solution. The average particle size 6.5 microns carried this pigment by vigorous stirring using a mechanical stirrer in the above-described mixing ratio of the composition beeasa © ine viscosity of 110 liters ? @ hs-sinities and showed neither the development of pressure in a closed container, nor of the development of bubbles, and even after two months of storage did not show any hard deposits or hardening,

This lacquer was diluted to a viscosity of 30 seconds using xylene in a Ford cup No. ₀ 4 and then sprayed in a thickness of 0.1 mm onto a sandblasted plate by means of air, on the back of which a misshapen piece of steel Electrically welded was _o - Hacadea one let trooknan for a week »^ mirde di © platfc © 700 hours of a damp and isalslialtigea ÜtaospliäE ¹ © © usg © s © tzt ₀ When these 700 hours were over, the flat © · ara · ®ag © wiES®n gaps and edges starting from © Korrosiom ₀

A © other steel plate (O _s O32 courses) _s di © nieht 'sandblasted, ■ but with a solution Mitt ©! cleaned x-faXj tiurde also provided by spraying with © iadE ¹ 0.1 β thick @ m LaekscMcht,

a ¥ oalie laag aa äis ³ Ίμ &% aitssa ^ θ! ©

"oeauglieli der dlir © kfc * © n Sefelasfostiglsiii ^ .®1 @" also d © ^ th impact strength gepsilfto In the "direct impact resistance test iresitrug di © -ub ^ raogen © Platt © © ia ©! © lasting yon 160

engIiscSi © a Pf «ai / imclbig A load ¥ on 100 g

te aucli lE © imerl @ i! _{© © iaträisSitigimg 9} SQ © Mü @ e fli © Platt © ₉ <Si © "den, "QbQjS'Bmfs, on the AnQS © as © i "fe © an £ t? ios _s raa ai5a © yes

as ©

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Example 2;

A solution of 50 g of the copolymer described in Example 1 in a solvent was prepared which was composed of 92.6 g Toluene, 38.75 g of the aromatic solvent described in Example 1 and from 38.75 g of that described in Example 1 aliphatic solvent. Then 2.5 g of treated bentonite were wetted with 0.8 g of propylene carbonate was added. Finally, 283 grams of zinc dust pigment was dispersed by vigorous stirring using a mechanical stirrer in the mixture. The resulting varnish had a viscosity of 100 Krebs units and developed no pressure in the closed container, showed no bubbles and not the formation of hard deposits after two months of storage.

This paint was made up by xylene in a # 4 Ford cup a viscosity of 30 seconds and then diluted in a thickness of 0.1 mm sprayed in an air stream onto a sandblasted steel plate, on the front side a U-shaped Steel piece was electrically welded on. After drying Within a week, the plate was kept in a salt spray atmosphere for 00 hours, with only beginning Corrosion showed in certain furrows and edges.

Another steel plate (0.032 gauge) that was not sandblasted but was cleaned with a solvent was also used provided by spraying with a layer of varnish 0.1 mm thick. The plate was then left in the air for a week left to age and then both with regard to the direct as well as reverse impact resistance. At the The plate or its coating a load of 160 pounds / inch and at reverse impact test a load of also 160 English pf and / inch. The coating also showed no deterioration or damage after using the Plate with the coating on the outside and a thorn one

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0.31 cm in diameter. So the adhesion was excellent in this case too.

Example 5:

Plates which had been produced and provided with a coating as described in Example 1 were provided with a. additional outermost coating in the form of a 0.075 n ™ thick film *, which consisted of a varnish that you by dissolving 76.9 g of the polymer described in Example 1, 7 * 7 g of chlorine-containing polyphenyls having a refractive index of 1.6 * and 7.7 g of chlorine-containing polyphenyls. Refractive index of 1.662 in 142.6 g of toluene and then adding 16 g of the aromatic hydrocarbon solvent described in Example 1, and 16 g of des aliphatic hydrocarbon solvent described in Example 1.

Then 57 g of titanium dioxide (rutile) were obtained by vigorous stirring dispersed in the solution using a mechanical stirrer until the particles are in suspension were less than 5 microns in size. The paint that was created in this way was put on a Ford cup No. 4 diluted a viscosity of 25 seconds and then for so long sprayed on by means of an air stream until the above-mentioned exterior coating with a thickness of 0.075 mn was obtained. Here resulted no elevations. The plate with the U-shaped stalk was kept in a salt spray atmosphere for 700 hours and thereafter showed only a very weak one Corrosion on one of its edges. ,

The other panel was tested (1) for direct impact strength and tolerated a load of 160 pounds per inch and (2) also for the reverse Impact resistance, with the load tolerance 120 English pounds per inch. The coating also showed no-

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lei impairment or other damage, if · the Plate with the coating on the outside, around a mandrel of a Diameter of 0.31 cm was bent. So the substrate adhesion and interlayer adhesion were. excellent. . ■;

Example 4;

50 g of a copolymer of 78 parts of vinyl chloride and 22 parts of 2-ethylhexyl vinyl ether were dissolved in 8517 g of toluene, 34.2 g of the. * Aromatic hydrocarbon solvent of the example, 1 and 34.2 g of the aliphatic hydrocarbon solvent of the Example 1 resolved. Then 2.5 g of a treated bentonite which had been wetted with 0.8 g of propylene carbonate was added to the solution and 450 g of zinc dust pigment were then dispersed in the mixture by vigorous stirring using a mechanical stirrer resulting paint "Tiatte * a viscosity of 100 Krebs units and showed neither \ '*' ■ pressure Education in a closed container, nor blistering, nor any hard deposits after two months of upward

• fr - * ■

maintain. _h ' .

This paint - was using xylene in a Ford cup no; 4 · diluted to a viscosity of 30 seconds and then by means of Air flow in a thickness of 0.1 mm on a sand-blasted one Sprayed on steel plate with a U-shaped on the front Stahlstuep was electrically welded. This record showed after a constant stay in a salt-spray atmosphere for 700 years only at certain furrowed places and edges an incipient corrosion. -

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OftlÖINAL

Claims (10)

Claims 1.) Anti-corrosion paint, characterized in that it (a) about 80 to about 95 parts by weight of a metallic zinc pigment; and (b) about 20 to about 5 parts by weight a resin binder composed of a copolymer of vinyl chloride and an alkyl vinyl ether whose alkyl group Contains 1 to 8 carbon atoms. 2.) anti-corrosion paint according to claim 1, characterized in that the ether consists of isobutyl vinyl ether. 3 ·) Anti-corrosion paint according to claim 1, characterized marked. · Doesn’t have a solvent as an additional ingredient for the resin binder. 4.) anti-corrosion paint according to claim 1, characterized in that that the metallic zinc pigment has a particle size from 1 to 25 microns. 5) anti-corrosion paint according to claim 4, characterized in that that the metallic zinc pigment has a particle size of 4 'to 7 microns. 6.) Process for the protection of iron or steel surfaces, characterized in that a varnish is applied to these surfaces which is about 80 to about 95% by weight metallic zinc pigment, as well as about 20 to about 5 wt .- # of resin binder, wherein the resin binder is a copolymer of vinyl chloride and an alkyl vinyl ether, whose alkyl group has 1 to 8 carbon atoms, is, and also sugegen a solvent for this resin, and then dries the paint. κ; ϊ lira 009850/2022 INSPKTED 7.} The method according to claim 6, characterized in that the ether consists of isobutyl vinyl ether 8.) The method according to claim 7 »characterized in that the resin binder is a copolymer of about 75 parts by weight of vinyl chloride and 25 parts by weight of disfiguring isobutyl vinyl ether . ■■ "" ■. '· 9 ·) Method according to claim 8, characterized in that the zinc pigment has a particle size of 1 to * 25 microns owns. 10.) The method according to claim 9, characterized in that the zinc pigment has a particle size of 4 to 7 microns owns. 009850/2022 ^G0PY