DK161974B - COATING MATERIAL FOR PROTECTION OF IRON METALS AGAINST CORROSION CONTAINING ORGANIC SILICATES AND FINISHED ZINC - Google Patents

Description

DK 161974 B

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The present invention relates to a coating material for the protection of ferrous metals from corrosion containing organic silicates and comminuted zinc.

Zinc-rich paints are effective in protecting steel against corrosion. The principle of the protective effect is attributed to the fact that zinc higher than iron in the electromotive series of elements reacts first in all environments that are conductive to the ionic solution (oxidation) of metals, thereby protecting the steel substrate.

As the name implies, zinc-rich paints contain a high concentration of zinc in the dry film. This is necessary to achieve the electrical continuity and thus conductivity required.

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2 is necessary for the electrochemical process to take place.

In order to obtain these zinc-rich paints on an ferrous substrate, a paint composition is used which contains very fine zinc dust prepared by distilling the metal under controlled condensation conditions. When the paint is applied, the metallic powder is held in place on the surface of a binder. The zinc-rich paints are divided according to the nature of the binder into organic and inorganic paints.

Organic zinc-rich paints use synthetic polymers as binder. Although such paints provide effective corrosion protection, their resistance to heat and solvents is limited.

Inorganic binders do not have these limitations. Such binders include water-soluble silicates rendered insoluble by a curing agent after application, as well as alkyl silicates which do not require post-cure. Although alkyl silicates contain organic chains, the zinc-rich paints produced therefrom are classified as inorganic because it is believed that upon drying, a completely inorganic matrix of SiO2 * is formed. This reaction occurs only slowly and proceeds through continuous hydrolysis stages.

The alkyl silicates which can be used for zinc-rich paints may vary in the level of hydrolysis. If a very low level of hydrolysis alkyl silicate is used, the curing reaction is so slow that the film remains uncured for a very long time. Use of higher-level hydrolyzed alkyl silicates reduces the time required to dry films. Unfortunately, as the drying time decreases due to the higher degree of hydrolysis, the stability of the product in turn decreases. This less stability manifests itself in various ways. One of these is an increasing tendency of the paint to gel in the container upon storage. Another is shorter shelf life when the alkyl silkate is mixed with the zinc dust, in which case gelation usually occurs within a few hours.

One way to avoid the paint instability in the container and premature gelling with the zinc is to pack the zinc separately from the alkyl silicate and then mix the two components immediately before application.

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This is done with the so-called zinc-rich two-component paints, and the working methods have been adapted to this peculiarity of the product or paint used for coating. However, the problems associated with a two-component paint such as dual manufacture, storage, inventory and stock lists, as well as on-site measurement and mixing for limited canister life, make a zinc rich single component paint base very desirable.

If zinc-rich paints with low hydrolysis alkyl silicates are produced, the stability of the alkyl silicate in the container as well as the primer can-shelf life after the addition of zinc dust to the alkyl silicate is significantly improved. However, the price of this improved stability is a greatly increased drying time. The problem that the chemist therefore faces is how to achieve curing a zinc rich single component paint primer with alkyl silicate within a reasonably short period of time while maintaining good packaging stability combined with the alkyl silicate not reacting with the zinc dust.

Several proposals have been made to solve this problem. Thus, according to U.S. Patent No. 3,653,930, a one-component zinc-rich paint was prepared by adding low molecular weight amines to ethyl silicate hydrolyzed to ca. 40%, along with nitro compounds to prevent gas formation. The same principle is described in Dutch Patent Application No. 69.00729.

In U.S. Patent No. 3,660,119, film formation of a 40% hydrolyzed alkyl silicate is obtained using strong bases such as sodium or potassium methoxide or ethoxide.

U.S. Patent No. 3,859,101 discloses the use of zinc chromate instead of nitro compounds as anti-gas-forming additives in a mixture of alkyl silicate and zinc dust.

U.S. Patent No. 3,917,648 uses a reaction product of alkyl silicates and polyols to form a product which is stable in the presence of zinc.

U.S. Patent No. 4,084,971 relates to a one-component alkyl silicate / zinc primer containing grease and amidoamines for stability.

All of the solutions mentioned suffer from the following drawbacks: 1. Low molecular weight amines are volatile and therefore alkaline binders containing their contents lose their efficiency in storage.

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4 2. Low molecular weight amines are water soluble, which is why a water sensitivity factor is introduced into a paint which is primarily intended for protection against corrosion.

3. Low molecular weight arains have high chemical reactivity. Thus, they react with such acids which arise from absorbed carbon dioxide during storage. This may be why they lose their effectiveness over time.

4. The low molecular weight amines present in the coating formed on the ferrous substrate have adverse effects on the zinc-rich film's resistance to surrounding agents and interfere with the adhesion and chemical resistance of the final paints applied. priming paint.

5. Low molecular weight amines are toxic and pose a potential safety risk to those who come in contact with the paints.

6. Strong bases such as alkali metal alkoxides or their corresponding hydroxide by-products adversely affect an amphoteric metal such as zinc.

7. The alkali metal alkoxides or their corresponding hydroxide - by-products remain in the zinc-rich film formed on the ferrous substrate and therefore cause a moment of sensitivity to water and chemicals that may adversely affect the properties of the final paints applied on top of the primer paint. .

8. Zinc-rich polyol silicate paints produce films that are more soft than desirable.

Accordingly, it is an object of the present invention to provide a zinc-rich coating material containing an alkyl silicate which, as primer paint, remains stable in the packaging for extended periods of time and upon application to an ferrous substrate rapidly forms a dry, hard, corrosion-resistant protective primer film.

The above purpose is met with a coating material for the protection of ferrous metals against corrosion comprising comminuted zinc, a non-hydrolyzed or partially hydrolyzed, up to approx. 40%, organic silicate and an amino group-containing compound, the coating material being characterized in that the amino-group-containing compound is a hydrolyzable silicon compound used in an amount of 5-45% by weight, based on the amount of

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5 are organic silicate and are (a) amino silanes of the formula

Q

t

Z-fN - R ^ - Ϊ M

where t is an integer from 0 to 10, Μ. Y, Q and Z are each R or - R1- Si - X3_b R is H, alkyl of 1-4 carbon atoms or hydroxyalkyl of 2 or 3 carbon atoms, R1 is -C2H4-, c3Hg- or -R2-o-R2-, and R 2 is an alkylene group of 1-8 carbon atoms, b is an integer from 0 to 2, provided that at least one M, Q, Y or Z is in 'b - R1 - Si - X3.b X is a hydrolyzable alkoxy group having 1-2 carbon atoms or an alkoxyalkoxyl group, (b) quaternary ammonium salts of the amino silanes of (a), and (c) the hydrolysates and condensates of the amino silanes of (a).

The coating materials described above are stable over extended periods of time in a closed container. Therefore, separate packaging is not necessary. When applied to an ferrous substrate, the materials dry quickly and result in the formation of a hard, continuous, smooth film with excellent corrosion protection properties.

The alkyl silicates used in the coating materials are known and include non-hydrolyzed alkyl and alkoxyalkyl silicates and alkyl and alkoxyalkyl silicates which are hydrolyzed up to approx.

40 percent. Alkyl silicates are prepared by reacting silicon tetrachloride and alcohols and alkoxy alcohols, usually in a reaction vessel equipped with a stirrer, condenser and a container purifier. Bee

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6 The product of hydrogen chloride is removed at reflux which can occur at reduced or atmospheric pressure. This method produces the most common TEOS (tetraethyl orthosilicate) products and Cellosolve (Union Carbid Corporation's registered trademark for ethylene glycol silicate monoalkyl ethers).

Afterwards, these products can be partially hydrolyzed by the addition of water and an acid catalyst. The amount of water added determines the degree of hydrolysis of the final product. The commercially available products derived from ethanol include non-hydrolyzed TEOS, Condensed E-thyl Silicate (about 7% hydrolysis), Ethyl Silicate 40 (40% hydrolysis containing 40% SiC 2) and Ethyl Silicate P-18 with a hydrolysis level of 80-85%.

The hydrolyzable silicon compounds used in the coating materials are also known and include a wide variety of compounds. Typical examples are γ-aminopropyl triethoxysilane of the form H

in 2 H 2 O - Si - CH CH CH NH 5 2 t 2 2 2 2 oc2h5 and Ν-β (aminoethyl) -γ-aminopropyltrimethoxysilane of formula OCHo CH3O - Si - CH2CH2CH2-NH-ch2ch2nh2 and3

Other examples of aminosilanes are: aminomethyl-1 TR Dimethoxy s in the LAN γ-aminopropyl trimethoxysilane γ-γ-methylaminopropyltrimethoxysilane aminopropy1tripropoxys Ilan γ-aminopropylmethyldiethoxysilane aminopropylethoxyldiethoxysilan γ-γ-γ-aminopropylphenyldiethoxysilan aminoisobutyltrimethoxysilan delta-delta-aminobutyltriethoxysilan aminobutylmethyldiethoxysilan β-aminoethyltriethoxys Ilan

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7 epsilon-aminopentylphenyldibutoxysilane N- ((3-aminoethyl) -γ-aminopropyltrimethoxysilane N- (β-aminoethylaminoethyl) -γ-aminopropyltrimethoxysilane N- (γ-aminopropyl) -γ-aminobutylmethyl .

In addition to the above-mentioned amino silanes containing one silane group, related amino silanes having two or more silane groups can also be used.

Examples include: Ν-β [Ν'-γ- (trimethoxysilylpropyl) -aminoethyl] -γ-aminopropyltrimethoxysilane? CH 3 h H OCH, 1 J »» in 3 CH3 ° -Si- (CH2) 3N-CH2CH2-N - (CH2) 3 Si-OCH3 OCH3 OCH3 Ν, Ν-β - [- / Ν'-γ- (trimethoxysilylpropyl) aminoethyl7-Y-aminopropyl-trimethoxysilane] AND, AND, J »3 CH30-Si- (CH2) 3N -CH 2 CH 2 -N- (CH 2) 3-Si-OCH 3 and 3 h (ch 2) 3 and 3 CH 30 - Si-OCH 3 and 3 Ν, Ν-β- [bis / N ', Ν'-γ-bis (trimethoxysilylpropyl) aminoethyl] _7 "Y" aminopropyltrimethoxysilane] AND,

I J

CH, O Si-OCH, 3 f 3 and 3 CCR2) 3 and 3 CH30-Si- (CH2) 3N-CH2CH2N- (CH2) 3- $ i-OCH3 ° ch3 (ch2) 3 and 3 CH O - Si-OCH3 3 t AND.

3 8

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and the like.

A typical process for preparing an alkoxysilylpropylamine is found in U.S. Patent No. 2,832,754, wherein γ-chloropropyl-triethoxysilane and liquid ammonia are about 1:20 is filled in a pressure vessel and heated by one. temperature of approx. 100 ° C for 12 hours. After cooling, filtration, washing and fractional distillation of the mixture, approx. 50% of the desired product.

Another method of preparing aminoalkyltrialkoxy silane is described in U.S. Patent No. 2,930,809, wherein a cyanoalkyltrichlorosilane described in U.S. Patent No. 2,837,551 is prepared followed by alcoholysis and hydrogenation. Thus hexachlorodisilane and acrylonitrile are sealed in a 1: 1 molar ratio in an autoclave and heated to a temperature of approx. 200 ° C for two hours. One of the products obtained by fractional distillation of the mixture is f-cyanoethyltrichlorosilane. Ethanolysis of this compound gives β-cyanoethyl triethoxysilane. This latter compound is filled into a stainless steel pressure vessel together with Raney nickel. The temperature of the container is then cooled to -78 ° C and excess ammonia is added. Hydrogen gas is charged into the system and the mixture is heated at a temperature of 100 ° C for 16 hours in a cradle autoclave. Then, the mixture is cooled to room temperature, filtered, washed with diethyl ether and distilled fractionally. One of the products produced is triethoxysilylpropylamine.

The hydrolysates and condensates of the above-described amino silanes can be prepared by known hydrolysis and condensation methods. As is well known in the art, hydrolysates represent the metathetic reaction products of water and corresponding hydrolysable amino silanes, while condensates represent the siloxane products obtained by condensation of the hydrolyzate reaction mixture. The amount of water used is not essential and depends solely on the desired degree of hydrolysis and condensation. Therefore, completely hydrolyzed as partially hydrolyzed products can be obtained. .

The preparation of quaternary salts of amino silanes is disclosed in U.S. Patent No. 3,389,160.

The hydrolyzable silicon compound is used, as mentioned, in an amount of 5-45% by weight, based on the amount of organic silicate.

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It has been found that at least 5% by weight of hydrolyzable silicon compound based on the weight of organic silicate is necessary to obtain a dry film during a practical exposure time, i.e. in 5-10 minutes. For practical reasons, there is no advantage in using more than 45% by weight of hydrolysable silicon compound.

While not essential to the practice of the present invention, the coating material of the invention may comprise a water removal agent. Suitable water removal agents include zeolites, silica gel, tetraalkyl silicates, trialkyl borates and the like. Zeolites are preferred because, unlike the others listed above, they do not produce a reaction product in the removal of water.

The water removal zeolite may be any of the well-known three-dimensional molecular sieve type molecular zeolites, either naturally occurring or synthetically produced by conventional hydrothermal crystallisation and with pore dimensions large enough to allow passage of water molecules. Typical of the naturally occurring zeolites are clinoptilolite, chabazite, gmelinite, mordenite, erionite, offretite, phillipsite and faujasite. Examples of synthetic molecular sieve zeolites are zeolite A, U.S. Patent No. 2,882,243, zeolite X, U.S. Patent No. 2,882,244, zeolite R, U.S. Patent No. 3,030,181, zeolite S, U.S. Patent No. 3,054,657 , zeolite T, U.S. Patent No. 2,950,952, zeolite F, U.S. Patent No. 2,996,358, zeolite B, U.S. Patent No. 3,008,803, zeolite M, U.S. Patent No. 2,995,423, zeolite H, U.S. Pat. No. 3,010,789, Zeolite J, U.S. Patent No. 3,011,809, Zeolite Y, U.S. Patent No. 3,130,007, and Zeolite L, U.S. Patent No. 3,216,789. The zeolite selected should preferably have a structural molar ratio of SiC> 2 to A₂Oø of less than 50 and preferably less than 20, as the highly silicon-containing zeolites tend to exhibit organophilic properties to the detriment of their hydrophilic properties. Particularly suitable because of their extremely high water sorption capacity are the different cation forms of zeolite A. The potassium cation form of zeolite A also has an effective pore diameter of between 3 and 5 Å and is thus capable of easily adsorbing water, but effectively excludes most

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10 other molecules in the system based on molecular size.

When used as an adsorbent, the zeolites must be at least partially dehydrated, preferably fully dehydrated, when heated in air or vacuum at moderate temperatures of approx. 250 to 350 ° C for several hours. Since the zeolite crystals are small, rarely larger than 10 micrometers, they can be appropriately mixed in the paints without adversely affecting the main properties. Alternatively, zeolite crystals can be formed into shaped agglomerates with conventional binders such as clays and included in the container in which the product is stored.

The invention will be further elucidated in the following by way of example, where all parts and percentages are by weight, unless otherwise stated.

Example 1

Zinc rich single component paint with ethyl silicate 40 and γ-aminopropyl triethoxysilane.

An iron metal paint is prepared by mixing 45 g of partially hydrolyzed ethyl polysilicate containing 40 wt.% SiO 2 with 5 g of γ-aminopropyl triethoxysilane and 30 g of finely divided zinc with a particle size of approx. 2 to approx. 15 Mm (American Melting and Refining Co. ASARCO L-15). In addition, to keep the mixture in anhydrous state, 5 g of an aqueous removal agent (Union Carbide Corp. molecular sieves 4 A) is added and the mixture is diluted with 50 g of a hydrocarbon solvent consisting of a mixture of 61% by volume paraffins and 39% by volume naphthenes with a boiling range of approx. 158-196 ° C (from American Mineral Spirits Company, "Mineral Spirits 66-3"). The liquid protective or primer paint obtained thereby has a packaging stability of more than 6 months.

When this paint is applied by spraying on sandblasted cold rolled steel sheets measuring approx. 10 x 10 x 0.2 cm, a smooth film is obtained which dries in less than 1C minutes. The steel plate painted in this way is subjected to 1000 hours spraying with salt (ASTM method B-117) and 1000 hours immersed in fresh water (ASTM method B-870). There was no evidence of corrosion or other defects on the plate painted in this way.

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Example 2

Zlnkriq single component paint with ethyl silicate 40 and Ν-β- (aminoethyl) - γ-aminopropyltrimethoxysilane

An iron metal paint is prepared by mixing 45 g of partially hydrolyzed ethyl polysilicate containing 40% by weight with 5 g of Ν-β- (aminoethyl) -γ-aminopropyltrimethoxysilane and 300 g of finely divided zinc dust (ASARCO L-15), 5 g of water removal agent (Union Carbide molecular sieves 4A ) and 50 g of Amsco Mineral Spirits 66-3.

The primer paint thus produced was stable for more than 6 months upon storage. After application to sandblasted steel sheets as in Example 1, the paint dried to a hard film in less than 10 minutes. After being subjected to salt spraying and immersion in water for 1000 hours, these steel plates presented no evidence of corrosion or other defect.

Example 3

Zinc rich single component paint with tetraethyl orthosilicate and Ν-β- (aminoethyl) -γ-aminopropyltrimethoxysilane

An iron metal protective paint is prepared by mixing 45 g of tetraethyl orthosilicate with 5 g of N-O- (aminoethyl) -γ-aminopropyl-methoxysilane and 300 g of ASARCO zinc dust L-15, 5 g of molecular sieves 4A and 50 g of Amsco Mineral Spirits 66-3 . The primer paint thus produced is stable when stored for more than 6 months. When applied as spray paint on a sandblasted steel plate, a dry film of less than 10 minutes is formed. When, as in Example 1, the plates are exposed for 1000 hours to the salt spray and immersion sample in water, no evidence of corrosion or other defect appears.

Example 4

Zinc-rich single-component paint with cellosolvesilicate and γ-aminopropyltriethoxysilane

A protective ferrous metal primer is prepared by mixing 45 g of partially hydrolyzed ethoxyethyl polysilicate containing 19% S1O2, 5 g of γ-aminopropyl triethoxysilane, 300 g of ASARCO L-15 zinc dust, 5 g of molecular sieves 4A and 50 g of Amsco Mineral Spirits 66-3. The primer paint thus obtained has a packaging stability of more than 6 months. When applied by spraying on sandblasted sheets, the paint dries to a hard film in less than 10 minutes. When exposed to salt spray and water immersion samples as described in Example 1 for 1000 hours, the plates show no signs of corrosion or other defects.

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Example 5

Zinc rich single component paint with tetraethyl orthosilicate and poly (amino-alkyl) dimethylpolysiloxane

An iron metal protective paint is prepared by mixing 45 g of tetraethyl orthosilicate with 5 g of a poly (aminoalkyl) dimethylpolysiloxane, 300 g of ASARCO zinc dust L-15, 5 g of molecular sieves 4A and 50 g of Amsco Mineral Spirits 66-3. The resulting paint is stable when stored for more than 6 months. When this paint is applied to sandblasted steel sheets, a dry film of less than 10 minutes is formed. When these plates are subjected to salt spray and water immersion as in Example 1 for 1000 hours, no evidence of corrosion or other defect appears.

Example 6

Zinc rich single component paint with ethyl silicate 40 and aminoalkylalkylalkoxysilane

An iron metal protective paint is prepared by mixing 45 grams of partially hydrolyzed ethyl polysilicate containing 40% by weight SiC> 2 with 5 g of an aminoalkylalkylalkoxysilane (Union Carbide Silane A-1902), 300 g of ASARCO zinc dust L-15, 5 g of molecular sieves 4A and 50 g Amsco Mineral Spirits 66-3. The resulting paint is stable for more than 6 months when stored. When this paint is applied to sandblasted steel sheets, a dry film of less than 10 minutes is formed. When these plates are subjected to salt spray and water immersion as in Example 1 for 1000 hours, no evidence of corrosion or other defect appears.

Example 7

Zinc rich single component paint with cellosol vesilicate and Ν-β- (aminoethyl) - γ-aminopropyltrimethoxysilane

An iron metal protective paint is prepared by mixing 45 g of partially hydrolyzed ethoxyethyl polysilicate containing 10% S1O2, 10 g of Ν-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, 300 g of ASARCO zinc dust L-15, 5 g of molecular sieves 4A and 50 g of Mineral Spirits 66-3. The resulting paint is stable when stored for more than 6 months. When this paint is applied to sandblasted steel sheets, a dry film of less than 10 minutes is formed. When the plates thus painted are subjected to salt spraying and water immersion for 1000 hours as in Example 1, no evidence of corrosion or other defect appears.

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Examples 8-11

Zinc rich single component paint with ethyl silicate 40 and varying concentrations of N-3- (aminoethyl) -γ-aminopropyltrimethoxysilane

Iron metal protective paints are prepared by mixing 45 g of partially hydrolyzed ethyl polysilicate containing 40% by weight SiO2, 2 g of molecular sieves 4A, 300 g of ASARCO zinc dust L-15 and 2, 5, 10 and 20 g of N-3- (aminoethyl) -γ aminopropyltrimethoxy-silane. In each example, the paints produced are stable for more than 6 months. When these paints are applied to sandblasted steel sheets, they form dry films in less than 10 minutes. When plates so treated for 1000 hours are subjected to salt spray and immersion in water as in Example 1, no evidence of corrosion or other defect appears.

Examples 12-15

Zinc-rich single-component paints with varying proportions of Ν-β- (aminoethyl) -γ-aminopropyltrimethoxysilane and mica

Protective coatings for iron metal are prepared by mixing the following components:

Component_12_13_14_15 ASARCO zinc dust L-15 600 g 600 g 600 g 600 g

Mica 40 g 40 g 40 g 40 g

Molecular Sights 4A 4g 4g 4g 4g

Partially hydrolyzed ethyl silicate containing 40% SiO9 109 g 105.5 g 102 g 98.5

Union Carbide Silicone A-1120 'Hg 22.5 g 33 g 45 g *) Ν-β- (aminoethyl) -γ-aminopropyltrimethoxysilane

The paints thus produced are stable for more than 6 months. When applied to sandblasted sheets, a dry film is formed in less than 10 minutes. These painted plates, when exposed to salt spray and immersion water for 1000 hours, showed no signs of corrosion or other defect.

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Example 16

Zinc rich single component paint with ethyl silicate 40 and N- (β-ethylenediaminoethyl) -β-aminoethoyltrimethoxysilane

An iron metal paint is prepared by mixing 45 g of partially hydrolyzed ethyl polysilicate containing 40% SiO 2, 10 g of N- (3-ethylenediaminoethyl) -β-aminoethyltrimethoxysilane, 300 g of ASARCO zinc dust L-15 and 5 g of molecular sieves 4A. The paint produced is stable for more than 6 months.

When the prepared paint is applied to sandblasted steel sheets, a dry film of less than 10 minutes is obtained. The plates so painted are subjected to salt spray and immersion in water as in Example 1 and show no signs of corrosion or other defect.

Example 17

Zinc rich single component paint with ethyl silicate 40 and Y-N- (Y-butylamino) propyl trimethoxysilane

An iron metal paint is prepared by mixing 45 g of partially hydrolyzed ethyl polysilicate containing 40% SiO2, 10 g of γ-N- (γ-butylamino) propyltrimethoxysilane, 300 g of ASARCO zinc dust L-15 and 5 g of molecular sieves 4A. The paint produced is stable for more than 6 months.

When the paint is applied to a sandblasted steel plate, a dry film of less than 10 minutes is obtained. The plates so painted are subjected to salt spray and immersion in water as in Example 1 and show no signs of corrosion or other defect.

Example 18

Zinc rich single component paint with ethyl silicate 40 and Ν, Ν-β- (bis-hydroxyethyl) -γ-aminopropyltriethoxysilane

An iron metal paint is prepared by mixing 45 g of partially hydrolyzed ethyl polysilkate containing 40% SiO2 with 10 g of Ν, Ν-β- (bis-hydroxyethyl) -γ-aminopropyl triethoxysilane, 300 g of ASARCO zinc dust L-15 and 5 g of molecular sieve 4A. The paint produced is stable for more than 6 months.

When this paint is applied to a sandblasted steel plate, a dry film of less than 10 minutes is obtained. The plates thus painted are subjected to salt spraying and immersion in water for 1000 hours as in Example 1 and show no signs of corrosion or other defect.

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Example 19

Zinc rich single component paint with ethyl silicate 40 and polyaminoalkyltri-alkoxysilane

An iron metal paint is prepared by mixing 45 g of partially hydrolyzed ethyl polysilkate containing 40% SiO2 with 10 g of polyaminoalkyltrialkoxysilane, 300 g of ASARCO zinc dust L-15 and 5 g of molecular sieves 4A. The paint is stable for more than 6 months.

When the paint is applied to a sandblasted steel plate, a dry film of less than 10 minutes is obtained. Plates thus painted are subjected to salt spraying and immersion in water for 1000 hours as in Example 1 and show no signs of corrosion or other defect.

Example 20

Zinc rich single component paint with ethyl silicate 40 and γ-Ν, Ν-dimethylammonium propyltrimethoxysilane acetate

An iron metal paint is prepared by mixing 45 g of partially hydrolyzed ethyl polysilicate containing 40% SiO2 with 10 g of γ-Ν, Ν dimethylammonium propyltrimethoxysilane acetate, 300 g of ASARCO zinc dust L-15 and 5 g of molecular sieves 4A. The paint produced is stable for more than 6 months.

When the paint is applied to a sandblasted steel plate, a dry film of less than 10 minutes is obtained. Plates thus painted are subjected to salt spray and immersion in water for 1000 hours as in Example 1 and show no signs of corrosion or other defect.

Example 21

Zinc War one-component paint with conductive elastomer pigment

An iron metal paint is prepared by mixing 45 g of partially hydrolyzed ethyl polysilicate containing 40% SiO2 with 5 g of Union Carbide Silane A-1120, 200 g of ASARCO zinc dust L-15, 100 g of ferrophosphite (an electrically conductive excipient pigment sold as "Ferrophos "2131 from Hooker Chemical Co. with an average particle size of 6 mm), 5 g of molecular sieves 4A and 50 g of Amsco Mineral Spirits 66-3. The paint produced is stable for more than 6 months.

When the paint is applied to a sandblasted steel plate, a dry film of less than 10 minutes is obtained. Plates thus painted are exposed

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16 for salt spraying and immersion in water for 1000 hours as in Example 1 and showing no signs of corrosion or other defect.

Example 22

Zinc rich single component paint with ethyl silicate 40 and og-β- [Ν'-γ- (trimethoxy-silylpropyl) -aminoethyl] -γ-aminopropyltrimethoxysilane

An iron metal paint is prepared by mixing 155.2 g of partially hydrolyzed ethyl polysilicate containing 40% by weight S1O2 with 38.8 g of Ν-β- [N'-γ- (trimethoxysilylpropyl) aminoethyl] -γ-aminopropyl trimethoxysilane and 892.5 g finely divided zinc with a particle size of approx. 2 to approx. 15 μπι (American Melting and Refining Co. ASARCO-L-15) and 74 g of finely divided extender (Water-Ground Mica 325 from The English Mica Co.). In addition, to keep the mixture in anhydrous state, add 7.5 g of an aqueous removal agent (Union Carbide Corp. molecular sieves 4A) and dilute the paint with 293.5 g of ethylene glycol monoethyl ether (Cellosolve). An antifouling agent is used to prevent hard precipitation (24 g of MPA-60-X, a hydrogenated castor oil from NL Industries) and 15.5 g of thickening agent (Ethocel Medium Premium 100 from Dow Chemical Co.) to add the desired viscosity. The produced liquid ethyl silicate protective or primer paint has a packaging stability of more than 3 months.

When the paint is sprayed by sandblasting, cold rolled steel sheets measuring approx. 10 x 20 x 0.2 cm, a smooth film that dries in less than 10 minutes is obtained. The steel plate thus painted is subjected to salt spraying for 500 hours (ASTM method B-117) and no evidence of corrosion or other signs of defects on the plate thus painted.

Example 23

Zinc rich single component paint with ethyl silicate 40 and og-β- [Ν'-γ- (triethoxy-silylpropyl) -aminoethyl] -γ-aminopropyltrimethoxysilane

An iron metal paint is prepared by mixing 174.6 g of ethyl silicate 40 with 19.4 g of Ν-β- [Ν'-γ- (trimethoxysilylpropyl) -aminoethyl] -γ-aminopropyltrimethoxysilane, 892.5 g of finely divided zinc dust (ASARCO L- 15), 7.5 g of a water removal agent (Union Carbide Molecular Sieve 4A), 74 g mica 325, 24 g MPA-60-X, 15.5 g Ethocel Medium Premium 100 and 293.4 g Cellosolve.

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The primer paint is stable when stored for 3 months. When applied to sandblasted steel sheets as in Example 1, the paint dries to a hard film in less than 10 minutes. When exposed to salt spray and immersion in water for 500 hours, these plates show no signs of corrosion or other defect.

Claims (11)

A coating material for the protection of ferrous metals from corrosion, including comminuted zinc, a non-hydrolyzed or partially hydrolyzed, up to approx. 40%, organic silicate and an amino group-containing compound, characterized in that the amino-group-containing compound is a hydrolyzable silicon compound used in an amount of 5-45% by weight, calculated on the amount of organic silicate, which is ( a) amino silanes having the alloy Q i, Z — NR · * · —— NEW M where t is an integer from 0 to 10, Μ, Y, Q and z are each R or i 'b - R1- Si - X3_b R is H, alkyl of 1-4 carbon atoms or hydroxyalkyl of 2 or 3 carbon atoms, R1 is -C2H4-, -C3H6- or -R2-0-R2- and R2 is an alkylene group of about 1-8 carbon atoms, b is an integer from 0 to 2, provided at least one of the symbols M, Q, Y and Z is 1 * b - R1- Si - X3_b and X is a hydrolyzable alkoxy group having 1-2 carbon atoms or an alkoxyalkoxyl group, (b) quaternary ammonium salts of the amino silanes of (a) and (c) the hydrolysates and condensates of the amino silanes of (a). Coating material according to claim 1, characterized in that X is an alkoxy group having 1 or 2 carbon atoms. Coating material according to claim 1, characterized in that X is an alkoxyalkoxyl group. Coating material according to claim 3, characterized in that the alkoxyalkoxyl group is -OC2H4OCH3. Coating material according to claim 1, characterized in that R is H. Coating material according to claim 1, characterized in that R is -CH 3. Coating material according to claim 1, characterized in that the organic silicate is an alkoxyalkyl polysilicate. Coating material according to claim 7, characterized in that the alkoxyalkyl polysilicate is ethoxyethyl polysilicate. Coating material according to claim 1, characterized in that the organic silicate is a tetraalkyl orthosilicate. Coating material according to claim 9, characterized in that the tetraalkyl orthosilicate is tetraethyl orthosilicate. Coating material according to claim 2, characterized in that the alkoxy group is -OCH3. «