DE2147299A1 - Binders for protective coating materials - Google Patents

Description

Binders for protective coating materials

The invention "relates to a binder, in particular a paint material, which in addition to the binding agent also contains a finely divided solid material, e.g. zinc and which after the latter gives galvanic protection when applied to a metal surface.

Many of the binders known to date and used for the purposes mentioned have only a short shelf life and are produced after application to a surface, only soft, dusty coatings during curing. It has also been difficult so far to be even Produce coatings if the binder-containing coating materials contain finely divided solid substances such as zinc was. Many of these binder-containing paints also had a tendency to crack after being applied to metal substrates during drying, whereby the underlay was exposed to attack from the environment.

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According to the invention there is provided a protective coating material for metal surfaces proposed which is free from the disadvantages mentioned above. This paint material contains a suitable one Binder and can be mixed with finely divided solid substances such as zinc. The proposed according to the invention Protective coating material with the binder according to the invention is characterized by a relatively long storage time so that it can be easily applied to a surface like paint. Cure by the binder according to the invention the coatings applied to a metal base turn into abrasion-resistant and well-adhering mimes. The ones on metal pads The applied coatings are also characterized by an increased resistance to solvents.

According to the invention, a binder is proposed which contains a hydrolyzed organotrihydrocarbonoxysilane and which can be combined with finely divided solid substances to form a color-like coating material with sufficient storage time or processing time.

The organotrihydrocarbonoxysilanes according to the invention for the production of the binder used can be expressed by the formulas

R Si (OR ¹ ) 3 and R Si (OR ¹¹ OR ¹ O ₅

represent. In the two formulas, R and R ¹ denote aliphatic or aromatic hydrocarbon radicals having up to about 10 carbon atoms, preferably about 1 to 6 carbon atoms; R "represents a divalent hydrocarbon radical with 2 to 6 carbon atoms; R" ¹ has the same meaning as R 'or represents hydrogen. *

Examples of suitable monovalent hydrocarbon ^{radicals which R, R 1} and R ¹ ″ can represent are alkyl radicals such as methyl, ethyl, butyl, hexyl, octyl and lecyl and aryl radicals such as phenyl,

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Tolyl and xylyl. R can also be any alkenyl radical such as Vinyl, allyl, hexenyl and butadienyl. Divalent hydrocarbon radicals which R "can represent are ethylene, trimethylene, Tetramethylene, hexamethylene, phenylene and the like.

Suitable organotrihydrocarbonoxysilanes are:

liethyltrimethoxy-, llethyltriäthoxy-, Methyl tr ipr op ox; / -, Methyltributoxy-, Metliyltrioctoxy-, Äthyltriäthoxy-, Propyltrimethoxy-, Propyltributoxy-, propyltrioetoxy-, propyltridecoxy-, butyltrimethoxy-, Butyltriethoxy, butyltributoxy, butyltrioctoxy, Butyltridecoxy, butyltriphenoxy, hexyltrimethoxy, hexyltriethoxy, Hexyltributoxy-, hexyltrioctoxy-, hexyltriphenoxy-, Phenyltrimethoxy, phenyltriethoxy, phenyltributoxy, phenyltrioctoxy, Allyltrimethoxy-, Allyltriäthoxy-, Vinyltrimethoxy-, Vinyltriäthoxy-, Vinyltributoxy- and Butadienyltrimethoxysilan as well as T.Iethyltri- (2-methoxy ~ ethoxy) silane, Ethyltri- (4-ethoxy-butoxy) silane, Ethyltri- (2-butoxy ~ ethoxy) silane, butyltri- (2-ethoxy-ethoxy) silane, Hexyltri- (2-methoxy-ethoxy) silane, phenyltri- (2-f-thoxy-ethoxy) silane, methyltri- (propylene glycol) -silane, Butyltri- (ethylene glycol) silane, phenyltri- (ethylene glycol) silane and mixing of the abovementioned substances with one another.

These organotrihydrocarbonoxysilanes can be prepared by various methods described in the relevant literature will. For example, hydrocarbonoxysilanes can be prepared by a Grignard synthesis if one of the corresponding Colilenhydrochlorid and an alkyl orthosilicate goes out. The reaction generally proceeds according to the following equation:

RX + Si (OR ') ₄ + Mg »R Si (OR' ) ^ + Mg XOR ¹

In this equation, R and R 'have the same meaning as given above; X represents halogen. In general, it is necessary to be heated to about 50 to about 130 ° C. during the reaction. It may also require a small amount of one

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Add reagent such as methyl magnesium chloride to the reaction initiate.

On the other hand, it is also possible to use methyltrichlorosilane To implement ethanol in the presence of ammonia, methyltriethoxysilane and ammonium chloride are formed. Phenyltrihydrocarbonoxysilane can be used in a corresponding manner made of phenylchlorosilane.

The organotrihydrocarbonoxysilanes can also be produced by placing finely divided silicon in the presence of an alcohol or phenol in a neutral or acidic phase at a temperature converts between 20 and 360 0, the silane formed from the The reaction mixture is separated off and then with an unsaturated hydrocarbon in the presence of a customary catalyst to react.

The hydrocarbonoxysilanes of the formula R Si (GR ¹¹ OR " ¹ ) ^ can be prepared by reacting a methyltrichlorosilane with suitable monoethers of alkylene glycols or mixtures of these substances, the oilan and HGl being formed. The alkylene glycol ethers are obtained by normal reactions corresponding alcohols (R "OH) with an alkylene glycol in a 1: 1 addition.

The binders according to the invention are obtained by a Organotrihydrocarbonoxysilane mixed with such an amount V / water that at least 0.8 mol, preferably about 1.0 to 4.5 Hol V / ater are present per hydrocarbonoxy group bonded to the silicon atom. If the ', Vassermen: e per hydrocarbonoxy group below about 0.8 mol, as has been found, the desired paints are not achieved with the finished paints Hardness and sufficient abrasion resistance.

The organotrihydrocarbonoxysilanes are hydrolyzed and condensed, to such an extent that the Siup content

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is between about 5 and 40 wt .- ^. Particularly good results are achieved with a condensate which contains about 15 to 30 fo SiOp.

Although not essential, it is beneficial to use a solvent in making the binders. Suitable solvents are higher-boiling ethers such as monoalkylene and dialkylene glycol monoalkyl ethers, dialkylene and monoalkylene glycol dialkyl ethers, Ketones such as acetone, alcohols such as ethanol, isopropanol, butanol, hexanol and diacetone alcohol, glycols such as Polyethylene glycols, hydrocarbons such as hexane, heptane, benzene, toluene and xylene, chlorinated hydrocarbons and water as well Mixtures of the solvents mentioned with one another. The drying time, viscosity, etc. can be adjusted, by choosing suitable solvents or solvent mixtures. The ratio of solvent to hydrocarbonoxysilane can be varied within wide limits which depend on the properties that the finished binder has target. In general, the ratio can be within a range from about 0.5 J 1 to 10: 1.

Although the amount of acid necessary for the hydrolysis of the organotrihydrocarbonoxysilane is required, is not critical per se, at least as much acid should preferably be present as that a pH of about 1.0 to about 5.5 results, preferably about 1.4 to 4.5. The amount of acid, preferably hydrogen chloride acid, can be about 0.001 to about 0.08, preferably about 0.005 to about 0.05 percent by weight. Other inorganic Acids such as sulfuric acid and hydrofluoric acid can either alone or in admixture with hydrochloric acid can also be used.

1- and 2-basic organic acids, which are free of hydroxyl groups and have the required strength, can also be used, used v / earth, as well as metal chlorides, nitrates and sulfates, in which the metal from one of the groups III or

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IY of the Periodic System of the Elements. Examples of suitable organic acids are vinegar, butter, capron, Caprine, palmitin, oil, üxal, fumar, Groton, acrylic, Maleic, Malon, Amber, Glutar, Adipine, Suberine and Sebacic acid and halogenated carboxylic acids ,, Y / purer organic Acids that can also be used are benzoic acid, toluenesulfonic acid, and alkyl phosphoric acids in which the alkyl groups Contain 1-4 carbon atoms.

In general, the amount of organic acid should be from about 0.1 to about 1.0, preferably from about 0.3 to about 0.8% by weight to the weight of the binder.

The methods of making binders are described in the relevant Industry known; the silane described here should preferably be dissolved in an organic solvent, whereupon so much Y / ater, preferably an acidified Y / ater, is added that at least 0.8 mol of water per hydrocarbonoxy group are present on the silicon atom. The solution is stirred, and after a short time it can be seen that an exotherm is occurring Reaction is running. As a result, the solution becomes quite warm and a homogeneous, clear liquid is created. Product.

It is not known exactly in which Y / eise the chemical reaction between the organotrihydrocarbonoxysilane and the Water drains; however, it can be assumed that hydrolysis first takes place, followed by intermolecular Condensation polymerization follows, which leads to an elimination of water and / or alcohol molecules between the silicon-containing Groups leads. For example, it is known that the reaction between water and the organotrihydrocarbonoxysilane leads to the formation of alcohols and silanol groups. The silanol groups condense with one another and with the hydrocarbonoxy groups with formation of Si-Ü-Si bonds, Y / ater and alcohol.

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The paints according to the invention are produced by one dos binder, which "has been obtained from the previous hydrolysis and condensation, with finely divided solid Substances, preferably zinc dust, mixed. Will such Paints applied to metal substrates give this galvanic protection. In many cases it is desirable, instead of pure zinc dust, a mixture of zinc dust and a suitable expanding or filling material such as Calcium and magnesium metasilicate or minerals containing these substances should be used. Other filling materials,

In particular, fibrous filler materials such as asbestos, fiber talc, fibrous calcium metasilicate, gypsum and others can also be used together used with zinc dust in painting or coating materials will. Other additives that can be added to the paints are coloring pigments, such as iron oxide, Cadmium sulfide, titanium dioxide as well as many of the lithopones.

The zinc / binder ratio depends essentially on the consumption requirements or on the requirements to be met Specifications. Generally the binder to zinc ratio is between 50:50 and 10:90 (on a weight basis). However, if the paint contains a filler, e.g. one of the calcium or magnesium metasilicates mentioned above, the ratio of binder: total amount of finely divided material (zinc and filler) of 10:90 range up to 70:30 (weight basis).

The coatings generally cure in about 24 hours at ambient temperature. Optionally, however, the coatings may be up to 500 ^0C cured in an oven at 'temperatures between about 40 and. At these high temperatures, the curing time is of course largely reduced.

The coating or paint material according to the invention has a flash point of about 27 to about 66 ^° C. (tag open cup method) and a pot life which meets practically all requirements in all essential fields of application.

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The coating materials can be applied to cleaned metal substrates by painting, spraying, or any other conventional technique be applied. They are characterized by excellent adhesive strength out; .in many cases, the coatings work with success can be applied to clean steel surfaces without the need to sandblast these surfaces beforehand subject. This was not possible with previously known coating materials. The adhesion to dew or even wet galvanized steel surface is very good. The "coating material does not freeze and is not adversely affected by bright sunlight at tropical temperatures. The coatings are also characterized by excellent resistance to sprayed salt solutions, fuels and organic Solvent off. Since the coating material can be easily pigmented, it can be used without a topcoat will.

Surprisingly, it has been found that the binders which are prepared with organic acids have better solvent resistance and have a better adhesive strength to metal substrates than corresponding agents with inorganic acids are produced.

The following examples serve to further illustrate the invention. As far as the term "parts" is used in the examples, parts by weight are always meant, unless expressly something other is indicated.

example 1

A binder was prepared by slowly adding 38 parts of deionized water, with stirring, to a reactor containing 250 parts of methyltriethoxysilane, 177 parts of ethylene glycol monoethyl ether and 0.05 part of 37% hydrochloric acid; the reaction mixture was stirred at a temperature of up to about 60 ^{° C. for about 2 hours.}

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The binder produced in this way was mixed with zinc dust (2 "to 7 microns) in a ratio of 30 parts binder to 70 parts zinc dust; the paint thus obtained was applied to a lightly sandblasted steel base. After drying for about 24 hours at freezing temperature, the coating was applied its hardness is tested according to the usual standard hardness test methods. In this test, different pencils with different degrees of hardness, ^{corresponding to the scale 1B, 2B, 3B, i 1} , H, 2H, 3H, 4-H, 5H, etc., are used. These values indicate a gradual increase in hardness. The pencil is held at a 45 ° angle against the zinc coating applied to the steel plate and moderate force is applied until the coating is removed. The hardness test results are shown in Table I.

Examples 2 to 11

In the Y / eise described in Example 1, different binders were prepared by adding different amounts of deionized water to a solution of methyltriethoxysilane, iithyleneglykolmonoäthyläther and hydrochloric acid gave. The prepared binders were mixed with zinc dust (2 to 6 microns), applied and allowed to dry for 24 hours tested for their hardness in the Y / iron described in Example 1. The results of these hardness tests are given in Table I. contain.

Example 12

A binder is prepared as described in Example 1 by adding 340 parts of deionized water to a reactor which already contains 250 parts of methyltriethoxysilane and 0.6 parts of 37% strength hydrochloric acid. The SiOg content of the resulting binder could be calculated to be about 14.3 1 ".

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- ίο -

The binder so prepared was coated with zinc dust (2 to 6 microns) in the ratio of 30 parts binder to 70 parts Zinc dust mixed; this paint was then applied to a lightly sandblasted base. After about 36 hours When dried at room temperature, the resulting coating showed a hardness of about 3H.

Example 13

A binder was prepared in the manner described in Example 12 by adding about 340 parts of deionized water to a reactor already containing 250 parts of methyltriethoxysilane and 0.69 parts of 37 percent hydrochloric acid. After etv / a 2 hours, the reaction product was raised up to etv / a heated 12O ⁰ C, remove the volatiles to. The product then present was diluted with ethylene glycol monoethyl ether so that a mixture with an SiOp content of about 18 $ was then obtained.

30 parts of this binder are mixed with 70 parts of zinc dust and applying the mixture to a clean steel plate, a satisfactory coating is obtained.

Example 14

A binder was again prepared using the procedure described in Example 1, but 108 parts of deionized water were added to 304 parts of butyltributoxysilane and 0.59 part of 37 percent strength hydrochloric acid in a reactor. The SiOP content of the resultant binder was calculated to be about 14.6 i ".

Mix 20 parts of this binder with 80 parts of zinc dust and if the resulting paint is applied to a clean steel plate, the result is a satisfactory coating.

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Example 15

In the manner described in Example 1, 1.108 parts of deionized water were added to a reactor that contained 240 parts Phenyltriethoxysilane and 0.3 part of 37% hydrochloric acid contained. The Siup content of the resulting binder was billed at about $ 17.2.

The binder prepared as described above was mixed with zinc dust (2 to 6 microns) in a ratio of 50 parts binder to 50 parts zinc dust; the resulting paint was applied to a lightly sandblasted steel base. After et \ va ^once: lndigem drying at a temperature of about 15O ⁰ C w:
Hardness value of about 3H.

Example 16

Temperature of about 15O ⁰ C the resulting coating had a

In the manner described in Example 1, 108 parts of deionized water containing 0.5 parts of 37% hydrochloric acid were placed in a reactor with 322 parts of methyltriphenoxysilane. The Siup content of the resulting binder was calculated to be about $ 13.9.

The binder so prepared was mixed with zinc dust (2 to 6 microns) in a ratio of 30 parts of binder to 70 parts of zinic dust; the paint obtained in this way was applied to a sandblasted steel base. After up to 5 hours, drying at a temperature of about 150 ⁰ C, the coating showed a harp on · 3H

Example 17

In the manner described in Example 1, 108 parts were deionized Put water into a reactor that already contains 430 parts of methyltrioctoxysilane and 0.6 parts of 37% hydrogen chloride

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acid contained. The SiOp content of the resulting binder was calculated to be about $ 11.1.

This binder was then mixed with zinc dust (2 to 6 microns) in a ratio of 50 parts binder to 50 parts zinc dust; the resulting paint was applied to a sandblasted steel base. After 2 hours of drying at a temperature of about 180 ⁰ G, the resulting coating had a hardness of 2H to 3H.

Example 18

A binder was prepared by slowly adding, with stirring, about 115 parts of deionized water, which was about 0.02 parts Parts containing 37% hydrochloric acid in a reactor with 250 parts of methyltriethoxysilane. The reaction mixture was stirred at a temperature of about 45 ° C. for about 2 hours and then mixed with about 93 parts of ethylene glycol monomebhyl ether.

The resulting binder was coated with zinc dust (2 to 6 microns) in a ratio of 60 parts binder to 40 parts Zinc dust mixed; the mixture obtained was applied to clean steel pads. After drying for about 24 hours the coatings had hardness values of about 4H.

Example 19

A binder was prepared in the manner described in Example 1. To this end, 115 parts of deionized water, which contained 0.02 parts of 31% hydrochloric acid, were slowly added, with stirring, to a reactor in which there were already 250 parts of methyltriethoxysilane and 93 parts of ethyl alcohol; The reaction mixture was then heated to a temperature of about 45 ^{° C. for two hours with continued stirring.}

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The binder thus prepared was mixed with zinc dust in a ratio of 60 parts of binder to 40 parts Zinc dust; the resulting paint became weak sandblasted steel pads applied. After about 24 hours After drying at room temperature, the resulting coatings had hardness values of about 3H.

Example 20

A binder was prepared by slowly adding 76 parts of deionized water, with stirring, to a reactor containing 250 parts of methyltriethoxysilane, 133 parts of ethylene glycol monomethyl ether and 0.05 part of 37 ' sequence of hydrochloric acid; the reaction mixture was then heated to a temperature of up to about 50 ° C. for about 2 hours with continued stirring. The reaction mass was then further heated to a temperature of about 120 ° C. in order to remove the volatile materials, while the SiOp content of the reaction mass was kept at about 18 $ by further addition of ethylene glycol monomethyl ether.

The binder produced in this way had a flash point of about 46 ^° C. ("tag open cup" method).

The binder was made with zinc dust (2 to 6 microns) in proportion 30 parts of binder mixed with 70 parts of zinc dust; the paint obtained was applied to a clean Steel base applied. Tray to dry for 36 hours at room temperature the resulting coating was excellent in hardness. -

Example 21

A binder was prepared by slowly adding 76 parts of deionized water with stirring to a reactor containing 268 parts of methyl tri- (2-methoxy-ethoxy) silane, 53 parts of ethylene

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glycol monoethyl ether and 0.05 part 37 ' sequence contained hydrochloric acid; the mixture was then heated to a temperature of up to about 75 ° C. for 2 hours with continued stirring.

The binder recovered was zinc numb (2 to 6 microns) in the ratio of 30 parts binder to 70 parts zinc dust mixed; the resulting paint was applied to a clean steel base. After drying for about 2 hours a temperature of about 100 ° C was a satisfactory coating.

Example 22

A binder was made in the manner described in Example 21 produced, but 226 parts of Ilethyl-tri- (ethylene glycol) -silane were used instead of methyl-tri- (2-methoxy-ethoxy) silane.

The binder obtained was coated with zinc dust (2 to 40 microns) in a ratio of 30 parts binder to 70 parts zinc dust mixed; the resulting paint was applied to a clean steel base. After drying for 2 hours at 100 g there was a satisfactory coating.

Example 23

A binder was prepared by slowly adding, with stirring, 500 parts of methyltriethoxysilane to a reactor in which there were 264 parts of ethylene glycol monoethyl ether, 152 parts of deionized water and 3 parts of acetic acid; then the reaction mixture was stirred for about 2 hours at a temperature up to about 31 ⁰ O. Thereafter, the reaction mixture was filtered so that a clear liquid was obtained.

The binder obtained on this Yfei.se was coated with zinc dust (2 to 7 microns) in a ratio of 30 parts of binder 70 parts of zinc dust mixed; the resulting paint

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was applied to lightly sandblasted steel substrates. After drying for about 24 hours at room temperature, the formed coatings have hardness values of about 2H. The coated substrates were characterized by excellent solvent resistance off when they are immersed in methyl ethyl ketone or ethylene glycol monoethyl ether for 4-8 hours. Appropriate Sample plates which had been coated in the manner described in Example 1 had practically no solvent resistance, if they have been brought into contact with one of the solvents mentioned above.

Example 24

A binder was prepared in the manner described in Example 23, but using toluenesulfonic acid instead of Used acetic acid.

A mixture of this binder with zinc dust showed good solvent resistance after application to a substrate against methyl ethyl ketone.

Example 25

A binder was prepared in the manner described in Example 23, except that beijpetic acid was used in place of acetic acid used.

If the binder obtained is combined with zinc dust and this mixture is applied to a metal base, the coating shows good solvent resistance.

Example 26

A binder was prepared in the manner described in Example 23 except that adipic acid was used in place of acetic acid used.

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A paint made from this binder with zinc dust after application to a metal substrate, resulted in coatings that were well solvent-resistant.

Example 27

About 100 parts of the binder prepared according to Example 7 were mixed with about 250 parts of zinc dust and 24 parts of a Calcium-magnesium-aluminum silicate with an average particle size of about 8.0 microns. To After mixing, the slurry was sandblasted on Iron surface applied. The coating showed after about 24- hourly drying to a hardness value of about 3H.

Example 28

To about. 125 parts of the binder prepared according to Example 7 250 parts of zinc dust and 70 parts of talc ("Asbestone 625", a fibrous magnesium-calcium silicate mineral) were added while stirring with a particle size of 2 microns) and 10 parts of red iron oxide. The resulting slurry was applied to a clean steel surface. It adheres well and achieves excellent hardness values in 24 hours.

The same as described in the preceding examples is repeated Working method and uses other hydrocarbonoxysilanes in the presence of other solvents and finely divided solids Materials, paints or coating compositions are also obtained which have properties which are those in the examples mentioned correspond.

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8th 9 GH ₃ Si (OG ₂ H ₅ ) ₅ solvent Table I. V / ater Calculated binder Hardness of the example 10 (Parts) Ether*
Parts HCl (Parts) Mole of water
per silane
ethoxy "Cover
(24 stan.) No. 11 250 177 37? 5
(Parts) 38 0.50 .18 1 500 318 0.05 99 0.65 18th 2 500 303 0.09 114 0.75 18th P-H 3 500 284 0.09 133 0.88 18th 2 H 4th 500 265 0.09 152 1.0 18th 2 H VJl 250 125 0.09 84 1.1 18th 3 H. 6th 500 250 0.05 180 1.2 18th 5 H. 7th 250 109 0.09 99 1.3 18th 6 H. 250 93 0.05 115 1.5 18th 6 H. 250 56 0.05 152 2.0 18th 6 H. 250 18th 0.05 190 2.5 18th 6 H + 0.05

Ethylene glycol monoethyl ether

Claims (19)

Claims 1. Binder, consisting of a condensate of silanes formula R Si (OR ¹ ), or R Si in which R and R 'hydrocarbon radicals with up to 10 Carbon atoms, R "is a divalent hydrocarbon radical having 2 to 6 carbon atoms and R " ^{1 is} a hydrocarbon radical with up to 10 carbon atoms or hydrogen mean which contains so much water that there is at least 0.8 mol of water per hydrocarbonoxy group bonded to the silicon atom result, and which with 0.1 to 1.0 wt .- $, based on the weight of the binder, an organic acid that is free of hydroxyl groups is added. 2. Binder according to claim 1, characterized in that the silane of the formula R Si (OR ') ₃ corresponds, in which R and R 'hydrocarbon radicals with mean up to 10 carbon atoms. 3. Binder according to claim 1, characterized in that the silane of the formula R Si (OR ¹¹ OR ¹ ") 3 corresponds, in which R and R " ^{1 represent} hydrocarbon radicals with 1 to 10 carbon atoms and R" represents a divalent hydrocarbon radical with 2 to 6 carbon atoms. 2098U / 1490 4. Binder according to claim 1, characterized in that R " ^{1 means} Y / hydrogen. 5. Binder according to claim 1, characterized in that it also contains an organic solvent. 6. Binder according to claim 5, characterized in that the solvent consists of a monoalkylene glycol monoalkyl ether, Monoalkylene glycol dialkyl ether, dialkylene glycol monoalkyl ether or dialkylene glycol dialkyl ether. 7. Binder according to claim 5, characterized in that the solvent consists of an alcohol having 1 to 8 carbon atoms consists. 8. Binder according to claim 5, characterized in that the water in an amount of 0.8 to 4.5 mol V / water per a hydrocarbonoxy group bonded to the silicon atom is present. 9. Binder according to claim 5, characterized in that the SiO ₂ content is between 5 and 40 fo . 10. Process for the preparation of the binder according to claim 1, characterized in that a silane of the formulas R Si (OR ') ₃ or R Si (OR ¹¹ OR "·) ₅ in which R, R ', R "and R"' have the meaning given in claim 1, in the presence of 0.1 to about 1.0% by weight, based on the weight of the binder, an organic acid that is free of hydroxyl groups, with that much water converts so that at least 0.8 mol of Y / water per hydrocarbonoxy group bonded to the silicon atom is obtained. 209814/1490 Π It -ΡΙΟ 11. The method according to claim 10, characterized in that the · reaction in the presence of an organic solvent is carried out. 12. Paints, "consisting of finely divided solid material and a binder according to claim 1, which according to the method according to claim 10 in the presence of so much acid, that results in a pH of about 1.0 to 5.5 has been established, the ratio of binder to finely divided solid material is between 50:50 and 10:90 on a weight basis. 13. Paint according to claim 12, characterized in that the finely divided material consists of zinc. 14 ·. Coating material according to claim 12, characterized in that that the binder has been prepared in the presence of an organic acid which is free of hydroxyl groups and is present in an amount from 0.1 to about 1.0 weight percent. 15 paints according to claim 12, characterized in that that the binder has been prepared in the presence of an inorganic acid, which in an amount of 0 £ D1 to about 0.08 wt. Ji is present. 16. A paint according to claim 13, characterized in that it contains a filler material in addition to the zinc, wherein the Total ratio of binder bu zinc to kill substance «Between 70: 30 and 10 ί 90, on weight baai ·, lies. 17. Coating material according to claim 16, characterized in that that the filler is made of an alkaline earth metal like Oalcium and / or magnesium silicate consists. 18. Paints naoh claim 16, characterized in that the filler consists of a fibrous mineral '' 209814/1490 BATH 19. A process for the preparation of a binder with a high flash point, characterized in that a silane is used Pormulas R Si (OR ¹ J ₅ or R Si (OR ¹ OB * ¹ ). ₃ in which R, R ¹ , R ^w and R ^M · have the meaning given in claim 1, with so much water that at least 0.8 mol of water are present per hydrocarbonoxy group bonded to the silicon atom, in the presence of so much acid that a pH of about 1.4 to 5.5 results, the volatile materials are removed and at the same time a high-boiling organic solvent which is miscible in the reaction _{mass is added in order to keep the SiO 2} content practically constant the removal of the volatile materials continues until the temperature of the reaction maee approximately corresponds to the boiling point of the added solvent Door Stauffer Chemical Company, Lew York, H.T. Y.St.A. BATH ORIGINAL 2Q98U / 1490