DE1769508A1 - Process for the production of water repellants - Google Patents

Description

In the case of water repellants for moldings and coatings inorganic binders containing or made from such binders existing masses is between water repellants, which are applied to the surface of the moldings or coatings and water repellants which contain the inorganic binder or which consist of such binders To distinguish masses added before shaping at the latest. The present invention relates to a method for the production of water repellants of the latter type.

The mixing of the compositions containing inorganic binders or consisting of such binders with the water repellants at the latest before the shaping has to be compared to the

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Application of water repellants to the finished moldings or coatings has the advantage that it enables the production of moldings and coatings that not only apply to their surface but are also water-repellent in all parts of their interior, which can be seen, for example, when cracks appear later has a beneficial effect, and that it requires considerably less work.

Among the previously "known water repellants, the inorganic Binding agents or compounds consisting of such binding agents are added prior to shaping at the latest Aqueous emulsions of organopolysiloxanes, water-containing pastes, consisting of, reaction products of organohalosilanes with aqueous hydrated lime, powders made by hydrolysis of organotrichlorosilanes, and metal salts of higher fatty acids. The aqueous emulsions of organopoly, iloxanes and the Pastes of the type described above have the disadvantage that they contain or consist of the inorganic binder Binding agents can only be added to existing masses when they are finally used and that their water content requires more effort for storage and transport. The above-mentioned addition of the water repellent to the inorganic Binders containing or consisting of such binders masses in the final application of these masses

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creates the possibility of many errors, in particular a more even mixing of the masses with the Water repellants are often not guaranteed. Because of their poor wettability, it is also difficult to produce powders that are produced by hydrolysis of organotrichlorosilanes, simultaneously with or after the addition of water to the inorganic binder containing or from such binders evenly distribute existing masses, and. The water repellency achieved by these powders is also often small amount. In the case of the metal salts of higher fatty acids, it can often be observed that they are the inorganic ones before or after shaping Binder and water-containing masses float on the surface of these masses and no longer in them Masses are evenly distributed. In addition, these soaps are in a relatively short time due to the weather and / or biodegraded and therefore ineffective.

By contrast, the process according to the invention results in pulverulent Water repellants obtained free from all of the above Disadvantages are, for example, compositions containing or consisting of inorganic binders or the additives for such masses, e.g. pigments,

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already added years before the final use of these compounds or, if desired, slightly just before, simultaneously with or evenly after the addition of water can be distributed without segregation phenomena in the inorganic binder-containing masses, and the production enable moldings and coatings that have a stronger water repellency than moldings and coatings of inorganic binders-containing masses, which before shaping with previously known water repellants ^ e.g. fine-grained Methylpolysiloxane were mixed. According to the invention Hydrophobizing agents produced also have the advantage over, for example, fine-grained methylpolysiloxane, that they are more easily accessible are.

The invention relates to a method for production of water repellants by converting ürganosilicon compounds with a basic calcium compound, characterized in that quicklime is mixed with an emulsion of organopolysiloxanes, which contain an average of 0.8 to 1.8 SiC-bonded hydrocarbon residues per silicon atom, extinguishes in water and the products thus obtained, if they are not yet powdery, are dried and, if necessary, ground.

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It can be assumed that the hydrophobizing agents prepared according to the invention contain free lime, while the reaction of hydrated lime with organohalosilanes neutralizes the free lime. Since one the other hand, for example, due to the interpreting see Patent 1,065,551 previously thought that free lime impaired silicon compounds, the water-repellent-making effect yon organo · is the efficiency of the hydrophobing agent according to the invention exceptionally Λ lent surprising.

The quicklime (CaO), sometimes also called "quicklime" or "Calcium oxide" can be in the form of lump lime or of Peinkalk can be used. About mixing the organopolysiloxane emulsion to facilitate with the quicklime and because a particularly finely divided water repellent is obtained with it the use of fine lime, i.e. powdered quicklime, preferred.

The SiC-bound hydrocarbon residues in the organopolysiloxanes in the emulsions used according to the invention Alkyl, alkenyl, cycloalkyl, cycloalkenyl, aryl, aralkyl or alkaryl radicals. They are preferably with alkyl radicals

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1 to 16 carbon atoms, such as methyl, ethyl, n-propyl, Isopropyl or n-butyl radicals, in particular methyl radicals, or Phenyl residues. In addition to the SiC-bonded hydrocarbon radicals and of course siloxane oxygen atoms - can be used in the framework Organopolysiloxanes used in the process according to the invention have an average of up to 1.25 Si-bonded hydrogen atoms and / or an average of up to 1.7 Si-bonded hydroxyl groups and / or an average of up to 1.7 Si-bonded alkoxy groups with 1 to 4 carbon atoms, especially methoxy or ethoxy groups, be present per silicon atom. Mixtures of different organopolysiloxanes can be used. It belongs to the Advantages of the process according to the invention that it is used as an organopolysiloxane also hydrolysates that boil above 70 ° C., in particular between 100 and 150 ° C., in each case at or around 760 mm Hg (abs.) Reaction products of methyl chloride with silicon can be used in the direct synthesis of methylchlorosilanes according to Rochow.

The viscosity of the organopolysiloxanes that are used to prepare the according to the invention The emulsions used should expediently be 1000 cSt, measured in 50 percent by weight toluene solution at 25 ° C, do not exceed.

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The organopolysiloxanes are preferably used in amounts of 10 up to 150 percent by weight, based on the weight of the quicklime, used.

The production of emulsions of organopolysiloxanes in water is generally known, and the production of the according to the invention emulsions used can be carried out according to these / known processes. E.- are also many emulsions of organopolysiloxanes, the average 0, ö to 1.8 SiC-bonded hydrocarbon radicals contained per silicon atom, in water, i.e. emulsions, which can be used in the process according to the invention, available in the stores.

Those for the production of emulsions of organopolysiloxanes Dispersants commonly used in water can also be used in the preparation of the organopolysiloxane emulsions used according to the invention can be used. Examples of such dispersants are protective colloids, such as polyvinyl alcohol, the optionally up to 40 mol percent acyl groups, e.g. acetyl groups or acyl groups derived from so-called Koch acids contains, gelatin and cellulose derivatives, e.g. water-soluble methylcellulose, anion-active emulsifiers, such as alkali metal or Ammonium salts of long-chain fatty acids, organic sulfonic acid

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acids or acid sulfuric acid esters, e.g. sodium laurate, Sodium oleate, sodium isopropylnaphthalene sulfonate, sodium * Dioctyl sulfosuccinate, triethanolammonium oleate and sodium lauryl sulfate; cationic emulsifiers, such as stearylammonium chloride, and non-ionic emulsifiers, such as sorbitol monolaurate, Polyoxyethylene ethers of mono- or polyhydric aliphatic alcohols or alkylphenols and block copolymers blocks of dimethylpolysiloxanes and polyethylene glycols connected by SiOC bonds. Mixtures of different Dispersants can be used. The dispersants are expediently used in amounts of 0.1 to 5 percent by weight, based on the weight of the organopolysiloxanes used.

In preparing the organopolysiloxane emulsions used according to the invention, the organopolysiloxanes can be used in solvent-free form or in the form of solutions in ^{organic solvents which are liquid under normal conditions (760 mm Hg abs./20 0} C) in the water. Preferably, in the preparation of the invention; used emulsions Golche solutions used. Examples of suitable solvents are aliphatic hydrocarbons, such as alkanes with boiling points in the range from 120 to 180 ^° C. at 760 mm Hg (abs.); aromatic hydrocarbons, such as

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Toluene, xylenes and trimethylbenzenes; Chlorinated hydrocarbons, • like trichlorethylene; Alcohols such as isopropyl alcohol and diacetone alcohol; Esters such as ethyl acetate; Ethers such as di-n-butyl ether; and ketones such as methyl ethyl ketone. Mixtures of different solvents can be used. The organic solvents are preferably used in amounts of 25 to 100 percent by weight, based on the weight of the organopolysiloxanes.

The proportion of water in the weight of the emulsions is not decisive. It is only to ensure that with the invention Extinguishing the lime in the presence of the organopolysiloxanes at least 1 mole of water per mole of CaO is present, because otherwise the quicklime will not be completely extinguished. The purely for economic reasons For reasons of expediency and therefore preferred upper limit of the amount of water is that which results in one from with the organopolysiloxane emulsion slaked lime existing mass that contains 10 percent by weight free water. If more water is used, so does not evaporate enough water through the heat of hydration and / or not enough water is bound as water of hydration>. It is then required, at least the 10 percent by weight of the mass obtained after extinguishing in excess of the amount of free water through Drying, which also includes the addition of known dehydrating agents, such as silica gel, to the slaked lime can be removed and, if necessary, after drying

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hold product to grind to the desired powder to obtain.

The water repellants according to the invention are preferably used in amounts of 0.1 to 2.0 percent by weight, in particular 0.5 to 1.0 percent by weight, based in each case on the dry weight of the inorganic binders containing or of sol- ^ chen binders existing masses, used.

The examples below show that the invention Surprisingly, the water-repellent agent produced, even without the use of the known, the effect of free lime are extremely effective on substances neutralizing organosilicon compounds. However, it cannot be ruled out entirely that through the use of substances neutralizing the effect of free lime on organosilicon compounds, such as vinyl resins including polymethyl methacrylate, Chlor- ™ rubber and magnesium carbonate, achieved even better results will.

As examples of compositions containing inorganic binders or consisting of such binders, which the invention manufactured water repellants can be added,

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may be mentioned: masses based on lime (CaO or Ca (OH) ,,), e.g. lime mortar and lime paints, Portland cement, high-grade plaster and water plaa paints, e.g. germ paints. These masses can be conventional additives and aggregates, such as sand, vermiculite (Brihglinnner), perlite (Blählava), gravel, wood flour, wood wool, Asbestos, retarders, gluconic acid, calcium gluconate, vinyl polymers and pigments, e.g. oxide paints.

Example 1 . ■

I) The between 100 and 150 ° C at 760 mm Hg (abs.) The reaction products of methyl chloride with silicon in the Direct synthesis of methylchlorosilanes according to Rochow poured in water. From the oily phase obtained in this way a solution containing 75 percent by weight organopolysiloxanes is prepared in toluene. From 400 g of this solution, 40 g a 10 weight percent aqueous solution of polyvinyl alcohol with remaining acetyl groups (saponification number, i.e. Milligrams of KOH, required for separation and neutralization of the remaining acetyl groups in 1 g of polyvinyl alcohol: 140; Viscosity measured in 4 percent by weight aqueous Solution at 20 ° C j 25eP) and 160 g of water becomes an emulsion

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manufactured. First 65 g are added to 420 g of the emulsion thus obtained and containing 50 percent by weight of organopolysiloxanes Water and then added 420 g of powdered quicklime with stirring. There are 640 g of a powder with a content of Obtained 25 percent by weight of organopolysiloxane and 2.6 percent by weight of free water.

Ha) A plaster consisting of a mixture of 2 parts by weight Weiükalk (see DIN regulation 1060, draft June 1952), 1 Part by weight of white portland cement, 8.5 parts by weight of sand with a maximum grain size of 1.5 mm and 0.5 part by weight of red iron oxide, is with 1 percent by weight, based on its weight, of the powdery water repellent, its preparation above was described under I), mixed. By adding 1 part by weight of water to 6 parts by weight of the thus obtained Mixture, in which no floating of the water repellent can be observed, becomes more plastic with a trowel workable mortar produced. From this mortar, with the help of a glass ring (inner diameter: 10 cm, height: 2 cm) Shaped discs (A).

b) For comparison, the procedure described above under Ha) is used repeated with the amendment that instead of

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1 percent by weight of the waterproofing agent, the preparation of which was described under I above, 0.25 percent by weight of powdered methylpolysiloxane, produced by hydrolysis of methyltriehlorosilane, be used. Disks (B) are obtained.

Because the water repellent, the preparation of which was described above under I), contains only 25 percent by weight of organopolysiloxane μ , the disks (B) contain as much organopolysiloxane as the disks (A).

c) For a further comparison, the procedure described under Ha) is used repeated with the modification that no water repellant is used. Slices (C) are obtained,

8 days of carrying out the Arbeitsweisena), b) and e) are the discs weighed and then placed 90 minutes so under water of 20 ⁰ O that the water surface 20 mm "on the disks' - is then the slices from the water. The water absorption in the case of the water storage described above, ie the weight increase in #, based on the weight of the dry panes, is given in Table I below:

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Table I.

Slices water absorption in wt.

(A) 0.17

(B) 14.2

(C) 17.2

Example 2

a) The reaction products of methyl chloride with silicon boiling between 100 and 150 ^° C. at 760 mm Hg (abs.) in the Rochow direct synthesis are poured into water. A solution containing 75 percent by weight of organopolysiloxanes in toluene is prepared from the oily phase obtained in this way.

m · represents. An emulsion containing 50 percent by weight of organopolysiloxanes is prepared from 2000 g of this solution, 200 g of a 10 percent by weight solution of polyvinyl alcohol of the type described in Example 1 and 800 g of water.

b) The procedure described above under a) is repeated with the modification that 1800 g of water are used instead of 800 g of water in the preparation of the emulsion. The emulsion (b) obtained in this way thus contains 37.5 percent by weight of organopolysiloxanes o

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c) The procedure described under a) is repeated with the modification that 3800 g of water are used instead of 800 g of water. The emulsion (c) thus obtained contains thus 25 percent by weight of organopolysiloxanes.

To 1600 g of each of the emulsions (a), (b) and (c), first 100 g of water and 1200 g of pulverulent quicklime are added given with stirring. Powders are obtained in each case.

Samples of plaster of the type described in Example 1 under Ha) are each with 1 percent by weight, based on her Weight of the water repellent prepared as described above mixed as described in Example 1 under.1Ia) mixed with water and formed into slices. After 5 days, the water absorption of the discs is as in Example 1 described determined. The results of this Determinations are given in Table II:

Table II

Water-repellent, manufactured to absorb water using emulsion in wt. 56

(a). . ■ 0.7

(b) 3.1

(c) 8.2

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Example 3

I) To a mixture heated to boiling under reflux
150 kg of methyltriethoxysilane and 100 ml of concentrated hydrochloric acid is a mixture of 15 within 3 hours
Liters of water and 15 liters of ethanol. After distilling off of up to 100 ⁰ C at 760 mm Hg (abs ·) BEFC boiling of the reaction mixture constituents will be a viscosity
from 15 to 25 cSt / 25 ° C having methylpolysiloxane with
Preserve ethoxy groups. A solution in toluene containing 75 percent by weight of organopolysiloxanes is prepared from 60 parts by weight of this methyl polysiloxane and 15 parts by weight of a dimethylpolysiloxane with a viscosity of 350 cSt / 25 ° C. With the modification that this solution is used instead of the solution described in Example 1, the procedure described in Example 1 under I) is repeated.

^w Ha) plaster of the type described in Example 1 under Ha) is mixed with 1 percent by weight, based on its weight, of the powdery water repellent, the preparation of which was described under I) above, mixed with water as described in Example 1 under Ha) and formed into disks (A)

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b) For comparison, the one described above under Ha) is used Procedure repeated with the modification that no water repellant is also used. Disks (B) are obtained.

14 days after working methods a) and b) have been carried out the water absorption of the discs as described in Example 1 certainly. The results of this determination are given in Table III.

Table III

Slices of water absorption in weight #

(A) 2.8

(B). 20.3

Example 4

a) An aggregate mixture containing as essential Component pigments and consisting of the following powdery components: 45 parts by weight dolomite, 15

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Parts by weight of titanium dioxide, 32 parts by weight of heavy spar, 4 parts by weight of red iron oxide and 4 parts by weight of yellow iron oxide, is initially with 0.2 percent by weight, based on its weight of the powdery water repellent, the production of which was described in Example 1 under I, and then with 125 percent by weight, based on its weight, a 25 percent by weight aqueous solution of potassium water ^ glass (molar ratio SiOo: KpO = 3.8) mixed. The thus obtained Water glass paint is painted on a concrete slab (paint a).

b) For "comparison, the procedure described above under a) is repeated with the modification _T that instead of the 0.2 percent by weight of the water repellent, the preparation of which was described in Example 1 under I), 1 percent by weight of a 25 percent by weight organopolysiloxane containing pulverför-. Migen product can be used by pouring the zwi-P see 100 to 150 ⁰ C at 760 mm Hg (abs.) boiling reaction products of methyl chloride with silicon in the direct synthesis according to Rochow in a slurry of GlimiBermehl and removal of the water and hydrogen chloride obtained from the mixture obtained in this way (paint b)

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c) For further comparison, the one described under a) is used Method of operation repeated, with the modification that no Water repellent is also used. (Painting c)

One day after performing work methods a), b) and c) 0.5 ml of water is dripped onto the surface of the paint and the time is determined in seconds, until the water disappeared or from the paintwork is absorbed «The following results are obtained:

Table IY

Painting seconds

a 2460

b 1080 c 184

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Claims (3)

Claims P 1. Process for the production of water repellants by order. etting of organosilicon compounds with a basic Caleiunverbindungen, thereby characterized in that one quick lime with an emulsion of organopolysiloxanes that on average 0.8 to 1.8 SiC-bonded hydrocarbon residues each silicon atom contained, extinguishes in water and the products thus obtained, if they are still are not powdery, dries and, if necessary, grinds. 2. The method according to claim 1, characterized in that the organopolysiloxanes in quantities from 10 to 150 percent by weight, based on the weight of the quicklime, can be used. - 21 -009883 / 2Q25 3. The method according to claim 1, d a d u r c h characterized, da3 the SiC-bonded hydrocarbon residues Are methyl radicals. 0098 83/20 25