DE1769508B2 - PROCESS FOR THE PRODUCTION OF HYDROPHOBIC AGENTS - Google Patents

Description

With the water repellants !! for moldings and covers made of inorganic binders Or masses consisting of such binders is between water repellants that are applied to the surface the moldings or coatings are applied, and water repellants. the the inorganic Compounds containing binders or consisting of such binders at the latest before shaping be added to distinguish. The present invention relates to a method of manufacture of water repellants of the latter type.

The mixing of the inorganic binders containing or consisting of such binders Compounds with the waterproofing agents at the latest before the shaping process has compared to the application of Hydrophobing agents on the finished molded body or nbcrzügec the advantage that it allows the production of Moldings and coatings made possible that not only on their surface, but also in all places 4: s their interior are water-repellent, which z. B. very favorable when cracks appear later and that it requires considerably less work.

/ ti the previously known water repellants. the compositions containing inorganic binders or consisting of such binders are added at the latest before animal shaping, include aqueous emulsions of organopolysiloxanes. water-containing pastes, consisting of reaction products of organohalosilanes with aqueous hydrated lime, powders produced by hydrolysis of organotrichlorosilanes, and metal salts of higher fatty acids. The aqueous emulsions of organopolysiloxanes and the pastes of the above-bcschrie- fio bcncn type have the disadvantage that they are the inorganic binder-containing or consisting of such binders masses of these compounds can be added only in the final application and that their higher water content effort ^ft 5 for Requires storage and tran ^r _f iort. The above-mentioned addition of the water repellants to the masses containing or consisting of such binders in the final application of these masses creates the possibility of many errors, in particular a more even mixing of the masses with the water repellants is not guaranteed. Because of their coagulated wettability, it is also difficult to g. Powders which are produced by hydrolysis of organotrichlorosilanes must be uniformly distributed simultaneously with or after the addition of water in the masses containing inorganic binders or consisting of such binders, and water removal is often also necessary. that is achieved by this powder is tiering. With the metal salts of higher fatty acids it can often be observed that they float on the surface of these masses before or after the molding of the inorganic binder and water-containing masses and are no longer evenly distributed in these masses. In addition, these soaps are biodegraded in a relatively short time by the effects of the weather and / or and are therefore ineffective.

The process according to the invention gives permanent powder-form water repellants which are free from all of the disadvantages described above. ie. For example, the inorganic binder containing or consisting of such binders masses or the additives for such masses, z. B. pigments, can be added long before the final use of these compositions, or, if desired, can be easily distributed shortly before, at the same time with or after the addition of water without any segregation in the compositions containing the inorganic binder, and the production of Allow moldings and coatings which have a stronger water repellency than moldings and coatings made from compositions containing inorganic binders, which prior to shaping with previously known water repellants. z. B. fine-grain Mcthylpolysiloxan were mixed. The water repellents according to the invention have the advantage over? .. as fine-grained Mcthylpolysiloxan also the advantage that they are more accessible.

The invention relates to a process for the preparation of HydrophobicrmitH.n by reaction of organopolysiloxanes with a basic calcium compound. characterized in that quicklime with an emulsion of organopolysiloxanes. the average 0.8 to I.XSiC-boundc Contains hydrocarbon residues per silicon atom, extinguishes in water and the products thus obtained, if they are not yet powdery, dry and, if necessary, grind.

It can be assumed that the inventively prepared Contain water repellant free lime. while in the implementation of hydrated lime with Organohalogensilancn the free lime is neutralized. B. due to the German Patent specification 1065 551 previously assumed that free lime had the water-repellent effect is impaired by organosilicon compounds the effectiveness of the waterproofing agents produced according to the invention is extremely surprising.

Also according to W. Noil, “Chemistry and Technology the silicones «. 2nd Edition. Weinheim. 1968. p. 525, is the implementation of calcium hydroxide with polysiloxanes in the field of silicone application described as undesirable in building protection.

IVr quicklime (CaO), sometimes also called »gehrannier Lime »or» calcium oxide «can be: ■ 1 ,, used by lump lime or fine lime will. LIm mixing the organopolysiloxane solution with the quicklime and w,; il with it a particularly finely divided hydrophobic fluid is obtained, the use of fine lime al · ,,,> .on pulverulent quicklime, is preferred.

The SiC-bonded hydrocarbon radicals in the <) i ..:; inopolysiloxanes in the emulsions according to the designation can be alkyl, alkenyl, cycloalk; I-. Cycloalkenyl-. Aryl. Aral'kyl- or alkaryl-, v- :, be. Preferably, sL-alkyl radicals with 1 to 1c are nucleus atoms. like metini. Ethyl-. ii-Propyk i- “.ρι · ορ \ | - or n-bulyl residues. especially methyl-κ ·.;. ·, or phenylresia. Except for the SiC-bound hydrocarbon residues! and of course silo. ”un-SLiuerstntfatomer. - In the organopolysiloxanes used in the process according to the invention, an average of up to 1.25 Si-bonded (kno 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, in particular KUihoxy- or ethoxy groups. Can be provided per silicon atom. Mixtures of different (.iLMiiopolysiloxanes can be used 100 and 150 C each at or about hot 76Π mm Hg labs.) Boiling reaction products of methylene jride with silicon in the direct synthesis of methylchlorosilane according to U ο ch ο w can be used.

The viscosity of the organopolysiloxanes. the emulsions used to prepare the emulsions used according to the specification should expediently be 100 cSt. measured in 50% by weight toluene solution at 2> C.

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

The preparation of emulsions of organopolysiloxanes in water is well known, and the Production of the emulsicins used according to the invention can have been carried out according to these known methods. There are also many emulsions of organopolysiloxanes. which contain an average of 0.8 to 1.8 SiC-bonded hydrocarbon radicals per silicon atom, in water, i.e. emulsions that are used in the invention Methods that can be used are commercially available.

Those commonly used for the preparation of emulsions of organopolysiloxanes in water Dispersants can also be used in the preparation of the organopolysiloxane emulsions used in accordance with the invention have been used. Examples of such dispersants are protective colloids, such as polyvinyl alcohol, which may contain up to 40 mol percent acyl groups, e.g. B. acetyl or so-mentioned Acv! Groups derived from cooking acids. Gelatin or cellulose derivatives, e.g. B. water soluble methyl cellulose. anion-active emulsifiers, such as alkali metal or ammonium salts of long-term fatty acids, organic sulfonic acids or acid sulfuric acid esters, z. B. Sodium Laurate. Sodium oleate, sodium isopropylnaphthalene sulfonate, Sodium dioclyl sulfosuccinate. Triethanolammonium olate or sodium lauryl sulfate. cationic emulsifiers such as stearylammonium chloride or non-ionogenic emulsifiers, like sorbitol monolaurate. Polyoxyethylene ethers of mono- or polyhydric aliphatic alcohols or Alkylphenols !! or block copolymers made from blocks of dimethylpolysiloxane linked by SiOC bonds and polyethylene glycols. Mixtures of different dispersants can be used will. The dispersants are expediently used in amounts of 0.1 to 5 percent by weight, based on the weight of the organopolysiloxanes. used.

When preparing the organopolysiloxane emulsions used according to the invention, the organo-

is polysiloxane in solvent-free form or in Form of solutions in case of normal conditions (760mm Hg abs.20'C) liquid organic solvents can be used in water. Preferably, in the preparation of the invention

ίο used emulsions used such solutions. Examples of suitable solvents are aliphatic hydrocarbons, such as alkanes with boiling points Range from 120 to 180 C at 760 mm Hg (abs.), Aromatic hydrocarbons, such as toluene, xylenes or Trimcthy'.benzole. Chlorinated hydrocarbons, such as Trichlorethylene, alcohols such as isopropyl alcohol or Diacetone alcohol. Esters, such as ethyl acetate. Ether how Di-n-butyl ether, or ketones, such as methyl ethyl ketone. Mixtures of different solvents can be used be used. The organic solvents are preferably used in amounts of 25 to 100 percent by weight, based on the weight of the organopolysiioxanes. used.

The proportion of water in the weight of the emulsions is not decisive. All you have to do is take care of it. that in the case of the deletion of the lime according to the invention 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 only is expedient and therefore preferred upper limit of the amount of water for economic reasons that which leads to a mass consisting of lime slaked with the organopolysiloxane emulsion, which contains 10 percent by weight of free water. If more water is used, not enough evaporates Water through the 1 Ivdratalionswürme. and / or not enough water is bound as water of hydration. It is then required to use at least the 10 weight percent of that obtained after deletion

so mass excess amount of free water by drying, including the addition of known water-resistant agents such as silica gel. may belong to the slaked lime, to remove and give up the after drying crhai-

ss tenc product to grind to the desired powder to obtain.

The water repellants produced according to the present invention are preferably in amounts of 0.1 to 2.0 percent by weight, in particular 0.5 to 1.0 percent by weight, in each case based on the dry weight of the inorganic binder containing or compositions consisting of such binders.

The examples below show that the

^ft s hydrophobicizers erfindimgsgcmäß made surprisingly of free lime on organo silicon compounds without Mitverwcndung the known, the effect of neutralizing substances hervor-

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are sufficiently effective. l ^; However, it cannot be completely ruled out that, through the avoidance of the action of free lime on organosilicon compounds, substances neutralizing, such as vinyl resins, including polymethyl methacrylate. Chlorinated rubber or magnesium carbonate. even better results will be achieved.

As examples of inorganic: containing binders or from such binders existing masses, which are prepared according to the invention Water repellants can be added, are mentioned: masses based on lime (CaO resp. Ca (OH),), e.g. lime mortar and lime paints, Portland cement, fine plaster or water glass paints, e.g. B. Germ colors. These masses can be conventional additives and aggregates such as sand. Vermiculite (Expanded mica), perlite (expanded lava), gravel, wood flour, wood wool, asbestos, setting retarders, oluconic acid. Calcium gluconate, vinyl polymers and pigments. z. B. oxide paints included.

Because the water repellent, the production of which was described above under 1), only 25 percent by weight Contains organopolysiloxane, the disks (B) contain as much organopolysiloxane as the disks (A).

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

5 days after the procedure a), b) and c) have been carried out, the disks are weighed and then placed for 90 minutes at 20 ° C. so that the surface of the water is 20 mm above the disks. The slices are then taken out of the water and weighed again after they have drained. The water absorption during the above-described storage in water, ie the weight increase in %, based on the weight of the dry panes, is given in Table I below:

Table I. example 1

I) The temperature between Ί00 and 150 C at 760 mm Hg (abs.) boiling reaction products of methyl chloride with silicon in the direct synthesis of methylchlorosilanes after Rochow are poured into water. The oily phase obtained in this way becomes a 75 percent by weight organopo'ysiloxane containing Solution made in toluene. From 400 g of this solution, 40 g of a 10 percent strength by weight aqueous solution of polyvinyl alcohol with residual acetyl groups (saponification number, i.e. milligrams of KOH. required for splitting off and neutralizing the remaining acetyl groups in 1 g of polyvinyl alcohol: 140: viscosity, measured in 4 weight percent aqueous solution at 20 C: 25 cP) and 160 g of water becomes an emulsion manufactured. To 420 g of the emulsion thus obtained containing 50 percent by weight orgariopolysiloxanes 65 g of water and then 420 g of powdered quicklime are added with stirring. It will S40 g of a powder with a content of 25 percent by weight Organopolysiloxane and 2.6 percent by weight of free water.

Ha) A plaster consisting of a mixture of 2 Gcwichistcilcn white lime (see DIN regulation 1060. June draft. 1952), I part by weight of white portland cement. 8.5 Parts by weight of sand not exceeding 1.5 mm Grain size and 0.5 weight percent iron oxide red, is 1 percent by weight, based on its weight. the powdery! Water repellants. the preparation of which was described above under I), mixed. By adding 1 part by weight of water to 6 parts by weight of the mixture thus obtained, wherein no floating of the water repellent to be observed a plastic mortar that can be worked with a trowel is produced. From this mortar disks (A) are formed with the aid of a glass ring (inner diameter: 10 cm. height: 2 cm). Go

b) For comparison, the procedure described under Ma) above is repeated with the change, that instead of νο, ι 1 weight percent of the Water repellants, the production of which under I has been described, 0.25 percent by weight powder feed f> 5 migcs methylpolysiioxane. produced by hydrolysis of methyltrichlorosilane can be used. It would wcrrlrn isrhnihen (B).

.Disks

(A)
(B)
(C)

W; i>ser; iiifn, ihme
in Ciewichlspro / eni

0.17
14.2
17.2

Example 2

a) The temperature between 100 and I 50 C at 760 mm Hg (abs.) boiling reaction products of methyl chloride with silicon in the direct synthesis according to R ο c η ο w poured in water. The oily phase obtained in this way becomes a 75 percent by weight organopolysiloxane containing solution prepared in toluene. From 2000 g of this solution. 200 g of a 10 percent by weight Solution of polyvinyl alcohol of the type described in Example I and SOO g Wa: .ser is a 50 weight percent organopolysiloxane-containing emulsion prepared.

b) The procedure described above under a) is repeated with the modification that an Instead of 100 g of water, 100 g of water can be used in the preparation of the emulsion. The thus obtained Emulsion Ib) thus contains 37.5 percent by weight of organ'-ipc'yi.iloxanc.

<:) The procedure described under a) is repeated with the modification that instead of SOO g of water, 3S00 g of water are used. The emulsion (c) thus obtained thus contains 25 percent by weight of organopolysiloxanes.

For 1600 g each of the emulsions (a). (hl and (c) are first 100 g of water and then 1200 g of powder Quicklime given while stirring. Powders are obtained in each case.

Samples of plaster as described in Example 1 under Ila) Species willow with 1 percent by weight, based on their weight, of that described above prepared water repellent mixed, as described in Example I under Ma) with Water added and formed into discs. After 5 days, the water absorption of the discs is as in Example 1 described determined. The results of this determination are given in Table II:

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7th B e i s ρ iel Winse
in (1, ¹ W up 0.7 Tables 3.1 lydroplidhiermillel.
• puts under Vcrwenclui ^
viin integration 8.2 (a) 3 (b) (C)

spnvcni

I) A mixture of 15 l of water and 15 l of ethanol is added over the course of 3 hours to a mixture of 150 kg of methyltriethoxysilane and 100 ml of concentrated hydrochloric acid, which is heated to boiling under reflux. After the constituents of the reaction mixture boiling up to 100 ° C. at 760 mm Hg (abs.) Have been distilled off, a methylpolysiloxane with a viscosity of 15 to 25 cSt / 25T with ethoxy groups is obtained A solution in toluene containing 75 percent by weight of organopolysiloxanes is prepared 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 1) is repeated.

II a) plaster of the type described in example 1 under II a) is 1 percent by weight, based on its weight, the powdery water repellent, the production of which was described above under I), mixed as described in Example 1 under Ha), mixed with water and shaped into disks (A).

b) For comparison, the procedure described under II a) above is repeated with the change, that no water repellant is used. Panes (B) will be heard.

14 days after carrying out the procedure a) and b), the water absorption of the discs is as in Example 1 described determined. The results of this determination are given in Table III.

Tabel HI Water intake c
in weight percentage Discs 2.8
20.3 (A)
(B)

Example 4

a) A mix of aggregates. Containing pigments as an essential component and consisting of the following powdery components: 45 parts by weight of dolomite, 15 parts by weight of titanium dioxide, 32 parts by weight Heavy spar, 4 parts by weight of red iron oxide and 4 parts by weight of iron oxide yellow with 0.2 percent by weight, based on its weight of the

ίο pulverulent water repellent, the preparation of which was described in Example 1 under I, and then mixed with 125 percent by weight, based on its face, of a 25 percent by weight aqueous solution of potassium waterglass (molar ratio SiO ₂ : K ₂ O = 3.8). The water glass paint obtained in this way is painted on a concrete slab (paint a).

b) For comparison, the procedure described under a) above is repeated with the change, that instead of the 0.2 percent by weight of the water repellent, its preparation in Example 1 under I) was described, 1 percent by weight of a 25 percent by weight organopolysiloxanes containing powdered product is used, which is obtained by pouring the temperature between 100 to 150 "C at 760 mm Hg (abs.) boiling reaction products of methyl chloride with silicon in the direct synthesis according to Rochow

. into a slurry of mica flour and removal of the water and hydrogen chloride the mixture obtained in this way can be used (paint b).

c) For a further comparison, the procedure described under a) is repeated with the change, that no water repellant is used (paint c).

One day after carrying out the work methods a), b) and c) are applied to the surface of each paint 0.5 ml of water is added dropwise and the time is determined in seconds until the water has disappeared or is soaked up by the paintwork. The following results are obtained:

Table IV

painting

Seconds

2460

1080
184

109 582 402

Claims (3)

Patent claims: 1. Process for the production of water repellants by reacting organopolysiloxanes with!: ier basic calcium compound, thereby marked that one quick lime with an emulsion of organopolysiloxanes. the average 0.1 to 1.8 SiC-bonded Contains hydrocarbon residues per silicon atom, extinguishes in water and the products thus obtained, if they are not yet powdery, dry and, if necessary, grind. 2. The method according to claim 1, characterized in that that the organopolysiloxanes in amounts of 10 to 150 percent by weight, based on the Weight of quicklime. 3. The method according to claim i. characterized, that the SiC-bonded hydrocarbon radicals of the polysiloxane used are methyl radicals are.