Field of the invention:
The present invention is related to a water based copolymer for imparting the water repellency at high alkali medium, more particularly a water soluble copolymer comprising silane, silanol and siloxane and process thereof hereinafter called "Protekta G".
Background of the Invention:
It is very important to safeguard the reinforcement and durability of the concrete of any structure. The attempts are made to ensure that hydrophilic building is made hydrophobic and no water can enter.
One of the methods to safeguard the building is impregnation of the concrete with water repellents. It is necessary to protect the building from pollutants and the environment. The ingress of water is accompanied with pollutants of environment like carbon dioxide, chloride and they damage the building by corrosion of reinforcement.
The only water based polymer or repellent is aqueous solution of alkyl metal organo siliconate like potassium methyl siliconates are used to waterproof the building.
However methylsiliconates are known to be not alkali stable due to the forming of calcium methylsiliconate precipitate by reaction with the free lime in the substrate to the hydrolysis of the methylsiloxane formed after impregnation.


Therefore it is not very successful impregnant.
Prior Art:
1 US patent no, 5626668 dated on May 6, 1997 teaches water-repellent plaster composition comprising an oxide or hydroxide of alkali or alkaline earth metals or mixtures of an oxide or hydroxide of alkali or alkaline earth metals and an organopolysiloxane which has hydroxyl and/or alkoxy groups bonded to silicon atoms, and a process for the water-repellent treatment of plaster. Water-repellent plaster compositions comprising the constituents (A) 100 parts by weight of gypsum plaster, (B) from 0.05 to 50 parts by weight of oxide or hydroxide of alkali or alkaline earth metals or a mixture thereof, and (C) from 0.05 to 20 parts by weight of an organopolysiloxane which has hydroxyl and/or alkoxy groups bonded to silicon atoms.
US patent no. 5624481 dated on April 29, 1997 teaches a process for the water-repellent impregnation of plaster. Plaster is rendered water-repellent by impregnation with organosiloxanes containing Si-bonded hydrogen atoms and with alkali metal silicate. In particular, the water-repellent action is improved in the case of shaped plaster articles treated at high drying temperatures.

us patent no. 5250106, teaches a process for rendering masonry water-repellent which comprises treating masonry which is alkaline, with a highly dispersed water-diluted impregnating composition which comprises (A) an organoalkoxysilane and/or (B) an organosiloxane containing alkoxy groups and (C) a water-soluble organic or inorganic acid salt of an organopolysiloxane, which in addition to other organosiloxane units contains siloxane units which carry monovalent SiC-bonded radicals containing basic nitrogen in amounts of at least 0.5% by weight, based on the weight of the organopolysiloxane. The treated masonry is particularly resistant to rising dampness.
U.S. Pat. No. 4,661,551 (H. Mayer et al.; published on Apr. 28, 1987 to Wacker-Chemie GmbH, Munich) describes the use of a highly dispersed water-diluted composition comprising isooctyltrimethoxysilane, a salt of a water-soluble acid and a nitrogen-containing organopolysiloxane, n-hexanol and glacial acetic acid for forming a barrier against rising dampness in a brick wall. This composition spreads rapidly in the damp masonry and reacts with the masonry to form a barrier which prevents further rising of the water. However, if the masonry is old, this composition does not perform well.
Object of the invention:
The main object of the invention is to develop a water based polymer and imparts the repellency to the surface where the medium is highly alkaline between 8 to 10.
An another object of this invention is that this product does not only provide water repellency but it impregnates at least 3-4 mm deep into the concrete so that it can protect

the concrete even if there is crack of 3-4mm because water will not intrude on account of this hydrophobic zone. Summary of the invention
The present invention relates to a water soluble silane, silanol, siloxane copolymer and process thereof, hereinafter called "Protekta G" , wherein the process comprising the following steps:(a) Melting the surfactant by heating to a temperature till the material melts to a liquid form; (b) Pouring the liquid surfactant into a alkaline methyl siliconate to obtain a homogeneous solution (c) Stirring the mixture, adding silane slowly to the said solution (d) Continue stirring slowly till the mixture becomes clear solution; (e) Diluting the concentrate with distilled water at least 9 to 10 times weight/ volume the concentrate.
According to another embodiment of the invention a water soluble silane, silanol, silaxone copolymer comprising surfactant dissolved in siliconate having silanes added to it and diluted with distilled water.
According to another embodiment of the invention surfactant is ethoxylate or emulsion with anionic or cationic or both.
According to another embodiment of the invention surfactant is dissolved with siliconate at reacting ratio of 1:2 to 1:20.
According to another embodiment of the invention the concentrate is diluted with distilled water at least 9 to 10 times weight/ volume the concentrate.
According to the present invention alkali metal propyl siliconates is better water repellent than alkali metal organo siliconates at high alkaline medium. The stability of the aqueous solution of this polymer would be dependent on the substituent attached to the siliconate and the quality and suitability of the surfactant system. This product is stable either in

very concentrated state or very dilute state. The surfactant system stabilizes the diluted product for example: number of surfactant systems are used but ethoxylates with 2E0 are found to be most suitable.
Detailed description of the invention:
According to the present invention a process foe preparing a water soluble silane, silanol, siloxane copolymer hereinafter called "Protekta G" comprising the following steps:(a) Melting the surfactant by heating to a temperature till the material melts to a liqui form; (b) Pouring the liquid surfactant into a alkaline methyl siliconate to obtain a homogeneous solution (c) Stirring the mixture, adding silane slowly to the said solution (d) Continue stirring slowly till the mixture becomes clear solution; (e) Diluting the concentrate with distilled water at least 9 to 10 times weight/ volume the concentrate.
The objective of this invention is to produce water based repellent, which can penetrate and impregnate into the concrete.
Selection of the surfactant is also very important stabilizing of the product. According to the present invention the stability of surfactant depends upon emulsion, which varies according to the medium of emulsion. This was achieved by taking a surfactant preferably ethoxylate or one of the surfactant as given in table 1
Emulsions or Impregnants
Emulsion with anionic
Emulsion with cationic
Emulsion with mixed cationic
& nonionic
Emulsion with acidified amine
ethoxylate
Table: 1
This surfactant is dissolved in small amount of siliconates and stirred till it is completely dispersed in the solution formed, additional amount of siliconate is added and the solution is stirred vigorously till it becomes a clear solution. At this point silanes namely alkyl triethoxy, propyl, n-octyl, isooctyl, isobutyl (any one of them) was added drop wise

into the solution with vigorously stirring. When the reaction gets initiated one can smell the evolution of ethanol. This solution is then stirred periodically for 24 hours and the concentrate so obtained can be diluted 13 times with water and when sprayed on concrete or any masonry structure shows excellent beading after 8 hrs.
When the concentration of surfactant in water is over the "critical micelle concentration" (CMC), surfactant molecules form micelles in aqueous solution with their hydrophobic hydrocarbon inside the micellar core and with the hydrophilic moieties towards the micellar surfaces. One of the important properties of surfactant micelles in solution in solubilisation. Solubilisation is the dissolution of a water insoluble substance in an aqueous surfactant solution at or above its CMC to form a clear homogeneous solution.
The increasing solubility of water insoluble materials in aqueous solutions of surfactants is due to the organic compound 'dissolving' in the surfactant micelle where the environment will closely approximate that of an organic phase. As nonionic surfactants can form micelles with large aggregation numbers at concentrations appreciably lower than that of the anionics or the cationics, nonionic surfactants are very useful and effective for solubilising organic materials in aqueous solution.
Initial solution contains siliconate, silanol, silane and oligomers. The comparison of polymers in this solution and with the structure of an alkylalcohol ethoxylate nonionic surfactant shows there are similarities in both Protekta G and the surfactant structures. The propyl group in the siliconate molecule may be considered as the "hydrophobic tail" while the siliconate [ - Si(OH)n,OK] or the silanor [ -Si(OH)n] groups may be regarded as the "hydrophilic head". In this respect, propylisiliconate possesses a structure equivalent to simple surfactant molecules (shown below)
Hydrophobic Hydrophilic
tail head

OH OH OH
Propylsilanetriol CH3CH2CH2 —Si;^OH

OH OK OH
Propylsiliconate CH3CH2CH2 Si^OK
Silanol (or siliconate) CH3CH2CH2 Si ~ OH
oligomer I
O I CHjCHjCHj Si — OH
Alkylalcohol ethoxylate
Nonionic surfactant CH3(CH2)mCH2 (OeH5CH2)nOH

Having similar structures as that of a surfactant, Protekta G may aggregate to form "micelles" in diluted aqueous solution with the propyl tail inside the micellar core while the hydrophilic heads of [-Si(OH)mOK] or [-Si(OH)n] are at the micellar surface towards the water just like a surfactant micellar solution (see figure below). However, Protekta G "micelle" may be very short-lived since the siliconate may rapidly condense to siloxane oligomers or insoluble polysiloxanes resulting in precipitation fi"om the solution. Experiments have shown that following dilution of Protekta G, the Protekta G solution is only clear for a short time, and then turns colloidal resulting in an observation initially of blue light scattering but precipitation from the solution in a short time.

micellar \ .OH
core CH3CH2CH2-i— Si ^OH

^ OH
The stabilization of Protekta G solution may also be attributed to the interaction between the surfactant and the siliconates. Apart from the hydrogen bonding between -Si(OH)mOK or -Si(OH)n groups of the siliconate and the ethoxylate chains of the surfactant, it is assumed that the re-esterification of silanol by the hydroxyl of the surfactant ethoxylate chain to form a permanent bond between the surfactant and the

siHconate may occur (Scheme 1). The alcoholysis of the siliconate oligomers (or siloxanes) by the hydroxyl of the surfactant may also occur (Scheme 2). It is possible to esterify colloidal silica with various alcohols such as glycol with one end bonding to the sol and the another end at the outer surface of the particle to obtain a modified silica sol which is soluble both in water and alcohols.
According to literature alcoholysis is catalysed under basic conditions and the re-esterification and alcoholysis reactions may be via a SN2-Si mechanism. As dilution of Protekta G concentrate may result in the formation of silanols and siliconate oligomers (or siloxanes), both re-esterification and alcoholysis may occur. The re-esterification may replace the reactive silanol group of the siliconate with inert surfactant ethoxylate resulting in reduction of the further condensation of the siliconate and an increase in the hydrophilicity of the siliconate oligomer in solution. It appears that the re-esterification or the alcoholysis may gradually play a part in stabilization of diluted Protekta G solution particularly in the later state of the stabilization while evidences show that the major stabilization effect may be due to the surfactant solubilisation.
R R
I I
— Si — OH + HO(CH2CH20) nR'^ - — Si- 0(CH2CH20) nR'
Scheme 1
R R , R R
-Si —0 —Si — + HO(CH2CH20) ^R^^ "* -eiCHzClliO) nR' +H0 "S
Scheme 2
Such re-esterification and alcoholysis reactions between the diluted siliconate and alkylalcohol ethoxylate nonionic surfactants have not been reported in the literature. The examination of these reactions in the complex siliconate system is beyond the scope of this project. However, certain adverse effects induced by the surfactant on the water

repellency of the substrate treated with the Protekta G impregnant may give indirect evidence to support the involvement of the surfactant in reaction with the siliconate water repellent.
The solubilisation effect of diluted Protekta G solution by polyoxyethylene nonionic surfactant varies according to the surfactant structure. Various fatty alkylalcohol ethoxylate and nonylphenol ethoxylate nonionic surfactants with different hydrophilic and lipophilic chain length have been tested for solubilisation effects for the diluted Protekta G solution. A standard test was carried out at 2G°C by titrating concentrated PPMS into distilled water which contained 0.1% of a surfactant, where the solution just started to change from clear to colloidal, resulting in the observation of blue light scattering, due to the condensation of Protekta G in the solution. The quantity of Protekta G added before this effect appeared was considered as the solubilisation ability of that surfactant. The solubilisation ability of the surfactant as a function of the surfactant hydrophilic chain length.
Example 1:
To make 1000 kg of concentrate it is first necessary to dissolve the ethoxylate with different HLB values in the siliconate. Take .26-15 % of ethoxylate and melt it at about 90°C and it is best to heat the ethoxylate to a little about the melting point to avoid it solidifying on addition to the methyl siliconate. Then pour the hot liquid Ethoxylate into 30- 55 % of any alkaline methyl siliconate like sodium / potassium or any other siliconate can be used and stir until dissolved. If it does not dissolve at this stage, then add more siliconate to the mixture and ensure it is dissolved. Then add this solution to the remaining 700-800 kg of siliconate and stir until homogeneous.
Now one has 68 to 95% of siliconate with ethoxylate dissolved in it. Now the silanes like alkyl triethoxy, propyl, n-octyl, isooctyl, isobutyl, octyltriethoxy (any one of them) must be added to this mixture. Vigorously stir the siliconate solution and slowly add the silane to it. Continue stirring until the mixture becomes clear. The time taken for the mixture
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to become clear varies depending on the ambient temperature. At a temperature of 20°C it may take up to 24 hrs to become clear. If possible during this 24 hrs, stir the mixture gently. This is the concentrate which is slightly coloured solution containing no solid. It may initially become clear but on stirring it will become cloudy again and finally after 24hrs becomes clear. If at any stage the reactor vessel gets heated it can be avoided by passing cold water through jacket of the reactor.
The concentrate so formed is termed as Protekta G heart and is diluted with 10 times distilled water (free from Chloride or SO4 ions) and applied on the surface wet to wet two times. After 8 hrs the surface shows excellent beading, however in some cases if too much product is sprayed some white patch may appear.
Example 2:
To make 100 kg of concentrate it is first necessary to dissolve the ethoxylate with different HLB values in the siliconate. Take .20 - 15 % of ethoxylate and melt it at about 90*'C and it is best to heat the ethoxylate to a little about the melting point to avoid it solidifying on addition to the methyl siliconate. Then pour the hot liquid Ethoxylate into 25- 50 % of any alkaline methyl siliconate like sodium / potassium or any other siliconate can be used and stir until dissolved. If it does not dissolve at this stage, then add more siliconate to the mixture and ensure it is dissolved. Then add this solution to the remaining 70-80 kg of siliconate and stir until homogeneous.
Now one has 65 to 90% of siliconate with ethoxylate dissolved in it. Now the silanes like alkyl triethoxy, propyl, n-octyl, isooctyl, isobutyl, octyltriethoxy (any one of them) must be added to this mixture. Vigorously stir the siliconate solution and slowly add the silane to it. Continue stirring until the mixture becomes clear. The time taken for the mixture to become clear varies depending on the ambient temperature. At a temperature of 20°C it may take up to 24 hrs to become clear. If possible during this 24 hrs, stir the mixture gently. This is the concentrate which is slightly coloured solution containing no solid. It may initially become clear but on stirring it will become cloudy again and finally after
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24hrs becomes clear. If at any stage the reactor vessel gets heated it can be avoided by passing cold water through jacket of the reactor.
The concentrate so formed is termed as Protekta G heart and is diluted with 10 times distilled water (free from Chloride or SO4 ions) and applied on the surface wet to wet two times. After 8 hrs the surface shows excellent beading, however in some cases if too much product is sprayed some white patch may appear.

We claim:
1. A process foe preparing a water soluble silane, silanol, siloxane copolymer hereinafter
called "Protekta G" comprising the following steps
(a) Melting the surfactant by heating to a temperature till the material melts to a liquid form;
(b) Pouring the liquid surfactant into a alkaline methyl siliconate to obtain a homogeneous solution;

(c) Stirring the mixture, adding silane slowly to the said solution;
(d) Continue stirring slowly till the mixture becomes clear solution;
(e) Diluting the concentrate with distilled water.

2. A process for preparing a water soluble silane, silanol, silaxone copolymer as claimed in claim 1, wherein the said surfactant is ethoxylate or emulsion with anionic or cationic or nonionic or combination of anionic, cationic and nonionic.
3. A process for preparing a water soluble silane, silanol, silaxone copolymer as claimed in claim 1, wherein the surfactant is dissolved with siliconate at reacting ratio of 1:2 to 1:20.
4. A process for preparing a water soluble silane, silanol, silaxone copolymer as claimed in claim 1, wherein the said alkaline methyl siliconate is selected from the group of sodium, potassium or any other siliconate.
5. A process for preparing a water soluble silane, silanol, silaxone copolymer as claimed in claim 1, wherein the said sialne is selected from the group consisting of alkyl triethoxy, propyl, n-octyl, isooctyl, isobutyl, octyltriethoxy.
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6. A process for preparing a water soluble silane, silanol, silaxone copolymer as claimed in claim 1, wherein the solution is allowed to cool down at ambient temperature stirring gently till the solution becomes clear. The period may vary for a period at least 24 hours.
7 A process for preparing a water soluble silane, silanol, silaxone copolymer as claimed in claim 1, wherein the said concentrate is diluted with distilled water at least 9 to 10 times weight/ volume the concentrate.
8. A water soluble silane, silanol, silaxone copolymer as claimed in claim 1 comprising
surfactant dissolved in siliconate having silanes added to it and diluted with distilled
water.
9. A water soluble silane, silanol, silaxone copolymer as claimed in claim 8, wherein the
said surfactant is ethoxylate or emulsion with anionic or cationic or both.
10. A water soluble silane, silanol, silaxone copolymer as claimed in claim 8, wherein the
said silane is selected from the group consisting of alkyl triethoxy, propyl, n-octyl, iso
octyl, isobutyl, octyltriethoxy.
11. A process for preparing a water soluble silane, silanol, silaxone copolymer
substantially as hereinbefore described with reference to the accompanying examples.
12. A water soluble silane, silanol, silaxone copolymer substantially as hereinbefore
described with reference to the accompanying examples.