CA2234946A1

CA2234946A1 - Hybrid inorganic-organic environmental resistant protective compositions

Info

Publication number: CA2234946A1
Application number: CA002234946A
Authority: CA
Inventors: Bo H. Gimvang; Hugh H. Wang
Original assignee: Individual
Current assignee: FMC Corp
Priority date: 1996-08-16
Filing date: 1996-08-16
Publication date: 1998-02-26
Also published as: WO1998007793A1

Abstract

Compositions useful for application to the surface of construction materials to improve resistance to and environment caused degradation that contain about 60 to 95 weight percent water and 5 to 40 weight percent of a mixture of an alkali metal siliconate, an organofunctional silane and a water-soluble alkali polysilicate in amounts and proportions that are within the blackened area of the above phase diagram.

Description

CA 02234946 1998-04-1~

WO ~ 3 PCTIUS96/13278 HYBRID INORGANIC-ORGANIC ENVIRONMENTAL RESISTANT
PROTECTIVE COMPOSITIONS

This invention concerns compositions that are applied to the surface of construction materials to improve resistance to weather and/or environment caused degradation.
Many different compositions and methods have been used in the field 10 to treat the surface of construction materials. The compositions have included organic-based chemicals such as silanes, siliconates, siloxanes, silicone resins, urethanes, methacrylates, styrene-butadiene copolymers, and inorganic-based chemicals such as sodium and potassium silic~tes.
For organic-based materials, they are either water-based or solvent based 15 or waterlsolvent-based.
A comprehensive evaluation was conducted on concrete sealers available commercially by the National Cooperative Highway Research Program (NCHRP). NCHRP Report 244 disclosed the test results along with the representative commercial products available in 1981. Among 21 20 products which the NCHRP program evaluated, four of the products could reduce water absorption by 75%. These four materials were two epoxy-based products, one methacr,vlate-based product, and one urethane-based product. All other materials based on linseed oil, silane, siloxane, siliconate,chlorinated rubber butadiene, etc., failed to reduce water absorption by 75%.
25 Some of the above organic-based products were highly hammful to the environment and unsafe to the user because they were solvent-based solutions.
Many prior art patents disclosed compositions and/or methods to treat the surface of construction materials and render the material water 30 repellent. U. S. Patent No. 3,772,065 disclosed a composition based on alkyltrialkoxysilane solution with alcohol as solvent. The composition was CA 02234946 1998-04-1~

WO ~ 7,73 PCT/US96/13278 U. S. Patent No. 3,772,065 disclosed a composition based on alkyltrialkoxysilane solution with alcohol as solvent. The composition was used for water-proofing on masonry applicalions. U. S. Patent No.

3,819,400 disclosed a composition based on silane and siloxane solution that can be used for surface protection of porous materials. U. S. Patent No. 3,879,206 disclosed a composition based on alkyltrialkoxysilane solution with alcoholic or benzene type solvent. The composition was used for the impregnation of masonry surfaces. U. S. Patent No. 4,341,560 disclosed a composition of the combination of alkaline metal alkylsiliconate or phenyl siliconates, calcium hydroxide or calcium oxide, andlor poly~ unsaturated carboxylic acid. The composition was used for waterproofing of gypsum molded products. U. S. Patent No. 4,536,534 disclosed an aqueous primer composition based on an alkali-soluble acrylic resin and siliconates. The composition was used for waterproofing strongly alkaline subsl,dles. U. S.
Patent No. 4,814,407 disclosed a composition based on an alkylalkoxysilane or a fluoroalkylalkoxysilane. The composition was used for reducing water absorption of substrates. U. S. Patent No. 4,816,506 disslosed a composition containing aqueous silicone disper~io"s based on the combination of poly diorganosiloxane, (organo)metallic compound(s), a siliconate, and an optional silicone resin. The composition was used for elastomeric coating or sealant applications. U. S. Patent No. 4,894,405 disclosed a composition based on the co",~inalion of a polyurethane and an organosilane. The composition was used for concrete and masonry waterproofing applications. U. S. Patent No. 4,476,282 clisclosecl a method to produce finely divided, stable oil-in-water emulsions of organo polysiloxanes. U. S. Patent No. 4,517,357 disclosed a composition of silanol solution prepared by hydrolysis of alkyltrialkoxysilanes. U. S. Patent No. 4,648,904 disclosed a composition based on an aqueous silane system.
The composition was used for rendering masonry surfaces water repellent.
U. S. Patent No. 5,356,716 disclosed a composition based on the CA 02234946 1998-04-1', WO ~ ,7 ,,3 PCT/US96113278 combination of mainly polyurethane, siliconate, and silicate. The composition was used for waterproofing concrete, masonry, and porous surfaces.
All of these prior art compositions are based on formation of a 5 hydrophobic film on the sub~ Les where they are applied. The compositions may provide adequate waterproofing to the substldLes for a short period of time, but, the compositions tend to deteriorate over time when exposed to environments such as uitraviolet radiation. They are also easily worn away when the substrates are subjected to frequent abrasion 10 such as occurs in parking garages and on highway pavement. Therefore, an "offensive" approach is needed to provide adequate waterproofing to the substrates to extend service life of the waterproofing and to reduce the possibility of substrate wearing. Such an approach can be enabled by the compositions which have water repellency function, are chemically reactive 15 to form strong bonding with the substrate, are capable of penetrating into substrate to form multilevel waterproofing layers, and can enhance the hardness of the s. bsL,dte to resist abrasion. The present invention is an example of this offensive approach.
The present invention concerns novel compositions which can be 20 used to treat the surface of construction ",atelials. The treatment can prevent the construction materials from deterioration associated with physical, chemical, and biological processes which in turn are associated with the penetration of moisture into the structures made with these materials. The products in this invention can also be used to prevent the 25 treated construction materials from deterioration associated with solvent attack, such as gasoline and motor oil, etc.
The term "construction materials" as used herein is intended to include concrete materials; wooden materials; natural and artificial stones"
plastic, metal, plaster, ceramic materials such as bricks, masonry, tile, CA 02234946 1998-04-1~

concrete aggregates which are subject to alkali-silica reactions etc.; and other materials with the potential of damage due to water absorption.
The term "concrete materials" as used herein is intended to include the systems containing cementitious materials, water, aggregates, and 5 ASTM C494 defined chemical admixtures such as water reducing, set accelerating and retarding admixtures, and other chemical admixtures added to concrete for various purposes such as corrosion control, shrinkage control, etc. Such systems can be concrete, grout, mortar, and products made therefrom.
The term "cemetitious materials" as used herein includes the systems which harden after being mixed with water. Such systems include portland cements such as described in ASTM C150, white portland cemellt~, calcium aluminate cements, etc. Such systems also include the above mentioned cements blended with ASTM C311 defined pozzolanic ",aterials such as fly 15 ash, raw or calcined natural pozzolans, ASTM C989 defined ground granuiated blast furnace slag, ASTM C-1240 defined silica fume materials.
The term "structures" as used herein is intended to include the elements made with previously mentioned material and/or materials. Such structures include highways, bridges, parking garages, stadiums, airport 20 runways, sidewalk ways, buildings, landmark architectures, historic structures, sewer pipes, and lining tile, and any other elements need to be protected from moisture/water intake.
The structures made with concrete, wooden, natural stone, plaster, and fibrous ceramic materials have a tendency to absorb water from the 25 environment. The water absorption into these materials can induce damage to the materials by physical, chemical, and biological processes. The processes can be aggravated by the presence of harmful chemicals in the water and surrounding environment.

CA 02234946 1998-04-1~

W03~ 7,,~ PCT~US96/13278 ~ or example, in the case of concrete structures, water can be transported into and out of the concrete matrix through the continuous capillary pores in the concrete. This mass exchange process of water with concrete will adversely affect the performance of concrete; for example:
5 1. Chemical deterioration: Water in the environment always contains harmful chemicals such as sulfate, chloride, sodium and potassium, etc.
When these chemicals penetrate into concrete accompanying with water, several destructive reactions will take place in concrete and will result in damage to concrete. Typical examples are as follows:
(1) sulfate attack;
(2) corrosion;
(3) alkali-silicate aggregate;

(4) leaching and (5) efflorescence.
15 2. Physical destruction: When water is subjected to temperature cycles causing freezing and thawing, its volume expands when it freezes.
When the water present in the concrete is confined in the pores of the concrete, the volume expansion will exert a force to its surrounding area of concrete. If the stress generated by this force is greater than the 20 st,~nyll, of the concrete, the concrete will disrupt and cause scaling on the surface and cracking through the body of the concrete.
It is obvious that in order to reduce the potential damage to construction materials due to water absorption, it is important to prevent water/moisture from penetrating into these materials. Water repellency 25 chemicals/products are frequently used to treat or coat the surface of the construction materials to render them repellent to liquid water.
The present invention provides compositions comprising quaternary systems which contain water, organofunctional silanes (referred to silane CA 02234946 1998-04-1~

thereafter), alkali metal organosiliconates (referred to as siliconate hereinafter), and water soluble alkali metals polysilicates (referred to hereinafter as silicate ).
Other than in the operating examples, or where otherwise indicated, 5 all numbers expressing quantities of ingredients or reaction conditions used herein are to be understood to be modified in all instances by the term "about".
The water used in the formulation of the compositions of this invention can be from tap water supplies for general public users.
The organofunctional silanes used in the practice of this invention should be water soluble and remain stable in the pH range of 7-11, depending on the water percentage in the formula. The silane used in the inventive compositions may be polymerized, for example to form a dimer or a trimer, as long as the polymerized silanes do not precipitate and separate 15 from the solution. Such silanes include, but are not limited to: vinyl-tris-(2-methoxyethoxy)silane, ~-amino-propyllli~liloxysilane, ~-aminopropyltrimethoxysilane, N-~-aminoethyl-r-aminopropyl-trimethoxysilane, triaminofunctionalsilanes, N-~-aminoethyl-,B-aminopropylmethyldimethoxysilane"~-amino-~-methylethyltriethoxysilane, r-20 aminopropyltriethoxysilane, r-aminobutyltrimethoxysilane, ~-aminohexyltriethoxy-silane, y-aminopropylmethyh~ielhoxysilane, r-aminopropylphenyldiethoxysilane N-methyl-r-aminopropyltriethoxysilane, N,N-dimethyl-y-aminopropyltriethoxysilane N-r-aminopropyl-r-aminobutyltriethoxysilane, aminomethylllill,ellloxysilane, ~-25 aminoethyltrimethoxysilane, ~-aminoethyltriethoxysilane,~-aminobutyltriethoxysilane ~-methylaminoethyltriethoxysilane, ,~-ethylaminoethyltriethoxysilane, y-methylamino-propyltrimethoxysilane, ~-propylaminopropyltriethoxysilane, r-ethylaminobutyltriethoxy-silane, r-phenylaminopropyltrimethoxysilane and r-phenylaminopropyltriethoxysilane.

CA 02234946 1998-04-1~

WO ~ ,7,73 PCT/US96113278 All of the above silanes can be hydrolyzed to produce their corresponding silanols and/or siloxanes. The corresponding silanols and/or siloxanes can also be employed in this invention. A typical example is r-aminoi~ropyltriethoxysilane which can be hydrolyzed to corresponding 5 silanols and/or siloxanes. A co",mercial example of a hydrolyzed ~-aminopropyltriethoxysilane is Siquest 1106TM.
The alkaii metal organosiliconates used in the invention can be sodium methyl siliconate and/or potassium methyl siliconate and/or mixtures thereof.
The alkali polysilicates used in the invention are selected from sodium silicate, potassium silicate, lithium polysilicate, and mixtures thereof, or thecombination of these three. The ratio range of SiO2: M2O (M = Na, K, and Li) is preferred to be between 2~10.
The proportion of each component, other than water, useful in 1~ practicing this invention is included in the blackened area of the following ternary phase diagram:

CA 02234946 1998-04-1~

WO ~ ;.3 PCI/US9U13278 ~,~
0.8 0.6 0.4 0.2 0 Silica~e The percentage of water is between about 60 and about 95%,by 5 weight, and the percentage of active chemicals (combination of silane, siliconate and silicate) is between about 5 and about 40%. The chemical components of the compositions in the ternary mixtures of the phase diagram include compositions containing about 0.1 to 0.6 parts of an alkali metal siliconate, 0.1 to 0.5 parts of an organofunctional silane and 0.2 to 0.8 10 parts of a water soluble alkali polysilicate.
The proportion of each chemical component is more accurately expressed in the ternary phase diagram of the Figure. Compositions that are contained inside the darkened region of the Figure are useful compositions of this invention. The proportion outside the darkened region 1~ will not yield either a stable or an effective product.

CA 02234946 1998-04-1~

g The procedure of manufacturing is cri~ical to obtain a stable and an effective composition. General procedure for high percentage of active component (higher than 20%) is as follows:
1. Add silane into water while stirring at the rate between 500 and about 5 1500 rpm, and let the silane hydrolyze for at least 6 hours, preferably overnight, before adding another ingredient.
2. Add alkali organosiliconate slowly into silane solution while stirring.
Optionally step one can be avoided by adding the alkali organosilicate to a hydrolyzed silane.
10 3. Add above prepared solution slowly into alkali polysilicate solution while stlrnng.
General procedure for low percentage of active component (less than 20%) is as follows:
1. Add the silane into water while stirring at the rate between 500 and about 1500 rpm, and let silane hydrolyze for at least 6 hours, pref~r~l)ly overnight, before adding other ingredients.
2. Add alkali organosiliconate slowly into the silane solution while stirrins.
Optionally step one can be avoided by adding the alkali organosiliconate to a hydrolyzed silane.
20 3. Add alkali polysilicate into above solution while stirring.
The following examples prepared using the foregoing procedures, further illustrate the invention and are not intended as limiting.

Example 1:
Table 1: Formulation of Example 1 Raw Material Supplier % Active Coi"ponenl Batch Wt. (g) Tap Water Any City 75.71 76.7 Dow Corning Z-6020TUDow Corning 7.29 23.0 Dow Corning 777TMDow Corning 7 44.6 Lifetech705~MFMC LithiumDivision 10 113.0 Table 2: Pe,F~.""ance of Example 1 SubstrateSurfacetreatment Pe,tu""ance ControlExample 1 Poroussandpape~ abraded WaterAbsor~Jtionat21 Days7.3 1.7 ConcreteWater Reductionat21 Days --- 76.8 Densesandpaperabraded WaterAbsor,ulionat21 Days 3.3 0.7 ConcreteWaterReductiQn at21 Days -- 80.1 Densesand blastedWaterAbsorption at21 Days 4.04 0.78 Concrete WaterReduction at21 Days --- 80.8 Abrasion saw cut Weight Loss (9) 2.80 1.70 Wearlndex 187 113 Example 2:
Table 3: Formulation of Example 2 Raw Material Supplier % Active Co",ponen~ Batch Wt. (g) Tap Water Any City 84.4 145 Dow Corning~ Z-6020T~Dow Corning 3.6 11.3 Dow Coming~ 777TM Dow Corning 7 42.5 Lifetech 705TMFMC Lithium Division 5 56.5 WO~'u7/y3 PCTtUS96/13278 Table 4: Be ru""ance of Example 2 SubstrateSurface t,~d~",ent Fe.f~""anceControlExample 2 Densesandpaper abraded Water Abso"~lion at 21 Days 3.3 1.0 ConcreteWater Reduction at 21 Days -- 69.8 Densesand blasted WaterAbsorption at21 Days 4.04 0.83 ConcreteWaterReductionat21 Days -- 79.4 Example 3:
Table 5: Formulation of Example 3 Raw Material Supplier % Active Co",~,onenl Batch Wt. ~9) Tap Water Any City 81.2 94 Dow Corning~ Z~020TM Dow Corning 1.8 5.67 Dow Corning~ 777TuDow Coming 7 42.5 Lifetech 705TMFMC Lithium Division 10 113 Table 6: Pe,ru,,,,ance of Ex~mple 3 SubstrateSurface t,~d~",enl Performance ControlExample :3 Densesandpaperabraded WaterAbsoi~tion at21 Days 3.3 1.1 Concrete WaterReductionat21 Days --- 67.5 Dense sandblasted WaterAbso".lionat21 Days 4.04 0.98 Concrete WaterReduction at21 Days --- 75.7 Example 4:
Table 7: Fomlulation of Example 4 Raw Material Supplier % Active Co""~onenl Batch Wt. (g) Tap Water Any City 83.4 113 Dow Corning~ Z-6020TU Dow Coming 3.6 11.3 Dow Coming~ 777T~Dow Coming 3 18.2 Lifetech 705TM FMC Lithium Division 10 113 WO 98/077g3 PCI/US96/~3278 Tabie 8: P~. r~" ",ance of Example 4 Substrate Surfacel,~d~",ent Pe,rul",ance Control E)~dhl,' Densesar,.J~,aperabradedWaterAbsG,~,tionat21 Days 3.3 0.9 Concrete WaterReductionat21 Days --- 72.2 Dense sand blastedWaterAbso"~tionat21 Days 4.04 0.80 Concrete WaterReductionat21 Days -- 80.2 Example 5:
Table 9: Formulation of Example 5 Raw Material Supplier % Active Con".onenL Batch Wt. (g) Tap Water Any City 72.6 37.5 Dow Corning~ Z-6020TMDow Coming 1.8 5.67 Dow Corning~ 777TMDow CoMing 7 42.5 Lifetech 705TUFMC, Lithium Division 15 170 Table 10: Pe,ru""d"ce of Example 5 SubstrateSurface ~,~al",e"l Pe,fi."",ance ControlExample 5 Densesan~Jpaperabraded WaterAbsor~t;~n at21 Days 3.3 1.
Concrete Water Reduction at 21 Days - 63.1 Dense sand blasted Water AbsGI~tion at 21 Days 4.04 0.78 Concrete WaterFeduction at21 Days --- 80.7 Example 6:
Table 11: Formulation of Example 6 Raw Material Supplier % Active Co"",onenl Batch Wt. (g) Tap Water Any City 74.4 31.8 Dow Corning~ Z-6020TMDow Corning 3.6 11.3 Dow Corning~ 777T~Dow Corning 7 42.5 Lifetech 705TMFMC, Lithium Division 15 170 WO 9810M93 PCTtUS96/13278 Table 12: Performance of Example 6 SubstrateSurface l,ea~",entPe~fum~allce ControlExample 6 Densesand~,aperabradedWaterAbsor~ tiûn at21 Days 3.3 0.9 Concrete WaterReduction at21 Days ~ 73.ii Dense sandblastedWaterAbsor~tionat21 Days 4.04 0.78 Concrete Water Reduction at 21 Days --- 80.8 In the foregoing examples Dow Corning Z-6020TM is identified as aminoethyl-aminopropyldimethoxxsilane, Dow Corning777TM as potassium methylsiliconate and Lifetech 705TMm as lithium polysilicate.

Claims

CLAIMS:

1. A composition characterized by 60 to 95 weight percent water and 5 to 40 weight percent of a mixture of an alkali metal siliconate, an organofunctional silane and a water soluble alkali metal polysilicate.

2. The composition of claim 1 characterized in that the mixture comprises an alkali metal organosiliconate, an organofunctional silane and a water soluble alkali polysilicate in amounts and proportions that are within the blackened area of the following phase diagram:

3. The composition of claim 2 characterized in that the alkali metal organosiliconate is selected from sodium methyl siliconate, potassium methyl siliconate and mixtures thereof.

4. The composition of claim 2 characterized in that the organofunctional silane is selected from vinyl-tris-(2-methoxyethoxy)silane, .gamma.-amino-propyltriethoxysilane, .gamma.-aminopropyltrimethoxysilane, N-,.beta.-aminoethyl-.gamma.-aminopropyl-trimethoxysilane, triaminofunctionalsilanes, N-.beta.-aminoethyl-.beta.-aminopropylmethyldimethoxysilane, .beta.-amino-.gamma.-methylethyltriethoxysilane, .gamma.-aminopropyltriethoxysilane, .gamma.-aminobutyl-trimethoxysilane, .omega.-aminohexyltriethoxy-silane, .gamma.-aminopropylmethyldiethoxysilane, .gamma.-aminopropylphenyldiethoxysilane, N-methyl-.gamma.-aminopropyltriethoxysilane, N,N-dimethyl-.gamma.-aminopropyltriethoxysilane, N-.gamma.-aminopropyl-.gamma.-aminobutyltriethoxysilane, aminomethyltrimethoxysilane, .beta.-aminoethyltrimethoxysilane,.beta.-aminoethyltriethoxy-silane, .gamma.-aminobutyltriethoxysilane, .beta.-methylaminoethyltriethoxysilane, .beta.-ethylamino-ethyltriethoxysilane, .gamma.-methylamino-propyltrimethoxysilane, .gamma.-propylaminopropyl triethoxysilane, .gamma.-ethylaminobutyltriethoxy-silane, .gamma.-phenylaminopropyltrimethoxysilane, .gamma.-phenylaminopropyltriethoxysilane and mixtures thereof.

5. The composition of claim 2 characterized in that the alkali metal silicate is selected from sodium silicate, potassium silicate, lithium polysilicate and mixtures thereof.

6. A composition produced by mixing together 5-40 weight of a mixture of 0.1 to 0.6 parts of an alkali metal siliconate, 0.1 to 0.5 parts of an organofunctional silane and 0.2 to 0.8 parts of a water soluble alkali polysilicate into 60 to 95 parts of water.

7. The composition of claim 6 characterized in that the alkali metal organosiliconate is selected from sodium methyl siliconate, potassium methyl siliconate and mixtures thereof.

8. The composition of claim 6 characterized in that the organofunctional silane is selected from vinyl-tris-(2-methoxyethoxy)silane, .gamma.-amino-propyltriethoxysilane, .gamma.-aminopropyltrimethoxysilane, N-.beta.-aminoethyl-.gamma.-aminopropyl-trimethoxysilane, triaminofunctionalsilanes, N-.beta.-aminoethyl-.beta.-aminopropylmethyldimethoxysilane, .beta.-amino-.gamma.-methylethyltriethoxysilane, .gamma.-aminopropyltriethoxysilane, .gamma.-aminobutyl-trimethoxysilane, .omega.-aminohexyltriethoxy-silane, .gamma.-aminopropylmethyldiethoxysilane, .gamma.-aminopropylphenyldiethoxysilane, N-methyl-.gamma.-aminopropyltriethoxysilane, N,N-dimethyl-.gamma.-aminopropyltriethoxysilane, N-.gamma.-aminopropyl-.gamma.-aminobutyltriethoxysilane, aminomethyltrimethoxysilane, .beta.-aminoethyltrimethoxysilane, .beta.-aminoethyltriethoxy-silane, .gamma.-aminobutyltriethoxysilane, .beta.-methylaminoethyltriethoxysilane, .beta.-ethylamino-ethyltriethoxysilane, .gamma.-methylamino-propyltrimethoxysilane, .gamma.-propylaminopropyl triethoxysilane, .gamma.-ethylaminobutyltriethoxy-silane, .gamma.-phenylaminopropyltrimethoxysilane, .gamma.-phenylaminopropyltriethoxysilane and mixtures thereof.

9. The composition of claim 6 characterized in that the alkali metal silicate is selected from sodium silicate, potassium silicate, lithium polysilicate and mixtures thereof. 10. Application of a protective amount of a composition of claim 2 to the surface of construction materials to prevent deterioration associated with water intake.

10. Application of a protective amount of a composition of claim 2 to concrete surfaces to prevent scaling.

11. Application of a protective amount of a composition of claim 2 to concrete surfaces to prevent cracking due to freeze-thaw cycle,

12. Application of a protective amount of a composition of claim 2 to concrete surfaces to prevent corrosion of rebars in concrete due to chloride penetration into the rebar reinforced concrete.

13. Application of a protective amount of a composition of claim 2 to concrete surfaces to prevent expansion and cracking of the concrete due to alkali-aggregate reactions.

14. Application of a protective amount of a composition of claim 2 to concrete surfaces to prevent expansion and cracking of the concrete due to sulfate attack.

15. Application of a protective amount of a composition of claim 2 to concrete surfaces to prevent the concrete from leaching.

16. The process for manufacturing stable and effective compositions of claim 2 containing a weight percentage of a mixture of an alkali metal organosiliconate, organofunctional silane and water soluble alkali metal polysilicate, present in an aggregate amount of higher than 20 weight percent, characterized by the following steps:
a) adding the alkali metal organosiliconate slowly while stirring into a hydrolyzed organofunctional silane; and b) slowly adding, with stirring, the prepared solution containing the organosiliconate and the organofunctional silane into the alkali metal polysilicate.

17. The process for manufacturing stable and effective compositions of claim 2 containing a weight percentage of a mixture of an alkali metal organosiliconate, organofunctional silane and water soluble alkali metal polysilicate, present in an aggregate amount of less than 20 weight percent, characterized by the following steps:
a) adding the alkali metal organosiliconate slowly while stirring into a hydrolyzed organofunctional silane; and b) slowly adding, with stirring, the alkali metal polysilicate into the prepared solution of step a)containing the organosiliconate and the organofunctional silane.

18. The process of claim 17 characterized in that the hydrolyzed organofunctional silane is obtained by adding an organofunctional silane to water while stirring at a rate of 500 to 1500 revolutions per minute and letting the silane hydrolyze for at least 6 hours.

19. The process of claim 18 characterized in that the hydrolyzed organofunctional silane is obtained by adding an organofunctional silane to water while stirring at a rate of 500 to 1500 revolutions per minute and letting the silane hydrolyze for at least 6 hours.