COFFEY RICKY W (US)
PEARSON ANDREW (US)
HAVENS JERRY (US)
| WO1995016752A1 | 1995-06-22 | |||
| WO1995022580A1 | 1995-08-24 |
| US20140020600A1 | 2014-01-23 | |||
| US20050107520A1 | 2005-05-19 | |||
| DE1069057B | ||||
| EP0234024A1 | 1987-09-02 | |||
| EP0340816A2 | 1989-11-08 | |||
| EP0631999A2 | 1995-01-04 | |||
| EP0907622A1 | 1999-04-14 | |||
| EP1147072A1 | 2001-10-24 | |||
| US8449666B2 | 2013-05-28 |
HANS-DIETER DORFLERGRENZFLACHENKOLLOIDCHEMIE: "Interfacial and Colloidal Chemistry", 1994, VCH, pages: 198
| WHAT IS CLAIMED IS: 1. An aqueous dispersion, comprising (A) at least one silane of the formula RaR2bSi(OR1)4-a-b (I), wherein R is identical or different and is a monovalent, SiC- bonded, optionally substituted hydrocarbon radical having at least 4 carbon atoms, R1 may be identical or different and are monovalent, optionally substituted hydrocarbon radicals having 1 to 18 carbon atoms, R2 may be identical or different and are monovalent, SiC-bonded, optionally substituted hydrocarbon radicals having 1 to 3 carbon atoms, a is 1, 2 or 3 and b is 0, 1 or 2, with the proviso that the sum of a and b is 1, 2 or 3, and/or the partial hydrolysis products thereof, (B) at least one nonionic emulsifier having an HLB value greater than or equal to 12, optionally as a mixture with nonionic emulsifiers having an HLB value of less than 12, (C) at least one compound selected from (Cl) polyisobutylene, (C2) polydialkylsiloxanes, (C3) amino-functional silanes, (C4) amino-functional siloxanes and mixtures thereof, (F) water and optionally (G) further components. with the proviso that the co-use of cationic surfactants is excluded. 2. The aqueous dispersion as claimed in claim 1, wherein (A) is isooctyltriethoxysilane. 3. The aqueous dispersion as claimed in claim 1 or 2, wherein component (B) is at least one nonionic emulsifier having an HLB value greater than or equal to 14, optionally as a mixture with nonionic emulsifiers having an HLB value of less than 12. 4. The aqueous dispersion as claimed in claim 1, 2 or 3, wherein compound (C2) is a dimethylpolysiloxane. 5. The aqueous dispersion as claimed in in one or more of claims 1 to 4, wherein compound (C3) is an amino-functional silane of the formula AR4cSi(OR5)3-c (H I) wherein A is an an amine-substituted radical of the formula -R6-[NR7-R8]XNR72 (IV), R4 is identical of different and a monovalent hydrocarbon radical having 1 to 18 carbon atoms, R5 is identical or different and a monovalent hydrocarbon radical having 1 to 18 carbon atoms, preferably 1 to 4 carbon atoms, R6 is identical or different and is a divalent Si-C-bonded hydrocarbon radical having 1 to 18 carbon atoms, R7 is a hydrogen atom or a monovalent linear, cyclic or branched, saturated or unsaturated hydrocarbon radical having 1 to 18 carbon atoms, R8 is identical or different and is a divalent hydrocarbon radical having 1 to 6 carbon atoms, c is 0, 1 or 2, preferably 0 or 1, and x is 0 or an integer from 1 to 4, preferably 0 or 1. 6. The aqueous dispersion as claimed in in one or more of claims 1 to 5, wherein compound (C4) is an amino-functional organopolysiloxane containing units of the formula AdR9e(OR10)fSiO(4-d-e-f)/2 (V) wherein A is as defined in claim 5, R9 is identical or different and is a monovalent, optionally substituted hydrocarbon radical having 1 to 18 carbon atoms, R10 is identical or different and is a hydrogen atom or a monovalent, optionally substituted hydrocarbon radical having 1 to 18, preferably 1 to 4 carbon atoms, d is 0, 1 or 2, preferably 0 or 1, e is 0, 1, 2 or 3, and f is 0, 1, 2 or 3, preferably 0 or 1, with the proviso that the sum of d+e+f is less than or equal to 3. 7. The aqueous dispersion as claimed in claims 5 or 6, wherein the amine-substituted radical A is a radical of the formula H2N(CH2)3- or H2N (CH2) 2NH (CH2) 3- . 8. The aqueous dispersion as claimed in in one or more of claim 1 to 7, which is an aqueous dispersion comprising (A) from 10 to 60% by weight of at least one silane (B) from 1.0 to 10% by weight of at least one nonionic emulsifier having an HLB value greater than or equal to 12, optionally as a mixture with nonionic emulsifiers having an HLB value of less than 12, (C) from 1 to 10% by weight of at least one compound selected from (Cl), (C2), (C3), (C4) and mixtures therof, (D) water and optionally (E) further components, with the proviso that the co-use of cationic surfactants is excluded. 9. A process for the preparation of the dispersions as claimed in one or more of claims 1 to 8 by mixing the components (A), (B), (C), (D) and optionally (E), with the proviso that no high-pressure homogenizers are used. 10. A process for the treatment of substrates, wherein the substrates are brought into contact with the dispersions as claimed in one or more of claims 1 to 8. 11. The process as claimed in claim 10, wherein the substrates to be treated are mineral substrates and wood-based materials. |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to aqueous dispersions of organosilicon compounds, the preparation thereof and the use thereof, in particular for the hydrophobing impregnation and mass hydrophobing of mineral and organic building materials.
2. Description of the Related Art
Silanes and siloxanes have long been used for the production of structures, for example solutions of silanes in organic solvents, as described, for example, in DE-A 1069057. For cost reasons, but not least also because of the health hazards, during handling of organic solvents and the associated environmental pollution, working with organic solvents is disadvantageous .
Aqueous formulations based on alkylalkoxysilanes and alkylalkoxysiloxanes are known. EP-A 234024 describes silane emulsions comprising nonionic emulsifiers which have an HLB value of from 4 to 15. According to EP-A 340816 the stability of these compositions is improved by the addition of buffer salts. EP-A 631 999 describes aqueous formulations based on alkylalkoxysilanes which contain cationic emulsifiers. According to WO-A 199516752 and EP-A 907 622, amine soaps are said to be suitable in particular for the preparation of silane/siloxane emulsions. WO-A 199522580 describes a series of further cationic emulsifiers in silane/siloxane emulsions. According to EP-A 1147 072, the stability of silane/siloxane emulsions is particularly good when ionic emulsifiers are used in combination with nonionogenic emulsifiers which have an HLB value of less than 11.
However, the aqueous structure preservatives prepared according to the prior art do not always have the desired stability and efficiency.
Aqueous dispersions of organosilicon compounds having the desired stability and efficiency are disclosed in US 8,449,666 B2. However, to prepare the aqueous dispersions of US 8,449,666 B2 the emulsions require homogenization using a high-pressure homogenizer.
Accordingly, there is a long sought need for silane emulsions having desired stability and efficiency, and not requiring the need for high pressure homogenization to produce the emulsion.
SUMMARY OF THE INVENTION
It has been surprisingly and unexpectedly discovered that highly stable emulsions of alkylalkoxy-functional organosilicon compounds may be prepared with conventional mixing equipment without the need for a high-pressure homogenizer, by including polyisobutylene, polydialkylsiloxane, amino-functional silane or aminofunctional organopolysiloxane into the emulsion.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention relates to aqueous dispersions comprising (A) at least one silane of the formula
RaR 2 bSi(OR 1 )4-a-b (I), in which
R is identical or different and is a monovalent, SiC- bonded, optionally substituted hydrocarbon radical having at least 4 carbon atoms,
R 1 is identical or different and is a monovalent, optionally substituted hydrocarbon radical having 1 to 18 carbon atoms R 2 is identical or different and is a monovalent, SiC- bonded, optionally substituted hydrocarbon radicals having 1 to 3 carbon atoms, a is 1, 2 or 3 and b is 0, 1 or 2, with the proviso that the sum of a and b is 1, 2 or 3, and/or the partial hydrolysis products thereof,
(B) at least one nonionic emulsifier having an HLB value greater than or equal to 12, preferably greater than or equal to 14, optionally as a mixture with nonionic emulsifiers having an HLB value of less than 12,
(C) at least one compound selected from (Cl) polyisobutylene
(C2) polydialkylsiloxanes (C3) amino-functional silanes (C4) aminofunctional siloxanes and mixtures thereof,
(D) water and optionally
(E) further components, with the proviso that the co-use of cationic surfactants is excluded.
The aqueous dispersion of the invention are preferably aqueous emulsions.
Examples of the radical R are 1-n-butyl, 2-n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl and tert-pentyl radical; hexyl radicals, such as the n-hexyl radical; heptyl radicals, such as the n-heptyl radical; octyl radicals, such as the n-octyl radical, and isooctyl radicals, such as the 2,2,4- trimethylpentyl radical; nonyl radicals, such as the n-nonyl radical; decyl radicals, such as the n-decyl radical; dodecyl radicals, such as the n-dodecyl radical; octadecyl radicals, such as the n-octadecyl radical; cycloalkyl radicals, such as the cyclopentyl, cyclohexyl, cycloheptyl and methylcyclohexyl radicals; aryl radicals, such as the phenyl, naphthyl, anthryl and phenanthryl radical; alkaryl radicals, such as o-, m- and p-tolyl radicals; xylyl radicals and ethylphenyl radicals; and aralkyl radicals, such as the benzyl radical and the a- and the b-phenylethyl radical.
Examples of substituted radicals R are halogenated alkyl readicals, glycidyloxypropyl radical and methacroylpropyl radical.
Radicals R are preferably hydrocarbon radicals having at least 4 carbon atoms, particularly preferably hydrocarbon radicals having 6 to 18 carbon atoms, in particular hexyl and octyl radicals, very particularly preferably the n-hexyl radical, n- octyl radical and isooctyl radical, such as the 2,2,4- trimethylpentyl radical.
Radicals R 1 are preferably optionally substituted alkyl radicals having 1 to 4 carbon atoms, particularly preferably the methyl, ethyl, n-butyl, 2-methoxyethyl and isopropyl radical, in particular the ethyl radical. Radicals R 2 are preferably alkyl radicals having 1 to 3 carbon atoms, such as methyl, ethyl, n-propyl and isopropyl radicals, particularly preferably the methyl radical.
The value of a is preferably 1.
The value of b is preferably 0 or 1.
Examples of silanes (A) are isobutyltriethoxysilane, hexyl- triethoxysilane, hexylmethyldiethoxysilane, n-octyltrimethoxy- silane, n-octyltriethoxysilane, n-octyltributoxysilane, isooctyltriethoxysilane, n-decyltriethoxysilane, dodecylmethyldimethoxysilane, hexadecyltrimethoxysilane, octadecylmethyldimethoxysilane, octadecylmethyldiethoxysilane and octadecyltriethoxysilane and aminoethylaminopropyl- triethoxysilane, glycidoxypropyltrimethoxysilane and methacroylpropyltriethoxysilane .
Silane (A) is preferably n-hexyltriethoxysilane, n-octyl- triethoxysilane and isooctyltriethoxysilane, n-octyl- triethoxysilane and isooctyltriethoxysilane being particularly preferred.
If (A) are partial hydrolysis products, those having 2 to 10 Si atoms are preferred. Partial hydrolysis products form when some of the radicals OR 1 in the silanes of the formula (I) are eliminated by reaction with water or steam and OH groups bonded to silicon form. These in turn can condense with elimination of water to give siloxane bonds, resulting in oligomers which may also contain OH groups in addition to groups OR 1 . Partial hydrolysis products of silanes of the formula (I) may also be present as an impurity in the silane of the formula (I). The dispersions according to the invention contain silane (A) in amounts of, preferably, from 5 to 70% by weight, particularly preferably from 30 to 65% by weight, based in each case on the total formulation.
Examples of the nonionogenic emulsifiers (B) used according to the invention are sorbitan fatty acid esters, ethoxylated sorbitan fatty acid esters, ethoxylated fatty acids, ethoxylated linear or branched alcohols having 10 to 20 carbon atoms, ethoxylated alkylphenols , pentaerythrityl fatty acid esters, glyceryl esters and alkylpolyglycosides.
The nonionogenic emulsifiers (B) are preferably sorbitan fatty acid esters, ethoxylated sorbitan fatty acid esters, ethoxylated fatty acids, ethoxylated linear or branched alcohols having 10 to 20 carbon atoms and ethoxylated triglycerides .
Preferably, the dispersions according to the invention contain no ethoxylated alkylphenols since it is known that these are not environmentally compatible.
The component (B) used according to the invention may be only one nonionogenic emulsifier having an HLB value of greater than or equal to 12, particularly greater than or equal to 14, or a mixture of a plurality of nonionogenic emulsifiers, with the proviso that at least one emulsifier has an HLB value greater than or equal to 12, in particular greater than or equal to 14.
Mixtures of nonionogenic emulsifiers, of which at least one emulsifier has an HLB value greater than or equal to 12, are preferably used as component (B). The proportion of emulsifiers having an HLB value greater than or equal to 12 in the emulsifier mixture (B) is preferably at least 30% by weight.
The HLB value is an expression of the equilibrium between hydrophilic and hydrophobic groups of an emulsifier. The definition of the HLB value and methods for determining it are generally known and are described, for example, in Journal of Colloid and Interface Science 298 (2006) 441-450 and the literature cited there.
The HLB value (HLB stands for hydrophilic-lipophilic balance) describes the hydrophilic and lipophilic component of mainly nonionic emulsifiers. The HLB value can be calculated for nonionic emulsifiers according to Hans-Dieter Dorfler, Grenzflachen- und Kolloidchemie [Interfacial and Colloidal Chemistry], VCH, Weinheim, 1994, p. 198, as follows:
In this formula, Mi is the molar mass of the lipophilic component of a molecule and M the molar mass of the whole molecule. The factor of 20 is a freely selected scaling factor. Examples of the nonionogenic emulsifiers (B) used according to the invention and having an HLB value greater than or equal to 12 are (HLB values according to manufacturer, POE is polyoxyethylene) :
1) Croda International Pic, Cowick Hall, Snaith Goole East Yorkshire UK
2) Sasol Germany GmbH, Marl
3) Cognis GmbH, Illertissen. Examples of nonionogenic emulsifiers which can additionally be used and have an HLB value < 12 are (HLB values according to manufacturer or table 3 in the abovementioned source, POE is polyoxyethylene) : 1 ) Croda International Pic, Cowick Hall, Snaith Goole East Yorkshire UK
2) Sasol Germany GmbH, Marl
3) Cognis GmbH, Illertissen. The dispersions according to the invention contain component (B) in amounts of, preferably, from 1.0 to 10% by weight, particularly preferably from 1.5 to 3% by weight, based in each case on the total formulation.
Component (C) is a compound selected from (Cl) polyisobutylene, (C2) polydialkylsiloxanes, (C3) amino-functional silanes, (C4) amino-functional organopolysiloxanes and mixtures thereof.
Polydialkylsiloxanes (C2) are preferably polydialkylsiloxanes of the formula
R 3 3 SiO(R 3 2 SiO) n SiR 3 3 (II) wherein
R 3 is identical or different and an alkyl radical with 1 to 18 carbon atoms, preferably an alkyl radical with 1 to 3 carbon atoms, more preferably a methyl radical and n is an integer from 10 to 100 preferably from 50 to 80
Polydialkylsiloxanes (C2) are preferably dimethylpolysiloxanes. The dimethylpolysilanes have preferably a viscosity from 50 to 110 mPa-s at 25°C.
The viscosity is determined according to DIN ISO 51562.
The amino-functional silanes (C3) are preferably silanes of the formula
AR 4 c Si(OR 5 ) 3-c (H I) wherein
A is an an amine-substituted radical of the formula
-R 6 -[NR 7 -R 8 ] X NR 7 2 (IV),
R 4 is identical of different and a monovalent hydrocarbon radical having 1 to 18 carbon atoms,
R 5 is identical or different and a monovalent hydrocarbon radical having 1 to 18 carbon atoms, preferably 1 to 4 carbon atoms,
R 6 is identical or different and is a divalent Si-C-bonded hydrocarbon radical having 1 to 18 carbon atoms,
R 7 is a hydrogen atom or a monovalent linear, cyclic or branched, saturated or unsaturated hydrocarbon radical having 1-18 carbon atoms,
R 8 is identical or different and is a divalent hydrocarbon radical having 1 to 6 carbon atoms, c is 0, 1 or 2, preferably 0 or 1, and x is 0 or an integer from 1 to 4, preferably 0 or 1.
Examples of amine-substituted radicals A include:
H 2 N (CH 2 ) 2 NH (CH 2 ) 3 - H 2 N(CH 2 ) 3 -
H 2 N (CH 2 ) 2 NH-CH 2 -CH (CH 3 )-CH 2 - H 2 N-CH 2 -CH (CH 3 )-CH 2 -
HsCNH (CH 2 ) 3 -
H 2 N (CH 2 ) 4 -
H 2 N (CH 2 ) 5 -
H (NHCH 2 CH 2 ) 3 -
C 4 H 9 NH (CH 2 ) 2 NH (CH 2 ) 2 - and cyclo-CeHuNH (CH 2 ) 3 -, wherein
H 2 N(CH 2 ) 3 - and
H 2 N (CH 2 ) 2 NH (CH 2 ) 3 - are particularly preferred.
Preferable examples of silane (C3) are
3- (2-aminoethylamino)propylmethyldimethoxysilane and 3- (2-aminoethylamino)propylmethyldiethoxysilane, Amino-functional organopolysiloxanes are preferably organopolysiloxanes containing units of the formula
A d R 9 e(OR 10 )fSiO(4-d-e-f ) /2 (V) wherein
A is as defined above,
R 9 is identical or different and is a monovalent, optionally substituted hydrocarbon radical having 1 to 18 carbon atoms,
R 10 is identical or different and is a hydrogen atom or a monovalent, optionally substituted hydrocarbon radical having 1 to 18, preferably 1 to 4 carbon atoms, d is 0, 1 or 2, preferably 0 or 1, e is 0, 1, 2 or 3, and f is 0, 1, 2 or 3, preferably 0 or 1, with the proviso that the sum of d+e+f is less than or equal to
3.
Amino-functional organopolysiloxanes are more preferably organopolysiloxanes of the formula
R* 3-y A y SiO[R 9 SiO] [RASiO]iSiA y R* 3-y (VI) wherein
R* is R 9 or a radical of formula -OR 10 ,
A, R 9 and R 10 are as defined above, k is an integer from 1 to 1000,
1 is an integer from 1 to 100 and y is 0 or 1, preferably 0.
Examples of radicals R 4 are alkyl radicals, such as the methyl, ethyl, n-propyl, isopropyl, 1-n-butyl, 2-n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl and tert-pentyl radical; hexyl radicals, such as the n-hexyl radical; heptyl radicals, such as the n-heptyl radicals; octyl radicals, such as the n-octyl radical, and isooctyl radicals, such as the 2,2,4-trimethylpentyl radical; nonyl radicals, such as the n- nonyl radical; decyl radicals, such as the n-decyl radical; dodecyl radicals, such as the n-dodecyl radical; octadecyl radicals, such as the n-octadecyl radical; cycloalkyl radicals, such as the cyclopentyl, cyclohexyl and cycloheptyl radical and methylcyclohexyl radicals; alkenyl radicals, such as the vinyl, 1-propenyl and 2-propenyl radical; aryl radicals, such as the phenyl, naphthyl, anthryl and phenanthryl radical; alkaryl radicals, such as the o-, m- and p-tolyl radicals; xylyl radicals and ethylphenyl radicals; and aralkyl radicals, such as the benzyl radical and the a- and the b-phenylethyl radical.
Examples of radicals R 4 are fully applicable to radicals R 9 . Examples of radicals R 1 are fully applicable to radicals R 5 and R 10 .
The dispersions according to the invention contain component (C) in amounts of, preferably, from 1 to 10% by weight, particularly preferably from 3 to 5% by weight, based in each case on the total amount of the dispersion.
The water (D) used according to the invention may be any desired type of water, such as, for example, natural waters, such as, for example, rainwater, groundwater, spring water, river water and seawater, chemical waters, such as, for example, demineralized water or distilled or (multiply) redistilled water, waters for medicinal or pharmaceutical purposes, such as, for example, purified water (Aqua purificata; Pharm. Eur. 3), Aqua deionisata, Aqua destillata,
Aqua bidestillata, Aqua ad injectionam or Aqua conservata, drinking water according to the German drinking water regulation and mineral waters.
The water (D) used according to the invention is preferably water having a conductivity of less than 10 pS/cm, in particular less than 2 pS/cm.
The dispersions according to the invention contain component (D) in amounts of, preferably, from 20 to 95% by weight, particularly preferably from 40 to 60% by weight, based in each case on the total amount of dispersion.
The further components (E) optionally used according to the invention may be all additives which have also been used to date in aqueous dispersions, such as, for example, thickeners, substances for adjusting the pH, buffer substances, fillers, fragrances, dyes, antifreezes, such as glycols and glycol ether, and preservatives.
Examples of optionally used thickeners (E) are polyacrylic acid, polyacrylates, cellulose ethers, such as carboxymethylcellulose and hydroxyethylcellulose, natural gums, such as xanthan gum, and polyurethanes.
Examples of substances for adjusting the pH are, in addition to aminosilanes, also amines, such as, for example, monoethanolamine, or alkali metal hydroxides. If required for ensuring the constancy of the pH over a relatively long period, buffer systems, such as salts of acetic acid, salts of phosphoric acid, salts of citric acid, in each case in combination with the free acid, may also be used, depending on the desired pH.
The dispersions according to the invention may contain silicon dioxide (silicic acids), titanium dioxide or aluminum oxide having a BET surface area of, preferably, from 20 to 1000 m 2 /g, a particle size of, preferably, less than 10 pm and an agglomerate size of, preferably, less than 100 pm as fillers (E).
The optionally used fillers (E) are particularly preferably silicic acids, in particular those having a BET surface area of from 50 to 800 m 2 /g. These silicic acids may be pyrogenic or precipitated silicic acids. In particular, pretreated silicic acids, such as, for example, commercially available completely or partly hydrophobed silicic acids, can be used as fillers (E). Examples of commercially available hydrophobic silicic acids which can be used according to the invention are pyrogenic, treated silicic acid having a BET surface area of 120 m 2 /g and a carbon content of 0.8% by weight (available under the name HDK ® H15 from Wacker Chemie AG, Germany), a pyrogenic treated silicic acid having a BET surface area of 140 m 2 /g and a carbon content of 2.8% by weight (available under the name HDK ® H2000 from Wacker Chemie AG, Germany) and a precipitated silicic acid treated with polydimethylsiloxane and having a BET surface area of 90 m 2 /g (available under the name "Sipernat D10" from Degussa AG, Germany).
The dispersions according to the invention are preferably free of water-immiscible solvents or contain water-immiscible solvents in amounts of not more than 1% by weight, based on the total amount of dispersion.
In the context of the present invention, "water-immiscible solvents" are to be understood as meaning all solvents which are soluble in amounts of not more than 1 g/1 in water at 20°C and a pressure of 101.325 kPa.
In particular, these water-immiscible solvents have a vapor pressure of 0.1 kPa or higher at 20°C. Examples of such water-immiscible solvents are benzene, toluene, xylene, hexane, cyclohexane and paraffinic hydrocarbon mixtures.
The dispersions according to the invention are particularly preferably those containing from 10 to 60% by weight of at least one silane (A), from 1.0 to 10% by weight of at least one nonionic emulsifier (B) having an HLB value greater than or equal to 12, optionally as a mixture with nonionic emulsifiers having an HLB value of less than 12, from 1.0 to 10.0% by weight of at least one compound (C) selected form (Cl), (C2), (C3), (C4) and mixtures thereof,
(D) water and optionally
(E) further components, with the proviso that the co-use of cationic surfactants is excluded.
In particular, the dispersions according to the invention contain no further components over and above the components (A), (B), (C), (D) and (E).
Conventional mixers are used for the preparation of the aqueous dispersions according to the invention. Usually, the preparation is carried out by simple stirring of all constituents at temperatures of preferably from 1 to 50°C and optionally subsequent homogenization, for example using rotor- stator homogenizers, preferably at peripheral speeds of from 5 to 40 m/s.
The invention furthermore relates to a process for the preparation of the dispersions according to the invention by mixing the components (A), (B), (C), (D) and optionally (E) with the proviso that no high-pressure homogenizers are used.
In a preferred embodiment of the process according to the invention, the component (B), a part of the water (D) and optionally component (C) are initially introduced, the component (A) is incorporated using a rotor-stator homogenizer, then unless also already initially introduced at the beginning, component (C), the remaining amount of water (D) and optionally component (E) are incorporated with homogenization. This is preferably followed by homogenization using a rotor-stator homogenizer .
The dispersions according to the invention are preferably milky, white to beige liquids.
The dispersions according to the invention have a pH of preferably from 5 to 9, in particular from 6 to 8.
The dispersions according to the invention have a proportion of nonvolatile compounds (for example determined according to ASTM D 5095) of preferably from 10 to 80% by weight, particularly preferably from 20 to 70% by weight.
The dispersions according to the invention have a volume- average particle size preferably from 0.1 to 10 pm, in particular from 0.3 to 1.5 pm.
The dispersions according to the invention have a viscosity of, preferably, less than 10 000 mPa.s, in particular less than 1000 mPa.s, measured in each case at 25°C. The dispersions according to the invention have the advantage that they have a very long shelf-life.
The dispersions according to the invention have the advantage that they can be prepared economically.
The dispersions according to the invention have the advantage that they are simple to handle.
The dispersions according to the invention have the advantage that they can be easily diluted and have a very long shelf-life even in dilute form.
The process for the preparation of the dispersions according to the invention has the advantage that it can be carried out in a simple manner without the need of a high-pressure homogenizer.
The dispersions according to the invention have the advantage that they develop a very good and stable impregnating effect and very good penetration behavior on different substrates.
The aqueous dispersions according to the invention can be used for all purposes for which dispersions based on organosilicon compounds have also been used to date. They are, for example, outstandingly suitable as preservatives for structures, in particular for hydrophobing various mineral or organic substrates. The manner in which such dispersions are used is known to the person skilled in the art.
The present invention furthermore relates to a process for the treatment of substrates, wherein the substrates are brought into contact with the dispersions according to the invention. Examples of substrates which can be treated with the dispersions according to the invention are mineral substances, such as masonry, mortar, brick, limestone, marble, sand-lime brick, sandstone, granite, porphyry, concrete and cellular concrete, and organic substances, such as wood, paper, board, textiles and manmade and natural fibers.
In the process according to the invention, the dispersions generally penetrate into the capillaries of the substrate and dry there.
In the process according to the invention, mineral substrates and wood-base materials are preferably used.
The treatment according to the invention preferably comprises impregnation, coating, priming and injection, particularly preferably impregnation, in particular the substrate being brought into contact with the dispersion and the dispersion penetrating partly or completely into the substrate.
The impregnation according to the invention preferably comprises hydrophobing impregnation and can be effected both as impregnation of the surface and as injection or as mass hydrophobing .
The water absorption of the substrate is drastically reduced by the hydrophobing according to the invention, which reduces the thermal conductivity but also prevents the destruction of the building materials by the influence of freezing and thawing cycles or salt or, in the case of wood-based materials, by rotting or fungal attack. Thus, not only is the value of the material thus treated preserved but, for example, lower energy consumption for heating and air conditioning is also ensured. For the impregnation applications according to the invention, the dispersions according to the invention are added to the surface of the substrate by customary distribution methods known to date, such as, for example, by brushing, spraying, knife coating, rolling, pouring, spreading with a trowel, immersion and roll coating. For masonry treatment, it is necessary for the preparations to penetrate far into the masonry. Low-viscosity dispersions are therefore preferred for the masonry treatment. The property of penetrating into the masonry may be a material property or the penetration is artificially promoted by transporting the dispersions into the masonry with elevated pressure.
The dispersions according to the invention can also be used in combinations with organic dispersions and pigments for formulating coating materials, in order to impart hydrophobic properties to these coating materials. This application can also be effected in combination with fluoroorganic polymer dispersions, for example if an oil- and dirt-repellent effect is also desired in addition to water-repellent effect, for example to prevent damage to the structure by graffiti.
In the process according to the invention, the dispersion according to the invention can be applied in concentrated form or in a form diluted with water, depending on substrate and the intended effect. If the application according to the invention is effected in dilute form, the content of component (A) in the dispersion used is then preferably from 2 to 35% by weight, in particular from 5 to 20% by weight.
The process for the treatment of substrates has the advantage that it is efficient and economical and that the substrates are protected in the long term from the influence of water.
In the following examples, all data relating to parts and percentages are based on weight, unless stated otherwise. Unless stated otherwise, the following examples are carried out at a pressure of the ambient atmosphere, i.e. at about 1000 hPa, and at room temperature, i.e. about 20°C, or a temperature which is established on combining the reactants at room temperature without additional heating or cooling.
Example 1
8 parts of isooctyltriethoxysilane (available under the name SILRES® BS 1701 from Wacker Chemie AG, Munich, Germany) are mixed with 4.5 parts of isoalkyl polyglycol ether (available under the name Imbentin T/77 from KLK OLEO, Hedingen, Switzerland (HLB = 15.2)) and 5 parts polyisobutylene (PIB) using a Turrax® mixer (IKA ® -Werke GmbH & Co.KG, Staufen, Germany) . Thereafter, 6 parts of deionized water are slowly added; a water-in-oil phase is formed. 35 parts of isooctytriethoxysilane are added along with 41.23 parts of deionized water. Finally, 0.20 parts triethanol amine (available under the name triethanol amine from Nexeo Solutions, The Woodlands, TX) and 0.07 parts 4,4- dimethyloxazolidine (available under the name Mergal® 192 available from Troy Corporation, Florham Park, New Jersey) are added to the emulsion and mixed. A low-viscosity oil-in-water emulsion of the invention is formed.
Example 2
A Turrax® mixer was used to produce a pre-blend of 3.00 parts isoalkyl polyglycol ether (available under the name Imbentin T/77 from KLK OLEO, Hedingen, Switzerland (HLB = 15.2)) and 4.50 parts deionized water. While mixing the pre-blend at approximately 8000 rpm, add 6.50 parts of dimethylpolysiloxane of a viscosity from 50 to 110 mPa-s at 25°C and mix until a water-in-oil phase is formed. Thereafter, 42.00 parts of isooctyltriethoxysilane (available under the name SILRES® BS 1701 from Wacker Chemie AG, Munich, Germany) are slowly added. Next, add in 0.50 parts of 3—(2— aminoethylamino)propylmethyldimethoxysilane (available under the name Geniosil® GF 95 from Wacker Chemie AG, Munich, Germany) . Then, 43.23 parts of deionized water is slowly added and the Turrax® speed is reduced to approximately 5000 rpm as resulting emulsion lets-down after inversion. Finally, 0.20 parts triethanol amine and 0.07 parts 4,4-dimethyloxazolidine are added to the emulsion and mixed. A low-viscosity oil-in water emulsion of the invention is formed.
Example 3
A Turrax® mixer was used to produce a pre-blend of 3.00 parts isoalkyl polyglycol ether (available under the name Imbentin T/77 and mix until from KLK OLEO, Hedingen, Switzerland (HLB = 15.2)) and 4.50 parts deionized water. While mixing the pre blend at approximately 8000 rpm, add 7.00 parts of poly(3-((2- aminoethyl)amino)propyl)methyl (dimethyl)siloxane, methoxy- terminated (available under the name WR1600 from Wacker Chemie AG, Munich, Germany) a water-in-oil phase is formed. Thereafter, 42.00 parts of isooctyltriethoxysilane (available under the name SILRES® BS 1701 from Wacker Chemie AG, Munich, Germany) are slowly added. Next, 43.23 parts of deionized water is slowly added and the Turrax® speed is reduced to approximately 5000 rpm as resulting emulsion lets-down after inversion. Finally, 0.20 parts triethanol amine and 0.07 parts 4,4-dimethyloxazolidine are added to the emulsion and mixed. A low-viscosity oil-in-water emulsion of the invention is formed. Comparative example 1
6.00 parts of isooctyltriethoxysilane (available under the name SILRES® BS 1701 from Wacker Chemie AG, Munich, Germany) are mixed with 2.00 parts of isoalkyl polyglycol ether (available under the name Imbentin T/77 from KLK OLEO, Hedingen, Switzerland (HLB = 15.2)) using a Turrax® mixer. Thereafter, 4.00 parts of deionized water are slowly added; a water-in-oil phase is formed. 46.00 parts of octylsilane triethoxy are added along with 39.93 parts of deionized water. Finally, 2.00 parts triethanol amine (available under the name triethanol amine from Nexeo Solutions, The Woodlands, TX) and 0.07 parts 4,4- dimethyloxazolidine (available under the name Mergal® 192 available from Troy Corporation, Florham Park, New Jersey) are added to the emulsion and mixed. A low-viscosity oil-in-water emulsion is formed.
Comparative example 2
12.00 parts of octylsilane triethoxy (available under the name SILRES® BS 1701 from Wacker Chemie AG, Munich, Germany) are mixed with 4.50 parts of isoalkyl polyglycol ether (available under the name Imbentin T/77 from KLK OLEO, Hedingen, Switzerland (HLB = 15.2)) using a Turrax® mixer. Thereafter, 6.00 parts of deionized water (conductivity ....) are slowly added; a water-in-oil phase is formed. 33.23 parts of octylsilane triethoxy are added along with 44.00 parts of deionized water. Finally, 0.20 parts triethanol amine (available under the name triethanol amine from Nexeo Solutions, The Woodlands, TX) and 0.07 parts 4,4-dimethyloxazolidine (available under the name Mergal® 192 available from Troy Corporation, Florham Park, New Jersey) are added to the emulsion and mixed. A low-viscosity oil-in-water emulsion is formed. Example 4
The stability of the examples 1 to 3 and comparative examples 1 and 2 were tested by storing the examples at elevated temperatures in a closed vessel for seven (7) months at 50° C, visual assessment of water and oil deposits and of the creaming of the emulsion were made. The results are shown in table 1.
Table 1:
Example 5
The inventive dispersions are used to reduce the capillary water uptake of mineral substrates. Accordingly, water absorption of substrates treated with the dispersions of the present invention was tested. The test was conducted on a standard substrate of ASTM C794 exposed aggregate concrete panels with a sample size of 3" x 6 x 3/8". For each example tested, three plates were used. Prior to impregnation of the substrate, the substrates were cleaned, and the initial weight of each substrate was measured (Wl). The substrates are then coated with the dispersion and stored for 7 days at 70°F and 50% relative humidity to allow for curing and development of full hydrophobicity. The samples are then weighted after the curing time (W2). The samples are then immersed for 24 hours in distilled water, the water column (head space) above the samples should be kept as close to 1 inch as possible. The samples are reweighted after 0.5hrs, 2hrs, 4hrs, 6hrs and 24 hrs. The panels are removed from the water and blot ted with a damp sponge to remove the excess water. For reference, three untreated substrates are tested as well. When samples are reweighed, the average weight increase can be calculated and used to determine the water absorption. The results are shown in table 2.
Table 2: