Fast wetting agent for dry-mix applications

Abstract

A particulate wetting and hydrophobing additive comprising components a) and b), where: component a) is a disiloxane having structure (I) Where R.sup.2 is selected from a branched or linear hydrocarbon group of 2 to 10 carbons, a substituted branched or substituted linear hydrocarbon group of 2 to 10 carbons, an aryl group, a substituted aryl group and an optionally substituted alkyl hydrocarbon group of 4 to 9 carbons containing aryl substituents of 6 to 20 carbons; R.sup.1, R.sup.3, R.sup.4 and R.sup.5 are each independently selected from the monovalent hydrocarbon groups of 1 to 4 carbons, substituted monovalent hydrocarbon groups of 1 to 4 carbon atoms, aryl, and a hydrocarbon group of 6 to 20 carbons containing an aryl group; Z is a linear or branched divalent hydrocarbon radical of 1 to 10 carbon atoms and R.sup.8 is selected from OH, H, monovalent hydrocarbon groups of 1 to 6 carbons and acetyl, each of the subscripts a, b and c are zero or positive provided that a+b+c1; and component b) is a carrier. ##STR00001##

Claims

1. A particulate wetting and hydrophobing additive comprising components a) and b), where: component a) is a disiloxane having structure ##STR00021## where R.sup.2 is selected from a branched or linear hydrocarbon group of 2 to 10 carbons, a substituted branched or substituted linear hydrocarbon group of 2 to 10 carbons, an aryl group, a substituted aryl group and an optionally substituted alkyl hydrocarbon group of 4 to 9 carbons containing aryl substituents of 6 to 20 carbons; R.sup.1, R.sup.3, R.sup.4 and R.sup.5 are each independently selected from the monovalent hydrocarbon groups of 1 to 4 carbons, substituted monovalent hydrocarbon groups of 1 to 4 carbons, aryl, and a hydrocarbon group of 6 to 20 carbons containing an aryl group; Z is a linear or branched divalent hydrocarbon radical of 1 to 10 carbons and R.sup.8 is selected from OH, H, monovalent hydrocarbon groups of 1 to 6 carbons and acetyl, each of the subscripts a, b and c are zero or positive provided that a+b+c1; and component b) is a carrier.

2. A particulate wetting and hydrophobing additive in accordance with claim 1 wherein R.sup.1, R.sup.3, R.sup.4 and R.sup.5 are each independently selected from monovalent hydrocarbon groups of 1 to 4 carbons, monovalent hydrocarbon groups of 1 to 4 carbons and at least one C-F bond, aryl, an optionally substituted hydrocarbon group of 6 to 20 carbons containing an aryl group; R.sup.2 is selected from a branched or linear hydrocarbon group of 2 to 10 carbons, an optionally substituted aryl group, and an alkyl hydrocarbon chain of 4 to 9 carbons having one or more aryl substituents of 6 to 20 carbons or a branched or linear hydrocarbon group of 2 to 6 carbons when R.sup.1 and R.sup.3 are independently an aryl group, or a hydrocarbon group of 6 to 20 carbons containing an aryl group; Z is a linear or branched divalent hydrocarbon radical of 2 to 10 carbons and R.sup.8 is selected from OH, H, monovalent hydrocarbon radicals of from 1 to 6 carbons and acetyl and each of the subscripts a, b and c are zero or positive provided that a+b+c1.

3. A particulate wetting and hydrophobing additive in accordance with claim 2 characterised in that in the disiloxane subscript a>1, subscript b0 and subscript c=0.

4. A particulate wetting and hydrophobing additive in accordance with claim 2 characterised in that in the disiloxane subscript a is 3 and b and c are both zero.

5. A particulate wetting and hydrophobing additive in accordance with claim 1 characterised in that in the disiloxane R.sup.1 and/or R.sup.3 is/are selected from the group of optionally substituted monovalent hydrocarbon radicals having 1 to 4 carbons, an optionally substituted aryl group, and a hydrocarbon group of 4 to 9 carbons containing an aryl group of 6 to 20 carbons and R.sup.4 and R.sup.5 are each independently selected from monovalent hydrocarbon radicals having 1 to 4 carbons.

6. A particulate wetting and hydrophobing additive in accordance with claim 1 characterised in that in the disiloxane R.sup.1 and/or R.sup.3 is/are optionally substituted aryl groups and R.sup.4 and R.sup.5 are each independently selected from monovalent hydrocarbon radicals having 1 to 4 carbons.

7. A particulate wetting and hydrophobing additive in accordance with claim 1 characterised in that in the disiloxane R.sup.2 is selected from a linear or branched hydrocarbon group of 8 to 12 carbons or an optionally substituted aryl group.

8. A particulate wetting and hydrophobing additive in accordance with claim 1 characterised in that the carrier is selected from one or more of gypsum, calcium sulphate formed in flue gas desulphurisation, magnesium sulphate or barium sulphate starch, native starch, methyl cellulose, carboxy methyl cellulose, sand, silica, alumino silicates, clay materials, zeolites, calcium carbonates, polystyrene beads and/or polyacrylate beads.

9. A particulate wetting and hydrophobing additive in accordance with claim 1 characterised in that the additive comprises granules which additionally comprise a water-soluble or water-dispersible binder material selected from one or more of polyvinyl alcohol, methyl cellulose, carboxy methyl cellulose, ethoxylated fatty alcohols and mixtures thereof with fatty acids and fatty acid esters.

10. A particulate wetting and hydrophobing additive in accordance with claim 1 characterised in that granules comprise based on a total weight of 100%, 5 to 80% by weight of carrier based on the total weight of the granular composition from 3 to 45% by weight of binder based on the total weight of the granular composition and from 5 to 90% disiloxane based on the total weight of the granular composition, based on the proviso that the total composition always comprises 100% by weight.

11. A particulate wetting and hydrophobing additive in accordance with claim 1 characterised in that the composition further comprises a trisiloxane have the following general formula: ##STR00022## where each R.sup.6 is independently a hydrocarbon having 1 to 4 carbons and R.sup.7 is
Z(OC.sub.2H.sub.4).sub.d(OC.sub.3H.sub.6).sub.e(OC.sub.4H.sub.8).sub.fR.sup.8 in which Z is a linear or branched divalent hydrocarbon radical of from 1 to 10 carbons and R.sup.8 is selected from OH, H, monovalent hydrocarbon radicals of from 1 to 6 carbons and acetyl, d is from 1 to 30 and e and f are independently from 0 to 10.

12. A particulate wetting and hydrophobing additive in accordance with claim 1 characterised in that the disiloxane is selected from one or more of the siloxanes in accordance with Formulas 1, 3, 5 and 7: ##STR00023## where y is an integer of from 2 to 7, and x is an integer of from 5 to 10; ##STR00024## where y is an integer of from 2 to 7, and x is an integer of from 5 to 10; ##STR00025## where y is an integer of from 2 to 7, z is an integer of from 5 to 15, and v is an integer of from 2 to 10; ##STR00026## where y is an integer of from 2 to 7, and x is an integer of from 5 to 10.

13. A cementitious material dry-mix comprising dry cement and a particulate wetting and hydrophobing additive as defined in claim 1 in an amount sufficient to give from 0.01 to 2% by weight of the disiloxane.

14. A cementitious material dry-mix in accordance with claim 13 additionally comprising one or more hydrophobing materials selected from palmitic acid salt(s), stearic acid salt(s) or oleic acid salt(s) of one or more of the following: zinc, iron, copper, barium, calcium, magnesium, lithium, sodium, potassium, aluminium and ammonia, silane or siloxane hydrophobic powder.

15. A process for imparting a hydrophobic character to cementitious material, comprising mixing into the cementitious material a particulate wetting and hydrophobing additive as defined in claim 1 and subsequently adding water.

Description

EXAMPLES

(1) There now follows a number of examples which illustrate the invention in detail but are not to be construed to limit the scope thereof. All parts and percentages in the examples are on a weight basis and all measurements were obtained at room temperature (typically 20 C.+/1-2 C.) unless indicated to the contrary.

(2) A series of samples were prepared as described below:

(3) Powdered organomodified siloxane 1

(4) 19.6 g diphenyl disiloxane having the following formula:

(5) ##STR00018##
(Where R.sup.1, R.sup.4 and R.sup.5 are each methyl groups) was mixed in 60.3 g of an aqueous polyvinyl alcohol solution containing 20% solid content for 3 minutes with a rotor/stator mixer (Ultraturrax) to form an emulsion. The polyvinyl alcohol used was Mowiol 4/88 from Kuraray which has a viscosity of 3.5 mPa.Math.s at 4% solid content using a Hppler viscometer and 88% hydrolysis (88% of polyvinyl acetate groups hydrolysed to alcohol groups during preparation). 39.8 g of the resultant creamy emulsion was poured over 100.1 g of zeolite (DOUCIL 4 A from INEOS) with a particle size of between 2 to 5 m and the whole was placed in a domestic kitchen food mixer under agitation at maximum mixer speed for a total mixing period of 15-30 seconds resulting in a granulated powder. The granulated powder was dried in a Strea-1cc fluidised bed from Niro for 15 minutes and sieved to remove any particles larger than 0.5 mm diameter. The resulting granulated powder is henceforth referred to as powdered organomodified siloxane 1.
Powdered Organomodified Siloxane 2

(6) 20 g of a disiloxane of the formula

(7) ##STR00019##
was mixed in 60 g of an aqueous polyvinyl alcohol solution 20% solid (Mowiol 4/88 from Kuraray) for 3 minutes with a rotor/stator mixer (Ultraturrax) to form an emulsion. 39.8 g of the resultant creamy emulsion was poured over 101 g of zeolite (DOUCIL 4A from INEOS), having a particle size of about 2 to 5 m in domestic kitchen food mixer under agitation at maximum mixer speed within a period of 15-30 seconds resulting in a granulated powder. The granulated powder was dried in a Strea-1cc fluidised bed from Niro for 15 minutes and sieved to remove any particles larger than 0.5 mm diameter. The resulting granulated powder is henceforth referred to as powdered organomodified siloxane 2.
Powdered Organomodified Siloxane 3

(8) 19.9 g of an n-octyldisiloxane of the following formula:

(9) ##STR00020##
was mixed in 60 g of an aqueous polyvinyl alcohol solution 20% solid (Mowiol 4/88 from Kuraray) for 3 minutes with a rotor/stator mixer (Ultraturrax) to form an emulsion. 39.8 g of the resultant creamy emulsion was poured over 101 g of zeolite (DOUCIL 4A from INEOS), having a particle size of about 2 to 5 m in a domestic kitchen food mixer under agitation at maximum mixer speed for a period of 15-30 seconds resulting in a granulated powder. The granulated powder was dried in a Strea-1cc fluidised bed from Niro for 15 minutes and sieved to remove any particles larger than 0.5 mm diameter. The resulting granulated powder is henceforth referred to as powdered organomodified siloxane 3.
Comparative Powdered Organomodified Siloxane 1

(10) 19.9 g 1,1,1,3,5,5,5-Heptamethyl-3-(propyl(poly(EO))acetate)trisiloxane was mixed in 60.2 g of an aqueous polyvinyl alcohol solution 20% solid (Mowiol 4/88 from Kuraray) for 3 minutes with a rotor/stator mixer (Ultraturrax). 40.3 g of the resultant creamy emulsion was poured over 104.3 g of zeolite (DOUCIL 4A from INEOS), having a particle size of about 2 to 5 m in a domestic kitchen food mixer under agitation at maximum mixer speed within a period of 15-30 seconds resulting in a granulated powder. The granulated powder was dried in a Strea-1 cc fluidised bed from Niro for 15 minutes and sieved to remove any particles larger than 0.5 mm diameter. The resulting granulated powder is henceforth referred to as Comparative powdered organomodified siloxane 1.

(11) Comparative Powdered Organomodified Siloxane 2

(12) 19.6 g of Trimethylsiloxy-terminated Dimethyl, Methyl(propyl(poly(EO)(PO)) hydroxy) Siloxane having a viscosity of 41 cSt at 25 C. using the glass capillary method (ASTM D445-11a Standard test Method for Kinematic Viscosity of Transparent and opaque Liquids), was mixed in 60.2 g of an aqueous polyvinyl alcohol solution 20% solid (Mowiol 4/88 from Kuraray) for 3 minutes with a rotor/stator mixer (Ultraturrax) to form an emulsion. 41.3 g of the resultant creamy emulsion was poured over 100.6 g of zeolite (DOUCIL 4A from INEOS), having a particle size of about 2 to 5 m in a domestic kitchen food mixer under agitation at maximum mixer speed within a period of 15-30 seconds resulting in a granulated powder. The granulated powder was dried in a Strea-1cc fluidised bed from Niro for 15 minutes and sieved to remove any particles larger than 0.5 mm diameter. The resulting granulated powder is henceforth referred to as Comparative powdered organomodified siloxane 2.

(13) The Dynamic Wetting of standard compositions containing an amount of each respective powdered organomodified siloxane 1, 2 and 3 and comparative powdered organomodified siloxane 1 were prepared by identical processes and are referred to as Examples 1, 2, 3 and Comparative 1 in Table 1 below, which compares their results to a reference material containing no wetting agent. Each siloxane was prepared for the test by the method described below (Preparation of Example 1), the only differences being in each case the replacement of sample 1 with each respective alternative powdered organomodified siloxanes or Comparative powdered organomodified siloxane 1.

Preparation of Example 1

(14) 0.52 g of powdered organomodified polysiloxane 1 was introduced into a Krups mixer (KA 940 model), having a 5 liters stainless steel 2 handle mixing bowl and a 1.5 Liters stainless steel blender, together with: 390 g of dried sand which has a granulometry of up to a maximum of 2 mm; 130 g of cement (CEM II 32.5 N); and 1.3 g of zinc stearate. The powders are then blended homogeneously for 60 seconds at level 2 speed.

(15) The resulting Examples and Comparatives were compared using the following Dynamic wetting test method:

(16) After having homogenized the powders, 65 g of water was introduced into the bowl at level 2 speed. The time needed by the water to totally wet the dry mix is timed and is henceforth referred to as the dynamic wetting time. The dynamic wetting time is compared with the reference dynamic wetting time of a Reference dry-mix that contains only the quantities of sand, cement and zinc stearate (dynamic wetting time that is lower than the reference dynamic wetting time induces an excellent wettability and thus a good ease of use). The results are obtained from an average of three measurements.

(17) TABLE-US-00001 TABLE 1 Dynamic wetting time (s) Example 1 9 Example 2 9 Example 3 10 Reference 28 Comparative 1 14

(18) These results show that examples 1, 2 and 3 are better than the reference and comparative examples because the time needed by the water to wet the dry-mix is significantly shorter.

(19) Static Wetting Test for standard compositions containing an amount of each respective powdered organomodified siloxane and comparative powdered organomodified siloxane prepared above were prepared in an identical process as follows using the siloxanes indicated in Table 2a

(20) TABLE-US-00002 TABLE 2a Example 4 Powdered organomodified siloxane 1 Example 5 Powdered organomodified siloxane 2 Example 6 Powdered organomodified siloxane 3 Reference None Comparative 2 Comparative powdered organomodified siloxane 1. Comparative 3 Comparative powdered organomodified siloxane 2.

Example 4

(21) A dry-mix composed of 54 g of dried sand which has a granulometry between 0 and 2 mm and 18 g of cement (CEM II 32.5N) is prepared within a closed pot. Then 0.18 g of zinc stearate and 0.072 g of powdered organomodified siloxane 1 was introduced into the closed pot. The dry-mix was then blended for 60 seconds.

(22) The preparation of Examples 5 and 6 and Comparatives 2 and 3 was analogous to the preparation of Example 4 with only the respective powdered organomodified siloxane replacing powdered organomodified siloxane 1. In the case of the Reference the only difference is that no siloxane is added.

(23) Reference:

(24) A dry-mix composed of 54 g of dried sand which has a granulometry between 0 and 2 mm and 18 g of cement (CEM II 32.5N) is prepared within a closed pot. Then 0.18 g of zinc stearate is introduced into the closed pot. The dry-mix is then blended for 60 seconds.

(25) The static wetting test was carried out as follows: Equal amounts by weight of each example and comparative was placed on separate plates. Five water drops are softly dropped onto the respective dry-mixes. The time for the water drops to totally wet the dry-mix is measured using a Hanhart sprint chronometer and is henceforth referred as static wetting time.

(26) The static wetting time is compared with the static wetting time of the Reference dry-mix containing only quantities of sand, cement and zinc stearate (static wetting time that is lower than the reference static wetting time induces an excellent wettability and thus a good ease of use). The results are obtained from an average of five measurements and are provided in Table 2b below in which SWT is Static Wetting Time.

(27) TABLE-US-00003 TABLE 2b SWT SWT SWT SWT SWT 1.sup.st 2.sup.nd 3.sup.rd 4.sup.th 5.sup.th Aver- Drop(s) Drop(s) Drop(s) Drop(s) Drop(s) age(s) Example 4 300 300 300 480 480 300 Example 5 180 360 360 360 480 300 Example 6 480 480 480 540 540 480 Reference 480 480 540 540 600 528 Comp 2 300 420 420 600 600 380 Comp 3 240 300 300 300 720 280

(28) Compared to the Reference in which only Zn stearate was utilised in the dry-mix, all other examples provide a better ease of use because the average drop entry time decreased from more than 500 seconds for the reference dry-mix to less than 300 seconds for modified dry-mixes.

(29) Protocol of Drop Entry Time and Beading Test

(30) Examples and comparatives were prepared to determine the drop entry time and beading for standard compositions containing an amount of each respective powdered organomodified siloxane and comparative powdered organomodified siloxane prepared above were prepared in an identical process as follows using the siloxanes indicated in Table 3a below:

(31) TABLE-US-00004 TABLE 3a Example 7 Powdered organomodified siloxane 1 Example 8a & 8b Powdered organomodified siloxane 2 Example 9a, 9b & 9c Powdered organomodified siloxane 3 Reference 2a, 2b & 2c None Reference 3a and 3b None Comparative 4a and 4b Comparative powdered organomodified siloxane 1 Comparative 5a and 5b Comparative powdered organomodified siloxane 2

Example 7

(32) 108 g of dried sand of granulometry between 0-2 mm, 36 g of cement (CEM II 32.5N), 0.36 g of zinc stearate and 0.144 g of powdered organomodified siloxane 1 are dry blended for one minute. Then 19 g of mixing water is added. The resulting slurry is then poured into a pre-prepared test piece mould measuring 606020 mm. The mould is place on a vibrating table for 3 minutes and then placed in a closed container at 100% Relative humidity. The test mortar block is de-moulded after 24 hours and allowed to cure in a chamber for a period of 7 days at a temperature of 25 C. and at 100% relative humidity. After 7 days of cure, the mortar block is dried for 24 hours in an oven at 50 C.

(33) The preparation of Examples 8, 9 and comparatives 4 and 5 were prepared in an analogous manner to using Powdered organomodified siloxane 1 in the preparation of Example 7 with the only difference being the replacement of the respective siloxane.

Reference 2a, 2b and 2c

(34) 108 g of dried sand of granulometry between 0-2 mm, 36 g of cement (CEM II 32.5N), 0.36 g of zinc stearate are dry blended for one minute. Then 19 g of mixing water is added. The resulting slurry is then poured into a pre-prepared test piece mould measuring 606020 mm. The mould is placed on a vibrating table for 3 minutes and then placed in a closed container at 100% Relative humidity. The test mortar block is de-moulded after 24 hours and allowed to cure in a chamber for a period of 7 days at a temperature of 25 C. and at 100% relative humidity. After 7 days of cure, the mortar block is dried for 24 hours in an oven at 50 C.

Reference 3a

(35) 108 g of dried sand of granulometry between 0-2 mm, 36 g of cement (CEM II 32.5N), 0.36 g of zinc stearate are dry blend for one minute. Then 19 g of mixing water is added. The resulting slurry is then poured into a pre-prepared test piece mould measuring 606020 mm. The mould is place on a vibrating table for 3 minutes and then placed in a closed container at 100% Relative humidity. The test mortar block is de-moulded after 24 hours and allowed to cure in a chamber for a period of 7 days at a temperature of 25 C. and at 100% relative humidity. After 7 days of cure, the mortar block is dried for 24 hours in an oven at 50 C.

Reference 3b

(36) 108 g of dried sand of granulometry between 0-2 mm, 36 g of cement (CEM II 32.5N), 0.504 g of zinc stearate are dry blend for one minute. Then 19 g of mixing water is added. The resulting slurry is then poured into a pre-prepared test piece mould measuring 606020 mm. The mould is placed on a vibrating table for 3 minutes and then placed in a closed container at 100% Relative humidity. The test mortar block is de-moulded after 24 hours and allowed to cure in a chamber for a period of 7 days at a temperature of 25 C. and at 100% relative humidity. After 7 days of cure, the mortar block is dried for 24 hours in an oven at 50 C.

(37) Protocol of Drop Entry Time and Beading Test

(38) A water droplet is gently deposited on the modified mortar surface with a pipette. The time needed to have the water droplet completely absorbed by the mortar surface is recorded (referred in this document as the drop entry time) and the average of 5 independent measurements is calculated.

(39) Beading effect is a qualitative comparison between the spreading and the shape of the water droplets deposited on the surface of the mortar block and is measured using a ranking scheme: from 0 (for a droplet that totally wets the surface of the mortar block, i.e. resulting in a flat droplet), to 5 (for a droplet that forms a perfect spherical droplet on the surface of the mortar block.

(40) TABLE-US-00005 TABLE 3b DET DET DET DET DET drop drop drop drop drop Aver- 1 2 3 4 5 age Beading (min) (min) (min) (min) (min) (min) Effect Ex 7 14 29 35 40 60 35.6 4 Ex 8a 18 26 27 30 43 28.8 3 Ex 8b 11 32 42 45 60 38 3 Ex 9a 7 9 11 11 18 11.2 4 Ex 9b 13 24 27 40 47 30.2 4 Ex 9c 4 24 29 35 60 30.4 4 Ref 2a 1 1 1 2 2 1.4 0 Ref 2b 1 1 1 3 3 1.8 0 Ref 2c 1 1 2 2 3 1.8 0 Ref 3a 2 4 5 7 12 6 1 Ref 3b 2 3 8 13 15 8.2 1 Comp 4a 6 17 22 22 30 19.4 3 Comp 4b 3 6 10 16 16 10.2 3 Comp 5a 6 8 14 17 20 13 2 Comp 5b 5 10 16 16 17 12.8 2

(41) The results show that reference examples 2a, 2b and 2c give very bad beading effect with a value of zero and a Drop Entry Time (DET) between 1 and 2 minutes, meaning that there is no hydrophobic treatment of the mortar block. Results regarding Reference examples 3a and 3b that are modified with stearate indicate a slight hydrophobic nature as the beading effect value is one and their DET is between 6 and 8 minutes. Comparative examples 4a, 4b, 5a and 5b that are modified with stearate and standard silicone superwetter also exhibit a higher hydrophobic nature than the References as the silicone surfactants help the stearate to be more homogeneously distributed over the mortar block. However, Examples 7, 8a, 8b, 9a, 9b and 9c exhibit on average an even better hydrophobic nature (i.e. a significantly better application onto the mortar block) as their beading effect value was between 3 and 4 and their DET was on average greater than 25 minutes. Examples show that new disiloxanes provide to mortar block hydrophilic effect in the first place and after degradation surprisingly provide high level of hydrophobicity to mortar block.