SILICONE EMULSION AND USES THEREOF

Abstract

Aqueous silicone emulsion compositions which cure utilising titanium-based reaction products as catalysts, and a process to prepare the same and their uses, are provided. The composition comprises (a) a titanium-based reaction product; (b) one or more silicon containing compounds having at least 2 or at least 3 hydroxyl and/or hydrolysable groups per molecule; (c) one or more surfactants; and (d) water. The titanium-based reaction product (a) is obtained or obtainable from a process comprising the steps of: (i) mixing a first ingredient, an alkoxy titanium compound having from 2 to 4 alkoxy groups with a second ingredient, a linear or branched polydiorganosiloxane having at least two terminal silanol groups per molecule and a viscosity of from 30 to 300,000 mPa.Math.s at 25 C.; (ii) enabling the first and second ingredients to react together by stirring under vacuum to form a reaction product; and (iii) collecting the reaction product of step (ii).

Claims

1. An aqueous silicone emulsion composition comprising: (a) a titanium-based reaction product obtained or obtainable from a process comprising the steps of: (i) mixing a first ingredient, an alkoxy titanium compound having from 2 to 4 alkoxy groups with a second ingredient, a linear or branched polydiorganosiloxane having at least two terminal silanol groups per molecule and a viscosity of from 30 to 300,000 mPa.Math.s at 25 C.; (ii) enabling the first and second ingredients to react together by stirring under vacuum to form a reaction product; and (iii) collecting the reaction product of step (ii); (b) one or more silicon containing compounds having at least 2, optionally at least 3, hydroxyl and/or hydrolysable groups per molecule; (c) one or more surfactants; and (d) water.

2. The aqueous silicone emulsion composition in accordance with claim 1, wherein the first ingredient in the method for the preparation of component (a) is Ti(OR).sub.4, Ti(OR).sub.3R.sup.1, Ti(OR).sub.2R.sup.1.sub.2 or a chelated alkoxy titanium molecule where there are two alkoxy (OR) groups present and a chelate bound twice to the titanium atom; where R is a linear or branched alkyl group having from 1 to 20 carbons and each R.sup.1 may be the same or different and is selected from an alkyl group, an alkenyl group or an alkynyl group in each case having up to 10 carbons.

3. The aqueous silicone emulsion composition in accordance with claim 1, wherein the second ingredient in the method for the preparation of component (a) is a dialkylsilanol terminated polydimethylsiloxane.

4. The aqueous silicone emulsion composition in accordance with claim 1, wherein the second ingredient has a viscosity of between 70 and 20,000 mPa.Math.s at 25 C.

5. The aqueous silicone emulsion composition in accordance with claim 1, wherein the method for the preparation of component (a) utilises a third ingredient, a polydialkylsiloxane having one terminal silanol group per molecule, which is introduced in step (i).

6. The aqueous silicone emulsion composition in accordance with claim 1, wherein component (b) is selected from silanes having at least 2 hydrolysable groups, optionally at least 3 hydrolysable groups per molecule or an organopolysiloxane polymer having at least two hydroxyl or hydrolysable groups per molecule of the formula
X.sub.3-nR.sup.3.sub.nSi(Z).sub.d(O).sub.q(R.sup.4.sub.ySiO.sub.(4-y)/2).sub.z(SiR.sup.4.sub.2Z).sub.dSiR.sup.3.sub.nX.sub.3-n(7) in which each X is independently a hydroxyl group or a hydrolysable group, each R.sup.3 is an alkyl, alkenyl or aryl group, each R.sup.4 is an X group, alkyl group, alkenyl group or aryl group and Z is a divalent organic group; d is 0 or 1, q is 0 or 1 and (d+q)=1; n is 0, 1, 2 or 3, y is 0, 1 or 2, optionally y is 2, and z is an integer such that the organopolysiloxane polymer has a viscosity of from 50 to 150,000 mPa.Math.s at 25 C.

7. The aqueous silicone emulsion composition in accordance with claim 1, wherein the composition also includes one or more additives selected from the group consisting of fillers, thickeners, preservatives and biocides, pH controlling agents, adhesion promoters, inorganic salts, dyes, perfumes, and mixtures thereof.

8. The aqueous silicone emulsion composition in accordance with claim 1, wherein the average volume particle size of a dispersed oil phase in a continuous aqueous phase of the emulsion is between 0.1 m and 150 m.

9. The aqueous silicone emulsion composition in accordance with claim 1, wherein component (b) is titanium free.

10. The aqueous silicone emulsion composition in accordance with claim 1, which is a one-part emulsion containing components (a) to (d), or is a two-part emulsion comprising: (i) an emulsion J containing components (a), (c) and (d) but not component (b); and an emulsion K containing components (b), (c) and (d) but not component (a); or (ii) an emulsion J containing components (a), (c), (d) and part of component (b); and an emulsion K containing (c), (d), and the rest of the component (b).

11. A method for preparing an aqueous silicone emulsion composition said method comprising: preparing a titanium-based reaction product (a) from a process comprising the steps of: (i) mixing a first ingredient, an alkoxy titanium compound having from 2 to 4 alkoxy groups with a second ingredient, a linear or branched polydiorganosiloxane having at least two terminal silanol groups per molecule and a viscosity of from 30 to 300,000 mPa.Math.s at 25 C.; (ii) enabling the first and second ingredients to react together by stirring under vacuum to form a reaction product; and (iii) collecting the reaction product of step (ii); and mixing the following components with the titanium-based reaction product (a) to form an emulsion: (b) one or more silicon containing compounds having at least 2, optionally at least 3, hydroxyl and/or hydrolysable groups per molecule; (c) one or more surfactants; and (d) water.

12. The method for preparing an aqueous silicone emulsion composition in accordance with claim 11, wherein the emulsion composition is prepared in two parts: an emulsion J, by mixing component (a) with component (c) and admixed with a sufficient amount of component (d) to form an emulsion; optionally, further shear mixing of the emulsion and/or diluting of the emulsion with component (d); and component (b) is separately mixed with components (c) and (d) and emulsified to form an emulsion K; or part of component (b) is mixed with component (a) and simultaneously or subsequently is mixed with component (c) admixed with a sufficient amount of component (d) to form an emulsion J; optionally, further shear mixing of the emulsion and/or diluting of the emulsion with component (d); and the remainder of component (b) is separately is-mixed with component (c) admixed with a sufficient amount of component (d) to form an emulsion K; optionally, further shear mixing of the emulsion and/or diluting of the emulsion with component (d).

13. The method for preparing an aqueous silicone emulsion composition in accordance with claim 12, wherein subsequently the two emulsions J and K are mixed together in any suitable weight:weight ratio to form the emulsion composition.

14. An elastomer, which is a product from the aqueous silicone emulsion composition in accordance with claim 1 upon the removal of water.

15. (canceled)

Description

EXAMPLES

[0136] All viscosity measurements were made using a Modular Compact Rheometer (MCR) 302 from Anton Paar GmbH of Graz, Austria using a 25 mm diameter rotational plate with a gap of 0.3 mm at a shear rate of 1 s.sup.1. All viscosities were measured at 25 C. unless otherwise indicated. The water used in the emulsification step herein was softened and demineralized.

[0137] The following ingredients were used in the Examples and are referred to using the short term in the Tables below: [0138] Polymer 1: a substantially linear dimethylsilanol terminated polydimethylsiloxane having a viscosity ca. 803 mPa.Math.s; [0139] Polymer 4: a trimethoxysilyl terminated polydimethylsiloxane having a viscosity ca 63,000 mPa.Math.s; [0140] Polymer 3: a triethoxysilyl terminated polydimethylsiloxane having a viscosity ca 60,000 mPa.Math.s; [0141] TiPT: Tetra isopropoxy Titanium; [0142] TtBT: Tetra t-butoxy Titanium; [0143] Lutensol XP 79: is a non-ionic surfactant containing C10-Guerbet alcohol and an average of 7 ethylene-oxide (EO) groups per molecule and is commercially available from BASF; and [0144] Brij L3 and Brij L23 are non-ionic surfactants containing ethoxylated natural fatty alcohols, based on lauryl alcohol, having 3 and 23 ethylene-oxide groups on average respectively and are commercially available from CRODA.

Preparation of Titanium-Based Reaction Products

[0145] Three component (a) reaction products RP1, RP2 and RP3 were prepared for use in the examples. The ingredients used in their preparation are depicted in Table 1 below and the process followed in each case was otherwise identical and as such is exemplified below with the preparation of RP1.

TABLE-US-00001 TABLE 1 Ingredients for the three component (a) reaction products used in the Examples Amount Amount weight ratio present present Ingredient 2/ Ingredient 1 (g) Ingredient 2 (g) Ingredient 1 RP1 TiPT 0.801 Polymer 1 199.997 250 RP2 TiPT 0.600 Polymer 1 199.990 333 RP3 TtBT 1.290 Polymer 1 199.961 155

[0146] Preparation of RP1

[0147] 199.997 g of Polymer 1was introduced into a plastic receptacle of a DAC 600 FVZ/VAC-P type SpeedMixer from Hauschild & Co. KG Germany. 0.801 g of TiPT was then added into the Polymer 1. A lid was placed on the receptacle and the initial weight of the ingredients, the receptacle and the lid were weighed together. Vacuum of about 160 mbar (16 kPa) was applied during mixing. The lid of the receptacle was pierced with 5 small holes to allow the volatile compounds to leave the mixture.

[0148] The ingredients were then mixed in a DAC 600 FVZ/VAC-P type SpeedMixer from Hauschild & Co. KG Germany for 6 periods of 4 minutes at 2350 rpm under vacuum.

[0149] After completion of the above mixing regime the receptacle, lid resulting reaction product, were re-weighed to determine weight loss due to the extraction of volatile alcohols. The weight loss was determined to be=0.662 g. The resulting loss of 0.662 g in weight accounted for approximately 97.9% of the alcohol content extractable as a by-product of the reaction between the first and second ingredients. The calculated SiOH/Ti molar ratio was about 9.6:1, assuming a number average molecular weight of the polymer of about 14,800.

[0150] The viscosity of RP1 generated via the above process was then determined to be 18,000 mPa.Math.s using a Modular Compact Rheometer (MCR) 302 from Anton Paar GmbH of Graz, Austria a diameter rotational plate with a gap of 0.3 mm at a shear rate of 1 s.sup.1. RP1 was then stored at room temperature in a glass bottle for a period of 28 days before the viscosity was re-measured using the same testing protocol is and was found to have remained pretty constant.

[0151] Two series of examples have been prepared, firstly using two-part emulsion compositions and secondly using one-part emulsion compositions.

Two-Part Emulsion Compositions

[0152] A series of two-part (K and J) emulsions were prepared. The type K emulsions contain components (b), (c) and (d) but not component (a). The compositions of the prepared type K emulsions are depicted as Examples 1 to 6 (E1 to 6) in Table 2a. The type J emulsions contain components (a), (c) and (d) but not component (b). The composition of the prepared type J emulsions are depicted as Examples 7 to 10 (E7 to 10) in Table 2b.

[0153] The type K emulsions and type J emulsions were prepared using one of two alternative processes, process 1 or process 2 using a SpeedMixer DAC 150.1 FV from Hauschild & Co. KG

[0154] Germany.

Process 1

[0155] Step 1: The respective component (a) or component (b) was introduced into the mixer and then the surfactant(s) was/were added and the combination was mixed for 35 sec at 3500 rpm to produce an oil phase. [0156] Step 2. Water was introduced into the oil phase product of step 1 stepwise using portions no bigger than 3% wt. (calculated over the entire weight of emulsion). Each addition was followed by mixing for 35 sec at 3500 rpm and this was repeated until a silicone-in-water emulsion which was easily and completely dispersible in water was obtained. [0157] Step 3. Dilution water was then added stepwise at portions of 5 to 15% wt. (calculated over the entire weight of emulsion) to the emulsion resulting from step 2 above. This was continued until a silicone-in-water emulsion of consisting of an oil phase which was 70-80 wt. % of the emulsion calculated over the entire weight of emulsion) was obtained.

Process 2

[0158] Step 1: The respective component (a) or component (b) was introduced into the mixer and then the surfactant(s) was/were added and the combination was mixed for 35 sec at 3500 rpm to produce an oil phase. [0159] Step 2. Sufficient water to obtain silicone-in-water emulsion was added in one step, followed by mixing for 35 sec at 3500 rpm. [0160] Step 3. Dilution water was then added stepwise at portions of 5 to. 15% wt. (calculated over the entire weight of emulsion) to the emulsion resulting from step 2 above. This was continued until a silicone-in-water emulsion of consisting of an oil phase which was 70-80 wt. % of the emulsion (calculated over the entire weight of emulsion) was obtained.

[0161] In both Tables 2a and 2b the highlighted water values in the examples below refer to the last amount of water added to in Step 2 regardless the process.

TABLE-US-00002 TABLE 2a K type emulsion comprising component (b) but not component (a) E1 E2 E3 E4 E5 E6 Emulsification process 1 1 2 2 1 2 Polymer 4 74.58% 75.22% 75.97% 76.05% 75.95% Polymer 3 76.38% Brij L3 0.75% 0.73% 0.74% 0.73% Brij L23 2.22% 2.21% 2.19% 2.22% Lutensol XP 79 3.05% 3.02% water 1 1.53% 2.55% 1.55% 1.50% 0.77% 1.24% water 2 1.53% 8.90% 9.68% 9.33% 0.44% 9.69% water 3 8.97% 10.30% 9.42% 10.26% 0.34% 10.17% water 4 10.33% 9.18% water 5 10.30% TOTAL 100.00% 100.00% 100.00% 100.00% 100.00% 100.00%

TABLE-US-00003 TABLE 2b J type emulsion comprising component (a) but not component (b) E7 E8 E9 E10 Emulsification 1 2 2 2 process RP1 76.46% 75.86% RP3 77.09% 75.92% Brij L3 0.73% 0.81% 0.74% 0.76% Brij L23 2.23% 2.41% 2.16% 2.20% water 1 2.77% 4.74% 5.48% 3.88% water 2 2.89% 10.43% 9.42% 12.65% water 3 9.61% 5.75% 5.11% 4.56% water 4 5.31% TOTAL 100.00% 100.00% 100.00% 100.00%

Particle Size of the 2-Part Emulsions

[0162] Typical emulsion particle sizes for two K type emulsions from Table 2a, namely E5 and E6 and two J type emulsions from Table 2b, namely, E8 and E10 were determined using a Masterziser 3000 from Malvern Pananalytical Ltd of Malvern, U.K. Tests were made to determine D.sub.10 (m) and D.sub.50 (m). For the avoidance of doubt D.sub.10 (m) means 10% of the particles in the sample are smaller than the value given in m and likewise D.sub.50 (m) (or D.sub.0.5 as identified above) means 50% of the particles in the sample are smaller than the value given. Furthermore, compositions E6 and E8 were mixed to give a final composition and the particles sizes for the said mixtures were also assessed. The results are provided in Table 3 below.

TABLE-US-00004 TABLE 3 Sample Name D.sub.10 (m) D.sub.50 (m) E5 (type K) 1.26 1.98 E6 (type K) 1.16 4.22 E8 (type J) 0.614 1.0 E10 (type J) 0.768 0.92 mix - E8:E6 wt. ratio 1:1 0.674 1.42 mix - E8:E6 wt. ratio 1:0.75 0.668 1.49 mix - E8:E6 wt. ratio 1:0.4 0.688 1.63

[0163] This example shows that the obtained emulsions have a mean particle size (D50) within the range of 0.3-5 um.

Film Forming of Mixed Two-Part Emulsions

[0164] Four mixed emulsions were prepared, MIX 1 to MIX 4 as indicated in Table 4 below. In each MIX a type K and a type J emulsion were mixed together. A several hundred micron thick film was applied onto a polyethylene substrate and left to dry (i.e. to let water to evaporate away for a period of 4 hours and then for and 1 week and the haptic attributes of the film were assessed for tackiness. Tackiness was reviewed by touching the coating gently with the finger and comparing the coatings relative to each other. Uncured films produce long strings when touched with a finger or spatula. The cured films, regardless of level of tackiness, were self-standing. Provided the film was cured the tackiness of the film may be varied to meet the desired effect of the application for which it is to be used.

TABLE-US-00005 TABLE 4 Ability of two-part Emulsions to form a film layer & tackiness thereof E3 (g) E6 (g) E8 (g) Tackiness (type K) (type K) (type J) Tackiness (4 h) (1 week) MIX 1 15.071 6.03 Very Tacky Not tacky MIX 2 10.101 10.0 Very Tacky Slightly tacky MIX 3 14.92 5.968 Not cured Tacky MIX 4 9.98 9.997 Not cured Tacky

[0165] It will be appreciated that given the two-part nature of the Mixes 1 to 4 one can modify the ratio of Emulsion K to Emulsion J so that one can dial the cure time of the elastomer as well as the properties of the obtained film.

Stability of Two-Part Emulsions

[0166] Emulsion of Examples E3, E6, E8, were subjected to accelerated ageing via storage at 50 C. oven for 4 weeks. All samples remain readily dispersible, no coalescence or creaming were observed and as such both K type and J type emulsions remain stable with time and as such may be stored prior to mixing and forming the combined emulsion.

One-Part Emulsion Compositions

[0167] A series of one-part emulsions were also prepared using one of two alternative processes, process 1 or process 2 using a SpeedMixer DAC 150.1 FV from Hauschild & Co. KG Germany. The same processes 1 and 2 were utilised with a slightly difference in step 1. In step 1 in both processes the respective component (a) and component (b) was first introduced into the mixer and then mixed for 35 sec at 3500 rpm before the introduction of the surfactant(s). Otherwise, the same processes were utilised.

[0168] In both Tables 5a and 5b the highlighted water values in the examples below refer to the last amount of water added to in Step 2 regardless the process.

TABLE-US-00006 TABLE 5a One-part Emulsion Compositions E11 E12 E13 E14 E15 Emulsification process 1 2 2 2 2 Polymer 4 23.27% 23.23% 39.70% 23.68% 22.25% RP1 58.02% 58.36% 40.30% RP2 58.54% 55.10% Brij L3 0.79% 0.83% 0.81% 0.82% 0.77% Brij L23 2.42% 2.41% 2.66% 2.46% 2.32% water 1 1.67% 4.66% 3.59% 3.67% 2.85% water 2 1.65% 10.51% 12.95% 10.83% 9.98% water 3 1.63% 6.73% water 4 10.54% TOTAL 100.00% 100.00% 100.00% 100.00% 100.00%

TABLE-US-00007 TABLE 5b One-part Emulsion compositions E16 E17 E18 E19 Emulsification 2 2 2 2 process Polymer 4 55.26% 43.89% RP1 22.27% 32.63% 38.00% 21.57% Polymer 3 38.28% 53.94% Brij L3 0.78% 0.75% 0.74% 0.73% Brij L23 2.31% 2.84% 2.20% 2.18% water 1 2.31% 1.89% 2.26% 2.72% water 2 10.12% 9.53% 9.68% 9.43% water 3 6.95% 8.48% 8.83% 9.44% TOTAL 100.00% 100.00% 100.00% 100.00%

Film Forming of One-Part Emulsion

[0169] A several hundred micron thick film of each of several one-part emulsions, E11, E12, E13, E18 and E19 was applied onto polyethylene substrates and left to enable water to evaporate away for a period of 4 hours. In each case after 4 hours (h), a self-sustaining elastic film of different tackiness was formed. Tackiness was assessed by the operator after 4 h and in some instances also after 1 week, recording the haptic attributes of each resulting film. Tackiness was determined by the same method as described above.

TABLE-US-00008 TABLE 6 Ability of one-part Emulsions to form a film layer & tackiness thereof Tackiness (4 h) Tackiness (1 week) E11 Very Tacky Not measured E12 Very Tacky Not measured E13 Slightly Tacky Not measured E18 Slightly Tacky Slightly Tacky E19 not tacky not tacky

[0170] The above results indicate that by modifying the amounts of the different components in the one-part emulsions herein ratio in Embodiment (1) one can tune the cure time of the elastomer as well as the properties of the obtained film.

Stability of One-Part Emulsions

[0171] Samples of two one-part emulsions E18 and E19 were subjected to accelerated ageing via storage at 50 C. oven for 4 weeks. All samples remain readily dispersible, no coalescence or creaming have been observed and as such it could be seen that the one-part emulsions herein also remain stable with time and as such may be stored prior to application.

COMPARATIVE EXAMPLE

[0172] Two comparative emulsions have been prepared.

[0173] Emulsion CE1 is a comparative J type emulsion for a two-part emulsion composition, i.e., an emulsion wherein component (a) was not pre-prepared but where ingredient 1 (titanate) and ingredient 2 (linear or branched polydiorganosiloxane having at least two terminal silanol groups per molecule) are introduced separately. In this case an analogous process to emulsion process 1 was used with the following differences: [0174] (i) unreacted polymer 1 is introduced in step 1 of the process instead of component (a); and [0175] (ii) TiPT was added after the completion of Step 3, followed by mixing for 35 sec. at 3500 RPM.
Emulsion CE1 is intended to be a comparative for E8 above.

[0176] Emulsion CE2 is a one-part emulsion prepared in accordance with emulsion process 2 and is intended to be comparative with E19. The same changes as described above for process 1 were made for process 2 to prepare one-part emulsion CE2.

[0177] The compositions used for making the comparatives are provided in Table 7 below:

TABLE-US-00009 TABLE 7 Comparative J type emulsion (CE1) and one-part emulsion (CE2) CE1 CE2 Polymer 1 75.62% 21.52% Polymer 3 0.00% 53.95% Brij L3 0.76% 0.75% Brij L23 2.28% 2.21% water 1 3.07% 2.61% water 2 1.21% 9.45% water 3 1.29% 9.41% water 4 1.36% water 5 1.24% water 6 1.28% water 7 1.82% water 8 9.78% TiPT -post-add 0.29% 0.10% TOTAL 100.00% 100.00% mass ratio Polymer/TiPT 259 210

[0178] The two comparative emulsions prepared above were then tested to see if they provide films and to assess their tackiness. In each case a several hundred micron thick film of each of a two-part emulsion (E3 and CE1) and CE2 were applied onto polyethylene substrates and left to enable water to evaporate away for a period of 4 hours. In each case after 4 hours, neither comparative emulsion had cured unlike the emulsions as described in this disclosure which after 4 hours provided a self-sustaining elastic film of different tackiness. The results of the two-part emulsions are depicted in Table 8 and of the one-part emulsions are given in Table 9.

TABLE-US-00010 TABLE 8 Ability of two-part Emulsions (E3 + E8) and comparative (E3 + CE1) to form a film layer & tackiness thereof E3 E8 CE1 Tackiness Tackiness (g) (g) (g) 4 h 1 week MIX 1 (inventive) 15.071 6.03 Very sticky Not sticky MIX 5 (non-inventive) 15.081 6.019 Not cured Not cured

TABLE-US-00011 TABLE 9 Ability of one-part Emulsions E19 and comparative CE2 to form a film layer & tackiness thereof Tackiness 4 h Tackiness 1 week E19 (inventive) Not sticky Not sticky CE2 (non-inventive) Not cured Not cured

[0179] It will be seen from Tables 8 and 9 that in both instances the comparative emulsions had not cured after 4 hours.