Organosiloxane compositions

Abstract

A copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl siloxane obtainable by reacting a dispersion of ingredient (i) an alkylfluoroalkyl siloxane and ingredient (ii) one or more polyalkylphenyl siloxane(s) in the presence of ingredient (iii) a basic catalyst at a temperature of between 40 C. to 300 C.

Claims

1. A method for preparing a copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl siloxane comprising reacting a dispersion of ingredient (i) an alkylfluoroalkyl siloxane comprising units of the following structure: ##STR00012## in which each R group may be the same or different and is selected from an alkyl having from 1 to 6 carbon atoms, n is an integer, x is zero or an integer from 1 to 6 and R.sup.1 is a perfluoroalkyl group which is either linear or branched and may contain from 1 to 12 carbon atoms; and ingredient (ii) one or more polyalkylphenyl siloxane(s) comprising units of the following structure: ##STR00013## in which each R.sup.2 group is the same or different and is selected from an alkyl group having from 1 to 6 carbon atoms and t is an integer; in the presence of ingredient (iii) a basic catalyst at a temperature of between 40 C. to 300 C.; and wherein ingredient (ii) comprises a trialkylsilyl terminated siloxane.

2. The method for preparing a copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl siloxane in accordance with claim 1, wherein: a) the alkylfluoroalkyl siloxane is linear or branched and has viscosity of from 100 cst to 100,000 cst (100 mm.sup.2s.sup.1 to 100,000 mm.sup.2s.sup.1) at 25 C. with a capillary viscometer according to ASTM D445-06; b) the polyalkylphenyl siloxane has a viscosity of from 250 cst to 50,000 cst (250 mm.sup.2s.sup.1 to 50,000 mm.sup.2s.sup.1) at 25 C. with a capillary viscometer according to ASTM D445-06; or c) both a) and b).

3. The method for preparing a copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl siloxane in accordance with claim 1, wherein the alkylfluoroalkyl siloxane is cyclic and n is from 3 to 15.

4. The method for preparing a copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl siloxane in accordance with claim 1, wherein R.sup.1 in the alkylfluoroalkyl siloxane is a perfluoroalkyl group which is either linear or branched and contains from 1 to 12 carbon atoms.

5. The method for preparing a copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl siloxane in accordance with claim 1, wherein ingredient (i) and ingredient (ii) are intermixed in a ratio of from between 10 weight % of ingredient (i): 90 weight % of ingredient (ii) to 90 weight % of ingredient (i): 10 weight % of ingredient (ii) based on the total weight of ingredient (i) and ingredient (ii) being 100 weight %.

6. The method for preparing a copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl siloxane in accordance with claim 1, wherein ingredient (ii) is a mixture of polyalkylphenyl siloxanes including the trialkylsilyl terminated siloxane.

7. The method for preparing a copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl siloxane in accordance with claim 1, wherein the basic catalyst is selected from one or more alkali metal hydroxides, alkali metal alkoxides or complexes of alkali metal hydroxides and an alcohol, alkali metal silanolates, tetra-alkyl phosphonium hydroxides and tetra-alkyl phosphonium silanolates, phosphonitrile halides, phosphazene bases and the catalyst derived by the reaction of a tetra-alkyl ammonium hydroxide and a siloxane tetramer.

8. The method for preparing a copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl siloxane in accordance with claim 4, wherein the perfluoroalkyl group is selected from perfluoromethyl, perfluoroethyl, perfluoro-n-propyl, perfluoro-iso-propyl, perfluoro-n-butyl, perfluoro-iso-butyl, perfluoro-tert-butyl, perfluoro-n-pentyl, perfluoro-isopentyl, perfluoroneo-pentyl, perfluorohexyl, perfluoroheptyl, perfluorooctyl, perfluorononyl, perfluorodecyl, perfluoroundecyl and perfluorododecyl or a mixture thereof.

9. The method for preparing a copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl siloxane in accordance with claim 7, wherein the basic catalyst is potassium hydroxide.

10. The method for preparing a copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl siloxane in accordance with claim 6, wherein ingredient (ii) comprises the trialkylsilyl terminated siloxane and a dialkylhydroxy terminated siloxane.

11. The method for preparing a copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl siloxane in accordance with claim 1, further comprising stirring ingredients i) and ii) to form the dispersion and at least one of: heating the dispersion and holding the temperature between 100 C. and 300 C. during reaction; sweeping the dispersion with nitrogen during reaction; cooling the dispersion after reaction; neutralizing the basic catalyst; and stripping the dispersion after reaction.

12. A method for preparing a copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl siloxane comprising: stirring ingredients (i) and (ii) to form a dispersion, wherein ingredient (i) is an alkylfluoroalkyl siloxane comprising units of the following structure: ##STR00014## in which each R group may be the same or different and is selected from an alkyl having from 1 to 6 carbon atoms, n is an integer, x is zero or an integer from 1 to 6 and R.sup.1 is a perfluoroalkyl group which is either linear or branched and may contain from 1 to 12 carbon atoms; and ingredient (ii) is one or more polyalkylphenyl siloxane(s) comprising units of the following structure: ##STR00015## in which each R.sup.2 group is the same or different and is selected from an alkyl group having from 1 to 6 carbon atoms and t is an integer; reacting the dispersion of ingredients (i) and (ii) in the presence of ingredient (iii), a basic catalyst, at a temperature of between 40 C. to 300 C.; and at least one of: sweeping the dispersion with nitrogen during reaction; cooling the dispersion after reaction; neutralizing ingredient (iii); and stripping the dispersion after reaction.

13. The method for preparing a copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl siloxane in accordance with claim 12, comprising at least one of sweeping the dispersion with nitrogen during reaction, and stripping the dispersion after reaction.

14. The method for preparing a copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl siloxane in accordance with claim 12, further comprising heating the dispersion and holding the temperature between 100 C. and 300 C. during reaction.

15. The method for preparing a copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl siloxane in accordance with claim 12, wherein: a) the alkylfluoroalkyl siloxane is linear or branched and has viscosity of from 100 cst to 100,000 cst (100 mm.sup.2s.sup.1 to 100,000 mm.sup.2s.sup.1) at 25 C. with a capillary viscometer according to ASTM D445-06; b) the polyalkylphenyl siloxane has a viscosity of from 250 cst to 50,000 cst (250 mm.sup.2s.sup.1 to 50,000 mm.sup.2s.sup.1) at 25 C. with a capillary viscometer according to ASTM D445-06; or c) both a) and b).

16. The method for preparing a copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl siloxane in accordance with claim 12, wherein the alkylfluoroalkyl siloxane is cyclic and n is from 3 to 15.

17. The method for preparing a copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl siloxane in accordance with claim 12, wherein R.sup.1 in the alkylfluoroalkyl siloxane is a perfluoroalkyl group which is either linear or branched and contains from 1 to 12 carbon atoms, optionally wherein the perfluoroalkyl group is selected from perfluoromethyl, perfluoroethyl, perfluoro-n-propyl, perfluoro-iso-propyl, perfluoro-n-butyl, perfluoro-iso-butyl, perfluoro-tert-butyl, perfluoro-n-pentyl, perfluoro-isopentyl, perfluoroneo-pentyl, perfluorohexyl, perfluoroheptyl, perfluorooctyl, perfluorononyl, perfluorodecyl, perfluoroundecyl and perfluorododecyl or a mixture thereof.

18. The method for preparing a copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl siloxane in accordance with claim 12, wherein ingredient (i) and ingredient (ii) are intermixed in a ratio of from between 10 weight % of ingredient (i): 90 weight % of ingredient (ii) to 90 weight % of ingredient (i): 10 weight % of ingredient (ii) based on the total weight of ingredient (i) and ingredient (ii) being 100 weight %.

19. The method for preparing a copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl siloxane in accordance with claim 12, wherein ingredient (ii) is a mixture of polyalkylphenyl siloxanes.

20. The method for preparing a copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl siloxane in accordance with claim 12, wherein the basic catalyst is selected from one or more alkali metal hydroxides, alkali metal alkoxides or complexes of alkali metal hydroxides and an alcohol, alkali metal silanolates, tetra-alkyl phosphonium hydroxides and tetra-alkyl phosphonium silanolates, phosphonitrile halides, phosphazene bases and the catalyst derived by the reaction of a tetra-alkyl ammonium hydroxide and a siloxane tetramer, optionally wherein the basic catalyst is potassium hydroxide.

Description

EXAMPLE 1

(1) Preparation of the Co-Polymer

(2) A Variety of Co-Polymers were Prepared Using the Process as Hereinbefore Described. The Resulting Products were Used in a Variety of Test Described in Detail Below.

(3) a.) 100.12 g of a trimethylsilyl terminated polymethylphenylsiloxane having a viscosity of 500 cst (500 mm.sup.2s.sup.1), 114.54 g trimethylsilyl terminated methyltrifluoropropylsiloxane having a viscosity of 300 cst (300 mm.sup.2s.sup.1) and 0.97 g KOH (1N) were added to a flask. The mixture was heated to 140 C. under vigorous stirring. A white dispersion is formed. The mixture is kept at 140 C. for one hour under a nitrogen stream. The mixture became clear after approx. 20 minutes. The mixture is then cooled down and dry ice is added to neutralize the KOH. A clear liquid having a viscosity of 80 mPa.Math.s at 40 C. was obtained. Si-NMR confirmed that a copolymer was formed during the reaction.

(4) b.) 151.51 g a trimethylsilyl terminated polymethylphenylsiloxane having a viscosity of 500 cst (500 mm.sup.2s.sup.1), 521 g trimethylsilyl terminated methyltrifluoropropylsiloxane having a viscosity of 300 cst (300 mm.sup.2s.sup.1) and 3.05 g KOH (1N) were added to a flask. The mixture was heated to 140 C. under vigorous stirring. A white dispersion is formed. The mixture is kept at 140 C. for one 30 minutes under a nitrogen stream. The mixture became clear after approx. 20 minutes. The mixture is then cooled down and dry ice is added to neutralize the KOH. A clear liquid having a viscosity of 67 mPa.Math.s at 40 C. was obtained.

(5) c.) 450.04 g a trimethylsilyl terminated polymethylphenylsiloxane having a viscosity of 500 cst (500 mm.sup.2s.sup.1), 172.72 g trimethylsilyl terminated methyltrifluoropropylsiloxane having a viscosity of 300 cst (300 mm.sup.2s.sup.1) and 3.07 g KOH (1N) were added to a flask. The mixture was heated to 140 C. under vigorous stirring. A white dispersion is formed. The mixture is kept at 140 C. for one hour under a nitrogen stream. The mixture became clear after approx. 20 minutes. The mixture is then cooled down and dry ice is added to neutralize the KOH. A clear liquid having a viscosity of 109 mPa.Math.s at 40 C. was obtained.

(6) d.) 303.02 g a trimethylsilyl terminated polymethylphenylsiloxane having a viscosity of 500 cst (500 mm.sup.2s.sup.1), 332.29 g trimethylsilyl terminated methyltrifluoropropylsiloxane having a viscosity of 1000 cst (1000 mm.sup.2s.sup.1) and 3.05 g KOH (1N) were added to a flask. The mixture was heated to 140 C. under vigorous stirring. A white dispersion is formed. The mixture is kept at 140 C. for one hour under a nitrogen stream. The mixture became clear after approx. 20 minutes. The mixture is then cooled down and dry ice is added to neutralize the KOH. A clear liquid having a viscosity of 90 mPa.Math.s at 40 C. was obtained.

(7) e.) The preparation utilized in example 1b above was repeated. However in this case once the crude product was obtained, volatiles were removed by using a wiped film evaporator (Pope Scientific Inc of Saukville, Wis.) at 200 C./66.66 Pa (0.5 mmHg). A clear liquid was obtained that had a viscosity of 298 mPa.Math.s at 40 C.

(8) f.) The preparation utilized in example 1a above was repeated. However in this case once the crude product was obtained, volatiles were removed by using a wiped film evaporator (Pope Scientific Inc of Saukville, Wis.) at 200 C./66.66 Pa (0.5 mmHg). A clear liquid was obtained that had a viscosity of 308 mPa.Math.s at 40 C.

(9) g.) The preparation utilized in example 1c above was repeated. However, in this case once the crude product was obtained, volatiles were removed by using a wiped film evaporator (Pope Scientific Inc of Saukville, Wis.) at 200 C./66.66 Pa (0.5 mmHg). A clear liquid was obtained that had a viscosity of 391 mPa.Math.s at 40 C.

EXAMPLE 2

(10) The Oxidation stability of the copolymers produced via methods 1b, 1c and 1d in Example 1 were tested. The test were undertaken using differential scanning calorimetry (DSC) with the oxidative onset temperature at a heating rate of 10 C./min under an air flow of 60 ml/min. Load carrying capacity (LCC) was also tested on the samples of the same copolymers using ASTM D5706-05 with a cylinder on plate geometry at a reduced oscillating frequency of 10 Hz. The LCC is expressed in OK load presenting the step (increased in 50N increments every 2 min) load where friction was stable.

(11) The following table shows a comparison between the copolymeric products produced in example 1 from methods 1b, 1c and 1d, trimethylsilyl terminated polydimethylsiloxane having a viscosity of 50 cSt (500 mm.sup.2s.sup.1), and the starting materials from Example 1a, 1b and 1c, trimethylsilyl terminated polymethylphenylsiloxane having a viscosity of 500 cSt (500 mm.sup.2s.sup.1) and trimethylsilyl terminated methyltrifluoropropylsiloxane having a viscosity of 300 cSt (500 mm.sup.2s.sup.1).
Table 1

(12) TABLE-US-00001 TABLE 1 Oxidation onset ( C.) (differential scanning calorimetry Ok load Material (DSC)) (N) (LCC) Example 1b 299 1650 Example 1c 339 1800 Example 1d 266 800 trimethylsilyl terminated 246 550 methyltrifluoropropylsiloxane trimethylsilyl terminated 300 300 polydimethylsiloxane trimethylsilyl terminated 376 150 polymethylphenylsiloxane

(13) The table shows that the copolymer has improved load carrying versus the homopolymers and a better oxidation stability than the trimethylsilyl terminated methyltrifluoropropylsiloxane and even polydimethylsiloxane.

EXAMPLE 3

(14) Four ball wear scars were determined for the products of the methods described in examples 1e, 1f and 1g in combination with a variety of standard additives in lubricant compositions as indicated in Table 2 below.

(15) Wear properties or lubrication performance may be evaluated by standard test method DIN 51350-3 Testing of lubricants in the Shell four-ball tester. The Shell Four Ball Tester (FBT) is a testing device used to determine welding and metal loads as well as different friction and wear characteristics of lubricants. The standard test consists of a rotating ball bearing being pressed onto three similar but immobile balls while applying a load of 100N, 400N and 800N for 1 hour test duration. Wear is determined by optically measuring the formed calotte (the worn depression area).

(16) This testing device is especially common in the lubricant industry where it is used for routine product development and quality control testing. The friction torque can be recorded continuously.

(17) In this instance the testing was done according to DIN 51350-3 and the wear scar is reported as the average of the three steel balls in mm after applying a load of 400N and 800N for 1 hour test duration (i.e. no 100N test undertaken). The results can be seen in Table 2 below:

(18) TABLE-US-00002 TABLE 2 Wear scar Wear scar (mm) at (mm) at Copolymer Additive 400 N 800 N Example 1e 0.55 1.81 Example 1e 1% VL622 0.51 0.71 Example 1e 2.5% VL 622 0.68 1.00 Example 1e 2.5% VL AZ 0.72 1.32 Example 1f 1.78 2.5 Example 1f 2.5% VL 622 0.55 1.03 Example 1f 2.5% VL AZ 0.51 1.07 Example 1g 1.53 Not measurable Example 1g 2.5% VL 622 2.20 2.38 Example 1g 4% Anglamol 0.90 1.47 99 trimethylsilyl terminated 1.18 1.17 methyltrifluoropropylsil- oxane trimethylsilyl terminated Not Not polymethylphenylsiloxane measurable measurable Comparative PAO 6 4% Anglamol 0.71 1.34 99 Comparative PFPE Y25 1.01 1.58 PAO 6 is a commercial polyalphaolefin named PAO SpectraSyn 6 from ExxonMobil Chemicals. PFPE Y25 is a commercial perfluoropolyether named Fomblin Y25 from Solvay. VL 622 and VL AZ are commercial additives named Vanlube 622 and Vanlube AZ from R.T. Vanderbilt. Anglamol 99 is a commercial additive named Anglamol 99 from Lubrizol.

EXAMPLE 4

(19) In this Example a cyclic methyltrifluoropropylsiloxane with n=3 is utilised in combination with two different polymethylphenylsiloxanes to prepare the copolymer, using the same method as discussed in Example 1.

(20) 26.78 g of a trimethylsilyl terminated polymethylphenylsiloxane having a viscosity of 500 cst, (500 mm.sup.2s.sup.1), 154.88 g of a hydroxydimethylsilyl terminated polymethylphenylsiloxane having a viscosity of 500 cst, (500 mm.sup.2s.sup.1). 68.37 g of a methyltrifluoropropylsiloxane cyclotrisiloxane and 0.18 g KOH were added to a flask. The mixture was heated to 140 C. under vigorous stirring. A white dispersion is formed initially. The mixture is kept at 140 C. for one hour under a nitrogen sweep. The mixture became clear after approx. 30 minutes. The mixture is then cooled down and dry ice is added to neutralize the KOH. Volatiles are removed from the product by using a wiped film evaporator (Pope Scientific Inc of Saukville, Wis.) at 200 C./66.66 Pa (0.5 mmHg). A clear liquid having a viscosity of 20,300 mPa.Math.s at 20 C. was obtained. Si-NMR confirmed that a copolymer was formed during the reaction. The resulting product had a wear scar of 1.5 mm at 400N and an oxidation onset of 475 C. using the methods described above in Examples 2 and 3.