Polyurethane-organopolysiloxanes

Abstract

The invention relates to polyurethane organopolysiloxanes and their applications, in particular for the finishing of textile fabrics and textile fibres.

Claims

1. A polysiloxane obtained by a method comprising: (i) providing at least one reaction product (I) of a compound (II) having the formula ##STR00018## wherein R.sup.1 may be identical or different and denotes an optionally substituted hydrocarbon radical with 1-18 carbon atoms per radical, A.sup.1 denotes independently of one another a divalent linear or branched group with up to 8 carbon atoms and optionally with up to 4 hetero atoms, x is an integer from 1-1000, and Z is ##STR00019## optionally substituted by C.sub.1-8-alkyl, with at least one compound (III) selected from primary amines, secondary amines and monohydric alcohols, which optionally contains at least one polyether radical, wherein at least one reaction product (I) contains at least one polyether radical that was introduced by the compound (III); (ii) optionally providing at least one compound (IV) of the formula ##STR00020## wherein R.sup.1 and x are as defined above, R.sup.2 is independently of one another a divalent branched or linear C.sub.2-8-alkyl, optionally substituted with carbonyl, A.sup.2 independently of one another is selected from the group consisting of O, C(O)O, OC(O), OC(O)O, C(O)NH, NHC(O), NHC(O)O and NHC(O)NH A.sup.3 independently of one another is selected from the group consisting of O, NH and NR, R is a monovalent hydrocarbon radical with 1 to 18 carbon atoms, n independently of one another is an integer from 1 to 20, preferably 2 or 3, and m independently of one another is an integer from 0 to 150; (iii) optionally equilibrating at least one reaction product (I) and/or at least one compound (IV) with a cyclic or linear polysiloxane, and (iv) reacting the reaction product (I) or the equilibrated reaction product (I) from paragraph (iii) and optionally the compound (IV) or the equilibrated compound (IV) from paragraph (iii) with at least one organic compound (V) that has at least two isocyanate groups per molecule.

2. The polysiloxane according to claim 1, wherein R.sup.1 is selected from the group consisting of C.sub.1-6-alkyl, aryl or benzyl.

3. The polysiloxane according claim 1, wherein A.sup.1 is C.sub.1-8-alkyl or C.sub.1-6-alkyl-OC.sub.1-6-alkyl.

4. The polysiloxane according to claim 1, wherein the compound (III) is selected from ##STR00021## wherein A.sup.2, m and n are as defined above, R.sup.3 is C.sub.1-22-alkyl, C.sub.2-C.sub.22-alkenyl, C.sub.2-C.sub.22-alkynyl, aryl, optionally substituted with at least one styryl, or C.sub.6-C.sub.22-alkaryl, R.sup.4 is H, C.sub.1-8 alkyl, heterocyclic, aryl or (C.sub.nH.sub.2n-A.sup.2).sub.m-R.sup.3, and R.sup.4 is C.sub.1-8 alkyl, heterocyclic, aryl or (C.sub.nH.sub.2n-A.sup.2).sub.m-R.sup.3.

5. The polysiloxane according to claim 1, wherein the equilibration of paragraph (iii) is performed and the polysiloxane for the equilibration is polydi-C.sub.1-6-alkylsiloxane.

6. The polysiloxane according to claim 1, wherein the compound (V) is selected from hexamethylene-1,6-diisocyanate, isophorone diisocyanate, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, phenylene-1,3-diisocynate, 4,4-methylene-bis(cyclohexyl isocyanate), 4,4-methylene-bis(phenyl isocyanate) and dimethylphenyl diisocyanate.

7. The polysiloxane according to claim 1, wherein in paragraph (iv) furthermore at least one compound (VI) comprising at least one isocyanate-reactive group is present, which is selected from
R.sup.4-(A.sup.2-C.sub.nH.sub.2n)m-A.sup.3-H,
HOR.sup.5NR.sup.6R.sup.5OH
HOR.sup.5NR.sup.6R.sup.6,
HOR.sup.5(NR.sup.6R.sup.6).sub.2,
HOR.sup.5(NR.sup.6R.sup.6).sub.3,
(HO).sub.2R.sup.5NR.sup.6R.sup.6,
HNR.sup.6R.sup.6,
H.sub.2NR.sup.5NR.sup.6R.sup.6,
R.sup.6R.sup.6NR.sup.5NR.sup.6R.sup.5NR.sup.6R.sup.6, and
R.sup.6R.sup.6NR.sup.5NR.sup.6R.sup.6, wherein R.sup.4, A.sup.2, A.sup.3, n and m are as defined above, R.sup.5 independently of one another is an optionally substituted divalent, trivalent or tetravalent C.sub.1-8-alkyl, C.sub.1-8-alkyl-OC.sub.1-8-alkyl or aryl, R.sup.6 is Han optionally substituted C.sub.1-18-alkyl or aryl, and R.sup.6 is an optionally substituted C.sub.1-18-alkyl or aryl, or R.sup.6 and R.sup.6 together with the nitrogen atom form a heterocycle, which can optionally contain further hetero atoms and is optionally substituted with C.sub.1-8-alkyl.

8. The polysiloxane according to claim 1, wherein in paragraph (iv) the molar ratio of isocyanate groups to isocyanate-reactive groups is between 0.4 and 1.

9. An aqueous emulsion comprising a polysiloxane according to claim 1, optionally further comprising at least one surfactant and/or a solvent and/or an acid.

10. A method for finishing textile fabrics or textile fibres, for treating paper or leather, for imparting softness or shine in cosmetic applications, or for reducing surface roughness or enhancing gloss in lacquers or in varnishes comprising applying or adding the suspension according to claim 9 thereto.

11. A method for finishing a textile fabric or fibres, comprising applying the emulsion according to claim 9 to the textile fabric or the fibres.

12. A method for finishing textile fabrics or textile fibres, for treating paper or leather, for imparting softness or shine in cosmetic applications or for reducing surface roughness or enhancing gloss in lacquers or in varnishes comprising applying or adding the polysiloxane according to claim 1 thereto.

13. Textile fabrics or fibres, comprising a polysiloxane according to claim 1.

14. A method for finishing a textile fabric or fibres, comprising applying the polysiloxane according to claim 1 to the textile fabric or the fibres.

15. The method of claim 1 wherein x is an integer from 1 to 500, and m is 0 to 70, and at least one compound (III) is selected from primary amines, and secondary amines, which optionally contains at least one polyether radical.

16. The method of claim 1 wherein at least one compound (IV) is provided and is equilibrated with a cyclic or linear polysiloxane, and the equilibrated compound (IV) is reacted with the at least one organic compound (V), and the reaction product (I) or an equilibrated reaction product (I).

17. The method of claim 1 wherein at least one compound (IV) is provided is reacted with the at least one organic compound (V), and the reaction product (I) or an equilibrated reaction product (I).

18. The polysiloxane according to claim 1, wherein R.sup.1 is selected from the group consisting of C.sub.1-6-alkyl.

19. The polysiloxane according to claim 1, wherein the equilibration of paragraph (iii) is performed and the polysiloxane for the equilibration is polydimethylsiloxane, oligodimethylsiloxane, cyclic oligo- or polydimethylsiloxane.

20. The polysiloxane according to claim 1, wherein in paragraph (iv) furthermore at least one compound (VI) comprising at least one isocyanate-reactive group is present.

Description

EXAMPLES

Comparative Example 1, not According to the Invention

(1) The preparation consists of an aqueous micro-emulsion containing 20 wt. % of FINISH WR 301 from the WACKER company, an aminoethylaminopropyl-functionalised organopolysiloxane, 10 wt. % of an isodecyl alcohol with 7 ethylene oxide groups, and 0.4 wt. % of 60% acetic acid. The total nitrogen content of the organopolysiloxane is 0.39 wt. %.

Comparative Example 2, not According to the Invention

(2) The commercially available preparation RUCOFIN SIQ consists of an aqueous micro-emulsion of a polysiloxane modified with quaternary ammonium functions with a dry substance content of 24.5%.

Comparative Example 3, not According to the Invention

(3) The preparation was prepared as described in WO 2004/044306, Table 2, mixture 12c. The dry substance was adjusted with water to 25 wt. %.

Comparative Example 4, not According to the Invention

(4) 516.6 g (0.1 mol) of an , -dihydrogen polydimethylsiloxane with 0.039 wt. % of Si-bound hydrogen are reacted similarly to Example 1 of EP 1753804 with 149.8 g (0.2 mol) of an alkyl alcohol polyether having the commercial name Pluriol A 750 R from the company BASF SE to form a polyether-modified polydimethylsiloxane of the formula

(5) ##STR00011##

(6) 120 g (0.036 mol OH) of the obtained organopolysiloxane are mixed with 2.4 g (0.040 mol OH) N-methyldiethanolamine and 0.7 g (0.007 mol NH) N-methylpiperazine and heated to 45 C. 50 mg of di-n-butyl tin dilaurate as well as 9.2 g (0.083 mol NCO) of isophorone diisocyanate are added to the mixture. After a rise in temperature of ca. 5 C. the mixture is stirred for a further 1 hour at 50 C. The completeness of the reaction is checked by means of NCO titration. A clear, highly viscous yellow oil is obtained.

(7) 25 g of the obtained oil are mixed with 1 g of 60% acetic acid and heated to 50 C. while stirring. 74 g of water are added in portions at 50 C. while stirring. A white emulsion is obtained having a mean particle size of 250 nm.

Example 5, According to the Invention

(8) The preparation of the polyether-functional organopolysiloxane is carried out by reacting 539.2 g (0.1 mol) of ,-diepoxypolydimethylsiloxane of the formula

(9) ##STR00012##

(10) with 150 g (0.2 mol) of a singly methyl-capped polyethylene glycol with a mean molecular weight of 750 g/mol, similarly to Example 1 of U.S. Pat. No. 6,495,727 B1.

(11) 30 g (0.009 mol OH) of the obtained organopolysiloxane are mixed with 84 g (0.025 mol OH) of the organopolysiloxane precursor obtained in comparative Example 4. 2.4 g (0.040 mol OH) N-methyldiethanolamine and 1.2 g (0.013 mol OH) N,N-dimethylethanolamine are added to the mixture and heated to 45 C. 50 mg of di-n-butyl tin dilaurate as well as 9.7 g of isophorone diisocyanate (0.088 mol NCO) are added to the mixture. After a rise in temperature of ca. 5 C. the reaction mixture is stirred for a further 1 hour at 45 C. The completeness of the reaction is checked by means of NCO titration. A clear, highly viscous yellow oil is obtained.

(12) The emulsification is carried out similarly to comparative Example 4. A whitish, transparent emulsion with a mean particle size of 150 nm is obtained.

Example 6, According to the Invention

(13) The preparation of the aminopolyether-functional organopolysiloxane is carried out by reacting 539.2 g (0.1 mol) of ,-diepoxypolydimethylsiloxane of the formula

(14) ##STR00013##

(15) with 120 g (0.2 mol) of an amino-functional, methyl-capped polyether having the commercial trade name Jeffamine M 600 with a mean molecular weight of ca. 600 g/mol.

(16) 36 g (0.011 mol NH, 0.011 mol OH) of the obtained organopolysiloxane are mixed with 84 g (0.025 mol OH) of the organopolysiloxane precursor obtained in comparative Example 4. 2.2 g (0.036 mol OH) of N-methyldiethanolamine and 1.2 g (0.013 mol OH) of N,N-dimethylethanolamine are added to the mixture and heated to 45 C. 50 mg of di-n-butyl tin dilaurate as well as 9.5 g (0.086 mol NCO) of isophorone diisocyanate are added to the mixture. After a rise in temperature of ca. 5 C. the mixture is stirred for a further 1 hour at 45 C. The completeness of the reaction is checked by means of NCO titration. A clear, highly viscous yellow oil is obtained.

(17) The emulsification is carried out similarly to comparative Example 4. A whitish, transparent emulsion with a mean particle size of 150 nm is obtained.

Example 7, According to the Invention

(18) 36 g (0.010 mol OH) of the organopolysiloxane precursor obtained in Example 5 are mixed with 84 g (0.025 mol OH) of the compound obtained in comparative Example 4. 2.4 g (0.040 mol OH) of N-methyldiethanolamine and 0.7 g (0.007 mol NH) of N-methylpiperazine are added to the mixture and heated to 45 C. 50 mg of di-n-butyl tin dilaurate as well as 9.2 g (0.083 mol NCO) of isophorone diisocyanate are added to the mixture. After a rise in temperature of ca. 5 C. the mixture is stirred for a further 1 hour at 45 C. The completeness of the reaction is checked by means of NCO titration. A clear, highly viscous yellow oil is obtained.

(19) The emulsification is carried out similarly to comparative Example 4. A whitish, transparent emulsion with a mean particle size of 140 nm is obtained.

Example 8, According to the Invention

(20) 120 g (0.036 mol OH) of the organopolysiloxane precursor obtained in Example 5 are mixed with 2.4 g (0.040 mol OH) of N-methyldiethanolamine and 0.7 g (0.007 mol NH) of N-methylpiperazine and heated to 45 C. 50 mg of di-n-butyl tin dilaurate as well as 9.3 g (0.083 mol NCO) of isophorone diisocyanate are added to the mixture. After a rise in temperature of ca. 5 C. the mixture is stirred for a further 1 hour at 45 C. The completeness of the reaction is checked by means of NCO titration. A clear, highly viscous yellow oil is obtained.

(21) The emulsification is carried out similarly to comparative Example 4. A whitish, transparent emulsion with a mean particle size of 120 nm is obtained.

(22) Weight composition of the produced organopolysiloxanes:

(23) TABLE-US-00001 Content of Content of PDMS polyether lateral Titratable content overall polyether basic nitrogen Example [wt. %] [wt. %] [wt. %] [wt. %] Comparative 72.9 20.4 0 0.35 Example 4 5 71.4 20.0 5.1 0.36 6 72.0 19.2 4.9 0.33 7 72.4 20.2 5.9 0.34 8 71.0 19.7 19.7 0.35

(24) Feel Evaluation

(25) Sections of a bleached, optically non-brightened cotton terry cloth were finished with an aqueous liquor containing 20 g/l of the respective preparation according to Examples 1-8 and 0.5 g/l of acetic acid (60%) on a laboratory padding machine with a wet uptake of 80% and were then dried for 2 minutes at 120 C. After the treatment the test fabric treated with the emulsion is conditioned for 2 hours in a standard atmosphere as described in ISO 139 at 65% relative atmospheric humidity and a temperature of 20 C. The evaluation of the feel character of the test fabric was then carried out. This evaluation is subject to individually different, subjective criteria. In order nevertheless to obtain valid meaningful results, an evaluation by at least 5 test persons is necessary. The evaluation of the results was carried out by statistical methods, in which the score 1.0 denotes the softest, most pleasant feel, and the score 5 denotes the hardest, least smooth surface and most unpleasant feel within the test series.

Feel Evaluation within the Test Series

(26) TABLE-US-00002 Comparative Example 1 1.1 Comparative Example 2 1.3 Comparative Example 3 2.3 Comparative Example 4 2.1 Example 5 1.4 Example 6 1.0 Example 7 1.3 Example 8 1.2 Untreated 5

(27) The preparations 5-8 according to the invention confer an excellent soft feel on the textiles finished with the preparations.

(28) Yellowing

(29) Sections of a bleached, non-optically brightened cotton modal knitwear were impregnated with an aqueous liquor containing 20 g/l of the respective preparations according to Examples 1-10 and 0.5 g/l of 60% acetic acid on a laboratory padding machine with a wet uptake of 80%, dried for 2 minutes at 120 C., and then thermally fixed for 2 minutes at 170 C. The whiteness of the sample according to Ganz was then measured on the Datacolor 600 whiteness meter of the company Datacolor international (Switzerland).

Whiteness According to Ganz

(30) TABLE-US-00003 Comparative Example 1 183 Comparative Example 2 205 Comparative Example 3 199 Comparative Example 4 201 Example 5 203 Example 6 200 Example 7 202 Example 8 204 Untreated 203

(31) The preparations according to the invention do not lead to any yellowing of the textile substrate. The whiteness of the substrates finished with the preparations according to the invention corresponds to that of the untreated textile.

(32) Alkali Stability

(33) The stability of the emulsions to alkalis in finishing liquors was carried out according to the following described test:

(34) 500 ml of an aqueous solution of the emulsion to be investigated having a concentration of 40 g/I were placed in a 1000 ml beaker and adjusted with sodium hydroxide solution (w(NaOH)=10%) to a pH of 11. The liquor was then stirred for 20 minutes with a paddle stirrer at 2000 rpm. The stirrer was then switched off and the liquid surface was evaluated after 1 hour as regards the formation of deposits.

(35) TABLE-US-00004 Evaluation after 1 hour Comparative Example 1 marked deposits Comparative Example 2 no deposits Comparative Example 3 slight deposits Comparative Example 4 slight deposits Example 5 no deposits Example 6 no deposits Example 7 no deposits Example 8 no deposits

(36) The preparations according to the invention have at pH 11 no tendency to form deposits. Such preparations can be classed as pH stable.

(37) Anion Stability

(38) The stability of the emulsions to anions in finishing liquors was carried out according to the following described test:

(39) 500 ml of an aqueous solution containing 10 g of the emulsion to be investigated and 20 ml of a 0.5% dodecylbenzenesulphonic acid solution were placed in a 1000 ml beaker and adjusted with 60% acetic acid to a pH of 4.5. The liquor was then heated to 40 C. and stirred at this temperature for 30 minutes with a paddle stirrer at 2000 rpm. The stirrer was then switched off and after stirring for 2 hours the solution was investigated as regards its turbidity, as well as the liquid surface and deposits.

(40) TABLE-US-00005 Appearance of the liquor Evaluation after after 2 hours 2 hours Comparative Example 1 Turbid Marked deposits Comparative Example 2 Turbid Marked deposits Comparative Example 3 Slightly turbid Slight deposits Comparative Example 4 Slightly turbid Slight deposits Example 5 Clear No deposits Example 6 Clear No deposits Example 7 Clear No deposits Example 8 Clear No deposits

(41) Hydrophilicity

(42) The hydrophilicity of the articles after the finishing was evaluated by the TEGEWA droplet test (Melliand textile reports 68 (1987), 581-583). To carry out the test the finished fabric is stretched horizontally on a suitable stretching device so that it does not come into contact with the base. From a height of 40 mm a water droplet of size 0.050 ml (10%) is dropped onto the fabric. The time measurement is started as soon as the droplet strikes the fabric to be tested. The time measurement is stopped when the droplet has completely sunk into the fabric and the shine has disappeared.

(43) TABLE-US-00006 Sinking time in Amount used in g/l seconds Comparative Example 1 20 >120 Comparative Example 2 20 <1 Comparative Example 3 20 4 Comparative Example 4 20 5 Example 5 20 1 Example 6 20 2 Example 7 20 1 Example 8 20 <1 Untreated 0 <1

(44) Foam Behaviour

(45) To evaluate the foam behaviour 1 litre of a liquor is made up with 3 g/l of the preparations prepared according to the examples. The liquor is added to a laboratory jet of the company MATHIS and rotated at 40 C. and 1000 rpm. After 10 minutes the foam height is measured. The maximum foam height is 10 cm, the minimum 0 cm. A low foam height should be regarded as positive.

(46) TABLE-US-00007 Foam height in cm Comparative Example 1 9 Comparative Example 2 8 Comparative Example 3 5 Comparative Example 4 6 Example 5 3 Example 6 2 Example 7 3 Example 8 1

(47) Dry Heat Fixing Fastness

(48) The testing of the finished textile fabrics for colour fastness is carried out according to EN ISO 105-P01. A sample having the dimensions of the heating device is removed from the coloured and finished textile to be investigated and placed between the two individual-fibre adjacent fabrics having the same dimensions and sown on a narrow side to form a test piece. The test piece is placed in the heating device and treated for 30 sec at 150, 180 or 210 C. The surface pressure on the test piece is 4 kPa. After the treatment the test piece is exposed for 4 hours to a standard climate as described in ISO 139 at 65% relative atmospheric humidity and a temperature of 20 C. The change in colour is evaluated according to the greyness scale (ISO 105 A02). The evaluation of the adjacent fabrics is carried out by a comparison between the stained adjacent fabrics and the adjacent fabrics treated in the blind test, using the greyness scale (ISO 105 A03) to evaluate the staining and bleeding. In this connection the best results are accorded a score of 5, and the worst results a score of 1.

(49) Evaluation of the Test Piece and Adjacent Fabric:

(50) TABLE-US-00008 Test piece Adjacent fabric 150 C. 180 C. 210 C. 150 C. 180 C. 210 C. Comparative 2-3 2 1 2-3 2 1 Example 1 Comparative 2-3 1 1 2 1 1 Example 2 Comparative 3-4 3 2 4 3-4 2 Example 3 Comparative 4 3 2 4-5 3-4 2-3 Example 4 Example 5 4-5 3-4 2-3 4 3-4 3 Example 6 5 4 3 4-5 4 3 Example 7 4-5 3-4 2-3 4-5 4 3 Example 8 4-5 4 3-4 4-5 3-4 2-3 Untreated 5 4-5 4 4-5 4 3

(51) The test pieces finished with the preparations 5-8 according to the invention have a significantly reduced colour change and a lower tendency to staining and bleeding, in particular compared to the test pieces that were finished with the preparations 1 and 2 that contained emulsifiers as additives.

(52) The present invention is described in more detail by the following points: 1. Polysiloxane obtainable by a method comprising the following steps: (i) providing at least one reaction product (I) of a compound (II) having the formula

(53) ##STR00014## wherein R.sup.1 may be identical or different and denotes an optionally substituted hydrocarbon radical with 1-18 carbon atoms per radical, A.sup.1 denotes independently of one another a divalent linear or branched group with up to 8 carbon atoms and optionally with up to 4 hetero atoms, x is an integer from 1 to 1000, preferably 1 to 500, and Z is

(54) ##STR00015## optionally substituted by C.sub.1-8-alkyl, with at least one compound (III) selected from primary amine, secondary amine and monohydric alcohol, which optionally contains at least one polyether radical, wherein at least one reaction product (I) contains at least one polyether radical that was introduced by the compound (III); (ii) optionally providing at least one compound (IV) of the formula

(55) ##STR00016## wherein R.sup.1 and x are as defined above, R.sup.2 is independently of one another a divalent branched or linear C.sub.2-8-alkyl, optionally substituted with carbonyl, A.sup.2 independently of one another is selected from the group consisting of O, C(O)O, OC(O), OC(O)O, C(O)NH, NHC(O), NH C(O)O and NHC(O)NH A.sup.3 independently of one another is selected from the group consisting of O, NHH and NR, R is a monovalent hydrocarbon radical with 1 to 18 carbon atoms, n independently of one another is an integer from 1 to 20, preferably 2 or 3, and m independently of one another is an integer from 0 to 150, preferably 0 to 70, more preferably 0 to 30; (iii) optionally equilibrating at least one reaction product (I) and/or at least one compound (IV) with a cyclic or linear polysiloxane, and (iv) reacting the reaction product (I) or of the equilibrated reaction product (I) from step (iii) and optionally the compound (IV) or the equilibrated compound (IV) from step (iii) with at least one organic compound (V) that having at least two isocyanate groups per molecule. 2. Polysiloxane according to point 1, wherein the reaction in step (i) results in a ring opening in the compound (II). 3. Polysiloxane according to any one of points 1 or 2, wherein R.sup.1 is selected from the group consisting of C.sub.1-6-alkyl, aryl or benzyl, preferably C.sub.1-6-alkyl, more preferably methyl or ethyl. 4. Polysiloxane according to any one of the preceding points, wherein A.sup.1 is C.sub.1-8-alkyl or C.sub.1-6-alkyl-OC.sub.1-6-alkyl, preferably CH.sub.2CH.sub.2CH.sub.2OCH.sub.2. 5. Polysiloxane according to any one of the preceding points, wherein the compound (III) is selected from

(56) ##STR00017## wherein A.sup.2, m and n are as defined above, R.sup.3 is C.sub.1-22-alkyl, C.sub.2-C.sub.22-alkenyl, C.sub.2-C.sub.22-alkynyl, aryl, optionally substituted with at least one styryl, or C.sub.6-C.sub.22-alkaryl, R.sup.4 is H, C.sub.1-8-alkyl, heterocyclyl, aryl or (C.sub.nH.sub.2n-A.sup.2).sub.m-R.sup.3, R.sup.4 is C.sub.1-8-alkyl, heterocyclyl, aryl or (C.sub.nH.sub.2n-A.sup.2).sub.m-R.sup.3. 6. Polysiloxane according to any one of the preceding points, wherein R.sup.2 is optionally substituted divalent C.sub.2-8-alkyl. 7. Polysiloxane according to any one of the preceding points, wherein the equilibration in step (iii) is base or acid catalysed, preferably base catalysed. 8. Polysiloxane according to any one of the preceding points, wherein the polysiloxane for the equilibration in step (iii) is polydi-C.sub.1-6-alkylsiloxane, preferably polydimethylsiloxane, preferably oligodimethylsiloxane, still more preferably cyclic oligo- or polydimethylsiloxane. 9. Polysiloxane according to any one of the preceding points, wherein the compound (V) is selected from hexamethylene-1,6-diisocyanate, isophorone diisocyanate, toluylene-2,4-diisocyanate, toluylene-2,6-diisocyanate, phenylene-1,3-diisocynate, 4,4-methylene-bis(cyclohexyl isocyanate), 4,4-methylene-bis(phenyl isocyanate) and dimethylphenyl diisocyanate. 10. Polysiloxane according to any one of the preceding points, wherein in step (iv) furthermore at least one compound (VI) comprising at least one isocyanate-reactive group is present. 11. Polysiloxane according to point 10, wherein the compound (VI) is selected from
R.sup.4-(A.sup.2-C.sub.nH.sub.2n).sub.m-A.sup.3-H,
HOR.sup.5NR.sup.6R.sup.5OH
HOR.sup.5NR.sup.6R.sup.6,
HOR.sup.5(NR.sup.6R.sup.6).sub.2,
HOR.sup.5(NR.sup.6R.sup.6).sub.3,
(HO).sub.2R.sup.5NR.sup.6R.sup.6,
HNR.sup.6R.sup.6,
H.sub.2NR.sup.5NR.sup.6R.sup.6,
R.sup.6R.sup.6NR.sup.5NR.sup.6R.sup.5NR.sup.6R.sup.6, and
R.sup.6R.sup.6NR.sup.5NR.sup.6R.sup.6, wherein R.sup.4, A.sup.2, A.sup.3, n and m are as defined above, R.sup.5 independently of one another is optionally substituted divalent, trivalent or tetravalent C.sub.1-8-alkyl, C.sub.1-8-alkyl-OC.sub.1-8-alkyl or aryl, R.sup.6 is H, optionally substituted C.sub.1-18-alkyl or aryl, and R.sup.6 is optionally substituted C.sub.1-18-alkyl or aryl, or R.sup.6 and R.sup.6 together with the nitrogen atom form a heterocycle, which may optionally contain further hetero atoms and is optionally substituted with C.sub.1-8-alkyl. 12. Polysiloxane according to any one of the preceding points, wherein in step (iv) the molar ratio of isocyanate groups to isocyanate-reactive groups is between 0.4 and 1, preferably between 0.6 and 1. 13. Polysiloxane according to any one of the preceding points, wherein the conversion in step (iv) is carried out above room temperature, optionally with the use of at least one solvent and/or a catalyst. 14. Aqueous emulsion comprising a polysiloxane according to any one of points 1 to 13. 15. Aqueous emulsion according to point 14, in addition comprising at least one surfactant and/or a solvent and/or an acid. 16. Use of a polysiloxane according to any one of points 1 to 13 or an emulsion according to point 14 or 15 for finishing textile fabrics or textile fibres. 17. Use of a polysiloxane according to any one of points 1 to 13 or an emulsion according to point 14 or 15 for treating paper or leather. 18. Use of a polysiloxane according to any one of points 1 to 13 or an emulsion according to point 14 or 15 for cosmetic applications. 19. Use of a polysiloxane according to any one of points 1 to 13 or an emulsion according to point 14 or 15 in lacquers or varnishes. 20. Textile fabrics or fibres comprising a polysiloxane according to any one of points 1 to 13. 21. Method for finishing textile fabrics or fibres, comprising applying the polysiloxane according to any one of points 1 to 13 or the emulsion according to point 14 or 15 to the textile fabric or the fibres.