SILOXANE-FUNCTIONALIZED SILICA

Abstract

A silica functionalized with a siloxane is of the general formula (I), [SiO.sub.4/2].sub.a [R.sup.1SiO.sub.3/2].sub.b [R.sup.3R.sup.1SiO.sub.2/2].sub.c [R.sup.1.sub.3SiO.sub.1/2].sub.d [O.sub.1/2R.sup.2].sub.e (I). The indices a, b, c, d, e each independently have integer values a from 0 to 100, b from 0 to 100, c from 0 to 50, d from 3 to 200, e from 0 to 50, with the proviso that the sum of a, b and c is at least 1 and for more than 50% of the siloxanes in the mixture the sum of a, b and c is ?4.

Claims

1-13. (canceled)

14. A silica functionalized with a siloxane of the general formula (I)
[SiO.sub.4/2].sub.a[R.sup.1SiO.sub.3/2].sub.b[R.sup.3R.sup.1SiO.sub.2/2].sub.c[R.sup.1.sub.3SiO.sub.1/2].sub.d[O.sub.1/2R.sup.2].sub.e(1), where the indices a, b, c, d, e each independently have integer values a from 0 to 100, b from 0 to 100, c from 0 to 50, d from 3 to 200, e from 0 to 50, with the proviso that the sum of a, b and c is at least 1 and for more than 50% of the siloxanes in the mixture the sum of a, b and c is ?4; where R.sup.1 is each independently H, an amino group, unsubstituted or substituted C.sub.1-C.sub.20-alkyl radical, unsubstituted or substituted C.sub.2-C.sub.20-alkenyl radical, unsubstituted or substituted C.sub.6-C.sub.14-aryl radical; where R.sup.2 is each independently H, an unsubstituted or substituted C.sub.1-C.sub.20-hydrocarbon radical; where R.sup.3 is each independently H, an amino group, unsubstituted or substituted C.sub.2-C.sub.20-alkyl radical, unsubstituted or substituted C.sub.2-C.sub.20-alkenyl radical, unsubstituted or substituted C.sub.6-C.sub.14-aryl radical, wherein substituted signifies that independently of one another at least one substituent is present from the group of OR.sup.Y, NR.sup.Y.sub.2, SH, SR.sup.Y, epoxy, COOR.sup.Y, CHO, CN, NCO, OCOOR.sup.Y, NR.sup.YCOOR.sup.Y, NR.sup.YCONR.sup.Y, SiR.sup.Y.sub.3 and OSiR.sup.Y.sub.3, where R.sup.Y is each independently H, an amino group, unsubstituted or substituted C.sub.1-C.sub.20-alkyl radical, unsubstituted or substituted C.sub.2-C.sub.20-alkenyl radical, unsubstituted or substituted C.sub.6-C.sub.14-aryl radical.

15. The silica as claimed in claim 14, wherein the indices a, b, c, d, e each independently have integer values a from 0 to 30, b from 0 to 30, c from 0 to 15, d from 3 to 60, e from 0 to 15.

16. The silica as claimed in claim 14, wherein the value of the index a and/or the index c is equal to 0.

17. The silica as claimed in claim 14, wherein the content of D-cycles is less than 250 ppmw, preferably less than 150 ppmw, particularly preferably less than 60 ppmw.

18. A process for producing a functionalized silica as claimed claim 14, comprising reacting an unfunctionalized silica with a siloxane of the general formula (I)
[SiO.sub.4/2].sub.a[R.sup.1SiO.sub.3/2].sub.b[R.sup.3R.sup.1SiO.sub.2/2].sub.c[R.sup.1.sub.3SiO.sub.1/2].sub.d[O.sub.1/2R.sup.2].sub.e(1), where the indices a, b, c, d, e each independently have integer values a from 0 to 100, b from 0 to 100, c from 0 to 50, d from 3 to 200, e from 0 to 50, with the proviso that the sum of a, b and c is at least 1 and for more than 50% of the siloxanes in the mixture the sum of a, b and c is ?4; where R.sup.1 is each independently H, an amino group, unsubstituted or substituted C.sub.1-C.sub.20-alkyl radical, unsubstituted or substituted C.sub.2-C.sub.20-alkenyl radical, unsubstituted or substituted C.sub.6-C.sub.14-aryl radical; where R.sup.2 is each independently H, an unsubstituted or substituted C.sub.1-C.sub.20-hydrocarbon radical; where R.sup.3 is each independently H, an amino group, unsubstituted or substituted C.sub.2-C.sub.20-alkyl radical, unsubstituted or substituted C.sub.2-C.sub.20-alkenyl radical, unsubstituted or substituted C.sub.6-C.sub.14-aryl radical, wherein substituted signifies that independently of one another at least one substituent is present from the group of OR.sup.Y, NR.sup.Y.sub.2, SH, SR.sup.Y, epoxy, COOR.sup.Y, CHO, CN, NCO, OCOOR.sup.Y, NR.sup.YCOOR.sup.Y, NR.sup.YCONR.sup.Y, SiR.sup.Y.sub.3 and OSiR.sup.Y.sub.3, where R.sup.Y is each independently H, an amino group, unsubstituted or substituted C.sub.1-C.sub.20-alkyl radical, unsubstituted or substituted C.sub.2-C.sub.20-alkenyl radical, unsubstituted or substituted C.sub.6-C.sub.14-aryl radical; and wherein the alkoxy group content, R.sup.2?H, is less than 5 mol % and the silanol group content, R.sup.2?H, is less than 500 ppm and the siloxane has a viscosity of 5 to 500 000 mPa*s, the viscosity being determined using a Stabinger rotational viscometer at 25? C. and in a temperature range from ?40 to 90? C.

19. The process as claimed in claim 18, wherein the indices a, b, c, d, e each independently have integer values a from 0 to 30, b from 0 to 30, c from 0 to 50, d from 3 to 60, e from 0 to 15.

20. The process as claimed in claim 18, wherein the value of the index a and/or the index c is 0.

21. The process as claimed in claim 18, wherein the siloxane is free from D-cycles.

22. The process as claimed in claim 19, wherein the ratio of the index d to the index b is 0.15 to 3, preferably 0.2 to 2, particularly preferably 0.3 to 1.

23. The process as claimed in claim 19, wherein R.sup.2 is each independently an unsubstituted C.sub.1-C.sub.12-hydrocarbon radical, preferably C.sub.1-C.sub.6-hydrocarbon radical, particularly preferably methyl or ethyl.

24. The process as claimed in claim 18, wherein the unfunctionalized silica has a surface area of 50 to 400 m.sup.2/g.

25. The process as claimed in claim 19, wherein the reaction is carried out at a temperature of 25 to 400? C., particularly preferably 200 to 400? C., especially 200 to 350? C.

26. The use of the silica as claimed in claim 14 as additive for controlling the rheology of liquid and pulverulent systems of toners and developers.

27. The use of the silica produced according to the process of claim 18 as additive for controlling the rheology of liquid and pulverulent systems of toners and developers.

Description

[0152] FIG. 1 shows a scheme of the different process variants for producing D-cycle-free siloxanes.

EXAMPLES

Reagents

[0153] Tetrachlorosilane (CAS: 10026-04-7), trichloromethylsilane (CAS: 75-79-6), chlorotrimethylsilane (CAS: 75-77-4), trimethoxymethylsilane (CAS: 1185-55-3), tetramethoxysilane (CAS: 681-84-5), hexamethyldisiloxane (CAS: 107-46-0), 1,1,3,3-dimethyl-1,3-divinyldisiloxane (CAS: 2627-95-4), 3-aminopropyltrimethoxysilane (CAS: 13822-56-5) and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AS1, CAS: 1760-24-3) were purchased from Sigma-Aldrich. Tonsil? was purchased from Clariant and Purolite? CT269 DR was purchased from Purolite.

Measurement Methods

[0154] 1) The viscosity was measured at 25? C. and in a temperature range of ?40 to 90? C. using a Stabinger SVM3000 rotational viscometer from Anton Paar. [0155] 2) The mass-average molar mass MW and also the number-average molar mass M.sub.n can be determined by size exclusion chromatography (SEC) against polydimethylsiloxane standards, in toluene, at 35? C., flow rate 0.7 ml/min and detection by RI (refractive index detector) on a MesoPore-OligoPore column set (Agilent, Germany) with an injection volume of 10 ?l. [0156] 3) The proportion of Q, T and M units in the siloxane mixture was determined by nuclear magnetic resonance spectroscopy (.sup.29Si-NMR; Bruker Avance III HD 500 (.sup.29Si: 99.4 MHz) spectrometer with BBO 500 MHz S2 probe head; inverse gated pulse sequence (NS=3000). 150 mg of Q/T/M siloxane mixture were taken up in 500 ?l of a 4*10-2 molar solution of Cr(acac).sub.3 in CD.sub.2Cl.sub.2. The proportion of other functionalities was determined by correlating the .sup.29Si-NMR data with the integrals from the .sup.1H-NMR spectrum (.sup.1H-NMR; Bruker Avance III HD 500 (.sup.1H: 500.2 MHz) spectrometer with BBO 500 MHz S2 probe head). 50 mg of Q/T/M siloxane mixture were taken up in 500 ?l of CD.sub.2Cl.sub.2. [0157] 4) The alkoxy content was determined by a combination of .sup.29Si- and .sup.1H-NMR spectroscopy (cf. Point 3). From the .sup.29Si-NMR spectra, the percentages of Q, [0158] T and M units can be determined. Taking into account any signal overlaps (for example the Si-Me units of MeSiO.sub.3/2 groups or Me.sub.3SiO.sub.1/2 groups) the relative ratios from the .sup.29Si-NMR spectrum can be assigned to the ratios from the .sup.1H-NMR spectrum. In this manner, the relative proportion of all functionalities (Q, T, M units, alkoxy groups, unsaturated functionalities, amine functionalities, etc.) was determined. The relative proportions of the observed species are multiplied by the respective molar masses of the associated fragments. The individual masses determined in this way are set in relation to the sum of all individual masses. The individual mass of the alkoxy groups in relation to the sum of all individual masses, multiplied by a factor of 100, gives the alkoxy content of the sample in percent by weight. [0159] 5) The average empirical formula was determined by a combination of NMR spectroscopy (cf. Point 3) and gel permeation chromatography (GPC, cf. Point 2). From the .sup.29Si-NMR spectra, the relative molar proportions of Q, T and M units can be determined. Taking into account any signal overlaps (for example the Si-Me units of MeSiO.sub.3/2 groups or Me.sub.3SiO.sub.1/2 groups) the relative ratios from the .sup.29Si-NMR spectrum can be assigned to the ratios from the .sup.1H-NMR spectrum. In this manner, the relative proportion of all functionalities (Q, T and M units, alkoxy groups, unsaturated functionalities, amine functionalities, etc.) was determined. The relative proportions thus obtained are referred to as the relative empirical formula. The relative proportions of the observed species are multiplied by the respective molar masses of the associated fragments. The total mass thus obtained is referred to as the relative total mass. According to point 2, the number-average molar mass M.sub.N of the sample to be analyzed was determined by GPC. The factor necessary to convert the relative molar mass to the number-average molar mass is then determined. The relative proportions are multiplied by this factor. In this way, the relative empirical formula is converted to the average empirical formula. [0160] 6) The content of unsaturated functionalities in the Q/T/M-based vinyl polymer substitutes is given by the iodine number according to Wijs. The measurement is carried out according to DIN 53241. [0161] 7) The amine number indicates how many mmol of KOH are equivalent to one gram of the substance to be determined. The amine number is determined according to DIN 16945 Version 1989-03. [0162] 8) The content of D-cycles is determined using a gas chromatograph with a flame ionization detector (GC-FID) (CES-Silicones Europe, Apr. 16, 2013 (Revised Version: Jan. 10, 2019)). The detection limit here is typically 60 ppmw. [0163] 9) The silanol group content can be determined by titration with 0.1N sodium hydroxide solution in saturated saline (Sears et al., Anal. Chem. 1956, 12. 1981). In the case of silicas, the sorption capacity for hydroxyl ions (OH.sup.?) is generally recorded. The relative sorption capacity can then be defined as the sorption capacity of the silica under study divided by the sorption capacity of the hydrophilic starting silica multiplied by 100. [0164] 10) The carbon content is determined in the oxygen flow at temperatures >1000? C., where the carbon content is determined from the combustion gases by means of a microprocessor (CS 530, Eltra or SC144DR, Leco). [0165] 11) The content of volatile components of the functionalized silica is determined at 105? C. and 300? C. in accordance with DIN ISO 787/2. 12) The thickening effect of the functionalized silicas is determined at 25? C. in a polyester resin using a rotational viscometer according to DIN 53019.

Examples 1 to 3: Production of D-Cycle-Free Hydrophobic Silicas by Functionalizing Fumed Silicas with T/M Siloxane

[0166] Three fumed silicas (HDK? V15A, HDK? N20, HDK? T30, Wacker Chemie AG) were used, the properties of which are shown in Table 2. For the functionalization, a T/M siloxane (5250) was used having a viscosity of 250 mPa*s and a residual methoxy content of 0.03% by weight.

TABLE-US-00002 TABLE 2 silicas and siloxane used Surface area Mass Silica S250 Ex. No. Silica [m.sup.2/g] [g] 1 HDK? V15A 150 18 2 HDK? N20 200 32 3 HDK? T30 300 48

General Experimental Setup for Functionalization:

[0167] In a 6 L reactor (quartz glass) equipped with stirrer, 100 g of the silica were fluidized under protective gas (argon) for 15 min at 800 rpm. At unchanged rotational speed, the T/M siloxane (S250) was fed from above via a gyro mist nozzle (model 121, bore 0.2 mm, 30? cone, Schlick) using a gear pump (MCP-Z, Ismatec, Z-1830 pump head), over 15 min in a nitrogen flow against 0.6 MPa. After 15 minutes homogenization, the reactor was heated to 300? C. and this temperature was maintained for 2 h with a jacket heater. For the last 30 minutes of the heating period, the system was switched from argon blanketing to nitrogen purging (100 L/h) to expel volatile components via a riser tube.

[0168] The functionalized silicas obtained were analyzed for the carbon content thereof, the volatile fractions at 105? C. and at 300? C. and also residual silanol content and thickening effect in polyester resin (rheological properties). The results are compiled in Table 3.

TABLE-US-00003 TABLE 3 Analytical results of functionalized silicas Thickening Residual effect Volatiles Volatiles Carbon silanol polyester Ex. 105? C. 300? C. content content resin No. [%] [%] [%] [%] [mPas] 1 0 1.1 3.4 17.6 7 2 0.2 5.5 6.5 19.3 8.7 3 0.3 7.5 8.4 21.0 6.1

[0169] Rheological properties were tested by dispersing the functionalized silica in epoxy resin. After storage for one day, the viscosity of the mixture is determined at a shear rate of 0.1 s.sup.?1 and 10 s.sup.?1 and 25? C. Dividing the low shear viscosity by the high shear viscosity gives the thixotropy index. The thixotropy index was determined for two epoxy resin systems:

Epoxy Resin System 1:

[0170] Mixture of 8 mol % of the functionalized silica and 92 mol % epoxy resin (Epikote? Resin 828 (epoxy resin based on bisphenol A and epichlorohydrin), Hexion).

Epoxy Resin System 2:

[0171] Mixture of 8 mol % of the functionalized silica (according to Ex. 1-3) in epoxy resin (Epikote? Resin 828) and 4 mol % HDK? N20 (fumed silica having a specific surface area of 200 m.sup.2/g) in amine hardener (Epikure? curing agent MGS? RIMH-137, Hexion), the mixing ratio being 79 mol % epoxy resin to 21 mol % amine hardener. For comparison, a conventional, commercially available, functionalized silica (HDK? H17) was investigated. The thixotropy indices of the functionalized silicas are shown in Table 4.

TABLE-US-00004 TABLE 4 Rheological testing Thixotropy index in epoxy Thixotropy index in epoxy Ex. No. resin system 1 resin system 2 1 34 48 2 42 56 3 34 54 HDK? H17 40 52

[0172] The silicas modified according to the invention have shear thickenings comparable to the commercial product HDK? H17.

[0173] D-cycles could not be detected for any of the functionalized silicas according to Examples 1 to 3. Analysis of the comparative silica HDK? H17 showed 220 ppm D5 and 70 ppm D6.

Examples 4 to 6: Production of D-Cycle-Free Partially Hydrophobic Silicas by Functionalizing Fumed Silicas with T/M Siloxane

[0174] The three fumed silicas used were HDK? V15A, HDK? N20, HDK? T30 (Wacker Chemie AG), the properties of which are shown in Table 5. Functionalization was carried out with T/M siloxane S250.

TABLE-US-00005 TABLE 5 silicas and siloxane used Surface area Mass Ex. Silica S250 No. Silica [m.sup.2/g] [g] 4 HDK? V15A 150 7.5 5 HDK? N20 200 13 6 HDK? T30 300 19.5

[0175] The experimental setup and implementation were analogous to Examples 1 to 3.

[0176] The functionalized silicas obtained were analyzed with respect to the carbon content thereof, the volatile fractions at 105? C. and at 300? C. and residual silanol content thereof and the thickening effect in polyester resin (rheological properties). The results are compiled in Table 6.

TABLE-US-00006 TABLE 6 Analytical results of functionalized silicas Thickening Residual effect Volatiles Volatiles silanol polyester Ex. 105? 300? Carbon content resin No. C. [%] C. [%] content[%] [%] [mPas] 4 0.3 1 1.9 35.2 3.6 5 0.3 0.8 3 29.5 5.2 6 0.4 6.4 4.4 40.3 4.8

[0177] The synthesis of the D-cycle-free T/M siloxane S250 used for functionalization was carried out in a 4 L three-neck flask equipped with a KPG stirrer, 1 L dropping funnel and olive. The flask is connected to 2 safety wash bottles and an exhaust gas wash bottle filled with a 25% aqueous NaOH solution. Before filling the apparatus, it is flushed with argon. A mixture of 1089 g of methanol and 592 g of hexamethyldisiloxane is initially charged in the flask and cooled to 0? C. At this temperature, a total of 1335 g of methyltrichlorosilane is added via the dropping funnel over a period of 4 h, and the mixture is heated to 50? C. At this temperature, 602 g of demineralized water are added over a period of 3 h via the dropping funnel. The mixture is then brought to room temperature (RT) and stirred for 10 h. The siloxane phase is separated from the aqueous methanolic phase using a separating funnel, neutralized with a saturated sodium hydrogen carbonate solution and dried over sodium sulfate. After filtration (pleated filter), most of the low molecular weight constituents are removed on a rotary evaporator at 80? C. and 10 mbar. The material obtained is a colorless liquid having a viscosity of 64 mPa*s and a residual methoxy content of 0.03% by weight. Subsequently, further low molecular weight constituents (esp. TM3) are removed on a laboratory thin-layer evaporator at 160? C. and 10 mbar. The product obtained is a colorless liquid having a viscosity of 250 mPa*s and a residual methoxy content of 0.03% by weight.

Production of Further D-Cycle-Free Siloxanes: General Apparatus Setup for Cohydrolysis of Halosilanes and Alkoxysilanes

[0178] A 4 L three-necked flask is equipped with a KPG stirrer, a 1 L pressure-equalizing dropping funnel and an olive. For variants A, B and C, the flask is connected to two safety wash bottles and an exhaust gas wash bottle filled with NaOH. Reactive reagents and solvents (for example hexamethyldisiloxane and methanol) are initially charged in the flask, unless described otherwise. Prior to filling the apparatus with the appropriate chlorosilanes, the entire apparatus is flushed with argon.

[0179] FIG. 1 shows the various process variants by means of a flow diagram. The underlying reaction setup for carrying out the process variants is first described below in general terms. Elucidation of variants A, B, C and D then follows.

Choice of Reactants

[0180] Halosilanes, alkoxysilanes, disiloxanes or mixtures thereof may be used as reactants for variant A. For variant C, at least one vinylhalosilane, vinylalkoxysilane or vinyldisiloxane is also added to this mixture. For variant B, the use of M sources is omitted in the hydrolysis. In variants A and C, an excess of water is used, based on the amount of water required to hydrolyze all alkoxy and halogen functionalities present in the mixture. In variant B, a deficiency of water is used.

[0181] The cohydrolyses (variant A, B or C) can be carried out starting from chlorosilanes or methoxysilanes or mixtures thereof. After cohydrolysis, phase separation is carried out in the A and C variants. The siloxane phase is then neutralized, dried over sodium sulfate for 2 h and isolated by filtration. In variant B, the hydrolysis product is used without further processing.

[0182] The products of variants A and B are generally characterized by a residual alkoxy content of >3% by weight. This can be reduced by post-treatments (paths A1, B1, B2, C1). If, after variant A or C, the residual alkoxy content is already in the desired range, no post-treatment is carried out.

Post-Treatment with Purolite? CT269 DR (in the Presence of a (Optionally Functionalized) Disiloxane: Paths A1, A2, B1, B2 and C1)

[0183] A 1 L single-necked flask (equipped with a reflux condenser) is filled with the siloxane to be treated, 7% by weight Purolite? CT269 DR (based on the siloxane weight), and 10-fold the molar amount of hexamethyldisiloxane, 1,1,3,3-dimethyl-1,3-divinyldisiloxane or mixtures thereof (based on the residual alkoxy content present in the siloxane). The mixture is heated to 100? C. for 2 h with intensive stirring, brought to RT and then isolated using a pleated filter (for low-viscosity siloxanes) or glass filter or glass frits with suction flask (for high-viscosity siloxanes). For siloxanes with high residual alkoxy content (from 15 to 30 mol %) after cohydrolysis, the catalyst content may be increased to 14% by weight. This post-treatment can reduce the content of TM, QTM- and QM-cycles in the siloxanes.

Post-Treatment with Tonsil? (in the Presence of a (Optionally Functionalized) Disiloxane; Paths A1, A2, B1, B2 and C1)

[0184] A 1 L three-necked flask (equipped with a reflux condenser) is filled with the siloxane to be treated, 10% by weight Tonsil? (based on the siloxane weight), and 10-fold the molar amount of hexamethyldisiloxane, 1,1,3,3-dimethyl-1,3-divinyldisiloxane or mixtures thereof (based on the residual alkoxy content present in the siloxane). The mixture is heated to 100? C. for a total of 12 h with stirring, brought to RT and then isolated using a pleated filter (for low-viscosity fluids) or glass filter or glass frits with suction flask (for high-viscosity fluids).

Post-Treatment with HCl (in the Presence of a (Optionally Functionalized) Disiloxane; Paths A1, A2, B1, B2 and C1)

[0185] To a stainless steel autoclave (1 L total volume, with analog and digital pressure transducer and resistance jacket heater with temperature sensor) are added 600 mL of a mixture of the siloxane to be treated and 10-fold the molar amount of hexamethyldisiloxane, 1,1,3,3-dimethyl-1,3-divinyldisiloxane or mixtures thereof (based on the residual alkoxy content present in the siloxane). The autoclave is sealed gas-tight and degassed (20 mbar for 3 min) and filled with 15 g of hydrogen chloride gas. The autoclave is heated to 100? C. for 3 h and then brought to RT. The gas atmosphere is passed through a gas scrubber and the gas chamber is purged with argon for 5 min. The siloxane phase is separated from the alcoholic phase, neutralized, and dried over sodium sulfate for 2 h and filtered.

Post-Treatment with KOH (Path A1)

[0186] A 1 L single-necked flask (equipped with a reflux condenser) is filled with the siloxane to be treated and an equimolar amount of KOH granules (based on the residual alkoxy content present in the siloxane). The mixture is heated to 100? C. with stirring for 2 h and then brought to RT. The silicone phase is neutralized with hydrochloric acid (1 mol/l) and freed from adhering solids by filtration. The siloxane phase is washed with demineralized water and then dried over sodium sulfate for 2 h. This post-treatment can be used in particular to reduce the cycle content of Q/T/M siloxanes. Materials subjected to this post-treatment have a residual hydroxy content even after neutralization, which results in increasing viscosities with increasing storage time. In order to obtain viscosity-stable materials, post-treatment with an acidic catalyst can then be carried out as described. The viscosity changes in the siloxane due to this post-treatment can be significant, and, in the case of TM siloxanes, restructuring is usually detectable.

[0187] After each of the aforementioned reaction steps, low molecular weight constituents such as methanol, ethanol, hexamethyldisiloxane, tetrakis(trimethylsiloxy)silane (QM4) such as tris(trimethylsiloxy)methylsilane (TM3) can be quantitatively removed on a rotary evaporator or thin film/short path evaporator.

Treatments with NaOMe in the Presence of an Aminoalkoxysilane (Variant D)

[0188] In a 1 L round-necked flask with reflux condenser, the siloxane to be treated is mixed with an aminoalkoxysilane and 500 ppm by weight (based on the total weight) of a sodium methoxide solution (20% by weight in methanol). The mixture is heated to 90? C. with stirring for 2 h. The reaction is monitored by .sup.29Si-NMR spectroscopy.

Reaction Sequences

[0189] After cohydrolysis (according to variant A), crude siloxanes are obtained having a residual alkoxy content. If this is outside the desired range, it can be reduced by post-treatments using an acidic or basic catalyst (path A1). If the residual alkoxy content is already in the desired range, no post-treatment is carried out.

[0190] The siloxanes can be converted in subsequent steps to alkenylsiloxanes (post-treatment with an acidic catalyst using, for example, 1,1,3,3-tetramethyl-1,3-divinyldisiloxane, path A2) or aminosiloxanes (post-treatment with NaOMe in the presence of an aminoalkoxysilane). Furthermore, the incorporation of unsaturated functionalities can be coupled with the reduction of the residual alkoxy content (path C1).

[0191] After partial hydrolysis according to variant B, Q-, QT- or T-alkoxy oligomers/polymers are obtained; M units are not used in the hydrolysis. In the context of post-treatment with an acidic catalyst using, for example, hexamethyldisiloxane (path B1), 1,1,3,3-dimethyl-1,3-divinyldisiloxane or mixtures thereof (path B2), the (alkenyl)siloxanes are produced.

[0192] A summary of the reactants used in the examples and weights thereof for producing the crude siloxanes (without vinyl or amine functionalities) is given in Table 8.

TABLE-US-00007 TABLE 8 *Conc. hydrochloric acid (32% by weight) was used as acid. Acid and demineralized water were mixed prior to adding and homogenized by intensive stirring for 5 minutes. Weight of Weight of Weight of Weight of Temp. A Weight of [Me.sub.3SiO.sub.1/2] [MeSiO.sub.3/2] [SiO.sub.4/2] demin. water and B Ex alcohol [g] source [g] source [g] source [g] [g] [? C.] 7 EtOH, 756 Me.sub.3SiCl, 254 MeSiCl.sub.3, 582 252 0; RT 8 MeOH, 1027 [Me.sub.3SiO.sub.1/2].sub.2, 568 MeSiCl.sub.3, 1281 577 0; 50 9 MeOH, 1001 [Me.sub.3SiO.sub.1/2].sub.2, 785 MeSiCl.sub.3, 506 SiCl.sub.4, 581 563 0; 50 10 MeOH, 1254 [Me.sub.3SiO.sub.1/2].sub.2, 983 MeSiCl.sub.3, 633 SiCl.sub.4, 727 705 0; 50 11 MeOH, 1013 [Me.sub.3SiO.sub.1/2].sub.2, 1064 SiCl.sub.4, 958 570 0; 50 12 MeOH, 1091 [Me.sub.3SiO.sub.1/2].sub.2, 942 SiCl.sub.4, 1084 613 0; 50 13 [Me.sub.3SiO.sub.1/2].sub.2, 72 MeSi(OMe).sub.3, 500 80 (+54 g HCl)* 50 14 MeSi(OMe).sub.3, 1500 245 (+15 g HCl)* 50 15 MeOH, 1089 [Me.sub.3SiO.sub.1/2].sub.2, 592 MeSiCl.sub.3, 1335 601 0; 50 16 MeSi(OMe).sub.3, 1500 220 (+6 g HCl)* 50 17 MeOH, 1088 [Me.sub.3SiO.sub.1/2].sub.2, 853 MeSiCl.sub.3, 550 SiCl.sub.4, 631 612 0; 50 18 MeOH, 1070 [Me.sub.3SiO.sub.1/2].sub.2, 1085 SiCl.sub.4, 1022 601 0; 50

[0193] A summary of the analytical data of the siloxanes before and after post-treatment can be found in Table 9.

TABLE-US-00008 TABLE 9 *For Example 19, the non-post-treated crude siloxane from Example 17 was used and reacted with HCl as catalyst according to the above procedure. Residual Viscosity alkoxy Residual of crude content of Viscosity alkoxy siloxane crude siloxane Post- of product content Ex. [mPa*s] [wt. %] treatment [mPa*s] [wt. %] 7 154 0.23 8 127.2 1.6 Purolite/Si2 1281 0.05 9 68.1 4.8 Purolite/Si2 184 0.22 10 573.5 2.8 KOH 14012 0.96 11 51.1 3.2 Purolite/Si2 187 0.33 12 1956.7 4.8 Purolite/Si2 21326 0.73 13 Purolite/Si2 7501 0.18 14 Purolite/Si2 9720 0.72 15 Purolite/Si2 138 0.08 16 Purolite/Si2 980 0.58 17 Tonsil/Si2 150 0.52 18 Purolite/Si2 80 0.19 19* HCl/Si2 175 <0.01

[0194] A summary of the weights and analytical data of the siloxanes after functionalization can be found in Table 10.

TABLE-US-00009 TABLE 10 *The catalyst addition of the NaOMe solution (20% by weight in MeOH) was 500 ppm by weight (based on the total mass of base siloxane and aminosilane). Residual Weight of alkoxy Amine Siloxane siloxane Reagent Cat. Viscosity content Iodine No. Ex. [Ex.] [g] [g] [g] [mPa*s] [wt. %] No. [meq/g] 20 15 251 VSi.sub.2, 14.5 Purolite, 20 179 <0.01 7.4 21 16 265 VSi.sub.2, 49.1 Purolite, 13 1081 0.04 15.4 22 17 300 VSi.sub.2, 17.1 Purolite, 21 290 0.06 6.8 23 18 352 VSi.sub.2, 40.2 Purolite, 27 145 0.82 6.6 24 13 738 AS1, 11.5 NaOMe* 6871 0.65 0.12 25 16 1296 AS1, 42.6 NaOMe* 856 1.64 0.28

[0195] For examples 7 to 25, the D-cycle content was investigated by GC-FID, with the result that no D-cycles could be detected.