PROCESS FOR PRODUCING HYDROSILYLABLE POLYOXYALKYLENE ETHERS

Abstract

Described are a process for producing hydrosilylable polyoxyalkylene ethers, comprising the steps of (1) alkoxylation of at least one terminally unsaturated alcohol with alkylene oxides to afford a polyoxyalkylene ether, (2) etherification of the polyoxyalkylene ether from step (1) and (3) neutralization of the product from step (2) under buffered conditions, and hydrosilylable polyoxyalkylene ether mixtures.

Claims

1. A process for producing hydrosilylable polyoxyalkylene ethers, comprising the steps of (1) alkoxylation of at least one terminally unsaturated alcohol with alkylene oxides to afford a polyoxyalkylene ether, (2) etherification of the polyoxyalkylene ether from step (1) and (3) neutralization of the product from step (2) under buffered conditions.

2. The process according to claim 1, wherein in step (3) the product from step (2) is admixed with a buffer solution before the acid addition.

3. The process according to claim 1, wherein step (3) is performed in the presence of water.

4. The process according to claim 1, wherein the buffer solution has a buffering range between pH 3.5 and 9.0.

5. The process according to claim 1, wherein the buffer solution comprises phosphate as the buffer substance.

6. The process according to claim 1 for producing mixtures of hydrosilylable polyoxyalkylene ethers comprising hydrosilylable propylene-containing polyoxyalkylene ethers.

7. The process according to claim 1 for producing hydrosilylable polyoxyalkylene ether mixtures comprising compounds of general formulae (1a) and (1b), ##STR00004## where R1 is independently at each occurrence a hydrogen radical or an alkyl group having 1 to 8 carbon atoms, R2 is independently at each occurrence a hydrogen radical, an alkyl group having 1 to 20 carbon atoms, an aryl or alkaryl group, or R1 and one of the R2 radicals may together form a ring which includes the atoms to which R1 and R2 are bonded; R3 is independently at each occurrence a saturated or unsaturated, aliphatic or aromatic, hydrocarbon radical having 2 to 30 carbon atoms, which is optionally further substituted, R4 is independently at each occurrence a hydrogen radical, an alkyl group having 1 to 8 carbon atoms, which may optionally be branched, and/or an unsaturated aliphatic group, preferably <10% hydrogen radical, reported % based on the entirety of all relevant molecules containing the R4 radical, R5 is hydrogen or methyl group, wherein a is from 1 to 1000, b is from 0 to 1000, preferably 1 to 500, with the proviso that the sum of a+b must be not less than 3 and with the proviso that the groups having the indices a+b are freely permutable over the molecular chain, and wherein the different monomer units of the fragments with the indices a and b may be in a blockwise structure with one another, wherein individual blocks may also occur multiple times and may be randomly distributed among one another or else are subject to a random distribution and further are freely permutable with one another in the sense that they may be arranged in any desired sequence.

8. A hydrosilylable polyoxyalkylene ether mixture comprising compounds of general formulae (1a) and (1b), ##STR00005## where R1 is independently at each occurrence a hydrogen radical or an alkyl group having 1 to 8 carbon atoms, R2 is independently at each occurrence a hydrogen radical, an alkyl group having 1 to 20 carbon atoms, an aryl or alkaryl group, or R1 and one of the R2 radicals may together form a ring which includes the atoms to which R1 and R2 are bonded; R3 is independently at each occurrence a saturated or unsaturated, aliphatic or aromatic, hydrocarbon radical having 2 to 30 carbon atoms, which is optionally further substituted, R4 is independently at each occurrence a hydrogen radical, an alkyl group having 1 to 8 carbon atoms, which may optionally be branched, and/or an unsaturated aliphatic group, preferably <10% hydrogen radical, reported % based on the entirety of all relevant molecules containing the R4 radical, R5 is hydrogen or methyl group, wherein a is from 1 to 1000, b is from 0 to 1000, with the proviso that the sum of a+b must be not less than 3 and with the proviso that the groups having the indices a+b are freely permutable over the molecular chain, and with the proviso that the different monomer units of the fragments with the indices a and b may be in a blockwise structure with one another, wherein individual blocks may also occur multiple times and may be randomly distributed among one another or else are subject to a random distribution and further are freely permutable with one another in the sense that they may be arranged in any desired sequence.

9. A hydrosilylable polyoxyalkylene ether mixtures according to claim 8.

10. The polyether siloxanes comprising hydrosilylable polyoxyalkylene ether mixtures according to claim 1.

11. A surface-active substance comprising the polyether siloxane according to claim 10 as a surface-active substance.

12. An additive comprising the polyether siloxanes according to claim 10 wherein the additive is a component for ceramic formulations, as an additive in coating compositions, polymeric moulding materials or thermoplastics, as a feed additive, as a wetting agent, as a substrate wetting agent, as a crosslinker, as a thickener, as an additive for polyurethane compounds, in the production of paints, adhesives, as a support for catalysts or in biomedical technology generally or as an added substance for cosmetic formulations and cleaning compositions.

13. A composition comprising a polyether siloxane according to claim 10 wherein the composition is a component for ceramic formulations, as an additive in coating compositions, polymeric molding materials or thermoplastics, as a feed additive, as a wetting agent, as a substrate wetting agent, as a crosslinker, as a thickener, as an additive for polyurethane compounds, in the production of paints, adhesives, as a support for catalysts or in biomedical technology generally or as an added substance for cosmetic formulations and cleaning compositions.

14. The process according to claim 1, wherein the buffer solution comprises hydrogenphosphate and/or dihydrogenphosphate.

15. The process according to claim 4, wherein the buffer solution comprises hydrogenphosphate and/or dihydrogenphosphate.

16. The process according to claim 7 wherein R1 is independently at each occurrence selected from the group consisting of hydrogen, methyl or ethyl, R2 is independently at each occurrence selected from the group consisting of hydrogen, methyl, ethyl, octyl, decyl, dodecyl, phenyl, benzyl, or R1 and one of the R2 radicals may together form a ring which includes the atoms to which R1 and R2 are bonded, wherein the ring comprises 5 to 8 carbon atoms, R3 is independently at each occurrence a saturated or unsaturated, aliphatic or aromatic, hydrocarbon radical having 2 to 24 carbon atoms, and R4 is independently at each occurrence less than 10% hydrogen radical reported % based on the entirety of all relevant molecules containing the R4 radical, an alkyl group having 1 to 8 carbon atoms.

17. The process according to claim 7 wherein R1 is hydrogen and R2 is selected from the group consisting of hydrogen, methyl and ethyl.

18. The process according to claim 7 wherein a is from 3 to 100, and b is from 1 to 500.

19. The process according to claim 7 wherein a is from 3 to 500, and b is from 1 to 200.

20. The process according to claim 7 wherein a is from 4 to 50, and b is 0.

Description

EXPERIMENTAL SECTION

Measurement Methods:

[0082] Parameters or measurements are preferably determined using the methods described hereinbelow. In particular, these methods were used in the examples of the present intellectual property right.

[0083] The propenyl content of the polyethers/polyether mixtures may be detected by .sup.1H-NMR. The signal (doublet) at a chemical shift of (x)=1.5 ppm (corresponds to the CH.sub.3 group of the propenyl unit) is related here to the signal (doublet of doublets) at (y)=5.1-5.4 ppm (corresponds to the signal of the CH.sub.2 group of the allyl unit) weighted for the number of protons.

##STR00003##

[0084] The NMR spectra were measured with a Bruker 400 MHz spectrometer using a 5 mm QMP head. Quantitative NMR spectra were measured in the presence of a suitable accelerating agent. The sample to be analysed was dissolved in a suitable deuterated solvent (methanol) and transferred into 5 mm or, if appropriate, 10 mm NMR tubes.

[0085] In the context of this invention, weight-average and number-average molecular weights are determined for the produced polyethers by gel permeation chromatography (GPC) calibrated against a polypropylene glycol standard. GPC was performed using an Agilent 1100 instrument fitted with an RI detector and an SDV 1000/10000 column combination consisting of an 0.85 cm pre-column and two 0.830 cm main columns at a temperature of 30 C. and a flow rate of 1 mL/min (mobile phase: THF). The sample concentration was 10 g/l and the injection volume was 20 l.

[0086] Wet chemistry analysis was performed according to international standard methods: iodine number (IN; DGF C-V 11 a (53); acid number (AN; DGF C-V 2); OH number (ASTM D 4274 C).

[0087] The examples adduced hereinafter describe the present invention by way of example, without any intention that the invention, the scope of application of which is apparent from the entirety of the description and the claims, be restricted to the embodiments specified in the examples.

Example 1: Inventive Example

1.1 Alkoxylation According to Process Step (1) of the Process According to the Invention

[0088] In a 5 L autoclave 337 g of allyl alcohol and 11 g of sodium methoxide were initially charged under nitrogen and evacuated to an internal pressure of 30 mbar. With stirring the reaction mixture was heated to 120 C. and at this temperature 2652 g of ethylene oxide (EO) were added onto the allyl alcohol. After quantitative conversion of the EO the reactor contents were deodorized by evacuation to 30 mbar to remove any traces of unconverted EO present. The analytical values for the product from example 1.1 are reported in table 1.

1.2 Etherification According to Process Step (2) of the Process According to the Invention

[0089] A stirred reactor with temperature and pressure control is filled under nitrogen with 1081 g of the product from example 1.1. 96 g (115 mol %) of sodium hydroxide powder are then added and the mixture is heated to 120 C. with stirring. Simultaneously the reactor is evacuated and water is distilled off until a pressure of 20 mbar is established (about 2.5 h). 108 g of methyl chloride are then added at 120 C. in such a way that the pressure does not exceed 1.0 bar (about 1 h). In what follows the reactor is evacuated to about 20 mbar. At the same temperature 24 g of methyl chloride are metered in over about 1 h. After a postreaction time of about 0.5 h the product is degassed at 95 C. and 20 mbar.

1.3 Buffered Workup According to Process Step (3) of the Process According to the Invention

[0090] The product from Example 1.2 (1081 g) is heated to 100 C. and 500 g of water are added. Subsequently 12.1 g of (about 45%) sodium dihydrogenphosphate solution are added and the mixture is stirred for 1 h. Dilute phosphoric acid (30%) is then added until a pH of 5 is attained. The water is distilled off at 100 C. and 10 mbar and the product is freed from salt residues by filtration. A colourless to yellowish product having the physical parameters summarized in table 1 is obtained. The analytical values before/after etherification are likewise reported in table 1.

Example 2: Comparative Example

[0091] The product from example 1.1 was converted as per example 1.2 and worked up as follows.

2.3 Unbuffered Workup

[0092] 1184 g of a product produced as per example 1.2 are heated to 100 C. and 550 g of water are added. Dilute phosphoric acid (30%) is then added until a pH of 5 is attained. The water is distilled off at 100 C. and 10 mbar and the product is freed from salt residues by filtration. A colourless to yellowish product having the physical parameters summarized in table 1 is obtained.

Example 3: Inventive Example

3.1 Alkoxylation According to Process Step (1) of the Process According to the Invention

[0093] The alkoxylation was performed as per example 1.1, wherein a mixture of 42 wt % of EO and 58 wt % of PO was added onto the starter allyl alcohol to afford a polyether having a molecular weight of about 1300 g/mol. A colourless to yellowish product having the physical parameters summarized in table 1 is obtained.

3.2 Etherification According to Process Step (2) of the Process According to the Invention

[0094] The etherification of the polyether from example 3.1 was performed as per example 1.2. A colourless to yellowish product having the physical parameters summarized in table 1 is obtained.

3.3 Buffered Workup According to Process Step (3) of the Process According to the Invention

[0095] The buffered workup of the polyether from example 3.2 was performed as per example 1.3 A colourless to yellowish product having the physical parameters summarized in table 1 is obtained.

Example 4: Comparative Example

[0096] The product from example 3.1 was converted as per example 3.2.

4.3 Unbuffered Workup

[0097] The unbuffered workup was effected as per example 2.3. A colourless to yellowish product having the physical parameters summarized in table 1 is obtained.

TABLE-US-00001 TABLE 1 Physical data for examples 1-4 Propenyl Iodine content number OH number Acid number Example [mol %] [g iodine/100 g] [mg KOH/g] [mg KOH/g] 1.1 = 2.1 1.2 50.3 108 3.5 1.2 = 2.2 2.9 n.d n.d n.d 1.3 2.9 46.5 6.5 0.2 2.3 0 45.5 7.5 0.2 3.1 = 4.1 1.4 18.0 43.0 4.1 3.2 = 4.2 4.3 n.d n.d n.d 3.3 4.3 17.5 2.5 0.10 4.3 0 17.0 3.0 0.18

[0098] The reactivity of the propenyl-containing polyether in the context of an SiC linkage was tested with reference to Pt-catalysed hydrosilylation of the polyethers produced by the process according to the invention onto heptamethyltrisiloxane (HMTS; CAS number: 1873-88-7).

Example 5: Hydrosilylation of the Polyether from Example 1.3 onto HMTS

[0099] In a 1 L three-necked flask having a thermometer, reflux cooler and KPG stirrer, 435.1 g of the polyether from example 1.3 were heated to 75 C. and at this temperature admixed with 74 mg of a solution of Karstedt catalyst (CAS number: 68478-92-2) in toluene (1.5% Pt). 120 g of HMTS (SiH value=5.11 eq/kg) were then added dropwise such that the temperature did not exceed 90 C. Once HMTS addition was complete the mixture was stirred at 90 C. until the SiH conversion was virtually quantitative (>99%).

[0100] Conversion was determined by gas-volumetric determination of the SiH value of the reaction mixture (decomposition of a weighed-in sample in a gas burette using a sodium butoxide solution). The conversion profile is summarized in Table 2. A yellowish, clear liquid was obtained as product.

Example 6: Hydrosilylation of the Polyether from Example 2.3 onto HMTS

[0101] In a 1 L three-necked flask having a thermometer, reflux cooler and KPG stirrer, 454.1 g of the polyether from example 2.3 were heated to 75 C. and at this temperature admixed with 77 mg of a solution of Karstedt catalyst (CAS number: 68478-92-2) in toluene (1.5% Pt). 125 g of HMTS (SiH value=5.01 eq/kg) were then added dropwise such that the temperature did not exceed 90 C. Once HMTS addition was complete the mixture was stirred at 90 C. until the SiH conversion was virtually quantitative (>99%).

[0102] Conversion was determined by gas-volumetric determination of the SiH value of the reaction mixture (decomposition of a weighed-in sample in a gas burette using a sodium butoxide solution). The conversion profile is summarized in Table 2. Since quantitative conversion could not be reported even after 6 h a further 38 mg of the catalyst solution were added. After a further stirring time of 1 h the target conversion was finally attained and a yellowish, clear liquid was obtained as product.

Example 7: Hydrosilylation of the Polyether from Example 3.3 onto HMTS

[0103] Example 7 was performed as per example 5 with identical stoichiometry of HMTS to polyether from example 3.3.

Example 8: Hydrosilylation of the Polyether from Example 4.3 onto HMTS

[0104] Example 8 was performed as per example 6 with identical stoichiometry of HMTS to polyether from example 4.3.

TABLE-US-00002 TABLE 2 Conversion profile of hydrosilylation of the polyether mixtures from examples 1.3, 2.3, 3.3 and 4.3. Conversion [mol %] after Example 1 h 2 h 3 h 4 h 5 h 6 h 7 h 5 64 76 92 98 >99 6 45 55 63 n.d n.d 83 >99 7 46 71 88 n.d 88 >99 8 52 72 78 n.d 89 95 >99

[0105] Surprisingly, the propenyl-containing polyethers according to the invention are markedly more reactive than prior art polyethers in the context of the SiC linking hydrosilylation reaction onto SiH-functional siloxanes.