DE19649998A1 - Preparation of alkoxy-silane compounds containing vinyl ether groups - Google Patents

Abstract

The preparation of compounds of formula CH2=CH-O-X-CH2CH2SiRy(OR')3-y (I) comprises reacting divinyl ethers of formula CH2=CH-O-X-CH=CH2 (II) with silanes of formula HSiRy(OR')3-y (III) at 70 - 150 deg C in the presence of a homogeneous hydrosilation catalyst. The catalyst is a platinum or rhodium compound, and the amount of Rh or Pt is 0.05 - 10 ppm with respect to (II and (III). R, R' = 1-6C alkyl or 6-10C aryl; X = 1-20C hydrocarbon, optionally substituted by halo and/or containing O atoms; and y = 0 - 2.

Description

The invention relates to a process for the preparation of alkoxy silanes with vinyl ether residues. A method of making the Water connections are already known from DE 21 20 711. In the Reaction of divinyl ethers with silanes, however, become carrier data analyzers, in which the catalytic substances on activated carbon are applied, used. Compared to such heterogeneous kata Analyzers are homogeneous catalysts that have no carrier are homogeneously distributed in the reaction mixture, not least because of it prefers that they have high activity and - if they can be used in sufficiently small quantities - on their recovery can be entirely dispensed with, resulting in less equipment and technical effort in the implementation tion of the reaction. In the known from EP-A-625 534 driving homogeneous catalysts are used, but are the amount of catalyst used is relatively high (over 10 ppm), what z. B. is disadvantageous due to the high catalyst costs.

The object of the present invention was therefore a method for the production of alkoxysilanes with vinyl ether radicals, where homogeneous catalysts only required in the smallest possible amounts will.

Accordingly, a process for the preparation of compounds of general formula

H₂C = CH-OXO-CH₂CH₂SiR _y (OR ′) _3-y I

where R and R 'independently of one another for a C₁-C₆ alkyl or are a C₅-C₁₀ aryl radical, X is a hydrocarbon or Halogenated hydrocarbon residue with 1 to 20 carbon atoms, which opp may also contain oxygen atoms, and y is 0.1 or can be 2, by reacting divinyl ethers of the formula

H₂C = CH-O-X-O-CH = CH₂ II

with silanes of the formula

HSiRy (OR ′) _3-y III

where R, R ′, X and y each have the meaning given above, which is characterized in that the divinyl ether with the Si lanes at temperatures from 70 to 150 ° C in the presence of a homogeneous NEN hydrosilylation catalyst from the group of the platinum or Rhodium compounds are reacted, the one amount of catalyst 0.05 to 10 ppm of platinum or rhodium, based on the reaction mixture of divinyl ether and silanes, is found.

Further statements relate to preferred embodiments of the Procedure.

Preferred compounds of formula I and correspondingly preferred Divinyl ethers of the formula II and silanes of the formula III are those in which R represents a methyl or a phenyl radical and R 'represents is a methyl, ethyl, propyl or iso-propyl radical.

X preferably represents a C₁-C₂₀-, in particular a C₁-C₁₀- Alkylene group which still contain 1 to 3 ether groups (-O-) can.

X particularly preferably has one of the meanings below:

X very particularly preferably stands for

-CH₂CH₂-, -CH₂CH₂CH₂CH₂,
-CH₂CH₂-O-CH₂CH₂-

When the divinyl ethers are reacted with the silanes, the Divinyl ether is preferably used in a molar excess. Before molar amounts of 1 to 20, in particular 3 to 15, mol are added Divinyl ether, based on 1 mol of silane.

The reaction temperature is 70 to 150, preferably 80 to 130 ° C.

Platinum or rhodium compounds are used as catalysts det, which are distributed homogeneously in the reaction mixture.  

In particular, there are complex compounds of platinum or rhodium into consideration. Platinum-O-divinylsiloxaneom should preferably be mentioned plexes such as platinum-divinyltetramethyldisiloxane complex or rhodium I-dicarbonylacetylacetonate. Other complex compounds are e.g. B. in EP-A-625 534.

The catalysts are preferred in amounts of 0.05 to 10 ppm as 0.1 to 5 ppm, particularly preferably 0.1 to 3 ppm platinum or rhodium, based on the reaction mixture of divinyl ether and silane.

The reaction time is preferably less than 10 hours, in total common are 0.5 to 5 hours of reaction time for a complete sufficient conversion of the silanes.

Unreacted starting material, e.g. B. the preferably in excess set divinyl ether, is recovered after the reaction. The Isolation of the reaction product can be done by simple distillation take place, with columns with few theoretical plates (e.g. <10) are sufficient. The product obtained generally contains mean more than 95% by weight, usually more than 98% by weight of the desired compound of formula I.

example 1

204.5 g (1.44 mol) of butanediol divinyl ether and 29.5 g (0.18 mol) of triethoxysilane are placed in a flask with a reflux condenser, stirrer and internal thermometer, heated over a heating bath and at 90 ° C. with 0.01 ml of a Approx. 2% rhodium dicarbonylacetylacetonate solution in toluene (corresponds to approx. 0.3 ppm rhodium with respect to the mixture). The mixture is heated further. An exothermic reaction occurs at approx. 100 ° C, the temperature rising to approx. 110-115 ° C. The reaction mixture is stirred for a further 30 minutes at a bath temperature of approx. 100 ° C. After this reaction time, the triethoxysilane has completely reacted. The mixture is then passed through a thin film evaporator to remove unreacted butanediol divinyl ether. The product is then distilled through a 30 cm long Vigreux column (inner diameter approx. 1.5 cm).
95% of unreacted butanediol divinyl ether was recovered in a purity of <99%.
42.0 g (76.3%) of 2- (4-vinyloxybutoxy) ethyltri ethoxysilane were isolated as product:
Boiling point: 105 ° C (1 mbar)
Purity gas chromatography (GC): 97-98%
NMR data of 2- (4-vinyloxyethoxy) ethyltriethoxysilane:
¹³C-NMR, δ (ppm): 13.0 (1C, C H₂Si CH₂); 18.3 (3C, OCH₂H₃); 26.1, 26.5 (2C, -OCH₂ C H₂ C H₂CH₂O-), 58.4 (3C, O C H₂CH₃), 66.5, 67.8, 69.9 (3C, ViO C H₂ C H₂O C H₂CH₂Si); 86.2 (1C, CH₂ = C H-O); 152.0 (1C, C H₂ = CH-O) ²⁹Si-NMR, δ (ppm) = -47.2

Example 2

98 g (0.86 mol) of ethylene glycol divinyl ether and 30.8 g (0.19 mol) of triethoxysilane are placed in a flask with a reflux condenser, stirrer and internal thermometer, heated over a heating bath and at 100 ° C. with 0.02 ml of a solution of the Platinum-divinyltetramethyldisi loxane complex in xylene (approx. 3-3.5% Pt, corresponds to approx. 5 ppm platinum with respect to the mixture) was added. The mixture is then stirred at 100 ° C. for a further 5 h. After this reaction time, the triethoxysilane has completely reacted. With a slight vacuum and a bath temperature of 85 ° C, the excess ethylene glycol divinyl ether is then distilled off. The product is then distilled through a 30 cm long Vigreux column (inner diameter approx. 1.5 cm). Unreacted ethylene glycol divinyl ether was recovered quantitatively in a purity of 98-99%.
35.9 g (69%) of 2- (2-vinyloxyethoxy) ethyltri ethoxysilane were isolated as product:
Boiling point: 69 ° C (0.015 mbar)
Purity GC: <99%
NMR data of 2- (2-vinyloxyethoxy) ethyltriethoxysilane:
¹³C-NMR, δ (ppm) = 13.0 (1C, C H₂Si CH₂); 18.3 (3C, OCH₂CH₃); 58.4 (3C, O C H₂CH₃) 67.2, 67.4, 68.6 (3C, ViO C H₂CH₂O C H₂CH₂Si); 86.5 (1C, CH₂ = C H-O); 151.9 (1C, C H₂-CH-O)
²⁹Si NMR, δ (ppm) = -47.5

Comparative experiment 1

213 g (1.5 mol) butanediol divinyl ether and 24.6 g (0.15 mol) tri ethoxysilane are placed in a flask with a reflux condenser, stirrer and internal thermometer, heated over a heating bath and at 100 ° C. with 0.37 ml of a platinum -divinyldisiloxane complex solution (with approx. 3% Pt) added (corresponds to approx. 45 ppm platinum with respect to the mixture). An exothermic reaction occurs, the temperature rising to approx. 110-115 ° C. The reaction mixture is stirred for a further 30 minutes at a bath temperature of approx. 100 ° C. After this reaction time, the triethoxysilane has reacted completely. The mixture is then passed through a thin film evaporator to remove unreacted butanediol divinyl ether. The product is then distilled through a 30 cm long Vigreux column (inner diameter approx. 1.5 cm from). Unreacted butanediol divinyl ether was recovered.
39.9 g (87%) of 2- (4-vinyloxybutoxy) ethyltri ethoxysilane were isolated as product:
Boiling point: 105 ° C (1 mbar)
Purity GC: 97%.

Comparative Example 2

The implementation corresponded to example 2 with the following changes:
Reaction of 29.5 g of triethoxysilane with 205.2 g of ethylene glycol divinyl ether; 0.45 ml of platinum divinyl disiloxane complex solution (with approx. 3% Pt) at 100 ° C; Reaction time 1 h; Yield of 2- (2-vinyloxyethoxy) ethyltriethoxysilane: 47% (GC purity: 91%)

Comparative Example 3 (compared to DE-A-21 20 711)

Butanediol divinyl ether and triethoxysilane were reacted in a molar ratio of 8: 1 at 125 ° C (15 hour reaction time). A supported catalyst (platinum on activated carbon) was used as the catalyst, the amount of platinum being 63 ppm, based on the reaction mixture.
The yield was 65% (GC purity: 88%)

Claims (2)

1. A process for the preparation of compounds of the general formula H₂C = CH-OXO-CH₂CH₂SiR _y (OR ') _3-y I where R and R' independently of one another are a C₁-C₆ alkyl or a C--C₁₀ aryl radical, X represents a hydrocarbon or halogenated hydrocarbon radical with 1 to 20 C atoms, which may optionally also contain oxygen atoms, and y can be 0, I or 2, by reacting divinyl ethers of the formula H₂C = CH-OXO-CH = CH₂ II with silanes the formula HSiRy (OR ') _3-y IIIworin R, R', X and y each have the meaning given above, characterized in that the divinyl ethers with the silanes at temperatures from 70 to 150 ° C in the presence of a homogeneous hydrosilylation catalyst from the group the platinum or rhodium compounds are reacted, the amount of catalyst used being 0.05 to 10 ppm of platinum or rhodium, based on the reaction mixture of divinyl ether and silanes. 2. The method according to claim 1, characterized in that it the rhodium compound is rhodium-I-dicarbonylacetyl acetonate.