NO156610B - Silanes. - Google Patents

Description

The present invention relates to a new class of organosilicon compounds. More specifically, the invention concerns new phenoxyalkyl and pyridyloxyalkylsilanes.

The new compounds according to the invention have the formula:

4 2

where R is -NR H, -NR_ or -CHO, R is methylene or propy-3 4

len and R and R are selected separately from methyl, cycloalkyl with 3-12 carbon atoms, aryl, alkaryl and aralkyl, where the alkyl group in the two latter radicals contains 1-12 carbon atoms.

The compounds according to the present invention are functionally substituted phenoxyalkyl or pyridyloxyalkylsilanes with one of the formulas indicated above. As the substituent R on the phenyl group, an amino group is preferred because of the many useful applications of this class of compounds. The substituent can be in the ortho, meta or para position in relation to the oxygen atom.

The pentoxy or pyridyloxy group is connected to the silicon atom by means of methylene or propylene in either linear or branched form. Compounds where R 2 is ethyl have been found to be so unstable in the presence of even trace amounts of aqueous acids or bases that they are useless for all practical purposes. In addition to the aforementioned alkylene groups, the silicon atom is also bound to three alkoxy or aryloxy groups represented by OR"^ in the preceding formula.

The present compounds are conveniently prepared by reacting an alkali metal salt, preferably the sodium salt of the desired phenol or hydroxypyridine, with a halogen-alkylsilane of the general formula XR 2 Si(OR 3)3- This reaction is strongly exothermic and is preferably carried out in an inert atmosphere in the absence of even trace amounts of water, knowing that water readily reacts with trihydroxy and triaryloxysilanes to give polymeric products. The reaction medium is a mixture of at least one liquid hydrocarbon which boils at 40-200°C, and a dipolar, aprotic liquid such as dimethylsulfoxide, N,N-dimethylformamide, tetramethylurea or hexamethylphosphoramide. The trialkoxyhaloalkylsilane is preferably gradually added to a reaction medium containing the alkali salt. When the addition is complete and any hexothermic reaction has subsided, it is usually desirable to heat the reaction mixture to a temperature of 70-150°C for several hours to ensure substantially complete conversion of the reactants to the desired phenoxyalkyl or pyridyloxyalkyl trihydro -carbyloxysilane. The present compounds, many of which are colorless, high-boiling, viscous oils, are soluble in the reaction medium and can be easily isolated by removal of the aforementioned liquid hydrocarbon and the dipolar solvent. Some of the compounds may darken if exposed to air or light for long periods of time.

The trihydrocarbyloxyhaloalkylsilanes used as

one of the reaction components in the preparation of the compounds according to the invention, are commercially available or can be easily prepared by reacting the corresponding halogen-12 2 1 2 alkyltrihalosilane, X R SiX , where X and X are chlorine, bromine

3

or iodine, with an alcohol, R OH, containing 1-12 carbon atoms. Alternatively, the hydroxyl group can be attached to a carbocyclic or heterocyclic ring structure such as a cyclohexyl, pyridyl or phenyl group. Hydrocarbyloxytrihalosilane can be prepared by reacting a haloalkene such as allyl chloride with a trihalosilane, HSiX<2>^ , at ambient temperature in the presence of a platinum catalyst. Methods for producing the silane intermediates are well known in the art. A detailed discussion of the reaction conditions is therefore not necessary here.

Examples of phenols that can be used for the preparation of the compounds according to the invention are aminophenols where the amino group is in the ortho-, meta- or para-position in relation to the hydroxyl group, isomeric hydroxybenzaldehydes and the isomeric esters of hydroxybenzoic acid where the alcohol residue in the ester contains 1-12 carbon atoms. If the alcohol contains a phenyl group, the number of carbon atoms is 7-18. Other substituents which may be present on the phenyl group are described in the present preparation.

The functionally substituted silanes according to the invention are useful as coupling agents for glass fiber-reinforced composites, as flocculating agents for water purification and as finishing agents for glass fibers or textiles. The present compounds can be reacted with liquid hydroxy- or alkoxy-terminated organopolysiloxanes together with optional fillers to form elastomeric products useful as coating materials, sealants and molding compounds. Connections where

1 o 4

R in the preceding formula is dialkylamine (-NR^), gives waxes and polishes resistance to detergents.

The following examples describe the preparation of preferred embodiments of the compounds according to the invention. All shares and percentages are parts by weight or weight percent, unless otherwise stated.

Example 1

Preparation of 3(p-formylphenoxy)propyl-trimethoxysilane

A reactor was charged with 62.2 g (0.55 mol) of p-hydroxybenzaldehyde, 112 cc of dimethylsulfoxide, 120 cc of toluene and 43.2 g of a 50% aqueous sodium hydroxide solution containing 0.54 mol of NaOH. All the water present was removed by azeotropic distillation at a temperature of approx. 110-115°C. The reaction mixture was heated to the boiling point while gradually adding 109 g (0.55 mol) of 3-chloropropyl-trimethoxysilane. The product, 3(p-formylphenoxy)propyl-trimethoxysilane, was isolated by filtration and removal of the solvents from the recovered liquid phase under reduced pressure followed by fractional distillation of the residue. The fraction boiling at 208°C at a pressure of 3 mm Hg was collected (yield 85% based on silane). The infrared and nuclear magnetic resonance spectra of the recovered product confirm the proposed structure

The vapor phase chromatogram of the product showed a purity of over 98%.

Example 2

Preparation of 3(3-pyridyloxy)propyltrimethoxysilane

Using the general procedure described in Example 1, a reactor was charged with 52.3 g (0.55 3 3 mol) of 3-hydroxypyridine, 112 cm dimethyl sulfoxide, 120 cm toluene and 43.2 g of a 50% 's aqueous sodium hydroxide solution. The water present in the reactor was removed by azeotropic distillation over a period of 64 hours. The temperature of the reaction mixture was maintained at 85-105°C during this period. A portion of 109 g of 3-chloropropyl-trimethoxysilane was gradually added while the temperature of the reaction mixture was maintained at 95°C. This temperature was maintained for 7 hours, after which a vapor phase chromatogram of the reaction mixture showed that the reaction was substantially complete. The reaction mixture was then filtered, and the diluents (toluene and dimethyl sulfoxide) were evaporated under a pressure of 5 mm Hg. The product, 3(3-pyridyloxy)propyl-trimethoxysilane, was collected at a temperature of 142°C under a pressure of 1 mm Hg. A vapor phase chromatogram showed that the product was 97% pure.

Claims (1)

Silane for use as a coupling agent for glass fiber-reinforced composites, as a flocculant for water purification, as a finishing agent for glass fibers and textiles, as an agent to give waxes and polishing agents resistance to detergents and as an intermediate for the production of elastomeric products that are applicable coating materials, sealing compounds and casting compounds, characterized in that it has the formula 14 4 2 where R is -NR H, -NR or -CHO, R is methylene or propylene-3 4 lene and R and R are selected separately from methyl, cycloalkyl with 3-12 carbon atoms, aryl, alkaryl and aralkyl, where the alkyl group in the two latter radicals contains 1-12 carbon atoms.