DE940679C - Process for the manufacture of water-repellent, fat-like products - Google Patents

Description

Process for the production of water-repellent fat-like products the The invention relates to silicon compounds of a fat-like consistency with water-repellent properties Properties.

It has been proposed to use water-repellent pastes by incorporation to manufacture water-repellent powders in organosilicon oils.

It has been found that when using silicon dioxide as water-repellent powder resulting from the combustion of silicon compounds and then in every way with methylchlorosilanes. has been made water-repellent, receives new products.

If you have such a water repellent made silica used, homogeneous, translucent pastes or fats are obtained, which let it apply very easily in a thin layer to glass itself and which on one sufficient silicon dioxide content, e.g. 150 / o, have an elevated dropping point and their physical properties, such as B. the consistency, against temperature fluctuations are not very sensitive.

While one of those described in the above-mentioned proposal Products to achieve fairly large quantities of water-repellent powder a good water-repellent product, are on the other hand with the water repellant silica according to the invention is much lower sufficient.

So you get with amounts below 20%, z. B. IoO / o, water repellent Fats, which give increased contact angles with water. In this way products of less are obtained Consistency that spreads by itself and penetrates into the smallest depressions, Which you want to protect with water-repellent material, which is the case with certain applications in the Electrical engineering is of great importance.

It should be particularly emphasized that the use of the invention water-repellent made silicon dioxide does not affect the production of fats with low consistency is limited. It is also possible to use larger amounts of powder than in the above-mentioned proposal, e.g. B. 2 parts by weight to 1 part of liquid, incorporated, which leads to tough and firm pastes.

By using such water repellant made silica there are also other advantages. So those produced by the wet method resulted in subsequently made water-repellent silica gels mainly with highly viscous ones organosilicon oils, e.g. B. have a higher viscosity than 1000 cSt, good results. The silicon dioxide according to the invention can be used to produce all types of organosilicon Oils from the most highly viscous to the lowest viscous, e.g. B. 50 cSt, use.

As organosilicon oils, which for imparting the water-repellent Made silicon dioxide according to the invention come into question, one must organosilicon Use water-insoluble and non-volatile liquids. In particular are the siloxanes from dimethylchlorosilanes and especially those which are at 200 to 3000 do not distill in vacuum, mentioned what excellent dielectric The properties of silicon dioxide are obtained from the combustion of silicon compounds can be obtained in several ways, e.g. B. by burning silicon chloride mixed with hydrogen. Such silica falls in the form of a white, fine, very light powder that is less than 50 g each Weighs liters. However, the present invention is not directed to silica limited so low density.

Before or after making the water repellent, the oxide can be compacted, to increase its density, e.g. B. to 100 g or more per liter.

The water repellency is made with the help of methylchlorosilanes. Hydrochloric acid formed can be removed by a stream of air; the The last traces can be removed more quickly by washing (e.g. ether) or by Neutralization (Ammomak, amino compounds, etc.) take place.

The incorporation in the liquid silicon compounds prepares no difficulty and can be done by usual known means. The look and the consistency of the products obtained depend, however, to a certain extent Degree depends on the means used. Mechanical processing of the mass (e.g. B. rolling or kneading) increases the homogeneity of the products.

These new greases can be applied to a wide variety of materials be e.g. B. Glass, ceramic objects, steatite, paper, cardboard, fabric, metals and all bodies which one protects from the action of water or moisture 'want. They can also be used to protect against moisture or to prevent water loss prevent zul (waterproof papers). They are especially valuable for protecting Parts or connectors of electrical apparatus, connectors, terminals, Kitten etc. against moisture. You can use other oils or fats that contain silicon or silicon-free, can be added.

The following examples show the practical application of the invention, without restricting them perm.

Example I One liter weight silica obtained by incineration of about 37 g is obtained by treating with a crude dimethylchlorosilane in the cold Made water-repellent and then freed from any trace of hydrochloric acid.

Mix g / parts by weight of water-repellent silicon dioxide with 91 parts by weight of an organosilicon oil. A liquid product is obtained that has a lower consistency than petroleum jelly and has good water-repellent properties owns.

Example 2 20 parts of water repellant silica which was used in Example I, by kneading in 80 parts of an organosilicon Oil with a viscosity of 70 cSt (methylsiloxane) introduced. By continued kneading you get a fat that resembles a petroleum jelly. If it is applied to glass, so there is a contact angle of more than 100.0 with water. This fat is for coating electrical organs, such as engine ignition devices, can be used, to protect them against moisture perm. Besides these water-repellent properties this fat has a low flammability and is very resistant to electrical Spark. This new fat can (to achieve coatings for objects) with organic solvents.

It should be mentioned that, diluted with a large volume of ether, forms an opalescent solution from which the starting material (the water-repellent made silicon dioxide) does not precipitate.

Claims (1)

PATENT CLAIM: Process for the production of water-repellent fat-like Products, characterized in that silicon dioxide is obtained by combustion a silicon compound and by treatment with methylchlorosilanes made water-repellent, a non-volatile water-insoluble organosilicon Incorporated liquid.