CS196141B1 - Method of preparing emulsions of silicon resins and their mixtures with linear polysiloxanes - Google Patents

Description

CZECHOSLOVAKCASOCIALISTREPUBLIC (1 ») COPYRIGHT CERTIFICATE DESCRIPTION 196141 (11) (Bl) Ø / 22 / Registered 09 03 78/21 / / PV 1484-78 / (51) Int. ClX C 09 D 3/82 C 08 L 83/04 (• KM Published 29 06 79 'OFFICE OFFICE (45) Issued 1 5 06 82 A DISCUSSIONS (75)

Author of the invention KÁLAL JOSEF ing., PODĚBRADY (54) Method of preparation of emulsions of silicone resins and their mixtures with linear liposiloxanes i

BACKGROUND OF THE INVENTION The present invention relates to a process for the preparation of silicone resins and mixtures thereof with linear polysiloxanes containing 0 to 5% by weight of a solvent. It is generally known to prepare aqueous emulsions of silicone resins and mixtures thereof with linear polysiloxanes containing all the organic solvent silicone resins. They are used to form a separating layer, particularly on paper, to hydrophobic treatment of paper and textiles. Mixing emulsions of silicone resins in organic solvent and aqueous dispersion plastics are binder coating and spray compositions.

A disadvantage in the treatment of these emulsions is the necessity of evaporating a large amount of the solvent in which the air is polluted. Possible solvent recovery requires expensive equipment.

We have now found a process for the preparation of emulsion-based resins and mixtures thereof with linear polysiloxanes containing only 0 to 5% solvent, which is first prepared from a solution of a mixture of silicone resin and linear polysiloxanes with a dry weight ratio of 10: 0 to 1: 9 , containing at least 30 wt. organic solvents which form an azeotropically boiling mixture with water and at least 1% by weight emulsifier; based on the weight of the polysiloxanes, the aqueous emulsion is then distilled off with a portion of the water to a temperature of 70 DEG C. in a cooker under reduced pressure. A stable polysiloxane emulsion is formed in which the polysiloxane and organic solvent content is dependent on the amount of distilled water.

Silicone resins are partially crosslinked products of hydrolysis or kohydrolysis, optionally condensation of mono- to tetrafunctional methyl chlorosilanes or phenyl chlorine, or mixtures thereof containing 30 to 70 wt. solvents which form a water-isotropic boiling mixture. 1

Linear polysiloxanes are products of hydrolysis of predominantly difunctional dimethyldichlorosilane, methyldichlorosilane or diphenyldichloro-silane, or mixtures thereof, which are most commonly termed trimethylsilyl or hydroxyl groups.

Emulsifiers are used which are suitable for emulsifying polysiloxanes. Nonionic, polyvinyl alcohol, ethylene xylated adducts of cellulose, fatty acids, higher alcohols, amines and alkylphenol higher alkyl, cationic, quaternary ammonium salts with higher alkyls, amino-active, alkyl or alkyl aryl sulfonates or alkyl sulfates also containing higher alkyls. Přikladl

A mixture of 150 g of methyl silicone resin with an R / Si ratio of 1.2 was prepared, which contained 50% w / w of toluene, 75 g of dimethylpolysiloxane oil having a viscosity of 500 mPa.s / 20 ° C, 45 g of an aqueous solution of polyvinyl alcohol. 10 wt. / viscosity 4 wt. 196141

Claims (3)

the aqueous solution is 20 mPa.s / 20 [deg.] C., the saponification number 140 and 180 g distilled water, which has been emulsified by a threefold passage through the colloid mill and the resulting emulsion is then vacuumed at 24,000 to 2,660 Pa and the temperature is 40-30 [deg.] C distilled 150 g of toluene-water mixture. A stable emulsion was formed which contained 50% by weight of polysiloxanes and did not contain toluene. 2 A mixture of 200 g of methylphenyl silicone resin having an R / Si1.05 ratio containing 30 wt. xylene, 5.6 g of an aqueous solution of alkyldimethylbenzyl ammonium chloride (50% by weight); and 195 g of distilled water, which was emulsified by a triple passage through the colloid mill and from the resulting emulsion P Ř ED Μ ET Process for the preparation of silicone resin emulsions and mixtures thereof with linear lipolysiloxanes containing 0 to 5% by weight of solvent, characterized in that an aqueous emulsion is prepared from the solution mixtures of silicone resin and linear polysiloxanes with a dry weight ratio of 10: 0 to 1: 9 were then distilled off 120 g of a mixture of ethylene-water in a vacuum of 867 to 733 Pa and a temperature of 46 to 32 ° C. A stable emulsion was formed which contained 50% by weight of polysiloxanes and 17% by weight. toluene. Example 3 A mixture of 200 g of methyl silicone resin was prepared with a ratio of R / Si = 1.0 which contained 50 wt. toluene, 75 g of an aqueous solution of an oleyl alcohol copolymer with 20 moles of ethylene oxide containing 8 percent by weight. and 125 g of distilled water, which was emulsified by a triple passage through a colloid mill, and 200 g of off-toluene-water was distilled off from the resulting emulsion under vacuum of 11,900 to 2,835 Pa and a temperature of 42 to 26 ° C. This gave a stable emulsion containing 50% by weight of polysiloxanes and did not contain toluene. DISCLOSURE OF THE INVENTION comprising at least 30% by weight of an organic solvent which forms an azeotropically boiling mixture with water, and an emulsifier of at least 17% by weight, based on the weight of the polysiloxanes, whereupon the solvent with a portion of water up to 70 ° C in the reboiler under reduced pressure, distil «Sevrroprafia. n. p ·. and 7. Moe (