HYDROPHILER SILICONKAUTSCHUKKOERPER UND VERFAHREN ZU SEINER HERSTELLUNG.

摘要

Silicone rubber articles (I) are made hydrophilic by a surface equilibration reaction with siloxanes (II), followed by hydrolysis. (II) are linear alpha, omega-organodimethylsiloxanes (III), Me3Si-terminated organomethylsiloxanes (IV), cyclic organomethyl- or diorgano-siloxanes (V), prepd. from SiH gp-contg. siloxanes and allyl cpds. contg. protected OH gps. in the presence of H2PtCl6 catalyst. The treated surface layer contains the units -(OSiMe2)x....-(OSiRR')y- where x is less than y; R = hydroxyalkyl (esp. hydroxypropyl): R'=R or Me; or the units R2 = OSiMe3, gp. (2). Pref. (III) is e.g. 1,3-bis(3-hydroxy propyl)-1,1,3,3 tetramethyldisiloxane (6 cpds. named), (V) is e.g. 2,4,6,8-tetrakis (3-tri-methyl silyloxypropyl) -2,4,6,8-tetramethyl cyclotetrasiloxane (7 cpds. named), and (IV) has the formula (IV) with n = 2, ca. 10-50. Equilibration is performed in an ether solvent with H2SO4 or a Lewis acid catalyst, esp. hexachlorocyclotriphosphazene. The substrate (I) is polydimethylsiloxane, and the treatment may be carried out by polymerisation in a plasma discharge at 5-500 mA, 100-1000 V, and at 10 power 1 10 power 3 torr.