| 摘要 |
<p>THE PRESENT INVENTION RELATES TO A POLYETHOXYSILOXANE (PES) MATERIAL TO BE OBTAINED IN THAT (A) A FIRST HYDROLYSIS CONDENSATION REACTION OF A MAXIMUM OF ONE GROUP X OF ONE OR MORE DIFFERENT Si COMPOUNDS OF THE FORMULA (I) SiX1 (I) IN WHICH THE GROUPS X ARE THE SAME OR DIFFERENT AND REPRESENT HYDROXY, HYDROGEN, OR ETHOXY (EtO), ARE CATALYZED IN AN ACIDIC FASHION AT AN INITIAL PH VALUE OF 0 TO ?7, IS CONDUCTED IN THE PRESENCE OF ETHANOL (EtOH) OR AN ETHANOL-WATER MIXTURE AS A SOLVENT OVER A TIME PERIOD OF 1 TO 24 HOURS AT A TEMPERATURE OF 0°C TO 78°C, (B) A SECOND HYDROLYSIS CONDENSATION REACTION OF THE MATERIAL OBTAINED IN STEP (A) IS CONDUCTED WHILE SIMULTANEOUSLY REMOVING THE SOLVENT BY SUCCESSIVE EVAPORATION IN A GAS DIFFUSION-TIGHT CONTAINER AT A PRESSURE OF 100 TO 1013 MBAR, PREFERABLY AT A SLIGHT NEGATIVE PRESSURE OF 300 MBAR TO 800 MBAR AND A TEMPERATURE OF 50-78°C UNTIL A DRASTIC INCREASE IN VISCOSITY (AT A SHEAR RATE OF 10 S-1 AT 4°C) TO 0.5 TO 2 PA.S UNTIL A CONSTANT WEIGHT IS ATTAINED AND A CYCLOTETRASILOXANE OF THE GENERAL FORMULA ((SiO(OH)0,75(OET)1,25 X 1/64 H20)4 AND A MOLAR MASS OF 4 * APPROX. 114 G = APPROX. 456 G; (C) SAID PES MATERIAL IS COOLED IN A CLOSED CONTAINER OVER A TIME PERIOD FROM A FEW MINUTES TO A FEW HOURS, AND (D) THE PES MATERIAL OBTAINED FROM STEP (C) IS CONVERTED INTO AN RPES MATERIAL BY A THIRD HYDROLYSIS CONDENSATION REACTION.</p> |
