| 摘要 |
<p>852,717. Release paper. GENERAL ELECTRIC CO. March 4, 1959 [March 26, 1958], No. 7549/59. Class 96. Paper, paper-board, pulpboard, parchment paper, linen rag paper, rice paper, or glassine &c. is rendered non-adherent e.g. to asphalt, tars, waxes, pastes, frozen foods &c., as by immersing the paper &c. in an aqueous emulsion comprising (1) a linear polydimethylsiloxane containing terminal, silicon-bonded hydroxy groups, (2) a methylpolysiloxane resin having a ratio of 1.05 to 1.4 methyl groups per silicon atom, (3) polyvinyl alcohol or other emulsifying agent, and (4) dibutyl tin laurate, there being two to six parts of (1) to one of (2); the treated paper &c. being subsequently dried. There may be 10 to 100,000 -(CH 3 ) 2 SiO- units in (1) and the viscosity of (1) may be 10 to 2,000,000 centipoises at 25‹ C. which may be reduced to 10 to 100,000 centipoises by blowing steam thereover &c. To one part of (2) there may be 3 to 75 of water, and there may be 0.05 to 10% of tin (as (4)) based on the weight of (1) and 0.1 to 3% of (3) based on the weight of the whole. After treatment the paper &c. is dried e.g. at 110‹ to 130‹ C. for 3 mins. Specification 542,655 is referred to.</p> |
