| 摘要 |
<p>The intermediate layer of compound glass comprises a polyvinyl ester prepared as described in Specification 462,165 by polymerizing the monomeric ester in the presence of a peroxide of a fatty acid having at least 4 carbon atoms. Softening agents may be added. For example two glass plates are coated with an ethyl acetate solution of the polyvinyl acetate obtained as described in example 1 of Specification 462,165 and dibutyl phthalate, dried, and united by heat and pressure. A mixed polymer similarly obtained from vinyl acetate and vinyl butyrate may replace the polyvinyl acetate. Alternatively, a film cut from a block of the polyvinyl acetate plasticized with dibutyl phthalate may be adhesively secured between glass sheets. The Specification as open to inspection under Sect. 91 describes also the use as softening agents of phenol and alkyl esters of phosphoric acid, e.g. tributyl phosphate, phthalates, e.g. dibutyl phthalate, camphor, castor oil, and condensation products of ether-di-carboxylic acids with polyhydric alcohols. Vinyl acetate may be polymerized with dibutyl phthalate and dioleyl peroxide or with ethyl acrylate and distearyl peroxide. Specification 447,131 is referred to. This subject-matter does not appear in the Specification as accepted.</p> |
