| 摘要 |
<p>842,438. Glass laminates. DU PONT DE NEMOURS & CO., E. I. Dec. 10, 1958 [Dec. 11, 1957], No. 39778/58. Drawings to Specification. Class 140. To reduce the danger of concussion and head laceration due to impact with laminated safety glass wind shields and the like in accidents the outer glass layers of the laminates are reduced in thickness and the central layer of polyvinyl butyral is increased in thickness and plasticizer content. The ranges of thickness specified are, for the two glass layers together: 0.100-0.250 inch, each layer preferably being 0.050- 0.100 inch, for the central layer 0.030-0.120 inch, for the total thickness of laminate 0.180- 0.370 inch. The composition of the central layer specified is polyvinyl alcohol 15-30%, polyvinyl acetate 0-2%, remainder polyvinyl butyral plus 25-40% thereof of plasticizer such as triethylene glycol di (2-ethyl butyrate), triethylene glycol dibutyl sebacate, triethylene glycol di [#-butoxyethyl) adipate, or triethylene glycol dioctylphthalate. Within the specified range the plasticizer content is selected such that the resistance of the laminate to breakage is substantially the same at 0‹ F. and 120‹ F.</p> |
