| 摘要 |
963,956. Laminates. PITTSBURGH PLATE GLASS CO. Oct. 19, 1962 [Oct. 23, 1961], No. 39613/62. Heading B5N. A laminated assembly comprises a pair of transparent sheets of a rigid material such as glass and a thermoplastic interlayer of flexible polyvinyl butyral therebetween which has a moisture content of less than 0.2% by weight of the interlayer. Preferably, the surfaces of the interlayer are embossed or roughened. The moisture content of the interlayer may be reduced by hanging the polyvinyl butyral sheets in a conditioning room maintained at 70‹ F. and 10% relative humidity for several weeks, or alternatively by exposing the sheets to a dry atmosphere maintained at a subatmospheric pressure at a temperature not exceeding 140‹ F. for about an hour. Two methods of laminating are described. In the first the sheet is then sandwiched between a pair of glass sheets, flexible rubber tubing is split lengthwise and applied around the entire periphery of the assembly and the assembly subjected to evacuation. Whilst maintaining the vacuum the assembly is then placed in an oven at a temperature of approximately 300‹ F. for 15 minutes. In the second method the assembly is placed in a plastic bag which is evacuated and then sealed by heat, and then the sealed bag is placed in an oven as above. The usual autoclave treatment has been eliminated. Other materials which may be laminated are the acrylates, organosilicons, polystyrene plastics, vinyl copolymers and cellulose esters. Specification 819,179 is referred to. |
