| 摘要 |
<p>1380918 Laminated films TOYO BOSEKI KK 29 Dec 1971 [29 Dec 1970 (2)] 60573/71 Headings B5B and B5N [Also in Divisions B2 and B8] A laminate comprises two layers, one of which is made from a biaxially drawn polyamide and the other from a thermoplastic resin which has a melting or softening point at least 50‹ C. below the melting or softening point of the polyamide. The polyamide contains not less than 70% (mol) of a repeating unit derived from metaxylylene diamine and anα,#-dicarboxylic acid having from 6 to 10 carbon atoms. Up to 30% (mol) of the metaxylylene diamine may be replaced by paraxylylene diamine. The polyamide is obtained by extrusion of a melt, the cooled film being then stretched longitudinally between two rolls and laterally by means of a tenter. The resulting film has specified values of the gas permeability constant, plane orientation index, degree of balance and the breaking and yielding strength and elongations. The second layer, which in Example 7 is polyethylene is extruded on in the form of a melt. The basically drawn polyamide film must have the following properties:- (1) Oxygen permeability constant (at 30‹ C.) of no more than 9 + 10<SP>-13</SP> ml. cm./cm.<SP>2</SP> sec. cm. Hg; (2) Plane orientation index of no less than 0À025; (3) Degree of balance of no more than 0À045; (4) Breaking strength of not less than 10 kg./ mm.<SP>2</SP> in machine and transverse directions; (5) Breaking elongation of 30 to 150% in machine and transverse directions; - (6) Yield strength of not less than 5 kg./mm.<SP>2</SP> in machine and transverse directions; and (7) Yield elongation of 2 to 6% in machine and transverse directions. The composite film has an oxygen transmission rate (at 30‹ C.) of no more than 50 ml./m.<SP>2</SP> 24 hr. atm.</p> |
