abstract |
Oriented polyester films primer coated in-line with a hydrolyzed aminosilane are disclosed. These silanes in the unhydrolyzed state have the formula: XSi(R2)a(R3)b wherein X is a radical selected from the group consisting of H2NR1HNR1-H2NR1HNR1HNR1-; the R1's are the same or different groups selected from the group consisting of C1 to C8 alkyl or phenyl; R2 is a hydrolyzable group selected from the group consisting of C1 to C8 alkoxy, an acetoxy group or a halide; R3 is a nonreactive, nonhydrolyzable group selected from the group consisting of C1 to C3 alkyl or phenyl; (a) is an integer ranging from 1 to 3; (b) is an integer ranging from 0 to 2, with the sum of (a) and (b) being 3. The hydrolyzed aminosilane is applied to the film in-line as an aqueous solution at any suitable stage during manufacture of the film, i.e., before, during, or after the stretching operation, but prior to heat setting the film. The resultant primed polyester film is found to exhibit excellent adhesion to other polymeric materials and can be readily laminated to other polymeric films. Adhesive qualities are maintained even at subfreezing temperatures. |