초록 ▼

A tear resistant film comprises at least three layers situated one on the other in a parallel array. The layers are individually selected from a stiff polyester or copolyester, a ductile sebacic acid based copolyester, and optionally, an intermediate material. Tear resistance may be measured in a Gr

A tear resistant film comprises at least three layers situated one on the other in a parallel array. The layers are individually selected from a stiff polyester or copolyester, a ductile sebacic acid based copolyester, and optionally, an intermediate material. Tear resistance may be measured in a Graves area test and reflects the ability of the film to absorb energy. The films of the invention are useful in many articles including security control laminates for glazing members.

대표청구항 ▼

[ We claim:] [1.] A tear resistant film comprising a total of at least three stiff and ductile layers situated one on the other in a parallel array, the layers occurring essentially randomly in the array wherein (a) at least one layer is a stiff polyester or copolyester that has a tensile modulus gr

[ We claim:] [1.] A tear resistant film comprising a total of at least three stiff and ductile layers situated one on the other in a parallel array, the layers occurring essentially randomly in the array wherein (a) at least one layer is a stiff polyester or copolyester that has a tensile modulus greater than 200 kpsi, (b) at least one other layer is a ductile sebacic acid based copolyester that (i) comprises at least 1 mole equivalent of sebacic acid, including ester derivatives thereof, based on 100 mole equivalents of acid components, including ester derivatives thereof, in the copolyester, (ii) has a tensile modulus less than 200 kpsi, (iii) has a tensile elongation greater than 50%, and (iv) provides from about 1 weight percent to 50 weight percent of the tear resistant film, and (c) the tear resistant film demonstrates a Graves area in one direction of the film which exceeds the Graves area, in the same direction, of a single layer film having a thickness substantially equal to the thickness of the tear resistant film, the single layer film including only the stiff polyester or copolyester of the tear resistant film.