Patent ID: 6423401
Filing Date: 2002-07-23
Classification: B29C,B29K,B32B,Y10S,Y10T

Abstract:
A coextruded, biaxially oriented, sealable polyester film with at least a base layer (B), with a sealable outer layer (A) arranged on outside of the base layer (B) and with another outer layer (C) arranged on the other side of the base layer (B), where the sealable outer layer (A) has a minimum sealing temperature of not more than about 110Â° C. and a seal seam strength of at least about 1.3 N/15 mm of film width, wherein the sealable outer layer (A) has an average surface roughness, expressed as Ra, of &lE;40 nm, and has a value measured for gas flow within the range from about 300 to about 4000 s, wherein the nonsealable outer layer (C) has a coefficient of friction COF of &lE;0.5, an average surface roughness, expressed as Ra, within the range of 40&lE;Ra&lE;150 nm, and a value measured for gas flow of &lE;140 s, and wherein, for the nonsealable outer layer (C), the number of elevations Nc per mm2 of film surface is correlated with their respective heights h via the following equations:AC1-BC1Â·log h/&mgr;mNC/mm2C2-BC2Â·log h/&mgr;m where0.01 &mgr;m&lE;h&lE;10 &mgr;m and AC1=0.29, BC1=3.30 and AC2=1.84, BC2=2.70.