Easy-to-tear stretched aliphatic-polyester film

Abstract

The easy-to-tear stretched aliphatic polyester film of the present invention is characterized in that the edge tear strength in the longitudinal direction and the transverse direction is not more than 22 N. The easy-to-tear stretched aliphatic polyester film of the present invention is produced by a method of irradiation of actinic rays on an aliphatic polyester film or a method of film-forming a film obtained by laminating aliphatic polyesters having different melting points in three layers of A/B/A under particular film-forming conditions.

1 . An easy-to-tear stretched aliphatic polyester film having an edge tear strength in the longitudinal direction and the transverse direction of not more than 22 N.  
     
     
         2 . An easy-to-tear aliphatic polyester film having a molecular absorption coefficient at a wavelength of 205 nm of not less than 1500.  
     
     
         3 . An easy-to-tear stretched aliphatic polyester film having a tear energy of 0.2-5 gf·mm/μm, and a tensile impact strength of not less than 0.5 j/mm 2 .  
     
     
         4 . The easy-to-tear stretched aliphatic polyester film of any one of  claims 1  to  3 , which is produced by irradiation of actinic rays on a stretched aliphatic polyester film.  
     
     
         5 . The easy-to-tear stretched aliphatic polyester film of any one of  claims 1  to  4 , wherein a main component of the stretched aliphatic polyester film is a lactic acid-based polyester resin.  
     
     
         6 . An easy-to-cut packaging bag produced using a film obtained by irradiation of actinic rays on an aliphatic polyester film.  
     
     
         7 . An easy-to-cut packaging bag obtained by irradiation of actinic rays on a packaging bag produced using an aliphatic polyester film.  
     
     
         8 . The easy-to-cut bag of any one of claims  6  and  7 , wherein a main component of the stretched aliphatic polyester film is a lactic acid-based polyester resin.  
     
     
         9 . A production method of a lactic acid-based polyester film, which comprises 
 stretching, in at least a monoaxial direction, a non-stretched laminate film comprising a lactic acid-based polyester resin layer (A) having a melting point: Tm A  and a resin (B) having a melting point: Tm B , which satisfies Tm B ≧Tm A +10° C., relative to Tm A , said resin (B) being laminated on at least one surface of layer (A) in a thickness of 5-60% of the thickness of a whole film, and then    performing a heat treatment at a temperature Ts satisfying Tm A −10° C.≦Ts<Tm B +10° C.