Stretched laminated film for use in piezoelectric polymer material, and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-9937688-B2
Application number	US-201415036076-A
Country	US
Kind code	B2
Filing date	Dec 3, 2014
Priority date	Dec 3, 2013
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

The object of the present invention is to provide a laminated film made of polylactic acids which is not prone to delamination while having excellent piezoelectric properties and a manufacturing method thereof. That is, the present invention is obtained by the stretched laminated film manufactured by a co-extrusion process for use in piezoelectric polymer materials, containing a layer (A) which has poly-L-lactic acid as the primary component and contains an impact modifier in the range of 0.1 to 10 mass % and a layer (B) which has poly-D-lactic acid as the primary component and contains an impact modifier in the range of 0.1 to 10 mass %.

First claim

The invention claimed is:

1. A stretched laminated film obtained by a co-extrusion process for use in piezoelectric polymer materials, comprising:
a layer (A) containing poly-L-lactic acid as the primary component and further containing an impact modifier in the range of 0.1 to 10 mass % as an added component,
and a layer (B) containing poly-D-lactic acid as the primary component and further containing an impact modifier in the range of 0.1 to 10 mass % as an added component,
wherein the film is a stretched film, and a ratio of the draw ratio in the principal orientation direction to the draw ratio in the direction orthogonal thereto (principal orientation direction/orthogonal direction) is 2 or greater,
wherein the draw ratio in the orthogonal direction is 1.8 or lower,
wherein the film has a piezoelectric property.

2. The stretched laminated film for use in piezoelectric polymer materials according to claim 1 , wherein the stretched laminated film has a piezoelectric constant d31 of less than 10 pC/N as determined by a forced vibration method.

3. The stretched laminated film for use in piezoelectric polymer materials according to claim 1 , wherein the ratio of the impact modifier contents of the layer (A) to the layer (B) (layer (A)/layer (B)) is in the range of 0.05 to 20.

4. The stretched laminated film for use in piezoelectric polymer materials according to claim 1 , wherein the stretched laminated film has a density of 1.22 to 1.27 g/cm 3 .

5. The stretched laminated film for use in piezoelectric polymer materials according to claim 1 , wherein the stretched laminated film has a thickness of 250 μm or less.

6. The stretched laminated film for use in piezoelectric polymer materials according to claim 1 , wherein the stretched laminated film generates an output voltage of 1 mVp-p or more when displaced with one end fixed.

Assignees

• Teijin Ltd
• A School Corporation Kansai Univ

Inventors

• Yoshida Tetsuo
• Tajitsu Yoshiro
• Kato Atsuko
• Yoshimura Tomoka

Classifications

• B29K2067/046

  PLA, i.e. polylactic acid or polylactide · CPC title

• H01L41/193

  Electricity · mapped topic

• H01L41/0986

  Electricity · mapped topic

• H01L41/113

  Electricity · mapped topic

• B29C47/0004

  Operations & Transport · mapped topic