Mitsubishi Plastics, Inc.

Mitsubishi Chemical Corporation

Yasushi Usami

Takeyoshi Yamada

Jun Takagi

Toru Terakawa

Satoshi Nakashima

Ryoichi Kato

Tomoyuki Nemoto

Manabu Hayashi

Akihiko Sakai

Kazutaka Sakaki

Satoshi Teshima

Miho Yamamoto

Kazutaka Sasaki

Kyosuke Watanabe

Yutaka Kawai

Masayoshi Tsujii

This polyolefin resin porous film can be easily produced, and when used as a non-aqueous electrolyte cell separator, can suppress clogging and can evince a high cell output. The polyolefin resin porous film is a porous film having a polyolefin resin as the primary component and is characterized by the average flow diameter pressure (P) being 1500-2500 kPa, the bubble point pressure (P) being 300-1500 kPa, and the ratio (Pa/P) of the air permeability (Pa) and the bubble point pressure (P) being no greater than 0.35 sec/(100 ml&#xb7;kPa).

Polyolefin resin porous film, and non-aqueous electrolyte cell separator using same

Provided is a porous polypropylene film having both air permeability properties and puncture strength. A porous polypropylene film which has an air permeability of 700 seconds/100 ml or less and a puncture strength of 1.5 N or greater, and has &#x3b2; activity can be obtained when the porous polypropylene film is made to have a tensile strength in the machine direction of the film, E, of 100 MPa or greater, a tensile strength in the transverse direction to the machine direction, E, of less than 100 MPa, and a ratio of Eand E, E/E, of 1.5 to 10.

Porous polypropylene film

An object of this invention is to improve battery performance such as a rate capability of a nonaqueous electrolyte solution secondary battery using a separator constituting a thermoplastic resin-based porous film containing a filler. This invention provides a nonaqueous electrolyte solution secondary battery separator which is formed from a porous film containing a thermoplastic resin and a filler contained in the thermoplastic resin and has a content of chlorine of 10 ppm or less or a content of iron of 100 ppm or less as well as relates to a nonaqueous electrolyte solution secondary battery using this separator.

Nonaqueous electrolyte solution secondary battery separator having filler and controlled impurities

A laminated porous film having at least two porous layers layered one upon another. One porous layer consists of a resin layer containing a polypropylene resin. The other layer is a heat-resistant layer consisting of a resin composition whose crystal fusion peak temperature is higher than that of the resin composition of the layer containing the polypropylene resin. The laminated porous film has a &#x3b2; activity and/or a &#x3b2; crystal generation power.

Laminated porous film and separator for battery

A process for producing a porous laminate having many micropores interconnected in the thickness direction, which comprises: a step in which a laminate is produced which comprises at least three layers comprising an interlayer made of a thermoplastic resin having a hard segment and a soft segment and two nonporous outer layers made of a filler-containing resin and located as outer layers respectively on both sides of the interlayer; a step in which the laminate obtained is impregnated with a supercritical or subcritical fluid and this state is relieved to vaporize the fluid and thereby make the interlayer porous; and a step in which the two nonporous outer layers located respectively on both sides are made porous by stretching.

Method for producing porous laminate and porous laminate

A laminated porous film having a shutdown (SD) property and a high breakdown (BD) property combined includes at least two layers, which are a porous membrane layer (A layer) having a thickness of 10 &#x3bc;m or greater other than non-woven fabric and a non-woven fabric layer (B layer) having a fiber diameter of 1 &#x3bc;m or less. A value of the ratio (AP/AP) between air permeability when heating at a heating temperature of 150&#xb0; C. to 200&#xb0; C. for three minutes (AP) and air permeability prior to heating (AP) is 10 or greater at any heating temperature between 150&#xb0; C. and 200&#xb0; C.

Laminated porous film and separator for cell

Provided is a laminated porous film having excellent shutdown characteristics and breakdown characteristics, good tearing strength and dimensional stability, and B activity. The laminated porous film comprises layer A, the main component of which is a polypropylene resin, and layer B which contains a polyethylene resin, and the ratio of the rearing strength (H) in the machine direction (MD) of the laminated porous film and the tearing strength (H) in the transverse direction (TD) of the laminated porous film with respect to the machine direction (H) (H) is 0.08 to 2.0.

Laminated porous film, separator for lithium cell, and cell

A subject for the invention is to improve the cycle characteristics of a high-capacity secondary battery containing an active material packed at a high density, by using a particulate active material having a low aspect ratio. The invention relates to a nonaqueous-electrolyte secondary battery comprising a negative electrode and a positive electrode each capable of occluding/releasing lithium, a separator, and a nonaqueous electrolyte solution comprising a nonaqueous solvent and a lithium salt, characterized in that the separator comprises a porous film made of a thermoplastic resin containing an inorganic filler, and at least either of the following is satisfied: the active material contained in the negative electrode is a particulate active material having an aspect ratio of from 1.02 to 3; and the active material contained in the positive electrode is a particulate active material having an aspect ratio of from 1.02 to 2.2.

Nonaqueous-electrolyte secondary battery

An object of this invention is to improve battery performance such as a rate capability of a nonaqueous electrolyte solution secondary battery using a separator constituting a thermoplastic resin-based porous film containing a filler. This invention provides a nonaqueous electrolyte solution secondary battery separator which is formed from a porous film containing a thermoplastic resin and a filler contained in the thermoplastic resin and has a ratio of an average pore diameter (&#x3bc;m) to a maximum pore diameter (&#x3bc;m) defined by ASTM F316-86 of 0.6 or more as well as relates to a nonaqueous electrolyte solution secondary battery using this separator.

Nonaqueous electrolyte solution secondary battery separator having defined ratio of average pore diameter to maximum pore diameter and nonaqueous electrolyte solution secondary battery using the same

It is to provide a porous film which is excellent in gas permeability (air permeability) and moisture permeability (water vapor permeability), and is excellent in anti-leakage properties and anti-bleeding properties against a liquid, hiding properties and masking properties at an adhesion portion, and a process for producing it. A porous film obtained by melting and kneading a resin composition containing a polyolefin resin {component (A)} and a bulking agent {component (B)} as the main components, and a silicone {component (C)}, or a silicone {component (C)} and castor oil {component (D)}, followed by drawing, which shrinks by from 40 to 95% in one direction and expands by from 5 to 40% in a direction transverse thereto, when soaked in a silicone oil of 200 C for 60 seconds, and a process for producing the above porous film, are provided.

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Shiga, Japan

Yasushi Usami