Sumitomo Chemical Company, Limited

Akihiko Shin

Rikuri Uejima

Koichiro Watanabe

Atsuhiro Takata

Atsushi Nakazawa

Yuji Takaoka

Hideyuki Sasaki

A desired drying capability is achieved while damage to a film is prevented. A film production method is arranged such that: a production process including a drying step is operated by setting a drying condition, under which to carry out the drying step, for each of at least two periods, the two periods being a first period and a second period later than the first period; the drying condition is changed in at least a part of the first period so as to be enhanced with time; and the drying condition is maintained in the second period so as to be substantially fixed.

Film production method

A method of producing a film is provided. The film includes a base material layer which is shrunk by heat and a functional layer which is dried while being restricted by the base material layer. The method involves heating the film while applying a tensile force in a direction of a length of the film so as to convey the film, and subjecting the film to a heat treatment while, in a distribution along a width of the film, a center part is higher in temperature than end parts. A center part sample of the film is smaller in curling amount with respect to the width of the film than an end part sample, or a standard deviation in curling amount with respect to the width is not more than 1 mm between two samples from respective end parts and a sample from the center part of the film.

Film manufacturing method, film manufacturing apparatus, and film

A drying roller includes: a cylindrical member for drying a separator original sheet, with hot water which is supplied into the cylindrical member and ejected from inside the cylindrical member, the separator original sheet being wrapped on an outer peripheral surface of the cylindrical member; and a discharge pipe for discharging the hot water toward one inner end surface of the cylindrical member, the heating medium being discharged at a position where a distance to the one end surface of the cylindrical member is longer than a distance to the other inner end surface of the cylindrical member.

Heating roller and film production method

A battery separator film that has a small curling amount and is highly handleable is provided. The battery separator film has a curling amount W of not more than 5 mm, the curling amount W being represented by the following equation (1):Curling amount W=W&#x2212;W&#x2003;&#x2003;(1)where Wis a width of a film that has been cut out in a longer side direction of the battery separator film, and Wis a projection width of a part of the film which part is smallest in projection width when seen from a direction perpendicular to a surface of the film while the film, to which a tension of 90 N/m is applied, is stretched between two rollers that are provided in parallel with each other at an interval of 1 m at a temperature of 23 degrees Celsius and a relative humidity of 50%.

Battery separator film, nonaqueous electrolyte secondary battery separator, and nonaqueous electrolyte secondary battery

The present invention resolves a problem that occurs to a film which is being washed. A film production method of the present invention includes the steps of: (i) passing a heat-resistant separator above rollers located above a washing tank; (ii) lowering another roller into water through a space between the rollers; and (iii) moving at least one of the rollers and the another roller so as to increase a surface area by which the heat-resistant separator is in contact with the another roller.

A drying device includes a first cylindrical member and a second cylindrical member. The first cylindrical member has an outer peripheral surface having a surface temperature that is higher on one width wise side where an end is present than on the other widthwise side where another end is present, whereas the second cylindrical member has an outer peripheral surface having a surface temperature that is lower on the one widthwise side where an end is present than on the other widthwise side where another end is present.

Nonaqueous electrolyte secondary battery separator heating device and nonaqueous electrolyte secondary battery separator production method

A transfer system includes an expander roll for removing a wrinkle in a separator original sheet, and (i) the expander roll and (ii) a transfer roller immediately followed by or following the expander roll are spaced from each other at a distance of not less than 1 m and not more than 10 m.

Battery separator producing method and battery separator producing apparatus

A film production method includes the steps of: (i) passing a heat-resistant separator above rollers located above a washing tank; (ii) lowering another roller into water through a space between the rollers; and (iii) moving at least one of the rollers and the another roller so as to increase a surface area by which the heat-resistant separator is in contact with the another roller. The method resolves a problem that occurs to a film which is being washed.

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Daegu, South Korea

Akihiko Shin