Porous epoxy resin membrane, separator for nonaqueous electrolyte electricity storage devices, nonaqueous electrolyte electricity storage device, composite semipermeable membrane, and production methods thereof

A method for producing a separator for nonaqueous electrolyte electricity storage devices that has a thickness ranging from 5 to 50 μm, the method comprising the steps of:

• preparing an epoxy resin composition containing an epoxy resin, a curing agent represented by H2N—(CH2)n—NH2 where n is an integer from 4 to 8, and a porogen;
• forming a cured product of the epoxy resin composition into a sheet shape or curing a sheet-shaped formed body of the epoxy resin composition, so as to obtain an epoxy resin sheet;
• and
• removing the porogen from the epoxy resin sheet by means of a halogen-free solvent.

A method for producing a nonaqueous electrolyte electricity storage device, the method comprising the steps of:

• preparing a cathode, an anode, and a separator;
• and
• assembling an electrode group from the cathode, the anode, and the separator, wherein
• the separator has a thickness ranging from 5 to 50 μm, and
• the step of preparing the separator comprises the steps of:
• (i) preparing an epoxy resin composition containing an epoxy resin, a curing agent represented by H2N—(CH2)n—NH2 where n is an integer from 4 to 8, and a porogen;
• (ii) forming a cured product of the epoxy resin composition into a sheet shape or curing a sheet-shaped formed body of the epoxy resin composition, so as to obtain an epoxy resin sheet;
• and
• (iii) removing the porogen from the epoxy resin sheet by means of a halogen-free solvent.

A separator for nonaqueous electrolyte electricity storage devices, comprising:

• a three-dimensional network structure composed of an epoxy resin and including a structure represented by N—(CH2)n—N where n is an integer from 4 to 8;
• and
• pores communicating with each other so that ions can move between a front surface and a back surface of the separator,
• the separator having a thickness ranging from 5 to 50 μm.

A composite semipermeable membrane comprising:

• a porous epoxy resin membrane comprising:
• a three-dimensional network structure composed of an epoxy resin and including a structure represented by N—(CH2)n—N where n is an integer from 4 to 8;
• and pores communicating with each other between a front surface and a back surface of the porous epoxy resin membrane;
• and
• a skin layer formed on a surface of the porous epoxy resin membrane.

A method for producing a composite semipermeable membrane, the method comprising the steps of:

• preparing an epoxy resin composition containing an epoxy resin, a curing agent represented by H2N—(CH2)n—NH2 where n is an integer from 4 to 8, and a porogen;
• forming a cured product of the epoxy resin composition into a sheet shape or curing a sheet-shaped formed body of the epoxy resin composition, so as to obtain an epoxy resin sheet;
• removing the porogen from the epoxy resin sheet by means of a halogen-free solvent so as to form a porous epoxy resin membrane;
• and
• forming a skin layer on a surface of the porous epoxy resin membrane.