1. A membrane for a fuel cell in which voids in a porous membrane are filled with a crosslinking type ion exchange resin having both cation-exchange group and anion-exchange group via a covalent bond, wherein the ion exchange resin has ion-exchange groups with either polarity more than ion-exchange groups with the opposite polarity and at least 40% of the ion-exchange groups of the opposite polarity form ion complexes with the ion-exchange groups of the major polarity.
2. The membrane for a fuel cell as claimed in claim 1, wherein the ion-exchange group with a major polarity is a cation-exchange group and the ion-exchange group with the opposite polarity is an anion-exchange group.
3. The membrane for a fuel cell as claimed in claim 2, wherein the cation-exchange group is a sulfonic acid group and the anion-exchange group is an anion-exchange group containing a primary to tertiary nitrogen atom.
4. The membrane for a fuel cell as claimed in claim 3, wherein the anion-exchange group containing a primary to tertiary nitrogen atom is an imidazolyl group.
5. The membrane for a fuel cell as claimed in claim 3, wherein the anion-exchange group containing a primary to tertiary nitrogen atom is a pyridyl group.
6. The membrane for a fuel cell as claimed in claim 1, wherein the amount of the ion-exchange group having a major polarity is less than 4.8 mmolg-dry mass based on the ion exchange resin filling the voids in the porous membrane.
7. The membrane for a fuel cell as claimed in claim 1, wherein the crosslinking type ion exchange resin is a resin comprising crosslinked polymer chains where both cation-exchange and anion-exchange groups are covalently bound in a random manner.
8. The membrane for a fuel cell as claimed in claim 1, wherein the amount of the ion-exchange group with a major polarity is 4.8 mmolg-dry mass or more based on the ion exchange resin filling the voids in the porous membrane.
9. The membrane for a fuel cell as claimed in claim 1, wherein the content of the low molecular-weight compound having an ion-exchange group with the opposite polarity is 0.05 mmolg-dry mass or less as the amount of the ion-exchange group.
10. The membrane for a fuel cell as claimed in claim 1, wherein the crosslinking type ion exchange resin is comprised of a mixture of a resin comprising crsslinked polymer chains where an ion-exchange group either cation-exchange group or anion-exchange group is covalently bound, and a resin comprising polymer chains where an ion-exchange group with the opposite polarity to the ion-exchange group of the major resin component is covalently bound.
11. The membrane for a fuel cell as claimed in claim 1, wherein the fuel cell is a direct methanol type fuel cell.
12. A process for producing a membrane for a fuel cell according to claim 1, comprising the steps of contacting a porous membrane with a polymerizable composition containing a polymerizable monomer in which cation-exchange-group introducible functional groups or cation-exchange groups are covalently bound, a polymerizable monomer in which anion-exchange-group introducible functional groups or anion-exchange groups are covalently bound, a crosslinking agent and a polymerization initiator to impregnate the voids in the porous membrane with the polymerizable composition; then polymerizing and curing the impregnated polymerizable composition; then introducing, if necessary, cation-exchange groups andor anion-exchange groups to the cation-exchange-group or anion-exchange-group introducible functional groups such that ion-exchange groups with either polarity become more than ion-exchange groups with the opposite polarity.
13. The process for producing a membrane for a fuel cell as claimed in claim 12, comprising the steps of contacting a porous membrane with a polymerizable composition containing a polymerizable monomer in which an aromatic hydrocarbon group is covalently bound, a polymerizable monomer in which an anion-exchange group containing a primary to tertiary nitrogen atom is covalently bound, a crosslinking agent and a polymerization initiator to impregnate the voids in the porous membrane with the polymerizable composition; then polymerizing and curing the impregnated polymerizable composition; then introducing a sulfonic acid group to the aromatic hydrocarbon group such that it becomes more than the anion-exchange group containing a primary to tertiary nitrogen atom.
14. The process for producing a membrane for a fuel cell as claimed in claim 13, wherein the polymerizable monomer in which an aromatic hydrocarbon group is covalently bound is a styrene type monomer, and the polymerizable monomer in which the anion-exchange group containing a primary to tertiary nitrogen atom is covalently bound is a vinylimidazole type monomer.
15. The process for producing a membrane for a fuel cell as claimed in claim 13, wherein the polymerizable monomer in which an aromatic hydrocarbon group is covalently bound is a styrene type monomer, and the polymerizable monomer in which the anion-exchange group containing a primary to tertiary nitrogen atom is covalently bound is a vinylpyridine type monomer.
16. A membrane for a fuel cell manufactured by the process as claimed in claim 12.
17. A process for producing a membrane for a fuel cell according to claim 1, comprising the steps of contacting a base ion-exchange membrane in which voids in a porous membrane are filled with a crosslinking type ion exchange resin having covalently bound cation-exchange groups or anion-exchange groups with a polymerizable monomer having covalently bound ion-exchange groups with the opposite polarity to that of the ion-exchange groups in the base ion-exchange membrane to impregnate the crosslinking type ion-exchange resin with the polymerizable monomer, and then polymerizing the impregnated polymerizable monomer.
18. The process for producing a membrane for a fuel cell as claimed in claim 17, wherein the ion exchange resin filling the voids in the porous membrane is a crosslinking type cation-exchange resin having a covalently bound cation-exchange group, to which is impregnated with a polymerizable monomer having a covalently bound anion-exchange group.
19. The process for producing a membrane for a fuel cell as claimed in claim 18, wherein the cation-exchange group covalently bound to the crosslinking type cation-exchange resin is a sulfonic acid group and the polymerizable monomer having the covalently bound anion-exchange group is a polymerizable monomer having a covalently bound anion-exchange group containing a primary to tertiary nitrogen atom.
20. The process for producing a membrane for a fuel cell as claimed in claim 19, wherein the polymerizable monomer having a covalently bound anion-exchange group containing a primary to tertiary nitrogen atom is a vinylimidazole type monomer.
21. The process for producing a membrane for a fuel cell as claimed in claim 19, wherein the polymerizable monomer having a covalently bound anion-exchange group containing a primary to tertiary nitrogen atom is a vinylpyridine type monomer.
22. The process for producing a membrane for a fuel cell as claimed in claim 17, comprising the step of, after polymerizing the polymerizable monomer in which the ion-exchange group with the opposite polarity is covalently bound, washing the product with an acidic or basic solution.
23. A membrane for a fuel cell manufactured by the process as claimed in claim 17.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A reusable dunnage system for use in transportation for supporting and securing goods during shipping and handling which is wedged between or beneath said goods to prevent injury from chaffing and for accepting and dissipating shock forces comprising,
a high density cellular polymer having indention force characteristics ranging between 50 and 500 whereby said polymer will compress under a shock force of up to 600 psi thereby absorbing said shock force and whereby said polymer will expand back to its original size when said shock force is dissipated,
an outer covering completely enclosing said polymer and affording protection from the elements by being fire retardant and water resistant while having a low coefficient of friction thereby aiding placement and removal of the reusable dunnage system.