Method for manufacturing fuel cell separator

Patent metadata

Field	Value
Publication number	US-9515324-B2
Application number	US-201314409874-A
Country	US
Kind code	B2
Filing date	Jul 3, 2013
Priority date	Jul 11, 2012
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

A separator is provided that has a metal substrate and a conductive resin layer on the surface of the metal substrate. The conductive resin layer contains a resin and a conductive substance dispersed in the resin. The separator is configured such that the proportion of the conductive substance to the resin increases continuously from the metal substrate toward the surface of the separator.

First claim

The invention claimed is:

1. A method for manufacturing a fuel cell separator, comprising:
a first step for applying a mixture of a resin and a first conductive substance onto a surface of a metal substrate to form an unhardened conductive resin layer;
a second step for applying a second conductive substance onto a surface of the unhardened conductive resin layer; and
a third step for hardening the unhardened conductive resin layer, wherein during the hardening, the metal substrate whose surface is covered is pressurized to force the resin into gaps between particles of the second conductive substance to cure the resin.

2. The method for manufacturing a fuel cell separator according to claim 1 , wherein the second step comprises a step for mixing the second conductive substance with a solvent, and applying the mixture onto the unhardened conductive resin layer formed in the first step, wherein the resin is hardly-soluble in the solvent.

3. A method for manufacturing a fuel cell separator, comprising:
a first step for applying a mixture of a sublayer resin and a sublayer conductive substance onto a surface of a metal substrate to form an unhardened conductive resin sublayer;
a step for hardening the unhardened conductive resin sublayer;
a second step for applying a mixture of a main-layer resin and a first conductive substance onto a surface of the conductive resin sublayer to form an unhardened conductive resin main layer;
a third step for applying a second conductive substance onto a surface of the unhardened conductive resin main layer; and
a fourth step for hardening the unhardened conductive resin main layer, wherein the metal substrate whose surface is covered is pressurized to force the main-layer resin into gaps between particles of the second conductive substance, and the main-layer resin is cured.

4. The method for manufacturing a fuel cell separator according to claim 3 , wherein the third step comprises a step for mixing the second conductive substance with a solvent, and applying the mixture onto the unhardened conductive resin sublayer formed in the first step, wherein the main-layer resin is hardly-soluble in the solvent.

5. A method for manufacturing a fuel cell separator, comprising:
a first step for applying a mixture of a sublayer resin and a sublayer conductive substance onto a surface of a metal substrate to form an unhardened conductive resin sublayer;
a step for hardening the unhardened conductive resin sublayer;
a second step for applying a main-layer resin onto a surface of the conductive resin sublayer to form an unhardened resin layer;

a third step for applying a conductive substance onto a surface of the unhardened resin layer; and
a fourth step for pressurizing the metal substrate, whose surface is covered, to force the main-layer resin contained in the unhardened resin layer into gaps between particles of the conductive substance to cure the resin, thereby forming a conductive resin main layer.

6. The method for manufacturing a fuel cell separator according to claim 5 , wherein the third step comprises a step for mixing the conductive substance with a solvent, and applying the mixture onto the unhardened conductive resin sublayer formed in the first step, wherein the main-layer resin is hardly-soluble in the solvent.

7. The method for manufacturing a fuel cell separator according to claim 3 , wherein
the metal substrate has a surface including a contact portion that contacts a gas diffusion layer or another separator in a fuel cell and a non-contact portion that cannot contact the gas diffusion layer or another separator and defines a water path,
in the first step, the sublayer resin and the sublayer conductive substance are applied to the contact portion and the non-contact portion of the metal substrate,
in the step for hardening the unhardened conductive resin sublayer, the unhardened conductive resin sublayer formed in the contact portion and the non-contact portion in the first step is hardened,
in the second step, a mixture of a main-layer resin and a first conductive substance is applied onto the surface of the conductive resin sublayer in the contact portion and the non-contact portion to form an unhardened conductive resin main layer,
in the third step, a second conductive substance is applied onto a portion of the unhardened conductive resin main layer formed in the second step, which portion covers the contact portion,
in the fourth step, the metal substrate whose surface is covered is pressurized to force the main-layer resin in the portion covering the contact portion into gaps between particles of the second conductive substance, and then the main-layer resin is cured, and
after the fourth step, the method further comprises a fifth step for hydrophilizing a portion of the conductive resin main layer that covers the non-contact portion.

Assignees

• Suzuki Yukihiro
• Morozumi Eiichiro
• Asaoka Takatoshi
• Toyota Auto Body Co Ltd

Inventors

• Suzuki Yukihiro
• Morozumi Eiichiro
• Asaoka Takatoshi

Classifications

• C23C18/50

  with alloys based on iron, cobalt or nickel · CPC title

• B05D3/12

  by mechanical means · CPC title

• H01M8/0226

  in the form of mixtures · CPC title

• H01M8/0221

  Organic resins; Organic polymers · CPC title

• H01M4/64

  Carriers or collectors · CPC title