CN-121988513-A - Method for curing UV curable adhesive and UV curable adhesive curing apparatus

Abstract

The invention provides a method for curing a UV-curable adhesive and a device for curing a UV-curable adhesive, which can improve the adhesion rate of GDL in the manufacturing process of a fuel cell unit. Several aspects of the present invention relate to a method for curing a UV-curable adhesive by UV irradiation in the manufacture of a fuel cell unit, wherein the oxygen concentration around the UV-curable adhesive at the start of UV irradiation is in the range of 0.075 vol% or more and 1.75 vol% or less, and the cumulative amount of UV light irradiated to the UV-curable adhesive is in the range of 1800mJ/cm 2 or more and 7340mJ/cm 2 or less.

Inventors

• Akishi Kitano

Assignees

• 丰田自动车株式会社

Dates

Publication Date

20260508

Application Date

20251103

Priority Date

20241107

Claims (5)

1. 1. A method for curing a UV-curable adhesive by UV irradiation in the production of a fuel cell unit, characterized in that, An oxygen concentration around the UV curable adhesive at the start of UV irradiation is in a range of 0.075% by volume or more and 1.75% by volume or less, and The cumulative amount of UV light irradiated to the UV curable adhesive is in the range of 1800mJ/cm 2 to 7340mJ/cm 2 .
2. 2. The method of claim 1, wherein the step of determining the position of the substrate comprises, The oxygen concentration around the UV curable adhesive at the start of UV irradiation is in the range of 0.10% by volume or more and 1.50% by volume or less.
3. 3. The method of claim 1, wherein the step of determining the position of the substrate comprises, The cumulative amount of UV light irradiated to the UV curable adhesive is in the range of 1800mJ/cm 2 to 5700mJ/cm 2 .
4. 4. A method according to any one of claim 1 to 3, wherein, The method is carried out in a UV curable adhesive curing apparatus.
5. 5. A UV curable adhesive curing device for curing a UV curable adhesive used in the manufacture of a fuel cell unit by UV irradiation, characterized in that, Comprises a UV light source, a UV irradiation chamber and a control unit, The UV irradiation chamber and the control unit are configured to adjust the oxygen concentration around the UV-curable adhesive at the start of UV irradiation to a range of 0.075 vol% to 1.75 vol%, and to adjust the cumulative UV light amount irradiated to the UV-curable adhesive to a range of 1800mJ/cm 2 to 7340mJ/cm 2 .

Description

Method for curing UV curable adhesive and UV curable adhesive curing apparatus Technical Field Several aspects of the present invention relate to a method of curing a UV curable adhesive. Background The fuel cell has a stack structure in which only a predetermined number of unit cells that generate electric power by a reaction between a fuel gas (hydrogen) and an oxidant gas (oxygen) are stacked. The unit cell includes a membrane electrode gas diffusion layer assembly (MEGA) and separators disposed on both sides of the MEGA. The MEGA has a Membrane Electrode Assembly (MEA) having anode and cathode catalyst layers on both sides of an electrolyte membrane, and gas diffusion layers disposed on both sides of the membrane electrode assembly. In the production of a fuel cell, a UV curable adhesive can be used for the adhesion of the laminate for a membrane electrode assembly to a support frame for supporting the laminate. As a UV curable adhesive curing apparatus capable of shortening the curing time of such a UV curable adhesive, patent document 1 discloses a UV curable adhesive curing apparatus used in the manufacture of a fuel cell, which is characterized by having an Ultraviolet (UV) light source, a flat plate of a material that does not block UV light, which is disposed between the UV light source and a workpiece, a gap capable of filling N 2 gas between the flat plate and the workpiece, and a pipe that supplies the N 2 gas to the gap. Patent document 1 Japanese patent application laid-open No. 2024-101082 Disclosure of Invention In the fuel cell, MEGA (anode side GDL-anode catalyst layer-electrolyte membrane-cathode catalyst layer-cathode side GDL) is formed by providing a Gas Diffusion Layer (GDL) for feeding gas into the catalyst on the surfaces of the anode catalyst layer and the cathode catalyst layer as catalyst layers. To ensure gas permeability, the GDL is formed to be porous. In order to prevent the GDL from being deviated during transportation in the production of the fuel cell unit, the GDL, for example, the cathode-side GDL is bonded to the electrolyte membrane and the UV curable adhesive applied to the cathode catalyst layer. The UV curable adhesive is tacky by UV curing, but is hindered by atmospheric oxygen. If curing inhibition occurs, uncured components of the UV curable adhesive existing near the surface of the porous GDL are absorbed into the GDL, and thus the tackiness derived from the adhesive also disappears. Therefore, the UV curable adhesive is preferably cured under a low oxygen atmosphere. However, in order to prevent the curing inhibition of the UV curable adhesive, it was confirmed that the tackiness disappeared as a result of curing the UV curable adhesive in an oxygen-free atmosphere. Accordingly, several embodiments of the present invention have an object to provide a method for curing a UV-curable adhesive that improves the GDL adhesion rate in a process for manufacturing a fuel cell. As a result of various studies to achieve the above object, the present inventors have found that in a UV curable adhesive curing apparatus used in the manufacture of a fuel cell, the oxygen concentration around the UV curable adhesive at the start of UV irradiation is set to be in the range of 0.075 vol% or more and 1.75 vol% or less, and further, the UV cumulative light quantity irradiated to the UV curable adhesive is set to be in the range of 1800mJ/cm 2 or more and 7340mJ/cm 2 or less, whereby the UV curable adhesive is cured and the GDL adhesion rate is improved, and completed several aspects of the present invention. That is, the gist of several aspects of the present invention is as follows. (1) A method for curing a UV curable adhesive by UV irradiation in the manufacture of a fuel cell unit, the method being characterized in that the oxygen concentration around the UV curable adhesive at the start of UV irradiation is in the range of 0.075 vol.% or more and 1.75 vol.% or less, and the cumulative amount of UV light irradiated to the UV curable adhesive is in the range of 1800mJ/cm 2 or more and 7340mJ/cm 2 or less. (2) The method according to (1), wherein the oxygen concentration around the UV-curable adhesive at the start of UV irradiation is in the range of 0.10% by volume or more and 1.50% by volume or less. (3) The method according to (1) or (2), wherein the cumulative amount of UV light irradiated to the UV-curable adhesive is in a range of 1800mJ/cm 2 to 5700mJ/cm 2. (4) The method according to any one of (1) to (3), wherein the method is carried out in a UV curable adhesive curing apparatus. (5) A UV-curable adhesive curing device for curing a UV-curable adhesive used in the manufacture of a fuel cell by UV irradiation, characterized by comprising a UV light source, a UV irradiation chamber and a control unit for adjusting the oxygen concentration around the UV-curable adhesive at the start of UV irradiation to a range of 0.075 to 1.75% by volume and adjusting the cumulative amoun