JP2017004607A - Manufacturing method of electrolyte membrane electrode structure with resin frame for fuel battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To strongly and excellently bond an electrolyte membrane electrode structure and a resin frame member with a simple step without generating a space inside an adhesive.SOLUTION: The manufacturing method of an electrolyte membrane electrode structure 10 with a resin frame includes the steps of: applying a liquid adhesive 26a to a junction of a solid polymer electrolyte membrane 18 and a resin frame member 24; and providing the junction to which the liquid adhesive 26a is applied with weight and gradually increasing the provided weight.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an electrolyte membrane / electrode structure with a resin frame for a fuel cell, comprising: a step MEA having a solid polymer electrolyte membrane sandwiched between a first electrode and a second electrode; and a resin frame member that goes around the outer periphery of the step MEA. It relates to the manufacturing method.

  In general, a polymer electrolyte fuel cell employs a polymer electrolyte membrane made of a polymer ion exchange membrane. The fuel cell includes an electrolyte membrane / electrode structure (MEA) in which an anode electrode is disposed on one surface of a solid polymer electrolyte membrane and a cathode electrode is disposed on the other surface of the solid polymer electrolyte membrane. Yes. The anode electrode and the cathode electrode each have a catalyst layer (electrode catalyst layer) and a gas diffusion layer (porous carbon).

  The electrolyte membrane / electrode structure is sandwiched between separators (bipolar plates) to form a power generation cell (unit fuel cell). This power generation cell is used as, for example, an in-vehicle fuel cell stack by stacking a predetermined number.

  In the electrolyte membrane / electrode structure, one gas diffusion layer is set to a plane size smaller than that of the solid polymer electrolyte membrane, and the other gas diffusion layer is set to substantially the same plane size as the solid polymer electrolyte membrane. The so-called step MEA may be configured. At that time, in order to reduce the amount of the relatively expensive solid polymer electrolyte membrane used and to protect the solid polymer electrolyte membrane having a thin film shape and low strength, an MEA with a resin frame incorporating a resin frame member is adopted. Has been.

  As a MEA with a resin frame, for example, a fuel cell stack disclosed in Patent Document 1 is known. In this fuel cell stack, the resin frame member has an inner peripheral end that protrudes to the outer peripheral side of the first electrode having a smaller planar dimension than the second electrode and contacts the outer peripheral edge of the solid polymer electrolyte membrane. . The inner peripheral edge is disposed at a boundary portion between the solid polymer electrolyte membrane and the outer periphery of the first electrode, and is joined to the outer peripheral edge of the solid polymer electrolyte membrane via an adhesive layer. Yes.

Japanese Patent No. 5683433

  By the way, as said adhesive bond layer, liquid adhesives other than solid adhesives, such as a hot-melt-adhesive, are used, for example. At that time, the liquid adhesive may require heating to be cured. However, since MEA is a member that easily absorbs moisture, when heat is applied, the moisture may evaporate and the moisture or water vapor may enter the adhesive. As a result, voids (pores) are generated inside the adhesive to cause a space, and there is a problem that the adhesive strength of the entire adhesive layer is lowered.

  The present invention solves this type of problem, and does not cause a space inside the adhesive, and the electrolyte membrane / electrode structure and the resin frame member are firmly and satisfactorily obtained in a simple process. It aims at providing the manufacturing method of the electrolyte membrane and electrode structure with a resin frame for fuel cells which can be joined.

  In the method for manufacturing an electrolyte membrane / electrode structure with a resin frame for a fuel cell according to the present invention, the electrolyte membrane / electrode structure with a resin frame for a fuel cell includes a step MEA and a resin frame member. In the step MEA, a first electrode is provided on one surface of the solid polymer electrolyte membrane, a second electrode is provided on the other surface of the solid polymer electrolyte membrane, and a plane of the first electrode is provided. The dimension is set to be larger than the planar dimension of the second electrode. The resin frame member is joined to the outer peripheral surface of the solid polymer electrolyte membrane exposed to the outside of the second electrode by an adhesive layer.

  The manufacturing method includes a step of applying a liquid adhesive to a joint portion between the solid polymer electrolyte membrane and the resin frame member, and applying a load to the joint portion to which the liquid adhesive is applied. And increasing the applied load stepwise.

  Moreover, in this manufacturing method, it is preferable that a load is provided in order of a 1st load, a 2nd load smaller than the said 1st load, and a 3rd load larger than the said 1st load.

  Furthermore, in this manufacturing method, it is preferable that the load is applied in the order of a first load, a second load smaller than the first load, and a third load that is the same as the first load.

  Furthermore, in this manufacturing method, it is preferable that the load is applied in the order of the first load and the second load larger than the first load.

  According to the present invention, a load is applied to the joint portion between the solid polymer electrolyte membrane and the resin frame member, and the applied load is increased stepwise. For this reason, even if a void occurs in the adhesive, the void can be pushed out or crushed by increasing the load. Therefore, no space is created inside the adhesive, and the electrolyte membrane / electrode structure and the resin frame member can be joined firmly and satisfactorily by a simple process.

It is a principal part disassembled perspective explanatory view of a polymer electrolyte power generation cell in which an electrolyte membrane / electrode structure with a resin frame to which the manufacturing method according to the present invention is applied is incorporated. It is II-II sectional view explanatory drawing in FIG. 1 of the said electric power generation cell. In the said manufacturing method, it is explanatory drawing at the time of forming CCM which comprises the said electrolyte membrane and electrode structure with a resin frame. In the said manufacturing method, it is explanatory drawing at the time of joining a resin frame member to level | step difference MEA. It is explanatory drawing of the joining operation | work of the said level | step difference MEA and the said resin frame member in the said manufacturing method. It is explanatory drawing of load control in the manufacturing method which concerns on the 1st Embodiment of this invention. It is explanatory drawing of load control in the manufacturing method which concerns on the 2nd Embodiment of this invention. It is explanatory drawing of load control in the manufacturing method which concerns on the 3rd Embodiment of this invention.

  As shown in FIGS. 1 and 2, an electrolyte membrane / electrode structure 10 with a resin frame to which the manufacturing method according to the present invention is applied is incorporated in a horizontally long (or vertically long) rectangular polymer electrolyte power generation cell 12. It is. The plurality of power generation cells 12 are stacked in, for example, an arrow A direction (horizontal direction) or an arrow C direction (gravity direction) to form a fuel cell stack. The fuel cell stack is mounted on, for example, a fuel cell electric vehicle (not shown) as an in-vehicle fuel cell stack.

  The power generation cell 12 sandwiches the electrolyte membrane / electrode structure 10 with a resin frame between the first separator 14 and the second separator 16. The first separator 14 and the second separator 16 have a horizontally long (or vertically long) rectangular shape. The first separator 14 and the second separator 16 are made of, for example, a steel plate, a stainless steel plate, an aluminum plate, a plating-treated steel plate, a metal plate whose surface is subjected to anticorrosion treatment, a carbon member, or the like.

  The electrolyte membrane / electrode structure 10 with a rectangular resin frame includes a step MEA 10a. The step MEA 10a includes, for example, a solid polymer electrolyte membrane (cation exchange membrane) 18 in which a perfluorosulfonic acid thin film is impregnated with water, and an anode electrode (first electrode) 20 sandwiching the solid polymer electrolyte membrane 18. And a cathode electrode (second electrode) 22. The solid polymer electrolyte membrane 18 may use an HC (hydrocarbon) based electrolyte in addition to the fluorine based electrolyte.

  The cathode electrode 22 has a smaller planar dimension (outer dimension) than the solid polymer electrolyte membrane 18 and the anode electrode 20. Instead of the above configuration, the anode electrode 20 may be configured to have a smaller planar dimension than the solid polymer electrolyte membrane 18 and the cathode electrode 22. At that time, the anode electrode 20 becomes the second electrode, and the cathode electrode 22 becomes the first electrode.

  As shown in FIG. 2, the anode electrode 20 includes a first electrode catalyst layer 20a bonded to one surface 18a of the solid polymer electrolyte membrane 18, and a first gas diffusion layer stacked on the first electrode catalyst layer 20a. Layer 20b. The first electrode catalyst layer 20a and the first gas diffusion layer 20b have the same external dimensions and are set to the same external dimensions as (or less than) the solid polymer electrolyte membrane 18.

  The cathode electrode 22 includes a second electrode catalyst layer 22a bonded to the surface 18b of the solid polymer electrolyte membrane 18, and a second gas diffusion layer 22b stacked on the second electrode catalyst layer 22a. The second electrode catalyst layer 22 a and the second gas diffusion layer 22 b have the same planar dimension and are set to a planar dimension smaller than the planar dimension of the solid polymer electrolyte membrane 18. An exposed surface 18be exposed to the outside of the cathode electrode 22 is provided on the outer peripheral edge of the solid polymer electrolyte membrane 18 on the surface 18b side.

  The second electrode catalyst layer 22a and the second gas diffusion layer 22b are set to have the same planar dimension, but the planar dimension of the second electrode catalyst layer 22a is the plane of the second gas diffusion layer 22b. It may have a dimension (or a dimension that is smaller) than the dimension.

  The first electrode catalyst layer 20a is formed by, for example, uniformly applying porous carbon particles having a platinum alloy supported on the surface thereof to the surface of the first gas diffusion layer 20b. The second electrode catalyst layer 22a is formed by, for example, uniformly applying porous carbon particles having a platinum alloy supported on the surface thereof to the surface of the second gas diffusion layer 22b.

  The first gas diffusion layer 20b is formed by a porous and conductive microporous layer 20b (m) and a carbon layer 20b (c) such as carbon paper or carbon cloth. The second gas diffusion layer 22b is formed of a microporous layer 22b (m) and a carbon layer 22b (c) such as carbon paper or carbon cloth. The planar dimension of the second gas diffusion layer 22b is set smaller than the planar dimension of the first gas diffusion layer 20b. The first electrode catalyst layer 20 a and the second electrode catalyst layer 22 a are formed on both surfaces of the solid polymer electrolyte membrane 18.

  The electrolyte membrane / electrode structure 10 with a resin frame circulates around the outer periphery of the solid polymer electrolyte membrane 18 and is joined to the outer peripheral surface of the solid polymer electrolyte membrane 18 as a film-like resin frame member (resin molding or Resin film) 24.

  The resin frame member 24 includes, for example, PPS (polyphenylene sulfide), PPA (polyphthalamide), PEN (polyethylene naphthalate), PES (polyethersulfone), LCP (liquid crystal polymer), PVDF (polyvinylidene fluoride), A silicone resin, a fluororesin, or m-PPE (modified polyphenylene ether resin) is used. The resin frame member 24 is further made of PET (polyethylene terephthalate), PBT (polybutylene terephthalate), modified polyolefin, or the like.

  The resin frame member 24 has a flat plate shape, and is provided with an adhesive surface 24 a that is bonded to the exposed surface 18 be of the solid polymer electrolyte membrane 18. The adhesive surface 24 a has a predetermined width dimension h from the inner peripheral end surface 24 e of the resin frame member 24 toward the outer peripheral end portion, and there is a gap between the inner peripheral end surface 24 e and the outer peripheral end portion of the cathode electrode 22. S is formed. The width dimension h is set in a range away from the inner peripheral end surface 24e of the resin frame member 24 to the inner side than the outer peripheral end surface 18e of the solid polymer electrolyte membrane 18.

  An adhesive layer 26 made of a liquid adhesive 26 a is provided between the exposed surface 18 be of the solid polymer electrolyte membrane 18 and the adhesive surface 24 a of the resin frame member 24. As the liquid adhesive 26a, for example, a liquid fluoroelastomer or a silicone-based liquid adhesive is used.

  As shown in FIG. 1, one end edge portion of the power generation cell 12 in the arrow B direction (horizontal direction in FIG. 1) communicates with each other in the arrow A direction that is the stacking direction, and the oxidant gas inlet communication hole 30 a. A cooling medium inlet communication hole 32a and a fuel gas outlet communication hole 34b are provided. The oxidant gas inlet communication hole 30a supplies an oxidant gas, for example, an oxygen-containing gas, while the cooling medium inlet communication hole 32a supplies a cooling medium. The fuel gas outlet communication hole 34b discharges fuel gas, for example, hydrogen-containing gas. The oxidant gas inlet communication hole 30a, the cooling medium inlet communication hole 32a, and the fuel gas outlet communication hole 34b are arranged in the direction of arrow C (vertical direction).

  The other end edge of the power generation cell 12 in the direction of arrow B communicates with each other in the direction of arrow A, the fuel gas inlet communication hole 34a for supplying fuel gas, the cooling medium outlet communication hole 32b for discharging the cooling medium, and the oxidation An oxidant gas outlet communication hole 30b for discharging the oxidant gas is provided. The fuel gas inlet communication hole 34a, the cooling medium outlet communication hole 32b, and the oxidant gas outlet communication hole 30b are arranged in the direction of arrow C.

  The surface 16a of the second separator 16 facing the electrolyte membrane / electrode structure 10 with a resin frame communicates with the oxidant gas inlet communication hole 30a and the oxidant gas outlet communication hole 30b and extends in the arrow B direction. An oxidant gas flow path 36 is provided.

  The surface 14a of the first separator 14 facing the electrolyte membrane / electrode structure 10 with a resin frame communicates with the fuel gas inlet communication hole 34a and the fuel gas outlet communication hole 34b and extends in the direction of arrow B. A fuel gas flow path 38 is formed. Between the surface 14b of the 1st separator 14 and the surface 16b of the 2nd separator 16 which adjoin each other, it communicates with the cooling-medium inlet communication hole 32a and the cooling-medium outlet communication hole 32b, and is extended in the arrow B direction. A cooling medium flow path 40 is formed.

  As shown in FIGS. 1 and 2, the first seal member 42 is integrated with the surfaces 14 a and 14 b of the first separator 14 around the outer peripheral end of the first separator 14. The second seal member 44 is integrated with the surfaces 16 a and 16 b of the second separator 16 around the outer peripheral end portion of the second separator 16.

  As shown in FIG. 2, the first seal member 42 includes a first convex seal 42 a that contacts the resin frame member 24 constituting the electrolyte membrane / electrode structure 10 with a resin frame, and a second seal of the second separator 16. And a second convex seal 42b in contact with the member 44. The second seal member 44 constitutes a flat seal in which the surface that contacts the second convex seal 42b extends in a flat shape along the separator surface. Instead of the second convex seal 42b, the second seal member 44 may be provided with a convex seal (not shown).

  For the first seal member 42 and the second seal member 44, for example, EPDM, NBR, fluororubber, silicone rubber, fluorosilicone rubber, butyl rubber, natural rubber, styrene rubber, chloroprene or acrylic rubber or the like, cushion material Alternatively, an elastic seal member such as a packing material is used.

  Next, a manufacturing method according to the first embodiment of the present invention for manufacturing an electrolyte membrane / electrode structure 10 with a resin frame will be described below.

  First, the step MEA 10a is manufactured, while the resin frame member 24 is injection-molded using a mold (not shown), or a member obtained by cutting a film is prepared. In the step MEA 10a, a slurry made of a mixture of carbon black and PTFE (polytetrafluoroethylene) particles is applied to a flat surface of the carbon paper and dried to form a microporous layer 20b (m) as an underlayer. .

  The first gas diffusion layer 20b is formed by bonding the carbon layer 20b (c) to the microporous layer 20b (m). Similarly, the microporous layer 22b (m) is formed, and the carbon layer 22b (c) is bonded to the microporous layer 22b (m), thereby forming the second gas diffusion layer 22b.

  On the other hand, after adding a solvent to the electrode catalyst, for example, a solution of a perfluoroalkylenesulfonic acid polymer compound is added as an ion conductive polymer binder solution. Then, an anode electrode ink and a cathode electrode ink are created by adding a solvent until a predetermined ink clay is obtained.

  Therefore, as shown in FIG. 3, the anode electrode ink is applied to the PET film 50a by screen printing and dried by heating, whereby the anode electrode sheet 52 provided with the first electrode catalyst layer 20a is formed. The first electrode catalyst layer 20 a is set to have the same planar dimensions as the solid polymer electrolyte membrane 18.

  Similarly, the cathode electrode ink is applied to the PET film 50b by screen printing and dried by heating, whereby the cathode electrode sheet 54 provided with the second electrode catalyst layer 22a is formed. The second electrode catalyst layer 22 a is set to have a smaller planar dimension than the solid polymer electrolyte membrane 18.

  Next, hot pressing is performed in a state where the solid polymer electrolyte membrane 18 is sandwiched between the anode electrode sheet 52 and the cathode electrode sheet 54. Then, the PET films 50a and 50b are peeled to form a joined body (CCM) (catalyst coated membrane). Further, the CCM is sandwiched between the first gas diffusion layer 20b and the second gas diffusion layer 22b and integrated by hot pressing to produce a step MEA 10a (see FIG. 4).

  And the liquid adhesive 26a is apply | coated on the exposed surface 18be of the solid polymer electrolyte membrane 18 through the dispenser which is not shown in figure, for example. The liquid adhesive 26 a may be applied to the adhesive surface 24 a of the resin frame member 24.

  Next, as shown in FIG. 5, the servo press machine 60 is applied to the bonding portion between the exposed surface 18be of the solid polymer electrolyte membrane 18 and the bonding surface 24a of the resin frame member 24 with the liquid adhesive 26a applied thereto. Is heated and pressurized. The servo press machine 60 includes a fixed base 62 and a movable base 64, and the movable base 64 can be moved forward and backward with respect to the fixed base 62 by a piston 66. In addition, you may employ | adopt the system which increases continuously as well as the system which gives a load stepwise.

  In the first embodiment, load control is performed as shown in FIG. Specifically, first, the first load L1 is applied to the joint portion between the solid polymer electrolyte membrane 18 and the resin frame member 24 by increasing the applied load for a predetermined time. Furthermore, after the load to be applied is decreased and the second load L2 smaller than the first load L1 is applied to the joint portion for a short time, the third load L3 larger than the first load L1 is applied for a predetermined time. Is given over the period. The liquid adhesive 26a is cured and the adhesive layer 26 is formed by completing the holding for a predetermined time while applying a load to the joining portion.

  In this case, in the first embodiment, the first load L1, the second load L2 that is smaller than the first load L1, and the third load L3 that is larger than the first load L1 are sequentially applied to the joint portion. ing. As described above, by temporarily reducing the applied load from the first load L1 to the second load L2, the voids that have entered the liquid adhesive 26a tend to overlap with each other and become large voids. For this reason, the void is easily removed from the liquid adhesive 26a.

  Moreover, the applied load is increased from the second load L2 to the third load L3 that is larger than the first load L1, so that the void generated inside the liquid adhesive 26a can be pushed out or crushed. Therefore, there is no space in the liquid adhesive 26a, and the effect that the step MEA 10a and the resin frame member 24 can be joined firmly and satisfactorily by a simple process is obtained.

  The operation of the power generation cell 12 configured as described above will be described below.

  First, as shown in FIG. 1, an oxidant gas such as an oxygen-containing gas is supplied to the oxidant gas inlet communication hole 30a, and a fuel gas such as a hydrogen-containing gas is supplied to the fuel gas inlet communication hole 34a. Supplied. Further, a cooling medium such as pure water, ethylene glycol, or oil is supplied to the cooling medium inlet communication hole 32a.

  Therefore, the oxidant gas is introduced from the oxidant gas inlet communication hole 30a into the oxidant gas flow path 36 of the second separator 16, moves in the direction of arrow B, and is supplied to the cathode electrode 22 of the step MEA 10a. On the other hand, the fuel gas is introduced into the fuel gas flow path 38 of the first separator 14 from the fuel gas inlet communication hole 34a. The fuel gas moves in the direction of arrow B along the fuel gas flow path 38 and is supplied to the anode electrode 20 of the step MEA 10a.

  Therefore, in each step MEA 10a, the oxidant gas supplied to the cathode electrode 22 and the fuel gas supplied to the anode electrode 20 are electrochemically reacted in the second electrode catalyst layer 22a and the first electrode catalyst layer 20a. It is consumed and power is generated.

  Next, the oxidant gas consumed by being supplied to the cathode electrode 22 is discharged in the direction of arrow A along the oxidant gas outlet communication hole 30b. Similarly, the fuel gas consumed by being supplied to the anode electrode 20 is discharged in the direction of arrow A along the fuel gas outlet communication hole 34b.

  The cooling medium supplied to the cooling medium inlet communication hole 32a is introduced into the cooling medium flow path 40 between the first separator 14 and the second separator 16, and then flows in the direction of arrow B. The cooling medium is discharged from the cooling medium outlet communication hole 32b after cooling the step MEA 10a.

  FIG. 7 is an explanatory diagram of load control in the manufacturing method according to the second embodiment of the present invention.

  In the second embodiment, first, the first load L1 is applied to the joint portion between the solid polymer electrolyte membrane 18 and the resin frame member 24 by increasing the applied load for a predetermined time. Furthermore, after the application of the load to the joint portion is once released, that is, after the second load L2 (substantially, load 0) smaller than the first load L1 is instantaneously applied to the joint portion. The applied load is decreased, and the third load L3 that is the same as the first load L1 is applied over a predetermined time. Then, when the application of the load to the joining portion is completed, the liquid adhesive 26a is cured and the adhesive layer 26 is formed.

  As described above, in the second embodiment, the joint portion includes the first load L1, the second load L2 (= 0) smaller than the first load L1, and the third load L3 that is the same as the first load L1. In the order. For this reason, as in the first embodiment, there is no space in the liquid adhesive 26a, and the step MEA 10a and the resin frame member 24 can be joined firmly and satisfactorily by a simple process. The effect that it becomes possible is obtained.

  FIG. 8 is an explanatory diagram of load control in the manufacturing method according to the third embodiment of the present invention.

  In the third embodiment, first, the first load L1 is applied to the joint portion between the solid polymer electrolyte membrane 18 and the resin frame member 24 by increasing the applied load for a predetermined time. Further, a second load L2 larger than the first load L1 is applied to the joint portion over a predetermined time. Then, when the application of the load to the joining portion is completed, the liquid adhesive 26a is cured and the adhesive layer 26 is formed.

  As described above, in the third embodiment, the first load L1 and the second load L2 that is larger than the first load L1 are applied to the joint portion in this order. Therefore, the void generated in the liquid adhesive 26a can be pushed out or crushed. Accordingly, the same effects as those of the first and second embodiments described above can be obtained, such as making it possible to join the step MEA 10a and the resin frame member 24 firmly and satisfactorily with a simple process.

10 ... Electrolyte membrane / electrode structure with resin frame 10a ... Step MEA
DESCRIPTION OF SYMBOLS 12 ... Power generation cell 14, 16 ... Separator 18 ... Solid polymer electrolyte membrane 18be ... Exposed surface 20 ... Anode electrode 20a, 22a ... Electrode catalyst layer 20b, 22b ... Gas diffusion layer 22 ... Cathode electrode 24 ... Resin frame member 24a ... Adhesion Surface 26a ... Liquid adhesive 30a ... Oxidant gas inlet communication hole 30b ... Oxidant gas outlet communication hole 32a ... Cooling medium inlet communication hole 32b ... Cooling medium outlet communication hole 34a ... Fuel gas inlet communication hole 34b ... Fuel gas outlet communication hole 36 ... Oxidant gas passage 38 ... Fuel gas passage 40 ... Cooling medium passage 42, 44 ... Seal member 52 ... Anode electrode sheet 54 ... Cathode electrode sheet 60 ... Servo press machine

Claims (4)

A first electrode is provided on one surface of the solid polymer electrolyte membrane, a second electrode is provided on the other surface of the solid polymer electrolyte membrane, and the planar dimensions of the first electrode are A step MEA set to a dimension larger than the planar dimension of the second electrode;
A resin frame member bonded to the outer peripheral surface of the solid polymer electrolyte membrane exposed to the outside of the second electrode by an adhesive layer;
A method for producing an electrolyte membrane / electrode structure with a resin frame for a fuel cell, comprising:
Applying a liquid adhesive to the joint portion between the solid polymer electrolyte membrane and the resin frame member;
A step of applying a load to the joint portion to which the liquid adhesive is applied and increasing the applied load stepwise;
A method for producing an electrolyte membrane / electrode structure with a resin frame for a fuel cell, comprising:   2. The fuel according to claim 1, wherein the load is applied in the order of a first load, a second load smaller than the first load, and a third load larger than the first load. A method for producing an electrolyte membrane / electrode structure with a resin frame for a battery.   2. The fuel according to claim 1, wherein the load is applied in the order of a first load, a second load smaller than the first load, and a third load that is the same as the first load. A method for producing an electrolyte membrane / electrode structure with a resin frame for a battery.   2. The manufacturing method according to claim 1, wherein the load is applied in the order of a first load and a second load larger than the first load. Manufacturing method.

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