JP2012114050A - Solid electrolyte membrane reinforcement material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid electrolyte membrane reinforcement material that is useful for reinforcement of a solid electrolyte membrane of a solid fuel cell, has excellent impregnation workability of an electrolyte, has the strength in a wet state, and high strength and elongation in a dry state of a paper.SOLUTION: A solid electrolyte membrane reinforcement material is made up of a glass fiber, an organic fiber, and an inorganic binder. The organic fiber is made up of a non-self-adhesive organic fiber and a thermal adhesive organic fiber. In the solid electrolyte membrane reinforcement material, the glass fiber is included by 30 to 70 wt%, the organic fiber is included by 15 to 65 wt%, and the inorganic binder is included by 0.1 to 30 wt%. In the whole composition, the thermal adhesive organic fiber is included by 10 to 50 wt%.

Description

  The present invention relates to a reinforcing material for reinforcing a solid electrolyte membrane (proton conductive membrane) of a fuel cell.

  For example, a membrane made of an organic polymer exhibiting proton conductivity is used as a solid electrolyte of a polymer electrolyte fuel cell (PEFC). At present, perfluoroalkylene is a main skeleton, and perfluorovinyl ether is partly used. A solid electrolyte membrane made of a fluorine-based polymer material having an ion exchange group such as a sulfonic acid group or a carboxylic acid group at the end of the side chain (for example, NAFION (registered trademark) of DuPont, USA) is mainly used.

  A polymer electrolyte fuel cell using a solid electrolyte membrane made of such a fluorine-based polymer material is limited to the heat-resistant temperature of the fluorine-based polymer material and is usually operated in a relatively low temperature range of 70 ° C. to 90 ° C. Is done. However, it is desirable to operate at a higher temperature in order to reduce poisoning due to carbon monoxide and to improve the overall power generation efficiency through efficient use of waste heat. For this reason, proton conductive materials having excellent heat resistance instead of the above-described fluorine-based polymer materials have been proposed. Typical examples include heat-resistant aromatic polymer materials such as polybenzimidazole, polybenzimidazole, and the like. Examples include ether sulfone, polyether ether ketone, and polyethylene oxide.

  However, solid electrolyte membranes made of these polymer materials are insufficient in strength and may be damaged when a membrane-electrode assembly is formed. Thus, a solid electrolyte membrane having higher strength and easy handling is desired. Furthermore, for solid electrolyte membranes made of fluorinated polymer materials, solid polymer fuel cells using them swell due to the water content of the fluorinated polymer material, resulting in increased dimensions, decreased mechanical strength, and long-term operation. There is a demand for a material having excellent dimensional and strength stability even in a wet state.

  Therefore, in order to obtain a solid electrolyte membrane having excellent stability and strength, it has been proposed to reinforce with a reinforcing material such as a woven fabric made of organic / inorganic fibers (for example, Patent Documents 1 and 2). Examples of such reinforcing fibers include fibers of polymer materials such as acrylic, polyester, polypropylene, and fluororesin, fibers of natural materials such as silk, cotton, and paper, fibers of inorganic materials such as glass fibers, and the like. Among these, it is described in Patent Document 1 that it is preferable to use glass fiber and the woven fabric because the strength of the reinforcing material and the affinity with the material constituting the solid electrolyte membrane are excellent.

  With regard to such a reinforcing material composed of glass fiber and a solid electrolyte membrane using the same, the present applicant has so far added an inorganic binder or an organic binder to a glass fiber forming body such as a woven fabric or non-woven fabric of glass fiber. Have been proposed (Patent Documents 3 to 5). In addition, for reinforcing materials made of these glass fibers, the glass fibers are bonded with an organic binder for the purpose of improving the ease of handling when assembling the fuel cell and enabling heat fusion with the solid electrolyte membrane. It has also been proposed to use an adhesive solidified non-woven fabric obtained by a method of adding an organic binder at the time of production or a glass fiber non-woven fabric (for example, Patent Document 6).

However, in order to improve the strength and prevent deformation (swelling and shrinkage), the above-mentioned conventional technique using a woven fabric, a nonwoven fabric or the like prepared by combining glass fibers and organic fibers as a reinforcing material for a solid electrolyte membrane of a fuel cell is as follows. There was a problem like this.
That is, in the process of studying the production of a solid electrolyte membrane reinforced with fibers by impregnating an electrolyte solution into a woven or non-woven fabric made of glass fibers and organic fibers, a reinforcing material as conventionally proposed It has been found that the tensile strength may be significantly reduced during the impregnation of the electrolyte solution. Thus, when tensile strength falls at the time of impregnation of electrolyte solution, there exists a problem that the process by the method of processing while winding with a roll will become difficult and manufacture will become difficult.
In addition, there was a tendency that the tensile strength at the time of impregnation with the electrolyte solution decreased due to the blending of the nonwoven fabric as the reinforcing material, particularly when the blending ratio of the organic fibers was small.
Further, even when the reinforcing material was dried, the reinforcing material having a very thin thickness tended to have a low tensile strength. For example, it has been found that when the thickness is about 50 μm, the tensile strength may be remarkably reduced to about 2 to 5 N / 25 mm width when the blending ratio of the organic fibers is small.

JP 2001-307545 A JP 2007-018995 A JP 2004-319421 A International Publication No. 2005/086265 International Publication No. 2006/057239 JP 2009-545841 A

  The present invention has been made paying attention to such conventional problems, the purpose of which is a nonwoven fabric containing glass fibers and non-self-adhesive organic fibers, and heat-adhesive organic fibers, An object of the present invention is to provide a reinforcing material having an excellent tensile strength even when impregnated with an electrolyte solution (when wet).

The solid electrolyte membrane reinforcing material of the present invention is a solid electrolyte membrane reinforcing material comprising glass fibers, organic fibers, and an inorganic binder as claimed in claim 1, wherein the organic fibers are non-self-adhesive organic fibers and heat-adhesive organic materials. The glass fiber is 30 to 70 wt%, the organic fiber is 15 to 65 wt% and the inorganic binder is 0.1 to 30 wt%, and the thermoadhesive organic fiber is 10 to 50 wt% in the total composition. % Content.
The solid electrolyte membrane reinforcing material according to claim 2 is the solid electrolyte membrane reinforcing material according to claim 1, wherein the glass fiber is 35 to 60 wt%, the organic fiber is 20 to 60 wt%, and the inorganic binder is 5 to 5 wt%. 20 wt%, and 15 to 45 wt% of the thermoadhesive organic fiber in the total composition.
Further, the solid electrolyte membrane reinforcing material according to claim 3 is the solid electrolyte membrane reinforcing material according to claim 2, wherein the glass fiber is 40 to 50 wt%, the organic fiber is 30 to 55 wt%, and the inorganic binder is 5 10 to 10 wt%, and 20 to 40 wt% of the thermoadhesive organic fiber in the total composition.
Further, the solid electrolyte membrane reinforcing material according to claim 4 is the solid electrolyte membrane reinforcing material according to any one of claims 1 to 3, wherein the thermal adhesive organic fiber is more than the blending amount of the non-self-adhesive organic fiber. It is characterized in that the blending amount of is excessive.
The solid electrolyte membrane reinforcing material according to claim 5 is the solid electrolyte membrane reinforcing material according to any one of claims 1 to 4, wherein the glass fiber has an average fiber diameter of 0.1 to 5 µm and the non-self-adhesive material. The average fiber diameter of the conductive organic fiber is 1 to 20 μm, and the average fiber diameter of the thermoadhesive organic fiber is 1 to 20 μm.
The solid electrolyte membrane reinforcing material according to claim 6 is characterized in that, in the solid electrolyte membrane reinforcing material according to any one of claims 1 to 5, the average particle size of the inorganic binder is 0.01 to 2 µm. And

  Thermal adhesion of polyester, polyethylene, polypropylene, polymethylpentene, ethylene-vinyl alcohol copolymer resin, ethylene vinyl acetate copolymer resin, etc. as organic fibers in solid electrolyte membrane reinforcing material consisting of glass fiber, organic fiber and inorganic binder Therefore, the tensile strength at the time of the impregnation processing of the electrolyte solution is imparted. This is because the adhesion point between the heat-adhesive organic fibers does not peel off even when the electrolyte solution is impregnated (when wet), that is, when wet with water, so that the strength can be maintained. In addition, when glass fibers are bonded with an organic binder resin that is not fibrous, a film is stretched between the fibers and the surfaces are bonded, resulting in poor ionic conductivity. Does not interfere. As described above, according to the present invention, a solid electrolyte membrane reinforcing material that does not significantly reduce the tensile strength when impregnated with an electrolyte solution and that does not inhibit ion conductivity can be obtained.

  The solid electrolyte membrane reinforcing material of the present invention is a solid electrolyte membrane reinforcing material comprising glass fibers, organic fibers, and an inorganic binder, wherein the organic fibers comprise non-self-adhesive organic fibers and heat-adhesive organic fibers, Glass fiber is 30 to 70 wt%, organic fiber is 15 to 65 wt%, inorganic binder is 0.1 to 30 wt%, and thermal adhesive organic fiber is contained in 10 to 50 wt% in the whole composition It is.

The glass fiber contributes to the formation of the skeleton of the reinforcing material and the securing of heat resistance, and glass fibers such as C glass fiber, E glass fiber, B glass fiber, silica fiber, AR glass fiber, and T glass fiber are used. A fiber having an average fiber diameter of 0.1 to 5 μm and an average fiber length of 1 to 15 mm is used. The average fiber diameter is preferably 0.4 to 1.0 μm because it can be obtained relatively inexpensively. Moreover, since the dispersion | distribution to water is easy, about 1-5 mm of average fiber length is preferable. In addition, since the electrolyte solution which produces an electrolyte membrane is acidic, C glass fiber and a silica fiber are preferable, and cheaper C glass fiber is more preferable.
Further, if the glass fiber content is less than 30 wt%, shrinkage of the reinforcing material (papermaking) occurs, and if it exceeds 70 wt%, it becomes brittle due to insufficient tensile strength, preferably 30 to 70 wt%, The blending amount is 35 to 60 wt%, more preferably 40 to 50 wt%.

  The organic fiber contributes to skeleton formation when the organic fibers are bonded to each other. Organic fibers such as polyester, polypropylene, nylon, polyacrylonitrile, and aromatic polyamide are used, and the fiber diameter is 1 to 20 μm, the fiber length. The thing of about 1-10 mm is used. Polyester fibers and polypropylene fibers are preferred because of their large variety, high production volume, and availability at a relatively low cost. Further, if the blending amount of the non-self-adhesive organic fiber is less than 5 wt%, the tensile strength is insufficient, the flexibility is lowered, and if it exceeds 65 wt%, shrinkage occurs. Is 20 to 60 wt%, more preferably 30 to 55 wt%.

The heat-adhesive organic fiber contributes to point bonding of these fibers without forming a film in the gap between the glass fiber and the non-self-adhesive organic fiber, or the heat-adhesive organic fiber. Organic fibers such as polyethylene, polypropylene and polymethylpentene are used, and those having a fiber diameter of about 1 to 20 μm and a fiber length of about 1 to 10 mm are used. In particular, it is preferable that the heat bonding temperature of the heat-adhesive organic fiber is 160 ° C. or lower because the strength of the non-self-adhesive organic fiber does not deteriorate.
The fiber diameter is preferably 1 to 10 μm because the tensile strength is increased and it can be easily obtained. Further, the fiber length is preferably 3 to 5 mm because it is dispersed in water and hardly re-aggregates.
Among polyesters, polyethylene terephthalate fiber, polyethylene fiber, and polypropylene fiber are preferable because they are many kinds and are produced in a large amount and are easily available at a relatively low cost.
Further, if the blending amount of the heat-adhesive organic fiber is less than 10 wt%, the wet tensile strength is insufficient, and if it exceeds 50 wt%, shrinkage occurs, so 10 to 50 wt%, preferably 15 to 45 wt%. %, More preferably 20-40 wt%.
In order to increase the tensile strength, it is preferable to add more heat-adhesive organic fibers than non-self-adhesive organic fibers. Specifically, the blending ratio of the heat-adhesive organic fiber to the non-self-adhesive organic fiber 1 is preferably 1 to 3, and the heat-adhesive organic fiber to the non-self-adhesive organic fiber 1 The blending ratio of 2 is optimally 2.
Moreover, in order to increase an adhesion point, since a thinner fiber can be obtained, it is preferable to use a thinner non-self-adhesive organic fiber. Specifically, Teijin Fiber Tepyrus 0.11 dtex (3 μm) as polyethylene terephthalate fiber, Daiwabo PZ0.6 dtex (10 μm) as polypropylene fiber, and Daicel Chemical Industries' tiara (0.2 μm) as aromatic polyimide fiber. .
Further, since the adhesive strength is increased and the tensile strength of the reinforcing material is increased, it is preferable to use non-self-adhesive fibers and heat-adhesive fibers of the same material type.

The inorganic binder contributes to the prevention of shrinkage of the reinforcing material (papermaking) and the improvement of the tensile strength. Synthetic inorganic sols such as silica sol, alumina sol, titania sol (dispersed in water as fine particles, and after drying and solidifying the gel) And hardened), natural mineral powders such as kaolin, clay, sepiolite, attapulgite, bentonite (dispersed in water and solidified upon drying), mineral scales such as mica and smectite, silica Synthetic products with few impurities such as flakes, synthetic flakes such as silica-titania flakes and alumina flakes (dispersed in water and solidified upon drying to form a self-film). Inorganic binders having an average particle size of 0.01 to 2 μm, preferably 0.1 to 1 μm, more preferably 0.2 to 0. 6 μm is used.
Silica flakes are preferred because a high binder effect can be obtained with a small amount of addition, and the yield during wet papermaking is good.
Further, if the blending amount of the inorganic binder is less than 0.1 wt%, the reinforcing material shrinks and the effect of suppressing shrinkage does not appear, and if it exceeds 30 wt%, the clogging effect increases, and the electrolyte solution Since impregnation is inhibited and ion conduction is also inhibited, the blending amount is 0.1 to 30 wt%, preferably 5 to 20 wt%, more preferably 5 to 10 wt%.
This inorganic binder is an essential component for papermaking, but after forming a conductive film, it is advantageous to use a smaller amount in order to increase the porosity.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the inventions described in the examples.

[Example 1]
45 wt% of C glass short fibers (CMLF306 manufactured by Nippon Sheet Glass Co., Ltd.) having an average fiber diameter of 0.6 μm as inorganic fibers, and 10 wt% of silica flakes having an average particle diameter of 0.5 μm (Sun Lovely LFS manufactured by AGC S-Tech Co., Ltd.) as inorganic binders The fine fiber has a fineness of 0.11 dtex (average fiber diameter of 3 μm), a fiber length of 3 mm polyester fiber (Tepyrus Tepyrus) 15 wt%, and the heat-adhesive fiber has a fineness of 1.1 dtex (average fiber diameter of 10 μm) and fiber length. Disperse and mix 5mm core-sheath type PET-PET fiber (Casven, manufactured by Unitika) in water, add an appropriate amount of polymer flocculant, and wet form with a square sheet machine for hand-making. After applying a pressure of 3 MPa with a press machine, it was dried at 110 ° C. and heat-treated at 200 ° C. for 3 minutes to obtain a basis weight of 19.9 g. m ^2, and to obtain a solid electrolyte membrane reinforcing material made of inorganic or organic fiber sheet substrate having a thickness of 0.1 mm.

When the tensile strength, tensile elongation, wet tensile strength, and wet tensile elongation of the obtained solid electrolyte membrane reinforcing material were measured, the tensile strength was 9.2 N / 25 mm width, the tensile elongation was 8.8%, and the wet tensile strength was 6.6 N. / 25 mm width and wet tensile elongation of 10.9% were obtained.
As is clear from the above measurement results, the strength and elongation during dry paper are higher than that of glass paper mainly composed of glass fiber, the strength when wet is sufficiently large, and the electrolyte impregnation workability is excellent.

[Example 2]
50 wt% of C glass short fiber (CMLF306 manufactured by Nippon Sheet Glass Co., Ltd.) having an average fiber diameter of 0.6 μm as inorganic fiber, 20 wt% of C glass short fiber (# 100 manufactured by Jones Manville Co., Ltd.) having an average fiber diameter of 0.3 μm, and inorganic binder Silica flake with an average particle size of 0.5 μm (Sun Lovely LFS manufactured by AGC S-Tech), polyester fiber with a fineness of 0.11 dtex (average fiber diameter of 3 μm) and a fiber length of 3 mm as an ultrafine organic fiber (Tepyrus Tepyrus) Disperse and mix 5 wt% and 10 wt% of core-sheath type PET-PET fiber (Tepyrus Co., Ltd. Tepyrus) with a fineness of 0.5 dtex (average fiber diameter of 7 μm) and a fiber length of 5 mm as a heat-adhesive fiber. After adding an appropriate amount of molecular flocculant, wet papermaking with a square sheet machine for handmaking, and applying a pressure of 2 MPa with a press machine A solid electrolyte membrane reinforcing material comprising a base material of an inorganic / organic fiber sheet having a basis weight of 20.5 g / m ² and a thickness of 0.1 mm is dried at 110 ° C. and heat-treated at 200 ° C. for 3 minutes. Obtained.

When the tensile strength, tensile elongation, wet tensile strength and wet tensile elongation of the obtained solid electrolyte membrane reinforcing material were measured, the tensile strength was 8.1 N / 25 mm width, the tensile elongation was 1.7%, and the wet tensile strength was 5.5 N. / 25 mm width and wet tensile elongation of 5.8% were obtained.
As is clear from the above measurement results, the strength and elongation during dry paper are higher than that of glass paper mainly composed of glass fiber, the strength when wet is sufficiently large, and the electrolyte impregnation workability is excellent.

[Example 3]
30 wt% of C glass short fiber (# 100, manufactured by Jones Manville) having an average fiber diameter of 0.3 μm as an inorganic fiber, and 5 wt% of silica flake (Sun Lovely LFS, manufactured by AGC S-Tech) as an inorganic binder. And a fine fiber of 0.11 dtex (average fiber diameter of 3 μm) as an ultrafine organic fiber, 15 wt% of a polyester fiber (Tepyrus Tepyrus) having a fiber length of 3 mm, and a fineness of 1.1 dtex (average fiber diameter of 7 μm) as a heat-adhesive fiber Disperse and mix 50 wt% of core-sheath type PET-PET fiber (Tepyrus manufactured by Teijin Ltd.) with a length of 5 mm in water, add an appropriate amount of polymer flocculant, and wet paper making with a square sheet machine for hand-making Then, after applying a pressure of 3.5 MPa with a press machine, the film was dried at 110 ° C. and heat-treated at 200 ° C. for 3 minutes to obtain a basis weight of 20.3 g / m ^2. A solid electrolyte membrane reinforcing material made of an inorganic / organic fiber sheet substrate having a thickness of 0.1 mm was obtained.

When the tensile strength, tensile elongation, wet tensile strength, and wet tensile elongation of the obtained solid electrolyte membrane reinforcing material were measured, the tensile strength was 10.1 N / 25 mm width, the tensile elongation was 16.5%, and the wet tensile strength was 7.5 N. / 25 mm width and wet tensile elongation of 18.4% were obtained.
As is clear from the above measurement results, the strength and elongation during dry paper are higher than that of glass paper mainly composed of glass fiber, the strength when wet is sufficiently large, and the electrolyte impregnation workability is excellent.

[Example 4]
69 wt% of C glass short fibers (# 100 manufactured by Jones Manville) having an average fiber diameter of 0.3 μm as inorganic fibers, and 1 wt% of silica flakes having an average particle diameter of 0.1 μm (Sun Lovely LFS manufactured by AGC S-Tech) as inorganic binders. And a fine fiber of 0.11 dtex (average fiber diameter of 3 μm) as an ultrafine organic fiber, 10 wt% of a polyester fiber having a fiber length of 3 mm (Tepyrus Tepyrus), and a thermal adhesive fiber of 0.5 dtex (average fiber diameter of 7 μm) and fiber Disperse and mix 20 wt% of core-sheath type PET-PET fiber (Tepyrus manufactured by Teijin Ltd.) with a length of 5 mm in water, add an appropriate amount of a polymer flocculant, and wet papermaking with a square sheet machine for handmaking Then, after applying a pressure of 2 MPa with a press machine, the film was dried at 110 ° C. and heat-treated at 200 ° C. for 3 minutes to obtain a basis weight of 20.4 g / m ² , a thickness. A solid electrolyte membrane reinforcing material consisting of a 0.1 mm thick inorganic / organic fiber sheet substrate was obtained.

When the tensile strength, tensile elongation, wet tensile strength, and wet tensile elongation of the obtained solid electrolyte membrane reinforcing material were measured, the tensile strength was 6.1 N / 25 mm width, the tensile elongation was 9.1%, and the wet tensile strength was 4.8 N. / 25 mm width and wet tensile elongation of 13.4% were obtained.
As is clear from the above measurement results, the strength and elongation during dry paper are higher than that of glass paper mainly composed of glass fiber, the strength when wet is sufficiently large, and the electrolyte impregnation workability is excellent.

[Example 5]
30 wt% of C glass short fibers (CMLF306 manufactured by Nippon Sheet Glass Co., Ltd.) having an average fiber diameter of 0.6 μm as inorganic fibers, and 1 wt% of silica flakes having an average particle diameter of 0.5 μm (Sun Lovely LFS manufactured by AGC SIT TECH) as inorganic binders, Ultrafine organic fiber with a fineness of 0.11 dtex (average fiber diameter of 3 μm), a polyester fiber with a fiber length of 3 mm (Tepyrus Tepyrus) 10 wt%, and a thermal adhesive fiber with a fineness of 0.5 dtex (average fiber diameter of 7 μm) and a fiber length of 5 mm Core-sheath type PET-PET fiber (Tepyrus Tepyrus Co., Ltd.) 25 wt% is dispersed and mixed in water, and an appropriate amount of a polymer flocculant is added, followed by wet papermaking with a hand-made square sheet machine. After applying a pressure of 1 MPa with a press machine, the film was dried at 110 ° C. and heat-treated at 200 ° C. for 3 minutes to obtain a basis weight of 23.3 g / m ² and a thickness. A solid electrolyte membrane reinforcing material comprising a 0.1 mm inorganic / organic fiber sheet substrate was obtained.

When the tensile strength, tensile elongation, wet tensile strength and wet tensile elongation of the obtained solid electrolyte membrane reinforcing material were measured, the tensile strength was 9.5 N / 25 mm width, the tensile elongation was 1.3%, and the wet tensile strength was 4.8 N. / 25 mm width and wet tensile elongation of 4.6% were obtained.
As is clear from the above measurement results, the strength and elongation during dry paper are higher than that of glass paper mainly composed of glass fiber, the strength when wet is sufficiently large, and the electrolyte impregnation workability is excellent.

[Example 6]
35 wt% of C glass short fibers (# 104 manufactured by Jones Manville) having an average fiber diameter of 0.45 μm as inorganic fibers, and 25 wt% of silica flakes having an average particle diameter of 0.5 μm (Sun Lovely LFS manufactured by AGC S-Tech) as inorganic binders. And a non-self-adhesive fiber having a fineness of 0.6 dtex (average fiber diameter of 10 μm), a fiber length of 5 mm of polypropylene fiber (manufactured by Daiwabo), and a thermal adhesive fiber having a fineness of 1.2 dtex (average fiber diameter of 10 μm), fiber Disperse and mix 30 wt% of core-sheath type PE-PET fiber (Tepyrus manufactured by Teijin Ltd.) with a length of 5 mm in water, add an appropriate amount of polymer flocculant, and wet paper making with a square sheet machine for hand-making and, after applying a pressure of 1MPa at a press machine and dried at 110 ° C., and heated for 3 minutes at 160 ° C., a basis weight of 21.5 g / m To obtain a solid electrolyte membrane reinforcing material made of inorganic or organic fiber sheet substrate having a thickness of 0.1 mm.

When the tensile strength, tensile elongation, wet tensile strength and wet tensile elongation of the obtained solid electrolyte membrane reinforcing material were measured, the tensile strength was 7.3 N / 25 mm width, the tensile elongation was 1.4%, and the wet tensile strength was 4.5 N. / 25 mm width and wet tensile elongation of 2.4% were obtained.
As is clear from the above measurement results, the strength and elongation during dry paper are higher than that of glass paper mainly composed of glass fiber, the strength when wet is sufficiently large, and the electrolyte impregnation workability is excellent.

[Example 7]
50 wt% of C glass short fibers (CMLF 306 manufactured by Nippon Sheet Glass Co., Ltd.) having an average fiber diameter of 0.6 μm as inorganic fibers, and 5 wt% of silica flakes having an average particle diameter of 0.5 μm (Sunlably LFS manufactured by AGC S-Tech Co., Ltd.) as inorganic binders Fine fiber 0.11 dtex (average fiber diameter 3 μm), fiber length 3 mm polyester fiber (Tepyrus Tepyrus) 30 wt%, thermal adhesive fiber fineness 1.1 dtex (average fiber diameter 10 μm), fiber length Disperse and mix 5 wt. Core-sheath type PET-PET fiber (Casven, manufactured by Unitika Co., Ltd.) in water, add a suitable amount of polymer flocculant, and wet form with a square sheet machine for hand-making. Then, after applying a pressure of 3 MPa with a press machine, it was dried at 110 ° C. and heat-treated at 200 ° C. for 3 minutes to obtain a basis weight of 19.9 g / ^2, to obtain a solid electrolyte membrane reinforcing material made of inorganic or organic fiber sheet substrate having a thickness of 0.1 mm.

When the tensile strength, tensile elongation, wet tensile strength, and wet tensile elongation of the obtained solid electrolyte membrane reinforcing material were measured, the tensile strength was 7.2 N / 25 mm width, the tensile elongation was 6.5%, and the wet tensile strength was 5.3 N. / 25 mm width and wet tensile elongation of 3.8% were obtained.
As is clear from the above measurement results, the strength and elongation during dry paper are higher than that of glass paper mainly composed of glass fiber, the strength when wet is sufficiently large, and the electrolyte impregnation workability is excellent.

[Example 8]
30 wt% of C glass short fibers (CMLF306 manufactured by Nippon Sheet Glass Co., Ltd.) having an average fiber diameter of 0.6 μm as inorganic fibers, and 5 wt% of silica flakes having an average particle diameter of 0.5 μm (Sun Lovely LFS manufactured by AGC SIT TECH) as inorganic binders Further, a fine fiber of 0.11 dtex (average fiber diameter of 3 μm) as an ultrafine organic fiber, 55 wt% of a polyester fiber having a fiber length of 3 mm (Tepyrus Tepyrus), a fineness of 1.1 dtex (average fiber diameter of 10 μm) as a heat-adhesive fiber, and a fiber length Disperse and mix 5mm core-sheath type PET-PET fiber (Unitika's Casbane) 10wt% in water, add an appropriate amount of polymer flocculant, and wet paper making with hand-made square sheet machine. Then, after applying a pressure of 3 MPa with a press machine, it was dried at 110 ° C. and heat-treated at 200 ° C. for 3 minutes to obtain a basis weight of 19.9 g / ^2, to obtain a solid electrolyte membrane reinforcing material made of inorganic or organic fiber sheet substrate having a thickness of 0.1 mm.

When the tensile strength, tensile elongation, wet tensile strength and wet tensile elongation of the obtained solid electrolyte membrane reinforcing material were measured, the tensile strength was 6.8 N / 25 mm width, the tensile elongation was 8.2%, and the wet tensile strength was 4.2 N. / 25 mm width and wet tensile elongation of 7.5% were obtained.
As is clear from the above measurement results, the strength and elongation during dry paper are higher than that of glass paper mainly composed of glass fiber, the strength when wet is sufficiently large, and the electrolyte impregnation workability is excellent.

[Example 9]
35 wt% of C glass short fibers (CMLF306 manufactured by Nippon Sheet Glass Co., Ltd.) having an average fiber diameter of 0.6 μm as inorganic fibers, and 5 wt% of silica flakes having an average particle diameter of 0.5 μm (Sun Lovely LFS manufactured by AGC S-Tech Co., Ltd.) as inorganic binders Further, a fine fiber of 0.11 dtex (average fiber diameter of 3 μm) as an ultrafine organic fiber, 20 wt% of a polyester fiber having a fiber length of 3 mm (Tepyrus Tepyrus), a fineness of 1.1 dtex (average fiber diameter of 10 μm) as a thermal adhesive fiber, and a fiber length Disperse and mix 5mm core-sheath type PET-PET fiber (Casven, manufactured by Unitika) in water, add an appropriate amount of polymer flocculant, and wet form with a square sheet machine for hand-making. Then, after applying a pressure of 3 MPa with a press machine, it was dried at 110 ° C. and heat-treated at 200 ° C. for 3 minutes to obtain a basis weight of 19.9 g / ^2, to obtain a solid electrolyte membrane reinforcing material made of inorganic or organic fiber sheet substrate having a thickness of 0.1 mm.

When the tensile strength, tensile elongation, wet tensile strength, and wet tensile elongation of the obtained solid electrolyte membrane reinforcing material were measured, the tensile strength was 8.5 N / 25 mm width, the tensile elongation was 7.9%, and the wet tensile strength was 6.8 N. / 25 mm width and wet tensile elongation of 8.6% were obtained.
As is clear from the above measurement results, the strength and elongation during dry paper are higher than that of glass paper mainly composed of glass fiber, the strength when wet is sufficiently large, and the electrolyte impregnation workability is excellent.

[Comparative Example 1]
Square sheet machine for hand-making by dispersing and mixing 100 wt% of C glass short fibers (CMLF306 manufactured by Nippon Sheet Glass Co., Ltd.) with an average fiber diameter of 0.6 μm as inorganic fibers in water and adding an appropriate amount of polymer flocculant. Wet paper making, applying a pressure of 2 MPa with a press machine, and then drying at 150 ° C. to obtain a base material of an inorganic / organic fiber sheet having a basis weight of 16.2 g / m ² and a thickness of 0.1 mm. It was.

The obtained base material was soft and free of stiffness. Tensile strength, tensile elongation, wet tensile strength, and wet tensile elongation were measured. The tensile strength was 3.6 N / 25 mm width, the tensile elongation was 2.8%, the wet tensile strength was 2.1 N / 25 mm width, and the wet tensile elongation was 2.5. % Results were obtained.
As is apparent from the above measurement results, a base material made only of glass fibers has a low strength during dry paper and is soft and difficult to handle. Further, since the strength when wet is extremely low, it is difficult to handle, and is unsuitable for electrolyte impregnation.

[Comparative Example 2]
55 wt% of C glass short fiber (CMLF306 manufactured by Nippon Sheet Glass Co., Ltd.) with an average fiber diameter of 0.6 μm as an inorganic fiber, polyester fiber with a fineness of 0.11 dtex (average fiber diameter of 3 μm), and a fiber length of 3 mm (manufactured by Teijin Ltd.) Tepyrus) 15 wt%, and heat-adhesive fiber with a fineness of 1.1 dtex (average fiber diameter 10 μm), a core-sheath type PET-PET fiber (Casvene manufactured by Unitika Ltd.) 30 wt% with a fiber length of 5 mm is dispersed and mixed in water. Further, an appropriate amount of a polymer flocculant is added, wet papermaking is performed with a square sheet machine for handmaking, a pressure of 6 MPa is applied with a press machine, and then dried at 110 ° C. and then at 200 ° C. for 3 minutes. Heat treatment was performed to obtain an inorganic / organic fiber sheet substrate having a basis weight of 14.6 g / m ² and a thickness of 0.1 mm.

The obtained base material was shrunk when dried, wavy, soft and free of stiffness. The tensile strength, tensile elongation, wet tensile strength, and wet tensile elongation were measured. The tensile strength was 3.9 N / 25 mm width, the tensile elongation was 18.7%, the wet tensile strength was 3.1 N / 25 mm width, and the wet tensile elongation was 16.8. % Results were obtained.
As is clear from the above measurement results, the substrate made of glass fiber and organic fiber has high strength and elongation when dry paper is soft, difficult to handle, low strength when wet, and unsuitable for electrolyte impregnation processing It was to become.

[Comparative Example 3]
70 wt% of C glass short fibers (CMLF306 manufactured by Nippon Sheet Glass Co., Ltd.) having an average fiber diameter of 0.6 μm as inorganic fibers, and 30 wt% of silica flakes having an average particle diameter of 0.5 μm (Sun Lovely LFS manufactured by AGC S-Tech Co., Ltd.) as inorganic binders Is dispersed and mixed in water, an appropriate amount of a polymer flocculant is added, wet papermaking is performed with a square sheet machine for handmaking, a pressure of 2 MPa is applied with a press machine, and then dried at 150 ° C. Thus, a base material of an inorganic / organic fiber sheet having a basis weight of 22.4 g / m ² and a thickness of 0.1 mm was obtained.

The obtained base material was in a state of being hard but flexible enough to be bent. Tensile strength, tensile elongation, wet tensile strength, wet tensile elongation were measured. Tensile strength 6.2 N / 25 mm width, tensile elongation 0.6%, wet tensile strength 2.1 N / 25 mm width, wet tensile elongation 0.5 % Results were obtained.
As is apparent from the above measurement results, the substrate made of glass fiber and inorganic binder has high strength when dry paper is low, but low elongation, low strength when wet, low elongation, and is not suitable for electrolyte impregnation processing. It was.

[Comparative Example 4]
77 wt% of C glass short fibers (CMLF306 manufactured by Nippon Sheet Glass Co., Ltd.) having an average fiber diameter of 0.6 μm as inorganic fibers, and 10 wt% of silica flakes having an average particle diameter of 0.5 μm (Sun Lovely LFS manufactured by AGC S-Tech Co., Ltd.) as inorganic binders Further, a fineness of 0.11 dtex (average fiber diameter of 3 μm) as an ultrafine organic fiber, 5 wt% of a polyester fiber having a fiber length of 3 mm (Tepyrus Tepyrus), a fineness of 1.1 dtex (average fiber diameter of 10 μm) as a thermal adhesive fiber, and a fiber length Disperse and mix 5 wt. Core-sheath type PET-PET fiber (Casven, manufactured by Unitika Co., Ltd.) in water, add a suitable amount of polymer flocculant, and wet form with a square sheet machine for hand-making. after applying a pressure of 3MPa at a press, and dried at 110 ° C., and heated for 3 minutes at 200 ° C., a basis weight of 19.9 g / m To obtain a solid electrolyte membrane reinforcing material made of inorganic or organic fiber sheet substrate having a thickness of 0.1 mm.

The obtained base material was soft and free of stiffness. The tensile strength, tensile elongation, wet tensile strength, and wet tensile elongation were measured. The tensile strength was 3.8 N / 25 mm width, the tensile elongation was 3.6%, the wet tensile strength was 2.4 N / 25 mm width, and the wet tensile elongation was 2.8. % Results were obtained.
As is apparent from the above measurement results, a base material made only of glass fibers has a low strength during dry paper and is soft and difficult to handle. Further, since the strength when wet is extremely low, it is difficult to handle, and is unsuitable for electrolyte impregnation.

[Comparative Example 5]
27 wt% of C glass short fibers (CMLF306 manufactured by Nippon Sheet Glass Co., Ltd.) having an average fiber diameter of 0.6 μm as inorganic fibers, and 5 wt% of silica flakes having an average particle diameter of 0.5 μm (Sun Lovely LFS manufactured by AGC S-Tech Co., Ltd.) as inorganic binders Further, a fineness of 0.11 dtex (average fiber diameter of 3 μm) as an ultrafine organic fiber, 5 wt% of a polyester fiber having a fiber length of 3 mm (Tepyrus Tepyrus), a fineness of 1.1 dtex (average fiber diameter of 10 μm) as a thermal adhesive fiber, and a fiber length Disperse and mix 5mm core-sheath type PET-PET fiber (Casven, manufactured by Unitika Co., Ltd.) in water, add an appropriate amount of polymer flocculant, and wet form with a square sheet machine for hand-making. after applying a pressure of 3MPa at a press, and dried at 110 ° C., and heated for 3 minutes at 200 ° C., a basis weight of 19.9 g / m To obtain a solid electrolyte membrane reinforcing material made of inorganic or organic fiber sheet substrate having a thickness of 0.1 mm.

  I tried to measure the tensile strength, tensile elongation, wet tensile strength, and wet tensile elongation of the obtained solid electrolyte membrane reinforcement, but the substrate contracted during the heat treatment from drying and wrinkles were generated. I could not.

[Comparative Example 6]
25 wt% of C glass short fibers (CMLF306 manufactured by Nippon Sheet Glass Co., Ltd.) having an average fiber diameter of 0.6 μm as inorganic fibers, and 5 wt% of silica flakes having an average particle diameter of 0.5 μm (Sun Lovely LFS manufactured by AGC S-Tech Co., Ltd.) as inorganic binders The fine fiber has a fineness of 0.11 dtex (average fiber diameter of 3 μm), a fiber length of 3 mm polyester fiber (Tepyrus Tepyrus) 65 wt%, and the thermal adhesive fiber has a fineness of 1.1 dtex (average fiber diameter of 10 μm) and fiber length. Disperse and mix 5 wt% of 5mm% core-sheath type PET-PET fiber (Cassben manufactured by Unitika Co.) in water, add an appropriate amount of polymer flocculant, and wet paper-making with a square sheet machine for hand-making. after applying a pressure of 3MPa at a press, and dried at 110 ° C., and heated for 3 minutes at 200 ° C., a basis weight of 19.9 g / m To obtain a solid electrolyte membrane reinforcing material made of inorganic or organic fiber sheet substrate having a thickness of 0.1 mm.

  I tried to measure the tensile strength, tensile elongation, wet tensile strength, and wet tensile elongation of the obtained solid electrolyte membrane reinforcing material. I could not.

[Comparative Example 7]
25 wt% of C glass short fibers (CMLF306 manufactured by Nippon Sheet Glass Co., Ltd.) having an average fiber diameter of 0.6 μm as inorganic fibers, and 5 wt% of silica flakes having an average particle diameter of 0.5 μm (Sun Lovely LFS manufactured by AGC S-Tech Co., Ltd.) as inorganic binders The fine fiber has a fineness of 0.11 dtex (average fiber diameter of 3 μm), a fiber length of 3 mm polyester fiber (Tepyrus Tepyrus) 15 wt%, and the heat-adhesive fiber has a fineness of 1.1 dtex (average fiber diameter of 10 μm) and fiber length. Disperse and mix 5% core-sheath type PET-PET fiber (Cassben manufactured by Unitika Co., Ltd.) in water, add an appropriate amount of a polymer flocculant, and wet form with a square sheet machine for hand-making. Then, after applying a pressure of 3 MPa with a press machine, it was dried at 110 ° C. and heat-treated at 200 ° C. for 3 minutes to obtain a basis weight of 19.9 g / ^2, to obtain a solid electrolyte membrane reinforcing material made of inorganic or organic fiber sheet substrate having a thickness of 0.1 mm.

  I tried to measure the tensile strength, tensile elongation, wet tensile strength, and wet tensile elongation of the obtained solid electrolyte membrane reinforcement, but the substrate contracted during the heat treatment from drying and wrinkles were generated. I could not.

[Comparative Example 8]
60 wt% of C glass short fibers (CMLF306 manufactured by Nippon Sheet Glass Co., Ltd.) having an average fiber diameter of 0.6 μm as inorganic fibers, and 10 wt% of silica flakes (Sun Lovely LFS manufactured by AGC S-Tech Co., Ltd.) having an average particle diameter of 0.5 μm as inorganic binders In addition, 30 wt% of core-sheath type PET-PET fiber (Cassven manufactured by Unitika) having a fineness of 1.1 dtex (average fiber diameter of 10 μm) and a fiber length of 5 mm is dispersed and mixed in water as a heat-adhesive fiber, and a polymer flocculant Is added in an appropriate amount, wet-made with a square sheet machine for hand-making, and after applying a pressure of 3 MPa with a press machine, dried at 110 ° C., and heat-treated at 200 ° C. for 3 minutes, A solid electrolyte membrane reinforcing material comprising an inorganic / organic fiber sheet substrate having a basis weight of 19.9 g / m ² and a thickness of 0.1 mm was obtained.

The obtained base material was soft and free of stiffness. Tensile strength, tensile elongation, wet tensile strength and wet tensile elongation were measured. The tensile strength was 3.7 N / 25 mm width, the tensile elongation was 15.1%, the wet tensile strength was 2.9 N / 25 mm width, and the wet tensile elongation was 13.7. % Results were obtained.
As is apparent from the above measurement results, a base material made only of glass fibers has a low strength during dry paper and is soft and difficult to handle. Furthermore, since the strength when wet is extremely low, it is difficult to handle and unsuitable for electrolyte impregnation.

[Comparative Example 9]
25 wt% of C glass short fibers (CMLF306 manufactured by Nippon Sheet Glass Co., Ltd.) having an average fiber diameter of 0.6 μm as inorganic fibers, and 5 wt% of silica flakes having an average particle diameter of 0.5 μm (Sun Lovely LFS manufactured by AGC S-Tech Co., Ltd.) as inorganic binders Further, a fine fiber of 0.11 dtex (average fiber diameter of 3 μm) as an ultrafine organic fiber, 40 wt% of a polyester fiber having a fiber length of 3 mm (Tepyrus Tepyrus), a fineness of 1.1 dtex (average fiber diameter of 10 μm) as a thermal adhesive fiber, and a fiber length Disperse and mix 5mm core-sheath type PET-PET fiber (Casven, manufactured by Unitika) in water, add an appropriate amount of polymer flocculant, and wet form with a square sheet machine for hand-making. Then, after applying a pressure of 3 MPa with a press machine, it was dried at 110 ° C. and heat-treated at 200 ° C. for 3 minutes to obtain a basis weight of 19.9 g / ^2, to obtain a solid electrolyte membrane reinforcing material made of inorganic or organic fiber sheet substrate having a thickness of 0.1 mm.

  I tried to measure the tensile strength, tensile elongation, wet tensile strength, and wet tensile elongation of the obtained solid electrolyte membrane reinforcing material. I could not.

The tensile strength, tensile elongation, wet tensile strength, and wet tensile elongation were measured as follows. The measuring method of tensile strength and tensile elongation is JIS P8113 “Paper and paperboard—Testing method of tensile properties—Part 2: Constant speed stretching method”, and the measuring method of wet tensile strength and wet tensile elongation is JIS P8135 “Paper. And paperboard-wet tensile strength test method ".
Tensile strength: Tensile strength at room temperature was measured with a constant velocity tensile tester. The sample dimensions were 25 mm width × 100 mm length, and the measurement conditions were a tensile speed of 10 mm / min and a distance between chucks of 50 mm.
Tensile elongation: When measuring the tensile strength at room temperature with a constant-speed tensile tester, the distance at the time of fracture is measured. The value obtained by subtracting the distance between the chucks from the distance at the time of breaking was divided by the distance between the chucks and multiplied by 100 to obtain the tensile elongation.
Wet tensile strength: measured at room temperature in the same way as tensile strength. However, the measurement sample was soaked in water for 30 seconds, wetted, placed on a Kim towel, which is a commercially available wiper (wiping paper), and then drained.
Wet tensile elongation: Similarly to tensile elongation, when measuring the wet tensile strength, the distance at break is measured. The value obtained by subtracting the distance between the chucks from the distance at the time of breaking was divided by the distance between the chucks and multiplied by 100 to obtain the wet tensile elongation.

Table 1 summarizes the formulations and evaluations of Example 1-9 and Comparative Example 1-9.

About the intensity | strength and elongation amount shown in the said Table 1, if it is more than the following values, there will be no malfunction in the handling at the time of manufacture and processing. If the tensile strength is 6N (per 25 mm width) or more, it has sufficient strength for handling. If the tensile elongation is 1% or more, the paper will be stretched a little at the time of handling, so there is no sudden paper break. If the wet tensile strength is 4N (per 25 mm width) or more, the wet tensile strength is sufficient to handle even in a wet state. If the wet tensile elongation is 2% or more, the paper is stretched when handled in a wet state, so that there is no sudden paper break.
For this reason, Example 1-9 satisfied all the evaluation items of tensile strength, tensile elongation, and wet tensile elongation, and was found to be superior to Comparative Example 1-9.

  The solid electrolyte membrane reinforcing material of the present invention has high strength and elongation at the time of dry paper, sufficiently high strength when wet, and excellent in electrolyte impregnation workability. The solid polymer fuel cell (PEFC) It is useful as a reinforcing material for solid electrolyte membranes.

Claims (6)

  A solid electrolyte membrane reinforcing material comprising glass fiber, organic fiber, and inorganic binder, wherein the organic fiber is composed of non-self-adhesive organic fiber and heat-adhesive organic fiber, and the glass fiber is 30-70 wt%, the organic A solid electrolyte membrane reinforcing material comprising 15 to 65 wt% of fibers and 0.1 to 30 wt% of the inorganic binder, and 10 to 50 wt% of the thermoadhesive organic fibers in the total composition.   35 to 60 wt% of the glass fiber, 20 to 60 wt% of the organic fiber, 5 to 20 wt% of the inorganic binder, and 15 to 45 wt% of the thermoadhesive organic fiber in the whole composition. 2. The solid electrolyte membrane reinforcing material according to claim 1, wherein   40-50 wt% of the glass fiber, 30-55 wt% of the organic fiber, 5-10 wt% of the inorganic binder, and 20-40 wt% of the thermoadhesive organic fiber in the entire composition. The solid electrolyte membrane reinforcing material according to claim 2.   The solid electrolyte membrane reinforcing material according to any one of claims 1 to 3, wherein the blending amount of the heat-adhesive organic fiber is made larger than the blending amount of the non-self-adhesive organic fiber.   The average fiber diameter of the glass fiber is 0.1 to 5 μm, the average fiber diameter of the non-self-adhesive organic fiber is 1 to 20 μm, and the average fiber diameter of the thermoadhesive organic fiber is 1 to 20 μm. The solid electrolyte membrane reinforcing material according to any one of claims 1 to 4, wherein the reinforcing material is a solid electrolyte membrane reinforcing material.   The solid electrolyte membrane reinforcing material according to any one of claims 1 to 5, wherein the inorganic binder has an average particle size of 0.01 to 2 µm.