TWI287316B - Polymer composite and die pressing method thereof - Google Patents

Abstract

Polymer composites and the die pressing method thereof are disclosed. Said polymer composites mainly mix the vinylester resin with good corrosion resistance and high strength and the graphitic powder and use the high speed stirring and kneading process to make them a homogeneous mixture. Then, the die pressing process is used to mold press the homogeneous mixture into a predetermined shape for bipolar plates used in fuel cells. In additional, during the fabrication, every needed type of additive must be added to promote the fabrication speed and the fabrication efficiency. The polymer composites obtained from the process have characteristics of conductivity, corrosion resistance, air tightness, light and thin, high mechanical strength and low surface roughness, and can be directly die pressed the design of channel and every type of hole site for the bipolar plates used for fuel cells.

Description

1287316 玖、發明說明： 【發明所屬之技術領域】 本發明係關於一種應用於燃料電池雙極板之高分子 複合材料及其壓模成型方法暨所使用之模具。 【先前技術】 習知質子交換膜燃料電池（PEMFC)又稱高分子薄膜燃 料電池，係由包含質子交換膜、觸媒層、擴散層之薄膜電 極組（membrane electrode assembly，MEA)夾於兩塊雙 極板（bipolar plate ’或稱流場板）、集電板（currentBACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer composite material for a fuel cell bipolar plate, a compression molding method thereof, and a mold used therefor. [Prior Art] A known proton exchange membrane fuel cell (PEMFC), also known as a polymer thin film fuel cell, is sandwiched between two membrane electrode assemblies (MEA) including a proton exchange membrane, a catalyst layer, and a diffusion layer. Bipolar plate (or flow field plate), collector plate (current

collector)與端板（end plate)間所組成，由前述薄膜 電極組分隔之兩邊分屬陽極（氫氣或重組氣體）與陰極（氧 氣或空氣）’陽極為氧化反應，陰極為還原反應。當陽極The collector is composed of an end plate, and the anodes (hydrogen or reformed gas) and the cathode (oxygen or air) anodes separated by the thin film electrode group are oxidized, and the cathode is a reduction reaction. When the anode

端之氫氣接觸到與質子交換膜相鄰之觸媒（一般為白金或 白金合金）時，氫氣分子會解離成為氫離子及電子，其中 電子會經由銜接陽極與陰極之電橋，經與電橋串接之負 載，自陽極游往陰極，而氫離子則直接自陽極^越質子交 換膜到達陰極。前述質子交換膜為含濕性之薄膜，且= 容許氫離子伴隨水分子穿越而其他氣體分子均办 之特性，於陰極端在觸媒的作用了，經由電 ; 與氧結合成氧離子，並隨即與穿越質子交換膜之 名么 ^形成水分子，此即為通稱之電化學氧化與還^反應^ 應用前述電化學反應過程使得質子交軸 (PEMFC)發電系統具有效率高、無污染、反應快了 '冗敍/ 串聯提高電橋電壓或增加電極反應面積提高電、☆旦： 優點，特別是燃料電池在源源不斷的氫氣及^ 用空氣)的供給下，它可以源源不斷的電力產“ ^載 5 1287316 丨點下’質子交換膜燃料電池⑽F。 可以疋小孓糸、、先電力的來源，也可以設計成 分散式電力及可移動電力。 入i冤厫 燃料電池組之主體外觀所見即為雙極板，其佔有整體 體積與重量之大部分，因此雙極板材料研究開發乃是^ 電池發展的重要指標。進—步而言，雙極板在電池組中扮 演之主，為：分配反應氣體至反應區域；分隔兩侧之 氫氣與氧氣荨反應氣體；電能與熱能之傳導；固定夾持薄 膜電極組、；並且，由於雙極板所處環境接觸燃料電池反應 區域，所以雙極板必須具備耐化學腐蝕性與耐熱性質；此 外，如前述雙極板佔有電池組之大部體積與重量，因此提 高其體積使用率與降低材料密度也是亟待研發的議題。整 體而言，對雙極板性質的基本需求為導電性、氣密性、耐 化學腐蝕性、耐熱性、輕量化與薄件化、高機械強度與低 表面粗糙度，在特殊需求時，亦必須具有良好之加工性 質。雙極板除了符合上述之規格需求，更重要的必須降低 其成本’包含材料成本與製程成本，而且必須有量產化之 技術’具有價格合理且性質良好之雙極板元件，方能使燃 料電池具有市場推廣價值。 使用的雙極板材料有高緻密碳板、複合碳板與金 屬板等等’而在高分子電解質膜或質子交換膜燃料電池 (PEMFC)使用之雙極板材料多為高緻密石墨材料。雙極板 ^其材料成本昂貴外，其流場溝槽之機械加工費用亦是昂 貴的支出。 一因此，為降低雙極板之成本，利用習知之複合材料技 術，配合燃料電池之使用特性，更改複合材料的配方與調 配方式，配合壓模或射出成型技術，將實現適用於燃料電 1287316 池的雙極板；而且以習知之複合材料技術而言，材料多可 使用已大量生產之化學品，原料成本便宜。再者，高緻密 碳板多製作成平板狀，必須經由機械加工才可使用，高分 子複&材料可直接成型設計的流道與孔位，便降低大^的 加工成本。此外，咼緻密碳板為多孔性材質，必須經由後 處理以填基孔洞，後處理之成本與量產化不易皆是其重大 =點，反之，利用複合材料技術製成之材料本身氣^性比 石反板良好，更毋須填塞孔洞。整體而言，以高分子複合碳 板配合量產製程將是實現雙極板商品化的最佳途徑。 但在習知之複合材料技術中，製成之材料多為低導電 性。由於燃料電池本身為發電元件，雙極板之電阻值將成 為影響電池性能的關鍵因素，所以首先必須有不同於以往 配方與調配方式，例如必須加入高比例的石墨粉，以增加 導電度；且因為配方的改變，所以配方可能必須添加夕 額外的添加劑來改善材料性質；此外，在配合製程 化的技術上，也必須在配方與成型模具上做適當 以增加製程之速度與良率。 。登’ 中華民國專利第399,348公告案，揭露一種製 電池雙極板之方法，該方法係將導電材料、樹脂與:、枓 加以混合，並在250°C至500°C之溫度範圍與約5〇〇 7劑 4000psi壓力範圍内，成型雙極板。在前述方法中^ 包含熱塑型樹脂、熱固型樹脂，導電材料可為 树月曰 黑、碳纖維等等。 ”、、墨粉、碳 美國第6, 436, 315號專利案，揭露一種燃料曹> 材料雙極板，其係以改良之射出成型技術， 射出樹脂與石When the hydrogen at the end contacts the catalyst (usually platinum or platinum alloy) adjacent to the proton exchange membrane, the hydrogen molecules will dissociate into hydrogen ions and electrons, and the electrons will pass through the bridge connecting the anode and the cathode, and the bridge. The tandem load travels from the anode to the cathode, while the hydrogen ions pass directly from the anode to the proton exchange membrane to the cathode. The proton exchange membrane is a moisture-containing membrane, and = allows hydrogen ions to pass through with water molecules and other gas molecules do the same, and acts on the catalyst at the cathode end, through electricity; combines with oxygen to form oxygen ions, and Immediately with the name of the proton exchange membrane, water molecules are formed, which is known as electrochemical oxidation and reaction. The use of the aforementioned electrochemical reaction process makes the proton transfer axis (PEMFC) power generation system highly efficient, pollution-free, and reactive. Faster 'redundant / series to increase the bridge voltage or increase the electrode reaction area to improve electricity, ☆ dan: advantages, especially the fuel cell in the continuous supply of hydrogen and ^ air, it can provide a steady stream of electricity" ^ Loaded 5 1287316 ' ' 'proton exchange membrane fuel cell (10) F. It can be used as a source of electric power, and can be designed as decentralized power and mobile power. See the appearance of the main body of the fuel cell stack. It is a bipolar plate, which occupies most of the overall volume and weight. Therefore, research and development of bipolar plate materials is an important indicator for the development of batteries. The main player in the battery pack is: distributing the reaction gas to the reaction zone; separating the hydrogen and oxygen helium reaction gases on both sides; conducting the conduction of electrical energy and heat; fixing the sandwiched electrode group; and, because the bipolar plate is located The environment is in contact with the reaction area of the fuel cell, so the bipolar plate must have chemical resistance and heat resistance; in addition, as the aforementioned bipolar plate occupies most of the volume and weight of the battery, it is also urgent to increase the volume utilization rate and reduce the material density. The topic of research and development. On the whole, the basic requirements for the properties of bipolar plates are conductivity, air tightness, chemical resistance, heat resistance, light weight and thinness, high mechanical strength and low surface roughness. When it is demanded, it must also have good processing properties. In addition to meeting the above specifications, bipolar plates must reduce their cost, including material cost and process cost, and must have mass production technology, which is reasonably priced and nature. Good bipolar plate components can make fuel cells have market value. The bipolar plate materials used are highly dense. Plates, composite carbon plates and metal plates, etc., and the bipolar plate materials used in polymer electrolyte membranes or proton exchange membrane fuel cells (PEMFC) are mostly high-density graphite materials. Bipolar plates are expensive in materials, The machining cost of the flow field trench is also an expensive expense. Therefore, in order to reduce the cost of the bipolar plate, the composite material technology is used, and the characteristics of the fuel cell are used to change the formulation and formulation of the composite material. Mold or injection molding technology will realize the bipolar plate suitable for the fuel electric 1287316 pool; and in the conventional composite technology, the material can use the chemicals which have been mass-produced, and the raw material cost is cheap. Moreover, the high-density carbon The plate is made into a flat plate and must be machined before it can be used. The polymer composite & material can directly form the flow path and the hole position of the design, thereby reducing the processing cost of the large ^. In addition, the compact carbon plate is made of porous material, and it must be post-treated to fill the pores. The cost and mass production of the post-treatment are not significant. On the contrary, the material made by the composite technology itself is gas-like. It is better than the stone counterplate, and it is not necessary to fill the hole. Overall, the use of polymer composite carbon sheets in conjunction with mass production processes will be the best way to commercialize bipolar plates. However, in the conventional composite technology, the materials produced are mostly low in electrical conductivity. Since the fuel cell itself is a power generating component, the resistance value of the bipolar plate will become a key factor affecting the performance of the battery. Therefore, it must first be different from the conventional formulation and blending method, for example, a high proportion of graphite powder must be added to increase the conductivity; Because of the change in formulation, the formulation may have to add additional additives to improve the material properties; in addition, in conjunction with the process technology, it is also necessary to make appropriate adjustments on the formulation and molding die to increase the speed and yield of the process. . [Announcement of the Republic of China Patent No. 399,348, which discloses a method of making a battery bipolar plate by mixing a conductive material, a resin, and a crucible, and at a temperature ranging from 250 ° C to 500 ° C with about 5双7 agent 4000 psi pressure range, forming bipolar plates. In the foregoing method, a thermoplastic resin or a thermosetting resin is contained, and the conductive material may be sapphire black, carbon fiber or the like. ",, toner, carbon, US Patent No. 6, 436, 315, discloses a fuel Cao> material bipolar plate which is modified by injection molding technology to inject resin and stone.

鑠炻；1m6丄山二、加u八-.' 〉也複合 墨粉末混合物成型為雙極板，並對於各式添加劑 與定義。 分類 7 1287316 美國第6, 248, 467號專利案，揭露一種燃料電池複合 材料雙極板’其係利用乙烯基醋樹脂（vinyles^ei： resin) 與石墨粉末進行混合，其中石墨粉粒徑主要在80網目至 325網目可獲得較佳的性質。 然而，習知雙極板技術，多為揭露配方與成型方式與 操作條件，並未能符合燃料電池之需求，尤其在配方之導 電性質、表面粗链度性質、氣密性質上多所缺乏；而且， 對於直接成型流道與孔洞的探討較少；另外，除了應在配 方上改善雙極板性質與製程設備外，配合燃料電池設計改 善成型拉具’更是必須全盤考量的 關鍵因素。 【發明内容】 本發明之目的在提供一種複合材料，具備導電性、耐 眭、氣密性、輕薄化、高機械強度與低表面粗糙度之 特點。 達到上述目的之複合材料包含：6〇〜8〇重量％之石墨粉 ’ U〜30重量％之乙烯基酯樹脂；及其他添加劑。 車交佳者，前述石墨粉末係為7〇〜80重量0/〇。 $佳者，前述添加劑係包含溶劑、低收縮劑、脫模劑、 目田基起始劑或流變調節劑。 旦，佳者，前述溶劑係為苯乙烯單體，其含量為3〜6重 里％ 〇 入旦^乜者，鈿述低收縮劑係為聚苯乙烯型低收縮劑，其 S里為1. 5〜3重量％ 0 k佳者，脫模劑係為硬脂酸鋅，其含 ，者，前述自由基起始劑係為過1為苯2甲=三丁 0曰’其含量為卜3phr。 1287316 較佳者，前述流變調節劑係為氧化鎂，其含量為 1〜3phr 〇 較佳者，前述電池係為燃料電池。 較佳者，前述複合材料係為燃料電池雙極板。 本發明之另一目的在提供一種直接壓模成型前述複 合材料之方法。 達到上述目的之壓模成型方法，包含下列步驟： (a) 將乙烯基酯樹脂與適當之添加劑混合形成混合溶 液； (b) 將前述步驟（a)之混合溶液置於攪拌器攪拌； (c) 將石墨粉與前述步驟（b)攪拌後之混合溶液倒入 模造混合物捏合機中攪拌捏合； (d) 將步驟（c)攪拌捏合後之模造混合物取出並密封 於室溫下增黏； (e) 將步驟（d)增黏後之模造混合物置入熱壓模具中 壓模成型；及 (f) 將模具脫模並將脫模後之成品烘乾使其硬化。 較佳者，前述步驟（a)之乙烯基酯樹脂之含量為15〜30 重量％。 較佳者，前述步驟（a)之添加劑包含溶劑、低收縮劑、 脫模劑、自由基起始劑或流變調節劑。 較佳者，前述步驟（b)之攪拌時間為20〜30分鐘。 較佳者，前述步驟（c)之石墨粉末之含量為60〜80重量 % 〇 較佳者，前述步驟（c)之攪拌捏合時間為30〜40分鐘。 較佳者，前述步驟（d)之增黏時間為48小時。 較佳者，前述步驟（e)之前增加一熱壓模具加熱步 1287316 驟其係將熱壓模具先加熱至140〜160¾。 计垃Ϊ佳者’前述步驟⑷之壓模壓力為謂〜驗g/cm2, 並持績加壓5〜1()分鐘。 較佳者’前述步驟（〇之烘乾程序係於i4〇〜i6〇t>c下持 頌小時。 較佳者，前述電池係為燃料電池。 車乂仏者，前述燃料電池雙極板係由前述所述方法所製 較佳者，前述模據係用於燃料電池雙極板壓模成型， 厂，具包含有複數凹槽，該凹槽之内圓角半徑為〇.3至 10111 ’外圓角半徑為〇· 1至0· 3mm，前述模具之拔模角在 5至15度間。 冷、佳者，前述燃料電池雙極板包含有複數流道，前述 木度在〇. 6至L2mm之間，流度寬度在0.8至1.5mm 之間’而流道與流道間距亦在〇· 8至丨· 5mm之間。 =、本發明之前述目的或特徵，將依據後附圖式加以詳細 說明’惟需明瞭的是，後附圖式及所舉之例，祇是做為說 明而非在限制或縮限本發明。 【實施方式】 本發明之複合材料，包含：6〇〜80重量％之石墨粉末、 15〜30重量％之乙烯基酯樹脂及其他添加劑，其中前述添加 月丨J係包含，但不限於溶劑、脫模劑（m〇ld reiease agent)、 流變調節劑（rheological modifier)、自由基起始劑 (initiator)或低收縮劑（i〇w profile agent)等。 前述添加劑以功用可分類為：溶劑、脫模劑（m〇ld release agent)、流變調節劑（rheological modifier)、 自由基起始劑（initiator)、低收縮劑（low profile 1287316 =t)等，添加劑之種類在習知技術已多有介紹 =擇與用量必須在實驗的基準上才可獲得，本發明^ 池使用之配方選擇與用量，並- 本發明使用之>谷劑係為3〜6重量％之苯乙烯單體 係為i.5~3重量％之聚笨乙烯型低收縮劑；自由其 2 =為卜3*之過氧笨甲酸一三丁醋；流 ； 為卜3phr之氧化鎂；脫模劑係為2〜6phr之硬脂酸鋅。，' 兄為了提高製程速度與良率’本發明賴模劑特別 如前述合適的選擇與用量，並配合後述模具之設計，以 到量產之目標。 、本發明之複合材料壓膜成型方法，如第一圖所示，該 方法10包含下列步驟：（約將乙烯基酯樹脂與適當之添加 劑混合形成混合溶液；（b)將前述步驟&)之混合溶液置於 攪拌裔攪拌；（c)將石墨粉末與前述步驟（b)攪拌後之混合 溶液倒入模造混合物捏合機中攪拌捏合；（d)將步驟（〇攪 拌捏合後之模造混合物取出並密封於室溫下增黏；（e)將步 驟（d)增黏後之模造混合物置入熱壓模具中壓模成型；及 將模具脫模並將脫模後之成品烘乾使其硬化。其中添加劑 以功用可分類為：溶劑、脫模劑、流變調節劑、自由基起 . 始劑、低收縮劑等。前述方法中添加之添加劑可依實際需_ 求做選擇並調整適當之含量，並不特別受限制。 本發明提出之用於電池雙極板之高分子複合材料配 方及其壓模成型方法耩由下述實施例詳細說明如下，唯所 述之所有的較佳實施例只做為說明，並非用以限定本發 明。 11 1287316 本實施例為乙烯基酯樹脂與石墨粉末捏合，形成之均 勻模造混合物（BMC，bulk molding compound)，其中石墨 粉末含量約在70至80重量％。而添加劑的部分，溶劑使 用苯乙烯單體，脫模劑使用硬脂酸鋅，流變調節劑使用氧 化鎂，自由基起始劑為過氧苯曱酸-三丁酯（TBPB)、低 收縮劑使用聚苯乙烯型低收縮劑，選用之原則除了適合複 合雙極板之性質外，合理價格亦是考量因素。有關實施例 一各種材料之比例如表一所示。铄炻; 1m6 丄山二, plus u 八-.' 〉 also composite ink powder mixture is formed into a bipolar plate, and for various additives and definitions. U.S. Patent No. 6, 12, 873, pp. 6, 248, 467, which discloses a fuel cell composite bipolar plate which is mixed with graphite powder using vinyl vinegar resin (vinyles^ei: resin), wherein the graphite powder particle size is mainly Preferred properties are obtained at 80 mesh to 325 mesh. However, the conventional bipolar plate technology mostly exposes the formulation and molding methods and operating conditions, and fails to meet the requirements of the fuel cell, especially in the conductive properties of the formulation, the surface thick chain property, and the gas tightness; Moreover, there is less discussion about direct molding flow channels and holes; in addition, in addition to improving the bipolar plate properties and process equipment in the formulation, the improvement of the forming device with the fuel cell design is a key factor that must be considered in its entirety. SUMMARY OF THE INVENTION An object of the present invention is to provide a composite material which is characterized by electrical conductivity, resistance to enthalpy, airtightness, lightness and thinness, high mechanical strength and low surface roughness. The composite material for achieving the above object comprises: 6 〇 to 8 〇% by weight of graphite powder ‘ U 〜 30% by weight of a vinyl ester resin; and other additives. In the case of a good car, the graphite powder is 7 〇 80 80 80 。. Preferably, the aforementioned additives comprise a solvent, a low shrinkage agent, a release agent, a field-based starter or a rheology modifier. In the best case, the solvent is a styrene monomer, and the content thereof is 3 to 6% by weight. The low shrinkage agent is a polystyrene type low shrinkage agent, and the S is 1. 5~3wt% 0k, the release agent is zinc stearate, and the above-mentioned free radical initiator is more than 1 is benzene 2 = tributyl 0 曰 'content is 3 phr . Preferably, the rheology modifier is magnesium oxide in an amount of from 1 to 3 phr. Preferably, the battery is a fuel cell. Preferably, the composite material is a fuel cell bipolar plate. Another object of the present invention is to provide a method of directly compression molding the aforementioned composite material. A compression molding method for achieving the above object, comprising the steps of: (a) mixing a vinyl ester resin with a suitable additive to form a mixed solution; (b) placing the mixed solution of the aforementioned step (a) in a stirrer; The graphite powder and the mixed solution of the foregoing step (b) are poured into a molding mixture kneader and kneaded; (d) the mold mixture after the step (c) is stirred and kneaded, and sealed and viscous at room temperature; e) molding the molded mixture obtained by the step (d) into a hot press mold; and (f) demolding the mold and drying the demolded product to harden it. Preferably, the content of the vinyl ester resin in the above step (a) is 15 to 30% by weight. Preferably, the additive of the aforementioned step (a) comprises a solvent, a low shrinkage agent, a release agent, a radical initiator or a rheology modifier. Preferably, the stirring time of the above step (b) is 20 to 30 minutes. Preferably, the content of the graphite powder in the above step (c) is 60 to 80% by weight. Preferably, the stirring and kneading time in the above step (c) is 30 to 40 minutes. Preferably, the tackifying time of the aforementioned step (d) is 48 hours. Preferably, before the step (e), a hot pressing mold heating step 1287316 is added to heat the hot pressing mold to 140~1603⁄4. The stamper pressure of the above step (4) is said to be g/cm2, and the pressurization is carried out for 5 to 1 () minutes. Preferably, the above step (the drying process of the crucible is carried out under i4〇~i6〇t>c. Preferably, the battery is a fuel cell. The rudder, the fuel cell bipolar plate system Preferably, the mold is used for compression molding of a fuel cell bipolar plate, and the factory has a plurality of grooves, and the radius of the groove is 〇.3 to 10111 ' The radius of the outer fillet is 〇·1 to 0·3 mm, and the draft angle of the above mold is between 5 and 15 degrees. Cold, preferably, the fuel cell bipolar plate comprises a plurality of flow channels, and the aforementioned woodiness is 〇. 6 Between L2mm, the width of the fluid is between 0.8 and 1.5mm' and the distance between the runner and the runner is also between 〇·8 and 丨·5mm. The foregoing objects or features of the present invention will be based on the following figures. The detailed description of the present invention is intended to be illustrative, and not to limit or limit the invention. [Embodiment] The composite material of the present invention comprises: 6〇~ 80% by weight of graphite powder, 15 to 30% by weight of vinyl ester resin and other additives, wherein the aforementioned addition The 丨J profile includes, but is not limited to, a solvent, a mold release agent, a rheological modifier, a free radical initiator, or a low shrinkage agent (i〇w profile agent). Etc. The aforementioned additives can be classified into: solvent, mold release agent, rheological modifier, free radical initiator, low shrinkage agent (low profile 1287316 = t ), etc., the types of additives have been introduced in the prior art = the choice and the amount must be obtained on the basis of the experiment, the formula selection and dosage of the invention used in the pool, and - the use of the > cereal system 3 to 6 wt% of the styrene single system is i. 5~3 wt% polystyrene type low shrinkage agent; free of 2 = is 3* peroxy benzoic acid monobutane vinegar; flow; 3phr of magnesium oxide; the release agent is 2~6phr of zinc stearate., 'In order to improve the process speed and yield', the mold of the present invention is especially suitable for the selection and the amount mentioned above, and is matched with the mold described later. Designed to achieve the goal of mass production. The composite film of the invention The molding method, as shown in the first figure, the method 10 comprises the steps of: (about mixing a vinyl ester resin with a suitable additive to form a mixed solution; (b) placing the mixed solution of the foregoing steps & (c) pouring the graphite powder and the mixed solution of the foregoing step (b) into a molding mixture kneader and kneading; (d) the step (the stirring and kneading of the molding mixture is taken out and sealed at room temperature to increase the viscosity); (e) placing the molded mixture obtained by the step (d) into a hot press mold by compression molding; and demolding the mold and drying the demolded product to harden it. Among them, additives can be classified into: solvent, mold release agent, rheology modifier, free radical starter, low shrinkage agent, and the like. The additive added in the above method can be selected according to actual needs and adjusted to an appropriate content, and is not particularly limited. The polymer composite material formulation for a battery bipolar plate and the compression molding method thereof according to the present invention are described in detail below by the following embodiments, but all the preferred embodiments described are for illustrative purposes only and are not intended to be used The invention is defined. 11 1287316 This embodiment is a method in which a vinyl ester resin is kneaded with a graphite powder to form a bulk molding compound (BMC) in which the graphite powder content is about 70 to 80% by weight. For the part of the additive, the solvent is styrene monomer, the release agent is zinc stearate, the rheology modifier is magnesium oxide, the free radical initiator is benzophenone-tributyl ester (TBPB), low shrinkage. The use of polystyrene-type low-shrinkage agent, the selection principle in addition to the nature of the composite bipolar plate, the reasonable price is also a consideration. The ratio of various materials in the first embodiment is shown in Table 1.

12 1287316 表一 原料分類 材料 比例 導電材 石墨粉末 70%〜80% 樹脂 乙烯基酯樹脂 15%〜25% 溶劑 苯乙烯單體 3% 〜6% 低收縮劑 聚苯乙稀型低收縮劑 L5% 〜3% 自由基起始劑 過氧苯甲酸-三丁酯（TBPB) lphr〜3phr 流變調節劑 氧化鎂 lphr〜3phr 脫模劑 硬脂酸鋅 2phr〜6phr 備註·· phr(per hundred parts of resin by weight)代表佔樹脂 重量之百分比。 本實施例之壓模成型之方法如下： a·將溶劑先行置入容器中，分別加入乙烯基酯樹脂與 聚本乙烯型低收縮劑，形成膠狀溶液，再加入自由基 起始劑、流變調節劑與脫模劑。 b·將a混合之溶液置於高速攪拌器，以乳化型葉片攪 拌20至30分鐘，攪拌時必須將放置溶液容器盡量密 封，以避免溶劑揮發。 c·將上述溶液與石墨粉末倒入模造混合物捏合機（BMc _12 1287316 Table 1 Raw material classification material ratio Conductive material graphite powder 70%~80% Resin vinyl ester resin 15%~25% Solvent styrene monomer 3% ~6% Low shrinkage agent polystyrene low shrinkage agent L5% ~3% free radical starter peroxybenzoic acid-tributyl ester (TBPB) lphr~3phr rheology modifier magnesium oxide lphr~3phr release agent zinc stearate 2phr~6phr remarks·· phr(per hundred parts of Resin by weight) represents a percentage of the weight of the resin. The method of compression molding of the present embodiment is as follows: a. The solvent is first placed in a container, and a vinyl ester resin and a polyethylene type low shrinkage agent are respectively added to form a colloidal solution, and then a radical initiator and a stream are added. Variable modifier and release agent. b. Place the mixed solution of a in a high-speed stirrer and stir it with the emulsified blade for 20 to 30 minutes. When stirring, the container should be sealed as much as possible to avoid solvent evaporation. c· Pour the above solution and graphite powder into a molding mixture kneader (BMc _

Kneader)，以強力型（Masticat〇r)擾拌葉片捏合 30至40分鐘。捏合過程中，可適當抽氣以避免氣體-被此&物包覆而造成製成成品的氣體孔洞，但亦必須 注意抽氣量，不可致使溶劑快速揮發。 、 d·將模k混合物自捏合機取出後，必須將混合物密封 在室溫下增黏48小時，即為熟成過程。 e·在熱壓成型時，必須先行估計混合物用量，並且秤 妥混合物用量，置入模具之模穴之中。此步驟之前， 熱壓模具必須先加熱至14〇至i6〇°c。 13 1287316 f·將混合物置入後，模具上下合模至壓模壓力達loo 至150kg/cm2，並且持續加壓5至1〇分鐘，使混人物 硬化。 /tb σ g·模具以自動脫料裝置將壓模成品脫模，蔣 1 " 町误座成品 取出後置於140至16(TC烘箱24小時，以杜# 人 Λ ^ 从確保混合 物完全硬化。 實施例二 本實施例之製程方法與實施例一之差別僅在於步驟 a，在實施例二中，係使用進口之乙烯基酯樹脂，其二含 低收Its劑成分’故在本實施例之步驟a中可略去實施例一 步驟a之聚苯乙烯型低收縮劑。有關實施例二之各種材料之 比例如表二所示。 表二 原料分類 材料 比例 導電材 石墨粉末 70%〜80% 樹脂 乙烯基酯樹脂 15%〜30% 溶劑 苯乙烯單體 3% 〜6% 自由基起始劑 過氧苯甲酸-三丁酯（TBPB) lphr〜3phr 流變調節劑 氧化鎂 lphr〜3phr 脫模劑 硬脂酸鋅 2phr〜6phr 備吞主· phr(per hundred parts of resin by weight)代表佔樹脂 重量之百分比。 依前述實施例一及實施例二製成之複合電池雙極板 材料性質測試結果如表三所示，由表三可知，導電性質低 於10 πιΩ，耐熱溫度高於150°C，氣密性、耐化學腐蝕性 與機械強度皆符合燃料電池用，此兩組實施例皆可實施於 燃料電池。 表三 1287316Kneader), stir the leaves with a strong type (Masticat〇r) for 30 to 40 minutes. During the kneading process, the gas can be appropriately pumped to avoid gas-filled by the & material to cause gas holes in the finished product, but it is also necessary to pay attention to the amount of pumping, so that the solvent cannot be quickly volatilized. d. After the mold k mixture is taken out from the kneader, the mixture must be sealed and allowed to stick at room temperature for 48 hours, which is the ripening process. e. In hot press forming, the amount of the mixture must be estimated first, and the amount of the mixture must be weighed and placed in the mold cavity. Prior to this step, the hot press mold must be heated to 14 〇 to i6 〇 °c. 13 1287316 f· After placing the mixture, the mold is clamped up and down to a pressure of loo to 150 kg/cm2, and the pressure is continued for 5 to 1 minute to harden the mixed character. /tb σ g·Mould with the automatic stripping device to demould the finished mold, Jiang 1 " Town misplaced finished product was taken out after 140 to 16 (TC oven for 24 hours, to Du #人Λ ^ from ensuring the mixture completely hardened Embodiment 2 The process method of the present embodiment differs from the first embodiment only in the step a. In the second embodiment, the imported vinyl ester resin is used, and the second contains the low-receiving component. Thus, in the embodiment. In the step a, the polystyrene type low shrinkage agent of the first step a can be omitted. The ratio of the various materials of the second embodiment is shown in Table 2. Table 2 Raw material classification material ratio Conductive material graphite powder 70%~80 % Resin Vinyl Ester Resin 15%~30% Solvent Styrene Monomer 3% ~6% Free Radical Starter Peroxybenzoic Acid-Tributyl Ester (TBPB) lphr~3phr Rheological Modifier Magnesium Oxide ~1phr Mould zinc stearate 2 phr~6 phr per hundred parts of resin by weight represents the percentage of the weight of the resin. The composite battery bipolar plate material properties test according to the first embodiment and the second embodiment The results are shown in Table 3. Thirdly, the conductive properties are lower than 10 πιΩ, the heat-resistant temperature is higher than 150 ° C, and the air tightness, chemical resistance and mechanical strength are all compatible with the fuel cell. Both sets of embodiments can be implemented in the fuel cell. Table 3 1287316

彎曲模數(psi) 度(。〇 電阻值(ιηΩ-cm) 159.3 153.8 抗姓性（//A/cm ) (PIN)之鹽酸水溶參中、Flexural modulus (psi) (. 电阻 resistance value (ιηΩ-cm) 159.3 153.8 anti-surname (//A/cm) (PIN) hydrochloric acid water-soluble ginseng,

比重^^(〇/〇) 氣密性Specific gravity ^^(〇/〇) air tightness

• 57-0.005 OK• 57-0.005 OK

1·65^016 OK1·65^016 OK

由前述兩組實施例製成之複合雙極板完成後，組成測 試用燃料電池實際測試，其使用之薄膜電極組規格為··由 美國Gore公司生產之高性能薄膜電極組，總面積1〇〇cm2, 活性面積25cm，以複合雙極板夾持組成測試用電池組， 實際測試結果與測試條件如第二圖所示，由第二圖之I -V 曲線可知兩組實施例之性能並不亞於商用產品（SchunkAfter the composite bipolar plates made by the two sets of the above embodiments are completed, the test fuel cells are actually tested, and the thin film electrode set used therein is a high performance thin film electrode group produced by Gore, USA, with a total area of 1〇. 〇cm2, active area 25cm, combined with the composite bipolar plate to form the test battery pack, the actual test results and test conditions are shown in the second figure, the performance of the two sets of examples can be seen from the I-V curve of the second figure. As much as commercial products (Schunk

Group、DuPont ),並證實前述兩組實施例之材料配方良 好。 本發明進一步提出用於前述壓模成型方法之模具，目 標在達成壓模設計與雙極板設計間之妥協設計，意即以燃 料電池容許之雙極板幾何尺寸為基準做壓模尺寸設計，尤 其設計燃料電池流道深度與寬度時，首先必須考量對流場 的影響，再配合設計模具適合之流道深度與寬度。如第三 圖所示之具有複數凹槽23之模具20為例，該模具20之 拔模角Θ會造成流道截面積縮小、外圓角21及内圓角22 會造成接觸面積縮小及接觸電阻增加，但前述拔模角與圓 15 1287316 角是對雙極板脫模影響很大的參數。因此，本發明特別針 對拔模角與圓角提出合適之設計理念；再者，低收縮劑之 選擇與用量，對脫模與幾何尺寸穩定性亦有影響，例如若 選用收縮率變化大者，容易造成幾何尺寸不穩定，收縮率 過小，不利於脫模，因此本發明對低收縮劑亦訂定合適的 選擇與用量。 進一步而言，如第三圖所示，拔模角θ定義為錯直方 向斜面與鉛直面之夾角，為角度在5至15度間之銳角； - 在圓角之設計上，分為外圓角21與内圓角22，内圓角22 通常為脫模最困難之處，多是因為應力集中與熱量集中效 ® 應，因此内圓角22半徑通常會大於於外圓角21半徑，以 利整體脫模，而外圓角21半徑在雙極板幾何形狀看來， 也必須盡量縮小，以增加雙極板與氣體擴散層間之接觸面 積，亦即，内圓角22半徑以0. 3至0. 8mm為佳，外圓角 21半徑以0· 1至0· 3mm為佳。 依據前述模具20所製成之雙極板30，具有複數流道 31及氣體進出口 32,如第四圖所示。前述雙極板30之其 氣體流道31之深度在（K 6至1. 2mm之間，寬度則在0· 8 0 至1. 5mm之間，而流道與流道間距亦在0. 8至1. 5mm之間， 使該流道31之深度與寬度符合流體力學設計。 - 16 1287316 【圖式簡單說明】 第一圖係顯示本發明壓模成型方法之之流程圖。 第二圖係顯示應用依據本發明第一及第二具體實施 例之方法成型之高分子複合材料之燃料電池與商用燃料 電池實際測試比較表。 第三圖係顯示本發明高分子複合材料脫模示意圖。 第四圖係顯示本發明燃料電池雙極板流道平面圖。 [主要元件符號對照說明] 10…複合材料壓模成型方法 20…模具 Θ…拔模角 21…外圓角 22···内圓角 30…雙極板 31…氣體流道 17Group, DuPont), and confirmed that the materials of the foregoing two sets of examples are well formulated. The invention further proposes a mold for the above-mentioned compression molding method, aiming at achieving a compromise design between the stamp design and the bipolar plate design, that is, the die size design based on the geometry of the bipolar plate allowed by the fuel cell. In particular, when designing the depth and width of the fuel cell runner, first of all, the influence on the flow field must be considered, and the depth and width of the runner suitable for the design of the mold must be matched. For example, the mold 20 having the plurality of grooves 23 shown in the third figure, the draft angle of the mold 20 causes the cross-sectional area of the flow path to be reduced, and the outer fillet 21 and the inner fillet 22 cause the contact area to be reduced and contacted. The resistance increases, but the aforementioned draft angle and the angle of the circle 15 1287316 are parameters that have a great influence on the demolding of the bipolar plate. Therefore, the present invention particularly proposes a suitable design concept for the draft angle and the round corner; in addition, the selection and amount of the low shrinkage agent also have an effect on demolding and geometric dimensional stability, for example, if the shrinkage ratio is changed greatly, It is easy to cause the geometrical size to be unstable, the shrinkage rate is too small, and it is not suitable for demolding. Therefore, the present invention also sets a suitable choice and amount for the low shrinkage agent. Further, as shown in the third figure, the draft angle θ is defined as the angle between the slope of the straight direction and the vertical plane, which is an acute angle between 5 and 15 degrees; - the design of the rounded corner is divided into outer circles. Angle 21 and fillet 22, fillet 22 is usually the most difficult part of demoulding, mostly because of stress concentration and heat concentration, so the radius of fillet 22 is usually larger than the radius of the fillet 21 to The radius of the inner fillet 22 is 0.3, the radius of the inner fillet 22 is 0.3, and the radius of the inner fillet 22 is 0.3. Preferably, the thickness of the outer fillet 21 is preferably from 0.1 to 0.3 mm. The bipolar plate 30 made in accordance with the aforementioned mold 20 has a plurality of flow paths 31 and a gas inlet and outlet 32 as shown in the fourth figure. The distance between the runner and the runner is also in the range of 0. 8 mm and 1. 5 mm, and the distance between the runner and the runner is also 0.8. Between 1.5 mm, the depth and width of the flow path 31 are in accordance with the hydrodynamic design. - 16 1287316 [Simplified description of the drawings] The first figure shows a flow chart of the compression molding method of the present invention. The actual test comparison table of the fuel cell and the commercial fuel cell using the polymer composite material formed by the method according to the first and second embodiments of the present invention is shown. The third figure shows the mold release diagram of the polymer composite material of the present invention. The figure shows a flow chart of the bipolar plate flow path of the fuel cell of the present invention. [Main component symbol comparison description] 10... Composite material compression molding method 20... Mold Θ... Draft angle 21... Outer fillet 22···Inner fillet 30 ...bipolar plate 31...gas flow channel 17

Claims (1)

轉⑵正替换Turn (2) positive replacement 申請專利範面： •種用於燃料電池雙極板之複合材料，包含： 60至80重量％之石墨粉末、 15至30重量％之乙烯基酯樹脂、 3至6重量％之溶劑、及 其中前逑石墨 其中前述溶劑 15至3重量％之聚苯乙烯型低收縮劑，但該聚笨乙 型低收縮劑含量不包含2至3重量％。 卿 •如申請專利範圍第1項所述之複合材料 粉末係為70至80重量0/〇。 3·如申請專利範圍第1項所述之複合材料 係為笨乙烯單體。 4·如申請專利範圍第1項所述之複合材料，其進〜步包人 脫模劑、自由基起始劑、戒流變調節劑。 I3 5·如申請專利範圍第4項所述之複合材料，其中前述 劑係為硬脂酸辞，其含量為2至6phr。 異 6·如申請專利範圍第4項所述之複合材料，其中前述自 基起始劑係為過氧笨曱酸-三丁酯，其含量為1至3 h 7·如申請專利範圍第4項所述之複合材料，其中前述= 調節劑係為氧化鎂，其含耋為1至3phr。 災笑 8· 一種利用如申請專利範園第1項所述之複合材料製傷燃 料電池雙極板的方法，包含下列步驟·· “、、 (a) 將15至3〇重量％之乙婦基酯樹脂、3至6重量％ 之溶劑與1.5至3重量。/0之聚苯乙烯型低收縮劑混合， 之後再加入脫模劑、自由基起始劑與流變調節劑，形成 混合溶液，其中前述聚苯乙烯型低收縮劑含量不包含2 至3重量％ ; (b) 將則述步驟（a)之混舍溶液置於攪拌器攪拌； J287316 (c) 將60至80重量％之石墨粉與前述步驟(b)攪拌後之 混合溶液倒入模造混合物捏合機中攪拌捏合； (d) 將步驟（c)攪拌捏合後之模造混合物取出並密封於 室溫下增黏； (e) 將步驟(d)增黏後之模造混合物置入熱壓模具中壓 模成型；及 (f) 將模具脫模並將脫模後之成品烘乾使其硬化。 9·如申請專利範圍第8項所述之方法，其中前述步驟(b)之 攪拌時間為20至30分鐘。 10·如申請專利範圍第8項所述之方法，其中前述步驟(c) 之攪拌捏合時間為30至40分鐘。 11·如申請專利範圍第8項所述之方法，其中前述步驟(d) 之增黏時間為48小時。 12 ·如申请專利範圍弟8項所述之方法’其係於前述步驟(g) 之前增加一熱壓模具加熱步驟，其係將熱壓模具先加熱 至 140°C 至 160°C。 13·如申請專利範圍第8項所述之方法，其中前述步驟(e) 之壓模壓力為100至15〇 kg/cm2，並持續加壓5至1〇 分鐘。 14·如申請專利範園第8項所述之方法，其中前述步驟⑴ 之烘乾程序係於140°C至160°C下持續24小時。 15·—種燃料電池雙極板，係包含： 60至80重量％之石墨粉末、 15至30重量％之乙烯基酯樹脂、 3至6重量％之溶劑、及 1·5至3重量％之聚苯乙烯型低收縮劑，但該聚苯乙烯 型低收縮劑含量不包含2至3重量％。 1287316 16. 如申請專利範圍第15項所述之燃料電池雙極板，其中 前述之石墨粉末係為70至80重量％。 17. 如申請專利範圍第15項所述之燃料電池雙極板，其中 前述溶劑係為苯乙烯單體。 18. 如申請專利範圍第15項所述之燃料電池雙極板，其進 一步包含脫模劑、自由基起始劑、或流變調節劑。 19. 如申請專利範圍第15項所述之燃料電池雙極板，其包 ’ 含複數流道，且前述流道深度在0.6至1.2mm之間，流 -度寬度在0.8至1.5mm之間，而流道與流道之間的間距 亦在0.8至1.5mm之間。 20. 如申請專利範圍第15項所述之燃料電池雙極板，其係 由模具壓模成型，前述模具之拔模角在5至15度間， 且包含有複數凹槽，該凹槽之内圓角半徑為0.3至 0.8mm、外圓角半徑為0.1至0.3mm。Patent application: • A composite material for fuel cell bipolar plates, comprising: 60 to 80% by weight of graphite powder, 15 to 30% by weight of vinyl ester resin, 3 to 6% by weight of solvent, and The front ruthenium graphite is a polystyrene type low shrinkage agent of 15 to 3% by weight of the aforementioned solvent, but the polystyrene type B low shrinkage agent content does not contain 2 to 3% by weight. Qing • The composite powder as described in claim 1 is 70 to 80 weight 0/〇. 3. The composite material as described in claim 1 is a stupid ethylene monomer. 4. The composite material according to claim 1 of the patent application, which comprises a release agent, a radical initiator, and a rheology modifier. The composite material of claim 4, wherein the aforementioned agent is stearic acid, and the content is 2 to 6 phr. The composite material according to the fourth aspect of the invention, wherein the self-based starting agent is peroxy alumic acid-tributyl ester, and the content thereof is 1 to 3 h 7 · as claimed in claim 4 The composite material according to the invention, wherein the aforementioned = modifier is magnesium oxide having a cerium content of from 1 to 3 phr.灾笑8· A method of using a composite material to inject a fuel cell bipolar plate as described in claim 1 of the patent application, including the following steps: ·, (a) 15 to 3% by weight of a woman The ester resin, 3 to 6% by weight of the solvent is mixed with 1.5 to 3 parts by weight of the polystyrene type low shrinkage agent, and then the release agent, the radical initiator and the rheology modifier are added to form a mixed solution. Wherein the aforementioned polystyrene type low shrinkage agent content does not contain 2 to 3% by weight; (b) the mixing solution of the step (a) is placed in a stirrer to stir; J287316 (c) 60 to 80% by weight The graphite powder and the mixed solution of the foregoing step (b) are poured into a molding mixture kneader and stirred and kneaded; (d) the mold mixture after the step (c) is stirred and kneaded, and sealed and viscous at room temperature; (e) The mold-forming mixture obtained by the step (d) is placed in a hot press mold for compression molding; and (f) the mold is demolded and the finished product is dried and hardened. 9· Patent Application No. 8 The method according to the item, wherein the stirring time of the aforementioned step (b) is 20 to 30 minutes. The method of claim 8, wherein the agitation kneading time of the aforementioned step (c) is 30 to 40 minutes. The method of claim 8, wherein the step (d) is viscosified. The time is 48 hours. 12 · The method described in claim 8 of the patent application, which is preceded by the above step (g), adding a hot pressing mold heating step, which heats the hot pressing mold to 140 ° C to 160 The method of claim 8, wherein the pressure of the aforementioned step (e) is from 100 to 15 〇kg/cm 2 and is continuously pressurized for 5 to 1 minute. The method of claim 8, wherein the drying procedure of the foregoing step (1) is performed at 140 ° C to 160 ° C for 24 hours. 15 - A fuel cell bipolar plate comprising: 60 to 80 weight % graphite powder, 15 to 30% by weight of vinyl ester resin, 3 to 6% by weight of solvent, and 1.5 to 3% by weight of polystyrene type low shrinkage agent, but the polystyrene type low shrinkage agent The content does not include 2 to 3% by weight. 1287316 16. The fuel electric power as described in claim 15 The bipolar plate, wherein the foregoing graphite powder is 70 to 80% by weight. 17. The fuel cell bipolar plate according to claim 15, wherein the solvent is a styrene monomer. The fuel cell bipolar plate of claim 15 further comprising a release agent, a radical initiator, or a rheology modifier. 19. The fuel cell bipolar plate according to claim 15 of the patent application, The package includes a plurality of flow channels, and the aforementioned flow channel depth is between 0.6 and 1.2 mm, the flow-degree width is between 0.8 and 1.5 mm, and the spacing between the flow channel and the flow channel is also between 0.8 and 1.5 mm. between. 20. The fuel cell bipolar plate according to claim 15, wherein the mold is formed by a die having a draft angle of 5 to 15 degrees and comprising a plurality of grooves, the groove The fillet radius is 0.3 to 0.8 mm and the fillet radius is 0.1 to 0.3 mm. 20 1287316 柒、指定代表圖： (一） 本案指定代表圖為：第（一）圖。 (二) 本代表圖之元件代表符號簡單說明: ίο…複合材料壓模成型方法 a…步驟 b…步驟 c…步驟 d…步驟 e…步驟 f…步驟 捌、本案若有化學式時，請揭示最能顯示發明特徵的化學式: 無20 1287316 柒, designated representative map: (1) The representative representative of the case is: (1). (2) The representative symbol of the representative figure is a simple description: ίο...Composite compression molding method a...Step b...Step c...Step d...Step e...Step f...Step 捌, If there is a chemical formula in this case, please reveal the most Chemical formula that shows the characteristics of the invention: None