201016911 六、發明說明： 【發明所屬之技術領域】 本發明係關於以中間相瀝青作爲原料 短纖維者，尤其是有關具有特定範圍之曲 子顯微鏡觀察之表面裂開受到控制之瀝青 【先前技術】 高性能碳纖維可分類爲以聚丙烯腈（ 之PAN系碳纖維及以一系列之瀝青類作 碳纖維。因此利用碳纖維在強度·彈性率 分子顯著的高之特徵，而被廣泛用於航空 築•土木用途、產業用機器人、運動·Ί PAN系碳纖維主要用於利用其強度之領域 維大多數是用於利用其彈性率之領域。 近年來，以省能源爲代表之能量效率 目，另一方面也意識到因高速化之CPU 引起之發熱成爲嚴重問題。又，以電子注 之電致發光元件中亦有顯著的同樣嚴重之 ，注意於形成各種元件之製程及要求環境 爲其對策爲替換成不添加鉛之所謂無鉛焊 料之融點比一般含鉛焊料高，因此要求有 之熱。因此，爲了解決源自該等製品•製 問題，因此需要達成熱之有效處理（熱管 之瀝青系石墨化 率且可藉掃插電 系石墨化短纖維 PAN )作爲原料 爲原料之瀝青系 上比一般合成高 •太空用途、建 长閒用途。又， ，而瀝青系碳纖 使用方法受到矚 或電路之焦耳熱 入作爲發光原理 問題。另一方面 關心型製程，作 料。由於無鉛焊 效率地使用製程 程內包含之熱之 理）0 -5- 201016911 一般碳纖維相較於其他合成高分子之導熱率雖較高， 但對於熱管理之用途須進一步檢討導熱之提升。過去，市 售之PAN系碳纖維之導熱率通常小於200W/ ( m . κ )。 此係由於PAN系碳纖維爲所謂的難石墨化之碳纖維，提 高負責熱傳導之石墨性極爲困難。相對於此，瀝青系碳纖 維稱爲易石墨化碳纖維，相較於PAN系碳纖維，由於可 提高石墨性，因此可知容易達成高導熱率。因此，考慮到 可有效率地展現導熱性之形狀有成爲高導熱性塡料之可能 性。 以下針對熱管理所用成型體之特徵加以檢討。使用一 般碳纖維之成型體由於具有長寬比故導熱材的碳纖維彼此 接觸，形成網路之可能性高。因此，容易發揮比使用如大 多數無機化合物般之球狀導熱材之成型體高的導熱率。然 而，很難說該等碳纖維一定亦可有效地形成網路。因此， 提出使用融熔吹塑法之具有曲率之碳纖維（專利文獻1) 〇 使用具有曲率之碳纖維之成型體，相較於直線狀之纖 維狀碳纖維，有發揮高導熱率之傾向。然而，並不是所有 的碳纖維必定有形成網路之功能。 (專利文獻1)日本特許第2838140號公報 【發明內容】 [發明欲解決之課題] 如上述，就要求導熱性優異之放熱材料之觀點而言， -6 - 201016911 導熱材較好爲在基質內形成網路之優異纖維狀物質。且， 此處所示之導熱材較好同時具有網路形成能及高的導熱性 。再者，較好爲成型性優異。 本發明之目的係提供一種可較好地用於製備在基質中 之網路形成能優異、具有高的導熱性之成型體之瀝青系石 墨化短纖維。 本發明者等有鑒於提供用以製作導熱性優異之放熱材 料之優異導熱材，發現具有特定範圍之曲率且表面具有開 裂之瀝青系石墨化短纖維在放熱構件中形成網路相當優異 ，可提供具有良好導熱率之放熱構件而完成本發明。 亦即，本發明之目的可藉由瀝青系石墨化短纖維而達 成，該瀝青系石墨化短纖維之特徵爲以中間相瀝青作爲原 料，全；部纖維中其曲率半徑爲10~60 cm之範圍的短纖維 比例爲60%〜99%，以掃描電子顯微鏡觀察時見到表面開 裂之短纖維之比例爲30%〜99%。 再者本發明之目的可藉由一組成物而達成，該組成物 含有包含上述瀝青系石墨化短纖維及選自熱可塑性樹脂、 熱旋化性樹脂、芳醯胺樹脂及橡膠所組成群組之至少一種 基質成分，且相對於100體積份之基質成分含有3〜200體 積份之瀝青系石墨化短纖維。 再者本發明之目的可藉由成型體達成，該成型體係以 選自由射出成形法、壓製成形法、砑光成形法、輥成形法 、擠出成形法、注模成形法、及吹塑成形法所組成群組之 至少一種方法使上述組成物成形而獲得。 201016911 【實施方式】 ' 以下就本發明之實施型態依序加以說明。 本發明之瀝青系石墨化短纖維之特徵爲具有特定範圍 之曲率，亦即全部纖維中曲率半徑爲10~60 cm之範圍的 短纖維比例爲60%~99%。曲率半徑超過60cm時會有石墨 化短纖維爲直線之情況，由於以一次元存在，因而難以使 石墨化短纖維彼此形成網路。相對於此，本發明之具有曲 率之石墨化短纖維之情況，由於石墨化短纖維以二次元或 三次元存在，因此石墨化短纖維彼此容易形成網路。曲率 半徑小於10cm時，由於曲率過大使得碳短纖維之二次元 廣度變小，難以使石墨化短纖維彼此形成網路。石墨化短 纖維彼此形成更多網路時，由於形成有導熱通道，因此導 熱變高。曲率半徑可藉光學顯微鏡觀察纖維，且藉觀察纖 維長度及曲率而求得。 本發明之瀝青系石墨化短纖維之全部纖維中，曲率半 徑爲10~60cm之範圍的纖維比例較好爲70~99%較有利。 最佳之瀝青系石墨化短纖維爲全纖維中曲率半徑爲 1 0〜5 0cm範圍內之纖維比例爲60〜99%，較好爲70〜99 %者 〇 曲率半徑在10〜60cm範圍內之纖維比例係以光學顯 微鏡下4倍觀察瀝青系石墨化短纖維，且利用比例尺對纖 維長度ΙΟΟμιη以上之瀝青系石墨化短纖維之特定條數求 得曲率半徑，且計算該等中曲率半徑爲10〜60cm纖維之 比例。 -8- 201016911 曲率半徑之計算方式示於圖2及圖3中。於具有曲率 之瀝青系石墨化短纖維中連結任意兩點，以兩點間之距離 作爲△ S，求得於其一點之接線與水平線之角度α，另一 點之連接線與水平線之角度爲〇:+△〇：，由式R = ^s/Z\a 求得曲率半徑（R )。 以下詳述之本發明瀝青系石墨化短纖維之較隹製造方 法係藉由融熔吹塑法使中間相瀝青纖維化，隨後獲得不融 f 化、經碳化之碳纖維網狀物，隨後粉碎並經石墨化之方法 。碳纖維網狀物可以特定之紡絲條件獲得，由於構成碳纖 維網狀物之碳纖維之曲率幾乎一定，因此使碳纖維網狀物 • 經粉碎後石墨化獲得之石墨化短纖維之曲率被認爲幾乎相 . 同。 針對纖維長度未達ΙΟΟμιη之短纖維而言，由於認爲 難以正確求得曲率半徑，因此自比例之規定範圍剔除未達 ΙΟΟμιη者，但本發明之瀝青系石墨化短纖維中亦包含纖維 (. 長度未達ΙΟΟμηι者。若爲使相同碳纖維網狀物經粉碎獲 得者，則纖維長度ΙΟΟμιη以上之短纖維，或纖維長度未 達ΙΟΟμιη之短纖維均可被視爲曲率相同。自相同碳纖維 網狀物獲得之石墨化短纖維時，如果曲率半徑成爲 10~60cm範圍之比例於纖維長度ΙΟΟμιη以上之瀝青系石 ’ 墨化短纖維中爲60〜99%，則就纖維長度未達ΙΟΟμιη之短 纖維而言亦被認爲處於相同曲率半徑及比例。 本發明之瀝青系石墨化短纖維其特徵爲曲率半徑爲 10~60cm範圍之短纖維比例佔纖維長度ΙΟΟμηι以上之瀝 201016911 青系石墨化短纖維中之60%~99%，但若測定纖維長度 ΙΟΟμπι以上者在該範圍內，則就全部纖維而言，曲率半徑 爲10〜60 cm範圍之短纖維比例亦可成爲60%~99%。 對於具有曲率之碳纖維較好使用融熔吹塑法。藉由融 熔吹塑法紡絲時，係對原料瀝青吹送空氣，但吹送之空氣 可自與紡絲方向不同之方向施力。再者，可藉由吹送之空 氣所形成之亂流施加三次元之力。 控制曲率半徑之方法並沒有特別限制，具體而言有控 制由吹送空氣紡絲之時間之方法、控制亂流之方法等。控 制由吹送空氣紡絲之時間之方法，具體而言有原料瀝青之 溫度、黏度、吹送空氣之溫度等。原料瀝青之溫度越高， 原料瀝青之黏度越低，難以長時間的紡絲。因此，造成曲 率變小。又，吹送空氣之溫度越高原料瀝青到達固化之時 間拉長，造成曲率變大。控制亂流並控制曲率半徑之方法 並沒有特別限制，具體而言可使吹送空氣相對於紡絲方向 成一角度加以控制，或在融熔吹塑之模嘴下方設置稱爲煙 囪（Chimney)之筒加以控制。 又，日本特許第28 3 8 1 40號公報雖已報導扭轉纖維之 方法，但扭轉纖維時，與基質複合之際，基質被拉攏至碳 纖維之經扭轉部份中，使複合化所需之基質之量變多，使 碳纖維難以高充塡，對於導熱之用途較不佳。 本發明之瀝青系石墨化短纖維以掃描電子顯微鏡觀察 時看見表面之開裂之短纖維比例爲3 0%〜99%。瀝青系石 墨化短纖維之表面開裂時，石墨化短纖維所佔有之空間變 -10- 201016911 大，使短纖維彼此容易形成網路。其中，以掃 鏡觀察時看見表面之開裂意指可觀察短纖維側 部，或者確認短纖維側面之線狀龜裂。圖1例 瀝青系石墨化短纖維之掃描電子顯微鏡觀察照 以箭頭表示之纖維方向之條紋開裂。求得看見 維之比例時，若可觀達到表面不管短纖維之長 〇 就使短纖維彼此之網路成爲有效之功能而 看見開裂之短纖維比例占全部纖維中之30%， 較好占40%~99%。 爲了獲得以掃描電子顯微鏡觀察時看見表 青系石墨化短纖維，較好使用融熔吹塑法。融 對融熔之中間相瀝青吹送空氣之紡絲法。融熔 青自噴嘴之前端流出時，因壓艙（ballast)效 面變成放射狀構造般。藉由對其吹送空氣使纖 射狀構造瓦解而變化成ΡΑΝ-AM (泛美航空公 )構造。關於ΡΑΝ-AM構造係定義於Carbon p741〜747中。PAN-AM構造由於係纖維分成 ，故在紡絲後之燒成及石墨化步驟中，使纖維 面開裂。 控制表面開裂之方法亦即易於獲得PAN-方法並無特別限制，具體而言有增加吹送風量 減低於熔融中間相瀝青離開噴嘴時施加之剪斷 亦即提高融熔中間相瀝青之黏度之方法，但關 描電子顯微 面打開之內 示實施例之 相，但圖中 開裂之短纖 度均可計入 言，於表面 -99%即可。 面開裂之瀝 熔吹塑法爲 之中間相瀝 果使纖維剖 維剖面之輻 司標之形狀 38(2000) 兩半之構造 收縮並使表 _AM構造之 之方法，或 力之方法， 於本發明之 .r·· η L ,：> i -11 - 201016911 瀝青系石墨化短纖維之較佳製造條件敘述於後。 本發明之瀝青系石墨化短纖維以光學顯微鏡觀測之平 均纖維直徑（D1)較好爲2〜2 0μιη。平均纖維直徑低於 2μιη時，與基質複合時由於該短纖維之條數變多，使基質 /短纖維混合物之黏度變高，而有難以成型之傾向。相反 地當平均纖維直徑超過2 0 μιη時，由於與基質複合時短纖 維之條數變少，使該短纖維彼此間不容易接觸，作爲複合 材時難以發揮有效的熱傳導。平均纖維直徑之較佳範圍爲 5〜15μιη，更好爲7〜13μιη。 本發明之瀝青系石墨化短纖維以光學顯微鏡觀測之瀝 青系石墨化短纖維中之纖維直徑分散（S1)相對於平均纖 維直徑（D1)之百分率（CV値）較好爲5〜15 %。CV値 爲纖維直徑偏差之指標，越小時製程安定性越高，意指製 品之變異小。CV値小於5%時，由於纖維直徑相當整齊， 因此***瀝青系石墨化短纖維之間隙中之纖維直徑細的短 纖維量少，與基質複合時會有難以形成縝密之充塡狀態之 傾向。結果是使瀝青系石墨化短纖維高充塡變得困難’不 易獲得高性能之複合材。相反的當CV値大於1 5 %時，與 基質複合時之分散性變差，使成型時之黏度上升’難以獲 得具有均勻性能之複合材。CV値較好爲5〜13%。CV値爲201016911 VI. Description of the Invention: [Technical Field of the Invention] The present invention relates to a medium-phase pitch as a raw material short fiber, in particular, an asphalt which is controlled by surface cracking with a specific range of music observed under the microscope [Prior Art] High The performance carbon fiber can be classified into polyacrylonitrile (PAN-based carbon fiber and a series of asphalts as carbon fiber). Therefore, carbon fiber is widely used in aviation and civil engineering applications because of its high strength and elastic modulus. Industrial robots, sports, and Ί PAN-based carbon fibers are mainly used in the field of utilizing their strength. Most of them are used in the field of utilizing their elastic modulus. In recent years, energy efficiency, represented by energy saving, has been realized. The heat generated by the high-speed CPU becomes a serious problem. In addition, the electroluminescent elements that are electronically injected are also significantly more serious. Pay attention to the process of forming various components and the environment required to replace them with no lead. The so-called lead-free solder has a higher melting point than the general lead-containing solder, so heat is required. Therefore, In order to solve the problems caused by these products, it is necessary to achieve an effective treatment of heat (the graphitization rate of the heat pipe and the graphitization of the heat-transferred graphitized short fiber PAN) as a raw material. High • Space use, long-term use, and, while the use of asphalt-based carbon fiber is subject to the principle of illuminating the enthalpy or the Joule heat of the circuit. On the other hand, the process of care is used, and the material is used because of the lead-free soldering efficiency. Including the heat of the law) 0 -5- 201016911 Although the thermal conductivity of carbon fiber is higher than that of other synthetic polymers, it is necessary to further review the improvement of heat conduction for the purpose of thermal management. In the past, the thermal conductivity of commercially available PAN-based carbon fibers was typically less than 200 W/(m. κ). This is because the PAN-based carbon fiber is a so-called non-graphitizable carbon fiber, and it is extremely difficult to improve the graphite property responsible for heat conduction. On the other hand, the pitch-based carbon fiber is referred to as an easily graphitizable carbon fiber, and since the graphite property can be improved as compared with the PAN-based carbon fiber, it is known that high thermal conductivity can be easily achieved. Therefore, it is considered that the shape which can exhibit heat conductivity efficiently has a possibility of becoming a highly thermally conductive material. The following is a review of the characteristics of the molded bodies used for thermal management. Since the molded body of the general carbon fiber has an aspect ratio, the carbon fibers of the heat conductive material are in contact with each other, and the possibility of forming a network is high. Therefore, it is easy to exhibit a higher thermal conductivity than a molded body using a spherical heat conductive material such as a large number of inorganic compounds. However, it is difficult to say that these carbon fibers must also form an effective network. Therefore, a carbon fiber having a curvature by a melt blow molding method has been proposed (Patent Document 1). A molded body of carbon fiber having curvature is used, and a high thermal conductivity tends to be exhibited as compared with a linear fibrous carbon fiber. However, not all carbon fibers must have the function of forming a network. [Patent Document 1] Japanese Patent No. 2838140 [Disclosure] [Problems to be Solved by the Invention] As described above, from the viewpoint of requiring an exothermic material having excellent thermal conductivity, the heat conductive material of -6 - 201016911 is preferably in the matrix. An excellent fibrous material that forms a network. Moreover, the heat conductive material shown here preferably has both network formation energy and high thermal conductivity. Further, it is preferably excellent in moldability. SUMMARY OF THE INVENTION An object of the present invention is to provide a pitch-based graphite short fiber which can be preferably used for producing a molded article excellent in network formation in a matrix and having high thermal conductivity. The inventors of the present invention have found that an excellent thermal conductive material for producing an exothermic material having excellent thermal conductivity has found that a pitch-based graphitized short fiber having a specific range of curvature and having a crack on the surface is excellent in forming a network in the heat releasing member, and is provided. The present invention has been completed by a heat releasing member having a good thermal conductivity. That is, the object of the present invention can be attained by a pitch-based graphitized short fiber characterized by using mesophase pitch as a raw material, and the radius of curvature of the fiber is 10 to 60 cm. The proportion of short fibers in the range is 60% to 99%, and the ratio of short fibers which are surface cracked when observed by a scanning electron microscope is 30% to 99%. Furthermore, the object of the present invention can be attained by a composition comprising the above-described pitch-based graphitized short fibers and a group selected from the group consisting of thermoplastic resins, heat-spinning resins, linalylamine resins, and rubbers. The at least one matrix component contains 3 to 200 parts by volume of the pitch-based graphitized short fiber with respect to 100 parts by volume of the matrix component. Furthermore, the object of the present invention can be attained by a molding system selected from the group consisting of injection molding, press molding, calender molding, roll forming, extrusion molding, injection molding, and blow molding. At least one of the groups consisting of the methods is obtained by shaping the above composition. 201016911 [Embodiment] Hereinafter, embodiments of the present invention will be described in order. The pitch-based graphitized short fibers of the present invention are characterized by having a specific range of curvature, that is, a ratio of short fibers having a radius of curvature of from 10 to 60 cm in all fibers is from 60% to 99%. When the radius of curvature exceeds 60 cm, there is a case where the graphitized short fibers are straight, and it is difficult to form the graphitized short fibers with each other due to the presence of a single element. On the other hand, in the case of the graphitized short fibers having the curvature of the present invention, since the graphitized short fibers are present in the secondary or tertiary elements, the graphitized short fibers easily form a network with each other. When the radius of curvature is less than 10 cm, the secondary element breadth of the carbon short fibers becomes small due to the excessive curvature, and it is difficult to form the graphitized short fibers into a network with each other. When the graphitized short fibers form more networks with each other, the heat conduction becomes higher due to the formation of the heat conduction passage. The radius of curvature can be observed by an optical microscope and is obtained by observing the length and curvature of the fiber. In all of the fibers of the pitch-based graphitized short fibers of the present invention, the proportion of fibers having a radius of curvature of 10 to 60 cm is preferably from 70 to 99%. The optimum pitch-type graphitized short fiber is a fiber having a radius of curvature of from 10 to 50 cm in the range of from 60 to 99%, preferably from 70 to 99%, and a radius of curvature of from 10 to 60 cm. The ratio of the fibers is obtained by observing the pitch-based graphitized short fibers 4 times under an optical microscope, and the radius of curvature is obtained by using a specific scale of the pitch-based graphitized short fibers having a fiber length of ΙΟΟμηη or more, and the radius of curvature is calculated as 10 ~60cm fiber ratio. -8- 201016911 The calculation of the radius of curvature is shown in Figures 2 and 3. Connect any two points in the pitch-based graphitized short fiber with curvature, and take the distance between the two points as Δ S to obtain the angle α between the wire at one point and the horizontal line. The angle between the connecting line and the horizontal line at the other point is 〇 :+△〇: The radius of curvature (R) is obtained from the formula R = ^s/Z\a. The more conventional method for producing the pitch-based graphitized short fibers of the present invention, which is detailed below, is to fibrillate the mesophase pitch by melt blow molding, and then obtain a carbon fiber network which is not melted, carbonized, and then pulverized. The method of graphitization. The carbon fiber mesh can be obtained under specific spinning conditions. Since the curvature of the carbon fiber constituting the carbon fiber mesh is almost constant, the curvature of the carbon fiber mesh • the graphitized short fiber obtained by pulverizing and graphitizing is considered to be almost Same as. For the short fibers whose fiber length is less than ΙΟΟμιη, since it is considered that it is difficult to accurately obtain the radius of curvature, the predetermined range from the ratio is excluded from the ΙΟΟμιη, but the pitch-based graphitized short fibers of the present invention also contain fibers (. If the length is less than ΙΟΟμηι, if the same carbon fiber mesh is obtained by pulverization, short fibers with a fiber length of ΙΟΟμηη or short fibers with a fiber length of less than ΙΟΟμηη can be regarded as the same curvature. When the graphitized short fiber obtained is obtained, if the radius of curvature is in the range of 10 to 60 cm, and the ratio of the fiber length to the fiber length ΙΟΟμηη is 60 to 99%, the fiber length is less than ΙΟΟμιη short fiber. It is also considered to be at the same radius of curvature and ratio. The pitch-based graphitized short fibers of the present invention are characterized by a ratio of short fibers having a radius of curvature of 10 to 60 cm, which accounts for a fiber length of ΙΟΟμηι or more, 201016911, a blue-based graphitized short fiber. 60% to 99% of the total, but if the fiber length ΙΟΟμπι or more is within the range, then all In terms of dimension, the ratio of short fibers having a radius of curvature of 10 to 60 cm may also be 60% to 99%. For carbon fibers having curvature, a melt blow molding method is preferably used. When spinning by melt blow molding, The air is blown to the raw material asphalt, but the air blown can be applied in a direction different from the spinning direction. Further, the force of three times can be applied by the turbulent flow formed by the air blown. The method of controlling the radius of curvature does not In particular, there are a method of controlling the time of spinning air blowing, a method of controlling turbulence, etc. A method of controlling the time of spinning air by blowing, specifically, temperature, viscosity, and blowing air of raw material pitch Temperature, etc. The higher the temperature of the raw asphalt, the lower the viscosity of the raw asphalt, and it is difficult to spin for a long time. Therefore, the curvature becomes smaller. Moreover, the higher the temperature of the blowing air, the longer the time at which the raw asphalt reaches the solidification, causing the curvature. The method of controlling the turbulent flow and controlling the radius of curvature is not particularly limited, and specifically, the blowing air can be controlled at an angle with respect to the spinning direction, or in the melt blowing A cylinder called a chimney is placed under the nozzle to control it. Further, although Japanese Patent No. 28 3 8 1 40 has reported a method of twisting fibers, when the fiber is twisted, when the matrix is compounded, the matrix is pulled. In the torsion portion of the carbon fiber, the amount of the matrix required for the composite is increased, so that the carbon fiber is difficult to be highly charged, and the use for heat conduction is poor. When the pitch-based graphitized short fiber of the present invention is observed by a scanning electron microscope When the surface of the asphalt-based graphitized short fibers is cracked, the space occupied by the graphitized short fibers is changed to -10-201016911, which makes the short fibers easy to form a network. Among them, the cracking of the surface as seen by the scanning mirror means that the side of the short fiber can be observed, or the linear crack of the side of the short fiber is confirmed. Fig. 1 shows a scanning electron microscope observation of a pitch-based graphitized short fiber. The stripe of the fiber direction is indicated by an arrow. When you can see the proportion of the dimension, if you can achieve the surface, regardless of the length of the short fiber, the network of short fibers becomes an effective function. The proportion of short fibers that see cracking accounts for 30% of the total fiber, preferably 40%. ~99%. In order to obtain a graphitic graphitized short fiber when observed by a scanning electron microscope, a melt blow molding method is preferably used. The spinning method of blowing air to the melted mesophase pitch. When the molten green flows out from the front end of the nozzle, the ballast effect becomes a radial structure. The ΡΑΝ-AM (Pan American Airlines) structure is changed by blowing air to blow the fibrous structure. The ΡΑΝ-AM structure is defined in Carbon p741~747. Since the PAN-AM structure is divided into the fibers, the fiber surface is cracked in the firing and graphitization steps after spinning. The method for controlling the surface cracking, that is, the method for easily obtaining the PAN- is not particularly limited, and specifically, the method of increasing the blowing air volume is lower than the shearing applied when the molten mesophase pitch leaves the nozzle, that is, the viscosity of the melted mesophase pitch is increased. However, the phase of the embodiment shown in the opening of the electron microscopic surface is turned off, but the shortness of the crack in the figure can be counted, and the surface is -99%. The surface cracking of the melt-blown blow molding method is the middle phase of the leach fruit to make the fiber section profile of the shape of the spokes of the shape of the 38 (2000) two-half structure shrinkage and the method of the table _AM structure, or the method of force, .r·· η L , :> i -11 - 201016911 of the present invention The preferred manufacturing conditions of the pitch-based graphitized short fibers are described later. The pitch-based graphitized short fibers of the present invention have an average fiber diameter (D1) of 2 to 20 μm as observed by an optical microscope. When the average fiber diameter is less than 2 μm, the number of the short fibers increases as the matrix is combined with the matrix, so that the viscosity of the matrix/short fiber mixture becomes high, and there is a tendency that molding is difficult. On the other hand, when the average fiber diameter exceeds 20 μm, the number of short fibers becomes small when the matrix is combined with the matrix, so that the short fibers are not easily contacted with each other, and it is difficult to exhibit effective heat conduction as a composite material. The average fiber diameter is preferably in the range of 5 to 15 μm, more preferably 7 to 13 μm. The pitch-dispersion (S1) of the pitch-based graphitized short fibers of the pitch-based graphitized short fibers of the present invention with respect to the average fiber diameter (D1) (CV値) is preferably from 5 to 15%. CV値 is an indicator of the deviation of the fiber diameter. The smaller the process, the higher the stability of the process, which means that the variation of the product is small. When the CV 値 is less than 5%, since the fiber diameter is relatively uniform, the amount of short fibers having a small fiber diameter in the gap inserted into the pitch-based graphitized short fibers tends to be small, and it tends to be difficult to form a dense and filled state when combined with the matrix. As a result, it becomes difficult to make the pitch-based graphitized short fibers high-filling, and it is not easy to obtain a high-performance composite material. On the contrary, when CV 値 is more than 15%, the dispersibility at the time of compounding with the matrix is deteriorated, and the viscosity at the time of molding is increased. It is difficult to obtain a composite having uniform properties. The CV 値 is preferably from 5 to 13%. CV値 is
I 調節紡絲時之融熔中間相瀝青之黏度，具體而言，以融熔 吹塑法紡絲時，可實現將紡絲時於噴嘴孔之融熔黏度調整 成爲 5.0~25.0Pa· S。 瀝青系石墨化短纖維通常有由平均纖維長度未達 -12- 201016911 1 mm所構成之中等纖維與由平均纖維長度在1 mm以上未 達1 0mm所構成之切斷纖維兩種類。中等纖維之外觀由於 爲粉狀因此有分散性優異之特徵，切斷纖維之外觀由於接 近纖維狀，因此有容易使纖維彼此接觸之特徵。 本發明之瀝青系石墨化短纖維相當於中等纖維，其平 均纖維長度（L1)較好爲5〜6 00μιη。其中，平均纖維長度 係設爲個數平均纖維長度，可藉光學顯微鏡使用測長器， ， 測定複數個視野中之特定條數，自其平均値求得。平均纖 維長度小於5μπι時，該短纖維彼此之間難接觸，不容易 期望有效的熱傳導。相反的，當平均纖維長度大於600μηι ' 時，與基質混合時，基質/短纖維混合物之黏度變高，會 . 有成型性變低之傾向。更好平均纖維長度爲20~300μιη之 範圍。獲得該等瀝青系石墨化短纖維之方法並無特別限制 ，可藉由調節硏磨條件，亦即以切割機等粉碎時之切割機 旋轉速、球磨機之轉速、噴射硏磨之氣流速度、粉碎機之 G 衝撞次數、硏磨裝置中之滯留時間而控制平均纖維長度。 又，可自硏磨後之瀝青系碳短纖維進行篩網等之分級操作 ，藉由去除短的纖維長度或長的纖維長度之瀝青系碳短纖 維而調整。 本發明之瀝青系石墨化短纖維較好爲藉由透過型電子 顯微鏡觀察纖維末端時，石墨薄片之端面閉合者。石墨薄 片之端面閉合時，不容易發生多餘官能基，或起因於形狀 之電子局部化。因此，不會在瀝青系石墨化短纖維中產生 活性點，與聚矽氧樹脂或環氧樹脂等熱硬化性樹脂混練時 -13- 201016911 ，由於觸媒活性點之降低使硬化之抑制成爲可能。又藉由 使石墨薄片之端面閉合，亦可降低水等之吸附，例如即使 與伴隨著如聚酯之水解之樹脂混練時，亦可顯著賦予濕熱 耐久性能之提升。 本發明之瀝青系石墨化短纖維在藉由放大至50萬 〜400萬倍之透過型電子顯微鏡之視野範圍，以石墨薄片 端面之80%爲閉合者較佳。石墨薄片端面之閉合率在80% 以下時，會引起多餘官能基之發生或起因於形狀之電子局 部化，有會促進與其他材料反應之可能性故而不適當。石 墨薄片端面之閉合率較好爲9 0%以上，更好爲95 %以上。 石墨薄片端面構造會因石墨化之前進行粉碎，或石墨 化之後進行粉碎而大有不同。亦即，於石墨化後進行粉碎 處理時，以石墨化成長之石墨薄片被切斷破斷，容易使石 墨薄片呈敞開狀態。另一方面，於進行粉碎後進行石墨化 處理時，石墨成長過程中石墨薄片之端面向上彎曲成U 字形，彎曲部分露出於瀝青系石墨化纖維之端部之構造， 亦即容易使石墨薄片端面成爲閉合之狀態。據此，爲了獲 得石墨薄片之端面閉合率超過80%之瀝青系石墨化短纖維 ，較好於進行粉碎後進行石墨化處理。 本發明之瀝青系石墨化短纖維以掃描電子顯微鏡側面 觀察表面較好爲實質平坦。此處，所謂的實質平坦意指瀝 青系石墨化短纖維中所不具有之如糾結構造之劇烈凹凸。 瀝青系石墨化短纖維之表面上存在著如劇烈凹凸之缺陷時 ，與基質混練時伴隨著表面積增大而引起黏度增大’使成 -14- 201016911 型性變差。因此，期望爲如表面凹凸之缺陷儘可能小之狀 態。更具體而言，以掃描電子顯微鏡在800倍〜1000倍下 觀察之像之觀察視野中，如凹凸之缺陷在10處以下。獲 得如此般之瀝青系石墨化短纖維之方法可藉由於進行硏磨 後實施石墨化處理而較好地獲得。 本發明中之瀝青系石墨化短纖維較好由石墨結晶構成 ，且原自六角網面之成長方向之結晶子尺寸爲20nm以上 。結晶子尺寸爲六角網面成長方向之任一種，對應於石墨 化度者，且爲了展現熱物性，有必要在一定尺寸以上。六 角網面之成長方向之結晶子尺寸可藉X射線繞射法求得 。測定方法較好使用集中法，解析方法較好使用學振法。 六角網面之成長方向之結晶子尺寸可使用自（110)面之 反射線求得。 瀝青系石墨化短纖維之真密度較好爲1.8〜2.3g/cm3。 在該範圍內時，石墨化度相當高，可發揮充分的導熱度， 同時用以石墨化之能量成本亦成爲與所得纖維塡料之特性 相抵者。.更好爲1.9〜2.3g/cm3。 瀝青系石墨化短纖維之纖維軸方向之導熱率較好爲 600 W/m· K以上。爲600W/m. K以上時，與基質混合製 作導熱性成型體時可獲得充分的導熱性。此處所示之導熱 率係由比電阻藉由計算導熱率與電阻抗之下列關係式（參 考專利第3 648 865號）求得， K=1272.4/ER-49.4 -15- 201016911 (K爲碳纖維之導熱率，ER爲碳纖維之比電阻）， 實質上與比電阻同義。 以下針對本發明之瀝青系石墨化短纖維之較佳製造方 法加以描述。本發明之瀝青系石墨化短纖維可較好地藉由 特定條件之融熔吹塑法使融熔之中間相瀝青纖維化，隨後 經不融化、碳化，獲得瀝青系碳纖維網狀物，接著粉碎、 石墨化而獲得。 瀝青系石墨化短纖維之原料舉例爲例如所謂的萘或菲 之縮合多環烴化合物、所謂的石油系瀝青或石碳系瀝青之 縮合雜環化合物等。其中以所謂的萘或菲之縮合多環烴化 合物較佳。 本發明之石墨化短纖維之原料係使用中間相瀝青。中 間相瀝青之中間相率至少爲9 0%以上，較好爲9 5 %以上， 更好爲99%以上。又，中間相瀝青之中間相率可藉偏光顯 微鏡觀察融熔狀態之瀝青而確認出。 再者，原料瀝青之軟化點較好爲230 °C〜340 °C。不融 化處理須要在低於軟化點之溫度下處理。據此，軟化點低 於230°C時，有必要在未達軟化點之低溫下進行不融化處 理，結果由於在不融化下需要長時間而不佳。另一方面， 軟化點超過340°C時，紡絲需要超過340°C之高溫，造成 瀝青之熱分解，由於發生之氣體而產生於絲中發生氣泡等 之問題而不佳。軟化點較佳之範圍爲250 °C〜320 °C，更好 爲260 °C〜3 10 °C。又’原料瀝青之軟化點係以梅特勒（ -16- 201016911I Adjust the viscosity of the melted mesophase pitch during spinning. Specifically, when the melt is blown by the melt blow molding method, the melt viscosity in the nozzle hole during spinning can be adjusted to 5.0 to 25.0 Pa·s. The pitch-based graphitized short fibers generally have two types of fibers, which are composed of an average fiber length of less than -12 to 201016911 1 mm, and a fiber having an average fiber length of 1 mm or more and less than 10 mm. Since the appearance of the medium fiber is powdery, it is excellent in dispersibility, and the appearance of the cut fiber is close to the fiber shape, so that the fibers are easily brought into contact with each other. The pitch-based graphitized short fiber of the present invention corresponds to a medium fiber, and the average fiber length (L1) thereof is preferably from 5 to 600 μm. Here, the average fiber length is set as the number average fiber length, and the length gauge of the plurality of fields of view can be measured by an optical microscope using a length measuring device, and the average number is obtained from the average. When the average fiber length is less than 5 μm, the short fibers are hard to contact each other, and efficient heat conduction is not easily expected. On the contrary, when the average fiber length is more than 600 μηι ', when the matrix is mixed with the matrix, the viscosity of the matrix/short fiber mixture becomes high, and the moldability tends to be low. A better average fiber length is in the range of 20 to 300 μm. The method for obtaining the pitch-based graphitized short fibers is not particularly limited, and the honing condition, that is, the rotational speed of the cutter when pulverizing the cutter, the rotation speed of the ball mill, the air flow speed of the jet honing, and the pulverization can be adjusted. The average fiber length is controlled by the number of collisions of the machine G and the residence time in the honing device. Further, the bitumen-based carbon short fibers after honing can be subjected to a classification operation of a sieve or the like, and adjusted by removing the pitch-based carbon short fibers having a short fiber length or a long fiber length. The pitch-based graphitized short fiber of the present invention is preferably one in which the end faces of the graphite sheets are closed when the fiber ends are observed by a transmission electron microscope. When the end face of the graphite sheet is closed, excess functional groups are less likely to occur or electron localization due to the shape. Therefore, an active point is not generated in the pitch-based graphitized short fibers, and when it is kneaded with a thermosetting resin such as a polyoxyxylene resin or an epoxy resin, it is possible to suppress the hardening due to a decrease in the catalytic activity point. . Further, by closing the end faces of the graphite flakes, the adsorption of water or the like can be reduced. For example, even when kneaded with a resin such as polyester, the wet heat durability can be remarkably enhanced. The pitch-based graphitized short fiber of the present invention is preferably closed by 80% of the end face of the graphite sheet by a field of view of a transmission electron microscope enlarged to 500,000 to 4,000,000 times. When the closing ratio of the end faces of the graphite flakes is 80% or less, the occurrence of excess functional groups or the localization of the shape due to the influence of the reaction with other materials may be caused. The closing ratio of the end face of the graphite sheet is preferably 90% or more, more preferably 95% or more. The end surface structure of the graphite flakes is greatly different by pulverization before graphitization or pulverization after graphitization. In other words, when the pulverization treatment is carried out after graphitization, the graphitized graphite sheet is cut and broken, and the graphite sheet is easily opened. On the other hand, when the graphitization is performed after the pulverization, the end face of the graphite flakes is bent upward into a U shape during the growth of the graphite, and the bent portion is exposed to the end portion of the pitch-based graphitized fiber, that is, the end face of the graphite flake is easily formed. Become closed. Accordingly, in order to obtain a pitch-based graphitized short fiber having an end face closure ratio of the graphite sheet of more than 80%, it is preferred to carry out a graphitization treatment after pulverization. The pitch-based graphitized short fibers of the present invention are preferably substantially flat on the side of the scanning electron microscope. Here, the term "substantially flat" means a severe unevenness such as a entangled structure which is not found in the lining type graphitized short fibers. When there is a defect such as severe unevenness on the surface of the pitch-based graphitized short fiber, the viscosity increases due to an increase in surface area when kneaded with the substrate, and the type is deteriorated to -14-201016911. Therefore, it is desirable to have a state in which the defects of the surface as small as possible are as small as possible. More specifically, in the observation field of the image observed by a scanning electron microscope at 800 to 1000 times, the defects such as the unevenness are 10 or less. The method of obtaining such a pitch-based graphitized short fiber can be preferably obtained by performing a graphitization treatment after honing. The pitch-based graphitized short fibers in the present invention are preferably composed of graphite crystals, and the crystallite size originally derived from the growth direction of the hexagonal mesh surface is 20 nm or more. The crystallite size is any one of the growth directions of the hexagonal mesh surface, and corresponds to the degree of graphitization, and it is necessary to have a certain size or more in order to exhibit thermal properties. The crystal size of the growth direction of the hexagonal mesh surface can be obtained by X-ray diffraction. The measurement method preferably uses a concentration method, and the analytical method preferably uses a vibration method. The crystal size of the growth direction of the hexagonal mesh surface can be obtained by using the reflection line from the (110) plane. The true density of the pitch-based graphitized short fibers is preferably from 1.8 to 2.3 g/cm3. Within this range, the degree of graphitization is relatively high, and sufficient thermal conductivity can be exerted, and the energy cost for graphitization also becomes incompatible with the characteristics of the obtained fiber strands. More preferably 1.9~2.3g/cm3. The thermal conductivity of the pitch-based graphitized short fibers in the fiber axis direction is preferably 600 W/m·K or more. When it is 600 W/m. K or more, sufficient thermal conductivity can be obtained when the thermally conductive molded body is produced by mixing with a matrix. The thermal conductivity shown here is obtained from the specific resistance by calculating the following relationship between thermal conductivity and electrical impedance (refer to Patent No. 3 648 865), K = 1272.4 / ER-49.4 -15 - 201016911 (K is carbon fiber Thermal conductivity, ER is the specific resistance of carbon fiber), and is essentially synonymous with specific resistance. The preferred manufacturing method of the pitch-based graphitized short fibers of the present invention is described below. The pitch-based graphitized short fiber of the present invention can be obtained by fibrillating the melted mesophase pitch by a melt blow molding method under specific conditions, and then obtaining a pitch-based carbon fiber mesh without being melted and carbonized, followed by pulverization. , obtained by graphitization. The raw material of the pitch-based graphitized short fiber is exemplified by a so-called condensed polycyclic hydrocarbon compound of naphthalene or phenanthrene, a so-called condensed heterocyclic compound of petroleum pitch or stone carbon pitch, and the like. Among them, a so-called condensed polycyclic hydrocarbon compound of naphthalene or phenanthrene is preferred. The raw material of the graphitized short fibers of the present invention is a mesophase pitch. The intermediate phase ratio of the intermediate phase pitch is at least 90% or more, preferably at least 95%, more preferably at least 99%. Further, the intermediate phase ratio of the mesophase pitch can be confirmed by observing the molten state of the asphalt by a polarizing microscope. Further, the softening point of the raw material pitch is preferably from 230 ° C to 340 ° C. The non-melting treatment needs to be treated at a temperature lower than the softening point. Accordingly, when the softening point is lower than 230 °C, it is necessary to carry out the non-melting treatment at a low temperature which does not reach the softening point, and as a result, it takes a long time without melting. On the other hand, when the softening point exceeds 340 ° C, the spinning needs to exceed a high temperature of 340 ° C, which causes thermal decomposition of the asphalt, and the occurrence of bubbles or the like in the yarn due to the generated gas is not preferable. The softening point is preferably in the range of 250 ° C to 320 ° C, more preferably 260 ° C to 3 10 ° C. Also, the softening point of raw asphalt is METTLER ( -16 - 201016911
Mettler )法求得。原料瀝青亦可適當的組合兩種以上使用 。組合之原料瀝青之中間相率至少在90%以上，軟化點以 23 0°C 〜3 40°C 較佳。 中間相瀝青係以融熔法紡絲，隨後經不融化、碳化、 粉碎、石墨化成爲瀝青系石墨化短纖維。依據情況而定， 亦可在粉碎後進行分級步驟。 以下針對各步驟之較佳樣態加以說明。 紡絲方法係使用目的爲使瀝青系碳纖維前驅物帶有曲 率或表面開裂，而使用熱風作爲霧化源之融熔吹塑法。以 下記載融熔吹塑法。 形成瀝青系碳纖維前驅物之紡絲噴嘴之形狀可爲任一 種者。通常使用真圓狀者，但使用適度橢圓等之異型形狀 之噴嘴也沒有任何問題。噴嘴孔之長度（LN )與孔徑（ DN )之比例（LN/DN )較好在2~20之範圍《當LN/DN超 過20時，會對通過噴嘴之中間相瀝青賦予強力的剪斷力 ，使纖維剖面展現放射狀構造。放射狀構造之展現會在石 墨化過程中於纖維剖面上產生裂痕，而造成機械特性之下 降，故而不佳。另一方面，LN/DN未達2時，無法對原 料瀝青賦予剪斷，結果成爲石墨之配向低之瀝青系碳纖維 前驅物。據此，即使石墨化亦無法充分提高石墨化度，難 以提高導熱性而不佳。就達成兼具機械強度與導熱性而言 ，必須對中間相瀝青適度的賦予剪斷。因此，噴嘴孔之長 度（LN )與孔徑（DN )之比（LN/DN )較好在2-20之範 圍較佳，更好爲3~12之範圍。 -17- 201016911 紡絲時之中間相瀝青於噴嘴孔之融熔黏度較好爲5.0~ 25.0 Pa · s之範圍。 通過噴嘴之中間相瀝青之融熔黏度小於5Pa · s時， 有曲率變小，且曲率半徑變大之傾向，又石墨化短纖維表 面難以開裂，成爲於觀察表面時看見開裂之短纖維之比例 未達30%。另一方面，中間相瀝青之融熔黏度超過2 5. OP a • s時，會對中間相瀝青賦予強的剪斷力，於纖維剖面形 成放射構造故而不佳。爲了對中間相瀝青賦予適當範圍之 剪斷力，且維持具有曲率之纖維形狀，有必要控制通過噴 嘴之中間相瀝青之融熔黏度。因此，中間相瀝青之融熔黏 度較好在5.0~25.0Pa.s之範圍。 中間相瀝青通過噴嘴時之剪斷速度較好爲 5 000〜1 5 000 s·1 ° 吹送氣流之方向並無特別限制，但相對於紡絲方向較 好爲20〜70度，更好爲30~60度。 自噴嘴吹送之風量較好爲線速5000~20000m/分鐘。 更好爲線速8000〜1 5000m/分鐘。 自噴嘴吹送之氣流之溫度較好爲330〜370°C，更好爲 340 〜360 °C 。 本發明之瀝青系石墨化短纖維之平均纖維直徑（D1 )爲2〜20μιη以下，但瀝青系石墨化短纖維之平均纖維直 徑之控制可藉由改變噴嘴之孔徑，或者改變來自噴嘴之原 料瀝青之噴出量’或者改變拖曳比調整。拖曳比之改變可 藉由將加溫至100〜4〇〇°C之線速5000~20000m/分鐘之氣體 -18- 201016911 吹送到細化點附近而達成。吹送之氣體並無特別限制，但 就成本效益與安全性方面而言較好爲空氣》 瀝青系碳纖維前驅物係捕集在金屬網等之輸送帶上成 爲瀝青系碳纖維前驅物網狀物。此時，可藉由輸送帶之輸 送速度調整成任意的單位面積重量，但亦可依據需要以交 叉鋪網等之方法層合。瀝青系碳纖維前驅物網狀物之單位 體積重量，考量生產性及步驟之安定性，較好爲 150~1000 g/m2 〇 如此獲得之瀝青系碳纖維前驅物網狀物經不融化處理 ，成爲瀝青系不融化纖維網狀物。不融化可在使用空氣、 或將臭氧、二氧化氮、氮、氧、碘、溴添加於空氣中而成 之氣體之氧化性氛圍下進行，但考慮安全性、便利性時以 在空氣中進行較佳。又，可以批式處理，亦可連續處理， 但考慮生產性以連續處理較佳。不融化處理係在1 5 0〜3 5 0 °(：之溫度下，賦予一定時間之熱處理而達成。更好之溫度 範圍爲16 0~3 40°C。升溫速度以1〜10°C/分鐘較適用，連 續處理之情況下可依序通過設定成任意溫度之複數個反應 室而達到上述之升溫速度。考慮生產性及步驟穩定性，升 溫速度更好範圍爲3〜9 °C /分鐘。 瀝青系不融化纖維網狀物係在600~2000°C之溫度下 ’於真空中，或在使用氮氣、氬氣、氪等惰性氣體之非氧 化性氛圍中經碳化處理，成爲瀝青系碳纖維網狀物。碳化 處理考慮成本面，以在常壓下且在氮氣氛圍下處理較佳。 又’可爲批式處理，亦可爲連續楚哩，但考量生產性較好 ϊ· L 5 i -19- 201016911 爲連續處理。 經碳化處理之瀝青系碳纖維網狀物爲了成爲期望之纖 維長度，而進行切斷、破碎、粉碎等處理。又，依據情況 而定，進行分級處理。處理方式係依據期望之纖維長度加 以選擇，但就切斷可較好地使用裁切機式、單軸、雙軸及 多軸旋轉式等切割機，破碎、粉碎可較好地使用利用衝擊 作用之鎚擊式、撞針式、球擊式、珠粒式及棒式，利用粒 子彼此衝撞之高速旋轉式、利用壓縮•撕裂作用之滾筒式 、圓錐式及螺旋式等之破碎機•粉碎機等。爲獲得期望之 纖維長度，亦可以多種複數種機器構成切斷與破碎•粉碎 。處理氛圍可爲濕式、乾式之任一者。分級處理係較好地 使用振動過篩式、離心分離式、慣性力式、過濾式等之分 級裝置等。期望之纖維長度不僅可藉由選定機種而得，亦 可藉由控制轉子•旋轉刀等之轉速、供給量、刀刃間之間 隙、系統內之滯留時間等而獲得。又，使用分級處理時， 亦可藉由調整篩網之網目孔徑等獲得所需纖維長度。 倂用上述之切斷、破碎、粉碎處理、及依據情況之分 級處理作成之瀝青系碳短纖維經加熱至2000〜3 5 00 °C並石 墨化最終成爲瀝青系石墨化短纖維。石墨化係以 Ache son 爐、電爐等實施，在真空中或使用氮、氬、氪等惰性氣體 之非氧化性氛圍中實施。 本發明中之瀝青系石墨化短纖維爲了使基質之親和性 更高，提高成型性或提高作爲複合材時之機械強度，亦可 經表面處理或上膠處理。又，亦可依據需要於表面處理後 -20- 201016911 經上膠處理。表面處理之方法並無特別限制，但具體而言 舉例爲電著處理、電鍍處理、臭氧處理、電漿處理、酸處 理等。上膠處理所用之上膠劑並無特別限制，但具體而言 可單獨使用環氧化物、水溶性聚醯胺化合物、飽和聚酯、 不飽和聚酯、乙酸乙烯酯、水、醇類、二醇類，或使用該 等之混合物。上膠劑相對於瀝青系石墨化短纖維只要可附 著0.01 ~10重量％即可。然而，附著上膠劑之瀝青系石墨 化短纖維由於亦有帶有活性點之可能性，因此上膠劑以儘 量少較佳。較佳之附著量爲0.1〜2.5重量％。上膠劑之種 類或使用量宜考慮目的或複合之基質而使用。 本發明之瀝青系石墨化短纖維可與基質複合獲得化合 物、薄片、油脂、接著劑等之成形材料或導熱性成型體。 此時，瀝青系石墨化短纖維相對於100體積份之基質係添 加3〜20 0體積份。添加量少於3體積份時，難以充分確保 導熱性。另一方面，多於200體積份時，瀝青系石墨化短 纖維對於基質之添加大多變困難。 基質爲選自由熱可塑性樹脂、熱硬化性樹脂、三聚氰 胺樹脂及橡膠所組成群組之至少一種。爲了對複合成型體 展現期望之物性，亦可適當的混合使用熱可塑性樹脂與熱 硬化性樹脂。 基質中可使用之作爲熱可塑性樹脂可舉例爲聚烯烴及 其共聚物（聚乙烯、聚丙烯、聚甲基戊嫌、聚氯乙烯、聚 偏氯乙烯、聚乙酸乙烯酯、聚乙烯醇、乙烯-乙酸乙烯酯 共聚物、乙烯-丙烯共聚物等乙烯烯烴共聚物等）、 -21 - 201016911 聚甲基丙烯酸及其共聚物 丙烯酸酯等）、聚炳烯酸及其共聚物'聚乙縮醒及其共聚 物、氟樹脂及其共聚物（聚偏氟乙嫌、聚四氣乙嫌等）、 聚酯及其共聚物（聚對苯二甲酸乙二酯、聚對苯二甲酸丁 二酯、聚伸乙基-2,6 -蔡二甲酸酯、液晶性聚合物等）、聚 苯乙嫌及其共聚物（苯乙烯-丙儲腈共聚物、ABS樹脂等 )、聚丙烯腈及其共聚物、聚苯酸（PPE)及其共聚物（ 亦包含改質之PPE樹脂等）、脂肪族聚醯胺及其共聚物 、聚碳酸酯及其共聚物、聚苯硫酸及其共聚物、聚碾及其 共聚物、聚醚碾及其共聚物、聚醚腈及其共聚物、聚醚酮 及其共聚物、聚醚醚酮及其共聚物、聚酮及其共聚物、彈 性體、液晶性聚合物等。 其中較好爲選自由聚碳酸酯、聚對苯二甲酸乙二酯、 聚對苯二甲酸丁二酯、聚伸乙基-2,6-萘二甲酸酯、脂肪族 聚醯胺、聚丙烯、聚乙烯、聚醚酮、聚苯硫醚' 及丙烯 腈-丁二烯-苯乙烯系共聚合樹脂所構成之群組之至少一種 樹脂。又可單獨使用該等之一種，亦可適當的組合兩種以 上使用。 又，作爲熱硬化性樹脂，舉例爲環氧樹脂、熱硬化性 丙烯酸樹脂、胺基甲酸酯樹脂、聚矽氧樹脂、酚樹脂、熱 硬化型改質之PPE樹脂及熱硬化型PPE樹脂、聚醯胺樹 脂及其共聚物、芳香族聚醯胺醯亞胺樹脂及其共聚物等。 該等可以一種單獨使用，亦可適當的組合兩種以上使用。 芳醯胺樹脂可例示爲源自由對苯二甲酸及/或間苯二 -22- 201016911 甲酸所構成之芳香族二羧酸成分，與選自由14·苯二胺、 1，3-苯二胺、3,4’-二胺基二苯基醚、4,4’_二胺基二苯基醚 及1，3-雙（3-胺基苯氧基）苯所構成群組之至少一種芳香 族二胺之全芳香族聚醯胺。 至於橡膠並無特別限制，可爲天然橡膠（NR)、丙 烯酸橡膠、丙烯腈丁二烯橡膠（NBR橡膠）、異戊間二 烯橡膠（IR)、胺基甲酸酯橡膠、乙烯丙烯橡膠（EPM) Γ 、表氯醇橡膠、氯丁二烯橡膠（CR)、矽氧橡膠及其共 聚物、苯乙烯丁二烯橡膠（SBR) 、丁二烯橡膠（BR)、 丁基橡膠等。 ' 本發明之組成物係混合瀝青系石墨化短纖維與基質製 - 作’但混合時較好適當的使用捏合機、各種混練機、摻合 機、輥、擠出機、硏磨機、自公轉式之攪拌機等之混合裝 置或混練裝置。 基質爲由熱可塑性樹脂組成之導熱性組成物時，可藉 (.. 由選自由射出成形法、壓製成形法、砑光成形法、輥成形 法、擠出成形法、注模成形法以及吹塑成形法所組成群組 之至少一種方法成型，獲得成型體。接著，薄片狀成型體 可藉由輥擠出，或藉由模嘴擠出等之擠出成形法成型。成 型條件係依成形方法及基質而定，且係在使提高溫度高於 該樹脂之融熔黏度之狀態下實施成形。 基質爲由熱硬化性樹脂組成之導熱性組成物時，可藉 由選自由射出成形法、壓製成形法、砑光成形法、輥成形 法、擠出成形法及注模成形法所組成群組之至少一種方法 -23- 201016911 成形，獲得成型體。成型條件係依成形方法及基質而定， 可舉例爲適當之型態中施加該樹脂之硬化溫度之方法。 基質爲由三聚氰胺樹脂所構成之導熱性組成物時，可 使三聚氰胺溶解於溶劑中，將瀝青系石墨化短纖維混合於 其中，使用澆鑄法成型。此處之溶劑只要可使三聚氰胺溶 解即無特別限制，但具體而言可使用N，N-二甲基乙醯胺 、N-甲基吡咯啶酮等醯胺系溶劑。 基質爲由橡膠所組成之導熱性組成物時，可藉由選自 由壓製成形法、砑光成形法、輥成形法所構成之群組之至 少一種方法成型，獲得成型體。成型條件係依成形方法與 基質而定，可舉例爲對該橡膠施以硫化溫度之方法。 爲了使本發明組成物之導熱率更高，亦可依據需要添 加瀝青系石墨化短纖維以外之塡充劑。具體而言舉例爲氧 化鋁、氧化鎂、氧化矽、氧化鋅等金屬氧化物、氫氧化鋁 、氫氧化鎂等金屬氫氧化物、氮化硼、氮化鋁等金屬氮化 物、氧化氮化鋁等金屬氧氮化物、碳化矽等金屬碳化物、 金、銀、銅、鋁等金屬或金屬合金、天然石墨、人造石墨 、膨脹石墨、鑽石等碳材料等。較好依據功能適宜添加該 等塡充劑。另外，亦可倂用兩種以上。 再者，爲了使成型性、機械物性等其他特性更高，亦 可依據所需之功能適宜添加玻璃纖維、鈦酸鉀晶鬚、氧化 鋅晶鬚、硼化鋁晶鬚、氮化硼晶鬚、芳醯胺纖維、氧化鋁 纖維、碳化矽纖維 '石綿纖維、石膏纖維、金屬纖維等纖 維狀塡充劑。亦可倂用兩種以上之該等塡充劑。亦可依據 -24- 201016911 需要適度的添加矽灰石、沸石、矽藻土、高嶺土、雲母、 黏土、葉蠟石、膨潤土、石綿、滑石、氧化鋁矽酸鹽等矽 酸鹽、碳酸鈣、碳酸鎂、白雲石等碳酸鹽、硫酸鈣、硫酸 鋇等硫酸鹽、玻璃珠、玻璃片及陶磁珠等非纖維狀塡充劑 。該等可爲中空，再者亦可倂用兩種以上之該等塡充劑。 但’上述化合物大多爲密度大於瀝青系石墨化短纖維者， 於輕量化之目的而言，有必要注意添加量或添加比率。 又’依據需要將複數種其他添加劑添加於組成物中亦 無妨。其他添加劑可舉例爲脫模劑、難燃劑、乳化劑、軟 化劑、可塑劑、界面活性劑。 將本發明之組成物成形爲平板狀且測定導熱率時顯示 2W/ (m· K)以上之導熱率。2W/ (m· K)之導熱率相較 於作爲基質用之樹脂約高一位數之導熱率。 本發明之組成物藉由利用其高的導熱率，可使用作爲 電子零件用散熱版。又，由於瀝青系石墨化短纖維之添加 量變多，可獲得高的導熱度，因此亦可較好地使用於電子 零件之比較要求耐熱性之汽車或需要大電流之產業用功率 模組之連接器等。更具體而言可用於散熱板、半導體封裝 用零件、散熱器、散熱板、裸晶墊、印刷電路板、冷卻鰭 板用零件、框體等。又，亦可作爲熱交換器之零件使用。 亦可用於加熱管中。再者，可利用瀝青系石墨化短纖維之 電波遮蔽性，尤其較好地使用作爲GHz帶之電波遮蔽用 零件。 -25- 201016911 實施例 以下顯示實施例’但本發明並不受該等之限制。又’ 本實施例中之各値係依循以下方法求得。 (1) 關於瀝青系石墨化短纖維，曲率半徑爲 10〜60cm者之比例係以光學顯微鏡放大4倍，測定2000 條纖維長度ιοομιη以上之纖維，且觀察曲率半徑爲 1 0〜6 0 c m之條數，求得相對於2 0 0 0條之比例。 (2) 瀝青系石墨化短纖維之平均纖維直徑及纖維直 徑分散（CV値） 平均纖維直徑（D 1 )係以光學顯微鏡下利用尺規測 定60條碳纖維之纖維直徑，且求得其平均値。另外’ CV 値爲所得平均纖維直徑（D1)與纖維直徑分散（SI) & 比率，且由下式決定。 CV = S1 /D 1 X 100 其中，S 1 ^((ΣΧ-D 1) 2/η)，X爲觀測値，η爲觀 測數。 (3) 瀝青系石墨化短纖維之個數平均纖維長度彳系& 光學顯微鏡放大至4倍，以尺規測定2000條’自其平均 値求得。 (4) 瀝青系石墨化短纖維之結晶子尺寸係測定由Μ 現X射線繞射之（110)面之反射，以學振法求得。 (5) 瀝青系碳短纖維之真密度係調整溴仿（密度 -26- 201016911 ' 2.90g/cc )與1，1 ,2,2-四氯乙烷（密度1.59g/cc)之混合比 而調整溶液密度之混合液中，投入碳纖維且由碳纖維之沉 降狀況決定。 (6)瀝青系石墨短纖維之導熱率，係以除了粉碎步 驟以外與比電阻之相同條件製作瀝青系石墨化纖維，使用 銀糊料固定以使瀝青系石墨化纖維兩端距離爲lcm，以測 試器測定20條兩端之電阻，且使用瀝青系碳纖維之半徑 (" 計算求得，且由導熱率與電阻之下列關係式（參考日本特 許3 64 8 865號）計算求得。 K=1272.4/ER-49.4 (K爲碳纖維之導熱率W/(m.K) ，ER爲碳纖維之 比電阻Αί Ω m ) (7) 瀝青系石墨化短纖維之端面係以透過型電子顯 微鏡，在100萬倍之倍率下觀察，於照片上放大至400萬 倍，確認爲石墨薄片。 (8) 瀝青系石墨化短纖維之開裂、表面形狀、有無 凹凸係以掃描電子顯微鏡在800倍之倍率下觀察。另外， 觀察條數爲5 0條。 (9) 平板狀成型體.之導熱率係以京都電子製造之 QTM-5 00 測定。 實施例1 -27- 201016911 以縮合多環烴化合物爲主、光學各向異性比例爲 100%、軟化點爲285 °c之瀝青，使用直徑0.2 mm φ孔之蓋 子’自狹長模嘴以相對於紡絲方向成45度角，以6000 m/ 分之線速度噴出350 °C之加熱空氣，使融熔之瀝青拉伸， 製作平均直徑11.3μηι之瀝青系碳纖維前驅物。此時之紡 絲溫度爲320°C，融熔黏度爲19.5Pa. s(195泊）。將紡 出之纖維收集於輸送帶上成爲網狀物，接著以交叉鋪置成 爲由單位面積重300g/m2之瀝青系碳纖維前驅物構成之瀝 青系碳纖維前驅物網狀物。 在空氣中，以平均升溫速度5 °C/分鐘使該瀝青系碳纖 維前驅物自170 °C升溫至300勺並不融化，再於800 °C下 進行燒成。使用切割機（TURBO工業製造）在800rpm下 將該瀝青系碳纖維網狀物粉碎後，在3000°C下石墨化， 獲得瀝青系石墨化短纖維。 所得瀝青系石墨化短纖維之平均纖維直徑爲8.2μιη， 相對於平均纖維直徑之纖維直徑分散比（CV値）爲1 0% 。個數平均纖維長度爲15 Ομπι。光學顯微鏡之4倍觀察例 示於圖2中。2000條纖維長度ΙΟΟμιη以上之纖維中，曲 率半徑10~60cm範圍之比例爲80%。 又，掃描電子顯微鏡之觀察例（800倍）示於圖1中 ’但照片中以箭頭指示觀察到石墨化短纖維之表面開裂之 位置。具有表面開裂之纖維之比例爲40%。源自瀝青系石 墨化短纖維之六角網面之成長方向之結晶尺寸爲70nm， 真密度爲2.2g/cm3，導熱率爲700W/m · K。藉由透過顯 -28- 201016911 微鏡觀察瀝青系石墨化短纖維之端面確定石墨薄片爲閉合 。又以掃描電子顯微鏡觀察瀝青系石墨化短纖維之表面， 爲具有1個凹凸之實質上平滑者。 實施例2 以縮合多環烴化合物爲主、光學各向異性比例爲 100%、軟化點爲285 °C之瀝青，使用直徑0.2mm(D孔之蓋 子，自狹長模嘴以相對於紡絲方向成45度角，以7000m/ 分之線速度噴出355 °C之加熱空氣，使融熔之瀝青拉伸， 製作平均直徑15, Ομιη之瀝青系碳纖維前驅物。此時之防 絲溫度爲3 5 5 °C，融熔黏度爲13.0Pa · s ( 130泊）。將紡 出之纖維收集於輸送帶上成爲網狀物，接著以交叉鋪置成 爲由單位面積重400g/m2之瀝青系碳纖維前驅物構成之瀝 青系碳纖維前驅物網狀物。 在空氣中，以平均升溫速度5 °C/分鐘使該瀝青系碳纖 維前驅物自170°C升溫至320°C並不融化，再於800°C下 進行燒成。使用切割機（TURBO工業製造）在800rpm下 將該瀝青系碳纖維網狀物粉碎後，在3 00(TC下石墨化， 獲得瀝青系石墨化短纖維。 所得瀝青系石墨化短纖維之平均纖維直徑爲9.9μιη， 相對於平均纖維直徑之纖維直徑分散比（CV値）爲8%。 個數平均纖維長度爲170 μπι。2000條纖維長度100 μιη以 上之纖維中，曲率半徑1 〇〜6 0 cm範圍之比例爲75%。又 ’掃描電子顯微鏡之觀察之具有表面開裂之纖維之比例爲 -29- 201016911 7 0%。源自瀝青系石墨化短纖維之六角網面之成長方向之 結晶尺寸爲70nm，真密度爲2.2g/cm3，導熱率爲700W/m • K。藉由透過型顯微鏡觀察瀝青系石墨化短纖維之端面 確定石墨薄片爲閉合。又以掃描電子顯微鏡觀察瀝青系石 墨化短纖維之表面，爲具有1個凹凸，實質上爲平滑。 實施例3 使用真空式自公轉混合機（THINKY製造之練太郎 ARV-310)，混合30體積份之實施例1獲得之瀝青系石 墨化短纖維、70體積份之矽氧樹脂（TOSHO ♦ DOW SILICONE製造，SE 1 740 ) 3分鐘，成爲複合漿料。以真 空壓製機（北川精機製造）壓製加工該漿料，獲得厚度 0.5 mm之平板狀複合成型體，且在130 °C下硬化2小時， 製備導熱性成型體。測定導熱性成型體之導熱率，爲 1 2.0W/ ( m · K )。 實施例4 使用雙軸混練機（栗本鐵工所製造）混練30體積份 之實施例1獲得之瀝青系石墨化短纖維、7〇體積份之聚 碳酸酯樹脂（帝人化成製造，L-1225WP)，成爲顆粒。 以射出成形機（名機製作所製造M-50B )使該顆粒成形’ 獲得厚度2mm之平板狀導熱性成型體。測定導熱性成型 體之導熱率，爲4.3W/(m.K)。 -30- 201016911 實施例5 使用雙軸混練機（栗本鐵工所製造）混練30體積份 之實施例1獲得之瀝青系石墨化短纖維、70體積份之聚 苯硫醚（Polyplastic公司製_造’ 0220A9) ’成爲顆粒。 以射出成形機（名機製作所製造M-5 0B)使該顆粒成形， 獲得厚度2mm之平板狀導熱性成型體。測定導熱性成型 體之導熱率爲5.2W/(m.K)。 實施例6 使用真空式自公轉混合機（THINKLY製造之練太郎 ARV-310)，混合30體積份之實施例2獲得之瀝青系石 墨化短纖維、70體積份之矽氧樹脂（TOSHO · DOW SILICONE製造，SE1 740 ) 3分鐘，成爲複合漿料。以真 空壓製機（北川精機製造）壓製加工該漿料，獲得厚度 0.5 mm之平板狀複合成型體，且在130 °C下硬化2小時， 製作導熱性成型體。測定導熱性成型體之導熱率，爲 1 1 _8W/ ( m · K )。 實施例7 使用雙軸混練機（栗本鐵工所製造）混練30體積份 之實施例2獲得之瀝青系石墨化短纖維、70體積份之聚 碳酸酯樹脂（帝人化成製造，L- 1225WP )，成爲顆粒。 以射出成形機（名機製作所製造M-5 0B)使該顆粒成形’ 獲得厚度2mm之平板狀導熱性成型體。測定導熱性成型 -31 - 201016911 體之導熱率，爲.4.1W/(m.K)。 實施例8 使用雙軸混練機（栗本鐵工所製造）混練30體積份 之實施例2獲得之瀝青系石墨化短纖維、70體積份之聚 苯硫醚（Polyplastic公司製造，0220A9)，成爲顆粒。 以射出成形機（名機製作所製造M-50B )使該顆粒成形， 獲得厚度2mm之平板狀導熱性成型體。測定導熱性成型 體之導熱率爲5.4W/ ( m · K )。 比較例1 以縮合多環烴化合物爲主、光學各向異性比例爲 100%、軟化點爲283 °C之瀝青，使用直徑0.05 mm(D孔之 蓋子，自蓋子擠出瀝青，且冷卻至室溫，獲得平均直徑 15μιη之瀝青系碳纖維前驅物。此時之紡絲溫度爲310 °C ，融熔黏度爲55.0Pa.s(550泊）。 在空氣中，以平均升溫速度5t/分鐘使該瀝青系碳纖 維前驅物自170°C升溫至 320 °C並不融化，再於800°C下 進行燒成。使用切割機（TURBO工業製造）在800rpm下 將該瀝青系碳纖維網狀物粉碎，在3000 °C下石墨化。瀝 青系石墨化短纖維之平均纖維直徑爲9.8μιη，相對於平均 纖維直徑之纖維直徑分散比（CV値）爲3%。個數平均纖 維長度爲160μιη。纖維長度ΙΟΟμηι以上之纖維中，幾乎 未觀察到具有曲率之短纖維，曲率半徑1 0〜6 0 cm範圍之 比例爲0%。又’以掃描電子顯微鏡觀察具有表面開裂之 -32- 201016911 ’ 纖維之比例爲40%。 源自瀝青系石墨化短纖維之六角網面之成長方向之結 晶尺寸爲40nm ’真密度爲2.2g/cm3，導熱率爲400W/m . K。藉由透過型顯微鏡觀察瀝青系石墨化短纖維之端面確 定石墨薄片爲閉合。又以掃描電子顯微鏡観察瀝青系石墨 化短纖維之表面，爲具有1個凹凸，實質上爲平滑。 比較例2 以縮合多環烴化合物爲主、光學各向異性比例爲 100%、’軟化點爲285 °C之瀝青，使用直徑0.2 mm Φ孔之蓋 子，自狹長模嘴以相對於紡絲方向成45度角，以4000m/ 分之線速度噴出358 °C之加熱空氣，使融熔之瀝青拉伸， 製作平均直徑15.Ομχη之瀝青系碳纖維前驅物。此時之紡 絲溫度爲3 5 0°C，融熔黏度爲4.0Pa . s ( 40泊）。將紡出 之纖維收集於輸送帶上成爲網狀物，接著以交叉鋪置成爲 由單位面積重400g/m2之瀝青系碳纖維前驅物構成之瀝青 系碳纖維前驅物網狀物。 在空氣中，以平均升溫速度5 °C/分鐘使該瀝青系碳纖 維前驅物自170°C升溫至320°C並不融化，再於80(TC下 進行燒成。使用切割機（TURBO工業製造）在800rpm下 將該瀝青系碳纖維網狀物粉碎後，在3000°C下石墨化。 瀝青系石墨化短纖維之平均纖維直徑爲9.7μιη，相對 於平均纖維直徑之纖維直徑分散比（CV値）爲20%。個 數平均纖維長度爲170μιη。纖維長度ΙΟΟμιη以上之纖維 -33- 201016911 中，曲率半徑10〜60 cm範圍之比例爲70%。又，掃描電 子顯微鏡觀察之具有表面開裂之纖維之比例爲10 % ^ 源自瀝青系石墨化短纖維之六角網面之成長方向之結 晶尺寸爲7〇nm，真密度爲2.2g/cm3，導熱率爲700W/m · K。藉由透過型顯微鏡觀察瀝青系石墨化短纖維之端面確 定石墨薄片爲閉合。又以掃描電子顯微鏡觀察瀝青系石墨 化短纖維之表面，爲具有1個凹凸，實質上爲平滑。 比較例3 使用真空式自公轉混合機（THINKY製造之練太郎 ARV-3 10)，混合30體積份之比較例1獲得之瀝青系石 墨化短纖維、70體積份之矽氧樹脂（TOSHO · DOW SILICONE製造，SE 1 740 ) 3分鐘，成爲複合漿料。以真 空壓製機（北川精機製造）壓製加工該漿料，獲得厚度 0.5mm之平板狀複合成型體，且在130°C下硬化2小時， 製備導熱性成型體。測定導熱性成型體之導熱率，爲 2.7W/ ( m · K )。 比較例4 使用雙軸混練機（栗本鐵工所製造）混練30體積份 之比較例1獲得之瀝青系石墨化短纖維、7〇體積份之聚 碳酸酯樹脂（帝人化成製造，L-1225WP)，成爲顆粒。 以射出成形機（名機製作所製造M-50B)使該顆粒成形， 獲得厚度2mm之平板狀導熱性成型體。測定導熱性成型 -34- 201016911 體之導熱率爲1_4W/ ( m · K)。 比較例5 使用雙軸混練機（栗本鐵工所製造）混練30 之比較例1獲得之瀝青系石墨化短纖維、7〇體積 苯硫醚（Polyplastic公司製造，0220Α9 )，成爲 以射出成形機（名機製作所製造M-50B)使該顆粒 獲得厚度2mm之平板狀導熱性成型體。測定導熱 體之導熱率爲1.7W/ ( m · K)。 比較例6 使用真空式自公轉混合機（THINKY製造之 ARV-310)，混合30體積份之比較例2獲得之瀝 墨化短纖維、70體積份之矽氧樹脂（TOSHO SILICONE製造，SE1 740 ) 3分鐘，成爲複合漿料 空壓製機（北川精機製造）壓製加工該漿料，獲 0.5mm之平板狀複合成型體，且在130°C下硬化2 製備導熱性成型體。測定導熱性成型體之導熱 8.8W/ ( m · K )。 比較例7 使用雙軸混練機（栗本鐵工所製造）混練30 之比較例2獲得之瀝青系石墨化短纖維' 70體積 碳酸酯樹脂（帝人化成製造，L- 1 225 WP )，成爲 體積份 份之聚 顆粒。 成形， 性成型 練太郎 青系石 • DOW 。以真 得厚度 小時， 率，爲 體積份 份之聚 顆粒。 -35- 201016911 以射出成形機（名機製作所製造M-50B)使該 獲得厚度2mm之平板狀導熱性成型體。測定 體之導熱率，爲3.1W/(m.K)。 比較例8 使用雙軸混練機（栗本鐵工所製造）混練 之比較例2獲得之瀝青系石墨化短纖維、70 苯硫醚（Polyplastic公司製造，0220A9) ， 以射出成形機（名機製作所製造M-50B)使該 獲得厚度2mm之平板狀導熱性成型體。測定 體之導熱率爲4_lW/(m.K)。 [發明效果] 本發明之瀝青系石墨化短纖維藉由控制具 率半徑，以及控制表面具有開裂且具有開裂之 率，進而藉由控制相對於平均纖維直徑之纖維 可獲得網狀物形成容易且高導熱率之複合成型 [產業上之可能利用性] 本發明之瀝青系石墨化短纖維可控制曲率 由掃描型電子顯微鏡觀察之表面，使用該等可 現高的導熱性。據此，對使用於要求高放熱特 爲可能，爲確實可實施熱管理者。 顆粒成形， 導熱性成型 3〇體積份 體積份之聚 成爲顆粒。 顆粒成形， 導熱性成型 有曲率之曲 短纖維之比 直徑分散， 體。 半徑以及藉 使複合材展 性之場所成 -36- 201016911 【圖式簡單說明】 圖1爲於實施例1獲得之瀝青系石墨化短纖維之掃描 電子顯微鏡觀察（800倍）。 ' 圖2爲於實施例1獲得之瀝青系石墨化短纖維之光學 顯微鏡（4倍）及曲率半徑之求得方式之圖示。 圖3爲說明曲率半徑求得方式之模式圖。Mettler) method is obtained. The raw material pitch may be used in combination of two or more kinds as appropriate. The raw material pitch of the combined raw material pitch is at least 90%, and the softening point is preferably from 23 0 ° C to 3 40 ° C. The mesophase pitch is spun by a melt method, and then becomes a pitch-based graphitized short fiber without being melted, carbonized, pulverized, or graphitized. Depending on the situation, the grading step can also be carried out after comminution. The preferred aspects of each step are described below. The spinning method uses a melt blow molding method in which a pitch-based carbon fiber precursor is subjected to curvature or surface cracking, and hot air is used as an atomizing source. The melt blow molding method is described below. The shape of the spinning nozzle forming the pitch-based carbon fiber precursor may be either. Usually, a true round shape is used, but there is no problem in using a nozzle of a profiled shape such as a moderate ellipse. The ratio of the length of the nozzle hole (LN) to the diameter of the aperture (DN) (LN/DN) is preferably in the range of 2 to 20. When LN/DN exceeds 20, a strong shear force is imparted to the mesophase pitch passing through the nozzle. To make the fiber profile show a radial structure. The appearance of the radial structure causes cracks in the fiber profile during the incineration process, which causes a decrease in mechanical properties, which is not preferable. On the other hand, when LN/DN is less than 2, it is impossible to impart shear to the raw material pitch, and as a result, it becomes a pitch-based carbon fiber precursor having a low alignment of graphite. Accordingly, even if graphitization is not sufficient to increase the degree of graphitization, it is difficult to improve the thermal conductivity. In order to achieve both mechanical strength and thermal conductivity, it is necessary to impart a moderate shear to the mesophase pitch. Therefore, the ratio of the length (LN) to the aperture (DN) of the nozzle hole (LN/DN) is preferably in the range of 2 to 20, more preferably in the range of 3 to 12. -17- 201016911 The melt viscosity of the mesophase pitch in the nozzle hole during spinning is preferably in the range of 5.0 to 25.0 Pa · s. When the melt viscosity of the mesophase pitch passing through the nozzle is less than 5 Pa·s, the curvature becomes small and the radius of curvature becomes large, and the surface of the graphitized short fiber is hard to be cracked, and becomes a ratio of short fibers which are seen to be cracked when the surface is observed. Less than 30%. On the other hand, the melt viscosity of the mesophase pitch exceeds 2 5. OP a • s gives a strong shearing force to the mesophase pitch, which is not good for the fiber structure to form a radiation structure. In order to impart a proper range of shear force to mesophase pitch and maintain a fiber shape having a curvature, it is necessary to control the melt viscosity of the mesophase pitch through the nozzle. Therefore, the melt viscosity of the mesophase pitch is preferably in the range of 5.0 to 25.0 Pa.s. The shearing speed of the mesophase pitch through the nozzle is preferably 5,000 to 15,000 s·1 °. The direction of the blowing gas flow is not particularly limited, but is preferably 20 to 70 degrees, more preferably 30, with respect to the spinning direction. ~60 degrees. The air volume blown from the nozzle is preferably a line speed of 5,000 to 20,000 m/min. Better for line speeds of 8000~1 5000m/min. The temperature of the gas stream blown from the nozzle is preferably from 330 to 370 ° C, more preferably from 340 to 360 ° C. The pitch-type graphitized short fibers of the present invention have an average fiber diameter (D1) of 2 to 20 μm or less, but the average fiber diameter of the pitch-based graphitized short fibers can be controlled by changing the pore diameter of the nozzle or changing the raw material pitch from the nozzle. The amount of discharge 'or change the drag ratio adjustment. The change in the drag ratio can be achieved by blowing a gas -18-201016911 which is heated to a line speed of 5,000 to 20,000 m/min to a vicinity of the refinement point. The gas to be blown is not particularly limited, but it is preferably air in terms of cost effectiveness and safety. The pitch-based carbon fiber precursor is trapped on a conveyor belt of a metal mesh or the like to form a pitch-based carbon fiber precursor mesh. In this case, the conveying speed of the conveyor belt can be adjusted to an arbitrary basis weight, but it can be laminated by a method such as cross-laying as needed. The unit volume weight of the pitch-based carbon fiber precursor mesh, considering the productivity and the stability of the step, is preferably 150-1000 g/m2. The thus obtained pitch-based carbon fiber precursor mesh is not melted and becomes asphalt. Does not melt the fibrous network. The non-melting can be carried out in an oxidizing atmosphere using air or a gas in which ozone, nitrogen dioxide, nitrogen, oxygen, iodine, and bromine are added to the air, but in the air in consideration of safety and convenience Preferably. Further, it may be batch-treated or continuously processed, but it is preferable to consider the productivity in a continuous process. The non-melting treatment is achieved by heat treatment at a temperature of 150 to 305 ° (for a certain period of time. The temperature range is preferably 16 0 to 3 40 ° C. The temperature rise rate is 1 to 10 ° C / The minute is more suitable. In the case of continuous treatment, the above-mentioned heating rate can be achieved by a plurality of reaction chambers set to any temperature. Considering the productivity and the stability of the steps, the heating rate is better in the range of 3 to 9 ° C /min. The asphalt-based non-melting fiber network is carbonized at a temperature of 600 to 2000 ° C in a vacuum or in a non-oxidizing atmosphere using an inert gas such as nitrogen, argon or helium to become a pitch-based carbon fiber. The carbonization treatment considers the cost surface and is preferably treated under normal pressure and under a nitrogen atmosphere. It can be batch-processed or continuous, but it is considered to be more productive. L 5 i -19- 201016911 is a continuous treatment. The carbonized web of carbonized carbon fiber is cut, crushed, pulverized, etc. in order to obtain the desired fiber length, and is classified according to the situation. According to expectations The length of the fiber is selected, but the cutting machine, the single-shaft, the double-shaft and the multi-axis rotary cutting machine can be preferably used for cutting. The crushing and pulverizing can better use the hammering type and the striker using the impact effect. Type, ball-type, bead type, and rod type, a high-speed rotary type in which particles collide with each other, a crusher, a crusher, etc., which are used in a drum type, a conical type, and a spiral type, which are used for compression and tearing, etc. The length of the fiber can also be cut, crushed and pulverized by a plurality of kinds of machines. The treatment atmosphere can be either wet or dry. The classification treatment is better by using vibration screening, centrifugal separation, inertial force, A classification device such as a filter type, etc. The desired fiber length can be obtained not only by the selected model, but also by controlling the rotation speed of the rotor, the rotary blade, the supply amount, the gap between the blades, and the residence time in the system. Further, when the grading treatment is used, the required fiber length can be obtained by adjusting the mesh aperture of the screen, etc. 倂 The above-mentioned cutting, crushing, pulverizing treatment, and grading according to the situation The prepared pitch-based carbon short fibers are heated to 2000 to 3 500 ° C and graphitized to finally form pitch-based graphitized short fibers. The graphitization is carried out in an Acheson furnace, an electric furnace, or the like, in a vacuum or using nitrogen or argon. It is carried out in a non-oxidizing atmosphere of an inert gas such as hydrazine. The pitch-based graphitized short fiber of the present invention may be subjected to surface treatment or in order to improve the moldability, improve moldability, or improve mechanical strength as a composite material. The sizing treatment can also be sizing after the surface treatment is -20- 201016911. The surface treatment method is not particularly limited, but specifically, it is an electrolysis treatment, a plating treatment, an ozone treatment, a plasma treatment. Treatment, acid treatment, etc. The topping agent used for the sizing treatment is not particularly limited, but specifically, an epoxide, a water-soluble polyamine compound, a saturated polyester, an unsaturated polyester, a vinyl acetate, or the like may be used alone. Water, alcohols, glycols, or mixtures of such. The sizing agent may be attached to the pitch-based graphitized short fiber in an amount of 0.01 to 10% by weight. However, the pitch-based graphitized short fibers to which the sizing agent is attached also have a possibility of having an active point, so that the sizing agent is preferably as small as possible. A preferred amount of adhesion is from 0.1 to 2.5% by weight. The type or amount of sizing agent should be used in consideration of the intended or composite matrix. The pitch-based graphitized short fibers of the present invention can be combined with a matrix to obtain a molding material such as a compound, a sheet, a grease, an adhesive, or the like, or a thermally conductive molded body. At this time, the pitch-based graphitized short fiber was added in an amount of 3 to 20 parts by volume with respect to 100 parts by volume of the matrix. When the amount added is less than 3 parts by volume, it is difficult to sufficiently ensure thermal conductivity. On the other hand, when it is more than 200 parts by volume, the addition of the pitch-based graphitized short fiber to the substrate is often difficult. The substrate is at least one selected from the group consisting of thermoplastic resins, thermosetting resins, melamine resins, and rubbers. In order to exhibit desired physical properties to the composite molded article, a thermoplastic resin and a thermosetting resin may be appropriately mixed. The thermoplastic resin which can be used in the matrix can be exemplified by polyolefin and its copolymer (polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyvinyl alcohol, ethylene). -vinyl acetate copolymer, ethylene-propylene copolymer and other ethylene olefin copolymers, etc.), -21 - 201016911 polymethacrylic acid and its copolymer acrylate, etc.), polyethylenic acid and its copolymer And copolymers thereof, fluororesins and copolymers thereof (polyvinyl fluoride, polytetraethylene, etc.), polyesters and copolymers thereof (polyethylene terephthalate, polybutylene terephthalate) , polyethylene-2,6-calyptate, liquid crystal polymer, etc.), polystyrene and its copolymers (styrene-acrylonitrile copolymer, ABS resin, etc.), polyacrylonitrile and copolymerization thereof , polybenzoic acid (PPE) and its copolymers (including modified PPE resins, etc.), aliphatic polyamines and copolymers thereof, polycarbonates and copolymers thereof, polyphenylsulfuric acid and its copolymers, poly Milling and copolymers thereof, polyether mills and copolymers thereof, polyether nitriles and copolymers thereof, polyethers And copolymers thereof, and copolymers thereof, polyetheretherketones, polyketones and copolymers thereof, elastomer, liquid crystal polymer. Preferably, it is selected from the group consisting of polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, aliphatic polyamine, poly At least one resin of the group consisting of propylene, polyethylene, polyether ketone, polyphenylene sulfide', and acrylonitrile-butadiene-styrene copolymer resin. These may be used alone or in combination of two or more. Further, examples of the thermosetting resin include an epoxy resin, a thermosetting acrylic resin, a urethane resin, a polyoxyxylene resin, a phenol resin, a thermosetting modified PPE resin, and a thermosetting PPE resin. Polyamide resin and copolymer thereof, aromatic polyamidoximine resin and copolymer thereof. These may be used alone or in combination of two or more. The linalylamine resin can be exemplified as an aromatic dicarboxylic acid component composed of source free terephthalic acid and/or m-phenylene-22-201016911 formic acid, and is selected from the group consisting of 14-phenylenediamine and 1,3-phenylenediamine. At least one aromatic group consisting of 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, and 1,3-bis(3-aminophenoxy)benzene A wholly aromatic polyamine of a family diamine. The rubber is not particularly limited and may be natural rubber (NR), acrylic rubber, acrylonitrile butadiene rubber (NBR rubber), isoprene rubber (IR), urethane rubber, ethylene propylene rubber ( EPM) 表, epichlorohydrin rubber, chloroprene rubber (CR), enamel rubber and copolymers, styrene butadiene rubber (SBR), butadiene rubber (BR), butyl rubber, etc. 'The composition of the present invention is a mixed pitch-based graphitized short fiber and a matrix-made' but it is preferable to use a kneader, various kneading machines, blenders, rolls, extruders, honing machines, and self-mixing. Mixing device or kneading device such as a rotary mixer. When the substrate is a thermally conductive composition composed of a thermoplastic resin, it can be selected from the group consisting of injection molding, press molding, calendering, roll forming, extrusion molding, injection molding, and blowing. At least one of the groups formed by the plastic molding method is molded to obtain a molded body. Then, the sheet-like formed body can be formed by roll extrusion or extrusion molding by die extrusion or the like. The molding conditions are formed by molding. The method and the substrate are carried out in a state in which the elevated temperature is higher than the melt viscosity of the resin. When the substrate is a thermally conductive composition composed of a thermosetting resin, it can be selected from the group consisting of injection molding, At least one of the group consisting of a press forming method, a calender forming method, a roll forming method, an extrusion molding method, and an injection molding method -23-201016911 Forming to obtain a molded body. The molding conditions are determined by the forming method and the substrate. For example, a method of applying a curing temperature of the resin in a suitable form may be exemplified. When the substrate is a thermally conductive composition composed of a melamine resin, the melamine may be dissolved in a solvent. The pitch-based graphitized short fiber is mixed therein and molded by a casting method. The solvent herein is not particularly limited as long as it can dissolve the melamine, but specifically, N,N-dimethylacetamide or N-methyl can be used. A guanamine-based solvent such as pyrrolidone. When the substrate is a thermally conductive composition composed of rubber, it can be formed by at least one selected from the group consisting of a press molding method, a calender molding method, and a roll molding method. The molding is obtained. The molding conditions are determined by the molding method and the substrate, and may be exemplified by a method of applying a vulcanization temperature to the rubber. In order to make the thermal conductivity of the composition of the present invention higher, it is also possible to add a pitch-based graphitization as needed. Specific examples of the filler other than fibers, such as metal oxides such as alumina, magnesia, cerium oxide, and zinc oxide, metal hydroxides such as aluminum hydroxide and magnesium hydroxide, metals such as boron nitride and aluminum nitride. Metal oxynitride such as nitride or aluminum oxynitride, metal carbide such as tantalum carbide, metal or metal alloy such as gold, silver, copper or aluminum, natural graphite, artificial graphite, expanded graphite, diamond Carbon materials, etc. It is preferable to add these sizing agents according to their functions. In addition, two or more types may be used in combination. In order to improve other properties such as moldability and mechanical properties, it may be suitable according to the desired function. Adding fiberglass, potassium titanate whiskers, zinc oxide whiskers, aluminum boride whiskers, boron nitride whiskers, linaloamide fibers, alumina fibers, tantalum carbide fibers, asbestos fibers, gypsum fibers, metal fibers, etc.塡 塡 。 。 。 。 。 。 。 。 。 。 。 。 两种 两种 两种 两种 两种 两种 两种 两种 两种 两种 两种 两种 两种 两种 两种 两种 两种 两种 两种 两种 两种 两种 -24 -24 -24 -24 -24 -24 -24 -24 -24 -24 -24 -24 -24 -24 -24 -24 -24 -24 Bentonite, asbestos, talc, alumina silicate such as citrate, calcium carbonate, magnesium carbonate, dolomite and other carbonates, calcium sulfate, barium sulfate and other non-fibrous strontium such as glass beads, glass flakes and ceramic beads Charges. These may be hollow, and more than two of these extenders may be used. However, most of the above compounds are those having a higher density than the pitch-based graphitized short fibers, and it is necessary to pay attention to the addition amount or the addition ratio for the purpose of weight reduction. Further, it is also possible to add a plurality of other additives to the composition as needed. Other additives may be exemplified by mold release agents, flame retardants, emulsifiers, softeners, plasticizers, and surfactants. When the composition of the present invention is formed into a flat shape and the thermal conductivity is measured, a thermal conductivity of 2 W/(m·K) or more is exhibited. The thermal conductivity of 2W/(m·K) is about one-digit higher than that of the resin used as the substrate. The composition of the present invention can be used as a heat-dissipating plate for electronic parts by utilizing its high thermal conductivity. In addition, since the addition amount of the pitch-based graphitized short fibers is increased, high thermal conductivity can be obtained, and therefore, it can be preferably used for the connection of an electronic component that requires heat resistance or an industrial power module that requires a large current. And so on. More specifically, it can be used for a heat sink, a component for a semiconductor package, a heat sink, a heat sink, a bare pad, a printed circuit board, a component for a cooling fin, a frame, and the like. Moreover, it can also be used as a part of a heat exchanger. Can also be used in heating tubes. Further, the radio wave shielding properties of the pitch-based graphitized short fibers can be utilized, and the components for radio wave shielding as the GHz band are particularly preferably used. -25- 201016911 EXAMPLES The following examples are shown but the invention is not limited thereto. Further, each of the enthalpy in the present embodiment was obtained by the following method. (1) For pitch-based graphitized short fibers, the ratio of the radius of curvature of 10 to 60 cm is 4 times that of an optical microscope, and 2000 fibers having a fiber length of ιοομιη or more are measured, and the radius of curvature is observed to be 10 to 60 cm. The number of articles is calculated relative to the ratio of 2,0. (2) Average fiber diameter and fiber diameter dispersion (CV値) of the pitch-based graphitized short fibers The average fiber diameter (D 1 ) is determined by measuring the fiber diameter of 60 carbon fibers using a ruler under an optical microscope, and the average 値 is obtained. . Further, 'CV 値 is the ratio of the obtained average fiber diameter (D1) to the fiber diameter dispersion (SI) & and is determined by the following formula. CV = S1 / D 1 X 100 where S 1 ^((ΣΧ-D 1) 2/η), X is the observed 値, and η is the observed number. (3) The number average fiber length of the pitch-based graphitized short fibers is magnified to 4 times by an optical microscope, and 2000 pieces are measured by a ruler' from the average. (4) The crystallite size of the pitch-based graphitized short fiber was measured by the vibration method by the reflection of the (110) plane of the X-ray diffraction. (5) The true density of pitch-based carbon short fibers is adjusted by mixing the ratio of bromoform (density -26- 201016911 ' 2.90g/cc ) to 1,1,2,2-tetrachloroethane (density 1.59g/cc). In the mixed solution in which the solution density is adjusted, carbon fibers are introduced and determined by the sedimentation state of the carbon fibers. (6) The thermal conductivity of the pitch-based graphite short fibers is such that the pitch-based graphitized fibers are produced under the same conditions as the specific resistance except for the pulverization step, and the silver-based paste is fixed so that the distance between the ends of the pitch-based graphitized fibers is 1 cm. The tester measures the resistance of the two ends, and uses the radius of the pitch-based carbon fiber (" calculated, and is calculated by the following relationship between the thermal conductivity and the resistance (refer to Japanese Patent No. 3 64 8 865). K= 1272.4/ER-49.4 (K is the thermal conductivity of carbon fiber W/(mK), ER is the specific resistance of carbon fiber Αί Ω m ) (7) The end face of asphalt-based graphitized short fiber is 1 million times that of a transmission electron microscope. The magnification was observed to be 4 million times in the photograph, and it was confirmed to be a graphite flake. (8) The cracking, surface shape, and presence or absence of the stigma-based graphitized short fiber were observed at a magnification of 800 times by a scanning electron microscope. The number of observations is 50. (9) The thermal conductivity of the flat molded body is measured by QTM-5 00 manufactured by Kyoto Electronics. Example 1 -27- 201016911 Mainly condensed polycyclic hydrocarbon compounds, optical The ratio of the opposite sex is 10 0%, asphalt with a softening point of 285 °c, using a cover with a diameter of 0.2 mm φ hole's self-small die mouth at a 45 degree angle with respect to the spinning direction, and 350 °C heating at a line speed of 6000 m/min The air is used to stretch the melted asphalt to produce a pitch-based carbon fiber precursor having an average diameter of 11.3 μm. The spinning temperature is 320 ° C and the melt viscosity is 19.5 Pa·s (195 poise). The fibers were collected on a conveyor belt to form a web, and then paved with a pitch-based carbon fiber precursor web composed of a pitch-based carbon fiber precursor having a basis weight of 300 g/m 2 in the air. In the air, the average heating rate was 5 The pitch-based carbon fiber precursor was heated from 170 ° C to 300 scoops at ° C / min and was not melted, and then fired at 800 ° C. The pitch-based carbon fiber web was used at 800 rpm using a cutter (manufactured by TURBO Industries). After pulverization, it was graphitized at 3000 ° C to obtain pitch-based graphitized short fibers. The obtained pitch-based graphitized short fibers had an average fiber diameter of 8.2 μm, and a fiber diameter dispersion ratio (CV値) with respect to the average fiber diameter. Is 10%. The fiber length is 15 Ομπι. The four-fold observation of the optical microscope is shown in Fig. 2. Among the fibers having a fiber length of ΙΟΟμιη or more, the ratio of the radius of curvature of 10 to 60 cm is 80%. Further, an observation example of a scanning electron microscope (800) This is shown in Fig. 1 'but the position where the surface of the graphitized short fibers is cracked is indicated by an arrow in the photograph. The ratio of the fibers having surface cracking is 40%. The hexagonal mesh surface derived from the bitumen-based graphitized short fibers The crystal size in the growth direction was 70 nm, the true density was 2.2 g/cm3, and the thermal conductivity was 700 W/m·K. The graphite flakes were closed by observing the end faces of the bituminized graphitized short fibers through a microscope of -28-201016911. Further, the surface of the pitch-based graphitized short fibers was observed by a scanning electron microscope to have substantially smoothness of one unevenness. Example 2 As a pitch mainly composed of a condensed polycyclic hydrocarbon compound, having an optical anisotropy ratio of 100% and a softening point of 285 ° C, a diameter of 0.2 mm (a lid of a D-hole, from a slit nozzle to a spinning direction) was used. At a 45-degree angle, 355 °C of heated air is sprayed at a line speed of 7000 m/min to stretch the melted asphalt to produce a pitch-based carbon fiber precursor having an average diameter of 15, Ομιη. The wire temperature is 3 5 at this time. At 5 ° C, the melt viscosity is 13.0 Pa · s (130 poise). The spun fibers are collected on a conveyor belt to form a web, and then cross-laid to become a pitch-based carbon fiber precursor with a weight per unit area of 400 g/m 2 . Asphalt carbon fiber precursor mesh composed of materials. The pitch carbon fiber precursor is heated from 170 ° C to 320 ° C at an average temperature increase rate of 5 ° C / min, and does not melt, and then at 800 ° C The pitch-based carbon fiber mesh was pulverized at 800 rpm using a cutter (manufactured by TURBO Industries), and then graphitized at 300 (TC) to obtain pitch-based graphitized short fibers. The obtained pitch was graphitized. The average fiber diameter of the fiber is 9.9 μmη. The fiber diameter dispersion ratio (CV値) for the average fiber diameter is 8%. The number average fiber length is 170 μπι. Among the fibers having 2000 fiber lengths of 100 μm or more, the ratio of the radius of curvature of 1 〇 to 60 cm is 75. %. The ratio of fibers with surface cracking observed by scanning electron microscopy is -29- 201016911 70%. The crystal size of the hexagonal mesh surface derived from pitch-based graphitized short fibers is 70 nm, and the true density is 2.2 g/cm3, thermal conductivity: 700 W/m • K. The graphite sheet was closed by observing the end face of the asphalt-based graphitized short fiber through a transmission microscope, and the surface of the asphalt-based graphitized short fiber was observed by a scanning electron microscope. It has one unevenness and is substantially smooth. Example 3 Using a vacuum type self-revolving mixer (Litaro ARV-310 manufactured by THINKY), 30 parts by volume of the pitch-based graphitized short fiber obtained in Example 1, 70 volumes were mixed. The epoxy resin (manufactured by TOSHO ♦ DOW SILICONE, SE 1 740) was used as a composite slurry for 3 minutes. The slurry was pressed and processed by a vacuum press (manufactured by Kitagawa Seiki Co., Ltd.) to obtain a thickness. A 0.5 mm flat composite molded body was fired at 130 ° C for 2 hours to prepare a thermally conductive molded body. The thermal conductivity of the thermally conductive molded body was measured and found to be 1 2.0 W / ( m · K ). The shaft kneading machine (manufactured by Kurimoto Iron Works Co., Ltd.) was kneaded into 30 parts by volume of the pitch-based graphitized short fiber obtained in Example 1, and 7 parts by volume of a polycarbonate resin (manufactured by Teijin Chemicals Co., Ltd., L-1225WP) to form pellets. An injection molding machine (M-50B manufactured by Nikko Seisakusho Co., Ltd.) was used to form the pellets to obtain a flat heat conductive molded body having a thickness of 2 mm. The thermal conductivity of the thermally conductive molded body was measured and found to be 4.3 W/(m.K). -30-201016911 Example 5 30 parts by volume of the pitch-based graphitized short fiber obtained in Example 1 and 70 parts by volume of polyphenylene sulfide (manufactured by Polyplastic Co., Ltd.) were kneaded using a biaxial kneading machine (manufactured by Kurimoto Iron Works Co., Ltd.). ' 0220A9) 'Become a pellet. The pellets were molded by an injection molding machine (M-5 0B manufactured by Konica Minolta Co., Ltd.) to obtain a flat heat conductive molded body having a thickness of 2 mm. The thermal conductivity of the thermally conductive molded body was measured to be 5.2 W/(m.K). Example 6 Using a vacuum type self-revolving mixer (Litaro ARV-310 manufactured by THINKLY), 30 parts by volume of the pitch-based graphitized short fiber obtained in Example 2 and 70 parts by volume of a silicone resin (TOSHO · DOW SILICONE) were mixed. Manufactured, SE1 740) 3 minutes, became a composite slurry. This slurry was pressed and processed by a vacuum press (manufactured by Kitagawa Seiki Co., Ltd.) to obtain a flat composite molded body having a thickness of 0.5 mm, and cured at 130 ° C for 2 hours to prepare a thermally conductive molded body. The thermal conductivity of the thermally conductive molded body was measured and found to be 1 1 _8 W / ( m · K ). Example 7 30 parts by volume of the pitch-based graphitized short fiber obtained in Example 2 and 70 parts by volume of a polycarbonate resin (manufactured by Teijin Chemicals Co., Ltd., L-1225WP) were kneaded using a biaxial kneading machine (manufactured by Kurimoto Iron Works Co., Ltd.). Become a granule. The pellets were molded by an injection molding machine (M-5 0B manufactured by Nikko Seisakusho Co., Ltd.) to obtain a flat heat conductive molded body having a thickness of 2 mm. Determination of thermal conductivity molding -31 - 201016911 The thermal conductivity of the body is .4.1 W / (m. K). Example 8 30 parts by volume of the pitch-based graphitized short fiber obtained in Example 2 and 70 parts by volume of polyphenylene sulfide (manufactured by Polyplastic Co., Ltd., 0220A9) were kneaded into a pellet using a biaxial kneading machine (manufactured by Kurimoto Iron Works Co., Ltd.). . This pellet was molded by an injection molding machine (M-50B manufactured by Nikko Seisakusho Co., Ltd.) to obtain a flat heat conductive molded body having a thickness of 2 mm. The thermal conductivity of the thermally conductive molded body was measured to be 5.4 W / ( m · K ). Comparative Example 1 As a pitch mainly composed of a condensed polycyclic hydrocarbon compound, having an optical anisotropy ratio of 100% and a softening point of 283 ° C, a diameter of 0.05 mm (D hole lid, extruded pitch from the lid, and cooled to the chamber) At the same temperature, a pitch-based carbon fiber precursor having an average diameter of 15 μm was obtained, and the spinning temperature was 310 ° C and the melt viscosity was 55.0 Pa·s (550 poise). In air, the average heating rate was 5 t/min. The pitch-based carbon fiber precursor was heated from 170 ° C to 320 ° C and was not melted, and then fired at 800 ° C. The pitch-based carbon fiber mesh was pulverized at 800 rpm using a cutter (manufactured by TURBO Industries). Graphitization at 3000 ° C. The average fiber diameter of the pitch-based graphitized short fibers is 9.8 μm, and the fiber diameter dispersion ratio (CV値) with respect to the average fiber diameter is 3%. The number average fiber length is 160 μm. The fiber length ΙΟΟμηι Among the above fibers, almost no short fibers having a curvature were observed, and the ratio of the radius of curvature of the range of 10 0 to 60 cm was 0%. Further, the ratio of the fibers having a surface crack of -32 to 201016911 was observed by a scanning electron microscope. For example, 40%. The crystal size of the hexagonal mesh surface derived from the pitch-based graphitized short fiber is 40 nm, the true density is 2.2 g/cm3, and the thermal conductivity is 400 W/m. K. The asphalt is observed by a transmission microscope. The end face of the graphitized short fiber is determined to be closed, and the surface of the pitch-based graphitized short fiber is observed by a scanning electron microscope to have one unevenness and is substantially smooth. Comparative Example 2 is mainly composed of a condensed polycyclic hydrocarbon compound. , an optical anisotropy ratio of 100%, a 'softening point of 285 °C asphalt, using a 0.2 mm diameter Φ hole cover, from the narrow long nozzle at a 45 degree angle with respect to the spinning direction, at a line of 4000 m / min The heated air of 358 °C was sprayed at a speed to stretch the melted asphalt, and a pitch-based carbon fiber precursor having an average diameter of 15. χμχη was produced. The spinning temperature was 350 ° C and the melt viscosity was 4.0 Pa. s (40 poise). The spun fibers are collected on a conveyor belt to form a web, and then cross-laid to form a pitch-based carbon fiber precursor web composed of a pitch-based carbon fiber precursor having a basis weight of 400 g/m2. In the air, to The average heating rate was 5 ° C / min. The pitch-based carbon fiber precursor was heated from 170 ° C to 320 ° C and did not melt, and then fired at 80 ° C. Using a cutting machine (manufactured by TURBO Industries) at 800 rpm The pitch-based carbon fiber mesh was pulverized and graphitized at 3000 ° C. The pitch-based graphitized short fibers had an average fiber diameter of 9.7 μm and a fiber diameter dispersion ratio (CV 値) of 20% with respect to the average fiber diameter. The number average fiber length was 170 μm. In the fiber having a fiber length of ΙΟΟμηη or more -33- 201016911, the ratio of the radius of curvature of 10 to 60 cm is 70%. Further, the ratio of the surface cracked fiber observed by a scanning electron microscope was 10% ^ The crystal size of the hexagonal mesh surface derived from the pitch-based graphitized short fiber was 7 〇 nm, the true density was 2.2 g/cm 3 , and the heat conductivity was The rate is 700 W/m · K. The end faces of the pitch-based graphitized short fibers were observed by a transmission microscope to confirm that the graphite sheets were closed. Further, the surface of the pitch-based graphitized short fibers was observed by a scanning electron microscope to have substantially one unevenness and was substantially smooth. Comparative Example 3 A vacuum type self-revolving mixer (Litaro ARV-3 10 manufactured by THINKY) was used, and 30 parts by volume of the pitch-based graphitized short fiber obtained in Comparative Example 1 and 70 parts by volume of the epoxy resin (TOSHO · DOW) were mixed. Manufactured by SILICONE, SE 1 740) 3 minutes to become a composite slurry. This slurry was press-processed with a vacuum press (manufactured by Kitagawa Seiki Co., Ltd.) to obtain a flat composite molded body having a thickness of 0.5 mm, and cured at 130 ° C for 2 hours to prepare a thermally conductive molded body. The thermal conductivity of the thermally conductive molded body was measured and found to be 2.7 W/(m · K ). Comparative Example 4 30 parts by volume of the pitch-based graphitized short fiber obtained in Comparative Example 1 and 7 parts by volume of a polycarbonate resin (manufactured by Teijin Chemicals Co., Ltd., L-1225WP) were kneaded using a biaxial kneading machine (manufactured by Kurimoto Iron Works Co., Ltd.). Become a particle. This pellet was molded by an injection molding machine (M-50B manufactured by Konica Minolta Co., Ltd.) to obtain a flat heat conductive molded body having a thickness of 2 mm. Determination of thermal conductivity molding -34- 201016911 The thermal conductivity of the body is 1_4W / ( m · K). Comparative Example 5 Asphalt-based graphitized short fibers obtained in Comparative Example 1 and a 7-inch-volume phenyl sulfide (manufactured by Polyplastic Co., Ltd., 0220Α9) obtained by kneading 30 in a biaxial kneading machine (manufactured by Kurimoto Iron Works Co., Ltd.) were used as an injection molding machine ( M-50B manufactured by Nihon Seiki Co., Ltd.) The pellet was obtained into a flat heat conductive molded body having a thickness of 2 mm. The thermal conductivity of the thermal conductor was measured to be 1.7 W/(m · K). Comparative Example 6 A vacuum type self-revolving mixer (ARV-310 manufactured by THINKY) was used, and 30 parts by volume of the liquefied short fiber obtained in Comparative Example 2 and 70 parts by volume of a decyloxy resin (manufactured by TOSHO SILICONE, SE1 740) were mixed. After 3 minutes, the slurry was pressed into a composite slurry air-pressing machine (manufactured by Kitagawa Seiki Co., Ltd.) to obtain a flat composite molded body of 0.5 mm, and hardened at 130 ° C to prepare a thermally conductive molded body. The heat conductivity of the thermally conductive molded body was measured to be 8.8 W / ( m · K ). Comparative Example 7 A pitch-based graphitized short fiber obtained in Comparative Example 2, which was kneaded by a biaxial kneading machine (manufactured by Kurimoto Iron Works Co., Ltd.), 70 volumes of carbonate resin (manufactured by Teijin Chemicals Co., Ltd., L-1 225 WP), was used as a part by volume. Part of the poly particles. Forming, Sexual Forming Lantaro Greenstone • DOW. The actual thickness is the hour, the rate, and the volume of the particles. -35-201016911 A flat-plate heat conductive molded body having a thickness of 2 mm was obtained by an injection molding machine (M-50B manufactured by Nikko Seisakusho Co., Ltd.). The thermal conductivity of the body was measured and found to be 3.1 W/(m.K). Comparative Example 8 Asphalt-based graphitized short fiber and 70 phenyl sulfide (manufactured by Polyplastic Co., Ltd., 0220A9) obtained by the mixing of the two-axis kneading machine (manufactured by Kurimoto Iron Works Co., Ltd.), were produced by an injection molding machine (Made Machine Manufacturing Co., Ltd.) M-50B) This was obtained as a flat heat conductive molded body having a thickness of 2 mm. The thermal conductivity of the measured body was 4_1 W/(m.K). [Effect of the Invention] The pitch-based graphitized short fiber of the present invention can be easily formed by controlling the radius of the radius and controlling the surface to have cracking and having a cracking rate, thereby controlling the fiber with respect to the average fiber diameter. Composite molding with high thermal conductivity [Industrial Applicability] The pitch-based graphitized short fibers of the present invention can control the surface of the surface observed by a scanning electron microscope, and can use such high thermal conductivity. According to this, it is possible to use a high heat release, and it is possible to implement a heat manager. Particle formation, thermal conductivity molding 3 parts by volume of the mixture of parts into particles. Particle forming, thermal conductivity molding Curved curvature Short fiber ratio Diameter dispersion, body. The radius and the place where the composite material is expanded are -36-201016911. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a scanning electron microscope observation (800 times) of the pitch-based graphitized short fiber obtained in Example 1. Fig. 2 is a view showing an optical microscope (4 times) and a radius of curvature of the pitch-based graphitized short fibers obtained in Example 1. Fig. 3 is a schematic view showing the manner in which the radius of curvature is obtained.
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