201124215 六、發明說明： 【發明所屬之技術領域】 本1發明係關於可低溫燒成之較好地使用作爲導電性組 成物之原料用之多結晶化平均粒徑3 0〜1 〇〇nm之銀微粒子及 其製造方法以及含有該銀微粒子之電糊、導電性膜及電子 裝置。 【先前技術】 電子裝置之電極或電路圖型之形成係使用含有金屬粒 子之電糊’將電極或電路圖形印刷於基板上之後，經加熱 燒成使電糊中所含之金屬粒子燒結而進行，但近年來，其 加熱燒成溫度有低溫化之傾向。 例如’作爲電子裝置之安裝基板，一般爲了可加熱至 3 00 °C左右故使用聚醯亞胺製之可撓性基板，但耐熱性雖 優異卻昂貴’故最近檢討以更便宜之PET (聚對苯二甲酸 乙二酯）基板或PEN (聚萘二甲酸乙二酯）基板作爲替代 材料。然而’ PET基板或PEN基板相較於聚醯亞胺製之可 撓性基板’其耐熱性較低，必須在20(TC以下進行加熱燒 成。 又’若可在比20(TC更低之溫度進行加熱燒成，則亦 可在聚碳酸酯或紙等基板上形成電極或電路，而期待擴大 各種電極材料等之用途。 至於成爲該種可低溫燒成之電糊之原料之金屬粒子， 奈米級之銀微粒子備受期待。其理由爲金屬粒子之大小爲 -5- 201124215 奈米級時由於表面活性變高，溶點亦較金屬塊者低，而成 爲可在低溫度燒結之故。又，金屬粒子中，舉例有銀微粒 子’其爲低電阻’價格亦比其他貴金屬便宜。 且’奈米級銀微粒子可在低溫下燒結，同時一次燒結 時可維持耐熱性，故亦期待作爲以往利用沒有焊錫性質之 無鉛之焊錫替代材料。 迄今爲止’作爲可低溫燒成之銀微粒子，提案有次微 米以下之銀微粒子，已知有使己基胺吸附於表面之平均粒 徑（DTEM ) 3〜2 0nm之銀微粉（專利文獻1 )、粒子表面以 有機保護劑覆蓋之平均粒徑（DTEM )爲5〇nm以下，單結晶 化度（DTEM/DX )爲2.0以下之銀粒子（專利文獻2 )，平 均粒徑爲40〜l〇〇nm，單結晶化度（Dtem/Dx )爲1〜5之銀 微粒子（專利文獻3 )，於粒子表面上以1 wt%以下附著硝 酸銀之胺絡物錯合物及胺之平均粒徑20〜lOOnm之銀微粒子 (專利文獻4 ) ’以表面處理劑被覆之平均粒徑未達2〇〇nm ’ BET比表面積爲以上之貴金屬爲粒子（專利文獻 5 ) ’含有未達1%之可溶性金屬之平均粒徑爲50~100nm， BET比表面積爲6〜25 m2/g之奈米粉末（專利文獻6)等。 [先前技術文獻] [專利文獻] [專利文獻1]特開2009-161808號公報 [專利文獻2]特開2007-19055號公報 [專利文獻3]特開2006-183072號公報 [專利文獻4]特開2009_144197號公報 201124215 [專利文獻5]特開2004-43 892號公報 [專利文獻6]特表2005-530048號公報 【發明內容】 [發明欲解決之課題] 爲使銀微粒子在低溫下燒結，有必要使銀微粒子爲活 性，但前述專利文獻1中揭示之平均粒徑爲2 0 nm以下之銀 微粒子之情況，由於活性太高而不安定故有必要以大量有 機物被覆。專利文獻1中’使用沸點爲1 3 0 °c左右之己基胺 作爲被覆物質，但即使選擇例如沸點較低之被覆物質亦難 以完全去除大量附著之被覆物。另外，專利文獻1中製造 銀微粒子方面由於施加50〜60 °C之溫度，故銀微粒子之結 晶子徑有變大之傾向，故成爲銀微粒子內部之反應性變低 ，對於低溫燒結不利。 另外，前述專利文獻2中雖記載粒子表面以有機保護 劑覆蓋之平均粒徑（DTEM )爲50nm以下，單結晶化度（ Dtem/Dx )爲2.0以下之銀粒子，但如前述，由於（ DTEM/DX)爲2.0以下而爲單結晶化度高者，故成爲銀微粒 子內部之反應性低者，對低溫燒結不利。 又，前述專利文獻3中雖記載平均粒徑爲40〜1 〇〇nm ’ 單結晶化度（DTEM/DX)爲1〜5之銀微粒子，但製造銀微粒 子方面由於將溫度調整至4 0 °C左右’故銀微粒子之結晶子 徑有變大之傾向。因此成爲銀微粒子內部之反應性降低者 ，對低溫燒結不利。 201124215 且，前述專利文獻4中雖記載於粒子表面以1 wt %以下 附著硝酸銀之胺絡物錯合物及胺之平均粒徑爲20〜lOOnm之 銀微粒子，但並未考慮還原反應中之反應溫度，且，由於 加熱至40°C使其乾燥故結晶粒徑有變大之傾向，成爲銀微 粒子內部之反應性降低者，對低溫燒結不利。 又，前述專利文獻5中雖記載利用表面處理劑被覆之 平均粒徑未達200nm、BET比表面積爲1.0m2/g以上之貴金 屬微粒子，但被覆粒子表面之表面處理劑均爲高沸點物質 ，故專利文獻5之實施例中即使在200°C之加熱條件下仍會 殘留表面處理劑，故難以使用於低溫燒結用之電糊之原料 。另外，由於BET比表面積値相對於粒徑小則活性愈低， 故對低溫燒結不利。 又，前述專利文獻6中雖記載含有未達1 %之可溶性金 屬之平均粒徑爲50〜lOOnm、BET比表面積爲6〜25m2/g之奈 米粉末，但含有源自製法之可溶性金屬，使用專利文獻6 中所示之奈米粉末獲得之燒結體由於含有阻礙導電性之雜 質金屬，故難以獲得具有期望之高導電性之燒結體。又， 因存在之可溶性金屬妨礙燒結，故難以在低溫下燒結。 因此，本發明之技術課題爲提供一種適合作爲可低溫 燒成之電糊之原料使用、平均粒徑30〜ΙΟΟηιη之多結晶化銀 微粒子。 [用以解決課題之手段] 前述技術之課題可利用下述之本發明達成。 -8 - 201124215 亦即’本發明爲一種銀微粒子，其特徵爲平均粒徑（ D s E Μ )爲3 0〜1 ο 〇 n m，多結晶化度[平均粒徑（D s E M )與結 晶子徑（Dx)之比（DSEM/DX)]爲2.8以上（本發明1)。 另外’本發明爲本發明1之銀微粒子，其中藉由加熱 造成之結晶子徑之變化率[(在1 5 0 °c加熱3 0分鐘後之銀微 粒子之結晶子徑/加熱前之銀微粒子之結晶子徑）X 1 〇〇]爲 1 5 0 %以上（本發明2 )。 又’本發明爲本發明1或2之銀微粒子，其中銀微粒子 之BET比表面積値（SSA ) ( m2/g )與平均粒徑（DSEM ) 具有下述式（1 )之關係（本發明3 ): SSA ( m2/g) 2-0.05xDsem + 7.4 …（1) 另外，本發明爲一種本發明1〜3中任一項之銀微粒子 之製造方法，其特徵爲將使用硝酸銀與水溶性或水可溶性 之沸點爲2 00 °C以下之胺之一種以上調製而成之硝酸銀之 胺錯合物之醇溶液，添加於將抗壞血酸或異抗壞血酸溶解 於水-醇混合溶劑中並經還原析出，將所得銀粒子分離•洗 淨後’在溫度3 0°C以下利用真空乾燥將銀粒子乾燥（本發 明4 )。 另外，本發明爲本發明4所述之銀微粒子之製造方法 ，其在獲得銀微粒子之前的所有步驟係在溫度30°C以下進 行（本發明5 )。 另外，本發明爲一種電糊，係包含本發明1 ~3中任一 項所述之銀微粒子（本發明6 )。 又，本發明爲一種導電性膜，係使用本發明6之電糊 -9 - 201124215 所形成（本發明7 )。 另外，本發明爲一種電子裝置，其具有本發明7所述 之導電性膜（本發明8 )。 [發明效果] 本發明之銀微粒子由於平均粒徑爲30〜lOOnm故不需要 如單一奈米級銀微粒子般以大量有機物被覆表面，且，由 於多結晶化度爲2.8以上故粒子內部之活性高，因此即使 在低溫下亦可進行銀微粒子彼此之燒結，故適用作爲可低 溫燒成之電糊等之原料。 【實施方式】 本發明之構成更詳細說明如下。 首先，針對本發明之銀微粒子加以描述。 本發明之銀微粒子之特徵係平均粒徑（DSEM )爲 30〜1 〇〇 nm，多結晶化度[平均粒徑（DSEM )與結晶子徑（ 〇\)之比（05〜/0乂）]爲2.8以上。 本發明之銀微粒子之平均粒徑（DSEM)爲30〜l〇〇nm， 較好爲40~100nm，更好爲50〜lOOnm。平均粒徑（dsem) 未達30nm時，銀微粒子具有之表面活性增高，爲了安定地 維持其微細粒徑而有必要附著大量有機物等，故較不佳。 另外，平均粒徑（DSEM )超過lOOnm時，銀微粒子具有之 表面活性變低，有損及低溫燒結性故而不佳。 本發明之銀微粒子之多結晶化度[平均粒子徑（Dsem -10- 201124215 )與結晶子徑（Dx )之比（DSEM/DX )]爲2.8以上， 爲3.0以上，又更好爲3.2以上。多結晶化度未達2.8時 微粒子中之結晶子徑變大，趨近於單結晶故而使銀微 中之反應性降低，會損及低溫燒結性故而不佳。前述 晶化度之上限値爲1 〇左右，較好爲8左右。 本發明之銀微粒子因加熱造成之結晶子徑之變1 (以15(TC加熱30分鐘後之銀微粒子之結晶子徑/加熱 銀微粒子之結晶子徑）X 1 〇〇]爲1 50%以上。結晶子徑 化率未達1 5 0 %時，難以謂爲低溫燒結性優異。本發明 較好以1 20°C加熱3〇分鐘時之結晶子徑之變化率亦在 以上，更好以1 〇〇 °C加熱30分鐘時，同樣地結晶子徑 率亦在1 5 0 %以上。 本發明之銀微粒子之BET比表面積（SSA)係在 述式（1 )表示之範圍。BET比表面積値（SSA )比下 (1 )之範圍小時，須以大量有機物處理銀微粒子表 造成表面活性降低，故難以獲得良好之低溫燒結性。 SS A ( m2/g ) ^ -0.05 xDsem + 7.4 ... (1) 本發明之銀微粒子之粒子形狀較好爲球狀或粒狀 本發明之銀微粒子之雜質金屬較好爲500PPm以下 好爲200PPm以下，又更好爲lOOppm以下。雜質金屬 量超過500PPm時，使用其所得之燒結體由於含有損害 性之雜質金屬，故難以獲得期望之具有高導電性之燒 。另外，由於存在之雜質金屬會阻礙燒結，故難以在 下燒結。 更好 ，銀 粒子 多結 .匕率[ 前之 之變 中， 1 5 0 % 變化 以下 述式 面， ，更 之含 導電 結體 低溫 -11 - 201124215 本發明之銀微粒子只要滿足上述特性之範圍，即使再 經表面處理亦無妨。表面處理劑較好爲沸點20CTC以下之 醇或胺。醇可使用乙醇、丙醇、丁醇、戊醇、己醇、庚醇 、辛醇、乙二醇等。且，胺可使用氨、甲胺、乙胺、丙胺 、丁胺、單乙醇胺等。 對銀微粒子施以表面處理時，被覆或附著之胺及/或 醇之量爲1重量％以下。超過1重量％時，低溫燒結性降低 故而不佳。更好爲0 · 9重量％以下，又更好爲〇 · 8重量％以下 〇 以下針對本發明之銀微粒子之製造方法加以敘述。 本發明之銀微粒子可藉由將使用硝酸銀與水溶性或水 可溶性之沸點爲200°C以下之胺之一種以上調製而成之硝 酸銀之胺錯合物之醇溶液，添加於將抗壞血酸或異抗壞血 酸溶解於水-醇混合溶劑中並經還原析出，將所得銀粒子 分離•洗淨後’在溫度3 0 °C以下利用真空乾燥將銀粒子乾 燥獲得。又，銀微粒子製造之全部步驟中，較好均在溫度 3 0°C以下進行。據此，可容易地維持規定之銀微粒子之多 結晶化度。 本發明之水溶性或水可溶性之沸點在2 〇 〇。<：以下之月安 可使用丁胺、丙胺、單乙醇胺等。其中，所謂水溶性意指 與水任意混合’且所g胃水可溶性意指在水中具有某種程度 之溶解度溶解。 本發明中之醇可使用與水具有相溶性者。考慮後步驟 之在溫度30°C以下利用真空乾燥去除，以沸點丨〇〇t以下之 -12- 201124215 醇較好。具體而言，可使用甲醇、乙醇、丙醇及異丙醇等 ，較好爲甲醇及乙醇。該等醇類可單獨使用亦可混合使用 〇 以下，使用水溶性或水可溶性之沸點200°c以下之胺 做爲代表之丁胺爲例加以描述’但丙胺、單乙醇胺等胺亦 可同樣地調製。 又，只要特徵爲使上述硝酸銀與使用一種以上之水溶 性或水可溶性之沸點在2〇〇°c以下之胺調製之硝酸銀之胺 絡物錯合物之醇溶液在水-醇混合溶劑中利用抗壞血酸或 異抗壞血酸還原之基本槪念相同’則不限定於以下之條件 。例如甲醇之量或水之量係依據所使用之胺之溶解性、反 應容器與攪拌機構之最適體積比率而變化。 首先，藉由硝酸銀與丁胺在醇溶劑中形成硝酸銀之胺 絡物錯合物。丁胺相對於銷酸銀較好爲2.0 ~2.5當量’更好 爲2.0〜2.3當量。丁胺之量相對於硝酸銀未達2 · 0當量時， 有容易生成大的粒子之傾向。 其次，使還原劑的抗壞血酸或異抗壞血酸溶解於水中 後，添加醇並混合。抗壞血酸或異抗壞血酸相對於硝酸銀 較好爲1.0〜2.0當量，更好爲1.0〜1.8當量。抗壞血酸或異 抗壞血酸超過2 · 0當量時，有生成之銀微粒子彼此凝聚之 傾向故不佳。 接著，將形成硝酸銀之胺絡合錯合物之醇溶液滴加於 溶解抗壞血酸或異抗壞血酸而成之水-醇溶液中，進行還 原反應藉此使銀微粒子析出。還原反應中之反應溫度在 -13- 201124215 15〜30°C之範圍，更好爲18〜3〇〇c。反應溫度超過30»c時， 結晶子徑變大，所得銀微粒子趨近單結晶故較不佳。 滴加結束後，持續搅拌一小時以上，以靜置使銀微粒 子沉降’以傾析去除上澄液後，使用醇及水洗淨剩餘之還 原劑、丁胺、硝酸銀等。 洗淨之銀微粒子在溫度3 (TC以下真空乾燥後，利用慣 用方法粉碎，可獲得本發明之銀微粒子。乾燥溫度超過 3 〇°C時結晶子徑變大，所得銀微粒子趨近單結晶故不佳。 以下’針對含有本發明之銀微粒子之電糊加以描述。 本發明之電糊係由本發明之銀微粒子及溶劑組成，亦 可視需要調配結合劑樹脂、硬化劑、分散劑、流變調整劑 等其他成分。 結合劑樹脂可使用該領域中習知者，列舉爲例如乙基 纖維素、硝基纖維素等纖維素系樹脂，聚酯樹脂、胺基甲 酸酯改質之聚酯樹脂、環氧改質之聚酯樹脂、丙烯酸改質 之聚酯樹脂等各種改質之聚酯樹脂，聚胺基甲酸酯樹脂、 氯乙烯•乙酸乙烯酯共聚物、丙烯酸樹脂、環氧樹脂、酣 樹脂、醇酸樹脂、丁醛樹脂、聚乙烯醇樹脂、聚醯亞胺、 聚醯胺醯亞胺等》該等結合劑樹脂可單獨使用或倂用兩種 以上。 溶劑可使用該領域中習知者’列舉爲例如十四碳院、 甲苯、二甲苯、乙基苯、二乙基苯、異丙基苯、胺基苯、 對-異丙基甲苯、十氫萘及石油系芳香族烴混合物等之烴 系溶劑；乙二醇單乙醚、乙二醇單丁醚、丙二醇單甲酸、 -14- 201124215 丙二醇單乙醚、丙二醇單正丁醚、丙二醇單第三丁醚、二 乙二醇單乙醚、二乙二醇單丁醚、二丙二醇單甲醚、二丙 二醇單丁醚、三丙二醇單甲醚等醚系或二醇醚系溶劑：乙 二醇單甲醚乙酸酯、乙二醇單乙醚乙酸酯、乙二醇單丁醚 乙酸酯、丙二醇單甲醚乙酸酯、丙二醇單乙醚乙酸酯等二 醇酯系溶劑；甲基異丁基酮、環己酮等酮系溶劑；松油醇 (terpineol)、芳樟醇（linalool)、香葉醇（geraniol) 、香茅醇（cntronellol )等萜烯醇；正丁醇、第二丁醇、 第三丁醇等醇系溶劑；乙二醇、二乙二醇等二醇系溶劑； γ-丁內酯及水等。溶劑可單獨使用或併用兩種以上。 電糊中之銀微粒子含量隨著用途而不同，例如形成配 線之用途之情況等較好儘可能接近1 00重量％。 本發明之電糊可藉由使用粉碎擂潰機、球磨機、三軸 輥硏磨機、旋轉式混合機、二軸混練機等各種混練機、分 散機，將各成分混合•分散而獲得。此時，即使在獲得電 糊之步驟中，爲了維持規定之銀微粒子之多結晶化度（增 大結晶子徑，所得銀微粒子無趨近單結晶之方式），較好 在30°C以下進行各操作。 本發明之電糊可使用於網版印刷、噴墨法 '凹版印刷 、轉印印刷、輥塗佈、流塗、噴霧塗佈、旋轉塗佈、浸漬 、刮板塗佈、電鍍等各種塗佈方法中。 又，本發明之電糊可使用於形成FPD (平板顯示器） 、太陽電池、有機EL等電極或形成LSI基板之配線，進而 可使用作爲細微溝槽、穿孔、接觸孔之埋入等之配線形成 -15- 201124215 材料·。又，在層合陶磁電容器或層合電感器之內部電極形 $ 等之在高溫之燒成用途中，由於可低溫燒成故適宜作 爲於可撓性基板或1(：卡、其他基板上之配線形成材料及電 Μ Μ成材料。又，可使用電磁波遮蔽膜或紅外線反射遮蔽 膜等作爲導電性被膜。亦可在電子安裝中作爲零件安裝用 接合材料使用。 〈作用〉 本發明之重要點爲平均粒徑（DSEM)爲30~100nm，多 結晶化度[平均粒子徑（DSEM )與結晶子徑（Dx )之比（ DSEM/DX)]爲2.8以上之銀微粒子可經低溫燒成之事實。 有關本發明之銀微粒子之低溫燒結性優異之理由，本 發明者認爲如下。亦即，爲了使銀微粒子在低溫下燒結， 有必要使銀微粒子成爲活性，但由於平均粒子尺寸爲20nm 以下時活性過高而不安定，故通常需被覆大量有機物，其 被覆物通常爲高分子，在低溫下無法去除，故難以降低燒 成溫度。雖認爲不必要以大量有機物被覆，儘可能使表面 活性高之粒子尺寸爲30〜lOOnm，但於以往該粒子尺寸之銀 微粒子之情況，由於在低溫下燒結表面活性能不足，故難 以低溫燒成。於本發明之銀微粒子之情況，粒子內部亦即 藉由使銀微粒子非爲單結晶而以多結晶體構成，可使粒子 內部之能fi變高，因此，認爲可在低溫下燒結。 [實施例] -16- 201124215 以下使用下述實施例更詳述本發明，但本發明並不限 於以下之實施例。顯示以下實施例中之評價方法。 銀微粒子之平均粒徑係使用掃描型電子顯微鏡照相「 S-4800」 （HITACHI製造）拍攝粒子之相片，使用該相片 對1 00個以上之粒子測定粒徑，算出其平均粒徑作爲平均 粒徑（dsem )。 銀微粒子之比表面積係使用「MONOSORB MS-l〗」（ QUANTA CHROME股份有限公司製造），以利用BET法測 定之値表示。 銀微粒子之結晶子徑（Dx )係使用X射線繞射裝置「 RINT 2 500」（RIG AKU股份有限公司製造），以Cu之Κα 線作爲線源求得面指數（1 , 1，1 )面峰之半値寬度，且利用 Scherrer之式計算結晶子徑。 銀微粒子之多結晶化度係以平均粒徑（DSEM )與結晶 子徑（Dx)之比（DSEM/DX)表示。 銀微粒子因加熱造成之結晶子徑之變化率（％ )係使 用將銀微粒子在150°C加熱30分鐘後之結晶子徑與加熱前 之銀微粒子之結晶子徑’依據下述數1算出之値。又，將 加熱條件換成在120°C歷時30分鐘、在丨00°C歷時30分鐘時 ，同樣求得結晶子徑之變化率。 〈數I〉 結晶子徑之變化率（％)=加熱後之銀微粒子之結晶子徑/加 熱前之銀微粒子之結晶子徑X1 00 -17- 201124215 銀微粒子之雜質金屬之含量係使用「誘導結合電漿發 光分光分析裝置SPS4000」（Seiko電子工業股份有限公司 製造）測定，以除了 Ag以外之元素之含有量較多者中之上 位三種元素之合計量表示。 導電性塗膜之比電阻係針對將後述之電糊塗佈於聚酯 薄膜上，在120°C預乾燥後，於150t加熱硬化30分鐘獲得 之導電性膜，使用四端子電阻測定裝置「LORESTA GP/MCP-T610」（DAIMOND INSTRUMENTS股份有限公司 製造）測定，由薄片電阻與膜厚算出比電阻。 〈實施例1 -1 :銀微粒子之製造〉 將硝酸銀40g與甲醇200mL添加於500mL燒杯中之後， 以水浴冷卻邊添加•搅拌37.9g之正丁胺，調製A液。另外 ，量取62.2g之抗壞血酸於2L之燒杯中，添加400mL之水且 搅拌溶解後，添加200mL甲醇調製B液。 接著，邊搅拌B液邊將A液於1小時2 0分鐘內滴加於B 液中。滴加中，反應溫度以維持在2 5 °C之方式調節。滴加 結束後，攪拌1 4小時後，靜置3 0分鐘使固形物沉降。以傾 析去除上澄液後，使用濾紙抽氣過濾，接著，使用甲醇與 純水洗淨•過濾。使所得銀微粒子之固形物在真空乾燥機 中於3 0 °C乾燥6小時後’以慣用方法粉碎獲得實施例I _丨之 銀微粒子。又’上述各處理中之溫度調節至不超過3〇t。 所得銀微粒子之平均粒徑（Ds EM )爲8 2.5 nm ,結晶子 -18- 201124215 徑（Dx)爲 21.3nm，多結晶化度（DSEM/Dx)爲 3 9，BET 比表面積値爲5 · 3 m2 / g ’結晶子徑之變化率（1 5 〇。(： x 3 〇分鐘 )爲245%，可丨谷性金屬之含里未達50ppm。 〈實施例2 - 1 :電糊之製造〉 對於本發明之銀微粒子1 00重量份添加聚醒樹脂i丨0 重量份及硬化劑1.4重量份，以使電糊中之銀微粒子之含 量成爲70wt%之方式添加二乙一醇單乙進行預混合後 ，使用三軸輥進行均句之混練•分散處理，獲得電糊。又 ，用以獲得電糊之上述各步驟之溫度係以不超過3〇 °C之方 式調節。 所得導電性塗膜之比電阻爲5.5x1 〇·5Ω · 。 依據前述實施例1 -1及實施例2 - 1製作銀微粒子及電糊 。列示各製造條件及所得銀微粒子粉末及電糊之諸特性。 實施例1 - 2 ~ 1 - 4及比較例1 - 1 ~ 1 - 2 : 藉由改變銀微粒子之種種生成條件獲得銀微粒子。 此時之製造條件示於表1，所得銀微粒子之諸特性示 於表2。 -19- [表1] 銀微粒子之製造 實施例 硝酸銀之胺絡合錯合物之形成 還原反應 乾燥 及 硝酸銀 醇 胺 還原劑 還原反應 乾燥條件 比較例 添加量 種類 種類 添加量 種類 添加量 溫度 溫度 裝置 (mol) (當量） (當量） (°C) (°C) 實施例卜1 1 甲醇 正丁胺 2.2 異抗壞血酸 1.5 25 30 真空乾燥 實施例1-2 1 甲醇 正丁胺 2.2 抗壞血酸 1.5 21 20 真空乾燥 實施例1-3 1 乙醇 正丁胺 2.1 異抗壞血酸 1.5 20 25 真空乾燥 實施例1-4 1 甲醇 單乙醇胺 2.2 抗壞血酸 1.5 25 20 真空乾燥 比較例1-1 1 甲醇 正丁胺 2.2 異抗壞血酸 1.5 45 30 真空乾燥 比較例1-2 1 甲醇 正丁胺 2.2 異抗壞血酸 1.5 25 40 乾燥機 201124215 -20- [表2] 銀微粒子之特性 實施例 粒子 平均粒 結晶子徑 多結晶化度 BET比 -0.05x 結晶子徑之變化率 雜質 及 形狀 徑 Dsem Dx (nm) Dsem/Dx 表面積値 Dsem +7.4 之値 100°Cx 120°Cx 150°Cx 金屬 比較例 (nm) (-) (實測値） (SSA) 30分鐘 30分鐘 30分鐘 (ppm) (SSA) (m2/g) (%) (%) (%) (m2/g) 實施例1-1 粒狀 82.5 21.3 3.9 5.3 3.3 211 221 245 <50 實施例1-2 粒狀 52.6 14.5 3.6 7.1 4.8 219 230 272 <50 實施例1-3 粒狀 80.1 19.7 4.1 5.7 3.4 220 238 309 <50 實施例1-4 粒狀 74.3 22.4 3.3 6.3 3.7 193 205 224 <50 比較例1-1 獄 85.4 41.2 2.1 2.8 3.1 105 113 123 <50 比較例1-2 粒狀 83.2 35.9 2.7 2.9 3.2 103 117 126 <50 201124215 〈導電性塗料之製造〉 實施例2 - 2〜2 - 4及比較例2 _丨〜2 _ 2 : 除使銀微粒子種類進行各種變化以外，餘依循前述實 施例2 -1之導電性塗料之製作方法製造導電性塗料及導電 性膜。 此時之製造條件及所得導電性塗膜之諸特性示於表3 [表3] 實施例及 比較例 電糊之製造 導電性塗膜之特性 銀微粒子之種類 加熱條件 比電阻(Ω · cm) 溫度(°C) 時間(min) 實施例2-1 實施例1-1 150 30 5·5χ10·5 實施例2-2 實施例1-2 120 30 4.5x10'5 實施例2-3 實施例1-3 100 30 5.7x1 (Γ5 實施例2-4 實施例1-4 150 30 4.2xl〇·5 比較例2-1 比較例1-1 150 30 7.6x10'4 比較例2-2 比較例1-2 120 30 9.3x10'4 [產業上之可能利用性] 本發明之銀微粒子由於平均粒徑爲3 0〜1 〇〇nm，故無必 要如單一奈米級之銀微粒子般以大量有機物被覆表面，且 ，由於多結晶化度爲2 · 8以上故粒子內部之活性高，故即 使在低溫下亦可進行銀微粒子彼此間之燒結，因此適用作 爲可低溫燒成之電糊等之原料。 -21 -[Technical Field] The present invention relates to a polycrystalline average particle diameter of 3 0 to 1 〇〇 nm which is preferably used as a raw material of a conductive composition for low-temperature firing. Silver fine particles, a method for producing the same, and an electric paste, a conductive film, and an electronic device containing the silver fine particles. [Prior Art] The formation of an electrode or a circuit pattern of an electronic device is performed by printing an electrode or a circuit pattern on a substrate using an electric paste containing metal particles, and then firing the metal particles contained in the electric paste by heating. However, in recent years, the heating and firing temperature tends to decrease. For example, 'as a mounting board for an electronic device, a flexible substrate made of polyimine is generally used to be heated to about 300 ° C, but the heat resistance is excellent but expensive. Therefore, it has recently been reviewed to make PET cheaper. A polyethylene terephthalate substrate or a PEN (polyethylene naphthalate) substrate is used as an alternative material. However, 'the PET substrate or the PEN substrate has a lower heat resistance than the flexible substrate made of polyimide. It must be heated at 20 (TC or less). If it is lower than 20 (TC) When the temperature is heated and fired, an electrode or a circuit can be formed on a substrate such as polycarbonate or paper, and it is expected to expand the use of various electrode materials, etc. As a metal particle which is a raw material of the electrically paste which can be fired at a low temperature, The nano-sized silver particles are expected. The reason is that the size of the metal particles is -5,242,242,150 nm. The surface activity is higher, the melting point is lower than that of the metal block, and it is sintered at a low temperature. Further, among the metal particles, silver fine particles are exemplified as 'low resistance', and the price is also cheaper than other precious metals. And 'nano-grade silver fine particles can be sintered at a low temperature, and heat resistance can be maintained at the time of primary sintering, so it is expected In the past, lead-free solders without soldering properties have been used as replacement materials. So far, as silver microparticles that can be fired at low temperatures, silver microparticles below submicron are proposed, and it is known to adsorb hexylamine on the surface. The average particle diameter (DTEM) of silver powder of 3 to 20 nm (Patent Document 1), the average particle diameter (DTEM) of the particle surface covered with an organic protective agent is 5 〇 nm or less, and the single crystallinity (DTEM/DX) is Silver particles of 2.0 or less (Patent Document 2), silver fine particles having an average particle diameter of 40 to 10 nm and a single crystallinity (Dtem/Dx) of 1 to 5 (Patent Document 3), 1 on the surface of the particles Silver fine particles having an average particle diameter of 20 to 100 nm with an amine-attached silver nitrate complex complex and an amine (Patent Document 4) 'The average particle diameter coated with a surface treatment agent is less than 2 〇〇 nm' BET specific surface area is The above noble metal is a particle (Patent Document 5) 'Nano powder containing an average particle diameter of less than 1% of soluble metal of 50 to 100 nm and a BET specific surface area of 6 to 25 m 2 /g (Patent Document 6). [Patent Document 1] [Patent Document 1] Japanese Laid-Open Patent Publication No. JP-A No. Hei. No. Hei. Japanese Patent Publication No. 2004-43197 (Patent Document 5) JP-A-2004-43 892 [Patent Document 6] Special Table 2005-5 [Invention of the Invention] [Problems to be Solved by the Invention] In order to sinter the silver fine particles at a low temperature, it is necessary to activate the silver fine particles. However, the silver fine particles having an average particle diameter of 20 nm or less disclosed in the above Patent Document 1 are disclosed. In the case where the activity is too high and it is not stable, it is necessary to coat a large amount of organic matter. In Patent Document 1, 'the hexylamine having a boiling point of about 130 ° C is used as the coating material, but even if the coating material having a lower boiling point is selected, for example, It is difficult to completely remove a large amount of attached coating. Further, in the case of producing silver fine particles in Patent Document 1, since the temperature of 50 to 60 °C is applied, the crystallite diameter of the silver fine particles tends to become large, so that the reactivity inside the silver fine particles is lowered, which is disadvantageous for low-temperature sintering. In addition, in the above-mentioned Patent Document 2, the average particle diameter (DTEM) of the particle surface covered with the organic protective agent is 50 nm or less, and the single crystallinity (Dtem/Dx) is 2.0 or less. However, as described above, Since /DX) is 2.0 or less and the degree of single crystallinity is high, the reactivity inside the silver fine particles is low, which is disadvantageous for low-temperature sintering. Further, in Patent Document 3, silver fine particles having an average particle diameter of 40 to 1 〇〇 nm 'single crystallinity (DTEM/DX) of 1 to 5 are described, but the temperature is adjusted to 40 ° by the temperature of silver fine particles. Around C, the crystallite diameter of silver particles tends to become larger. Therefore, the reactivity within the silver fine particles is lowered, which is disadvantageous for low-temperature sintering. In the above-mentioned Patent Document 4, silver nitrate fine particles in which an amine nitrate complex of silver nitrate and an amine have an average particle diameter of 20 to 100 nm are attached to the surface of the particle, but the reaction in the reduction reaction is not considered. The temperature is increased by heating to 40 ° C, so that the crystal grain size tends to increase, and the reactivity within the silver fine particles is lowered, which is disadvantageous for low-temperature sintering. Further, in Patent Document 5, the noble metal fine particles having an average particle diameter of less than 200 nm and a BET specific surface area of 1.0 m 2 /g or more are coated with a surface treatment agent, but the surface treatment agents on the surface of the coated particles are all high-boiling substances. In the examples of Patent Document 5, even if the surface treatment agent remains under heating conditions of 200 ° C, it is difficult to use the raw material of the electric paste for low-temperature sintering. Further, since the BET specific surface area 値 is smaller with respect to the particle diameter, the activity is lower, which is disadvantageous for low-temperature sintering. Further, in the above-mentioned Patent Document 6, a nano-powder containing an average particle diameter of less than 1% of a soluble metal of 50 to 100 nm and a BET specific surface area of 6 to 25 m 2 /g is described, but a soluble metal containing a source-made method is used. Since the sintered body obtained by the nano powder shown in Patent Document 6 contains an impurity metal which inhibits conductivity, it is difficult to obtain a sintered body having a desired high conductivity. Moreover, since the soluble metal present interferes with sintering, it is difficult to sinter at a low temperature. Therefore, the technical problem of the present invention is to provide a polycrystalline silver microparticle which is suitable for use as a raw material of a low-temperature calcinable electric paste and has an average particle diameter of 30 to ΙΟΟηη. [Means for Solving the Problem] The problems of the above-described technology can be achieved by the present invention described below. -8 - 201124215 That is, the present invention is a silver fine particle characterized by an average particle diameter (D s E Μ ) of 30 to 1 ο 〇 nm, polycrystallinity [average particle diameter (D s EM ) and crystallization The ratio of the sub-diameter (Dx) (DSEM/DX)] is 2.8 or more (Invention 1). Further, the present invention is the silver fine particle of the present invention, wherein the rate of change of the crystal seed diameter by heating [(the crystal seed diameter of the silver fine particles after heating for 30 minutes at 150 ° C / the silver fine particles before heating) The crystal seed diameter) X 1 〇〇] is 150% or more (Invention 2). Further, the present invention is the silver fine particles of the invention 1 or 2, wherein the BET specific surface area 値 (SSA ) ( m 2 /g ) of the silver fine particles has a relationship with the average particle diameter (DSEM ) of the following formula (1) (Inventive 3 In addition, the present invention is a method for producing silver fine particles according to any one of the inventions 1 to 3, characterized in that silver nitrate is used and water-soluble or An alcohol solution of a silver nitrate amine complex prepared by dissolving one or more kinds of amines having a boiling point of water of 200 ° C or less, which is added to dissolve the ascorbic acid or erythorbic acid in a water-alcohol mixed solvent and to reduce and precipitate After the obtained silver particles are separated and washed, the silver particles are dried by vacuum drying at a temperature of 30 ° C or lower (Invention 4). Further, the present invention is a method for producing silver fine particles according to Invention 4, wherein all the steps before obtaining the silver fine particles are carried out at a temperature of 30 ° C or lower (Invention 5). Further, the present invention is an electric paste comprising the silver fine particles according to any one of the items 1 to 3 of the present invention (Invention 6). Further, the present invention is a conductive film formed by using the electric paste of the present invention No. -9 - 201124215 (Invention 7). Further, the present invention is an electronic device comprising the conductive film of the seventh aspect of the invention (Invention 8). [Effect of the Invention] Since the silver fine particles of the present invention have an average particle diameter of 30 to 100 nm, it is not required to coat the surface with a large amount of organic matter as a single nano-sized silver fine particle, and since the degree of polycrystallization is 2.8 or more, the activity inside the particles is high. Therefore, even if the silver fine particles are sintered to each other at a low temperature, it is suitable as a raw material for an electric paste which can be fired at a low temperature. [Embodiment] The constitution of the present invention will be described in more detail below. First, the silver fine particles of the present invention will be described. The silver microparticles of the present invention have a characteristic average particle diameter (DSEM) of 30 to 1 〇〇nm, a polycrystallinity [ratio of average particle diameter (DSEM) to crystallite diameter (〇\) (05 to /0). ] is 2.8 or more. The average particle diameter (DSEM) of the silver fine particles of the present invention is 30 to 10 nm, preferably 40 to 100 nm, more preferably 50 to 100 nm. When the average particle diameter (dsem) is less than 30 nm, the surface activity of the silver fine particles is increased, and it is necessary to adhere a large amount of organic substances in order to maintain the fine particle diameter stably, which is not preferable. Further, when the average particle diameter (DSEM) exceeds 100 nm, the surface activity of the silver fine particles is lowered, which is disadvantageous in that the low-temperature sintering property is impaired. The degree of polycrystallization of the silver fine particles of the present invention [ratio of the average particle diameter (Dsem -10- 201124215) to the crystallite diameter (Dx) (DSEM/DX)] is 2.8 or more, 3.0 or more, and more preferably 3.2 or more. . When the degree of polycrystallization is less than 2.8, the crystallite diameter in the fine particles becomes large, and the single crystal is close to the single crystal, so that the reactivity in the silver microparticles is lowered, which may impair the low-temperature sintering property. The upper limit of the degree of crystallization is about 1 ,, preferably about 8. The crystallite diameter of the silver microparticles of the present invention is changed by 1 due to heating (15 (the crystallite diameter of the silver microparticles after 30 minutes of heating by TC/the crystallite diameter of the heated silver microparticles) X 1 〇〇] is 1 50% or more When the crystal diameter reduction ratio is less than 150%, it is difficult to say that it is excellent in low-temperature sinterability. In the present invention, it is preferred that the rate of change of the crystal seed diameter when heated at 10 ° C for 3 Torr is also above, more preferably When the temperature is 30 ° C for 30 minutes, the crystal seed diameter ratio is also 150% or more. The BET specific surface area (SSA) of the silver fine particles of the present invention is in the range represented by the formula (1). When S(SSA) is smaller than the range of (1) below, it is necessary to treat the silver microparticles with a large amount of organic matter to cause a decrease in surface activity, so it is difficult to obtain good low-temperature sinterability. SS A ( m2/g ) ^ -0.05 xDsem + 7.4 .. (1) The particle shape of the silver fine particles of the present invention is preferably spherical or granular. The impurity metal of the silver fine particles of the present invention is preferably 500 ppm or less, preferably 200 ppm or less, more preferably 100 ppm or less. The amount of the impurity metal exceeds 500 ppm. When the sintered body obtained therefrom is used, it contains a damaging impurity gold. Therefore, it is difficult to obtain a desired high-conductivity burning. In addition, since the impurity metal present hinders sintering, it is difficult to sinter underneath. More preferably, the silver particles are multi-knotted. The enthalpy rate [in the past, 150% The change is in the following formula, and further includes the conductive layer low temperature -11 - 201124215. The silver fine particles of the present invention may be subjected to surface treatment as long as the above characteristics are satisfied. The surface treatment agent is preferably an alcohol having a boiling point of 20 CTC or less. The alcohol may be ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, ethylene glycol, etc. Further, the amine may be ammonia, methylamine, ethylamine, propylamine, butylamine or monoethanolamine. When the surface of the silver fine particles is subjected to a surface treatment, the amount of the amine and/or the alcohol to be coated or adhered is 1% by weight or less. When the amount is more than 1% by weight, the low-temperature sinterability is lowered, which is not preferable, and more preferably 0.9% by weight. Hereinafter, it is more preferable that the method for producing silver fine particles of the present invention is described below. The silver fine particles of the present invention can be used by using silver nitrate with a water-soluble or water-soluble boiling point of 200. An alcohol solution of a silver nitrate amine complex prepared by dissolving ascorbic acid or erythorbic acid in a water-alcohol mixed solvent and being reduced by precipitation, and separating and washing the obtained silver particles 'The silver particles are dried by vacuum drying at a temperature of 30 ° C or lower. Further, in all the steps of producing the silver fine particles, it is preferably carried out at a temperature of 30 ° C or lower. Accordingly, the prescribed silver fine particles can be easily maintained. The degree of crystallization is sufficient. The water-soluble or water-soluble boiling point of the present invention is 2 〇〇. <: The following month, butylamine, propylamine, monoethanolamine, etc. may be used. Here, the term "water-soluble" means arbitrarily mixed with water, and the water-soluble water means that it has a certain degree of solubility in water. The alcohol in the present invention can be used in compatibility with water. Considering the latter step, it is removed by vacuum drying at a temperature of 30 ° C or less, and preferably -12-201124215 alcohol having a boiling point of 丨〇〇t or less. Specifically, methanol, ethanol, propanol, isopropanol or the like can be used, and methanol and ethanol are preferred. These alcohols may be used singly or in combination, and a butylamine represented by a water-soluble or water-soluble amine having a boiling point of 200 ° C or less is used as an example. However, an amine such as propylamine or monoethanolamine may be similarly used. modulation. Further, it is characterized in that the alcohol solution of the silver nitrate and the amine complex complex of silver nitrate prepared by using one or more kinds of water-soluble or water-soluble amines having a boiling point of 2 ° C or less is used in a water-alcohol mixed solvent. The basic complication of ascorbic acid or erythorbic acid reduction is not limited to the following conditions. For example, the amount of methanol or the amount of water varies depending on the solubility of the amine used, the optimum volume ratio of the reaction vessel to the agitation mechanism. First, an amine complex complex of silver nitrate is formed by silver nitrate and butylamine in an alcohol solvent. The butanamine is preferably from 2.0 to 2.5 equivalents to more preferably from 2.0 to 2.3 equivalents based on the silver acetate. When the amount of butylamine is less than 2.0% equivalent to silver nitrate, large particles tend to be formed. Next, after the ascorbic acid or erythorbic acid of the reducing agent is dissolved in water, the alcohol is added and mixed. Ascorbic acid or isoascorbic acid is preferably from 1.0 to 2.0 equivalents, more preferably from 1.0 to 1.8 equivalents, based on the silver nitrate. When ascorbic acid or erythorbic acid exceeds 2.0%, the tendency of the generated silver fine particles to aggregate with each other is not preferable. Next, an alcohol solution forming an amine complex complex of silver nitrate is added dropwise to a water-alcohol solution obtained by dissolving ascorbic acid or erythorbic acid, and a reduction reaction is carried out to precipitate silver fine particles. The reaction temperature in the reduction reaction is in the range of -13 to 201124215 15 to 30 ° C, more preferably 18 to 3 ° C. When the reaction temperature exceeds 30»c, the crystallite diameter becomes large, and the obtained silver microparticles tend to be close to single crystal, which is not preferable. After the completion of the dropwise addition, stirring is continued for one hour or more, and the silver fine particles are allowed to settle by standing. After the supernatant is removed by decantation, the remaining reducing agent, butylamine, silver nitrate or the like is washed with alcohol and water. The washed silver fine particles are pulverized by a conventional method at a temperature of 3 (TC or less vacuum drying), and the silver fine particles of the present invention can be obtained. When the drying temperature exceeds 3 〇 ° C, the crystallite diameter becomes large, and the obtained silver fine particles approach a single crystal. The following description is directed to an electric paste containing the silver fine particles of the present invention. The electric paste of the present invention is composed of the silver fine particles and the solvent of the present invention, and may also be formulated with a binder resin, a hardener, a dispersant, and a rheological adjustment. Other components such as a solvent. The binder resin can be used as a cellulose resin such as ethyl cellulose or nitrocellulose, and a polyester resin or a urethane modified polyester resin. Various modified polyester resins such as epoxy modified polyester resin and acrylic modified polyester resin, polyurethane resin, vinyl chloride/vinyl acetate copolymer, acrylic resin, epoxy resin, Anthracene resin, alkyd resin, butyral resin, polyvinyl alcohol resin, polyimine, polyamidimide, etc. These binder resins may be used singly or in combination of two or more. It is exemplified by those skilled in the art as, for example, fourteen carbon institutes, toluene, xylene, ethylbenzene, diethylbenzene, cumene, aminobenzene, p-isopropyltoluene, decahydronaphthalene and Hydrocarbon solvent such as petroleum aromatic hydrocarbon mixture; ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monocarboxylic acid, -14- 201124215 propylene glycol monoethyl ether, propylene glycol mono-n-butyl ether, propylene glycol mono-tert-butyl ether, Ether or glycol ether solvent such as diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monobutyl ether or tripropylene glycol monomethyl ether: ethylene glycol monomethyl ether acetate a glycol ester solvent such as ester, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate; methyl isobutyl ketone, ring a ketone solvent such as ketone; a terpene alcohol such as terpineol, linalool, geraniol, cntronol, etc.; n-butanol, second butanol, third An alcohol solvent such as butanol; a glycol solvent such as ethylene glycol or diethylene glycol; γ-butyrolactone and water; The content of the silver fine particles in the electric paste varies depending on the use, and is preferably as close as possible to 100% by weight, for example, in the case of forming a wiring. The electric paste of the present invention can be used by using pulverized mash. Various kneading machines and dispersing machines, such as a crusher, a ball mill, a three-axis roll honing machine, a rotary mixer, and a two-axis kneading machine, are obtained by mixing and dispersing the components. At this time, even in the step of obtaining the electric paste, In order to maintain the degree of crystallinity of the predetermined silver fine particles (increasing the crystallite diameter, the obtained silver fine particles do not approach a single crystal), it is preferred to carry out each operation at 30 ° C or lower. The electric paste of the present invention can be used for a net. Various printing methods such as printing, inkjet printing, gravure printing, transfer printing, roll coating, flow coating, spray coating, spin coating, dipping, blade coating, and plating. Further, the electric paste of the present invention can be used for forming an electrode such as an FPD (flat panel display), a solar cell, or an organic EL, or a wiring for forming an LSI substrate, and can be formed by using wiring as a fine groove, a via, or a buried hole. -15- 201124215 Materials·. In addition, in the high-temperature firing application, such as the internal electrode shape of the laminated ceramic capacitor or the laminated inductor, it can be suitably used as a flexible substrate or 1 (: card, other substrate) because it can be fired at a low temperature. In addition, an electromagnetic wave shielding film or an infrared reflection shielding film can be used as the conductive film. It can also be used as a component mounting bonding material in electronic mounting. <Action> Important points of the present invention The average particle diameter (DSEM) is 30 to 100 nm, and the degree of polycrystallinity (the ratio of the average particle diameter (DSEM) to the crystallite diameter (Dx) (DSEM/DX)) of 2.8 or more can be fired at a low temperature. The reason why the silver fine particles of the present invention are excellent in low-temperature sinterability is considered as follows. In other words, in order to sinter the silver fine particles at a low temperature, it is necessary to make the silver fine particles active, but the average particle size is 20 nm. In the following, when the activity is too high and not stable, it is usually required to coat a large amount of organic matter, and the coating material is usually a polymer, and cannot be removed at a low temperature, so it is difficult to lower the firing temperature. In order to coat a large amount of organic matter, the particle size of the surface activity is as high as 30 to 100 nm. However, in the case of the silver fine particles of the conventional particle size, since the surface active energy at the low temperature is insufficient, it is difficult to burn at a low temperature. In the case of the silver fine particles of the invention, the inside of the particles is formed of a polycrystalline body by making the silver fine particles non-single crystal, and the energy inside the particles can be increased. Therefore, it is considered that the particles can be sintered at a low temperature. -16- 201124215 The present invention will be described in more detail below using the following examples, but the present invention is not limited to the following examples. The evaluation methods in the following examples are shown. The average particle diameter of silver fine particles is photographed using a scanning electron microscope. S-4800" (manufactured by HITACHI) photographs the particles, and uses the photograph to measure the particle size of 100 or more particles, and calculates the average particle diameter as the average particle diameter (dsem). The specific surface area of the silver particles is "MONOSORB MS". -l〗 (manufactured by QUANTA CHROME Co., Ltd.), which is measured by the BET method. The crystallite diameter (Dx) of silver particles is X-ray. The line diffraction device "RINT 2 500" (manufactured by RIG AKU Co., Ltd.) uses the Cu Κα line as the line source to obtain the half-width of the surface index (1, 1,1), and uses the Scherrer formula to calculate the crystal. The degree of crystallinity of silver microparticles is expressed by the ratio of average particle diameter (DSEM) to crystallite diameter (Dx) (DSEM/DX). The rate of change (%) of crystallite diameter due to heating is used. The crystallite diameter after the silver microparticles were heated at 150 ° C for 30 minutes and the crystallite diameter of the silver microparticles before heating were calculated according to the following number 1. Further, the heating conditions were changed to 120 ° C for 30 minutes. The rate of change of the crystallite diameter was also determined at 00 ° C for 30 minutes. <Number I> Change rate of crystal seed diameter (%) = crystal seed diameter of heated silver microparticles / crystal particle diameter of silver microparticles before heating X1 00 -17- 201124215 Impurity metal content of silver microparticles is used In combination with the plasma emission spectroscopic analyzer SPS4000" (manufactured by Seiko Electronics Co., Ltd.), the total amount of the upper three elements in the content of the elements other than Ag was measured. The specific resistance of the conductive coating film is a conductive film obtained by applying an electric paste described later on a polyester film, pre-drying at 120 ° C, and heat-hardening at 150 t for 30 minutes, using a four-terminal resistance measuring device "LORESTA GP". /MCP-T610" (manufactured by DAIMOND INSTRUMENTS Co., Ltd.) measured the specific resistance from the sheet resistance and the film thickness. <Example 1-1: Production of silver fine particles> After adding 40 g of silver nitrate and 200 mL of methanol to a 500 mL beaker, 37.9 g of n-butylamine was added while stirring in a water bath to prepare a liquid A. Separately, 62.2 g of ascorbic acid was weighed into a 2 L beaker, 400 mL of water was added thereto, and the mixture was stirred and dissolved, and then 200 mL of methanol was added to prepare a B solution. Next, the solution A was added dropwise to the solution B while stirring the solution B for 1 hour and 20 minutes. During the dropwise addition, the reaction temperature was adjusted in such a manner as to maintain at 25 °C. After the completion of the dropwise addition, the mixture was stirred for 14 hours, and then allowed to stand for 30 minutes to precipitate a solid matter. After the supernatant was removed by decantation, it was filtered with a filter paper, and then washed with methanol and pure water. The solid matter of the obtained silver fine particles was dried in a vacuum dryer at 30 ° C for 6 hours, and then pulverized by a conventional method to obtain silver fine particles of Example I. Further, the temperature in each of the above treatments is adjusted to not more than 3 Torr. The average particle diameter (Ds EM ) of the obtained silver microparticles was 8 2.5 nm, the crystallite-18-201124215 diameter (Dx) was 21.3 nm, the polycrystallinity (DSEM/Dx) was 39, and the BET specific surface area 値 was 5 · The change rate of 3 m2 / g 'crystal sub-path (15 〇. (: x 3 〇 min) is 245%, and the content of glutinous metal is less than 50 ppm. <Example 2 - 1 : Manufacture of electric paste 〉 For the silver fine particles of the present invention, 100 parts by weight of the silicone resin and 1.4 parts by weight of the curing agent are added, and the content of the silver fine particles in the electric paste is 70% by weight. After mixing, a three-axis roller is used for kneading and dispersing the uniform sentence to obtain an electric paste. Further, the temperature of each of the above steps for obtaining the electric paste is adjusted so as not to exceed 3 ° C. The obtained conductive coating film The specific resistance was 5.5 x 1 〇 · 5 Ω · Silver fine particles and an electric paste were prepared according to the above Example 1-1 and Example 2-1, and the respective production conditions and characteristics of the obtained silver fine particle powder and electric paste were listed. 1 - 2 ~ 1 - 4 and Comparative Example 1 - 1 ~ 1 - 2 : By changing the various conditions for the formation of silver particles Silver fine particles were obtained. The production conditions at this time are shown in Table 1, and the properties of the obtained silver fine particles are shown in Table 2. -19- [Table 1] Production Example of Silver Fine Particles Formation Reduction Reaction of Silver Nitrate Amine Complex Complex Drying and silver nitrate alcohol reducing agent reduction reaction drying conditions comparison example addition amount type type addition amount type addition amount temperature temperature device (mol) (equivalent) (equivalent) (°C) (°C) Example 1 1 methanol butyl Amine 2.2 Isoascorbic acid 1.5 25 30 Vacuum drying Example 1-2 1 Methanol n-butylamine 2.2 Ascorbic acid 1.5 21 20 Vacuum drying Example 1-3 1 Ethanol n-butylamine 2.1 Isoascorbic acid 1.5 20 25 Vacuum drying Example 1-4 1 Methanol monoethanolamine 2.2 Ascorbic acid 1.5 25 20 Vacuum drying Comparative Example 1-1 1 Methanol n-butylamine 2.2 Isoascorbic acid 1.5 45 30 Vacuum drying Comparative Example 1-2 1 Methanol n-butylamine 2.2 Isoascorbic acid 1.5 25 40 Dryer 201124215 -20- [Table 2] Characteristics of Silver Microparticles Example Particle Average Particle Crystal Diameter Polycrystallinity BET Ratio -0.05x Change Rate of Crystallinity Diameter Impurity and Shape Diameter Dsem Dx (nm) Dsem/Dx Surface area 値Dsem +7.4 値100°Cx 120°Cx 150°Cx Metal Comparative Example (nm) (-) (measured 値) (SSA) 30 minutes 30 minutes 30 minutes (ppm) (SSA) (m2/g) (%) (%) (%) (m2/g) Example 1-1 Granular 82.5 21.3 3.9 5.3 3.3 211 221 245 <50 Example 1-2 Granular 52.6 14.5 3.6 7.1 4.8 219 230 272 <50 Example 1-3 Granular 80.1 19.7 4.1 5.7 3.4 220 238 309 <50 Example 1-4 Granular 74.3 22.4 3.3 6.3 3.7 193 205 224 <50 Comparative Example 1-1 Prison 85.4 41.2 2.1 2.8 3.1 105 113 123 <50 Comparative Example 1-2 Granular 83.2 35.9 2.7 2.9 3.2 103 117 126 <50 201124215 <Manufacture of Conductive Coatings> Example 2 - 2 to 2 - 4 and Comparative Example 2 _丨~2 _ 2 : In addition to various changes in the type of silver fine particles, a conductive paint and a conductive film were produced in accordance with the method for producing a conductive paint of the above Example 2-1. The production conditions at this time and the properties of the obtained conductive coating film are shown in Table 3 [Table 3] Examples of the conductive pastes of the examples and the comparative examples. Properties of the conductive coating film. Types of the silver fine particles Heating conditions Specific resistance (Ω · cm) Temperature (°C) Time (min) Example 2-1 Example 1-1 150 30 5·5χ10·5 Example 2-2 Example 1-2 120 30 4.5x10'5 Example 2-3 Example 1 -3 100 30 5.7x1 (Γ5 Example 2-4 Example 1-4 150 30 4.2xl〇·5 Comparative Example 2-1 Comparative Example 1-1 150 30 7.6x10'4 Comparative Example 2-2 Comparative Example 1 2 120 30 9.3x10'4 [Industrial Applicability] Since the silver fine particles of the present invention have an average particle diameter of 30 to 1 〇〇 nm, it is not necessary to coat a large amount of organic matter like a single nano-sized silver fine particle. In addition, since the degree of polycrystallization is 2·8 or more, the activity inside the particles is high, so that the silver fine particles can be sintered at a low temperature, and therefore, it is suitable as a raw material for electric paste which can be fired at a low temperature. twenty one -