201139544 六、發明說明： 【發明所屬之技術領域】 本發明係關於一種太陽能電池模組用封止材薄片及太 陽能電池模組。 【先前技術】 利用太陽光的潔淨之發電技術，太陽能電池近年來備 受矚目。於太陽能電池中，存在結晶矽、非晶矽、化合物 半導體、有機色素等多樣之方式。其中，由於結晶矽系太 陽能電池係具有優異的耐候性及耐久性且具有較高的光電 轉換效率，最爲普及進展中。 一般之結晶矽系太陽能電池模組係由前面玻璃、背光 片、光電轉換單元、封止材層所構成，成爲以封止材層完 全封止前面玻璃與背光片之間所配置的光電轉換單元之構 造。 於構成如此太陽能電池之材料中，尋求經得起長期使 用下之優異的耐候性。其中，由於封止材係由接著保持背 光片與光電轉換單元之材料，具有長期保持優異的緊貼性 之必要。另外，由於封止材也被配置於光電變換元件之受 光面側，也尋求不失去透明性。 一般而言，封止材係將具有適度之緊貼性與透明性之 EVA(乙烯-醋酸乙烯酯共聚物）作爲主要成分之樹脂使用。 於此EVA中，大多之情形，以使長期耐久性、與玻璃或背 背光片之緊貼性提高之目的下而添加交聯劑、交聯助劑、 矽烷耦合劑、光安定劑、紫外線吸收劑等之添加劑（例如， 201139544 專利文獻1至3)。 專利文獻1 :日本專利特許第3 3 2 3 5 6 0號公報 專利文獻2 :日本專利特許第4〇3 43 82號公報 專利文獻3 :日本專利特開2008 -23 5 8 8 2號公報 【發明内容】 〔發明所欲解決之問題〕 然而，如在專利文獻1至3所記載的習知封止材兼顧 充分之緊貼性與交聯密度係困難。因此，針對太陽能電池 用之封止材，期望更提高在長期使用下之信賴性。 本發明之目的係提供一種太陽能電池模組用封止材薄 片及使用該太陽能電池模組用封止材薄片之太陽能電池模 組，其能夠穩定地形成具有優異的緊貼性與高的交聯密度 之封止材層，且能夠製造於長期使用下具有高的信賴性之 太陽能電池模組。 〔解決問題之手段〕 本發明係用以解決該問題而採用以下之結構： 〔1〕一種太陽能電池模組用封止材薄片，其特徵爲含有乙 烯-醋酸乙烯酯共聚物（以下，稱爲「EVA」）、有機過氧化 物及矽烷耦合劑，符合下列條件（1)及（2): (1) 2.5 ^ (AxB)/C ^3.5 (2) 3.〇xl〇-3^ Ax(D/E)^ Ι.ΟχΙΟ'2 (但是’A係由有機過氧化物1分子所發生的理論氧自由基 量，B係有機過氧化物之莫耳量、c係矽烷耦合劑之莫耳 量’ D係相對於1 〇〇質量份的EVA之有機過氧化物之含量 201139544 (質量份），E係有機過氧化物之分子量）。 〔2〕該〔1〕中記載之太陽能電池模組用封止材薄片，其 中相對於該EVA全部單位醋酸乙烯酯單位的醋酸乙烯酯單 位之含量爲20至40質量％。 〔3〕一種太陽能電池模組，其係具有：太陽能電池單元、 封止該太陽能電池單元之封止材層、保護該封止材層表面 側之表面保護構件、及保護該封止材層背面側之背面保護 構件； 該封止材層係藉由在該〔1〕或〔2〕中記載之太陽能 電池模組用封止材薄片而所形成。 〔發明之效果〕 本發明之太陽能電池模組用封止材薄片能夠穩定地形 成具有優異的緊貼性與高的交聯密度之封止材層，且能夠 製造於長期使用下具有高的信賴性之太陽能電池模組。 另外，由於本發明之太陽能電池模組係使用該太陽能 電池模組用封止材薄片，具有優異的緊貼性與高的交聯密 度之封止材層，長期使用下信賴性高。 【實施方式】 <太陽能電池模組用封止材薄片> 以下’針對本發明之太陽能電池模組用封止材薄片（以 下’稱爲「封止材薄片」）的實施形態之一例而詳細說明。 本發明之封止材薄片係含有EVA、有機過氧化物及矽 烷耦合劑。 形成本發明之封止材薄片之樹脂基材較佳爲將EVA作 201139544 爲主要成分使用。EVA係具有高的透明性且爲廉價，在過 去的使用實效爲龐大之觀點爲有利。所謂以EVA作爲主要 成分係意指相對於樹脂基材之總量，使EVA成爲95質量 %以上。 於本發明之封止材薄片中，除了 EVA之外，也可以含 有其他之樹脂。其他之樹脂可舉例：聚乙烯、聚丙烯等之 聚烯烴；離子聚合物；乙烯-甲基丙烯酸共聚物；乙烯-丙 烯酸共聚物；聚氟乙烯：聚氯乙烯、或此等之共聚物等。 本發明之封止薄片的樹脂基材中之EVA比例較佳爲 95質量％以上，更佳爲97質量％以上，特佳爲100質量 %。 可用於本發明之封止薄片的EVA係相對於全部單位的 醋酸乙烯酯單位之含量較佳爲20至40質量％。若醋酸乙 燦醋單位之含量爲20質量％以上的話，使高的交聯密度及 優異的緊貼性變得容易獲得。若醋酸乙烯酯單位之含量爲 40質量％以下的話，容易抑制未反應之醋酸乙烯酯側鏈受 到熱或紫外線等之刺激而脫離且導致樹脂之劣化。 有機過氧化物係發揮作爲使E V A交聯反應起始的交聯 劑之作用。 有機過氧化物可舉例：丨，丨-二（三級丁過氧）環己烷、三 級丁過氧-2-乙基己基單碳酸酯、丨，丨_二（三級己過氧）環己 院、正丁基4，4·二（三級丁過氧）戊酸酯、三級丁過氧-3，5,5-二甲基己酸醋、2,5-二甲基- 2,5-二（三級己過氧）己烷、過氧 化二級丁基異丙苯酯、2,2_二（三級丁過氧）丁烷等^ 201139544 砍院親合劑係具有使藉由含有EVA之樹脂基材所形成 的封止材 '與保護其表面及背面之表面保護構件及背面保 護構件的緊貼性得以提高之作用。 砍院親合劑可舉例：γ-甲基丙烯醯氧基丙基三甲氧基 砍垸、三甲氧基丙基矽烷、三甲氧基甲基矽烷、乙烯基三 甲氧基矽烷、乙烯基三乙氧基矽烷、三氯丙基矽烷、三乙 氧基苯基矽烷等。 本發明之封止材薄片中之有機過氧化物及矽烷耦合劑 係符合下列條件（1)及條件（2)的方式來予以含有： (1 ) 2.5 ^ (AxB)/C ^3.5 (2 ) 3.0 X 1 Ο·3 $ A X (D/E) $ 1 · Ο X 1 0-2 (其中’ A係由有機過氧化物1分子產生的理論氧自由基 量’ B係有機過氧化物之莫耳量，C係矽烷耦合劑之莫耳 量’ D係相對於丨00質量份的EVA之有機過氧化物之含量 (質量份），E係有機過氧化物之分子量）。 從條件（1)中之有機過氧化物1分子產生的理論氧自由 基量A係下式（1-1)所示之量。 A = a X 2 ( 1 -1) (其中，式（1-1)中之a係有機過氧化物中之過氧化鍵的數 目。） 於本發明之封止材薄片中，從有機過氧化物1分子產 生的理論氧自由基量A與有機過氧化物之莫耳量B之積、 與矽烷耦合劑之莫耳量C的比（AxB)/C之値爲2.5至3.5, 更佳爲2.9至3.1 ^ 201139544 若比（AxB)/C爲2.5以上的話，EVA之交聯反應容易 充分進行，能夠抑制封止材層中引起變黃等之樹脂劣化。 若比（A X B)/C爲3 . 5以下的話，可以獲得優異的緊貼性，能 夠抑制封止材層、與表面保護構件及背面保護構件之剝離。 另外，於封止材薄片中，該Ax(D/E)之値爲3.0χ10·3 至 1·〇χ10_2，較佳爲 4·0χ10·3 至 7·〇χ10·3。若該 Ax(D/E) 之値爲3·〇χ 1(Γ3以上的話，EVA之交聯反應將充分進行， 能夠抑制封止材層中引起變黃等之樹脂劣化。若該Ax (D/E) 之値爲1·〇χ10_2以下的話，封止材薄片之成形加工時的安 定性將變高。 另外，於本發明之封止薄片中，除了該有機過氧化物 及矽烷耦合劑之外，也可以含有促進交聯反應之交聯助 劑。交聯助劑可舉例：異氰酸三烯丙酯、鄰苯二酸二烯丙 酯、氰酸三烯丙酯等。 另外，於本發明之封止薄片中，從所形.成的封止材層 之耐光性及熱安定性之觀點，也可以含有紫外線吸收劑、 抗氧化劑等之安定化劑。 用以提高耐光性所用之紫外線吸收劑可舉例：2 - ( 5 ·甲 基-2-羥苯基）苯并三唑、2-(3-三級丁基-5-甲基-2-羥苯 基）-5-氯苯并三唑、2-(4,6-二苯基-1，3,5-三阱-2-基）-5-〔（己 基）側氧〕酚、2,4-二羥基二苯甲酮、2-二羥基-4-正辛氧基 二苯甲酮等。 用以提高熱安定性所用之抗氧化劑可舉例：1，6-己二 醇雙〔3-(3,5-二（三級丁基）-4-羥苯基）丙酸酯〕、季戊四醇 201139544 四〔3-(3,5-二（三級丁基）·4-羥苯基）丙酸酯〕、三（2,4-二（三 級丁基）苯基）亞磷酸酯、2,4·雙（正辛硫基）-6-(4-羥基-3，5-二（三級丁基）苯胺基）-1，3,5-三阱、雙（2,2,6,6-四甲基-4-哌 啶基）癸酸酯等。 (封止材薄片之製造方法） 本發明之封止材薄片係使其符合該條件（1)及條件（2) 的方式來含有有機過氧化物及矽烷耦合劑以外，也利用習 知之製造方法而能夠製造。例如，可舉例具有如下之製膜 步驟的方法：使用具有直線狀狹縫之T模頭等，利用共擠 出法，進行將有機過氧化物與矽烷耦合劑、及必要時所添 加的其他添加劑混入該樹脂基材中，以使其加熱熔融的樹 脂而製膜。 另外，於該製膜步驟中，爲了防止結塊，藉由使熱熔 融的狀態之樹脂薄片表面緊貼於已實施凹凸圖案的輥（金 屬或橡膠製）上，使該輥之凹凸圖案轉印至該封止材薄片單 面或雙面，對封止材薄片實施壓紋加工。 於使用習知之封止材薄片的太陽能電池模組中，具有 根據封止薄片之組成而無法獲得充分之緊貼性或交聯密 度。本發明人等針對於此點而詳細探討後，得知以提高緊 貼性之目的下而於封止材薄片中含有矽烷耦合劑之情形 下，緊貼性將提高，另一方面，藉由該封止材薄片而所形 成的封止材層之交聯密度將降低。而且，發現藉由使其符 合該條件（1)及條件（2)的方式來含有有機過氧化物與矽烷 耦合劑而使緊貼性提高，同時也能夠抑制封止材層之交聯 -10- 201139544 密度的降低。 如此方式，由於使本發明之封止材薄片符合該條件（1) 及條件（2)的方式來含有有機過氧化物與矽烷耦合劑’能夠 安定地形成兼具高的交聯密度與優異的緊貼性之封止材 層。因此，使得使用該封止薄片的太陽能電池模組長期使 用之信賴性將變高。 <太陽能電池模組> 本發明之太陽能電池模組係具有：太陽能電池單元、 封止該太陽能電池單元之封止材層、保護該封止材層表面 側之表面保護構件、與保護該封止材層背面側之背面保護 構件：該封止材層係藉由上述本發明之封止材薄片而所形 成的模組。以下，顯示本發明之太陽能電池模組的實施形 態之一例而詳細加以說明。 如第1圖所示，本實施形態之太陽能電池模組1係具 有太陽能電池單元4, 4、封止太陽能電池單元4，4之封止 材層3、保護封止材層3表面側之表面保護構件2、保護封 止材層3背面側之背面保護構件5。 (太陽能電池單元） 太陽能電池單元4係具有依照光電效果而電性變換射 入受光面之機能的單元。太陽能電池單元4係於太陽能電 池模組1內，藉電極（省略圖面）而連接複數個（於第1圖中 爲2個）。太陽能電池單元4之數目並未予以特別限定。 太陽能電池單元4之材料，例如，可舉例：結晶系砂。 其中，從製造簡便性與成本面之觀點，特佳爲多結晶砂。 -11- 201139544 (封止材層） 封止材層3係使太陽能電池單元4, *之層包埋而封 止，藉由本發明之封止材薄片而所形成。 封止材層3之厚度較佳爲〇.3至〇.6mm。 (表面保護構件） 表面保護構件2較佳爲具有優異的耐久性、耐候性、 透明性者’例如，可舉例··玻璃板、聚對苯二甲酸乙二醋 等之樹脂薄片等。另外’也可以使用聚碳酸酯等之樹脂薄 片。 表面保護構件2之厚度較佳爲3至6 mm。 (背面保護構件） 背面保護構件5較佳爲具有優異的耐久性、耐候性 者’例如’可列舉：聚對苯二甲酸乙二酯、聚氟乙烯、EVA 等之樹脂薄片、及此等之積層體等。另外，也可以在該樹 脂薄片或積層體上積層賦予水蒸氣遮斷性或氧氣遮斷性之 遮斷層。 背面保護構件5之厚度較佳爲〇·2至〇.4mm。 (製造方法） 以下’本發明之太陽能電池模組的製造方法之—例係 說明上述太陽能電池模組1之製造方法。但是，本發明之 太陽能電池模組之製造方法並不受以下之方法所限定。 如第2圖所示，依序積層背面保護構件2、封止材薄 片3A、太陽能電池單位4, 4、封止材薄片3B、表面保護構 件5而作成積層體1 A。接著，進行真空狀態下加熱加壓積 -12- 201139544 層體1 A之真空積層，使太陽能電池單位4, 4埋沒於封止 材薄片3A、3B內，並使封止材薄片3A、3B之樹脂基材（EVA) 交聯硬化而接著一體化來使封止材層3形成。藉此，可以 獲得太陽能電池模組1。 封止材薄片3A與封止材薄片3B係本發明之封止薄 片，可以爲相同組成之封止材薄片，也可以爲不同組成之 封止材薄片，從藉由形成均句交聯構造而可以容易獲得良 好品質的模組之觀點，較佳爲相同組成之封止材薄片。 由於以上所說明的太陽能電池模組係使用本發明之封 止材薄片，安定地形成以高的交聯密度且具有優異的緊貼 性之封止材層，長期使用下具有高的信賴性。 〔實施例〕 以下，顯示實施例及比較例而詳細說明本發明。但是， 本發明係根據以下之記載而未予以限定。 〔使用原料〕 以下顯示在本實施例所使用的原料。 (EVA) EVA-1 :醋酸乙烯酯單位之含量爲30質量％之EVA。 (有機過氧化物） I- 1 :三級丁過氧-2-乙基己基單碳酸酯 (矽烷耦合劑） II- 1: γ-甲基丙烯醯氧基丙基三甲氧基矽烷 (交聯助劑） ΙΙΙ-1 :三烯丙基異氰酸酯 -13- 201139544 (抗氧化劑） IV-1 :三（2,4-二（三級丁基）苯基）亞磷酸酯 〔實施例1〕 相對於100質量份的EVA-1，使用摻合0.6質量份的 有機過氧化物1-1、0.4質量份的矽烷耦合劑11-1、〇.6質量 份的交聯助劑III-1、及0.1質量份的抗氧化劑IV-1之樹脂 材料，利用T-模頭法而製得厚度0.4 mm之封止材薄片。 於所獲得之封止材薄片中，（AxB)/C=3.0且Ax(D/E) =4·9χ 1(Γ3。 接著，使用所獲得之封止材薄片、與作爲表面保護構 件之厚度3 mm的白板玻璃、作爲光電變換元件之多晶矽 單元、及作爲背面保護構件之聚對苯二甲酸乙二酯薄膜， 如第2圖所例示，形成依序積層此等表面保護構件、封止 材薄片、光電轉換單元、封止材薄片及背面保護構件之積 層體。其後，將該積層體配置於上蓋側與積層室內分別能 夠抽真空之積層機內，一邊將積層體室內之溫度維持於120 °C且一邊在上蓋側與積層體室內兩者進行90秒鐘之抽真 空，然後一邊進行該積層體內部之脫氣且一邊暫時壓黏（真 空脫氣/暫時壓黏）。 完成該暫時壓黏之後，使積層體室內之溫度成爲150°C， 解除積層體上蓋側之真空狀態，藉一大氣壓而使該積層體 熱壓黏1 0分鐘（正式壓黏）而獲得太陽能電池模組。 〔實施例2〕 除了有機過氧化物1-1之添加量爲0.55質量份、矽烷 -14- 201139544 親合劑π - 1之添加量爲0.4 3質量份以外，進行相同於實施 例1之方式而製作封止材薄片。之後，進行相同於實施例 1之方式而製作太陽能電池模組。 〔實施例3〕 除了有機過氧化物1-1之添加量爲0.65質量份、矽烷 耦合劑Π -1之添加量爲0 · 3 7質量份以外，進行相同於實施 例1之方式而製作封止材薄片。之後，進行相同於實施例 1之方式而製作太陽能電池模組。 〔實施例4〕 除了有機過氧化物1-1之添加量爲0.75質量份、矽烷 耦合劑II- 1之添加量爲0.5質量份以外，進行相同於實施 例1之方式而製作封止材薄片。之後，進行相同於實施例 1之方式而製作太陽能電池模組。 〔比較例1〕 除了有機過氧化物1-1之添加量爲0.55質量份、矽烷 耦合劑11 -1之添加量爲0.2 7質量份以外，進行相同於實施 例1之方式而製作封止材薄片。之後’進行相同於實施例 1之方式而製作太陽能電池模組。 〔比較例2〕 除了有機過氧化物1-1之添加量爲〇.6質量份、矽烷耦 合劑11 - 1之添加量爲〇 . 6質量份以外’進行相同於實施例 1之方式而製作封止材薄片。之後’進行相同於實施例1 之方式而製作太陽能電池模組。 〔比較例3〕 -15- 201139544 除了有機過氧化物1-1之添加量爲0.25質量份 耦合劑11 - 1之添加量爲0.1 7質量份以外，進行相同 例1之方式而製作封止材薄片。之後，進行相同於 1之方式而製作太陽能電池模組。 〔評估方法〕 針對實施例及比較例之太陽能電池模組而進行 層之交聯密度、與背面保護構件/封止材層間之接著 評估。 (交聯密度） 藉由從各例所製作的太陽能電池模組撕下封止 將其中之1 g浸漬於二甲苯100 mL中，於110 °ci] 小時熔融之後，測定非熔融成分之質量，算出下式 比而求出交聯密度（單位：％ )。 交聯密度=〔非熔融成分之質量（g)/熔融前之質量（1 g: (接著強度） 在聚對苯二甲酸乙二酯與封止材層之界面，趁 利用切割刀而劃入刻痕，將聚對苯二甲酸乙二酯固 著強度測定機之夾頭，以90°之角度而測定聚對苯二 二酯/封止材層間之接著強度（單位：N/1.5 cm)。接 測定機係使用 ORIENTEC 製 TENSILON(RTC-1250) 條件係設定1 . 5 cm寬度之接著強度測定，剝離速度 3 0 mm/分鐘。 將實施例及比較例中之封止材層的交聯密度、 保護構件/封止材層間之接著強度的評估結果顯示於 、矽烷 於實施 實施例 封止材 強度的 材層， £其12 之質量 ))X 100 剝離時 定於接 甲酸乙 著強度 。測定 係設定 與背.面 表1。 -16 - 201139544 〔表1〕 ⑴ (AxB)/C (2) Ax(D/E) 交聯密度 〔％〕 接著強度 〔Ν/1 ·5 cm〕 實施例1 3.0 4.9xl0'3 86.1 52.9 實施例2 2.5 4.5χ10'3 87.0 53.9 實施例3 3.5 5.3χ10'3 91.5 51.3 實施例4 3.0 ό.ΙχΙΟ'3 90.2 54.5 比較例1 4.0 4.5χ10_3 87.4 39.5 比較例2 2.0 4.9xl0'3 43.7 68.7 比較例3 3.0 2.〇χ10'3 74.3 28.2 如表1所示，使其符合該條件（1)及條件（2)的方式來使 用含有有機過氧化物與矽烷耦合劑之封止·材薄片的實施例 1至4中，能夠製作交聯密度高且具優越之接著強度、具 優越之長期使用下之信賴性的太陽能電池模組。 另一方面，於使用條件（1)之（AxB)/C的値超過3.5之 封止材薄片的比較例1中，接著強度低且較實施例之緊貼 性爲差。 於使用條件（1)之（AxB)/C的値低於2.5之封止材薄片 的比較例2中，封止材層之交聯密度低。 於使用條件（2)之Ax(D/E)的値低於3.〇xl(T3之封止材 薄片的比較例3中，較實施例之交聯密度爲低，另外接著 強度也爲低。 【圖式簡單說明】 第1圖係顯示本發明之太陽能電池模組實施形態之一 例的剖面圖。 第2圖係顯示第1圖之太陽能電池模組製造方法之一 步驟的剖面圖。 -17- 201139544 【主要元件符號說明】 1 太陽能電池模組 2 表面保護構件 3 封止材層 3 A、3 B 封止材薄片 4 光電變換元件 5 背面保護構件 -18-201139544 VI. Description of the Invention: [Technical Field of the Invention] The present invention relates to a sealing material sheet for a solar cell module and a solar battery module. [Prior Art] Solar cells have attracted attention in recent years due to the clean power generation technology using sunlight. Among solar cells, there are various methods such as crystallization enthalpy, amorphous bismuth, compound semiconductor, and organic dye. Among them, since the crystalline lanthanum solar battery has excellent weather resistance and durability and has high photoelectric conversion efficiency, it is most popular. The general crystallization solar cell module is composed of a front glass, a backlight, a photoelectric conversion unit, and a sealing material layer, and is a photoelectric conversion unit that completely seals the front glass and the backlight between the sealing materials. Construction. Among the materials constituting such a solar cell, it is sought to withstand excellent weather resistance under long-term use. Among them, since the sealing material is composed of the material of the back sheet and the photoelectric conversion unit, it is necessary to maintain excellent adhesion for a long period of time. Further, since the sealing material is also disposed on the light-receiving surface side of the photoelectric conversion element, it is also sought not to lose transparency. In general, the sealing material is a resin having EVA (ethylene-vinyl acetate copolymer) having a moderate adhesion and transparency as a main component. In this case, in many cases, a crosslinking agent, a crosslinking assistant, a decane coupling agent, a light stabilizer, and ultraviolet absorption are added for the purpose of improving long-term durability and adhesion to a glass or a back backlight sheet. Additives such as agents (for example, 201139544 Patent Documents 1 to 3). Patent Document 1: Japanese Patent Laid-Open No. 3 3 2 3 5 0 0 Patent Document 2: Japanese Patent No. 4 〇 3 43 82 Patent Document 3: Japanese Patent Laid-Open No. 2008-23 5 8 8 2 Disclosure of the Invention [Problems to be Solved by the Invention] However, the conventional sealing materials described in Patent Documents 1 to 3 are difficult to achieve both sufficient adhesion and crosslinking density. Therefore, it is desired to improve the reliability of long-term use for the sealing material for solar cells. An object of the present invention is to provide a solar cell module sealing material sheet for a solar cell module and a solar cell module using the solar cell module sealing material sheet, which can be stably formed to have excellent adhesion and high crosslinking. The sealing material layer of density can be manufactured into a solar cell module having high reliability under long-term use. [Means for Solving the Problem] The present invention has the following structure for solving the problem: [1] A sealing material sheet for a solar cell module, which comprises an ethylene-vinyl acetate copolymer (hereinafter referred to as "EVA"), organic peroxides and decane coupling agents, which meet the following conditions (1) and (2): (1) 2.5 ^ (AxB)/C ^3.5 (2) 3.〇xl〇-3^ Ax( D/E)^ Ι.ΟχΙΟ'2 (But 'A is the theoretical amount of oxygen radicals produced by one molecule of organic peroxide, the molar amount of B-based organic peroxide, and the molar of c-based decane coupling agent. The amount 'D is the amount of the organic peroxide of the EVA relative to 1 part by mass of 201139544 (parts by mass), and the molecular weight of the E-based organic peroxide). [2] The sealing material sheet for a solar cell module according to the above [1], wherein the content of the vinyl acetate unit per unit of the ethylene oxide unit of the EVA is 20 to 40% by mass. [3] A solar cell module comprising: a solar cell unit, a sealing material layer for sealing the solar cell unit, a surface protecting member for protecting a surface side of the sealing material layer, and a back surface of the sealing material layer The back surface protective member is formed by the sealing material sheet for a solar cell module described in the above [1] or [2]. [Effects of the Invention] The sealing material sheet for a solar cell module of the present invention can stably form a sealing material layer having excellent adhesion and high crosslinking density, and can be manufactured with high reliability for long-term use. Solar battery module. In addition, the solar cell module of the present invention uses the sealing material sheet for a solar cell module, and has a sealing material layer having excellent adhesion and high crosslinking density, and has high reliability in long-term use. [Embodiment] <The sealing material sheet for a solar cell module> The following is an example of an embodiment of the sealing material sheet for a solar cell module of the present invention (hereinafter referred to as "sealing material sheet"). Detailed description. The sealing material sheet of the present invention contains EVA, an organic peroxide and a decane coupling agent. The resin substrate forming the sealing material sheet of the present invention is preferably used as the main component of EVA as 201139544. The EVA system is highly transparent and inexpensive, and is advantageous in view of the fact that the past use effect is enormous. The term "EVA as a main component" means that the EVA is 95% by mass or more based on the total amount of the resin substrate. In the sealing material sheet of the present invention, in addition to EVA, other resins may be contained. Other resins may, for example, be polyolefins such as polyethylene and polypropylene; ionic polymers; ethylene-methacrylic acid copolymers; ethylene-acrylic acid copolymers; polyvinyl fluoride: polyvinyl chloride, or copolymers thereof. The ratio of EVA in the resin substrate of the sealing sheet of the present invention is preferably 95% by mass or more, more preferably 97% by mass or more, and particularly preferably 100% by mass. The content of the EVA which can be used for the sealing sheet of the present invention is preferably from 20 to 40% by mass based on the total amount of the vinyl acetate unit. When the content of the acetic acid ethyl acetate unit is 20% by mass or more, a high crosslinking density and excellent adhesion are easily obtained. When the content of the vinyl acetate unit is 40% by mass or less, it is easy to suppress the unreacted vinyl acetate side chain from being irritated by heat or ultraviolet rays, and the resin is deteriorated. The organic peroxide functions as a crosslinking agent which initiates the crosslinking reaction of E V A . The organic peroxide can be exemplified by ruthenium, osmium-bis (tertiary butyl peroxy) cyclohexane, tertiary butyl peroxy-2-ethylhexyl monocarbonate, hydrazine, hydrazine _ two (three-stage hexyl peroxy) Cyclohexanin, n-butyl 4,4·di (tri-tert-butyl peroxy) valerate, tertiary di-peroxy-3,5,5-dimethylhexanoic acid vinegar, 2,5-dimethyl- 2,5-di (tertiary hexyl peroxy)hexane, dibutyl cumyl peroxide, 2,2_bis (tertiary butyl peroxy) butane, etc. 201139544 The sealing material formed by the resin substrate containing EVA has an effect of improving the adhesion between the surface protective member and the back surface protective member which protect the surface and the back surface. Examples of the cleavage affinity agent are: γ-methacryloxypropyltrimethoxy chopping, trimethoxypropyl decane, trimethoxymethyl decane, vinyl trimethoxy decane, vinyl triethoxy Decane, trichloropropyl decane, triethoxyphenyl decane, and the like. The organic peroxide and the decane coupling agent in the sealing material sheet of the present invention are contained in such a manner as to satisfy the following conditions (1) and (2): (1) 2.5 ^ (AxB) / C ^ 3.5 (2 ) 3.0 X 1 Ο·3 $ AX (D/E) $ 1 · Ο X 1 0-2 (where 'A is the amount of theoretical oxygen radicals produced by one molecule of organic peroxide' B is an organic peroxide The amount of the ear, the molar amount of the C-based decane coupling agent 'D is the content of the organic peroxide (parts by mass) relative to 00 parts by mass of EVA, and the molecular weight of the E-based organic peroxide). The theoretical oxygen free radical amount A produced from the molecule of the organic peroxide 1 in the condition (1) is an amount represented by the following formula (1-1). A = a X 2 ( 1 -1) (wherein the number of peroxygen bonds in the a-type organic peroxide in the formula (1-1).) In the sealing material sheet of the present invention, from organic peroxidation The ratio of the theoretical oxygen radical amount A produced by the molecule 1 to the molar amount B of the organic peroxide and the molar amount C of the decane coupling agent (AxB)/C is 2.5 to 3.5, more preferably 2.9 to 3.1 ^ 201139544 When the ratio (AxB)/C is 2.5 or more, the crosslinking reaction of EVA is easily performed sufficiently, and deterioration of the resin such as yellowing in the sealing material layer can be suppressed. When the ratio (A X B)/C is 3.5 or less, excellent adhesion can be obtained, and peeling of the sealing material layer and the surface protective member and the back surface protective member can be suppressed. Further, in the sealing material sheet, the enthalpy of the Ax (D/E) is 3.0 χ 10·3 to 1·〇χ 10_2, preferably 4·0 χ 10·3 to 7· 〇χ 10·3. When the Ax (D/E) is 3·〇χ 1 (Γ3 or more, the crosslinking reaction of EVA is sufficiently performed, and deterioration of the resin such as yellowing in the sealing material layer can be suppressed. If the Ax (D) /E) When the thickness is 1·〇χ10_2 or less, the stability of the sealing material sheet during molding is increased. Further, in the sealing sheet of the present invention, in addition to the organic peroxide and the decane coupling agent Further, a crosslinking assistant which promotes a crosslinking reaction may be contained. Examples of the crosslinking assistant may be, for example, triallyl isocyanate, diallyl phthalate or triallyl cyanate. The sealing sheet of the present invention may contain a stabilizer such as an ultraviolet absorber or an antioxidant from the viewpoint of light resistance and thermal stability of the formed sealing material layer. Examples of the ultraviolet absorber are: 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-(3-tert-butyl-5-methyl-2-hydroxyphenyl)-5-chloro Benzotriazole, 2-(4,6-diphenyl-1,3,5-trit-2-yl)-5-[(hexyl)xyloxy]phenol, 2,4-dihydroxydiphenyl Ketone, 2-dihydroxy-4-n-octyloxybenzophenone Etc. The antioxidant used to improve the thermal stability can be exemplified by 1,6-hexanediol bis[3-(3,5-di(tri-butyl)-4-hydroxyphenyl)propionate], Pentaerythritol 201139544 tetra[3-(3,5-di(tributyl)-4-hydroxyphenyl)propionate], tris(2,4-di(tributyl)phenyl)phosphite, 2,4·bis(n-octylthio)-6-(4-hydroxy-3,5-di(tri-butyl)anilino)-1,3,5-tri-trap, bis(2,2,6 (6-tetramethyl-4-piperidinyl) phthalate or the like. (Method for Producing Sealing Sheet) The sealing material sheet of the present invention is in such a manner as to satisfy the conditions (1) and (2) In addition to the organic peroxide and the decane coupling agent, it can be produced by a known production method. For example, a method having the following film forming step can be exemplified: using a T die having a linear slit, etc., using coextrusion In the method of preparing a film, an organic peroxide and a decane coupling agent and, if necessary, other additives are mixed in the resin substrate to form a film by heating the molten resin. Prevent caking, borrow The surface of the resin sheet in a heat-melted state is adhered to a roll (metal or rubber) on which the uneven pattern has been applied, and the uneven pattern of the roll is transferred to one or both sides of the sealing material sheet, and the sealing material is applied to the sealing material. The embossing process is carried out on the sheet. In the solar cell module using the conventional sealing material sheet, sufficient adhesion or crosslink density cannot be obtained according to the composition of the sealing sheet. The present inventors have directed After a detailed discussion, it was found that in the case where the decane coupling agent is contained in the sealing material sheet for the purpose of improving the adhesion, the adhesion is improved, and on the other hand, the sealing material sheet is formed. The crosslink density of the sealant layer will decrease. Further, it has been found that by including the organic peroxide and the decane coupling agent in such a manner that the conditions (1) and (2) are satisfied, the adhesion is improved, and the crosslinking of the sealing material layer can be suppressed. - 201139544 Reduced density. In this manner, the sealing material sheet of the present invention contains the organic peroxide and the decane coupling agent in such a manner that the conditions of the sealing material sheet (1) and the condition (2) can be stably formed to have a high crosslinking density and excellent Adhesive sealing material layer. Therefore, the reliability of long-term use of the solar cell module using the sealing sheet will become high. <Solar battery module> The solar battery module of the present invention comprises: a solar battery unit, a sealing material layer for sealing the solar battery unit, a surface protection member for protecting the surface side of the sealing material layer, and the protection The back surface protective member on the back side of the sealing material layer: the sealing material layer is a module formed by the above-described sealing material sheet of the present invention. Hereinafter, an embodiment of the solar battery module of the present invention will be described in detail. As shown in Fig. 1, the solar battery module 1 of the present embodiment has solar battery cells 4, 4, a sealing material layer 3 for sealing solar battery cells 4, 4, and a surface on the surface side of the protective sealing material layer 3. The protective member 2 protects the back surface protective member 5 on the back side of the sealing material layer 3. (Solar Cell Unit) The solar cell unit 4 has a function of electrically converting the function of entering the light receiving surface in accordance with the photoelectric effect. The solar battery cells 4 are housed in the solar battery module 1, and are connected to a plurality of electrodes (two in Fig. 1) by electrodes (omitted from the drawing). The number of solar battery cells 4 is not particularly limited. The material of the solar battery unit 4 can be, for example, crystalline sand. Among them, polycrystalline sand is particularly preferred from the viewpoints of ease of manufacture and cost. -11-201139544 (sealing material layer) The sealing material layer 3 is formed by embedding and sealing the layers of the solar battery cells 4, * by the sealing material sheet of the present invention. The thickness of the sealing material layer 3 is preferably from 〇.3 to 〇.6 mm. (Surface protection member) The surface protection member 2 preferably has excellent durability, weather resistance, and transparency. For example, a resin sheet such as a glass plate or polyethylene terephthalate can be exemplified. Further, a resin sheet such as polycarbonate can also be used. The thickness of the surface protection member 2 is preferably from 3 to 6 mm. (Back surface protective member) The back surface protective member 5 preferably has excellent durability and weather resistance, and examples thereof include resin sheets such as polyethylene terephthalate, polyvinyl fluoride, and EVA, and the like. Laminated body, etc. Further, a barrier layer which imparts water vapor barrier properties or oxygen barrier properties may be laminated on the resin sheet or the laminate. The thickness of the back surface protective member 5 is preferably 〇·2 to 〇.4 mm. (Manufacturing Method) Hereinafter, a method of manufacturing the solar cell module of the present invention will be described. However, the method of manufacturing the solar cell module of the present invention is not limited by the following methods. As shown in Fig. 2, a laminated body 1 A is formed by sequentially laminating the back surface protective member 2, the sealing material sheet 3A, the solar cell units 4, 4, the sealing material sheet 3B, and the surface protective member 5. Then, the vacuum laminate of the layer 1A of the heating and pressurization product -12-201139544 is vacuum-charged, and the solar cell units 4, 4 are buried in the sealing material sheets 3A and 3B, and the sealing material sheets 3A and 3B are placed. The resin substrate (EVA) is cross-linked and hardened, and then integrated to form the sealing material layer 3. Thereby, the solar cell module 1 can be obtained. The sealing material sheet 3A and the sealing material sheet 3B are the sealing sheets of the present invention, and may be a sealing material sheet of the same composition, or may be a sealing material sheet of different composition, by forming a uniform cross-linking structure. The viewpoint of a good quality module can be easily obtained, and is preferably a sealing material sheet of the same composition. In the solar battery module described above, the sealing material sheet of the present invention is used to stably form a sealing material layer having a high crosslinking density and excellent adhesion, and has high reliability in long-term use. [Examples] Hereinafter, the present invention will be described in detail by showing examples and comparative examples. However, the present invention is not limited by the following description. [Use of Raw Material] The raw materials used in the examples are shown below. (EVA) EVA-1: EVA having a content of vinyl acetate of 30% by mass. (Organic peroxide) I-1 : Tertiary butoxy-2-ethylhexyl monocarbonate (decane coupling agent) II- 1: γ-methyl propylene methoxy propyl trimethoxy decane (crosslinking) Auxiliary) ΙΙΙ-1 : triallyl isocyanate-13- 201139544 (antioxidant) IV-1: tris(2,4-di(tributyl)phenyl)phosphite [Example 1] 100 parts by mass of EVA-1, blending 0.6 parts by mass of the organic peroxide 1-1, 0.4 parts by mass of the decane coupling agent 11-1, 〇.6 parts by mass of the crosslinking assistant III-1, and 0.1 A mass of the resin material of the antioxidant IV-1 was obtained by a T-die method to obtain a sealing material sheet having a thickness of 0.4 mm. In the obtained sealing material sheet, (AxB)/C=3.0 and Ax(D/E)=4·9χ 1 (Γ3. Next, using the obtained sealing material sheet and the thickness as the surface protective member 3 mm whiteboard glass, polycrystalline germanium unit as photoelectric conversion element, and polyethylene terephthalate film as back surface protective member, as exemplified in FIG. 2, sequentially forming such surface protective members and sealing materials a laminated body of a sheet, a photoelectric conversion unit, a sealing material sheet, and a back surface protective member. Thereafter, the laminated body is placed in a laminator capable of evacuating the upper cover side and the laminated chamber, and the temperature in the laminated body chamber is maintained at At 120 ° C, the vacuum was applied to both the upper lid side and the laminate chamber for 90 seconds, and then the inside of the laminate was degassed and temporarily pressed (vacuum degassing / temporary pressure bonding). After the pressure-bonding, the temperature in the laminated body was 150 ° C, the vacuum state on the upper cover side of the laminated body was released, and the laminated body was heat-pressed for 10 minutes (formally pressed) by a large air pressure to obtain a solar battery module. 〔 Example 2] The same procedure as in Example 1 was carried out except that the amount of the organic peroxide 1-1 added was 0.55 parts by mass, and the amount of the decane-14-201139544 affinity agent π-1 was 0.43 parts by mass. After sealing the sheet, the solar cell module was produced in the same manner as in Example 1. [Example 3] The amount of the organic peroxide 1-1 added was 0.65 part by mass, and the decane coupling agent Π-1 was used. A sealing material sheet was produced in the same manner as in Example 1 except that the amount of addition was 0.37 parts by mass. Then, a solar battery module was produced in the same manner as in Example 1. [Example 4] The sealing material sheet was produced in the same manner as in Example 1 except that the amount of the peroxide 1-1 added was 0.75 parts by mass and the amount of the decane coupling agent II-1 added was 0.5 parts by mass. A solar cell module was produced in the same manner as in Example 1. [Comparative Example 1] The same procedure was carried out except that the amount of the organic peroxide 1-1 added was 0.55 part by mass, and the amount of the decane coupling agent 11-1 added was 0.27 part by mass. On the side of embodiment 1 A sealing material sheet was prepared in the same manner. Then, a solar cell module was produced in the same manner as in Example 1. [Comparative Example 2] The amount of the organic peroxide 1-1 added was 〇6 parts by mass, and decane coupling. The addition amount of the agent 11 - 1 was 〇. 6 parts by mass, except that the sealing material sheet was produced in the same manner as in Example 1. Thereafter, a solar battery module was produced in the same manner as in Example 1. [Comparative Example] 3] -15-201139544 A sealing material sheet was produced in the same manner as in Example 1 except that the amount of the organic peroxide 1-1 added was 0.25 parts by mass and the amount of the coupling agent 11 - 1 was 0.17 parts by mass. Thereafter, a solar cell module was produced in the same manner as in 1. [Evaluation method] The cross-linking density of the layers and the subsequent evaluation between the back surface protective member and the sealing material layer were carried out for the solar cell modules of the examples and the comparative examples. (crosslinking density) The mass of the non-melted component was measured by immersing 1 g of the solar cell module produced in each of the examples in 100 mL of xylene and melting at 110 ° C]. The cross-linking density (unit: %) was calculated by calculating the following formula. Crosslinking density = [mass of non-melted component (g) / mass before melting (1 g: (follow strength) at the interface between polyethylene terephthalate and the sealing material layer, 趁 is cut by a cutter Scratch, the collet of the polyethylene terephthalate fixing strength measuring machine, the bonding strength between the layers of polyparaphenylene dicarboxylate/blocking material was measured at an angle of 90° (unit: N/1.5 cm) The measurement machine was set to the TENSILON (RTC-1250) condition by ORIENTEC, and the adhesion strength of 1.5 cm width was set, and the peeling speed was 30 mm/min. The crosslinking of the sealing material layers in the examples and the comparative examples was carried out. The evaluation results of the density, the adhesion strength between the protective member/blocking material layer, and the decane in the layer of the strength of the sealing material of the embodiment, the mass of 12 of which) X 100 was peeled off and the strength of the formic acid was determined. The measurement system is set with the back surface. -16 - 201139544 [Table 1] (1) (AxB) / C (2) Ax (D / E) Crosslink density [%] Then strength [Ν / 1 · 5 cm] Example 1 3.0 4.9xl0'3 86.1 52.9 Implementation Example 2 2.5 4.5χ10'3 87.0 53.9 Example 3 3.5 5.3χ10'3 91.5 51.3 Example 4 3.0 ό.ΙχΙΟ'3 90.2 54.5 Comparative Example 1 4.0 4.5χ10_3 87.4 39.5 Comparative Example 2 2.0 4.9xl0'3 43.7 68.7 Comparative Example 3 3.0 2.〇χ10'3 74.3 28.2 As shown in Table 1, the use of the sealing material sheet containing the organic peroxide and the decane coupling agent was carried out in such a manner as to satisfy the conditions (1) and (2). In Examples 1 to 4, it is possible to produce a solar cell module having a high crosslinking density, excellent bonding strength, and superior reliability in long-term use. On the other hand, in Comparative Example 1 in which the sealing material sheet of (AxB)/C of the condition (1) exceeded 3.5, the strength was low and the adhesion was inferior to that of the example. In Comparative Example 2 in which the sealing material sheet of (AxB)/C of the condition (1) was less than 2.5, the crosslinking density of the sealing material layer was low. In the comparative example 3 of the Ax (D/E) of the use condition (2), the crosslink density of the comparative example 3 of the T3 was lower than that of the comparative example 3 of the T3 sealing material sheet, and the strength was also low. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional view showing an embodiment of a solar battery module according to the present invention. Fig. 2 is a cross-sectional view showing a step of a method for manufacturing a solar battery module according to Fig. 1. 17- 201139544 [Explanation of main component symbols] 1 Solar cell module 2 Surface protection member 3 Sealing material layer 3 A, 3 B Sealing material sheet 4 Photoelectric conversion element 5 Back surface protection member -18-