200848397 九、發明說明： 【發明所屬之技術領域】 本發明係相關於1 -甲氧基-2 -丙醇之製造方法，具高環 氧丙烷的轉化率，且以高選擇率製造1 -甲氧基-2 -丙醇之方 法。 【先前技術】 1-烷氧基-2-丙烷係與其他乙二醇醚類相同，首先應用 於塗料或油墨的樹脂溶劑，亦用於煞車油、編織物或皮製 品的染色偶合劑等，係具有異於廣泛溶劑的市場性之有益 的工業用品。 製造1 -烷氧基-2-丙醇之慣用方法，已知例如在催化劑 的存在下，使醇和環氧丙烷反應而製造之方法，惟經常生 成2-烷氧基-1-丙醇及二丙二醇單烷基醚等具高沸點的化 合物爲其副生成物。例如醇係甲醇時，爲分離1 -甲氧基-2-丙醇和副生成物，且降低副生成物之含量可進行蒸餾，惟 1_甲氧基-2-丙醇和2-甲氧基-1-丙醇乃沸點相近，不易完全 地分離二者。已知例如使用作爲工業製品的1-甲氧基-2-丙醇中，混合有大約3 0 0ppm的2-甲氧基-1-丙醇。已知2-甲氧基-1 -丙醇具有強毒性（生殖毒性等），使用於工業的 製品中，儘可能降低2-甲氧基-1-丙醇的含量乃重要課題。 特開昭5 6- 1 5 229號公報（專利文獻1 )記載在第三級 胺的存在下，相對於環氧丙烷而言醇的莫耳比約爲2以 上，使低級一價醇與環氧丙烷反應，製造1 -院氧基-2 -丙醇 之方法。 該製造方法中，使甲醇和環氧丙烷在第三級胺的存在 200848397 下反應，可製得1-甲氧基-2-丙醇。該方法中， 甲氧基-2 -丙醇和副生成物（2 -甲氧基-1 -丙醇等 化合物等），且降低副生成物（特別是2 -甲氧3 之含量而蒸餾，惟如上所述，因1 -甲氧基-2 ·丙 基-1 -丙醇之沸點相近，不易藉由蒸餾而效率良 又亦可藉由加大回流比，增加蒸餾塔的高度， 效率，惟成本高不實用。 因此，爲可進行慣用的蒸餾操作，且有效 氧基-2-丙醇和副生成物，需求其他的對策。其 策，例如提升環氧丙烷的轉化率及1-甲氧基-2 _ 率，預先降低副生成物之含量並蒸餾之方法等 1記載，若使甲醇和環氧丙烷於8 (TC以下反應 可以環氧丙烷的轉化率9 3.2〜9 8 · 8 % ，且9 2.9〜 擇率製造1-甲氧基-2-丙醇。^ 特開平7-20 6744號公報（專利文獻2)記 化烯烴和醇製造乙二醇醚之方法中，在第三級 下，使甲醇和環氧丙烷於80°C、100°C、120°C 環氧丙烷的轉化率97〜100% ，且94〜95%的選 甲氧基-2-丙醇。惟該文獻的方法之選擇率亦不 如上述般，1-甲氧基-2-丙醇係廣泛使用爲 同時2-甲氧基-1 -丙醇具有非常強的毒性，因此 生成物（特別是2-甲氧基-卜丙醇）之含量，換 丙烷的轉化率及1 ·甲氧基-2 -丙醇的選擇率必須 【專利文獻1】特開昭5 6 - 1 5 22 9號公報（申言1 實施例） 爲分離1 _ 具高沸點的 g -1 -丙醇） 醇和2 -甲氧 好地分離。 而提升蒸飽 地分離1 -甲 他有效的對 •丙醇的選擇 。專利文獻 、蒸餾後， 9 6 · 5 %的選 載，在由氧 胺的存在 反應，可以 擇率製造1-佳。 工業用品， 更要降低副 :言之，環氧 I更加提升。 I專利範圍、 200848397 【專利文獻2】特開平7-206744號公報（申請專利範圍、 實施例） 【發明內容】 發明欲解決之 因此’本發明之目的係提供一種可以高轉化率及高選 擇率來製造1-甲氧基-2-丙醇之方法。 本發明之其他目的係提供一種可降低有毒的副生成物 的含量來製造1-甲氧基丙醇之方法。 又’本發明進一步之其他目的係提供一種即使爲工業 規模’亦可以低成本而有效率地製造i _甲氧基-2 _丙醇之方 法。 解決課穎之方法 本發明者等，爲達成上述課題而致力硏究之結果，發 現一種使甲醇和環氧丙烷在特定的溫度反應並蒸餾後，可 選擇地製造1 -甲氧基-2 -丙醇，可降低有毒的副生成物的含 量來製造1-甲氧基-2-丙醇之方法，而完成本發明。 亦即’本發明的方法係在第三級胺之存在下，經過使 甲醇和環氧丙烷於90〜110 °C反應而得反應粗液之反應步 驟，和使反應粗液蒸餾之蒸餾步驟，而製造1-甲氧基-2-丙醇。 該方法中，可使甲醇和環氧丙烷以甲醇相對於環氧丙 烷而言爲2〜1 0倍莫耳左右之比例進行反應，又，亦可以第 三級胺相對於甲醇、環氧丙烷及第三級胺之總計而言爲 0.1〜1 0重量％左右之比例而使用。 於該方法中，亦可使用塔型反應器，該塔型反應器的 200848397 內部可具備由可流通傳熱介質的螺旋狀管構成的溫度控制 單位。本發明的方法係連續地供應甲醇、環氧丙烷及第三 級胺至上述反應器，使來自反應器的反應粗液連續地蒸 餾。更可直列地設置複數的反應器。又，亦可使在反應步 驟製得的反應粗液，於塡充著規則塡充物之塡充塔進行蒸 餾。 發明之效果 本發明係在第三級胺的存在下，因使甲醇和環氧丙烷 f 於特定的溫度反應，故可提升環氧丙烷的轉化率及1 -甲氧 基-2-丙醇的選擇率，降低具有強毒性的副生成物之含量， 可選擇性地製造1 -甲氧基-2-丙醇。再者，因可抑制高沸點 的副生成物（2-甲氧基-1-丙醇及二丙二醇單甲醚等）之生 成，以慣用且穩定條件下之蒸餾操作，可有效率地分離1 -甲氧基-2-丙醇和副生成物。因此，即使爲工業規模，也能 夠以低成本且效率佳地製造1-甲氧基-2-丙醇。 【實施方式】 I: 篮行發明之最佳形態 本發明係在第三級胺之存在下，經過使甲醇和環氧丙 烷於規定溫度反應而得反應粗液之反應步驟，和使反應粗 液蒸餾之蒸餾步驟，而製造1-甲氧基-2-丙醇。 [反應步驟] 反應步驟的反應器係一般常用的反應器即可，例如塔 型、槽型、管型等。可爲可連續操作的連續式反應器，亦 可爲可分批操作（或半分批操作）的分批式反應器。使用 的反應器，宜具備一種緩和伴隨反應的溫度變化，有助於 200848397 維持預期的反應溫度之溫度控制單位。溫度控制單位，例 如可流通傳熱介質（例如水、水蒸氣、油等），以螺旋狀、 圓筒狀等的管構成之單位（旋管狀溫度控制單位）、可收納 反應器，且與反應器之間可流通上述傳熱介質之單位（套 管）等。從溫度控制效率、生產效率之觀點，本發明宜使 用塔型反應器（反應塔）。亦可使用一種特別是反應器內部 具備溫度控制單位（例如由可流通傳熱介質的螺旋狀管構 成之溫度控制單位）之塔型反應器（反應塔）。 反應器的個數無特別的限制，可爲1座，爲以高反應 收率製得生成物，亦可組合複數座（2座以上）。由反應效 率、設備及能量成本等觀點，一般反應器爲2〜3座（特別 是2座）。複數的反應器係可直列地排列（設置），亦可並 列地排列，亦可組合直列和並列而排列。一般，複數的反 應器係直列地排列。使用複數的反應器時，複數的反應器 中，宜於至少1座（特別是供應反應成份的第1反應器） 具備旋管狀溫度控制單位。 爲提升反應效率（反應收率），亦可依需求使用塡充著 塡充物之塔型反應器（反應塔）。塡充物例如波爾環、拉西 環、萊辛環等環狀塡充物、鞍、麥克馬洪塡料等鞍狀塡充 物、球狀塡充物、思路紮塡料等其他形狀之塡充物等。這 些塡充物係可單獨或組合二種以上而使用。理想的塡充物 係環狀塡充物（例如拉西環等）。 甲醇和環氧丙烷之比例，相對於環氧丙烷而言例如使 甲醇爲2倍莫耳以上（例如2〜10倍莫耳）’宜爲3〜9倍莫 耳，尤宜4〜8倍莫耳（特別是5〜7倍莫耳）°相對於環氧丙 200848397 烷而言，若甲醇的比例小，則環氧丙烷的高級附加物（例 如二丙二醇單甲醚等）等的高沸點副生成物之含量增加。 第三級胺例如第三級脂肪族胺、第三級芳香族胺、第 三級雜環胺等。第三級脂肪族胺例如三甲胺、三乙胺、三 正丙胺等三烷胺（特別是三Cm烷胺）、二甲基乙胺等二烷 基烷胺（特別是二CL6烷基C〃6烷胺）等。第三級芳香族 胺例如N，N-二甲苯胺、N，N-二乙苯胺等N-烷基-N-烷苯胺 (特別是N-Cm烷基-N-Cm烷苯胺）等。第三級雜環胺例 如吡啶、皮考啉、喹啉等。這些第三級胺係可單獨或組合 二種以上而使用。 本發明中，宜使用具有比1-甲氧基-2-丙酮的沸點更低 的沸點之第三級胺，例如三甲胺、三乙胺、二甲基乙胺等 三Cu烷胺、吡啶等。特別適用的第三級胺係三乙胺。 第三級胺之比例，相對於甲醇、環氧丙烷及第三級胺 之總計而言爲0.1〜10重量％ ，宜爲0.2〜7重量％ ，更宜爲 0.5〜5重量％ ，尤宜0.7〜2重量％ (例如0.8〜1.5重量％ ) U 左右。 甲醇、環氧丙烷及第三級胺係可以分批（或半分批） 供應至上述反應器，從工業生產性之觀點，一般爲連續地 供應。供應甲醇、環氧丙烷及第三級胺至反應器之速度’ 以線速度而言，爲2.0〜5.0m/h，宜爲2.1〜4.6m/h，尤宜 2.2〜4.2m/ho 本發明的方法係在第三級胺之存在下，使甲醇和環氧 丙烷於90〜110°C，宜爲95〜110°C，尤宜95〜105°C左右反 應。若於比上述溫度範圍更低之溫度下反應，則有環氧丙 -10- 200848397 烷的轉化率變低的趨勢。另一方面，若於比上述溫度圍更 高之溫度下反應，則副生成物2 -甲氧基-：1 -丙醇及二丙二醇 單甲醚的含量有增加之趨勢。 爲製造環氧丙烷的轉化率高，且上述副生成物的含量 低之1-甲氧基-2-丙醇，如上述般，宜將反應溫度維持於特 定溫度（90〜11 〇°C )，爲此，控制反應溫度（反應系的溫度） 即爲有效。反應溫度的控制係可使用上述溫度控制單位， 特別是上述旋管狀溫度控制單位。例如旋管狀溫度控制單 位（特別是由螺旋狀管構成的溫度控制單位），係使傳熱介 質流通於上述旋管狀溫度控制單位中，可提升傳熱效率， 可簡便且效率佳地控制反應溫度。又，連續地供應反應物 質至反應器使進行反應時，一般，因反應系的組成變化及 反應所引發的溫度變化大，不易控制及維持反應溫度（反 應系的溫度），即使如此，使傳熱介質（特別是水）流通於 上述旋管狀溫度控制單位（特別是由螺旋狀管構成的溫度 控制單位）中，可簡單地控制溫度，可使反應溫度（反應 # 系的溫度）維持於特定的溫度。亦可使用油（矽油等）等 作爲上述傳熱介質，惟一般係使用水。上述介質（特別是 水）之溫度，可因應反應溫度而選擇，惟宜爲比反應溫度 更低之溫度。例如上述介質的溫度和預期的反應溫度之差 値，可爲5〜30 °C，宜爲7〜25 °C，尤宜10〜20 °C左右。若上 述介質的溫度和預期的反應溫度之差値過大，則不易維持 反應系的溫度於一定（幾乎一定）。 反應系的壓力，係取決於反應物質的組成及反應溫度 之蒸氣壓’和爲了安全地進行反應所壓封（或壓入）的惰 -11- 200848397 性氣體（氮氣等）的氣壓之總和，可爲hWkg/cn^G (与 1.0父105〜20\1〇5?〇左右，宜爲2〜15]^/(：1112〇(与2〇><1〇5〜15 xl05Pa)’ 尤宜 3〜10kg/cm2G (与 3.0xl05〜10xl05Pa)左右。 [蒸餾步驟] 蒸餾步驟係使經過反應步驟而製得的反應粗液進行蒸 餾。 蒸餾所需的裝置（蒸餾裝置），係一般使用的蒸餾裝置 (蒸餾塔），例如可以是板式塔（多孔板塔、泡罩塔等）、 〔塡充塔等。本發明爲抑制裝置內的壓力損失，宜使用塡充 塔。塡充塔的塡充物可爲不規則塡充物（random packing )， 惟爲抑制裝置內的壓力損失且提升蒸餾效率，宜使用規則 塡充物（structured packing)。規則塡充物可爲廣泛使用的 規則塡充物，例如由鈦、鉻等金屬或其合金、不銹鋼（例 如奧氏體系不銹鋼等）、陶瓷等構成。規則塡充物亦可爲片 狀（板狀）、篩狀（網狀）、柵狀（格子狀）等。該類規則 塡充物可單獨或組合二種以上而使用。 I 蒸餾塔係隨著蒸餾塔的板數（理論板數）之增加，其 分離性能亦提昇，因此宜使用板數（理論板數）爲30段以 上（例如30〜60段，宜爲32〜55段，尤宜35〜50段）之蒸 餾塔。蒸餾塔的個數無特別的限制，可爲1座，亦可組合 複數座（2座以上），由反應收率、設備及能量成本等觀點， 一般蒸餾塔係可使用1〜2座（特別是2座）。爲提升蒸餾效 率（分離效率），宜以多階段進行蒸餾。一般，由目的生成 物的回收效率之觀點，以2〜3階段（特別是2階段）進行 蒸餾。於各階段，使用的蒸餾塔數可相同或相異。例如於 -12 - 200848397 第1階段，使用2座的蒸餾塔，於第2階段以後，亦可使 用1座的蒸飽ί合。本發明中’例如可於第1階段的蒸飽操 作，蒸餾出低沸點成分（未反應的甲醇、第三級胺等），於 第2階段的蒸餾操作，去除高沸點成分（甲氧基_丨_丙醇、 二丙二醇單甲醚等副生成物等）。又，於第1階段的蒸餾操 作蒸餾出的甲醇及第三級胺，可再度循環使用爲反應物質。 上述反應步驟和蒸餾步驟，亦可個別進行，惟從工業 生產性之觀點’連續地進行上述2個步驟係有助益。若連 ( ' 續地進行上述反應步驟和蒸餾步驟，可以環氧丙院的轉化 率爲99吴耳％以上（例如99.1〜99.9莫耳％，宜爲99 2〜99.8 旲耳％ ’更宜爲99.3〜99.7莫耳％ ，尤宜99.4〜99.6莫耳％ 左右）而製造1-甲氧基-2-丙醇。又，1-甲氧基-2 -丙醇之選 擇率（以環氧丙烷爲基準）爲9 9 · 9莫耳％以上（例如 99.910〜99.999莫耳％ ，宜爲99.930〜99.995莫耳％ ，更宜爲 99.950 〜99.992 莫耳 ％ ，尤宜 99.960-99.990 莫耳 ％ 左右）。 此外，2-甲氧基-1-丙醇之選擇率（以環氧丙烷爲基準）爲 ( 0.001〜0.03莫耳％ (例如0.002〜0.028莫耳％ ，尤宜 0.003〜0.026莫耳％ )左右。依據本發明的方法，可製造強 毒性的2-甲氧基-1-丙醇的含量極低之丨_甲氧基丙醇。 應__用於產業之可能件 本發明的方法，因即使爲工業規模亦可製造強毒性的 副生成物的含量低之1 -甲氧基-2 -丙醇，製得的1 -甲氧基-2 -丙醇係安全性非常高，首先應用於塗料或油墨的樹脂溶 劑’亦用於煞車油、編織物或皮製品的染色偶合劑等工業 用品。 -13- 200848397 實施例 以下，依據實施例更詳細地說明本發明，惟本發明不 受限於這些實施例。 實施例及比較例係使用以下組成之反應物質、反應 器、蒸餾裝置。 反應物質；甲醇：3462kg/h(108.1kmol/h) 環氧丙烷：1 046 kg/h ( 18.0kmol/h) 三乙胺：45.5 kg/h ( 0.45kmol/h) [甲醇/環氧丙烷（莫耳比）=6，三乙胺之 濃度=1 · 0重量％ ] 反應器1;內部塡充著拉西環之塔型反應器（三井造 船（股）製，內徑1450mmCp，高度14698mm) 反應器2;內部塡充著拉西環之塔型反應器（三井造 船（股）製，內徑500mm(J)，高度15708mm) 蒸餾塔1 ;以高度20200mm塡充著規則塡充物（住重 設備工程技術（股）製，住友 SFLOW 2 5 0MY )之塡充塔 (三井造船（股）製，內徑llOOmmCp，高度30948mm，理 論板數4 5 ) 蒸餾塔2;泡罩塔（.三井造船（股）製，內徑llOOmmcp， 高度3 09 4 8mm，實際板數60，理論板數36 )。 實施例及比較例中，環氧丙烷之轉化率及各成份之選 擇率係以下述方法求得。 [轉化率] 環氧丙烷之轉化率，係以氣相色譜來分析反應生成 物，測定反應液中的環氧丙烷之含量，求出與反應前的環 -14- 200848397 氧丙烷的含量之比例。亦即，以反應前的環氧丙烷之含量 (莫耳數）爲C，以反應液中的環氧丙烷之含量（莫耳數） 爲C’ ，則轉化率（莫耳％ ) = ( C’ /C ) X100。 [各成份之選擇率] 各成份之選擇率，例如1-甲氧基-2_丙醇之選擇率係以 氣相色譜來分析反應生成物，測定反應液中的1 -甲氧基-2-丙醇之含量，求出與反應生成物的總量之比例。亦即，以 反應液中的1-甲氧基-2-丙醇之含量（莫耳數）爲S，以反 ζ ^ 應生成物之總量（總莫耳數）爲S ’ ，則選擇率（莫耳％ ) =(S / S ’ ）X 1 0 0。其他成份亦依據相同做法求得。 [實施例1] 連續地供應反應物質至內部具備由可流通傳熱介質的 螺旋狀管構成的溫度控制單位之反應器1，且由反應器1 流通至反應器2，進行反應。於反應器1中，使8 0 °c的水 流至上述單位內，控制’反應系的溫度爲9 7 °C，進行反應。 製得的反應粗液中，環氧丙院之轉化率爲9 9 · 6莫耳％ 。1 - f , 甲氧基-2-丙醇、2-甲氧基-1-丙醇、二丙二醇單甲醚及其他 成份之選擇率（以環氧丙烷爲基準），分別爲8 7 · 7莫耳％ 、 6 · 3莫耳％ 、2.3莫耳％ 、3.7莫耳％ 。其次使用蒸餾塔1， 使反應粗液於回流比3.2、餾出率8 6.5 %之條件下進行蒸 餾。求出蒸餾而製得的精製液中，環氧丙烷之轉化率及各 成份之選擇率（以環氧丙烷爲基準）。 [實施例2] 除使用蒸餾塔2取代蒸餾塔1以外，進行和實施例1 相同的操作，求出製得的精製液中，環氧丙烷之轉化率及 -15- 200848397 各成份之選擇率（以環氧丙烷爲基準）。 [比較例1 ] 除不控制反應系的溫度以外，和實施例1相同做法， 進行反應。使用蒸餾塔2來蒸餾製得之反應粗液。求出蒸 餾而製得的精製液中，環氧丙烷之轉化率及各成份之選擇 率（以環氧丙烷爲基準）。 [比較例2 ] 使反應物質進行和實施例1相同的反應。求出製得的 $ 反應粗液中，環氧丙烷之轉化率及各成份之選擇率（以環 氧丙烷爲基準）。 [比較例3 ] 除不控制反應系的溫度以外，和實施例1相同做法， 進行反應。求出製得的反應粗液中，環氧丙烷之轉化率及 各成份之選擇率（以環氧丙烷爲基準）。 實施例及比較例之結果如表1所示。表中的「轉化率_ 表示爲環氧丙烷之轉化率，「1-MMPG」、「2-MMPG」、「高沸 • 點成分」、「其他」分別表示爲1 -甲氧基-2 -丙醇、2 -甲氧基 -1-丙醇、二丙二醇單甲醚及其他成份之選擇率（以環氧丙 烷爲基準）。 16- 200848397 (表1 ) 實施例1 實施例2 比較例1 比較例2 比較例3 反應溫度rc) 97 97 135 97 135 轉化率（mol% ) 99.6 99.6 99.4 99.6 99.4 l-MMPG(mol% ) 99.991 99.968 99.949 87.7 85.6 2-MMPG (mol°/〇 ) 0.003 0.026 0.038 6.3 8.5 高沸點成分（mol% ) 0.006 0.006 0.005 2.3 2.5 其他（mol% ) <0.0001 <0.0001 0.009 3.7 3.4 從表1清楚可知，若使上述反應物質於特定的溫度範 圍進行反應、蒸餾，可製得一種環氧丙烷之轉化率及卜甲 氧基-2-丙醇之選擇率相當高，且副生成物之含量比廣泛用 於工業的1 -甲氧基-2 -丙醇中所含副生成物的含量更低之1 -甲氧基-2 -丙醇。又，於蒸餾步驟，若使用塡充著規則塡充 物之塡充塔爲蒸餾塔’其效果更加顯著。 【圖式簡單說明】 Μ 〇 【主要元件符號說明】 無。 -17-200848397 IX. INSTRUCTIONS OF THE INVENTION: TECHNICAL FIELD The present invention relates to a method for producing 1-methoxy-2-propanol, which has a conversion rate of high propylene oxide and which is manufactured at a high selectivity. A method of oxy-2-propanol. [Prior Art] 1-alkoxy-2-propane is the same as other glycol ethers, first used in resin solvents for coatings or inks, and also as dyeing couplers for brake oils, braids or leather products. It is a market-friendly and beneficial industrial product that is different from a wide range of solvents. A conventional method for producing 1-alkoxy-2-propanol, for example, a method in which an alcohol and propylene oxide are reacted in the presence of a catalyst, but 2-alkoxy-1-propanol and 2 are often produced. A compound having a high boiling point such as a propylene glycol monoalkyl ether is a by-product thereof. For example, in the case of an alcohol-based methanol, 1-methoxy-2-propanol and a by-product are separated, and the content of the by-product is lowered to carry out distillation, but 1-methoxy-2-propanol and 2-methoxy- 1-propanol has similar boiling points and it is not easy to completely separate the two. It is known to use, for example, 1-methoxy-2-propanol as an industrial product, and about 300 ppm of 2-methoxy-1-propanol is mixed. 2-methoxy-1-propanol is known to have strong toxicity (reproductive toxicity, etc.) and is used in industrial products, and it is an important subject to reduce the content of 2-methoxy-1-propanol as much as possible. Japanese Patent Publication No. 5-6-1552 (Patent Document 1) discloses that in the presence of a tertiary amine, the molar ratio of alcohol to propylene oxide is about 2 or more, and the lower monovalent alcohol and ring are obtained. A method of producing 1-o-oxy-2-propanol by reacting oxypropane. In the production method, 1-methoxy-2-propanol can be obtained by reacting methanol and propylene oxide in the presence of a tertiary amine in 200848397. In this method, methoxy-2-propanol and a by-product (such as a compound such as 2-methoxy-1-propanol) are reduced, and the by-product (especially 2-methoxy 3) is reduced to be distilled. As described above, since the boiling point of 1-methoxy-2-propyl-1-propanol is similar, it is not easy to be efficient by distillation, and it is also possible to increase the height and efficiency of the distillation column by increasing the reflux ratio. The cost is high and it is not practical. Therefore, in order to carry out the conventional distillation operation, and effective oxy-2-propanol and by-products are required, other countermeasures are required, such as increasing the conversion ratio of propylene oxide and 1-methoxy group. -2 _ rate, a method of reducing the content of by-products in advance and distilling, etc. 1. If methanol and propylene oxide are reacted at 8 (TC or less, the conversion of propylene oxide can be 9 3.2 to 9 8 · 8 %, and 9 2.9~ Selectivity to produce 1-methoxy-2-propanol. ^ Unexamined-Japanese-Patent No. 7-20-6744 (Patent Document 2) In the method of producing a glycol ether from an olefin and an alcohol, in the third stage The conversion of methanol and propylene oxide to propylene oxide at 80 ° C, 100 ° C, 120 ° C is 97 to 100%, and 94 to 95% of methoxy-2-propanol. However, the selectivity of the method of this document is also not as good as above, 1-methoxy-2-propanol is widely used as a simultaneous 2-methoxy-1-propanol which has very strong toxicity, so the product (especially The content of 2-methoxy-propanol), the conversion ratio of propane and the selectivity of 1 -methoxy-2-propanol must be [Patent Document 1] JP-A-Open 5-6 - 1 5 22 9 (Proposal 1 Example) For the separation of 1 _ high boiling point g -1 -propanol) alcohol and 2-methoxyl well separated. And to enhance the selection of 1-propanol effective p-propanol by steaming. After the patent literature, after distillation, 9 6 · 5 % of the selected load, in the presence of oxyamine, can be produced at a rate of 1. - Industrial supplies, but also reduce the vice: In other words, the epoxy I is more enhanced. Scope of the Invention [Patent Document 2] Japanese Laid-Open Patent Publication No. Hei No. Hei 7-206744 (Application No. Patent Application Serial No.) Method of 1-methoxy-2-propanol. Other objects of the present invention are to provide a toxic reduction The method of producing 1-methoxypropanol by the content of by-products. Further, the other object of the present invention is to provide an efficient production of i-methoxy-2 at a low cost even on an industrial scale. The method of the present invention, the inventors of the present invention, and the like, in order to achieve the above-mentioned problems, have found that a reaction can be made by selectively reacting methanol and propylene oxide at a specific temperature and distilling them. The present invention has been accomplished by a method of producing methoxy-2-propanol which can reduce the content of toxic by-products to produce 1-methoxy-2-propanol. That is, the method of the present invention is a reaction step of reacting methanol and propylene oxide at 90 to 110 ° C in the presence of a third-stage amine, and a distillation step of subjecting the reaction crude liquid to distillation, And 1-methoxy-2-propanol was produced. In this method, methanol and propylene oxide can be reacted in a ratio of methanol to propylene oxide of about 2 to 10 moles, and third amine can be reacted with methanol or propylene oxide. The total amount of the third-stage amine is used in a ratio of about 0.1 to 10% by weight. In this method, a column reactor can also be used, and the temperature of the reactor of the type of reactor 200848397 can be made up of a spiral tube through which a heat transfer medium can flow. The process of the present invention continuously supplies methanol, propylene oxide and a tertiary amine to the above reactor to continuously distill the reaction crude liquid from the reactor. It is also possible to arrange a plurality of reactors in series. Further, the crude reaction liquid obtained in the reaction step may be subjected to distillation in a ruthenium charged with a regular ruthenium. EFFECT OF THE INVENTION The present invention is capable of increasing the conversion of propylene oxide and 1-methoxy-2-propanol in the presence of a tertiary amine by reacting methanol and propylene oxide f at a specific temperature. The selectivity is selected to reduce the content of the highly toxic by-product, and 1-methoxy-2-propanol can be selectively produced. Further, since the formation of a high-boiling by-product (2-methoxy-1-propanol, dipropylene glycol monomethyl ether, etc.) can be suppressed, the distillation operation under the usual and stable conditions can be efficiently separated. -Methoxy-2-propanol and by-products. Therefore, even on an industrial scale, 1-methoxy-2-propanol can be produced at low cost and with high efficiency. [Embodiment] I: The best form of the basket invention The present invention is a reaction step of reacting methanol and propylene oxide at a predetermined temperature in the presence of a third-stage amine to obtain a reaction crude liquid, and a reaction crude liquid. A distillation step of distillation was carried out to produce 1-methoxy-2-propanol. [Reaction Step] The reactor in the reaction step may be a reactor which is generally used, for example, a column type, a tank type, a tube type or the like. It can be a continuous reactor that can be operated continuously, or a batch reactor that can be operated in batches (or semi-batch operations). The reactor used should have a temperature control unit that mitigates the temperature change accompanying the reaction and contributes to the maintenance of the expected reaction temperature in 200848397. The temperature control unit, for example, a unit capable of circulating a heat transfer medium (for example, water, steam, oil, etc.) in a spiral or cylindrical tube (rotating tubular temperature control unit), allowing the reactor to be housed, and reacting with the reaction unit The unit (casing) of the above heat transfer medium can be circulated between the devices. From the viewpoint of temperature control efficiency and production efficiency, the column reactor (reaction column) is preferably used in the present invention. It is also possible to use a column type reactor (reaction column) having a temperature control unit (e.g., a temperature control unit composed of a spiral tube through which a heat transfer medium can flow) inside the reactor. The number of the reactors is not particularly limited, and may be one, and the product may be obtained in a high reaction yield, or a plurality of seats (two or more) may be combined. From the viewpoints of reaction efficiency, equipment, and energy cost, the general reactor is 2 to 3 seats (especially 2 seats). The plurality of reactors may be arranged in series (arranged), may be arranged in parallel, or may be arranged in a combination of in-line and side by side. Generally, the plural reactors are arranged in series. When a plurality of reactors are used, it is preferred that at least one of the plurality of reactors (especially the first reactor to which the reaction component is supplied) has a rotary tubular temperature control unit. In order to increase the reaction efficiency (reaction yield), a column reactor (reaction tower) which is filled with the ruthenium may be used as needed. Fillings such as Boer ring, Lacy ring, Lessing ring and other ring-shaped fillings, saddles, McMahon materials, etc. Saddle-shaped fillings, spherical fillings, ideas, and other shapes Things and so on. These chelates may be used singly or in combination of two or more. The ideal filling is a cyclic filling (e.g., Raschig ring, etc.). The ratio of methanol to propylene oxide is, for example, more than 2 times molar (for example, 2 to 10 times moles) of methanol relative to propylene oxide, and is preferably 3 to 9 times moles, particularly preferably 4 to 8 times. Ear (especially 5 to 7 times moles) ° Relative to the propylene oxide 200848397 alkane, if the proportion of methanol is small, the high-boiling point of advanced additives such as propylene oxide (such as dipropylene glycol monomethyl ether) The content of the product is increased. The third-grade amine is, for example, a tertiary aliphatic amine, a tertiary aromatic amine, a tertiary heterocyclic amine or the like. a third-stage aliphatic amine such as a trialkylamine such as trimethylamine, triethylamine or tri-n-propylamine (particularly a tri-Cm alkylamine) or a dialkylalkylamine such as dimethylethylamine (particularly a di-CL6 alkyl C〃) 6 alkylamine) and the like. The third-stage aromatic amine is N-alkyl-N-alkylaniline (especially N-Cm alkyl-N-Cm alkylaniline) such as N,N-dimethylaniline or N,N-diethylaniline. The third-stage heterocyclic amines are, for example, pyridine, picoline, quinoline and the like. These third-stage amines may be used singly or in combination of two or more. In the present invention, it is preferred to use a tertiary amine having a boiling point lower than the boiling point of 1-methoxy-2-propanone, such as tricalineamine such as trimethylamine, triethylamine or dimethylethylamine, pyridine, or the like. . A particularly suitable tertiary amine is triethylamine. The ratio of the third-stage amine is 0.1 to 10% by weight, preferably 0.2 to 7% by weight, more preferably 0.5 to 5% by weight, particularly preferably 0.7, based on the total of methanol, propylene oxide and tertiary amine. ~2% by weight (for example, 0.8 to 1.5% by weight) U is about. Methanol, propylene oxide and tertiary amines can be supplied to the above reactors in batches (or semi-batchwise), and are generally continuously supplied from the viewpoint of industrial productivity. The speed at which methanol, propylene oxide and tertiary amine are supplied to the reactor is 2.0 to 5.0 m/h in line speed, preferably 2.1 to 4.6 m/h, particularly preferably 2.2 to 4.2 m/ho. The method is to react methanol and propylene oxide at a temperature of 90 to 110 ° C, preferably 95 to 110 ° C, particularly preferably 95 to 105 ° C in the presence of a third-stage amine. If the reaction is carried out at a temperature lower than the above temperature range, the conversion ratio of the propylene oxide-10-200848397 alkane tends to be low. On the other hand, if the reaction is carried out at a temperature higher than the above temperature range, the contents of the by-products 2-methoxy-: 1-propanol and dipropylene glycol monomethyl ether tend to increase. In order to produce 1-methoxy-2-propanol having a high conversion ratio of propylene oxide and a low content of the above-mentioned by-product, as described above, it is preferred to maintain the reaction temperature at a specific temperature (90 to 11 〇 ° C). For this reason, it is effective to control the reaction temperature (temperature of the reaction system). The control of the reaction temperature can use the above temperature control unit, particularly the above-mentioned rotary tubular temperature control unit. For example, a rotary tubular temperature control unit (especially a temperature control unit composed of a spiral tube) allows a heat transfer medium to flow through the above-mentioned rotary tubular temperature control unit, thereby improving heat transfer efficiency and easily and efficiently controlling the reaction temperature. . Further, when the reaction product is continuously supplied to the reactor to carry out the reaction, generally, the composition change of the reaction system and the temperature change caused by the reaction are large, and it is difficult to control and maintain the reaction temperature (temperature of the reaction system), and even if so, The heat medium (especially water) flows through the above-mentioned spiral tube temperature control unit (particularly a temperature control unit composed of a spiral tube), and the temperature can be simply controlled, and the reaction temperature (temperature of the reaction system) can be maintained at a specific temperature. temperature. Oil (such as eucalyptus oil) or the like may be used as the heat transfer medium, but water is generally used. The temperature of the above medium (especially water) may be selected depending on the reaction temperature, and is preferably a temperature lower than the reaction temperature. For example, the difference between the temperature of the above medium and the expected reaction temperature may be 5 to 30 ° C, preferably 7 to 25 ° C, particularly preferably about 10 to 20 ° C. If the difference between the temperature of the medium and the expected reaction temperature is too large, it is difficult to maintain the temperature of the reaction system at a certain level (almost). The pressure of the reaction system depends on the composition of the reaction material and the vapor pressure of the reaction temperature and the sum of the gas pressures of the inert gas -11-200848397 gas (nitrogen gas, etc.) which are pressure-sealed (or pressed) for safely performing the reaction. Can be hWkg/cn^G (with 1.0 parent 105~20\1〇5?〇, preferably 2~15]^/(:1112〇(with 2〇><1〇5~15 xl05Pa)' It is particularly preferable to use about 3 to 10 kg/cm 2 G (and 3.0 x 105 to 10 x 10 5 Pa). [Distillation step] The distillation step is to carry out distillation of the reaction crude liquid obtained by the reaction step. The apparatus required for distillation (distillation apparatus) is generally used. The distillation apparatus (distillation column) may be, for example, a plate column (a perforated tray column, a bubble column, etc.), a [charge column, etc.. The present invention is to suppress the pressure loss in the device, and it is preferable to use a charge column. The filling may be a random packing, but to suppress the pressure loss in the device and to improve the distillation efficiency, it is preferable to use a structured packing. The rule filling may be a widely used rule. Filling, for example, a metal such as titanium or chromium or an alloy thereof, stainless steel (for example Austenitic stainless steel, etc., ceramics, etc. The regular fillings may also be in the form of sheets (plates), sieves (mesh), grids (lattices), etc. Such regular fillings may be used alone or It is used in combination of two or more types. I Distillation tower system increases the separation performance of the distillation column as the number of plates (the number of theoretical plates) increases. Therefore, the number of plates (the number of theoretical plates) should be 30 or more (for example, 30~) The distillation column of 60 sections, preferably 32 to 55 sections, especially 35 to 50 sections. The number of distillation towers is not particularly limited, and may be one, or a plurality of blocks (two or more) may be combined. From the viewpoints of rate, equipment, and energy cost, generally 1 to 2 seats (especially 2 seats) can be used in the distillation column. In order to increase the distillation efficiency (separation efficiency), distillation should be carried out in multiple stages. Generally, recovery from the desired product is carried out. From the viewpoint of efficiency, distillation is carried out in stages 2 to 3 (especially in two stages). The number of distillation columns used may be the same or different at each stage. For example, in the first stage of -12 - 200848397, a two-stage distillation column is used. After the second stage, you can also use a steamed one. For example, in the first stage of the steaming operation, low-boiling components (unreacted methanol, tertiary amine, etc.) are distilled off, and the high-boiling component (methoxy-丨_) is removed in the second-stage distillation operation. Further, by-products such as propanol and dipropylene glycol monomethyl ether, etc.), the methanol and the tertiary amine distilled in the first-stage distillation operation can be recycled to the reaction materials. The above reaction step and distillation step are also It can be carried out individually, but it is helpful to continuously carry out the above two steps from the viewpoint of industrial productivity. If even (continuing the above reaction steps and distillation steps, the conversion rate of the epoxy propylene institute can be 99 wuer % or more (for example, 99.1 to 99.9 mol%, preferably 99 2 to 99.8 旲 ear % 'more preferably 99.3 to 99.7 mol%, especially 99.4 to 99.6 mol% or so) to produce 1-methoxy-2 -propanol. Further, the selectivity of 1-methoxy-2-propanol (based on propylene oxide) is 99. 9 mol% or more (for example, 99.910 to 99.999 mol%, preferably 99.930 to 99.995 mol%, More preferably 99.950 ~ 99.992 Mo %, especially 99.960-99.990 Mo %%). Further, the selectivity of 2-methoxy-1-propanol (based on propylene oxide) is (0.001 to 0.03 mol% (for example, 0.002 to 0.028 mol%, particularly preferably 0.003 to 0.026 mol%). According to the method of the present invention, 强-methoxypropanol having a very low content of highly toxic 2-methoxy-1-propanol can be produced. Even if 1-methoxy-2-propanol with a low content of highly toxic by-products can be produced on an industrial scale, the 1-methoxy-2-propanol obtained is very safe and is first applied. The resin solvent of the coating or ink is also used in industrial products such as dyeing agents for brake oils, woven fabrics or leather products. -13- 200848397 EXAMPLES Hereinafter, the present invention will be described in more detail based on examples, but the invention is not limited. In the examples and comparative examples, a reaction material, a reactor, and a distillation apparatus of the following composition were used. Reaction substance; methanol: 3462 kg/h (108.1 kmol/h) Propylene oxide: 1 046 kg/h (18.0 kmol) /h) Triethylamine: 45.5 kg / h (0.45 kmol / h) [methanol / propylene oxide (mole ratio) = 6, three B Concentration = 1 · 0% by weight] Reactor 1; a column reactor equipped with a Raschig ring (manufactured by Mitsui Shipbuilding Co., Ltd., inner diameter 1450 mm Cp, height 14698 mm); reactor 2; Ring tower reactor (manufactured by Mitsui Shipbuilding Co., Ltd., inner diameter 500mm (J), height 15708mm) Distillation tower 1; with a height of 20200mm 塡 filled with regular 塡 filling (stay heavy equipment engineering technology (shares) system, Sumitomo SFLOW 2 5 0MY) 塡 charging tower (Mitsui shipbuilding (stock) system, inner diameter llOOmmCp, height 30948mm, theoretical plate number 4 5) distillation tower 2; bubble tower (. Mitsui shipbuilding (stock) system, inner diameter llOOmmcp, The height is 3 09 4 8 mm, the actual number of plates is 60, and the number of theoretical plates is 36. In the examples and comparative examples, the conversion ratio of propylene oxide and the selectivity of each component were determined by the following method. [Conversion] Propylene oxide The conversion rate was analyzed by gas chromatography, and the content of propylene oxide in the reaction liquid was measured, and the ratio of the content of oxypropylene to the ring-14-200848397 before the reaction was determined. The content of propylene oxide (molar number) is C, and the propylene oxide in the reaction liquid The content (molar number) is C', then the conversion rate (% by mole) = (C' / C) X100. [Selection rate of each component] The selectivity of each component, for example, 1-methoxy-2_- The selectivity of the alcohol was analyzed by gas chromatography, and the content of 1-methoxy-2-propanol in the reaction liquid was measured, and the ratio to the total amount of the reaction product was determined. That is, the content of 1-methoxy-2-propanol (molar number) in the reaction solution is S, and the total amount of the product (total molar number) is S'. Rate (mole%) = (S / S ' ) X 1 0 0. Other ingredients are also obtained on the same basis. [Example 1] A reactor 1 having a temperature control unit composed of a spiral tube through which a heat transfer medium can flow was continuously supplied, and the reactor 1 was passed through the reactor 2 to carry out a reaction. In the reactor 1, water of 80 ° C was allowed to flow into the above unit, and the temperature of the reaction system was controlled to be 9 7 ° C to carry out a reaction. In the obtained reaction crude liquid, the conversion ratio of the epoxy propylene compound was 9 9 · 6 mol%. The selectivity of 1 - f , methoxy-2-propanol, 2-methoxy-1-propanol, dipropylene glycol monomethyl ether and other components (based on propylene oxide), respectively 8 7 · 7 Molar %, 6 · 3 mol %, 2.3 mol %, 3.7 mol %. Next, using the distillation column 1, the reaction crude liquid was subjected to distillation under the conditions of a reflux ratio of 3.2 and a distillation rate of 86.5 %. The conversion ratio of propylene oxide and the selectivity of each component (based on propylene oxide) in the purified liquid obtained by distillation were determined. [Example 2] The same operation as in Example 1 was carried out except that the distillation column 2 was used instead of the distillation column 1, and the conversion ratio of propylene oxide and the selectivity of each component of -15-200848397 in the obtained purified liquid were determined. (Based on propylene oxide). [Comparative Example 1] The reaction was carried out in the same manner as in Example 1 except that the temperature of the reaction system was not controlled. The reaction crude liquid obtained by distillation was distilled using the distillation column 2. The conversion ratio of propylene oxide and the selectivity of each component (based on propylene oxide) in the purified liquid obtained by distillation were determined. [Comparative Example 2] The same reaction as in Example 1 was carried out on the reaction material. The conversion rate of propylene oxide and the selectivity of each component (based on oxirane) in the obtained reaction crude liquid were determined. [Comparative Example 3] The reaction was carried out in the same manner as in Example 1 except that the temperature of the reaction system was not controlled. The conversion ratio of propylene oxide and the selectivity of each component (based on propylene oxide) in the obtained reaction crude liquid were determined. The results of the examples and comparative examples are shown in Table 1. In the table, "conversion rate _ is expressed as conversion ratio of propylene oxide, "1-MMPG", "2-MMPG", "high boiling point component", and "other" are represented as 1-methoxy-2 - The selectivity of propanol, 2-methoxy-1-propanol, dipropylene glycol monomethyl ether and other components (based on propylene oxide). 16-200848397 (Table 1) Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Reaction temperature rc) 97 97 135 97 135 Conversion (mol%) 99.6 99.6 99.4 99.6 99.4 l-MMPG (mol%) 99.991 99.968 99.949 87.7 85.6 2-MMPG (mol°/〇) 0.003 0.026 0.038 6.3 8.5 High boiling point component (mol%) 0.006 0.006 0.005 2.3 2.5 Others (mol%) <0.0001 <0.0001 0.009 3.7 3.4 It is clear from Table 1 that When the reaction substance is reacted and distilled in a specific temperature range, the conversion ratio of propylene oxide and the selectivity of methoxy-2-propanol are relatively high, and the content ratio of by-products is widely used. 1-methoxy-2-propanol having a lower content of by-products contained in industrial 1-methoxy-2-propanol. Further, in the distillation step, if the crucible filled with the regular ruthenium is used as the distillation column, the effect is more remarkable. [Simple description of the diagram] Μ 〇 [Description of main component symbols] None. -17-