JP2004083883A - Method for producing organopolysiloxane resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an organopolysiloxane resin, extremely scarcely forming precipitation, capable of reusing unreacted raw materials and by-products which are left over after reaction, and having excellent productivity. <P>SOLUTION: This method for producing the organopolysiloxane resin has a process (1) for hydrolyzing (A) one, two or more kinds of hydrolyzable silanes including a silane expressed by the formula: R<SP>1</SP>SiX<SB>3</SB>(R<SP>1</SP>is a non-hydrolyzable monovalent organic group; and X is a hydrolyzable group) or (B) a mixture of the silane and a hydrolyzable siloxane with (D) an aqueous hydrogen chloride solution in the presence of (C) an alcohol, a process (2) for removing hydrogen chloride by heating, a process (3) for conducting hydrolyzing polycondensation reaction by adding water or another aqueous hydrogen chloride solution thereto, and a process (4) for removing a mixture containing the alcohol and the hydrogen chloride by heating, so as to produce the organopolysiloxane resin containing siloxane units expressed by the formula: R<SP>3</SP>SiO<SB>3/2</SB>(R<SP>3</SP>is a monovalent organic residue). <P>COPYRIGHT: (C)2004,JPO

Description

尚、表１の化合物を使用した場合、加水分解性シランのグラム当量に対する、塩化水素水溶液中の水とアルコールの合計グラム当量の比率は、次式の通り計算される。
【式１】

【０００９】
加水分解方法は、（Ｃ）成分と（Ｄ）成分の混合物中に（Ａ）成分または（Ｂ）成分を滴下する方法が一般的であるが、（Ａ）成分または（Ｂ）成分中に（Ｃ）成分と（Ｄ）成分を滴下してもよい。尚、（Ｃ）成分中の水分や、副生したハロゲン化水素と（Ｃ）成分との反応により生成した水が、工程（１）の加水分解に関与することがあるが、本発明の進行上なんら差し支えない。またこのとき、（Ｄ）成分を２回に分けて投入してもよい。この場合、１回目の（Ｄ）成分の混合時に（Ｃ）成分全量を併用することが好ましい。１回目と２回目の（Ｄ）成分の比率は任意である。塩化水素濃度については、２回目に加える（Ｄ）成分の塩化水素濃度が２０重量％より大きいことが好ましく、前述した通り飽和塩化水素水溶液が一般的である。１回目の（Ｄ）成分には飽和塩化水素水溶液を使用してもよいが、工程（４）で除去した共沸成分中に存在する水と塩化水素の混合物を利用してもよい。このとき、水と塩化水素の合計量に対する塩化水素の割合が、２０重量％より大きいことが好ましい。さらに工程（１）では、反応を制御するために加水分解反応に対して（Ｆ）不活性な有機溶媒を用いることが好ましい。不活性な有機溶媒とは実質的に水と相溶しないものであり、具体的には、ベンゼン，トルエン，キシレン，石油エーテル，石油ベンジン，ガソリン，ナフサ，シクロヘキサンのような炭化水素系溶剤；トリクロロエチレン，テトラクロロエチレン，クロロベンゼンのようなハロゲン化炭化水素系溶剤；酢酸エチル，酢酸ブチルのようなエステル系溶剤；およびこれらの混合物が例示される。その使用量は、（Ａ）成分または（Ｂ）成分１００重量部に対して５０〜５００重量部が好ましく、１００〜３００重量部がより好ましい。これは、この範囲より少ないと反応を制御することが難しく、多いと製造効率が低下するためである。具体的な方法としては、（Ａ）成分または（Ｂ）成分と（Ｆ）成分の混合物と、（Ｃ）成分と（Ｄ）成分と（Ｆ）成分の混合物を混合した後、さらに（Ｄ）成分を加える方法が挙げられる。
【００１０】
工程（２）は、塩化水素を排除することにより反応系の酸濃度を低下させて、反応をコントロールする工程である。加熱温度は特に限定されないが、４０℃以上であることが好ましく、６０℃以上がより好ましい。加熱時間は、製造効率を考慮すると１２０分以下が望ましい。この工程は、反応系の酸濃度が１／１０以下になるまで還流条件のもとで遂行されるのが好ましく、時間を短縮するためにバブリングまたは減圧等の手段を用いてもよい。尚、この工程で塩化水素と共に排除された揮発成分は、冷却により系内にもどすことが好ましい。
【００１１】
また、工程（２）の後、工程（３）の前に不活性な有機溶媒を投入することにより、反応系の酸濃度を調整すると共に工程（３）の反応を制御して、沈殿物の発生をより一層抑えることができる。不活性な有機溶媒としては前記（Ｆ）成分と同様のものが挙げられ、単一物でも混合物でもどちらでもよい。また、工程（１）で（Ｆ）成分を使用した場合には同じ溶媒でもよく、異なる別の溶媒を使用してもよい。配合量は任意であるが、一般に、その量が多いほど加水分解縮合反応の制御が容易となる。具体的には、反応混合物１００重量部に対して５重量部以上であることが好ましく、５０重量部以上がより好ましい。
【００１２】
工程（３）では、塩化水素水溶液、水またはこれらの混合物が使用できる。使用される塩化水素水溶液の塩化水素濃度は任意であるが、２０重量％より大きいことが好ましく、２５重量％以上がより好ましい。一般に、入手のし易さから飽和塩化水素水溶液（３５重量％以上）が使用される。加水分解縮合反応は、工程（１）、（２）を経て得られた加水分解生成物を加熱攪拌しながら、これに、水や塩化水素水溶液を滴下する方法が一般的であるが、水や塩化水素水溶液に加水分解生成物を加えてもよい。このときの滴下時間、反応時間および反応温度は、所望のオルガノポリシロキサンレジンを得るために適宜選択されるが、時間を短縮するために加熱しながら短時間で反応させることが望ましい。水および塩化水素水溶液の配合量は制限されないが、得られるオルガノポリシロキサンレジンを反応中間体以外の用途に使用する場合には、加水分解生成物中のアルコキシ基を加水分解するのに必要な化学当量以上の量であることが好ましい。また、反応系の酸濃度が低いほど加水分解縮合反応の制御が容易になるので、所望のオルガノポリシロキサンレジンを安定に得るためには、規定の酸濃度になるように、水や塩化水素水溶液と水との混合物を使用することが好ましい。
【００１３】
工程（４）では、加熱により、副生したアルコール、塩化水素、水分、有機溶媒を共沸組成で系外に除去する。加熱温度は反応混合物の還流温度前後であることが好ましく、加熱時間は製造効率を考慮すると５時間以内が好ましい。この工程では、反応系の酸濃度（塩化水素濃度）を３００ｐｐｍ以下まで低減することが好ましく、後処理を容易にするためには、５０ｐｐｍ以下であることがより好ましい。酸濃度が所望の濃度に達しない場合は、アルコールまたは水を系内に加えて留去したり水洗することにより、酸濃度を低下させることができる。但し、ここで使用するアルコールや水の量が多いと廃棄物が多くなり、またその回数が多いと製造効率が低くなるので、少量で数回行うことが望ましい。また、使用した有機溶媒の沸点が水やアルコールよりも高い場合には、共沸成分の沸点の差を利用して２種類の留分を得ることができる。即ち、１回目の留分として最初に、アルコール、塩化水素、水分、少量の有機溶媒を留出させた後、さらに加熱を続けることにより、２回目の留分として、有機溶媒を留出させることができる。尚、１回目の留分は工程（１）の（Ｃ）成分と（Ｄ）成分の混合物として再利用でき、２回目の留分は工程（２）と工程（３）の間に投入する有機溶媒として再利用できる。
【００１４】
本発明の方法は上記した工程（１）〜工程（４）からなり、工程（１）、工程（２）、工程（３）、工程（４）の順に進行するが、必要に応じて、得られた反応生成物を中和またはろ過してもよい。中和には一般的な中和剤が使用でき、例えば、アンモニアガス，活性炭および酸化マグネシウムの他、炭酸ナトリウム，炭酸カルシウム等の塩類が挙げられる。
【００１５】
本発明の方法により得られるオルガノポリシロキサンレジンは、
（Ｅ）平均組成式：Ｒ^３ _ａＳｉＯ_{（４−ａ）／２}で示され、かつ、式：Ｒ^３ＳｉＯ_３／２で示されるシロキサン単位を必須構成単位とする。式中、Ｒ^３は一価有機基であり、上記Ｒ^１と同様の基に加えて、その一部が、メトキシ基，エトキシ基，イソプロポキシ基，ｎ−ブトキシ基，イソブトキシ基，メトキシエトキシ基などのアルコキシ基であってもよい。さらにＲ^３の一部が水酸基に置換されていてもよい。０＜ａ＜３であり、０．２＜ａ＜２が好ましく、０．４＜ａ＜１．８がより好ましい。上式以外のシロキサン単位としては、式：Ｒ^３ _２ＳｉＯ_２／２，式：ＳｉＯ_４／２，式：Ｒ^３ _３ＳｉＯ_１／２で示されるシロキサン単位が挙げられる。このオルガノポリシロキサンレジン中、式：Ｒ^３ＳｉＯ_３／２で示されるシロキサン単位の比率は、５０モル％以上であることが好ましく、７０モル％以上がより好ましい。またその分子構造は、網状、三次元構造だけでなく、分岐鎖状でもよい。その重量平均分子量は、３００〜１，０００，０００の範囲が好ましく、５００〜１００，０００の範囲がより好ましく、７００〜５０，０００の範囲が特に好ましい。室温における性状は、液状または固体状である。このようなオルガノポリシロキサンレジンとしては、メチルポリシロキサンレジン，メチルプロピルポリシロキサンレジン，メチルフェニルポリシロキサンレジン，フェニルポリシロキサンレジン，メチルビニルポリシロキサンレジン，ビニルポリシロキサンレジン，エポキシ基含有ポリシロキサンレジン，アクリル基含有ポリシロキサンレジン，メタクリル基含有ポリシロキサンレジンが挙げられる。
【００１６】
以上のような本発明の製造方法は、アルコール存在下、加水分解性シランまたは該シランと加水分解性シロキサンとの混合物を、塩化水素水溶液により加水分解した後、反応系中の酸を低減してから縮合させるので、ゲル状物質や微結晶性の沈殿物の発生が極めて少ないという特徴を有する。このため、静置する時間が不要であり、ろ過工程の時間が大幅に短縮でき、また、収量の損失が極めて少ないという利点を有する。さらに本発明では、工程（４）で除去したアルコールや塩化水素や有機溶媒を再度使用できるので、安価に製造できるという利点を有する。加えて、加水分解に使用する水分およびアルコールが少量であり、かつ、反応後に残存する塩化水素やアルコールを共沸脱水により除去できるので、水洗が実質的に省略できるという特徴を有する。これにより、水洗工程で産出される、特別な処理を必要とする酸性のアルコール性水溶液が廃棄物として産出されず、相分離に要する時間が不要となって製造時間が短縮でき、また、スラリー等による収率の低下を回避できる。このため、本発明の製造方法はオルガノポリシロキサンレジンの工業生産に好適であり、特にメチルポリシロキサンレジンの工業生産に極めて好適である。尚、本発明の製造方法は、バッチ方式、連続方式のどちらの方法にも応用可能である。
【００１７】
【実施例】
以下、実施例により、本発明を具体的に説明する。実施例中、飽和塩化水素水溶液の塩化水素濃度は３６重量％である。酸価は、単位重量あたりのレジン溶液に対して中和に要するＫＯＨのモル数であり、酸濃度は、反応系中の塩化水素量を測定したものである。
【００１８】
【実施例１】
攪拌機、温度計、冷却管および滴下ロートを備えた１リットル４つ口フラスコに、メチルトリクロロシラン１５９ｇ、ジメチルジクロロシラン２４ｇおよびトルエン１０９ｇを仕込み、この中に、イソプロピルアルコール８２ｇ、飽和塩化水素水溶液１３．７ｇおよびトルエン１９２ｇの混合物を滴下した。滴下終了後、１０分間攪拌して、さらに飽和塩化水素水溶液２７．４ｇを滴下して１０分間攪拌した。このとき、クロロシランの合計グラム当量に対する飽和塩化水素水溶液中の水とイソプロピルアルコールの合計グラム当量の比率は１．２であった。次いで、０．３Ｌ／ｍｉｎの流量の窒素ガスでバブリングを行いながら７５℃まで加熱して、塩化水素を排除した。これにより反応系の酸価は、４．７２ｍｏｌ／ｋｇから０．１９ｍｏｌ／ｋｇに低下した。次いでトルエンを３００ｇ投入して、再び７５℃まで昇温し、水１２．３ｇを滴下して３０分間加熱還流を行った。加熱還流後、常圧下に加熱して低沸分１９５ｇを留出させた。次いで、０．３Ｌ／ｍｉｎの流量の窒素ガスでバブリングを行いながら常圧下に加熱して、さらに低沸分３６３ｇを留出させて、反応生成物を得た。その酸濃度は２９ｐｐｍであり、不揮発分は４９．９重量％であった。
このようにして得られたオルガノポリシロキサンレジンのトルエン溶液の外観を目視により測定したところ、ゲル状物質や沈殿物の発生は認められなかった。このトルエン溶液１８０ｇを、フィルター［ろ過精度０．９〜４μ］を用いて、窒素による１ｋｇ／ｃｍ^２の圧力下でろ過したところ、３分間で全量のろ過が終了した。また、^２９Ｓｉ−ＮＭＲ分析により、このオルガノポリシロキサンレジンは、ＣＨ_３ＳｉＯ_３／２単位８５．１モル％と、（ＣＨ_３）_２ＳｉＯ_２／２単位１４．９モル％からなるメチルポリシロキサンレジンであることが判明した。さらに^１３Ｃ−ＮＭＲ分析により、ケイ素原子結合メチル基から換算されるケイ素原子の積分値と、ケイ素原子結合イソプロポキシ基中の酸素原子に隣接する炭素原子の積分値との比が１：０．０６１であり、フーリエ変換赤外分光光度分析（以下、ＦＴ−ＩＲ分析）によるシラノール基残存量がレジン固形分の０．６５重量％であったことから、このメチルポリシロキサンレジンは、少量のイソプロポキシ基とシラノール基を含有することが判明した。得られたメチルポリシロキサンレジンは室温で固体状であり、ＧＰＣ分析による重量平均分子量は３７２７であり、分子量分布は３．５７であり、収率は９９％であった。
【００１９】
【実施例２】
攪拌機、温度計、冷却管および滴下ロートを備えた１リットル４つ口フラスコに、イソプロピルアルコール８２ｇ、飽和塩化水素水溶液１３．７ｇおよびトルエン１９２ｇを仕込み、この中に、メチルトリクロロシラン１７４ｇ、ジメチルジクロロシラン２６ｇおよびトルエン１０９ｇの混合物を、反応温度が４０℃を超えないように冷却しながら滴下した。滴下終了後、１０分間攪拌してからさらに飽和塩化水素水溶液２７．４ｇを滴下して１０分間攪拌した。このとき、クロロシランの合計グラム当量に対する飽和塩化水素水溶液中の水とイソプロピルアルコールの合計グラム当量の比率は１．１であった。次いで、０．３Ｌ／ｍｉｎの流量の窒素ガスでバブリングを行いながら７２℃まで加熱して、塩化水素を排除した。これにより酸価は４．８４ｍｏｌ／ｋｇから０．３ｍｏｌ／ｋｇに低下した。次いでトルエンを３００ｇ投入して、再び７５℃まで昇温し、水１０．８ｇと飽和塩化水素水溶液２．３ｇの混合物を滴下して３０分間加熱還流を行った。加熱還流後、常圧下に加熱して、低沸分２１８ｇを留出させた（１回目の留分）。次いで、０．３Ｌ／ｍｉｎの流量の窒素ガスでバブリングを行いながら、常圧下に加熱してさらに低沸分３５０ｇを留出させて（２回目の留分）、反応生成物を得た。その酸濃度は３２ｐｐｍであり、不揮発分は５０．２重量％であった。また、ここで得られた留分は、ガスクロマトグラフ、電量滴定および中和滴定により、以下の成分から構成されることが判明した。
【表２】

このようにして得られたオルガノポリシロキサンレジンのトルエン溶液の外観を目視により測定したところ、ゲル状物質や沈殿物の発生は認められなかった。このトルエン溶液１８０ｇを、フィルター［ろ過精度０．９〜４μ］を用いて、窒素による１ｋｇ／ｃｍ^２の圧力の下でろ過したところ、１分間で全量のろ過が終了した。また、^２９Ｓｉ−ＮＭＲ分析により、このオルガノポリシロキサンレジンは、ＣＨ_３ＳｉＯ_３／２単位８４．９モル％と、（ＣＨ_３）_２ＳｉＯ_２／２単位１５．１モル％からなるメチルポリシロキサンレジンであることが判明した。さらに^１３Ｃ−ＮＭＲ分析により、ケイ素原子結合メチル基から換算されるケイ素原子の積分値と、ケイ素原子結合イソプロポキシ基中の酸素原子に隣接する炭素原子の積分値との比が１：０．０６９であり、ＦＴ−ＩＲ分析によるシラノール基残存量がレジン固形分の０．７０重量％であったことから、このメチルポリシロキサンレジンは、少量のイソプロポキシ基とシラノール基を含有することが判明した。得られたメチルポリシロキサンレジンは室温で固体状であり、ＧＰＣ分析による重量平均分子量は３２１７であり、分子量分布は３．２４であり、収率は９２％であった。
【００２０】
【実施例３】
実施例２で回収した１回目の留分２１８ｇに、イソプロピルアルコールおよび水を加えて、イソプロピルアルコールが８２ｇ、水分が８．８ｇになるように調整してから、攪拌機、温度計、冷却管および滴下ロートを備えた１リットル４つ口フラスコに全量を仕込んだ。次いでこれに、メチルトリクロロシラン１７４ｇ、ジメチルジクロロシラン２６ｇおよびトルエン１０９ｇの混合物を、反応温度が４０℃を超えないように冷却しながら滴下した。滴下終了後、１０分間攪拌してからさらに飽和塩化水素水溶液２７．４ｇを滴下して１０分間攪拌した。このとき、クロロシランの合計グラム当量に対する飽和塩化水素水溶液中の水とイソプロピルアルコールの合計グラム当量の比率は１．１であった。次いで、０．３Ｌ／ｍｉｎの流量の窒素ガスでバブリングを行いながら７７℃まで加熱して、塩化水素を排除した。これにより酸価は、４．５６ｍｏｌ／ｋｇから０．１８ｍｏｌ／ｋｇに低下した。次いで、実施例２で回収した２回目の留分を３００ｇ投入して７５℃まで昇温し、水１２．３ｇを滴下して３０分間加熱還流を行った。加熱還流後、常圧下に加熱して低沸分２０８ｇを留出させた。次いで、０．３Ｌ／ｍｉｎの流量の窒素ガスでバブリングを行いながら、常圧下に加熱して低沸分３５８ｇを留出させて、反応生成物を得た。その酸濃度は２５ｐｐｍであり、不揮発分は５０．１重量％であった。
このようにして得られたオルガノポリシロキサンレジンのトルエン溶液の外観を目視により測定したところ、ゲル状物質や沈殿物の発生は認められなかった。このトルエン溶液１８０ｇを、フィルター［ろ過精度０．９〜４μ］を用いて、窒素による１ｋｇ／ｃｍ^２の圧力の下でろ過したところ、１分間で全量のろ過が終了した。また、^２９Ｓｉ−ＮＭＲ分析により、このオルガノポリシロキサンレジンは、ＣＨ_３ＳｉＯ_３／２単位８４．７モル％と、（ＣＨ_３）_２ＳｉＯ_２／２単位１５．３モル％からなるメチルポリシロキサンレジンであることが判明した。さらに^１３Ｃ−ＮＭＲ分析により、ケイ素原子結合メチル基から換算されるケイ素原子の積分値と、ケイ素原子結合イソプロポキシ基中の酸素原子に隣接する炭素原子の積分値との比が１：０．０６０であり、ＦＴ−ＩＲ分析によるシラノール基残存量がレジン固形分の０．６６重量％であったことから、このメチルポリシロキサンレジンは、少量のイソプロポキシ基とシラノール基を含有することが判明した。得られたメチルポリシロキサンレジンは室温で固体状であり、ＧＰＣ分析による重量平均分子量は２９０５であり、分子量分布は２．９５であり、収率は９５％であった。
【００２１】
【比較例１】
攪拌機、温度計、冷却管および滴下ロートを備えた１リットル４つ口フラスコに、イソプロピルアルコール８２ｇ、水８．８ｇおよびトルエン１９２ｇを仕込み、次いでこれに、メチルトリクロロシラン１７４ｇ、ジメチルジクロロシラン２６ｇおよびトルエン１０９ｇの混合物を、反応温度が４０℃を超えないように冷却しながら滴下した。滴下終了後、１０分間攪拌してからさらに水１７．５ｇを滴下して１０分間攪拌した。このとき、クロロシランの合計グラム当量に対する水とイソプロピルアルコールの合計グラム当量の比率は１．１であった。次いで、０．３Ｌ／ｍｉｎの流量の窒素ガスでバブリングを行いながら７１℃まで加熱して、塩化水素を排除した。これにより酸価は４．７７ｍｏｌ／ｋｇから０．３ｍｏｌ／ｋｇに低下した。次いでトルエンを３００ｇ投入して再び７５℃まで昇温し、水１２．３ｇを滴下して３０分間加熱還流を行った。加熱還流後、常圧下に加熱して低沸分１９５ｇを留出させた。次いで、０．３Ｌ／ｍｉｎの流量の窒素ガスでバブリングを行いながら常圧下に加熱して低沸分２２０ｇを留出させた。さらに０．３Ｌ／ｍｉｎの流量の窒素ガスでバブリングを行いながら常圧下に加熱して低沸分３５０ｇを留出して、反応生成物を得た。その酸濃度は３２ｐｐｍであり、不揮発分は５０重量％であった。
このようにして得られたオルガノポリシロキサンレジンのトルエン溶液の外観を目視により測定したところ、微結晶性の沈殿物が認められた。このトルエン溶液１８０ｇを、フィルター［ろ過精度０．９〜４μ］を用いて、窒素による１ｋｇ／ｃｍ^２の圧力の下でろ過したところ、６０分経過後も終了しなかった。また、^２９Ｓｉ−ＮＭＲ分析により、このオルガノポリシロキサンレジンは、ＣＨ_３ＳｉＯ_３／２単位８５モル％と、（ＣＨ_３）_２ＳｉＯ_２／２単位１５モル％からなるメチルポリシロキサンレジンであることが判明した。さらに^１３Ｃ−ＮＭＲ分析により、ケイ素原子結合メチル基から換算されるケイ素原子の積分値と、ケイ素原子結合イソプロポキシ基中の酸素原子に隣接する炭素原子の積分値との比が１：０．０６０であり、ＦＴ−ＩＲ分析によるシラノール基残存量がレジン固形分の０．５５重量％であったことから、このメチルポリシロキサンレジンは、少量のイソプロポキシ基とシラノール基を含有することが判明した。得られたメチルポリシロキサンレジンは室温で固体状であり、ＧＰＣ分析による重量平均分子量は４５３１であり、分子量分布は３．７６であり、収率は７０％であった。
【００２２】
【比較例２】
攪拌機、温度計、冷却管および滴下ロートを備えた１リットル４つ口フラスコに、イソプロピルアルコール７０ｇ、水１３４ｇおよびトルエン２１１ｇを仕込み、この中に、メチルトリクロロシラン１８４ｇ、ジメチルジクロロシラン２２ｇおよびトルエン７３ｇの混合物を、反応温度が４０℃を超えないように冷却しながら滴下した。滴下終了後、室温下に１時間攪拌してから８０℃まで加熱して、３０分間加熱還流を行った。これを冷却した後、温水を用いて水層が中性になるまで繰り返し５回以上洗浄した。次いで、常圧下に加熱して不揮発分が５０重量％になるまで低沸分を留去して、オルガノポリシロキサンレジンのトルエン溶液を得た。
このようにして得られたトルエン溶液の外観を目視により測定したところ、微結晶性の沈殿物が認められた。このトルエン溶液１８０ｇを、フィルター［ろ過精度０．９〜４μ］を用いて、窒素による１ｋｇ／ｃｍ^２の圧力の下でろ過したところ、６０分経過後も終了しなかった。また、^２９Ｓｉ−ＮＭＲ分析により、このオルガノポリシロキサンレジンは、ＣＨ_３ＳｉＯ_３／２単位８４モル％と、（ＣＨ_３）_２ＳｉＯ_２／２単位１６モル％からなるメチルポリシロキサンレジンであることが判明した。さらに^１３Ｃ−ＮＭＲ分析により、ケイ素原子結合メチル基から換算されるケイ素原子の積分値と、ケイ素原子結合イソプロポキシ基中の酸素原子に隣接する炭素原子の積分値との比が１：０．０１５であり、ＦＴ−ＩＲ分析によるシラノール基残存量がレジン固形分の０．２９重量％であったことから、このメチルポリシロキサンレジンは、少量のイソプロポキシ基とシラノール基を含有することが判明した。得られたメチルポリシロキサンレジンは室温で固体状であり、ＧＰＣ分析による重量平均分子量は７８３０であり、分子量分布は６．１１であり、収率は５４％であった。
【００２３】
【表３】

【００２４】
【発明の効果】
本発明の製造方法によれば、ゲル状物質や微結晶性の沈殿物の発生が極めて少ないので、極めて短時間でろ過が可能である。したがって、オルガノポリシロキサンレジンを収率良く、生産性良く製造することができる。加えて、実質的に水洗操作が省略できるうえに、反応後の未反応原料や副生物を再利用できるので、環境への影響が少なく安価であり、オルガノポリシロキサンレジンの工業生産に好適であるという特徴を有する。[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a method for producing an organopolysiloxane resin, and more particularly, to a method for producing an organopolysiloxane resin which is extremely low in the amount of precipitates, can reuse unreacted raw materials and by-products after the reaction, and has excellent productivity. .
[0002]
[Prior art]
In general, a method for producing an organopolysiloxane resin by hydrolyzing and condensing an organohalogenosilane as a main raw material is known. However, this method has a disadvantage that it is difficult to control the condensation reaction between silanol groups when the reaction proceeds at a stretch. In particular, the formula: RSiO_3/2A siloxane unit represented by the formula: SiO_4/2When synthesizing an organopolysiloxane resin containing a large number of siloxane units represented by the formula, a gel-like substance or a microcrystalline precipitate is easily generated due to a high crosslinking density, and as a result, the production time is extremely long. And there are problems such as increased waste. In particular, the methyl polysiloxane resin has a problem in that microcrystalline by-products that are difficult to filter are liable to be produced, and the productivity is low. In order to solve such problems, there has been proposed a method for producing an organopolysiloxane resin in which an appropriate amount of a silanol group or an alkoxy group remains by controlling the reaction by using an alcohol. For example, JP-B-46-41396 (corresponding foreign patent: GB1192506) and JP-B-48-14680 (corresponding foreign patent: GB1294196) describe a method for stably obtaining an organopolysiloxane resin by using alcohol and acetone. Have been. However, this method has a disadvantage that the efficiency of the reactor is low because a large amount of water is used. It was also extremely difficult to recover, purify, and reuse the used organic solvent. On the other hand, in Japanese Patent Application Laid-Open No. 50-77500 (corresponding foreign patent: US Pat. No. 3,846,358), an organohalosilane is alkoxylated by reacting with an alcohol and water, and then an alcohol is further added to adjust the acidity to 1 to 300 ppm. Then, a method of hydrolyzing by adding water has been proposed. However, this method has the drawbacks that the production process is complicated, the time for removing hydrogen halide is long, and the production efficiency is low. In addition, there is a disadvantage that a large amount of precipitate is generated during the synthesis of the methylpolysiloxane resin.
[0003]
[Problems to be solved by the invention]
The present inventors have conducted intensive studies to solve the above problems, and as a result, have reached the present invention.
That is, an object of the present invention is to provide a method for producing an organopolysiloxane resin having excellent productivity, in which the generation of precipitates is extremely small, and unreacted raw materials and by-products after the reaction can be reused.
[0004]
[Means for Solving the Problems]
The present invention provides a process (1): (A) having the general formula: R¹Six₃(Where R¹Is a non-hydrolyzable monovalent organic group, and X is a hydrolyzable group. Or (B) a mixture of the silane and the hydrolyzable siloxane represented by the general formula: R²OH (where R²Is an alkyl group having 1 to 8 carbon atoms or an alkyloxyethyl group. (D) a step of hydrolyzing with an aqueous solution of hydrogen chloride in the presence of an alcohol [in this step, the water in the component (D) and the (C) in the gram equivalent of the component (A) or the component (B), The ratio of the total gram equivalent of the component (D) is 0.9 to 2.0, and the ratio of the gram equivalent of only water in the component (D) is 0.3 to 0.95. ],
Step (2): a step of removing hydrogen chloride by heating,
Step (3): a step of adding water or an aqueous solution of hydrogen chloride to carry out a hydrolytic condensation reaction,
Step (4): a step of removing a mixture containing alcohol and hydrogen chloride by heating;
(E) average composition formula: R³ _aSiO_{(4-a) / 2}And the formula: R³SiO_3/2An organopolysiloxane resin containing a siloxane unit represented by³Is a monovalent organic group, and 0 <a <3. )).
[0005]
BEST MODE FOR CARRYING OUT THE INVENTION
Step (1) is a step of hydrolyzing a hydrolyzable silane or a mixture of the silane and a hydrolyzable siloxane. The component (A) used in this step has a general formula: R¹Six₃One or two or more hydrolyzable silanes containing a silane represented by the following formula, specifically, a hydrolyzable silane represented by the above formula alone or a mixture of the silane and another hydrolyzable silane is there. The component (B) is a mixture of the silane and the hydrolyzable siloxane, and specifically, is a mixture of the silane of the above formula and the hydrolyzable siloxane, or a mixture of the silane of the above formula and other silane. It is a mixture of a hydrolyzable silane and a hydrolyzable siloxane. In the above formula, R¹Is a non-hydrolyzable monovalent organic group, and examples thereof include an unsubstituted or substituted monovalent hydrocarbon group and a functional organic group bonded to a silicon atom via a carbon atom. Specifically, alkyl groups such as methyl group, ethyl group, propyl group, butyl group and hexyl group; alkenyl groups such as vinyl group and allyl group; cycloalkyl groups such as cyclohexyl group; Unsubstituted monovalent hydrocarbon groups such as aralkyl groups such as aryl group, benzyl group and styrenyl group; perfluoroalkyl groups such as 3,3,3-trifluoropropyl group and halogen-substituted monovalent groups such as chlorophenyl group Hydrocarbon group; 2,3-epoxypropyl group, 3,4-epoxybutyl group, 4,5-epoxypentyl group, 2-glycidoxyethyl group, 3-glycidoxypropyl group, 4-glycidoxybutyl Group containing an epoxy group such as a 2- (3,4-epoxycyclohexyl) ethyl group or a 3- (3,4-epoxycyclohexyl) propyl group Groups; (meth) acrylic group-containing organic groups such as acryloxymethyl group, 3-acryloxypropyl group, methacryloxymethyl group, and 3-methacryloxypropyl group; and 3-mercaptopropyl group and 3-hydroxypropyl group. You. Among them, a methyl group, a propyl group, a vinyl group or a phenyl group is preferable from the viewpoint of heat resistance and availability of the resulting organopolysiloxane resin, and a combination thereof may be used. X is a hydrolyzable group bonded to a silicon atom, and is a halogen atom such as a chlorine atom or a bromine atom; an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group or a butoxy group; an alkenoxy group; an acyloxy group; an amide group; Groups. Among these, a halogen atom is preferable, and a chlorine atom is particularly preferable from the viewpoint of easy availability, easy removal in the step (2), economical reasons, and the like. The hydrolyzable groups X in one molecule may be the same, or may be two or more different groups. Hydrolyzable silanes other than the silane represented by the above formula include those represented by the formula: R¹ ₂Six₂A silane represented by the formula: SiX₄A silane represented by the formula: R¹ ₃A silane represented by SiX is included. R in the formula¹And X are the same as described above. As the component (A), specifically, a compound represented by the formula: R¹Six₃Or a silane represented by the formula:¹Six₃And a silane represented by the formula: R¹ ₂Six₂A mixture of silanes represented by the general formula:₄Or a silane represented by the formula: R¹ ₃A silane represented by SiX may be used in combination. As the hydrolyzable siloxane of the component (B), a low molecular weight siloxane oligomer to a high molecular weight linear organopolysiloxane can be used. Among them, a linear siloxane having a hydrolyzable group bonded to a silicon atom can be used. Typical are cyclic, cyclic and branched siloxane oligomers. The degree of polymerization is preferably from a dimer to a degree of polymerization lower than the degree of polymerization of the organopolysiloxane resin. Examples of the hydrolyzable group include the same groups as those described above for X, and groups other than the hydrolyzable group include the above-described R.¹And the same groups as mentioned above. Incidentally, the hydrolyzable siloxane (B) may be a partially hydrolyzed condensate of the component (A). Examples of such a component (B) include hexamethoxydisiloxane, hexaethoxydisiloxane, dimethyltetraethoxydisiloxane, tri (methoxydimethylsiloxy) silane, and ethyl polysilicate.
[0006]
The component (C) is a component that suppresses the formation of a gel-like substance or a microcrystalline precipitate, and has a general formula: R²Indicated by OH. Where R²Is an alkyl group having 1 to 8 carbon atoms or an alkyloxyethyl group. This is because if the number of carbon atoms is more than 8, the reactivity at the time of hydrolysis is reduced, and the solid state is inconvenient to handle. Specifically, monohydric unsubstituted alcohols such as methanol, ethanol, isopropanol, n-butanol and isobutanol; ether alcohols such as methoxyethanol, ethoxyethanol and butoxyethanol are exemplified. A mixture of the above may be used. Among them, methanol, ethanol or isopropanol is preferred because the reactivity of the hydrolyzate is good, an appropriate reflux temperature is obtained in steps (2) to (4), and the handleability is excellent.
[0007]
Component (D) is one of the features of the present invention, and is a component that hydrolyzes components (A) and (B). The concentration of hydrogen chloride in the component (D) is optional, but is preferably greater than 20% by weight, more preferably 25% by weight or more. Generally, a saturated aqueous solution of hydrogen chloride (35% by weight or more) is used because of easy availability.
[0008]
In the step (1), the compounding amount of the component (C) and the component (D) is the total gram equivalent of the water in the component (D) and the component (C) with respect to the gram equivalent of the component (A) or the component (B). Is an amount such that the ratio is 0.9 to 2.0, preferably 1.0 to 1.5, and more preferably 1.0 to 1.3. If the amount is less than this range, a large amount of unreacted hydrolyzable groups remain, making it difficult to control the reaction at the time of the hydrolytic condensation in step (3). This is because the production efficiency decreases. Further, the ratio of the gram equivalent of water in the component (D) to the gram equivalent of the component (A) or the component (B) is in the range of 0.3 to 0.95, and 0.5 to 0.9. A range is preferred. This is because if the amount is less than this range, the generation of a gel-like substance or a microcrystalline precipitate increases, and if it is too large, the production efficiency decreases. In addition, the gram equivalent is obtained by calculating the blending amount (g) by the chemical equivalent. Table 1 below shows the method of calculating the chemical equivalent and gram equivalent of a representative compound of each component.
[Table 1]

When the compounds in Table 1 are used, the ratio of the total gram equivalent of water and alcohol in the aqueous hydrogen chloride solution to the gram equivalent of the hydrolyzable silane is calculated as follows.
(Equation 1)

[0009]
The hydrolysis method is generally a method of dropping the component (A) or the component (B) into a mixture of the component (C) and the component (D). The component (C) and the component (D) may be dropped. The water in the component (C) or the water produced by the reaction between the by-produced hydrogen halide and the component (C) may be involved in the hydrolysis in the step (1). No problem. At this time, the component (D) may be charged in two portions. In this case, it is preferable to use the entire amount of the component (C) at the time of the first mixing of the component (D). The ratio of the component (D) in the first and second times is arbitrary. As for the concentration of hydrogen chloride, the concentration of hydrogen chloride of the component (D) added for the second time is preferably more than 20% by weight, and a saturated aqueous solution of hydrogen chloride is generally used as described above. For the first component (D), a saturated aqueous solution of hydrogen chloride may be used, or a mixture of water and hydrogen chloride present in the azeotropic component removed in step (4) may be used. At this time, the ratio of hydrogen chloride to the total amount of water and hydrogen chloride is preferably larger than 20% by weight. Further, in the step (1), it is preferable to use an organic solvent (F) inert to the hydrolysis reaction in order to control the reaction. The inert organic solvent is substantially insoluble in water, and specifically, hydrocarbon solvents such as benzene, toluene, xylene, petroleum ether, petroleum benzine, gasoline, naphtha and cyclohexane; trichloroethylene And halogenated hydrocarbon solvents such as tetrachloroethylene and chlorobenzene; ester solvents such as ethyl acetate and butyl acetate; and mixtures thereof. The amount used is preferably 50 to 500 parts by weight, more preferably 100 to 300 parts by weight, per 100 parts by weight of the component (A) or the component (B). This is because if it is less than this range, it is difficult to control the reaction, and if it is too large, the production efficiency is reduced. As a specific method, a mixture of the component (A) or the component (B) and the component (F), a mixture of the component (C), the component (D), and the component (F) are mixed, and then the mixture of the component (D) There is a method of adding a component.
[0010]
Step (2) is a step of controlling the reaction by reducing the acid concentration of the reaction system by eliminating hydrogen chloride. The heating temperature is not particularly limited, but is preferably 40 ° C. or higher, more preferably 60 ° C. or higher. The heating time is desirably 120 minutes or less in consideration of production efficiency. This step is preferably performed under reflux conditions until the acid concentration of the reaction system becomes 1/10 or less, and means such as bubbling or reduced pressure may be used to shorten the time. It is preferable that the volatile components removed together with the hydrogen chloride in this step be returned to the system by cooling.
[0011]
Further, after the step (2) and before the step (3), an inert organic solvent is added to adjust the acid concentration of the reaction system and to control the reaction of the step (3) to remove the precipitate. Generation can be further suppressed. As the inert organic solvent, those similar to the above-mentioned component (F) can be mentioned, and either a single substance or a mixture may be used. When the component (F) is used in the step (1), the same solvent may be used, or another different solvent may be used. The mixing amount is arbitrary, but generally, the larger the amount, the easier the control of the hydrolysis-condensation reaction. Specifically, it is preferably at least 5 parts by weight, more preferably at least 50 parts by weight, per 100 parts by weight of the reaction mixture.
[0012]
In the step (3), an aqueous solution of hydrogen chloride, water or a mixture thereof can be used. The concentration of hydrogen chloride in the aqueous hydrogen chloride solution used is arbitrary, but is preferably greater than 20% by weight, more preferably 25% by weight or more. Generally, a saturated aqueous hydrogen chloride solution (35% by weight or more) is used because of its availability. The hydrolysis condensation reaction is generally carried out by dropping water or an aqueous hydrogen chloride solution while heating and stirring the hydrolysis product obtained through the steps (1) and (2). The hydrolysis product may be added to the aqueous hydrogen chloride solution. The dropping time, reaction time, and reaction temperature at this time are appropriately selected in order to obtain a desired organopolysiloxane resin, but it is desirable that the reaction be performed in a short time while heating to shorten the time. The amounts of water and aqueous hydrogen chloride are not limited, but when the resulting organopolysiloxane resin is used for purposes other than reaction intermediates, the chemicals required to hydrolyze the alkoxy groups in the hydrolysis product are used. The amount is preferably equal to or more than the equivalent. In addition, the lower the acid concentration of the reaction system is, the easier the control of the hydrolysis-condensation reaction becomes.Therefore, in order to stably obtain a desired organopolysiloxane resin, water or an aqueous solution of hydrogen chloride must be adjusted to a specified acid concentration. It is preferred to use a mixture of water and water.
[0013]
In the step (4), alcohol, hydrogen chloride, moisture, and organic solvent produced as by-products are removed from the system by an azeotropic composition by heating. The heating temperature is preferably around the reflux temperature of the reaction mixture, and the heating time is preferably within 5 hours in consideration of production efficiency. In this step, the acid concentration (hydrogen chloride concentration) of the reaction system is preferably reduced to 300 ppm or less, and more preferably 50 ppm or less to facilitate post-treatment. If the acid concentration does not reach the desired concentration, the acid concentration can be reduced by adding alcohol or water to the system and distilling or washing with water. However, if the amount of alcohol or water used here is large, the amount of waste increases, and if the number of times is large, the production efficiency is lowered. When the boiling point of the organic solvent used is higher than that of water or alcohol, two types of fractions can be obtained by utilizing the difference in boiling points of the azeotropic components. That is, first, an alcohol, hydrogen chloride, water, and a small amount of an organic solvent are distilled out as a first fraction, and then the organic solvent is distilled as a second fraction by further heating. Can be. In addition, the first fraction can be reused as a mixture of the component (C) and the component (D) in the step (1), and the second fraction is an organic substance to be introduced between the step (2) and the step (3). Can be reused as a solvent.
[0014]
The method of the present invention comprises the above-mentioned steps (1) to (4), and proceeds in the order of step (1), step (2), step (3) and step (4). The reaction product obtained may be neutralized or filtered. For neutralization, a general neutralizing agent can be used, and examples thereof include salts such as sodium carbonate and calcium carbonate, in addition to ammonia gas, activated carbon and magnesium oxide.
[0015]
The organopolysiloxane resin obtained by the method of the present invention is
(E) Average composition formula: R³ _aSiO_{(4-a) / 2}And the formula: R³SiO_3/2The siloxane unit represented by is defined as an essential constituent unit. Where R³Is a monovalent organic group;¹In addition to the groups described above, some of them may be alkoxy groups such as methoxy group, ethoxy group, isopropoxy group, n-butoxy group, isobutoxy group, and methoxyethoxy group. Further R³May be partially substituted with a hydroxyl group. 0 <a <3, preferably 0.2 <a <2, and more preferably 0.4 <a <1.8. As the siloxane unit other than the above formula, a compound represented by the formula: R³ ₂SiO_2/2, Formula: SiO_4/2, Formula: R³ ₃SiO_1/2And a siloxane unit represented by In this organopolysiloxane resin, the formula: R³SiO_3/2Is preferably 50 mol% or more, and more preferably 70 mol% or more. Further, the molecular structure may be not only a network and a three-dimensional structure, but also a branched chain. The weight average molecular weight is preferably in the range of 300 to 1,000,000, more preferably in the range of 500 to 100,000, and particularly preferably in the range of 700 to 50,000. The properties at room temperature are liquid or solid. Examples of such an organopolysiloxane resin include methylpolysiloxane resin, methylpropylpolysiloxane resin, methylphenylpolysiloxane resin, phenylpolysiloxane resin, methylvinylpolysiloxane resin, vinylpolysiloxane resin, epoxy group-containing polysiloxane resin, An acrylic group-containing polysiloxane resin and a methacryl group-containing polysiloxane resin are exemplified.
[0016]
The production method of the present invention as described above comprises, in the presence of an alcohol, hydrolyzing a hydrolyzable silane or a mixture of the silane and a hydrolyzable siloxane with an aqueous hydrogen chloride solution, and then reducing the acid in the reaction system. Since it is condensed from water, it is characterized in that generation of a gel-like substance and a microcrystalline precipitate is extremely small. Therefore, there is an advantage that the time for standing is unnecessary, the time for the filtration step can be greatly reduced, and the loss of the yield is extremely small. Further, in the present invention, since the alcohol, hydrogen chloride and the organic solvent removed in the step (4) can be used again, there is an advantage that the production can be performed at low cost. In addition, water and alcohol used for hydrolysis are small, and hydrogen chloride and alcohol remaining after the reaction can be removed by azeotropic dehydration, so that washing with water can be substantially omitted. As a result, the acidic alcoholic aqueous solution produced in the water washing process and requiring special treatment is not produced as waste, and the time required for phase separation is not required, so that the production time can be shortened. Can be avoided. For this reason, the production method of the present invention is suitable for industrial production of organopolysiloxane resin, and is particularly suitable for industrial production of methylpolysiloxane resin. The manufacturing method of the present invention can be applied to both a batch method and a continuous method.
[0017]
【Example】
Hereinafter, the present invention will be specifically described with reference to examples. In the examples, the hydrogen chloride concentration of the saturated aqueous hydrogen chloride solution is 36% by weight. The acid value is the number of moles of KOH required for neutralization with respect to the resin solution per unit weight, and the acid concentration is a value obtained by measuring the amount of hydrogen chloride in the reaction system.
[0018]
Embodiment 1
12. A 1-liter four-necked flask equipped with a stirrer, a thermometer, a condenser tube, and a dropping funnel was charged with 159 g of methyltrichlorosilane, 24 g of dimethyldichlorosilane, and 109 g of toluene. A mixture of 7 g and 192 g of toluene was added dropwise. After completion of the dropwise addition, the mixture was stirred for 10 minutes, and 27.4 g of a saturated aqueous hydrogen chloride solution was further added dropwise and stirred for 10 minutes. At this time, the ratio of the total gram equivalent of water and isopropyl alcohol in the saturated aqueous hydrogen chloride solution to the total gram equivalent of chlorosilane was 1.2. Next, the mixture was heated to 75 ° C. while bubbling with nitrogen gas at a flow rate of 0.3 L / min to remove hydrogen chloride. This reduced the acid value of the reaction system from 4.72 mol / kg to 0.19 mol / kg. Next, 300 g of toluene was added, the temperature was raised again to 75 ° C., 12.3 g of water was added dropwise, and the mixture was heated and refluxed for 30 minutes. After heating under reflux, the mixture was heated under normal pressure to distill 195 g of a low-boiling component. Next, the mixture was heated under normal pressure while bubbling with a nitrogen gas at a flow rate of 0.3 L / min, and 363 g of a low boiling point was distilled off to obtain a reaction product. Its acid concentration was 29 ppm, and its nonvolatile content was 49.9% by weight.
The appearance of the toluene solution of the organopolysiloxane resin thus obtained was visually measured, and no generation of a gel-like substance or a precipitate was observed. Using a filter [filtration accuracy of 0.9 to 4 µ], 180 g of this toluene solution was applied at 1 kg / cm 2 with nitrogen.²When filtration was performed under a pressure of, the filtration of the entire amount was completed in 3 minutes. Also,²⁹According to Si-NMR analysis, this organopolysiloxane resin was CH 4₃SiO_3/285.1 mol% of a unit and (CH₃)₂SiO_2/2It was found to be a methylpolysiloxane resin consisting of 14.9 mol% of units. further^ThirteenAccording to C-NMR analysis, the ratio of the integrated value of the silicon atom converted from the silicon-bonded methyl group to the integrated value of the carbon atom adjacent to the oxygen atom in the silicon-bonded isopropoxy group was 1: 0.061. Since the residual amount of silanol groups in the Fourier transform infrared spectrophotometric analysis (hereinafter referred to as FT-IR analysis) was 0.65% by weight of the resin solids, this methylpolysiloxane resin contained a small amount of isopropoxy group. And a silanol group. The resulting methylpolysiloxane resin was solid at room temperature, had a weight average molecular weight of 3,727, a molecular weight distribution of 3.57, and a yield of 99% by GPC analysis.
[0019]
Embodiment 2
82 g of isopropyl alcohol, 13.7 g of a saturated aqueous hydrogen chloride solution and 192 g of toluene were charged into a 1-liter four-necked flask equipped with a stirrer, a thermometer, a condenser tube and a dropping funnel. A mixture of 26 g and 109 g of toluene was added dropwise while cooling so that the reaction temperature did not exceed 40 ° C. After completion of the dropwise addition, the mixture was stirred for 10 minutes, and then 27.4 g of a saturated aqueous hydrogen chloride solution was further added dropwise and stirred for 10 minutes. At this time, the ratio of the total gram equivalent of water and isopropyl alcohol in the saturated aqueous hydrogen chloride solution to the total gram equivalent of chlorosilane was 1.1. Next, the mixture was heated to 72 ° C. while bubbling with a nitrogen gas at a flow rate of 0.3 L / min to remove hydrogen chloride. This reduced the acid value from 4.84 mol / kg to 0.3 mol / kg. Next, 300 g of toluene was added, the temperature was raised again to 75 ° C., a mixture of 10.8 g of water and 2.3 g of a saturated aqueous hydrogen chloride solution was added dropwise, and the mixture was heated under reflux for 30 minutes. After heating under reflux, the mixture was heated under normal pressure to distill 218 g of a low-boiling component (first fraction). Then, while bubbling with a nitrogen gas at a flow rate of 0.3 L / min, the mixture was heated under normal pressure to further distill out 350 g of a low-boiling component (second fraction) to obtain a reaction product. Its acid concentration was 32 ppm, and its nonvolatile content was 50.2% by weight. The fraction obtained here was found to be composed of the following components by gas chromatography, coulometric titration and neutralization titration.
[Table 2]

The appearance of the toluene solution of the organopolysiloxane resin thus obtained was visually measured, and no generation of a gel-like substance or a precipitate was observed. Using a filter [filtration accuracy of 0.9 to 4 µ], 180 g of this toluene solution was applied at 1 kg / cm 2 with nitrogen.²Filtration was performed under a pressure of 1. The filtration was completed in 1 minute. Also,²⁹According to Si-NMR analysis, this organopolysiloxane resin was CH 4₃SiO_3/284.9 mol% of a unit and (CH₃)₂SiO_2/2It was found to be a methylpolysiloxane resin consisting of 15.1 mol% of units. further^ThirteenAccording to C-NMR analysis, the ratio of the integrated value of the silicon atom converted from the silicon-bonded methyl group to the integrated value of the carbon atom adjacent to the oxygen atom in the silicon-bonded isopropoxy group was 1: 0.069. In addition, since the residual amount of the silanol group by the FT-IR analysis was 0.70% by weight of the resin solid, it was found that this methylpolysiloxane resin contained a small amount of isopropoxy group and silanol group. The obtained methylpolysiloxane resin was solid at room temperature, had a weight average molecular weight of 3,217, a molecular weight distribution of 3.24, and a yield of 92% by GPC analysis.
[0020]
Embodiment 3
Isopropyl alcohol and water were added to 218 g of the first fraction recovered in Example 2 to adjust the isopropyl alcohol to 82 g and the water content to 8.8 g, and then the stirrer, the thermometer, the cooling pipe, and the dropper were added. The whole amount was charged into a 1-liter four-necked flask equipped with a funnel. Next, a mixture of 174 g of methyltrichlorosilane, 26 g of dimethyldichlorosilane and 109 g of toluene was added dropwise thereto while cooling so that the reaction temperature did not exceed 40 ° C. After completion of the dropwise addition, the mixture was stirred for 10 minutes, and then 27.4 g of a saturated aqueous hydrogen chloride solution was further added dropwise and stirred for 10 minutes. At this time, the ratio of the total gram equivalent of water and isopropyl alcohol in the saturated aqueous hydrogen chloride solution to the total gram equivalent of chlorosilane was 1.1. Next, the mixture was heated to 77 ° C. while bubbling with nitrogen gas at a flow rate of 0.3 L / min to remove hydrogen chloride. This reduced the acid value from 4.56 mol / kg to 0.18 mol / kg. Next, 300 g of the second fraction collected in Example 2 was added, the temperature was raised to 75 ° C., 12.3 g of water was added dropwise, and the mixture was heated and refluxed for 30 minutes. After heating under reflux, the mixture was heated under normal pressure to distill 208 g of a low-boiling component. Next, while performing bubbling with nitrogen gas at a flow rate of 0.3 L / min, the mixture was heated under normal pressure to distill out 358 g of a low-boiling component to obtain a reaction product. Its acid concentration was 25 ppm and its nonvolatile content was 50.1% by weight.
The appearance of the toluene solution of the organopolysiloxane resin thus obtained was visually measured, and no generation of a gel-like substance or a precipitate was observed. Using a filter [filtration accuracy of 0.9 to 4 µ], 180 g of this toluene solution was applied at 1 kg / cm 2 with nitrogen.²Filtration was performed under a pressure of 1. The filtration was completed in 1 minute. Also,²⁹According to Si-NMR analysis, this organopolysiloxane resin was CH 4₃SiO_3/284.7 mol% of a unit and (CH₃)₂SiO_2/2It turned out to be a methylpolysiloxane resin consisting of 15.3 mol% of units. further^ThirteenAccording to C-NMR analysis, the ratio of the integrated value of the silicon atom converted from the silicon-bonded methyl group to the integrated value of the carbon atom adjacent to the oxygen atom in the silicon-bonded isopropoxy group was 1: 0.060. In addition, since the residual amount of the silanol group by the FT-IR analysis was 0.66% by weight of the resin solid, it was found that this methylpolysiloxane resin contained a small amount of isopropoxy group and silanol group. The obtained methylpolysiloxane resin was solid at room temperature, had a weight average molecular weight determined by GPC analysis of 2905, a molecular weight distribution of 2.95, and a yield of 95%.
[0021]
[Comparative Example 1]
82 g of isopropyl alcohol, 8.8 g of water and 192 g of toluene were charged into a 1-liter four-necked flask equipped with a stirrer, a thermometer, a condenser tube and a dropping funnel, and then 174 g of methyltrichlorosilane, 26 g of dimethyldichlorosilane and 109 g of the mixture were added dropwise with cooling so that the reaction temperature did not exceed 40 ° C. After completion of the dropwise addition, the mixture was stirred for 10 minutes, and then 17.5 g of water was further added dropwise and stirred for 10 minutes. At this time, the ratio of the total gram equivalent of water and isopropyl alcohol to the total gram equivalent of chlorosilane was 1.1. Next, the mixture was heated to 71 ° C. while bubbling with nitrogen gas at a flow rate of 0.3 L / min to remove hydrogen chloride. This reduced the acid value from 4.77 mol / kg to 0.3 mol / kg. Next, 300 g of toluene was added, the temperature was raised again to 75 ° C., 12.3 g of water was added dropwise, and the mixture was heated and refluxed for 30 minutes. After heating under reflux, the mixture was heated under normal pressure to distill 195 g of a low-boiling component. Next, the mixture was heated under normal pressure while bubbling with a nitrogen gas at a flow rate of 0.3 L / min to distill out 220 g of a low boiling point. Further, while bubbling with a nitrogen gas at a flow rate of 0.3 L / min, the mixture was heated under normal pressure to distill out 350 g of a low boiling point to obtain a reaction product. Its acid concentration was 32 ppm and its non-volatile content was 50% by weight.
The appearance of the toluene solution of the organopolysiloxane resin thus obtained was visually measured, and a microcrystalline precipitate was observed. Using a filter [filtration accuracy of 0.9 to 4 µ], 180 g of this toluene solution was applied at 1 kg / cm 2 with nitrogen.²Filtration under a pressure of 5% did not complete after 60 minutes. Also,²⁹According to Si-NMR analysis, this organopolysiloxane resin was CH 4₃SiO_3/2Unit (85 mol%) and (CH₃)₂SiO_2/2It turned out to be a methylpolysiloxane resin consisting of 15 mol% of units. further^ThirteenAccording to C-NMR analysis, the ratio of the integrated value of the silicon atom converted from the silicon-bonded methyl group to the integrated value of the carbon atom adjacent to the oxygen atom in the silicon-bonded isopropoxy group was 1: 0.060. In addition, since the residual amount of silanol groups was 0.55% by weight of the resin solids by FT-IR analysis, it was found that this methylpolysiloxane resin contained small amounts of isopropoxy groups and silanol groups. The obtained methylpolysiloxane resin was solid at room temperature, had a weight average molecular weight of 4531, a molecular weight distribution of 3.76, and a yield of 70% by GPC analysis.
[0022]
[Comparative Example 2]
70 g of isopropyl alcohol, 134 g of water and 211 g of toluene were charged into a 1-liter four-necked flask equipped with a stirrer, a thermometer, a cooling tube and a dropping funnel. The mixture was added dropwise while cooling so that the reaction temperature did not exceed 40 ° C. After completion of the dropwise addition, the mixture was stirred at room temperature for 1 hour, heated to 80 ° C., and heated under reflux for 30 minutes. After cooling, washing was repeated 5 times or more using warm water until the aqueous layer became neutral. Then, the mixture was heated under normal pressure to remove low-boiling components until the nonvolatile content became 50% by weight, thereby obtaining a toluene solution of an organopolysiloxane resin.
When the appearance of the toluene solution thus obtained was visually measured, a microcrystalline precipitate was observed. Using a filter [filtration accuracy of 0.9 to 4 µ], 180 g of this toluene solution was applied at 1 kg / cm 2 with nitrogen.²Filtration under a pressure of 5% did not complete after 60 minutes. Also,²⁹According to Si-NMR analysis, this organopolysiloxane resin was CH 4₃SiO_3/2Unit (84 mol%) and (CH₃)₂SiO_2/2It turned out to be a methylpolysiloxane resin consisting of 16 mol% of units. further^ThirteenAccording to C-NMR analysis, the ratio of the integrated value of the silicon atom converted from the silicon-bonded methyl group to the integrated value of the carbon atom adjacent to the oxygen atom in the silicon-bonded isopropoxy group was 1: 0.015. In addition, since the residual amount of silanol groups was 0.29% by weight of the resin solids by FT-IR analysis, it was found that this methylpolysiloxane resin contained small amounts of isopropoxy groups and silanol groups. The resulting methylpolysiloxane resin was solid at room temperature, had a weight average molecular weight determined by GPC analysis of 7,830, a molecular weight distribution of 6.11, and a yield of 54%.
[0023]
[Table 3]

[0024]
【The invention's effect】
According to the production method of the present invention, since the generation of a gel-like substance and a microcrystalline precipitate is extremely small, filtration can be performed in a very short time. Therefore, an organopolysiloxane resin can be produced with high yield and high productivity. In addition, the water washing operation can be substantially omitted, and the unreacted raw materials and by-products after the reaction can be reused, so that they have a low environmental impact and are inexpensive, and are suitable for industrial production of organopolysiloxane resins. It has the feature.

Claims (10)

Step (1): (A) including a silane represented by the general formula: R ¹ SiX ₃ (wherein R ¹ is a non-hydrolyzable monovalent organic group and X is a hydrolyzable group). One or more kinds of hydrolyzable silanes or (B) a mixture of the silane and the hydrolyzable siloxane are represented by (C) a general formula: R ² OH (wherein R ² is a group having 1 to 8 carbon atoms) (D) a step of hydrolyzing with an aqueous hydrogen chloride solution in the presence of an alcohol represented by the following formula: [In this step, the gram equivalent of the component (A) or the component (B), The ratio of the total gram equivalent of water in the component (D) to the component (C) is 0.9 to 2.0, and the ratio of the gram equivalent of only water in the component (D) is 0.3 to 2.0. 0.95. ],
Step (2): a step of removing hydrogen chloride by heating,
Step (3): a step of adding water or an aqueous solution of hydrogen chloride to carry out a hydrolytic condensation reaction;
Step (4): removing a mixture containing alcohol and hydrogen chloride by heating;
(E) an organopoly containing a siloxane unit represented by an average composition formula: R ³ _a SiO _{(4-a) / 2} and represented by a formula: R ³ SiO _3/2 A method for producing a siloxane resin (wherein R ³ is a monovalent organic group and 0 <a <3). The method for producing an organopolysiloxane resin according to claim 1, wherein the hydrolyzable group X is one or more halogen atoms. In the step (1), the component (D) is mixed with the component (A) or the component (B) in two portions, and the total amount of the component (C) is used together with the first mixing of the component (D). The method for producing an organopolysiloxane resin according to claim 1, wherein: The method for producing an organopolysiloxane resin according to claim 1, wherein in the step (1), the hydrogen chloride concentration of the component (D) is more than 20% by weight. The method for producing an organopolysiloxane resin according to claim 1, wherein step (1) is performed in the presence of (F) an inert organic solvent. The method for producing an organopolysiloxane resin according to claim 1, wherein the acid concentration is reduced to 1/10 or less by the step (2). The method for producing an organopolysiloxane resin according to claim 1, wherein an inert organic solvent is added before removing the hydrogen chloride in the step (2) and before the step (3). The method for producing an organopolysiloxane resin according to claim 1, wherein the acid concentration is reduced to 300 ppm or less in the step (4). The method for producing an organopolysiloxane resin according to claim 1, wherein the mixture containing the alcohol and hydrogen chloride removed in the step (4) is reused in the step (1). Component (A), the general ^formula: R 1 SiX ₃ with a silane and the general formula ^shown: silane (wherein represented by ^{_R 1} ₂ SiX 2, _R 1 is a non-hydrolysable monovalent organic group, X . is a hydrolyzable group) is a mixture of organopolysiloxane resin has the ^formula: siloxane units of the formula R _{3 SiO ^3/2:} siloxane units (represented by the formula _R 3 _{2 SiO 2/2} Wherein R ³ is a monovalent organic group.) The production method according to any one of claims 1 to 9, wherein