JP3945398B2 - Solvent-type silicone composition for release paper - Google Patents

Description

（式中、Ｒ¹はビニル基、Ｒ²は脂肪族不飽和結合を含有しない一価有機基を示し、Ｘは以下の式で示される基である。）
【化５】

（式中、ａ、ｂ、ｃ、ｄ、ｅは、該オルガノポリシロキサンの３０重量％トルエン溶液の２５℃での粘度が１．５〜７０Ｐａ・ｓを満たし、重合度ａ＋ｂ＋ｃ×（ｄ＋ｅ＋１）＋２が３，０００〜２０，０００の範囲を満たす正数から選ばれ、ｂ、ｃ、ｄ、ｅは０であってもよい。）
（Ｂ）下記一般式（２）で示される、１分子中に少なくとも１個のビニル基をもつオルガノポリシロキサン１０〜７０重量部、
【化６】

（式中、Ｒ¹はビニル基、Ｒ³はＲ²と同じか又はＲ¹と同じ基であり、ｆとｇは該オルガノポリシロキサンの２５℃での粘度が０．１〜５００Ｐａ・ｓを満たし、ビニル基含有量が、該オルガノポリシロキサン１００ｇ当たり０．００１〜０．１モルであり、かつ（Ａ）成分のビニル基含有量の０．２〜５倍のモル数の範囲に入るような正数から選ばれるが、ｆは６０〜２，０００の範囲，ｇは１〜３００の範囲である。）
（Ｃ）１分子中にケイ素原子に結合した水素原子を少なくとも３個有するオルガノハイドロジェンポリシロキサンであって、含有されるケイ素原子に結合した水素原子のモル数が、（Ａ）成分と（Ｂ）成分に含まれるビニル基の合計モル数の１〜５倍に相当する量、
（Ｄ）触媒量の白金族金属系触媒、
（Ｅ）任意量の有機溶剤
を必須成分とするものである。
【００１０】
ここで、本発明のシリコーン組成物を構成する（Ａ）成分のオルガノポリシロキサンは、上記一般式（１）で示される構造を有し、１分子中に少なくとも２個のアルケニル基をもつ高重合度のものである。このＲ¹は、ビニル基、アリル基、プロペニル基などの好ましくは炭素数２〜６のアルケニル基、Ｒ²は炭素数１〜１２、特に１〜８のものが好ましく、メチル基、エチル基、プロピル基、ブチル基などのアルキル基、シクロヘキシル基などのシクロアルキル基、フェニル基、トリル基などのアリール基あるいはこれらの基の炭素原子に結合した水素原子の一部又は全部をハロゲン原子、シアノ基などで置換したクロロメチル基、トリフルオロプロピル基、シアノエチル基などのような非置換又は置換１価炭化水素基、更にはメトキシ基、エトキシ基、プロポキシ基、メトキシエトキシ基などのアルコキシ基、水酸基、エポキシ基などから選択される有機基であるが、脂肪族不飽和結合は含有しない。Ｒ¹はビニル基が工業的に好ましく、（Ａ）成分のオルガノポリシロキサン全体に含まれるＲ²はその少なくとも８０％がメチル基であることが製造上及び特性上好ましい。
【００１１】
（Ａ）成分のオルガノポリシロキサンの１分子がもつアルケニル基は２個以上であるが、２個未満では硬化後も未架橋分子が残る可能性が高く、キュアー性の低下となるため望ましくない。望ましくは、オルガノポリシロキサン１００ｇ当たりの含有量としては０．００１〜０．１モルであり、０．００１モル未満ではキュアー性が低下し、０．１モルを超えるとポットライフが短くなり、取り扱いが難しくなる場合が生じる。相当する式（１）及び置換基Ｘのａ、ｂ、ｃ、ｄ、ｅとしては、１分子がもつアルケニル基の数ｂ＋ｃ×ｅが２〜１，５００の範囲になるように選ばれる。
【００１２】
（Ａ）成分のオルガノポリシロキサンの３０重量％トルエン溶液での２５℃における粘度の範囲は、１．５〜７０Ｐａ・ｓであり、粘度が１．５Ｐａ・ｓ未満では密着性の向上効果が得られ難く、７０Ｐａ・ｓを超えると作業性が低下する。望ましくは、粘度が３０Ｐａ・ｓ以上である。相当する式（１）及び置換基Ｘのａ、ｂ、ｃ、ｄ、ｅとしては、重合度ａ＋ｂ＋ｃ×（ｄ＋ｅ＋１）＋２が３，０００〜２０，０００の範囲になるように選ばれる。
【００１３】
（Ａ）成分のオルガノポリシロキサンの主骨格構造は直鎖であるが、ｃが０でない場合で示されるように分岐鎖構造を含むものも使用できる。
【００１４】
一方、本発明のシリコーン組成物を構成する（Ｂ）成分のオルガノポリシロキサンは、一般式（２）で示される、１分子中に少なくとも１個のアルケニル基をもつ低重合度のオルガノポリシロキサンであり、（Ａ）成分１００重量部に対して１０〜７０重量部、好ましくは１０〜２５重量部が使用される。
【００１５】
【化７】

【００１６】
式中、Ｒ¹はアルケニル基、Ｒ³はＲ¹又はＲ²と同じ基から選ばれる。ｆとｇはオルガノポリシロキサンの２５℃での粘度が０．１〜５００Ｐａ・ｓを満たす正数から選ばれ、好ましくは相当するｆは６０〜２，０００、ｇは１〜３００の範囲である。粘度が０．１Ｐａ・ｓ未満では塗工性が悪化し、５００Ｐａ・ｓを超えると密着性の向上が見られなくなる。望ましくは０．２〜２００Ｐａ・ｓ、更に望ましくは０．５〜１００Ｐａ・ｓの範囲である。
【００１７】
このように低重合度と高重合度のオルガノポリシロキサンを適度に組み合わせて使用することにより、丈夫で伸び易い皮膜が形成され、機械強度が向上する。
このような皮膜は、外力が加えられ、内部応力が発生しても、適度に歪んで応力を緩和し、皮膜の破壊から脱落に至ることを防ぐと考えられる。
【００１８】
もう一つの効果は、ポットライフを向上させるものであるが、触媒を添加した後の時間経過によっても密着性は変わることなく良好に保たれる。低重合度と高重合度のオルガノポリシロキサンを適度に組み合わせて使用することで、時間経過による架橋剤の性能低下を抑制するものと考えられる。
【００１９】
低重合度オルガノポリシロキサンである（Ｂ）成分が１０重量部未満では、密着性を向上させる効果が十分ではなく、７０重量部を超えて配合しても効果は得られなくなるばかりか、剥離力が大きくなるなど、剥離特性の変化が大きくなってしまう。これは皮膜が硬くなり、脆くなるためではないかと考えられる。望ましくは１０〜２５重量部、特に１５〜２５重量部であり、この範囲であれば塗工性も良好に維持することができる。
【００２０】
一般式（２）のｇが１以上でなければならないのは、（Ｂ）成分のオルガノポリシロキサンは側鎖の位置にアルケニル基をもっている必要があるからである。
分子鎖末端にのみアルケニル基をもっている場合でも密着性は向上するが、得られる効果は小さくなってしまう。側鎖に位置するアルケニル基の方が末端よりも付加反応が遅いことが知られているが、このために硬化が進む皮膜中に捕えられずに基材との界面付近に集まりやすくなり、より有効に作用するのではないかと推測される。
【００２１】
このような皮膜中での偏在化に影響する要素として、（Ｂ）成分が低重合度であることも有利に働いていると考えられるが、（Ｂ）成分が有するアルケニル基の個数も重要である。アルケニル基が少ない方が偏在化をより促進できると考えられるが、キュアー性が低下してしまうため、アルケニル基の個数は分子当たり１個が下限である。逆に多すぎると皮膜中に捕えられやすく剥離特性の変化が大きくなるため、（Ｂ）成分のアルケニル基含有量は、（Ａ）成分のアルケニル基含有量の０．２〜５倍、特に０．５〜３倍のモル数の範囲に入るように選ばれる。
望ましいアルケニル基含有量は、オルガノポリシロキサン１００ｇ当たりの含有量として０．００１〜０．１モルであり、特には０．００２〜０．０９モルである。０．００１モル未満ではキュアー性が低く、０．１モルを超えるとポットライフが短くなり、取り扱いが難しくなる。
【００２２】
本発明の（Ｃ）成分として用いることのできるオルガノハイドロジェンポリシロキサンは、下記平均組成式
Ｒ² _hＨ_iＳｉＯ_(4-h-i)/2
（式中、Ｒ²は上記と同様の意味を示し、ｈは０〜３、ｉは０〜３で、ｈ＋ｉは１〜３の実数である。）
で示され、１分子中にケイ素原子に直接結合する水素原子（Ｓｉ−Ｈ基）を少なくとも３個有することが必要である他は特に限定されず、分子構造は直鎖状、分岐鎖状もしくは環状のいずれであってもよい。粘度も数ｍＰａ・ｓ〜数万ｍＰａ・ｓの範囲であればよい。オルガノハイドロジェンポリシロキサンの具体例として、下記のオルガノポリシロキサンを挙げることができる。
【００２３】
【化８】

【００２４】
但し、上記構造式及び組成式において、Ｍｅはメチル基、ＹとＺは以下の構造式で示される基である。
【００２５】
【化９】

【００２６】
また、ｘ１、ｘ５、ｘ７は３〜５００、ｘ６、ｘ９、ｘ１２は１〜５００、ｘ２、ｘ３、ｘ４、ｘ８、ｘ１０、ｘ１１、ｘ１３、ｘ１４、ｘ１５、ｘ１６は０〜５００の範囲の整数である。
【００２７】
上記（Ｃ）成分のオルガノハイドロジェンポリシロキサン配合量は、含有されるケイ素原子に結合した水素原子（Ｓｉ−Ｈ基）のモル数が、（Ａ）成分と（Ｂ）成分に含まれるアルケニル基の合計モル数の１〜５倍に相当する量である。（Ｃ）成分の配合量に含有されるＳｉ−Ｈ基のモル数が（Ａ）成分と（Ｂ）成分に含まれるアルケニル基の合計モル数の下限未満では硬化性が不充分となる一方、上記上限を超えて配合しても効果の顕著な増加は見られず、かえって経時変化の原因となるうえ、経済的にも不利となる。一般的なオルガノハイドロジェンポリシロキサンでの配合重量部としては、（Ａ）成分のポリオルガノシロキサン１００重量部に対して０．１〜２０重量部の範囲である。
【００２８】
本発明の組成物に使用する（Ｄ）成分としての触媒は、（Ａ）成分及び（Ｂ）成分と（Ｃ）成分のいわゆる架橋反応（付加反応）を促進し、硬化被膜を形成するために用いられる。かかる付加反応用触媒としては、たとえば、白金黒、塩化白金酸、塩化白金酸−オレフィンコンプレックス、塩化白金酸−アルコール配位化合物、ロジウム、ロジウム−オレフィンコンプレックス等の白金族金属系触媒が挙げられる。上記付加反応用触媒は、（Ａ）成分及び（Ｂ）成分としてのポリオルガノシロキサン、（Ｃ）成分としてのオルガノハイドロジェンポリシロキサンの合計重量に対し、白金の量又はロジウムの量として５〜１，０００ｐｐｍ（重量比）配合することが、充分な硬化被膜を形成する上で好ましいが、前記成分の反応性又は所望の硬化速度に応じて適宜増減させることができる。
【００２９】
本発明の組成物に使用する（Ｅ）成分としての有機溶剤は、処理浴安定性及び各種基材に対する塗工性の向上、塗工量及び粘度の調整を目的としている。たとえばトルエン、キシレン、酢酸エチル、アセトン、メチルエチルケトン、ヘキサン等の、組成物を均一に溶解できる有機溶剤が使用できる。なお、塗布性等の点から（Ａ）〜（Ｄ）成分の合計濃度が０．１〜３０重量％になるように有機溶剤を使用することが好ましい。
【００３０】
本発明の組成物は、前記（Ａ）、（Ｂ）、（Ｃ）、（Ｄ）、（Ｅ）の各成分を均一に混合することにより容易に製造することができるが、十分なポットライフを確保するため、（Ｄ）成分はコーティングをする直前に添加混合すべきである。また、有機溶剤を使用する場合は、（Ａ）成分及び（Ｂ）成分を（Ｅ）成分に均一に溶解した後、（Ｃ）、（Ｄ）成分を混合するのが有利である。
【００３１】
なお、本発明の組成物には、必要に応じて顔料、レベリング剤、バスライフ延長剤等の添加剤を配合することもできる。
【００３２】
本発明の組成物を使用して塗工する場合には、本発明の組成物を直接又は適当な有機溶剤で希釈した後、バーコーター、ロールコーター、リバースコーター、グラビアコーター、エアナイフコーター、更に薄膜の塗工には高精度のオフセットコーター、多段ロールコーター等の公知の塗布方法により、紙等の基材に塗布する。
【００３３】
本発明の組成物の基材への塗布量は塗布すべき基材の材質の種類によっても異なるが、固形分の量として０．１〜５０ｇ／ｍ²の範囲が好ましい。上記のようにして本発明の組成物を塗布した基材を８０〜１８０℃で６０〜５秒間加熱することにより基材表面に硬化被膜を形成せしめ、所望の合成樹脂シート製造に適した特性を有する塗工シートを得ることができる。
【００３４】
【実施例】
以下、実施例によって本発明を更に詳述するが、本発明はこれによって限定されるものではない。
【００３５】
［実施例１］
（Ａ）成分として、３０％トルエン溶液の２５℃での粘度が４０Ｐａ・ｓであり、分子鎖の両末端はジメチルビニルシリル基で封鎖され、主骨格はメチルビニルシロキサン単位が０．７モル％でジメチルシロキサン単位が９９．３モル％で構成されているポリオルガノシロキサン（ビニル基含有量＝０．０１モル／１００ｇ）を１００重量部、（Ｂ）成分として、２５℃での粘度が３０Ｐａ・ｓであり、分子鎖の両末端はトリメチルシリル基で封鎖され、主骨格はメチルビニルシロキサン単位が１．５モル％でジメチルシロキサン単位が９８．５モル％で構成されているポリオルガノシロキサン（ビニル基含有量＝０．０２モル／１００ｇ）を２５重量部、（Ｅ）成分としてトルエン２，３７５重量部をフラスコに取り、２０〜４０℃で撹拌溶解した。
【００３６】
得られた溶液に、（Ｃ）成分として、分子鎖両末端がトリメチルシリル基で封鎖され、ＭｅＨＳｉＯ_2/2で表されるメチルハイドロジェンシロキサン単位を９５モル％含有し、粘度が２５ｍＰａ・ｓであるメチルハイドロジェンポリシロキサン（Ｓｉ−Ｈ基含有量＝１．５モル／１００ｇ）を３重量部（ケイ素に直結した水素基モル数が（Ａ）成分と（Ｂ）成分の含有するビニル基に対し３倍に相当）、バスライフ延長剤として、３−メチル−１−ブチン−３−オールを１重量部加え、２０〜４０℃で１時間撹拌混合した。基材に塗工する直前に、（Ｄ）成分として、白金とビニルシロキサンとの錯塩を白金換算量１００ｐｐｍ添加して、組成物を調製した。
【００３７】
調製した組成物を２５℃，湿度６０％において開放状態で３０分放置した後、メイヤーバーを用いてグラシン紙へ均一に塗工し、所定条件にてキュアーして、塗工量が１．０ｇ／ｍ²の経時初期の評価用試料を作成した。調製した組成物を２５℃，湿度６０％において開放状態で８時間放置した後、同様に塗工、キュアーして、塗工量が１．０ｇ／ｍ²の経時８時間後の評価用試料を作成した。評価は下記の硬化皮膜特性の評価方法の記載に従って行った。その結果を表１に示す。
【００３８】
［実施例２］
実施例１において、（Ｂ）成分を７０重量部、（Ｃ）成分を４．５重量部（ケイ素に直結した水素基モル数が（Ａ）成分と（Ｂ）成分の含有するビニル基に対し３倍に相当）とした以外は同様に組成物を調製し、評価用試料を作成した。評価は下記の硬化皮膜特性の評価方法の記載に従って行い、その結果を表１に示した。
【００３９】
［実施例３］
実施例１において、（Ｂ）成分として、２５℃での粘度が０．５Ｐａ・ｓであり、分子鎖の両末端はジメチルビニルシリル基で封鎖され、主骨格はメチルビニルシロキサン単位が０．７モル％でジメチルシロキサン単位が９９．３モル％で構成されているポリオルガノシロキサン（ビニル基含有量＝０．０２モル／１００ｇ）を２５重量部とした以外は同様に組成物を調製し、評価用試料を作成した。評価は下記の硬化皮膜特性の評価方法の記載に従って行い、その結果を表１に示した。
【００４０】
［比較例１］
実施例１において、（Ｂ）成分を９重量部、（Ｃ）成分を２．４重量部（ケイ素に直結した水素基モル数が（Ａ）成分と（Ｂ）成分の含有するビニル基に対し３倍に相当）とした以外は同様に実施して組成物を調製し、評価用試料を作成した。評価は下記の硬化皮膜特性の評価方法の記載に従って行い、その結果を表１に示した。
【００４１】
［比較例２］
実施例１において、（Ｂ）成分を８０重量部、（Ｃ）成分を５重量部（ケイ素に直結した水素基モル数が（Ａ）成分と（Ｂ）成分の含有するビニル基に対し３倍に相当）とした以外は同様に組成物を調製し、評価用試料を作成した。評価は下記の硬化皮膜特性の評価方法の記載に従って行い、その結果を表１に示した。
【００４２】
［比較例３］
実施例１において、（Ｂ）成分として、２５℃での粘度が１Ｐａ・ｓであり、分子鎖の両末端はジメチルビニルシリル基で封鎖され、主骨格はジメチルシロキサン単位のみで構成されているポリオルガノシロキサン（ビニル基含有量＝０．０１モル／１００ｇ）を２５重量部、（Ｃ）成分を２．５重量部（ケイ素に直結した水素基モル数が（Ａ）成分と（Ｂ）成分の含有するビニル基に対し３倍に相当）とした以外は同様に組成物を調製し、評価用試料を作成した。評価は下記の硬化皮膜特性の評価方法の記載に従って行い、その結果を表１に示した。
【００４３】
［比較例４］
実施例１において、（Ｂ）成分として、２５℃での粘度が８０ｍＰａ・ｓであり、分子鎖の両末端はトリメチルシリル基で封鎖され、主骨格はメチルビニルシロキサン単位が２モル％でジメチルシロキサン単位が９８モル％で構成されているポリオルガノシロキサン（ビニル基含有量＝０．０３モル／１００ｇ）を２５重量部、（Ｃ）成分を３．５重量部（ケイ素に直結した水素基モル数が（Ａ）成分と（Ｂ）成分の含有するビニル基に対し３倍に相当）とした以外は同様に組成物を調製し、評価用試料を作成した。評価は下記の硬化皮膜特性の評価方法の記載に従って行い、その結果を表１に示した。
【００４４】
［比較例５］
実施例１において、（Ｂ）成分として、２５℃での粘度が６００Ｐａ・ｓであり、分子鎖の両末端はトリメチルシリル基で封鎖され、主骨格はメチルビニルシロキサン単位が１．５モル％でジメチルシロキサン単位が９８．５モル％で構成されているポリオルガノシロキサン（ビニル基含有量＝０．０２モル／１００ｇ）を２５重量部、（Ｃ）成分を３重量部（ケイ素に直結した水素基モル数が（Ａ）成分と（Ｂ）成分の含有するビニル基に対し３倍に相当）とした以外は同様に組成物を調製し、評価用試料を作成した。評価は下記の硬化皮膜特性の評価方法の記載に従って行い、その結果を表１に示した。
【００４５】
［比較例６］
実施例１において、（Ｂ）成分として、２５℃での粘度が３０Ｐａ・ｓであり、分子鎖の両末端はトリメチルシリル基で封鎖され、主骨格はメチルビニルシロキサン単位が０．１モル％でジメチルシロキサン単位が９９．９モル％で構成されているポリオルガノシロキサン（ビニル基含有量＝０．００１モル／１００ｇ）を２５重量部、（Ｃ）成分を２重量部（ケイ素に直結した水素基モル数が（Ａ）成分と（Ｂ）成分の含有するビニル基に対し３倍に相当）とした以外は同様に組成物を調製し、評価用試料を作成した。評価は下記の硬化皮膜特性の評価方法の記載に従って行い、その結果を表１に示した。
【００４６】
［比較例７］
実施例１において、（Ｂ）成分として、２５℃での粘度が３０Ｐａ・ｓであり、分子鎖の両末端はトリメチルシリル基で封鎖され、主骨格はメチルビニルシロキサン単位が５モル％でジメチルシロキサン単位が９５モル％で構成されているポリオルガノシロキサン（ビニル基含有量＝０．０７モル／１００ｇ）を２５重量部、（Ｃ）成分を５．５重量部（ケイ素に直結した水素基モル数が（Ａ）成分と（Ｂ）成分の含有するビニル基に対し３倍に相当）とした以外は同様に組成物を調製し、評価用試料を作成した。評価は下記の硬化皮膜特性の評価方法の記載に従って行い、その結果を表１に示した。
硬化皮膜特性の評価方法
（１）塗工性
経時初期の組成物を熱風循環式乾燥機で１２０℃，２０秒間加熱処理して作製した評価用試料の硬化皮膜表面状態を観察し、以下の基準で評価した。
【００４７】
○：滑らかで均一な表面
×：スジやヨリが見られる
（２）硬化性
熱風循環式乾燥機で１２０℃，２０秒間加熱処理して作製した評価用試料の硬化皮膜表面を指でこすり、皮膜表面のくもりの度合を観察し、以下の基準で評価した。
○：くもりが全くない
△：くもりがわずかに生ずる
×：濃いくもりが生ずる
（３）密着性
熱風循環式乾燥機で１２０℃，２０秒間加熱処理して作製した評価用試料を２５℃，湿度６０％で１週間放置後、硬化皮膜表面を指でこすり、皮膜表面の脱落の度合を観察し、以下の基準で評価した。
○：脱落が全くない
△：脱落がわずかに生ずる
×：容易に脱落が生ずる
（４）剥離力
経時初期の組成物を熱風循環式乾燥機で１４０℃，３０秒間加熱処理して評価用試料を作成し、その硬化皮膜表面にアクリル系溶剤型粘着剤〔オリバインＢＰＳ−５１２７（東洋インキ製造（株）製）〕を塗布して１００℃で３分間熱処理し、次いで、この処理面に坪量６４ｇ／ｍ²の上質紙を貼り合わせて２ｋｇローラーで１往復圧着し、２５℃で２０時間エージングさせた。この試料を５ｃｍ幅に切断し、引張り試験機を用いて１８０°の角度で剥離速度０．３ｍ／分で貼合わせ紙を引張り、剥離するのに要する力（Ｎ）を測定した。測定はオートグラフＤＳＣ−５００（島津製作所株式会社製）を使用した。
【００４８】
【表１】

注１ ２５℃での３０％トルエン溶液粘度
注２ Ｈ／Ｖｉ：Ｓｉ−Ｈ基／ビニル基（モル比）
【００４９】
【発明の効果】
本発明によれば、形成される皮膜の機械強度が向上することにより、剥離特性に影響を与えることなく基材との密着性に優れた硬化皮膜が得られる。また、本組成物は、経時後も良好なキュアー性を維持することから、剥離特性の再現性に優れた硬化皮膜が得られ、作業性も向上する。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a solvent-type silicone composition for release paper having excellent adhesion to a substrate.
[0002]
[Prior art]
A method for obtaining a material exhibiting peelability with respect to pressure-sensitive adhesive materials such as pressure-sensitive adhesives by forming a peelable cured film on the surface of various substrates such as paper, laminated paper, and plastic films has long been known. . A silicone composition is used as a material for forming such a peelable cured film. For example, Japanese Patent Publication No. 49-26798 and Japanese Patent Application Laid-Open No. 62-86061 disclose alkenyl group-containing organopolysiloxanes and organohydrosiloxanes. A silicone composition composed of genpolysiloxane and a platinum compound has been proposed.
[0003]
This type of silicone composition is still used as a main material because it has excellent curing properties and good pot life. However, the adhesion of the cured film to the base material is not sufficient, and the base materials that can be applied have been limited, and problems such as the need for pretreatment of the base material have been pointed out for some time.
[0004]
Recent trends in the base materials used include increasing the use of plastic film base materials that have uniform and stable quality, high smoothness, and can be made into thin films. Now that it can be used as a product, the demand for improved adhesion of silicone compositions has become stronger than before.
[0005]
Proposals for improving the adhesion have also been made from the viewpoint of silicone compositions. For example, as a method of using a material having better adhesion, attempts have been made to add an organic resin or add a silane coupling agent. However, this method limits the conditions that can be used to reduce the peelability. As a method for improving the base polymer structure of the composition, those having a branched structure containing RSiO _3/2 units are disclosed in JP-A-63-251465, JP-B-3-19267, and JP-A-9-9. No. 78032 and Japanese Patent Application Laid-Open No. 11-193366. These methods are aimed at the effect of light release and improved curability when peeled at a high speed, and as a secondary effect, only improvement in adhesion can be seen. In addition, JP 2000-169794 A and JP 2000-177058 A use a solvent-type silicone composition and a solvent-free silicone composition in combination to reduce the peeling rate dependency without improving the base polymer structure. However, the present invention does not exceed the current solvent-type silicone composition in terms of adhesion.
[0006]
[Patent Document 1]
Japanese Patent Publication No. 49-26798 [Patent Document 2]
JP-A-62-86061 [Patent Document 3]
JP 63-251465 A [Patent Document 4]
Japanese Patent Publication No. 3-19267 [Patent Document 5]
JP-A-9-78032 [Patent Document 6]
JP-A-11-193366 [Patent Document 7]
JP 2000-169794 A [Patent Document 8]
Japanese Patent Laid-Open No. 2000-177058
[Problems to be solved by the invention]
As described above, there is no appropriate method for improving the adhesion without affecting the peelability of the silicone composition.
The present invention has been made in view of the above circumstances, and can be applied to the surface of paper, laminated paper, plastic film, etc. to form a non-adhesive film having excellent adhesion to various substrate surfaces. An object of the present invention is to provide a reaction-curable solvent-type silicone composition for release paper.
[0008]
Means for Solving the Problem and Embodiment of the Invention
As a result of intensive studies to achieve the above object, the present inventor has used alkenyl group-containing organopolysiloxane having a high degree of polymerization and a low degree of polymerization in a specific ratio, more specifically, As the base siloxane, an alkenyl group-containing organopolysiloxane having a 30% toluene solution viscosity of 1.5 to 70 Pa · s and an alkenyl group-containing organopolysiloxane having a viscosity of 0.1 to 500 Pa · s are 100/10 to 100/70. When used together in a weight ratio, the cured film has excellent adhesion to the substrate by improving the mechanical strength of the film formed compared to using only an alkenyl group-containing organopolysiloxane of medium polymerization degree. It was found that can be obtained. In addition, conventional adhesion improvement methods have unavoidable effects on release characteristics, but methods that use alkenyl group-containing organopolysiloxanes with high and low polymerization levels have almost no effect on release characteristics. The treatment bath prepared from the composition in which the high polymerization degree and the low polymerization degree alkenyl group-containing organopolysiloxane are used together maintains a good curing property even after aging, Since the change in the peeling characteristics is small, it was found that a cured film excellent in reproducibility of mold release performance was obtained and the workability was improved, and the present invention was made.
[0009]
Hereinafter, the present invention will be described in more detail.
The solvent-type silicone composition for release paper of the present invention is
Shown in (A) represented by the following general formula (1), Chi also at least two vinyl groups in a molecule and a vinyl group content per organopolysiloxane 100g is 0.001 to 0.1 mol organo 100 parts by weight of polysiloxane,
[Formula 4]

(In the formula, R ¹ represents a vinyl group, R ² represents a monovalent organic group not containing an aliphatic unsaturated bond, and X represents a group represented by the following formula.)
[Chemical formula 5]

(Wherein, a, b, c, d, e are the viscosity of a 30 wt% toluene solution of the organopolysiloxane at 25 ° C. satisfying 1.5 to 70 Pa · s , and the degree of polymerization is a + b + c × (d + e + 1) +2 Is selected from positive numbers satisfying the range of 3,000 to 20,000, and b, c, d, and e may be 0.)
(B) 10 to 70 parts by weight of an organopolysiloxane represented by the following general formula (2) having at least one vinyl group in one molecule;
[Chemical 6]

(In the formula, R ¹ is a vinyl group, R ³ is the same as R ² or the same group as R ^1, and f and g have a viscosity of 0.1 to 500 Pa · s at 25 ° C. of the organopolysiloxane. So that the vinyl group content is 0.001 to 0.1 mol per 100 g of the organopolysiloxane and 0.2 to 5 times the vinyl group content of the component (A). A positive number is selected, f is in the range of 60 to 2,000, and g is in the range of 1 to 300. )
(C) an organohydrogenpolysiloxane having at least three hydrogen atoms bonded to silicon atoms in one molecule, wherein the number of moles of hydrogen atoms bonded to the silicon atoms contained is the component (A) and (B ) An amount corresponding to 1 to 5 times the total number of moles of vinyl groups contained in the component,
(D) a catalytic amount of a platinum group metal catalyst,
(E) An arbitrary amount of an organic solvent is an essential component.
[0010]
Here, the organopolysiloxane of component (A) constituting the silicone composition of the present invention has a structure represented by the above general formula (1) and has a high polymerization having at least two alkenyl groups in one molecule. Of the degree. This R ¹ is preferably an alkenyl group having 2 to 6 carbon atoms such as a vinyl group, an allyl group or a propenyl group, R ² is preferably one having 1 to 12 carbon atoms, particularly 1 to 8 carbon atoms, a methyl group, an ethyl group, Alkyl groups such as propyl group and butyl group, cycloalkyl groups such as cyclohexyl group, aryl groups such as phenyl group and tolyl group, or some or all of hydrogen atoms bonded to carbon atoms of these groups are halogen atoms, cyano groups An unsubstituted or substituted monovalent hydrocarbon group such as a chloromethyl group, a trifluoropropyl group, a cyanoethyl group, and the like, an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, and a methoxyethoxy group, a hydroxyl group, An organic group selected from epoxy groups and the like, but does not contain an aliphatic unsaturated bond. From the viewpoint of production and characteristics, R ¹ is preferably a vinyl group industrially, and at least 80% of R ² contained in the whole organopolysiloxane of component (A) is a methyl group.
[0011]
The molecule (A) of the organopolysiloxane has two or more alkenyl groups, but if it is less than two, there is a high possibility that uncrosslinked molecules remain after curing, which is not desirable because the curing property is lowered. Desirably, the content per 100 g of the organopolysiloxane is 0.001 to 0.1 mol, and if it is less than 0.001 mol, the curing property is lowered, and if it exceeds 0.1 mol, the pot life is shortened. May become difficult. The a, b, c, d, and e of the corresponding formula (1) and substituent X are selected so that the number b + c × e of alkenyl groups in one molecule is in the range of 2 to 1,500.
[0012]
The viscosity range at 25 ° C. in a 30 wt% toluene solution of the organopolysiloxane of component (A) is 1.5 to 70 Pa · s, and if the viscosity is less than 1.5 Pa · s, the effect of improving the adhesion is obtained. It is hard to be done, and when it exceeds 70 Pa · s, workability decreases. Desirably, the viscosity is 30 Pa · s or more. The a, b, c, d, and e of the corresponding formula (1) and substituent X are selected so that the polymerization degree a + b + c × (d + e + 1) +2 is in the range of 3,000 to 20,000.
[0013]
The main skeleton structure of the organopolysiloxane of component (A) is a straight chain, but those containing a branched chain structure as shown in the case where c is not 0 can also be used.
[0014]
On the other hand, the organopolysiloxane of component (B) constituting the silicone composition of the present invention is a low-polymerization degree organopolysiloxane having at least one alkenyl group per molecule represented by the general formula (2). Yes, 10 to 70 parts by weight, preferably 10 to 25 parts by weight, are used per 100 parts by weight of component (A).
[0015]
[Chemical 7]

[0016]
In the formula, R ¹ is an alkenyl group, and R ³ is selected from the same group as R ¹ or R ² . f and g are selected from positive numbers satisfying the viscosity of the organopolysiloxane at 25 ° C. of 0.1 to 500 Pa · s, preferably the corresponding f is in the range of 60 to 2,000, and g is in the range of 1 to 300. . When the viscosity is less than 0.1 Pa · s, the coating property is deteriorated, and when it exceeds 500 Pa · s, the improvement in adhesion cannot be seen. The range is desirably 0.2 to 200 Pa · s, and more desirably 0.5 to 100 Pa · s.
[0017]
Thus, by using an appropriate combination of organopolysiloxane having a low degree of polymerization and a high degree of polymerization, a strong and easily stretched film is formed, and the mechanical strength is improved.
Even if an external force is applied to such a film and an internal stress is generated, it is considered that the film is moderately distorted to relieve the stress and prevent the film from being broken down to falling off.
[0018]
Another effect is to improve the pot life, but the adhesiveness is kept good without changing with the passage of time after the addition of the catalyst. It is considered that the performance degradation of the crosslinking agent with the passage of time is suppressed by using an appropriate combination of organopolysiloxane having a low polymerization degree and a high polymerization degree.
[0019]
If the component (B), which is a low-polymerization degree organopolysiloxane, is less than 10 parts by weight, the effect of improving the adhesiveness is not sufficient. As a result, the change in the peeling characteristics becomes large. This is thought to be because the film becomes hard and brittle. Desirably, it is 10 to 25 parts by weight, particularly 15 to 25 parts by weight, and within this range, the coatability can be maintained well.
[0020]
The reason why g in the general formula (2) must be 1 or more is that the organopolysiloxane of the component (B) needs to have an alkenyl group at the side chain position.
Even when the molecular chain terminal has an alkenyl group only, the adhesion is improved, but the obtained effect is reduced. It is known that the addition reaction of the alkenyl group located in the side chain is slower than the terminal, but for this reason, the alkenyl group tends to gather near the interface with the base material without being trapped in the coating where curing proceeds. It is presumed that it works effectively.
[0021]
It is considered that the component (B) has a low degree of polymerization as an element affecting the uneven distribution in the film, but the number of alkenyl groups that the component (B) has is also important. is there. Although it is considered that uneven distribution can be promoted more when the number of alkenyl groups is smaller, the curing property is lowered, so the number of alkenyl groups is one per molecule. On the other hand, if the amount is too large, it is likely to be trapped in the film, and the change in peeling characteristics becomes large. Therefore, the alkenyl group content of the component (B) is 0.2 to 5 times the alkenyl group content of the component (A), particularly 0. .5-3 times the number of moles.
Desirable alkenyl group content is 0.001-0.1 mol as content per 100 g of organopolysiloxane, and especially 0.002-0.09 mol. If it is less than 0.001 mol, the curing property is low, and if it exceeds 0.1 mol, the pot life is shortened and handling becomes difficult.
[0022]
The organohydrogenpolysiloxane that can be used as the component (C) of the present invention has the following average composition formula R ² _h H _i SiO _{(4-hi) / 2}
(In the formula, R ² represents the same meaning as above, h is 0 to 3, i is 0 to 3, and h + i is a real number of 1 to ^3. )
The molecular structure is not particularly limited, except that it is necessary to have at least three hydrogen atoms (Si-H groups) directly bonded to silicon atoms in one molecule, and the molecular structure is linear, branched or Any of cyclic | annular form may be sufficient. The viscosity may be in the range of several mPa · s to tens of thousands mPa · s. Specific examples of the organohydrogenpolysiloxane include the following organopolysiloxanes.
[0023]
[Chemical 8]

[0024]
However, in the above structural formula and composition formula, Me is a methyl group, and Y and Z are groups represented by the following structural formula.
[0025]
[Chemical 9]

[0026]
X1, x5, and x7 are 3 to 500, x6, x9, and x12 are 1 to 500, x2, x3, x4, x8, x10, x11, x13, x14, x15, and x16 are integers in the range of 0 to 500. is there.
[0027]
The amount of the organohydrogenpolysiloxane compounded as the component (C) is such that the number of moles of hydrogen atoms (Si—H groups) bonded to the silicon atoms contained is the alkenyl group contained in the components (A) and (B). Is an amount corresponding to 1 to 5 times the total number of moles. On the other hand, if the number of moles of Si-H groups contained in the compounding amount of component (C) is less than the lower limit of the total number of moles of alkenyl groups contained in components (A) and (B), curability is insufficient. Even if it exceeds the above upper limit, a remarkable increase in the effect is not observed, which causes a change with time and is disadvantageous economically. As a compounding weight part with a general organohydrogenpolysiloxane, it is 0.1-20 weight part with respect to 100 weight part of polyorganosiloxane of (A) component.
[0028]
The catalyst as the component (D) used in the composition of the present invention promotes the so-called crosslinking reaction (addition reaction) of the component (A) and the component (B) and the component (C) to form a cured film. Used. Examples of such an addition reaction catalyst include platinum group metal catalysts such as platinum black, chloroplatinic acid, chloroplatinic acid-olefin complex, chloroplatinic acid-alcohol coordination compound, rhodium, and rhodium-olefin complex. The catalyst for addition reaction is 5 to 1 as the amount of platinum or the amount of rhodium with respect to the total weight of the polyorganosiloxane as the component (A) and the component (B) and the organohydrogenpolysiloxane as the component (C). 2,000 ppm (weight ratio) is preferable for forming a sufficient cured film, but can be appropriately increased or decreased depending on the reactivity of the components or the desired curing rate.
[0029]
The organic solvent as the component (E) used in the composition of the present invention is intended to improve treatment bath stability and coating properties on various substrates, and to adjust the coating amount and viscosity. For example, an organic solvent that can uniformly dissolve the composition, such as toluene, xylene, ethyl acetate, acetone, methyl ethyl ketone, and hexane, can be used. In addition, it is preferable to use an organic solvent so that the total density | concentration of (A)-(D) component may be 0.1-30 weight% from points, such as applicability | paintability.
[0030]
The composition of the present invention can be easily produced by uniformly mixing the components (A), (B), (C), (D), and (E), but has a sufficient pot life. In order to ensure the above, component (D) should be added and mixed immediately before coating. When an organic solvent is used, it is advantageous to mix the components (C) and (D) after the components (A) and (B) are uniformly dissolved in the component (E).
[0031]
In addition, additives, such as a pigment, a leveling agent, and a bath life extending agent, can also be mix | blended with the composition of this invention as needed.
[0032]
When coating using the composition of the present invention, the composition of the present invention is directly or diluted with a suitable organic solvent, and then coated with a bar coater, roll coater, reverse coater, gravure coater, air knife coater, and further a thin film. The coating is performed on a substrate such as paper by a known coating method such as a high-precision offset coater or a multi-stage roll coater.
[0033]
The coating amount of the base material of the compositions of the present invention varies depending on the kind of material of the substrate to be coated, the range of 0.1 to 50 g / m ² is preferred as the amount of solids. The substrate coated with the composition of the present invention as described above is heated at 80 to 180 ° C. for 60 to 5 seconds to form a cured film on the surface of the substrate, and has characteristics suitable for producing a desired synthetic resin sheet. The coating sheet which has can be obtained.
[0034]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention further in full detail, this invention is not limited by this.
[0035]
[Example 1]
As component (A), the viscosity of a 30% toluene solution at 25 ° C. is 40 Pa · s, both ends of the molecular chain are blocked with dimethylvinylsilyl groups, and the main skeleton is 0.7 mol% of methylvinylsiloxane units. And 100 parts by weight of polyorganosiloxane (vinyl group content = 0.01 mol / 100 g) composed of 99.3 mol% of dimethylsiloxane units and having a viscosity of 30 Pa · at 25 ° C. polyorganosiloxane (vinyl group) in which both ends of the molecular chain are blocked with trimethylsilyl groups and the main skeleton is composed of 1.5 mol% of methylvinylsiloxane units and 98.5 mol% of dimethylsiloxane units. 25 parts by weight of content = 0.02 mol / 100 g) and 2,375 parts by weight of toluene as the component (E) are placed in a flask and stirred at 20 to 40 ° C. It was the solution.
[0036]
In the obtained solution, as the component (C), both ends of the molecular chain are blocked with a trimethylsilyl group, contain 95 mol% of a methylhydrogensiloxane unit represented by MeHSiO _2/2 , and the viscosity is 25 mPa · s. 3 parts by weight of methyl hydrogen polysiloxane (Si—H group content = 1.5 mol / 100 g) (the number of moles of hydrogen groups directly bonded to silicon is relative to the vinyl groups contained in the components (A) and (B)) 3 times equivalent), 1 part by weight of 3-methyl-1-butyn-3-ol was added as a bath life extender, and the mixture was stirred and mixed at 20 to 40 ° C. for 1 hour. Immediately before coating on the substrate, a complex salt of platinum and vinylsiloxane was added as a component (D) in an amount of 100 ppm in terms of platinum to prepare a composition.
[0037]
The prepared composition is allowed to stand for 30 minutes in an open state at 25 ° C. and a humidity of 60%, and then uniformly coated on glassine paper using a Mayer bar and cured under predetermined conditions. A sample for evaluation at the beginning of time / m ² was prepared. The prepared composition was allowed to stand for 8 hours in an open state at 25 ° C. and 60% humidity, and then coated and cured in the same manner, and an evaluation sample after 8 hours elapsed with a coating amount of 1.0 g / m ² was prepared. Created. Evaluation was performed according to the description of the evaluation method of the cured film characteristic below. The results are shown in Table 1.
[0038]
[Example 2]
In Example 1, 70 parts by weight of component (B) and 4.5 parts by weight of component (C) (the number of moles of hydrogen groups directly bonded to silicon are relative to the vinyl groups contained in components (A) and (B)) A sample for evaluation was prepared in the same manner except that the composition was equivalent to 3 times. The evaluation was performed according to the description of the evaluation method of the cured film characteristics below, and the results are shown in Table 1.
[0039]
[Example 3]
In Example 1, as the component (B), the viscosity at 25 ° C. is 0.5 Pa · s, both ends of the molecular chain are blocked with dimethylvinylsilyl groups, and the main skeleton is 0.7 methylvinylsiloxane unit. A composition was prepared and evaluated in the same manner except that 25 parts by weight of polyorganosiloxane (vinyl group content = 0.02 mol / 100 g) composed of 99.3 mol% of dimethylsiloxane units in mol% was used. A sample was prepared. The evaluation was performed according to the description of the evaluation method of the cured film characteristics below, and the results are shown in Table 1.
[0040]
[Comparative Example 1]
In Example 1, component (B) is 9 parts by weight, component (C) is 2.4 parts by weight (the number of moles of hydrogen groups directly bonded to silicon is relative to the vinyl groups contained in component (A) and component (B)). A composition was prepared in the same manner except that it was equivalent to 3 times), and an evaluation sample was prepared. The evaluation was performed according to the description of the evaluation method of the cured film characteristics below, and the results are shown in Table 1.
[0041]
[Comparative Example 2]
In Example 1, the component (B) is 80 parts by weight, the component (C) is 5 parts by weight (the number of moles of hydrogen groups directly connected to silicon is 3 times the vinyl groups contained in the components (A) and (B)) The composition was prepared in the same manner except that the sample for evaluation was prepared. The evaluation was performed according to the description of the evaluation method of the cured film characteristics below, and the results are shown in Table 1.
[0042]
[Comparative Example 3]
In Example 1, as component (B), the viscosity at 25 ° C. is 1 Pa · s, both ends of the molecular chain are blocked with dimethylvinylsilyl groups, and the main skeleton is composed only of dimethylsiloxane units. 25 parts by weight of organosiloxane (vinyl group content = 0.01 mol / 100 g) and 2.5 parts by weight of component (C) (the number of moles of hydrogen groups directly connected to silicon are components (A) and (B) A composition was prepared in the same manner except that it was equivalent to 3 times the vinyl group contained), and an evaluation sample was prepared. The evaluation was performed according to the description of the evaluation method of the cured film characteristics below, and the results are shown in Table 1.
[0043]
[Comparative Example 4]
In Example 1, as component (B), the viscosity at 25 ° C. is 80 mPa · s, both ends of the molecular chain are blocked with trimethylsilyl groups, the main skeleton is 2 mol% of methylvinylsiloxane units and dimethylsiloxane units. 25 parts by weight of polyorganosiloxane (vinyl group content = 0.03 mol / 100 g) composed of 98 mol% and 3.5 parts by weight of component (C) (the number of moles of hydrogen groups directly connected to silicon is A composition for evaluation was prepared in the same manner except that the component (A) and the component (B) corresponded to 3 times the vinyl group). The evaluation was performed according to the description of the evaluation method of the cured film characteristics below, and the results are shown in Table 1.
[0044]
[Comparative Example 5]
In Example 1, as component (B), the viscosity at 25 ° C. is 600 Pa · s, both ends of the molecular chain are blocked with trimethylsilyl groups, the main skeleton is 1.5 mol% methylvinylsiloxane units and dimethyl 25 parts by weight of polyorganosiloxane (vinyl group content = 0.02 mol / 100 g) composed of 98.5 mol% of siloxane units and 3 parts by weight of component (C) (hydrogen group mol directly bonded to silicon) A composition was prepared in the same manner except that the number was equivalent to 3 times the vinyl group contained in the component (A) and the component (B), and an evaluation sample was prepared. The evaluation was performed according to the description of the evaluation method of the cured film characteristics below, and the results are shown in Table 1.
[0045]
[Comparative Example 6]
In Example 1, as component (B), the viscosity at 25 ° C. is 30 Pa · s, both ends of the molecular chain are blocked with trimethylsilyl groups, the main skeleton is 0.1 mol% of methylvinylsiloxane units and dimethyl 25 parts by weight of polyorganosiloxane (vinyl group content = 0.001 mol / 100 g) composed of 99.9 mol% of siloxane units and 2 parts by weight of component (C) (hydrogen group mol directly bonded to silicon) A composition was prepared in the same manner except that the number was equivalent to 3 times the vinyl group contained in the component (A) and the component (B), and an evaluation sample was prepared. The evaluation was performed according to the description of the evaluation method of the cured film characteristics below, and the results are shown in Table 1.
[0046]
[Comparative Example 7]
In Example 1, as component (B), the viscosity at 25 ° C. is 30 Pa · s, both ends of the molecular chain are blocked with trimethylsilyl groups, the main skeleton is 5 mol% of methylvinylsiloxane units and dimethylsiloxane units. 25 parts by weight of polyorganosiloxane (vinyl group content = 0.07 mol / 100 g) composed of 95 mol% and 5.5 parts by weight of component (C) (the number of moles of hydrogen groups directly connected to silicon is A composition for evaluation was prepared in the same manner except that the component (A) and the component (B) corresponded to 3 times the vinyl group). The evaluation was performed according to the description of the evaluation method of the cured film characteristics below, and the results are shown in Table 1.
Evaluation method of cured film characteristics (1) Coating properties The surface condition of a cured film surface of an evaluation sample prepared by heat-treating the composition at the initial stage with a hot-air circulating dryer at 120 ° C. for 20 seconds, is as follows. It was evaluated with.
[0047]
○: smooth and uniform surface x: streaks and twists are observed (2) The cured film surface of the evaluation sample prepared by heat treatment at 120 ° C. for 20 seconds with a curable hot-air circulating dryer is rubbed with a finger, and the film The degree of cloudiness on the surface was observed and evaluated according to the following criteria.
○: No cloudiness Δ: Slightly cloudy ×: Thick clouding occurs (3) Adhesive hot-circulation dryer at 120 ° C. for 20 seconds and prepared for evaluation at 25 ° C., humidity 60 % For 1 week, the surface of the cured film was rubbed with a finger, the degree of dropout of the film surface was observed, and evaluated according to the following criteria.
○: No dropout Δ: Dropout occurs slightly ×: Dropout occurs easily (4) Peeling force The composition at the initial stage was heat-treated at 140 ° C. for 30 seconds with a hot air circulation dryer to prepare a sample for evaluation. An acrylic solvent-type pressure-sensitive adhesive [Olivein BPS-5127 (manufactured by Toyo Ink Manufacturing Co., Ltd.)] was applied to the surface of the cured film and heat-treated at 100 ° C. for 3 minutes. / M ² high-quality paper was pasted and pressed once with a 2 kg roller, and aged at 25 ° C. for 20 hours. This sample was cut into a width of 5 cm, and a tension tester was used to pull the laminated paper at an angle of 180 ° at a peeling speed of 0.3 m / min, and the force (N) required for peeling was measured. The measurement used an autograph DSC-500 (manufactured by Shimadzu Corporation).
[0048]
[Table 1]

* 1 30% toluene solution viscosity at 25 ° C * 2 H / Vi: Si-H group / vinyl group (molar ratio)
[0049]
【The invention's effect】
According to the present invention, by improving the mechanical strength of the formed film, a cured film having excellent adhesion to the substrate can be obtained without affecting the peeling characteristics. In addition, since the present composition maintains good curing properties even after aging, a cured film having excellent reproducibility of peeling characteristics can be obtained, and workability can be improved.

Claims (2)

(A) represented by the following general formula (1), Chi also at least two vinyl groups, and a vinyl group content per organopolysiloxane 100 g is at 0.001 to 0.1 moles per molecule 100 parts by weight of organopolysiloxane,

(In the formula, R ¹ represents a vinyl group, R ² represents a monovalent organic group not containing an aliphatic unsaturated bond, and X represents a group represented by the following formula.)

(Wherein, a, b, c, d, e are the viscosity of a 30 wt% toluene solution of the organopolysiloxane at 25 ° C. satisfying 1.5 to 70 Pa · s , and the degree of polymerization is a + b + c × (d + e + 1) +2 Is selected from positive numbers satisfying the range of 3,000 to 20,000, and b, c, d, and e may be 0.)
(B) 10 to 70 parts by weight of an organopolysiloxane represented by the following general formula (2) having at least one vinyl group in one molecule;

(In the formula, R ¹ is a vinyl group, R ³ is the same as R ² or the same group as R ^1, and f and g have a viscosity of 0.1 to 500 Pa · s at 25 ° C. of the organopolysiloxane. So that the vinyl group content is 0.001 to 0.1 mol per 100 g of the organopolysiloxane and 0.2 to 5 times the vinyl group content of the component (A). A positive number is selected, f is in the range of 60 to 2,000, and g is in the range of 1 to 300. )
(C) an organohydrogenpolysiloxane having at least three hydrogen atoms bonded to silicon atoms in one molecule, wherein the number of moles of hydrogen atoms bonded to the silicon atoms contained is the component (A) and (B ) An amount corresponding to 1 to 5 times the total number of moles of vinyl groups contained in the component,
(D) a catalytic amount of a platinum group metal catalyst,
(E) A solvent-type silicone composition for release paper containing an arbitrary amount of an organic solvent as an essential component.   The solvent-type silicone composition for release paper according to claim 1, wherein the amount of component (B) is 10 to 25 parts by weight per 100 parts by weight of component (A).