JP4158030B2 - Silicone composition for coating, release sheet for producing synthetic resin sheet, and method for producing synthetic resin sheet - Google Patents

Description

【００１６】
本発明の（Ｂ−１）成分は、下記平均組成式（ｉｉ）
Ｒ¹ _cＨ_dＳｉＯ_(4-c-d)/2 （ｉｉ）
（式中、Ｒ¹は上記と同様の意味を示し、ｃは０≦ｃ≦３、ｄは０＜ｄ≦３、ｃ＋ｄは１≦ｃ＋ｄ≦３である。）
で表され、１分子中にケイ素原子に直接結合した水素原子（ＳｉＨ基）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る。
【００１７】
Ｒ¹は上記と同様の意味を示し、ｃは０≦ｃ≦３、ｄは０＜ｄ≦３、ｃ＋ｄは１≦ｃ＋ｄ≦３であり、特にｃは０．５≦ｃ≦２．４、ｄは０．１≦ｄ≦１．０、ｃ＋ｄは１．５≦ｃ＋ｄ≦２．５が好ましい。
【００１８】
本発明のオルガノハイドロジェンポリシロキサンは、１分子中にケイ素原子に直接結合した水素原子（ＳｉＨ基）を少なくとも３個有するが、特に３〜１０００個有することが好ましい。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。粘度は数ｍＰａ・ｓ〜数万ｍＰａ・ｓの範囲であればよい。
【００１９】
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ハイドロジェンポリシロキサンを挙げることができる。
【００２０】
【化２】

【００２１】
但し、上記組成式において、Ｍｅはメチル基、Ｙは下記構造式で示される基であり、ｉ，ｒ，ｔは３〜５００、ｋ，ｗ，ｖ，ｙは１〜５００、ｊ，ｑ，ｓ，ｕ，ｘ，ｏ，ｐは０〜５００の正の整数である。
【００２２】
【化３】

【００２３】
（Ｂ−１）成分の配合量は、ケイ素原子に直接結合した水素原子のモル数が（Ａ−１）成分中のアルケニル基のモル数の１〜５倍に相当する質量部である。特に１．５〜４．５倍に相当する質量部が好ましい。ケイ素原子に直接結合した水素原子のモル数が（Ａ−１）成分のアルケニル基のモル数の１倍未満だと、本発明のコーティング用シリコーン組成物の硬化性が不十分となる一方、５倍を超えるても顕著な効果の増加は見られず、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。
【００２４】
（Ｂ−２）成分は、上記平均組成式（ｉｉ）で表されるオルガノハイドロジェンポリシロキサン又は下記平均組成式（ｉｖ）
Ｒ¹ _gＲ³ _hＳｉＯ_(4-g-h)/2 （ｉｖ）
（式中、Ｒ¹は上記と同様の意味を示し、Ｒ³は加水分解性基を示し、ｇは０≦ｇ≦３、ｈは０＜ｈ≦３、ｇ＋ｈは１≦ｇ＋ｈ≦３である。）
で表され、１分子中にケイ素原子に直接結合した加水分解性基を少なくとも３個有するオルガノポリシロキサンである。
【００２５】
Ｒ³は加水分解性基を示し、加水分解性基としては、ケイ素原子に直接結合したメトキシ基、エトキシ基、プロポキシ基、ブトキシ基、メトキシエトキシ基、イソプロペノキシ基等のアルコキシ基、アセトキシ基等のアシルオキシ基、エチルアミノ基等のアミノ基、アミド基、エチルメチルブタノキシム基等のオキシム基、塩素、臭素等のハロゲン原子等が挙げられる。この中で特にメトキシ基が好ましい。
【００２６】
ｇは０≦ｇ≦３、ｈは０＜ｈ≦３、ｇ＋ｈは１≦ｇ＋ｈ≦３であり、特にｇは０≦ｇ≦２、ｈは０．１≦ｈ≦３、ｇ＋ｈは１．５≦ｇ＋ｈ≦３．０が好ましい。
【００２７】
上記平均組成式（ｉｖ）で表され、分子中にケイ素原子に直接結合した加水分解性基を少なくとも３個有するオルガノポリシロキサンとしては、下記のオルガノポリシロキサンが挙げられる。尚、下記構造式におけるｚは０〜５００の整数を示す。また、Ｍｅはメチル基、Ｅｔはエチル基である。
【００２８】
【化４】

尚、Ｘは下記で示されるものである。
【００２９】
【化５】

【００３０】
（Ｂ−２）成分の配合量は、オルガノハイドロジェンポリシロキサン中のケイ素原子に直接結合した水素原子とオルガノポリシロキサン中の加水分解性基のモル数が（Ａ−２）成分中のシラノール基のモル数の５〜２００倍に相当する質量部であり、特に１０〜２００倍が好ましい。水素原子と加水分解性基の合計モル数が（Ａ−２）成分のシラノール基の５倍未満では本発明のコーティング用シリコーン組成物の硬化性が不十分となる一方、２００倍を超えて配合しても顕著な効果の増加は見られず、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。
【００３１】
一般的な（Ｂ）成分の配合質量部としては、（Ａ）成分のオルガノポリシロキサン１００質量部に対して０．１〜２０質量部の範囲である。０．１質量部未満ではシリコーン組成物の硬化性が不十分となり、２０質量部を超えて配合しても顕著な効果の増加は見られない。
【００３２】
本発明の（Ｃ）成分は、平均粒子径０．５〜２０μｍのシリコーンゴム微粉体であり、本発明の特徴をなす成分である。シリコーンゴム微粉体は、シリコーンゴムをジェットミル等の粉砕機を用いて粉砕して得ることができる。シリコーンゴムとしては、付加型シリコーンゴム組成物を乳化後、架橋することによって得られたものが好ましく、例えば、上記式（ｉ）で表されるオルガノポリシロキサン１００質量部と上記式（ｉｉ）で表されるオルガノハイドロジェンポリシロキサン０．１〜２０質量部をホモミキサーで撹拌し、水を加えて乳化させ、付加反応触媒を添加して硬化させたものを用いることができる。
【００３３】
微粉体の平均粒子径は０．５〜２０μｍであり、特に１〜１５μｍの範囲が好ましい。平均粒子径が０．５μｍ未満では添加効果が得られにくく、２０μｍを超えると、コーティング量にもよるが面状態に影響を与え、好ましくない。微粉体の形状は特に限定されるものではなく、シリコーンゴムを微粉砕することによって得られるような不定形のものでもよい。
【００３４】
さらに、例えば特開平７−１９６８１５号公報に提案されているような、表面がオルガノシルセスキオキサンで被覆されたシリコーンゴム微粉体も好ましく利用できる。このような微粉体は耐溶剤性が改良されることから、合成樹脂シート製造時に溶解性の大きな溶剤を使用する場合に有効な方法である。
【００３５】
オルガノシルセスキオキサンで表面を被覆する方法は公知の方法を用いることができ、例えばシリコーンゴム微粉体の水分散液に、アルカリ性物質又はアルカリ性水溶液と、オルガノトリアルコキシシランを添加し、オルガノトリアルコキシシランを加水分解、縮合重合させる方法が挙げられる。
【００３６】
（Ｃ）成分の配合量は（Ａ）成分１００質量部に対して５〜１５０質量部であり、５質量部未満では添加効果に乏しく、また１５０質量部を超えると基材への接着性が低下し、好ましくない。シリコーンゴム微粉体は耐熱性に優れることは勿論、（Ａ）及び（Ｂ）成分の主成分に対する分散性にも優れていることから、組成物に配合した場合に配合量が多くても容易に均一分散でき、分散状態の経時変化も小さく安定しており、綺麗な塗工面を得ることができる。硬化皮膜とした場合には皮膜内に強固に取り込まれているため耐久性にも優れている。
【００３７】
（Ｄ−１）成分は触媒量の付加反応触媒、（Ｄ−２）成分は、触媒量の縮合反応触媒である。触媒は、（Ａ）成分と（Ｂ）成分のいわゆる架橋反応を促進し、硬化皮膜を形成するために用いられる。（Ｄ−１）成分の付加反応触媒としては、例えば、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等の白金又は白金化合物、ロジウム、ロジウム−オレフィンコンプレックス等の白金属金属系触媒が挙げられる。（Ｄ−１）成分の付加反応触媒は、（Ａ−１）成分のオルガノポリシロキサンと（Ｂ−１）成分のオルガノハイドロジェンポリシロキサンの合計質量に対し、白金の量又はロジウムの量として５〜１０００ｐｐｍ（質量比）配合することが、充分な硬化皮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。
【００３８】
（Ｄ−２）成分の縮合反応触媒としては、塩酸、リン酸、メタンスルホン酸、パラトルエンスルホン酸、マレイン酸、トリフロロ酢酸等の酸類、水酸化ナトリウム、水酸化カリウム、ナトリウムエトキシド、テトラエチルアンモニウムヒドロキシド等のアルカリ類、塩化アンモニウム、酢酸アンモニウム、フッ化アンモニウム、炭酸ナトリウム等の塩類、マグネシウム、アルミニウム、錫、亜鉛、鉄、コバルト、ニッケル、ジルコニウム、セリウム、チタン等の金属の有機酸塩、アルコキシド、キレート化合物等の有機金属化合物が挙げられる。例えば、ジオクチル錫ジアセテート、亜鉛ジオクテート、チタンテトライソプロポキシド、アルミニウムトリブトキシド、ジルコニウムテトラアセチルアセトネート等が挙げられる。縮合反応触媒の配合量は触媒量であるが、通常（Ａ−２）成分のオルガノポリシロキサンと（Ｂ−２）成分のオルガノハイドロジェンポリシロキサン又はオルガノポリシロキサンの合計１００質量部に対して１〜１０質量部である。
【００３９】
（Ｅ）成分の有機溶剤は、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製を目的として配合される成分であり、例えばトルエン、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、塗工方法によっては（Ｅ）成分は配合されなくてもよい。
【００４０】
本発明の組成物には、必要に応じて本発明の目的を損なわない範囲で、顔料、レベリング剤、バスライフ延長剤として公知のものを配合することもできる。
【００４１】
本発明の組成物は（Ａ）〜（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。この混合に際しては、（Ａ）成分を（Ｅ）成分に均一に溶解した後、（Ｂ）、（Ｃ）、（Ｄ）成分を混合するのが有利である。また、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ることが好ましい。
【００４２】
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、さら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。
【００４３】
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０．１〜５．０ｇ／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皮膜を形成せしめ、所望の合成樹脂シート製造に適した特性を有する離型シートを得ることができる。
【００４４】
この場合、基材としては上質紙、クレーコート紙、ミラーコート紙、ＰＥラミネート紙、グラシン紙、クラフト紙等が挙げられる。
【００４５】
また、この基材に形成した本発明の組成物の硬化皮膜上に合成樹脂をシート状成形した後、該合成樹脂シートを本発明の組成物の硬化皮膜から剥離、除去して、合成樹脂シートを製造する場合、合成樹脂シートとしてはウレタン樹脂、エポキシ樹脂、塩化ビニル樹脂等のシートを挙げることができる。
【００４６】
【実施例】
以下、実施例及び比較例を示し、本発明を具体的に説明するが、本発明は下記の実施例に制限されるものではない。
【００４７】
［オルガノポリシロキサンゴム微粉体調製例１］
下記式（ｖ）で表されるメチルビニルシロキサン５００ｇと、下記式（ｖｉ）で表されるメチルハイドロジェンポリシロキサン２０ｇをビーカーに取り、ホモミキサーを用いて２０００ｒｐｍで撹拌した後、ポリオキシエチレン（付加モル＝９モル）オクチルフェニルエーテル５ｇ、水１５０ｇを加えて６０００ｒｐｍで撹拌を継続したところ、転相が起こり増粘が認められたが、さらにそのまま２０００ｒｐｍで撹拌しながら水３２５ｇを加えたところ、Ｏ／Ｗ型エマルジョンが得られた。これに塩化白金酸−オレフィン錯体のトルエン溶液（白金含有量０．０５質量％）１ｇとポリオキシエチレン（付加モル＝９モル）オクチルフェニルエーテル１ｇの混合物を室温で撹拌しながら添加し、１２時間反応してオルガノポリシロキサンゴム微粉体水分散液〔１〕を得た。この液をろ過して得られたケーキ状物を１０５℃で乾燥し、ジェットミルで解砕して、平均粒径３μｍのオルガノポリシロキサンゴム微粉体を得た。
【００４８】
【化６】

【００４９】
［オルガノポリシロキサンゴム微粉体調製例２］
オルガノポリシロキサンゴム微粉体調製例１の途中で得られたオルガノポリシロキサンゴム微粉体水分散液〔１〕５８０ｇ、アンモニア水（濃度２８質量％）６０ｇ、水２２９０ｇをフラスコに取り、羽回転数２００ｒｐｍで撹拌しながら、メチルトリメトキシシラン６５ｇを１０℃で２０分かけて添加し、５〜１５℃で４時間さらに撹拌した後、５５〜６０℃まで加熱して１時間撹拌した。この液をろ過して得られたケーキ状物を１０５℃で乾燥し、ジェットミルで解砕して、平均粒径３μｍのオルガノシルセスキオキサンで被覆されたオルガノポリシロキサンゴム微粉体を得た。
【００５０】
［実施例１］
（Ａ−１）成分として、２５℃における３０質量％トルエン溶液の粘度が５０００ｍＰａ・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％で構成されているオルガノポリシロキサン（ビニル基含有量＝０．０２モル／１００ｇ）１００質量部に、（Ｅ）成分として、トルエン１８００質量部を添加し、２０〜４０℃で撹拌溶解した。得られた溶液に、（Ｂ−１）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（Ｈ含有量＝１．５モル／１００ｇ）を３質量部、（Ｃ）成分として、調製例１で得られた平均粒子径が３μｍのオルガノポリシロキサンゴム微粉体を５０質量部、バスライフ延長剤として、３−メチル−１−ブチン−３−オール１質量部を添加し、２０〜４０℃で１時間撹拌混合した。
基材に塗工する直前に、（Ｄ−１）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、組成物を調製した。
これをメイヤーバーを用いてポリエチレンラミネート紙へ均一に塗工し、所定条件にてキュアーして、塗工量が固型分で１．０ｇ／ｍ²の評価用試料を作製し、下記硬化皮膜特性の評価方法に従い評価した。結果を表１に示す。
【００５１】
［実施例２］
実施例１において、（Ｃ）成分を、調製例２で得られた平均粒子径が３μｍで表面がオルガノシルセスキオキサンで被覆されたオルガノポリシロキサンゴム微粉体１５０質量部とした以外は実施例１と同様に組成物を調製して評価用試料を作製し、下記硬化皮膜特性の評価方法に従い評価した。結果を表１に示す。
【００５２】
［参考例１］
（Ａ−２）成分として、２５℃における３０質量％トルエン溶液の粘度が５０００ｍＰａ・ｓであり、分子鎖の両末端はジメチルヒドロキシシリル基で封鎖され、主骨格はジメチルシロキサン単位で構成されているオルガノポリシロキサン（重合度６０００、水酸基含有量＝０．０００５モル／１００ｇ）を１００質量部、（Ｅ）成分として、トルエン１８００質量部を添加し、２０〜４０℃で撹拌溶解した。得られた溶液に、（Ｂ−２）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（Ｈ含有量＝１．５モル／１００ｇ）を３質量部、（Ｃ）成分として調製例１で得られた平均粒子径が３μｍのオルガノポリシロキサンゴム微粉体５０質量部を２０〜４０℃で１時間撹拌混合した。基材に塗工する直前に、（Ｄ−２）成分として、ジオクチル錫ジオクテートを５質量部添加した以外は実施例１と同様に組成物を調製して評価用試料を作製し、下記硬化皮膜特性の評価方法に従い評価した。結果を表１に示す。
【００５３】
［比較例１］
実施例１において、（Ｃ）成分を、調製例１で得られた平均粒子径が３μｍのオルガノポリシロキサンゴム微粉体３質量部とした以外は実施例１と同様に組成物を調製して評価用試料を作製し、下記硬化皮膜特性の評価方法に従い評価した。結果を表１に示す。
【００５４】
［比較例２］
実施例１において、（Ｃ）成分を、調製例１で得られた平均粒子径が３μｍのオルガノポリシロキサンゴム微粉体２００質量部とした以外は実施例１と同様に組成物を調製して評価用試料を作製し、下記硬化皮膜特性の評価方法に従い評価した。結果を表１に示す。
【００５５】
［比較例３］
実施例１において、（Ｃ）成分を、調製例１と類似の方法で得られた平均粒子径が０．３μｍのオルガノポリシロキサンゴム微粉体１００質量部とした以外は実施例１と同様に組成物を調製して評価用試料を作製し、下記硬化皮膜特性の評価方法に従い評価した。結果を表１に示す。
【００５６】
［比較例４］
実施例１において、（Ｃ）成分を、調製例１と類似の方法で得られた平均粒子径が３０μｍのオルガノポリシロキサンゴム微粉体１００質量部とした以外は実施例１と同様に組成物を調製して評価用試料を作製し、下記硬化皮膜特性の評価方法に従い評価した。結果を表１に示す。
【００５７】
［比較例５］
実施例１において、（Ｃ）成分を、粒子径が約３μｍのシリカ微粉体１００質量部とした以外は実施例１と同様に組成物を調製して評価用試料を作製し、下記硬化皮膜特性の評価方法に従い評価した。結果を表１に示す。
【００５８】
［比較例６］
実施例１において、（Ｃ）成分を、粒子径が約３μｍのアクリル樹脂微粉体１００質量部とした以外は実施例１と同様に組成物を調製して評価用試料を作製し、下記硬化皮膜特性の評価方法に従い評価した。結果を表１に示す。
【００５９】
Ａ．硬化皮膜特性の評価方法
１）硬化性
触媒添加したシリコーン組成物をポリエチレンラミネートした上質紙（坪量１００ｇ／ｍ²）に固型分で１．０ｇ／ｍ²塗布し、１００℃の熱風循環式乾燥機で３０秒間で加熱処理して硬化皮膜を形成して評価用試料を作製した。
試料の硬化皮膜表面を指でこすり、皮膜表面のくもり及び脱落の度合を観察し、以下の基準で評価した。
○：くもり及び脱落が全くない。
△：くもり又は脱落がわずかに生ずる。
×：くもり及び脱落が生ずる。
２）密着性
触媒添加したシリコーン組成物をポリエチレンラミネートした上質紙（坪量１００ｇ／ｍ²）に固型分で１．０ｇ／ｍ²塗布し、１４０℃の熱風循環式乾燥機で３０秒間加熱処理して硬化皮膜を形成して評価用試料を作製した。
試料を２５℃，５０％ＲＨで１日放置後、硬化皮膜表面を指でこすり、皮膜表面のくもり及び脱落の度合を観察し、以下の基準で評価した。
○：くもり及び脱落が全くない。
△：くもり又は脱落がわずかに生ずる。
×：くもり及び脱落が生ずる。
３）光沢度
上記２）密着性の評価と同様に評価用試料を作製し、硬化皮膜表面を光沢計ＶＧ−２０００（日本電色工業株式会社製）を用い測定角度６０゜で測定した。尚、光沢低減の目標値は５以下である。
４）離型性
上記２）密着性の評価と同様に評価用試料を作製し、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ＤＣＳ−５００（島津製作所株式会社製）を使用した。
５）耐久性
上記４）離型性の評価と同様に評価用試料を作製し、粘着剤塗工、熱処理、貼り合せ、エージング、測定の操作を同じ評価用試料を用いて３回繰り返し、離型性の変化により耐久性を評価した。
６）合成樹脂シート成型性
上記２）密着性と同様に評価用試料を作製し、その硬化皮膜表面に一液型ポリウレタン溶液〔クリスボン５５１６Ｓ（大日本インキ化学工業（株）製）〕を塗膜の厚さが３０μｍとなるように塗布し、１３０℃で２分間熱処理した。次いでこの処理面にニットー３１Ｂテープを貼り合わせて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後、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／分で貼合わせテープを引張り剥離した。ポリウレタン側の剥離面の光沢度を測定し、５以下に光沢を低減できていた良好な場合を○、光沢が５を超えてしまった場合を×とした。また、剥離する際にポリウレタン樹脂が一部評価用試料面に残る等、綺麗な剥離面が得られなかったり、離型性が悪く剥離し難い等の異常が見られた場合も×とした。
７）保存安定性
触媒を配合していないシリコーン組成物を４０℃で２ヶ月間放置した後、外観を観察した。初期の範囲内にあるものを○、分離沈降等の異常があるものを×とした。
【００６０】
【表１】

【００６１】
本発明の組成物によれば、塗工面の光沢を極端に低減でき、皮膜の特性も良好で耐久性及び耐熱性にも優れた離型シートを作製することができ、保存安定性にも優れることからその作業性も良好である。このように得られた離型シートは、合成樹脂シート製造に使用するのに最適な性能を有する。
【００６２】
【発明の効果】
本発明の組成物は、紙、ラミネート紙、プラスチックフィルム等に塗布して加熱硬化させることにより、速やかに硬化し、硬化皮膜を形成できる。形成された硬化皮膜は、各種の基材に対して良好な密着性を示し、合成樹脂シート等の離型性に優れるとともにその表面の光沢を低下させる効果にも優れている。また、シェルフライフ及びポットライフが良好で、作業性にも優れており安定な特性を得られる。従来の本用途組成物に比べてより容易に剥離性を調製可能であり、合成樹脂シートの製造に好ましく使用できる離型シートが得られる。[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a coating silicone composition suitable for the production of synthetic resin sheets.For synthetic resin sheet manufacturingRelease sheetAnd method for producing synthetic resin sheetAbout.
[0002]
[Prior art]
It has been known for a long time to obtain a material that exhibits peelability for pressure-sensitive adhesives and other adhesive materials by forming a peelable cured film on the surface of various substrates such as paper, synthetic resin film, and synthetic fiber cloth. It has been. Moreover, there exists what is used for synthetic resin sheet manufacture as one application example of such a peelable cured film.
[0003]
Conventionally, for the purpose of producing the above synthetic resin sheet, those obtained by laminating a polypropylene resin on various substrates and those coated with an amino alkyd resin are known (Patent Documents 1 to 4: JP-A 56-10548). 11, 1980, 14550, 14556). However, all of them are sufficient for so-called mirror tone in which high gloss is expressed on the surface of the synthetic resin, but are insufficient for matte tone with reduced gloss. The former is superior in durability but inferior in heat resistance, and the latter is excellent in heat resistance and gloss control, but is inferior in stability as a treatment agent, and has a difficulty in uniformity of the coating surface, resulting in low yield. This is disadvantageous in that it is not industrially satisfactory (see Patent Document 5: JP-A-60-158249).
[Patent Document 1]
JP-A-56-10548
[Patent Document 2]
JP 56-11980 A
[Patent Document 3]
JP 56-14550 A
[Patent Document 4]
JP-A-56-14556
[Patent Document 5]
JP 60-158249 A
[0004]
[Problems to be solved by the invention]
  The present invention has been made in view of the above circumstances, and is a coating silicone composition suitable for synthetic resin sheet production.For synthetic resin sheet manufacturingRelease sheetAnd method for producing synthetic resin sheetThe purpose is to provide.
[0005]
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 obtained a coating that can be applied to various substrates by adding silicone rubber fine powder to a conventional silicone composition for release paper. Since the surface can extremely reduce the gloss, the surface has a so-called matte finish with no gloss, and is excellent in uniformity. It has been found that can be produced, and the present invention has been made.
[0006]
  Therefore, the present invention,
(A-1) The following average composition formula (i)
  R¹ _aR² _bSiO_{(4-ab) / 2}                                      (I)
(Wherein R¹IsC1-C12 alkyl group, cycloalkyl group, aryl group or aralkyl group, R²Is an alkenyl group, 0 ≦ a ≦ 3, 0 <b ≦ 3, 1 ≦ a + b ≦ 3. )
100 parts by mass of an organopolysiloxane having at least two alkenyl groups directly bonded to silicon atoms in one molecule
(B-1) The following average composition formula (ii)
  R¹ _cH_dSiO_{(4-cd) / 2}                                      (Ii)
(Wherein R¹Indicates the same meaning as above, and 0 ≦ c ≦ 3, 0 <d ≦ 3, and 1 ≦ c + d ≦ 3. )
An organohydrogenpolysiloxane having at least three hydrogen atoms (SiH groups) directly bonded to silicon atoms in one molecule
              In the component (A-1), the number of moles of hydrogen atoms directly bonded to silicon atoms is
              Parts by mass corresponding to 1 to 5 times the number of moles of the alkenyl group
(C) Silicone rubber fine powder having an average particle size of 0.5 to 20 μm, 5 to 150 parts by mass
(D-1) A catalytic amount of addition reaction catalyst
And if necessary
(E) Any amount of organic solvent
Is an essential component, and is used as a release sheet for producing a synthetic resin sheet.,
TheA synthetic resin is formed into a sheet on a release sheet for producing a synthetic resin sheet on which a cured film of the silicone composition is formed, and a cured film of the silicone composition formed on the base material, and then the synthetic resin sheet is formed. A method for producing a synthetic resin sheet is provided, wherein the synthetic resin sheet is peeled off and removed from the cured film.
[0007]
  Hereinafter, the present invention will be described in more detail.
  The component (A-1) of the present invention has the following average composition formula (i)
  R¹ _aR² _bSiO_{(4-ab) / 2}                                      (I)
(Wherein R¹IsC1-C12 alkyl group, cycloalkyl group, aryl group or aralkyl group, R²Is an alkenyl group, a is 0 ≦ a ≦ 3, b is 0 <b ≦ 3, and a + b is 1 ≦ a + b ≦ 3. )
It is an organopolysiloxane having at least two alkenyl groups bonded directly to silicon atoms in one molecule.
[0008]
R¹Is preferably a monovalent hydrocarbon group having 1 to 12 carbon atoms, particularly 1 to 10 carbon atoms, other than the same or different unsubstituted or substituted alkenyl groups. Specific examples thereof include a methyl group, an ethyl group, a propyl group, and a butyl group. In the present invention, an alkyl group such as a group, a cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, an aryl group such as a phenyl group and a naphthyl group, and a hydrocarbon group such as an aralkyl group such as a benzyl group and a phenylethyl group are exemplified. Is R¹It is preferable that 80 mol% or more of is a methyl group. R²As the alkenyl group, those having 2 to 8 carbon atoms are preferable, and examples thereof include a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, and a heptenyl group, and industrially a vinyl group is preferable.
[0009]
Moreover, it is preferable to have at least 2 alkenyl groups bonded directly to silicon atoms in one molecule, particularly 3 or more. The alkenyl group may be present at the molecular chain terminal or in the molecular chain.
[0010]
a is 0 ≦ a ≦ 3, b is 0 <b ≦ 3, a + b is 1 ≦ a + b ≦ 3, in particular, a is 0.5 ≦ a ≦ 2.5, b is 0.0002 ≦ b ≦ 1, a + b Is preferably 1.5 ≦ a + b ≦ 2.5.
[0011]
The component (A-2) has the following average composition formula (iii)
R¹ _e(OH)_fSiO_{(4-ef) / 2}                              (Iii)
(Wherein R¹Is a monovalent hydrocarbon group other than the same or different unsubstituted or substituted alkenyl group as described above, e is 0 ≦ e ≦ 3, f is 0 <f ≦ 3, e + f is 1 ≦ e + f ≦ 3 is there. )
And an organopolysiloxane having at least two silanol groups in one molecule.
[0012]
The component (A-2) contains at least two silanol groups in one molecule. e is 0 ≦ e ≦ 3, f is 0 <f ≦ 3, and e + f is 1 ≦ e + f ≦ 3. In particular, e is 1.0 ≦ e ≦ 2.5, and f is 0.0001 ≦ f ≦ 0. 5, e + f is preferably 1.5 ≦ e + f ≦ 2.5.
[0013]
The molecular structure of the organopolysiloxane of the components (A-1) and (A-2) is not particularly limited, but has a linear or branched chain structure and has a viscosity at 25 ° C. 100 mPa · s or more is preferable, 200 mPa · s or more is particularly preferable, and raw rubber may be used.
[0014]
Specific examples of the components (A-1) and (A-2) include organopolysiloxanes represented by the following structural formulas. In the formula, m is 0 to 1000, n is 10 to 9000, and Me represents a methyl group (hereinafter the same).
[0015]
[Chemical 1]

[0016]
The component (B-1) of the present invention has the following average composition formula (ii)
R¹ _cH_dSiO_{(4-cd) / 2}                                      (Ii)
(Wherein R¹Indicates the same meaning as above, c is 0 ≦ c ≦ 3, d is 0 <d ≦ 3, and c + d is 1 ≦ c + d ≦ 3. )
It is an organohydrogenpolysiloxane having at least three hydrogen atoms (SiH groups) directly bonded to silicon atoms in one molecule.
[0017]
R¹Indicates the same meaning as above, c is 0 ≦ c ≦ 3, d is 0 <d ≦ 3, c + d is 1 ≦ c + d ≦ 3, particularly c is 0.5 ≦ c ≦ 2.4, d is 0.1 ≦ d ≦ 1.0 and c + d are preferably 1.5 ≦ c + d ≦ 2.5.
[0018]
The organohydrogenpolysiloxane of the present invention has at least 3 hydrogen atoms (SiH groups) directly bonded to silicon atoms in one molecule, and preferably 3 to 1000 in particular. The molecular structure may be linear, branched or cyclic. The viscosity may be in the range of several mPa · s to tens of thousands mPa · s.
[0019]
Specific examples of the organohydrogenpolysiloxane include the following organohydrogenpolysiloxanes.
[0020]
[Chemical 2]

[0021]
In the above compositional formula, Me is a methyl group, Y is a group represented by the following structural formula, i, r, and t are 3 to 500, k, w, v, and y are 1 to 500, j, q, s, u, x, o, and p are positive integers from 0 to 500.
[0022]
[Chemical 3]

[0023]
(B-1) The compounding quantity of a component is a mass part in which the number of moles of the hydrogen atom directly bonded to the silicon atom corresponds to 1 to 5 times the number of moles of the alkenyl group in the component (A-1). A mass part corresponding to 1.5 to 4.5 times is particularly preferable. When the number of moles of hydrogen atoms directly bonded to the silicon atom is less than 1 times the number of moles of the alkenyl group of the component (A-1), the curability of the coating silicone composition of the present invention becomes insufficient. Even if it exceeds twice, no significant increase in effect is observed, which causes a change with time and is disadvantageous economically.
[0024]
The component (B-2) is an organohydrogenpolysiloxane represented by the above average composition formula (ii) or the following average composition formula (iv)
R¹ _gR^Three _hSiO_{(4-gh) / 2}                                    (Iv)
(Wherein R¹Indicates the same meaning as above, R^ThreeRepresents a hydrolyzable group, g is 0 ≦ g ≦ 3, h is 0 <h ≦ 3, and g + h is 1 ≦ g + h ≦ 3. )
It is an organopolysiloxane having at least three hydrolyzable groups directly bonded to silicon atoms in one molecule.
[0025]
R^ThreeRepresents a hydrolyzable group, and as the hydrolyzable group, an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a methoxyethoxy group or an isopropenoxy group directly bonded to a silicon atom, or an acyloxy group such as an acetoxy group And an amino group such as an ethylamino group, an amide group, an oxime group such as an ethylmethylbutanoxime group, and a halogen atom such as chlorine and bromine. Of these, a methoxy group is particularly preferred.
[0026]
g is 0 ≦ g ≦ 3, h is 0 <h ≦ 3, g + h is 1 ≦ g + h ≦ 3, particularly g is 0 ≦ g ≦ 2, h is 0.1 ≦ h ≦ 3, and g + h is 1.5. ≦ g + h ≦ 3.0 is preferable.
[0027]
Examples of the organopolysiloxane represented by the above average composition formula (iv) and having at least three hydrolyzable groups directly bonded to silicon atoms in the molecule include the following organopolysiloxanes. In the following structural formula, z represents an integer of 0 to 500. Me is a methyl group, and Et is an ethyl group.
[0028]
[Formula 4]

X is as shown below.
[0029]
[Chemical formula 5]

[0030]
The blending amount of the component (B-2) is such that the number of moles of the hydrogen atom directly bonded to the silicon atom in the organohydrogenpolysiloxane and the hydrolyzable group in the organopolysiloxane is the silanol group in the component (A-2). Is a mass part corresponding to 5 to 200 times the number of moles, and particularly preferably 10 to 200 times. When the total number of moles of hydrogen atoms and hydrolyzable groups is less than 5 times the silanol group of the component (A-2), the curing property of the silicone composition for coating of the present invention is insufficient, while it exceeds 200 times. However, there is no remarkable increase in the effect, which causes a change with time and is disadvantageous economically.
[0031]
As a compounding mass part of a general (B) component, it is the range of 0.1-20 mass parts with respect to 100 mass parts of organopolysiloxane of (A) component. If it is less than 0.1 part by mass, the curability of the silicone composition becomes insufficient, and even if it exceeds 20 parts by mass, no significant increase in effect is observed.
[0032]
Component (C) of the present invention is a silicone rubber fine powder having an average particle size of 0.5 to 20 μm, and is a component that characterizes the present invention. The silicone rubber fine powder can be obtained by pulverizing silicone rubber using a pulverizer such as a jet mill. As the silicone rubber, those obtained by emulsifying and crosslinking the addition-type silicone rubber composition are preferable. For example, 100 parts by mass of the organopolysiloxane represented by the above formula (i) and the above formula (ii) It is possible to use 0.1 to 20 parts by mass of the organohydrogenpolysiloxane represented by stirring with a homomixer, adding water to emulsify, and adding and curing an addition reaction catalyst.
[0033]
The average particle diameter of the fine powder is 0.5 to 20 μm, and particularly preferably in the range of 1 to 15 μm. If the average particle size is less than 0.5 μm, it is difficult to obtain the effect of addition. The shape of the fine powder is not particularly limited, and may be an indefinite shape obtained by finely pulverizing silicone rubber.
[0034]
Further, for example, a fine silicone rubber powder whose surface is coated with an organosilsesquioxane as proposed in JP-A-7-196815 can be preferably used. Since such a fine powder has improved solvent resistance, it is an effective method when a solvent having high solubility is used during the production of the synthetic resin sheet.
[0035]
A known method can be used to coat the surface with organosilsesquioxane. For example, an alkaline substance or an alkaline aqueous solution and an organotrialkoxysilane are added to an aqueous dispersion of fine silicone rubber powder, and an organotrialkoxysilane is added. A method of hydrolyzing and condensation polymerizing silane can be mentioned.
[0036]
Component (C) is blended in an amount of 5 to 150 parts by weight per 100 parts by weight of component (A), and if it is less than 5 parts by weight, the effect of addition is poor, and if it exceeds 150 parts by weight, the adhesion to the substrate is poor. This is not preferable. Silicone rubber fine powder has excellent heat resistance, as well as excellent dispersibility of the components (A) and (B) with respect to the main component. Uniform dispersion is possible, the change in dispersion state over time is small and stable, and a beautiful coated surface can be obtained. In the case of a cured film, it is excellent in durability because it is firmly incorporated in the film.
[0037]
The component (D-1) is a catalytic amount of an addition reaction catalyst, and the component (D-2) is a catalytic amount of a condensation reaction catalyst. The catalyst is used to promote a so-called cross-linking reaction between the component (A) and the component (B) to form a cured film. Examples of the addition reaction catalyst of component (D-1) include platinum or platinum compounds such as platinum black, chloroplatinic acid, chloroplatinic acid-olefin complex, chloroplatinic acid-alcohol coordination compound, rhodium, rhodium-olefin complex. And white metal-based catalysts such as The addition reaction catalyst of component (D-1) is 5 as the amount of platinum or rhodium with respect to the total mass of the organopolysiloxane of component (A-1) and the organohydrogenpolysiloxane of component (B-1). ˜1000 ppm (mass ratio) is preferably added to form a sufficient cured film, but can be appropriately increased or decreased depending on the reactivity of the components or the desired curing rate.
[0038]
(D-2) Component condensation reaction catalysts include hydrochloric acid, phosphoric acid, methanesulfonic acid, p-toluenesulfonic acid, maleic acid, trifluoroacetic acid and other acids, sodium hydroxide, potassium hydroxide, sodium ethoxide, tetraethylammonium Alkalis such as hydroxide, salts such as ammonium chloride, ammonium acetate, ammonium fluoride, sodium carbonate, organic acid salts of metals such as magnesium, aluminum, tin, zinc, iron, cobalt, nickel, zirconium, cerium, titanium, And organometallic compounds such as alkoxides and chelate compounds. For example, dioctyltin diacetate, zinc dioctate, titanium tetraisopropoxide, aluminum tributoxide, zirconium tetraacetylacetonate and the like can be mentioned. The blending amount of the condensation reaction catalyst is a catalytic amount, but is usually 1 with respect to 100 parts by mass in total of (A-2) component organopolysiloxane and (B-2) component organohydrogenpolysiloxane or organopolysiloxane. -10 parts by mass.
[0039]
The organic solvent (E) is a component that is blended for the purpose of improving the stability of the treatment bath, improving the coating properties for various substrates, and adjusting the coating amount and viscosity. For example, toluene, xylene, ethyl acetate, acetone An organic solvent capable of uniformly dissolving a composition such as methyl ethyl ketone or hexane can be used, and the component (E) may not be blended depending on the coating method.
[0040]
In the composition of the present invention, those known as pigments, leveling agents, and bath life extenders can be blended as needed, as long as the object of the present invention is not impaired.
[0041]
The composition of the present invention can be easily produced by uniformly mixing the components (A) to (E). In this mixing, it is advantageous to mix the components (B), (C), and (D) after the component (A) is uniformly dissolved in the component (E). Moreover, in order to ensure sufficient pot life, it is preferable to add and mix the component (D) immediately before coating.
[0042]
When coating using the composition of the present invention, the composition of the present invention is diluted directly or with an appropriate organic solvent, and then coated with a bar coater, roll coater, reverse coater, gravure coater, air knife coater, or 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.
[0043]
The amount of the composition of the present invention applied to the substrate varies depending on the type of the material of the substrate to be coated, but is 0.1 to 5.0 g / m as the solid content.²The range of is preferable. 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. A release sheet having the same can be obtained.
[0044]
In this case, examples of the base material include high-quality paper, clay coated paper, mirror coated paper, PE laminated paper, glassine paper, and craft paper.
[0045]
Further, after the synthetic resin is formed into a sheet on the cured film of the composition of the present invention formed on this substrate, the synthetic resin sheet is peeled off and removed from the cured film of the composition of the present invention. In the case of manufacturing the sheet, examples of the synthetic resin sheet include urethane resin, epoxy resin, vinyl chloride resin and the like.
[0046]
【Example】
EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example.
[0047]
[Preparation Example 1 of Organopolysiloxane Rubber Fine Powder]
500 g of methylvinylsiloxane represented by the following formula (v) and 20 g of methylhydrogenpolysiloxane represented by the following formula (vi) were placed in a beaker and stirred at 2000 rpm using a homomixer. (Addition mole = 9 mol) When 5 g of octylphenyl ether and 150 g of water were added and stirring was continued at 6000 rpm, phase inversion occurred and thickening was observed, but 325 g of water was further added while stirring at 2000 rpm. An O / W type emulsion was obtained. A mixture of 1 g of a toluene solution of a chloroplatinic acid-olefin complex (platinum content 0.05% by mass) and 1 g of polyoxyethylene (addition mole = 9 mol) octylphenyl ether was added with stirring at room temperature for 12 hours. Reaction was performed to obtain an aqueous dispersion [1] of an organopolysiloxane rubber fine powder. The cake-like product obtained by filtering this liquid was dried at 105 ° C. and crushed by a jet mill to obtain an organopolysiloxane rubber fine powder having an average particle size of 3 μm.
[0048]
[Chemical 6]

[0049]
[Organopolysiloxane rubber fine powder preparation example 2]
Organopolysiloxane rubber fine powder aqueous dispersion [1] 580 g, ammonia water (concentration 28 mass%) 60 g, and water 2290 g obtained in the middle of Preparation Example 1 of organopolysiloxane rubber fine powder were placed in a flask, and the blade rotation speed was 200 rpm. While stirring at 65 ° C., 65 g of methyltrimethoxysilane was added at 10 ° C. over 20 minutes, further stirred at 5-15 ° C. for 4 hours, heated to 55-60 ° C. and stirred for 1 hour. The cake-like product obtained by filtering this liquid was dried at 105 ° C. and crushed with a jet mill to obtain an organopolysiloxane rubber fine powder coated with an organosilsesquioxane having an average particle size of 3 μm. .
[0050]
[Example 1]
As the component (A-1), the viscosity of a 30% by mass toluene solution at 25 ° C. is 5000 mPa · s, both ends of the molecular chain are blocked with dimethylvinylsilyl groups, and the main skeleton has a methylvinylsiloxane unit of 1.5. Add 1800 parts by mass of toluene as component (E) to 100 parts by mass of organopolysiloxane (vinyl group content = 0.02 mol / 100 g) composed of 98.5 mol% of dimethylsiloxane units in mol% And dissolved with stirring at 20 to 40 ° C. In the obtained solution, as the component (B-1), both ends of the molecular chain are blocked with trimethylsilyl groups, and MeHSiO_2/2Preparation Example 1 containing 95 parts by mass of a methylhydrogenpolysiloxane (H content = 1.5 mol / 100 g) having a viscosity of 25 mPa · s and containing 3 parts by mass of (C) component 50 parts by mass of the organopolysiloxane rubber fine powder having an average particle size of 3 μm obtained in 1 above, and 1 part by mass of 3-methyl-1-butyn-3-ol as a bath life extender was added at 20 to 40 ° C. Stir and mix for 1 hour.
Immediately before coating on the substrate, a complex salt of platinum and vinylsiloxane as a component (D-1) was added in an amount of 100 ppm in terms of platinum to prepare a composition.
This is uniformly coated on polyethylene laminated paper using a Mayer bar and cured under predetermined conditions, so that the coating amount is 1.0 g / m in solid form.²Samples for evaluation were prepared and evaluated according to the following evaluation method for cured film characteristics. The results are shown in Table 1.
[0051]
[Example 2]
Example 1 Example 1 except that component (C) was changed to 150 parts by mass of an organopolysiloxane rubber fine powder having an average particle size of 3 μm obtained in Preparation Example 2 and the surface coated with organosilsesquioxane. A composition was prepared in the same manner as in Example 1 to prepare an evaluation sample, and evaluated according to the following evaluation method for cured film characteristics. The results are shown in Table 1.
[0052]
    [Reference example 1]
  As component (A-2), the viscosity of a 30% by weight toluene solution at 25 ° C. is 5000 mPa · s, both ends of the molecular chain are blocked with dimethylhydroxysilyl groups, and the main skeleton is composed of dimethylsiloxane units. 100 parts by weight of organopolysiloxane (degree of polymerization 6000, hydroxyl group content = 0.0005 mol / 100 g) and 1800 parts by weight of toluene as component (E) were added and dissolved by stirring at 20 to 40 ° C. In the resulting solution, both ends of the molecular chain are blocked with trimethylsilyl groups as the component (B-2), and MeHSiO_2/2In Preparation Example 1, 3 parts by mass of methylhydrogenpolysiloxane (H content = 1.5 mol / 100 g) having a viscosity of 25 mPa · s, containing 95 mol% of the unit represented by 50 parts by mass of the resulting organopolysiloxane rubber fine powder having an average particle size of 3 μm was stirred and mixed at 20 to 40 ° C. for 1 hour. Immediately before coating on the substrate, a composition for evaluation was prepared in the same manner as in Example 1 except that 5 parts by mass of dioctyltin dioctate was added as component (D-2). The evaluation was performed according to the property evaluation method. The results are shown in Table 1.
[0053]
[Comparative Example 1]
In Example 1, a composition was prepared and evaluated in the same manner as in Example 1 except that the component (C) was 3 parts by mass of the organopolysiloxane rubber fine powder having an average particle size of 3 μm obtained in Preparation Example 1. Samples were prepared and evaluated according to the following evaluation methods for cured film characteristics. The results are shown in Table 1.
[0054]
[Comparative Example 2]
In Example 1, a composition was prepared and evaluated in the same manner as in Example 1 except that the component (C) was 200 parts by mass of the organopolysiloxane rubber fine powder having an average particle diameter of 3 μm obtained in Preparation Example 1. Samples were prepared and evaluated according to the following evaluation methods for cured film characteristics. The results are shown in Table 1.
[0055]
[Comparative Example 3]
In Example 1, composition (C) was the same as in Example 1 except that 100 parts by mass of an organopolysiloxane rubber fine powder having an average particle size of 0.3 μm obtained by the same method as in Preparation Example 1 was used. An evaluation sample was prepared by preparing a product, and evaluated according to the following evaluation method of cured film characteristics. The results are shown in Table 1.
[0056]
[Comparative Example 4]
In Example 1, component (C) was prepared in the same manner as in Example 1 except that 100 parts by mass of an organopolysiloxane rubber fine powder having an average particle size of 30 μm obtained by the same method as in Preparation Example 1 was used. A sample for evaluation was prepared and evaluated according to the following evaluation method for cured film characteristics. The results are shown in Table 1.
[0057]
[Comparative Example 5]
In Example 1, the composition was prepared in the same manner as in Example 1 except that the component (C) was changed to 100 parts by mass of silica fine powder having a particle size of about 3 μm, and an evaluation sample was prepared. Evaluation was performed according to the evaluation method. The results are shown in Table 1.
[0058]
[Comparative Example 6]
In Example 1, except that the component (C) was 100 parts by mass of acrylic resin fine powder having a particle size of about 3 μm, a composition was prepared in the same manner as in Example 1 to prepare an evaluation sample, and the cured film shown below The evaluation was performed according to the property evaluation method. The results are shown in Table 1.
[0059]
A. Evaluation method for cured film properties
1) Curability
High-quality paper (basis weight 100 g / m) obtained by polyethylene-lamination of the catalyst-added silicone composition²) 1.0g / m in solid form²The sample for evaluation was prepared by coating and forming a cured film by heat treatment for 30 seconds with a 100 ° C. hot air circulating dryer.
The surface of the cured film of the sample was rubbed with a finger, and the degree of clouding and falling off of the film surface was observed and evaluated according to the following criteria.
○: No cloudiness or omission.
Δ: Slightly cloudy or falling off occurs.
X: Cloudy and falling off occur.
2) Adhesion
High-quality paper (basis weight 100 g / m) obtained by polyethylene-lamination of the catalyst-added silicone composition²) 1.0g / m in solid form²This was applied and heated for 30 seconds with a hot air circulating dryer at 140 ° C. to form a cured film, thereby preparing a sample for evaluation.
After leaving the sample at 25 ° C. and 50% RH for 1 day, the surface of the cured film was rubbed with a finger, and the degree of cloudiness and falling off of the film surface was observed and evaluated according to the following criteria.
○: No cloudiness or omission.
Δ: Slightly cloudy or falling off occurs.
X: Cloudy and falling off occur.
3) Glossiness
The sample for evaluation was produced similarly to evaluation of said 2) adhesiveness, and the cured film surface was measured at the measurement angle of 60 degrees using gloss meter VG-2000 (made by Nippon Denshoku Industries Co., Ltd.). The target value for gloss reduction is 5 or less.
4) Releasability
2) A sample for evaluation was prepared in the same manner as in the evaluation of adhesion, and an acrylic solvent-type pressure-sensitive adhesive [Olivein BPS-5127 (manufactured by Toyo Ink Co., Ltd.)] was applied to the cured film surface at 100 ° C. Heat treated for 3 minutes and then a basis weight of 64 g / m²The 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. For the measurement, Autograph DCS-500 (manufactured by Shimadzu Corporation) was used.
5) Durability
4) An evaluation sample is prepared in the same manner as in the evaluation of releasability, and the adhesive coating, heat treatment, bonding, aging, and measurement operations are repeated three times using the same evaluation sample to change the releasability. Thus, durability was evaluated.
6) Synthetic resin sheet moldability
2) A sample for evaluation was prepared in the same manner as the adhesiveness, and a one-component polyurethane solution [Chrisbon 5516S (manufactured by Dainippon Ink and Chemicals)] was applied on the surface of the cured film to a thickness of 30 μm. And then heat-treated at 130 ° C. for 2 minutes. Next, the Nitto 31B tape was bonded to this treated surface, pressed once with a 2 kg roller, aged at 25 ° C. for 20 hours, then cut into a 5 cm width, and peeled off at an angle of 180 ° using a tensile tester. The laminated tape was pulled and peeled at a speed of 0.3 m / min. The glossiness of the release surface on the polyurethane side was measured, and a good case where the glossiness could be reduced to 5 or less was rated as ◯, and a glossiness exceeding 5 was rated as x. Further, when peeling, a part of the polyurethane resin remained on the sample surface for evaluation, such as a beautiful peeling surface was not obtained, or abnormalities such as poor releasability and difficulty in peeling were observed.
7) Storage stability
The silicone composition containing no catalyst was allowed to stand at 40 ° C. for 2 months, and then the appearance was observed. Those in the initial range were marked with ○, and those with abnormalities such as separation and sedimentation were marked with ×.
[0060]
[Table 1]

[0061]
According to the composition of the present invention, the gloss of the coated surface can be extremely reduced, a release sheet having good film properties, excellent durability and heat resistance can be produced, and storage stability is also excellent. Therefore, the workability is also good. The release sheet thus obtained has optimum performance for use in the production of synthetic resin sheets.
[0062]
【The invention's effect】
The composition of the present invention can be cured quickly by applying it to paper, laminated paper, plastic film, etc. and heat-curing to form a cured film. The formed cured film exhibits good adhesion to various base materials, is excellent in mold release properties such as a synthetic resin sheet, and is also excellent in the effect of reducing the gloss of the surface. In addition, shelf life and pot life are good, workability is excellent, and stable characteristics can be obtained. A release sheet that can be more easily prepared than conventional compositions for the present application and can be preferably used for the production of a synthetic resin sheet is obtained.

Claims (4)

(A-1) The following average composition formula (i)
R ¹ _a R ² _b SiO _{(4-ab) / 2} (i)
(Wherein R ¹ is an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, an aryl group or an aralkyl group , R ² is an alkenyl group, and 0 ≦ a ≦ 3, 0 <b ≦ 3, 1 ≦ a + b ≦ 3)
100 parts by mass of an organopolysiloxane having at least two alkenyl groups bonded directly to silicon atoms in one molecule (B-1) The following average composition formula (ii)
R ¹ _c H _d SiO _{(4-cd) / 2} (ii)
(In the formula, R ¹ has the same meaning as above, and 0 ≦ c ≦ 3, 0 <d ≦ 3, and 1 ≦ c + d ≦ 3.)
An organohydrogenpolysiloxane having at least three hydrogen atoms (SiH groups) directly bonded to silicon atoms in one molecule
In the component (A-1), the number of moles of hydrogen atoms directly bonded to silicon atoms is
1 part to 5 times the number of moles of the alkenyl group of (C) 5 to 150 parts by weight of a silicone rubber fine powder having an average particle size of 0.5 to 20 μm (D-1) A catalytic amount of addition reaction catalyst is essential A silicone composition for coating, which is used as a component and a release sheet for producing a synthetic resin sheet. (C) according to claim 1 for coating the silicone composition, wherein the silicone rubber fine powder component is made by coating a polyorganosilsesquioxane the fine powder surface. A release sheet for producing a synthetic resin sheet, on which a cured film of the silicone composition according to claim 1 or 2 is formed. A synthetic resin is formed on a cured film of the silicone composition according to claim 1 or 2 formed on a substrate, and then the synthetic resin sheet is peeled off and removed from the cured film. Manufacturing method of resin sheet.