JP3967542B2 - Method for storing silicone composition and packaging kit - Google Patents

Description

【００１２】
等が挙げられる。これらベースポリマーは単独でのみならず、複数混合して用いることもできる。 縮合型反応における（ｂ）成分の架橋剤としては、例えばエチルシリケート、プロピルシリケート、メチルトリメトキシシラン、ビニルトリメトキシシラン、メチルトリエトキシシラン、ビニルトリエトキシシラン、メチルトリス（メトキシエトキシ）シラン、ビニルトリス（メトキシエトキシ）シラン、メチルトリプロペノキシシランのごときアルコキシシラン類；メチルトリアセトキシシラン、ビニルトリアセトキシシランのごときアセトキシシラン類；メチルトリ（アセトンオキシム）シラン、ビニルトリ（アセトンオキシム）シラン、メチルトリ（メチルエチルケトキシム）シラン、ビニルトリ（メチルエチルケトキシム）シランのごときオキシムシラン類およびこれらの部分加水分解物を挙げることができる。さらに、ヘキサメチル−ビス（ジエチルアミノキシ）シクロテトラシロキサン、テトラメチルジブチル−ビス（ジエチルアミノキシ）シクロテトラシロキサン、ヘプタメチル（ジエチルアミノキシ）シクロテトラシロキサン、ペンタメチル−トリス（ジエチルアミノキシ）シクロテトラシロキサン、ヘキサメチル−ビス（メチルエチルアミノキシ）シクロテトラシロキサン、テトラメチル−ビス（ジエチルアミノキシ）−モノ（メチルエチルアミノキシ）シクロテトラシロキサンのような環状シロキサン等も用いることができる。
【００１３】
このように、架橋剤はシランやシロキサン構造のいずれでもよく、またそのシロキサン構造は直鎖状、分岐状および環状のいずれでもよい。さらに、これらを使用する際には、１種類に限定される必要はなく、２種以上の併用も可能である。
【００１４】
（ｂ）成分の架橋剤の配合量は（ａ）成分のベースポリマー１００重量部に対し０．１〜２０重量部が好ましい。架橋剤の使用量が０．１重量部未満では、硬化体に十分な強度が得られず、また２０重量部を超えると得られる硬化体が脆くなり、いずれも実用に耐え難い。
【００１５】
縮合型反応における（ｃ）成分の硬化用触媒としては、例えばオクタン酸鉄、オクタン酸コバルト、オクタン酸マンガン、ナフテン酸スズ、カプリル酸スズ、オレイン酸スズのようなカルボン酸金属塩；ジオレイン酸ジメチルスズ、ジラウリル酸ジメチルスズ、ジ酢酸ジブチルスズ、ジオクタン酸ジブチルスズ、ジラウリル酸ジブチルスズ、ジオレイン酸ジブチルスズ、ジ酢酸ジフェニルスズ、酸化ジブチルスズ、ジブチルスズジメトキシド、ジブチルビス（トリエトキシシロキシ）スズ、ジラウリル酸ジオクチルスズのような有機スズ化合物等が用いられる。
【００１６】
（ｃ）成分の硬化用触媒の配合量は（ａ）成分のベースポリマー１００重量部に対し０．０１〜５．０重量部が好ましい。これより少ない量では硬化用触媒として不十分であって硬化に長時間を要し、また空気との接触面から遠い内部での硬化が不良となる。一方、これよりも多い場合には、保存安定性が低下する。より好ましい配合量の範囲としては、０．１〜３．０重量部の範囲である。
【００１７】
前記（２）の付加型反応における（ａ）成分のベースポリマーとしては、例えば前記基本構造を有するポリオルガノシロキサンであってしかも１分子中のケイ素原子に結合した有機基のうち、少なくとも２個がビニル、プロペニル、ブテニル、ヘキセニルなどのアルケニル基であるポリオルガノシロキサンが好ましく用いられる。特に合成の容易さ、原料の入手のしやすさから、上記基の中でもビニル基を有するものが好ましい。ポリオルガノシロキサンの代表的なものとしては、例えば
【００１８】
【化２】

【００１９】
（ただし、Ｐｈはフェニル基を示す。以下同じ。）
等が挙げられる。これらベースポリマーは単独でのみならず、複数混合して用いることもできる。
【００２０】
付加型反応における（ｂ）成分の架橋剤としては、例えば前記基本構造を有しかつケイ素原子に結合した水素原子を１分子中に少なくとも平均２個を超える数で有するポリオルガノシロキサンが好ましく用いられる。このようなポリオルガノシロキサンの代表的なものとしては、例えば
【００２１】
【化３】

【００２２】
等が挙げられる。これら架橋剤は単独でのみならず、複数混合して用いることもできる。
【００２３】
（ｂ）成分の架橋剤の配合量は、（ａ）成分中のアルケニル基１個に対し、架橋剤中のケイ素原子に結合した水素原子が０．５〜４．０個となるような量が好ましく、さらに好ましくは１．０〜３．０個となるような量である。水素原子の量が０．５個未満である場合は、組成物の硬化が十分に進行せずに、硬化後の組成物の硬さが低くなり、また水素原子の量が４．０個を超えると硬化後の組成物の物理的性質と耐熱性が低下する。
【００２４】
付加型反応における（ｃ）成分の硬化用触媒としては、例えば塩化白金酸、白金オレフィン錯体、白金ビニルシロキサン錯体、白金黒、白金トリフェニルホスフィン錯体等の白金系触媒が用いられる。（ｃ）成分の硬化用触媒の配合量は、（ａ）成分のベースポリマーに対し白金元素量で１〜１，０００ｐｐｍの範囲となる量が好ましい。硬化用触媒の配合量が白金元素量として１ｐｐｍ未満では、十分に硬化が進行せず、また１，０００ｐｐｍを超えても特に硬化速度の向上等が期待できない。
【００２５】
上記硬化可能なシリコーン組成物のうち、硬化時の副生成物がないこと、寸法安定性が優れていること及び耐着色性の観点から（２）の付加型反応による組成物が好ましい。
【００２６】
なお、本発明において、硬化可能なシリコーン組成物には、必要に応じてその物性を著しく低下させない範囲で、さらに充填剤や添加剤を配合することができる。
【００２７】
かかる充填剤として代表的なものを具体的に示せば、煙霧質シリカ、沈澱法シリカ、けいそう土のごとき補強性充填剤；酸化アルミニウム；マイカ；クレイ；炭酸亜鉛；ガラスビーズ；ポリオルガノシルセスキオサンのようなシリコーン樹脂粉末；ポリテトラフルオロエチレン、ポリビニリデンフルオライドのごときフルオロカーボン樹脂粉末；カーボンブラック；ガラス繊維；複合フィラー（無機酸化物とポリマーの複合体を粉砕したもの）等が挙げられる。
【００２８】
また、添加剤としては、例えば黒色白金あるいは微粒パラジウムのごとき水素ガス吸収剤、反応抑制剤、紫外線吸収剤、可塑剤、顔料、酸化防止剤、抗菌剤等が挙げられる。
【００２９】
本発明における硬化可能なシリコーン組成物は、（ｂ）成分の架橋剤と（ｃ）成分の硬化用触媒は共存しない形態（保存中に縮合型反応もしくは付加型反応が起こらない形態）に分包され、通常、ペースト／ペースト型、液／液型あるいはペースト／液型等として調製される。減圧時の成分の揮発しにくさおよび混練作業の簡便性を考えるとペースト／ペースト型のものが望ましい。
【００３０】
この分包形態の代表的例としては、前記（１）の縮合型反応においては、（ａ）ポリオルガノシロキサンベースポリマーと（ｂ）ポリオルガノシラン架橋剤と煙霧質シリカを基本成分とする一方の分包組成物、（ａ）ベースポリマーと（ｃ）有機スズ化合物と煙霧質シリカを基本成分とする他方の分包組成物の組合せを挙げることができる。
【００３１】
前記（２）の付加型反応においては、代表例として（ａ）ポリオルガノシロキサンベースポリマーと（ｂ）ポリオルガノシロキサン架橋剤と煙霧質シリカを基本成分とする一方の分包組成物、（ａ）ベースポリマーと（ｃ）白金ビニルシロキサン錯体と煙霧質シリカを基本成分とする他方の分包組成物の組合せを挙げることができる。
【００３２】
これら組成物は、硬化に供される各成分、充填材および添加剤その他の中から必要成分を適量計量し、ニーダー、プラネタリー等の一般的な混練機あるいは一般的な攪拌機によって均一になるまで混練あるいは攪拌することにより、ペースト状あるいは液状の組成物として調製することができる。
【００３３】
上記のようにして調製された各分包用組成物は、分包されたのち、好ましくは容器に充填される。本発明において、これらの分包された組成物は減圧下に保持される。容器に充填した後直ちに減圧にし、その後封入体中に保存してもよいし、容器に充填したのち一旦そのままの状態で維持し、必要に応じて減圧にした後、封入体中に保存してもよい。しかし、保存期間中はできるだけ減圧の状態に維持することが好ましい。減圧にして保存する封入体としては、例えば袋体、ビン、ケース等が挙げられる。封入体は減圧可能な構造になっていれば特に限定されない。
【００３４】
保存時の真空度の程度は特に限定されないが、０．１ｍｍＨｇ〜６００ｍｍＨｇが好適である。０．１ｍｍＨｇ未満であると減圧時に容器内のペーストがあふれでることがあり、また硬化用触媒成分（キレート化剤）が揮発し、操作余裕時間や硬化体の物性に影響するために好ましくない。６００ｍｍＨｇを超えると気泡除去の効果が薄れるために好ましくない。特に、封入体の真空気密保持および気泡除去の観点から、１００〜４００ｍｍＨｇが好ましい。
【００３５】
分包された組成物を充填する容器としては、特に限定されず、例えばシリンジやチューブ等が挙げられる。シリンジとしては、（ａ）ベースポリマーと（ｂ）架橋剤を基本成分とする組成物および（ａ）ベースポリマーと（ｃ）硬化用触媒を基本成分とする組成物のそれぞれが、２本のシリンジが隣接して一体化されたカートリッジのそれぞれのシリンジに充填されるようにして用いられる該カートリッジが好ましい。カートリッジのシリンジのそれぞれに充填された２つの分包組成物は、ディスペンサーで押出した際に、シリンジの先端に取り付けられたスタティックミキサーを経由して混合されて硬化可能なシリコーン組成物を形成する。
【００３６】
減圧で保存する方法としては、代表的には、容器ごと封入体中に入れ、真空ポンプで減圧にした後、封入体を熱シールする方法、チャック式封入体を利用する方法；容器ごと封入体中に入れ、専用の密封包装機を用いて真空パックする方法；容器をミキスライダー（シーリングテープ）と逆止弁付きの圧縮袋に入れ、ミキスライダー（シーリングテープ）を綴じた後、吸引機で逆止弁から減圧にする方法；歯科医院にあるバキュームを用いて減圧にする方法等がある。なお、一旦開封した容器についても同様な方法を用いて減圧にすることで本発明の効果を十分に維持することができる。
【００３７】
袋体は分包剤が充填された容器の形に合わせて形を変えられることから、封入体として特に好適である。袋体の素材としては、例えばポリエチレン、ポリプロピレン、ポリ塩化ビニル、ポリ塩化ビニリデン、セルロースアセテート、ポリアミド樹脂等が挙げられる。その素材の中で特に好ましくは、酸素透過率および窒素透過率の低いポリアミド樹脂である。また、これらは２種類以上を張り合せて使用してもよい。さらには、樹脂とアルミ箔等とのラミネート、シリカ等の微粉を表面に蒸着させたフィルムも好適に用いられる。
【００３８】
【実施例】
本発明をさらに具体的に説明するために実施例を示すが、本発明はこれらの実施例に限定されるものではない。尚、粘度は２５℃における値である。
【００３９】
実施例１〜３、比較例１〜３
ベースモノマーである両末端ジメチルビニルシロキシ基封鎖ジメチルシロキサン（５０，０００ｃＳｔ）６０重量部、ポリメチルシルセスキオキサン粒子（平均粒径２μｍ）４０重量部および白金−ポリメチルビニルシロキサン錯体２０ｐｐｍから成る（Ａ）ペーストを調整した。また、ベースモノマーである両末端ジメチルビニルシロキシ基封鎖ジメチルシロキサン（５０，０００ｃＳｔ）６０重量部、ポリメチルシルセスキオキサン粒子（平均粒径２μｍ）４０重量部および両末端トリメチルシリル基で封鎖されそしてケイ素に結合した水素原子の含有率が０．７重量％のポリメチルハイドロジェンシロキサン（２０ｃＳｔ）１．５重量部から成る（Ｂ）ペーストを調整した。上記（Ａ）および（Ｂ）のペーストを２５ｇずつ２つのシリンジを備えたカートリッジ中に充填し、押子（ピストンとシリコーンＯ-リング）で封をした。このカートリッジを、外側が１５μｍのナイロン６フィルムで内側６０μｍのポリエチレンフィルムであるラミネートフィルムからなる袋に入れ、２７０ｍｍＨｇに減圧してヒートシールした。
【００４０】
袋体内に減圧でヒートシールしたものと、カートリッジをそのまま常圧で、室温（実施例１、比較例１）、２５℃恒温槽（実施例２、比較例２）、１日をワンサイクルとして１５℃に１２時間そして３０℃に１２時間保持することがプログラムされた槽（実施例３、比較例３）に、それぞれ６ヶ月保存した。その後、カートリッジにミキシングチップを取りつけ、ディスペンサーで押出して２つのペーストを混練し、１ｇ当りの硬化体中の気泡数を調べた。実施例、比較例において、同条件についてそれぞれ５個測定してその平均値を平均気泡数とした。結果を表１に示す。
【００４１】
また、ＪＩＳ−３号型ダンベル状試験片（厚さ２ｍｍ）を３個作製し、３７℃の水中に一晩保存した後、オートグラフ（島津製作所コンピューター計測制御式精密万能試験機ＡＧ５０００Ｄ型）により、ロードセル容量５ｋｇｆ、クロスヘッドスピード１０ｍｍ／ｍｉｎで破断時の引張り強度を測定した。その結果も併せて表１に示す。
【００４２】
【表１】

【００４３】
表１の結果から、付加型反応で硬化するシリコーン組成物において、本発明の減圧下に保存したものから作製した硬化体の気泡数は、３つの保存状態において、常圧で保存したものから作製した硬化体と比較して平均気泡数がはるかに少なかった。また、減圧下に保存したものから作製した硬化体の引張り強度は、３つの保存状態において、常圧で保存したものから作製した硬化体と比較して引張り強度が大きかった。このことから、本発明の保存方法は効果があることが分かる。
【００４４】
実施例４〜６、比較例４〜６
ベースモノマーであるシラノール基で両末端を封鎖されたポリジメチルシロキサン（１０，０００ｃＳｔ）８０重量部、ポリメチルシロキサンで表面処理された煙霧質シリカ（比表面積２００ｍ²／ｇ）２０重量部およびメチルトリス（ブタノンオキシム）シラン１０重量部から成る（Ｃ）ペーストを調整した。また、ベースモノマーであるシラノール基で両末端を封鎖されたポリジメチルシロキサン（１０，０００ｃＳｔ）８０重量部、ポリメチルシロキサンで表面処理された煙霧質シリカ（比表面積２００ｍ²／ｇ）２０重量部およびジラウリル酸ジブチルスズ０．３重量部から成る（Ｄ）ペーストを調整した。（Ｃ）および（Ｄ）のペーストを２５ｇずつ２つのシリンジを備えたカートリッジ中に常圧化に充填し、押し子で封をした。それらのカートリッジを、外側が１５μｍのナイロン６フィルムで内側が６０μｍのポリエチレンフィルムであるラミネートフィルムからなる袋に入れ、２７０ｍｍＨｇに減圧してヒートシールした。
【００４５】
袋体内に減圧下にヒートシールしたものと、カートリッジをそのまま常圧で保管したものについて、室温（実施例４、比較例４）、２５℃恒温槽（実施例５、比較例５）、１日をワンサイクルとして１５℃に１２時間３０℃に１２時間保持するようにプログラムされた槽（実施例６、比較例６）に、それぞれ６ヶ月保存した。その後、カートリッジにミキシングチップを取りつけ、ディスペンサーで押出して２つのペーストを混練し、硬化体中の気泡数を調べた。実施例、比較例において、同条件についてそれぞれ５個測定してその平均値を平均気泡数とした。結果を表２に示す。また、実施例１〜３および比較例１〜３と同様の方法で引張り強度を測定した。その結果も表２に示す。
【００４６】
【表２】

【００４７】
表２の結果から、縮合型反応で硬化するシリコーン組成物においても、本発明の減圧下に保存にしたものから作製した硬化体の気泡数は、３つの保存状態において、常圧で保存にしたものから作製した硬化体と比較して平均気泡数がはるかに少なかった。また、減圧下に保存したしたものから作製した硬化体の引張り強度は、３つの保存状態において、常圧で保存したものから作製した硬化体と比較して引張り強度が大きかった。このことからも、本発明の保存方法は効果があることが分かる。
【００４８】
【発明の効果】
本発明の保存方法によれば、シリコーン組成物の硬化体中の気泡をきわめて少なくすることができる。そのことによって、硬化体の強度物性の低下を防ぎ、気密性を保つことができるようになる優れた特徴を有する。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for storing packaged components and a packaging kit for packaging and mixing to form a curable silicone composition.
[0002]
[Prior art]
Silicone materials have excellent weather resistance, electrical properties, low compression set, heat resistance, cold resistance, etc., and in recent years, various fields including electronic equipment, automobiles, architecture, medical care, foods, etc. Widely used in. These silicone materials that cure at room temperature are used for materials such as heat-resistant paints, adhesives, coating materials, architectural sealing materials, dental silicone rubber impression materials, and soft denture soft lining materials.
[0003]
[Problems to be solved by the invention]
However, a silicone material that cures at room temperature has a property that air is gradually taken in from a gap between containers during storage, and air is easily dissolved in a paste or a solution. Once dissolved, the air cannot be dissolved in the material at the time of curing, and eventually remains as bubbles in the cured body. The cured body containing bubbles has various problems such as a decrease in strength of the material itself, surface roughness due to easy cutting of the surface of the material, a decrease in transparency, and a decrease in airtightness. We have discovered that curable silicone materials have these problems as we research and develop these materials for many years.
[0004]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the inventors of the present invention can obtain a silicone composition having extremely few bubbles in a cured product by storing the packaging material of each component for the silicone composition under reduced pressure. In addition, the present inventors have found that a cured product with extremely few bubbles can prevent a decrease in strength, surface roughness, and the like, and has completed the present invention.
[0005]
That is, the present invention is a method for storing a packaging agent that forms a silicone composition that cures by an addition-type reaction, which can be cured by mixing two or more packaging agents. The inside is the storage method described above, wherein each packing agent is enclosed and held in a reduced-pressure enclosure. Another invention is a packaging kit comprising the packaging agent that forms a curable silicone composition by mixing the two or more packaging agents, and each packaging agent is stored during storage. Is a wrapping kit for forming a curable silicone composition, wherein the container is filled in a container and the container is sealed in an enclosure whose pressure is reduced.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, the curable silicone composition is a polyorganosiloxane composition that can be cured by mixing two or more sachets, (a) a polyorganosiloxane base polymer, The basic components are b) a crosslinking agent and (c) a curing catalyst. Further, various additives used as necessary can be uniformly dispersed in the composition.
[0007]
Each of the above components used in this composition, that is, (a) a polyorganosiloxane base polymer, (b) a crosslinking agent, and (c) a curing catalyst is a curing reaction mechanism for obtaining a rubber elastic body or a viscoelastic body. It is appropriately selected depending on. As the reaction mechanism of curing in the present invention, (1) curing by condensation type reaction, (2) curing by addition type reaction, and the like are known. Depending on the reaction mechanism, (a) component, (b) component and ( c) Preferred combinations of the components are determined. The curable silicone composition in the present invention is cured by (2) addition reaction.
[0008]
The basic structure of the polyorganosiloxane as the base polymer of the component (a) used in such various reaction mechanisms includes, for example, a monovalent substituted or unsubstituted hydrocarbon group such as a methyl group, an ethyl group, a propyl group, An alkyl group such as a butyl group, a hexyl group or a dodecyl group; an aryl group such as a phenyl group; an unsubstituted hydrocarbon group or a chloromethyl group such as an aralkyl group such as a β-phenylethyl group or a β-phenylpropyl group; Examples thereof include polysiloxanes having organic groups such as substituted hydrocarbon groups such as 3,3,3-trifluoropropyl groups, and polysiloxanes in which some of these molecules are further modified depending on the type of curing reaction mechanism. Of these, polysiloxane having a methyl group as an organic group is preferably used because of ease of synthesis.
[0009]
Hereinafter, (a) the polyorganosiloxane base polymer, (b) the crosslinking agent, and (c) the curing catalyst in each of the curing reaction mechanisms (1) and (2) will be specifically described.
[0010]
As the base polymer of the component (a) in the condensation reaction (1), for example, a polyorganosiloxane having the above basic structure and having a hydroxyl group at both ends is preferably used. A specific example of such a polyorganosiloxane is:
[0011]
[Chemical 1]

[0012]
Etc. These base polymers can be used alone or in combination. Examples of the crosslinking agent for the component (b) in the condensation reaction include ethyl silicate, propyl silicate, methyltrimethoxysilane, vinyltrimethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, methyltris (methoxyethoxy) silane, vinyltris ( Alkoxysilanes such as methoxyethoxy) silane and methyltripropenoxysilane; Acetoxysilanes such as methyltriacetoxysilane and vinyltriacetoxysilane; Methyltri (acetoneoxime) silane, Vinyltri (acetoneoxime) silane, Methyltri (methylethylketoxime) Mention may be made of oxime silanes such as silane, vinyltri (methylethylketoxime) silane and their partial hydrolysates. Further, hexamethyl-bis (diethylaminoxy) cyclotetrasiloxane, tetramethyldibutyl-bis (diethylaminoxy) cyclotetrasiloxane, heptamethyl (diethylaminoxy) cyclotetrasiloxane, pentamethyl-tris (diethylaminoxy) cyclotetrasiloxane, hexamethyl-bis ( Cyclic siloxanes such as methylethylaminoxy) cyclotetrasiloxane and tetramethyl-bis (diethylaminoxy) -mono (methylethylaminoxy) cyclotetrasiloxane can also be used.
[0013]
Thus, the cross-linking agent may be either a silane or siloxane structure, and the siloxane structure may be linear, branched or cyclic. Furthermore, when using these, it is not necessary to be limited to one type, and two or more types can be used together.
[0014]
Component (b) is preferably added in an amount of 0.1 to 20 parts by weight per 100 parts by weight of component (a). If the amount of the crosslinking agent used is less than 0.1 part by weight, sufficient strength cannot be obtained in the cured product, and if it exceeds 20 parts by weight, the resulting cured product becomes brittle and both are difficult to withstand practical use.
[0015]
Examples of the curing catalyst for the component (c) in the condensation reaction include carboxylic acid metal salts such as iron octoate, cobalt octoate, manganese octoate, tin naphthenate, tin caprylate and tin oleate; dimethyltin dioleate , Organotin compounds such as dimethyltin dilaurate, dibutyltin diacetate, dibutyltin dioctanoate, dibutyltin dilaurate, dibutyltin dioleate, diphenyltin diacetate, dibutyltin oxide, dibutyltin dimethoxide, dibutylbis (triethoxysiloxy) tin, dioctyltin dilaurate Etc. are used.
[0016]
The blending amount of the curing catalyst (c) is preferably 0.01 to 5.0 parts by weight with respect to 100 parts by weight of the base polymer (a). If the amount is less than this, it is insufficient as a curing catalyst, and it takes a long time for curing, and curing in the interior far from the contact surface with air becomes poor. On the other hand, when it is more than this, the storage stability is lowered. A more preferable blending amount range is 0.1 to 3.0 parts by weight.
[0017]
The base polymer of the component (a) in the addition type reaction (2) is, for example, a polyorganosiloxane having the above basic structure, and at least two organic groups bonded to silicon atoms in one molecule. Polyorganosiloxanes which are alkenyl groups such as vinyl, propenyl, butenyl and hexenyl are preferably used. Of these groups, those having a vinyl group are particularly preferred from the viewpoint of ease of synthesis and availability of raw materials. Representative examples of polyorganosiloxane include, for example:
[Chemical 2]

[0019]
(However, Ph represents a phenyl group. The same shall apply hereinafter.)
Etc. These base polymers can be used alone or in combination.
[0020]
As the crosslinking agent of component (b) in the addition reaction, for example, a polyorganosiloxane having the above basic structure and having an average of at least two hydrogen atoms bonded to silicon atoms in one molecule is preferably used. . Representative examples of such polyorganosiloxane include, for example:
[Chemical 3]

[0022]
Etc. These cross-linking agents can be used alone or in combination.
[0023]
The blending amount of the crosslinking agent of component (b) is such that the number of hydrogen atoms bonded to silicon atoms in the crosslinking agent is 0.5 to 4.0 with respect to one alkenyl group in component (a). The amount is preferably 1.0 to 3.0. When the amount of hydrogen atoms is less than 0.5, curing of the composition does not proceed sufficiently, the hardness of the composition after curing becomes low, and the amount of hydrogen atoms is 4.0. When it exceeds, the physical property and heat resistance of the composition after hardening will fall.
[0024]
As the catalyst for curing the component (c) in the addition type reaction, for example, a platinum-based catalyst such as chloroplatinic acid, platinum olefin complex, platinum vinylsiloxane complex, platinum black, platinum triphenylphosphine complex is used. The blending amount of the curing catalyst for component (c) is preferably an amount in the range of 1 to 1,000 ppm in terms of platinum element relative to the base polymer for component (a). If the blending amount of the curing catalyst is less than 1 ppm as the platinum element amount, curing does not proceed sufficiently, and if it exceeds 1,000 ppm, no improvement in the curing rate can be expected.
[0025]
Among the curable silicone compositions, a composition by addition reaction of (2) is preferable from the viewpoint of absence of by-products upon curing, excellent dimensional stability, and coloring resistance.
[0026]
In the present invention, the curable silicone composition can be further blended with a filler or an additive as long as the physical properties thereof are not significantly lowered, if necessary.
[0027]
Specific examples of such fillers include reinforcing silica such as fumed silica, precipitated silica, and diatomaceous earth; aluminum oxide; mica; clay; zinc carbonate; glass beads; Examples thereof include silicone resin powders such as osane; fluorocarbon resin powders such as polytetrafluoroethylene and polyvinylidene fluoride; carbon black; glass fibers; composite fillers (pulverized composites of inorganic oxide and polymer).
[0028]
Examples of the additive include a hydrogen gas absorbent such as black platinum or fine palladium, a reaction inhibitor, an ultraviolet absorbent, a plasticizer, a pigment, an antioxidant, and an antibacterial agent.
[0029]
The curable silicone composition in the present invention is packaged in a form in which the crosslinking agent of component (b) and the curing catalyst of component (c) do not coexist (condensation reaction or addition reaction does not occur during storage). Usually, it is prepared as a paste / paste type, a liquid / liquid type or a paste / liquid type. Considering the difficulty of volatilization of components during decompression and the ease of kneading work, a paste / paste type is desirable.
[0030]
As a typical example of this packaging form, in the condensation reaction of (1), one of the basic components of (a) a polyorganosiloxane base polymer, (b) a polyorganosilane crosslinking agent, and fumed silica is used. Examples of the packaging composition include (a) a base polymer, (c) an organic tin compound, and another combination of the packaging composition containing fumed silica as basic components.
[0031]
In the addition type reaction of (2), as one representative example, (a) one packaging composition containing (a) a polyorganosiloxane base polymer, (b) a polyorganosiloxane crosslinking agent and fumed silica as basic components, A combination of the base polymer, (c) the other packaging composition containing platinum vinylsiloxane complex and fumed silica as basic components can be mentioned.
[0032]
In these compositions, an appropriate amount of necessary ingredients are weighed out from each component, filler, additive and the like used for curing, until they are made uniform by a general kneader such as a kneader or a planetary or a general stirrer. It can be prepared as a paste or liquid composition by kneading or stirring.
[0033]
Each packaging composition prepared as described above is preferably packaged and then filled into a container. In the present invention, these packaged compositions are kept under reduced pressure. Immediately after filling the container, the pressure may be reduced, and then stored in the inclusion body. Alternatively, after filling the container, maintain it as it is, and after reducing the pressure as necessary, store it in the inclusion body. Also good. However, it is preferable to keep the pressure as low as possible during the storage period. Examples of the enclosure that is stored under reduced pressure include bags, bottles, cases, and the like. The inclusion body is not particularly limited as long as it has a structure capable of reducing pressure.
[0034]
The degree of vacuum during storage is not particularly limited, 0.1MmHg～600mmHg is Ru Oh preferred. If it is less than 0.1 mmHg, the paste in the container may overflow at the time of decompression, and the curing catalyst component (chelating agent) volatilizes, which affects the operating time and the physical properties of the cured product. If it exceeds 600 mmHg, the effect of removing bubbles is reduced, which is not preferable. In particular, 100 to 400 mmHg is preferable from the viewpoint of maintaining the sealed body in a vacuum-tight state and removing bubbles.
[0035]
It does not specifically limit as a container filled with the packaged composition, For example, a syringe, a tube, etc. are mentioned. As the syringe, each of (a) a base polymer and (b) a composition having a cross-linking agent as basic components and (a) a composition having a base polymer and (c) a curing catalyst as basic components are each two syringes. Is preferably used in such a manner that each syringe of a cartridge integrated adjacent to each other is filled. The two packaging compositions filled in each of the cartridge syringes are mixed via a static mixer attached to the tip of the syringe to form a curable silicone composition when extruded with a dispenser.
[0036]
As a method of storing under reduced pressure, typically, the entire container is placed in an enclosure, and after reducing the pressure with a vacuum pump, the enclosure is heat sealed, a method using a chuck-type enclosure; Place the container inside and vacuum-pack with a special sealed packaging machine; put the container in a compression bag with a MIKI slider (sealing tape) and check valve, bind the MIKI slider (sealing tape), and then use a suction machine There is a method of reducing pressure from a check valve; a method of reducing pressure using a vacuum in a dental clinic. Note that the effects of the present invention can be sufficiently maintained by reducing the pressure using a similar method for a container that has been once opened.
[0037]
Since the shape of the bag can be changed in accordance with the shape of the container filled with the packaging material, the bag is particularly suitable as an enclosure. Examples of the material for the bag include polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, cellulose acetate, and polyamide resin. Among these materials, a polyamide resin having a low oxygen permeability and a low nitrogen permeability is particularly preferable. These may be used in combination of two or more. Furthermore, a film obtained by laminating a resin and an aluminum foil or the like and depositing fine powder such as silica on the surface is also preferably used.
[0038]
【Example】
Examples are provided to describe the present invention more specifically, but the present invention is not limited to these examples. The viscosity is a value at 25 ° C.
[0039]
Examples 1-3, Comparative Examples 1-3
It consists of 60 parts by weight of a dimethylvinylsiloxy group-blocked dimethylsiloxane (50,000 cSt) as a base monomer, 40 parts by weight of polymethylsilsesquioxane particles (average particle size 2 μm) and 20 ppm of a platinum-polymethylvinylsiloxane complex ( A) The paste was adjusted. Further, 60 parts by weight of dimethylsiloxane having both ends dimethylvinylsiloxy group (50,000 cSt) as base monomers, 40 parts by weight of polymethylsilsesquioxane particles (average particle size 2 μm) and trimethylsilyl groups at both ends and silicon A paste (B) consisting of 1.5 parts by weight of polymethylhydrogensiloxane (20cSt) having a hydrogen atom content of 0.7% by weight was prepared. Each of the above pastes (A) and (B) was filled in a cartridge equipped with two syringes in an amount of 25 g and sealed with a pusher (piston and silicone O-ring). This cartridge was put in a bag made of a laminate film of nylon 6 film having an outer side of 15 μm and a polyethylene film having an inner side of 60 μm, and heat-sealed by reducing the pressure to 270 mmHg.
[0040]
What was heat-sealed under reduced pressure in the bag and the cartridge as it was at normal pressure, room temperature (Example 1, Comparative Example 1), 25 ° C. constant temperature bath (Example 2, Comparative Example 2) Each was stored for 6 months in a bath (Example 3, Comparative Example 3) programmed to hold at 12 ° C. for 12 hours and at 30 ° C. for 12 hours. Thereafter, a mixing chip was attached to the cartridge, and the two pastes were kneaded by extruding with a dispenser, and the number of bubbles in the cured body per gram was examined. In Examples and Comparative Examples, five samples were measured under the same conditions, and the average value was defined as the average number of bubbles. The results are shown in Table 1.
[0041]
In addition, three JIS-3 type dumbbell-shaped test pieces (thickness 2 mm) were prepared and stored overnight in 37 ° C. water, and then autographed (Shimadzu Corporation computer measurement control precision universal testing machine AG5000D type). The tensile strength at break was measured at a load cell capacity of 5 kgf and a crosshead speed of 10 mm / min. The results are also shown in Table 1.
[0042]
[Table 1]

[0043]
From the results in Table 1, the number of bubbles of the cured product prepared from the silicone composition cured by the addition-type reaction and stored under reduced pressure of the present invention was prepared from those stored at normal pressure in three storage states. The average number of bubbles was much smaller compared to the cured product. Moreover, the tensile strength of the hardened | cured material produced from what was preserve | saved under pressure reduction was large compared with the hardened | cured material produced from what was preserve | saved at normal pressure in three preservation | save states. This shows that the preservation method of the present invention is effective.
[0044]
Examples 4-6, Comparative Examples 4-6
80 parts by weight of polydimethylsiloxane (10,000 cSt) blocked at both ends with a silanol group as a base monomer, 20 parts by weight of fumed silica (specific surface area 200 m ² / g) surface-treated with polymethylsiloxane and methyltris ( A (C) paste comprising 10 parts by weight of butanone oxime) silane was prepared. Further, 80 parts by weight of polydimethylsiloxane (10,000 cSt) blocked at both ends with a silanol group as a base monomer, 20 parts by weight of fumed silica (specific surface area 200 m ² / g) surface-treated with polymethylsiloxane, and A paste (D) consisting of 0.3 parts by weight of dibutyltin dilaurate was prepared. Each of the pastes (C) and (D) was filled at 25 g in a cartridge equipped with two syringes at normal pressure and sealed with a pusher. These cartridges were put in a bag made of a laminate film of nylon 6 film having an outer side of 15 μm and polyethylene film having an inner side of 60 μm, and heat-sealed by reducing the pressure to 270 mmHg.
[0045]
About what was heat-sealed under reduced pressure in a bag and what stored the cartridge as it was at normal pressure, room temperature (Example 4, comparative example 4), 25 degreeC thermostat (Example 5, comparative example 5), 1 day Were stored in a tank (Example 6, Comparative Example 6) programmed to hold 12 hours at 30 ° C. for 12 hours at 15 ° C. for 6 months each. Thereafter, a mixing chip was attached to the cartridge, and the two pastes were kneaded by extruding with a dispenser, and the number of bubbles in the cured body was examined. In Examples and Comparative Examples, five samples were measured under the same conditions, and the average value was defined as the average number of bubbles. The results are shown in Table 2. Moreover, tensile strength was measured by the method similar to Examples 1-3 and Comparative Examples 1-3. The results are also shown in Table 2.
[0046]
[Table 2]

[0047]
From the results shown in Table 2, the number of bubbles in the cured product prepared from the one stored in a reduced pressure of the present invention was also stored at normal pressure in three storage states even in the silicone composition cured by a condensation reaction. The average number of bubbles was much smaller than the cured product made from the product. Moreover, the tensile strength of the hardened | cured material produced from what was preserve | saved under reduced pressure was large compared with the hardened | cured material produced from what was preserve | saved at normal pressure in three preservation | save states. This also shows that the storage method of the present invention is effective.
[0048]
【The invention's effect】
According to the storage method of the present invention, bubbles in the cured body of the silicone composition can be extremely reduced. As a result, it has an excellent feature that prevents deterioration of strength properties of the cured body and maintains airtightness.

Claims (3)

A method of preserving the sachet that forms a silicone composition curable by an addition-type reaction, which is curable by mixing sachets packaged in two or more, wherein each sachet is stored during storage. A storage method, wherein the agent is sealed and held in a depressurized inclusion body. A packaging kit comprising the packaging agent that forms a silicone composition that cures by an addition-type reaction that can be cured by mixing two or more packaging materials. A wrapping kit for forming a curable silicone composition, characterized in that a packaging material is filled in a container and the container is enclosed in an enclosure containing reduced pressure.   The packaging kit according to claim 2, wherein the inclusion body is a bag body.