JP4071562B2 - Silicone easy-adhesive polyester film - Google Patents

Description

【００２０】
ここで、ｍは１から５００の正の整数であり、ｎは１から２００の正の整数であり、ｘとｙとｚは１から１５０の正の整数である。Ｍは水素原子、アシル基または炭化水素基である。
【００２１】
本発明において、シランカップリング剤とアルコキシ変性シリコーン化合物との量比は、シランカップリング剤１００重量部に対してアルコキシ変性シリコーン化合物が好ましくは１〜３０重量部、さらに好ましくは５〜２０重量部である。
【００２２】
アルコキシ変性シリコーン化合物をこの量比の範囲で用いることにより、シランカップリング剤の反応性を制御し均一に塗工することができ、十分なシリコーン易接着性を得ることができる。フィルム加工時の塗膜の削れを抑制することができる
塗布液は、シランカップリング剤およびアルコキシ変性シリコーン化合物を含有する水性塗布液であり、水溶液または水分散液であることが好ましい。水性塗布液にはアニオン系界面活性剤、カチオン系界面活性剤、ノニオン系界面活性剤等の界面活性剤を適宜添加して用いてもよい。
【００２３】
塗布液には、本発明の効果を消失させない範囲で、例えば帯電防止剤、紫外線吸収剤、顔料、無機フィラ−、有機フィラ−、潤滑剤、ブロッキング防止剤等の添加剤を混合することができる。
【００２４】
かかる塗布液をポリエステルフィルムの少なくとも片面に塗布し、次いで乾燥させることで、塗布層を設けることができる。
【００２５】
塗布は、ポリエステルフィルムの製造中にフィルムの配向結晶化が完了する前に行なってもよく、製造後にフィルムの配向結晶化が完了してから行なってもよい。配向結晶化が完了する前に塗付する場合には、工程中で結晶配向化が完了する前のポリエステルフィルムの片面または両面に水性塗布液として塗布する。配向結晶化が完了する前のポリエステルフィルムとしては、ポリエステルを熱溶融してそのままフィルム状とした未延伸フィルム、未延伸フィルムを縦方向（長手方向）または横方向（幅方向）の何れか一方に延伸した一軸延伸フィルム、さらには縦方向および横方向の二方向に低倍率延伸させた二軸延伸フィルム（最終的に、縦方向または横方向に再延伸せしめて配向結晶化を完了せしめる前の二軸延伸フィルム）を挙げることができる。
【００２６】
製造後にフィルムの配向結晶化が完了してから行なう場合、通常のプライマー塗布工程を採用することができる。この工程を採用する場合、塵埃等を巻き込みやすいのでクリーンな雰囲気での塗工が望ましい。
【００２７】
塗布液中の固形分濃度は、好ましくは３０重量％以下、特に好ましくは１０重量％以下である。塗布液の塗布量は、走行しているフィルム１ｍ²当り好ましくは０．５〜２０ｇ、特に好ましくは１〜１０ｇである。
【００２８】
ポリエステルフィルムへの塗布液の塗布は、公知の塗工法を適用して行なうことができる。例えばロールコート法、グラビアコート法、マイクログラビアコート法、リバースコート法、ロールブラッシュ法、スプレーコート法、エアーナイフコート法、含浸法およびカーテンコート法を挙げることができ、これらを単独でまたは組み合わせて適用すると良い。水性塗付液には、塗剤の安定性または塗工性を助ける目的で若干量の有機溶剤を含ませてもよい。
【００２９】
ポリエステルフィルムに塗布された塗布液は、乾燥され、熱架橋される。例えば水性塗付液を塗布した縦一軸延伸ポリエステルフィルムの場合、ポリエステルフィルムがステンターに導かれて加熱された後横延伸および熱固定される間、塗布液は乾燥される。
【００３０】
ポリエステルフィルムの配向結晶化の条件、例えば延伸、熱固定の条件には、従来から当業界に蓄積された条件をとることができる。
【００３１】
本発明における塗布層は、ポリエステルフィルムに対して優れた密着性を有し、かつシリコーンに対して優れた易接着性を有する。従って、本発明のシリコーン易接着性ポリエステルフィルムを用い、例えば塗布層の上にシリコーン離型層を設けると、耐久性の優れた離型フィルムが得られる。
【００３２】
［シリコーン離型層］
シリコーン離型層としては、例えばビニル基のような不飽和炭化水素基を持つポリオルガノシロキサンとケイ素原子に直接結合した水素原子を持つポリオルガノシロキサンとを白金化合物を触媒として付加反応させた硬化被膜、あるいはケイ素原子に結合した水酸基を持つポリオルガノシロキサンと加水分解可能な官能基（例えば、アルコキシ基、オキシム基、アセトキシ基）を持つオルガノシラン、またはポリシロキサンを有機スズや有機チタン化合物を触媒として縮合反応させた硬化被膜等を好ましく挙げることができる。
【００３３】
かかる硬化被膜は、該被膜を形成する成分を含む塗布液を塗布層上に塗布し、塗布層上で硬化させることによって形成される。硬化被膜を形成する成分は、例えばトルエン、酢酸エチル、ｎ−ヘキサン、メチルエチルケトン、シクロヘキサノン等の溶媒に溶解して塗布液を調製するが、この塗布液には重合反応促進のための有機白金化合物の如き触媒を微量加えるのが好ましい。この塗布液の塗布方法としては、例えば、グラビアコート法、マイクログラビアコート法、リバースコート法、スプレーコート法、バーコート法を用いることができる。
【００３４】
シリコーン離型層の厚さは、乾燥状態で、好ましくは０．０１〜１０μｍ、さらに好ましくは０．０２〜５μｍである。この厚さとすることにより離形性を良好に維持しながらシリコーンの粘着剤への転写を抑制することができる。
【００３５】
このようにして得られる離型層は、該塗布層を介してポリエステルフィルムとの密着性に優れ、粘着剤等への離形層成分の転写が少なく、耐久性に優れる。
【００３６】
【実施例】
以下、実施例を挙げて本発明をさらに詳細に説明する。
【００３７】
なお、フィルムの各特性値は下記の方法で測定、評価した。
（１）塗工性
光学顕微鏡で塗布層の表面を観察する。下記の通りに評価した。
◎ ：未塗布部の面積が０％
○ ：未塗布部の面積が０％より大きく１０％未満
△ ：未塗布部の面積が１０％以上３０％未満
× ：未塗布部の面積が３０％以上５０％未満
××：未塗布部の面積が５０％以上
【００３８】
（２）シリコーン易接着性
ポリジメチルシロキサンとメチルハイドロゲンポリシロキサンの混合液に白金触媒を加えて付加反応させ硬化させるタイプの硬化型シリコーン樹脂（信越化学株式会社製、ＫＳ−７７２）を、トルエンに溶解させて固形分濃度５％の溶液を調製し、この溶液を、架橋プライマー層上に、塗布量１ｇ／ｍ²で塗布し、１５０℃、１分間で乾燥および硬化反応を行ない、離型フィルムを得て易接着性を評価した。
【００３９】
（ａ）初期易接着性
離型層塗設直後（塗布乾燥直後）の離型フィルムの離型層表面を指先で数回摩擦し、離型層の脱落や密着状態を観察し下記の基準で初期易接着性を評価した。
【００４０】
（ｂ）耐久易接着性
離型フィルムを６０℃×８０％ＲＨの雰囲気に一週間保持した後、離型層表面を指先で数回摩擦し、離型層の脱落や密着状態を観察し、下記の基準で耐久易接着性を評価した。
［評価基準］
◎ ：離型層の変化が全く認められない …………………易接着性良好
○ ：離型層剥離による白化が若干認められる …………易接着性やや良好
△ ：離型層剥離による白化が殆どの部分に認められる…易接着性やや不良
× ：離型層が完全に剥離して失われる …………………易接着性不良
【００４１】
（ｃ）背面非転写性（残留接着率）
ポリエステル粘着テープ（ニットー３１Ｂ）をＪＩＳ Ｇ４３０５に既定する冷間圧延ステンレス板（ＳＵＳ３０４）に貼り付けた後の剥離力を測定し、基礎接着力（ｆ₀）とした。次に、新しい前述のポリエステル粘着テープを離型フィルムの離型層塗設面を２ｋｇの圧着ローラーで圧着し、３０秒間維持した後粘着テープを剥がす。そして、その剥がした粘着テープを上記のステンレス板に貼り、剥離力を測定し、残留接着力（ｆ）とした。得られた基礎接着力（ｆ₀）と残留接着力（ｆ）より下記式を用いて残留接着率を求めた。
残留接着率（％）＝（ｆ／ ｆ₀）×１００
なお、残留接着率は８５％以上が好ましい。残留接着率が８５％未満であると、例えばロール状に巻いて保管する際に、隣接するフィルム表面に転写し、離型特性が低下することがあるため好ましくない。この原因として、架橋プライマー層の成分がシリコーン離型層の硬化性等に悪影響を及ぼす場合があるためこの評価を行なう。
【００４２】
［実施例１〜３及び比較例１、２］
３５℃のｏ−クロロフェノール中で測定した固有粘度が０．６０のポリエチレンテレフタレート（平均粒径０．１μｍのシリカ微粒子を０．２重量％含有）を押出機にて溶融し、フィルム状の溶融ポリマ−をダイスから約２０℃に維持してある回転冷却ドラム上に押出し、静電密着法を用いて該フィルム状の溶融ポリマ−を冷却ドラムに密着させながら急冷して未延伸フィルムを得た。次いで該未延伸フィルムを１２０℃にて縦方向に３．６倍延伸して一軸延伸フィルムを得た。この一軸延伸フィルムの片面に、表１に示す塗布液（固形分濃度３重量％）を調液後、室温（２３℃）で１日間経った後にウェット塗布量４ｇ／ｍ²でキスコート法にて塗布した。続いて１０５℃にて横方向に３．８倍に延伸し、さらに２１０℃で熱固定を行ない、厚さ３８μｍの塗布層を有する二軸延伸ポリエチレンテレフタレートフィルムであるシリコンー易接着性ポリエステルフィルムを得た。評価結果を表１に示す。
【００４３】
［実施例４および比較例３］
実施例１および比較例１と同様の条件で製膜を行ないフィルムを得た。、塗布液を調液後、室温（２３℃）で１４日間経った後に塗布層を形成して、塗布層を有する二軸延伸ポリエチレンテレフタレートフィルムであるシリコーン易接着性ポリエステルフィルムを得た。
【００４４】
［実施例５］
３５℃のｏ−クロロフェノール中で測定した固有粘度が０．６２のポリエチレンナフタレート（平均粒径０．１μｍのシリカ微粒子を０．２重量％含有）を押出機にて溶融し、フィルム状の溶融ポリマ−をダイスから約２０℃に維持してある回転冷却ドラム上に押出し、静電密着法を用いて該フィルム状の溶融ポリマ−を冷却ドラムに密着させながら急冷して未延伸フィルムを得た。次いで該未延伸フィルムを１４０℃にて縦方向に３．６倍延伸して一軸延伸フィルムを得た。この一軸延伸フィルムの片面に、表１に示す塗布液（固形分濃度３重量％）をウェット塗布量４ｇ／ｍ²でキスコート法にて塗布した。続いて１３５℃にて横方向に３．８倍に延伸し、さらに２３０℃で熱固定を行ない、厚さ３８μｍの塗布層を有する二軸延伸ポリエチレンナフタレートフィルムであるシリコーン易接着性ポリエステルを得た。
【００４５】
これらフィルムの品質を表２に示す。
【００４６】
【表１】

【００４７】
なお表中の符号は以下の通りである。
（１）シランカップリング剤
Ｓ−１：γ−グリシドキシプロピルトリメトキシシラン（ＴＳＬ８３５０ ＧＥ東芝シリコーン製）
Ｓ−２：ビニルトリエトキシシラン（ＴＳＬ８３１１ ＧＥ東芝シリコーン製）
【００４８】
（２）アルコキシ変性シリコーン
Ｏ−１：ポリオキシアルキレンジメチルポリシロキサンコポリマー（Ｌ−７７日本ユニカー製）
Ｏ−２：ポリオキシアルキレンジメチルポリシロキサンコポリマー（ＴＳＦ４４４０ ＧＥ東芝シリコーン製）
【００４９】
（３）界面活性剤
Ｗ−１：ポリオキシエチレンアルキルエーテル（サンノニックＳＳ−７０ 三洋化成工業製）
【００５０】
【表２】

【００５１】
表２から明らかのように、本発明のシリコーン易接着性ポリエステルフィルムは塗布液の塗工性が良く、簡便に均一膜を形成し、シリコーン離型層に対する接着性に極めて優れている。
【００５２】
【発明の効果】
本発明によれば、ポリエステルフィルムとの密着して均一な塗膜を形成することができ、耐久性に優れ、シリコーン層に対して優れた接着性を有するシリコーン易接着性フィルムを提供することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a silicone easily adhesive polyester film.
[0002]
[Prior art]
The release film is used as a pressure-sensitive adhesive surface protective film for pressure-sensitive adhesives, adhesives, adhesives, etc., or for forming a curable resin sheet such as urethane resin, epoxy resin, unsaturated polyester resin, or thermoplastic resin sheet. It is used as a protective film for carrier sheets and polarizing plates of liquid crystal members, and its amount is being greatly expanded.
[0003]
As such a release film, a polyester film provided with a film made of an addition-polymerized cured product of a silicon compound having a vinylsiloxane group, a condensation-polymerized cured product of an alkyloxysilane or an oxysilane compound on at least one side of a polyester film has been conventionally used. It has been. This cured product has the advantage that it is non-adhesive and has an excellent mold release effect, but on the other hand, it has a problem that its adhesion with a polyester film as a base film is insufficient and its durability is low.
[0004]
As a method for improving the adhesion between the silicone layer and the polyester film, a method of providing a crosslinked primer layer of a silane coupling agent (JP-A-1-5838) has been proposed. However, in this method, it is difficult to control the reactivity of the silane coupling agent, the pot life of the coating liquid is short, it is difficult to form a uniform film, and the productivity is low.
[0005]
In addition, in order to improve the adhesion between the polyester film and the silicone layer, there is a method of using silicone-modified urethane or acrylic resin as a release layer, but this method has an essential drawback that the release layer of the release layer is inferior. There is.
[0006]
[Problems to be solved by the invention]
The object of the present invention is to solve the above-mentioned problems, to form a uniform coating film in close contact with a polyester film, excellent in durability, and having an excellent adhesion to a silicone layer. It is to provide a polyester film.
[0007]
[Means for Solving the Problems]
That is, the present invention is a silicone easy-adhesive polyester film in which a coating layer containing a silane coupling agent and an alkoxy-modified silicone compound is provided on at least one side of the polyester film.
[0008]
Hereinafter, the present invention will be described in detail.
[0009]
[Polyster film]
In the present invention, the polyester constituting the polyester film is a linear saturated polyester synthesized from an aromatic dibasic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof.
[0010]
Specific examples of the polyester include polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate, poly (1,4-cyclohexylenedimethylene terephthalate), and polyethylene-2,6-naphthalenedicarboxylate. The polyester may be a copolymer or may be used as a mixture with a small proportion of other resins. Polyethylene terephthalate and polyethylene-2,6-naphthalenedicarboxylate are preferable as the polyester, and polyethylene-2,6-naphthalenedicarboxylate is preferable when higher strength and heat resistance are required.
[0011]
The polyester preferably contains a lubricant having a particle size of 0.1 to 5 μm, preferably 0.03 to 3.0% by weight, and more preferably 0.1 to 1.0% by weight. As the lubricant, an inorganic lubricant or an organic lubricant can be used. Examples of the inorganic lubricant include silicon dioxide, calcium carbonate, kaolin, and silicone particles.
[0012]
If necessary, stabilizers, colorants, antioxidants, and other additives may be blended in the polyester as long as the original performance is not impaired.
[0013]
The polyester film used in the present invention is obtained by melt-extruding the polyester into a film and winding it around a casting drum to cool and solidify it into an unstretched film. The unstretched film is heated to 80 to 150 ° C. and stretched once or twice or more in the longitudinal direction so that the total magnification becomes 3 to 7 times. Thereafter, the film is stretched so that the width direction is 3 to 5 times at 90 to 150 ° C., and then heat-treated at 200 to 250 ° C. for 0.1 to 10 seconds, and the width direction is 10 to 20 ° C. lower than the heat treatment temperature. Re-heat treatment is performed while shrinking 2 to 20%.
[0014]
The thickness of the polyester film is preferably 5 to 200 μm, more preferably 25 to 100 μm.
[0015]
[Coating layer]
A coating layer containing a silane coupling agent and an alkoxy-modified silicone compound is applied to at least one surface of the polyester film to form a coating layer.
[0016]
[Silane coupling agent]
The silane coupling agent in the present invention is a compound represented by the general formula YRSiX ₃ . Here, Y is an organic functional group such as an epoxy group, amino group, vinyl group or mercapto group, R is an alkylene group such as methylene, ethylene or propylene group, and X is a methoxy group or ethoxy group. An alkoxy group such as The Y moiety is preferably an epoxy group, amino group, vinyl group, more preferably an epoxy group. Specifically, the silane coupling agent is γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N-β (aminoethyl) -γ. Aminopropyltrimethoxysilane, N-β (aminoethyl) -γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane can be preferably used.
[0017]
The silane coupling agent is preferably water-soluble or water-dispersible because it is preferably used as an aqueous solution or an aqueous dispersion from the viewpoint of prevention of environmental pollution and explosion-proof properties. Moreover, the thing which does not contain a halogen element from a viewpoint of ensuring the rust prevention property of manufacturing equipment and preventing generation | occurrence | production of toxic gas at the time of product disposal incineration is preferable.
[0018]
[Alkoxy-modified silicone compound]
The alkoxy-modified silicone compound in the present invention is a silicone compound having an alkoxy group. Examples of alkoxy-modified silicone compounds include octamethyltrisiloxane, decamethyltetrasiloxane, methylpolysiloxane, octamethylcyclosiloxane, decamethylcyclopentasiloxane, methylcyclopolysiloxane, methylphenylpolysiloxane, polyoxyethylenemethylpolysiloxane copolymer Examples thereof include a polymer, a polyoxyethylene / polyoxypropylene methyl polysiloxane copolymer, and a polyoxypropylene methyl polysiloxane copolymer. The alkoxy-modified silicone compound is preferably water-soluble or water-dispersible for the same reason as the silane coupling agent, and preferably does not contain a halogen element. Since the compatibility with the silane coupling agent is particularly good and the coating property of the silane coupling agent can be easily uniformed, the alkoxy-modified silicone compound is preferably an alkoxy-modified silicone compound having a polyoxyalkylene group. A compound represented by the following formula is preferred.
[0019]
[Chemical 2]

[0020]
Here, m is a positive integer from 1 to 500, n is a positive integer from 1 to 200, and x, y, and z are positive integers from 1 to 150. M is a hydrogen atom, an acyl group or a hydrocarbon group.
[0021]
In the present invention, the amount ratio of the silane coupling agent to the alkoxy-modified silicone compound is preferably 1-30 parts by weight, more preferably 5-20 parts by weight of the alkoxy-modified silicone compound with respect to 100 parts by weight of the silane coupling agent. It is.
[0022]
By using the alkoxy-modified silicone compound in the range of this quantitative ratio, the reactivity of the silane coupling agent can be controlled and applied uniformly, and sufficient silicone easy adhesion can be obtained. The coating liquid that can suppress the abrasion of the coating film during film processing is an aqueous coating liquid containing a silane coupling agent and an alkoxy-modified silicone compound, and is preferably an aqueous solution or an aqueous dispersion. A surfactant such as an anionic surfactant, a cationic surfactant, or a nonionic surfactant may be appropriately added to the aqueous coating solution.
[0023]
In the coating solution, additives such as an antistatic agent, an ultraviolet absorber, a pigment, an inorganic filler, an organic filler, a lubricant, and an antiblocking agent can be mixed as long as the effects of the present invention are not lost. .
[0024]
The coating layer can be provided by coating such a coating solution on at least one side of the polyester film and then drying it.
[0025]
The application may be performed before the completion of the orientation crystallization of the film during the production of the polyester film, or after the orientation crystallization of the film is completed after the production. In the case of applying before orientation crystallization is completed, it is applied as an aqueous coating solution on one or both sides of the polyester film before completion of crystal orientation in the process. As the polyester film before the orientation crystallization is completed, an unstretched film in which the polyester is melted by heat is formed as it is, and the unstretched film is either in the longitudinal direction (longitudinal direction) or in the lateral direction (width direction). A stretched uniaxially stretched film and a biaxially stretched film that has been stretched at a low magnification in both the machine direction and the transverse direction (finally before reorientation in the machine direction or the transverse direction to complete orientation crystallization. Axially stretched film).
[0026]
When the film is produced after the orientation crystallization of the film is completed after production, a normal primer coating process can be employed. When this step is employed, it is desirable to apply in a clean atmosphere because dust and the like are easily involved.
[0027]
The solid content concentration in the coating solution is preferably 30% by weight or less, particularly preferably 10% by weight or less. The coating amount of the coating solution is preferably 0.5 to 20 g, particularly preferably 1 to 10 g, per 1 m ² of the running film.
[0028]
Application | coating of the coating liquid to a polyester film can be performed by applying a well-known coating method. For example, a roll coating method, a gravure coating method, a micro gravure coating method, a reverse coating method, a roll brush method, a spray coating method, an air knife coating method, an impregnation method and a curtain coating method can be mentioned, and these can be used alone or in combination. It is good to apply. The aqueous coating solution may contain a slight amount of an organic solvent for the purpose of assisting the stability or coating property of the coating agent.
[0029]
The coating solution applied to the polyester film is dried and thermally crosslinked. For example, in the case of a longitudinally uniaxially stretched polyester film coated with an aqueous coating solution, the coating solution is dried while the polyester film is guided by a stenter and heated and then laterally stretched and heat-set.
[0030]
Conditions that have been accumulated in the art can be used for the orientation crystallization conditions of the polyester film, such as stretching and heat setting.
[0031]
The coating layer in the present invention has excellent adhesion to the polyester film and excellent adhesion to silicone. Therefore, when the silicone easy-adhesive polyester film of the present invention is used and, for example, a silicone release layer is provided on the coating layer, a release film having excellent durability can be obtained.
[0032]
[Silicone release layer]
As the silicone release layer, for example, a cured coating obtained by addition reaction of a polyorganosiloxane having an unsaturated hydrocarbon group such as a vinyl group and a polyorganosiloxane having a hydrogen atom directly bonded to a silicon atom using a platinum compound as a catalyst. Alternatively, polyorganosiloxane having a hydroxyl group bonded to a silicon atom and organosilane having a hydrolyzable functional group (eg, alkoxy group, oxime group, acetoxy group) or polysiloxane using organotin or organotitanium compound as a catalyst Preferred examples include a cured film obtained by condensation reaction.
[0033]
Such a cured film is formed by applying a coating solution containing a component for forming the film on the coating layer and curing the coating solution on the coating layer. The component that forms the cured film is prepared by dissolving in a solvent such as toluene, ethyl acetate, n-hexane, methyl ethyl ketone, or cyclohexanone to prepare a coating solution. This coating solution contains an organic platinum compound for promoting the polymerization reaction. It is preferable to add a small amount of such a catalyst. As a coating method of this coating solution, for example, a gravure coating method, a micro gravure coating method, a reverse coating method, a spray coating method, or a bar coating method can be used.
[0034]
The thickness of the silicone release layer is preferably 0.01 to 10 μm, more preferably 0.02 to 5 μm in a dry state. By setting this thickness, it is possible to suppress the transfer of silicone to the pressure-sensitive adhesive while maintaining good releasability.
[0035]
The release layer thus obtained is excellent in adhesion to the polyester film through the coating layer, has little transfer of the release layer component to the pressure-sensitive adhesive, etc., and is excellent in durability.
[0036]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples.
[0037]
Each characteristic value of the film was measured and evaluated by the following method.
(1) The surface of the coating layer is observed with a coating optical microscope. Evaluation was performed as follows.
: The area of the uncoated part is 0%
○: The area of the uncoated part is larger than 0% and less than 10%. Δ: The area of the uncoated part is 10% or more and less than 30%. X: The area of the uncoated part is 30% or more and less than 50%. XX: The area is 50% or more. [0038]
(2) A curable silicone resin (KS-772, manufactured by Shin-Etsu Chemical Co., Ltd.), which is cured by adding a platinum catalyst to a mixed liquid of polydimethylsiloxane and methylhydrogenpolysiloxane, which is easy to adhere to silicone, is added to toluene. Dissolve to prepare a 5% solid content solution, apply this solution on the cross-linked primer layer at a coating amount of 1 g / m ² , perform drying and curing reaction at 150 ° C. for 1 minute, release film And easy adhesion was evaluated.
[0039]
(A) The release layer surface of the release film immediately after application of the initial easy-adhesive release layer (immediately after coating and drying) is rubbed with the fingertip several times, and the release layer and the adhesion state of the release layer are observed, and the following criteria are used. Initial easy adhesion was evaluated.
[0040]
(B) After holding the durable easy-adhesive release film in an atmosphere of 60 ° C. × 80% RH for one week, the surface of the release layer is rubbed several times with a fingertip, and the release layer of the release layer and the adhesion state are observed, Durability and easy adhesion were evaluated according to the following criteria.
[Evaluation criteria]
◎: No change in release layer is observed at all ... ………… Good adhesion easily ○: Whitening due to release layer peeling is slightly observed ………… Slightly good adhesion Δ: Release layer peeling Whitening due to water is recognized in almost all parts ... Slightly poor adhesion ×: The release layer is completely peeled off and lost.
(C) Back surface non-transferability (residual adhesion rate)
The peel strength after the polyester adhesive tape (Nitto 31B) was attached to a cold rolled stainless steel plate (SUS304) defined in JIS G4305 was measured and used as the basic adhesive strength (f ₀ ). Next, the new polyester pressure-sensitive adhesive tape described above is pressure-bonded to the release layer-coated surface of the release film with a 2 kg pressure roller, maintained for 30 seconds, and then peeled off. And the peeled adhesive tape was affixed on said stainless steel plate, peeling force was measured, and it was set as the residual adhesive force (f). Based on the obtained basic adhesive strength (f ₀ ) and residual adhesive strength (f), the residual adhesive rate was determined using the following formula.
Residual adhesion rate (%) = (f / f ₀ ) × 100
The residual adhesion rate is preferably 85% or more. When the residual adhesion rate is less than 85%, for example, when stored in a roll shape, it is not preferable because it may be transferred to an adjacent film surface and the release characteristics may be deteriorated. This is evaluated because the components of the crosslinked primer layer may adversely affect the curability of the silicone release layer.
[0042]
[Examples 1 to 3 and Comparative Examples 1 and 2]
Polyethylene terephthalate (containing 0.2% by weight of silica fine particles with an average particle size of 0.1 μm) having an intrinsic viscosity of 0.60 measured in o-chlorophenol at 35 ° C. is melted in an extruder and melted in a film form The polymer was extruded from a die onto a rotating cooling drum maintained at about 20 ° C., and the film-like molten polymer was rapidly cooled while closely contacting the cooling drum using an electrostatic contact method to obtain an unstretched film. . Next, the unstretched film was stretched 3.6 times in the longitudinal direction at 120 ° C. to obtain a uniaxially stretched film. On one side of this uniaxially stretched film, the coating liquid shown in Table 1 (solid content concentration 3% by weight) was prepared, and after one day at room temperature (23 ° C.), the wet coating amount was 4 g / m ² by kiss coating method. Applied. Subsequently, the film was stretched 3.8 times in the transverse direction at 105 ° C. and heat-set at 210 ° C. to obtain a silicon-adhesive polyester film which is a biaxially stretched polyethylene terephthalate film having a coating layer with a thickness of 38 μm. It was. The evaluation results are shown in Table 1.
[0043]
[Example 4 and Comparative Example 3]
Film formation was carried out under the same conditions as in Example 1 and Comparative Example 1 to obtain a film. After coating the coating solution, the coating layer was formed after 14 days at room temperature (23 ° C.) to obtain a silicone easy-adhesive polyester film which is a biaxially stretched polyethylene terephthalate film having the coating layer.
[0044]
[Example 5]
Polyethylene naphthalate having an intrinsic viscosity of 0.62 measured in o-chlorophenol at 35 ° C. (containing 0.2% by weight of silica fine particles having an average particle size of 0.1 μm) was melted in an extruder, The molten polymer is extruded from a die onto a rotating cooling drum maintained at about 20 ° C., and the film-like molten polymer is rapidly cooled while being in close contact with the cooling drum using an electrostatic contact method to obtain an unstretched film. It was. Next, the unstretched film was stretched 3.6 times in the machine direction at 140 ° C. to obtain a uniaxially stretched film. On one side of this uniaxially stretched film, the coating solution shown in Table 1 (solid content concentration 3% by weight) was applied by a kiss coating method at a wet coating amount of 4 g / m ² . Subsequently, the film is stretched 3.8 times in the transverse direction at 135 ° C., heat-fixed at 230 ° C., and a silicone easy-adhesive polyester which is a biaxially stretched polyethylene naphthalate film having a coating layer with a thickness of 38 μm is obtained. It was.
[0045]
Table 2 shows the quality of these films.
[0046]
[Table 1]

[0047]
In addition, the code | symbol in a table | surface is as follows.
(1) Silane coupling agent S-1: γ-glycidoxypropyltrimethoxysilane (TSL8350 GE manufactured by Toshiba Silicone)
S-2: Vinyltriethoxysilane (TSL8311 GE manufactured by Toshiba Silicone)
[0048]
(2) Alkoxy-modified silicone O-1: polyoxyalkylenedimethylpolysiloxane copolymer (L-77 manufactured by Nihon Unicar)
O-2: Polyoxyalkylene dimethyl polysiloxane copolymer (TSF4440 GE manufactured by Toshiba Silicone)
[0049]
(3) Surfactant W-1: Polyoxyethylene alkyl ether (Sannonic SS-70, manufactured by Sanyo Chemical Industries)
[0050]
[Table 2]

[0051]
As is apparent from Table 2, the silicone easy-adhesive polyester film of the present invention has a good coating solution, easily forms a uniform film, and is extremely excellent in adhesion to the silicone release layer.
[0052]
【The invention's effect】
According to the present invention, it is possible to provide a silicone easy-adhesive film that can form a uniform coating film in close contact with a polyester film, has excellent durability, and excellent adhesion to a silicone layer. it can.

Claims (5)

A silicone easy-adhesive polyester film in which a coating layer containing a silane coupling agent and an alkoxy-modified silicone compound is provided on at least one surface of a polyester film. The silicone easy-adhesive polyester film according to claim 1, wherein the silane coupling agent has at least one substituent selected from an epoxy group, an amino group, and a vinyl group. The silicone-adhesive polyester film according to claim 1, wherein the alkoxy-modified silicone compound has a polyoxyalkylene group. The silicone-adhesive polyester film according to claim 1, wherein the alkoxy-modified silicone compound is represented by the following chemical formula.

(Where m is a positive integer from 1 to 500, n is a positive integer from 1 to 200, x, y and z are positive integers from 1 to 150. M is a hydrogen atom, an acyl group or a hydrocarbon. Group.) The silicone-adhesive polyester film according to claim 1, wherein the polyester film is a polyethylene terephthalate film or a polyethylene-2,6-naphthalate film.